bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing key assumptions of network meta‐analysis: a review of methods
Authors: Donegan Sarah , Williamson Paula , D'Alessandro Umberto , Tudur Smith Catrin 
Published: August 2013

BackgroundHomogeneity and consistency assumptions underlie network meta‐analysis (NMA). Methods exist to assess the assumptions but they are rarely and poorly applied. We review and illustrate methods to assess homogeneity and consistency.MethodsEligible articles focussed on indirect comparison or NMA methodology. Articles were sought by hand‐searching and scanning references (March 2013). Assumption assessment methods described in the articles were reviewed, and applied to compare anti‐malarial drugs.Results116 articles were included. Methods to assess homogeneity were: comparing characteristics across trials; comparing trial‐specific treatment effects; using hypothesis tests or statistical measures; applying fixed‐effect and random‐effects pair‐wise meta‐analysis; and investigating treatment effect‐modifiers. Methods to assess consistency were: comparing characteristics; investigating treatment effect‐modifiers; comparing outcome measurements in the referent group; node‐splitting; inconsistency modelling; hypothesis tests; back transformation; multidimensional scaling; a two‐stage approach; and a graph‐theoretical method.For the malaria example, heterogeneity existed for some comparisons that was unexplained by investigating treatment effect‐modifiers. Inconsistency was detected using node‐splitting and inconsistency modelling. It was unclear whether the covariates explained the inconsistency.ConclusionsPresently, we advocate applying existing assessment methods collectively to gain the best understanding possible regarding whether assumptions are reasonable. In our example, consistency was questionable; therefore the NMA results may be unreliable. Copyright © 2013 John Wiley & Sons, Ltd.
Intraoperative fluid administration is associated with perioperative outcomes in pancreaticoduodenectomy: A single center retrospective analysis
Authors: Eng Oliver S. , Goswami Julie , Moore Dirk , Chen Chunxia , Gannon Christopher J. , August David A. , Carpizo Darren R. 
Published: August 2013

AbstractBackgroundRecent studies on perioperative fluid administration in patients undergoing major abdominal surgery have suggested that increased fluid loads are associated with worse perioperative outcomes. However, results of retrospective analyses of the relationship between intraoperative fluid (IOF) administration and perioperative outcomes in patients undergoing pancreaticoduodenectomy (PD) are conflicted. We sought to investigate this relationship in patients undergoing PD at our academic center.MethodsA retrospective analysis of 124 patients undergoing PD from 2007 to 2012 was performed. IOF administration rate (ml/kg/hr) was correlated with perioperative outcomes. Outcomes were also stratified by preoperative serum albumin level.ResultsRegression analyses were performed comparing independent perioperative variables, including IOF rate, to four outcomes variables: length of stay, severity of complications, number of complications per patient, and 30‐day mortality. Both univariate and multivariate regression analyses showed IOF rate correlated with one or more perioperative outcomes. Patients with an albumin ≤3.0 g/dl who received more than the median IOF rate experienced more severe complications, while patients with an albumin >3.0 g/dl did not.ConclusionIncreased IOF administration is associated with worse perioperative outcomes in patients undergoing PD. Patients with low preoperative serum albumin levels (≤3.0 g/dl) may be a group particularly sensitive to volume overload. J. Surg. Oncol. 2013 108:242–247. © 2013 Wiley Periodicals, Inc.
Clinical outcome of neoadjuvant chemoradiation therapy with oxaliplatin and capecitabine or 5‐fluorouracil for locally advanced rectal cancer
Authors: Lu Jun‐Yang , Xiao Yi , Qiu Hui‐Zhong , Wu Bin , Lin Guo‐Le , Xu Lai , Zhang Guan‐Nan , Hu Ke 
Published: August 2013

AbstractBackground and ObjectivesThis study evaluated the safety and efficiency of preoperative chemoradiation therapy (CRT) with the XELOX or FOLFOX regimen in locally advanced rectal cancer patients.MethodsOne hundred forty‐four patients (T3/T4 or N+) were enrolled between 2005 and 2011. The patients received preoperative concomitant CRT (XELOX or FOLFOX regimen). Patients were divided into four groups: pCR (pT0N0), downstaging, no‐downstaging, and progression group. Clinical outcome with overall survival (OS) and disease‐free survival (DFS) were compared for each group.ResultsOne hundred thirty‐eight patients received radical resection after preoperative CRT. Twenty‐seven patients (20%) achieved pCR. The response rate (pCR + downstaging) was 67%. The most common side effects were nausea (64%), diarrhea (49%), and leucopenia (49%). The overall estimated 5‐year OS was 86% for all patients. The estimated 5‐year OS was significantly better in the responders (pCR + downstaging) than the non‐responders (no‐downstaging + progression, 94% vs. 68%, P = 0.001). There was also statistical difference in 3‐year DFS between the two groups (93% vs. 68%, P = 0.000).ConclusionspCR and downstaging after neoadjuvant CRT are associated with improved survival for locally advanced rectal cancer patients. Preoperative CRT with the XELOX or FOLFOX regimen is well tolerated and has mild adverse events. J. Surg. Oncol. 2013 108:213–219. © 2013 Wiley Periodicals, Inc.
Golden eagle population trends in the western United States: 1968–2010
Authors: Millsap Brian A. , Zimmerman Guthrie S. , Sauer John R. , Nielson Ryan M. , Otto Mark , Bjerre Emily , Murphy Robert 
Published: August 2013

AbstractIn 2009, the United States Fish and Wildlife Service promulgated permit regulations for the unintentional lethal take (anthropogenic mortality) and disturbance of golden eagles (Aquila chrysaetos). Accurate population trend and size information for golden eagles are needed so agency biologists can make informed decisions when eagle take permits are requested. To address this need with available data, we used a log‐linear hierarchical model to average data from a late‐summer aerial‐line‐transect distance‐sampling survey (WGES) of golden eagles in the United States portions of Bird Conservation Region (BCR) 9 (Great Basin), BCR 10 (Northern Rockies), BCR 16 (Southern Rockies/Colorado Plateau), and BCR 17 (Badlands and Prairies) from 2006 to 2010 with late‐spring, early summer Breeding Bird Survey (BBS) data for the same BCRs and years to estimate summer golden eagle population size and trends in these BCRs. We used the ratio of the density estimates from the WGES to the BBS index to calculate a BCR‐specific adjustment factor that scaled the BBS index (i.e., birds per route) to a density estimate. Our results indicated golden eagle populations were generally stable from 2006 to 2010 in the 4 BCRs, with an estimated average rate of population change of −0.41% (95% credible interval [CI]: −4.17% to 3.40%) per year. For the 4 BCRs and years, we estimated annual golden eagle population size to range from 28,220 (95% CI: 23,250–35,110) in 2007 to 26,490 (95% CI: 21,760–32,680) in 2008. We found a general correspondence in trends between WGES and BBS data for these 4 BCRs, which suggested BBS data were providing useful trend information. We used the overall adjustment factor calculated from the 4 BCRs and years to scale BBS golden eagle counts from 1968 to 2005 for the 4 BCRs and for 1968 to 2010 for the 8 other BCRs (without WGES data) to estimate golden eagle population size and trends across the western United States for the period 1968 to 2010. In general, we noted slightly declining trends in southern BCRs and slightly increasing trends in northern BCRs. However, we estimated the average rate of golden eagle population change across all 12 BCRs for the period 1968–2010 as +0.40% per year (95% CI = −0.27% to 1.00%), suggesting a stable population. We also estimated the average rate of population change for the period 1990–2010 was +0.5% per year (95% CI = −0.33% to 1.3%). Our annual estimates of population size for the most recent decade range from 31,370 (95% CI: 25,450–39,310) in 2004 to 33,460 (95% CI: 27,380–41,710) in 2007. Our results clarify that golden eagles are not declining widely in the western United States. © 2013 The Wildlife Society.
Carbazole‐Substituted Triphenylamine and Diketopyrrolopyrrole Alternating Copolymer for Photovoltaic Cells
Authors: Bian Linyi , Yang Dong , Yin Liangming , Zhang Jian , Tang Weihua 
Published: August 2013

A new alternating conjugated polymer (PTCDPP) of carbazole‐substituted triarylamine and diketopyrrolopyrrole is prepared and characterized in detail. The polymer exhibits two strong absorption bands at 345 and 600 nm. With highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of −5.13 eV and −3.67 eV, PTCDPP displays an energy gap of 1.66 eV. PTCDPP‐based bulk heterojunction solar cells with a structure of fluorinated tin oxide (FTO)/TiO2/PTCDPP:[6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM)/MoO3/Ag are fabricated. The devices are optimized by adjusting the composition of the PTCDPP:PCBM active layer, thermal treatment, and addition of processing additives. The device based on PTCDPP:PCBM (1:4, w/w) shows a power conversion efficiency (PCE) of 2.31%, with a short‐circuit current of 4.17 mA cm−2, an open‐circuit voltage of 0.79 V, and a fill factor of 0.35. The best cell performance (2.65% PCE) is achieved by using 1,8‐diiodooctane (3%, v/v) as a processing additive and annealing the active layer at 80 °C.
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Novel Bisphosphonated Methacrylates: Synthesis, Polymerizations, and Interactions with Hydroxyapatite
Authors: Bilgici Zeynep Sarayli , Turker Sebnem Begum , Avci Duygu 
Published: August 2013

Five novel methacrylates containing either bisphosphonate (1 and 2), bisphosphonic acid (3), carboxylic acid (4), or both bisphosphonic and carboxylic acid together (5), are synthesized. The monomers 1 and 2 are synthesized by the reactions of tetraethyl 1‐hydroxyethane‐1,1‐diyl­diphosphonate with ethyl α‐bromomethacrylate and tert‐butyl α‐bromomethacrylate; the same procedure fails with tetraethyl hydroxy(phenyl)methylenediphosphonate. 1 is converted to 3 by hydrolysis with trimethylsilyl bromide (TMSBr), and 2 is converted to 4 by hydrolysis with trifluoroacetic acid (TFA). Monomer 5 is obtained by hydrolysis of 2 first with TMSBr and then with TFA. The hydrolytic stability, the properties of the copolymerizations with commercial dental monomers, and HAP interactions make these monomers promising candidates for dental adhesives.
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Controlled One‐Pot Synthesis of Polystyrene‐block‐Polycaprolactone Copolymers by Simultaneous RAFT and ROP
Authors: de Freitas Augusto G. O. , Trindade Suelen G. , Muraro Paulo I. R. , Schmidt Vanessa , Satti Angel J. , Villar Marcelo A. , Ciolino Andrés E. , Giacomelli Cristiano 
Published: August 2013

A convenient one‐pot method for the controlled synthesis of polystyrene‐block‐polycaprolactone (PS‐b‐PCL) copolymers by simultaneous reversible addition–fragmentation chain transfer (RAFT) and ring‐opening polymerization (ROP) processes is reported. The strategy involves the use of 2‐(benzylsulfanylthiocarbonylsulfanyl)ethanol (1) for the dual roles of chain transfer agent (CTA) in the RAFT polymerization of styrene and co‐initiator in the ROP of ε‐caprolactone. One‐pot poly­merizations using the electrochemically stable ROP catalyst diphenyl phosphate (DPP) yield well‐defined PS‐b‐PCL in a relatively short reaction time (≈4 h; = 9600−43 600 g mol−1; / = 1.21−1.57). Because the hydroxyl group is strategically located on the Z substituent of the CTA, segments of these diblock copolymers are connected through a trithiocarbonate group, thus offering an easy way for subsequent growth of a third segment between PS and PCL. In contrast, an oxidatively unstable Sn(Oct)2 ROP catalyst reacts with (1) leading to multimodal distributions of polymer chains with variable composition.
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Noise estimation from averaged diffusion weighted images: Can unbiased quantitative decay parameters assist cancer evaluation?
Authors: Dikaios Nikolaos , Punwani Shonit , Hamy Valentin , Purpura Pierpaolo , Rice Scott , Forster Martin , Mendes Ruheena , Taylor Stuart , Atkinson David 
Published: August 2013

PurposeMultiexponential decay parameters are estimated from diffusion‐weighted‐imaging that generally have inherently low signal‐to‐noise ratio and non‐normal noise distributions, especially at high b‐values. Conventional nonlinear regression algorithms assume normally distributed noise, introducing bias into the calculated decay parameters and potentially affecting their ability to classify tumors. This study aims to accurately estimate noise of averaged diffusion‐weighted‐imaging, to correct the noise induced bias, and to assess the effect upon cancer classification.MethodsA new adaptation of the median‐absolute‐deviation technique in the wavelet‐domain, using a closed form approximation of convolved probability‐distribution‐functions, is proposed to estimate noise. Nonlinear regression algorithms that account for the underlying noise (maximum probability) fit the biexponential/stretched exponential decay models to the diffusion‐weighted signal. A logistic‐regression model was built from the decay parameters to discriminate benign from metastatic neck lymph nodes in 40 patients.ResultsThe adapted median‐absolute‐deviation method accurately predicted the noise of simulated (R2 = 0.96) and neck diffusion‐weighted‐imaging (averaged once or four times). Maximum probability recovers the true apparent‐diffusion‐coefficient of the simulated data better than nonlinear regression (up to 40%), whereas no apparent differences were found for the other decay parameters.ConclusionsPerfusion‐related parameters were best at cancer classification. Noise‐corrected decay parameters did not significantly improve classification for the clinical data set though simulations show benefit for lower signal‐to‐noise ratio acquisitions. Magn Reson Med 71:2105–2117, 2014. © 2013 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance.
Single Acquisition Quantitative Single‐Point Electron Paramagnetic Resonance Imaging
Authors: Jang Hyungseok , Subramanian Sankaran , Devasahayam Nallathamby , Saito Keita , Matsumoto Shingo , Krishna Murali C. , McMillan Alan B. 
Published: August 2013

PurposeElectron paramagnetic resonance imaging has emerged as a promising noninvasive technology to dynamically image tissue oxygenation. Owing to its extremely short spin–spin relaxation times, electron paramagnetic resonance imaging benefits from a single‐point imaging scheme where the entire free induction decay signal is captured using pure phase encoding. However, direct T2*/pO2 quantification is inhibited owing to constant magnitude gradients which result in time‐decreasing field of view. Therefore, conventional acquisition techniques require repeated imaging experiments with differing gradient amplitudes (typically 3), which results in long acquisition time.MethodsIn this study, gridding was evaluated as a method to reconstruct images with equal field of view to enable direct T2*/pO2 quantification within a single imaging experiment. Additionally, an enhanced reconstruction technique that shares high spatial k‐space regions throughout different phase‐encoding time delays was investigated (k‐space extrapolation).ResultsThe combined application of gridding and k‐space extrapolation enables pixelwise quantification of T2* from a single acquisition with improved image quality across a wide range of phase‐encoding time delays. The calculated T2*/pO2 does not vary across this time range.ConclusionsBy utilizing gridding and k‐space extrapolation, accurate T2*/pO2 quantification can be achieved within a single data set to allow enhanced temporal resolution (by a factor of 3). Magn Reson Med, 70:1173–1181, 2013. © 2013 Wiley Periodicals, Inc.
Acute sleep deprivation increases food purchasing in men
Authors: Chapman Colin D. , Nilsson Emil K. , Nilsson Victor C. , Cedernaes Jonathan , Rångtell Frida H. , Vogel Heike , Dickson Suzanne L. , Broman Jan‐Erik , Hogenkamp Pleunie S. , Schiöth Helgi B. , Benedict Christian 
Published: August 2013

ObjectiveTo investigate if acute sleep deprivation affects food purchasing choices in a mock supermarket.Design and MethodsOn the morning after one night of total sleep deprivation (TSD) or after one night of sleep, 14 normal‐weight men were given a fixed budget (300 SEK—approximately 50 USD). They were instructed to purchase as much as they could out of a possible 40 items, including 20 high‐caloric foods (>2 kcal/g) and 20 low‐caloric foods (<2 kcal/g). The prices of the high‐caloric foods were then varied (75%, 100% (reference price), and 125%) to determine if TSD affects the flexibility of food purchasing. Before the task, participants received a standardized breakfast, thereby minimizing the potential confound produced by hunger. In addition, morning plasma concentrations of the orexigenic hormone ghrelin were measured under fasting conditions.ResultsIndependent of both type of food offered and price condition, sleep‐deprived men purchased significantly more calories (+9%) and grams (+18%) of food than they did after one night of sleep (both P < 0.05). Morning plasma ghrelin concentrations were also higher after TSD (P < 0.05). However, this increase did not correlate with the effects of TSD on food purchasing.ConclusionsThis experiment demonstrates that acute sleep loss alters food purchasing behavior in men.
Determinants of suicidal ideation in patients with breast cancer
Authors: Kim Jae‐Min , Jang Ji‐Eun , Stewart Robert , Kim Seon‐Young , Kim Sung‐Wan , Kang Hee‐Ju , Shin Il‐Seon , Park Min‐Ho , Yoon Jung‐Han , Yoon Jin‐Sang 
Published: August 2013

AbstractBackgroundBreast cancer survivors are at higher risk of psychological problems including suicidal ideation. However, studies on suicidal ideation in breast cancer survivors have been rare and have not been investigated prospectively. This study aimed to investigate the prevalence and independent risk factors for suicidal ideation within 1 week and at 1 year after breast surgery for breast cancer.MethodsA total of 284 patients with breast cancer were evaluated within 1 week after breast surgery, and 244 (84%) were followed up 1 year later. Suicidal ideation was ascertained using the item ‘suicidal thoughts’ from the Beck Depression Inventory. Various factors potentially related to suicidal ideation were evaluated including sociodemographic and clinical characteristics, and genetic polymorphisms on serotonin and brain‐derived neurotrophic factor (BDNF) systems.ResultsSuicidal ideation was present in 10.9% of participants at 1 week and 11.4% at 1 year after breast surgery. Suicidal ideation was independently associated with depression and physical disability at 1 week and with living alone, anxiety, advanced cancer stage, and the BDNF met allele (but not with genetic polymorphisms on serotonergic system) at 1 year after breast surgery.ConclusionsSuicidal ideation was common and had similar prevalences in both short‐term and longer‐term follow‐ups after breast cancer. However, associated factors were substantially different between the two evaluation points, which suggest that time‐specific programs may be needed for identifying and managing suicidal risk in patients with breast cancer. Copyright © 2013 John Wiley & Sons, Ltd.
Cool horizons for entangled black holes
Authors: Maldacena J. , Susskind L. 
Published: August 2013

AbstractGeneral relativity contains solutions in which two distant black holes are connected through the interior via a wormhole, or Einstein‐Rosen bridge. These solutions can be interpreted as maximally entangled states of two black holes that form a complex EPR pair. We suggest that similar bridges might be present for more general entangled states. In the case of entangled black holes one can formulate versions of the AMPS(S) paradoxes and resolve them. This suggests possible resolutions of the firewall paradoxes for more general situations.
Thermal deactivation of lifetime‐ limiting grown‐in point defects in n‐type Czochralski silicon wafers
Authors: Rougieux F. E. , Grant N. E. , Macdonald D. 
Published: August 2013

AbstractIn this study, we uncover a recombination‐active grown‐in defect reducing the minority carrier lifetime of Czochralski grown n‐type silicon from 5 ms to below 2 ms. We also demonstrate that the defect can be de‐activated by annealing between 300 °C and 360 °C. Our experimental findings suggest that vacancy‐related pairs incorporated during ingot growth may be responsible for the decreased minority carrier lifetime. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Co‐diffusion from solid sources for bifacial n‐type solar cells
Authors: Rothhardt Philip , Keding Roman , Wolf Andreas , Biro Daniel 
Published: August 2013

AbstractWe present a simplified process sequence for the fabrication of large area n‐type silicon solar cells. The boron emitter and full area phosphorus back surface field are formed in one single high temperature step using doped glasses deposited by plasma enhanced chemical vapour deposition (PECVD) as diffusion sources. By optimizing the gas composition during the PECVD process, we not only prevent the formation of a boron rich layer (BRL), but also achieve doping profiles that exhibit a low dark saturation current density while allowing for contact formation by screen printing. The presented co‐diffusion process allows for major process simplification compared to the state of the art diffusion process relying on multiple high temperature processes, masking and wet chemistry steps.magnified imageSolar cell based on n‐type silicon featuring a co‐diffused boron emitter and phosphorus back‐surface field (BSF).(© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combined control with sliding mode and partial feedback linearization for 3D overhead cranes
Authors: Tuan Le Anh , Lee Soon‐Geul , Ko Deok Hyeon , Nho Luong Cong 
Published: August 2013

SUMMARYA 3D overhead crane is an underactuated system consisting of five outputs: trolley position, bridge translation, cable length, and two cargo swings. These outputs are controlled by three actuators for cargo hoisting, trolley motion, and bridge traveling. This study proposes the use of a nonlinear controller that performs five tasks concurrently: cargo hoisting, trolley tracking, bridge motion, payload vibration suppression during transport, and cargo swing elimination at the destination. The proposed algorithm is combined with two control components: (i) partial feedback linearization, which is a precursor to controller design, to suppress cargo vibration; and (ii) sliding mode method, which provides robust control in lifting the payload and driving trolley and bridge motions against model imprecision and uncertainty. These two control mechanisms are successfully merged into a combined controller because the kinematic relationships between the state variables are made apparent in the system dynamics. Simulation and experimental results show that the proposed controller asymptotically stabilizes all system responses.Copyright © 2013 John Wiley & Sons, Ltd.