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PURPOSE/OBJECTIVE(S) Women living with HIV are at an increased risk of acquiring HPV-related cervical atypia that can progress to cervical cancer. In sub-Saharan Africa, cervical cancer makes up the largest proportion of years of life lost due to cancer, largely due to women diagnosed at younger ages, typically between 35 and 50 years. Botswana has the second highest prevalence of HIV in the world. Current World Health Organization guidelines for cervical cancer recommend screening between ages of 30-49 years; however, data suggest that women with HIV who get cervical cancer are diagnosed at a younger age. We assessed characteristics of women diagnosed with cervical cancer to further inform and refine screening guidelines. MATERIALS/METHODS We prospectively enrolled women diagnosed with cervical cancer from January 2015 to March 2020 at two tertiary hospitals in Gaborone, Botswana. We performed chi-square and ANOVA analyses to evaluate the association between categorical age at diagnosis and HIV status, CD4 count, viral load and other sociodemographic and clinical factors. RESULTS Data were available for 1,130 women who were diagnosed with cervical cancer, 69.3% were women living with HIV (WLWH). Of the total 1130 women (median age 47.9 (IQR 41.2-59.1), 1.3 % were < 30 years of age, 19.1 % were 30-39 and 37.2% were 40-49. Overall, 20.4% (n = 231) of cancers were in women < 40 years. When analyzed by age, 86.7% of patients < 30 years of age were WLWH (mean CD4 371.6 cells/µL), 86.1% in patients 30-39 years (mean CD4 671.8 cells/µL). Overall, 86.1% of women who were < 40 years of age were WLWH compared to 64.9% of women who were ≥40 years old (P < 0.001). Mean CD4 counts for WLH who were < 40 years was 655.10 cells/µL and 18.2% had detectable viral load, while mean CD4 count for ≥40 years was 619.58 cells/µL with 23.8% having a detectable viral load. The most common FIGO stage of presentation in patients < 40 years was stage II (39.9%) compared to stage III (39.7%) in ≥40-year-old women (P = 0.08). Over three quarters (84.0%) of women < 40 years old were single compared to 60.8 % in those ≥40 years. Among women < 40 years old who were screened for cervical cancer, 87.4% (n = 111) were WLHV, and among women ≥40 years 70.5% (n = 308) were WLHV. Women < 40 years were more likely to have ever been screened than women ≥40 years old (59.1% vs 50.7%, P = 0.03). CONCLUSION Age of cervical cancer diagnosis may be younger in countries with higher prevalence of HIV, like Botswana. Approximately 20% of the patients present with cancer < 40 years of age and should have been screened 10 years prior to cancer diagnosis to prevent cancer. However, these patients will not be screened per the current WHO screening guidelines. Changing international cervical cancer screening guidelines to women at younger ages than 30-49 years should be urgently considered especially in setting with high prevalence of HIV. Furthermore, engaging women without HIV in screening programs is critical for cervical cancer elimination.

Purpose/Objective(s) Polyethylene glycol hydrogel has increasingly been used in brachytherapy for organ-at-risk sparing. This study evaluated visualization and dosimetry with hydrogel in gynecologic brachytherapy. Materials/Methods Women with gynecologic cancer received hydrogel injection prior to brachytherapy on a prospective clinical trial. Two researchers rated the appearance immediately after hydrogel injection and measured volume at initial injection, and at 3 and 6 months follow-up on T2w MRI. Visualization was rated as: (1) not visualized; (2) faint or trace visibility (shadow or haze); (3) visible but indistinct borders (definable entity, not just haze); (4) partially distinct border, partial haze; and (5) clearly visualized, unequivocal. Cohen's Kappa statistic assessed interobserver variability. For patients that had spacer injected during the second implant of brachytherapy, EQD2 rectal D2cc and CTVHR D90 absolute and ratio values were calculated between the first and second implants to determine the difference in dose to tumor after placement of hydrogel. A paired t-test was performed. Results 28 women were enrolled and had an average patient age of 57.2 years (38-77). Brachytherapy applicators used in treatment included the Syed (33.3%, n = 9), Tandem and Ring (29.6%, n = 8), and Syed and Tandem (37.04%, n = 11). Diagnoses included cervical cancer (57.1%, n = 16), vaginal (23.4%, n = 6), endometrial (17.9%, n = 5), and urethral cancer (3.6%, n = 1). The average rating of hydrogel amount was 3.4/5, and did not differ by type of applicator used or by diagnosis. Inter-rater reliability (kappa statistic) for the 2 readers on the 5-point scale was 0.37. Average hydrogel volumes on 3 and 6 month T2 MRIs were 69.3 ± 53.4% and 43.7 ± 34.2%, relative to day of injection. Five patients had spacer placed at the time of the second fraction, and when compared to the first fraction, the EQD2 CTVHR D90 increase (per fraction) was 1.43 Gy10 (P = 0.006) and the average reduction in rectum EQD2 D2cc dose to the rectum was 0.39 Gy3 (P = 0.34) per fraction. The rectum EQD2 D2cc to CTVHR D90 ratio decreased from 0.65 to 0.49, on average, after hydrogel injection. Conclusion Hydrogel demonstrated moderate inter-rater reliability and progressive decrease in size over 6 months on MRI. There was a significant increase in D90 and decrease in the ratio of rectal D2cc/D90 after hydrogel injection in those that had first (without) and second (with hydrogel) fraction comparative implants. Author Disclosure M. Morcos: None. R. Bhatia: None. K. Li: None. A.N. Viswanathan: Research Grant; National Cancer Institute. Honoraria; NCI Uterine Cancer Task Force Chair.

Objective One of the largest barriers towards the utilization and overall success of health interventions for minority communities is the difference between the cultures of healthcare services and service users. Medical students, physicians, and healthcare systems are taught to be culturally competent, yet multiple studies demonstrate the persistence of differences in perception of care and disparities in outcomes for communities of colour. This article aims to offer a patient-centred, culturally nuanced medium for teaching cultural competency. Study design This is a brief report based on experiential learning, observations, and a short literature review on understanding culture through traditional dances. Methods To address cultural disconnect between clinical medicine and diverse patients, we recommend encouraging patients from diverse backgrounds to teach physicians how to perform cultural dances. Results Traditional dance appears to be a culturally rich source for holistically educating physicians on cultural competency. Conclusion This process of learning a cultural dance can improve cultural humility and cultural competency, and clinical communication between the provider and public.

Alginate hydrogels have shown great promise for applications in wound dressings, drug delivery, and tissue engineering. This report details the fabrication and rheological properties of a multicomponent hydrogel consisting of alginate and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers, and the achievement of thick, castable gels with tunable, thermoreversible behavior at physiological temperatures. PEO-PPO-PEO triblock copolymers can form temperature-sensitive hydrogels that exist as liquids at low temperatures and soft solids at high temperatures. In this work, we have employed PEO-PPO-PEO triblock copolymers to impart thermoresponsive properties to alginate hydrogels in the form of a multicomponent hydrogel. These systems can transition between a weak gel and a stiff gel, with a corresponding increase in the viscoelastic moduli of approximately two orders of magnitude as temperature is increased. The temperatures corresponding to the upper and lower boundaries of the stiff gel region, as well as the storage modulus at physiological temperatures (e.g., 36–40 °C), can be controlled through the PEO-PPO-PEO concentration. Optically clear gels that are homogeneous on the microscale can be fabricated in a scalable manner to create flat, large-area thick films, making these systems favorable for applications in wound healing, soft tissue repair, and biomedical device coatings.

We report the dynamics of aqueous dispersions of the disk-shaped colloidal clay laponite® with poly(ethylene oxide) (PEO) chains of moderate molecular weight, explored via angle-dependent dynamic light scattering (DLS) and rheology. The PEO chains adsorb onto the laponite® surfaces, causing interesting dynamic behavior, including transitions from arrested states to liquid states as the concentration and molecular weight of PEO is increased. This re-entrant behavior has been attributed to formation of particle clusters induced free PEO chains. Our DLS results are consistent with a slow diffusive dynamic process, suggesting the formation of large particle clusters, in samples at aging times

3D printing is an emerging technology for the fabrication of energy storage devices, offering advantages over traditional manufacturing methods. However, optimization and design of such devices requires an understanding of the meso‑structure formation during the 3D printing process. This study utilizes operando coherent X-ray scattering, X-ray Photon Correlation Spectroscopy (XPCS), to study the spatiotemporally-resolved far-from-equilibrium dynamics during direct ink writing 3D printing. Lithium Titanate (LTO) based ink is prepared and rheologically tested for its shear-thinning properties. Two-time intensity-intensity functions are calculated to be used in subsequent quantitative analysis, which allows for an overall characterization of the dynamics, description of an initial fast decorrelation and identification of sudden rearrangements of subdomains of the sample. The results show the dynamics to be anisotropic, spatiotemporally heterogenous and marked by distinct rearrangement events, all of which impact the electrochemical performance of energy storage devices. The studied 3D printing ink is used to fabricate electrodes which are then electrochemically tested, showing good performance in cycling and retaining structural integrity. This work furthers the understanding of the far-from-equilibrium material dynamics during 3D printing, giving quantitative characterization of this process, and highlights aspects of structure formation relevant to the electrochemical performance of the resultant energy storage device.

Perfluorocarbon (PFC) nanoemulsions have great potential in biomedical applications due to their unique chemical stability, biocompatibility, and possibilities for enhanced oxygen supply. The addition of amphiphilic block copolymers promotes the formation and long-term stability of emulsion-based gels. In this work, we report the systematic study of the impact of adding amphiphilic triblock copolymers to water-in-perfluorocarbon nanoemulsions on their structure and viscoelasticity, utilizing small-angle neutron and X-ray scattering (SANS and SAXS) and rheology. We find that an intermediate concentration of copolymer yields the highest strength of attraction between droplets, corresponding to a maximum in the elasticity and storage modulus. The stability and viscoelastic moduli can be tuned via the amount of copolymer and surfactant along with the volume fraction of aqueous phase. SANS provides the detail on nanostructure and can be fit to a spherical core-shell form factor with a square-well hard sphere structure factor. The PFC nanoemulsion system displays thermoresponsive and thermoreversible properties in temperature sweeps.

We report on the nanoscale assembly of poly(lactic acid)-b-poly(ethylene oxide)-b-poly(lactic acid) (PLA-PEO-PLA) triblock copolymers in water, focusing on the effect of stereochemistry, where the PLA blocks are statistical copolymers of l -lactide and d -lactide with l/d ratios of 100/0, 95/5, 90/10, 85/15, 75/25, and 50/50. Small-angle neutron scattering (SANS) shows a nearly constant d-spacing as concentration varies in triblock systems with l/d ratios of 90/10 and 95/5, which we attribute to inhomogeneity in the structure of these gels, supported by previous USANS and confocal microscopy studies. The SANS data fit well to a core-shell ellipsoid form factor model with a hard-sphere structure factor. Polymeric micelles with l/d ratios from 75/25 to 85/15 displayed very high aggregation numbers, consistent with a strong interaction between PLA chains and the enhanced storage modulus observed in rheological studies of these systems. While the 90/10 and 95/5 samples showed lower aggregation numbers, their SANS profiles shows close spacing between micelles, which may promote a high fraction of intermicellar bridging chains, also consistent with a higher storage modulus. Overall, these results provide insight into the micellar assembly behavior of block copolymers with a crystallizable block, and indicate that tuning stereochemistry of PLA-based block copolymers is an effective means of modifying micellar properties for specific applications.

The mechanical properties of a new type of nanocomposite gel, consisting of varying concentrations of the biopolymer alginate and the synthetic clay Laponite®, together with the temperature-sensitive copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO, trade name Pluronic® F127), are reported. These “ALP” gels (alginate-Laponite®-Pluronic®) were prepared and studied using rheology. Gels with multiple networks and gelation mechanisms have been explored as one strategy to strengthen and stiffen conventional hydrogels, which usually consist of a single polymer network. This work shows that the ALP gels exhibit significantly higher storage and loss modulus (G′, G″) values than gels composed of only alginate and Laponite®. Moreover, the interaction between the components appears to be synergistic; that is, the resulting multicomponent hydrogels are much more elastic than the additive effects of individual components. For example, the G′ of one series of the nanocomposite gels containing F127 Pluronic® experiences two orders of magnitude enhancement compared to its respective control containing only alginate and Laponite®. Furthermore, the ALP gels show a 20-40x enhancement in storage modulus, with values as high as 10,000–20,000 Pa, over the 30–55 °C temperature range. The large degree of enhancement in the storage modulus of the ALP gels with addition of Pluronic® is quite remarkable, compared to alginate-Laponite® gels on their own at comparable concentrations and temperatures, which form relatively weak gels. These results provide a simple strategy for significantly increasing the mechanical properties of polymer hydrogels used in biomaterials applications.

Structural arrest in an aging colloid-polymer mixture of charged colloidal disks and weakly interacting polymers is primarily governed by the spatial arrangement of microstructural domains in the system. Here we present a detailed ultra-small angle x-ray scattering (USAXS) study of the polymer induced microstructural changes occurring in systems containing laponite ® and poly(ethylene oxide) (PEO). Laponite ® suspensions are known to transition from a homogeneous fluid to an arrested phase as a function of time. USAXS results show that when polymer chains are added to this colloidal system, the microstructural changes are found to depend on (i) polymer-colloid size ratio, (ii) particle and polymer concentration. Large length scale structures (300–1000 nm) of non-uniformly varying size appear with increasing concentration of high molecular weight PEO ( R g / R ∼ 2.4). However with shorter PEO chains ( R g / R ∼ 0.5), we observe the formation of intermediary structures with a characteristic length scale of 50–60 nm. With increasing particle concentration, we observe a more compact structure for the high molecular weight PEO and no signature of a percolating network in the case of the low molecular PEO. We believe that these results add to our understanding of the complex aging behavior of clay-polymer systems.

Understanding particle motion during drying of colloidal and nanoparticle mixtures can be of great significance to processes such as stratification during film formation. Much of the current research in this field focuses on theory and simulation; however, additional experimental approaches are needed to support these studies. Here, we report a novel way to study film structures by applying an in-situ small angle X-ray scattering (SAXS) approach. We present studies of binary films containing two different sizes of silica particles. Our analysis allows us to probe the difference in particle packing in different layers and at different drying times. Furthermore, we can compare film samples consisting of particles with different initial concentrations and size ratios. Although the sample series presented here is limited, the data demonstrates proof-of-concept of the experimental technique. The method will be beneficial for future studies of structure formation in relatively thick films containing inorganic nanoparticles.

Particle-scale rearrangements occurring in mixtures containing anisotropic disk-shaped colloids and polymers often lead to the development of unusual viscoelastic features that can play a crucial role in applications. Here, we report the early aging behavior of a series of mixtures containing laponite, a model disk-shaped colloid, and poly(ethylene oxide) (PEO) chains of three different molecular weights, 35 kg/mol, 20 kg/mol and 4.6 kg/mol. The concentrations of PEO were varied within their respective dilute and semi-dilute un-entangled regions. Rheological experiments were utilized to describe the effects of chain number and length on the macroscopic behavior of suspensions and dynamic light scattering (DLS) was used as a tool to establish a correlation between the macroscopic behavior and dynamics seen at smaller length scales. For dilute concentrations of PEO, the rheology is consistent with a glass–liquid–glass phase transition, a trend that resembles the re-entrant behavior observed in many colloid–polymer systems. However, in more concentrated PEO solutions, samples re-stabilize and remain stable for a longer period of time. Interestingly, at lower length scales the stabilization that is seen in the concentrated region is characterized by an increase in the first and second relaxation timescales, suggesting that tightly bound stable clusters diffuse through the medium. To our knowledge, this type of behavior in an anisotropic colloid–polymer system has not been previously observed.

Applications of solid lipid nanoparticles (SLNs) in drug delivery and the encapsulation of bioactive, lipophilic compounds have been hindered by the tendency of SLN suspensions to undergo uncontrolled aggregation due to polymorphic transformation of the lipid crystals. Second generation lipid nanoparticle systems have been developed by mixing liquid lipid with solid lipid to form more stable nanostructured lipid carriers (NLCs). In this study, we investigated the effect of chemical formulation on the aggregation behavior and rheology of NLC dispersions. We found that NLC suspension viscosity could be modified by an order of magnitude by controlling particle aggregation with different surfactant and/or oil concentrations. The viscosity could be tuned by decreasing the amount of surfactant and/or oil to achieve a desired level of particle aggregation. Oscillatory sweep tests showed that non-aggregated and aggregated dispersions exhibited typical behaviors of a viscoelastic liquid and a viscoelastic solid, respectively. Modeling results suggested a stronger particle–particle bonding force and a higher aggregation efficiency as the amount of surfactant and/or oil was decreased. Both experimental and modeling results indicated that aggregated samples had an interconnected network structure, while no indication of network formation was observed for non-aggregated samples. Collectively these results suggest that controlled NLC aggregation can be exploited to develop dispersions with tunable viscosity for applications such as rheology modification.

The effect of hydrophobic modification on the mechanical and structural characteristics of hydrophobically modified alginate (HMA) solutions and hydrogels were evaluated. The HMA systems consisted of alkyl chains, C 8 , grafted onto alginate backbones. With an increase in degree of substitution of hydrophobic tails, the association became stronger in solution, but same was not true for gels. The contribution of ionic crosslinking was found to be the dominant factor in determining the mechanical strength of hydrogels. Rheological measurements of 2 wt% HMA gels reveal formation of a strongly crosslinked network with an elastic modulus close to 100 kPa. Small-angle X-ray scattering (SAXS) experiments indicate that HMA assembles into a disordered structure with regions rich in the hydrophobic domain surrounded by a crosslinked hydrophilic network.

Obstructed transport of biological molecules can result in improper release of pharmaceuticals or biologics from biomedical devices. Recent studies have shown that nonionic surfactants, such as Pluronic® F68 (F68), positively alter biomaterial properties such as mesh size and microcapsule diameter. To further understand the effect of F68 (incorporated at concentrations well above the critical micelle concentration (CMC)) in traditional biomaterials, the transport properties of BSA and riboflavin were investigated in F68-alginate composite hydrogels, formed by both internal and external cross-linking with divalent cations. Results indicate that small molecule transport (represented by riboflavin) was not significantly hindered by F68 in homogeneously (internally) cross-linked hydrogels (up to an 11% decrease in loading capacity and 14% increase in effective diffusion coefficient, D(eff)), while protein transport in homogeneously cross-linked hydrogels (represented by BSA) was significantly affected (up to a 43% decrease in loading capacity and 40% increase in D(eff)). For inhomogeneously cross-linked hydrogels (externally cross-linked by CaCl(2) or BaCl(2)), the D(eff) increased up to 50 and 83% for small molecules and proteins, respectively. Variation in the alginate gelation method was shown to affect transport through measurable changes in swelling ratio (30% decrease) and observable changes in cross-linking structure as well as up to a 3.6- and 11.8-fold difference in D(eff) for riboflavin and BSA, respectively. Aside from the expected significant changes due to the cross-linking method utilized, protein transport properties were altered due to mesh size restrictions (10-25 nm estimated by mechanical properties) and BSA-F68 interaction (DLS). Taken as a whole, these results show that incorporation of a nonionic surfactant at concentrations above the CMC can affect device functionality by impeding the transport of large biological molecules.

Two mono-adducts of fullerene C60 have been synthesised using new aryl azides in good yields. These were characterized with spectroscopic techniques and then used to fabricate bulk heterojunction solar cells with regioregular poly (3-hexylthiophene) (RR-P3HT). A photocurrent density of 3.89 mA/cm2, open-circuit voltage of 0.53 V and power conversion efficiency of 0.89% for adduct I and photocurrent density of 2.93 mA/cm2, open-circuit voltage of 0.53 V and power conversion efficiency of 0.71% for adduct II have been achieved.

Bio-oil formed by the fast pyrolysis of biomass has tremendous potential as a renewable feedstock to make liquid transportation fuels. However, the presence of char particles in the bio-oil causes problems in storage and end-use. Currently there is no well-established technology to remove char particles less than 10 μm in size. This study focuses on the application of a liquid-phase microfiltration process to remove char particles from bio-oil down to slightly sub-micron levels. Tubular ceramic membranes of nominal pore sizes 0.5 and 0.8 μm were employed to carry out the microfiltration, which was conducted in the cross-flow mode at temperatures ranging from 38 to 45 °C and at three different trans-membrane pressures varying from 1 to 3 bars. Microscopic and ash content analysis of the feed and permeate streams were conducted to determine the efficacy of the process. The results demonstrated the removal of the major quantity of char particles with a significant reduction in overall ash content of the bio-oil. Water extraction and gas chromatography were employed to characterize the chemical composition of the bio-oil, and no significant change was observed due to the microfiltration process. Results of fouling analysis obtained from longer runs of bio-oil through the membranes are also presented in this study. The results clearly showed that the cake formation mechanism of fouling is predominant in this process. A membrane cleaning protocol for the fouled membrane was developed, comprising successive treatments with methanol, sodium hydroxide, and acetic acid.

Soil physico-chemical properties, microbial biomass, and functional microbial diversity were investigated in two adjacent fields located in a semi-arid dryland farming region of Maharashtra state, India. In organically cultivated field (OCF) large annual inputs of composted cow manure, no tillage and no removal of crop residues is being practiced for the past 14 years. The neighboring plot which was not cultivated for the same period remained as fallow grassland (FGL) served as check for comparison. Soil samples collected from OCF had higher pH, moisture, total organic carbon and nitrogen, microbial biomass, C and N, and enzymatic activities compared to FGL soil. Microbial community structure in the two soils was assessed, using Biolog Eco and GN2 plates. OCF soil showed significant (P = 0.01) increase of microbial diversity and evenness, suggesting an improvement of functional microbial diversity. Principal component analysis (PCA) separates the two soil samples based on 10 most discriminating carbon sources for each with the maximum positive and negative scores. To the best of our knowledge this is the first study on soil quality and microbial functional diversity of soil in a semi-arid region indicating that conversion from FGL to OCF led to significant soil quality improvement due to the enhanced microbial functional diversity.

Soft tissue tumours of hand are common. This article reviews the most relevant literature with regards to epidemiology, diagnosis and management.

There has been an increasing interest in understanding how the mechanical properties of the microenvironment influence stem cell fate. We describe studies of the proliferation and differentiation of neural stem cells (NSCs) encapsulated within three-dimensional scaffolds--alginate hydrogels--whose elastic moduli were varied over two orders of magnitude. The rate of proliferation of neural stem cells decreased with increase in the modulus of the hydrogels. Moreover, we observed the greatest enhancement in expression of the neuronal marker beta-tubulin III within the softest hydrogels, which had an elastic modulus comparable to that of brain tissues. To our knowledge, this work represents the first demonstration of the influence of modulus on NSC differentiation in three-dimensional scaffolds. Three-dimensional scaffolds that control stem cell fate would be broadly useful for applications in regenerative medicine and tissue engineering.

AOT-based water-in-oil microemulsions display an anomalous maximum in the viscosity with X, the water to surfactant ratio. Several explanations for this phenomenon have been offered. In this work, we investigate viscosity and droplet interactions in Ca(AOT)(2)/water/n-decane and KAOT/water/n-decane microemulsions and compare our results with the commonly studied NaAOT/water/oil system. The Ca(AOT)(2) system demonstrates a maximum in relative viscosity and droplet attraction near X=15, similar to the NaAOT system, although the maximum occurs at a higher value of X in the Ca(AOT)(2) system. By contrast, the viscosity and interparticle interactions in the KAOT system do not strongly depend on the amount of water in the system. We attribute the differences in behavior between the two systems to different hydration characteristics of the counterion, and we believe that our results are consistent with a previously proposed model that attributes interdroplet attractions to charge fluctuations and surfactant exchange. Our findings support the connection between the viscosity anomaly and interparticle interactions.

We investigate the sensitivity of an inverse population balance equation (PBE) modeling technique for extracting single particle functions from transient size distribution measurements. A dynamic PBE model of a turbulently agitated batch emulsification vessel is used to generate volume size distribution data under the assumption of negligible drop coalescence. The distribution data are subjected to various types of error consistent with available measurement technologies and then introduced as input data to the inverse PBE modeling algorithm, which includes validation of the self-similar assumption. The errors considered include measurement noise, data skewed towards smaller or larger drops, skewed data due to the presence of large dust peaks, and reduced resolution caused by data binning. For each case, the computed functions for the drop breakage rate and the distribution of daughter drops are compared to the actual functions to assess the impact of input data errors on the effectiveness of the inverse PBE modeling approach. The type of measurement errors considered generally lead to underprediction of the breakage rate and, consequently, to overprediction of the number of large drops. Because the estimated and actual breakage rates tend to converge at small drop sizes, the inverse algorithm generates accurate predictions of the drop size distribution at sufficiently long batch times when small drops dominate. Implications for our future work on PBE modeling of drop size distributions in pharmaceutical emulsions prepared with high pressure homogenization are discussed.

We have achieved nearly zero order sustained release behavior for periods up to 10–20 days for two hydrophobic drugs, sulindac and tetracaine, from 5 wt.% micellar solutions of poly(lactide)-poly(ethylene oxide)-poly(lactide) (PLA–PEO–PLA) triblock copolymer. The effect of PLA block length and crystallinity on the drug release profiles was studied. A series of polymers with constant PEO molecular weight of 8900 Da and PLA molecular weight varying in the range of 4100–6500 Da were examined. Drug release was found to be much faster for polymers with crystalline PLA blocks as compared to those with amorphous PLA blocks. The drug release rate also depends significantly on the length of the PLA block. Sustained release of sulindac was observed up to 20 days, and for tetracaine up to 10 days. By comparison, release of these drugs without polymeric carriers occurs over 4–6 h. This result, along with a proposed mechanism for drug release, suggests that polymer–drug interactions significantly impact release profiles, causing slow and sustained release of the drug.

Recent advances in the use of polyelectrolyte materials for cell encapsulation are reviewed, with a focus on three current challenges: tunable mechanical properties, controlled cell adhesion, and enhanced oxygen supply. New notable results include methods for creating stable alginate–silica complexes, techniques for incorporating RGD-containing peptides into alginate gels, and an improved understanding of the effect of charge density on cell–material interactions.

Recent experimental results from ultra-small-angle neutron and X-ray scattering (USANS and USAXS) studies of complex fluids, including colloidal dispersions, colloidal glasses, polymer blends, and biopolymer gels, are reviewed. We focus on data analysis and interpretation in the low q regime. New notable results include the apparent existence of large-scale structure in attractive colloidal glasses, the discovery of new morphological transitions in polymer blends via USANS, and the detection of micron-scale water channels in biopolymer gels.

Whole meal, deoiled meal and protein concentrate (PC) of tomato seeds were fed to male albino rats to study weight gain, along with standard and non-protein diets. Corrected protein efficiency ratio was 1.82 for whole meal, 1.93 for deoiled meal and 1.99 for PC as compared to 2.5 for casein. The net protein retention (NPR) was highest for casein (2.91), followed by whole meal (2.65) and deoiled meal (2.52) and least for PC (2.51). Tomato seeds contained high quality plant proteins that could be supplemented into various food products.

Replacement of solvent-borne primers with low-VOC water-based coatings has created the problem of tannin bleed for cedar siding finishers. Three amphiphilic block copolymers, poly(styrene-b-acrylic acid) (PS-PAA), poly(styrene-b-ethylene oxide) (PS-PEO), and poly(styrene-b-methacrylic acid) (PS-PMAA), were investigated as potential water-based coating components that could create a hydrophobic barrier to block tannin extraction. Resistance to extractive bleed was determined by measuring topcoat color change under ambient and humid exposure of coated wood panels. Contact angles of water on the copolymer-coated surfaces were measured to reveal the relative hydrophobicity of the coating surface. Adhesion characteristics of the experimental coatings on wood substrates were determined with a standard tape test. The block copolymer coatings were found to have less darkening and yellowing of the topcoat than the unprimed control and commercial oil-based primer. They also exhibited bleed resistance similar to that of a commercial water-soluble tannin-blocking polymer, but did not perform as well as a commercial water-based tannin-blocking coating. Most copolymers had contact angles close to or greater than 90°, indicating hydrophobic surfaces, with four coatings exhibiting surfaces as hydrophobic as a commercial oil-based primer. Adhesion of the copolymer coatings was found to be adequate under ambient conditions but poor for substrates exposed to humidity. Thus, the amphiphilic block copolymers appear to be potential waterborne tannin-blocking agents with other properties suitable for wood coatings.

We report detailed rheological data on aqueous gels formed from triblock copolymers of L-lactide and ethylene oxide including the dependence of the viscoelastic moduli on frequency and applied stress of these systems for the first time. We are able to create strong gels with elastic moduli greater than 10,000 Pa, which is an order of magnitude higher than previously achieved with related biocompatible physically associated gels of similar chemistry. Moreover, the value of the elastic modulus strongly depends on PLLA block length, offering a mechanism to control the mechanical properties as desired for particular applications. At the gel point, we observe scaling that is characteristic of a percolated network, G' approximately G" approximately omega(Delta), but with an exponent that is lower than predicted by percolation, Delta=0.36. Our results have implications for the design of new materials for soft tissue engineering, where native tissues have moduli in the kPa range.

Cell surface macromolecules such as receptors and ion channels serve as the interface link between the cytoplasm and the extracellular region. Their density, distribution, and clustering are key spatial features influencing effective and proper physical and biochemical cellular responses to many regulatory signals. In this study, the effect of plasma-membrane receptor clustering on local cell mechanics was obtained from maps of interaction forces between antibody-conjugated atomic force microscope tips and a specific receptor, a vascular endothelial growth factor (VEGF) receptor. The technique allows simultaneous measurement of the real-time motion of specific macromolecules and their effect on local rheological properties like elasticity. The clustering was stimulated by online additions of VEGF, or antibody against VEGF receptors. VEGF receptors are found to concentrate toward the cell boundaries and cluster rapidly after the online additions commence. Elasticity of regions under the clusters is found to change remarkably, with order-of-magnitude stiffness reductions and fluidity increases. The local stiffness reductions are nearly proportional to receptor density and, being concentrated near the cell edges, provide a mechanism for cell growth and angiogenesis.

We have conducted a study to analyze monitoring of the cold chain of 674 OPV field samples collected at four different levels of vaccine distribution viz., immunization clinics, district stores, hospitals and Primary Health Centers (PHC) from states of Uttar Pradesh, Madhya Pradesh, and Delhi. The study design included: collection and scoring of vaccine vial monitor (VVM) status of the samples and testing for total oral polio virus concentration (TOPV) by standard WHO protocol. Ten samples each were exposed to 25 degrees C and 37 degrees C, and 10 samples as controls were kept at -20 degrees C. VVM were scored daily till they attained grade 4 and each sample was subsequently subjected to potency testing for individual polio serotypes 1, 2 and 3, and TOPV. Of the 674 samples tested it was observed that: samples from immunization clinics and district stores had an acceptable VVM score of grade 1 and 2; however the probable risk that a sub potent vaccine could have been administered was 2.15%. In 2.5% samples received from district stores vaccine had a VVM score of grade 3 (i.e., discard point), although vaccine when tested was found to be potent (i.e., leading to the vaccine wastage). With exposure to higher temperatures, VVM changed score to grade 2 and 3 when the vaccine was kept at 25 degrees C/37 degrees C, and the titres of individual serotypes 1, 2 and 3 and TOPV were beyond the acceptable limits. Important observations at the different levels of vaccine distribution network and correlation of VVM and potency status of OPV are discussed in the paper which will be of help to the EPI program managers at different transit levels.

Recent experimental studies on the rheology of block copolymer micelles are reviewed. Where appropriate, we draw analogies between the viscoelastic properties of polymeric micelles and those of colloidal dispersions. We also present some important differences between these two classes of complex fluids, namely the ability to tune self-assembly through solvent–polymer interactions. Finally, new experimental results for attractive micellar solutions of polyelectrolytes are presented.

Introduction Fractures of the distal radius are one the commonest orthopaedic injuries. Recent advances in implant technology have seen a dramatic rise in the number of fractures treated with volar locked plates, as they permit accurate peri-articular reconstruction. The surgical approach along the bed of flexor carpii radialis (FCR) tendon encounters a number of key soft tissue and neurovascular structures during the dissection to the fracture plane. The aim of this study was to describe the exact position of such structures involved (and hence at risk) during the FCR approach. Methods 100 adult MRI scans were reviewed. The relationships between the brachioradialis tendon (BR), flexor carpi radialis (FCR) tendon, flexor pollicis longus (FPL) tendon, median nerve (MN) and radial artery (RA) were measured. Results The male to female ratio was 35:65. Average age was 39. FCR tendon was 7.4 mm (SD 1.46) from the RA and 7.01 mm (SD 2.37) from the MN. The distance between BR and RA was significantly different between male and female (5.06 mm vs. 4.1 mm, p = 0.034). Conclusion This study highlights the precise nature of the surgical anatomy involved in dissection to the fracture site. Vigilance is needed during the initial steps of the FCR-bed approach to avoid damage to the radial artery and median nerve which lie in close proximity. If the approach is extended to include a brachioradialis tenotomy, we suggest this should be made under direct vision, given its relationship with the radial artery.

The relative affinity of glucocorticosteroids for lung surfactant was determined for the purpose of identifying chemopreventive agents with a high therapeutic index for lung cancer. The aqueous solubility and the extent of solubilization in Survanta, a native extract of bovine lung, of budesonide, triamcinolone acetonide, dexamethasone, and flunisolide were determined as a function of temperature by a dialysis technique. The aqueous solubilites at 37 degrees C were 19.6, 35.8, 104 and 120 microg/ml for the above listed compounds, respectively. The temperature dependence of the solubilities was modest consistent with the hydrophobic properties of the steroids. The amount of drug in solution was significantly enhanced in the presence of Survanta with solubilization ratios of 0. 019, 0.023, 0.014, and 0.02 microg drug dissolved per microg of Survanta phospholipid, respectively. In addition, the extent of solubilization also generally increased with temperature, although the phase transition of the surfactant lipid appeared to complicate the functional relation between temperature and solubilization. These results show that there is enhanced solubilization of glucocortosteroids by lung surfactant which is secreted by the cancer susceptible type II cells of the lung.

INTRODUCTIONFractures of the distal radius are common upper limb injuries, representing a substantial proportion of the trauma workload in orthopaedic units. With ever increasing advancements in implant technology, operative intervention is becoming more frequent. As growing numbers of surgeons are performing operative fixation of distal radial fractures, an accurate understanding of the relevant surgical anatomy is paramount. The flexor carpi radialis (FCR) tendon forms the cornerstone of the Henry approach to the volar cortex of the distal radius. A number of key neurovascular structures around the wrist are potentially at risk during this approach, especially when the FCR is mobilised and placed under retractors. METHODSIn order to clarify the safe margins of the FCR approach, ten fresh frozen human cadaver limbs were dissected. The location of the radial artery, the median nerve, the palmar cutaneous branch of the median nerve and the superficial branch nerve were measured with respect to the FCR tend...

An analytical and numerical study of vaporization and combustion of an isolated liquid hydrocarbon droplet containing a single metal particle in its core is presented. The objective is to formulate a simplified vaporization model that can be used in spray combustion calculations. Further, the model is extended to include the combustion of the liquid fuel, so that ignition characteristics of the metal particle can be studied. The gas phase includes the effects of variable thermophysical properties and nonunitary Lewis number. The liquid phase includes the effects of transient heating and circulation. Results are presented for both a spherically symmetric configuration, and an axisymmetric case, where the liquid motion is analytically given. Calculations are made for both liquid vaporization without combustion and vaporization followed by combustion. The effects associated with varying solid loading are studied. The vaporization rates for a composite droplet are found to be close to those for a corresponding all-liquid droplet. Ignition times for the metal particle are found to depend on the solid mass loading, and can be several times larger than the liquid fuel burnout time. The heat transfer to the particle is convection dominated.

Aim: To evaluate the assessment and decision making in suspected scaphoid fractures by emergency medicine orthopaedic staff. Introduction: Scaphoid fracturesmayprogress to chronic arthrosis and this has led to over-treatment of clinically suspected scaphoid fractures. Currently, there is a lack of consensus regarding clinical and radiological tests used for diagnosis. Materials and methods: Casenotes were identified by ICD codes for patients with wrist, scaphoid and distal radius injuries (n=142)whopresented to our institution between01/02/2007 and 31/07/2007. Patients with suspected or confirmed scaphoid fracture, who attended subsequent fracture clinic, were included in the analysis (n=38). Data analyzed included the grade of assessor, adequacy of clinical examination, adequacy of radiographs, mode of treatment and clinical outcome. Results: In the emergency department, 50% (n=19/38) of patients were reviewed by an Emergency Nurse Practitioner or junior doctor. Scaphoid views were taken in 71% (n=27). Clinical examination was complete in 21% (n=8). Thirty-two percent (n=12) had a scaphoid fracture on initial radiography. Ninety-two percent (n=35) were immobilized in plaster of Paris. No patient was discussed with the orthopaedic team. The mean time to fracture clinic was 12 days. In fracture clinic, clinical examination was complete in 27% (7/26) of those with negative initial radiographs. Fifty-fivepercent (n=14)underwent repeat plain radiography. Two further scaphoid fractures were identified. Twenty-nine percent were discharged after their first clinic attendance. Conclusion: Management of potential scaphoid injuries have been shown to be sub-optimal. This has led to unnecessary plaster cast immobilization and follow-up inmany cases. However, the potentially disasterous consequences affecting a young and active population justify current evidence based guidelines to address management shortfalls.