bluuebunny/crossref_metadata_2025 huggingface dataset:
Uncertainty quantification of CO2 leakage through a fault with multiphase and nonisothermal effects
Authors: Lu Chuanhe , Sun Yunwei , Buscheck Thomas A. , Hao Yue , White Joshua A. , Chiaramonte Laura
Published: December 2012

The potential for CO2 leakage through a permeable fault is a key concern for geologic CO2 sequestration (GCS) in saline formations. If CO2 migrates vertically upward through a fault from the storage reservoir to an overlying fresh‐water aquifer, phase change can occur because temperature and pressure decrease with decreasing depth. The decrease in CO2 density during phase transition causes an additional reduction in temperature. In this paper, we present a computational model for simulating the behaviour of a leaky fault connecting a saline CO2 storage reservoir and an overlying fresh‐water aquifer. We address phase transition, considering the nonlinear CO2 enthalpy and viscosity functions. The model results indicate that the CO2 leakage rate initially increases when CO2 migration is driven by both buoyancy and overpressure during the period of injection. In the post‐injection period, CO2 leakage is only driven by buoyancy and the leakage rate decreases. The influence of nonisothermal conditions is more pronounced during the first stage. The deterministic model of this faulted reservoir system is used within an uncertainty quantification (UQ) framework to rigorously quantify the sensitivity of the brine and CO2 leakage in response to the uncertain model parameters. The results demonstrate that fault permeability is the most sensitive factor affecting both CO2 and brine leakage rate. Reduced‐order models of CO2 and brine leakage are developed for the emulation of a large number of sample points, from which probability distributions are derived and can be incorporated in risk assessment of groundwater contamination resulting from CO2 and brine leakage. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd
Formal Synthesis of (−)‐Cephalotaxine
Authors: Gonçalves‐Martin Monica G. , Zigmantas Sarunas , Renaud Philippe
Published: December 2012

A formal synthesis of (−)‐cephalotaxine (1) by means of a highly stereoselective radical carboazidation process is reported. The synthesis begins with the protected (S)‐cyclopent‐2‐en‐1‐ol derivative 10 and uses the concept of self‐reproduction of a stereogenic center (Schemes 5 and 6). For this purpose, the double bond adjacent to the initial chiral center in 10 is converted into an acetonide after stereoselective dihydroxylation. The initial alcohol function is used to build an exocyclic methylene group suitable for the carboazidation process 8→7 (Scheme 7). Finally the protected diol moiety is converted back to an alkene (14→15→6) and used for the formation of ring B via a Heck reaction (6→(−)‐16; Scheme 8).
Alkylations of Chiral Nickel(II) Complexes of Glycine under Phase‐Transfer Conditions
Authors: Houck Daniel , Luis Aceña José , Soloshonok Vadim A.
Published: December 2012

Alkylation reactions of nickel(II) complex 6 derived from glycine and 2‐[(1‐benzyl‐L‐prolyl)amino]benzophenone (BPBP) were studied under phase‐transfer‐catalysis (PTC) conditions. The goal of this work was to find an alternative suitable solvent for these reactions to replace the commonly used CH2Cl2 which leads to the formation of several by‐products, thus lowering the yield of target compounds. We demonstrate that 1,2‐dichloroethane is a markedly better solvent providing higher yields (75–99%) of the desired products 10 with 36–88% diastereoisomer purity (Scheme 3 and Table). Furthermore, we show that the stereochemical outcome of these PTC reactions (kinetic control) can be easily improved to >95% de by treatment of the PTC products with MeONa/MeOH. The scope of these reactions includes alkylations with methyl iodide as well as activated halides such as benzyl, allyl or propargyl, bromides and most notably ethyl 2‐bromoacetate (Table).
Organization Change and Social Organizing Strategies: Employee‐Initiated Organization Development
Authors: Githens Rod Patrick
Published: December 2012

Lesbian, gay, bisexual, transgender, and queer (LGBTQ) employees create formal and informal groups within workplaces to provide social support and to seek organizational change at their places of employment. I present a case study of a coalition of these groups working together to attain domestic partner benefits within a large three‐campus university system. These groups worked together to conduct employee‐initiated organization development (OD). This development occurred through various approaches to organizational change and social organizing strategies. The study illustrates the distinct differences between employee‐initiated OD in the corporate sector and in universities. It also demonstrates the utility in organizing through a structured activist group and a looser grassroots coalition at various stages of the effort. Successes were attained at various stages through both the more highly structured groups and through loose‐knit coalitions. Additionally, this study illustrates successes in social organizing around both fixed, ethnic‐type identities and through more fluid queer approaches. Both approaches were utilized to varying degrees as the activists worked toward goals of concern to (a) diverse groups (not just LGBTQ individuals) and (b) LGBTQ‐specific constituents.
Commitment to Change: Its Role in the Relationship Between Expectation of Change Outcome and Emotional Exhaustion
Authors: Ning Jing , Jing Runtian
Published: December 2012

Successful implementation of organizational changes greatly depends on committed employees. It is crucial for managers, leaders, and HRD professionals to understand the antecedents and outcomes of commitment to change. The purpose of this study is to investigate the relationships among expectation of change outcome at the individual level, commitment to change, and emotional exhaustion. Four hundred and sixty‐three usable surveys were returned from managers and employees from three companies in the Chinese telecom industry that were undergoing large‐scale organizational changes. Results of correlation analysis demonstrated that expectation of change outcome was positively correlated with affective and normative commitments to change and negatively correlated with continuance commitment to change. Affective and normative commitments to change were both negatively correlated with emotional exhaustion, while continuance commitment to change was positively correlated with emotional exhaustion. Structural equation modeling analysis indicated that a full mediation model fitted best to the data. The relationships between the two dimensions of expectation of change outcome and emotional exhaustion were fully mediated by affective and normative commitments to change. This study offers insights into understanding the complex nature of commitment to change, how to cultivate commitment to change, and how to use commitment to change as an intervention solution to reduce stress.
Part I: Development and optimization of solid‐lipid nanoparticles using Box–Behnken statistical design for ocular delivery of gatifloxacin
Authors: Kalam Mohd. Abul , Sultana Yasmin , Ali Asgar , Aqil Mohd. , Mishra Anil K. , Aljuffali Ibrahim A. , Alshamsan Aws
Published: December 2012

This study aims to improve gatifloxacin bioavailability to the eye using solid‐lipid nanoparticles (SLN). Cationic SLNs were prepared by o/w‐microemulsion method using stearylamine. The generated formulations were optimized by three‐factor, three‐level Box–Behnken statistical design. The independent variables were the lipidmix concentration (X1), poloxamers‐188 (X2), and sodium‐taurocholate (X3), while the dependent variables were drug release (Y1), encapsulation efficiency (EE) (Y2), and particle size (Y3) with applied constraints of maximizing drug release and EE and minimizing particle size. Response surface plots were drawn, statistical validity of the polynomials was established, optimized formulations were selected by feasibility and grid search, and the optimization process was validated. Particle size, polydispersity index, and zeta‐potentials were measured by photon correlation spectroscopy. Particle's morphology was evaluated by transmission electron microscopy. Differential scanning calorimetry (DSC) and wide‐angle X‐ray diffraction (WXRD) studies were performed to characterize state of drug and lipid modification. SLN size was (250–305 nm) and zeta‐potential (29–36 mV) after 3‐month storage. Entrapment efficiencies were 46.58 and 78.55%, and loading efficiencies were 29.60 and 20.70 for SLN‐C and SLN‐D, respectively. DSC and WXRD analyses showed low‐crystalline SLN and amorphous drug dispersion in SLN. In vitro release data were fitted to release kinetics equations, where the release pattern was found to follow Korsmeyer–Peppas model. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Robotic deposition and in vitro characterization of 3D gelatin−bioactive glass hybrid scaffolds for biomedical applications
Authors: Gao Chunxia , Rahaman Mohamed N. , Gao Qiang , Teramoto Akira , Abe Koji
Published: December 2012

The development of inorganic−organic hybrid scaffolds with controllable degradation and bioactive properties is receiving considerable interest for bone and tissue regeneration. The objective of this study was to create hybrid scaffolds of gelatin and bioactive glass (BG) with a controlled, three‐dimensional (3D) architecture by a combined sol−gel and robotic deposition (robocasting) method and evaluate their mechanical response, bioactivity, and response to cells in vitro. Inks for robotic deposition of the scaffolds were prepared by dissolving gelatin in a sol−gel precursor solution of the bioactive glass (70SiO2−25CaO−5P2O5; mol%) and aging the solution to form a gel with the requisite viscosity. After drying and crosslinking, the gelatin−BG scaffolds, with a grid‐like architecture (filament diameter ∼350 µm; pore width ∼550 µm), showed an elasto−plastic response, with a compressive strength of 5.1 ± 0.6 MPa, in the range of values for human trabecular bone (2−12 MPa). When immersed in phosphate‐buffered saline, the crosslinked scaffolds rapidly absorbed water (∼440% of its dry weight after 2 h) and showed an elastic response at deformations up to ∼60%. Immersion of the scaffolds in a simulated body fluid resulted in the formation of a hydroxyapatite‐like surface layer within 5 days, indicating their bioactivity in vitro. The scaffolds supported the proliferation, alkaline phosphatase activity, and mineralization of osteogenic MC3T3‐E1 cells in vitro, showing their biocompatibility. Altogether, the results indicate that these gelatin−BG hybrid scaffolds with a controlled, 3D architecture of inter‐connected pores have potential for use as implants for bone regeneration. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Low elastic modulus contributes to the osteointegration of titanium alloy plug
Authors: Zhang Yongquan , Wang Junlin , Wang Pan , Fan Xiangli , Li Xiaokang , Fu Jun , Li Shujun , Fan Hongbin , Guo Zheng
Published: December 2012

Resurfacing of cartilage defect with mini titanium plug is considered a promising alternative for the treatment of focal chondral defects. Elastic modulus of the metal implant plays a significant role in force transmission which influences the stability of plug. This study assessed the effects of two kinds of titanium alloy plug with different elastic modulus, that is, titanium 2448 (Ti2448) plug and titanium–6 aluminum–4 vanadium (TAV) plug on osteointegration. The full‐thickness chondral defects were created in bilateral knees of dogs and then TAV and Ti2448 plugs were implanted, respectively. After 12 weeks, radiographic evaluation did not reveal any signs of disassembly, subsidence, or periprosthetic radiolucency in both groups. Microcomputed tomography analysis revealed that bone histomorphometric parameters in Ti2448 group were all significantly better than those of TAV group. Furthermore, the value of pullout force in Ti2448 group was also significantly higher. Histology showed that the screw threads of Ti2448 plug were well integrated into the newly formed bone. In contrast, the trabecular bone was sparsely distributed around TAV plug. In conclusion, Ti2448 plug with low elastic modulus showed more favorable characteristics in osteointegration. Ti2448 may be a promising biomaterial for fabricating mini plug applied for cartilage resurfacing. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Trends in glycemic control over a 2‐year period in 126 US hospitals
Authors: Bersoux Sophie , Cook Curtiss B. , Kongable Gail L. , Shu Jianfen
Published: December 2012

BACKGROUND

Cross‐sectional data on inpatient glucose control in a large sample of US hospitals are now available, but little is known about changes in glycemic control over time in these institutions.

OBJECTIVE

To evaluate trends in glycemic control in US hospitals over 2 years.

DESIGN

Retrospective analysis.

METHODS

Point‐of‐care blood glucose (POC‐BG) test results at 126 hospitals during January to December 2007 and January to December 2009 were extracted using the Remote Automated Laboratory System‐Plus (Medical Automation Systems, Charlottesville, VA), and patient‐day‐weighted mean glucose levels were compared.

SETTING/PATIENTS

Hospitalized patients.

RESULTS

A total of 12,541,929 POC‐BG measurements from 1,010,705 patients were analyzed for 2007, and 10,659,418 POC‐BG measurements from 656,206 patients were analyzed for 2009. Patient‐day‐weighted mean POC‐BG in 2009 decreased by 5 mg/dL in the non‐intensive care unit (non‐ICU) data compared with that in 2007 (154 mg/dL vs 159 mg/dL, respectively; P < 0.001). However, POC‐BG values were clinically unchanged in intensive care unit (ICU) data from 2009 vs 2007 (167 mg/dL vs 166 mg/dL; P < 0.001). From 2007 to 2009, the proportion of patient‐day‐weighted mean POC‐BGs that were >180 mg/dL declined from 28% to 25% in non‐ICU patients (P < 0.001), but not in ICU. Decreases in patient‐day‐weighted mean POC‐BG values in non‐ICU patients were significant regardless of hospital size, type, and geographic region (all P < 0.001), but similar decreases were not found in ICU data.

CONCLUSIONS

In this first analysis of glucose changes in US hospitals, improvements over 2 years occurred in non‐ICU patients. Ongoing analysis will determine whether this trend continues. Journal of Hospital Medicine 2013;8:121–125. © 2012 Society of Hospital Medicine
Association of a functional polymorphism in the promoter region of TLR‐3 with osteoarthritis: A two‐stage case–control study
Authors: Yang Hsin‐Yi , Lee Herng‐Sheng , Lee Chian‐Her , Fang Wen‐Hui , Chen Hsiang‐Cheng , Salter Donald M. , Su Sui‐Lung
Published: December 2012

Recent studies have suggested that polymorphisms in toll‐like receptor 9 (TLR‐9), an endosomal TLR, are associated with knee osteoarthritis (OA). TLR‐3, ‐7, and ‐8 are also found on the surface of endosomes and to investigate whether similar associations exist with polymorphisms in these TLR genes we performed a two‐stage case–control study and genotyped 11 TLR single nucleotide polymorphisms (SNPs) in 823 OA cases and 594 healthy controls by polymerase chain reaction restriction fragment length polymorphism assays. Real‐time PCR was performed to assess the functional expression of an identified promoter polymorphism in TLR‐3 following dexamethasone stimulation of articular chondrocytes. An association between TLR‐3 SNPs at rs3775296 and rs3775290 and OA was identified in both populations. In males the allelic frequencies of TLR‐7 rs179010 and TLR‐8 rs5744080 were significantly different between OA cases and healthy controls. The ATCA, CTCA, and CCTA haplotypes of TLR‐3 were associated with OA susceptibility. A significant difference in TLR‐3 gene expression following dexamethasone treatment was seen among the various genotypes of rs3775296 (p = 0.004). Our findings indicate that a SNP in the promoter region of TLR‐3 is associated with elevated TLR‐3 gene expression and susceptibility to knee OA in a Chinese Han population. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 680–685, 2013
Selective laser melting‐produced porous titanium scaffolds regenerate bone in critical size cortical bone defects
Authors: Van der Stok Johan , Van der Jagt Olav P. , Amin Yavari Saber , De Haas Mirthe F. P. , Waarsing Jan H. , Jahr Holger , Van Lieshout Esther M. M. , Patka Peter , Verhaar Jan A. N. , Zadpoor Amir A. , Weinans Harrie
Published: December 2012

Porous titanium scaffolds have good mechanical properties that make them an interesting bone substitute material for large bone defects. These scaffolds can be produced with selective laser melting, which has the advantage of tailoring the structure's architecture. Reducing the strut size reduces the stiffness of the structure and may have a positive effect on bone formation. Two scaffolds with struts of 120‐µm (titanium‐120) or 230‐µm (titanium‐230) were studied in a load‐bearing critical femoral bone defect in rats. The defect was stabilized with an internal plate and treated with titanium‐120, titanium‐230, or left empty. In vivo micro‐CT scans at 4, 8, and 12 weeks showed more bone in the defects treated with scaffolds. Finally, 18.4 ± 7.1 mm3 (titanium‐120, p = 0.015) and 18.7 ± 8.0 mm3 (titanium‐230, p = 0.012) of bone was formed in those defects, significantly more than in the empty defects (5.8 ± 5.1 mm3). Bending tests on the excised femurs after 12 weeks showed that the fusion strength reached 62% (titanium‐120) and 45% (titanium‐230) of the intact contralateral femurs, but there was no significant difference between the two scaffolds. This study showed that in addition to adequate mechanical support, porous titanium scaffolds facilitate bone formation, which results in high mechanical integrity of the treated large bone defects. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 792–799, 2013
Interior penalty discontinuous Galerkin methods with implicit time‐integration techniques for nonlinear parabolic equations
Authors: Song Lunji , Gie Gung‐Min , Shiue Ming‐Cheng
Published: December 2012

We prove existence and numerical stability of numerical solutions of three fully discrete interior penalty discontinuous Galerkin methods for solving nonlinear parabolic equations. Under some appropriate regularity conditions, we give the l2(H1) and l∞(L2) error estimates of the fully discrete symmetric interior penalty discontinuous Galerkin–scheme with the implicit θ ‐schemes in time, which include backward Euler and Crank–Nicolson finite difference approximations. Our estimates are optimal with respect to the mesh size h. The theoretical results are confirmed by some numerical experiments. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Children's Oncology Group's 2013 blueprint for research: Non‐Hodgkin lymphoma
Authors: Bollard Catherine M. , Lim Megan S. , Gross Thomas G. ,   on behalf of the COG Non‐Hodgkin Lymphoma Committee
Published: December 2012

Non‐Hodgkin lymphomas account for approximately 7% of cancers diagnosed in patients less than 20 years of age, with approximately 800 cases diagnosed annually at COG institutions. With current therapies, cure rates range from 70% to over 90%, even for children with disseminated disease. However, two major challenges need to be overcome: (i) to optimize upfront treatment to prevent relapse since prognosis for patients with relapsed disease remains poor and (ii) minimize long‐term side effects in survivors. Hence, the future initiatives for the treatment of pediatric NHL are to utilize novel targeted therapies to not only improve outcomes but to decrease bystander organ toxicities and late effects. Pediatr Blood Cancer 2013; 60: 979–984. © 2012 Wiley Periodicals, Inc.
Children's Oncology Group's 2013 blueprint for research: Central nervous system tumors
Authors: Gajjar Amar , Packer Roger J. , Foreman N.K. , Cohen Kenneth , Haas‐Kogan Daphne , Merchant Thomas E. ,   on behalf of the COG Brain Tumor Committee
Published: December 2012

In the US, approximately 2,500 children are diagnosed annually with brain tumors. Their survival ranges from >90% to <10%. For children with medulloblastoma, the most common malignant brain tumor, 5‐year survival ranges from >80% (standard‐risk) to 60% (high‐risk). For those with high‐grade gliomas (HGGs) including diffuse intrinsic pontine gliomas, 5‐year survival remains <10%. Sixty‐five percent patients with ependymoma are cured after surgery and radiation therapy depending on the degree of resection and histopathology of the tumor. Phase II trials for brain tumors will investigate agents that act on cMET, PDGFRA, or EZH2 in HGG, DIPG, or medulloblastoma, respectively. Phase III trials will explore risk‐based therapy stratification guided by molecular and clinical traits of children with medulloblastoma or ependymoma. Pediatr Blood Cancer 2013; 60: 1022–1026. © 2012 Wiley Periodicals, Inc.
Children's Oncology Group's 2013 blueprint for research: Bone tumors
Authors: Gorlick Richard , Janeway Katherine , Lessnick Stephen , Randall R. Lor , Marina Neyssa ,   on behalf of the COG Bone Tumor Committee
Published: December 2012

In the US, approximately 650 children are diagnosed with osteosarcoma and Ewing sarcoma (ES) each year. Five‐year survival ranges from 65% to 75% for localized disease and <30% for patients with metastases. Recent findings include interval‐compressed five drug chemotherapy improves survival with localized ES. In osteosarcoma a large international trial investigating the addition of ifosfamide/etoposide or interferon to standard therapy has completed accrual. For ES an ongoing trial explores the addition of cyclophosphamide/topotecan to interval‐compressed chemotherapy. Trials planned by the Children's Oncology Group will investigate new target(s) including IGF‐1R and mTOR in ES, and RANKL and GD2 in osteosarcoma. Pediatr Blood Cancer 2013; 60: 1009–1015. © 2012 Wiley Periodicals, Inc.
Comparison of PET–CT and conventional imaging in staging pediatric rhabdomyosarcoma
Authors: Federico Sara M. , Spunt Sheri L. , Krasin Matthew J. , Billup Catherine A. , Wu Jianrong , Shulkin Barry , Mandell Gerald , McCarville M. Beth
Published: December 2012

Background

Over the past decade, PET–CT has been used to assess rhabdomyosarcoma (RMS) in children. However, the role of PET–CT in staging RMS is unknown.

Procedure

Thirty subjects with RMS, median age 7.3 years, underwent PET–CT before therapy. PET–CTs and conventional imaging (CI) were independently reviewed by two radiologists and two nuclear medicine physicians to determine the presence of metastases. Accuracy, sensitivity, and specificity of PET–CT for detecting metastases were compared to CI using biopsy and clinical follow‐up as reference standards. Maximum standardized uptake values (SUVmax) of primary tumors, lymph nodes, and pulmonary nodules were measured.

Results

Primary tumors had an average SUVmax of 7.2 (range, 2.5–19.2). Accuracy rates for 17 subjects with nodal disease were 95% for PET–CT and 49% for CI. PET–CT had 94% sensitivity and 100% specificity for nodal disease. Of seven pulmonary nodules detected by CI, three were not identified by PET–CT, two were indeterminate, and one was malignant with a SUVmax (3.4) > twice that of benign nodules. Two subjects had bone disease; both were identified by PET–CT but only one by CI. Four subjects had bone marrow disease, two had positive PET–CTs but none had positive CI. Two subjects had soft tissue metastases detected by PET–CT but not CI.

Conclusions

PET–CT performed better than CI in identifying nodal, bone, bone marrow, and soft tissue disease in children with RMS. CI remains essential for detection of pulmonary nodules. We recommend PET–CT for staging of children with RMS. CI with Tc99m bone scan can be eliminated. Pediatr Blood Cancer 2013; 60: 1128–1134. © 2012 Wiley Periodicals, Inc.
Effects of the functionalizing agent, itaconic acid, on the mechanical properties of microemulsion‐made core/shell polymers
Authors: Rabelero Martin , Trujillo Agustín , Ceja Israel , Canché Gonzálo , Mendizábal Eduardo , Esquena Jordi , Solans Conxita , Puig Jorge E.
Published: December 2012

The effect of itaconic acid (IA) as functionalizing agent on the static mechanical properties (Young's modulus, tensile stress, ultimate properties, and hardness) of core/shell polymers made of styrene and butyl acrylate by a two‐stage microemulsion polymerization process is reported. High‐polymer content (>35 wt%) was obtained in the first stage (seed) by adding more monomer semicontinuously to the parent microemulsion‐latex; however, the characteristics of microemulsion‐made latexes were preserved, that is, nanometer particles (<50 nm) and high molar masses (>2 × 106 g/mol). The IA content in the shell was varied from 0 to 20 wt% with respect to that of the polymer in the shell, either polystyrene or poly(butyl acrylate) (PBA). High conversions in both stages (>84 %), final core‐shell latex with relatively high‐polymer content (ca. 20 wt%), and particle with diameters smaller than 78 nm were obtained. The fact that particle size grew from the first (ca. 50 nm) to the second stages (ca. 75 nm) and that the polymers showed two glass transitions suggests that a core shell structure was obtained. The presence of the functionalizing agent (IA) modified the mechanical properties, especially when PBA was in the shell. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers.
Mechanical and crystalline properties of monomer casting Nylon‐6/Sio2 composites prepared via in situ polymerization
Authors: Xu Sheng , Zhao Xiaowen , Ye Lin
Published: December 2012

A series of monomer casting (MC) nylon‐6/SiO2 composites were prepared via in situ polymerization. It was found that the tensile strength, storage modulus, and notched charpy impact strength of the composites were improved and reached maximum at 3–5 wt% loading of SiO2. The α relaxation peak corresponding to the glass transition temperature (Tg) shifted to high temperature with increasing SiO2 content. Addition of SiO2 led to an increase of the melting and crystallization temperatures, and crystallinity. It also reduced the induction time of crystallization, advance the crystallization process of MC nylon‐6, and improve the crystal growth rate. The self‐nucleation crystallization analysis indicated that SiO2 particles played the role of facilitating the crystallization of the matrix mainly via accelerating the generation of crystal nucleus. By addition of SiO2 particles, the fracture surface of MC nylon‐6 changed to distant striations with many yield folds accompanied by a large number of stress whitening, displaying much obvious character of tough fracture. SiO2 particles can be pulled‐out under stress by being covered with MC nylon‐6 resin due to strong interfacial interaction and presented a skin–core structure. © 2012 Society of Plastics Engineers.
Synthesis of high molecular weight and narrow molecular weight distribution poly(acrylonitrile) via RAFT polymerization
Authors: Niu Shaogan , Zhang Lifen , Zhu Jian , Zhang Wei , Cheng Zhenping , Zhu Xiulin
Published: December 2012

Well‐defined polyacrylonitrile (PAN) of high viscosity‐average molecular weight (Mη = 405,100 g/mol) was successfully synthesized using reversible addition‐fragmentation chain transfer polymerization. The polymerization exhibits controlled characters: molecular weights of the resultant PANs increasing approximately linearly with monomer conversion and keeping narrow molecular weight distributions. The addition of 0.01 equiv (relative to monomer acrylonitrile) of Lewis acid AlCl3 in the polymerization system afforded the obtained PAN with an improved isotacticity (by 8%). In addition, the influence of molecular weights and molecular weight distributions of PANs on the morphology of the electrospun fibers was investigated. The results showed that, under the same conditions of electrospinning, average diameter (247–1094 nm) of fibers increased with molecular weights of PANs, and it was much easier to get “uniform” diameter fibers while using PANs with narrow molecular weight distributions as the precursor of electrospinning. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Molecular level studies of polymer behaviors at the water interface using sum frequency generation vibrational spectroscopy
Authors: Hankett Jeanne M. , Liu Yuwei , Zhang Xiaoxian , Zhang Chi , Chen Zhan
Published: December 2012

Industrial plastics, biomedical polymers and numerous other polymeric systems are contacted with water for everyday functions and after disposal. Probing the interfacial molecular interactions between widely used polymers and water yields valuable information that can be extrapolated to macroscopic polymer/water interfacial behaviors so scientists can better understand polymer bio‐compatibility, hygroscopic tendencies and improve upon beneficial polymer behavior in water. There is an ongoing concerted effort to elucidate the molecular level behaviors of polymers in water by using sum frequency generation vibrational spectroscopy (SFG). SFG stands out for its utility in probing buried interfaces in situ and in real time without disrupting interfacial chemistry. Included in this review are SFG water interfacial studies performed on poly(methacrylate) and (acrylate)s, poly(dimethyl siloxane)s, poly(ethylene glycol)s, poly(electrolyte)s and other polymer types. The driving forces behind common water/polymer interfacial molecular features will be discussed as well as unique molecular reorientation phenomena and resulting macroscopic behaviors from microscopic polymer rearrangement. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Morphology of polylactic acid crystallized during annealing after uniaxial deformation
Authors: Hébert Jean‐Sébastien , Wood‐Adams Paula , Heuzey Marie‐Claude , Dubois Charles , Brisson Josée
Published: December 2012

Uniaxial deformation of amorphous L‐polylactic acid films was performed at two different temperatures at which thermal degradation was minimal, 70 °C or Tg + 10 and 90 °C or Tg + 30. Samples were annealed postdeformation for long times (either 15 or 45 min) to approach equilibrium conditions. Samples deformed and annealed at 70 °C showed low crystallinity and poor crystalline order or crystal size, as determined by wide‐angle X‐ray diffraction. At 90 °C, high crystallinity and order parameters were observed. In addition, once the oriented chains had crystallized at this temperature, nonoriented chains also underwent crystallization, and a small fraction of nonordered crystal phase was therefore observed after long annealing times. These observations are explained on the basis of different morphologies in samples drawn at the two temperatures. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
A pulmonary exacerbation risk score among cystic fibrosis patients not receiving recommended care
Authors: Sawicki Gregory S. , Ayyagari Rajeev , Zhang Jie , Signorovitch James E. , Fan Liangyi , Swallow Elyse , Latremouille‐Viau Dominick , Wu Eric Q. , Shi Lizheng
Published: December 2012

Background

Pulmonary exacerbations (PEx) lead to substantial morbidity in cystic fibrosis (CF), and guidelines recommend chronic medication including dornase alfa and inhaled tobramycin. However PEx risk and medication use vary across patients.

Objective

To develop a PEx risk score among CF patients not receiving guideline‐recommended chronic respiratory medications.

Methods

A cohort of patients with FEV1%‐predicted between 25% and 75% without evidence of dornase alfa or inhaled tobramycin use in an index year, despite meeting guideline recommended criteria, was identified from the CF Foundation Patient Registry (2002–2008). This sample was randomly split into 2/3 for a development sample and 1/3 for a validation sample. A multivariable risk score was developed to predict PEx requiring hospitalization or home IV treatment using available patient characteristics. Its predictive performance was assessed in the validation sample.

Results

Among 3,069 patient‐years, 1,275 (42%) had PEx in the subsequent year. The risk score included, in order of decreasing impact on PEx risk, prior PEx,Pseudomonas aeruginosa, allergic bronchopulmonary aspergillosis, depression, methicillin‐resistantStaphylococcus aureus, CF‐related diabetes,Burkholderia cepacia, prior use of dornase alfa, bronchodilator use, prior use of inhaled tobramycin and lower FEV1%‐predicted. Stratifying patients by risk score in the validation sample identified actual risks ranging from 14% in the lowest decile to 90% in the highest. The c‐statistic was 0.8.

Conclusions

A PEx risk score for CF patients not receiving guideline‐recommended chronic therapies was developed and validated, and identified patients with a wide range of risk. This score could identify high‐risk patients in whom chronic therapies should be initiated or continued.Pediatr Pulmonol. 2013; 48:954–961.© 2012 Wiley Periodicals, Inc.
Hydrophobic Nano‐Silica for the Surface Modification of Graphite Flake
Authors: Ning Gongtao , Li Ping , Zhang Tonglai , Zhou Zunning , Li Dongyang
Published: December 2012

Graphite flake is an electromagnetic interference material of importance for IR screening. In this study, an attempt to improve the performance of graphite flake by coating it with nano‐silica using cyclomix (Hosokawa) and hybridizer (Nara) processes was made. Uncoated and coated graphite flakes were examined by scanning electron microscopy (SEM). It was shown that a more uniform coating was obtained using the hybridizer process. Coated graphite flake with a mass ratio of nano‐silica equal to 5.25 % exhibited the best hydrophobic properties. The test chamber experiments demonstrated that the deposition velocity of coated graphite flake decreased from 0.227 cm s−1 to 0.187 cm s−1 and its IR interference performance was improved, compared with uncoated graphite flake. The obtained results showed that the coatings on the graphite flake powder with hydrophobic nano‐silica enhanced the moisture resistance and electromagnetic interference performance of the graphite flake.
One thousand genomes imputation in the national cancer institute breast and prostate cancer cohort consortium aggressive prostate cancer genome‐wide association study
Authors: Machiela Mitchell J. , Chen Constance , Liang Liming , Diver W. Ryan , Stevens Victoria L. , Tsilidis Konstantinos K. , Haiman Christopher A. , Chanock Stephen J. , Hunter David J. , Kraft Peter ,   on behalf of the National Cancer Institute Breast and Prostate Cancer Cohort Consortium
Published: December 2012

BACKGROUND

Genotype imputation substantially increases available markers for analysis in genome‐wide association studies (GWAS) by leveraging linkage disequilibrium from a reference panel. We sought to (i) investigate the performance of imputation from the August 2010 release of the 1000 Genomes Project (1000GP) in an existing GWAS of prostate cancer, (ii) look for novel associations with prostate cancer risk, (iii) fine‐map known prostate cancer susceptibility regions using an approximate Bayesian framework and stepwise regression, and (iv) compare power and efficiency of imputation and de novo sequencing.

METHODS

We used 2,782 aggressive prostate cancer cases and 4,458 controls from the NCI Breast and Prostate Cancer Cohort Consortium aggressive prostate cancer GWAS to infer 5.8 million well‐imputed autosomal single nucleotide polymorphisms (SNPs).

RESULTS

Imputation quality, as measured by correlation between imputed and true allele counts, was higher among common variants than rare variants. We found no novel prostate cancer associations among a subset of 1.2 million well‐imputed low‐frequency variants. At a genome‐wide sequencing cost of $2,500, imputation from SNP arrays is a more powerful strategy than sequencing for detecting disease associations of SNPs with minor allele frequencies (MAF) above 1%.

CONCLUSIONS

1000GP imputation provided dense coverage of previously identified prostate cancer susceptibility regions, highlighting its potential as an inexpensive first‐pass approach to fine mapping in regions such as 5p15 and 8q24. Our study shows 1000GP imputation can accurately identify low‐frequency variants and stresses the importance of large sample size when studying these variants. Prostate 73: 677–689, 2013. © 2012 Wiley Periodicals, Inc.
Analysing malaria drug trials on a per‐individual or per‐clone basis: a comparison of methods
Authors: Jaki Thomas , Parry Alice , Winter Katherine , Hastings Ian
Published: December 2012

There are a variety of methods used to estimate the effectiveness of antimalarial drugs in clinical trials, invariably on a per‐person basis. A person, however, may have more than one malaria infection present at the time of treatment. We evaluate currently used methods for analysing malaria trials on a per‐individual basis and introduce a novel method to estimate the cure rate on a per‐infection (clone) basis. We used simulated and real data to highlight the differences of the various methods. We give special attention to classifying outcomes as cured, recrudescent (infections that never fully cleared) or ambiguous on the basis of genetic markers at three loci. To estimate cure rates on a per‐clone basis, we used the genetic information within an individual before treatment to determine the number of clones present. We used the genetic information obtained at the time of treatment failure to classify clones as recrudescence or new infections. On the per‐individual level, we find that the most accurate methods of classification label an individual as newly infected if all alleles are different at the beginning and at the time of failure and as a recrudescence if all or some alleles were the same. The most appropriate analysis method is survival analysis or alternatively for complete data/per‐protocol analysis a proportion estimate that treats new infections as successes. We show that the analysis of drug effectiveness on a per‐clone basis estimates the cure rate accurately and allows more detailed evaluation of the performance of the treatment. Copyright © 2012 John Wiley & Sons, Ltd.
Epigenetic Regulation of Nanog by MiR-302 Cluster-MBD2 Completes Induced Pluripotent Stem Cell Reprogramming
Authors: Lee Man Ryul , Prasain Nutan , Chae Hee-Don , Kim Young-June , Mantel Charlie , Yoder Mervin C. , Broxmeyer Hal E.
Published: December 2012

While most somatic cells undergoing induced pluripotent stem (iPS) cell reprogramming with Yamanaka factors accumulate at stable partially reprogrammed stages, the molecular mechanisms required to achieve full reprogramming are unknown. MicroRNAs (miRNAs) fine-tune mRNA translation and are implicated in reprogramming, but miRNA functional targets critical for complete iPS cell reprogramming remain elusive. We identified methyl-DNA binding domain protein 2 (MBD2) as an epigenetic suppressor, blocking full reprogramming of somatic to iPS cells through direct binding to NANOG promoter elements preventing transcriptional activation. When we overexpressed miR-302 cluster we observed a significant increase in conversion of partial to fully reprogrammed iPS cells by suppressing MBD2 expression, thereby increasing NANOG expression. Thus, expression of exogenous miR-302 cluster (without miR-367) is efficient in attaining a fully reprogrammed iPS state in partially reprogrammed cells by relieving MBD2-mediated inhibition of NANOG expression. Our studies provide a direct molecular mechanism involved in generating complete human iPS cell reprogramming to study disease pathogenesis, drug screening, and for potential cell-based therapies.
N=2 supergravity counterterms, off and on shell
Authors: Chemissany W. , Ferrara S. , Kallosh R. , Shahbazi C. S.
Published: December 2012

Abstract

We study N=2 supergravity deformed by a genuine supersymmetric completion of the λR
4 term, using the underlying off shell N=2 superconformal framework. The gauge-fixed superconformal model has unbroken local supersymmetry of N=2 supergravity with higher derivative deformation. Elimination of auxiliary fields leads to the deformation of the supersymmetry rules as well as to the deformation of the action, which becomes a Born-Infeld with higher derivative type action. We find that the gravitino supersymmetry deformation starts from
$ \lambda {\partial^4}{{\mathcal{F}}^3} $
and has higher graviphoton couplings. In the action there are terms
$ {\lambda^2}{\partial^8}{{\mathcal{F}}^6} $
and higher, in addition to original on shell counterterm deformation. These deformations are absent in the on shell superspace and in the candidate on shell counterterms of N=4, 8 supergravities, truncated down to N=2. We conclude therefore that the undeformed on shell superspace candidate counterterms break the N=2 part of local supersymmetry.
Good Candidates for a Third Liver Resection of Colorectal Metastasis
Authors: Yamazaki Shintaro , Takayama Tadatoshi , Okada Shunji , Iwama Atsuko , Midorikawa Yutaka , Moriguchi Masamichi , Nakayama Hisashi , Higaki Tokio , Sugutani Masahiko
Published: December 2012

Background

Having three liver resections for colorectal metastases has long been considered to be associated with a high risk of postoperative complications. The present study was designed to assess the feasibility and survival benefits of three liver resections.

Methods

Between 2004 and 2011, data for 273 consecutive patients with colorectal metastases were analyzed. The patient characteristics, tumor status, operation‐related variables, degree of liver steatosis, and short‐ and long‐term outcomes were compared according to the number of liver resections.

Results

The history of preoperative chemotherapy was higher for patients who had had three liver resections as compared with other resections: i.e., one resection 41.0 %, versus two resections 56.8 %, versus three resections 81.8 %; p = 0.04. Patients receiving three liver resections had a high rate of liver steatosis (17.9 vs. 32.4 vs. 59.1 %; p = 0.03). The median operative time for three resections was significantly longer than for the other resections (359 min [range: 115–579 min] vs. 395 min [range: 178–740 min], vs. 482 min [range: 195–616 min]; p = 0.04). However, the complication rate and the postoperative hospital stay did not differ among the three groups. The 1‐, 3‐ and 5‐year survival rates did not differ significantly among the three groups (83.3, 57.5, and 44.6 % for one resection vs. 92.3, 52.1, and 35.7 % for two resections vs. 93.3, 49.0, and 34.1 % for three resections). Patients who had <5 tumors at a third liver resection and a recurrence interval of ≥500 days from the second resection were good candidates for three resections.

Conclusions

Undergoing three resections of colorectal metastasis is feasible and provides a similar survival benefit as one or two resections, without increasing morbidity or mortality.
Medial Versus Lateral Approach in Laparoscopic Colorectal Resection: A Systematic Review and Meta‐analysis
Authors: Ding Jie , Liao Guo‐qing , Xia Yu , Zhang Zhong‐min , Pan Yang , Liu Sheng , Zhang Yi , Yan Zhong‐shu
Published: December 2012

Background

The aim of this study was to investigate the safety and efficacy of the medial approach (MA) and the lateral approach (LA) in the treatment of colorectal disease.

Methods

Studies published since 1994 that compared MA versus LA in laparoscopic colorectal resection were collected. Data on conversion rate, operative time, blood loss, number of harvested lymph nodes, hospital stay, complications, mortality, rate of recurrence, and hospitalization costs for MA and LA were meta‐analyzed using fixed‐effect and random‐effect models.

Results

Five cohort studies (2 randomized controlled trials and 3 retrospective studies) that included 881 patients were studied. Of these patients, 475 and 582 had undergone laparoscopic colorectal resection via MA and LA, respectively. There were significant reductions in conversion rate and operative time and possible reductions in blood loss and hospitalization costs for MA compared to LA; however, there were fewer harvested lymph nodes for MA compared with LA, which remains to be further studied. Other outcome variables such as postoperative complications, postoperative immune function, mortality, and rate of recurrence were not found to be statistically significant for either group. Sensitivity analysis on the pooled data from randomized controlled trials showed that the conversion rates were not significantly different between MA and LA.

Conclusions

Compared with the lateral approach, the medial approach has the advantages of shorter operative time and possibly lower conversion rate; it also can be as safe as the lateral approach. Whether the MA has less blood loss and lower hospitalization costs remains to be confirmed, and its oncological safety and long‐term prognosis are not clear. Due to insufficient data from a limited number of studies, inadequate assessment of the results may arise.
Long‐term Outcome after Proximal Gastrectomy with Jejunal Interposition for Gastric Cancer Compared with Total Gastrectomy
Authors: Nozaki Isao , Hato Shinji , Kobatake Takaya , Ohta Koji , Kubo Yoshirou , Kurita Akira
Published: December 2012

Background

Proximal gastrectomy (PG) has been widely accepted as treatment for early gastric cancer located in the upper third of the stomach. Reconstruction by jejunal interposition has been known to reduce reflux esophagitis for PG patients. The aim of this study was to compare the long‐term outcomes of patients who underwent PG with jejunal interposition with those treated by total gastrectomy (TG).

Methods

Data on 102 cases of PG with jejunal interposition and 49 cases of TG with Roux‐Y reconstruction for gastric cancer were analyzed retrospectively in terms of overall survival, weight maintenance, anemia and nutritional status, and endoscopic findings.

Results

Median follow‐up time was 59 months in the both groups. There was no significant difference in the overall 5‐year survival rate between the PG group (94 %) and the TG group (84 %). The PG group showed significantly better body weight maintenance at the first year. The laboratory blood tests showed that the PG group had a significantly better red blood cell count and hemoglobin and hematocrit levels at the second and third year. However, postoperative endoscopic surveillance detected reflux esophagitis (3 %), peptic ulcer (9 %), and metachronous gastric cancer (5 %) in the PG group.

Conclusions

Proximal gastrectomy maintains comparable oncological radicality to TG and is preferred over TG in terms of preventing postoperative anemia. However, periodic endoscopic follow‐up is necessary to monitor the upper gastrointestinal tract.
Changes in Developmental Contexts as Predictors of Transitions in HIV‐Risk Behaviors Among Young Men Who Have Sex with Men (YMSM)
Authors: Wong Carolyn F. , Schrager Sheree M. , Chou Chih-Ping , Weiss George , Kipke Michele D.
Published: December 2012

Emerging adulthood is a transitional time often marked by instability in many areas of life, including residential status, work, school, and romantic relationships. The purpose of this study is to examine transitions in HIV‐risk related behaviors among a cohort of ethnically‐diverse young men who have sex with men (YMSM) and to reveal how changes in developmental contexts during emerging adulthood might be associated with these behavioral changes. Hidden Markov models were used to examine movement across different stages of behavioral risk‐taking over time. Semi‐annual surveys were administered across 2 years; analyses included those with at least three of the five waves of data. Results indicated substantial movement at the individual‐level transitions. Additionally, high variability in sexual risk, alcohol misuse, and illicit drug‐risk behaviors was predicted by age, ethnicity, and correlates of emerging adulthood, such as residential status, work, post‐secondary school enrollment, and primary‐relationship status. Findings provide evidence of great change in risky behaviors among YMSM during this pivotal time, particularly among those who actively experiment in varying levels of risk‐taking. In order to prevent experimental behaviors from evolving into more serious risk, interventions must consider ways to assist YMSM to adjust to life changes brought on by emerging adulthood.