bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behavioral flexibility of vervet monkeys in response to climatic and social variability
Authors: McFarland Richard , Barrett Louise , Boner Ria , Freeman Natalie J. , Henzi S. Peter 
Published: April 2014

ABSTRACTResponses to environmental variability sheds light on how individuals are able to survive in a particular habitat and provides an indication of the scope and limits of its niche. To understand whether climate has a direct impact on activity, and determine whether vervet monkeys have the behavioral flexibility to respond to environmental change, we examined whether the amount of time spent resting and feeding in the nonmating and mating seasons were predicted by the thermal and energetic constraints of ambient temperature. Our results show that high temperatures during the nonmating season were associated with an increase in time spent resting, at the expense of feeding. Cold temperatures during the nonmating season were associated with an increase in time spent feeding, at the expense of resting. In contrast, both feeding and resting time during the mating season were independent of temperature, suggesting that animals were not adjusting their activity in relation to temperature during this period. Our data indicate that climate has a direct effect on animal activity, and that animals may be thermally and energetically compromised in the mating season. Our study animals appear to have the behavioral flexibility to tolerate current environmental variability. However, future climate change scenarios predict that the time an animal has available for behaviors critical for survival will be constrained by temperature. Further investigations, aimed at determining the degree of behavioral and physiological flexibility displayed by primates, are needed if we are to fully understand the consequences of environmental change on their distribution and survival. Am J Phys Anthropol 154:357–364, 2014. © 2014 Wiley Periodicals, Inc.
Surmounting retraining limits in Musicians' dystonia by transcranial stimulation
Authors: Furuya Shinichi , Nitsche Michael A. , Paulus Walter , Altenmüller Eckart 
Published: April 2014

ObjectiveAbnormal cortical excitability is evident in various movement disorders that compromise fine motor control. Here we tested whether skilled finger movements can be restored in musicians with focal hand dystonia through behavioral training assisted by transcranial direct current stimulation to the motor cortex of both hemispheres.MethodsThe bilateral motor cortices of 20 pianists (10 with focal dystonia, 10 healthy controls) were electrically stimulated noninvasively during bimanual mirrored finger movements.ResultsWe found improvement in the rhythmic accuracy of sequential finger movements with the affected hand during and after cathodal stimulation over the affected cortex and simultaneous anodal stimulation over the unaffected cortex. The improvement was retained 4 days after intervention. Neither a stimulation with the reversed montage of electrodes nor sham stimulation yielded any improvement. Furthermore, the amount of improvement was positively correlated with the severity of the symptoms. Bihemispheric stimulation without concurrent motor training failed to improve fine motor control, underlining the importance of combined retraining and stimulation for restoring the dystonic symptoms. For the healthy pianists, none of the stimulation protocols enhanced movement accuracy.InterpretationThese results suggest a therapeutic potential of behavioral training assisted by bihemispheric, noninvasive brain stimulation in restoring fine motor control in focal dystonia. ANN NEUROL 2014;75:700–707
Simultaneous Spray Self‐Assembly of Highly Loaded ZIF‐8–PDMS Nanohybrid Membranes Exhibiting Exceptionally High Biobutanol‐Permselective Pervaporation
Authors: Fan Hongwei , Shi Qi , Yan Hao , Ji Shulan , Dong Jinxiang , Zhang Guojun 
Published: April 2014

AbstractThe ability to obtain a maximum loading of inorganic nanoparticles while maintaining uniform dispersion in the polymer is the key to the fabrication of mixed‐matrix membranes with high pervaporation performance in bioalcohol recovery from aqueous solution. Herein, we report the simultaneous spray self‐assembly of a zeolitic imidazolate framework (ZIF)–polymer suspension and a cross‐linker/catalyst solution as a method for the fabrication of a well‐dispersed ZIF‐8–PDMS nanohybrid membrane with an extremely high loading. The ZIF‐8–PDMS membrane showed excellent biobutanol‐permselective pervaporation performance. When the ZIF‐8 loading was increased to 40 wt %, the total flux and separation factor could reach 4846.2 g m−2 h−1 and 81.6, respectively, in the recovery of n‐butanol from 1.0 wt % aqueous solution (80 °C). This new method is expected to have serious implications for the preparation of defect‐free mixed‐matrix membranes for many applications.
Bor‐Radikalkationen durch Oxidation elektronenreicher Diborene
Authors: Bissinger Philipp , Braunschweig Holger , Damme Alexander , Kupfer Thomas , Krummenacher Ivo , Vargas Alfredo 
Published: April 2014

AbstractDie Herstellung eines Phosphan‐stabilisierten Diborens, Et3P⋅(Mes)BB(Mes)⋅PEt3 (4), durch Reduktion von Et3P⋅B2Me s2Br2 mit KC8 in Benzol ermöglichte erstmals eine detaillierte Untersuchung der elektronischen Eigenschaften der BB‐Bindung im Vergleich mit dem kürzlich beschriebenen NHC‐stabilisierten Diboren IMe⋅(Dur)BB(Dur)⋅IMe (1). Ein entscheidendes Merkmal dieser Spezies ist die Gegenwart ungewöhnlich elektronenreicher Borzentren. Cyclovoltammetrie, UV/Vis‐Spektroskopie und DFT‐Rechnungen offenbarten eine starke Abhängigkeit der Reduktionspotentiale und Absorptionseigenschaften der BB‐Bindung von der Lewis‐Base. Demnach bedingt die stärkere σ‐Donorfähigkeit und höhere Elektronegativität des NHC‐Liganden ein energetisch höherliegendes HOMO, was 1 zu einem stärkeren neutralen Reduktionsmittel macht als 4 (1: E1/2=−1.55 V; 4: −1.05 V), sowie einen kleineren HOMO‐LUMO‐Abstand in 1, verbunden mit einer signifikanten Rotverschiebung der niederenergetischsten Absorptionsbande im Vergleich zu 4. Wegen ihrer stark negativen Reduktionspotentiale können die Diborene 1 und 4 relativ einfach zu sehr seltenen Bor‐zentrierten Radikalkationen oxidiert werden (5 und 6).
Entropy is Key to the Formation of Pentacyclic Terpenoids by Enzyme‐Catalyzed Polycyclization
Authors: Syrén Per‐Olof , Hammer Stephan C. , Claasen Birgit , Hauer Bernhard 
Published: April 2014

AbstractPolycyclizations constitute a cornerstone of chemistry and biology. Multicyclic scaffolds are generated by terpene cyclase enzymes in nature through a carbocationic polycyclization cascade of a prefolded polyisoprene backbone, for which electrostatic stabilization of transient carbocationic species is believed to drive catalysis. Computational studies and site‐directed mutagenesis were used to assess the contribution of entropy to the polycyclization cascade catalyzed by the triterpene cyclase from A. acidocaldarius. Our results show that entropy contributes significantly to the rate enhancement through the release of water molecules through specific channels. A single rational point mutation that results in the disruption of one of these water channels decreased the entropic contribution to catalysis by 60 kcal mol−1. This work demonstrates that entropy is the key to enzyme‐catalyzed polycyclizations, which are highly relevant in biology since 90 % of all natural products contain a cyclic subunit.
In Situ Synthesis of Robust Conductive Cellulose/Polypyrrole Composite Aerogels and Their Potential Application in Nerve Regeneration
Authors: Shi Zhuqun , Gao Huichang , Feng Jiao , Ding Beibei , Cao Xiaodong , Kuga Shigenori , Wang Yingjun , Zhang Lina , Cai Jie 
Published: April 2014

AbstractNanostructured conductive polymers can offer analogous environments for extracellular matrix and induce cellular responses by electric stimulation, however, such materials often lack mechanical strength and tend to collapse under small stresses. We prepared electrically conductive nanoporous materials by coating nanoporous cellulose gels (NCG) with polypyrrole (PPy) nanoparticles, which were synthesized in situ from pyrrole monomers supplied as vapor. The resulting NCG/PPy composite hydrogels were converted to aerogels by drying with supercritical CO2, giving a density of 0.41–0.53 g cm−3, nitrogen adsorption surface areas of 264–303 m2 g−1, and high mechanical strength. The NCG/PPy composite hydrogels exhibited an electrical conductivity of up to 0.08 S cm−1. In vitro studies showed that the incorporation of PPy into an NCG enhances the adhesion and proliferation of PC12 cells. Electrical stimulation demonstrated that PC12 cells attached and extended longer neurites when cultured on NCG/PPy composite gels with DBSA dopant. These materials are promising candidates for applications in nerve regeneration, carbon capture, catalyst supports, and many others.
Surface‐Enhanced Raman Spectroscopy: Concepts and Chemical Applications
Authors: Schlücker Sebastian 
Published: April 2014

AbstractSurface‐enhanced Raman scattering (SERS) has become a mature vibrational spectroscopic technique during the last decades and the number of applications in the chemical, material, and in particular life sciences is rapidly increasing. This Review explains the basic theory of SERS in a brief tutorial and—based on original results from recent research—summarizes fundamental aspects necessary for understanding SERS and provides examples for the preparation of plasmonic nanostructures for SERS. Chemical applications of SERS are the centerpiece of this Review. They cover a broad range of topics such as catalysis and spectroelectrochemistry, single‐molecule detection, and (bio)analytical chemistry.
A highly efficient β‐nucleating agent for impact‐resistant polypropylene copolymer
Authors: Liu Yi‐Min , Tong Zai‐Zai , Xu Jun‐Ting , Fu Zhi‐Sheng , Fan Zhi‐Qiang 
Published: April 2014

ABSTRACTIn this work, we reported calcium tetrahydrophthalate as a high efficient β‐nucleating agent (β‐NA) for impact‐resistant polypropylene copolymer (IPC). The relative fraction of the β‐crystal can reach as high as 93.5% when only 0.03% β‐NA is added. The non‐isothermal and isothermal crystallization behaviors, morphology, lamellar structure and mechanical properties of IPCs with various β‐NA contents were studied. During non‐isothermal crystallization, the cooling rate has an important influence on the relative fraction of the β‐crystal, which decreases remarkably as the cooling rate increases. The β‐NA also greatly accelerates crystallization rate of IPC, resulting from both more crystal nuclei and larger Avrami exponent. The small angle X‐ray scattering characterization shows that more amorphous components are included into the inter‐lamellae after addition of β‐NA. Dynamical mechanical analysis (DMA) reveals that the storage modulus at low temperature and the loss factor above 0 °C from the PP component can be enhanced upon addition of β‐NA and reach a maximum at the β‐NA content of 0.05 wt %. Impact test shows that the impact strength of the IPC at 0°C can be improved as much as 40% when the content of calcium tetrahydrophthalate is 0.10 wt %. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40753.
Further evidence for FGF16 truncating mutations as the cause of X‐linked recessive fusion of metacarpals 4 / 5
Authors: Jamsheer Aleksander , Śmigiel Robert , Jakubiak Aleksandra , Zemojtel Tomasz , Socha Magdalena , Robinson Peter N. , Mundlos Stefan 
Published: April 2014

BackgroundMetacarpal 4–5 fusion (MF4; MIM#309630) is a rare congenital malformation of the hand characterized by the partial or complete fusion of the fourth and fifth metacarpals. The anomaly occurs as an isolated trait or part of a genetic syndrome. Recently, we have identified FGF16 nonsense mutations as the underlying cause of isolated X‐linked recessive MF4.MethodsIn this report, we provide a detailed clinical description of a sporadic male patient showing MF4 in whom we performed Sanger sequencing of the entire coding sequence of FGF16.ResultsIn addition to MF4 symptoms, the patient presented with generalized joint laxity and hypermobility. FGF16 sequencing detected a novel truncating mutation (c.474_477del; p.E158DfsX25) in exon 3 of the gene. A heterozygous mutation was found in a clinically and radiologically unaffected mother of the proband.ConclusionOur finding confirms that truncating mutations of FGF16 are causative for X‐linked recessive metacarpal 4–5 fusion. Importantly, the mutation detected in this study was located in last exon of the gene (exon 3), like the only two FGF16 disease‐causing variants identified to date. Thus, all FGF16 mutations known to give rise to this rare skeletal hand malformation are C‐terminal and most probably do not result in a nonsense mediated decay. Additionally, our proband showed mild symptoms of a connective tissue disorder, as some other patients previously reported to have X‐linked MF4. Therefore, we suggest that impaired FGF16 function may also be responsible for connective tissue symptoms in MF4 patients. Birth Defects Research (Part A) 100:314–318, 2014. © 2014 Wiley Periodicals, Inc.
A sensitive and selective method for the quantitative analysis of miglitol in rat plasma using unique solid‐phase extraction coupled with liquid chromatography–tandem mass spectrometry
Authors: Mizuno‐Yasuhira Akiko , Kinoshita Kohnosuke , Jingu Shigeji , Yamaguchi Jun‐ichi 
Published: April 2014

ABSTRACTA sensitive, selective and robust liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method was developed for the quantification of miglitol in rat plasma. The sample preparation procedures involved protein precipitation and unique solid‐phase extraction, which efficiently removed sources of ion suppression and column degradation interference present in the plasma. Chromatographic separation was achieved on an amide column using 10 mmol/L CH3COONH4 and CH3CN:CH3OH (90:10, v/v) as the mobile phase under gradient conditions. Detection was performed using tandem mass spectrometry equipped with an electrospray ionization interface in positive ion mode.The selected reaction monitoring transitions for miglitol and a stable isotope‐labeled internal standard were m/z 208 → m/z 146 and m/z 212 → m/z 176, respectively. The correlation coefficients of the calibration curves ranged from 0.9984 to 0.9993 over a concentration range of 0.5–100 ng/mL plasma. The quantification limit of the proposed method was more than 10 times lower than those of previously reported LC‐MS/MS methods. The novel method was successfully validated and applied to a pharmacokinetic study in rats. Copyright © 2014 John Wiley & Sons, Ltd.
Extraordinary Thermal Stability of an Oligodeoxynucleotide Octamer Constructed from Alternating 7‐Deaza‐7‐iodo guanine and 5‐Iodocytosine Base Pairs – DNA Duplex Stabilization by Halogen Bonds?
Authors: Ramzaeva Natalya , Eickmeier Henning , Rosemeyer Helmut 
Published: April 2014

AbstractA reinvestigation of the published X‐ray crystal‐structure analyses of 7‐halogenated (Br, I) 8‐aza‐7‐deaza‐2′‐deoxyguanosines Br7c7z8Gd; 1a and I7c7z8Gd, 1b, as well as of the structurally related 7‐deaza‐7‐iodo‐2′‐deoxy‐β‐D‐ribofuranosyladenine (β‐I7c7Ad; 2=6e in Table 1) and its α‐D‐anomer (α‐I7c7Ad; 3) clearly revealed the existence of halogen bonds between corresponding halogen substituents and the adjacent N(3)‐atoms of neighboring nucleoside molecules within the single crystals. These halogen bonds can be rationalized by the presence of a region of positive electrostatic potential, the σ‐hole, on the outermost portion the halogen's surface, while the three unshared pairs of electrons produce a belt of negative electrostatic potential around the central part of the halogen substituent. The N(3) atoms of the halogenated nucleosides carry a partial negative charge. This novel type of bonding between nucleosides was tentatively used to explain the extraordinary high stability of oligodeoxynucleotides constructed from halogenated nucleotide building blocks.
Dynamics of Fatty‐Acid Composition of Neutral Acylglycerols in Maturing Euonymus Fruits
Authors: Sidorov Roman A. , Zhukov Anatoly V. , Pchelkin Vasily P. , Vereshchagin Andrei G. , Tsydendambaev Vladimir D. 
Published: April 2014

AbstractThe dynamics of the fatty‐acid (FA) composition of neutral acylglycerols (NAGs) composed of 1,2,3‐triacyl‐sn‐glycerols (TAGs) and 3‐acetyl‐1,2‐diacyl‐sn‐glycerols (acDAGs) was determined in the fruit seeds and arils of three Euonymus L. species at three stages of their maturity. The NAG composition comprised 29 FAs, linoleic, oleic, palmitic, and α‐linolenic acids being predominant. Noticeable amounts of other FAs, such as lauric, myristic, hexadec‐9‐enoic, stearic, (Z)‐vaccenic, and arachidic acid, etc., could also be present. In the course of maturation, the qualitative composition of major FAs remained nearly unchanged, while the unsaturation index of FAs in seeds and in TAGs, as well as, but to a lesser extent, in arils and in acDAGs, respectively, always decreased. This decline was brought about by a sharp fall of the α‐linolenate level, a decrease of the linoleate content, and a corresponding rise in the oleate content. It is suggested that, in both seeds and arils, both classes of NAGs were formed at the expense of the same FA pool; the quantitative composition of this pool was characteristic of a given fruit part and strongly changed during maturation. The accumulation of TAGs in E. europaeus fruits was accompanied by a conversion of hexadec‐9‐enoic acid into (Z)‐vaccenic acid via the C2‐elongation reaction.
Volatile Compounds in Thymus sect. Teucrioides (Lamiaceae): Intraspecific and Interspecific Diversity, Chemotaxonomic Significance and Exploitation Potential
Authors: Pitarokili Danae , Constantinidis Theophanis , Saitanis Costas , Tzakou Olga 
Published: April 2014

AbstractThymus sect. Teucrioides comprises three species, namely, T. hartvigii, T. leucospermus, and T. teucrioides, distributed in Greece and Albania. The volatile constituents of all species of the section were obtained by hydrodistillation and investigated by GC‐FID and GC/MS analyses. Twenty populations were sampled and a total of 103 compounds were identified, representing 98.0–99.9% of the oil compositions. The oils were mainly characterized by high contents of monoterpene hydrocarbons (42.7–92.4%), with the exception of three oils for which oxygenated monoterpenes were the dominating constituents, viz., that of T. hartvigii ssp. macrocalyx, with linalool as main compound (89.2±0.5%), and those of T. hartvigii ssp. hartvigii and of one population of T. teucrioides ssp. candilicus, containing thymol as major component (46.4±3.1 and 38.2±3.9%, resp.). The most common compound in the oils of the 20 populations of the section was p‐cymene. Considerable variation was detected within and among populations, and seven chemotypes were distinguished, i.e., p‐cymene, linalool, p‐cymene/thymol, p‐cymene/γ‐terpinene, p‐cymene/borneol, p‐cymene/γ‐terpinene/borneol, and p‐cymene/linalool chemotypes. Different chemotypes may exist in the same population. Multivariate statistical analyses enabled the segregation of the oils within Thymus sect. Teucrioides into two groups, one consisting of the three subspecies of T. teucrioides and the second comprising the species T. hartvigii and T. leucospermus. A linalool‐rich chemotype, unique within the section, distinguished the oil of T. hartvigii ssp. macrocalyx from all other oils. The high oil content of p‐cymene and the preference for serpentine substrates render T. teucrioides species promising for future exploitation.
Cytotoxic and Apoptosis‐Inducing Activities, and Anti‐Tumor‐Promoting Effects of Cyanogenated and Oxygenated Triterpenes
Authors: Kikuchi Takashi , Ishii Kenta , Ogihara Eri , Zhang Jie , Ukiya Motohiko , Tokuda Harukuni , Iida Takashi , Tanaka Reiko , Akihisa Toshihiro 
Published: April 2014

AbstractTwo of each semisynthetic lanostane‐ and cycloartane‐type triterpenes with a cyano‐enone functionality, i.e., 13 and 18, and 23 and 28, respectively, sixteen of their synthetic intermediates, 9–12, 14–17, 19–22, and 24–27, along with seven semisynthetic oxygenated triterpene acetates, 29–35, and eight natural hydroxy triterpenes, 1–8, were evaluated for their cytotoxic activities against leukemia (HL60), lung (A549), stomach (AZ521), and breast (SK‐BR‐3) cancer cell lines. One natural triterpene, 8, and ten semisynthetic triterpenes, 9, 13, 15, 18, 23, 25, 28, 29, 32, and 33, exhibited potent cytotoxicities against one or more cell lines with IC50 values in the range of 1.4–9.9 μM. Two lanostane‐type triterpenes with a cyano‐enone functionality, 3‐oxolanosta‐1,8,24‐triene‐2‐carbonitrile (13) and 3‐oxolanosta‐1,8‐diene‐2‐carbonitrile (18), induced apoptosis in HL60 cells, as observed by membrane phospholipid exposure in flow cytometry. Western blot analysis showed that 13 and 18 significantly reduced procaspases‐3, ‐8, and ‐9, and increased cleaved caspases‐3, ‐8, and ‐9. These findings indicated that compounds 13 and 18 induced apoptosis in HL60 cells via both the mitochondrial and the death receptor‐mediated pathways. In addition, upon evaluation of the inhibitory effects on EpsteinBarr virus early antigen (EBV‐EA) activation induced with 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) in Raji cells, seven natural triterpenes, 1–6 and 8, and ten semisynthetic triterpenes, 9, 10, 14, 15, 19, 20, 24, 25, 29, and 30, exhibited inhibitory effects which were higher than that of β‐carotene, a vitamin A precursor studied widely in cancer‐chemoprevention animal models.
Silylation Improves the Photodynamic Activity of Tetraphenylporphyrin Derivatives In Vitro and In Vivo
Authors: Horiuchi Hiroaki , Hosaka Masahiro , Mashio Hiroyuki , Terata Motoki , Ishida Shintaro , Kyushin Soichiro , Okutsu Tetsuo , Takeuchi Toshiyuki , Hiratsuka Hiroshi 
Published: April 2014

AbstractThe effects of silyl and hydrophilic groups on the photodynamic properties of tetraphenylporphyrin (TPP) derivatives have been studied in vitro and in vivo. Silylation led to an improvement in the quantum yield of singlet oxygen sensitization for both sulfo and carboxy derivatives, although the silylation did not affect other photophysical properties. Silylation also improved the cellular uptake efficiency for both sulfo and carboxy derivatives, enhancing the in vitro photodynamic activity of the photosensitizer in U251 human glioma cells. The carboxy derivative (SiTPPC4) was found to show higher cellular uptake efficiency and in vitro photodynamic activity than the corresponding sulfo derivative (SiTPPS4), which indicates that the carboxy group is a more promising hydrophilic group than the sulfo group in the silylated porphyrin. SiTPPC4 was found to show high selective accumulation efficiency in tumors, although almost no tumor selectivity was observed for the nonsilylated porphyrin. The concentration of SiTPPC4 in tumors was 13 times higher than that in muscle 12 h after drug administration. We also studied tumor response after treatment and found that silylation enhanced in vivo photodynamic activity significantly. SiTPPC4 shows higher photodynamic activity than NPe6 with white light irradiation.