bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model for the Degradation Performance of a Single‐Cell Direct Methanol Fuel Cell under Varying Operational Conditions
Authors: Kianimanesh A. , Yang Q. , Park S. S. , Xue D. , Freiheit T. 
Published: November 2013

AbstractThe effect of varying operating parameters on the degradation of a single‐cell direct methanol fuel cell (DMFC) with serpentine flow channels was investigated. Fuel cell internal temperature, methanol concentration, and air and methanol flow rates were varied in experimental tests and fuel cell performance was chronologically recorded. A DMFC semi‐empirical performance model was developed to predict the polarization curves of the DMFC and validated at different operating conditions. Performance degradation was observed and modeled over time by a linear regression model. Unlike previous studies, the cumulative exposure of the operating factors to the fuel cell was considered in the degradation analysis. The degradation model shows the cell voltage generation capacity does not significantly degrade. However, the Tafel slope of the cell changes with cumulative exposure to methanol concentration and air flow, and the ohmic resistance changes with cumulative exposure to temperature, methanol and air flow.
Preparation and Characterization of Semi‐IPN Fluorine Containing Polybenzimidazole/Nafion Composite Membrane for Fuel Cells
Authors: Chang Z. , Pu* H. , Zhao Z. , Pan H. , Li B. , Wan D. 
Published: November 2013

AbstractA facile way to prepare semi‐interpenetrating polymer network (semi‐IPN) membrane which adopted 1,3‐benzenedisulfonyl azide (1,3‐BDSA) to crosslink with fluorine containing polybenzimidazole (Aliphatic‐16F‐PBI) in the Aliphatic‐16F‐PBI/Nafion composite membranes was proposed. By means of Fourier transformed infrared (FTIR) spectra analysis, the possible crosslinking reaction mechanism was investigated. Results suggested that 1,3‐BDSA molecule loses a nitrogen and forms nitrene upon heating. Then this nitrene reacts with C–H bond of Aliphatic‐16F‐PBI. Scanning electron microscope (SEM) images showed that the compatibility of PBI and Nafion improved while hexadecafluoro‐octyl groups were implanted into Aliphatic‐16F‐PBI molecule. The properties of Aliphatic‐16F‐PBI/Nafion composite membranes for fuel cell applications were determined through tests of gel fraction, thermogravimetry (TG), dimensional stability, mechanical property and proton conductivity. The gel fraction could reach 27.9% when 7.4% 1,3‐BDSA was added into the composite membranes. The proton conductivity of the semi‐IPN Aliphatic‐16F‐PBI/Nafion composite membranes could reach 0.69 × 10–2 S cm–1 at 120 °C at 100% relative humidity. Such high crosslink degree resulted in the improvement of the tensile strength, dimensional stability and chemical oxidative stability of semi‐IPN Aliphatic‐16F‐PBI/Nafion composite membranes. Nonetheless, it had little effect on the thermal stability.
Histologic and systemic prognosticators for local control and survival in margin‐negative transoral laser microsurgery treated oral cavity squamous cell carcinoma
Authors: Sinha Parul , Mehrad Mitra , Chernock Rebecca D. , Lewis James S. , El‐Mofty Samir K. , Wu Ningying , Nussenbaum Brian , Haughey Bruce H. 
Published: November 2013

ABSTRACTBackgroundAppreciable local recurrence rates observed in patients with margin‐negative, transoral laser microsurgery (TLM)‐treated oral cavity squamous cell carcinoma (SCC) necessitate identification of new prognosticators for local control and survival. A histopathologic index (Brandwein–Gensler score [BGS]) and intrinsic/iatrogenic/chronic conditions causing immune compromise are investigated.MethodsFrom a prospectively assembled database of TLM‐treated oral cavity SCC, specimens for 60 patients with a minimum of 2‐years follow‐up could undergo BGS assignment. Local control, disease‐specific survival (DSS), and overall survival (OS) were study endpoints.Results“Low‐BGS” was recorded in 28 patients (47%) and “high‐BGS” in 32 patients (53%), whereas immune compromise was observed in 18%. In multivariate analyses, immune compromise was the only predictor for local control. T classification and immune compromise were prognostic for DSS and OS. “High‐BGS” was prognostic only for OS.Conclusion“High‐BGS” was associated with recurrences but immune compromise was the most significant predictor of local control and survival in margin‐negative, TLM‐treated oral cavity SCC. Strategies that maintain/restore tumor‐specific immune responses in immune compromised oral cavity SCC hosts need to be developed. © 2014 Wiley Periodicals, Inc. Head Neck 37: 52–63, 2015
Physicochemical modulation of chitosan‐based hydrogels induces different biological responses: Interest for tissue engineering
Authors: Rami Lila , Malaise Sebastien , Delmond Samantha , Fricain Jean‐Christophe , Siadous Robin , Schlaubitz Silke , Laurichesse Eric , Amédée Joëlle , Montembault Alexandra , David Laurent , Bordenave Laurence 
Published: November 2013

AbstractPolysaccharide‐based hydrogels are remarkable materials for the development of tissue engineering strategies as they meet several critical requirements for such applications and they may partly mimic the extracellular matrix. Chitosan is widely envisioned as hydrogel in biomedical fields for its bioresorbability, biocompatibility, and fungistatic and bacteriostatic properties. In this study, we report that the modulation of the polymer concentration, the degree of acetylation, the gelation processes [or neutralization routes (NR)] in the preparation of different chitosan‐based hydrogels lead to substantially and significantly different biological responses. We show that it is possible to tune the physicochemical characteristics, mechanical properties, and biological responses of such matrices. Physical hydrogels prepared from highly acetylated chitosan were softer, degraded quickly in vivo, and were not suitable for in vitro culture of human mesenchymal stem and progenitor derived endothelial cells. In contrast, for a same chitosan concentration and obtained by the same processing route, a low degree of acetylation chitosan hydrogel provided a more elastic material, better cell adhesion on its surface and tissue regeneration, and restored tissue neo‐vascularization as well. This work offers promising and innovative perspectives for the design of hydrogel materials with tunable properties for tissue engineering and regenerative medicine. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3666–3676, 2014.
Cortical and Trabecular Bone Benefits of Mechanical Loading Are Maintained Long Term in Mice Independent of Ovariectomy
Authors: Warden Stuart J , Galley Matthew R , Hurd Andrea L , Richard Jeffrey S , George Lydia A , Guildenbecher Elizabeth A , Barker Rick G , Fuchs Robyn K 
Published: November 2013

ABSTRACT

Skeletal loading enhances cortical and trabecular bone properties. How long these benefits last after loading cessation remains an unresolved, clinically relevant question. This study investigated long-term maintenance of loading-induced cortical and trabecular bone benefits in female C57BL/6 mice and the influence of a surgically induced menopause on the maintenance. Sixteen-week-old animals had their right tibia extrinsically loaded 3 days/week for 4 weeks using the mouse tibial axial compression loading model. Left tibias were not loaded and served as internal controls. Animals were subsequently detrained (restricted to cage activities) for 0, 4, 8, 26, or 52 weeks, with ovariectomy (OVX) or sham-OVX surgery being performed at 0 weeks detraining. Loading increased midshaft tibia cortical bone mass, size, and strength, and proximal tibia bone volume fraction. The cortical bone mass, area, and thickness benefits of loading were lost by 26 weeks of detraining because of heightened medullary expansion. However, loading-induced benefits on bone total area and strength were maintained at each detraining time point. Similarly, the benefits of loading on bone volume fraction persisted at all detraining time points. The long-term benefits of loading on both cortical and trabecular bone were not influenced by a surgically induced menopause because there were no interactions between loading and surgery. However, OVX had independent effects on cortical bone properties at early (4 and 8 weeks) detraining time points and trabecular bone properties at all detraining time points. These cumulative data indicate loading has long-term benefits on cortical bone size and strength (but not mass) and trabecular bone morphology, which are not influenced by a surgically induced menopause. This suggests skeletal loading associated with physical activity may provide long-term benefits by preparing the skeleton to offset both the cortical and trabecular bone changes associated with aging and menopause. © 2014 American Society for Bone and Mineral Research.
Flow‐Through Potentiometric Sensors for Alizarin Red S Dye and Their Application for Aluminum Determination
Authors: Hassan Saad S. M. , Kamel Ayman H. , El‐Naby Heba Abd 
Published: November 2013

AbstractNovel selective and sensitive poly (vinyl chloride) membrane sensors are developed for measuring alizarin red S (AR) based on the use of aliquate 336, MgIIphthalocyanine (MgPc), CuIIphthalocyanine (CuPc) and FeII phthalocyanine (FePc) plasticized poly (vinyl chloride) membrane. The sensors display Nernestian response with slopes of ‐50.6 ± 0.6 , ‐37.4 ± 0.5 , ‐37.7 ± 0.8 and ‐35.0 ± 0.7 mV decade−1 over the range of 5.2 × 10−6 to 1 × 10−2 mol L−1 for all of them and detection limits of 5.9 × 10−7, 1.9 × 10‐−6 2.3 × 10−6 and 1.9 × 10−6 mol L−1 for aliquate, MgPc, CuPc and FePc membrane based sensor, respectively. The sensors exhibit long life span, long term potential stability, high reproducibility, fast response and good discrimination ability towards alizarinate ion in comparison with many other anions. A tubular detector based on aliquate, MgPc, CuPc and FePc was further developed and coupled to a flow‐injection system for alizarin (AR) determination. Under optimized conditions, the linearity range is 1.0 × 10−5‐ 1.0 × 10−1 mol L−1, with a slope of ‐52.1 ± 0.8, 20.9 ± 0.7, 23.6 ± 0.4 and 25 ± 1.1 mV decade−1 and a reproducibility of ± 0.8 mV (n = 6) for aliquate, MgPc, CuPc and FePc membrane based sensors, respectively. The sensor based on aliquate is further utilized for a potentiodynamic quantification of aluminum in sludge samples and deodorants. The buffered solution of alizarin was allowed to react in a flow system with aluminum. The calibration curve of Al was found to be linear over a concentration range of 0.1 to 1.8 and 1.0 ‐ 40 μg mL−1 with a slope = 16.9 (r2 = 0.993) and 1.76 (r2 = 0.994) mV (μg/mL)−1 and a detection limit of 0.08 and 0.5 μg mL−1 for 10−4 and 10−3 mol L−1 AR− as a carrier, respectively. The method was successfully used for determining aluminum in sludge samples and deodorants. The data agree fairly well the nominal values and with results obtain by continuous flow hydride generation inductively coupled plasma (ICP) method.
Update in hospital palliative care
Authors: Anderson Wendy G. , Flint Lynn A. , Horton Jay R. , Johnson Kimberly , Mourad Michelle , Sharpe Bradley A. 
Published: November 2013

BACKGROUNDSeriously ill patients frequently receive care in hospitals, and palliative care is a core competency for hospitalists. We aimed to summarize and critique recent research that has the potential to impact the clinical practice of palliative care in the hospital.METHODSWe reviewed articles published between January 2012 and May 2013, identified through a hand‐search of leading journals and PubMed. The authors collectively selected 9 articles based on their scientific rigor and relevance to hospital practice. We review their findings, strengths, and limitations and make recommendations for practice.RESULTSKey findings include: indwelling pleural catheters and talc pleurodesis provide similar relief of dyspnea in patients with malignant pleural effusions; oxygen many not be needed to prevent dyspnea in many dying patients; docusate may not be needed in addition to sennosides to treat opioid‐induced constipation; atropine is no more effective than placebo in treating respiratory rattles in dying patients; many older adult survivors of in‐hospital cardiopulmonary resuscitation (CPR) are alive up to 1 year after discharge; observing CPR may decrease family post‐traumatic stress; surrogates of intensive care unit patients often interpret prognostic information optimistically; many patients with metastatic cancer feel that chemotherapy may cure their disease; viewing a goals‐of‐care video may decrease preference for CPR in patients being admitted to skilled nursing facilities.CONCLUSIONSRecent research provides important insights into the effectiveness of medications and interventions for symptom management, outcomes of CPR for patients and families, and communication and advance care planning in the hospital. Journal of Hospital Medicine 2013;8:715–720. © 2013 Society of Hospital Medicine
Response stratification and survival analysis of hepatocellular carcinoma patients treated with intra‐arterial therapy using MR imaging‐based arterial enhancement fraction
Authors: Bonekamp Susanne , Bonekamp David , Geschwind Jean‐Francois H. , Corona‐Villalobos Celia Pamela , Reyes Diane K. , Pawlik Timothy M. , Kamel Ihab R. 
Published: November 2013

PurposeTo investigate the feasibility that arterial enhancement fraction (AEF) is associated with response of hepatocellular carcinoma (HCC) following intra‐arterial therapy (IAT) and to compare AEF response with currently used tumor response metrics.Materials and MethodsThe AEF, Response Evaluation Criteria in Solid Tumors (RECIST), modified RECIST (mRECIST), and European Association for the Study of the Liver (EASL) of the largest treated index lesion and AEF of the tumor‐free hepatic parenchyma was measured on representative axial images in 131 patients (108 male; mean age, 61.9 years). Clinical measures and patient survival were assessed. Statistical analysis included Wilcoxon signed‐rank test and the COX proportional hazards model.ResultsAfter IAT, the mean AEF of the tumor decreased by 22% (66.7–44.8%, P < 0.0001), while the mean AEF of the tumor‐free parenchyma remained unchanged (27.2–26.5%, P = 0.50). Median survival of all 131 patients with liver cancer was 17 months. Patients were stratified into AEF‐responders if they had an AEF‐decrease ≥35% (AEF‐responders: n = 67; AEF‐nonresponders: n = 64). AEF‐responders survived longer than nonresponders (34.8 months versus 10.8 months, hazard ratio = 0.39; P < 0.0001). Responders according to RECIST, mRECIST, or EASL did not survive significantly longer compared with nonresponders.ConclusionEvaluating the AEF values based on tri‐phasic MRI is associated with tumor response in patients with unresectable HCC treated with IAT. J. Magn. Reson. Imaging 2014;40:1103–1111. © 2013 Wiley Periodicals, Inc.
Aqueductal cerebrospinal fluid pulsatility in healthy individuals is affected by impaired cerebral venous outflow
Authors: Beggs Clive B. , Magnano Christopher , Shepherd Simon J. , Marr Karen , Valnarov Vesela , Hojnacki David , Bergsland Niels , Belov Pavel , Grisafi Steven , Dwyer Michael G. , Carl Ellen , Weinstock‐Guttman Bianca , Zivadinov Robert 
Published: November 2013

PurposeTo investigate cerebrospinal fluid (CSF) dynamics in the aqueduct of Sylvius (AoS) in chronic cerebrospinal venous insufficiency (CCSVI)‐positive and ‐negative healthy individuals using cine phase contrast imaging.Materials and MethodsFifty‐one healthy individuals (32 CCSVI‐negative and 19 age‐matched CCSVI‐positive subjects) were examined using Doppler sonography (DS). Diagnosis of CCSVI was established if subjects fulfilled ≥2 venous hemodynamic criteria on DS. CSF flow and velocity measures were quantified using a semiautomated method and compared with clinical and routine 3T MRI outcomes.ResultsCCSVI was associated with increased CSF pulsatility in the AoS. Net positive CSF flow was 32% greater in the CCSVI‐positive group compared with the CCSVI‐negative group (P = 0.008). This was accompanied by a 28% increase in the mean aqueductal characteristic signal (ie, the AoS cross‐sectional area over the cardiac cycle) in the CCSVI‐positive group compared with the CCSVI‐negative group (P = 0.021).ConclusionCSF dynamics are altered in CCSVI‐positive healthy individuals, as demonstrated by increased pulsatility. This is accompanied by enlargement of the AoS, suggesting that structural changes may be occurring in the brain parenchyma of CCSVI‐positive healthy individuals.J. Magn. Reson. Imaging 2014;40:1215–1222. © 2013 Wiley Periodicals, Inc.
Detection of infragenual arterial disease using non–contrast‐enhanced MR angiography in patients with diabetes
Authors: Liu Xin , Zhang Na , Fan Zhaoyang , Feng Fei , Yang Qi , Zheng Hairong , Liu Pengcheng , Li Debiao 
Published: November 2013

PurposeTo evaluate the diagnostic performance of a newly developed non–contrast‐enhanced MR angiography (NCE‐MRA) technique using flow‐sensitive dephasing (FSD) prepared steady‐state free precession (SSFP) for detecting calf arterial disease in patients with diabetes.Materials and MethodsForty‐five patients with diabetes who underwent routine contrast‐enhanced MR angiography (CE‐MRA) of lower extremities were recruited for NCE‐MRA at the calf on a 1.5 Tesla MR system. Image quality evaluated on a 4‐point scale and diagnostic performance for detecting more than 50% arterial stenosis were statistically analyzed, using CE‐MRA as the standard of reference.ResultsA total of 264 calf arterial segments were obtained in the 45 patients with 88 legs. The percentage of diagnostic arterial segments was all 98% for NCE‐ and CE‐MRA. The image quality, SNR, CNR was 3.3, 177, 138, and 3.5, 103, 99, for NCE‐MRA and CE‐MRA, respectively. The average sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of NCE‐MRA were 97%, 96%, 90%, 99%, and 96%, respectively on a per‐segment basis and 90%, 84%, 82%, 91%, and 87%, respectively, on a per‐patients basis.ConclusionThe NCE‐MRA technique demonstrates adequate image quality in the delineation of calf arteries and consistent diagnostic performance for detecting significant stenosis with CE‐MRA in patients with diabetes. J. Magn. Reson. Imaging 2014;40:1422–1429. © 2013 Wiley Periodicals, Inc.
Long axis strain by MRI and echocardiography in a postmyocardial infarct population
Authors: Gjesdal Ola , Almeida André L.C. , Hopp Einar , Beitnes Jan Otto , Lunde Ketil , Smith Hans‐Jørgen , Lima Joáo A.C. , Edvardsen Thor 
Published: November 2013

PurposeTo compare long axis strain (LAS) by magnetic resonance imaging (MRI) and echocardiography in a postinfarct patient population. Long axis left ventricle (LV) function is a sensitive index of incipient heart failure by echocardiography, but is less well established in MRI. LAS is an index of global LV function, which is easily assessed in cine loops provided by most cardiac MRI protocols.Materials and MethodsIn all, 116 patients (57 ± 9 years) were studied the same day using echocardiography and MRI 7.4 ± 4.1 months after a first myocardial infarction. LV length was measured in end diastole and end systole in conventional cine images with a temporal resolution of 50 msec or less, and LAS (%) was calculated as the change in LV length, relative to end diastole. Infarct mass was assessed by contrast‐enhanced MRI.ResultsLAS was progressively reduced in patients with larger infarcts, and demonstrated good correlations with infarct mass (r = 0.55, P < 0.01). There was a good agreement between LAS assessed by echocardiography and MRI (r = 0.77, P < 0.01), and between LAS by MRI and speckle tracking strain by echocardiography (r = 0.74, P < 0.01).ConclusionLAS is an index that allows measurement of LV long axis function by conventional cine MRI.J. Magn. Reson. Imaging 2014;40:1247–1251. © 2013 Wiley Periodicals, Inc.
Serological cross reactivity to CMV and EBV causes problems in the diagnosis of acute hepatitis E virus infection
Authors: Hyams Catherine , Mabayoje Diana A. , Copping Ruth , Maranao Desmond , Patel Mauli , Labbett Wendy , Haque Tanzina , Webster Daniel P. 
Published: November 2013

AbstractHepatitis E virus (HEV) infection is an important public health concern as a major cause of enterically‐transmitted hepatitis worldwide. The detectable window of viraemia is narrow, and HEV IgM and IgG rise simultaneously in acute infection. Furthermore, previous investigators have shown HEV IgM false positive reactions occur against EBV, CMV and potentially hepatitis A. A retrospective analysis of HEV serology testing was performed at a London tertiary referral hospital over a 3‐year period. A thousand four hundred and twenty three serum samples were tested for HEV serology, with 33 samples HEV IgM positive and 28 HEV IgM equivocal. One hundred and eleven samples were HEV IgG positive but IgM negative suggesting past infection. No patients with HEV IgM positivity had false positive reactions against hepatitis A. A high degree of EBV and CMV cross reactivity was noted, with 33.3% and 24.2% of HEV IgM positive samples also testing positive for EBV and CMV IgM, respectively. HEV RNA was detected in four HEV IgM positive samples, indicating true positivity, although three demonstrated cross reactivity against EBV. Only 13.3% of samples with positive HEV IgM were HEV PCR positive, highlighting a low positive predictive value of serology testing. Overall a high level of HEV, EBV and CMV IgM cross reactivity was demonstrated, indicating that serology is unreliable in the diagnosis of acute viral hepatitis. It is concluded that that the diagnosis of viral hepatitis should be based on clinical features, raised transaminases, serology, and confirmatory PCR testing. J. Med. Virol. 86:478–483, 2014. © 2013 Wiley Periodicals, Inc.
An experiment in intra‐seasonal agricultural drought monitoring and early warning in the Sudano‐Sahelian Belt of Nigeria
Authors: Usman M. T. , AbdulKadir A. 
Published: November 2013

AbstractThe highly variable rainfall and recurring drought in dry sub‐humid and semi‐arid regions constitute a major socio‐economic problem that influences people's livelihoods. Agricultural drought is the most common of all drought types and is the most challenging to track and forecast owing to its ease of occurrence and impact on socio‐economic sustainability. In Nigeria as is the case in large parts of sub‐Saharan Africa, drought frequency, intensity and effect have dominated the literature since the great Sahelian drought of the late 1960s and early 1970s. This study proposes a simple drought monitoring and early warning (EW) methodology based on an experiment over Kano, Nigeria, hinged on an Intra‐seasonal Rainfall Monitoring Index (IRMI, Usman and Abdulkadir, 2012) determined for each pentad, using daily rainfall totals for a period of 30 years. The onset dates and drought intensity levels were used to define EW statements at three levels: advisory, alert and emergency. An experimental application of the scheme identified and detected late initiation conditions of real monsoon onset (RMO) in those seasons that eventually witnessed disastrous rainfall situations. Generally, the result reveals that the years between 1970 and 1990 over Kano, Nigeria, which ended as years of severe drought or worse, showed enough signals of poor rainfall distribution (deficient moisture) at the beginning for the scheme to have enabled a very high degree of forecast accuracy. It is concluded that strict monitoring of the rainfall regime especially during its onset phase is capable of revealing danger signals in the rainfall regime early enough to enable mitigation. Such mitigation is critical for the management of agricultural productivity in the predominantly rainfall‐dependent farming systems in the Sudan‐Sahel zone as confirmed by earlier studies.