93 results on '"James DK"'
Search Results
2. Prenatal Screening for Down Syndrome : Talking About Risks
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Pilnick, AM, Fraser, DM, James, DK, and van den Berg, M.
- Published
- 2004
Catalog
3. Resolution Enhancement for AR/VR Displays Based on LC Sub-pixel Frame Shift
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James Dk Kim, Kyookeun Lee, Myongjo Choi, Jaeyeol Ryu, Nikolay V. Muravyev, Dmitry Evgenievich Piskunov, and Kyu-Sub Kwak
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Physics ,Pixel ,business.industry ,Resolution (electron density) ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Screen-door effect ,Synchronizing ,020207 software engineering ,02 engineering and technology ,Virtual reality ,0202 electrical engineering, electronic engineering, information engineering ,Augmented reality ,Computer vision ,Artificial intelligence ,business ,Image resolution - Abstract
We propose a resolution enhancement method for AR/VR displays based on sub-pixel frame shift. The resolution of the native display engine is doubled by synchronizing the display engine and a LC deflector. Experimental results using commercial electronic devices, Samsung Gear VR and Galaxy S8, show that the resolution is doubled and the screen door effect is reduced. more...
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- 2018
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4. Resolution Enhancement for AR/VR Displays Based on LC Sub-pixel Frame Shift
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Lee, Kyookeun, primary, Muravyev, Nikolay, additional, Piskunov, Dmitry, additional, Ryu, Jaeyeol, additional, Kwak, Kyusub, additional, Choi, Myongjo, additional, and Kim, James DK, additional
- Published
- 2018
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5. PEDIATRIC BUPROPION EXPOSURES REPORTED IN TEXAS: 1998-1999
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Shepherd, G, Velez, LI, James, DK, and Keyes, DC
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Bupropion -- Adverse and side effects ,Poisoning, Accidental -- Demographic aspects ,Pediatric toxicology -- Case studies ,Environmental issues ,Health ,Pharmaceuticals and cosmetics industries - Abstract
Background: Currently there is limited information describing the effects of ingestions of bupropion in young children. Bupropion is available in the US under 2 different trade names for separate indications. The purpose of this retrospective case review is to describe the characteristics of bupropion exposures in this age group. Methods: A retrospective review of all cases of bupropion ingestion in children 6 years old and younger that were reported in Texas during 1998-1999. Cases without follow up or cases involving multiple substances were excluded. Evaluation was based on American Association of Poison Control Centers data coding and reviews of the written case record. This review evaluated dose, certainty of ingestion, dosage form, management site, clinical effects, therapies, outcome and duration of observation. Results: Of 142 cases 114 met the criteria for evaluation. Reasons for exposures were either therapeutic errors (n = 1) or unintentional general (n = 113). Most cases (78%) involved Wellbutrin[R]. 85% of the cases involved SR dosage forms. Most cases (79%) were evaluated in health care facilities. No differences in poison center triage patterns or outcome could be detected with respect to dosage form or brand name. Self-referral was 50% more frequent for Wellbutrin[R] than for Zyban[R]. Decontamination was performed in 57% of the cases. Follow-up/observation times ranged from 1 to 24 hours. Over half of the cases were observed for over 6 hours. Most ingestions were 2 tablets or less. Ingestion was observed in 61 cases. There were no seizures, deaths, moderate or major outcomes. Most patients (92%) did not develop any symptoms. Conclusions: There were no significant clinical effects reported in this population. Decontamination did not appear to make a difference in outcome. Public perception of the toxicity of a medication may be influenced by the indication for which the drug is prescribed., Shepherd G, Velez LI, James DK, Keyes DC. North Texas Poison Center, Dallas, Texas, [...] more...
- Published
- 2001
6. ADULT BUPROPRION EXPOSURES REPORTED IN TEXAS DURING 1998 AND 1999
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Shepherd, G, Velez, LI, Keyes, C, and James, DK
- Subjects
Bupropion -- Adverse and side effects ,Poisoning -- Demographic aspects ,Poison control centers -- Research ,Environmental issues ,Health ,Pharmaceuticals and cosmetics industries - Abstract
Background: Currently there is limited information describing the effects of adult ingestion of buproprion. The purpose of this retrospective case review is to describe the amounts ingested, therapy and clinical effects. Methods: 633 cases of buproprion exposures in adults that were reported to the Texas Poison Center Network during 1998-1999 were reviewed. Cases with poor follow-up (n = 193) were excluded. Evaluation was based on TESS coding and review of the written case record. This review was performed cases that were coded as having seizures, a moderate, major or death outcome. It evaluated dose, dosage form, management site, clinical effects, therapy, outcomes and duration of observation. Another important point that this review addressed was the temporal relationship between ingestion, therapy, and clinical effects. Results: Reasons included intentional ingestion (n = 253), therapeutic errors (n = 154), and adverse drug reactions (n = 33). The female to male ratios were 1.3:1 overall and 2:1 for adverse reactions. Deaths were reported in 2 cases that involved other substances. Seizures were reported in 33 cases, 2 of which developed status epilepticus. The time of onset of seizures ranged from 1 to 14 hours (mode = 2). They occurred most commonly in patients that ingested more than 2500 mg or were also using stimulants at the time of exposure. Seizures were not observed following accidental double doses. Other prominent clinical findings included: lethargy, tachycardia, hyperytension, hallucinations, and tremor. Decontamination therapy was used in 50% of reviewed cases. Conclusions: Seizures are most likely occur within 4 hours, especially following large ingestions or when stimulants are co-administered. Adverse reactions were reported twice as frequently in women. Prospective studies are needed to better define therapy and risk factors for seizures., Shepherd G, Velez LI, Keyes C, James DK. North Texas Poison Center, Dallas, [...] more...
- Published
- 2000
7. The effect of spongy layer (sl) isolated from amniotic membrane on ocular cells growth
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LAZUTINA, E, primary, SULEMAN, H, additional, DUA, HS, additional, TINT, NL, additional, JAMES, DK, additional, and HOPKINSON, A, additional
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- 2008
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8. Diagnosis and treatment of ruptured splenic artery aneurysm in pregnancy
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Jack S, James Dk, and Hammond R
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medicine.medical_specialty ,Pregnancy ,Text mining ,Splenic artery aneurysm ,business.industry ,medicine ,Obstetrics and Gynecology ,business ,medicine.disease ,Surgery - Published
- 1998
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9. Worldwide utilization of caesarean section
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Broadhead, TJ, primary and James, DK, additional
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- 1995
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10. Cardiotocography only versus cardiotocography plus PR-interval analysis in intrapartum surveillance: a randomised, multicentre trial. FECG Study Group.
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Strachan BK, van Wijngaarden WJ, Sahota D, Chang A, James DK, Strachan, B K, van Wijngaarden, W J, Sahota, D, Chang, A, and James, D K
- Abstract
Background: There is a need to improve the sensitivity and specificity of fetal monitoring during labour. We compared the gold standard, cardiotocography, with cardiotocography plus time-interval analysis of the fetal electrocardiogram in fetal surveillance. The aim was to find out whether time-interval analysis decreased the need for operative intervention due to fetal distress.Methods: We did a randomised, prospective trial in five hospitals in the UK, Hong Kong, the Netherlands, and Singapore. 1038 women undergoing high-risk labours were randomly assigned fetal monitoring by cardiotocography alone, or cardiotocography plus fetal electrocardiography (ECG). Outcomes measured were rates of operative intervention, and neonatal outcome. Analysis was by intention to treat.Findings: 515 women were assigned management by cardiotocography, and 523 cardiotocography plus fetal ECG. There was a trend towards fewer operative interventions for presumed fetal distress in the time-interval analysis plus cardiotocography group (63 [13%] vs 78 [16%]), but this was not significant (relative risk 0.80 [95% CI 0.59-1.08], p=0.17). There was no significant difference between groups in the proportion of babies who had an umbilical arterial pH of 7.15 or less (51 [11%] vs 49 [11%]; 1.01 [0.7-1.47]), or in the frequency of unsuspected acidaemia (42 [9%] vs 35 [8%]; 1.17 [0.76-1.79]).Interpretation: The addition of time-interval analysis of the fetal electrocardiogram during labour did not show a significant benefit in decreasing operative intervention. There was no significant difference in neonatal outcome. [ABSTRACT FROM AUTHOR] more...- Published
- 2000
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11. Abrupt transitions in a southwest USA desert grassland related to the Pacific Decadal Oscillation.
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Christensen EM, James DK, Randall RM, and Bestelmeyer BT
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- Southwestern United States, Poaceae, Climate Change, Ecosystem, Grassland
- Abstract
Prediction of abrupt ecosystem transitions resulting from climatic change will be an essential element of adaptation strategies in the coming decades. In the arid southwest USA, the collapse and recovery of long-lived perennial grasses have important effects on ecosystem services, but the causes of these variations have been poorly understood. Here we use a quality-controlled vegetation monitoring dataset initiated in 1915 to show that grass cover dynamics during the 20th century were closely correlated to the Pacific decadal oscillation (PDO) index. The relationship out-performed models correlating grasses to yearly precipitation and drought indices, suggesting that ecosystem transitions attributed only to local disturbances were instead influenced by climate teleconnections. Shifts in PDO phase over time were associated with the persistent loss of core grass species and recovery of transient species, so recovery of grasses in aggregate concealed significant changes in species composition. However, the relationship between PDO and grass cover broke down after 1995; grass cover is consistently lower than PDO would predict. The decoupling of grass cover from the PDO suggests that a threshold had been crossed in which warming or land degradation overwhelmed the ability of any grass species to recover during favorable periods., (Published 2023. This article is a U.S. Government work and is in the public domain in the USA.) more...
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- 2023
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12. Landscape characteristics shape surface soil microbiomes in the Chihuahuan Desert.
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Hansen FA, James DK, Anderson JP, Meredith CS, Dominguez AJ, Pombubpa N, Stajich JE, Romero-Olivares AL, Salley SW, and Pietrasiak N
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Introduction: Soil microbial communities, including biological soil crust microbiomes, play key roles in water, carbon and nitrogen cycling, biological weathering, and other nutrient releasing processes of desert ecosystems. However, our knowledge of microbial distribution patterns and ecological drivers is still poor, especially so for the Chihuahuan Desert., Methods: This project investigated the effects of trampling disturbance on surface soil microbiomes, explored community composition and structure, and related patterns to abiotic and biotic landscape characteristics within the Chihuahuan Desert biome. Composite soil samples were collected in disturbed and undisturbed areas of 15 long-term ecological research plots in the Jornada Basin, New Mexico. Microbial diversity of cross-domain microbial groups (total Bacteria, Cyanobacteria, Archaea, and Fungi) was obtained via DNA amplicon metabarcode sequencing. Sequence data were related to landscape characteristics including vegetation type, landforms, ecological site and state as well as soil properties including gravel content, soil texture, pH, and electrical conductivity., Results: Filamentous Cyanobacteria dominated the photoautotrophic community while Proteobacteria and Actinobacteria dominated among the heterotrophic bacteria. Thaumarchaeota were the most abundant Archaea and drought adapted taxa in Dothideomycetes and Agaricomycetes were most abundant fungi in the soil surface microbiomes. Apart from richness within Archaea ( p = 0.0124), disturbed samples did not differ from undisturbed samples with respect to alpha diversity and community composition ( p ≥ 0.05), possibly due to a lack of frequent or impactful disturbance. Vegetation type and landform showed differences in richness of Bacteria, Archaea, and Cyanobacteria but not in Fungi. Richness lacked strong relationships with soil variables. Landscape features including parent material, vegetation type, landform type, and ecological sites and states, exhibited stronger influence on relative abundances and microbial community composition than on alpha diversity, especially for Cyanobacteria and Fungi. Soil texture, moisture, pH, electrical conductivity, lichen cover, and perennial plant biomass correlated strongly with microbial community gradients detected in NMDS ordinations., Discussion: Our study provides first comprehensive insights into the relationships between landscape characteristics, associated soil properties, and cross-domain soil microbiomes in the Chihuahuan Desert. Our findings will inform land management and restoration efforts and aid in the understanding of processes such as desertification and state transitioning, which represent urgent ecological and economical challenges in drylands around the world., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Hansen, James, Anderson, Meredith, Dominguez, Pombubpa, Stajich, Romero-Olivares, Salley and Pietrasiak.) more...
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- 2023
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13. Biocrust carbon exchange varies with crust type and time on Chihuahuan Desert gypsum soils.
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Hoellrich MR, James DK, Bustos D, Darrouzet-Nardi A, Santiago LS, and Pietrasiak N
- Abstract
Introduction: In dryland systems, biological soil crusts (biocrusts) can occupy large areas of plant interspaces, where they fix carbon following rain. Although distinct biocrust types contain different dominant photoautotrophs, few studies to date have documented carbon exchange over time from various biocrust types. This is especially true for gypsum soils. Our objective was to assess the carbon exchange of biocrust types established at the world's largest gypsum dune field at White Sands National Park., Methods: We sampled five different biocrust types from a sand sheet location in three different years and seasons (summer 2020, fall 2021, and winter 2022) for carbon exchange measurements in controlled lab conditions. Biocrusts were rehydrated to full saturation and light incubated for 30 min, 2, 6, 12, 24, and 36 h. Samples were then subject to a 12-point light regime with a LI-6400XT photosynthesis system to determine carbon exchange., Results: Biocrust carbon exchange values differed by biocrust type, by incubation time since wetting, and by date of field sampling. Lichens and mosses had higher gross and net carbon fixation rates than dark and light cyanobacterial crusts. High respiration rates were found after 0.5 h and 2 h incubation times as communities recovered from desiccation, leveling off after 6 h incubation. Net carbon fixation of all types increased with longer incubation time, primarily as a result of decreasing respiration, which suggests rapid recovery of biocrust photosynthesis across types. However, net carbon fixation rates varied from year to year, likely as a product of time since the last rain event and environmental conditions preceding collection, with moss crusts being most sensitive to environmental stress at our study sites., Discussion: Given the complexity of patterns discovered in our study, it is especially important to consider a multitude of factors when comparing biocrust carbon exchange rates across studies. Understanding the dynamics of biocrust carbon fixation in distinct crust types will enable greater precision of carbon cycling models and improved forecasting of impacts of global climate change on dryland carbon cycling and ecosystem functioning., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling editor VF declared a past collaboration with the author NP., (Copyright © 2023 Hoellrich, James, Bustos, Darrouzet-Nardi, Santiago and Pietrasiak.) more...
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- 2023
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14. Movement of Ixodes pacificus and Dermacentor occidentalis (Acari: Ixodidae) adult ticks in chaparral under natural conditions in Northern California, U.S.A.
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James DK, Mendoza S, and Hui L
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- Male, Female, Animals, Seasons, California, Ixodes, Dermacentor, Ixodidae
- Abstract
The movement of Ixodes pacificus and Dermacentor occidentalis adult ticks down a hill slope under natural conditions was investigated using the mark-release-recapture (MRR) method. We evaluated the movement of host-seeking adult ticks down a hill slope to determine if ticks travel downhill from an uphill area to trail margins below. During the tick seasons in 2016-2018, the ticks were collected by flagging, marked with paint, released at a predetermined location, and recaptured by weekly flagging. Of the 188 female and 114 male I. pacificus marked and released 30 m above the trail in 2016, 11 (5.8%) females and one (0.9%) male were recaptured at the trail. In 2017, of the 71 female and 52 male I. pacificus , none were recaptured. In 2018, nine (3.6%) female and one (0.4%) male I. pacificus were recaptured of the 247 female and 287 males marked and released. Fifteen (18.5%) female and six (7.3%) male D. occidentalis were recaptured of the 81 females and 82 males marked and released in 2017. The trail deterred further movement with only 0.6% of I. pacificus and 8.3% of D. occidentalis recaptured on the opposite side of the trail. This study demonstrated that some I. pacificus and D. occidentalis adults found along the uphill side of trails may have originated from an area 30 m from the trail margin, some travelling at a rate of 1.6-1.9 m/day under natural conditions in chaparral. more...
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- 2022
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15. Laser-Induced Graphene: From Discovery to Translation.
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Ye R, James DK, and Tour JM
- Abstract
Laser-induced graphene (LIG) is a 3D porous material prepared by direct laser writing with a CO
2 laser on carbon materials in ambient atmosphere. This technique combines 3D graphene preparation and patterning into a single step without the need for wet chemical steps. Since its discovery in 2014, LIG has attracted broad research interest, with several papers being published per month using this approach. These serve to delineate the mechanism of the LIG-forming process and to showcase the translation into many application areas. Herein, the strategies that have been developed to synthesize LIG are summarized, including the control of LIG properties such as porosity, composition, and surface characteristics, and the advancement in methodology to convert diverse carbon precursors into LIG. Taking advantage of the LIG properties, the applications of LIG in broad fields, such as microfluidics, sensors, and electrocatalysts, are highlighted. Finally, future development in biodegradable and biocompatible materials is briefly discussed., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.) more...- Published
- 2019
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16. Laser-Induced Graphene.
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Ye R, James DK, and Tour JM
- Abstract
Research on graphene abounds, from fundamental science to device applications. In pursuit of complementary morphologies, formation of graphene foams is often preferred over the native two-dimensional (2D) forms due to the higher available area. Graphene foams have been successfully prepared by several routes including chemical vapor deposition (CVD) methods and by wet-chemical approaches. For these methods, one often needs either high temperature furnaces and highly pure gases or large amounts of strong acids and oxidants. In 2014, using a commercial laser scribing system as found in most machine shops, a direct lasing of polyimide (PI) plastic films in the air converted the PI into 3D porous graphene, a material termed laser-induced graphene (LIG). This is a one-step method without the need for high-temperature reaction conditions, solvent, or subsequent treatments, and it affords graphene with many five-and seven-membered rings. With such an atomic arrangement, one might call LIG "kinetic graphene" since there is no annealing in the process that causes the rearrangement to the preferred all-six-membered-ring form. In this Account, we will first introduce the approaches that have been developed for making LIG and to control the morphology as either porous sheets or fibrils, and to control porosity, composition, and surface properties. The surfaces can be varied from being either superhydrophilic with a 0° contact angle with water to being superhydrophobic having >150° contact angle with water. While it was initially thought that the LIG process could only be performed on PI, it was later shown that a host of other polymeric substrates, nonpolymers, metal/plastic composites, and biodegradable and naturally occurring materials and foods could be used as platforms for generating LIG. Methods of preparation include roll-to-roll production for fabrication of in-plane electronics and two different 3D printing (additive manufacturing) routes to specific shapes of LIG monoliths using both laminated object manufacturing and powder bed fabrication methods. Use of the LIG in devices is performed very simply. This is showcased with high performance supercapacitors, fuel cell materials for oxygen reduction reactions, water splitting for both hydrogen and oxygen evolution reactions coming from the same plastic sheet, sensor devices, oil/water purification platforms, and finally applications in both passive and active biofilm inhibitors. So the ease of formation of LIG, its simple scale-up, and its utility for a range of applications highlights the easy transition of this substrate-bound graphene foam into commercial device platforms. more...
- Published
- 2018
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17. Teslaphoresis of Carbon Nanotubes.
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Bornhoeft LR, Castillo AC, Smalley PR, Kittrell C, James DK, Brinson BE, Rybolt TR, Johnson BR, Cherukuri TK, and Cherukuri P
- Abstract
This paper introduces Teslaphoresis, the directed motion and self-assembly of matter by a Tesla coil, and studies this electrokinetic phenomenon using single-walled carbon nanotubes (CNTs). Conventional directed self-assembly of matter using electric fields has been restricted to small scale structures, but with Teslaphoresis, we exceed this limitation by using the Tesla coil's antenna to create a gradient high-voltage force field that projects into free space. CNTs placed within the Teslaphoretic (TEP) field polarize and self-assemble into wires that span from the nanoscale to the macroscale, the longest thus far being 15 cm. We show that the TEP field not only directs the self-assembly of long nanotube wires at remote distances (>30 cm) but can also wirelessly power nanotube-based LED circuits. Furthermore, individualized CNTs self-organize to form long parallel arrays with high fidelity alignment to the TEP field. Thus, Teslaphoresis is effective for directed self-assembly from the bottom-up to the macroscale. more...
- Published
- 2016
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18. Graphene: powder, flakes, ribbons, and sheets.
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James DK and Tour JM
- Abstract
Graphene's unique physical and electrical properties (high tensile strength, Young's modulus, electron mobility, and thermal conductivity) have led to its nickname of "super carbon." Graphene research involves the study of several different physical forms of the material: powders, flakes, ribbons, and sheets and others not yet named or imagined. Within those forms, graphene can include a single layer, two layers, or ≤10 sheets of sp² carbon atoms. The chemistry and applications available with graphene depend on both the physical form of the graphene and the number of layers in the material. Therefore the available permutations of graphene are numerous, and we will discuss a subset of this work, covering some of our research on the synthesis and use of many of the different physical and layered forms of graphene. Initially, we worked with commercially available graphite, with which we extended diazonium chemistry developed to functionalize single-walled carbon nanotubes to produce graphitic materials. These structures were soluble in common organic solvents and were better dispersed in composites. We developed an improved synthesis of graphene oxide (GO) and explored how the workup protocol for the synthesis of GO can change the electronic structure and chemical functionality of the GO product. We also developed a method to remove graphene layers one-by-one from flakes. These powders and sheets of GO can serve as fluid loss prevention additives in drilling fluids for the oil industry. Graphene nanoribbons (GNRs) combine small width with long length, producing valuable electronic and physical properties. We developed two complementary syntheses of GNRs from multiwalled carbon nanotubes: one simple oxidative method that produces GNRs with some defects and one reductive method that produces GNRs that are less defective and more electrically conductive. These GNRs can be used in low-loss, high permittivity composites, as conductive reinforcement coatings on Kevlar fibers and in the fabrication of large area transparent electrodes. Using solid carbon sources such as polymers, food, insects, and waste, we can grow monolayer and bilayer graphene directly on metal catalysts, and carbon-sources containing nitrogen can produce nitrogen-doped graphene. The resulting graphene can be transferred to other surfaces, such as metal grids, for potential use in transparent touch screens for applications in personal electronics and large area photovoltaic devices. Because the transfer of graphene from one surface to another can lead to defects, low yields, and higher costs, we have developed methods for growing graphene directly on the substrates of interest. We can also produce patterned graphene to make GNRs or graphane/graphene superlattices within a single sheet. These superlattices could have multiple functions for use in sensors and other devices. This Account only touches upon this burgeoning area of materials chemistry, and the field will continue to expand as researchers imagine new forms and applications of graphene. more...
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- 2013
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19. A test of critical thresholds and their indicators in a desertification-prone ecosystem: more resilience than we thought.
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Bestelmeyer BT, Duniway MC, James DK, Burkett LM, and Havstad KM
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- Animals, Conservation of Natural Resources, Models, Biological, Desert Climate, Ecosystem, Herbivory, Poaceae growth & development, Prosopis growth & development
- Abstract
Theoretical models predict that drylands can cross critical thresholds, but experimental manipulations to evaluate them are non-existent. We used a long-term (13-year) pulse-perturbation experiment featuring heavy grazing and shrub removal to determine if critical thresholds and their determinants can be demonstrated in Chihuahuan Desert grasslands. We asked if cover values or patch-size metrics could predict vegetation recovery, supporting their use as early-warning indicators. We found that season of grazing, but not the presence of competing shrubs, mediated the severity of grazing impacts on dominant grasses. Recovery occurred at the same rate irrespective of grazing history, suggesting that critical thresholds were not crossed, even at low cover levels. Grass cover, but not patch size metrics, predicted variation in recovery rates. Some transition-prone ecosystems are surprisingly resilient; management of grazing impacts and simple cover measurements can be used to avert undesired transitions and initiate restoration., (Published 2012. This article is a U.S. Government work and is in the public domain in the USA.) more...
- Published
- 2013
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20. New routes to graphene, graphene oxide and their related applications.
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Zhu Y, James DK, and Tour JM
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- Diazonium Compounds chemistry, Electrodes, Nanotubes chemistry, Transistors, Electronic, Graphite chemistry, Oxides chemistry
- Abstract
Recent research has focused upon the growth of the graphene, with a concentration on the synthesis of graphene and related materials using both solution processes and high temperature chemical vapor and solid growth methods. Protocols to prepare high aspect ratio graphene nanoribbons from multi-walled carbon nanotubes have been developed as well as techniques to grow high quality graphene for electronics and other applications where high quality is needed. Graphene materials have been manipulated and modified for use in applications such as transparent electrodes, field effect transistors, thin film transistors and energy storage devices. This review summarizes the development of graphene and related materials., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.) more...
- Published
- 2012
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21. Epidermal growth factor variations in amniotic membrane used for ex vivo tissue constructs.
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Gicquel JJ, Dua HS, Brodie A, Mohammed I, Suleman H, Lazutina E, James DK, and Hopkinson A
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- Amnion ultrastructure, Basement Membrane metabolism, Basement Membrane ultrastructure, Enzyme-Linked Immunosorbent Assay, Epithelial Cells metabolism, Gene Expression Regulation, Humans, RNA, Messenger genetics, RNA, Messenger metabolism, Specimen Handling, Thermolysin metabolism, Amnion metabolism, Epidermal Growth Factor genetics, Epidermal Growth Factor metabolism, Tissue Engineering
- Abstract
Introduction: The amniotic membrane (AM) is used for engineering ex vivo tissue constructs used in ocular surface reconstruction. Epidermal growth factor (EGF) content of the AM is believed to play a key role in supporting corneal epithelial cell expansion on AM. This study investigated EGF content in AM in relation to intra- and inter-donor variations and the effect of processing and preservation (handling)., Methods: Fifteen human AM, both fresh and handled, were analyzed for EGF gene and protein expression by real-time polymerase chain reaction and ELISA, respectively., Results: EGF gene expression was predominantly seen in the AM epithelium (p<0.01). Similarly, EGF protein too was predominantly seen in the epithelial layer (p<0.01) for fresh and handled samples. EGF protein content varied between membranes (inter-donor) and at different sites within the same membrane (intra-donor). The highest EGF protein concentration was noted in the AM apical and mid-region epithelium. Significant EGF protein loss (p<0.01) was observed after handling., Conclusion: There is a considerable variation in EGF content between and within donors. This is further affected by handling of the AM. Such variations could affect the clinical efficacy of tissue constructs. Current use of AM for ex vivo expansion of epithelial cells is not standardized and remains an area of concern. more...
- Published
- 2009
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22. Optimization of amniotic membrane (AM) denuding for tissue engineering.
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Hopkinson A, Shanmuganathan VA, Gray T, Yeung AM, Lowe J, James DK, and Dua HS
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- Amnion ultrastructure, Basement Membrane metabolism, Edetic Acid pharmacology, Epithelium metabolism, Eye metabolism, Female, Humans, Immunohistochemistry methods, Microscopy, Electron, Microscopy, Electron, Scanning, Microscopy, Electron, Transmission, Pregnancy, Thermolysin chemistry, Amnion metabolism, Amnion physiology, Tissue Engineering methods
- Abstract
Introduction: Amniotic membrane (AM) has gained increasing popularity as a useful carrier for ex vivo-expanded cells for tissue engineering, particularly in ocular surface reconstruction. However, current methods employed for denuding AM are highly variable, and the consequent effects on the structural and molecular composition of the AM basement membrane (BM) are ambiguous. We compare the effects of the main denuding procedures, and propose a highly effective standardized alternative., Methods: AMs preserved for transplantation were denuded using published ethylenediaminetetraacetic acid (EDTA)- and dispase-based methodologies and our novel thermolysin-based procedure. Scanning and transmission electron microscopy and immunohistochemistry, for BM components (collagens IV and VII, laminin 5, and integrins alpha6 and beta4), were used to assess effectiveness of denuding epithelium, whilst maintaining the integrity of the BM., Results: EDTA- and dispase-based denuding techniques resulted in the disaggregation and even destruction of the BM structure and molecular composition. Employing thermolysin effectively denuded epithelium whilst maintaining BM structural and molecular integrity., Conclusion: Current procedures for preparing AM are variable and often ineffective, resulting in nonstandard membranes. Our novel thermolysin-based technique effectively denudes the AM whilst preserving an essentially intact and consistent BM. Therefore, we propose that this novel thermolysin procedure may potentially improve overall generation of tissue-engineered constructs using AM. more...
- Published
- 2008
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23. Are we teaching sufficient anatomy at medical school? The opinions of newly qualified doctors.
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Fitzgerald JE, White MJ, Tang SW, Maxwell-Armstrong CA, and James DK
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- Career Choice, Clinical Medicine trends, Data Collection, Humans, United Kingdom, Anatomy education, Curriculum trends, Education, Medical, Graduate trends, Education, Medical, Undergraduate trends
- Abstract
In recent decades wide-ranging changes have occurred in medical school curricula. Time spent studying gross anatomy has declined amidst controversy as to how, what, and when teaching is best delivered. This reduced emphasis has led to concerns amongst clinicians that a new generation of doctors are leaving medical school with insufficient anatomical knowledge. Previous studies have established that medical students value their anatomy teaching during medical school. None have sought to establish views on the sufficiency of this teaching. We investigate the opinions of newly qualified doctors at a UK medical school and relate these opinions to career intentions and academic performance in the setting of a traditional dissection and prosection-based course. Overall nearly half of respondents believe they received insufficient anatomy teaching. A substantial proportion called for the integration of anatomy teaching throughout the medical school course. Trainees intent on pursuing a surgical career were more likely to believe anatomy teaching was insufficient than those pursuing a nonsurgical career; however, overall there was no statistical difference in relation to the mean for any individual career group. This study adds to the current debates in anatomical sciences education, indicating that overall, regardless of career intentions, new doctors perceive the need for greater emphasis on anatomical teaching., ((c) 2008 Wiley-Liss, Inc.) more...
- Published
- 2008
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24. Amniotic membrane for ocular surface reconstruction: donor variations and the effect of handling on TGF-beta content.
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Hopkinson A, McIntosh RS, Tighe PJ, James DK, and Dua HS
- Subjects
- Amnion transplantation, Antigens, Viral metabolism, Blotting, Western, Corneal Diseases surgery, Electrophoresis, Polyacrylamide Gel, Humans, Immunohistochemistry, Intracellular Signaling Peptides and Proteins metabolism, Latent TGF-beta Binding Proteins, Nuclear Proteins metabolism, Reverse Transcriptase Polymerase Chain Reaction, Transforming Growth Factor beta1, Amnion metabolism, Specimen Handling, Tissue Donors, Transforming Growth Factor beta metabolism
- Abstract
Purpose: Amniotic membrane (AM) transplantation is an accepted procedure in ocular surgery. However, little is known of the interdonor and intradonor variability within the membrane. In addition, the effects of the methods of processing, storage, and preoperative preparation on the membrane are not fully elucidated. The purpose of this study was to use TGF-beta as an example to investigate interdonor and intradonor variability and to determine the effect of "handling " on TGF-beta1 within fresh, processed and stored, and transplantation-ready AM (TRAM)., Methods: Seventeen human AMs, both fresh and handled, were analyzed for TGF-beta1 by real-time polymerase chain reaction, immunohistochemistry, SDS-PAGE, and Western blotting., Results: TGF-beta1 was the highest normalized expressed isoform of TGF-beta in all samples, but it varied between membranes of different donors and at different sites within the same membrane. The highest concentration was noted in the spongy layer. Removal of the spongy layer successfully removed the bulk of TGF-beta1 from TRAM. Latency-associated protein (LAP) and a latent TGF-beta-binding protein (LTBP) were also detected., Conclusion: TGF-beta1 is present in various regulatory forms in the AM. A degree of intermembrane and intramembrane variation is modified by handling. Unless a standardized protocol is adopted that delivers a membrane with consistent constituents, clinical outcomes may vary and comparisons may be invalid. more...
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- 2006
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25. Do screening-preventative interventions in asymptomatic pregnancies reduce the risk of preterm delivery--a critical appraisal of the literature.
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Varma R, Gupta JK, James DK, and Kilby MD
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- Anti-Infective Agents therapeutic use, Female, Humans, Incidence, Infant, Newborn, Infant, Premature, Mass Screening, Obstetric Labor, Premature drug therapy, Pregnancy, Pregnancy Complications prevention & control, Premature Birth, Risk Factors, Vaginosis, Bacterial prevention & control, Obstetric Labor, Premature prevention & control, Pregnancy Complications diagnosis, Primary Prevention, Vaginosis, Bacterial diagnosis
- Abstract
Recent research has suggested that women who experience preterm delivery (PTD) may be identified earlier in pregnancy and before onset of symptoms. Interventions commenced at this earlier asymptomatic stage may offer an opportunity to prevent PTD or lengthen gestation sufficiently to reduce adverse perinatal outcome. Our objective was to examine the evidence that supports or refutes this approach to preventing PTD. We therefore conducted a systematic search and critical appraisal of the identified literature. We found evidence that introducing screening-preventative strategies for asymptomatic pregnancies may reduce the rate of PTD. Evidence for screening and selective treatment exists for: asymptomatic bacteriuria; bacterial vaginosis in low-risk population groups; elective cervical cerclage in high-risk pregnancies; indicated cervical cerclage in women with short cervical length on ultrasound; prophylactic progesterone supplementation in high-risk pregnancies, and smoking cessation. However, for most other strategies, such as increased antenatal attendance, or routine administration of prophylactic micronutrients, the evidence is inconsistent and conflicting. Information on neonatal outcomes apart from PTD (such as serious neonatal morbidity and mortality) was found to be lacking in most studies. It was therefore not possible to establish whether preventing PTD or prolonging gestation would correlate to improved perinatal outcome, and this lessened the potential clinical usefulness of any proposed preventative strategy. No studies were found that evaluated the effectiveness of combining screening-preventative strategies. The review concludes with a suggested an antenatal management plan designed to prevent PTD based on current practice and the evidence presented in this article. more...
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- 2006
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26. Analytical techniques for characterization of organic molecular assemblies in molecular electronics devices.
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James DK and Tour JM
- Abstract
The analytical techniques used for the physical characterization of organic molecular electronic-based devices are surveyed and discussed. These protocols include methods that are used to probe molecular assemblies such as single wavelength ellipsometry, water contact angle goniometry, cyclic voltammetry, infrared spectroscopy, and X-ray photoelectron spectroscopy, and methods used to measure charge transport properties of devices such as scanning tunneling microscopy, and inelastic electron tunneling spectroscopy. Examples from our laboratory and the literature are given for each of these analytical techniques. more...
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- 2006
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27. Vertex haemangioma: an unusual cause of intrapartum haemorrhage.
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Fynn JK, Ducket R, Wardle SP, and James DK
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- Adult, Diagnosis, Differential, Female, Head and Neck Neoplasms diagnosis, Hemangioma diagnosis, Humans, Magnetic Resonance Imaging, Skin Neoplasms diagnosis, Head and Neck Neoplasms complications, Hemangioma complications, Hemorrhage etiology, Scalp, Skin Neoplasms complications
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- 2005
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28. Molecular wires.
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James DK and Tour JM
- Abstract
Molecular wires are compounds that are proposed to be used in molecular electronic and optoelectronic devices to replace the metal and silicon-based wires in semiconductor devices. We review the field, including organic molecular wires such as oligo(2,5-thiophene ethynylene)s, oligo(1,4-phenylene ethynylene)s, oligo(1,4-phenylene vinylene)s, aromatic ladder oligomers, oligophenylenes, polyphenylenes, acetylene oligomers, carbon nanotubes, and organometallic molecular wires. We briefly review the measurement of conduction in molecular wires and conclude that fully conjugated organic aromatic molecular wires are the best candidates for introduction into new electronic devices as replacements for the Al or Cu wiring presently used in logic and memory devices. more...
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- 2005
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29. T cell lymphoma in the lumbar spine of a domestic ferret (Mustela putorius furo).
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Hanley CS, Wilson GH, Frank P, James DK, Carmichael KP, Pesti D, and Ritchie B
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- Animals, Blood Chemical Analysis veterinary, Diagnosis, Differential, Lymphoma, T-Cell diagnosis, Lymphoma, T-Cell diagnostic imaging, Male, Spinal Neoplasms diagnosis, Spinal Neoplasms diagnostic imaging, Tomography, X-Ray Computed veterinary, Ultrasonography, Ferrets, Lumbar Vertebrae, Lymphoma, T-Cell veterinary, Spinal Neoplasms veterinary
- Abstract
A 22-month-old castrated male ferret developed acute pelvic limb paresis. Radiographs and computed tomography revealed a soft tissue mass with associated bony lysis of L5, and ultrasound-guided fine needle aspirates suggested that it was a lymphoma. Treatment with prednisone at immunosuppressive doses did not produce any detectable improvement in the ferret's clinical signs and it became moribund less than two weeks after they developed. A postmortem biopsy confirmed the presence of a lymphoma which had invaded the vertebral bone. No viruses were detected by cell culture, or electron microscopy. more...
- Published
- 2004
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30. Fetal brain activity and hemodynamic response to a vibroacoustic stimulus.
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Fulford J, Vadeyar SH, Dodampahala SH, Ong S, Moore RJ, Baker PN, James DK, and Gowland P
- Subjects
- Acoustic Stimulation, Adult, Female, Humans, Magnetic Resonance Imaging, Vibration, Brain embryology, Brain physiology, Cerebrovascular Circulation physiology, Fetus physiology, Pregnancy
- Abstract
Previous studies have demonstrated the practicality of using functional magnetic resonance imaging (fMRI) techniques to assess fetal brain activity. The purpose of this study was to compare the fetal hemodynamic response to that of the adult. Seventeen pregnant subjects, all of whom were at more than 36 weeks gestation were scanned while the fetus was exposed to a vibroacoustic stimulus. Thirteen adult subjects were scanned with an equivalent acoustic stimulus. Of the fetal subjects, two could not be analyzed due to technical problems, eight did not show significant activation, and seven showed significant activation. In all cases, activation was localized within the temporal region. Measures of fetal hemodynamic responses revealed an average time to peak (ttp) of 7.36 +/- 0.94 sec and an average percentage change of 2.67 +/- 0.93%. In contrast, activation was detected in 5 of 13 adults with an average ttp of 6.54 +/- 0.54 sec and an average percentage change of 1.02 +/- 0.40%. The measurement of changes in the fetal hemodynamic response may be important in assessing compromised pregnancies., (Copyright 2004 Wiley-Liss, Inc.) more...
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- 2004
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31. Vascular endothelial cadherin and beta-catenin in human fetoplacental vessels of pregnancies complicated by Type 1 diabetes: associations with angiogenesis and perturbed barrier function.
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Leach L, Gray C, Staton S, Babawale MO, Gruchy A, Foster C, Mayhew TM, and James DK
- Subjects
- Adult, Blood Glucose metabolism, Blotting, Western, Capillary Permeability physiology, Diabetes Mellitus, Type 1 pathology, Diabetic Angiopathies physiopathology, Endothelium, Vascular physiology, Female, Fluorescent Antibody Technique, Direct, Humans, Infant, Newborn, Microscopy, Confocal, Neovascularization, Pathologic physiopathology, Phosphorylation, Placenta blood supply, Placenta physiopathology, Pregnancy, Pregnancy Outcome, Pregnancy in Diabetics pathology, Pregnancy in Diabetics physiopathology, Regional Blood Flow physiology, beta Catenin, Cadherins metabolism, Cytoskeletal Proteins metabolism, Diabetes Mellitus, Type 1 complications, Diabetic Angiopathies pathology, Endothelium, Vascular metabolism, Fetus blood supply, Neovascularization, Pathologic pathology, Placenta metabolism, Pregnancy in Diabetics metabolism, Trans-Activators metabolism
- Abstract
Aims/hypothesis: Increased angiogenesis of fetoplacental vessels is a feature of pregnancies complicated by Type 1 diabetes mellitus, but the underlying molecular mechanisms are unknown. This investigation tests whether the diabetic maternal environment alters the phenotypic expression of placental vascular endothelial cadherin and beta-catenin, which have been implicated as key molecules in barrier formation and angiogenesis in the endothelium., Methods: Term placental microvessels from normal pregnancies (n=8) and from those complicated by Type 1 diabetes (n=8) were perfused with 76-Mr dextran tracers (1 mg/ml) and subjected to immunocytochemistry, immunoblotting and microscopy. Junctional integrity, localisation and phosphorylation were investigated along with total protein levels of vascular endothelial cadherin, beta-catenin and vascular endothelial growth factor. Stereological sampling and estimation tools were used to quantify aspects of angiogenesis and endothelial proliferation., Results: In the Type 1 diabetic placentae, junctional localisations of vascular endothelial cadherin and beta-catenin altered significantly, with more than 50% of microvessels showing complete loss of immunoreactivity and with no overall loss of total protein. Tracer leakage was associated with these vessels. There was a two- to three-fold increase in vessels showing junctional phospho-tyrosine immunoreactivity and hyperphosphorylated beta-catenin. Vascular endothelial growth factor levels were higher in these placentae. A four-fold increase in endothelial proliferation was observed, along with an increase in total length of capillaries without any change in luminal diameter., Conclusions/interpretation: Molecular perturbations of vascular endothelial cadherin and beta-catenin occur in fetoplacental vessels of pregnancies complicated by Type 1 diabetes. Phosphorylation and loss of these molecules from the adherens junctional domains may be influenced in part by the elevated levels of vascular endothelial growth factor in the placenta. Perturbations of the junctional proteins may explain the observed breach in barrier integrity and may contribute to the mechanisms that drive proliferation and increases in capillary length. more...
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- 2004
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32. Presenting and discussing nuchal translucency screening for fetal abnormality in the UK.
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Pilnick AM, Fraser DM, and James DK
- Subjects
- Adult, Congenital Abnormalities diagnostic imaging, Decision Making, Female, Fetal Diseases diagnostic imaging, Humans, Neck diagnostic imaging, Nurse-Patient Relations, Patient Acceptance of Health Care, Pregnancy, Pregnancy, High-Risk, Surveys and Questionnaires, United Kingdom, Congenital Abnormalities diagnosis, Fetal Diseases diagnosis, Mass Screening psychology, Mass Screening standards, Midwifery standards, Mothers psychology, Neck embryology, Ultrasonography, Prenatal
- Abstract
Objective: to investigate the relationship between information giving by midwives and decision-making by women offered nuchal translucency (NT) screening. To establish how risk figures are discussed in practice, with the intention of relating this to the existing, and often critical, literature on women's accounts of antenatal screening., Design: a qualitative study following women through the process of being offered and deciding to undergo NT screening. Tape recording of consultations, analysed in their entirety, was combined with post-screening interviews., Setting: a large teaching hospital in the UK., Participants: fourteen pregnant women eligible for NT screening at the time of recruitment., Data Collection: (i) tape recordings of consultations between community midwives and pregnant women where nuchal translucency screening was offered; (ii) tape recordings of consultations between hospital midwives and pregnant women immediately post-screening; (iii) individual face-to-face interviews with pregnant women between two and six weeks after the screening, carried out by the first author., Findings: NT screening was in general well received, particularly by those women who had undergone serum screening with previous pregnancies. However, communicating the nature of a risk figure is an interactionally complex process. A large amount of interactional work is required by midwives both before and after screening to ensure that women comprehend this information. Despite the emphasis placed in these consultations on understanding the purpose of NT screening and the status of the results, women often framed their decision to undergo NT screening in terms of it being a formality, or of presuming that all was well. This sometimes created practical and personal difficulties in terms of decision-making., Key Conclusions and Implications for Practice: previous sociological and psychological research has tended to be critical of midwives in terms of ensuring informed choice in screening, but this research is often based on post hoc accounts. Examining actual consultations with these accounts helps to illustrate the other factors that affect women's perceptions of testing, and the way in which risk, choice and decision-making are introduced and discussed in practice. Encouraging women to consider what action they might take on the basis of a personally unfavourable NT result in advance of undergoing the scan may help them to decide whether the information gained will be useful to them. Recognising the complex interactional work required in making sure that women understand the nature of the results that will be obtained is an important issue for the education and training of midwives. more...
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- 2004
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33. Fetal brain activity in response to a visual stimulus.
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Fulford J, Vadeyar SH, Dodampahala SH, Moore RJ, Young P, Baker PN, James DK, and Gowland PA
- Subjects
- Female, Fetus physiology, Frontal Lobe embryology, Gestational Age, Humans, Magnetic Resonance Imaging, Photic Stimulation methods, Pregnancy, Pregnancy Trimester, Third, Brain embryology, Light
- Abstract
Previous studies have demonstrated the use of functional magnetic resonance imaging (fMRI) to assess fetal brain activity. To extend these studies, a fetal fMRI experiment using a visual stimulus has been performed at 0.5 T. This used a block fMRI paradigm with a bright, constant-intensity light source being shone at the maternal abdomen for 8 sec followed by 16 sec of darkness. This was repeated typically 40 times on nine subjects all of whom were greater than 36 weeks gestational age. Of these, one could not be analysed due to motion, three did not show significant activation, and five showed significant activation (P < 0.0085). In all cases, activation was localised within the frontal cortex. Exact localisation was difficult but this may correspond to the frontal eye fields and dorsolateral prefontal cortex. In no cases was significant activation present within the occipital region as would have been expected and was observed in 2/8 adult subjects. Hum. Brain Mapping 20:239-245, 2003., (Copyright 2003 Wiley-Liss, Inc.) more...
- Published
- 2003
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34. Fetal learning: a prospective randomized controlled study.
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James DK, Spencer CJ, and Stepsis BW
- Subjects
- Female, Fetal Movement physiology, Gestational Age, Heart Rate, Fetal physiology, Humans, Male, Memory physiology, Pregnancy, Prospective Studies, Embryonic and Fetal Development physiology, Infant, Newborn psychology, Learning physiology, Music Therapy methods, Prenatal Care methods
- Abstract
Objectives: To examine whether prenatal exposure to a music stimulus alters fetal behavior and whether this continues into the newborn period., Subjects and Methods: A prospective randomized control trial was conducted using an exposure learning model in 20 normal term pregnancies. Music was played to ten fetuses via a headphone on the maternal abdomen. Ten controls had the headphone without sound. All fetal studies took place within 72 h prior to elective delivery. All 20 newborns were exposed to the same music on days 3-5. Computerized assessment of fetal heart rate and activity was documented and neonatal behavioral states were recorded. Nonparametric statistical analysis was used., Results: For the first hour of study, exposed fetuses had higher mean heart rates (FHR) and spent more time exhibiting high FHR variation compared to unexposed fetuses, but neither of these differences was statistically significant. However, by the fourth hour the exposed fetuses not only demonstrated these two features but also exhibited more state transitions (P = 0.01) and higher FHR variation (P = 0.04) compared to unexposed fetuses. These effects were carried over into the neonatal period with prenatally exposed newborns manifesting more state transitions (P = 0.01) and spending a higher proportion of time in awake states (P = 0.05) when exposed to the same music stimulus., Conclusion: Prenatal music exposure alters the fetal behavioral state and is carried forward to the newborn period. This suggests that a simple form of fetal programming or learning has occurred. more...
- Published
- 2002
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35. Warfarin dosage in postpartum women: a case-control study.
- Author
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Brooks C, Rutherford JM, Gould J, Ramsay MM, and James DK
- Subjects
- Adult, Case-Control Studies, Dose-Response Relationship, Drug, Female, Humans, International Normalized Ratio, Pregnancy, Retrospective Studies, Time Factors, Anticoagulants administration & dosage, Blood Coagulation Disorders drug therapy, Puerperal Disorders drug therapy, Warfarin administration & dosage
- Abstract
Objective: To investigate the clinical suspicion that postpartum women are more difficult to anticoagulate with warfarin than non-pregnant women due to the physiological changes in coagulation proteins that persist into the postpartum period., Design: A retrospective case-control study., Setting: University Hospital, Nottingham, UK., Sample: Twenty-three postpartum women discharged from the obstetric wards on warfarin and 23 age-matched control women discharged from the medical wards on warfarin were identified using hospital databases., Methods: Warfarin doses and international normalised ratio values were recorded from day one to 35. The number of days and total warfarin dose to achieve therapeutic international normalised ratio were recorded. Doses were compared with those recommended by a dosing nomogram., Results: The postpartum group took significantly longer and significantly larger doses of warfarin to reach therapeutic international normalised ratio (P < 0.05). The postpartum group required a persistently higher maintenance dose of warfarin. Comparing the warfarin dose given on day three with a standardised nomogram, 79% of women in the postpartum group compared with 57% in the control group were under-dosed., Conclusion: Postpartum women require larger doses of warfarin to reach therapeutic international normalised ratio than non-pregnant women. We would recommend the use of a dosing nomogram. more...
- Published
- 2002
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36. A comparison of fetal behaviour in term fetuses exposed to anticonvulsant medication with unexposed controls.
- Author
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Kean LH, Gargari SS, Suwanrath C, Sahota DS, and James DK
- Subjects
- Adult, Cardiotocography methods, Epilepsy drug therapy, Female, Heart Rate, Fetal drug effects, Humans, Pregnancy, Ultrasonography, Doppler, Ultrasonography, Prenatal, Anticonvulsants adverse effects, Fetal Movement drug effects, Fetus drug effects, Pregnancy Complications drug therapy
- Abstract
Objective: To compare behaviour in term fetuses exposed to anticonvulsants with unexposed controls., Design: An observational study., Setting: Pregnancy Assessment Centre, University Hospital, Nottingham, UK., Sample: Seventeen fetuses whose mothers were taking anticonvulsants and 94 fetuses whose mothers were on no medication between 28 and 41 weeks., Methods: Behaviour (fetal heart rate and activity) was recorded with the use of Doppler ultrasound. The duration of recording was 60 minutes or more in all but four recordings (minimum 49 minutes)., Main Outcome Measures: Behavioural criteria studied were: 1. the relative percentage time spent in low and high variation fetal heart rate patterns; 2. the duration and recurrence of fetal activity; 3. the number of accelerations in low and high fetal heart rate variation; and 4. the number of fetal behavioural state transitions., Results: The two groups were comparable in terms of maternal age, parity. birthweight, Apgar scores and absence of neonatal problems. There was less fetal activity in the anticonvulsant group, but this was only statistically significant at 33-36 weeks in fetal heart rate pattern B (equivalent to state 2F)., Conclusions: This study showed that fetuses exposed to anticonvulsant medication exhibited a trend of being less active. There were no other significant differences in behaviour. The data do not support the hypothesis of substantial differences in behaviour in fetuses exposed to anticonvulsants. more...
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- 2001
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37. The information content of Doppler ultrasound signals from the fetal heart.
- Author
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Shakespeare SA, Crowe JA, Hayes-Gill BR, Bhogal K, and James DK
- Subjects
- Electrocardiography, Female, Heart Rate, Humans, Pregnancy, Signal Processing, Computer-Assisted, Fetal Heart diagnostic imaging, Fetal Monitoring methods, Ultrasonography, Doppler methods, Ultrasonography, Prenatal methods
- Abstract
Knowledge of the content of Doppler ultrasound signals from the fetal heart is essential if the performance of fetal heart rate (FHR) monitors based upon this technology is to be improved. For this reason instrumentation was constructed to enable the simultaneous collection of Doppler audio signals and the transabdominal fetal ECG (for signal registration), with a total of 22 recordings being made with an average length of around 20 minutes. These data demonstrate the transient nature of the Doppler audio data with wide variations in the signal content observable on a beat-to-beat basis. Short-time Fourier analysis enabled the content of the Doppler signals to be linked to six cardiac events, four valve and two wall motions, with higher frequency components being associated with the latter. This differing frequency content together with information regarding the direction of movement that can be discerned from Doppler signals provided a potential means of discriminating between these six events (which are unlikely to all contribute to the Doppler signal within the same cardiac cycle). Analysis of 100 records showed that wall contractions generate the most prominent signals, with atrial contraction recognisable in all records and ventricular wall contraction in 95% (although its amplitude is only around 30% of that of the atrial signal). Valve motion, with amplitudes between 15 and 25% that of the atrial wall signal, were visible in 75% of records. These results suggest means by which the six events that contribute to the Doppler signal may be distinguished, providing information that should enable an improvement in the current performance of Doppler ultrasound-based FHR monitors. more...
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- 2001
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38. Computerised analysis of the fetal heart rate and relation to acidaemia at delivery.
- Author
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Strachan BK, Sahota DS, van Wijngaarden WJ, James DK, and Chang AM
- Subjects
- Acidosis physiopathology, Algorithms, Delivery, Obstetric, Female, Fetal Diseases physiopathology, Humans, Hydrogen-Ion Concentration, Infant, Newborn, Pregnancy, Retrospective Studies, Acidosis diagnosis, Cardiotocography methods, Diagnosis, Computer-Assisted methods, Fetal Diseases diagnosis, Heart Rate, Fetal physiology
- Abstract
Objective: To identify the individual features of the computerised analysis of the cardiotocograph that relate to arterial pH and base deficit at delivery., Design: Retrospective observational study., Setting: Teaching hospital labour wards., Participants: 679 women requiring continuous intrapartum fetal monitoring., Methods: Fetal heart and uterine contraction data were obtained using the Nottingham Fetal ECG monitor. Fetal heart rate patterns for the last half-hour preceding delivery were analysed using a computer algorithm developed for intrapartum application. The significance of the areas under receiver operator characteristic curves were calculated., Main Outcome Measures: Umbilical arterial pH and base deficit at delivery., Results: Three parameters, fetal bradycardia, total deceleration area and the deceleration area after a contraction had receiver operator characteristic curves that significantly predict a low umbilical arterial pH and base deficit at delivery (areas under receiver-operator characteristic curves = 0.53, SD 0.01 P = 0.03; 0.60, SD 0.03 P = 0.002; 0.62 SD 0.04 P < 0.001, respectively). Tachycardia, accelerations and variability did not., Conclusions: The individual components of the computerised analysis of the fetal heart rate that predict acidaemia at delivery are identified. more...
- Published
- 2001
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39. Computerized analysis of acute and chronic changes in fetal heart rate variation and fetal activity in association with maternal smoking.
- Author
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Coppens M, Vindla S, James DK, and Sahota DS
- Subjects
- Adult, Female, Gestational Age, Humans, Male, Pregnancy, Pulsatile Flow, Signal Processing, Computer-Assisted, Ultrasonography, Prenatal, Umbilical Arteries physiology, Fetal Movement, Heart Rate, Fetal, Maternal-Fetal Exchange, Smoking adverse effects
- Abstract
Objective: To investigate the acute and chronic changes in fetal heart rate and fetal activity in association with maternal smoking by means of a computerized fetal behavior assessment program., Study Design: In 13 term nonsmokers and 13 term smokers, fetal behavior was analyzed for 2 consecutive periods of >60 minutes. In between these 2 periods, the smokers were allowed to smoke 1 cigarette, the nonsmokers were allowed a short break of comparable time span. Fetal heart rate variation and fetal activity were recorded by a single 1.5-MHZ ultrasound transducer. The percentage of time spent in low and high fetal heart rate variation and fetal activity were analyzed by computer before and after the short break for nonsmokers and before and after the smokers smoked the 1 cigarette. Smoking-induced changes in Doppler umbilical artery recordings were also investigated. Chronic exposure to cigarette smoke was objectively evaluated by measuring the carbon monoxide concentration in expired air in all participating women after breath holding., Results: Fetuses chronically exposed to cigarette smoke spent significantly more time in a low fetal heart rate variation pattern, while fetal activity was decreased both in high and low fetal heart rate variation periods. After maternal smoking, no acute changes were observed in fetal heart rate variation, yet a reduction in fetal activity was noted; however, this only reached statistical significance in periods of high fetal heart rate variation. No significant change in mean fetal heart rate was observed, yet a significant reduction in the frequency of accelerations was noted. Smoking caused an acute and transient increase in the mean pulsatility index in the umbilical artery., Conclusion: The computer program was able to detect changes in fetal behavioral variables in association with acute and chronic smoking. These changes may be suggestive of altered neurodevelopmental maturation possibly resulting from chronic fetal hypoxemia. This computer program offers a real possibility that analysis of fetal behavioral variables can be brought into routine clinical practice. Incorporating an analysis of these behavioral variables into smoking cessation programs may render them more successful. more...
- Published
- 2001
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40. Compact long-term recorder for the transabdominal foetal and maternal electrocardiogram.
- Author
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Piéri JF, Crowe JA, Hayes-Gill BR, Spencer CJ, Bhogal K, and James DK
- Subjects
- Electrocardiography, Ambulatory methods, Female, Fetal Monitoring methods, Heart Rate physiology, Humans, Pregnancy, Signal Processing, Computer-Assisted, Software, Electrocardiography, Ambulatory instrumentation, Fetal Monitoring instrumentation, Heart Rate, Fetal physiology
- Abstract
Foetal heart rate (FHR) monitoring is a proven means of assessing foetal health during the antenatal period. Currently, the only widely available instrumentation for producing these data is based on Doppler ultrasound, a technology that is unsuitable for long-term use. For nearly a century, it has been known that the foetal electrocardiogram (FECG) can be detected using electrodes placed on the maternal abdomen. Although these signals suggest an alternative means of FHR derivation, their use has been limited owing to problems of poor signal-to-noise ratio. However, the eminent suitability of the transabdominal FECG for long-term FHR monitoring has suggested that perseverance with the technique would be worthwhile. The paper describes the design, construction and use of a compact, long-term recorder of three channels of 24 h antenatal transabdominal data. Preliminary use of the recorder in around 400 short recording sessions demonstrates that FHR records of equivalent quality to those from Doppler ultrasound-based instruments can be extracted from such data. The success of FHR derivation is, on average, around 65% of the recording period from around 20 weeks gestation (although this figure is reduced from around 28-32 weeks, and the success rates exhibit a wide range when individual subjects are considered). These results demonstrate that the technique offers, not only a means of acquiring long-term FHR data that are problematic to obtain by other means, but also a more patient-friendly alternative to the Doppler ultrasound technique. more...
- Published
- 2001
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41. Influenza virus infection in the second and third trimesters of pregnancy: a clinical and seroepidemiological study.
- Author
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Irving WL, James DK, Stephenson T, Laing P, Jameson C, Oxford JS, Chakraverty P, Brown DW, Boon AC, and Zambon MC
- Subjects
- Adolescent, Adult, Case-Control Studies, Cohort Studies, England epidemiology, Female, Humans, Immunoglobulin M blood, Influenza A virus, Maternal-Fetal Exchange physiology, Pregnancy, Pregnancy Trimester, Second, Pregnancy Trimester, Third, Seroepidemiologic Studies, Hemagglutination, Viral physiology, Influenza, Human epidemiology, Pregnancy Complications, Infectious epidemiology
- Abstract
Objective: To determine whether maternal influenza virus infection in the second and third trimesters of pregnancy results in transplacental transmission of infection, maternal auto-antibody production or an increase in complications of pregnancy., Design: Case-control cohort study., Population: Study and control cohorts were derived from 3,975 women who were consecutively delivered at two Nottingham teaching hospitals between May 1993 and July 1994. A complete set of three sera was available for 1,659 women., Methods: Paired maternal ante- and postnatal sera were screened for a rise in anti-influenza virus antibody titre by single radial haemolysis and haemagglutination inhibition. Routine obstetric data collected during and after pregnancy were retrieved from the Nottingham obstetric database. Cord samples were tested for the presence of IgM anti-influenza antibodies, and postnatal infant sera were tested for the persistence of influenza-virus specific IgG. Paired antenatal and postnatal sera were tested against a standard range of auto-antigens by immunofluorescence., Main Outcome Measures: Classification of women as having definite serological evidence of an influenza virus infection in pregnancy (cases) or as controls., Results: Intercurrent influenza virus infections were identified in 182/1,659 (11.0%) pregnancies. None of 138 cord sera from maternal influenza cases was positive for influenza A virus specific IgM. IgG anti-influenza antibodies did not persist in any of 12 infant sera taken at age 6-12 months. Six of 172 postnatal maternal sera from cases of influenza were positive for auto-antibodies. In all cases the corresponding antenatal serum was also positive for the same auto-antibody. There were no significant differences in pregnancy outcome measures between cases and controls. Overall, there were significantly more complications of pregnancy in the cases versus the controls, but no single type of complication achieved statistical significance., Conclusions: Influenza infection in the second and third trimesters of pregnancy is a relatively common event. We found no evidence for transplacental transmission of influenza virus or auto-antibody production in pregnancies complicated by influenza infections. There was an increase in the complications of pregnancy in our influenza cohort. more...
- Published
- 2000
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42. Effects of gestational diabetes on junctional adhesion molecules in human term placental vasculature.
- Author
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Babawale MO, Lovat S, Mayhew TM, Lammiman MJ, James DK, and Leach L
- Subjects
- Antigens, CD, Birth Weight, Cesarean Section, Diabetes, Gestational drug therapy, Endothelium, Vascular physiology, Female, Gestational Age, Glycated Hemoglobin analysis, Humans, Infant, Newborn, Insulin therapeutic use, Membrane Proteins analysis, Occludin, Organ Size, Phosphoproteins analysis, Reference Values, Zonula Occludens-1 Protein, beta Catenin, Cadherins analysis, Cytoskeletal Proteins analysis, Diabetes, Gestational physiopathology, Endothelium, Vascular physiopathology, Placenta anatomy & histology, Placenta blood supply, Pregnancy physiology, Trans-Activators
- Abstract
Aims/hypothesis: The aim of this study was to investigate whether gestational diabetes mellitus, which occurs in the microvascular remodelling phase of placental development, causes alterations in surface expression of tight and adherens junctional molecules involved in endothelial barrier function and angiogenesis., Methods: Term placenta, delivered by elective Caesarian section, from normal pregnancy (n = 5) and those complicated by gestational diabetes (n = 5) were perfusion-fixed and analysed by indirect immunofluorescence and confocal scanning microscopy. Using systematic random sampling, the surface expression of endothelial junctional proteins and the relative incidences of immunostained vessels were compared between the two study groups. Total vessel lengths were measured by stereological techniques., Results: The adherens junctional molecules, vascular-endothelial cadherin and beta-catenin, and the tight junctional molecules, occludin and zonula occludens-1 were localised to paracellular clefts in both study groups. The diabetic placentae showed pronounced reductions in the intensity of immunofluorescence and in the number of immuno-positive vessels. A corresponding statistically significant increase (from 19% to 56%) in the percentage of vessels showing junctional anti-phosphotyrosine immunoreactivity was found. The differences observed represented real changes in the absolute lengths of immunostained regions along the vessels. The stereological measurements failed to detect any statistically significant change in the combined length of fetal vessels in gestational diabetic placenta., Conclusion/interpretation: Our results suggest that even short duration diabetic insult, alters the surface expression of placental junctional proteins. This alteration could be mediated by the tyrosine-phosphorylation pathway. The changes suggest impaired barrier function rather than accelerated vascular growth. more...
- Published
- 2000
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43. Reduced fetal movements and maternal medication - new pregnancy risk factors for neurodevelopmental disability in childhood.
- Author
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James DK, Telfer FM, Keating NA, Blair ME, Wilcox MA, and Chilvers C
- Abstract
A case-control study was undertaken of 471 children on the Nottingham Special Needs Register (SNR) who were born in one of the two maternity units in the city between 1987 and 1993 (inclusive). Controls were selected as the next infant born at the same hospital following each index case. The aim of the study was to identify risk factors on the Nottingham Obstetric Database for a baby subsequently appearing on the SNR. Disability was analysed by both ICD-9 coding and functional assessment. Factors which independently and significantly predicted a child's likelihood of being on the SNR were breech presentation (adjusted odds ratio (OR) = 4.0), congenital abnormality (OR=4.9), intrapartum fetal distress (OR=1.7), fetal growth restriction (OR=2.0), socioeconomic deprivation (OR=1.8), prematurity (OR=2.2), reduced fetal movements (OR=2.5) and medication in pregnancy (OR=10.4). To our knowledge the last two factors have not previously been reported as risk predictors for neurodevelopmental disability. more...
- Published
- 2000
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44. Effect of fetal magnetic resonance imaging on fetal heart rate patterns.
- Author
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Vadeyar SH, Moore RJ, Strachan BK, Gowland PA, Shakespeare SA, James DK, Johnson IR, and Baker PN
- Subjects
- Female, Fetus physiology, Humans, Pregnancy, Statistics, Nonparametric, Transducers, Cardiotocography, Fetus anatomy & histology, Heart Rate, Magnetic Resonance Imaging
- Abstract
Objective: Our aim was to record the fetal heart rate before and during magnetic resonance imaging to observe the effects of the magnetic resonance imaging process on fetal heart rate parameters during imaging., Study Design: Fetal heart rate recordings were obtained in 10 pregnant volunteers at the time of magnetic resonance imaging. All the pregnant women were at term (37-41 weeks) with singleton fetuses in the cephalic presentation. The scanning was performed on a 0.5-T purpose-built superconductive magnet by use of echo-planar imaging. The fetal heart recordings were obtained with a modified Sonicaid Meridian 800 (Oxford) Doppler ultrasound monitor. Recordings of the fetal heart were made for a period of at least 15 minutes outside the magnet and then for at least 15 minutes inside the magnet., Results: There were no significant changes in any fetal heart rate parameters before and during the magnetic resonance imaging, as determined by the Wilcoxon matched-pairs signed-ranks test (P >.3)., Conclusion: This is the first report of fetal heart rate recording during magnetic resonance imaging of the fetus. Magnetic resonance imaging does not produce demonstrable effects on fetal heart rate patterns. more...
- Published
- 2000
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45. The fetal electrocardiogram: relationship with acidemia at delivery.
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Strachan B, Sahota D, van Wijngaarden WJ, James DK, and Chang AZ
- Subjects
- Electrocardiography, Female, Fetal Blood, Humans, Hydrogen-Ion Concentration, Infant, Newborn, Pregnancy, ROC Curve, Acidosis blood, Delivery, Obstetric, Fetal Diseases blood, Prenatal Diagnosis
- Abstract
Objective: This study was undertaken to analyze the relationship between the fetal electrocardiogram and arterial pH and base excess at delivery., Study Design: In the labor wards of three teaching hospitals a retrospective observational study was conducted on fetal monitor recordings of 679 women for whom there was an indication for continuous fetal monitoring during labor. These women had been recruited as part of either observational studies or a prospective randomized trial related to the Nottingham fetal electrocardiographic project. Fetal heart and uterine contraction data were obtained with the Nottingham fetal electrocardiographic analyzer. Morphologic and time interval analyses of the fetal electrocardiogram were performed. Evaluation was carried out for the last half hour before delivery. Main outcome measures were umbilical arterial pH and base excess at delivery., Results: The study demonstrated a relationship between time interval analysis of the fetal electrocardiogram and a low umbilical arterial pH and base excess at delivery. Analysis of the morphologic characteristics of the fetal electrocardiogram (ST segment and T-wave height) showed no significant relationship., Conclusions: Time interval analysis of the fetal electrocardiogram during labor is related to relative acidemia at delivery. more...
- Published
- 2000
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46. Improving intrapartum surveillance: an individualised T/QRS ratio?
- Author
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van Wijngaarden WJ, Strachan BK, Sahota DS, and James DK
- Subjects
- Anesthesia, Epidural, Apgar Score, Female, Gestational Age, Humans, Labor, Obstetric, Oxygen administration & dosage, Predictive Value of Tests, Pregnancy, Reference Values, Electrocardiography, Fetal Distress diagnosis, Fetal Monitoring standards
- Abstract
Objectives: To test the T/QRS ratio of the fetal electrocardiogram for normal distribution and assess the potential value of an individualised T/QRS ratio threshold to depict abnormality in the detection of fetal compromise during labour., Study Design: A retrospective analysis of twenty intrapartum fetal electrocardiogram recordings obtained on the labour ward of the Queen's Medical Centre, Nottingham., Results: In two of the twenty cases the T/QRS ratio was normally distributed. An increase in the T/QRS ratio over the 97.5th and 99.5th centile for 2 consecutive minutes, calculated on an individual basis, would appear to discriminate best between biochemically compromised and non-compromised fetuses. In no case was the T/QRS ratio seen to exceed 0.25 for periods previously described to be related to poor outcome., Conclusion: T/QRS ratio changes with individually calculated criteria for abnormality may be of benefit in the detection of fetal compromise but the effect on the intervention rate remains to be established. The use of an absolute threshold for T/QRS ratio abnormality which is based on the assumption of a normal distribution needs to be viewed with caution. more...
- Published
- 2000
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47. A comparison of fetal behaviour in breech and cephalic presentations at term.
- Author
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Kean LH, Suwanrath C, Gargari SS, Sahota DS, and James DK
- Subjects
- Birth Weight, Breech Presentation, Female, Gestational Age, Humans, Pregnancy, Pregnancy Outcome, Fetal Movement physiology, Fetus physiology, Heart Rate, Fetal physiology, Labor Presentation
- Abstract
Objective: To evaluate fetal behaviour in breech and cephalic fetuses at term, using a computerised fetal behaviour program., Design: An observational study., Setting: Pregnancy Assessment Centre, University Hospital, Nottingham., Sample: Twenty-six breech and 58 cephalic fetuses between 36 and 41 weeks., Methods: Behaviour (fetal heart rate and activity) was recorded with the use of Doppler ultrasound. The duration of recording was 60 minutes or more in all but four recordings (minimum 49 minutes)., Main Outcome Measures: Behavioural criteria studied were 1. the relative percentage time spent in low and high variation fetal heart rate patterns; 2. the duration and recurrence of fetal activity; 3. the number of accelerations in low and high fetal heart rate variation; and 4. the number of fetal behavioural state transitions., Results: Breech fetuses differed from the cephalic group in that they were lighter than the cephalic fetuses (median 3105 g vs 3400 g; P < 0.01) and were born to older mothers (median maternal age 30 years vs 28 years; P < 0.01). No significant differences were found in rates of movement, numbers of accelerations and time exhibiting low and high fetal heart rate variation. However, breech fetuses exhibited significantly more state transitions (median 5.2/h vs 3.69/h; P = 0.01)., Conclusions: This study shows that breech fetuses are neurologically different from their cephalic counterparts in otherwise healthy pregnancies, and that subtle behavioural differences can be demonstrated in utero using this computerised method. more...
- Published
- 1999
- Full Text
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48. Computerised analysis of behaviour in normal and growth-retarded fetuses.
- Author
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Vindla S, James DK, Sahota DS, and Coppens M
- Subjects
- Computers, Female, Fetal Movement, Gestational Age, Heart Rate, Fetal, Humans, Pregnancy, Transducers, Ultrasonography, Prenatal, Behavior, Fetal Growth Retardation physiopathology, Fetus physiology
- Abstract
Fetal behaviour [fetal heart rate (FHR) variation and movements (FA)] was studied in 27 normally grown fetuses and in 18 fetuses with intrauterine growth restriction (IUGR). FHR and FA were recorded using a single 1.5 MHz ultrasound transducer and analyzed by computer. The IUGR fetuses had significantly lower FA rates than the normally grown fetuses at all gestation times. They also spent a significantly lower proportion of time exhibiting high FHR variation at 28-31 weeks. Only two of the eighteen IUGR fetuses had abnormal biophysical profile scores (BPS) at the time of recording and yet all but one of them had either FHR or FA patterns that were outside the 10-90th centile range for the normally grown fetuses, suggesting that FHR and FA abnormalities predated BPS changes. More of the IUGR fetuses had abnormalities of FA than FHR. Finally, within the IUGR fetuses, those with small head circumferences (less than 3rd centile) had lower FA rates during periods of both low and high FHR variation, though this was only statistically significant for periods of low FHR variation (P < 0.05). This preliminary study offers the possibility that such objective evaluation of fetal behaviour could be used in a clinical setting and provide a more sensitive method of fetal assessment than the BPS. more...
- Published
- 1997
- Full Text
- View/download PDF
49. Computerised analysis of fetal behaviour.
- Author
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Vindla S, Sahota DS, Coppens M, and James DK
- Subjects
- Computer Simulation, Female, Gestational Age, Humans, Pregnancy, ROC Curve, Reproducibility of Results, Sensitivity and Specificity, Ultrasonography, Doppler, Ultrasonography, Prenatal, Embryonic and Fetal Development physiology, Fetus physiology, Heart Rate, Fetal, Software
- Abstract
Conventional analysis of fetal behaviour is laborious and time-consuming. For it to have a role in a clinical setting, practical and more objective methods are necessary. We describe a computerised fetal behavioural analysis programme. Fetal behaviour (in the form of heart rate and movement) was recorded using a conventional Doppler ultrasound transducer. Data are presented comparing the method with conventional forms of behavioural analysis and documenting its limitations. more...
- Published
- 1997
- Full Text
- View/download PDF
50. Computerized analysis of behavior in fetuses with congenital abnormalities.
- Author
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Vindla S, Sahota DS, Coppens M, and James DK
- Subjects
- Abnormalities, Multiple diagnostic imaging, Adult, Female, Gestational Age, Humans, Male, Pregnancy, Abnormalities, Multiple physiopathology, Fetal Movement physiology, Heart Rate, Fetal physiology, Image Processing, Computer-Assisted, Ultrasonography, Doppler methods, Ultrasonography, Prenatal
- Abstract
An observational study was undertaken to evaluate a computerized fetal behavior program in a clinical setting. Behavior of normal fetuses was compared with that of fetuses with a variety of congenital abnormalities. Forty-three fetuses were studied at 28-36 weeks; 26 were normal (49 recordings) and 16 had congenital abnormalities (26 recordings; ten had structural abnormalities of the central nervous system, one had Down's syndrome and five had other abnormalities). Behavior was recorded with the use of Doppler ultrasound. The duration of each recording was 60 min or more in all but two instances. The behavioral criteria studied were (1) the relative percentage of time spent in low and high fetal heart rate (FHR) variation; and (2) the percentage of time fetal activity was detected in low and high FHR variation. Fetuses with abnormalities exhibited varying patterns of behavior: only eight had patterns of FHR variation that were within the 10th and 90th centiles for normal fetuses and only one fetus exhibited a fetal activity pattern that was between the 10th and 90th centiles for the normal group. All the abnormal fetuses had a FHR pattern and/or fetal activity rate outside the 10th or 90th centiles. This study suggests that such a computerized behavioral analysis program may serve as a functional adjunct to the evaluation of a fetus with structural abnormalities. more...
- Published
- 1997
- Full Text
- View/download PDF
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