bluuebunny/crossref_metadata_2025_split huggingface dataset:
Signatures of transient Wannier-Stark localization in bulk gallium arsenide
Authors: Schmidt C. , Bühler J. , Heinrich A.-C. , Allerbeck J. , Podzimski R. , Berghoff D. , Meier T. , Schmidt W. G. , Reichl C. , Wegscheider W. , Brida D. , Leitenstorfer A. 
Published: July 2018

AbstractMany properties of solids result from the fact that in a periodic crystal structure, electronic wave functions are delocalized over many lattice sites. Electrons should become increasingly localized when a strong electric field is applied. So far, this Wannier–Stark regime has been reached only in artificial superlattices. Here we show that extremely transient bias over the few-femtosecond period of phase-stable mid-infrared pulses may localize electrons even in a bulk semiconductor like GaAs. The complicated band structure of a three-dimensional crystal leads to a strong blurring of field-dependent steps in the Wannier–Stark ladder. Only the central step emerges strongly in interband electro-absorption because its energetic position is dictated by the electronic structure at an atomic level and therefore insensitive to the external bias. In this way, we demonstrate an extreme state of matter with potential applications due to e.g., its giant optical non-linearity or extremely high chemical reactivity.
Improving the mechanical properties of a high density carbon block from mesocarbon microbeads according to oxidative stabilization
Authors: Im Ui-Su , Kim Jiyoung , Lee Byung-Rok , Peck Dong-Hyun , Jung Doo-Hwan 
Published: July 2018

AbstractIn this study, a high density carbon block without binder was manufactured by mesocarbon microbeads (MCMB) from coal tar pitch. To develop the high density carbon block without a binder, MCMBs were oxidized at different levels of temperature. To verify the effect of oxygen content in the carbonized carbon block (CCB), an elementary analysis (EA) and X-ray photoelectron spectroscopy (XPS) were performed. The morphological and mechanical properties of the CCBs were investigated by using scanning electron microscopy (SEM), a shore hardness test, and a flexural strength evaluation. The results revealed that the oxygen content increased with stabilization temperature and the physical properties of the CCBs were considerably improved via oxidative stabilization. Small cracks between MCMB particles were observed in the CCBs that were stabilized over 250 °C. From the results of this study, the CCB from MCMBs stabilized at 200 °C for 1 h showed optimum mechanical properties and high density.
Shorter-lived neural taste representations in obese compared to lean individuals
Authors: Hardikar Samyogita , Wallroth Raphael , Villringer Arno , Ohla Kathrin 
Published: July 2018

AbstractPrevious attempts to uncover a relation between taste processing and weight status have yielded inconclusive results leaving it unclear whether lean and obese individuals process taste differently, and whether group differences reflect differential sensory encoding or evaluative and reward processing. Here, we present the first comparison of dynamic neural processing as assessed by gustatory evoked potentials in obese and lean individuals. Two supra-threshold concentrations of sweet and salty tastants as well as two sizes of blue and green squares were presented to 30 lean (BMI 18.5–25) and 25 obese (BMI > 30) individuals while recording head-surface electroencephalogram (EEG). Multivariate pattern analyses (MVPA) revealed differential taste quality representations from 130 ms until after stimulus offset. Notably, taste representations faded earlier and exhibited a reduced strength in the obese compared to the lean group; temporal generalization analysis indicated otherwise similar taste processing. Differences in later gustatory response patterns even allowed decoding of group membership. Importantly, group differences were absent for visual processing thereby excluding confounding effects from anatomy or signal-to-noise ratio alone. The latency of observed effects is consistent with memory maintenance rather than sensory encoding of taste, thereby suggesting that later evaluative aspects of taste processing are altered in obesity.
Hippocampal metabolism of amino acids by L-amino acid oxidase is involved in fear learning and memory
Authors: Usuda Kento , Kawase Takahiro , Shigeno Yuko , Fukuzawa Susumu , Fujii Kazuki , Zhang Haolin , Tsukahara Takamitsu , Tomonaga Shozo , Watanabe Gen , Jin Wanzhu , Nagaoka Kentaro 
Published: July 2018

AbstractAmino acids participate directly and indirectly in many important biochemical functions in the brain. We focused on one amino acid metabolic enzyme, L-amino acid oxidase (LAO), and investigated the importance of LAO in brain function using LAO1 knockout (KO) mice. Compared to wild-type mice, LAO1 KO mice exhibited impaired fear learning and memory function in a passive avoidance test. This impairment in LAO1 KO mice coincided with significantly reduced hippocampal acetylcholine levels compared to wild-type mice, while treatment with donepezil, a reversible acetylcholine esterase inhibitor, inhibited this reduction. Metabolomic analysis revealed that knocking out LAO1 affected amino acid metabolism (mainly of phenylalanine [Phe]) in the hippocampus. Specifically, Phe levels were elevated in LAO1 KO mice, while phenylpyruvic acid (metabolite of Phe produced largely by LAO) levels were reduced. Moreover, knocking out LAO1 decreased hippocampal mRNA levels of pyruvate kinase, the enzymatic activity of which is known to be inhibited by Phe. Based on our findings, we propose that LAO1 KO mice exhibited impaired fear learning and memory owing to low hippocampal acetylcholine levels. Furthermore, we speculate that hippocampal Phe metabolism is an important physiological mechanism related to glycolysis and may underlie cognitive impairments, including those observed in Alzheimer’s disease.
In vitro biological screening of a critically endangered medicinal plant, Atropa acuminata Royle Ex Lindl of north western Himalaya
Authors: Rahman Khaista , Khan Shahid Ullah , Fahad Shah , Shinwari Zabta Khan , Khan Dilfaraz , Kamal Sajid , Ullah Ikram , Anjum Syed Ishtiaq , Man Shad , Khan Abdul Jamil , Khan Wasim Ullah , Khan Muhammad Hafeez Ullah , Jan Mehmood , Adnan Muhammad , Noor Muhammad 
Published: July 2018

AbstractAtropa acuminata Royle Ex Lindl (Atropa acuminata) under tremendous threat of extinction in its natural habitat. However, the antimicrobial, antileishmanial and anticancer effects of the plant’s extracts have not been reported yet. In the current study, an attempt has been made to evaluate the pharmacological potential of this plant’s extracts against microbes, Leishmania and cancer. The roots, stems and leaves of Atropa acuminata were ground; then, seven different solvents were used alone and in different ratios to prepare crude extracts, which were screened for pharmacological effects. The aqueous, methanolic and ethanolic extracts of all parts carried a broad spectrum of anti-bacterial activities, while no significant activity was observed with combined solvents. Three types of cytotoxicity assays were performed, i.e., haemolytic, brine shrimp and protein kinase assays. The aqueous extract of all the parts showed significant haemolytic activity while n-hexane extracts of roots showed significant activity against brine shrimp. The acetone extracts strongly inhibited protein kinase while the methanolic extracts exhibited significant cytotoxic activity of roots and stem. The anti-leishmanial assays revealed that the methanolic extract of leaves and roots showed significant activity. These findings suggest that this plant could be a potential source of natural product based drugs.
Urine-derived cells: a promising diagnostic tool in Fabry disease patients
Authors: Slaats Gisela G. , Braun Fabian , Hoehne Martin , Frech Laura E. , Blomberg Linda , Benzing Thomas , Schermer Bernhard , Rinschen Markus M. , Kurschat Christine E. 
Published: July 2018

AbstractFabry disease is a lysosomal storage disorder resulting from impaired alpha-galactosidase A (α-Gal A) enzyme activity due to mutations in the GLA gene. Currently, powerful diagnostic tools and in vivo research models to study Fabry disease are missing, which is a major obstacle for further improvements in diagnosis and therapy. Here, we explore the utility of urine-derived primary cells of Fabry disease patients. Viable cells were isolated and cultured from fresh urine void. The obtained cell culture, modeling the renal epithelium, is characterized by patient-specific information. We demonstrate that this non-invasive source of patient cells provides an adequate cellular in vivo model as cells exhibit decreased α-Gal A enzyme activity and concomitant globotriaosylceramide accumulation. Subsequent quantitative proteomic analyses revealed dysregulation of endosomal and lysosomal proteins indicating an involvement of the Coordinated Lysosomal Expression and Regulation (CLEAR) network in the disease pathology. This proteomic pattern resembled data from our previously described human podocyte model of Fabry disease. Taken together, the employment of urine-derived primary cells of Fabry disease patients might have diagnostic and prognostic implications in the future. Our findings pave the way towards a more detailed understanding of pathophysiological mechanisms and may allow the development of future tailored therapeutic strategies.
Regulation of biomass degradation by alternative σ factors in cellulolytic clostridia
Authors: Ortiz de Ora Lizett , Lamed Raphael , Liu Ya-Jun , Xu Jian , Cui Qiu , Feng Yingang , Shoham Yuval , Bayer Edward A. , Muñoz-Gutiérrez Iván 
Published: July 2018

AbstractBacteria can adjust their genetic programs via alternative σ factors to face new environmental pressures. Here, we analyzed a unique set of paralogous alternative σ factors, termed σIs, which fine-tune the regulation of one of the most intricate cellulolytic systems in nature, the bacterial cellulosome, that is involved in degradation of environmental polysaccharides. We combined bioinformatics with experiments to decipher the regulatory networks of five σIs inClostridium thermocellum, the epitome of cellulolytic microorganisms, and one σIinPseudobacteroides cellulosolvenswhich produces the cellulosomal system with the greatest known complexity. Despite high homology between different σIs, our data suggest limited cross-talk among them. Remarkably, the major cross-talk occurs within the main cellulosomal genes which harbor the same σI-dependent promoter elements, suggesting a promoter-based mechanism to guarantee the expression of relevant genes. Our findings provide insights into the mechanisms used by σIs to differentiate among their corresponding regulons, representing a comprehensive overview of the regulation of the cellulosome to date. Finally, we show the advantage of using a heterologous host system for analysis of multiple σIs, since information generated by their analysis in their natural host can be misinterpreted owing to a cascade of interactions among the different σIs.
Tight-binding model for opto-electronic properties of penta-graphene nanostructures
Authors: Bravo Sergio , Correa Julián , Chico Leonor , Pacheco Mónica 
Published: July 2018

AbstractWe present a tight-binding parametrization for penta-graphene that correctly describes its electronic band structure and linear optical response. The set of parameters is validated by comparing to ab-initio density functional theory calculations for single-layer penta-graphene, showing a very good global agreement. We apply this parameterization to penta-graphene nanoribbons, achieving an adequate description of quantum-size effects. Additionally, a symmetry-based analysis of the energy band structure and the optical transitions involved in the absorption spectra is introduced, allowing for the interpretation of the optoelectronic features of these systems.
SCN4A as modifier gene in patients with myotonic dystrophy type 2
Authors: Binda Anna , Renna Laura V. , Bosè Francesca , Brigonzi Elisa , Botta Annalisa , Valaperta Rea , Fossati Barbara , Rivolta Ilaria , Meola Giovanni , Cardani Rosanna 
Published: July 2018

AbstractA patient with an early severe myotonia diagnosed for Myotonic Dystrophy type 2 (DM2) was found bearing the combined effects of DM2 mutation and Nav1.4 S906T substitution. To investigate the mechanism underlying his atypical phenotype,whole-cell patch-clamp in voltage- and current-clamp mode was performed in myoblasts and myotubes obtained from his muscle biopsy. Results characterizing the properties of the sodium current and of the action potentials have been compared to those obtained in muscle cells derived from his mother, also affected by DM2, but without the S906T polymorphism. A faster inactivation kinetics and a +5 mV shift in the availability curve were found in the sodium current recorded in patient’s myoblasts compared to his mother. 27% of his myotubes displayed spontaneous activity. Patient’s myotubes showing a stable resting membrane potential had a lower rheobase current respect to the mother’s while the overshoot and the maximum slope of the depolarizing phase of action potential were higher. These findings suggest that SCN4A polymorphisms may be responsible for a higher excitability of DM2 patients sarcolemma, supporting the severe myotonic phenotype observed. We suggest SCN4A as a modifier factor and that its screening should be performed in DM2 patients with uncommon clinical features.
Enhanced photocatalytic dye degradation and hydrogen production ability of Bi25FeO40-rGO nanocomposite and mechanism insight
Authors: Basith M. A. , Ahsan Ragib , Zarin Ishrat , Jalil M. A. 
Published: July 2018

AbstractA comprehensive comparison between BiFeO3-reduced graphene oxide (rGO) nanocomposite and Bi25FeO40-rGO nanocomposite has been performed to investigate their photocatalytic abilities in degradation of Rhodamine B dye and generation of hydrogen by water-splitting. The hydrothermal technique adapted for synthesis of the nanocomposites provides a versatile temperature-controlled phase selection between perovskite BiFeO3 and sillenite Bi25FeO40. Both perovskite and sillenite structured nanocomposites are stable and exhibit considerably higher photocatalytic ability over pure BiFeO3 nanoparticles and commercially available Degussa P25 titania. Notably, Bi25FeO40-rGO nanocomposite has demonstrated superior photocatalytic ability and stability under visible light irradiation than that of BiFeO3-rGO nanocomposite. The possible mechanism behind the superior photocatalytic performance of Bi25FeO40-rGO nanocomposite has been critically discussed.
Habitat suitability for the invasion of Bombus terrestris in East Asian countries: A case study of spatial overlap with local Chinese bumblebees
Authors: Naeem Muhammad , Yuan Xiaolong , Huang Jiaxing , An Jiandong 
Published: July 2018

AbstractInvasive species such as Bombus terrestris represent a severe threat that can result in the decline of local biodiversity. We examined the habitat suitability for B. terrestris invasion in East Asian countries and the risk of habitat overlap with 24 bumblebee species from different groups in China. All East Asian countries were predicted to be susceptible to invasion by B. terrestris, with the highest habitat suitability occurring in China followed by Japan, North Korea, South Korea and Mongolia. Within China, which is a global biodiversity hotspot for bumblebees, three different regions, north-west, central to south-east and north-east, were predicted as being highly suitable for invasion. In China, the group of species closely related to B. terrestris showed higher sensitivity (89%) to habitat overlap with B. terrestris than did the group of non-closely related species (73%). The risk of overlap for the three major regional bumblebees within China decreased in the order southern region, northern region and Tibetan Plateau region. Due to the sensitivity of habitat suitability and overlap, the use of the introduced European bumblebee B. terrestris for pollination services should be discouraged in regions with overlapping habitats in China, and management strategies should be implemented to conserve the vulnerable bumblebees in all East Asian countries.
Three-Dimensional Printed Model-Assisted Screw Installation in Treating Posterior Atlantoaxial Internal Fixation
Authors: Yang Minyi , Zhang Nannan , Shi Haodong , Li Hui , Liu Shichang , Song Zongrang , Shan Lequn , Wu Qining , Hao Dingjun 
Published: July 2018

AbstractThe aim of this study was to evaluate the efficacy and feasibility of a life-size 3-dimensional printing assisted posterior internal fixation. We performed a retrospective review of 138 patients who received posterior atlantoaxial internal fixation from October 2009 to March 2015 with a minimum follow-up period of 12 months. Group A included 76 patients who received the conventional free-hand technique. Group B included 62 patients who were treated with internal fixation assisted by 3D printing. The placement accuracy of the screw was evaluated in the computed tomography images according to the methods of Hojo and clinical outcomes were evaluated using the visual analogue scale, the Japanese Orthopedic Association Score, and the Neck Disability Index score. There were no significant differences in the clinical results at any of the follow-up time points regarding the JOA, VAS, or NDI scores between two group. However, compared to Group A, Group B had better results for screw installation (P = 0.003), shorter surgery time (P = 0.001), and less blood loss (P = 0.037). Compared to the conventional free-hand technique, 3D printed model–assisted is helpful to screw placement in atlantoaxial internal fixation, which can be used as a common tool to provides important guidance for upper cervical surgery.
Hydrolysis of Extracellular Pyrophosphate increases in post-hemodialysis plasma
Authors: Azpiazu Daniel , González-Parra Emilio , Egido Jesús , Villa-Bellosta Ricardo 
Published: July 2018

AbstractVascular calcification (VC) is associated with significant morbidity and mortality of dialysis patients. Previous studies showed an association between loss of plasma pyrophosphate and VC. Moreover, loss of pyrophosphate occurs during dialysis in this population, suggesting that therapeutic approaches that prevent reduction of plasma pyrophosphate levels during dialysis could improve the quality of life of dialysis patients. This study found that pyrophosphate hydrolysis was 51% higher in post- than pre-dialysis plasma. Dialysis sessions modified the kinetic behavior of alkaline phosphatase, increasing its Vmax and reducing its Km, probably due to the elimination of uremic toxins during dialysis. At least 75% of alkaline phosphatase activity in human plasma was found to depend on a levamisole-sensitive enzyme probably corresponding to tissue non-specific alkaline phosphatase (TNAP). Dialysis increased total plasma protein concentration by 14% and reduced TNAP enzyme by 20%, resulting in an underestimation of pyrophosphate hydrolysis in post-dialysis plasma. Levamisole inhibited TNAP activity (IC50, 7.2 µmol/L), reducing pyrophosphate hydrolysis in plasma and increasing plasma pyrophosphate availability. Alkaline phosphatase is also found in many tissues and cells types; therefore, our results in plasma may be indicative of changes in phosphatase activity in other locations that collectively could contribute significantly to pyrophosphate hydrolysis in vivo. In conclusion, these findings demonstrate that dialysis increases pyrophosphate hydrolysis, which, taken together with previously reported increases in alkalization and calcium ion levels in post-dialysis plasma, causes VC and could be prevented by adding calcification inhibitors during dialysis.
The effect of nanometre-scale V-pits on electronic and optical properties and efficiency droop of GaN-based green light-emitting diodes
Authors: Zhou Shengjun , Liu Xingtong , Yan Han , Gao Yilin , Xu Haohao , Zhao Jie , Quan Zhijue , Gui Chengqun , Liu Sheng 
Published: July 2018

AbstractThe development of efficient green light-emitting diodes (LEDs) is of paramount importance for the realization of colour-mixing white LEDs with a high luminous efficiency. While the insertion of an InGaN/GaN superlattice (SL) with a lower In content before the growth of InGaN/GaN multiple quantum wells (MQWs) is known to increase the efficiency of LEDs, the actual mechanism is still debated. We therefore conduct a systematic study and investigate the different mechanisms for this system. Through cathodoluminescence and Raman measurements, we clearly demonstrate that the potential barrier formed by the V-pit during the low-temperature growth of an InGaN/GaN SL dramatically increases the internal quantum efficiency (IQE) of InGaN quantum wells (QWs) by suppressing non-radiative recombination at threading dislocations (TDs). We find that the V-pit potential barrier height depends on the V-pit diameter, which plays an important role in determining the quantum efficiency, forward voltage and efficiency droop of green LEDs. Furthermore, our study reveals that the low-temperature GaN can act as an alternative to an InGaN/GaN SL structure for promoting the formation of V-pits. Our findings suggest the potential of implementing optimized V-pits embedded in an InGaN/GaN SL or low-temperature GaN structure as a beneficial underlying layer for the realization of highly efficient green LEDs.
Type I Interferon Potentiates IgA Immunity to Respiratory Syncytial Virus Infection During Infancy
Authors: Hijano Diego R. , Siefker David T. , Shrestha Bishwas , Jaligama Sridhar , Vu Luan D. , Tillman Heather , Finkelstein David , Saravia Jordy , You Dahui , Cormier Stephania A. 
Published: July 2018

AbstractRespiratory syncytial virus (RSV) infection is the most frequent cause of hospitalization in infants and young children worldwide. Although mucosal RSV vaccines can reduce RSV disease burden, little is known about mucosal immune response capabilities in children. Neonatal or adult mice were infected with RSV; a subset of neonatal mice received interferon alpha (IFN-α) (intranasal) prior to RSV infection. B cells, B cell activating factor (BAFF) and IgA were measured by flow cytometry. RSV specific IgA was measured in nasal washes. Nasal associated lymphoid tissue (NALT) and lungs were stained for BAFF and IgA. Herein, we show in a mouse model of RSV infection that IFN-α plays a dual role as an antiviral and immune modulator and age-related differences in IgA production upon RSV infection can be overcome by IFN-α administration. IFN-α administration before RSV infection in neonatal mice increased RSV-specific IgA production in the nasal mucosa and induced expression of the B-cell activating factor BAFF in NALT. These findings are important, as mucosal antibodies at the infection site, and not serum antibodies, have been shown to protect human adults from experimental RSV infection.
Mass spectrometry quantitation of proteins from small pools of developing auditory and vestibular cells
Authors: Krey Jocelyn F. , Scheffer Deborah I. , Choi Dongseok , Reddy Ashok , David Larry L. , Corey David P. , Barr-Gillespie Peter G. 
Published: July 2018

AbstractHair cells of the inner ear undergo postnatal development that leads to formation of their sensory organelles, synaptic machinery, and in the case of cochlear outer hair cells, their electromotile mechanism. To examine how the proteome changes over development from postnatal days 0 through 7, we isolated pools of 5000 Pou4f3-Gfp positive or negative cells from the cochlea or utricles; these cell pools were analysed by data-dependent and data-independent acquisition (DDA and DIA) mass spectrometry. DDA data were used to generate spectral libraries, which enabled identification and accurate quantitation of specific proteins using the DIA datasets. DIA measurements were extremely sensitive; we were able to detect proteins present at less than one part in 100,000 from only 312 hair cells. The DDA and DIA datasets will be valuable for accurately quantifying proteins in hair cells and non-hair cells over this developmental window.