bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast and fully-scalable synthesis of reduced graphene oxide
Authors: Abdolhosseinzadeh Sina , Asgharzadeh Hamed , Seop Kim Hyoung 
Published: May 2015

AbstractExfoliation of graphite is a promising approach for large-scale production of graphene. Oxidation of graphite effectively facilitates the exfoliation process, yet necessitates several lengthy washing and reduction processes to convert the exfoliated graphite oxide (graphene oxide, GO) to reduced graphene oxide (RGO). Although filtration, centrifugation and dialysis have been frequently used in the washing stage, none of them is favorable for large-scale production. Here, we report the synthesis of RGO by sonication-assisted oxidation of graphite in a solution of potassium permanganate and concentrated sulfuric acid followed by reduction with ascorbic acid prior to any washing processes. GO loses its hydrophilicity during the reduction stage which facilitates the washing step and reduces the time required for production of RGO. Furthermore, simultaneous oxidation and exfoliation significantly enhance the yield of few-layer GO. We hope this one-pot and fully-scalable protocol paves the road toward out of lab applications of graphene.
Evolutionary origin and demographic history of an ancient conifer (Juniperus microsperma) in the Qinghai-Tibetan Plateau
Authors: Shang Hui-Ying , Li Zhong-Hu , Dong Miao , Adams Robert P. , Miehe Georg , Opgenoorth Lars , Mao Kang-Shan 
Published: May 2015

AbstractAll Qinghai-Tibetan Plateau (QTP) endemic species are assumed to have originated recently, although very rare species most likely diverged early. These ancient species provide an excellent model to examine the origin and evolution of QTP endemic plants in response to the QTP uplifts and the climate changes that followed in this high altitude region. In this study, we examined these hypotheses by employing sequence variation from multiple nuclear and chloroplast DNA of 239 individuals of Juniperus microsperma and its five congeners. Both phylogenetic and population genetic analyses revealed that J. microsperma diverged from its sister clade comprising two species with long isolation around the Early Miocene, which corresponds to early QTP uplift. Demographic modeling and coalescent tests suggest that J. microsperma experienced an obvious bottleneck event during the Quaternary when the global climate greatly oscillated. The results presented here support the hypotheses that the QTP uplifts and Quaternary climate changes played important roles in shaping the evolutionary history of this rare juniper.
Impaired cell envelope resulting from arcA mutation largely accounts for enhanced sensitivity to hydrogen peroxide in Shewanella oneidensis
Authors: Wan Fen , Mao Yinting , Dong Yangyang , Ju Lili , Wu Genfu , Gao Haichun 
Published: May 2015

AbstractOxidative stress is one of the major challenges thatShewanellaencounter routinely because they thrive in redox-stratified environments prone to reactive oxygen species (ROS) formation, letting alone that ROS can be generated endogenously. As respiration is the predominant process for endogenous ROS, regulators mediating respiration have been demonstrated and/or implicated to play a role in oxidative stress response. In our efforts to unveil the involvement of global regulators for respiration in the oxidative stress response, we found that loss of the Arc system increasesS. oneidensissensitivity to H2O2whereas neither Fnr nor Crp has a significant role. A comparison of transcriptomic profiles of the wild-type and its isogenicarcAmutant revealed that the OxyR regulon is independent of the Arc system. We then provided evidence that the enhanced H2O2sensitivity of thearcAmutant is due to an increased H2O2uptake rate, a result of a cell envelope defect. Although one of three proteases of the ArcA regulon when in excess is partially accountable for the envelope defect, the major contributors remain elusive. Overall, our data indicate that the Arc system influences the bacterial cell envelope biosynthesis, a physiological aspect that has not been associated with the regulator before.
Simple structured hybrid WOLEDs based on incomplete energy transfer mechanism: from blue exciplex to orange dopant
Authors: Zhang Tianyou , Zhao Bo , Chu Bei , Li Wenlian , Su Zisheng , Yan Xingwu , Liu Chengyuan , Wu Hairuo , Gao Yuan , Jin Fangming , Hou Fuhua 
Published: May 2015

AbstractExciplex is well known as a charge transfer state formed between electron-donating and electron-accepting molecules. However, exciplex based organic light emitting diodes (OLED) often performed low efficiencies relative to pure phosphorescent OLED and could hardly be used to construct white OLED (WOLED). In this work, a new mechanism is developed to realize efficient WOLED with extremely simple structure by redistributing the energy of triplet exciplex to both singlet exciplex and the orange dopant. The micro process of energy transfer could be directly examined by detailed photoluminescence decay measurement and time resolved photoluminescence analysis. This strategy overcomes the low reverse intersystem crossing efficiency of blue exciplex and complicated device structure of traditional WOLED, enables us to achieve efficient hybrid WOLEDs. Based on this mechanism, we have successfully constructed both exciplex-fluorescence and exciplex-phosphorescence hybrid WOLEDs with remarkable efficiencies.
Colossal positive magnetoresistance in surface-passivated oxygen-deficient strontium titanite
Authors: David Adrian , Tian Yufeng , Yang Ping , Gao Xingyu , Lin Weinan , Shah Amish B. , Zuo Jian-Min , Prellier Wilfrid , Wu Tom 
Published: May 2015

AbstractModulation of resistance by an external magnetic field, i.e. magnetoresistance effect, has been a long-lived theme of research due to both fundamental science and device applications. Here we report colossal positive magnetoresistance (CPMR) (>30,000% at a temperature of 2 K and a magnetic field of 9 T) discovered in degenerate semiconducting strontium titanite (SrTiO3) single crystals capped with ultrathin SrTiO3/LaAlO3 bilayers. The low-pressure high-temperature homoepitaxial growth of several unit cells of SrTiO3 introduces oxygen vacancies and high-mobility carriers in the bulk SrTiO3 and the three-unit-cell LaAlO3 capping layer passivates the surface and improves carrier mobility by suppressing surface-defect-related scattering. The coexistence of multiple types of carriers and inhomogeneous transport lead to the emergence of CPMR. This unit-cell-level surface engineering approach is promising to be generalized to others oxides and to realize devices with high-mobility carriers and interesting magnetoelectronic properties.
Flexible conformable hydrophobized surfaces for turbulent flow drag reduction
Authors: Brennan Joseph C , Geraldi Nicasio R , Morris Robert H , Fairhurst David J , McHale Glen , Newton Michael I 
Published: May 2015

AbstractIn recent years extensive work has been focused onto using superhydrophobic surfaces for drag reduction applications. Superhydrophobic surfaces retain a gas layer, called a plastron, when submerged underwater in the Cassie-Baxter state with water in contact with the tops of surface roughness features. In this state the plastron allows slip to occur across the surface which results in a drag reduction. In this work we report flexible and relatively large area superhydrophobic surfaces produced using two different methods: Large roughness features were created by electrodeposition on copper meshes; Small roughness features were created by embedding carbon nanoparticles (soot) into Polydimethylsiloxane (PDMS). Both samples were made into cylinders with a diameter under 12 mm. To characterize the samples, scanning electron microscope (SEM) images and confocal microscope images were taken. The confocal microscope images were taken with each sample submerged in water to show the extent of the plastron. The hydrophobized electrodeposited copper mesh cylinders showed drag reductions of up to 32% when comparing the superhydrophobic state with a wetted out state. The soot covered cylinders achieved a 30% drag reduction when comparing the superhydrophobic state to a plain cylinder. These results were obtained for turbulent flows with Reynolds numbers 10,000 to 32,500.
Ultralight boron nitride aerogels via template-assisted chemical vapor deposition
Authors: Song Yangxi , Li Bin , Yang Siwei , Ding Guqiao , Zhang Changrui , Xie Xiaoming 
Published: May 2015

AbstractBoron nitride (BN) aerogels are porous materials with a continuous three-dimensional network structure. They are attracting increasing attention for a wide range of applications. Here, we report the template-assisted synthesis of BN aerogels by catalyst-free, low-pressure chemical vapor deposition on graphene-carbon nanotube composite aerogels using borazine as the B and N sources with a relatively low temperature of 900 °C. The three-dimensional structure of the BN aerogels was achieved through the structural design of carbon aerogel templates. The BN aerogels have an ultrahigh specific surface area, ultralow density, excellent oil absorbing ability and high temperature oxidation resistance. The specific surface area of BN aerogels can reach up to 1051 m2 g−1, 2-3 times larger than the reported BN aerogels. The mass density can be as low as 0.6 mg cm−3, much lower than that of air. The BN aerogels exhibit high hydrophobic properties and can absorb up to 160 times their weight in oil. This is much higher than porous BN nanosheets reported previously. The BN aerogels can be restored for reuse after oil absorption simply by burning them in air. This is because of their high temperature oxidation resistance and suggests broad utility as water treatment tools.
Enzyme-activated intracellular drug delivery with tubule clay nanoformulation
Authors: Dzamukova Maria R. , Naumenko Ekaterina A. , Lvov Yuri M. , Fakhrullin Rawil F. 
Published: May 2015

AbstractFabrication of stimuli-triggered drug delivery vehicle s is an important milestone in treating cancer. Here we demonstrate the selective anticancer drug delivery into human cells with biocompatible 50-nm diameter halloysite nanotube carriers. Physically-adsorbed dextrin end stoppers secure the intercellular release of brilliant green. Drug-loaded nanotubes penetrate through the cellular membranes and their uptake efficiency depends on the cells growth rate. Intercellular glycosyl hydrolases-mediated decomposition of the dextrin tube-end stoppers triggers the release of the lumen-loaded brilliant green, which allowed for preferable elimination of human lung carcinoma cells (А549) as compared with hepatoma cells (Hep3b). The enzyme-activated intracellular delivery of brilliant green using dextrin-coated halloysite nanotubes is a promising platform for anticancer treatment.
Cysteine-specific ubiquitination protects the peroxisomal import receptor Pex5p against proteasomal degradation
Authors: Schwartzkopff Benjamin , Platta Harald W. , Hasan Sohel , Girzalsky Wolfgang , Erdmann Ralf 
Published: May 2015

Peroxisomal matrix protein import is mediated by dynamic import receptors, which cycle between the peroxisomal membrane and the cytosol. Proteins with a type 1 peroxisomal targeting signal (PTS1) are bound by the import receptor Pex5p in the cytosol and guided to the peroxisomal membrane. After cargo translocation into the peroxisomal matrix, the receptor is released from the membrane back to the cytosol in an ATP-dependent manner by the AAA-type ATPases Pex1p and Pex6p. These mechanoenzymes recognize ubiquitinated Pex5p-species as substrates for membrane extraction. The PTS1-receptor is either polyubiquitinated via peptide bonds at two certain lysines and results in proteasomal degradation or monoubiquitinated via a thioester-bond at a conserved cysteine, which enables the recycling of Pex5p and further rounds of matrix protein import. To investigate the physiological relevance of the conserved N-terminal cysteine of Pex5p, the known target amino acids for ubiquitination were substituted by site-directed mutagenesis. In contrast with Pex5pC6A, Pex5pC6K turned out to be functional in PTS1 import and utilization of oleic acid, independent of the lysines at position 18 and 24. In contrast with wild-type Pex5p, Pex5pC6K displays an ubiquitination pattern, similar to the polyubiquitination pattern of Pex4p or Pex22p mutant strains. Moreover, Pex5pC6K displays a significantly reduced steady-state level when the deubiquitinating enzyme Ubp15p is missing. Thus, our results indicate that not the cysteine residue but the position of ubiquitination is important for Pex5p function. The presence of the cysteine prevents polyubiquitination and rapid degradation of Pex5p.
Si‐based Ge0.9Sn0.1 photodetector with peak responsivity of 2.85 A/W and longwave cutoff at 2.4 μm
Authors: Pham T.N. , Du W. , Conley B.R. , Margetis J. , Sun G. , Soref R.A. , Tolle J. , Li B. , Yu S.‐Q. 
Published: May 2015

High performance Si‐based Ge0.9Sn0.1 photoconductive infrared detectors have been demonstrated. The device fabrication is fully compatible with the complementary metal‐oxide‐semiconductor (CMOS) process. The room temperature responsivity at 1.55 μm is 0.26 A/W and comparable with that of commercially available InGaAs and Ge photovoltaic detectors. Temperature‐dependent study shows an increased peak responsivity of 2.85 A/W at 77 K. The spectral response has a longwave cutoff of 2.4 and 2.2 μm at 300 and 77 K, respectively. Specific detectivity (D*) was calculated and compared side by side with D* of market dominating infrared detectors.
Fully integrated 60 GHz switched‐beam phased antenna array in glass‐IPD technology
Authors: Chang Chia‐Chan , Lin Chun‐Chi , Cheng Wei‐Kuo 
Published: May 2015

A 1 × 4 double‐sided dipole antenna array with an associated Butler matrix beamforming network was designed and implemented at 60 GHz using glass‐based integrated passive device (IPD) technology. Owing to the chip area limitation, the spacing between the antenna elements is ∼0.32λ0. Experimental results show that beams are successfully generated in the −62°, −23°, 22° and 50° directions, with total array gains of 2.5, 3.8, 4.3 and 3.0 dBi, respectively, which agree with simulation predictions. This successful demonstration provides a feasible solution for 60 GHz radio in heterogeneous system‐in‐package (SiP) integration.
Giant thermal spin-torque–assisted magnetic tunnel junction switching
Authors: Pushp Aakash , Phung Timothy , Rettner Charles , Hughes Brian P. , Yang See-Hun , Parkin Stuart S. P. 
Published: May 2015

Significance
One of the most promising emerging memory technologies is magnetic random access memory (MRAM), which promises to be a high-performance, nonvolatile memory. The essential feature of MRAM is the efficient switching of the magnetic tunnel junction (MTJ) memory cell between two distinct resistance states associated with the relative magnetic orientation of the ferromagnetic electrodes which sandwich the tunnel barrier by using magnetic fields, charge currents, or pure spin currents. In this paper, a temperature difference of just a few kelvin across an ultrathin (∼1 nm) MgO tunnel barrier is found to generate giant spin currents sufficient to significantly influence the switching of the MTJ. These spin currents get created only in those devices that show a large asymmetry in their tunneling conductance across zero bias voltage.
Effect of sialylation on EGFR phosphorylation and resistance to tyrosine kinase inhibition
Authors: Yen Hsin-Yung , Liu Ying-Chih , Chen Nai-Yu , Tsai Chia-Feng , Wang Yi-Ting , Chen Yu-Ju , Hsu Tsui-Ling , Yang Pan-Chyr , Wong Chi-Huey 
Published: May 2015

Significance
This report reveals the influence of sialylation on the activation of epidermal growth factor receptor (EGFR) and sensitivity to tyrosine kinase inhibitors (TKIs) against EGFR phosphorylation. By utilizing biochemical approaches, we demonstrated that EGFR sialylation suppresses EGFR phosphorylation by inhibiting EGF binding and EGFR dimerization. In the TKI-resistant lung cancer cell line with L858R/T790M mutations on EGFR, the levels of phosphorylation at Y1068, Y1086, and Y1173 are upregulated, and sialylation can partially suppress the phosphorylation of EGFR at these sites and enhance EGFR sensitivity to TKI. These findings suggest that sialylation has an important role in tumorigenesis and sensitivity to TKIs by modulating EGFR phosphorylation and the associated signaling network and provide insights for therapeutic intervention.
Bedaquiline susceptibility testing of Mycobacterium tuberculosis in an automated liquid culture system
Authors: Torrea Gabriela , Coeck Nele , Desmaretz Christel , Van De Parre Tim , Van Poucke Tijs , Lounis Nacer , de Jong Bouke C. , Rigouts Leen 
Published: May 2015

Abstract

Objectives
The objective of this study was to evaluate the performance of the BACTEC MGIT960 system to test the susceptibility to bedaquiline for Mycobacterium tuberculosis complex.

Methods
We determined the quality control (QC) range of bedaquiline using the M. tuberculosis H37Rv reference strain and the epidemiological cut-off (ECOFF) in MGIT960 and on Middlebrook 7H11 agar (M7H11) using 47 strains from bedaquiline treatment-naive patients. The accuracy of MGIT960 was evaluated versus M7H11 using 74 ‘probably susceptible to bedaquiline’ and 18 ‘probably resistant to bedaquiline’ strains. Repeatability and reproducibility of MGIT960 were assessed using five strains showing different resistance levels.

Results
The QC range for the H37Rv strain was between 0.125 and 0.50 mg/L. The WT MIC distribution ranged from ≤0.03 to 1.00 mg/L in MGIT960 and from ≤0.008 to 0.25 mg/L on M7H11 with suggested ECOFFs of 1.00 and 0.25 mg/L, respectively. Applying these ECOFFs, the probably susceptible and probably resistant strains were distinguishable by both methods, albeit with only a 2-fold increased MIC for one of the resistant strains compared with the ECOFF. Intermethod agreement to classify the isolates was excellent (100%). All replicates in the repeatability and reproducibility experiments fell within the normal range.

Conclusions
The MGIT960 system proved to be highly stable, reproducible and accurate relative to the M7H11 agar method for determining the bedaquiline MIC. The small margin between the suggested ECOFF and the lowest MIC for the mutant strains risks making both methods prone to discordant results. Further validation in clinical settings linked to treatment outcome data is needed.
Comparative genetic structure of sympatric leporids in southern Illinois
Authors: Berkman Leah K. , Nielsen Clayton K. , Roy Charlotte L. , Heist Edward J. 
Published: May 2015

Abstract
Many leporid species have overlapping ranges, but ecological differences may make for profoundly different population structure in the same area. In southern Illinois, swamp rabbits (Sylvilagus aquaticus) and eastern cottontails (S. floridanus) co-exist, but swamp rabbits are habitat specialists associated with floodplain forests and eastern cottontails exhibit more general habitat preferences. Additionally, swamp rabbits exist at the northern edge of their range in southern Illinois, whereas eastern cottontails are well within the core of their range. To determine whether these differences resulted in differences in genetic structure, we assessed the population differentiation of these 2 sympatric species in southern Illinois using polymorphic microsatellite markers. We employed a combination of sampling techniques including tissue sampling from trapped rabbits and collection of fecal pellets from swamp rabbit latrine logs. Swamp rabbits appeared to be differentiated within 50 km of Illinois’ Cache River watershed (K = 4 populations) suggesting that local populations are relatively isolated, whereas eastern cottontails exhibited no discernable genetic structure (K = 1). Such a result confirms the expected relationship of greater genetic structure in a habitat specialist (i.e., swamp rabbits) versus a habitat generalist (i.e., eastern cottontails). Unlike eastern cottontails, our results suggest that swamp rabbits experience low genetic connectivity in southern Illinois likely due to restricted dispersal, linear distribution of habitat, and smaller effective population size as mediated by habitat fragmentation.
Prevalence, Incidence, and Clearance of Anogenital Warts in Kenyan Men Reporting High-Risk Sexual Behavior, Including Men Who Have Sex With Men
Authors: Neme Santiago , Wahome Elizabeth , Mwashigadi Grace , Thiong'o Alexander N. , Stekler Joanne D. , Wald Anna , Sanders Eduard J. , Graham Susan M. 
Published: May 2015

Abstract
Background.  Human papillomavirus (HPV) causes a spectrum of disease, ranging from warts to cancer. Prevalence, incidence, and factors associated with anogenital warts in East African men are unknown.
Methods.  Kenyan men reporting high-risk sexual behavior were inspected for anogenital warts at enrollment and follow-up visits. Logistic regression was performed to identify associations with anogenital warts at baseline. Cox regression was performed to analyze predictors of incident anogenital warts, and Kaplan–Meier curves were used to estimate clearance.
Results.  Baseline anogenital wart prevalence in 1137 men was 2.9% (95% confidence interval [CI], 2.0%–4.0%) overall, 2.0% in human immunodeficiency virus (HIV)-uninfected men, and 9.4% in HIV-1-infected men (adjusted odds ratio, 5.43; 95% CI, 2.03–11.29). Over a median of 1.4 years, anogenital wart incidence among 1104 men was 5.3 (95% CI, 4.3–6.5) per 100 person-years. Having HIV-1 infection at baseline (adjusted hazard ratio [aHR], 1.66; 95% CI, 1.01–2.72) or a genital syndrome during follow-up (aHR, 4.78; 95% CI, 3.03–7.56) was associated with increased wart incidence. Wart clearance was lower in HIV-1-infected men (log-rank P&lt;.001).
Conclusions.  Anogenital wart prevalence and incidence were increased in HIV-1-infected men, and anogenital warts co-occurred with other genital syndromes. Quadrivalent HPV vaccination should be recommended for young men in settings with high HIV-1 prevalence.