bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimizing gelling parameters of gellan gum for fibrocartilage tissue engineering
Authors: Lee Haeyeon , Fisher Stephanie , Kallos Michael S. , Hunter Christopher J.
Published: May 2011

Gellan gum is an attractive biomaterial for fibrocartilage tissue engineering applications because it is cell compatible, can be injected into a defect, and gels at body temperature. However, the gelling parameters of gellan gum have not yet been fully optimized. The aim of this study was to investigate the mechanics, degradation, gelling temperature, and viscosity of low acyl and low/high acyl gellan gum blends. Dynamic mechanical analysis showed that increased concentrations of low acyl gellan gum resulted in increased stiffness and the addition of high acyl gellan gum resulted in greatly decreased stiffness. Degradation studies showed that low acyl gellan gum was more stable than low/high acyl gellan gum blends. Gelling temperature studies showed that increased concentrations of low acyl gellan gum and CaCl2 increased gelling temperature and low acyl gellan gum concentrations below 2% (w/v) would be most suitable for cell encapsulation. Gellan gum blends were generally found to have a higher gelling temperature than low acyl gellan gum. Viscosity studies showed that increased concentrations of low acyl gellan gum increased viscosity. Our results suggest that 2% (w/v) low acyl gellan gum would have the most appropriate mechanics, degradation, and gelling temperature for use in fibrocartilage tissue engineering applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Long‐term stability of self‐assembled monolayers on electropolished L605 cobalt chromium alloy for stent applications
Authors: Kaufmann Christopher , Mani Gopinath , Marton Denes , Johnson David , Agrawal C. Mauli
Published: May 2011

Commercially available drug‐eluting stents have the potential to induce inflammatory and hypersensitive adverse reactions due to their polymer coating. The use of self assembled monolayers (SAMs) as an alternate drug delivery platform for stents has recently been demonstrated. In this study, the formation and stability of phosphonic acid SAMs were investigated using the material and surface preparation commonly used to make ultra‐thin stent struts—electropolished L605 Cobalt Chromium (CoCr) alloy. Methyl (CH3) and carboxylic acid (COOH) terminated phosphonic acid SAMs were coated on electropolished CoCr alloy using a combination of solution immersion and dip‐evaporation cycle deposition methods. SAMs‐coated CoCr alloy specimens were thoroughly characterized using contact angle goniometry, Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). These characterizations suggested that uniform and well‐ordered monolayers were coated on the electropolished CoCr alloy. The long‐term physiological stability of monolayers was investigated in tris‐buffered saline (TBS) at 37°C for up to 28 days. Contact angles, FTIR, XPS, and AFM suggested that both CH3 and COOH terminated phosphonic acid SAMs desorb from electropolished CoCr alloy surfaces in a biphasic manner. A significant desorption of CH3 and COOH terminated SAMs occurs within 1–3 days followed by a slower desorption for up to 28 days. Thus, there is a need to develop techniques that can improve the long‐term stability of SAMs on electropolished CoCr alloy for stent and other biomedical applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Tau splicing and the intricacies of dementia
Authors: Andreadis Athena
Published: May 2011

Tau is a microtubule‐associated protein that fulfills several functions critical for neuronal formation and health. Tau discharges its functions by producing multiple isoforms via regulated alternative splicing. These isoforms modulate tau function in normal brain by altering the domains of the protein, thereby influencing its localization, conformation, and post‐translational modifications and hence its availability and affinity for microtubules and other ligands. Disturbances in tau expression result in disruption of the neuronal cytoskeleton and formation of tau structures (neurofibrillary tangles) found in brains of dementia sufferers. More specifically, aberrations in tau splicing regulation directly cause several neurodegenerative diseases, which lead to dementia. In this review, I present our cumulative knowledge of tau splicing regulation in connection with neurodegeneration and also briefly go over the still‐extensive list of questions that are connected to tau (dys)function. J. Cell. Physiol. 227: 1220–1225, 2012. © 2011 Wiley Periodicals, Inc.
Amelioration of type I diabetes‐induced osteoporosis by parathyroid hormone is associated with improved osteoblast survival
Authors: Motyl Katherine J. , McCauley Laurie K. , McCabe Laura R.
Published: May 2011

Type 1 diabetic osteoporosis results from impaired osteoblast activity and death. Therefore, anti‐resorptive treatments may not effectively treat bone loss in this patient population. Intermittent parathyroid hormone (PTH) treatment stimulates bone remodeling and increases bone density in healthy subjects. However, PTH effects may be limited in patients with diseases that interfere with its signaling. Here, we examined the ability of 8 and 40 µg/kg intermittent PTH to counteract diabetic bone loss. PTH treatment reduced fat pad mass and blood glucose levels in non‐diabetic PTH‐treated mice, consistent with PTH‐affecting glucose homeostasis. However, PTH treatment did not significantly affect general body parameters, including the blood glucose levels, of type 1 diabetic mice. We found that the high dose of PTH significantly increased tibial trabecular bone density parameters in control and diabetic mice, and the lower dose elevated trabecular bone parameters in diabetic mice. The increased bone density was due to increased mineral apposition and osteoblast surface, all of which are defective in type 1 diabetes. PTH treatment suppressed osteoblast apoptosis in diabetic bone, which could further contribute to the bone‐enhancing effects. In addition, PTH treatment (40 µg/kg) reversed preexisting bone loss from diabetes. We conclude that intermittent PTH may increase type 1 diabetic trabecular bone volume through its anabolic effects on osteoblasts. J. Cell. Physiol. 227: 1326–1334, 2012. © 2011 Wiley Periodicals, Inc.
NADPH oxidase‐derived superoxide Anion‐induced apoptosis is mediated via the JNK‐dependent activation of NF‐κB in cardiomyocytes exposed to high glucose
Authors: Tsai Kun‐Hsi , Wang Wei‐Jan , Lin Cheng‐Wen , Pai Peiying , Lai Tung‐Yuan , Tsai Chen‐Yen , Kuo Wei‐Wen
Published: May 2011

Hyperglycemia‐induced generation of reactive oxygen species (ROS) can lead to cardiomyocyte apoptosis and cardiac dysfunction. However, the mechanism by which high glucose causes cardiomyocyte apoptosis is not clear. In this study, we investigated the signaling pathways involved in NADPH oxidase‐derived ROS‐induced apoptosis in cardiomyocytes under hyperglycemic conditions. H9c2 cells were treated with 5.5 or 33 mM glucose for 36 h. We found that 33 mM glucose resulted in a time‐dependent increase in ROS generation as well as a time‐dependent increase in protein expression of p22phox, p47phox, gp91phox, phosphorylated IκB, c‐Jun N‐terminal kinase (JNK) and p38, as well as the nuclear translocation of NF‐kB. Treatment with apocynin or diphenylene iodonium (DPI), NADPH oxidase inhibitors, resulted in reduced expression of p22phox, p47phox, gp91phox, phosphorylated IκB, c‐Jun N‐terminal kinase (JNK) and p38. In addition, treatment with JNK and NF‐kB siRNAs blocked the activity of caspase‐3. Furthermore, treatment with JNK, but not p38, siRNA inhibited the glucose‐induced activation of NF‐κB. Similar results were obtained in neonatal cardiomyocytes exposed to high glucose concentrations. Therefore, we propose that NADPH oxidase‐derived ROS‐induced apoptosis is mediated via the JNK‐dependent activation of NF‐κB in cardiomyocytes exposed to high glucose. J. Cell. Physiol. 227: 1347–1357, 2012. © 2011 Wiley Periodicals, Inc.
Nutrient and carbon balances in organic vegetable production on an irrigated, sandy soil in northern Oman
Authors: Siegfried Konrad , Dietz Herbert , Schlecht Eva , Buerkert Andreas
Published: May 2011

Our understanding of nutrient and carbon (C) fluxes in irrigated organic cropping systems of subtropical regions is limited. Therefore, leaching of mineral nitrogen (N) and phosphorus (P), gaseous emissions of NH3, N2O, CO2, and CH4, and total matter balances were measured over 24 months comprising a total cropping period of 260 d in an organic‐cropping‐systems experiment near Sohar (Oman). The experiment on an irrigated sandy soil with four replications comprised two manure types (ORG1 and ORG2) characterized by respective C : N ratios of 19 and 25 and neutral detergent fiber (NDF)‐to‐soluble carbohydrates (SC) ratios of 17 and 108. A mineral‐fertilizer (MIN) treatment with equivalent levels of mineral N, P, and potassium (K) served as a control. The three treatments were factorially combined with a cropping sequence comprising radish (Raphanus sativus L.) followed by cauliflower (Brassica oleracea L. var. botrytis) or carrot (Daucus carota subsp. sativus). Over the 24‐months experimental period gaseous N emissions averaged 45 kg ha–1 (59% NH3‐N, 41%N2O‐N) for MIN, 55 kg N ha–1 (69% NH3‐N, 31%N2O‐N) for ORG1, and 49 kg N ha–1 (59% NH3‐N, 41% N2O‐N) for ORG2. Carbon losses were 6.2 t ha–1 (98% CO2‐C, 2% CH4‐C) for MIN, 9.7 t C ha–1 (99% CO2‐C, 1% CH4‐C) for ORG1, and 10.6 t ha–1 (98% CO2‐C, 2% CH4‐C) for ORG2. Exchange resin–based cumulative leaching of mineral N amounted to 30 kg ha–1 for MIN, 10 kg ha–1 for ORG1, and 56 kg ha–1 for ORG2. Apparent surpluses of 361 kg N ha–1 and 196 kg P ha–1 for radish‐carrot and 299 kg N ha–1 and 184 kg P ha–1 for radish‐cauliflower were accompanied by K deficits of –59 kg ha–1 and –73 kg ha–1, respectively, for both cropping systems. Net C balances for MIN, ORG1, and ORG2 plots were –7.3, –3.1, and 1.5 t C ha–1 for radish‐carrot and –5.0, 1.3, and 4.6 t C ha–1 for radish‐cauliflower. The results underline the difficulty to maintain soil C levels in intensively cultivated, irrigated subtropical soils.
Hydrophilic interaction chromatography separation mechanisms of tetracyclines on amino‐bonded silica column
Authors: Li Ruiping , Zhang Yi , Lee Charles C. , Liu Liming , Huang Yingping
Published: May 2011

Effects of mobile‐phase variations on the chromatographic separation on amino‐bonded silica column in hydrophilic interaction chromatography (HILIC) were investigated for four zwitterionic tetracyclines (TCs): oxytetracycline, doxycycline, chlortetracycline, and tetracycline. A mixed‐mode retention mechanism composed of partitioning, adsorption, and ion exchange interactions was proposed for the amino HILIC retention process. Buffer type and pH significantly influenced the retention of TCs, but showed similar separation selectivity for the tested analytes. Experiments varying buffer salt concentration and pH demonstrated the presence of ion exchange interactions in TCs retention. The type and concentration of organic modifier also affected the retention and selectivity of the analytes, providing direct evidence supporting the Alpert retention model for HILIC. The retention time of the analytes increased in the following order of organic modifiers: tetrahydrofuran < methanol < isopropanol < acetonitrile. The linear relationships of logk′ versus %water (v/v) curve and logk′ versus logarithm of %water (v/v) in the mobile phase indicated that TCs separation on the amino phase was controlled by partitioning and adsorption. The developed method was successfully utilized in the detection of TCs in both river water and wastewater samples using solid‐phase extraction (SPE) for sample cleanup.
Facile preparation of monolithic immobilized metal affinity chromatography capillary columns for selective enrichment of phosphopeptides
Authors: Zhang Liyuan , Wang Hui , Liang Zhen , Yang Kaiguang , Zhang Lihua , Zhang Yukui
Published: May 2011

The selective enrichment of phosphopeptides with good reproducibility is vital for the in‐depth study of the phosphoproteome. Herein, we presented a novel method to prepare monolithic Ti4+ or Zr4+ immobilized metal affinity chromatography (IMAC) columns. Since succinimide was of high reaction activity with nitrilotriacetic acid (NTA) than traditional epoxy group, through the reaction of succinimide group on the monolithic matrix with nitrilotriacetic acid, the preparation of monolithic IMAC columns became facile. By the developed new method, not only the time required for Ti4+ or Zr4+ immobilization could be shortened from 10 to 1 h, but also the RSD of obtained phosphopeptide peak area was below 13%, even with IMAC columns prepared in different batches (n=3). With such monolithic Ti4+‐ and Zr4+‐IMAC columns, ten and seven phosphopeptides were effectively identified from the digests of a mixture of β‐casein and BSA, even with the molar ratio as low as 1:100, respectively. The phosphopeptide recovery was over 73%, and the loading capacity was over 0.8 μmol/mL. Compared with commercial IMAC beads, the monolithic IMAC columns provide outstanding reproducibility, good selectivity, large loading capacity, and high recovery, which demonstrates that such monolithic IMAC columns might facilitate the in‐depth analysis of phosphoproteomes.
Progress and technical challenge for planar waveguide devices: silica and silicon waveguides
Authors: Okamoto K.
Published: May 2011

The paper reviews progress and future prospects of two kinds of planar waveguide devices; they are (a) silica and silicon photonics multi/demultiplexers for communications and signal‐processing applications, and (b) a novel waveguide spectrometer based on Fourier transform spectroscopy for sensing applications.
Novel Controlled Polymerization of Cyclo‐olefins, Dienes, and Trienes by Utilizing Reaction Properties of Late Transition Metals
Authors: Takeuchi Daisuke
Published: May 2011

Pd complexes with diimine ligands promote polymerization of cyclopentenes, 1,6‐dienes, and 1,6,11‐trienes to afford polymers having 1,2‐ or 1,3‐five‐membered ring in every repeating unit. The Pd complexes with C2 symmetrical structure catalyze the polymerization reactions to produce polymers with high stereoselectivity. Some of the obtained polymers show characteristic properties such as thermoreversible gelation and liquid crystal formation. Ni complexes bring about the cyclopolymerization of the dienes to afford polymers containing five‐ and/or six‐membered rings in controlled stereochemistry.

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Ex Situ Solvent‐Assisted Preparation of Magnetic Poly(propylene) 8nocomposites Filled with Fe@FeO Nanoparticles
Authors: Wei Suying , Patil Rahul , Sun Luyi , Haldolaarachchige Neel , Chen Xuelong , Young David P. , Guo Zhanhu
Published: May 2011

Isotactic PP nanocomposites filled with Fe@FeO nanoparticles are fabricated by a facile ex situ method. The nanofillers are dispersed in a boiling PP/xylene solution. X‐ray diffraction is used to determine the nanofiller effects on the crystallinity of PP. The crystallinity along the (040) plane is found to decrease with the incorporation of nanoparticles. Thermal properties and crystallinity are studied by TGA and DSC, respectively. Enhanced thermal stability and influenced crystallinity are observed in the PP nanocomposites compared with those of pure PP. An increased dielectric property without percolation threshold is observed. In addition, the nanocomposites are found to exhibit ferromagnetic properties.

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Methacrylated Calix[6]arenes as Low Shrinking Additives for Dental Restorative Composites
Authors: Moszner Norbert , Angermann Jörg , Fischer Urs , Gianasmidis Alexandros , Tabatabai Monir , Ritter Helmut , Utterodt Andreas
Published: May 2011

p‐tert‐Butylcalix[6]arene was acylated with different carboxylic acid anhydrides to improve their solubility in dimethacrylate cross‐linkers. An esterification of p‐tert‐butylcalix[6]arene 1 with octanoic anhydride followed by methacrylation of the residual hydroxy groups with methacrylic anhydride resulted mainly in the formation of a pentaoctanoatemonomethacrylate 2a. In the radical polymerization of methyl methacrylate the inhibition effect of residual hydroxy groups in 2a was evaluated. Dimethacrylate containing composites based on a monomer matrix of cross‐linking dimethacrylates and 0–30 wt.% of 2a were prepared. The addition of 2a resulted in a significant decrease of the polymerization shrinkage, whereas the modulus of elasticity of the visible light cured composites was not affected.

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Controlled Dispersion of Silver Nanoparticles into the Bulk of Thermosensitive Polymer Microspheres: Tunable Plasmonic Coupling by Temperature Detected by Surface Enhanced Raman Scattering
Authors: Yin Peng‐Gang , Chen Ying , Jiang Li , You Ting‐Ting , Lu Xian‐Yong , Guo Lin , Yang Shihe
Published: May 2011

By in situ reduction of Ag+ ions pre‐dispersed inside thermosensitive microspheres of poly[(N‐isopropylacrylamide)‐co‐(methacrylic acid)] (P(NIPAM‐co‐MAA)), a 3D copolymer‐supported network of silver nanoparticles is created and extensively characterized by surface‐enhanced Raman scattering (SERS). The effective dispersion and the suitable density of the silver nanoparticles in the composite microspheres are demonstrated by the thermal‐induced SERS signal and its high reproducibility during thermocycling. When the temperature of the system increases above 32 °C, spatial separation of the silver nanoparticles decreases and the numbers of Ag nanoparticles and P(NIPAM‐co‐MAA) microspheres under illumination spot increase as a result of the shrinkage of the P(NIPAM‐co‐MAA) chains, leading to the ramp of the SERS effect. By means of the high reversibility of the thermosensitive phase transition of the P(NIPAM‐co‐MAA) microspheres, SERS activity of the silver nanoparticle network embedded in the microsphere can be well controlled by thermal‐induced variation of special separation.

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Coarse‐Grained Simulations of Model Polymer Nanofibres
Authors: Milani Alberto , Casalegno Mosè , Castiglioni Chiara , Raos Guido
Published: May 2011

We describe the development of a coarse‐grained (CG) force field for nylon‐6 (polycaprolactam) and its application to the simulation of the structure and macromolecular dynamics within cylindrical fibres formed by this polymer, having diameters in the 14–28 nm range. Our CG model is based on the MARTINI force field for the non‐bonded interactions and on Boltzmann‐inverted gas‐phase atomistic simulations for intramolecular stretching and bending energies. The simulations are carried out on infinite, isolated nanofibres at temperatures of 300, 400 and 500 K, with different starting configurations. Starting from ordered chain‐extended configurations, we simulate the melting of the polymer in the nanofibres and, after cooling back to room temperature, its re‐crystallization in a chain‐folded lamellar configuration. This agrees with experimental observations on electrospun nylon‐6 nanofibres and demonstrated the suitability of the approach for the simulation of these systems. The effect of nanoscale confinement on the structure and dynamics of the polymer chains is extensively discussed.

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Phase‐based arterial input function measurements in the femoral arteries for quantification of dynamic contrast‐enhanced (DCE) MRI and comparison with DCE‐CT
Authors: Korporaal Johannes G. , van den Berg Cornelis A. T. , van Osch Matthias J. P. , Groenendaal Greetje , van Vulpen Marco , van der Heide Uulke A.
Published: May 2011

Dynamic contrast‐enhanced (DCE) MRI is useful for diagnosis, treatment monitoring and follow‐up of prostate cancer. However, large differences have been reported in the parameter range of the transfer constant Ktrans, making longitudinal studies and comparison of DCE‐MRI findings between studies difficult. Large part of this inconsistency in Ktrans values can be attributed to problems with the accurate measurement of the arterial input function (AIF) from the magnitude signal (AIFMAGN). Phase‐based AIF measurements (AIFPHASE) have been proposed as a more robust alternative to AIFMAGN measurements. This study compares AIFPHASE with AIFs measured with DCE‐CT (AIFCT), and the corresponding Ktrans maps in 12 prostate cancer patients. The shape of AIFPHASE and AIFCT are similar, although differences in the peak height and peak width exist as a result of differences in injection protocol. No significant differences in Ktrans values were found between the DCE‐MRI and DCE‐CT exams, with median Ktrans values of 0.10 and 0.08 min−1 for healthy peripheral zone tissue and 0.44 and 0.36 min−1 for regions suspected of tumor respectively. Therefore, robust quantification of Ktrans values from DCE‐MRI exams in the cancerous prostate is feasible with the use of AIFPHASE. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Nonrigid retrospective respiratory motion correction in whole‐heart coronary MRA
Authors: Schmidt Johannes F. M. , Buehrer Martin , Boesiger Peter , Kozerke Sebastian
Published: May 2011

A nonrigid retrospective respiratory motion correction scheme is presented for whole‐heart coronary imaging with interleaved acquisition of motion information. The quasi‐periodic nature of breathing is exploited to populate a 3D nonrigid motion model from low‐resolution 2D imaging slices acquired interleaved with a segmented 3D whole‐heart coronary scan without imposing scan time penalty. Reconstruction and motion correction are based on inversion of a generalized encoding equation. Therein, a forward model describes the transformation from the motion free image to the motion distorted k‐space data, which includes nonrigid spatial transformations. The effectiveness of the approach is demonstrated on 10 healthy volunteers using free‐breathing coronary whole‐heart scans. Although conventional respiratory‐gated acquisitions with 5‐mm gating window resulted in an average gating efficiency of 51% ± 11%, nonrigid motion correction allowed for gate‐free acquisitions, and hence scan time reduction by a factor of two without significant penalty in image quality. Image scores and quantitative image quality measures for the left coronary arteries showed no significant differences between 5‐mm gated and gate‐free acquisitions with motion correction. For the right coronary artery, slightly reduced image quality in the motion corrected gate‐free scan was observed as a result of the close vicinity of anatomical structures with different motion characteristics. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Magnetic resonance elastography of the lung parenchyma in an in situ porcine model with a noninvasive mechanical driver: Correlation of shear stiffness with trans‐respiratory system pressures
Authors: Mariappan Yogesh K. , Kolipaka Arunark , Manduca Armando , Hubmayr Rolf D. , Ehman Richard L. , Araoz Philip , McGee Kiaran P.
Published: May 2011

Quantification of the mechanical properties of lung parenchyma is an active field of research due to the association of this metric with normal function, disease initiation and progression. A phase contrast MRI‐based elasticity imaging technique known as magnetic resonance elastography is being investigated as a method for measuring the shear stiffness of lung parenchyma. Previous experiments performed with small animals using invasive drivers in direct contact with the lungs have indicated that the quantification of lung shear modulus with 1H based magnetic resonance elastography is feasible. This technique has been extended to an in situ porcine model with a noninvasive mechanical driver placed on the chest wall. This approach was tested to measure the change in parenchymal stiffness as a function of airway opening pressure (Pao) in 10 adult pigs. In all animals, shear stiffness was successfully quantified at four different Pao values. Mean (±STD error of mean) pulmonary parenchyma density corrected stiffness values were calculated to be 1.48 (±0.09), 1.68 (±0.10), 2.05 (±0.13), and 2.23 (±0.17) kPa for Pao values of 5, 10, 15, and 20 cm H2O, respectively. Shear stiffness increased with increasing Pao, in agreement with the literature. It is concluded that in an in situ porcine lung shear stiffness can be quantitated with 1H magnetic resonance elastography using a noninvasive mechanical driver and that it is feasible to measure the change in shear stiffness due to change in Pao. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Mobile Phone Tools for Field‐Based Health care Workers in Low‐Income Countries
Authors: DeRenzi Brian , Borriello Gaetano , Jackson Jonathan , Kumar Vikram S. , Parikh Tapan S. , Virk Pushwaz , Lesh Neal
Published: May 2011

In low‐income regions, mobile phone–based tools can improve the scope and efficiency of field health workers. They can also address challenges in monitoring and supervising a large number of geographically distributed health workers. Several tools have been built and deployed in the field, but little comparison has been done to help understand their effectiveness. This is largely because no framework exists in which to analyze the different ways in which the tools help strengthen existing health systems. In this article we highlight 6 key functions that health systems currently perform where mobile tools can provide the most benefit. Using these 6 health system functions, we compare existing applications for community health workers, an important class of field health workers who use these technologies, and discuss common challenges and lessons learned about deploying mobile tools.Mt Sinai J Med 78:406–418, 2011. © 2011 Mount Sinai School of Medicine
Confronting Intimate Partner Violence: A Global Health Priority
Authors: Chibber Karuna S. , Krishnan Suneeta
Published: May 2011

Intimate partner violence—physical, psychological, or sexual abuse of women perpetrated by intimate partners—is one of the most common forms of violence against women, and is associated with adverse women's reproductive and maternal health outcomes. We review the opportunities for addressing intimate partner violence by the health system, examine promising approaches, and outline future challenges for developing effective health‐systems responses to violence. Evidence shows that women seldom approach support services in response to violence, but do seek health care at some point in their lives. In fact, women's utilization of reproductive‐health services in particular has been increasing globally. These services have a broad reach and represent an important opportunity to engage in violence prevention. Although health systems–based responses to intimate partner violence have emerged, rigorous evaluations to guide program planning and policy efforts to reduce violence are limited. Programs in the United States have expanded from improving individual provider prevention practices to instituting system‐wide changes to ensure sustainability of these practices. Developing‐country program responses, though limited, have been system‐wide and multisectoral right from the start. Our review highlights 3 challenges for developing and expanding health‐systems responses to violence. First, interventions should focus on creating a supportive environment within the health system and strengthening linkages across health care and allied sectors. Second, rigorous evaluations of health sector–based interventions are needed for a sound evidence base to guide programmatic and policy decisions. Finally, research is needed to identify the entry points for engaging men on violence prevention, and to examine the feasibility and effectiveness of such interventions. Mt Sinai J Med 78:449–457, 2011. © 2011 Mount Sinai School of Medicine
Community Health Workers in Global Health: Scale and Scalability
Authors: Liu Anne , Sullivan Sarah , Khan Mohammed , Sachs Sonia , Singh Prabhjot
Published: May 2011

Community health worker programs have emerged as one of the most effective strategies to address human resources for health shortages while improving access to and quality of primary healthcare. Many developing countries have succeeded in deploying community health worker programs in recognition of the potential of community health workers to identify, refer, and in many cases treat illnesses at the household level. However, challenges in program design and sustainability are expanded when such programs are expanded at scale, particularly with regard to systems management and integration with primary health facilities. Several nongovernmental organizations provide cases of innovation on management of community health worker programs that could support a sustainable system that is capable of being expanded without being stressed in its functionality nor effectiveness—therefore, providing for stronger scalability. This paper explores community health worker programs that have been deployed at national scale, as well as scalable innovations found in successful nongovernmental organization–run community health worker programs. In exploration of strategies to ensure sustainable community health worker programs at scale, we reconcile scaling constraints and scalable innovations by mapping strengths of nongovernmental organizations' community health worker programs to the challenges faced by programs currently deployed at national scale. Mt Sinai J Med 78:419–435, 2011 © 2011 Mount Sinai School of Medicine
Strategic, Value‐Based Delivery in Global Health Care: Innovations at Harvard University and Brigham and Women's Hospital
Authors: Weintraub Rebecca L. , Talbot Julie , ole‐MoiYoi Kileken , Wachter Keri , Sullivan Erin , House Amy , Baron Jennifer , Beals Aaron , Beauvais Sophie , Rhatigan Joseph
Published: May 2011

Investments in global health have more than doubled over the past decade, generating a cadre of new institutions. To date, most of the funded research in global health has focused on discovery, and, more recently, on the development of new tools, which has tightened the implementation bottleneck. This article introduces the concept of global health delivery and the need to catalog and analyze current implementation efforts to bridge gaps in delivery. Global health delivery is complex and context‐dependent and requires an interdisciplinary effort, including the application of strategic principles. Furthermore, delivery is necessary to ensure that the investments in research, discovery, and development generate value for patients and populations. This article discusses the application of value‐based delivery to global health. It provides some examples of approaches to aggregating implicit knowledge to inform practice. With global health delivery, the aim is to transform global health scale‐up from a series of well‐intentioned but often disconnected efforts to a value‐based movement based upon 21st‐century technology, standards, and efficiency. Mt Sinai J Med 78:458–469, 2011 © 2011 Mount Sinai School of Medicine
Obstetric Fistula in Low and Middle Income Countries
Authors: Capes Tracy , Ascher‐Walsh Charles , Abdoulaye Idrissa , Brodman Michael
Published: May 2011

Vesicovaginal fistula secondary to obstructed labor continues to be an all‐too‐common occurrence in underdeveloped nations throughout Africa and Asia. Vesicovaginal fistula remains largely an overlooked problem in developing nations as it affects the most marginalized members of society: young, poor, illiterate women who live in remote areas. The formation of obstetric fistula is a result of complex interactions of social, biologic, and economic influences. The key underlying causes of fistula are the combination of a lack of functional emergency obstetric care, poverty, illiteracy, and low status of women. In order to prevent fistula, some strategies include creation of governmental policy aimed toward reducing maternal mortality/morbidity and increasing availability of skilled obstetric care, as well as attempts to increase awareness about its prevention and treatment among policymakers, service providers, and communities. Whereas prevention will require the widespread development of infrastructure within these developing countries, treatment of fistula is an act which can be done “in the now.” Treatment and subsequent reintegration of fistula patients requires a team of specialists including surgeons, nurses, midwives, and social workers, which is largely unavailable in developing countries. However, there is increasing support for training of fistula surgeons through standardized programs as well as establishment of rehabilitation centers in many nations. The eradication of fistula is dependent upon building programs that target both prevention and treatment. Mt Sinai J Med 78:352–361, 2011 © 2011 Mount Sinai School of Medicine
Synthesis and photoinduced electron transfer characteristic of a bis (zinc porphyrin)‐perylene bisimide array
Authors: Wang Fuling , Tang Jianguo , Liu Jixian , Wang Yao , Wang Rui , Niu Lin , Huang Linjun , Huang Zhen
Published: May 2011

In this article, a donor–acceptor array consisting of two zinc porphyrin (ZnPOR) units attached to the 1,7‐positions of perylene‐3,4:9,10‐bis(dicarboximide) (PDI) was synthesized and characterized. This double‐wing molecule exhibits very broad absorption in the region from 300 to 900 nm. Especially, its lower energy absorption feature presumably arises from donor–acceptor interactions. The fluorescence emission spectra confirmed that photoinduced electron transfer occurred from POR to perylene bisimide moiety in this triad. In contrast to previously studied systems incorporating POR and PDI groups, this array shows the evidence of a relatively strong ground‐state electronic coupling between the donor and acceptor moieties. Additionally, highest occupied molecular orbital and lowest unoccupied molecular orbital values of the array were acquired by cyclic voltammetry (CV). The results showed that these energy values fulfill the energetic conditions required for the proposed electron transfer. More importantly, the photocurrent measurement showed that this molecule exhibits a high capacity to form a photoinduced charge‐separated state and to produce steady and prompt cathodic photocurrent responses. These results confirmed the role of this new array toward harvesting light energy and generating photocurrent during the operation of a photoelectrochemical cell. Copyright © 2011 John Wiley & Sons, Ltd.
Volatiles emitted by Carya illinoinensis (Wang.) K. Koch as a prelude for semiochemical investigations to focus on Acrobasis nuxvorella Nuenzig (Lepidoptera: Pyralidae)
Authors: Corella‐Madueño Maria A , Harris Marvin K , Fu‐Castillo Agustin A , Martínez‐Téllez Miguel A , Valenzuela‐Soto Elisa M , Gálvez‐Ruiz Juan C , Vargas‐Arispuro Irasema
Published: May 2011

BACKGROUND: Plant volatiles have complex intra‐ and interspecific effects in the environment that include plant/herbivore interactions. Identifying the quantity and quality of volatiles produced by a plant is needed to aid the process of determining which chemicals are exerting what effects and then examining whether these effects can be manipulated to benefit society. The qualitative characterization of volatile compounds emitted by pecan, Carya illinoinensis (Wang.) K. Koch, was begun in order to establish a database for investigating how these volatiles affect Acrobasis nuxvorella Nuenzig, a monophagous pest of pecan. Headspace solid‐phase microextraction combined with gas chromatography–mass spectrometry was used for the analysis of the volatile constituents of pecan during three phenological stages (dormant buds, intact new shoot growth and intact nutlets) of the Western Schley and Wichita cultivars.

RESULTS: About 111 distinct compounds were identified from the two cultivars, accounting for ∼99% of the headspace volatiles. The chromatographic profiles of both varieties revealed variations in the volatile composition and proportion between cultivars, with a predominance of terpene hydrocarbons, of the sesquiterpenes class, as well as monoterpenes.

CONCLUSION: The significantly higher responsiveness recorded for the larvae of A. nuxvorella to C. illinoinensis shoots indicates that the larvae may be activated by terpenes emanating from the new shoot growth. This is the first study that has examined volatiles of pecan in Mexico. Copyright © 2011 Society of Chemical Industry
First‐principles investigation of the electronic structures of edge dislocations in GaN
Authors: Mishra K. C. , Johnson K. H. , Schmidt P. C.
Published: May 2011

Using a first‐principles band structure approach, we have investigated the electronic structures of edge dislocations associated with the $\left\langle {11\overline {2} 0} \right\rangle \{ 0001]$ slip system. This edge dislocation has been simulated using a 4 × 4 × 3 supercell from which a half‐plane perpendicular to the basal plane along the $\left\langle {1\overline {1} 00} \right\rangle $ direction was removed in every unit cell. The electronic structures were then calculated within the framework of density functional theory with a plane wave basis set using the projector augmented wave technique as implemented in the Vienna ab initio simulation package (VASP). The optimized structure yields slightly larger lattice parameters A/4 = 3.216 Å, C/3 = 5.234 Å compared to experiment and the GaN bond lengths, dGa‐N = 1.965 and 1.973 Å. A detailed analysis of the partial density of states (DOS) shows that the edge atoms along the ${\left[ {1\overline {1} 00} \right]}$ direction and the surface atoms on either side of the missing plane introduce new states in the band gap. The edge atoms introduce more localized states inside the gap, which could act as electron and hole traps. The highest occupied and lowest unoccupied states are N 2p like edge states and above these states at about 0.5 eV we find 4s like surface states of Ga. The band gap for the defect system vanishes due to states introduced by the dislocation. How the localized states introduced by the dislocation would affect the recombination of electron–hole pairs is discussed in detail.
Characterization of long‐term stability of hydrophilized PEG‐grafted PDMS within different media for biotechnological and pharmaceutical applications
Authors: Demming Stefanie , Lesche Claudia , Schmolke Hannah , Klages Claus‐Peter , Büttgenbach Stephanus
Published: May 2011

Poly(dimethylsiloxane) (PDMS) is broadly utilized for the development of disposable lab‐on‐a‐chip systems. For many microfluidic applications hydrophilic surface characteristics are indispensable. In this work, an easy, reliable and stable surface hydrophilization procedure based on poly(ethylene glycol) (PEG)‐silanization is presented that overcomes the hydrophobic nature of PDMS. Furthermore, the long‐term stability of the grafting as well as the effect of different parameters (e.g., applied solvent) on the hydrophilicity according to the measured contact angles (CAs) are analyzed within different media. Finally, the successful hydrophilization of different PDMS microfluidic devices and the effect of its performance are demonstrated (e.g., in a micro‐emulsification component).

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Effect of the surface properties of PDMS‐structured devices on the performance of drop emulsification with regard to the CA: (a) bare, hydrophobic and (b) PEG‐grafted, hydrophilic PDMS.
Application of carbazole‐containing polymer materials as recording media
Authors: Andries A. , Abaskin V. , Achimova E. , Meshalkin A. , Prisacar A. , Sergheev S. , Robu S. , Vlad L.
Published: May 2011

The research of polymer materials with advanced performance for information recording is an active branch in material science and photonics. The series of carbazole‐containing compounds: poly‐epoxypropylcarbazole (PEPC), poly‐epithiopropylcarbazole (PETPC), and copolymers of PETPC:glycidyl butyrate (PETPC:GB) were synthesized and investigated. The presented characteristics of thin films structures based on polymers mentioned above show the possibility to use them for both holographic and e‐beam recording. The interesting feature has been found concerning the formation of hidden gratings which have been revealed only by etching.
Pressure and temperature tuning of red laser diodes towards yellow and green
Authors: Bohdan Roland , Yvonyak Yurij , Mrozowicz Milan , Trzeciakowski Witold
Published: May 2011

Two InGaP/AlGaInP red laser diodes are studied at pressures up to 16 kbar and at temperatures down to 80 K. Emission wavelengths below 570 nm have been obtained, with low thresholds and high efficiencies. Pressure dependence of threshold currents is very different for the two lasers indicating that electron leakage occurs predominantly to L minima in one laser and to X minima in another laser.
Screening of Australian Plants for Antimicrobial Activity against Campylobacter jejuni
Authors: Kurekci Cemil , Bishop‐Hurley Sharon L. , Vercoe Philip E. , Durmic Zoey , Al Jassim Rafat A. M. , McSweeney Christopher S.
Published: May 2011

Campylobacter jejuni is the most common cause of acute enteritis in humans, with symptoms such as diarrhoea, fever and abdominal cramps. In this study, 115 extracts from 109 Australian plant species were investigated for their antimicrobial activities against two C. jejuni strains using an in vitro broth microdilution assay. Among the plants tested, 107 (93%) extracts showed activity at a concentration between 32 and 1024 µg/mL against at least one C. jejuni strain. Seventeen plant extracts were selected for further testing against another six C. jejuni strains, as well as Campylobacter coli, Escherichia coli, Salmonella typhimurium, Bacillus cereus, Proteus mirabilis and Enterococcus faecalis. The extract from Eucalyptus occidentalis demonstrated the highest antimicrobial activity, with an inhibitory concentration of 32 µg/mL against C. jejuni and B. cereus. This study has shown that extracts of selected Australian plants possess antimicrobial activity against C. jejuni and thus may have application in the control of this organism in live poultry and retail poultry products. Copyright © 2011 John Wiley & Sons, Ltd.
In Vitro Cytotoxic Effect of Ethanol Extract Prepared From Sporophyll of Undaria pinnatifida on Human Colorectal Cancer Cells
Authors: Nishibori Naoyoshi , Itoh Mari , Kashiwagi Mari , Arimochi Hideki , Morita Kyoji
Published: May 2011

Brown seaweed Undaria pinnatifida (Harvey) Suringar is popular as a foodstuff, and used for medical care in East Asian countries. The major components of this seaweed are shown to benefit hypertension and hyperlipidemia, and considered to reduce the risks of infarction and ischemic diseases. Furthermore, the intake of dietary fiber of seaweeds is considered to prevent the production and proliferation of cancer in the gastrointestinal tract. The direct effect of an ethanol extract prepared from Undaria pinnatifida sporophyll (mekabu) on HCT116 human colorectal cancer cells was examined, and the mekabu extract was shown to induce the non‐oxidative apoptotic damage to the cells, thus resulting in the reduction of their viabilities in a concentration‐dependent manner. Moreover, the cytotoxic effects of carcinostatic drugs, such as 5‐fluorouracil (5‐FU) and irinotecan (CPT‐11), were observed only in the medium containing sera, while the mekabu extract could effectively reduce the cell viabilities even in the serum‐free medium. These findings suggest that the mekabu extract may contain a potential active substance inducing the non‐oxidative apoptotic cell death probably through a mechanism different from those of 5‐FU and CPT‐11, and hence mekabu is possibly useful as an auxiliary drug to the chemotherapy of colorectal cancer. Copyright © 2011 John Wiley & Sons, Ltd.
The diurnal cycle of precipitation over the Maritime Continent in a high‐resolution atmospheric model
Authors: Love Barnaby S. , Matthews Adrian J. , Lister Grenville M. S.
Published: May 2011

Climate models can exhibit systematic errors in their mean precipitation over the Maritime Continent of the Indonesian archipelago at the heart of the tropical warm pool. These can often be traced back to an erroneous simulation of the diurnal cycle, and can lead to errors in global climate, through planetary wave propagation. Here, we examine the simulation of the diurnal cycle over the Maritime Continent in a series of high‐resolution integrations of the UK Met Office atmospheric model, with horizontal resolutions of 40 and 12 km (where the convection is parametrised) and 4 km (where the convection is explicitly resolved), as part of the Cascade project. In these models, the vertical heating profile over the islands changes from a convective profile with a mid‐tropospheric maximum in the early afternoon to a more stratiform profile with upper‐tropospheric heating and mid‐tropospheric cooling later. The convective heating profile forces a first internal mode gravity wave that propagates rapidly offshore; the deep warm anomalies behind its downwelling wavefront suppress convection offshore during early afternoon. The stratiform heating profile forces a gravity wave with a higher‐order vertical mode that propagates slowly offshore later in the afternoon. This mode has a negative, destabilising temperature anomaly in the mid‐troposphere. Together with the convergence zone between the wave fronts of the two modes, favourable conditions are created for offshore convection. In the 4 km explicit convection model, the offshore convection responds strongly to this gravity wave forcing, in agreement with observations, supporting a gravity wave–convection paradigm for the diurnal cycle over the Maritime Continent. However, the convective response in the lower‐resolution models is much less coherent, leading to errors in the diurnal cycle and mean precipitation. Hence, to improve climate model simulations, sensitivity to gravity wave forcing should be a factor in future convective parametrisation schemes. Copyright © 2011 Royal Meteorological Society
Nocturnal low‐level jet and ‘atmospheric streams’ over the rain shadow region of Indian Western Ghats
Authors: Prabha T. V. , Goswami B. N. , Murthy B. S. , Kulkarni J. R.
Published: May 2011

Spatial and temporal characteristics of a nocturnal low‐level jet (LLJ) on the east side of the Western Ghat mountain range over India's west coast and processes leading to the formation of the jet are discussed. The boundary‐layer jet has a regional scale extent, as revealed by high‐resolution Advanced Research Weather Research and Forecasting (ARW) model simulations, and contributes to the formation of ‘atmospheric streams’ of water vapor over the selected land regions. Simulations indicate that the formation of LLJ is mainly attributed to the baroclinicity of the valley atmosphere due to the gently rolling terrain, which is assisted by the persistence of an unstable residual layer above the developing stable boundary layer in the valley and cooling over the slopes. Prior to the formation of LLJ, the boundary layer is dominated by deep roll circulations. The LLJ followed a gust front zone associated with a mountain wave. The low‐level flow below the jet is decoupled from the upper‐level flow as a result of strong vorticity below the jet and suppression of turbulence at the jet core. A conceptual model for the boundary layer interactions, dynamics of the mountain wave, LLJ, etc. are proposed for Western Ghat region. Copyright © 2011 Royal Meteorological Society