bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantified CSF antibody reactivity against myelin in multiple sclerosis
Authors: Sun Xingwen , Bakhti Mostafa , Fitzner Dirk , Schnaars Mareike , Kruse Niels , Coskun Ünal , Kremser Christiane , Willecke Klaus , Kappos Ludwig , Kuhle Jens , Simons Mikael 
Published: November 2015

AbstractBackgroundSynthesis of clonal IgG is a consistent feature of patients with multiple sclerosis (MS). Whether oligoclonal bands (OCBs) represent unspecific disease bystanders or active components in MS pathology is an open question. The aim of this study was to develop a method to quantify and compare the reactivity of cerebrospinal fluid (CSF) antibodies from patients with and without MS.MethodsWe collected CSF from 262 patients from two different cohorts, which included 148 patients with MS and 114 with other neurological diseases (OND). We established a highly sensitive electrochemiluminescence (ECL)‐based assay to measure CSF antibody reactivity against purified myelin particles and biotin anchored liposomes. The diagnostic value of the ECL score against myelin particles was assessed with receiver operating characteristic curves.ResultsCSF from patients with MS have higher reactivity toward purified myelin particles as compared to those with OND with OCBs. Using liposomes with defined lipid compositions and myelin particles from ceramide synthase 2 (CerS2) knockout mice, we find that some of the CSF antibody reactivity is directed against cerebrosides.ConclusionThe ECL‐based assay system expands the currently available toolbox for the detection of autoantibodies in MS and related diseases.
Toxizität von Graphenoxid: Endoperoxide als Ursache
Authors: Pieper Hanna , Chercheja Serghei , Eigler Siegfried , Halbig Christian E. , Filipovic Milos R. , Mokhir Andriy 
Published: November 2015

AbstractPotentielle biomedizinische Anwendungen von Graphenoxid (GO), z. B. als Träger von Biomolekülen, Reagentien für die photothermische Therapie oder Biosensoren, werden durch die Zytotoxizität und Mutagenität dieses Materials eingeschränkt. Es wird davon ausgegangen, dass diese Eigenschaften zumindest zum Teil auf eine von GO verursachte Erhöhung des oxidativen Stresses in Zellen zurückzuführen ist. Es ist jedoch nicht bekannt, auf welchen chemischen Fragmenten dieser ungünstige Effekt beruht. In dieser Arbeit wurden vier GOs entwickelt, welche verschiedene redoxaktive Gruppen wie Mn2+, C‐zentrierte Radikale sowie Endoperoxide (EPs) auf der Oberfläche besitzen. Der Vergleich der Fähigkeit der Materialien, reaktive Sauerstoffspezies in humanen Gebärmutterhalskrebszellen zu generieren, zeigt, dass EPs eine entscheidende Rolle im GO‐induzierten oxidativen Stress spielen. Diese Ergebnisse können für die gezielte Entwicklung von biokompatiblem und nicht‐toxischem GO für biomedizinische Anwendungen verwendet werden.
Semiconductive Nanotube Array Constructed from Giant [PbII18I54(I2)9] Wheel Clusters
Authors: Wang Guan‐E , Xu Gang , Liu Bin‐Wen , Wang Ming‐Sheng , Yao Ming‐Shui , Guo Guo‐Cong 
Published: November 2015

AbstractCrystalline nanotube array would create great opportunity for novel electrical application. Herein we report the first example of a metal halide based crystalline nanotube array which is constructed from an unprecedented giant [PbII18I54(I2)9] wheel cluster, as determined by synchrotron X‐ray diffraction. The electrical properties of the single crystal were studied and the present compound shows typical semiconductivity and highly anisotropic conductivity.
Stufenweise Bildung eines 1,3‐Butadien‐Analogons aus gemischten schwereren Elementen der Gruppe 15
Authors: Seidl Michael , Balázs Gábor , Timoshkin Alexey Y. , Scheer Manfred 
Published: November 2015

AbstractDie Reaktion des Phosphinidenkomplexes [Cp*P{W(CO)5}2] (1 a) mit Di‐tert‐butylcarboimidophosphen führt zur P‐C‐Käfigverbindung 6 und dem Lewis Säure‐Base‐Addukt [Cp*P{W(CO)5}2(CNtBu)] (2 a). Der analoge Arsinidenkomplex bildet dagegen bei tiefen Temperaturen den Arsaphosphenkomplex [{W(CO)5}{η2‐(Cp*)AsP(tBu)}{W(CO)5}] (3), der bei diesen Temperaturen mit einem zweiten Äquivalent an Carboimidophosphen zu [{W(CO)5}{η2‐{(Cp*)(tBu)P}AsP(tBu)}{W(CO)5}] (5) reagiert, wahrscheinlich durch Insertion einer Phosphiniden‐Einheit (tBuP) in eine As‐C‐Bindung. Bei Raumtemperatur führt eine Radikalreaktion von 3 zu [{(tBu)PAsAsP(tBu)}{W(CO)5}4] (4), dem ersten neutralen 1,3‐Butadien‐Analogon, das ausschließlich gemischte schwerere Elemente der Gruppe 15 enthält. Verbindung 4 setzt sich aus zwei P‐As‐Doppelbindungen zusammen, die über die Arsenatome verbunden sind.
Borane‐Catalyzed Reductive α‐Silylation of Conjugated Esters and Amides Leaving Carbonyl Groups Intact
Authors: Kim Youngchan , Chang Sukbok 
Published: November 2015

AbstractDescribed herein is the development of the B(C6F5)3‐catalyzed hydrosilylation of α,β‐unsaturated esters and amides to afford synthetically valuable α‐silyl carbonyl products. The α‐silylation occurs chemoselectively, thus leaving the labile carbonyl groups intact. The reaction features a broad scope of both acyclic and cyclic substrates, and the synthetic utility of the obtained α‐silyl carbonyl products is also demonstrated. Mechanistic studies revealed two operative steps: fast 1,4‐hydrosilylation of conjugated carbonyls and then slow silyl group migration of a silyl ether intermediate.
Stepwise Formation of a 1,3‐Butadiene Analogue of Mixed Heavier Group 15 Elements
Authors: Seidl Michael , Balázs Gábor , Timoshkin Alexey Y. , Scheer Manfred 
Published: November 2015

AbstractThe reaction of the phosphinidene complex [Cp*P{W(CO)5}2] (1 a) with di‐tert‐butylcarboimidophosphene leads to the PC cage compound 6 and the Lewis acid–base adduct [Cp*P{W(CO)5}2(CNtBu)] (2 a). In contrast, the arsinidene complex shows a different reactivity. At low temperatures, the arsaphosphene complex [{W(CO)5}{η2‐(Cp*)AsP(tBu)}{W(CO)5}] (3) is formed. At these temperatures, 3 reacts further with a second equivalent of carboimidophosphene to form [{W(CO)5}{η2‐{(Cp*)(tBu)P}AsP(tBu)}{W(CO)5}] (5), probably by the insertion of a phosphinidene unit (tBuP) into an AsC bond. In contrast, at room temperature 3 reacts further by a radical‐type reaction to form [{(tBu)PAsAsP(tBu)}{W(CO)5}4] (4). Compound 4 is the first example of a neutral, 1,3‐butadiene analogue containing only mixed heavier Group 15 elements. It consists of two PAs double bonds connected by arsenic atoms.
Methyl‐, Ethenyl‐, and Ethynyl‐Bridged Cationic Digold Complexes Stabilized by Coordination to a Bulky Terphenylphosphine Ligand
Authors: Espada María F. , Campos Jesús , López‐Serrano Joaquín , Poveda Manuel L. , Carmona Ernesto 
Published: November 2015

AbstractReactions of the gold(I) triflimide complex [Au(NTf2)(PMe2Ar)] (1) with the gold(I) hydrocarbyl species [AuR(PMe2Ar)] (2 a–2 c) enable the isolation of hydrocarbyl‐bridged cationic digold complexes with the general composition [Au2(μ‐R)(PMe2Ar)2][NTf2], where Ar=C6H3‐2,6‐(C6H3‐2,6‐iPr2)2 and R=Me (3), CHCH2 (4), or CCH (5). Compound 3 is the first alkyl‐bridged digold complex to be reported and features a symmetric [Au(μ‐CH3)Au]+ core. Complexes 4 and 5 are the first species of their kind that contain simple, unsubstituted vinyl and acetylide units, respectively. In the series of complexes 3–5, the bridging carbon atom systematically changes its hybridization from sp3 to sp2 and sp. Concomitant with this change, and owing to variations in the nature of the bonding within the [Au(μ‐R)Au]+ unit, there is a gradual decrease in aurophilicity, that is, the strength of the Au⋅⋅⋅Au bonding interaction decreases. This change is illustrated by a monotonic increase in the Au–Au distance by approximately 0.3 Å from R=CH3 (2.71 Å) to CHCH2 (3.07 Å) and CCH (3.31 Å).
Defect‐Controlled Preparation of UiO‐66 Metal–Organic Framework Thin Films with Molecular Sieving Capability
Authors: Zhang Caiqin , Zhao Yajing , Li Yali , Zhang Xuetong , Chi Lifeng , Lu Guang 
Published: November 2015

AbstractMetal–organic framework (MOF) UiO‐66 thin films are solvothermally grown on conducting substrates. The as‐synthesized MOF thin films are subsequently dried by a supercritical process or treated with polydimethylsiloxane (PDMS). The obtained UiO‐66 thin films show excellent molecular sieving capability as confirmed by the electrochemical studies for redox‐active species with different sizes.
Pentannulation of Heterocycles by Virtue of Precious Metal Catalysis
Authors: Petrović Martina , Occhiato Ernesto G. 
Published: November 2015

AbstractPentannulated heterocycles are the key structural subunit of many natural and biologically active compounds. Over the last decades, many precious metal‐assisted pentannulations have been described as a consequence of an extensive research. This Focus Review gives an overview of precious metal‐catalyzed reactions applied to the synthesis of cyclopenta‐fused heterocycles in the last five years.
Improved strategy for recombinant production and purification of antimicrobial peptide tachyplesin I and its analogs with high cell selectivity
Authors: Panteleev Pavel V. , Ovchinnikova Tatiana V. 
Published: November 2015

AbstractHere, we report an efficient procedure for recombinant production and purification of tachyplesin I (THI) with a final yield of 17 mg/L of the culture medium. The peptide was expressed in Escherichia coli as a part of the thioredoxin fusion protein. With the use of soluble expression followed by immobilized metal–ion affinity chromatography, the recombinant protein cleavage and reversed‐phase high‐performance liquid chromatography, a yield of THI did not exceed 6.5 mg/L of the culture medium. Further optimization studies were carried out to improve the protein expression level and simplify purification procedure of the target peptide. To achieve better yield of the peptide, we used high‐cell‐density bacterial expression. The formed inclusion bodies were highly enriched with the fusion protein, which allowed us to perform direct chemical cleavage of the inclusion bodies solubilized in 6 M guanidine–HCl with subsequent selective precipitation of proteins with trifluoroacetic acid. This enabled us to avoid an extra step of purification by immobilized metal–ion affinity chromatography. The developed procedure has made it possible to obtain biologically active THI and was used for screening a number of its mutant analogs. As a result, several selective and nonhemolytic analogs were developed. Significant reduction in hemolytic activity without losing antimicrobial activity was achieved by substitution of tyrosine or isoleucine residue in the β‐turn region of the molecule with hydrophilic serine. The present study affords further insight into molecular mechanism of antimicrobial action of tachyplesin and gains a better understanding of structure–activity relationships in its analogs. This is aimed at searching for novel antibiotics on the basis of antimicrobial peptides with reduced cytotoxicity.
Efficient kinetic resolution of (±)‐menthol by a lipase from Thermomyces lanuginosus
Authors: De Yan Hong , Li Qin , Wang Zhao 
Published: November 2015

AbstractA lipase from Thermomyces lanuginosus (Lipozyme TL IM) exhibited high enantioselectivity for kinetic resolution of (±)‐menthol in organic solvent. The various reaction parameters affecting the conversion and enantioselectivity were studied. The optimum reaction conditions for the transesterification reaction were found with vinyl acetate in the solvent of methyl tert‐butyl ether with a vinyl acetate:(±)‐menthol molar ratio of 5:1 and an enzyme concentration of 200 g/L at 30 °C. In these conditions, (−)‐menthyl acetate with 99.3% enantiomeric excess was obtained, whereas the conversion was 34.7% with the reaction time of 12 H at the substrate concentration of 0.5 M. In addition, the enzyme allowed the substrate loading to be increased up to 1.5 M without the decrease of the enantioselectivity. These results indicated that Lipozyme TL IM was a promising biocatalyst in the resolution of (±)‐menthol.
Exposure Duration‐Dependent Ovarian Recovery in Methoxychlor‐Treated Mice
Authors: Tannenbaum Lawrence V. , Flaws Jodi A. 
Published: November 2015

The pesticide methoxychlor (MXC) is known to target ovarian antral follicles in the mouse. In previous in vivo studies, MXC administration for 20 days increased atresia, but did not affect female fertility immediately after dosing. Thus, we hypothesized that perhaps not enough time had elapsed between the onset of MXC‐induced atresia and actual follicle loss to result in reduced fertility. The current study was undertaken to determine whether MXC treatment for 20 days results in reduced antral follicle numbers and fertility at 30 and 60 days after dosing. To test this hypothesis, adult CD‐1 female mice were dosed with vehicle control or MXC (64 mg/kg/day) for 20 days. At 30 and 60 days postdosing, the mice were either subjected to fertility tests or their ovaries were collected and subjected to histological evaluation of follicle numbers and atresia. The results indicate that at 30 days after the completion of dosing, MXC significantly increased atresia and reduced primordial and total follicle numbers, but did not affect fertility compared to controls. At 60 days after completion of dosing, MXC did not significantly affect fertility, follicle numbers, or atresia compared to controls. Collectively, these data indicate that the ovary may be able to recover from MXC treatment for 20 days
Changes in insulin sensitivity and secretion after sleeve gastrectomy
Authors: Casella G , Soricelli E , Castagneto-Gissey L , Redler A , Basso N , Mingrone G 
Published: November 2015

Abstract

Background
Sleeve gastrectomy is indicated for the treatment of obesity and related co-morbidity including diabetes. The dynamic changes in insulin secretion and sensitivity after sleeve gastrectomy are unknown.

Methods
Whole-body insulin sensitivity was measured by the euglycaemic hyperinsulinaemic clamp technique, and insulin secretion by C-peptide deconvolution after an oral glucose tolerance test (OGTT), before and 3, 6 and 12 months after sleeve gastrectomy in morbidly obese subjects. The time course of glucagon-like peptide (GLP) 1, as a marker of insulin secretion following OGTT, was also assessed.

Results
Ten patients were included in the study. Median (range) baseline insulin sensitivity (M-value) increased from 84·0 (20·2–131·4) mmol per kg per min at baseline to 122·8 (99·0–179·3) mmol per kg per min at 12 months after surgery (P = 0·015). Fasting insulin sensitivity, measured by homeostatic model assessment of insulin resistance, which represents a surrogate index of hepatic insulin resistance, decreased from 3·3 (1·9–5·5) to 0·7 (0·5–1·1) mg/dl·µunits/ml (P &lt; 0·001). Total insulin secretion, measured as incremental area under the curve (AUC), after OGTT decreased from 360·4 (347·9–548·0) to 190·1 (10·1–252·0) mmol/l·180 min at 12 months (P = 0·011). The AUC for GLP-1 increased from 258·5 (97·5–552·6) to 5531·8 (4143·0–7540·9) pmol/l·180 min at 12 months after sleeve gastrectomy (P &lt; 0·001). In multiple regression analysis, 51 per cent of the M-value variability was explained by GLP-1 secretion.

Conclusion
Sleeve gastrectomy improved insulin sensitivity and reduced insulin secretion within 6 months after surgery. Although there was a correlation between insulin sensitivity and bodyweight, the major driver of the improvement in insulin sensitivity was GLP-1 secretion.
New Fluorescence Domain “Excited Multimer” Formed upon Photoexcitation of Continuously Stacked Diaroylmethanatoboron Difluoride Molecules with Fused π‐Orbitals in Crystals
Authors: Sakai Atsushi , Ohta Eisuke , Yoshimoto Yuichi , Tanaka Mirai , Matsui Yasunori , Mizuno Kazuhiko , Ikeda Hiroshi 
Published: November 2015

AbstractThe crystal‐packing structures of seven derivatives of diaroylmethanatoboron difluoride (1 a–gBF2) are characterized by no overlap of the π‐conjugated main units of two adjacent molecules (type I), overlap of the benzene ring π‐orbitals of two adjacent molecules (type II), and overlap of the benzene and dihydrodioxaborinine rings π‐orbitals of adjacent molecules (type III). The crystal‐packing structures govern the fluorescence (FL) properties in the crystalline states. The FL domain that is present in type I crystals, in which intermolecular orbital interactions are absent, leads to excited monomer‐like FL properties. In the case of the type II crystals, the presence of intermolecular overlap of the benzene rings π‐orbitals generates new FL domains, referred to as “excited multimers”, which possess allowed S0–S1 electronic transitions and, as a result, similar FL lifetimes at longer wavelengths than the FL of the type I crystals. Finally, intermolecular overlap of the benzene and dihydrodioxaborinine ring π‐orbitals in the type III crystals leads to “excited multimer” domains with forbidden S0–S1 electronic transitions and longer FL lifetimes at similar wavelengths as that in type I crystals.
On the Triple Role of Fluoride Ions in Palladium‐Catalyzed Stille Reactions
Authors: Hervé Marius , Lefèvre Guillaume , Mitchell Emily A. , Maes Bert U. W. , Jutand Anny 
Published: November 2015

AbstractThe mechanism of Stille reactions (cross‐coupling of ArX with Ar′SnnBu3) performed in the presence of fluoride ions is established. A triple role for fluoride ions is identified from kinetic data on the rate of the reactions of trans‐[ArPdBr(PPh3)2] (Ar=Ph, p‐(CN)C6H4) with Ar′SnBu3 (Ar′=2‐thiophenyl) in the presence of fluoride ions. Fluoride ions promote the rate‐determining transmetallation by formation of trans‐[ArPdF(PPh3)2], which reacts with Ar′SnBu3 (Ar′=Ph, 2‐thiophenyl) at room temperature, in contrast to trans‐[ArPdBr(PPh3)2], which is unreactive. However, the concentration ratio [F−]/[Ar′SnBu3] must not be too high, because of the formation of unreactive anionic stannate [Ar′Sn(F)Bu3]−. This rationalises the two kinetically antagonistic roles exerted by the fluoride ions that are observed experimentally, and is found to be in agreement with the kinetic law. In addition, fluoride ions promote reductive elimination from trans‐[ArPdAr′(PPh3)2] generated in the transmetallation step.
A Metal–Organic Framework/DNA Hybrid System as a Novel Fluorescent Biosensor for Mercury(II) Ion Detection
Authors: Wu Lan‐Lan , Wang Zhuo , Zhao Shu‐Na , Meng Xing , Song Xue‐Zhi , Feng Jing , Song Shu‐Yan , Zhang Hong‐Jie 
Published: November 2015

AbstractMercury(II) ions have emerged as a widespread environmental hazard in recent decades. Despite different kinds of detection methods reported to sense Hg2+, it still remains a challenging task to develop new sensing molecules to replenish the fluorescence‐based apparatus for Hg2+ detection. This communication demonstrates a novel fluorescent sensor using UiO‐66‐NH2 and a T‐rich FAM‐labeled ssDNA as a hybrid system to detect Hg2+ sensitively and selectively. To the best of our knowledge, it has rarely been reported that a MOF is utilized as the biosensing platform for Hg2+ assay.
A Serendipitous Rendezvous with a Four‐Center Two‐Electron Bonded Intermediate in the Aerial Oxidation of Hydrazine
Authors: Banerjee Ambar , Ganguly Gaurab , Roy Lisa , Pathak Shubhrodeep , Paul Ankan 
Published: November 2015

AbstractOxidation by dioxygen has a rich repertoire of mechanistic intricacies. Herein, we report a hitherto unknown paradigm of dioxygen activation reaction which propagates through a four center two electron (4c–2e) bound species. Using static DFT and ab initio quantum chemical techniques we have unraveled the oxidation pathway for hydrazine and its methylated analogues by dioxygen which involves formation of this unconventional 4c–2e bonded species en route to the oxidation products. Inconvertible evidence in favor of such an unprecedented dioxygen activation route is provided by capturing the events of formation of the 4c–2e species in aqueous phase for hydrazine and its congeners and the experimentally observed products from the respective 4c–2e species, like H2O2 and N2H2, diazene in the case of hydrazine using Car–Parrinello molecular dynamics simulations.
Me2Zn‐Mediated Catalytic Enantio‐ and Diastereoselective Addition of TosMIC to Ketones
Authors: Keeri Abdul Raheem , Gualandi Andrea , Mazzanti Andrea , Lewinski Janusz , Cozzi Pier Giorgio 
Published: November 2015

AbstractThe first catalytic asymmetric addition of TosMIC to unactivated ketones is presented. A combination of Me2Zn and aminoalcohol catalyst promoted the aldol addition/cyclization reaction to render oxazolines possessing a fully substituted stereocenter with excellent yields (up to 92 %), high enantioselectivities (up to 96 %), and complete diastereoselectivity. The chiral oxazolines were then used to give, after a straightforward acid hydrolysis, enantioenriched building blocks bearing tertiary alcohol motifs such as hydroxylaldehydes, hydroxylacids, and hydroxylesters without racemization.
Aminobenzimidazoles and Structural Isomers as Templates for Dual‐Acting Butyrylcholinesterase Inhibitors and hCB2R Ligands To Combat Neurodegenerative Disorders
Authors: Dolles Dominik , Nimczick Martin , Scheiner Matthias , Ramler Jacqueline , Stadtmüller Patricia , Sawatzky Edgar , Drakopoulos Antonios , Sotriffer Christoph , Wittmann Hans‐Joachim , Strasser Andrea , Decker Michael 
Published: November 2015

AbstractA pharmacophore model for butyrylcholinesterase (BChE) inhibitors was applied to a human cannabinoid subtype 2 receptor (hCB2R) agonist and verified it as a first‐generation lead for respective dual‐acting compounds. The design, synthesis, and pharmacological evaluation of various derivatives led to the identification of aminobenzimidazoles as second‐generation leads with micro‐ or sub‐micromolar activities at both targets and excellent selectivity over hCB1 and AChE, respectively. Computational studies of the first‐ and second‐generation lead structures by applying molecular dynamics (MD) on the active hCB2R model, along with docking and MD on hBChE, has enabled an explanation of their binding profiles at the protein levels and opened the way for further optimization. Dual‐acting compounds with “balanced” affinities and excellent selectivities could be obtained that represent leads for treatment of both cognitive and pathophysiological impairment occurring in neurodegenerative disorders.
Generalized Synthesis of Hierarchical Transition Metal Dichalcogenide Nanosheets from Polyoxometalates
Authors: He Peilei , Li Haoyi , Liu Huiling , Wang Xun 
Published: November 2015

AbstractTransition metal dichalcogenides (TMDs, such as MoS2, WS2 and MoSe2) with lamellar structures have attracted tremendous attention owing to their similar structure to graphite. However, two‐dimensional (2D) TMD nanomaterials display a strong tendency to restack and condense, which leads to a marked decrease of performance in their applications. In this study, we report the synthesis of TMDs by using polyoxometalates (POMs) as tungsten or molybdenum precursors. Hierarchical TMDs with novel structures can be formed below 200 °C, including WS2 rods, MoS2 rods and MoSe2 hollow spheres. All of these structures assembled from the corresponding nanosheets. Meanwhile the epitaxial growth of noble metal nanoparticles (NPs) on TMDs could be achieved very easily. The obtained Pt/WS2 and Pt/MoS2 hybrids were highly active and durable HER catalysts. In addition, the Pt NPs on the surface of TMDs could improve the HER activity sharply, which was likely due to the synergistic effect between Pt NPs and MoS2 rods.