bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poly(p‐phenyleniminoboran): ein Bor‐Stickstoff‐Analogon von Poly(p‐phenylenvinylen)
Authors: Lorenz Thomas , Crumbach Merian , Eckert Thomas , Lik Artur , Helten Holger 
Published: February 2017

AbstractDer isoelektronische und isostere Austausch ausgewählter CC‐ durch BN‐Einheiten in π‐konjugierten organischen Systemen (BN/CC‐Isosterie) hat sich als erfolgreiche Strategie zur Entwicklung BN‐dotierter polycyclischer aromatischer Kohlenwasserstoffe (PAKs) mit faszinierenden Eigenschaften und Funktionen erwiesen. Unlängst haben erste Beispiele die Nützlichkeit dieses Konzepts in der Polymerchemie gezeigt. Hier stellen wir die Synthese und Charakterisierung des ersten Poly(p‐phenyleniminoborans) vor. Dieses neue anorganisch‐organische Hybridpolymer kann als BN‐Analogon des bekannten Poly(p‐phenylenvinylens) (PPV) angesehen werden. Photophysikalische Untersuchungen am Polymer und einer Reihe von Modelloligomeren geben eindeutige Hinweise auf π‐Konjugation über die B=N‐Bindungen und eine Erweiterung der Konjugationslänge mit wachsender Kettenlänge. TD‐DFT‐Rechnungen verschaffen einen tieferen Einblick in die elektronische Struktur der neuen Materialien.
Einfluss der Wärmespeicherfähigkeit auf Heizwärmebedarf und thermischen Komfort
Authors: Schlitzberger Stephan , Kempkes Christoph , Maas Anton , Schäfers Martin 
Published: February 2017

AbstractAnhand eines Einfamilienhauses und eines Mehrfamilienhauses wird mithilfe dynamisch‐thermischer Simulationsberechnungen der Einfluss der Wärmekapazität der Außen‐ und Innenbauteile auf den Nutzenergiebedarf für Heizen einerseits und den sommerlichen Temperaturkomfort andererseits aufgezeigt. Hierbei werden baupraktische Wand‐, Decken‐ und Bodenkonstruktionen jeweils in einer Ausführung in Kalksandstein (schwere Bauart) bzw. Holz (leichte Bauart) zugrunde gelegt und es werden die Fälle mit und ohne nächtliche Temperaturreduktion betrachtet. Das Wärmeschutzniveau wird dabei in drei Varianten entsprechend den Niveaus EnEV 2016, KfW‐Effizienzhaus 55 sowie KfW‐Effizienzhaus 40 gewählt. Die Nutzungsrandbedingungen entsprechen soweit möglich den Vorgaben gemäß DIN V 4108‐6, DIN V 18599‐10 und DIN 4108‐2; für die Klimarandbedingungen wird generell der Klimadatensatz TRY04 (Potsdam, Normaljahr) zugrunde gelegt.Es zeigt sich, dass eine schwere Bauart Vorteile sowohl hinsichtlich des Nutzenergiebedarfs Heizen als auch besonders hin sichtlich des thermischen Komforts im Sommer aufweist. Die ermittelten Einsparungen an Heizwärme betragen abhängig von der Gebäudegeometrie, dem Wärmeschutzniveau und den Nutzungsrandbedingungen (Nachtabsenkung) bis zu 4 %, ein thermischer Komfort im Sommer lässt sich im Vergleich zur leichten Bauart auch ohne Kühlung relativ leicht bewerkstelligen, ebenso wie die Einhaltung der gesetzlichen Mindestanforderungen.
Assessment of knowledge of participants on basic molecular biology techniques after 5‐day intensive molecular biology training workshops in Nigeria
Authors: Yisau J. I. , Adagbada A. O. , Bamidele T. , Fowora M. , Brai B. I. C. , Adebesin O. , Bamidele M. , Fesobi T. , Nwaokorie F. O. , Ajayi A. , Smith S. I. 
Published: February 2017

AbstractThe deployment of molecular biology techniques for diagnosis and research in Nigeria is faced with a number of challenges, including the cost of equipment and reagents coupled with the dearth of personnel skilled in the procedures and handling of equipment. Short molecular biology training workshops were conducted at the Nigerian Institute of Medical Research (NIMR), to improve the knowledge and skills of laboratory personnel and academics in health, research, and educational facilities. Five‐day molecular biology workshops were conducted annually between 2011 and 2014, with participants drawn from health, research facilities, and the academia. The courses consisted of theoretical and practical sessions. The impact of the workshops on knowledge and skill acquisition was evaluated by pre‐ and post‐tests which consisted of 25 multiple choice and other questions. Sixty‐five participants took part in the workshops. The mean knowledge of molecular biology as evaluated by the pre‐ and post‐test assessments were 8.4 (95% CI 7.6–9.1) and 13.0 (95 CI 11.9–14.1), respectively. The mean post‐test score was significantly greater than the mean pre‐test score (p < 0.0001). The five‐day molecular biology workshop significantly increased the knowledge and skills of participants in molecular biology techniques. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(4):313–317, 2017.
Simultaneous determination of eight bioactive components of Qishen Yiqi dripping pills in rat plasma using UFLC–MS/MS and its application to a pharmacokinetic study
Authors: Shao Yaping , Zhang Wen , Tong Ling , Huang Jingyi , Li Dongxiang , Nie Wei , Zhu Yan , Li Yunfei , Lu Tao 
Published: February 2017

AbstractIn this study, a rapid and reliable ultra‐fast liquid chromatography–tandem mass spectrometry method was developed and validated for the simultaneous determination of eight active ingredients, including astragaloside IV, ononin, tanshinol, protocatechualdehyde, protocatechuic acid, salvianolic acid D, rosmarinic acid and ginsenoside Rg1, in rat plasma. The plasma samples were pretreated by protein precipitation with acetonitrile. Chromatographic separation was performed on a Waters Acquity UPLC® BEH C18 column (1.7 μm particles, 2.1 × 100 mm). The mobile phase consisted of 0.1% aqueous formic acid (A)–acetonitrile with 0.1% formic acid (B) at a flow rate of 0.4 mL/min. Quantification was performed on a triple quadruple tandem mass spectrometry with electrospray ionization by multiple reaction monitoring both in the negative and in the positive ion mode. The lower limit of quantification of tanshinol was 2.0 ng/mL and the others were 5.0 ng/mL. The extraction recoveries, matrix effects, intra‐ and inter‐day precision and accuracy of eight tested components were all within acceptable limits. The validated method was successfully applied to the pharmacokinetic study of the eight active constituents after intragastric administration of three doses (1.0, 3.0, 6.0 g/kg body weight) of Qishen Yiqi Dripping Pills to rats.
Development and validation of a reversed‐phase high‐performance liquid chromatographic method with solid‐phase extraction for the quantification of hydrochlorothiazide in ex vivo permeation studies
Authors: Onnainty R. , Schenfeld E.M. , Longhi M.R. , Quevedo M.A. , Granero G.E. 
Published: February 2017

AbstractHydrochlorothiazide (HCT) is a diuretic used to treat hypertension. In order to study its intestinal permeation behavior applying an ex vivo methodology, a rapid, sensitive and selective reversed‐phase liquid chromatography (RP‐HPLC) method coupled with UV detection (RP‐HPLC UV) was developed for the analysis of HCT in TC199 culture medium used as mucosal and serosal solutions in the everted rat intestinal sac model. Also, analytical procedures for the quantification of HCT by RP‐HPLC with UV detection required a sample preparation step by solid‐phase extraction. The method was validated in the concentration range of 8.05 × 10−7 to 3.22 × 10−5 m for HCT. Chromatographic parameters, namely carry‐over, lower limit of quantification (1.4491 × 10−7 m), limit of detection (3.8325 × 10−8 m), selectivity, inter‐ and intraday precision and extraction recovery, were determined and found to be adequate for the intended purposes. The validated method was successfully used for permeability assays across rat intestinal epithelium applying the ex vivo everted rat gut sac methodology to study the permeation behavior of HCT.
Crystal Structures of Diaryliodonium Fluorides and Their Implications for Fluorination Mechanisms
Authors: Lee Yong‐Sok , Chun Joong‐Hyun , Hodošček Milan , Pike Victor W. 
Published: February 2017

AbstractThe radiofluorination of diaryliodonium salts is of value for producing radiotracers for positron emission tomography. We report crystal structures for two diaryliodonium fluorides. Whereas diphenyliodonium fluoride (1 a) exists as a tetramer bridged by four fluoride ions, 2‐methylphenyl(phenyl)iodonium fluoride (2 a) forms a fluoride‐bridged dimer that is further halogen bonded to two other monomers. We discuss the topological relationships between the two and their implications for fluorination in solution. Both radiofluorination and NMR spectroscopy show that thermolysis of 2 a gives 2‐fluorotoluene and fluorobenzene in a 2 to 1 ratio that is in good agreement with the ratio observed from the radiofluorination of 2‐methylphenyl(phenyl)iodonium chloride (2 b). The constancy of the product ratio affirms that the fluorinations occur via the same two rapidly interconverting transition states whose energy difference dictates chemoselectivity. From quantum chemical studies with density functional theory we attribute the “ortho‐effect” to the favorable electrostatic interaction between the incoming fluoride and the o‐methyl in the transition state. By utilizing the crystal structures of 1 a and 2 a, the mechanisms of fluoroarene formation from diaryliodonium fluorides in their monomeric, homodimeric, heterodimeric, and tetrameric states were also investigated. We propose that oligomerization energy dictates whether the fluorination occurs through a monomeric or an oligomeric pathway.
Das Molkonzept durch Experiential Learning
Authors: Barke Hans‐Dieter , Indriyanti Nurma Yunita 
Published: February 2017

AbstractDer Einsatz des Molbegriffs wird an deutschen Schulen heftig diskutiert: an Realschulen verzichtet man oftmals auf das Stöchiometrische Rechnen, weil Lernende uninteressiert und intellektuell überfordert sind. Deshalb wird ein Weg erprobt, das „Zählen durch Wiegen“ mit Hilfe von Bonbons handlungsorientiert einzuführen und eine durch Lernende kreierte, fiktive Zähleinheit auf den Molbegriff zu übertragen. Es werden gute, aber unterschiedliche Ergebnisse in beiden Ländern festgestellt – vor allem verbessert sich die Motivationslage der deutschen Probanden.
Inhibition of α5 subunit‐containing GABAA receptors facilitated spinal nociceptive transmission and plasticity
Authors: Xue M. , Liu J.P. , Yang Y.H. , Suo Z.W. , Yang X. , Hu X.D. 
Published: February 2017

AbstractBackgroundγ‐Aminobutyric acid (GABA) type A receptors (GABAARs) locate at both synaptic and extrasynaptic membrane, which generate phasic and tonic inhibition, respectively. In spinal cord dorsal horn, the phasic inhibition produced by transient activation of synaptic GABAARs plays an important role in the gating control over nociceptive conveyance. Although extrasynaptic GABAARs that contain α5 subunits (α5‐GABAARs) are also detectable in spinal dorsal horn, much less is known about the function of these receptors.MethodsThe C fibre‐evoked field potentials were recorded in superficial dorsal horn of spinal cord, and the effects of α5‐GABAAR inverse agonist L‐655708 on basal synaptic transmission and long‐term potentiation (LTP) of C‐fibre responses were examined. The possible changes of glutamate receptor function and pain sensitivity after α5‐GABAAR inhibition were investigated by western blot and behavioural tests.ResultsInhibition of α5‐GABAARs by L‐655708 boosted the basal synaptic transmission and facilitated the induction of N‐methyl‐d‐aspartate subtype glutamate receptors (NMDARs)‐dependent LTP. L‐655708 was found to enhance the phosphorylation and synaptic accumulation of NMDARs and α‐Amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic Acid receptors (AMPARs). Intrathecal L‐655708 injection also decreased the pain thresholds of intact mice in a dose‐dependent manner.Conclusionsα5‐GABAARs were critical for the tonic inhibition of glutamatergic neurotransmission and plasticity in spinal dorsal horn.SignificanceTonic inhibition generated by α5‐GABAARs is important for information processing. However, whether and how α5‐GABAARs regulate the conveyance of nociceptive signals in spinal cord is largely unknown. Here, we revealed a negative control by α5‐GABAARs over nociceptive transmission and plasticity.
Structural Analysis of G1691S Variant in the Human Filamin B Gene Responsible for Larsen Syndrome: A Comparative Computational Approach
Authors: P Sneha , D Kumar Thirumal , Tanwar Himani , R Siva , C George Priya Doss , Zayed Hatem 
Published: February 2017

ABSTRACTLarsen syndrome (LRS) is a rare genetic disease associated with variable manifestations including skeletal malformations, dislocations of the large joints, and notable changes in facial and limb features. Genetic variants in the Filamin B (FLNB) gene are associated with the development of LRS. We searched two literature databases (OMIM and PubMed) and three gene variant databases (HGMD, UniProt, & dbSNP) to capture all the possible variants associated with LRS phenotype, which may have an impact on the FLNB function. Our search yielded 77 variants that might impact the FLNB protein function in patients with LRS. We performed rigorous computational analysis such as conservational, biochemical, pathogenicity, and structural computational analyses to understand the deleterious effect of the G1691S variant. Further, the structural changes of the G1691S variant was compared with a null variant (G1691A) and the native protein through a molecular dynamic simulation study of 50 ns. We found that the variant G1691S was highly deleterious and destabilize the protein when compared to the native and variant G1691A. This might be due to the physicochemical changes in the variant G1691S when compared to the native and variant G1691A. The destabilization was further supported by transformation of bend to coil in variant G1691S whereas bend was retained in native and variant G1691A through molecular dynamics analysis. Our study shed light on the importance of computational methods to understand the molecular nature of genetic variants and structural insights on the function of the FLNB protein. J. Cell. Biochem. 118: 1900–1910, 2017. © 2017 Wiley Periodicals, Inc.
Computational Modelling of Cough Function and Airway Penetrant Behavior in Patients with Disorders of Laryngeal Function
Authors: Hoffman Ruddy Bari , Nadun Kuruppumullage Don , Carnaby Giselle , Crary Michael , Lehman Jeffery , Ilegbusi Olusegun J. 
Published: February 2017

Objective/HypothesisPatients with laryngeal disorders often exhibit changes to cough function contributing to aspiration episodes. Two primary cough variables (peak cough flow: PCF and compression phase duration: CPD) were examined within a biomechanical model to determine their impact on characteristics that impact airway compromise.Study DesignComputational studyMethodsA Computational Fluid Dynamics (CFD) technique was used to simulate fluid flow within an upper airway model reconstructed from patient CT images. The model utilized a finite‐volume numerical scheme to simulate cough‐induced airflow, allowing for turbulent particle interaction, collision, and break‐up. Liquid penetrants at 8 anatomical release locations were tracked during the simulated cough. Cough flow velocity was computed for a base case and four simulated cases. Airway clearance was evaluated through assessment of the fate of particles in the airway following simulated cough.ResultsPeak‐expiratory phase resulted in very high airway velocities for all simulated cases modelled. The highest velocity predicted was 49.96 m/s, 88 m/s, and 117 m/s for Cases 1 and 3, Base case, and Cases 2 and 4 respectively. In the base case, 25% of the penetrants cleared the laryngeal airway. The highest percentage (50%) of penetrants clearing the laryngeal airway are observed in Case 2 (with −40% CPD, +40% PCF), while only 12.5% cleared in Case 3 (with +40% CPD, −40% PCF). The proportion that cleared in Cases 1 and 4 was 37.5%.ConclusionAirway modelling may be beneficial to the study of aspiration in patients with impaired cough function including those with upper airway and neurological diseases. It can be used to enhance understanding of cough flow dynamics within the airway and to inform strategies for treatment with “cough‐assist devices” or devices to improve cough strength.Level of EvidenceN/A.
Chemiegeschichte: Staudingers Kautschukmodell auf dem Prüfstand
Authors: Requardt Axel 
Published: February 2017

AbstractHermann Staudinger konzipierte im Jahr 1920 seine Theorie der Makromoleküle, die sein Doktorand Jakob Fritschi von 1920 bis 1922 experimentell untersuchte. Fritschi prüfte, ob die Kautschukkolloidteilchen Moleküle oder Mizellen sind, und verwendete als Erster in einer Publikation den Begriff „Makromolekül“.
Workshop für junge Wissenschaftler im tunesischen Hammamet
Authors: Hopf Henning , Limbach Hans , Ellouze Mohamed 
Published: February 2017

AbstractBereits zum sechsten Male gab es einen von GDCh und Alexander‐von‐Humboldt‐Stiftung unterstützten Workshop für junge Wissenschaftler aus arabischen Ländern: Dieses Mal fand die zweitägige Veranstaltung im September 2016 in Hammamet statt, einem Ferienort in Tunesien.
Recent Advances in Effect‐directed Enzyme Assays based on Thin‐layer Chromatography
Authors: Bräm Sarah , Wolfram Evelyn 
Published: February 2017

AbstractThin‐layer chromatography (TLC) together with its more modern form high‐performance thin‐layer chromatography (HPTLC) is a rapid and cost effective analytical tool with a long tradition in quality control of medicinal plants, extracts and natural products. Separated compounds are fixed on the solid silica phase to form a compound library. Through direct coupling of visualisable enzyme reactions on the TLC plate, this compound library can also be used for activity screening. Such TLC‐based bioautographic enzyme and enzyme inhibition assays complement first stage development activity screening assays. They provide not only phytochemical results by chromatographic separation, but also additional information about the activity of constituents or fractions in multi‐compound mixtures, and thus can reveal and distinguish artefacts generated by certain compound classes. This review summarises recently introduced TLC bioautographic enzyme assays as well as advances in already existing procedures. Bioautographic enzyme and enzyme inhibitory assays offer a rapid, high‐throughput method for screening of secondary metabolite profiles for potential enzyme and enzyme inhibitory activities. Copyright © 2017 John Wiley & Sons, Ltd.
Cognitive and behavioural predictors of adolescents' communicative perspective‐taking and social relationships
Authors: Nilsen Elizabeth S. , Bacso Sarah A. 
Published: February 2017

ABSTRACTGiven the pivotal role that social interactions play for adolescents' well‐being, understanding the factors that influence communication is key. The present study examined relations between adolescents' communicative perspective‐taking, executive function skills, and ADHD traits and explored the role communicative perspective‐taking plays in peer relations. Data was collected from a community sample of 15 to 19‐years‐olds (N = 46) in Waterloo, Canada. Two communicative perspective‐taking tasks required participants to infer speakers' communicative intentions. A battery of tasks assessed adolescents' working memory and inhibitory control. Elevated ADHD traits were associated with weaker working memory, inhibitory control, and communicative perspective‐taking. Working memory was the strongest predictor of communicative perspective‐taking. Highlighting the importance of communicative perspective‐taking for social interactions, adolescents with weaker skills in this area reported worse peer relations. Findings underscore the importance of communicative perspective‐taking for adolescents' social relations and have relevance for understanding the social difficulties faced by adolescents with elevated ADHD traits.
Dendritic cell MST1 inhibits Th17 differentiation
Authors: Li Chunxiao , Bi Yujing , Li Yan , Yang Hui , Yu Qing , Wang Jian , Wang Yu , Su Huilin , Jia Anna , Hu Ying , Han Linian , Zhang Jiangyuan , Li Simin , Tao Wufan , Liu Guangwei 
Published: February 2017

AbstractAlthough the differentiation of CD4+T cells is widely studied, the mechanisms of antigen-presenting cell-dependent T-cell modulation are unclear. Here, we investigate the role of dendritic cell (DC)-dependent T-cell differentiation in autoimmune and antifungal inflammation and find that mammalian sterile 20-like kinase 1 (MST1) signalling from DCs negatively regulates IL-17 producing-CD4+T helper cell (Th17) differentiation. MST1 deficiency in DCs increases IL-17 production by CD4+T cells, whereas ectopic MST1 expression in DCs inhibits it. Notably, MST1-mediated DC-dependent Th17 differentiation regulates experimental autoimmune encephalomyelitis and antifungal immunity. Mechanistically, MST1-deficient DCs promote IL-6 secretion and regulate the activation of IL-6 receptor α/β and STAT3 in CD4+T cells in the course of inducing Th17 differentiation. Activation of the p38 MAPK signal is responsible for IL-6 production in MST1-deficient DCs. Thus, our results define the DC MST1–p38MAPK signalling pathway in directing Th17 differentiation.
226Ra and 222Rn in Natural Waters in Two Typical Locations in Spain
Authors: Soto J. , Quindos L.S. , Diaz-Caneja N. , Gutierrez I. , Fernández P.L. 
Published: February 2017

Abstract
A preliminary study is presented, preliminary to a full-scale national survey on 226Ra and 222Rn levels in surface and underground waters in two regions of Spain of very different geological composition, which were selected as representative of the two main geological types existing in the Iberian peninsula. 222Rn concentrations in the different natural waters collected show values ranging from 0.8 to 75 Bq.l-1 in the first area and from 20 to 25,000 Bq.l-1 in the second. 226Ra concentrations in domestic water supplied were found to be over the detection limit for almost all the samples collected, with values reaching about 4 Bq.l-1 in some cases.
Cellulose Nanocrystal Reinforced Chitosan Coatings for Improving the Storability of Postharvest Pears Under Both Ambient and Cold Storages
Authors: Deng Zilong , Jung Jooyeoun , Simonsen John , Wang Yan , Zhao Yanyun 
Published: February 2017

AbstractCellulose nanocrystal (CNC, 0%, 5%, and 10% w/w, in chitosan, dry basis) reinforced 2% chitosan aqueous coatings were evaluated for delaying the ripening and quality deterioration of postharvest green D'Anjou (Pyrus communis L.) and Bartlett (Pyrus communis L.) pears during 3 wk of ambient storage (20 ± 2 °C and 30 ± 2% RH) or 5 mo of cold storage (–1.1 °C and 90% RH), respectively. Ethylene and CO2 production, color, firmness, and internal fruit quality were monitored during both storage conditions. Moisture and gas barrier, antibacterial activity, and surface morphology of the derived films were also evaluated to investigate the mechanisms of delayed fruit ripening and quality deterioration. In the ambient storage study, the 5% CNC reinforced chitosan coating significantly (P < 0.05) delayed green chlorophyll degradation of pear peels, prevented internal browning, reduced senescence scalding, and improved retained fruit firmness. During cold storage, the 5% CNC reinforced chitosan coating showed a competitive effect on delaying fruit postharvest quality deterioration compared to a commercial product (Semperfresh™, Pace International, Wapato, Wash., U.S.A.). The 5% CNC coating strongly adhered to the pear surface, provided a superior gas barrier and a more homogenous matrix in comparison with the other coatings tested. Hence, it was effective in delaying ripening and improving the storability of postharvest pears during both ambient and cold storage.