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Radiance and temperature profiles for the first time have been measured along the mesa side of Gunn diode samples, using an infrared microscope with a spatial resolution of 2.5 µm. Bulk heat generation occurs in the transit region, but measurements have shown a small amount of additional ohmic heating in the substrate layer, which will influence the maximum temperature of the device. The presented thermal measurements have been used to improve the existing thermal finite-element model of the diode. The measurements also represent an alternative method to obtain a more accurate temperature of the diode top contact without coating the sample with a high emissivity layer. [ABSTRACT FROM AUTHOR]

The paper reports on infra-red (IR) measurements made on silicon and gallium arsenide substrates which are transparent to IR radiation. The work showed that the measured emissivity is dependent on the wafer back-face technology, for example, a gold heat-sink or epoxy attachment. The work also indicated that the measured emissivity for the thermal mapping of a device is a function of the emitted radiation from the front, back face and layer interfaces, as well as internally reflected radiation and will be dependent on the thickness of the semiconductor wafer. Experimental work has shown that the two-temperature emissivity correction method will give a very accurate value of the total surface emissivity received from the sample. [ABSTRACT FROM AUTHOR]

In this letter, we present a fully complementary-metal-oxide-semiconductor (CMOS) compatible microelectromechanical system thermopile infrared (IR) detector employing vertically aligned multi-walled carbon nanotubes (CNT) as an advanced nano-engineered radiation absorbing material. The detector was fabricated using a commercial silicon-on-insulator (SOI) process with tungsten metallization, comprising a silicon thermopile and a tungsten resistive micro-heater, both embedded within a dielectric membrane formed by a deep-reactive ion etch following CMOS processing. In-situ CNT growth on the device was achieved by direct thermal chemical vapour deposition using the integrated micro-heater as a micro-reactor. The growth of the CNT absorption layer was verified through scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The functional effects of the nanostructured ad-layer were assessed by comparing CNT-coated thermopiles to uncoated thermopiles. Fourier transform IR spectroscopy showed that the radiation absorbing properties of the CNT adlayer significantly enhanced the absorptivity, compared with the uncoated thermopile, across the IR spectrum (3 μm-15.5 μm). This led to a four-fold amplification of the detected infrared signal (4.26 μm) in a CO2 non-dispersive-IR gas sensor system. The presence of the CNT layer was shown not to degrade the robustness of the uncoated devices, whilst the 50% modulation depth of the detector was only marginally reduced by 1.5 Hz. Moreover, we find that the 50% normalized absorption angular profile is subsequently more collimated by 8°. Our results demonstrate the viability of a CNT-based SOI CMOS IR sensor for low cost air quality monitoring. [ABSTRACT FROM AUTHOR]

Uterine and placental infections are the leading cause of abortion, stillbirth, and preterm delivery in the mare. Whereas uterine and placental infections in women have been studied extensively, a comprehensive examination of the pathogenic processes leading to this unsatisfactory pregnancy outcome in the mare has yet to be completed. Most information in the literature relating to late-term pregnancy loss in mares is based on retrospective studies of clinical cases submitted for necropsy. Here we report the development and application of a novel approach, whereby transgenically modified bacteria transformed with lux genes of Xenorhabdus luminescens or Photorhabdus luminescens origin and biophotonic imaging are utilized to better understand pathogen-induced preterm birth in late-term pregnant mares. This technology uses highly sensitive bioluminescence imaging camera systems to localize and monitor pathogen progression during tissue invasion by measuring the bioluminescent signatures emitted by the lux-modified pathogens. This method has an important advantage in that it allows for the potential tracking of pathogens in vivo in real time and over time, which was hitherto impossible. Although the application of this technology in domestic animals is in its infancy, investigators were successful in identifying the fetal lungs, sinuses, nares, urinary, and gastrointestinal systems as primary tissues for pathogen invasion after experimental infection of pregnant mares with lux-modified Escherichia coli. It is important that pathogens were not detected in other vital organs, such as the liver, brain, and cardiac system. Such precision in localizing sites of pathogen invasion provides potential application for this novel approach in the development of more targeted therapeutic interventions for pathogen-related diseases in the equine and other domestic species. [ABSTRACT FROM AUTHOR]

There is increasing interest in conducting fabrics and their uses at radio frequencies and microwave frequencies. The reflection and transmission measurements of bobbinet and knitted materials from around 8 GHz into the milli-metric frequency range 110 GHz, where the material geometry is comparable to the wavelength of the wave are considered. Bobbinet materials were found to behave like lossy dielectrics and may be useful in the construction of thin lightweight screening and absorption planes. While the knitted materials, with very small mesh geometry, gave a reflection coefficient which was comparable to a metal foil. [ABSTRACT FROM AUTHOR]

Objective: Primary studies and systematic reviews provide estimates of varying accuracy for different factors in the prediction of pre-eclampsia. The aim of this study was to review published systematic reviews to collate evidence on the ability of available tests to predict pre-eclampsia, to identify high-value avenues for future research and to minimize future research waste in this field.Methods: MEDLINE, EMBASE and The Cochrane Library including DARE (Database of Abstracts of Reviews of Effects) databases, from database inception to March 2017, and bibliographies of relevant articles were searched, without language restrictions, for systematic reviews and meta-analyses on the prediction of pre-eclampsia. The quality of the included reviews was assessed using the AMSTAR tool and a modified version of the QUIPS tool. We evaluated the comprehensiveness of search, sample size, tests and outcomes evaluated, data synthesis methods, predictive ability estimates, risk of bias related to the population studied, measurement of predictors and outcomes, study attrition and adjustment for confounding.Results: From 2444 citations identified, 126 reviews were included, reporting on over 90 predictors and 52 prediction models for pre-eclampsia. Around a third (n = 37 (29.4%)) of all reviews investigated solely biochemical markers for predicting pre-eclampsia, 31 (24.6%) investigated genetic associations with pre-eclampsia, 46 (36.5%) reported on clinical characteristics, four (3.2%) evaluated only ultrasound markers and six (4.8%) studied a combination of tests; two (1.6%) additional reviews evaluated primary studies investigating any screening test for pre-eclampsia. Reviews included between two and 265 primary studies, including up to 25 356 688 women in the largest review. Only approximately half (n = 67 (53.2%)) of the reviews assessed the quality of the included studies. There was a high risk of bias in many of the included reviews, particularly in relation to population representativeness and study attrition. Over 80% (n = 106 (84.1%)) summarized the findings using meta-analysis. Thirty-two (25.4%) studies lacked a formal statement on funding. The predictors with the best test performance were body mass index (BMI) > 35 kg/m2 , with a specificity of 92% (95% CI, 89-95%) and a sensitivity of 21% (95% CI, 12-31%); BMI > 25 kg/m2 , with a specificity of 73% (95% CI, 64-83%) and a sensitivity of 47% (95% CI, 33-61%); first-trimester uterine artery pulsatility index or resistance index > 90th centile (specificity 93% (95% CI, 90-96%) and sensitivity 26% (95% CI, 23-31%)); placental growth factor (specificity 89% (95% CI, 89-89%) and sensitivity 65% (95% CI, 63-67%)); and placental protein 13 (specificity 88% (95% CI, 87-89%) and sensitivity 37% (95% CI, 33-41%)). No single marker had a test performance suitable for routine clinical use. Models combining markers showed promise, but none had undergone external validation.Conclusions: This review of reviews calls into question the need for further aggregate meta-analysis in this area given the large number of published reviews subject to the common limitations of primary predictive studies. Prospective, well-designed studies of predictive markers, preferably randomized intervention studies, and combined through individual-patient data meta-analysis are needed to develop and validate new prediction models to facilitate the prediction of pre-eclampsia and minimize further research waste in this field. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Impact ionization in GaAs-based planar Gunn diodes is studied through electroluminescence (EL) analysis with the aim of reducing its magnitude by means of contact design and shaping, and thus enhance device performance and reliability. Designs in which the diode ohmic anode has an overhanging Schottky extension (composite anode contact) are shown to result in a significantly reduced amount of impact ionization, as compared with a simple ohmic contact design. The EL results are consistent with Monte Carlo simulations, which show a reduced impact ionization in composite anode contact devices due to a reduced electron density beneath the anode Schottky extension that, on the one hand, weakens the Gunn domain electric field and softens its variations near the anode edge, and, on the other hand, reduces the number of electrons capable of generating holes by impact ionization. A comparison between standard and composite anode contact approaches in terms of radio-frequency operation of the devices is made showing oscillations up to 109 GHz with an output power of -5 dBm in devices featuring the composite anode contact and no oscillations from all-ohmic contact devices. The findings reported in this paper may be useful not only for the design and the fabrication of planar Gunn diodes but also for other devices such as high-electron-mobility transistors where impact ionization can result in reliability limitations. [ABSTRACT FROM AUTHOR]

Abstract: Our objectives were to develop an ovine model for Escherichia coli-induced preterm delivery, and monitor E. coli (lux modified for photonic detection) invasion of the fetal environment—ewes (124±18d of gestation) received intrauterine inoculations using E. coli-lux as follows: control (n =5), 1.2×106 CFU/ml (n =5), 5.6×106 CFU/ml (n =5) E. coli-lux. Preterm delivery occurred between 48 and 120h post-inoculation in 60%, 60% of ewes infected with 1.2, and 5.6×106 CFU/ml E. coli-lux, respectively, with presence of emitting bacteria confirmed by real-time imaging of lamb tissues. In summary, preterm delivery and/or fetal distress were observed in a majority of inoculated ewes. Finally, the use of photonic bacteria with imaging was a feasible means to monitor bacterial presence ex vivo. [Copyright &y& Elsevier]

Consumption of wild-type (toxic) endophyte-infected tall fescue (E+) by horses during late gestation is known to adversely affect pregnancy outcome; however, little is known of the potential disruptive consequences of E+ consumption by mares during the critical phases of placentation and fetal development in early pregnancy. The objective of this study was to evaluate the detrimental effects of feeding E+ to mares during early gestation. Mares (n = 12) paired by stage of gestation (d 65 to 100) were assigned to diets (six per diet) consisting of endophyte-free (E-) or E+ tall fescue seed (50% E- or E+ tall fescue seed, 45% sweet feed, and 10% molasses fed at 1.0% of BW/d). Mares also had ad libitum access to E+ or E- annual ryegrass hay, and were fed diets for 10 d. Following removal from the tall fescue diet on d 11, mares were placed on common bermudagrass pasture and monitored until d 21. Morning and evening rectal temperatures were recorded and daily blood samples were collected for progesterone and prolactin (PRL) analyses, whereas samples for 3,4-dihydroxyphenyl acetic acid (a catecholamine metabolite) analysis were collected on alternate days. For clinical chemistry analysis, blood samples were collected on d 0, 5, 10 and 21. Daily urine samples were collected for ergot alkaloid analysis, and ultrasonography was performed for presence of echogenic material in fetal fluids. Rectal temperatures (E+ 37.76 ± 0.03; E- 37.84 ± 0.03°C) and serum PRL concentrations (E+ 14.06 ± 0.76; E- 12.11 ± 0.76 ng/mL) did not differ (P = 0.96) between treatments. Measuring the change in basal serum concentration from d 0 over time, progesterone concentrations did not differ (−0.64 ± 1.49 and −0.55 ± 1.47 ng/mL for E+ and E- mares, respectively). There was no negative pregnancy outcome, and ultrasonography indicated no increase in echogenic material in fetal fluids. Plasma 3,4-dihydroxyphenyl acetic acid concentrations decreased (P < 0.05) in E+ compared with Emares (2.1 ± 0.14 and 4.4 ± 0.43 ng/mL, respectively). Urinary ergot alkaloid concentration was greater (P < 0.01) in mares consuming E+ compared with E-(532.12 ± 52.51 and 13.36 ± 2.67 ng/mg of creatinine, respectively). Although no fetal loss was observed during the current study, elevated concentrations of urinary ergot alkaloid were consistent with depressed endogenous catecholamine activity, suggestive of an endocrine disruptive effect of hypothalamic origin. [ABSTRACT FROM AUTHOR]

Background: Exchange of modular components is a treatment option for the correction of recurrent dislocation of a total hip replacement. In this study, we reviewed our experience with this technique in order to define patient selection criteria and to report the outcome of treatment.Methods: Of 2935 hips treated with primary porous-coated total hip arthroplasty, fourteen (in fourteen patients) that met certain preoperative and intraoperative criteria were treated with modular component exchange because of recurrent hip instability. The primary arthroplasties in these fourteen patients had been performed through a posterior approach. At the revisions, we removed any sources of osseous or soft-tissue impingement that contributed to dislocation. Acceptable stability at the completion of component exchange was defined as stability in maximum flexion, in full extension with external rotation, and in at least 45 degrees of internal rotation with the hip in 90 degrees of flexion and maximum adduction.Results: One patient was lost to follow-up. At a mean of 5.8 years (range, 2.8 to 11.8 years) after the revision, ten of the remaining thirteen patients had not had a dislocation. Of the three patients in whom the hip dislocated after the modular component exchange, only one had recurrent dislocation; thus, recurrent dislocation was eliminated in twelve of thirteen patients.Conclusions: In selected cases, modular component exchange for the treatment of recurrent hip dislocation has a success rate comparable with that of more extensive operations. This method should be considered because it avoids the morbidity associated with revision of well-fixed components. However, to ensure the appropriateness of this surgical option, each patient must be thoroughly evaluated to identify all factors that contribute to instability and adequate intraoperative stability must be achieved. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to assess the rate of union, time to union, and complications associated with the extended slide trochanteric osteotomy. We also evaluated how outcomes were influenced by the preoperative cortical-bone thickness, the preoperative cancellous-bone quality of the greater trochanter, the number of cables used to reattach the trochanteric osteotomy fragment, and the use of cortical strut augmentation.Methods: We reviewed the results for forty-six hips in forty-five patients who underwent a revision total hip arthroplasty with an extended slide trochanteric osteotomy between December 1991 and December 1996. Twenty-three patients were men, and twenty-two were women; the mean age at the time of the operation was 66.3 years. Two hips had an isolated acetabular revision, fifteen had an isolated femoral revision, and twenty-nine had acetabular and femoral revisions. One patient (one hip) was lost to follow-up.Results: At a mean of forty-four months after the operation, the rate of union of the distal osteotomy site was 98 percent (forty-four of forty-five hips), with no change in the femoral component position. The time to union was not significantly correlated with the number of cables, the preoperative cortical-bone thickness, or the preoperative cancellous-bone quality of the greater trochanter. Interestingly, the time to bridging-callus union was significantly longer in the hips with a strut allograft than in the hips without a strut allograft (p = 0.04, t test for independent samples). Two fractures of the osteotomy fragment occurred, but neither necessitated another revision.Conclusions: The extended slide trochanteric osteotomy allows extensive acetabular and femoral exposure, facilitates removal of distal cement or a well fixed porous-coated stem, and allows reliable reattachment and healing of the trochanteric fragment. [ABSTRACT FROM AUTHOR]

In a test of theoretical predictions made by MacRae and Falahee (1995), trained assessors evaluated water samples which sometimes contained 10-5 mg/l of trichloroanisole, using three different procedures. Compared with the blue-book method of single-sample assessment, providing a reference sample identified to the assessor as beingodour-free increased the proportion of responses reporting an odour.This decreased the number of odorous samples missed. Although this outcome may be valuable in itself, discrimination between odorous and odour-free samples was not really enhanced since `false alarms' increased correspondingly. Incorporating additional, different odours intothe sequence of samples and giving knowledge of results when these were judged, dramatically improved performance - the rates both of missing trichloroanisole and of mistakenly attributing odour to odour-free samples were halved. [ABSTRACT FROM AUTHOR]

Melatonin is a strong antioxidant and causes an increase in uteroplacental blood flow when supplemented during gestation. The objective of the current study was to examine the effects of supplemental melatonin on uterine blood flow from mid- to late- gestation in cattle. Commercial beef heifers (n = 32) and cows (n = 25) were artificially inseminated and assigned to one of two treatment groups supplemented with (MEL) or without (CON) melatonin delivered as two- 24 mg implants or placebo at d 180, 210, and 240 of gestation. Uterine artery blood flow was determined using color Doppler ultrasonography. At birth, calf body weight, thoracic girth, abdominal girth, curved crown rump (CCR) length, and ponderal index (BW [kg]/CCR [m]3) were determined. Total uterine artery blood flow (summation of left and right arteries) were analyzed using repeated measures of the MIXED procedure of SAS and the model statement included day, treatment, breed, fetal sex and the respective interaction. Calf morphometric measurements were analyzed using the MIXED procedure of SAS and the model statement included treatment, calf sex and the respective interaction with gestation length as a covariant. Heifers and cows were analyzed separately due to a difference in breed between the two groups. In heifers, a treatment by day interaction (P = 0.01) was observed for total uterine artery blood flow, whereby total uterine artery blood flow was increased in MEL vs. CON on d 240 of gestation. In cows, total uterine artery blood flow increased (P < 0.05) in MEL vs. CON. Gestation length was increased (P < 0.05) in MEL heifers gestating male calves vs. female calves, while CON heifers gestating male and female calves were intermediate. In cows, gestation length was not different (P = 0.15) between treatments. At birth, calf weight, thoracic girth, abdominal girth, CCR, and ponderal index were not different (P > 0.05) between treatments in heifers. In cows, calf weight, thoracic girth, and abdominal girth were not different (P > 0.05) between treatments. However, CCR was increased (P = 0.03) and ponderal index was decreased (P = 0.01) in calves born to MEL treated cows vs. CON. In summary, melatonin supplementation increased uterine blood flow in mid- to lategestating cattle but this was not accompanied by an increase in calf birth weight. Additional studies regarding the physiological impact of these hemodynamic changes on nutrient transport and offspring development are warranted. [ABSTRACT FROM AUTHOR]

Melatonin supplementation during mid to late gestation increases uterine blood flow, thereby altering the flux of nutrients delivered to the developing fetus by the dam. Changes in the amount and composition of fatty acids available to the fetus can alter the long-term growth and developmental potential of the offspring in postnatal life. The objective of this study was to determine the effect of supplementing melatonin to beef heifers during mid to late gestation on fatty acid composition of maternal, umbilical, and fetal plasma as well as fetal perirenal adipose tissue. A total of 32 pregnant heifers were treated with (MEL) or without (CON) two 24-mg melatonin implants every 30 d starting on d 180 and ending on d 240 of gestation. On d 240 of gestation (approximately 85% of gestation), 6 CON and 6 MEL heifers were randomly selected to undergo Cesarean sections to collect fetal blood and tissues. Maternal blood (MB) was collected from the tail vein of the dams immediately prior to the surgery. Before excising the fetus, the umbilical cord was clamped on the fetal and maternal ends to collect blood from the umbilical artery (UA) and umbilical vein (UV). Fetal peripheral blood (FB) was collected during exsanguination, and perirenal (PR) adipose tissue was dissected from the fetal kidney following evisceration. Plasma and PR adipose tissue samples were directly derivatized for fatty acid quantification on a gas chromatography system to determine fatty acid concentration and percentage by internal calibration. Data were analyzed using the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC), and statistical significance was determined at P ≤ 0.05. There was no difference in total plasma fatty acid concentrations between the CON and MEL groups in MB, UA, UV, FB or PR (P > 0.324). Total SFA, MUFA, and PUFA in UA, UV, MB, FB, or PR also did not differ between treatments (P ≥ 0.11). However, MEL tended to increase C22:6 fatty acid concentration in MB (P = 0.065), UV (P = 0.079), and FB (P = 0.068). Additionally, there was a tendency for increased (P = 0.080) C20:5n-3 fatty acid in PR adipose tissue in fetuses from MEL-treated dams. Both C22:6 and C20:5n-3 fatty acids improve fetal development and immune function. Therefore, additional research is warranted to determine the specific effect of MEL on these fatty acids and their long-term impacts on offspring growth and physiology. [ABSTRACT FROM AUTHOR]

Melatonin is a strong antioxidant that contributes to circadian rhythm in several mammalian species. Melatonin has been shown to influence uteroplacental hemodynamics in both sheep and cattle. The objective was to examine fetal liver and placental steroid and eicosanoid enzyme activity during maternal melatonin supplementation. Commercial beef heifers (n = 12) were bred via AI and delegated to receive two 24-mg subdermal melatonin implants (MEL; n = 6) or act as part of a nonimplant control group (CON; n = 6). All treatments were applied at d 180, 210, and 240 of gestation, and heifers underwent Caesarian removal of the fetus at 243 ± 2 d of gestation. Placental samples were collected and separated into maternal (caruncle [CAR]) and fetal (cotyledon [COT]) portions. Additionally, the fetal liver was harvested. Cytochrome P450 1A (CYP1A), 2C (CYP2C), and 3A (CYP3A) and uridine 5'-diphospho-glucuronosyltransferase (UGT) activities were determined via luminogenic substrates. Activities were expressed per milligram of protein, and data were analyzed, using the Wilcoxon rank sum test, within tissue using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) with treatment, fetal sex, and the interaction thereof in the model. Statistical significance was declared at P = 0.05. Activity of CYP1A in CAR was decreased (P = 0.02) in male vs. female fetuses from CON dams. Activity of CYP1A was not different (P ≥ 0.25) in COT tissues; however, activity of CYP1A in the fetal liver was increased (P = 0.01) in male vs. female fetuses. Activity of CYP2C was observed only in CAR and was not different between treatments (P ≥ 0.59). Activity of CYP3A was observed only in the fetal liver and was not different between treatments (P ≥ 0.41). Activity of UGT in COT was decreased (P = 0.03) in male fetuses from MEL dams vs. female fetuses from MEL dams and male fetuses from CON dams. Activity of UGT was not different (P ≥ 0.34) between treatments in CAR; however, activity of UGT was increased (P = 0.002) in the fetal liver from MEL dams compared with the fetal liver from CON dams. In conclusion, melatonin supplementation did alter hormone metabolizing enzymes in fetal liver and placental tissues of gestating cattle. Moreover, the difference in activity of steroid and eicosanoid metabolizing enzymes in male and female fetuses may indicate a physiological adaptation to decrease excessive exposure. [ABSTRACT FROM AUTHOR]

Discusses the abstract of the study 'Use of betamethasone to advance fetal maturation in mares with high-risk pregnancies,' presented at the American Society of Animal Science's Southern Section conference on January 31-February 4, 2003, in Mobile, Alabama.