bluuebunny/crossref_metadata_2025_split huggingface dataset:
Occurrence and Production of Aluminum
Authors: Kvande Halvor 
Published: December 2015

Abstract

Production of primary aluminum involves two independent processes to transform the ore to the metal. It starts with the mineral bauxite, which has the highest grade of commercially mined metal ores, and is also the most easily purified. Bauxite typically contains about 50% aluminum oxide, while the rest of the mineral consists of oxides of iron, silicon, titanium, and other metals. Aluminum oxide (Al
2
O
3
), or alumina, is extracted from bauxite by means of the Bayer process. Then the alumina is electrolyzed in large electrolysis cells to produce molten aluminum by the Hall–Héroult process, named after the inventors. These two industrial processes were invented in 1886 and 1887, and for almost 130 years they have resisted numerous attempts to replace them with new alternative processes.

The aluminum industry is presently facing three main challenges: the economy, its electric energy consumption, and its carbon footprint. The economy has been difficult for several years, due to low metal prices, high global aluminum inventory, and current overcapacity and oversupply. Electric power dominates the cost, because even under ideal conditions alumina needs a large amount of energy to be reduced to aluminum, and in addition the process as conventionally conducted is not very energy efficient. Furthermore, the production of alumina and aluminum generates significant amounts of CO
2
, both from the chemistry of the reduction process itself and from the electric power plants based on fossil fuels such as coal and natural gas.

However, there are positive signs for the aluminum industry as well. The world will continue to need aluminum, and experts expect a doubling of the world's aluminum production from 2010 to 2020.
Quantitative Beladung eines Proteinkäfigs mit aktiven Enzymen
Authors: Azuma Yusuke , Zschoche Reinhard , Tinzl Matthias , Hilvert Donald 
Published: December 2015

AbstractProteine, die genetisch mit einer super‐positiv geladenen Variante des grün fluoreszierenden Proteins verbunden wurden, können quantitativ in ein Lumazin‐Synthase‐Kapsid geladen werden, das mit einer negativ geladenen Innenfläche ausgestattet ist. Dieses einfache System ist eine ebenso robuste wie vielseitige Methode, um hierarchisch geordnete Proteinkomplexe herzustellen, die dann als Nanoreaktoren verwendet werden können. Die allgemeine Anwendbarkeit dieser Beladungsstrategie und ihre Auswirkung auf die Enzymaktivität wurden mit acht strukturell und mechanistisch verschiedenen Enzymen untersucht.
Mass Determination of Entire Amyloid Fibrils by Using Mass Spectrometry
Authors: Doussineau Tristan , Mathevon Carole , Altamura Lucie , Vendrely Charlotte , Dugourd Philippe , Forge Vincent , Antoine Rodolphe 
Published: December 2015

AbstractAmyloid fibrils are self‐assembled protein structures with important roles in biology (either pathogenic or physiological), and are attracting increasing interest in nanotechnology. However, because of their high aspect ratio and the presence of some polymorphism, that is, the possibility to adopt various structures, their characterization is challenging and basic information such as their mass is unknown. Here we show that charge‐detection mass spectrometry, recently developed for large self‐assembled systems such as viruses, provides such information in a straightforward manner.
Ionic Covalent Organic Frameworks with Spiroborate Linkage
Authors: Du Ya , Yang Haishen , Whiteley Justin Michael , Wan Shun , Jin Yinghua , Lee Se‐Hee , Zhang Wei 
Published: December 2015

AbstractA novel type of ionic covalent organic framework (ICOF), which contains sp3 hybridized boron anionic centers and tunable countercations, was constructed by formation of spiroborate linkages. These ICOFs exhibit high BET surface areas up to 1259 m2 g−1 and adsorb a significant amount of H2 (up to 3.11 wt %, 77 K, 1 bar) and CH4 (up to 4.62 wt %, 273 K, 1 bar). Importantly, the materials show good thermal stabilities and excellent resistance to hydrolysis, remaining nearly intact when immersed in water or basic solution for two days. The presence of permanently immobilized ion centers in ICOFs enables the transportation of lithium ions with room‐temperature lithium‐ion conductivity of 3.05×10−5 S cm−1 and an average Li+ transference number value of 0.80±0.02. Our approach thus provides a convenient route to highly stable COFs with ionic linkages, which can potentially serve as absorbents for alternative energy sources such as H2, CH4, and also as solid lithium electrolytes/separators for the next‐generation lithium batteries.
Disentangling the urbanization effect, multi‐decadal variability, and secular trend in temperature in eastern China during 1909–2010
Authors: Qian Cheng 
Published: December 2015

AbstractUnderstanding surface air temperature (SAT) changes in China during the past 100 years is important; however, this is difficult because the impacts of multi‐decadal variability (MDV), the urbanization effect, and other anthropogenic forcings are combined in instrumental records. The present study attempts to disentangle these factors recorded in observations in eastern China based on recently homogenized SAT data during 1909–2010. The estimated linear trend (secular nonlinear trend) in the data after deurbanization is 1.08 (1.74)°C (100 years)−1. The MDV has enhanced warming in the early 20th century and during the past 30 years, contributing approximately 30% to the latter period.
Inference for low‐ and high‐dimensional multigroup repeated measures designs with unequal covariance matrices
Authors: Happ Martin , Harrar Solomon W. , Bathke Arne C. 
Published: December 2015

We propose tests for main and simple treatment effects, time effects, as well as treatment by time interactions in possibly high‐dimensional multigroup repeated measures designs. The proposed inference procedures extend the work by Brunner et al. (2012) from two to several treatment groups and remain valid for unbalanced data and under unequal covariance matrices. In addition to showing consistency when sample size and dimension tend to infinity at the same rate, we provide finite sample approximations and evaluate their performance in a simulation study, demonstrating better maintenance of the nominal α‐level than the popular Box‐Greenhouse–Geisser and Huynh–Feldt methods, and a gain in power for informatively increasing dimension. Application is illustrated using electroencephalography (EEG) data from a neurological study involving patients with Alzheimer's disease and other cognitive impairments.
A CatalyCEST MRI Contrast Agent that Can Simultaneously Detect Two Enzyme Activities
Authors: Fernández‐Cuervo Gabriela , Sinharay Sanhita , Pagel Mark D. 
Published: December 2015

AbstractThe simultaneous detection of multiple enzyme activities can improve the specificity of disease diagnoses. We therefore synthesized and characterized a diamagnetic chemical exchange saturation transfer (CEST) MRI contrast agent that can simultaneously detect two enzyme activities. Sulfatase and esterase enzymes cleave the ligands of the CEST agent, releasing salicylic acid that can be detected with CEST MRI. Importantly, both enzymes are required to activate the agent to produce a CEST MRI contrast, and the CEST agent was stable without enzyme treatment. These results established that this diamagnetic CEST MRI contrast agent is a platform technology with a modular design that can be potentially exploited to detect other combinations of enzyme activities, which can expand the armamentarium of contrast agents for molecular imaging.
Expression of osteoclastogenic factor transcripts in osteoblast‐like UMR‐106 cells after exposure to FGF‐23 or FGF‐23 combined with parathyroid hormone
Authors: Teerapornpuntakit Jarinthorn , Wongdee Kannikar , Krishnamra Nateetip , Charoenphandhu Narattaphol 
Published: December 2015

AbstractAs a bone‐derived hormone, fibroblast growth factor‐23 (FGF‐23) negatively regulates phosphate and calcium metabolism, while retaining growth‐promoting action for mesenchymal cell differentiation. Elevated FGF‐23 levels, together with hyperparathyroidism, are often observed in chronic kidney disease, which is associated with impaired bone mineralization and enhanced bone resorption. Although overexpression of osteoblast‐derived osteoclastogenic cytokines might contribute to this metabolic bone disease, whether FGF‐23 alone and FGF‐23 plus parathyroid hormone (PTH) directly modulated the expression of osteoblast‐derived osteoclastogenic genes remained elusive. Herein, we demonstrated the direct effects of FGF‐23 on proliferation and mRNA expression of osteoblast‐specific differentiation and osteoclastogenic markers in rat osteoblast‐like UMR‐106 cells in the presence or absence of PTH. FGF‐23 was found to suppress UMR‐106 cell proliferation, while increasing FGF‐23 expression, the latter of which suggested the presence of positive feedback regulation of FGF‐23 expression in osteoblasts. FGF‐23 also upregulated the mRNA expression of osteoblast differentiation markers (e.g., Runx2, osterix, AJ18, Dlx5, alkaline phosphatase, and osteopontin), osteoclastogenic factors (e.g., MCSF, MCP‐1, IL‐6, and TNF‐α), and bone resorption regulators (RANKL and osteoprotegerin). However, combined PTH and FGF‐23 exposure did not alter the levels of FGF‐23‐induced transcripts, suggesting that both hormones had no additive effect. In conclusion, FGF‐23 directly suppressed osteoblast proliferation, while inducing osteoclastogenic gene expression in UMR‐106 cells, and the FGF‐23‐induced transcripts were not altered by long‐standing PTH exposure.
Transcatheter aortic valve replacement versus surgical aortic valve replacement in patients with cirrhosis
Authors: Thakkar Badal , Patel Aashay , Mohamad Bashar , Patel Nileshkumar J. , Bhatt Parth , Bhimani Ronak , Patel Achint , Arora Shilpkumar , Savani Chirag , Solanki Shantanu , Sonani Rajesh , Patel Samir , Patel Nilay , Deshmukh Abhishek , Mohamad Tamam , Grines Cindy , Cleman Michael , Mangi Abeel , Forrest John , Badheka Apurva O. 
Published: December 2015

ObjectivesTo compare the in‐hospital outcomes in cirrhosis patients undergoing transcatheter aortic valve replacement (TAVR) versus those undergoing surgical aortic valve replacement (SAVR).BackgroundOver the last 10 years, TAVR has emerged as a therapeutic option for treating severe aortic stenosis in high‐risk patients. Cirrhosis patients have a high risk of operative morbidity and mortality while undergoing cardiac surgery. This study's hypothesis was that TAVR is a safer alternative compared to SAVR in cirrhosis patients.MethodsThe study population was derived from the National Inpatient Sample (NIS) for the years 2011–2012 using ICD‐9‐CM procedure codes 35.21 and 35.22 for SAVR, and 35.05 and 35.06 for TAVR. Patients <50 years of age and those who concomitantly underwent other valvular procedures were excluded. ICD‐9‐CM diagnosis codes were used to identify patients with liver cirrhosis, portal hypertension, and esophageal varices. Using propensity score matching, two matched cohorts were derived in which the outcomes were compared using appropriate statistical tests.ResultsThere were 30 patients in the SAVR and TAVR group each. Compared to the TAVR group, the patients in SAVR group had significantly higher rate of transfusion of whole blood or blood products (p = 0.037), longer mean postprocedural length of stay (p = 0.006), and nonsignificantly higher mean cost of hospitalization (p = 0.2), any complications rate (p = 0.09), and liver complications rate (p = 0.4). In‐hospital mortality rate was same in the both the groups. No patients in the TAVR group required open‐heart surgery or cardiopulmonary bypass.ConclusionTAVR could be a viable option for aortic valve replacement in cirrhosis patients. © 2015 Wiley Periodicals, Inc.
Transcatheter valve‐in‐ring implantation of a repositionable valve system for treatment of severe mitral regurgitation
Authors: Lauterbach Michael , Sontag Bruno , Paraforos Alexandros , Friedrich Ivar , Hauptmann Karl‐Eugen 
Published: December 2015

IntroductionYears after mitral valve surgery, progressive degeneration of reconstructed mitral valves or bioprostheses might lead to severe mitral valve regurgitation. Patients with significant comorbidity, or impaired left ventricular function are poor candidates for redo surgery at an acceptable risk at that later time point.Methods and resultsThis study reports the first‐in‐man transapical valve‐in‐ring implantations in the mitral position of the fully repositionable Lotus valve system approved for transcatheter aortic valve replacement in Europe. Transapical valve‐in‐ring implantations with this valve system were successfully performed in a 64‐year‐old female, and a 53‐year‐old male patient. Both patients were NHYA class IV, and carried an unacceptably high risk of cardiac surgery due to clinical condition and comorbidity. The first patient was successfully implanted a 25 mm valve, improved to NYHA class II, and was discharged 2 weeks after the procedure. The second patient required a short episode of cardiopulmonary resuscitation after valve implantation (27 mm), and was placed on veno‐venous ECMO for 24 hr to improve oxygenation. He developed stroke on day 7, and deceased from fatal, toxic rhabdomyolysis 13 days after the procedure.ConclusionTransapical valve‐in‐ring implantation of the repositionable Lotus valve system in the mitral position is a feasible and promising option that merits further evaluation. © 2015 Wiley Periodicals, Inc.
High‐dimensional quantitative structure–activity relationship modeling of influenza neuraminidase a/PR/8/34 (H1N1) inhibitors based on a two‐stage adaptive penalized rank regression
Authors: Algamal Zakariya Yahya , Lee Muhammad Hisyam , Al‐Fakih Abdo Mohammed 
Published: December 2015

AbstractOutliers in the biological activity variable or the heavy tailed distribution of the error are often encountered in practice. Under these circumstances, the quantittative structure–activity relationship (QSAR) model using multiple linear regression is not efficient. In this paper, a two‐stage adaptive penalized rank regression is proposed for constructing a robust and efficient high‐dimensional QSAR model of influenza virus neuraminidase A/PR/8/34 (H1N1) inhibitors. The results demonstrate the effectiveness of our proposed method in simultaneously estimating a robust QSAR model and selecting informative molecular descriptors. Furthermore, the results prove that the proposed method can significantly encourage the grouping effect. The proposed method, because of the high predictive ability and robustness, could be a useful method in high‐dimensional QSAR modeling. Copyright © 2015 John Wiley & Sons, Ltd.
Quantum Mechanics/Molecular Mechanics Modeling of Enzymatic Processes: Caveats and Breakthroughs
Authors: Quesne Matthew G. , Borowski Tomasz , de Visser Sam P. 
Published: December 2015

AbstractNature has developed large groups of enzymatic catalysts with the aim to transfer substrates into useful products, which enables biosystems to perform all their natural functions. As such, all biochemical processes in our body (we drink, we eat, we breath, we sleep, etc.) are governed by enzymes. One of the problems associated with research on biocatalysts is that they react so fast that details of their reaction mechanisms cannot be obtained with experimental work. In recent years, major advances in computational hardware and software have been made and now large (bio)chemical systems can be studied using accurate computational techniques. One such technique is the quantum mechanics/molecular mechanics (QM/MM) technique, which has gained major momentum in recent years. Unfortunately, it is not a black‐box method that is easily applied, but requires careful set‐up procedures. In this work we give an overview on the technical difficulties and caveats of QM/MM and discuss work‐protocols developed in our groups for running successful QM/MM calculations.
Small‐Molecule and Peptide Inhibitors of the Pro‐Survival Protein Mcl‐1
Authors: Beekman Andrew M. , Howell Lesley A. 
Published: December 2015

AbstractThe ability of protein–protein interactions to regulate cellular processes in both beneficial and detrimental ways has made them obvious drug targets. The Bcl‐2 family of proteins undergo a series of protein–protein interactions which regulate the intrinsic cell‐death pathway. The pro‐survival members of the Bcl‐2 family, including Bcl‐2, Bcl‐xL, and Mcl‐1, are commonly overexpressed in a number of human cancers. Effective modulators of members of the Bcl‐2 family have been developed and are undergoing clinical trials, but the efficient modulation of Mcl‐1 is still not represented in the clinic. In addition, Mcl‐1 is a major cause of resistance to radio‐ and chemotherapies, including inhibitors that target other Bcl‐2 family members. Subsequently, the inhibition of Mcl‐1 has become of significant interest to the scientific community. This review covers the progress made to date in modulating the activity of Mcl‐1, by both stapled peptides and small molecules. The development of peptides as drug candidates, and the advancement of experimental and computational techniques used to discover small molecules are also highlighted.
An optimized GPU‐based 2D convolution implementation
Authors: Perrot Gilles , Domas Stéphane , Couturier Raphaël 
Published: December 2015

SummaryWith the increasing sophistication of image processing algorithms, and because of its low computation complexity, convolution should fully benefit from the ever‐increasing capacities of state‐of‐the‐art graphics processing units, such as Nvidia's Kepler and Maxwell family cards. Currently, it tends to be used as a preprocessing stage within more intricate image manipulations and has recently been implemented quite efficiently by several teams. However, either their implementations do not come near hardware's peak performance or are unable to process large mask sizes. Such limitations are overrun by our original parallel register‐only convolution filter implementation of two‐dimensional convolution filters that can process 32‐bit floating‐point images on a NVidia K40 card using mask sizes up to 127×127 and at the same time achieving pixel throughputs over 29GP/s, which is, as far as we know, the highest rate known to date. Such results were obtained by using registers sparingly and by designing memory access patterns that cancel both load and store replays at warp levels, along with optimizing cache use. Copyright © 2015 John Wiley & Sons, Ltd.
Artificial Formation and Tuning of Glycoprotein Networks on Live Cell Membranes: A Single‐Molecule Tracking Study
Authors: Möckl Leonhard , Lindhorst Thisbe K. , Bräuchle Christoph 
Published: December 2015

AbstractWe present a method to artificially induce network formation of membrane glycoproteins and show the precise tuning of their interconnection on living cells. For this, membrane glycans are first metabolically labeled with azido sugars and then tagged with biotin by copper‐free click chemistry. Finally, these biotin‐tagged membrane proteins are interconnected with streptavidin (SA) to form an artificial protein network in analogy to a lectin‐induced lattice. The degree of network formation can be controlled by the concentration of SA, its valency, and the concentration of biotin on membrane proteins. This was verified by investigation of the spatiotemporal dynamics of the SA‐protein networks employing single‐molecule tracking. It was also proven that this network formation strongly influences the biologically relevant process of endocytosis as it is known from natural lattices on the cell surface.
Elucidation of the CO‐Release Kinetics of CORM‐A1 by Means of Vibrational Spectroscopy
Authors: Klein Moritz , Neugebauer Ute , Schmitt Michael , Popp Jürgen 
Published: December 2015

AbstractCO‐releasing molecules (CORMs) are developed for investigations of the interaction between the signaling molecule carbon monoxide (CO) and cells or tissue. Prior to their application these molecules must be fully characterized with respect to their CO‐release mechanism. One widely used CORM for biological application is sodium boranocarbonate (CORM‐A1), which shows pH‐dependent CO liberation. The complete reaction mechanism of CORM‐A1 is not fully understood yet. Therefore, in this contribution time‐resolved gas‐phase IR spectroscopy is used to monitor the headspace above decaying CORM‐A1 solutions at four different pH values (5.8 to 7.4). Borane carbonyl is found as an intermediate in the gas phase, which is formed during CORM degradation and further decays to CO. Concentration profiles of a pseudoconsecutive first‐order reaction are successfully fitted to specific band areas of the measured gas‐phase spectra, and the rate constants are obtained. The production of borane carbonyl is strongly pH dependent (half‐lives between 5 and 106 min), whereas the decay of borane carbonyl in the gas phase is nearly constant with a half‐life of about 33 min. The ratio of liberated CO molecules per CORM‐A1 is determined to be 0.91±0.09, and boric acid is identified as further end product.
Ultrafast Magic‐Angle Spinning: Benefits for the Acquisition of Ultrawide‐Line NMR Spectra of Heavy Spin‐ Nuclei
Authors: Pöppler Ann‐Christin , Demers Jean‐Philippe , Malon Michal , Singh Amit Pratap , Roesky Herbert W. , Nishiyama Yusuke , Lange Adam 
Published: December 2015

AbstractThe benefits of the ultrafast magic‐angle spinning (MAS) approach for the acquisition of ultrawide‐line NMR spectra—spectral simplification, increased mass sensitivity allowing the fast study of small amounts of material, efficient excitation, and application to multiple heavy nuclei—are demonstrated for tin(II) oxide (SnO) and the tin complex [(LB)SnIICl]+[SnIICl3]− [LB=2,6‐diacetylpyridinebis(2,6‐diisopropylanil)] containing two distinct tin environments. The ultrafast MAS experiments provide optimal conditions for the extraction of the chemical‐shift anisotropy tensor parameters, anisotropy, and asymmetry for heavy spin‐
nuclei.
A survey of IEEE 802.15.4 effective system parameters for wireless body sensor networks
Authors: Moravejosharieh Amirhossein , Lloret Jaime 
Published: December 2015

SummaryWireless body sensor networks are offered to meet the requirements of a diverse set of applications such as health‐related and well‐being applications. For instance, they are deployed to measure, fetch and collect human body vital signs. Such information could be further used for diagnosis and monitoring of medical conditions. IEEE 802.15.4 is arguably considered as a well‐designed standard protocol to address the need for low‐rate, low‐power and low‐cost wireless body sensor networks. Apart from the vast deployment of this technology, there are still some challenges and issues related to the performance of the medium access control (MAC) protocol of this standard that are required to be addressed. This paper comprises two main parts. In the first part, the survey has provided a thorough assessment of IEEE 802.15.4 MAC protocol performance where its functionality is evaluated considering a range of effective system parameters, that is, some of the MAC and application parameters and the impact of mutual interference. The second part of this paper is about conducting a simulation study to determine the influence of varying values of the system parameters on IEEE 802.15.4 performance gains. More specifically, we explore the dependability level of IEEE 802.5.4 performance gains on a candidate set of system parameters. Finally, this paper highlights the tangible needs to conduct more investigations on particular aspect(s) of IEEE 802.15.4 MAC protocol. Copyright © 2015 John Wiley & Sons, Ltd.