bluuebunny/crossref_metadata_2025_split huggingface dataset:
Step‐function luminopsins for bimodal prolonged neuromodulation
Authors: Berglund Ken , Fernandez Alejandra M. , Gutekunst Claire‐Anne N. , Hochgeschwender Ute , Gross Robert E. 
Published: April 2019

AbstractAlthough molecular tools for controlling neuronal activity by light have vastly expanded, there are still unmet needs which require development and refinement. For example, light delivery into the brain is still a major practical challenge that hinders potential translation of optogenetics in human patients. In addition, it would be advantageous to manipulate neuronal activity acutely and precisely as well as chronically and non‐invasively, using the same genetic construct in animal models. We have previously addressed these challenges by employing bioluminescence and have created a new line of opto‐chemogenetic probes termed luminopsins by fusing light‐sensing opsins with light‐emitting luciferases. In this report, we incorporated Chlamydomonas channelrhodopsin 2 with step‐function mutations as the opsin moiety in the new luminopsin fusion protein termed step‐function luminopsin (SFLMO). Bioluminescence‐induced photocurrent lasted longer than the bioluminescence signal due to very slow deactivation of the mutated channel. In addition, bioluminescence was able to activate most of the channels on the cell surface due to the extremely high light sensitivity of the channel. This efficient channel activation was partly mediated by radiationless bioluminescence resonance energy transfer due to the proximity of luciferase and opsin. To test the utility of SFLMOs in vivo, we transduced the substantia nigra unilaterally via a viral vector in male rats. Injection of the luciferase substrate as well as conventional photostimulation via fiber optics elicited circling behaviors. Thus, SFLMOs expand the current approaches for manipulation of neuronal activity in the brain and add more versatility and practicality to optogenetics in freely behaving animals.
Optimization and Characterization of Biosurfactant Rhamnolipid Production by Pseudomonas aeruginosa Isolated from an Artificially Contaminated Soil
Authors: Câmara Jéssica Maria D.A. , Sousa Magna Angélica S.B. , Barros Neto Eduardo L. 
Published: April 2019

AbstractBiosurfactants are surfactants biologically produced by microorganisms, presenting several advantages when compared to synthetic surfactants. Pseudomonas aeruginosa is known for producing rhamnolipids, considered one of the most interesting types of biosurfactants due to their high yields, when compared to other types. In this work, the production of rhamnolipid from P. aeruginosa was optimized. At first, the Plackett–Burman design was used to select most significant variables affecting the biosurfactant production yield among nine variables—carbon–nitrogen ratio, carbon concentration, nitrogen source, pH, cultivation time, potassium and magnesium concentrations, agitation, and temperature. Then, using main variables, a central point experimental design aiming to optimize rhamnolipid production was performed. The maximum biosurfactant concentration obtained was 0.877 mg L−1. The rhamnolipid also displayed a great emulsification rate, reaching approximately 67%, and the ability to reduce water surface tension from 72.02 to 35.26 mN m−1 at a critical micelle concentration (CMC) of 127 mg L−1, in addition to presenting a good stability when exposed to wide pH and salinity ranges. The results suggest that rhamnolipids are promising substitutes for synthetic surfactants, especially due to lower impacts on the environment.
Liquid Gallium Nanospheres Emitting White Light
Authors: Xiang Jin , Chen Jingdong , Jiang Shuai , Panmai Mingcheng , Li Peilian , Xu Yi , Dai Qiaofeng , Tie Shaolong , Lan Sheng 
Published: April 2019

AbstractGallium (Ga) is not only a metal possessing surface plasmon resonance in the ultraviolet region but also a phase‐change material with very low melting point. Spherical Ga nanoparticles composed of liquid Ga cores and solid Ga2O3 shells, which exhibit surface plasmonic resonances spanning the ultraviolet to near‐infrared spectral region, are fabricated by using femtosecond laser ablation. Under the excitation of femtosecond laser light, only second harmonic generation is observed in the Ga nanospheres placed on a glass substrate. In sharp contrast, white light emission can be generated in such Ga nanospheres when they are placed on a thin silver film. It is revealed numerically and confirmed experimentally that a Fano resonance originating from the interference between the mirror‐image‐induced magnetic dipole mode and the gap plasmon mode is formed in the backward scattering spectra of the Ga nanospheres. Efficient white light emission can be achieved by resonantly exciting either the magnetic dipole resonance or the Fano resonance. Based on spectral analysis, the white light emission is identified as the hot‐electron intraband luminescence. The fabricated core–shell Ga nanospheres provide an ideal platform on which the optical properties and practical applications of liquid Ga nanoparticles can be systematically investigated.
Predicting impacts of climate change on the potential distribution of two interacting species in the forests of western Iran
Authors: Malekian Mansoureh , Sadeghi Maedeh 
Published: April 2019

AbstractPredicting the distribution of suitable habitats for species under climate change is essential for conservation planning. In the past three decades, the number of Persian squirrels (Sciurus anomalus) and the area covered by the Persian oak (Quercus brantii) have decreased due to various factors such as habitat degradation. Habitat suitability of the above interacting species was assessed under the current conditions and future (2050) climate change scenarios in western Iran, using a maximum entropy model (MaxEnt). The model performed well with an average area under the curve of above 0.9 for the two species. Precipitation in winter was the factor that contributed most to habitat suitability of both species. The MaxEnt projection for the year 2050 revealed a reduction in the area of suitable habitats for both species. Based on the outputs from the Hadley Centre for Climate Prediction and Research Coupled Model (HadCM) scenarios, the fundamental niche (the range of environmental conditions in which the species can survive) of the Persian squirrel will reduce by between 0.12 and 1.1%. However, under the Centre National de Recherches Météorologiques Coupled Model scenarios, small gains in potential habitats may be observed. The area of suitable habitats for the oak was reduced under all scenarios except HadCM (representative concentration pathway 2.6). The results showed that the loss of suitable habitats for both species was more evident in the northern part of the range where the best habitats currently exist. In contrast, small gains in suitable habitats may be observed in the southern and eastern part of the range.
Stochastic semi‐discretization for linear stochastic delay differential equations
Authors: Sykora Henrik T , Bachrathy Daniel , Stepan Gabor 
Published: April 2019

SummaryAn efficient numerical method is presented to analyze the moment stability and stationary behavior of linear stochastic delay differential equations. The method is based on a special kind of discretization technique with respect to the past effects. The resulting approximate system is a high dimensional linear discrete stochastic mapping. The convergence properties of the method is demonstrated with the help of the stochastic Hayes equation and the stochastic delayed oscillator.
Qualitative thematic analysis based on descriptive phenomenology
Authors: Sundler Annelie J. , Lindberg Elisabeth , Nilsson Christina , Palmér Lina 
Published: April 2019

AbstractAimThe aim of this paper was to discuss how to understand and undertake thematic analysis based on descriptive phenomenology. Methodological principles to guide the process of analysis are offered grounded on phenomenological philosophy. This is further discussed in relation to how scientific rigour and validity can be achieved.DesignThis is a discursive article on thematic analysis based on descriptive phenomenology.ResultsThis paper takes thematic analysis based on a descriptive phenomenological tradition forward and provides a useful description on how to undertake the analysis. Ontological and epistemological foundations of descriptive phenomenology are outlined. Methodological principles are explained to guide the process of analysis, as well as help to understand validity and rigour. Researchers and students in nursing and midwifery conducting qualitative research need comprehensible and valid methods to analyse the meaning of lived experiences and organize data in meaningful ways.
Downregulation of CENPF Remodels Prostate Cancer Cells and Alters Cellular Metabolism
Authors: Shahid Muhammad , Kim Minhyung , Lee Min Young , Yeon Austin , You Sungyong , Kim Hyung L. , Kim Jayoung 
Published: April 2019

AbstractMetabolic alterations in prostate cancer (PC) are associated with progression and aggressiveness. However, the underlying mechanisms behind PC metabolic functions are unknown. The authors’ group recently reported on the important role of centromere protein F (CENPF), a protein associated with the centromere–kinetochore complex and chromosomal segregation during mitosis, in PC MRI visibility. This study focuses on discerning the role of CENPF in metabolic perturbation in human PC3 cells. A series of bioinformatics analyses shows that CENPF is one gene that is strongly associated with aggressive PC and that its expression is positively correlated with metastasis. By identifying and reconstructing the CENPF network, additional associations with lipid regulation are found. Further untargeted metabolomics analysis using gas chromatography‐time‐of‐flight‐mass spectrometry reveals that silencing of CENPF alters the global metabolic profiles of PC cells and inhibits cell proliferation, which suggests that CENPF may be a critical regulator of PC metabolism. These findings provide useful scientific insights that can be applied in future studies investigating potential targets for PC treatment.
Determination of the structural ensemble of the molten globule state of a protein by computer simulations
Authors: Shimizu Masahiro , Kajikawa Yukihito , Kuwajima Kunihiro , Dobson Christopher M. , Okamoto Yuko 
Published: April 2019

AbstractWe have used computer simulations to investigate the structural nature of the molten globule (MG) state of canine milk lysozyme. To sample the conformational space efficiently, we performed replica‐exchange umbrella sampling simulations with the radius of gyration as a reaction coordinate. We applied the Weighted Histogram Analysis Method to the trajectory of the simulations to obtain the potential of mean force, from which we identified representative structures corresponding to local minima in the free energy surface. The representative structures obtained in this way are in accord with the characteristics of the MG state reported previously by experimental studies. We conjecture that the MG state comprises a series of partially structured states undergoing relatively fast conformational interchange.
Sequence and structure‐based characterization of ubiquitination sites in human and yeast proteins using Chou's sample formulation
Authors: Kumar Vanitha Shyamili , Vellaichamy Adaikkalam 
Published: April 2019

AbstractUbiquitination is an important post‐translational event responsible for half‐life and turnover of proteins inside the cell. Proteins are ubiquitinated by forming an iso‐peptide bond between their lysine residue and C‐terminal glycine residue of ubiquitin leading to rapid degradation of proteins by 26S proteosome complex. Deregulation of ubiquitination is manifested by aberrant expression of E3‐ligase activity or mutation in the surroundings of ubiquitination sites. Many new experimentally validated ubiquitinated lysines have been recently identified that motivated the study of the environments surrounding the ubiquitinated lysines. With the help of known ubiquitinated proteins, here we present a comprehensive study of sequence and spatial environment of ubiquitination sites of human and yeast proteins. To identify position‐specific features, this work distinguishes the spatial environments as proximity and distal regions. Certain amino acids specific to these regions, well differentiate the ubiquitination sites from non‐ubiquitination sites are revealed. Additionally, amino acid signatures that contribute for protein disordered regions and solvent accessibility of amino acids are found to be contributing factors in ubiquitination sites. These results suggest that the ubiquitination site environment of the substrate determines the recognition and unfolding of substrate to facilitate the entry into 26S proteosomal complex. We believe that these findings will help in better prediction of ubiquitination sites using the sequence and spatial information.
Molecular modeling study on the differential microtubule‐stabilizing effect in singly‐ and doubly‐bonded complexes with peloruside A and paclitaxel
Authors: Zúñiga Matías A. , Alderete Joel B. , Jaña Gonzalo A. , Navarrete Karen R. , Jiménez Verónica A. 
Published: April 2019

AbstractMicrotubules (MT) are dynamic cytoskeletal components that play a crucial role in cell division. Disrupting MT dynamics by MT stabilizers is a widely employed strategy to control cell proliferation in cancer therapy. Most MT stabilizers bind to the taxol (TX) site located at the luminal interface between protofilaments, except laulimalide and peloruside A (PLA), which bind to an interfacial pocket on outer MT surface. Cryo‐electron microscopy MTs reconstructions have shown differential structural effects on the MT lattice in singly‐ and doubly‐bonded complexes with PLA, TX, and PLA/TX, as PLA is able to revert the lattice heterogeneity induced by TX association leading to more regular MT assemblies. In this work, fully‐atomistic molecular dynamics simulations were employed to examine the single and double association of MT stabilizers to reduced MT models in the search for structural and energetic evidence that could be related to the differential regularization and stabilization effects exerted by PLA and TX on the MT lattice. Our results revealed that the double association of PLA/TX (a) strengthens the lateral contact between tubulin dimers compared to singly‐bonded complexes, (b) favors a more parallel arrangement between tubulin dimers, and (c) induces a larger restriction in the interdimeric conformational motion increasing the probability of finding structures consistent with 13‐protofilaments arrangements. These results and are valuable to increase understanding about the molecular mechanism of action of MT stabilizers, and could account for an overstabilization of MTs in doubly‐bonded complexes compared to singly‐bonded systems.
Finite‐time boundedness of large‐scale systems with actuator faults and gain fluctuations
Authors: Tharanidharan V. , Sakthivel R. , Kaviarasan B. , Alzahrani Faris , Marshal Anthoni S. 
Published: April 2019

SummaryThis paper addresses the issue of finite‐time boundedness of large‐scale interconnected systems with the use of a distributed nonfragile fault‐tolerant controller. The objective of this paper is to design a state‐feedback controller consisting of a time‐varying delay such that the resulting closed‐loop system is finite‐time bounded under a prescribed extended passivity performance level even in the presence of all admissible uncertainties and possible actuator faults. More precisely, based on the Lyapunov‐Krasovskii stability theory, a new set of sufficient conditions is obtained in the framework of linear matrix inequality constraints that ensures finite‐time boundedness and satisfies the prescribed extended passivity performance index of the considered system. Finally, two numerical examples, including the interconnected inverted pendulum, are given to show the effectiveness of the proposed controller design technique.
Synthesis of A Novel Cross‐linker with High Reactivity for Enhancing Compressive Strength of High‐performance Organic Fibers
Authors: Dai Yu , Feng Jiabao , Meng Chenbo , Luo Longbo , Liu Xiangyang 
Published: April 2019

AbstractLow axial compressive strength of high‐performance organic fibers is one of the most prominent problems for their application in advanced technologies. In this paper, N, N’‐diphenyl‐1,4‐phenylacetyleneamide (DPAA) as a novel external cross‐linker was synthesized. It was confirmed that DPAA could react itself and quickly form cross‐linking network above 210 °C with pore width of 1–30 nm. Then DPAA was introduced into some typical high‐performance organic fibers through post‐swelling process, followed by annealing at 250 °C. It was found that DPAA would in‐situ form cross‐linking network inside the fiber, which was regarded as semi‐interpenetration structure. Compressive strength of Kevlar‐49 fiber modified through this method increased by nearly 70% and corresponding tensile strength didn't deteriorate. When PBO, heterocyclic aramid and polyimide fibers were modified by the same procedure, their compressive strength showed 25, 36 and 72% enhancement respectively. Therefore, DPAA is an effective modifier to enhance compressive strength of high‐performance organic fibers and shows great universality.
The Binary Effect on Methicillin‐Resistant Staphylococcus aureus of Polymeric Nanovesicles Appended by Proline‐Rich Amino Acid Sequences and Inorganic Nanoparticles
Authors: Bassous Nicole J. , Webster Thomas J. 
Published: April 2019

AbstractPrevalent research underscores efforts to engineer highly sophisticated nanovesicles that are functionalized to combat antibiotic‐resistant bacterial infections, especially those caused by methicillin‐resistant Staphylococcus aureus (MRSA), and that aid with wound healing or immunomodulation. This is especially relevant for patients who are susceptible to Staphylococcus aureus infections postoperatively. Here, antibacterial formulations are incorporated into polymeric, biocompatible vesicles called polymersomes (PsNPs) that self‐assemble via hydrophobic interactions of admixed aqueous and organic substances. Nano‐PsNPs are synthesized using a high molecular weight amphiphilic block copolymer, and are conjugated to include antimicrobial peptides (AMPs) along the peripheral hydrophilic region and silver nanoparticles (AgNPs) inside their hydrophobic corona. In vitro testing on bacterial and human cell lines indicates that finely tuned treatment concentrations of AMP and AgNPs in PsNPs synergistically inhibits the growth of MRSA without posing significant side effects, as compared with other potent treatment strategies. A ratio of silver‐to‐AMP of about 1:5.8 corresponding to ≈11.6 µg mL−1 of silver nanoparticles and 14.3 × 10−6 m of the peptide, yields complete MRSA inhibition over a 23 h time frame. This bacteriostatic activity, coupled with nominal cytotoxicity toward native human dermal fibroblast cells, extends the potential for AMP/AgNP polymersome therapies to replace antibiotics in the clinical setting.
Tape‐Imprinted Hierarchical Lotus Seedpod‐Like Arrays for Extraordinary Surface‐Enhanced Raman Spectroscopy
Authors: Wang Yandong , Zhang Mengyuan , Feng Lei , Dong Bin , Xu Ting , Li Dong , Jiang Lin , Chi Lifeng 
Published: April 2019

AbstractA novel two‐side‐activatable high‐performance surface‐enhanced Raman spectroscopy (SERS) substrate is developed based on the tape‐imprinting method. It features 3D full‐space‐distributed hot spots originating from the hierarchical lotus seedpod‐like silver arrays, which offer ultrasensitive, uniform, reproducible, and reliable quantitative measurements with an inherent internal standard. This excellent SERS substrate also holds great promise in practical in situ molecule detection on curved surfaces, such as pesticides on fruit, which is not yet possible with the traditional rigid or flexible material‐based SERS counterparts.
2D Free‐Standing Nitrogen‐Doped Ni‐Ni3S2@Carbon Nanoplates Derived from Metal–Organic Frameworks for Enhanced Oxygen Evolution Reaction
Authors: Lin Yifan , Chen Gen , Wan Hao , Chen Fashen , Liu Xiaohe , Ma Renzhi 
Published: April 2019

Abstract2D metal–organic frameworks (2D MOFs) are promising templates for the fabrication of carbon supported 2D metal/metal sulfide nanocomposites. Herein, controllable synthesis of a newly developed 2D Ni‐based MOF nanoplates in well‐defined rectangle morphology is first realized via a pyridine‐assisted bottom‐up solvothermal treatment of NiSO4 and 4,4′‐bipyridine. The thickness of the MOF nanoplates can be controlled to below 20 nm, while the lateral size can be tuned in a wide range with different amounts of pyridine. Subsequent pyrolysis treatment converts the MOF nanoplates into 2D free‐standing nitrogen‐doped Ni‐Ni3S2@carbon nanoplates. The obtained Ni‐Ni3S2 nanoparticles encapsulated in the N‐doped carbon matrix exhibits high electrocatalytic activity in oxygen evolution reaction. A low overpotential of 284.7 mV at a current density of 10 mA cm−2 is achieved in alkaline solution, which is among the best reported performance of substrate‐free nickel sulfides based nanomaterials.
Pregnancies alters spine number in cortical and subcortical limbic brain regions of old rats
Authors: Flores‐Vivaldo Yaredit Margarita , Camacho‐Abrego Israel , Picazo Ofir , Flores Gonzalo 
Published: April 2019

AbstractPregnancy is a complex process, involving a number of hormones and trophic factors, many of which are formed in the placenta. Several of these trophic factors have an effect at the neuronal level, such as BDNF. Consequently, recent reports have shown that exposure to these hormones (estrogen and progesterone) and trophic factors such as BDNF exert a neuroprotective effect. Here, we study the effect of the number of pregnancies on dendritic morphology of aged female rats (18 months of age). Rats of the 18‐month‐old Sprague Dawley strain with zero, one, two, and three gestations were evaluated for locomotor activity, and Golgi–Cox stain was performed to evaluate the dendritic morphology parameters, the number of dendritic spines, total dendritic length, and branching order number. Adult nulliparous rats (3 months of age) were used as another control group. Adult nulliparous and aging rats with two pregnancies showed an increase in locomotor activity. Adult nulliparous showed an increase in the dendritic spine number compared to old nulliparous rats in both layers of the PFC, the DG, and NAcc. Old rats with two and three pregnancies also showed an increase in the number of dendritic spines compared to old nulliparous rats in layers 3 and 5 of the PFC and in the CA1. Aging animals with one pregnancy also showed an increase in dendritic length compared to old nulliparous rats in the CA1. Our results clearly suggest that two and three pregnancies increase the dendritic spines number in the PFC and CA1 of aged female rats.
A framework for sustainable supply chain in emerging economies
Authors: Queiroz Maciel M. 
Published: April 2019

AbstractSustainable supply chains (SSC) are an essential topic in emerging economies for achieving sustainable development. Because of their rapid economic growth, emerging economies are experiencing both sides of this development: the well‐being enhancement and the environmental impact. However, decision makers and practitioners do not have robust models for managing supply networks that consider the sustainability complexities. This study aims to provide a better understanding of SSC in emerging economies and proposes a generic framework to improve the decision‐making process. Based on a review of the literature, a decision framework for sustainability is proposed. A green sustainable decision concept is also discussed in the SSC literature. This study has implications for scholars, decision makers, and practitioners interested in advancing the SSC field based on an extension of the framework.