bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Options and Limitations of Methanol‐Based Production and Storage for Mobile Applications
Authors: Poetzsch D. , Bach T. , Zerpa Unda J. E. , Roduner E.
Published: April 2014

Methanol is considered a promising liquid fuel in context with electrochemical energy conversion and storage for mobile applications. It is shown here that a direct methanol fuel cell can be used for spontaneous charging and discharging a supercapacitor (SC) for intermediate storage of chemical energy. Thereby, protons and electrons of the methanol‐derived hydrogen are stored separately in the electrical double layer of the SC electrode. The charging and discharging of this fuel cell–SC hybride device is investigated in experiments of spontaneous conditions (closed circuit) and also under externally enforced constant voltage sweep rate (cyclic voltammetry) and under constant current conditions. Alternatively, gas phase hydrogen is generated from methanol in an electro‐reforming process. When more efficient anode electrocatalysts become available this may become the method of choice for on‐board and on demand hydrogen production in mobile applications.
Analysis of spatio‐temporal brain imaging patterns by hidden markov models and serial MRI images
Authors: Wang Ying , Resnick Susan M. , Davatzikos Christos ,   the Baltimore Longitudinal Study of Aging and the Alzheimer's Disease Neuroimaging Initiative
Published: April 2014

Brain changes due to development and maturation, normal aging, or degenerative disease are continuous, gradual, and variable across individuals. To quantify the individual progression of brain changes, we propose a spatio‐temporal methodology based on Hidden Markov Models (HMM), and apply it on four‐dimensional structural brain magnetic resonance imaging series of older individuals. First, regional brain features are extracted in order to reduce image dimensionality. This process is guided by the objective of the study or the specific imaging patterns whose progression is of interest, for example, the evaluation of Alzheimer‐like patterns of brain change in normal individuals. These regional features are used in conjunction with HMMs, which aim to measure the dynamic association between brain structure changes and progressive stages of disease over time. A bagging framework is used to obtain models with good generalization capability, since in practice the number of serial scans is limited. An application of the proposed methodology was to detect individuals with the risk of developing MCI, and therefore it was tested on modeling the progression of brain atrophy patterns in older adults. With HMM models, the state‐transition paths corresponding to longitudinal brain changes were constructed from two completely independent datasets, the Alzheimer Disease Neuroimaging Initiative and the Baltimore Longitudinal Study of Aging. The statistical analysis of HMM‐state paths among the normal, progressive MCI, and MCI groups indicates that, HMM‐state index 1 is likely to be a predictor of the conversion from cognitively normal to MCI, potentially many years before clinical symptoms become measurable. Hum Brain Mapp 35:4777–4794, 2014. © 2014 Wiley Periodicals, Inc.
Head and neck multidisciplinary team meetings: Effect on patient management
Authors: Brunner Markus , Gore Sinclair M. , Read Rebecca L. , Alexander Ashlin , Mehta Ankur , Elliot Michael , Milross Chris , Boyer Michael , Clark Jonathan R.
Published: April 2014

Background

The purpose of this study was for us to present our findings on the prospectively audited impact of head and neck multidisciplinary team meetings on patient management.

Methods

We collected clinical data, the pre‐multidisciplinary team meeting treatment plan, the post‐multidisciplinary team meeting treatment plans, and follow‐up data from all patients discussed at a weekly multidisciplinary team meeting and we recorded the changes in management.

Results

One hundred seventy‐two patients were discussed in 39 meetings. In 52 patients (30%), changes in management were documented of which 20 (67%) were major. Changes were statistically more likely when the referring physician was a medical or radiation oncologist, when the initial treatment plan did not include surgery, and when the histology was neither mucosal squamous cell cancer nor a skin malignancy. Compliance to the multidisciplinary team meeting treatment recommendation was 84% for all patients and 70% for patients with changes in their treatment recommendation.

Conclusion

Head and neck multidisciplinary team meetings changed management in almost a third of the cases. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1046–1050, 2015
Reversal of Hepatocyte Senescence After Continuous In Vivo Cell Proliferation
Authors: Wang Min-Jun , Chen Fei , Li Jian-Xiu , Liu Chang-Cheng , Zhang Hai-Bin , Xia Yong , Yu Bing , You Pu , Xiang Dao , Lu Lian , Yao Hao , Borjigin Uyunbilig , Yang Guang-Shun , Wangensteen Kirk J. , He Zhi-Ying , Wang Xin , Hu Yi-Ping
Published: April 2014

A better understanding of hepatocyte senescence could be used to treat age-dependent disease processes of the liver. Whether continuously proliferating hepatocytes could avoid or reverse senescence has not yet been fully elucidated. We confirmed that the livers of aged mice accumulated senescent and polyploid hepatocytes, which is associated with accumulation of DNA damage and activation of p53-p21 and p16ink4a-pRB pathways. Induction of multiple rounds continuous cell division is hard to apply in any animal model. Taking advantage of serial hepatocyte transplantation assays in the fumarylacetoacetate hydrolase-deficient (Fah−/−) mouse, we studied the senescence of hepatocytes that had undergone continuous cell proliferation over a long time period, up to 12 rounds of serial transplantations. We demonstrated that the continuously proliferating hepatocytes avoided senescence and always maintained a youthful state. The reactivation of telomerase in hepatocytes after serial transplantation correlated with reversal of senescence. Moreover, senescent hepatocytes harvested from aged mice became rejuvenated upon serial transplantation, with full restoration of proliferative capacity. The same findings were also true for human hepatocytes. After serial transplantation, the high initial proportion of octoploid hepatocytes decreased to match the low level of youthful liver.

Conclusion :

These findings suggest that the hepatocyte “ploidy conveyer” is regulated differently during aging and regeneration. The findings of reversal of hepatocyte senescence could enable future studies on liver aging and cell therapy. (Hepatology 2014;60:349–361)
A Convenient and Simple Synthesis of Densely Functionalized Cyclopenta[cd]azulenes and Cyclopenta[ef]heptalenes
Authors: Devendar Badugu , Ku Chien‐Kuo , Cheng Ling‐Yu , Yang Shu‐Juan , Chen Jun‐Xiong , Wu Chi‐Phi
Published: April 2014

Syntheses of novel cyclopenta[cd]azulenes, 5, 8, and 13, 1,2‐dihydrocyclopenta[cd]azulenes, 6 and 12, and cyclopenta[ef]heptalenes, 10, 15, and 16, by simple procedures starting from tropolone in 6–8 steps are described.
Stereoselective Total Synthesis of Botryolide E and Ophiocerin C
Authors: Yadav Jhillu S. , Mallikarjuna Reddy N. , Ataur Rahman Md. , Mallikarjuna Reddy A. , Prasad Attaluri R.
Published: April 2014

A highly stereoselective approach to the total synthesis of the γ‐lactone derivative botryolide E and tetrahydropyran derivative ophiocerin C via a common polyketide precursor by means of Prins cyclization and MacMillan α‐aminoxylation sequence is described. The method can conveniently be utilized for the preparation of further related γ‐lactone and tetrahydropyran derivatives.
Further Biphenyl Lignans with a Tetrahydrofuran Moiety from Gymnotheca chinensis
Authors: Xiao Shiji , He Dahai , Fang Dongmei , Chen Fang , Ding Lisheng , Zhou Yan
Published: April 2014

Four new biphenyl lignans, 1–4, with a tetrahydrofuran moiety were isolated from the MeOH extract of the whole plant of Gymnotheca chinensis. Their chemical structures were established by means of spectroscopic analysis, including 1D and 2D NMR spectroscopy and comparison with previously reported data. Compounds 1–4 occur as mixtures of atropisomers as revealed by variable‐temperature NMR experiments.
Further Diterpenes from the Seeds of Caesalpinia minaxHance
Authors: Ma Guo‐Xu , Wu Hai‐Feng , Yuan Jing‐Quan , Wei Hua , Wang Shuo , Zhang Xiao‐Po , Tian Yu , Yang Jun‐Shan , Xu Xu‐Dong
Published: April 2014

Three new cassane‐type diterpenes, neocaesalpin AF (1), neocaesalpin AG (2), and neocaesalpin AH (3), were isolated from the seeds of Caesalpinia minax Hance. Their structures were elucidated on the basis of extensive spectroscopic analyses. The partially hydrogenated lactone unit in a tetracyclic cassane diterpene in 2 is rarely encountered in the cassane diterpenes isolated from the genus Caesalpinia. All compounds were evaluated for their in vitro cytotoxic activities against HCT‐8 and MCF‐7 human cancer cell lines.
Stereoselective Total Synthesis of Oxylipins: (6S,7E,9R,10S)‐6,9,10‐Trihydroxyoctadec‐7‐enoic Acid and (6Z,8R,9R,10S)‐8,9,10‐Trihydroxyoctadec‐6‐enoic Acid
Authors: Singh Yadav Jhillu , Shiva Shankar Kattela , Srinivas Reddy Anugu , Subba Reddy Basi V.
Published: April 2014

The stereoselective total syntheses of oxylipins 1b and 1c are described starting from readily accessible natural sugars via the Grubbs cross‐metathesis, Wittig olefination, and Zn‐mediated reductive elimination as key steps.
Overexpression of PrPc, combined with MGr1‐Ag/37LRP, is predictive of poor prognosis in gastric cancer
Authors: Zhou Lin , Shang Yulong , Liu Changhao , Li Jinge , Hu Hao , Liang Cong , Han Yanan , Zhang Wei , Liang Jie , Wu Kaichun
Published: April 2014

Prion protein (PrPc) has been previously reported to be involved in gastric cancer (GC) development and progression. However, the association between expression of PrPc and GC prognosis is yet poorly characterized. In the present study, the expressions of PrPc and MGr1‐Ag/37LRP, a protein interacting with PrPc, were detected using the tissue microarray technique and immunohistochemical method to compare clinicopathological parameters of 238 GC patients. We found that the expressions of PrPc and MGr1‐Ag/37LRP were upregulated in GC lesions compared with their expressions in adjacent noncancerous tissues (p < 0.01). High expression of PrPc was detected in 37.39% (89/238) of GC patients and positively correlated with the expression of MGr1‐Ag/37LRP (r = 0.532, p < 0.001). PrPc expression was associated with a number of clinicopathological parameters including depth of invasion and lymph node metastasis of the tumor (p < 0.001). High expression of PrPc brought a poorer prognosis than low PrPc expression. Moreover, GC patients with high level of PrPc and high level of MGr1‐Ag/37LRP had the poorest prognosis. Multivariate survival analysis suggested that, along with other parameters, combined expression of PrPc and MGr1‐Ag/37LRP was independent prognostic factors for GC patients. These data indicates that overexpression of PrPc, combined with MGr1‐Ag/37LRP, is predictive of poor prognosis in GC and thereby could be used to guide the clinical decision.
Population pharmacokinetic‐pharmacodynamic modeling analysis of intrinsic FXa and bleeding from edoxaban treatment
Authors: Song SaeHeum , Kang Dongwoo , Halim Abdel‐Baset , Miller Raymond
Published: April 2014

Edoxaban is an oral, once‐daily, direct factor Xa (FXa) inhibitor that has been evaluated for the prevention of stroke in patients with atrial fibrillation (AF) and for the treatment and prevention of venous thromboembolism (VTE) recurrence. Pharmacokinetic (PK) and pharmacodynamic (PD) modeling and logistic regression analyses were used to explore the clinical data from phase 1 and 2 studies to determine the relationship among PK exposure, PD response, and bleeding risk. Population PK/PD modeling was performed using plasma edoxaban concentration data from combined phase 1 and 2 studies and using intrinsic FXa data from a phase 2 AF study. A 2‐compartment PK model adequately described the combined PK data, and a dynamic binding model characterized the dynamics of the intrinsic factor X activity (iFXa) data. Logistic regression analysis then identified the relationship between the iFXa and the observed bleeding risk. The more protracted suppression of FXa over the dosing interval for a 30‐mg twice‐daily dose compared with a 60‐mg once‐daily dose offers an explanation for the significantly higher bleeding rate at the former dose.
Reproductive responses of the endangered snail kite to variations in prey density
Authors: Cattau Christopher E. , Darby Philip C. , Fletcher Robert J. , Kitchens Wiley M.
Published: April 2014

Understanding how predators respond to fluctuations in prey density has important conservation and management implications, particularly for threatened and endangered specialists. However, directly linking prey densities to predator behavior and demography over broad spatial and temporal scales is rare, in part, because it can be prohibitively expensive and time‐consuming to quantify prey density over large areas. We link nesting data collected by a long‐term monitoring program for the endangered snail kite (Rostrhamus sociabilis plumbeus) with 44 density estimates of its primary prey, the Florida apple snail (Pomacea paludosa), collected by multiple, smaller‐scale studies from 2002 to 2010. We found evidence that key components of kite breeding biology—nest density and the number of young fledged per successful nest—were positively related to snail density. Although previous studies have shown that densities greater than approximately 0.1–0.2 snails/m2may be necessary to sustain profitable foraging and that capture times for individual foraging kites begin to level off as snail densities exceed approximately 0.4 snails/m2, we found continued numerical responses in snail kite reproductive parameters at greater snail densities. At occupied sites (i.e., snail‐sampling sites in which ≥1 snail kite nest was present within a 2‐km radius during the primary sampling period: Mar–May), the average snail density was 0.45 snails/m2(SE = 0.12,n = 17), whereas that of unoccupied sites was 0.12 snails/m2(SE = 0.02,n = 27). Along the snail density gradient from 0.2 to 0.4 to 1.2 snails/m2, model predictions indicated that 1) the probability of site occupancy (by nesting kites) increased from 0.48 to 0.69 to 0.90, 2) local nest abundance of occupied sites increased from 4 to 7 to 16 nests, and 3) the probability of a successful nesting attempt fledging more than 1 young increased from 0.02 to 0.07 to 0.43. We found no evidence of a snail density effect on nest survival. Understanding the differential effects of snail density on various components of snail kite breeding biology is essential to the development and implementation of management tools used for snail kite conservation and Everglades restoration. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Progressive hepatic mitochondrial dysfunction in premanifest Huntington's disease
Authors: Hoffmann Rainer , Stüwe Sven H. , Goetze Oliver , Banasch Matthias , Klotz Peter , Lukas Carsten , Tegenthoff Martin , Beste Christian , Orth Michael , Saft Carsten
Published: April 2014

Background

A subclinical, hepatic involvement in manifest and premanifest Huntington's disease (HD) was recently demonstrated by using the 13C‐methionine breath test (MeBT). In this longitudinal pilot study, we investigated whether there is evidence for progressive hepatic mitochondrial dysfunction in premanifest HD.

Methods

The MeBT was performed within a group of 25 well‐characterized premanifest HD mutation carriers at baseline and in a 14.5‐month follow‐up.

Results

The total group of mutation carriers (P = 0.033; Cohen's d = 0.6) and the subgroup of mutation carriers from our PreHD‐B subgroup (nearer to disease onset; P = 0.030; Cohen's d = 1.12) revealed a lower amount of exhaled 13CO2 in the follow‐up.

Conclusions

This study demonstrates in vivo progressive, subclinical, hepatic involvement in premanifest HD. Limitations of the study, such as high variance in breath test results, are discussed. © 2014 International Parkinson and Movement Disorder Society © 2014 International Parkinson and Movement Disorder Society
Evaluation of mild cognitive impairment subtypes in Parkinson's disease
Authors: Cholerton Brenna A. , Zabetian Cyrus P. , Wan Jia Y. , Montine Thomas J. , Quinn Joseph F. , Mata Ignacio F. , Chung Kathryn A. , Peterson Amie , Espay Alberto J. , Revilla Fredy J. , Devoto Johnna , Watson G. Stennis , Hu Shu‐Ching , Leverenz James B. , Edwards Karen L.
Published: April 2014

Mild cognitive impairment in Parkinson's disease (PD‐MCI) is common and increases the risk for dementia. Establishing distinct PD‐MCI cognitive subtypes could be valuable for eventually predicting those most likely to convert to dementia. However, the study of PD‐MCI subtypes has not yielded consistent results among cohorts. To determine whether there are distinct cognitive subtypes among participants diagnosed with PD‐MCI in the Pacific Northwest Udall Center Clinical Consortium, we cognitively subtyped 95 patients with PD‐MCI, using the Movement Disorders Society Task Force diagnostic guidelines. Psychometric test scores were then subjected to principle components factor analysis to determine whether similar cognitive subgroups could be identified using statistical methodology. Multiple‐domain PD‐MCI was diagnosed in 95% of the sample, and a range of cognitive impairments were noted. Factor analysis yielded seven factors and demonstrated overlap of phonemic verbal fluency on two factors, as well as the loading of verbal fluency on the same factor as a visuospatial measure; however, these factors did not partition the sample into distinct cognitive subtypes. Separation of cognitive subtypes based on the current PD‐MCI criteria, or via statistical methods, may not provide sufficient information to describe distinct PD groups. Future efforts to validate the PD‐MCI criteria and identify combinations of genetic or other risk factors for cognitive impairment are warranted. © 2014 International Parkinson and Movement Disorder Society
Obstetric fistula in a district hospital in DR Congo: Fistula still occur despite access to caesarean section
Authors: Loposso Matthieu Nkumu , Ndundu Jean , De Win Gunter , Ost Dieter , Punga Augustin Maole , De Ridder Dirk
Published: April 2014

Objective

To study the profile of classification, etiology, and the relation between initial classification, and the results of vesicovaginal fistula surgery in a district hospital in DR Congo.

Methods

This study was based on the analysis of all consecutive patients being treated for VVF in Kisantu between November 2006 and November 2012. The fistula was classified according to the classification of Waaldijk. The location of VVF and degree of fibrosis were noted. Post‐operatively, the first examination of patients took place a few days after catheter removal and subsequent review 2–3 months later.

Statistical analysis was done in Graphpad Prism 6.

Results

Among 146 patients with VVF, 117 had a primary fistula. The majority of fistula was type I (56%) followed by type III (21%). The majority underwent a caesarean section (63.4%). The mean duration of labor was 30.7 hr. Delay in getting a caesarean in time was due to difficulties in reaching the hospital in 55%. Overall, the closure rate after the first surgical treatment was 65%. The continence rate of the patients with a successful closure was 63%.

Conclusion

VVF can occur after caesarean section because of the prolonged labor that already causes ischemia and necrosis of the bladder wall and vesicovaginal septum before or while the caesarean section is being performed. Access to general hospitals and the management of the pregnant women needs to be improved. Despite a reasonable closure rate of 65%, post‐fistula incontinence remains an important clinical problem. Neurourol. Urodynam. 34:434–437, 2015. © 2014 Wiley Periodicals, Inc.
Solving multitrip vehicle routing under order incompatibilities: A VRP arising in supply chain management
Authors: Derigs Ulrich , Pullmann Markus
Published: April 2014

In this study, we introduce a new class of vehicle routing problems (VRP): the multidepot multitrip VRP with order incompatibilities. The problem is motivated by a specific two‐echelon distribution system arising in supply chain management, where products come to the depots from different factories by semitrailers and these semitrailers are also used for short‐haul distribution, that is, the load from different factories is not consolidated at the depots. This VRP is rather challenging as it combines several synchronisation constraints occurring in other well‐known standard VRP. In this article, we describe several problem variants, we model the problem as a set partitioning problem, and we show how the heuristic concept of concurrent (LS/LNS) neighborhood search which has shown to be rather effective for other complex VRP‐classes can be customized. Our computational study shows that this approach is effective and efficient for this VRP‐class, too. © 2014 Wiley Periodicals, Inc. NETWORKS, Vol. 64(1), 29–39 2014
Review of Tolvaptan for Autosomal Dominant Polycystic Kidney Disease
Authors: Baur Brian P. , Meaney Calvin J.
Published: April 2014

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by bilateral renal cysts, kidney pain, hypertension, and progressive loss of renal function. It is a leading cause of end‐stage renal disease and the most common inherited kidney disease in the United States. Despite its prevalence, disease‐modifying treatment options do not currently exist. Tolvaptan is an orally active, selective arginine vasopressin V2 receptor antagonist already in use for hyponatremia. Tolvaptan exhibits dose‐proportional pharmacokinetics with a half‐life of ~12 hours. Metabolism occurs through the cytochrome P450 3A4 isoenzyme, and tolvaptan is a substrate for P‐glycoprotein, resulting in numerous drug interactions. Recent research has highlighted the beneficial effect of tolvaptan on delaying the progression of ADPKD, which is the focus of this review. Pharmacologic, preclinical, and phase II and III clinical trial studies have demonstrated that tolvaptan is an effective treatment option that targets underlying pathogenic mechanisms of ADPKD. Tolvaptan delays the increase in total kidney volume (surrogate marker for disease progression), slows the decline in renal function, and reduces kidney pain. However, tolvaptan has significant adverse effects including aquaretic effects (polyuria, nocturia, polydipsia) and elevation of aminotransferase enzyme concentrations with the potential for acute liver failure. Appropriate patient selection is critical to optimize long‐term benefits while minimizing adverse effects and hepatotoxic risk factors. Overall, tolvaptan is the first pharmacotherapeutic intervention to demonstrate significant benefit in the treatment of ADPKD, but practitioners and regulatory agencies must carefully weigh the risks versus benefits. Additional research should focus on incidence and risk factors of liver injury, cost‐effectiveness, clinical management of drug–drug interactions, and long‐term disease outcomes.
A Comprehensive Framework for Sustainable Project Portfolio Selection Based on Structural Equation Modeling
Authors: Khalili-Damghani Kaveh , Tavana Madjid
Published: April 2014

Project selection problems are inherently complex problems with multiple and often conflicting objectives. The complexity of project selection problems is due to the high number of projects from which a subset (portfolio) has to be chosen. Various analytical methods, ranging from the simple weighted sum to complex mathematical programming have been proposed to solving these problems. We propose an integrated approach for strategic and sustainable project portfolio selection, which is composed of two distinct but interrelated modules. In the first module, we use the strategic planning and sustainability concepts to select a set of promising projects. In the second module, we use a project portfolio selection procedure to choose among the promising projects identified in the first module. A structural equation model is used to analyze and explain the relationships among different factors in the proposed framework. More specifically, we investigate the effects of: (1) strategic level performance on sustainability, post-implementation, and overall performance; (2) implementation performance on post-implementation and overall performance; (3) portfolio selection performance on implementation and overall performance; and (4) post-implementation performance on overall performance. A case study in investment banking is presented to demonstrate the applicability of the proposed model and exhibit the efficacy of the procedures and algorithms.
Proteomic analysis of patient tissue reveals PSA protein in the stroma of benign prostatic hyperplasia
Authors: O'Malley Katherine J. , Eisermann Kurtis , Pascal Laura E. , Parwani Anil V. , Majima Tsuyoshi , Graham Lara , Hrebinko Katherine , Acquafondata Marie , Stewart Nicolas A. , Nelson Joel B. , Yoshimura Naoki , Wang Zhou
Published: April 2014

BACKGROUND

Benign prostatic hyperplasia (BPH) is an age‐related disease frequently associated with lower urinary tract symptoms (LUTS) that involves hyperplasia of both epithelial and stromal cells. Stromal fibrosis is a distinctive feature of BPH, but the exact mechanisms underlying this phenomenon are poorly understood.

METHODS

In the current study, proteomics analyses were utilized to identify proteins altered in the BPH stromal compartment from patients with symptomatic BPH. Stromal cells were isolated from histological nodules of BPH by laser capture microdissection (LCM) and subjected to liquid chromatography/mass spectrometry.

RESULTS

Proteins identified included several stromal‐specific proteins involved in extracellular matrix (ECM) remodeling, focal adhesion, and cellular junctions. Additionally, the proteomics array identified the presence of luminal epithelial secretory protein PSA. Immunostaining, ELISA, and in situ hybridization analyses of BPH tissues verified the presence of PSA protein but absence of PSA mRNA in the stromal compartment. E‐cadherin was down‐regulated in BPH epithelial cells compared to normal adjacent tissues, suggesting that alteration of cellular junctions could contribute to the presence of luminal epithelial secreted proteins PSA and KLK2 in the stromal compartment.

CONCLUSIONS

The above findings suggest that the presence of secreted proteins PSA and KLK2 from prostate luminal epithelial cells in BPH stroma is a hallmark of BPH nodules, which could in part be due to alterations in cellular junction proteins and/or increased epithelial barrier permeability. Elucidating the cause and consequence of these secreted proteins in the stromal compartment of BPH may lead to new understanding of BPH pathogenesis as well as approaches to prevent and/or treat this common disease. Prostate 74:892–900, 2014. © 2014 Wiley Periodicals, Inc.
Improving field‐emission properties of SiC nanowires treated by H2 and N2 plasma
Authors: Li Zhenjiang , Li Weidong , Wang Xianlin , Zhang Meng
Published: April 2014

β‐SiC nanowires (SiC NWs) were modified by H2 and N2 plasma treatment for improving the field‐emission (FE) properties. The FE property of SiC NWs treated by H2 and N2 plasma was significantly improved, their turn‐on field and threshold field were 3.2 and 6.7 V µm−1 for a 10‐min H2 treatment, 3.0 and 6.3 V µm−1 for a 20‐min H2 treatment, and 2.8 and 6.0 V µm−1 for a 10‐min N2 treatment, respectively, while SiC NWs treated by N2 for 20 min displayed poorer FE properties compared with untreated SiC NWs. The results of scanning electron microscope (FE‐SEM), transmission electron microscopy, high‐resolution transmission electron microscopy, selected‐area electronic diffraction, and X‐ray diffraction showed that the surface of the SiC NWs became rough, but their microstructure did not change after the plasma treatments. The point effect was proposed to explain the improvement of FE properties. A new, simple, and effective method for improving SiC NWs FE properties was discovered, and it may serve as a referential work for enhancing FE properties of other one‐dimensional nonmaterials.
Characterization of CdMnTe crystal grown with vertical Bridgman method under Te‐rich conditions
Authors: Zhang Jijun , Wang Linjun , Min Jiahua , Huang Jian , Liang Xiaoyan , Tang Ke , Shen Ping , Shen Min , Liang Wei , Huang Nansen , Xia Yiben
Published: April 2014

In this study, the Indium (In) doped Cd1–xMnx Te (xMn=0.1, CdMnTe) crystals with excess Te in the amount of 0 and 1.2 at% were grown by the Bridgman method. The segregation coefficient of In dopants distributions in the CdMnTe crystals with and without excess Te were determined to be 0.08 and 0.11, respectively. The IR transmission microscopy shown that the size of Te inclusions in CdMnTe crystal with excess Te increased to 5–13 μm with the concentrations of (2–3)×105 cm–3. The PL spectra indicated the formation of Te antisite donor and the compensation of Cd vacancies by Te antisites. The Current‐Voltage measurements were performed and the resistivity of the CdMnTe crystal with excess Te was in the range of 108–109 Ω·cm, increased by one order as compared to the crystal without excess Te. Under the radiation of 59.5 keV 241Am, The CdMnTe planar detectors fabricated from the crystal with excess Te revealed the energy resolution of 8.4%, however, no energy response is resolved in the CdMnTe detectors without excess Te. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and characterization of arc deposited magnetic (Cr,Mn)2AlC MAX phase films
Authors: Mockute Aurelija , Persson Per O. Å. , Magnus Fridrik , Ingason Arni Sigurdur , Olafsson Sveinn , Hultman Lars , Rosen Johanna
Published: April 2014

(Cr1–xMnx)2AlC MAX phase thin films were synthesized by cathodic arc deposition. Scanning transmission electron microscopy including local energy dispersive X‐ray spectroscopy analysis of the as‐deposited films reveals a Mn incorporation of as much as 10 at% in the structure, corresponding to x = 0.2. Magnetic properties were characterized with vibrating sample magnetometry, revealing a magnetic response up to at least room temperature. We thus verify previous theoretical predictions of an antiferromagnetic or ferromagnetic ground state for Cr2AlC upon alloying with Mn. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two 1D Coordination Polymers with Bis[4‐(pyridin‐4‐yl)pyrimidinyl]disulfide (4‐ppds) as Bridging Ligand
Authors: Zhu Hai‐Bin , Wu Yan‐Fang , Shan Ru‐Yu , Chen Yun‐Di , Lou Yong‐Bing
Published: April 2014

Solution assembly of heterocyclic disulfide ligand, 4‐ppds {4‐ppds = bis[4‐(pyridin‐4‐yl)pyrimidinyl]disulfide}, with Cu(OAc)2 and ZnI2 resulted in two 1D (one‐dimensional) coordination polymers 1 and 2, which were well characterized by infrared spectroscopy, elemental analysis, powder X‐ray diffraction, single‐crystal X‐ray diffraction, diffuse‐reflectance UV/Vis as well as photoluminescence spectroscopy. Single crystal X‐ray crystallography discloses that 1 shows an achiral zigzag chain structure built up by alternate linking of paddlewheel Cu2(OAc)4 dicopper unit and 4‐ppds ligand with opposite configurations, whereas 2 exhibits a helical chain structure constructed by alternate linkage of tetrahedral zinc atom and 4‐ppds ligand with the same chirality (P‐ or M‐configuration). It is supposed that the flexible coordination environment around the tetrahedral ZnII ion might be beneficial to homochiral arrangement of 4‐ppds ligand.
Accessing (Ba1–xSrx)Al2Si2O8:Eu Phosphors for Solid State White Lighting via Microwave‐assisted Preparation: Tuning Emission Color by Coordination Environment
Authors: Brgoch Jakoah , Kloß Simon D. , Denault Kristin A. , Seshadri Ram
Published: April 2014

The preparation of Eu2+‐substituted barium aluminum silicates is achieved using a rapid microwave‐assisted preparation. The phase evolution of two BaAl2Si2O8:Eu2+ polymorphs, the higher temperature hexagonal phase (hexacelsian), and the lower temperature monoclinic phase (celsian), is explored by varying the ramp time and soak time. This preparation method significantly reduces the reaction time needed to form these phases compared to conventional solid state routes. The luminescent properties of the two phases are identified under UV excitation with the hexagonal phase emitting in the UV region (λem = 372 nm) and the monoclinic phase emitting in the blue region (λem = 438 nm). The differences in optical properties of the two polymorphs are correlated to the coordination number and arrangement of the alkali earth site. The optical properties of the monoclinic phase can be further tuned through the substitution of Sr2+, forming the solid solution (Ba1–xSrx)Al2Si2O8:Eu2+. Changes in the crystal structure due to Sr2+ substitution produce a surprising blue‐shift in the emission spectrum, which is explained by a greater dispersion of bond lengths in the (Ba/Sr)–O polyhedra. The entire monoclinic solid solution exhibits excellent quantum yields of nearly 90 %, owing to the structural rigidity provided by the highly connected tetrahedral network.
Noble Metal Complexes with 4, 4′‐ and 5, 5′‐Pyridyl‐Functionalized (S)‐2, 2′‐Bis(diphenylphosphanyl)‐1, 1′‐binaphthyl Ligands
Authors: Lestari Witri Wahyu , Lönnecke Peter , Hey‐Hawkins Evamarie
Published: April 2014

Six metal complexes based on AuI, PdII, or PtII with functionalized (S)‐4, 4′‐ or 5, 5′‐bis(3‐pyridyl)‐2, 2′‐bis(diphenylphosphanyl)‐1, 1′‐binaphthyl ligands (L1, L2) have been prepared and fully characterized. According to single‐crystal X‐ray analysis, the AuI complexes (S)‐[Au2Cl2(L1)] (1) and (S)‐[Au2Cl2(L2)] (2) show an almost linear Cl–Au–P arrangement, and the PdII and PtII complexes (S)‐[PdCl2(L1)] (3), (S)‐[PdCl2(L2)] (4), (S)‐[PtI2(L1)] (5), and (S)‐[PtI2(L2)] (6) exhibit distorted square‐planar geometries.
Cost‐Effectiveness of the Ponseti Method for Treatment of Clubfoot in Pakistan
Authors: Hussain Hamidah , Burfat Aziza Moiz , Samad Lubna , Jawed Fayez , Chinoy Muhammad Amin , Khan Mansoor Ali
Published: April 2014

Background

Clubfoot is disabling, with an incidence of 0.9/1,000 live births to 7/1,000 live births. It affects mobility, productivity, and quality of life. Patients are treated surgically or non‐surgically using the Ponseti method. We estimated the cost per patient treated with both methods and the cost‐effectiveness of these methods in Pakistan.

Methods

Parents of patients treated, either surgically or with the Ponseti method, at the Indus Hospital’s free program for clubfoot were interviewed between February and May 2012. We measured the direct and indirect household expenditures for pre‐diagnosis, incomplete treatment, and current treatment until the first brace for Ponseti method and the first corrective surgery for surgically treated patients. Hospital expenditure was measured by existing accounts.

Results

Average per‐patient cost was $349 for the Ponseti method and $810 for patients treated surgically. Of these, the Indus hospital costs were $170 the for Ponseti method and $452 for surgically treated patients. The direct household expenditure was $154 and $314 for the Ponseti and surgical methods, respectively. The majority of the costs were incurred pre‐diagnosis and after inadequate treatment, with the largest proportion spent on transportation, material, and fee for service. The Ponseti method is shown to be the dominant method of treatment, with an incremental cost‐effectiveness ratio of $1,225.

Conclusions

The Ponseti method is clearly the treatment of choice in resource‐constrained settings like Pakistan. Household costs for clubfoot treatment are substantial, even in programs offering free diagnostics and treatments and may be a barrier to service utilization for the poorest patients.
Correlation between Preoperative Imaging and Intraoperative Risk Assessment in the Prediction of Postoperative Pancreatic Fistula Following Pancreatoduodenectomy
Authors: Frozanpor Farshad , Loizou Louiza , Ansorge Christoph , Lundell Lars , Albiin Nils , Segersvärd Ralf
Published: April 2014

Background

Prediction of postoperative pancreatic fistula (POPF) can be carried out with the intraoperative assessment of pancreatic consistency (PC) and via pancreatic duct width (iPDW). Preoperative computed tomography (CT) calculated pancreatic remnant volume (PRV) and duct width (rPDW) have also been shown to offer useful information about the risk of POPF.

Objective

The objective of this study was to determine the predictive value of the preoperative radiological features as compared with the intraoperative risk estimation for the subsequent development of POPF.

Method

All patients undergoing pancreatoduodenectomy between September 2007 and March 2012 at the Karolinska University Hospital Stockholm were included. PRV and rPDW were determined on preoperative CT and in parallel, intraoperative PC and iPDW of the remnant pancreas were independently assessed.

Results

A total of 296 consecutive pancreatoduodenectomies were included. POPF occurred in 45 patients (15.2 %). Of those with a preoperatively calculated PRV < 23.0 cm3, 2.8 % developed POPF compared with 25.7 % of those with a corresponding volume > 46.0 cm3. In patients with an rPDW > 7.0 mm, 4.1 % had a POPF as compared with 38.7 % for those with rPDW < 2.0 mm. The POPF risk estimates based on PRV and rPDW and the intraoperative risk assessments were found to be identical (p < 0.001). In the receiver operating characteristic analysis, area under the curve was 0.80 (95 % confidence interval [CI] 0.72–0.87) and 0.80 (95 % CI 0.72–0.88) for the CT‐based and intraoperative risk prediction models, respectively.

Conclusions

Preoperative CT‐based and intraoperative gland risk assessments offer comparable predictive information on the risk of POPF after pancreatoduodenectomy. These results imply that accurate POPF risk estimation can be carried out in the preoperative setting to opt for improved patient selection into relevant research protocols and the availability of surgical expertise and techniques.
Demographic and Experiential Correlates of Public Attitudes Towards Cell‐Free Fetal DNA Screening
Authors: Sayres Lauren C. , Allyse Megan , Goodspeed Taylor A. , Cho Mildred K.
Published: April 2014

This study seeks to inform clinical application of cell‐free fetal DNA (cffDNA) screening as a novel method for prenatal trisomy detection by investigating public attitudes towards this technology and demographic and experiential characteristics related to these attitudes. Two versions of a 25‐item survey assessing interest in cffDNA and existing first‐trimester combined screening for either trisomy 13 and 18 or trisomy 21 were distributed among 3,164 members of the United States public. Logistic regression was performed to determine variables predictive of interest in screening options. Approximately 47 % of respondents expressed an interest in cffDNA screening for trisomy 13, 18, and 21, with a majority interested in cffDNA screening as a stand‐alone technique. A significantly greater percent would consider termination of pregnancy following a diagnosis of trisomy 13 or 18 (52 %) over one of trisomy 21 (44 %). Willingness to consider abortion of an affected pregnancy was the strongest correlate to interest in both cffDNA and first‐trimester combined screening, although markedly more respondents expressed an interest in some form of screening (69 % and 71 %, respectively) than would consider termination. Greater educational attainment, higher income, and insurance coverage predicted interest in cffDNA screening; stronger religious identification also corresponded to decreased interest. Prior experience with disability and genetic testing was associated with increased interest in cffDNA screening. Several of these factors, in addition to advanced age and Asian race, were, in turn, predictive of respondents’ increased willingness to consider post‐diagnosis termination of pregnancy. In conclusion, divergent attitudes towards cffDNA screening—and prenatal options more generally – appear correlated with individual socioeconomic and religious backgrounds and experiences with disability and genetic testing. Clinical implementation and counseling for novel prenatal technologies should take these diverse stakeholder values into consideration.
Saddlepoint Approximations of the Distribution of the Person Parameter in the Two Parameter Logistic Model
Authors: Biehler Martin , Holling Heinz , Doebler Philipp
Published: April 2014

Large sample theory states the asymptotic normality of the maximum likelihood estimator of the person parameter in the two parameter logistic (2PL) model. In short tests, however, the assumption of normality can be grossly wrong. As a consequence, intended coverage rates may be exceeded and confidence intervals are revealed to be overly conservative. Methods belonging to the higher-order-theory, more specifically saddlepoint approximations, are a convenient way to deal with small-sample problems. Confidence bounds obtained by these means hold the approximate confidence level for a broad range of the person parameter. Moreover, an approximation to the exact distribution permits to compute median unbiased estimates (MUE) that are as likely to overestimate as to underestimate the true person parameter. Additionally, in small samples, these MUE are less mean-biased than the often-used maximum likelihood estimator.
Blood Management May Have an Impact on Length of Stay after Total Hip Arthroplasty
Authors: Bou Monsef Jad , Boettner Friedrich
Published: April 2014

Background

The steady rise in demand for total hip arthroplasty constitutes a significant and increasing burden on health care resources. The biggest contributors to the total cost of hip replacement procedures other than the price of the implant are hospital stay and postoperative rehabilitation. Blood management is one of the most adjustable factors that can impact length of stay and cost-efficiency while improving patient safety.

Questions/Purposes

The primary purpose of this retrospective study was to assess the potential impact of blood management interventions on length of hospital stay after primary unilateral total hip arthroplasty. This was achieved by first identifying which patient and surgical factors are associated with an increased risk of prolonged hospital stay. Subsequently, the significant factors were controlled for through a multivariate regression analysis to quantify the association between blood transfusions and increased hospital stay.

Methods

Retrospectively, the study included 2,104 primary total hip replacements. Eight hundred eighty-eight procedures were performed on males and 1,216 on females, with a mean age of 64 years at the time of the surgery (range 18–94 years) and BMI of 28.6 kg/m2 (range 12–51.5 kg/m2). The correlation between each factor and length of stay was analyzed separately using univariate regression analysis. Those variables with p ≤ 0.05 in the univariate model were selected for inclusion in the multivariate logistic regressions. Multiple linear regression was used to analyze the effect of each significant factor and derive odds ratios with adjustment for the other variables.

Results

Multivariate Poisson regression revealed that increased length of stay was significantly correlated to patient age ( p = 0.05), the use of coumadin ( p = 0.02) or lovenox/heparin ( p = 0.007) as opposed to aspirin for anticoagulation, and allogeneic blood transfusion ( p < 0.0001). The data shows that allogeneic blood transfusion is associated with a longer hospital stay regardless of absolute drop in hemoglobin level postoperatively or at discharge or the number of units transfused (OR = 1.18, 95% CI = 1.09 to 1.28, p < 0.001).

Conclusion

Transfusion of allogeneic blood is independently associated with increased hospital stay after total hip arthroplasty. Blood management modalities that can significantly reduce transfusion risk could impact length of stay as well as the total cost of hip replacement procedures.
Community-Based Asset Building and Community Wealth
Authors: Nembhard Jessica Gordon
Published: April 2014

The author traces involvement in the wealth inequality movement since 1999 and the frustrations with realistically addressing wealth inequality and racial wealth gaps. This paper outlines the journey from understanding the importance of wealth in African American and other communities, to addressing collective structures for accumulating assets and wealth for low-income people of color. The author explores the role cooperatives play in creating community and collective wealth, and proposes alternatives to the mainstream savings strategies usually proposed.
Geophysical, magmatic, and metallogenic manifestations of a mantle plume in the upper reaches of the Aldan and Amur Rivers
Authors: Petrishchevsky A.M. , Yushmanov Yu.P.
Published: April 2014

Gravity models of the crust and upper mantle to a depth of 100 km are analyzed to study structural relationships of tectonic and tectonophysical media of different rigidities with the distribution of shallow ore deposits above the Aldan–Zeya plume. The spatial correlation of ore clusters and districts with high crustal viscosity inhomoheneities at depths of 10, 20, and 35 km shows distinct stepwise behavior. On the other hand, media of decreased viscosity are observed in the lower crust (at depths of 25–30 km), subcrustal (40–50 km) layers, and asthenosphere (at a depth below 70 km). They are related to chambers of the complete or partial melting (heat sources) of magmatic and ore occurrences near the Earth’s surface. Lateral metallogenic zoning in the spatial distribution of the ore deposits is due to the spread and redistribution of magmas and ore-forming fluids, shielded by rigid plates in the lower crust. A naturally determined series of ore parageneses is observed from center to flanks of the plume: Au, Mo → Au, Ag, Pb, Zn → Au, Pb, Zn → Au, W → Au, Sb → W, Sn → Sn. The mutual position of the tectonomagmatic structures of different ranks within the plume head obeys hierarchical and fractal laws.
Geologic stages of the Paleogene and Neogene evolution of the Arctic shelf in the Ob’ region (
West Siberia
)
Authors: Volkova V.S.
Published: April 2014

The paper is concerned with the structure of the Arctic shelf sediments in the Ob’ region in the Paleogene and Neogene, sampled from boreholes drilled on the Yamal Peninsula, in the lower reaches of the Pur and Taz Rivers. The specifics of Paleogene marine sedimentation in the central and northern West Siberian Plain are studied. The effect of abiotic (tectonic) factors on the completeness of the geologic record is considered as well as the effect of recent (Oligocene–Neogene) tectonic processes on topography and sedimentation. The borehole sections are compared with the main seismic sections of the Kara Sea and Lomonosov Ridge.