bluuebunny/crossref_metadata_2025 huggingface dataset:
Mycofabricated biosilver nanoparticles interrupt Pseudomonas aeruginosa quorum sensing systems
Authors: Singh Braj R. , Singh Brahma N. , Singh Akanksha , Khan Wasi , Naqvi Alim H. , Singh Harikesh B.
Published: September 2015

Quorum sensing (QS) is a chemical communication process that Pseudomonas aeruginosa uses to regulate virulence and biofilm formation. Disabling of QS is an emerging approach for combating its pathogenicity. Silver nanoparticles (AgNPs) have been widely applied as antimicrobial agents against human pathogenic bacteria and fungi, but not for the attenuation of bacterial QS. Here we mycofabricated AgNPs (mfAgNPs) using metabolites of soil fungus Rhizopus arrhizus BRS-07 and tested their effect on QS-regulated virulence and biofilm formation of P. aeruginosa. Transcriptional studies demonstrated that mfAgNPs reduced the levels of LasIR-RhlIR. Treatment of mfAgNPs inhibited biofilm formation, production of several virulence factors (e.g. LasA protease, LasB elastrase, pyocyanin, pyoverdin, pyochelin, rhamnolipid and alginate) and reduced AHLs production. Further genes quantification analyses revealed that mfAgNPs significantly down-regulated QS-regulated genes, specifically those encoded to the secretion of virulence factors. The results clearly indicated the anti-virulence property of mfAgNPs by inhibiting P. aeruginosa QS signaling.
Exosomal miR-223 Contributes to Mesenchymal Stem Cell-Elicited Cardioprotection in Polymicrobial Sepsis
Authors: Wang Xiaohong , Gu Haitao , Qin Dongze , Yang Liwang , Huang Wei , Essandoh Kobina , Wang Yigang , Caldwell Charles C. , Peng Tianqing , Zingarelli Basilia , Fan Guo-Chang
Published: September 2015

Mesenchymal stem cells (MSCs) have been shown to elicit cardio-protective effects in sepsis. However, the underlying mechanism remains obscure. While recent studies have indicated that miR-223 is highly enriched in MSC-derived exosomes, whether exosomal miR-223 contributes to MSC-mediated cardio-protection in sepsis is unknown. In this study, loss-of-function approach was utilized and sepsis was induced by cecal ligation and puncture (CLP). We observed that injection of miR-223-KO MSCs at 1 h post-CLP did not confer protection against CLP-triggered cardiac dysfunction, apoptosis and inflammatory response. However, WT-MSCs were able to provide protection which was associated with exosome release. Next, treatment of CLP mice with exosomes released from miR-223-KO MSCs significantly exaggerated sepsis-induced injury. Conversely, WT-MSC-derived-exosomes displayed protective effects. Mechanistically, we identified that miR-223-KO exosomes contained higher levels of Sema3A and Stat3, two known targets of miR-223 (5p & 3p), than WT-exosomes. Accordingly, these exosomal proteins were transferred to cardiomyocytes, leading to increased inflammation and cell death. By contrast, WT-exosomes encased higher levels of miR-223, which could be delivered to cardiomyocytes, resulting in down-regulation of Sema3A and Stat3. These data for the first time indicate that exosomal miR-223 plays an essential role for MSC-induced cardio-protection in sepsis.
Activation of bacterial channel MscL in mechanically stimulated droplet interface bilayers
Authors: Najem Joseph S. , Dunlap Myles D. , Rowe Ian D. , Freeman Eric C. , Grant John W. , Sukharev Sergei , Leo Donald J.
Published: September 2015

MscL, a stretch-activated channel, saves bacteria experiencing hypo-osmotic shocks from lysis. Its high conductance and controllable activation makes it a strong candidate to serve as a transducer in stimuli-responsive biomolecular materials. Droplet interface bilayers (DIBs), flexible insulating scaffolds for such materials, can be used as a new platform for incorporation and activation of MscL. Here, we report the first reconstitution and activation of the low-threshold V23T mutant of MscL in a DIB as a response to axial compressions of the droplets. Gating occurs near maximum compression of both droplets where tension in the membrane is maximal. The observed 0.1–3 nS conductance levels correspond to the V23T-MscL sub-conductive and fully open states recorded in native bacterial membranes or liposomes. Geometrical analysis of droplets during compression indicates that both contact angle and total area of the water-oil interfaces contribute to the generation of tension in the bilayer. The measured expansion of the interfaces by 2.5% is predicted to generate a 4–6 mN/m tension in the bilayer, just sufficient for gating. This work clarifies the principles of interconversion between bulk and surface forces in the DIB, facilitates the measurements of fundamental membrane properties and improves our understanding of MscL response to membrane tension.
Physical Intimacy of Breast Cancer Cells with Mesenchymal Stem Cells Elicits Trastuzumab Resistance through Src Activation
Authors: Daverey Amita , Drain Allison P. , Kidambi Srivatsan
Published: September 2015

The development of resistance to trastuzumab is a major obstacle for lasting effective treatment of patients with ErbB2-overexpressing tumors. Here, we demonstrate that the physical contact of breast cancer cells with mesenchymal stem cells (MSCs) is a potential modulator of trastuzumab response by activation of nonreceptor tyrosine kinase c-Src and down regulation of phosphatase and tensin homolog (PTEN). Using anin vitropatterned breast cancer/MSC co-culture model, we find that the presence of MSCs results in Src activation that is missing in cancer cells monoculture, transwell co-culture and cells treated with MSCs conditioned media. Interestingly, the co-culture model also results in PTEN loss and activation of PI3K/AKT pathway that has been demonstrated as fundamental proliferative and survival pathways in clinical settings. To our knowledge, this is thefirst reportthat showed PTEN loss without the use of chemical inhibitors, matrix stiffness, or silencing RNAs. In addition, breast cancer cells in co-culture with MSCs conferred trastuzumab resistancein vitroas observed in the lack of inhibition of proliferative and migrative properties of the cancer cells. Our findings show that MSCs are potent mediators of resistance to trastuzumab and might reveal targets to enhance trastuzumab efficacy in patients.
Rapid tumor induction in zebrafish by TALEN-mediated somatic inactivation of the retinoblastoma1 tumor suppressor rb1
Authors: Solin Staci L. , Shive Heather R. , Woolard Kevin D. , Essner Jeffrey J. , McGrail Maura
Published: September 2015

Investigating the in vivo role of tumor suppressor genes in cancer is technically challenging due to their essential requirement during early animal development. To address this bottleneck, we generated genetic mosaic adult zebrafish using TALEN genome editing and demonstrate somatic inactivation of the tumor suppressor retinoblastoma1 (rb1) induces tumorigenesis at high frequency. 11–33% of 1-cell stage embryos injected with TALEN mRNAs targeting rb1 exon 2 or 3 develop tumors beginning as early as 3.5 months of age. Lesions predominantly arise in the brain and show features of neuroectodermal-like and glial-like tumors. Mutant allele analysis is consistent with tumor initiation due to somatic inactivation of rb1, revealing a conserved role for rb1 in tumor suppression across vertebrates. In contrast to genetic mosaics, heterozygous rb1−/+ adults show no evidence of neoplasia, while homozygous mutant rb1−/− are larval lethal. This is the first demonstration that somatic inactivation of a tumor suppressor causes cancer in zebrafish and highlights the utility of site-specific nucleases to create genetic mosaic zebrafish for tumor suppressor gene discovery. Somatic inactivation with site-directed nucleases in zebrafish presents a rapid and scalable strategy to study tumor suppressor gene function in cancer.
A double barrier memristive device
Authors: Hansen M. , Ziegler M. , Kolberg L. , Soni R. , Dirkmann S. , Mussenbrock T. , Kohlstedt H.
Published: September 2015

We present a quantum mechanical memristive Nb/Al/Al2O3/NbxOy/Au device which consists of an ultra-thin memristive layer (NbxOy) sandwiched between an Al2O3 tunnel barrier and a Schottky-like contact. A highly uniform current distribution for the LRS (low resistance state) and HRS (high resistance state) for areas ranging between 70 μm2 and 2300 μm2 were obtained, which indicates a non-filamentary based resistive switching mechanism. In a detailed experimental and theoretical analysis we show evidence that resistive switching originates from oxygen diffusion and modifications of the local electronic interface states within the NbxOy layer, which influences the interface properties of the Au (Schottky) contact and of the Al2O3 tunneling barrier, respectively. The presented device might offer several benefits like an intrinsic current compliance, improved retention and no need for an electric forming procedure, which is especially attractive for possible applications in highly dense random access memories or neuromorphic mixed signal circuits.
Epigenetic Regulation of Antibody Responses by the Histone H2A Deubiquitinase MYSM1
Authors: Jiang Xiao-Xia , Chou YuChia , Jones Lindsey , Wang Tao , Sanchez Suzi , Huang Xue F , Zhang Lei , Wang Changyong , Chen Si-Yi
Published: September 2015

B cell-mediated antibody response plays critical roles in protective immunity, as well as in the pathogenesis of allergic and autoimmune diseases. Epigenetic histone and DNA modifications regulate gene transcription and immunity; however, so far, little is known about the role of epigenetic regulation in antibody responses. In this study, we found that mice deficient in the histone H2A deubiquitinase MYSM1, despite their severe defect in B cell development, exhibit an enhanced antibody response against both T cell-dependent and independent antigens. We revealed that MYSM1 intrinsically represses plasma cell differentiation and antibody production. Mechanistic studies demonstrated that MYSM1 is a transcriptional activator of Pax5, the repressors of plasma cell differentiation, by facilitating key transcriptional factor recruitment and coordinating histone modifications at the Pax5 loci. Hence, this study uncovers a critical role for MYSM1 in epigenetically repressing plasma cell differentiation and antibody production, in addition to its opposing, active role in B cell development. Importantly, this study further provides a new target and strategy to modulate antibody production and responses with profound therapeutic implications.
Network Meta-analysis of Randomized Trials on the Safety of Vascular Closure Devices for Femoral Arterial Puncture Site Haemostasis
Authors: Jiang Jun , Zou Junjie , Ma Hao , Jiao Yuanyong , Yang Hongyu , Zhang Xiwei , Miao Yi
Published: September 2015

The safety of vascular closure devices (VCDs) is still debated. The emergence of more related randomized controlled trials (RCTs) and newer VCDs makes it necessary to further evaluate the safety of VCDs. Relevant RCTs were identified by searching PubMed, EMBASE, Google Scholar and the Cochrane Central Register of Controlled Trials electronic databases updated in December 2014. Traditional and network meta-analyses were conducted to evaluate the rate of combined adverse vascular events (CAVEs) and haematomas by calculating the risk ratios and 95% confidence intervals. Forty RCTs including 16868 patients were included. Traditional meta-analysis demonstrated that there was no significant difference in the rate of CAVEs between all the VCDs and manual compression (MC). Subgroup analysis showed that FemoSeal and VCDs reported after the year 2005 reduced CAVEs. Moreover, the use of VCDs reduced the risk of haematomas compared with MC. Network meta-analysis showed that AngioSeal, which might be the best VCD among all the included VCDs, was associated with reduced rates of both CAVE and haematomas compared with MC. In conclusion, the use of VCDs is associated with a decreased risk of haematomas and FemoSeal and AngioSeal appears to be better than MC for reducing the rate of CAVEs.
Effects of Carbon Dioxide Aerosols on the Viability of Escherichia coli during Biofilm Dispersal
Authors: Singh Renu , Monnappa Ajay K. , Hong Seongkyeol , Mitchell Robert J. , Jang Jaesung
Published: September 2015

A periodic jet of carbon dioxide (CO2) aerosols is a very quick and effective mechanical technique to remove biofilms from various substrate surfaces. However, the impact of the aerosols on the viability of bacteria during treatment has never been evaluated. In this study, the effects of high-speed CO2 aerosols, a mixture of solid and gaseous CO2, on bacteria viability was studied. It was found that when CO2 aerosols were used to disperse biofilms of Escherichia coli, they led to a significant loss of viability, with approximately 50% of the dispersed bacteria killed in the process. By comparison, 75.6% of the biofilm-associated bacteria were viable when gently dispersed using Proteinase K and DNase I. Indirect proof that the aerosols are damaging the bacteria was found using a recombinant E. coli expressing the cyan fluorescent protein, as nearly half of the fluorescence was found in the supernatant after CO2 aerosol treatment, while the rest was associated with the bacterial pellet. In comparison, the supernatant fluorescence was only 9% when the enzymes were used to disperse the biofilm. As such, these CO2 aerosols not only remove biofilm-associated bacteria effectively but also significantly impact their viability by disrupting membrane integrity.
Visual Features: Featural Strength and Visual Strength Are Two Dissociable Dimensions
Authors: Huang Liqiang
Published: September 2015

Visual features are often assumed to be the general building blocks for various visual tasks. However, it is well known that some stimulus categories (i.e., basic features) can be processed in parallel, but others (e.g., Ts in different orientations) need to be scanned serially and this difference in featural strength seems to be on a fundamentally different dimension from differences in visual strength (e.g., reduction in contrast). This study compared two high-level tasks, namely tasks that require a lot of attentional operations (change detection and pattern comparison), with one low-level task, namely a task that requires few attentional operations (perceptual discrimination). The results confirmed that featural strength has substantial effects on high-level tasks but only a negligible effect on the low-level task. The results also revealed a complementary interaction: Visual strength has a substantial effect on the low-level task, but a negligible effect on high-level tasks. Overall, featural strength and visual strength are two dissociable dimensions in processing of visual features. The present results, along with other findings, challenge the generality of processing visual features.
Simultaneous Stress and Field Control of Sustainable Switching of Ferroelectric Phases
Authors: Finkel P. , Staruch M. , Amin A. , Ahart M. , Lofland S.E.
Published: September 2015

In ferroelectrics, manifestation of a strong electromechanical coupling is attributed to both engineered domain morphology and phase transformations. However, realization of large sustainable and reversible strains and polarization rotation has been limited by fatigue, nonlinearity and hysteresis losses. Here, we demonstrate that large strain and polarization rotation can be generated for over 40 × 106 cycles with little fatigue by realization of a reversible ferroelectric-ferroelectric phase transition in [011] cut Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) relaxor ferroelectric single crystal. Direct tuning of this effect through combination of stress and applied electric field, confirmed both macroscopically and microscopically with x-ray and Raman scattering, reveals the local symmetry while sweeping through the transition with a low applied electric field (<0.2 MV/m) under mechanical stress. The observed change in local symmetry as determined by x-ray scattering confirms a proposed polarization rotation mechanism corresponding to a transition between rhombohedral and orthorhombic phases. These results shed more light onto the nature of this reversible transformation between two ferroelectric phases and advance towards the development of a wide range of ferroic and multiferroic devices.
Adenylate Cyclase Toxin promotes bacterial internalisation into non phagocytic cells
Authors: Martín César , Etxaniz Asier , Uribe Kepa B. , Etxebarria Aitor , González-Bullón David , Arlucea Jon , Goñi Félix M. , Aréchaga Juan , Ostolaza Helena
Published: September 2015

Bordetella pertussis causes whooping cough, a respiratory infectious disease that is the fifth largest cause of vaccine-preventable death in infants. Though historically considered an extracellular pathogen, this bacterium has been detected both in vitro and in vivo inside phagocytic and non-phagocytic cells. However the precise mechanism used by B. pertussis for cell entry, or the putative bacterial factors involved, are not fully elucidated. Here we find that adenylate cyclase toxin (ACT), one of the important toxins of B. pertussis, is sufficient to promote bacterial internalisation into non-phagocytic cells. After characterization of the entry route we show that uptake of “toxin-coated bacteria” proceeds via a clathrin-independent, caveolae-dependent entry pathway, allowing the internalised bacteria to survive within the cells. Intracellular bacteria were found inside non-acidic endosomes with high sphingomyelin and cholesterol content, or “free” in the cytosol of the invaded cells, suggesting that the ACT-induced bacterial uptake may not proceed through formation of late endolysosomes. Activation of Tyr kinases and toxin-induced Ca2+-influx are essential for the entry process. We hypothesize that B. pertussis might use ACT to activate the endocytic machinery of non-phagocytic cells and gain entry into these cells, in this way evading the host immune system.
Preparation of topological modes by Lyapunov control
Authors: Shi Z. C. , Zhao X. L. , Yi X. X.
Published: September 2015

By Lyapunov control, we present a proposal to drive quasi-particles into a topological mode in quantum systems described by a quadratic Hamiltonian. The merit of this control is the individual manipulations on the boundary sites. We take the Kitaev’s chain as an illustration for Fermi systems and show that an arbitrary excitation mode can be steered into the Majorana zero mode by manipulating the chemical potential of the boundary sites. For Bose systems, taking the noninteracting Su-Schrieffer-Heeger (SSH) model as an example, we illustrate how to drive the system into the edge mode. The sensitivity of the fidelity to perturbations and uncertainties in the control fields and initial modes is also examined. The experimental feasibility of the proposal and the possibility to replace the continuous control field with square wave pulses is finally discussed.
Comprehensive Proteomics Analysis of Laticifer Latex Reveals New Insights into Ethylene Stimulation of Natural Rubber Production
Authors: Wang Xuchu , Wang Dan , Sun Yong , Yang Qian , Chang Lili , Wang Limin , Meng Xueru , Huang Qixing , Jin Xiang , Tong Zheng
Published: September 2015

Ethylene is a stimulant to increase natural rubber latex. After ethylene application, both fresh yield and dry matter of latex are substantially improved. Moreover, we found that ethylene improves the generation of small rubber particles. However, most genes involved in rubber biosynthesis are inhibited by exogenous ethylene. Therefore, we conducted a proteomics analysis of ethylene-stimulated rubber latex and identified 287 abundant proteins as well as 143 ethylene responsive latex proteins (ERLPs) with mass spectrometry from the 2-DE and DIGE gels, respectively. In addition, more than 1,600 proteins, including 404 ERLPs, were identified by iTRAQ. Functional classification of ERLPs revealed that enzymes involved in post-translational modification, carbohydrate metabolism, hydrolase activity and kinase activity were overrepresented. Some enzymes for rubber particle aggregation were inhibited to prolong latex flow and thus finally improved latex production. Phosphoproteomics analysis identified 59 differential phosphoproteins; notably, specific isoforms of rubber elongation factor and small rubber particle protein that were phosphorylated mainly at serine residues. This post-translational modification and isoform-specific phosphorylation might be important for ethylene-stimulated latex production. These results not only deepen our understanding of the rubber latex proteome but also provide new insights into the use of ethylene to stimulate rubber latex production.
Giant Kerr nonlinearity and low-power gigahertz solitons via plasmon-induced transparency
Authors: Bai Zhengyang , Huang Guoxiang , Liu Lixiang , Zhang Shuang
Published: September 2015

We propose a method to enhance Kerr nonlinearity and realize low-power gigahertz solitons via plasmon-induced transparency (PIT) in a new type of metamaterial, which is constructed by an array of unit cell consisting of a cut-wire and a pair of varactor-loaded split-ring resonators. We show that the PIT in such metamaterial can not only mimic the electromagnetically induced transparency in coherent three-level atomic systems, but also exhibit a crossover from PIT to Autler-Townes splitting. We further show that the system suggested here also possess a giant third-order nonlinear susceptibility and may be used to create solitons with extremely low generation power. Our study raises the possibility for obtaining strong nonlinear effect of gigahertz radiation at very low intensity based on room-temperature metamaterials.
Strong Optomechanical Interaction in Hybrid Plasmonic-Photonic Crystal Nanocavities with Surface Acoustic Waves
Authors: Lin Tzy-Rong , Lin Chiang-Hsin , Hsu Jin-Chen
Published: September 2015

We propose dynamic modulation of a hybrid plasmonic-photonic crystal nanocavity using monochromatic coherent acoustic phonons formed by ultrahigh-frequency surface acoustic waves (SAWs) to achieve strong optomechanical interaction. The crystal nanocavity used in this study consisted of a defective photonic crystal beam coupled to a metal surface with a nanoscale air gap in between and provided hybridization of a highly confined plasmonic-photonic mode with a high quality factor and deep subwavelength mode volume. Efficient photon-phonon interaction occurs in the air gap through the SAW perturbation of the metal surface, strongly coupling the optical and acoustic frequencies. As a result, a large modulation bandwidth and optical resonance wavelength shift for the crystal nanocavity are demonstrated at telecommunication wavelengths. The proposed SAW-based modulation within the hybrid plasmonic-photonic crystal nanocavities beyond the diffraction limit provides opportunities for various applications in enhanced sound-light interaction and fast coherent acoustic control of optomechanical devices.
Robust Direct Bandgap Characteristics of One- and Two-Dimensional ReS2
Authors: Yu Zhi Gen , Cai Yongqing , Zhang Yong-Wei
Published: September 2015

Two-dimensional (2D) transition-metal dichalcogenides (TMDs), most notably, MoS2 and WS2, have attracted significant attention due to their sizable and direct bandgap characteristics. Although several interesting MoS2 and WS2-based optoelectronic devices have been reported, their processability and reproducibility are limited since their electrical properties are strongly dependent of the number of layers, strain and sample sizes. It is highly desirable to have a robust direct bandgap TMD, which is insensitive to those factors. In this work, using density functional theory, we explore the effects of layer number, strain and ribbon width on the electronic properties of ReS2, a new member in the TMD family. The calculation results reveal that for monolayer ReS2, the nature (direct versus indirect) and magnitude of its bandgap are insensitive to strain. Importantly, the predicted bandgap and also charge carrier mobilities are nearly independent of the number of layers. In addition, the direct bandgap of ReS2 nanoribbons is only weakly dependent on their width. These robust characteristics strongly suggest that ReS2 has great potential for applications in optoelectronic nanodevices.
Probing cytochrome c in living mitochondria with surface-enhanced Raman spectroscopy
Authors: Brazhe Nadezda A. , Evlyukhin Andrey B. , Goodilin Eugene A. , Semenova Anna A. , Novikov Sergey M. , Bozhevolnyi Sergey I. , Chichkov Boris N. , Sarycheva Asya S. , Baizhumanov Adil A. , Nikelshparg Evelina I. , Deev Leonid I. , Maksimov Eugene G. , Maksimov Georgy V. , Sosnovtseva Olga
Published: September 2015

Selective study of the electron transport chain components in living mitochondria is essential for fundamental biophysical research and for the development of new medical diagnostic methods. However, many important details of inter- and intramembrane mitochondrial processes have remained in shadow due to the lack of non-invasive techniques. Here we suggest a novel label-free approach based on the surface-enhanced Raman spectroscopy (SERS) to monitor the redox state and conformation of cytochrome c in the electron transport chain in living mitochondria. We demonstrate that SERS spectra of living mitochondria placed on hierarchically structured silver-ring substrates provide exclusive information about cytochrome c behavior under modulation of inner mitochondrial membrane potential, proton gradient and the activity of ATP-synthetase. Mathematical simulation explains the observed enhancement of Raman scattering due to high concentration of electric near-field and large contact area between mitochondria and nanostructured surfaces.
The identification of an integral membrane, cytochrome c urate oxidase completes the catalytic repertoire of a therapeutic enzyme
Authors: Doniselli Nicola , Monzeglio Enrico , Dal Palù Alessandro , Merli Angelo , Percudani Riccardo
Published: September 2015

In living organisms, the conversion of urate into allantoin requires three consecutive enzymes. The pathway was lost in hominid, predisposing humans to hyperuricemia and gout. Among other species, the genomic distribution of the two last enzymes of the pathway is wider than that of urate oxidase (Uox), suggesting the presence of unknown genes encoding Uox. Here we combine gene network analysis with association rule learning to identify the missing urate oxidase. In contrast with the known soluble Uox, the identified gene (puuD) encodes a membrane protein with a C-terminal cytochromec. The 8-helix transmembrane domain corresponds to DUF989, a family without similarity to known proteins. Gene deletion in a PuuD-encoding organism (Agrobacterium fabrum) abolished urate degradation capacity; the phenotype was fully restored by complementation with a cytosolic Uox from zebrafish. Consistent with H2O2production by zfUox, urate oxidation in the complemented strain caused a four-fold increase of catalase. No increase was observed in the wild-type, suggesting that urate oxidation by PuuD proceeds through cytochromec-mediated electron transfer. These findings identify a missing link in purine catabolism, assign a biochemical activity to a domain of unknown function (DUF989) and complete the catalytic repertoire of an enzyme useful for human therapy.
Identification and comparative expression analysis of odorant binding protein genes in the tobacco cutworm Spodoptera litura
Authors: Gu Shao-Hua , Zhou Jing-Jiang , Gao Shang , Wang Da-Hai , Li Xian-Chun , Guo Yu-Yuan , Zhang Yong-Jun
Published: September 2015

Insect odorant binding proteins (OBPs) are thought to involve in insects’ olfaction perception. In the present study, we identified 38 OBP genes from the antennal transcriptomes ofSpodoptera litura.Tissue expression profiles analysis revealed that 17 of the 38 SlitOBP transcripts were uniquely or primarily expressed in the antennae of both sexes, suggesting their putative role in chemoreception. The RPKM value analysis revealed that seven OBPs (SlitPBP1-3, SlitGOBP1-2, SlitOBP3andSlitOBP5) are highly abundant in male and female antennae. MostS. lituraantennal unigenes had high homology with Lepidoptera insects, especially genes of the genusSpodoptera. Phylogenetic analysis of the Lepidoptera OBPs demonstrated that the OBP genes from the genusSpodoptera(S. litura,Spodoptera littoralisandSpodoptera exigua) had a relatively close evolutionary relationship. Some regular patterns and key conserved motifs of OBPs in genusSpodopteraare identified by MEME and their putative roles in detecting odorants are discussed here. The motif-patterns between Lepidoptera OBPs and CSPs are also compared. TheSlitOBPsidentified here provide a starting point to facilitate functional studies of insect OBPs at the molecular level bothin vivoandin vitro.
Insight on Tafel slopes from a microkinetic analysis of aqueous electrocatalysis for energy conversion
Authors: Shinagawa Tatsuya , Garcia-Esparza Angel T. , Takanabe Kazuhiro
Published: September 2015

Microkinetic analyses of aqueous electrochemistry involving gaseous H2or O2, i.e., hydrogen evolution reaction (HER), hydrogen oxidation reaction (HOR), oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), are revisited. The Tafel slopes used to evaluate the rate determining steps generally assume extreme coverage of the adsorbed species (θ ≈ 0 or ≈1), although, in practice, the slopes are coverage-dependent. We conducted detailed kinetic analyses describing the coverage-dependent Tafel slopes for the aforementioned reactions. Our careful analyses provide a general benchmark for experimentally observed Tafel slopes that can be assigned to specific rate determining steps. The Tafel analysis is a powerful tool for discussing the rate determining steps involved in electrocatalysis, but our study also demonstrated that overly simplified assumptions led to an inaccurate description of the surface electrocatalysis. Additionally, in many studies, Tafel analyses have been performed in conjunction with the Butler-Volmer equation, where its applicability regarding only electron transfer kinetics is often overlooked. Based on the derived kinetic description of the HER/HOR as an example, the limitation of Butler-Volmer expression in electrocatalysis is also discussed in this report.
Extraordinary slow degradation of dissolved organic carbon (DOC) in a cold marginal sea
Authors: Kim Tae-Hoon , Kim Guebuem , Lee Shin-Ah , Dittmar Thorsten
Published: September 2015

Dissolved organic carbon (DOC) is the largest organic carbon reservoir in the ocean and the amount of carbon in this reservoir rivals that in atmospheric CO2. In general, DOC introduced into the deep ocean undergoes a significant degradation over a centennial time scale (i.e., ~50 μM to ~34 μM in the North Atlantic and Mediterranean Sea). However, we here show that high concentrations of DOC (58 ± 4 μM) are maintained almost constantly over 100 years in the entire deep East/Japan Sea (EJS). The degradation rate in this sea is estimated to be 0.04 μmol C kg−1 yr−1, which is 2–3 times lower than that in the North Atlantic and Mediterranean Sea. Since the source of DOC in the deep EJS is found to be of marine origin on the basis of δ13C-DOC signatures, this slow degradation rate seems to be due to low temperature (<1 oC) in the entire deep water column. This observational result suggests that the storage capacity of DOC in the world ocean is very sensitive to global warming and slowdown of global deep-water overturning.
Polymeric and Solid Lipid Nanoparticles for Sustained Release of Carbendazim and Tebuconazole in Agricultural Applications
Authors: Campos Estefânia Vangelie Ramos , Oliveira Jhones Luiz de , da Silva Camila Morais Gonçalves , Pascoli Mônica , Pasquoto Tatiane , Lima Renata , Abhilash P. C. , Fernandes Fraceto Leonardo
Published: September 2015

Carbendazim (MBC) (methyl-2-benzimidazole carbamate) and tebuconazole (TBZ) ((RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)pentan-3-ol) are widely used in agriculture for the prevention and control of fungal diseases. Solid lipid nanoparticles and polymeric nanocapsules are carrier systems that offer advantages including changes in the release profiles of bioactive compounds and their transfer to the site of action, reduced losses due to leaching or degradation and decreased toxicity in the environment and humans. The objective of this study was to prepare these two types of nanoparticle as carrier systems for a combination of TBZ and MBC and then investigate the release profiles of the fungicides as well as the stabilities and cytotoxicities of the formulations. Both nanoparticle systems presented high association efficiency (>99%), indicating good interaction between the fungicides and the nanoparticles. The release profiles of MBC and TBZ were modified when the compounds were loaded in the nanoparticles and cytotoxicity assays showed that encapsulation of the fungicides decreased their toxicity. These fungicide systems offer new options for the treatment and prevention of fungal diseases in plants.
Lithium isotope traces magmatic fluid in a seafloor hydrothermal system
Authors: Yang Dan , Hou Zengqian , Zhao Yue , Hou Kejun , Yang Zhiming , Tian Shihong , Fu Qiang
Published: September 2015

Lithium isotopic compositions of fluid inclusions and hosted gangue quartz from a giant volcanogenic massive sulfide deposit in China provide robust evidence for inputting of magmatic fluids into a Triassic submarine hydrothermal system. The δ7Li results vary from +4.5‰ to +13.8‰ for fluid inclusions and from +6.7‰ to +21.0‰ for the hosted gangue quartz(9 gangue quartz samples containing primary fluid inclusions). These data confirm the temperature-dependent Li isotopic fractionation between hydrothermal quartz and fluid (i.e., Δδ7Liquartz-fluid = –8.9382 × (1000/T) + 22.22(R2 = 0.98; 175 °C–340 °C)), which suggests that the fluid inclusions are in equilibrium with their hosted quartz, thus allowing to determine the composition of the fluids by using δ7Liquartz data. Accordingly, we estimate that the ore-forming fluids have a δ7Li range from −0.7‰ to +18.4‰ at temperatures of 175–340 °C. This δ7Li range, together with Li–O modeling , suggest that magmatic fluid played a significant role in the ore formation. This study demonstrates that Li isotope can be effectively used to trace magmatic fluids in a seafloor hydrothermal system and has the potential to monitor fluid mixing and ore-forming process.
Recruiting a new strategy to improve levan production in Bacillus amyloliquefaciens
Authors: Feng Jun , Gu Yanyan , Quan Yufen , Zhang Wei , Cao Mingfeng , Gao Weixia , Song Cunjiang , Yang Chao , Wang Shufang
Published: September 2015

Microbial levan is an important biopolymer with considerable potential in food and medical applications. Bacillus amyloliquefaciens NK-ΔLP strain can produce high-purity, low-molecular-weight levan, but production is relatively low. To enhance the production of levan, six extracellular protease genes (bpr, epr, mpr, vpr, nprE and aprE), together with the tasA gene (encoding the major biofilm matrix protein TasA) and the pgsBCA cluster (responsible for poly-γ-glutamic acid (γ-PGA) synthesis), were intentionally knocked out in the Bacillus amyloliquefaciens NK-1 strain. The highest levan production (31.1 g/L) was obtained from the NK-Q-7 strain (ΔtasA, Δbpr, Δepr, Δmpr, Δvpr, ΔnprE, ΔaprE and ΔpgsBCA), which was 103% higher than that of the NK-ΔLP strain (ΔpgsBCA) (15.3 g/L). Furthermore, the NK-Q-7 strain also showed a 94.1% increase in α-amylase production compared with NK-ΔLP strain, suggesting a positive effect of extracellular protease genes deficient on the production of endogenously secreted proteins. This is the first report of the improvement of levan production in microbes deficient in extracellular proteases and TasA and the NK-Q-7 strain exhibits outstanding characteristics for extracellular protein production or extracellular protein related product synthesis.
Bias field tailored plasmonic nano-electrode for high-power terahertz photonic devices
Authors: Moon Kiwon , Lee Il-Min , Shin Jun-Hwan , Lee Eui Su , Kim Namje , Lee Won-Hui , Ko Hyunsung , Han Sang-Pil , Park Kyung Hyun
Published: September 2015

Photoconductive antennas with nano-structured electrodes and which show significantly improved performances have been proposed to satisfy the demand for compact and efficient terahertz (THz) sources. Plasmonic field enhancement was previously considered the dominant mechanism accounting for the improvements in the underlying physics. However, we discovered that the role of plasmonic field enhancement is limited and near-field distribution of bias field should be considered as well. In this paper, we clearly show that the locally enhanced bias field due to the size effect is much more important than the plasmonic enhanced absorption in the nano-structured electrodes for the THz emitters. Consequently, an improved nano-electrode design is presented by tailoring bias field distribution and plasmonic enhancement. Our findings will pave the way for new perspectives in the design and analysis of plasmonic nano-structures for more efficient THz photonic devices.
Differentiation of early germ cells from human skin-derived stem cells without exogenous gene integration
Authors: Ge Wei , Ma Hua-Gang , Cheng Shun-Feng , Sun Yuan-Chao , Sun Li-Lan , Sun Xiao-Feng , Li Lan , Dyce Paul , Li Julang , Shi Qing-Hua , Shen Wei
Published: September 2015

Infertility has long been a difficult issue for many couples. The successful differentiation of germ cells and live progeny from pluripotent stem cells brings new hope to the couples suffering with infertility. Here we successfully isolated human fetus skin-derived stem cells (hfSDSCs) from fetus skin tissue and demonstrated that hfSDSCs can be differentiated into early human germ cell-like cells (hGCLCs). These cells express human germ cell markers DAZL and VASA. Moreover, these pluripotent stem cell-derived hGCLCs are free of exogenous gene integration. When hfSDSCs were differentiated in porcine follicle fluid (PFF) conditioned media, which has been shown to promote the differentiation of mouse and porcine SDSCs into oocyte-like cells (OLCs), we observed some vesicular structures formed from hfSDSCs. Moreover, when hfSDSCs were cultured with specific conditioned media, we observed punctate and elongated SCP3 staining foci, indicating the initiation of meiosis. Ploidy analysis and fluorescent in situ hybridization (FISH) analysis indicated that a small percentage of putative 1N populations formed from hfSDSCs when compared with positive controls. In conclusion, our data here, for the first time, demonstrated that hfSDSCs possess the differentiation potential into germ lines and they may differentiate both male and female hGCLCs in vitro under appropriate conditions.
TSC2 mediates hyperosmotic stress-induced inactivation of mTORC1
Authors: Plescher Monika , Teleman Aurelio A. , Demetriades Constantinos
Published: September 2015

mTOR complex 1 (mTORC1) regulates cell growth and metabolism. mTORC1 activity is regulated via integration of positive growth-promoting stimuli and negative stress stimuli. One stress cells confront in physiological and pathophysiological contexts is hyperosmotic stress. The mechanism by which hyperosmotic stress regulates mTORC1 activity is not well understood. We show here that mild hyperosmotic stress induces a rapid and reversible inactivation of mTORC1 via a mechanism involving multiple upstream signaling pathways. We find that hyperosmotic stress causes dynamic changes in TSC2 phosphorylation by upstream kinases, such as Akt, thereby recruiting TSC2 from the cytoplasm to lysosomes where it acts on Rheb, the direct activator of mTORC1. This work puts together a signaling pathway whereby hyperosmotic stress inactivates mTORC1.
Discovery of a selective, safe and novel anti-malarial compound with activity against chloroquine resistant strain of Plasmodium falciparum
Authors: Agarwal Ankita , Paliwal Sarvesh , Mishra Ruchi , Sharma Swapnil , Kumar Dwivedi Anil , Tripathi Renu , Gunjan Sarika
Published: September 2015

In recent years the DNA minor groove has attracted much attention for the development of anti-malarial agents. In view of this we have attempted to discover novel DNA minor groove binders through in-silico and in-vitro workflow. A rigorously validated pharmacophore model comprising of two positive ionizable (PI), one hydrophobic (HY) and one ring aromatic (RA) features was used to mine NCI chemical compound database. This led to retrieval of many hits which were screened on the basis of estimated activity, fit value and Lipinski’s violation. Finally two compounds NSC639017 and NSC371488 were evaluated for their in-vitro anti-malarial activities against Plasmodium falciparum 3D7 (CQ sensitive) and K1 (CQ resistant) strains by SYBR green-I based fluorescence assay. The results revealed that out of two, NSC639017 posses excellent anti-malarial activity particularly against chloroquine resistant strain and moreover NSC639017 also appeared to be safe (CC50 126.04 μg/ml) and selective during cytotoxicity evaluation.
Modeling the transmission dynamics of Ebola virus disease in Liberia
Authors: Xia Zhi-Qiang , Wang Shi-Fu , Li Shen-Long , Huang Liu-Yu , Zhang Wen-Yi , Sun Gui-Quan , Gai Zhong-Tao , Jin Zhen
Published: September 2015

Ebola virus disease (EVD) has erupted many times in some zones since it was first found in 1976. The 2014 EVD outbreak in West Africa is the largest ever, which has caused a large number of deaths and the most serious country is Liberia during the outbreak period. Based on the data released by World Health Organization and the actual transmission situations, we investigate the impact of different transmission routes on the EVD outbreak in Liberia and estimate the basic reproduction number R0 = 2.012 in the absence of effective control measures. Through sensitivity and uncertainty analysis, we reveal that the transmission coefficients of suspected and probable cases have stronger correlations on the basic reproduction number. Furthermore, we study the influence of control measures (isolation and safe burial measures) on EVD outbreak. It is found that if combined control measures are taken, the basic reproduction number will be less than one and thus EVD in Liberia may be well contained. The obtained results may provide new guidance to prevent and control the spread of disease.
An optimized method for high-titer lentivirus preparations without ultracentrifugation
Authors: Jiang Wei , Hua Rui , Wei Mengping , Li Chenhong , Qiu Zilong , Yang Xiaofei , Zhang Chen
Published: September 2015

Lentiviral technology has proven to be a powerful tool to express exogenous genes in dividing and non-dividing cells. Currently, most protocols for generating high-titer lentivirus require ultracentrifugation, which can be an instrumental barrier for routine operations in a laboratory. In this study, the effect of relative centrifugal force (RCF) on the concentration efficiency of the lentivirus was systematically explored and it was found that sucrose gradient centrifugation with a relatively low speed (≤10,000 g) robustly produces a high-titer virus (up to 2 × 108 TU/ml). The optimal sucrose concentration is 10% and the recovery rate of the functional virus is greater than 80%. The infection efficiency of both concentrated and un-concentrated lentivirus decreases rapidly when the viruses are stored at 4 °C (τ ≈ 1.3 days) or subjected to multiple freeze-thaw cycles (τ = 1.1 rounds). In summary, we describe an efficient and easy-to-handle protocol for high-titer lentivirus purification.
Aluminum doping tunes band gap energy level as well as oxidative stress-mediated cytotoxicity of ZnO nanoparticles in MCF-7 cells
Authors: Akhtar Mohd Javed , Alhadlaq Hisham A. , Alshamsan Aws , Majeed Khan M.A. , Ahamed Maqusood
Published: September 2015

We investigated whether Aluminum (Al) doping tunes band gap energy level as well as selective cytotoxicity of ZnO nanoparticles in human breast cancer cells (MCF-7). Pure and Al-doped ZnO nanoparticles were prepared by a simple sol-gel method. Characterization study confirmed the formation of single phase of AlxZn1-xO nanocrystals with the size range of 33–55 nm. Al-doping increased the band gap energy of ZnO nanoparticles (from 3.51 eV for pure to 3.87 eV for Al-doped ZnO). Al-doping also enhanced the cytotoxicity and oxidative stress response of ZnO nanoparticles in MCF-7 cells. The IC50 for undoped ZnO nanoparticles was 44 μg/ml while for the Al-doped ZnO counterparts was 31 μg/ml. Up-regulation of apoptotic genes (e.g. p53, bax/bcl2 ratio, caspase-3 & caspase-9) along with loss of mitochondrial membrane potential suggested that Al-doped ZnO nanoparticles induced apoptosis in MCF-7 cells through mitochondrial pathway. Importantly, Al-doping did not change the benign nature of ZnO nanoparticles towards normal cells suggesting that Al-doping improves the selective cytotoxicity of ZnO nanoparticles toward MCF-7 cells without affecting the normal cells. Our results indicated a novel approach through which the inherent selective cytotoxicity of ZnO nanoparticles against cancer cells can be further improved.
Deterministic Creation of Macroscopic Cat States
Authors: Lombardo Daniel , Twamley Jason
Published: September 2015

Despite current technological advances, observing quantum mechanical effects outside of the nanoscopic realm is extremely challenging. For this reason, the observation of such effects on larger scale systems is currently one of the most attractive goals in quantum science. Many experimental protocols have been proposed for both the creation and observation of quantum states on macroscopic scales, in particular, in the field of optomechanics. The majority of these proposals, however, rely on performing measurements, making them probabilistic. In this work we develop a completely deterministic method of macroscopic quantum state creation. We study the prototypical optomechanical Membrane In The Middle model and show that by controlling the membrane’s opacity and through careful choice of the optical cavity initial state, we can deterministically create and grow the spatial extent of the membrane’s position into a large cat state. It is found that by using a Bose-Einstein condensate as a membrane high fidelity cat states with spatial separations of up to ∼300 nm can be achieved.
Dystrophin deficiency reduces atherosclerotic plaque development in ApoE-null mice
Authors: Shami Annelie , Knutsson Anki , Dunér Pontus , Rauch Uwe , Bengtsson Eva , Tengryd Christoffer , Murugesan Vignesh , Durbeej Madeleine , Gonçalves Isabel , Nilsson Jan , Hultgårdh-Nilsson Anna
Published: September 2015

Dystrophin of the dystrophin-glycoprotein complex connects the actin cytoskeleton to basement membranes and loss of dystrophin results in Duchenne muscular dystrophy. We have previously shown injury-induced neointima formation of the carotid artery in mice with the mdx mutation (causing dystrophin deficiency) to be increased. To investigate the role of dystrophin in intimal recruitment of smooth muscle cells (SMCs) that maintains plaque stability in atherosclerosis we applied a shear stress-modifying cast around the carotid artery of apolipoprotein E (ApoE)-null mice with and without the mdx mutation. The cast induces formation of atherosclerotic plaques of inflammatory and SMC-rich/fibrous phenotypes in regions of low and oscillatory shear stress, respectively. Unexpectedly, presence of the mdx mutation markedly reduced the development of the inflammatory low shear stress plaques. Further characterization of the low shear stress plaques in ApoE-null mdx mice demonstrated reduced infiltration of CD3+ T cells, less laminin and a higher SMC content. ApoE-null mdx mice were also found to have a reduced fraction of CD3+ T cells in the spleen and lower levels of cytokines and monocytes in the circulation. The present study is the first to demonstrate a role for dystrophin in atherosclerosis and unexpectedly shows that this primarily involves immune cells.
An ionic liquid improved HPLC-ICP-MS method for simultaneous determination of arsenic and selenium species in animal/plant-derived foodstuffs
Authors: Fang Guozhen , Lv Qinghui , Liu Cuicui , Huo Miaomiao , Wang Shuo
Published: September 2015

An ionic liquid improved HPLC-ICP-MS method for the simultaneous determination of arsenic and selenium species in foodstuffs.