bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ste24
Metalloproteases
Authors: Quigley Andrew , Pryor Edward E , Clark Kathleen M , Wiener Michael C , Carpenter Elisabeth P , Dumont Mark E 
Published: December 2015

Abstract

The transmembrane proteases of the Ste24 family catalyze dual proteolytic cleavages as part of a pathway of protein isoprenylation at
C
‐terminal CaaX (cysteine‐aliphatic‐aliphatic‐anything) sequences. The only known substrate for the yeast enzyme Ste24p is the precursor to the mating pheromone
a
‐factor. The only known substrate for the human enzyme ZMPSTE24 is prelamin A, the precursor to a nuclear scaffold protein. Defects in processing of prelamin A by ZMPSTE24 result in premature aging. The function of Ste24 enzymes appears to be conserved across eukaryotic organisms and more distantly related Ste24‐related proteases of the M48 family are found in all kingdoms of life. Ste24 enzymes are zinc metalloproteases containing a conserved HEXXH sequence motif. On the basis of the structures of the human and yeast enzymes, the active site of Ste24 exhibits striking structural similarity to that of the well‐studied zinc metalloprotease thermolysin. Significant aspects of Ste24 proteolysis, such as the basis for cleavage at multiple unrelated cleavage sites, the mechanisms of substrate access to the large internal cavity, and the relationship between Ste24 proteolysis and other steps of protein isoprenyl processing, remain to be defined.
Aluminum‐Based Catalysis
Authors: Mason Mark R. 
Published: December 2015

Abstract
The applications of aluminum compounds to homogeneous and heterogeneous catalyses are reviewed. This article starts with a brief overview of the synthesis, reactivity, and Lewis acidity of catalytically relevant aluminum alkyls, aluminum hydrides, and aluminum complexes, including insertion of small molecules into Al–H and Al–C bonds. The following section focuses on alkylaluminoxanes with emphasis on the synthesis, structure, and reactivity of methylaluminoxane (MAO) and modified methylaluminoxanes (MMAO). Polymerization and oligomerization of alkenes are the subjects of the next section. Coverage includes the use of organoaluminum activators, such as triethylaluminum, MAO, and MMAO, for large‐scale transition metal‐catalyzed reactions including Ziegler–Natta and single‐site metallocene‐catalyzed polymerization of alkenes and selective alkene dimerization and trimerization processes. Also discussed are aluminum‐catalyzed oligomerization of ethylene to long‐chain terminal alkenes, polymerization of ethylene by cationic aluminum complexes, and the Lewis pair polymerization of conjugated polar alkenes catalyzed by frustrated Lewis pairs of aluminum. The ring‐opening polymerization of epoxides, lactides, and lactones is then reviewed. Proposed monometallic and bimetallic mechanisms are discussed. This section also includes the aluminum‐catalyzed copolymerization of epoxides with carbon dioxide to give polycarbonates and conversion of epoxides to cyclic carbonates. The next‐to‐last section of this article overviews the roles of aluminum in heterogeneous catalysis, and includes acid‐catalyzed reactions on alumina, zeolites, and aluminophosphates. Transition metal catalysts supported on alumina are also discussed, both those where the transition metal is the active catalyst and bifunctional catalysts where both the alumina support and the transition metal contribute to the catalytic activity. This includes a brief discussion of large‐scale commercial processes such as methanol to olefins technology and the hydrodesulfurization, hydrodenitrogenation, catalytic cracking, and reforming of petroleum. The final section briefly provides a few examples of the applications of aluminum catalysts to organic synthesis and fine chemicals production. Readers are referred to leading works that more adequately describe the extensive use of homogeneous and heterogeneous aluminum catalysts in these areas. One hundred four reviews and original works are cited.
Diagnosing congenital syphilis using Hutchinson's method: Differentiating between syphilitic, mercurial, and syphilitic‐mercurial dental defects
Authors: Ioannou Stella , Sassani Sadaf , Henneberg Maciej , Henneberg Renata J. 
Published: December 2015

ABSTRACTObjectivesThis study focuses on the dental abnormalities observed by Sir Jonathan Hutchinson, Henry Moon and Alfred Fournier in patients with congenital syphilis and in those treated with mercury, in order to define alterations in dental morphology attributable to each of these causes. These definitions are applied to reported paleopathological cases, exploring various etiologies behind the defects, in order to aid in the diagnosis of congenital syphilis.MethodsOriginal works were examined for descriptions of dental abnormalities in congenital syphilis and in mercurial treatments. These descriptions were compared with dentitions of paleopathological cases (n = 4) demonstrating abnormalities attributed to congenital syphilis.ResultsDistinct morphological differences were recognized between congenital syphilitic teeth and teeth affected by mercury. Mercury produces a pronounced deficiency in enamel of incisors, canines and first permanent molars that become rugged and pitted, and of dirty grey honeycombed appearance. Mercury‐induced dental changes are evident in three out of four cases studied here. In one case, only syphilitic changes were present.DiscussionDental changes in congenital syphilis range from no visible signs to those beyond the classical models of Hutchinson, Moon and Fournier. Treatment of neonates and infants with mercury produces additional changes. Signs of disease and treatment with mercury on teeth may occur together; permanent incisors, first molars and canines, are typically affected, premolars and second/third molars are usually spared. Signs of treatment with mercury might be the only evidence of the occurrence of the disease as mercury was rarely used to treat other diseases. Am J Phys Anthropol 159:617–629, 2016. © 2015 Wiley Periodicals, Inc.
Ringmethylierung kontrolliert die Wasserstoffbrücken‐Andockstelle bei Anisol
Authors: Gottschalk Hannes C. , Altnöder Jonas , Heger Matthias , Suhm Martin A. 
Published: December 2015

AbstractEin Methanolmolekül kann mit seiner OH‐Gruppe entweder über einen OH⋅⋅⋅O‐ oder einen OH⋅⋅⋅π‐Kontakt an ein Anisolmolekül binden. Wie durch FTIR‐Absorptionsspektroskopie nachgewiesen wird, lässt sich das Verhältnis der Häufigkeiten dieser beiden Motive in Überschallexpansionen um eine Größenordnung verändern, indem Anisol am aromatischen Ring ein‐ bis dreifach methyliert oder mit einer tert‐Butylgruppe substituiert wird. Diese starke Abhängigkeit vom Methylierungsgrad liefert einen auf kJ mol−1 genauen Maßstab für die Vorhersagequalität quantenchemischer Methoden und kann zu einem besseren Verständnis von induktiven, mesomeren und dispersionsgesteuerten Effekten beitragen. Auf B3LYP‐D3/aVTZ‐Niveau mit Schwingungsnullpunktkorrektur gelingt eine ausgewogene Beschreibung der beiden Wasserstoffbrückenmotive, wie auch mit einem Wellenfunktions‐basierten Protokoll, das auf Einzelpunktrechnungen auf MP2‐ und CCSD(T)‐Niveau an den optimierten Strukturen basiert. Dagegen überschätzt das M06‐2X‐Funktional systematisch die Stabilität des OH⋅⋅⋅π‐Motivs.
[Cu(NHC)]‐Catalyzed C−H Allylation and Alkenylation of both Electron‐Deficient and Electron‐Rich (Hetero)arenes with Allyl Halides
Authors: Xie Weilong , Chang Sukbok 
Published: December 2015

AbstractNew reactivity of a [Cu(NHC)] (NHC=N‐heterocyclic carbene) catalyst is disclosed for the efficient C−H allylation of polyfluoroarenes using allyl halides in benzene at room temperature. The same catalyst system also promotes an isomerization‐induced alkenylation of initially the generated allyl arenes when the reaction is run in tetrahydrofuran. Significantly, not only electron‐deficient but also electron‐rich (hetero)arenes undergo this double‐bond migration process, thus leading to alkenylated products. The present system features mild reaction conditions, broad scope with respect to the arene substrates and allyl halide reactants, good functional‐group tolerance, and high stereoselectivity.
Quantitative Packaging of Active Enzymes into a Protein Cage
Authors: Azuma Yusuke , Zschoche Reinhard , Tinzl Matthias , Hilvert Donald 
Published: December 2015

AbstractGenetic fusion of cargo proteins to a positively supercharged variant of green fluorescent protein enables their quantitative encapsulation by engineered lumazine synthase capsids possessing a negatively charged lumenal surface. This simple tagging system provides a robust and versatile means of creating hierarchically ordered protein assemblies for use as nanoreactors. The generality of the encapsulation strategy and its effect on enzyme function were investigated with eight structurally and mechanistically distinct catalysts.
Control over the Hydrogen‐Bond Docking Site in Anisole by Ring Methylation
Authors: Gottschalk Hannes C. , Altnöder Jonas , Heger Matthias , Suhm Martin A. 
Published: December 2015

AbstractThe supramolecular docking of methanol to anisole may occur via an OH⋅⋅⋅O hydrogen bond or via an OH⋅⋅⋅π contact. The subtle balance between these two structures can be varied in supersonic jets by one order of magnitude through single to triple methylation of the aromatic ring and introduction of a single tert‐butyl substituent, as evidenced by infrared spectroscopy. This steep variation makes it possible to assess the accuracy of relative quantum‐chemical energy predictions on a kJ mol−1 level, promising insights into inductive, mesomeric, and dispersive effects. The zero‐point‐corrected B3LYP‐D3/aVTZ level is shown to provide an accurate relative description of the two very different hydrogen bonds, similar to a wavefunction‐based protocol including CCSD(T) corrections applied to the same structures. M06‐2X alone systematically overestimates the stability of π coordination.
Cyclohexane Rings Reduce Membrane Permeability to Small Ions in Archaea‐Inspired Tetraether Lipids
Authors: Koyanagi Takaoki , Leriche Geoffray , Onofrei David , Holland Gregory P. , Mayer Michael , Yang Jerry 
Published: December 2015

AbstractExtremophile archaeal organisms overcome problems of membrane permeability by producing lipids with structural elements that putatively improve membrane integrity compared to lipids from other life forms. Herein, we describe a series of lipids that mimic some key structural features of archaeal lipids, such as: 1) single tethering of lipid tails to create fully transmembrane tetraether lipids and 2) the incorporation of small rings into these tethered segments. We found that membranes formed from pure tetraether lipids leaked small ions at a rate that was about two orders of magnitude slower than common bilayer‐forming lipids. Incorporation of cyclopentane rings into the tetraether lipids did not affect membrane leakage, whereas a cyclohexane ring reduced leakage by an additional 40 %. These results show that mimicking certain structural features of natural archaeal lipids results in improved membrane integrity, which may help overcome limitations of many current lipid‐based technologies.
Solid state polymerization in a micro‐reactor: The case of poly(tetramethylene terephthalamide)
Authors: Papaspyrides Constantine D. , Porfyris Athanasios D. , Vouyiouka Stamatina , Rulkens Ruud , Grolman Eric , Poel Geert Vanden 
Published: December 2015

ABSTRACTThe aim of this work was to develop and optimize a direct solid state polymerization (DSSP) process on a micro scale for alkyldiammonium‐terephthalate salts. This was successfully demonstrated for the first time by the case of tetramethylenediammonium‐terepththalate salt (4T salt). The derived polymer (PA4T) presents interesting properties, but the temperature‐favored acid catalyzed cyclization of tetramethylenediamine (TMD) to mono‐functional pyrrolidine and ammonia inhibits a high polymerization conversion. DSSP was performed in a thermogravimetrical analysis (TGA) chamber, and the continuously monitored weight loss was correlated to polymerization conversion via the release of water, excluding any mass and heat transfer limitations. It was found that the conditions under which the DSSP is performed and the morphology of the starting material affect both the reaction rate and the product quality. The effect of the critical process parameters, namely vent size, heating rate to reach SSP temperature, and reaction temperature were quantified by the observed mass loss and by 1H NMR analysis. It was noticed that, besides the water formed by amidation, other volatile compounds were also released during the DSSP reaction, with main component, the TMD. In particular, it was observed that conditions favoring the evaporation of TMD also favored a higher reaction rate. The TMD loss was minimized by optimization of the aforementioned process conditions, leading to a more thermally stable and a higher molecular weight final product. The thermal stability of the PA4T was found to be inversely correlated to the concentration of carboxylic end groups present in the formed polymer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43271.
Maleopimaric acid‐modified two‐component waterborne polyurethane for coating applications
Authors: Si Hongyan , Liu He , Shang Shibin , Song Jie , Liao Shengliang , Wang Dan , Song Zhanqian 
Published: December 2015

ABSTRACTMaleopimaric acid (MPA), an important rosin derivative, was used to partially substitute isophthalic acid for the preparation of an anionic polyol (MPP) dispersion. The MPP dispersion was then applied to prepare a novel maleopimaric acid‐modified two‐component waterborne polyurethane (MPP‐2K‐WPU). The influences of NCO:OH molar ratio on the thermal properties, water absorption, surface free energy, and application properties of MPP‐2K‐WPU films were investigated. With increasing NCO:OH molar ratio, the thermal stability, pencil hardness, and ethanol resistance of MPP‐2K‐WPU films were improved, but the water resistance was enhanced firstly and then weakened. The surface free energy of MPP‐2K‐WPU films mainly depended on the dispersion interaction which was related to the structure of macromolecules. In addition, compared with the control sample of PP‐2K‐WPU(1.5:1) film, the MPP‐2K‐WPU(1.5:1) film exhibited improved thermal stability, water resistance, gloss, pencil hardness, and ethanol resistance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43292.
Sustained release of potassium diclofenac from a pH‐responsive hydrogel based on gum arabic conjugates into simulated intestinal fluid
Authors: Reis Adriano V. , Moia Thais A. , Sitta Danielly L. A. , Mauricio Marcos R. , Tenório‐Neto Ernandes T. , Guilherme Marcos R. , Rubira Adley F. , Muniz Edvani C. 
Published: December 2015

ABSTRACTThis work describes the preparation, the swelling properties and the potassium diclofenac (KDF) release profile of hydrogels of gum arabic (GA), N′,N′‐dimethylacrylamide, and methacrylic acid. In order to convert GA into a hydrogel, the polysaccharide was vinyl‐modified with glycidyl methacrylate. The hydrogels showed pH‐responsive swelling changes, which were more expressive in the basic environment. Release data of KDF were adjusted to a diffusion‐based kinetic model that provides an important insight on affinity of the drug for hydrogel and solvent, which may be the leading parameter for release of guest molecules from polymers. The KDF release from the hydrogels into simulated intestinal fluid decreases when the amount of modified GA increases. This was demonstrated to be due to the higher affinity of KDF for GA‐richer hydrogel, which makes the anti‐inflammatory release less favorable. The analysis of released drug half‐time (t1/2 = 16.10 and 21.51 h) indicated sustained release characteristics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43319.
Incorporation of Hexa‐peri‐hexabenzocoronene (HBC) into Carbazole–Benzo‐2,1,3‐thiadiazole Copolymers to Improve Hole Mobility and Photovoltaic Performance
Authors: Gao Chen , Jiang Pei , Shi Keli , Ma Di , Li Yongfang , Yu Gui , Li Xiaoyu , Wang Haiqiao 
Published: December 2015

AbstractHexa‐peri‐hexabenzocoronene (HBC) is a discotic‐shaped conjugated molecule with strong π–π stacking property, high intrinsic charge mobility, and good self‐assembly properties. For a long time, however, organic photovoltaic (OPV) solar cells based on HBC demonstrated low power conversion efficiencies (PCEs). In this study, two conjugated terpolymers, poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5′‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)] (PCDTBT)‐5 HBC and PCDTBT‐10 HBC, were synthesized by incorporating different amounts of HBC as the third component into poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5′‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)] (PCDTBT) through Suzuki coupling polymerization. For comparison, the donor–acceptor (D–A) conjugated dipolymer PCDTBT was also synthesized to investigate the effect of HBC units on conjugated polymers. The HBC‐containing polymers exhibited higher thermal stabilities, broader absorption spectra, and lower highest‐occupied molecular orbital (HOMO) energy levels. In particular, the field‐effect mobilities were enhanced by more than one order of magnitude after the incorporation of HBC into the conjugated polymer backbone on account of increased interchain π–π stacking interactions. The bulk heterojunction (BHJ) polymer solar cells (PSCs) fabricated with the polymers as donor and PC71BM as acceptor demonstrated gradual improvement of open‐circuit voltage (VOC) and short‐circuit current (JSC) with the increase in HBC content. As a result, the PCEs were improved from 3.21 % for PCDTBT to 3.78 % for PCDTBT‐5 HBC and then to 4.20 % for PCDTBT‐10 HBC.
A Pyrene‐functionalized Polynorbornene for Ratiometric Fluorescence Sensing of Pyrophosphate
Authors: Ge Jin‐Zhu , Liu Zhanghua , Cao Qian‐Yong , Chen Yong , Zhu Jiang‐Hua 
Published: December 2015

AbstractA novel pyrene‐functionalized polynorbornene (P1) bearing sulfonamide NH and triazolium donors has been synthesized for ratiometric fluorescence sensing of PPi in aqueous solution. In addition, P1 is also used to monitor intracellular PPi and to detect PPi released during polymerase chain reaction.
Regulation of mesenchymal stem cell 3D microenvironment: From macro to microfluidic bioreactors
Authors: Sart Sébastien , Agathos Spiros N. , Li Yan , Ma Teng 
Published: December 2015

AbstractHuman mesenchymal stem cells (hMSCs) have emerged as an important cell type in cell therapy and tissue engineering. In these applications, maintaining the therapeutic properties of hMSCs requires tight control of the culture environments and the structural cell organizations. Bioreactor systems are essential tools to achieve these goals in the clinical‐scale expansion and tissue engineering applications. This review summarizes how different bioreactors provide cues to regulate the structure and the chemico‐mechanical microenvironment of hMSCs with a focus on 3D organization. In addition to conventional bioreactors, recent advances in microfluidic bioreactors as a novel approach to better control the hMSC microenvironment are also discussed. These advancements highlight the key role of bioreactor systems in preserving hMSC's functional properties by providing dynamic and temporal regulation of in vitro cellular microenvironment.
Case-matched comparison of ABO-incompatible and ABO-compatible living donor liver transplantation
Authors: Kim J M , Kwon C H D , Joh J-W , Han S B , Sinn D H , Choi G-S , Kang E-S , Lee J H , Kim G S , Lee S-K 
Published: December 2015

Abstract

Background
ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) has a high success rate. There are few detailed comparisons regarding biliary complications, infective complications and patient survival between ABO-compatible (ABO-C) and ABO-I LDLT. The aim was to compare the outcomes of ABO-I LDLT with those of ABO-C LDLT using the matched-pairs method.

Methods
Patients who underwent ABO-I LDLT procedures between 2010 and 2013 were studied. They were matched for significant variables with patients who had ABO-C LDLT (1 : 2 matching).

Results
Forty-seven ABO-I LDLT procedures were included. Ninety-four patients who had ABO-C LDLT were selected as a comparator group. The incidence of cytomegalovirus, bacterial and fungal infections during the first 3 months was similar after ABO-I LDLT and ABO-C LDLT (85 versus 76 per cent, 28 versus 37 per cent, and 13 versus 20 per cent, respectively). Antibody-mediated rejection occurred after two procedures within 2 weeks of transplantation, but liver function improved with plasma exchange in both patients. There were no differences in the rate of acute rejection and biliary complications between ABO-I and ABO-C groups (P = 0·478 and P = 0·511 respectively). Three patients who had ABO-I LDLT developed diffuse intrahepatic biliary complications and progressed to graft failure. The 1-, 2- and 3-year patient survival rates after ABO-I LDLT and ABO-C LDLT were 89 versus 87 per cent, 85 versus 83 per cent, and 85 versus 79 per cent, respectively.

Conclusion
The short-term outcomes of ABO-I LDLT were comparable to those of ABO-C LDLT in this study. ABO-I LDLT is an effective and safe transplant option with the potential to expand the pool of live donors.
Clinical outcomes of left hepatic trisectionectomy for hepatobiliary malignancy
Authors: Farid S G , White A , Khan N , Toogood G J , Prasad K R , Lodge J P A 
Published: December 2015

Abstract

Background
Left hepatic trisectionectomy (LHT) is a challenging major anatomical hepatectomy with a high complication rate and a worldwide experience that remains limited. The aim of this study was to describe changes in surgical practice over time, to analyse the outcomes of patients undergoing LHT for hepatobiliary malignancy, and to identify factors associated with morbidity and mortality.

Methods
A cohort study was undertaken of patients who underwent LHT at a single tertiary hepatobiliary referral centre between January 1993 and March 2013. Univariable and multivariable analysis was used to identify factors associated with short- and long-term outcomes following LHT.

Result
Some 113 patients underwent LHT for colorectal liver metastasis (57), hilar cholangiocarcinoma (22), intrahepatic cholangiocarcinoma (12) and hepatocellular carcinoma (11); 11 patients had various other indications. Overall morbidity and 90-day mortality rates were 46·0 and 9·7 per cent respectively. Overall 1- and 3-year survival rates were 71·3 and 44·4 per cent respectively. Total hepatic vascular exclusion and intraoperative blood transfusion were independent predictors of postoperative morbidity, whereas blood transfusion was the only factor predictive of in-hospital mortality. Time period analysis revealed a decreasing trend in blood transfusion, duration of hospital stay, and postoperative morbidity and mortality in the last 5 years.

Conclusion
Morbidity, mortality and long-term survival after LHT support its use in selected patients with a significant tumour burden.