bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper‐Mediated Formation of Aryl, Heteroaryl, Vinyl and Alkynyl Difluoromethylphosphonates: A General Approach to Fluorinated Phosphate Mimics
Authors: Ivanova Maria V. , Bayle Alexandre , Besset Tatiana , Poisson Thomas , Pannecoucke Xavier 
Published: September 2015

AbstractA general and efficient access to aryl, heteroaryl, vinyl and alkynyl difluoromethylphosphonates is described. The developed methodology using TMSCF2PO(OEt)2, iodonium salts and a copper salt provided a straightforward manifold to reach these highly relevant products. The reaction proved to be highly functional group tolerant and proceeded under mild conditions, giving the corresponding products in good to excellent yields. This method represents the first general synthetic route to this important class of fluorinated scaffolds, which are well‐recognized as in vivo stable phosphate surrogates.
Bioorthogonal Enzymatic Activation of Caged Compounds
Authors: Ritter Cornelia , Nett Nathalie , Acevedo‐Rocha Carlos G. , Lonsdale Richard , Kräling Katja , Dempwolff Felix , Hoebenreich Sabrina , Graumann Peter L. , Reetz Manfred T. , Meggers Eric 
Published: September 2015

AbstractEngineered cytochrome P450 monooxygenase variants are reported as highly active and selective catalysts for the bioorthogonal uncaging of propargylic and benzylic ether protected substrates, including uncaging in living E. coli. observed selectivity is supported by induced‐fit docking and molecular dynamics simulations. This proof‐of‐principle study points towards the utility of bioorthogonal enzyme/protecting group pairs for applications in the life sciences.
Endothelial Cells Expressing Endothelial and Mesenchymal Cell Gene Products in Lung Tissue From Patients With Systemic Sclerosis–Associated Interstitial Lung Disease
Authors: Mendoza Fabian A. , Piera‐Velazquez Sonsoles , Farber John L. , Feghali‐Bostwick Carol , Jiménez Sergio A. 
Published: September 2015

ObjectiveTo examine whether lung endothelial cells (ECs) from patients with systemic sclerosis (SSc)–associated interstitial lung disease (ILD) express mesenchymal cell–specific proteins and gene transcripts, indicative of the occurrence of endothelial‐to‐mesenchymal phenotypic transition (EndoMT).MethodsLung tissue from 6 patients with SSc‐associated pulmonary fibrosis was examined by histopathology and immunohistochemistry. Confocal laser microscopy was utilized to assess the simultaneous expression of EC and myofibroblast molecular markers. CD31+CD102+ ECs were isolated from the lung tissue of 2 patients with SSc‐associated ILD and 2 normal control subjects, and the expression of EC and mesenchymal cell markers and other relevant genes was analyzed by quantitative polymerase chain reaction, immunofluorescence microscopy, and Western blotting.ResultsImmunohistochemical staining revealed cells expressing the EC‐specific marker CD31 in the subendothelial, perivascular, and parenchymal regions of the lungs from all SSc patients. Confocal microscopy identified cells displaying simultaneous expression of von Willebrand factor and α‐smooth muscle actin in small and medium‐sized arterioles in the SSc lung tissue but not in normal control lungs. CD31+CD102+ ECs isolated from SSc lungs expressed high levels of mesenchymal cell–specific genes (type I collagen, type III collagen, and fibronectin), EC‐specific genes (type IV collagen and VE‐cadherin), profibrotic genes (transforming growth factor β1 and connective tissue growth factor), and genes encoding EndoMT‐related transcription factors (TWIST1 and SNAI2).ConclusionCells coexpressing EC‐ and mesenchymal cell–specific molecules are present in the lungs of patients with SSc‐associated ILD. CD31+CD102+ ECs isolated from SSc lungs simultaneously expressed mesenchymal cell– and EC‐specific transcripts and proteins. Collectively, these observations demonstrate the occurrence of EndoMT in the lungs of patients with SSc‐associated ILD.
Short‐Term Total Hip Arthroplasty Outcomes in Patients With Psoriatic Arthritis or Psoriatic Skin Disease Compared to Patients With Osteoarthritis
Authors: Mandl Lisa A. , Zhu Rebecca , Huang Wei‐Ti , Zhang Meng , Alexiades Michael M. , Figgie Mark P. , Goodman Susan M. 
Published: September 2015

ObjectiveOutcomes of total hip arthroplasty (THA) in patients with psoriasis have been poorly studied. This study was undertaken to assess whether patients with psoriatic arthritis (PsA) or those with cutaneous psoriasis (PsC) without evidence of inflammatory joint disease are at an increased risk for worse outcomes after THA as compared to patients with osteoarthritis (OA).MethodsAmong subjects in a prospective THA registry, PsA and PsC cases were identified by International Classification of Diseases, Ninth Revision codes, and all cases were matched with patients with OA as controls. Analyses were performed to identify predictors of poor postoperative pain or function.ResultsOf the 289 potential cases of PsA or PsC, 63 with PsA and 153 with PsC were validated. Self‐report data were available postoperatively from 75% of PsA patients, 69% of PsC patients, and 94% of OA controls. In total, 51% of PsA patients and 56% of PsC patients were male, compared to 45% of OA controls (P = 0.04). Body mass index was higher in those with PsA or PsC (P = 0.002 versus controls). There were no differences in race or education between the 3 groups. PsA patients and PsC patients had more comorbidities than OA controls. PsA patients were more likely than PsC patients and OA controls to be current or previous smokers. Moreover, 54% of PsA patients were being treated with biologics or nonbiologic disease‐modifying antirheumatic drugs, compared to 8% of PsC patients. There were no significant differences in pre‐ or postoperative Western Ontario and McMaster Universities OA Index scores for pain or function between the 3 groups. Short‐Form 36 mental component summary scores were significantly better in the OA controls, both pre‐ and postoperatively (P = 0.006 and P < 0.001, respectively, versus PsA or PsC). EuroQol 5‐domain health‐related quality of life scores were significantly worse postoperatively for those with PsA or PsC (P < 0.0001 versus OA controls). In regression analyses, neither PsA nor PsC were risk factors for worse THA outcomes. Satisfaction with the outcomes of THA was similarly high among all 3 groups (P = 0.54).ConclusionNeither PsA nor PsC are risk factors for poor outcomes after THA. This is important information to convey to patients with either PsA or PsC who are contemplating surgical intervention with THA.
Variable stars in the Bochum Galactic Disk Survey
Authors: Kaderhandt L. , Barr Domínguez A. , Chini R. , Hackstein M. , Haas M. , Pozo Nuñez F. , Murphy M. 
Published: September 2015

AbstractWe present a first overview of variable stars in the Bochum Galactic Disk Survey (GDS) with emphasis on eclipsing binaries (EBs). This ongoing survey is performed by a robotic twin refractor at the Universitätssternwarte Bochum located near Cerro Armazones in Chile. It comprises a mosaic of 268 fields in a stripe of Δb = ±3° along the Galactic plane observed once per month simultaneously in the Sloan r and i filters with a detection limit of rs ∼ 16 mag and is ∼ 15 mag. The data from the first three years until the end of February 2014 yields a total of 41718 variable stars with variability amplitudes between 0.1–6 mag. A cross‐match with SIMBAD identified 11 465 of these variables unambiguously, while 2184 had multiple matches; most of the remaining stars could be matched with 2MASS objects. Among the SIMBAD‐listed objects with single matches, only 1982 turned out as known variables while a further 256 are suspected of variability. That leaves a total of 39480 potentially new variables. The group of known variables comprises 419 stars (21 %) that are classified as EBs while 443 (22%) are of other types; for the remaining 1120 catalogued variables (57 %) the type is unknown. Investigating variability as a function of spectral type, we find that SIMBAD provides spectral types for 2811 (25 %) of the identified stars. Spectral classes B (26 %), A (20 %), and M (25%) contain the most numerous variables, while all other classes contribute less than 10% each. More than half of the B (55 %) and A (56%) stars are designated as EBs, suggesting that hundreds of new B‐ and A‐type EBs may be contained in the GDS archive. In contrast, among the numerous M stars no EBs are known. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Formation of accretion centers in simulations of colliding uniform density H2 cores
Authors: Arreaga‐García G. , Klapp J. 
Published: September 2015

AbstractWe test here the first stage of a route of modifications to be applied to the public GADGET2 code for dynamically identifying accretion centers during the collision process of two adjacent and identical gas cores. Each colliding core has a uniform density profile and rigid body rotation; its mass and size have been chosen to represent the observed core L1544; for the thermal and rotational energy ratios with respect to the potential energy, we assume the values α = 0.3 and β = 0.1, respectively. These values favor the gravitational collapse of the core. We here study cases of both head‐on and off‐center collisions, in which the pre‐collision velocity increases the initial sound speed of the barotropic gas by up to several times. In a simulation the accretion centers are formed by the highest density particles, so we here report their location and properties in order to realize the collision effects on the collapsing and colliding cores. In one of the models, we observe a roughly spherical distribution of accretion centers located at the front wave of the collision. In a forthcoming publication we will apply the full modified GADGET code to study the collision of turbulent cores. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Engineering the hematopoietic stem cell niche: Frontiers in biomaterial science
Authors: Choi Ji Sun , Mahadik Bhushan P. , Harley Brendan A. C. 
Published: September 2015

AbstractHematopoietic stem cells (HSCs) play a crucial role in the generation of the body's blood and immune cells. This process takes place primarily in the bone marrow in specialized 'niche' microenvironments, which provide signals responsible for maintaining a balance between HSC quiescence, self‐renewal, and lineage specification required for life‐long hematopoiesis. While our understanding of these signaling mechanisms continues to improve, our ability to engineer them in vitro for the expansion of clinically relevant HSC populations is still lacking. In this review, we focus on development of biomaterials‐based culture platforms for in vitro study of interactions between HSCs and their local microenvironment. The tools and techniques used for both examining HSC‐niche interactions as well as applying these findings towards controlled HSC expansion or directed differentiation in 2D and 3D platforms are discussed. These novel techniques hold the potential to push the existing boundaries of HSC cultures towards high‐throughput, real‐time, and single‐cell level biomimetic approaches that enable a more nuanced understanding of HSC regulation and function. Their application in conjunction with innovative biomaterial platforms can pave the way for engineering artificial bone marrow niches for clinical applications as well as elucidating the pathology of blood‐related cancers and disorders.
Minimal genome: Worthwhile or worthless efforts toward being smaller?
Authors: Choe Donghui , Cho Suhyung , Kim Sun Chang , Cho Byung‐Kwan 
Published: September 2015

AbstractMicrobial cells are versatile hosts for the production of value‐added products due to the well‐established background knowledge, various genetic tools, and ease of manipulation. Despite those advantages, efficiency of newly incorporated synthetic pathways in microbial cells is frequently limited by innate metabolism, product toxicity, and growth‐mediated genetic instability. To overcome those obstacles, a minimal genome harboring only the essential set of genes was proposed, which is a fascinating concept with potential for use as a platform strain. Here, we review the currently available artificial reduced genomes and discuss the prospects for extending use of the genome‐reduced strains as programmable chasses. The genome‐reduced strains generally showed comparable growth to and higher productivity than their ancestral strains. In Escherichia coli, about 300 genes are estimated as the minimal number of genes under laboratory conditions. However, recent advances revealed that there are non‐essential components in essential genes, suggesting that the design principle of minimal genomes should be reconstructed. Current technology is not efficient enough to reduce large amount of interspaced genomic regions or to synthesize the genome. Furthermore, construction of minimal genome frequently has failed due to lack of genomic information. Technological breakthroughs and intense systematic studies on genomes remain tasks.
Polyphosphate as a metabolic fuel in Metazoa: A foundational breakthrough invention for biomedical applications
Authors: Wang Xiaohong , Schröder Heinz C. , Müller Werner E. G. 
Published: September 2015

AbstractIn animals, energy‐rich molecules like ATP are generated in the intracellular compartment from metabolites, e.g. glucose, taken up by the cells. Recent results revealed that inorganic polyphosphates (polyP) can provide an extracellular system for energy transport and delivery. These polymers of multiple phosphate units, linked by high‐energy phosphoanhydride bonds, use blood platelets as transport vehicles to reach their target cells. In this review it is outlined how polyP affects cell metabolism. It is discussed that polyP influences cell activity in a dual way: (i) as a metabolic fuel transferring metabolic energy through the extracellular space; and (ii) as a signaling molecule that amplifies energy/ATP production in mitochondria. Several metabolic pathways are triggered by polyP, among them biomineralization/hydroxyapatite formation onto bone cells. The accumulation of polyP in the platelets allows long‐distance transport of the polymer in the extracellular space. The discovery of polyP as metabolic fuel and signaling molecule initiated the development of novel techniques for encapsulation of polyP into nanoparticles. They facilitate cellular uptake of the polymer by receptor‐mediated endocytosis and allow the development of novel strategies for therapy of metabolic diseases associated with deviations in energy metabolism or mitochondrial dysfunctions.
Involvement of Lipocalin‐like CghA in Decalin‐Forming Stereoselective Intramolecular [4+2] Cycloaddition
Authors: Sato Michio , Yagishita Fumitoshi , Mino Takashi , Uchiyama Nahoko , Patel Ashay , Chooi Yit‐Heng , Goda Yukihiro , Xu Wei , Noguchi Hiroshi , Yamamoto Tsuyoshi , Hotta Kinya , Houk Kendall N. , Tang Yi , Watanabe Kenji 
Published: September 2015

AbstractUnderstanding enzymatic Diels–Alder (DA) reactions that can form complex natural product scaffolds is of considerable interest. Sch 210972 1, a potential anti‐HIV fungal natural product, contains a decalin core that is proposed to form through a DA reaction. We identified the gene cluster responsible for the biosynthesis of 1 and heterologously reconstituted the biosynthetic pathway in Aspergillus nidulans to characterize the enzymes involved. Most notably, deletion of cghA resulted in a loss of stereoselective decalin core formation, yielding both an endo (1) and a diastereomeric exo adduct of the proposed DA reaction. Complementation with cghA restored the sole formation of 1. Density functional theory computation of the proposed DA reaction provided a plausible explanation of the observed pattern of product formation. Based on our study, we propose that lipocalin‐like CghA is responsible for the stereoselective intramolecular [4+2] cycloaddition that forms the decalin core of 1.
Ion‐Transport Processes in Dual‐Ion Cells Utilizing a Pyr1,4TFSI/LiTFSI Mixture as the Electrolyte
Authors: Balabajew Marco , Kranz Tobias , Roling Bernhard 
Published: September 2015

AbstractIn dual‐ion cells, the extraction of ions from the electrolyte during charging leads to the formation of ion concentration gradients and to ion transport processes. In order to obtain information about these processes, we examine changes in the electrolyte resistance in an exemplary dual‐ion cell utilizing a Pyr1,4TFSI/LiTFSI mixture as electrolyte. The negative and the positive electrode are metallic lithium and graphite, respectively. The individual changes in the electrolyte resistance in both half‐cells are monitored in situ by means of three‐electrode electrochemical impedance spectroscopy. The results are compared to finite element simulations, for which concentration‐dependent diffusion and conductivity data of Pyr1,4TFSI/LiTFSI mixtures are used as input parameters. We show that differences in the mobilities of the three types of ions play a decisive role for the time evolution of the ion concentration gradients and the resulting resistance changes in the two half‐cells.
Mesoporous Silica Nanoparticles Decorated with Carbosilane Dendrons as New Non‐viral Oligonucleotide Delivery Carriers
Authors: Martínez Ángel , Fuentes‐Paniagua Elena , Baeza Alejandro , Sánchez‐Nieves Javier , Cicuéndez Mónica , Gómez Rafael , de la Mata F. Javier , González Blanca , Vallet‐Regí María 
Published: September 2015

AbstractA novel nanosystem based on mesoporous silica nanoparticles covered with carbosilane dendrons grafted on the external surface of the nanoparticles is reported. This system is able to transport single‐stranded oligonucleotide into cells, avoiding an electrostatic repulsion between the cell membrane and the negatively charged nucleic acids thanks to the cationic charge provided by the dendron coating under physiological conditions. Moreover, the presence of the highly ordered pore network inside the silica matrix would make possible to allocate other therapeutic agents within the mesopores with the aim of achieving a double delivery. First, carbosilane dendrons of second and third generation possessing ammonium or tertiary amine groups as peripheral functional groups were prepared. Hence, different strategies were tested in order to obtain their suitable grafting on the outer surface of the nanoparticles. As nucleic acid model, a single‐stranded DNA oligonucleotide tagged with a fluorescent Cy3 moiety was used to evaluate the DNA adsorption capacity. The hybrid material functionalised with the third generation of a neutral dendron showed excellent DNA binding properties. Finally, the cytotoxicity as well as the capability to deliver DNA into cells, was tested in vitro by using a human osteoblast‐like cell line, achieving good levels of internalisation of the vector DNA/carbosilane dendron‐functionalised material without affecting the cellular viability.
Insertion/Rearrangement Reactivity of a Lutetacyclopentadiene towards N,N′‐Diphenylcarbodiimide: Cooperative Effect of the Metal Center, Concentration of LiCl, and Solvent
Authors: Xu Ling , Wei Junnian , Zhang Wen‐Xiong , Xi Zhenfeng 
Published: September 2015

AbstractThe reactivity of lutetacyclopentadiene towards N,N′‐diphenylcarbodiimide (DPC) was systematically investigated to efficiently construct three types of new N‐containing fused cyclic complexes. The outcome of these reactions significantly depended on the the metal center, the concentration of LiCl, the number of equivalents of DPC, and the solvent. Thus, two unexpected reaction modes of amidinate were discovered for the first time, which were ascribed to an unusual κ1 coordination mode of amidinate driven by a rigid seven‐membered ring. These results are in striking contrast with the previously well‐investigated zirconacyclopentadiene, which reacts with DPC to give azazirconacyclopentene and alkyne through β,β′ CC bond cleavage. The difference in reactivity between lutetacyclopentadiene and zirconacyclopentadiene can be attributed to the highly ionic character of the LuC(sp2) bonds. DFT calculations agreed well with the experimental results.
PdII‐Catalyzed Intermolecular Amination of Unactivated C(sp3)H Bonds
Authors: Gou Quan , Liu Gang , Liu Zi‐Ning , Qin Jun 
Published: September 2015

AbstractPdII‐catalyzed intermolecular amination of unactivated C(sp3)H bonds has been successfully developed for the first time. This method provides a new way to achieve the challenging intermolecular amination of unactivated C(sp3)H bonds, producing a variety of unnatural β2‐amino carboxylic acid analogues. This C(sp3)H amination protocol is demonstrated with a broad substrate scope, good functional‐group tolerance, and chemoselectivity. It is operated without use of phosphine ligand or external oxidant.
Photocyclodehydrofluorination
Authors: Li Zhe , Twieg Robert J. 
Published: September 2015

AbstractMallory‐type photocyclization involves a series of photoreactions of stilbenes, o‐terphenyls and related derivatives, which undergo intramolecular cyclization via dihydrophenanthrene intermediates. In typical Mallory photocyclizations, oxidants are usually needed to produce the final phenanthrene‐containing product. In the research described here, appropriately fluorinated stilbenes and o‐terphenyls undergo ring closure and HF is eliminated. This photocyclodehydrofluorination (PCDHF) reaction is very useful to produce a wide range of selectively fluorinated polynuclear aromatic hydrocarbons that possess a phenanthrene (or heterocyclic analogue of phenanthrene) substructure. These fluorinated products are of great interest in various aspects of the materials science.
Prins Cyclization Catalyzed by a FeIII/Trimethylsilyl Halide System: The Oxocarbenium Ion Pathway versus the [2+2] Cycloaddition
Authors: Pérez Sixto J. , Purino Martín , Miranda Pedro O. , Martín Víctor S. , Fernández Israel , Padrón Juan I. 
Published: September 2015

AbstractThe different factors that control the alkene Prins cyclization catalyzed by iron(III) salts have been explored by means of a joint experimental–computational study. The iron(III) salt/trimethylsilyl halide system has proved to be an excellent promoter in the synthesis of crossed all‐cisdisubstituted tetrahydropyrans, minimizing the formation of products derived from side‐chain exchange. In this iron(III)‐catalyzed Prins cyclization reaction between homoallylic alcohols and non‐activated alkenes, two mechanistic pathways can be envisaged, namely the classical oxocarbenium route and the alternative [2+2] cycloaddition‐based pathway. It is found that the [2+2] pathway is disfavored for those alcohols having non‐activated and non‐substituted alkenes. In these cases, the classical pathway, via the key oxocarbenium ion, is preferred. In addition, the final product distribution strongly depends upon the nature of the substituent adjacent to the hydroxy group in the homoallylic alcohol, which can favor or hamper a side 2‐oxonia‐Cope rearrangement.
Hierarchical Mesoporous Metal–Organic Frameworks for Enhanced CO2 Capture
Authors: Mao Yiyin , Chen Danke , Hu Pan , Guo Yi , Ying Yulong , Ying Wen , Peng Xinsheng 
Published: September 2015

AbstractHierarchical porous materials are promising for catalyst, separation and sorption applications. A ligand‐assisted etching process is developed for template‐free synthesis of hierarchical mesoporous MOFs as single crystals and well‐intergrown membranes at 40 °C. At 223 K, the hierarchical porous structures significantly improve the CO2 capture capacity of HKUST‐1 by more than 44 % at pressures up to 20 kPa and 13 % at 100 kPa. Even at 323 K, the enhancement of CO2 uptake is above 25 % at pressures up to 20 kPa and 7 % at 100 kPa. The mesoporous structures not only enhance the CO2 uptake capacity but also improve the diffusion and mass transportation of CO2. Similarly, well‐intergrown mesoporous HKUST‐1 membranes are synthesized, which hold the potential for film‐like porous devices. Mesoporous MOF‐5 crystals are also obtained by a similar ligand‐assisted etching process. This may provide a facile way to prepare hierarchical porous MOF single crystals and membranes for wide‐ranging applications.