bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Chemistry of Silacyclopropenes
Authors: Ishikawa Mitsuo , Naka Akinobu , Ohshita Joji 
Published: August 2015

AbstractThe synthesis and reactions of silacyclopropenes are summarized. Addition of silylenes to acetylenes and photochemical isomerization of alkynyldisilanes are known as two major routes for the synthesis of silacyclopropenes. Silacyclopropenes had been thought to be highly reactive and difficult to handle until the first crystal structure of a stable one was reported in 1980. Currently, however, it is commonly accepted that those molecules are stable under ambient conditions when sufficiently bulky substituents are introduced onto the strained three‐membered ring system to stabilize it kinetically. The reactivity of silacyclopropenes is interesting and depends on the nature of substituents. They, indeed, undergo a variety of reactions, such as photolysis, thermolysis, and transition‐metal‐catalyzed reactions, leading to the formation of reactive intermediates including silylenes and silapropadienes, and their transition‐metal complexes, through which numerous transformations into silicon‐containing cyclic and acyclic compounds are possible.
Dendronisierte hochverzweigte Makromoleküle: weiche Materie mit einer neuartigen Segmentverteilung
Authors: Lederer Albena , Burchard Walther , Hartmann Tobias , Haataja Johannes S. , Houbenov Nikolay , Janke Andreas , Friedel Peter , Schweins Ralf , Lindner Peter 
Published: August 2015

AbstractDie Dendronisierung von hochverzweigten Polyestern mit Dendronen unterschiedlicher Generationen führt zu pseudo‐dendritischen Strukturen. Der hochverzweigte Kern wurde durch divergente Kopplung von geschützten Monomereinheiten an die funktionellen Gruppen modifiziert. Verglichen mit Dendrimeren ist der präparative Aufwand hier deutlich geringer; die Eigenschaften sind Dendrimeren höherer Generationen jedoch sehr ähnlich. Die Anzahl der funktionellen Gruppen, die Molmasse und das rheologische Verhalten von Dendrimeren höherer Generationen (G5–G8) wird schon von Pseudo‐Dendrimeren niedrigerer Generationen (G1–G4) widergespiegelt. Der Vergleich mit perfekten Dendrimeren hinsichtlich ihrer Segment‐ und internen Struktur ist mittels SANS, dynamischer Lichtstreuung und Viskositätsanalysen, Mikroskopie und molekulardynamischer Simulationen gegeben. Die Interpretation der Ergebnisse zeigt einzigartige strukturelle Eigenschaften auf, die auf einer niedrigeren Segmentdichte im Kern beruhen, der schon in der ersten Generation zu einer weichen nanoskaligen Kugel mit glatter Oberfläche wird.
Structural Insights into the Incorporation of the Mo Cofactor into Sulfite Oxidase from Site‐Directed Spin Labeling
Authors: Hahn Aaron , Engelhard Christopher , Reschke Stefan , Teutloff Christian , Bittl Robert , Leimkühler Silke , Risse Thomas 
Published: August 2015

AbstractMononuclear molybdoenzymes catalyze a broad range of redox reactions and are highly conserved in all kingdoms of life. This study addresses the question of how the Mo cofactor (Moco) is incorporated into the apo form of human sulfite oxidase (hSO) by using site‐directed spin labeling to determine intramolecular distances in the nanometer range. Comparative measurements of the holo and apo forms of hSO enabled the localization of the corresponding structural changes, which are localized to a short loop (residues 263–273) of the Moco‐containing domain. A flap‐like movement of the loop provides access to the Moco binding‐pocket in the apo form of the protein and explains the earlier studies on the in vitro reconstitution of apo‐hSO with Moco. Remarkably, the loop motif can be found in a variety of structurally similar molybdoenzymes among various organisms, thus suggesting a common mechanism of Moco incorporation.
B‐Cell Lymphoma‐2 Localization in the Female Reproductive Tract of the Chinese Soft‐Shelled Turtle, Pelodiscus Sinensis and Its Relationship With Sperm Storage
Authors: Le Yuan , Chen Shaofan , Hu Lisi , Zhang Linli , Ullah Shakeeb , Liu Tengfei , Yang Ping , Liu Yi , Chen Qiusheng 
Published: August 2015

ABSTRACTThe aim of the present study was to investigate the expression and localization of B‐cell lymphoma‐2 (Bcl‐2) in the oviduct of the Chinese soft‐shelled turtle, Pelodiscus sinensis, during the reproductive cycle to analyze the relationship between Bcl‐2 and sperm storage. Bcl‐2 expression was confirmed in the P. sinensis oviduct by western blot analysis. Hematoxylin‐eosin staining showed that female P. sinensis stored sperm from November to April of the following year. The oviduct showed positive immunostaining for Bcl‐2 of epithelial ciliated cells, gland ducts, and gland cells. Bcl‐2 expression in the oviduct was associated with sperm storage occurrence. This indicates that the survival factor Bcl‐2 may play a role in P. sinensis sperm storage. Anat Rec, 298:2011–2017, 2015. © 2015 Wiley Periodicals, Inc.
Fluorescence resonance energy transfer between bovine serum albumin and fluoresceinamine
Authors: Bai Zhijun , Liu Yushuang , Zhang Ping , Guo Jun , Ma Yuxing , Yun Xiaoling , Zhao Xinmin , Zhong Ruibo , Zhang Feng 
Published: August 2015

AbstractPhysical binding‐mediated organic dye direct‐labelling of proteins could be a promising technology for bio‐nanomedical applications. Upon binding, it was found that fluorescence resonance energy transfer (FRET) occurred between donor bovine serum albumin (BSA; an amphiphilic protein) and acceptor fluoresceinamine (FA; a hydrophobic fluorophore), which could explain fluorescence quenching found for BSA. FRET efficiency and the distance between FA and BSA tryptophan residues were determined to 17% and 2.29 nm, respectively. Using a spectroscopic superimposition method, the saturated number of FAs that bound to BSA was determined as eight to give a complex formula of FA8–BSA. Finally, molecular docking between BSA and FA was conducted, and conformational change that occurred in BSA upon binding to FA molecules was also studied by three‐dimensional fluorescence microscopy. Copyright © 2015 John Wiley & Sons, Ltd.
Adsorptive removal of dyes from synthetic and real textile wastewater using magnetic iron oxide nanoparticles: Thermodynamic and mechanistic insights
Authors: Nassar Nashaat N. , Marei Nedal N. , Vitale Gerardo , Arar Laith A. 
Published: August 2015

AbstractMagnetic iron‐oxide nanoparticles exhibit high efficiency in wastewater treatment for many important reasons, including that they can remove contaminants from wastewater rapidly owing to their high external surface area/unit mass and interstice reactivity. Additionally, this type of iron oxide can easily be separated using a magnet after finishing the treatment process, can be used as a catalyst for the decomposition of adsorbed contaminants and thus reduce sludge formation, and can cost‐effectively meet the environmental regulations for wastewater treatment since it can be prepared in situ where treatment is needed via various techniques. In this study, we use magnetic iron oxide nanoparticles for dye removal from synthetic and real textile wastewater for the first time. The effects of different experimental parameters on dye removal, such as contact time, initial concentration, solution pH, and coexisting ions, were investigated. Computational modelling of the interaction of different dye molecules with different surfaces of γ‐Fe2O3 nanoparticles is performed to obtain more mechanistic insights on the adsorption behaviour. The results showed that dye adsorption was fast, as external adsorption was dominated. The adsorption equilibrium data fit very closely to the Langmuir adsorption isotherm model, confirming monolayer adsorption, which is supported by the adsorption computational calculations. The adsorption was spontaneous, endothermic, and physical in nature.
Comprehensive experimental study and numerical simulation of vapour extraction (VAPEX) process in heavy oil systems
Authors: Mohammadpoor Mehdi , Torabi Farshid 
Published: August 2015

AbstractThere are significant heavy oil and bitumen resources in Canada. Global energy demand is rising while environmental constraints make heavy oil recovery more challenging. Therefore, looking for an economically viable and environmentally‐friendly heavy oil recovery technique is essential. Recently, solvent‐based heavy oil recovery techniques (i.e., VAPEX) have attracted attention due to their economic and environmental advantages over thermal methods. In this research, an extensive experimental and numerical simulation study on the VAPEX technique was carried out to provide more in‐depth information about key parameters which affect the ultimate performance of the VAPEX process. For this purpose, VAPEX experiments were conducted in two large‐scale physical models and various solvents were utilized. PVT experiments were also carried out, and CMG's STARSTM was used for numerical simulation studies and to history‐match the experimental results. Image analysis of the VAPEX chamber evolution showed that the highest sweep efficiency was observed after injecting propane, followed by butane, a propane/carbon dioxide mixture, a propane/methane mixture, carbon dioxide, and methane. The experiments were simulated numerically, and satisfactory history‐matching results were achieved. The major difference between the experimental and simulation results was observed after the first breakthrough of the solvent. In addition, the results showed that injection and production well configurations significantly affected the recovery performance of the process. A longer distance between the injection and production wells alongside the drainage height will increase the production rate in VAPEX.
Changes in body mass index in long‐term childhood cancer survivors
Authors: van Santen Hanneke M. , Geskus Ronald B. , Raemaekers Steven , van Trotsenburg A. S. Paul , Vulsma Thomas , van der Pal Helena J. H. , Caron Hubert N. , Kremer Leontien C. M. 
Published: August 2015

BACKGROUNDPrevious studies have reported changes in the body mass index (BMI) with time in childhood cancer survivors (CCSs) during follow‐up. The limitations of these studies include that they described only a subgroup of survivors or used questionnaires with self‐reported heights and weights. The goal of this study was to examine BMI in a large cohort of long‐term CCSs and relate this to the BMI at diagnosis, age, sex, tumor type, treatment, and endocrine defects.METHODSAll patients treated for childhood cancer at the Emma Children's Hospital/Academic Medical Center between 1966 and 1996 who had survived for at least 5 years were eligible for inclusion. For 893 CCSs with a mean follow‐up of 14.9 years, the BMI at the late effects outpatient clinic was compared with the BMI for the general Dutch population.RESULTSFor girls, an increased prevalence of obesity was found. Risk factors for developing a high BMI at follow‐up were a younger age and a high BMI at diagnosis and treatment with cranial radiotherapy. A significantly increased prevalence of severe underweight was found in all adult subgroups except for females aged 26 to 45 years. An association was found between a low BMI at diagnosis and a low BMI at follow‐up. No treatment‐related variables could be related to changes in BMI.CONCLUSIONSThe BMI at diagnosis is one of the most important predictors for the BMI at follow‐up, and this suggests an important genetic or environmental cause. Adult CCSs are at high risk for developing severe underweight at follow‐up. Future studies should focus on the causes and clinical consequences of underweight. Cancer 2015;121:4197–4204. © 2015 American Cancer Society.
Compiler transformation of nested loops for general purpose GPUs
Authors: Tian Xiaonan , Xu Rengan , Yan Yonghong , Chandrasekaran Sunita , Eachempati Deepak , Chapman Barbara 
Published: August 2015

SummaryManycore accelerators have the potential to significantly improve performance of scientific applications when offloading computationally intensive program portions to accelerators. Directive‐based high‐level programming models, such as OpenACC and OpenMP, are used to create applications for accelerators through annotating regions of code meant for offloading. OpenACC is an emerging directive‐based programming model for programming accelerators that typically enable inexperienced programmers to achieve portable and productive performance within applications. In this paper, we present our research in developing challenges and solutions when creating an open‐source OpenACC compiler in an industrial framework (OpenUH as a branch of Open64). We then discuss in detail techniques we developed for loop scheduling reduction operations on general purpose GPUs. The compiler is evaluated with benchmarks from the NAS Parallel Benchmarks suite and self‐written micro‐benchmarks for reduction operations. This implementation has been designed to serve as a compiler infrastructure for researchers to explore advanced compiler techniques, extend OpenACC to other programming models, and build performance tools used in conjunction with OpenACC programs. Copyright © 2015 John Wiley & Sons, Ltd.
The Transition States for CO2 Capture by Substituted Ethanolamines
Authors: Gangarapu Satesh , Marcelis Antonius T. M. , Alhamed Yahia A. , Zuilhof Han 
Published: August 2015

AbstractQuantum chemical studies are used to understand the electronic and steric effects on the mechanisms of the reaction of substituted ethanolamines with CO2. SCS‐MP2/6‐311+G(2d,2p) calculations are used to obtain the activation energy barriers and reaction energies for both the carbamate and bicarbonate formation. Implicit solvent effects are included with the universal solvation model SMD. Carbamate formation is more favorable than bicarbonate formation for monoethanolamine (MEA) both kinetically and thermodynamically. Increase of the steric hindrance on the C atoms around the N atom in substituted ethanolamines favors bicarbonate formation over carbamate formation with lower activation barriers and thereby higher reaction rates. In contrast, substitution by an N‐methyl or N‐ethyl group on MEA leads to a lower activation barrier for both carbamate formation and bicarbonate formation. As a result, higher reaction rates are expected as compared to MEA, and therefore these compounds have significant potential as industrial CO2 capturing solvents.
Validated MicroRNA Target Databases: An Evaluation
Authors: Ji (Diana) Lee Yun , Kim Veronica , Muth Dillon C. , Witwer Kenneth W. 
Published: August 2015

ABSTRACT

Preclinical Research

Positive findings from preclinical and clinical studies involving depletion or supplementation of microRNA (miRNA) engender optimism about miRNA‐based therapeutics. However, off‐target effects must be considered. Predicting these effects is complicated. Each miRNA may target many gene transcripts, and the rules governing imperfectly complementary miRNA: target interactions are incompletely understood. Several databases provide lists of the relatively small number of experimentally confirmed miRNA: target pairs. Although incomplete, this information might allow assessment of at least some of the off‐target effects. We evaluated the performance of four databases of experimentally validated miRNA: target interactions (miRWalk 2.0, miRTarBase, miRecords, and TarBase 7.0) using a list of 50 alphabetically consecutive genes. We examined the provided citations to determine the degree to which each interaction was experimentally supported. To assess stability, we tested at the beginning and end of a five‐month period. Results varied widely by database. Two of the databases changed significantly over the course of 5 months. Most reported evidence for miRNA: target interactions were indirect or otherwise weak, and relatively few interactions were supported by more than one publication. Some returned results appear to arise from simplistic text searches that offer no insight into the relationship of the search terms, may not even include the reported gene or miRNA, and may thus, be invalid. We conclude that validation databases provide important information, but not all information in all extant databases is up‐to‐date or accurate. Nevertheless, the more comprehensive validation databases may provide useful starting points for investigation of off‐target effects of proposed small RNA therapies. Drug Dev Res 76 : 389–396, 2015. © 2015 Wiley Periodicals, Inc.
Synthesis of CaTiO3 Nanofibers with Controllable Drug‐Release Kinetics
Authors: Zhang Qiuhong , Li Xiang , Ren Zhaohui , Han Gaorong , Mao Chuanbin 
Published: August 2015

AbstractCalcium titanate (CaTiO3) nanofibers with controlled microstructure were fabricated by a combination of sol–gel and electrospinning approaches. The fiber morphology has been found to rely significantly on the precursor composition. Altering the volume ratio of ethanol to acetic acid from 3.5 to 1.25 enables the morphology of the CaTiO3 nanofibers to be transformed from fibers with a circular cross section to curved ribbon‐like structures. Ibuprofen (IBU) was used as a model drug to investigate the drug‐loading capacity and drug‐release profile of the nanofibers. It was found that the BET surface area and the pore volume decrease markedly with the utilization of F127 surfactant. The nanofibers synthesized without F127 surfactant present the highest drug‐loading capacity and the most sustained release kinetics. This study suggests that calcium titanate nanofibers can offer a promising platform for localized drug delivery.
Postfunctionalization of the BODIPY Core: Synthesis and Spectroscopy
Authors: Boens Noël , Verbelen Bram , Dehaen Wim 
Published: August 2015

AbstractIn this review we describe the various new methodologies for synthetic postmodification of the BODIPY core designed and developed by our research groups, as well as their electronic spectroscopic properties. We discuss the different strategies created for functionalization of the BODIPY framework at the pyrrole C‐ring positions and the meso‐position. Halogenated boron dipyrrins are substrates for nucleophilic substitution or Pd‐catalyzed cross‐coupling reactions. α‐Unsubstituted BODIPYs can be functionalized with N and C nucleophiles through oxidative or vicarious nucleophilic substitution (VNS) of the α‐hydrogen atoms. Combining this methodology with reversible Michael addition onto nitrostyrenes provides a route to 3‐styrylated BODIPYs. Furthermore, the one‐step, Pd‐catalyzed C–H arylation of 3,5‐unsubstituted BODIPYs leads to 3‐ and 3,5‐arylated dyes. Finally, radical C–H arylation at the 3,5‐positions of α‐unsubstituted BODIPYs provides an additional synthesis route to arylated dyes.
Access to Indene Derivatives by a Sequence of Intermolecular anti‐Carbopalladation, Heck Reaction, and Electrophilic Attack
Authors: Pawliczek Martin , Jones Peter G. , Werz Daniel B. 
Published: August 2015

AbstractEnynes substituted with a tertiary hydroxyl group attached to one of the alkyne units react with iodobenzenes in a Pd‐catalyzed domino reaction. The cascade consists of an intermolecular anti‐carbopalladation and a terminating Heck reaction. This process leads to arene‐substituted dienes. One tetrasubstituted double bond is embedded in a six‐membered ring system, and the other trisubstituted alkene is located in an exocyclic position. On treatment with acid, the emerging tertiary carbocation is attacked by the arene to give a five‐membered ring, and thus results in the formation of alkylated indenes.
Improving the Conversion and Energy Efficiency of Carbon Dioxide Splitting in a Zirconia‐Packed Dielectric Barrier Discharge Reactor
Authors: Van Laer Koen , Bogaerts Annemie 
Published: August 2015

AbstractThe use of plasma technology for CO2 splitting is gaining increasing interest, but one of the major obstacles to date for industrial implementation is the considerable energy cost. We demonstrate that the introduction of a packing of dielectric zirconia (ZrO2) beads into a dielectric barrier discharge (DBD) plasma reactor can enhance the CO2 conversion and energy efficiency up to a factor 1.9 and 2.2, respectively, compared to that in a normal (unpacked) DBD reactor. We obtained a maximum conversion of 42 % and a maximum energy efficiency of 9.6 %. However, it is the ability of the packing to almost double both the conversion and the energy efficiency simultaneously at certain input parameters that makes it very promising. The improved conversion and energy efficiency can be explained by the higher values of the local electric field and electron energy near the contact points of the beads and the lower breakdown voltage, demonstrated by 2 D fluid modeling.
Altered prefrontal activity and connectivity predict different cognitive deficits in schizophrenia
Authors: Ferrarelli Fabio , Riedner Brady A. , Peterson Michael J. , Tononi Giulio 
Published: August 2015

AbstractBackgroundCognitive dysfunction is considered a core feature of schizophrenia, and impaired performances in episodic memory (EM) and executive function (EF) tasks are consistently reported in schizophrenia patients. Traditional fMRI and EEG studies have helped identifying brain areas, including the prefrontal cortex (PFC), involved in these tasks. However, it is unclear whether intrinsic defects in prefrontal function per se contribute to poor performance in schizophrenia, given the presence of confounds like reduced motivation and psychotic symptoms. TMS/hd‐EEG measurements are obtained without cognitive effort, and can be calculated in any cortical area.MethodsWe performed TMS/hd‐EEG recordings in parietal, motor, premotor, and PFC in healthy individuals (N = 20) and schizophrenia patients (N = 20). Source modeling of TMS‐evoked responses was performed, and measures of cortical activity (significant current density, SCD) and connectivity (significant current scattering, SCS) were computed. Patients with schizophrenia also performed Penn Word memory delayed (CPWd) and Penn Conditional Exclusion Test (PCET). CPWd evaluates EM and involves primarily PFC, whereas PCET reflects EF and implicates PFC with other brain regions.FindingsWe found no difference in SCD and SCS after TMS of parietal/motor cortices, whereas those parameters were reduced in premotor/prefrontal areas in schizophrenia patients. In PFC, where these measures were most defective, SCD was negatively correlated with performance in CPWd whereas higher SCS values were associated with more errors in PCET.ConclusionThese findings indicate that schizophrenia patients have intrinsic defects in both activity and connectivity of PFC, and that these defects are specifically associated with impairments in cognitive abilities. Hum Brain Mapp 36:4539–4552, 2015. © 2015 Wiley Periodicals, Inc.