bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Radical Pathway for Direct Substitution of Benzyl Alcohols with Water‐Soluble Copper Catalyst in Water
Authors: Hikawa Hidemasa , Mori Yuki , Kikkawa Shoko , Azumaya Isao 
Published: February 2016

AbstractWe have developed a novel strategy for the direct substitution of benzyl alcohols with anthranilic acids using water‐soluble copper catalysts through a radical pathway in water, which offers efficient and environmentally friendly N‐, S‐, and C‐benzylations under neutral conditions. Radical scavengers strongly inhibited the benzylation. Radical clock experiments using α‐cyclopropylbenzyl alcohol were conducted to observe the rapid isomerization of the cyclopropylmethyl radical to the allylmethyl radical. Hammett plots could be fitted to a two‐parameter Hammett relationship containing both radical and polar contributions [log (kX/kH)=−1.24 σ.–0.38 σ, R2=0.99]. The relative parameter ρ./ρ of 3.3 suggested that these reactions involved a strong radical character with minor polar influence at the transition state.magnified image
Structure and Composition of the 200 K‐Superconducting Phase of H2S at Ultrahigh Pressure: The Perovskite (SH−)(H3S+)
Authors: Gordon Elijah E. , Xu Ke , Xiang Hongjun , Bussmann‐Holder Annette , Kremer Reinhard K. , Simon Arndt , Köhler Jürgen , Whangbo Myung‐Hwan 
Published: February 2016

AbstractAt ultrahigh pressure (>110 GPa), H2S is converted into a metallic phase that becomes superconducting with a record Tc of approximately 200 K. It has been proposed that the superconducting phase is body‐centered cubic H3S (Im
m, a=3.089 Å) resulting from the decomposition reaction 3 H2S→2 H3S+S. The analogy between H2S and H2O led us to a very different conclusion. The well‐known dissociation of water into H3O+ and OH− increases by orders of magnitude under pressure. H2S is anticipated to behave similarly under pressure, with the dissociation process 2 H2S→H3S++SH− leading to the perovskite structure (SH−)(H3S+). This phase consists of corner‐sharing SH6 octahedra with SH− ions at each A site (the centers of the S8 cubes). DFT calculations show that the perovskite (SH−)(H3S+) is thermodynamically more stable than the Im
m structure of H3S, and suggest that the A site hydrogen atoms are most likely fluxional even at Tc .
A Water‐Stable Cationic Metal–Organic Framework as a Dual Adsorbent of Oxoanion Pollutants
Authors: Desai Aamod V. , Manna Biplab , Karmakar Avishek , Sahu Amit , Ghosh Sujit K. 
Published: February 2016

AbstractA three‐dimensional water‐stable cationic metal–organic framework (MOF) pillared by a neutral ligand and with NiII metal nodes has been synthesized employing a rational design approach. Owing to the ordered arrangement of the uncoordinated tetrahedral sulfate (SO42−) ions in the channels, the compound has been employed for aqueous‐phase ion‐exchange applications. The compound exhibits rapid and colorimetric aqueous‐phase capture of environmentally toxic oxoanions (with similar geometries) in a selective manner. This system is the first example of a MOF‐based system which absorbs both dichromate (Cr2O72−) and permanganate (MnO4−) ions, with the latter acting as a model for the radioactive contaminant pertechnetate (TcO4−).
Numeric Estimates of Teratogenic Severity from Embryo–Fetal Developmental Toxicity Studies
Authors: Wise L. David 
Published: February 2016

A developing organism exposed to a toxicant will have a response that ranges from none to severe (i.e., death or malformation). The response at a given dosage may be termed teratogenic (or developmental toxic) severity and is dependent on exposure conditions. Prenatal/embryo–fetal developmental (EFD) toxicity studies in rodents and rabbits are the most consistent and definitive assessments of teratogenic severity, and teratogenesis screening assays are best validated against their results. A formula is presented that estimates teratogenic severity for each group, including control, within an EFD study. The developmental components include embryonic/fetal death, malformations, variations, and mean fetal weight. The contribution of maternal toxicity is included with multiplication factors to adjust for the extent of mortality, maternal body weight change, and other parameters deemed important. The derivation of the formula to calculate teratogenic severity is described. Various EFD data sets from the literature are presented to highlight considerations to the calculation of the various components of the formula. Each score is compared to the concurrent control group to obtain a relative teratogenic severity. The limited studies presented suggest relative scores of two‐ to <fivefold higher than control have detectable but a low level of teratogenic severity, and scores ≥fivefold higher than control have increasingly more severe teratogenicity. Such scores may help refine the concept of an exposure‐based validation list for use by proponents of screening assays (Daston et al., 2014) by estimating the severity of “positive” exposures, or in other situations by defining the severity of a LOAEL (lowest observed adverse effect level)
Modeling bond correlations in denatured proteins and polypeptides
Authors: Betancourt Marcos R. 
Published: February 2016

ABSTRACTBond‐orientational correlations for finite‐length homopolypeptides and a selected group of denatured proteins are obtained by numerical simulations using a polypeptide model with a potential of mean force. These correlations characterize the stiffness of the polypeptide backbone and are generally described by either an exponential or a power‐law decay in the asymptotic limit. However, for finite length polypeptides and unfolded proteins the correlations significantly deviate from either single exponential or power‐law behavior. A heuristic model is developed to analyze the correlations of homopolypeptides, which depends on the chain length and the side‐chain properties. The model contains power‐law and multi‐exponential terms, the latter which could be interpreted as local persistence lengths. In the asymptotic limit, the model reduces to the expected power‐law behavior. Simulations of denatured proteins show that the power‐law behavior of the correlations is significantly suppressed and only the multi‐exponential term is needed to model the correlations. In addition, average persistence lengths (ranging from 2.0 to 2.5 nm) are obtained from the correlations by fitting single exponentials and shown to be in general agreement with experiments, which also assume single exponential decay. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 312–323, 2016.
Virtual substitution scan via single‐step free energy perturbation
Authors: Chiang Ying‐Chih , Wang Yi 
Published: February 2016

ABSTRACTWith the rapid expansion of our computing power, molecular dynamics (MD) simulations ranging from hundreds of nanoseconds to microseconds or even milliseconds have become increasingly common. The majority of these long trajectories are obtained from plain (vanilla) MD simulations, where no enhanced sampling or free energy calculation method is employed. To promote the “recycling” of these trajectories, we developed the Virtual Substitution Scan (VSS) toolkit as a plugin of the open‐source visualization and analysis software VMD. Based on the single‐step free energy perturbation (sFEP) method, VSS enables the user to post‐process a vanilla MD trajectory for a fast free energy scan of substituting aryl hydrogens by small functional groups. Dihedrals of the functional groups are sampled explicitly in VSS, which improves the performance of the calculation and is found particularly important for certain groups. As a proof‐of‐concept demonstration, we employ VSS to compute the solvation free energy change upon substituting the hydrogen of a benzene molecule by 12 small functional groups frequently considered in lead optimization. Additionally, VSS is used to compute the relative binding free energy of four selected ligands of the T4 lysozyme. Overall, the computational cost of VSS is only a fraction of the corresponding multi‐step FEP (mFEP) calculation, while its results agree reasonably well with those of mFEP, indicating that VSS offers a promising tool for rapid free energy scan of small functional group substitutions. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 324–336, 2016.
Feedback from each retinal neuron population drives expression of subsequent fate determinant genes without influencing the cell cycle exit timing
Authors: Kei Jeremy Ng Chi , Dudczig Stefanie , Currie Peter D. , Jusuf Patricia R. 
Published: February 2016

ABSTRACTDuring neurogenesis, progenitors balance proliferation and cell cycle exit together with expression of fate determinant genes to ensure that the correct number of each of these neuron types is generated. Although intrinsic gene expression acting cell autonomously within each progenitor drives these processes, the final number of neurons generated is also influenced by extrinsic cues, representing a potential avenue to direct neurogenesis in developmental disorders or regenerative settings without the requirement to change intrinsic gene expression. Thus, it is important to understand which of these stages of neurogenesis are amenable to such extrinsic influences. Additionally, all types of neurons are specified in a highly conserved histogenic order, although its significance is unknown. This study makes use of conserved patterns of neurogenesis in the relatively simple yet highly organized zebrafish retina model, in which such histogenic birth order is well characterized. We directly visualize and quantify birth dates and cell fate determinant expression in WT vs. environments lacking different neuronal populations. This study shows that extrinsic feedback from developing retinal neurons is important for the temporal expression of intrinsic fate determinants but not for the timing of birth dates. We found no changes in cell cycle exit timing but did find a significant delay in the expression of genes driving the generation only of later‐ but not earlier‐born cells, suggesting that the robustness of this process depends on continuous feedback from earlier‐formed cell types. Thus, extrinsic cues selectively influence cell fate determinant progression, which may explain the function of the retinal histogenic order observed. J. Comp. Neurol. 524:2553–2566, 2016. © 2016 Wiley Periodicals, Inc.
Tectothalamic inhibitory projection neurons in the avian torus semicircularis
Authors: Ito Tetsufumi , Atoji Yasuro 
Published: February 2016

ABSTRACTInhibitory feedforward projection is one of key features of the organization of the central auditory system. In mammals, the inferior colliculus (IC) is the origin of a substantial inhibitory feedforward projection as well as an excitatory projection to the auditory thalamus. This inhibitory feedforward projection is provided by large γ‐aminobutyric acid (GABA)ergic (LG) neurons, which are characterized by their receipt of dense excitatory axosomatic terminals positive for vesicular glutamate transporter (VGLUT) 2. In the avian torus semicircularis (TS), which is the homolog of the IC, neither the homology of cell types nor the presence of inhibitory feedforward inhibition have been established. In this study, we tested the presence of LG neurons in pigeon and chicken by neuroanatomical techniques. The TS contained two types of GABAergic neurons of different soma size. Of these, larger GABA + cells were encircled by dense VGLUT2 + axosomatic terminals. Ultrastructural analyses revealed that more than 30% of the perimeter of a large GABA+, but not small GABA + or GABA−, soma was covered by presumptive excitatory axosomatic terminals, suggesting that large GABA + cells are the sole recipient of dense excitatory axosomatic synapses. After injection of a retrograde tracer into the auditory thalamus, many retrogradely labeled neurons were found bilaterally in the TS, a few of which were GABA+. Almost all tectothalamic GABA + neurons had large somata, and received dense VGLUT2 + axosomatic terminals. These results clearly demonstrated the presence of LG neurons in birds. The similar morphology of LG neurons implies that the function of tectothalamic inhibition is similar among amniotes. J. Comp. Neurol. 524:2604–2622, 2016. © 2016 Wiley Periodicals, Inc.
A quantitative comparison of the hemispheric, areal, and laminar origins of sensory and motor cortical projections to the superior colliculus of the cat
Authors: Butler Blake E. , Chabot Nicole , Lomber Stephen G. 
Published: February 2016

ABSTRACTThe superior colliculus (SC) is a midbrain structure central to orienting behaviors. The organization of descending projections from sensory cortices to the SC has garnered much attention; however, rarely have projections from multiple modalities been quantified and contrasted, allowing for meaningful conclusions within a single species. Here, we examine corticotectal projections from visual, auditory, somatosensory, motor, and limbic cortices via retrograde pathway tracers injected throughout the superficial and deep layers of the cat SC. As anticipated, the majority of cortical inputs to the SC originate in the visual cortex. In fact, each field implicated in visual orienting behavior makes a substantial projection. Conversely, only one area of the auditory orienting system, the auditory field of the anterior ectosylvian sulcus (fAES), and no area involved in somatosensory orienting, shows significant corticotectal inputs. Although small relative to visual inputs, the projection from the fAES is of particular interest, as it represents the only bilateral cortical input to the SC. This detailed, quantitative study allows for comparison across modalities in an animal that serves as a useful model for both auditory and visual perception. Moreover, the differences in patterns of corticotectal projections between modalities inform the ways in which orienting systems are modulated by cortical feedback. J. Comp. Neurol. 524:2623–2642, 2016. © 2016 Wiley Periodicals, Inc.
Rapid analysis and quantification of major neutral lipid species and free fatty acids by HPLC‐ELSD from microalgae
Authors: Donot Florentin , Strub Caroline , Fontana Angélique , Jouy Nicolas , Delbes Christelle , Gunata Ziya , Schorr‐Galindo Sabine 
Published: February 2016

A method based on normal‐phase high performance liquid chromatography combined with evaporative light‐scattering detector was developed to quantify major neutral lipids from microalgae. A binary gradient enabled a good resolution of hydrocarbons and major neutral lipids by classes in less than 13 min. A good linearity was observed from 0.9 to 30 μg. Limits of detection (LOD) and quantification (LOQ) was from 3 to 64 ng depending on the analyte. The intra‐ and inter‐run precision (% RSD) of analysis was found less than 10%. The method was successfully applied to microalgae lipid extracts from Botryococcus braunii, Chlorella vulgaris, Spirulina platensis, and Porphyridium cruentum. B. braunii was distinguished by the highest levels of lipids, triacylglycerol (TAGs), and diacylglycerol (DAGs) being the major compounds.Practical applications: Neutral lipids produced by the microalgae are an interesting way for the development of biofuel from renewable carbon. A simple quantification of these lipids is important in the implementation of oleaginous microalgae screening as well as in the bioprocess optimization of algal lipid production. Besides, determining quantitatively the major lipid classes provides information in the understanding of the biosynthetic pathways and the accumulation of these lipids in relation with algal culture conditions.Normal‐phase HPLC conditions were studied to establish a method allowing a rapid separation of TAGs, DAGs, MAGs, and FFA but also HC by classes in a single run. Their quantification through evaporative light‐scattering detector (ELSD) was performed. The developed method was applied on lipid extracts from the different algal cultures.
Dysgenetic polycystic disease of the minor and submandibular salivary glands
Authors: Koudounarakis Eleftherios , Willems Stefan , Karakullukcu Baris 
Published: February 2016

AbstractBackgroundDysgenetic polycystic salivary gland disease is a rare pathology. No case of minor salivary gland involvement has been reported in the literature.MethodsA female patient presented with bilateral tumors of the parotid glands, bilateral submandibular gland enlargement, and multiple cystic lesions of the oral mucosa. MRI of the neck was performed along with fine‐needle aspiration (FNA) of the parotid tumors and excisional biopsy of an oral lesion.ResultsImaging and FNA findings of the parotid glands were suggestive of bilateral Warthin tumors. Excisional biopsy of the oral lesion revealed a minor salivary gland with histopathological features of dysgenetic polycystic salivary gland disease. Submandibular gland enlargement was also attributed to this rare entity based on the imaging characteristics.ConclusionThis is the first report of dysgenetic polycystic salivary gland disease of the minor salivary glands, combined with involvement of the submandibular glands and bilateral Warthin tumors of the parotid gland. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2437–E2439, 2016
Abstinence from cocaine‐self‐administration activates the nELAV/GAP ‐43 pathway in the hippocampus: A stress‐related effect?
Authors: Pascale Alessia , Osera Cecilia , Moro Federico , Di Clemente Angelo , Giannotti Giuseppe , Caffino Lucia , Govoni Stefano , Fumagalli Fabio , Cervo Luigi 
Published: February 2016

ABSTRACTWe previously demonstrated that nELAV/GAP‐43 pathway is pivotal for learning and its hippocampal expression is up‐regulated by acute stress following repeated cocaine administration. We therefore hypothesized that abstinence‐induced stress may sustain nELAV/GAP‐43 pathway during early abstinence following 2 weeks of cocaine self‐administration. We found that contingent, but not non‐contingent, cocaine exposure selectively increases hippocampal nELAV, but not GAP‐43, expression immediately after the last self‐administration session, an effect that wanes after 24 h and that comes back 7 days later when nELAV activation becomes associated with increased expression of GAP‐43, an effect again observed only in animals self‐administering the psychostimulant. Such effect is specific for nELAV since the ubiquitous ELAV/HuR is unchanged. This nELAV profile suggests that its initial transient alteration is perhaps related to the daily administration of cocaine, while the increase in the nELAV/GAP‐43 pathway following a week of abstinence may reflect the activation of this cascade as a target of stressful conditions associated with drug‐related memories. © 2016 Wiley Periodicals, Inc.
Probability of combined high sea levels and large rains in Malmö, Sweden, southern Öresund
Authors: Bengtsson Lars 
Published: February 2016

AbstractObservations of sea level and precipitation in Malmö, Sweden in the southeastern part of the sound Öresund have been used to estimate the probabilities of local compound events of high sea level and large daily and hourly rains. There are observations of sea level and daily rains extending back to 1930. The observations of short‐term rainfall are from 1980 and onwards. Most large rainfalls come in the summer, while the highest sea levels are in the autumn and in the winter. The highest observed sea level is about 130 cm above mean sea level, and the largest daily rain is close to 100 mm. However, the highest sea level observed during a day with rainfall corresponding to the 1‐year rain is less than 60 cm. The highest sea level observed during an hour with 1‐year hourly rainfall is 30 cm.From the statistics of daily rains, hourly rains and sea level, extreme values for each of them have been computed. For events with frequency higher than one per four years the probabilities of combined events sea level – rainfall are determined directly from the observations. For more rare events, marginal distributions of sea level and rainfall are determined. Copulas and conditional probabilities are used. When the sea level exceeds 20 cm above mean sea level, daily rains exceeding 10 mm are almost independent of the sea level and so are hourly rains exceeding 5 mm. It is extremely rare that large rains occur when the sea level is very high. The combination of 1‐year rainfall and the 1‐year sea level has a return period of more than 200 years.
Multidecadal climate variability over northern France during the past 500 years and its relation to large‐scale atmospheric circulation
Authors: Dieppois B. , Lawler D. M. , Slonosky V. , Massei N. , Bigot S. , Fournier M. , Durand A. 
Published: February 2016

ABSTRACTWe examine secular changes and multidecadal climate variability on a seasonal scale in northern France over the last 500 years and examine the extent to which they are driven by large‐scale atmospheric variability. Multiscale trend analysis and segmentation procedures show statistically significant increases of winter and spring precipitation amounts in Paris since the end of the 19th century. This changes the seasonal precipitation distribution from one with a pronounced summer peak at the end of the Little Ice Age to an almost uniform distribution in the 20th century. This switch is linked to an early warming trend in winter temperature. Changes in spring precipitation are also correlated with winter precipitation for time scales greater than 50 years, which suggests a seasonal persistence. Hydrological modelling results show similar rising trends in river flow for the Seine at Paris. However, such secular trends in the seasonal climatic conditions over northern France are substantially modulated by irregular multidecadal (50–80 years) fluctuations. Furthermore, since the end of the 19th century, we find an increasing variance in multidecadal hydroclimatic winter and spring, and this coincides with an increase in the multidecadal North Atlantic Oscillation (NAO) variability, suggesting a significant influence of large‐scale atmospheric circulation patterns. However, multidecadal NAO variability has decreased in summer. Using Empirical Orthogonal Function analysis, we detect multidecadal North Atlantic sea‐level pressure anomalies, which are significantly linked to the NAO during the Modern period. In particular, a south‐eastward (south‐westward) shift of the Icelandic Low (Azores High) drives substantial multidecadal changes in spring. Wetter springs are likely to be driven by potential changes in moisture advection from the Atlantic, in response to northward shifts of North Atlantic storm tracks over European regions, linked to periods of positive NAO. Similar, but smaller, changes in rainfall are observed in winter.