bluuebunny/crossref_metadata_2025_split huggingface dataset:
Composites with graphene as reinforcement
Authors: Surendranathan A O 
Published: October 2019

Abstract
In this paper, the developments in the area of graphene-reinforced composite have been reviewed. It also depicts the work guided by the author. In the work, WC powder with 6% cobalt (Co) and graphene (0.2%) in the form of graphene nanoplatelets (GPLs) was prepared by high energy rate ball milling and ultrasonification. The mixture was sintered using spark plasma sintering at 1250ºC for 10 min. To study the effects of graphene reinforcement, the sample was analyzed for the physical (density), magnetic (coercivity, and magnetic saturation), microstructural (porosity) and mechanical properties (hardness, fracture toughness). Under Visual Inspection of the Spark Plasma Sintered (SPS) sample, the top surface showed more homogeneous distribution of the constituents than the bottom surface. The results of the surface measurements showed that the top and bottom surfaces have almost the same roughness. It was found that the SPS sample exceeded liquid phase sintered (LPS) specimens with respect to hardness and fracture toughness values. The coercive force was found to be higher for the LPS sample whereas the saturation magnetization value was found to be higher for the SPS sintered specimen. The density value is higher for the LPS sintered specimen. The presence of pores is seen in the back scattered electron (BSE) image. There was certain amount carbon pick up from the graphite die used in SPS. There was uniform distribution of the cobalt binder. The x-ray diffraction pattern for the SPS sintered sample indicates the presence of WC, Co and GNP.
Metastable states of graphene Dirac fermion in potential barrier
Authors: Kuwata S , Takehisa D 
Published: October 2019

Abstract
Weak quantization of the Dirac equation under a potential barrier (with height V0) indicates that while the bound state of Dirac fermion (with energy E0
∈ ℝ and mass m) is allowed for |E
0| < m, the Dirac fermion is metastable for |E
0| > m. Under the condition V0
» m, which is well satisfied for typical graphene, it is found that the tunneling time Δt and the lifetime τ for the metastable state are related as Δt ≳ 2τ. As m decreases, it follows that Δt/τ tends to increase and behaves as log(l/m) up to higher order logarithmic correction.
Preparation and application of a novel high temperature resistant filtration reducer in water-based drilling fluids
Authors: Chang X F , Sun J S , Zhang F , Lv K H 
Published: October 2019

Abstract
4-vinylpyridine (VP), N, N-dimethylacrylamide (DMAA), 2-Acrylamido-2-methylpropane sulfonic acid (AMPS) and sodium styrene sulfonate (SSS) were synthesized to a novel filtrate reducer in aqueous solution by free radical copolymerization using ammonium persulfate and sodium bisulfite as redox systems. The structure of copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR). Thermogravimetric analysis (TGA) showed that the thermal decomposition temperature of the copolymer was higher than 310°C, which indicated that the copolymer had excellent high temperature resistance. At the same time, the rheological and filtration properties of water-based drilling fluids (WBDFs) were further evaluated by adding copolymer as a filtrate reducer. The results showed that the fluid loss (FLAPI) of WBDFs was only 5.0 mL when the copolymer content is 2.0 wt%, Even after hot rolling at 260°C for 16 hours, the FLAPI of WBDFs was 8.2 mL. The FLAPI of fresh water mud was 25.2 mL, and that of aged fresh water mud was 48 mL. In addition, WBDFs with copolymer effectively resists salt and calcium intrusion before and after hot rolling at high temperature for 16 hours, which indicates that the copolymer can be used as an efficient filtration reducer in ultra-deep well drilling operations.
Prediction of parameters of microscale coating-metal interface phase based on finite element method
Authors: Jia Z K , Zhang Y , Xin J H , Cheng Q 
Published: October 2019

Abstract
The coating-metal transition interface can form a stable gradient interface phase composite. In this paper, a finite element model of gradient interface phase is established based on Tyson Polygon Method (TPM), and the microstructure equivalent parameters of interface material of the element are obtained by means of average method. By analyzing the functional relationship between the equivalent elastic parameters of the gradient interface element and the metal volume ratio, the functional expression of the microstructure parameter distribution of the interface phase is obtained. The results show that the equivalent elastic modulus and equivalent shear modulus of the interface satisfy the distribution of exponential function, linear function and power function in the local scope. The change rule of equivalent Poisson’s ratio with metal phase volume fraction in local scope can be expressed by logistic function. It is found that the global parameter distribution of interface phase is different from that of local material. The equivalent elastic modulus and equivalent shear modulus of the global interface satisfy the double exponential function distribution, while the distribution law of the equivalent Poisson’s ratio can be piecewise expressed by the logistic function and the exponential function.
Computational design of dummy molecularly imprinted polymers via hydrogen bonding investigation for oxytetracycline determination
Authors: Reyes N B D , Pajarito B B 
Published: October 2019

AbstractOxytetracycline (OTC), a banned broad-spectrum antibiotic, currently requires highly selective and specific determination methods to measure its concentration below 200 ppb in foods of animal origin. Molecular imprinting technology could be utilized to construct a highly selective and cost-effective synthetic receptor for OTC. In this work, we investigated different monomers in designing a dummy MIP for OTC detection using TC as the dummy template. Template-monomer complexes of pre-polymerization mixtures were modeled using density functional theory for geometry optimization, intermolecular hydrogen-bonding situation, and interaction energies. O-phenylenediamine (OPD) at TC:OPD molar ratio = 1:7 was shown to be the optimum monomer, forming 11 stable intermolecular hydrogen bonds with TC and having the lowest interaction energy among the complexes. We also presented indole, pyrrole, and carbazole to be plausible monomers for imprinting TC; however, they are energetically less-favored than OPD. This study provides aid in dummy MIP design for OTC concentration measurement using the molecular level interaction of different monomers with the template TC.
Microstructure and mechanical properties of Al/SiC surface composite with different volume fractions using friction stir process
Authors: El-Mahallawy N A , Zoalfakar S H , Maboud A A G A 
Published: October 2019

Abstract
Friction stir processing (FSP) was used to produce Al/SiC composites on the surface of Al 1050 sheets. SiC particles of 1 µm size were added on the Al sheet surface inside grooves with different sizes in order to obtain different composite volume fractions. FSP was applied with a square shape tool rotating at 1500 rpm and with a feed rate of 116 mm/min. The effect of SiC volume fraction on microstructure, and mechanical properties was investigated and the results were compared with samples treated by FSP but without SiC reinforcement. Different SiC volume fractions were obtained ranging from 7% to 16% depending on the groove size. Optical microscopic analysis (OM) in collaboration with scanning electron microscope (SEM) were used to fully discuss the microstructural changes within each sample. Mechanical properties were investigated through microhardness and tension test (including yield strength, ultimate tensile strength and percentage elongation). The results show significant improvement in microstructure changes in the FSPed composites, where equiaxed and refined grains structure were obtained due to the effect of the severe plastic deformation and continuous dynamic recrystallization caused by FSP compared to the elongated and coarse grains of the base metal. Microhardness and strength of the FSPed composites improved up to 112% and 9.7%, respectively compared to the as-received material.
Cross-validation of the Invalid Forgetting Frequency Index (IFFI) from the Test of Memory Malingering
Authors: Olsen Daniel H , Schroeder Ryan W , Martin Phillip K 
Published: October 2019

Abstract

Objective
To increase sensitivity of the Test of Memory Malingering (TOMM), adjustments have been proposed, including adding consistency indices. The Invalid Forgetting Frequency Index (IFFI) is the most recently developed consistency index. While strong classification accuracy rates were originally reported, it currently lacks cross-validation.

Method
A sample of 184 outpatients was utilized. Valid performers passed all criterion performance validity tests (PVTs) and invalid performers failed two or more PVTs. Classification accuracy statistics were calculated.

Results
AUC for the IFFI was 0.80, demonstrating adequate discrimination between valid and invalid groups. A score of 3 or more inconsistent responses resulted in sensitivity and specificity rates of 63% and 92%, respectively.

Conclusions
This is the first article to cross-validate the IFFI. In both the original IFFI study and the current study, the same cut-off was found to maintain at least 90% specificity while producing higher sensitivity rates than those achieved by traditional TOMM indices.
Mitochondrial miR-181a-5p promotes glucose metabolism reprogramming in liver cancer by regulating the electron transport chain
Authors: Zhuang Xiang , Chen Yuwei , Wu Zhenru , Xu Qing , Chen Menglin , Shao Mingyang , Cao Xiaoyue , Zhou Yongjie , Xie Mingjun , Shi Yujun , Zeng Yong , Bu Hong 
Published: October 2019

Abstract
Liver cancer and other malignant tumor cells rely on the glycolytic pathway to obtain energy (i.e. the Warburg effect); however, the underlying mechanism is unclear. Mitochondria are sites of oxidative phosphorylation and adenosine triphosphate (ATP) production. The 13 constituent respiratory chain proteins encoded by the mitochondrial genome (namely, mtDNA) play essential roles. We found that in human hepatocellular carcinoma (HCC) tissues, 11 out of the 13 mtDNA-encoded genes exhibited decreased mRNA levels and 5 genes displayed decreased protein levels, including the cytochrome B (mt-CYB) and cytochrome C oxidase II (mt-CO2) genes. Mitochondrial gene sequencing revealed abnormalities in the levels of a large number of mitochondrial miRNAs (mitomiRs). MicroRNA-181a-5p (mir-181a-5p), which potentially targets genes encoding mt-CYB and mt-CO2 protein, was screened out from 549 downregulated mitomiRs via bioinformatic analysis. After overexpression of mitomiR-181a-5p, mt-CYB and mt-CO2 levels were reduced in HCC cells, and the mitochondrial membrane potential (MMP) maintained by the electron transport chain (ETC) was decreased. Furthermore, the expression of hexokinase 2 (HK2) and glucose transporter type 1 (GLUT1) was upregulated, accompanied by elevated glucose, lactic acid release, and activity of lactate dehydrogenase (LDH). In vivo experiments confirmed that constitutive mitomiR-181a-5p expression caused reprogramming of glucose metabolism and promoted tumor growth and early lung metastasis in liver cancer. In summary, the present study reveals the important role of mitomiRs in glucose metabolism reprogramming in liver cancer, which is of considerable value in exploring new therapeutic targets for HCC.
Antiretroviral Therapy–Induced Bone Loss Is Durably Suppressed by a Single Dose of Zoledronic Acid in Treatment-Naive Persons with Human Immunodeficiency Virus Infection: A Phase IIB Trial
Authors: Ofotokun Ighovwerha , Collins Lauren F , Titanji Kehmia , Foster Antonina , Moran Caitlin A , Sheth Anandi N , Lahiri Cecile D , Lennox Jeffrey L , Ward Laura , Easley Kirk A , Weitzmann M Neale 
Published: October 2019

AbstractBackgroundHuman immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) are associated with bone loss leading to increased fracture rate among persons with HIV (PWH). We previously showed long-acting antiresorptive zoledronic acid (ZOL) prevented ART-induced bone loss through 48 weeks of therapy and here investigate whether protection persisted.MethodsWe randomized 63 nonosteoporotic, treatment-naive adult PWH initiating ART to ZOL (5 mg) versus placebo in a double-blinded, placebo-controlled, phase IIb trial. Here we analyzed the long-term outcome data (144 weeks). Plasma bone turnover markers and bone mineral density (BMD) were quantified at weeks 0, 12, 24, 48, 96, and 144. Primary outcome was change in bone resorption marker C-terminal telopeptide of collagen (CTx). Repeated-measures analyses using mixed linear models were used to estimate and compare study endpoints.ResultsAt 96 weeks, mean CTx was 62% lower with ZOL relative to placebo (n = 46; CTx = 0.123 vs 0.324 ng/mL; P &lt; .001); at 144 weeks a 25% difference between arms was not statistically significant. At 48 weeks, lumbar spine BMD with ZOL was 11% higher than placebo (n = 60; P &lt; .001) and remained 9–11% higher at 96 (n = 46) and 144 (n = 41; P &lt; .001) weeks. 144 weeks after ZOL infusion, BMD did not change at the lumbar spine (P = .22) but declined at the hip (P = .04) and femoral neck (P = .02).ConclusionsA single dose of ZOL administered at ART initiation blunts bone resorption and BMD loss at key fracture-prone anatomical sites in treatment-naive PWH for 3 years. A multicenter randomized phase III clinical trial validating these results in a larger population is needed.Clinical Trials RegistrationNCT01228318.
Carbon/nitrogen homeostasis control in cyanobacteria
Authors: Forchhammer Karl , Selim Khaled A 
Published: October 2019

ABSTRACTCarbon/nitrogen (C/N) balance sensing is a key requirement for the maintenance of cellular homeostasis. Therefore, cyanobacteria have evolved a sophisticated signal transduction network targeting the metabolite 2-oxoglutarate (2-OG), the carbon skeleton for nitrogen assimilation. It serves as a status reporter for the cellular C/N balance that is sensed by transcription factors NtcA and NdhR and the versatile PII-signaling protein. The PII protein acts as a multitasking signal-integrating regulator, combining the 2-OG signal with the energy state of the cell through adenyl-nucleotide binding. Depending on these integrated signals, PII orchestrates metabolic activities in response to environmental changes through binding to various targets. In addition to 2-OG, other status reporter metabolites have recently been discovered, mainly indicating the carbon status of the cells. One of them is cAMP, which is sensed by the PII-like protein SbtB. The present review focuses, with a main emphasis on unicellular model strains Synechoccus elongatus and Synechocystis sp. PCC 6803, on the physiological framework of these complex regulatory loops, the tight linkage to metabolism and the molecular mechanisms governing the signaling processes.
Thomae-Weber Formula: Algebraic Computations of Theta Constants
Authors: Celik Turku Ozlum 
Published: October 2019

Abstract
We give an algebraic method to compute the fourth power of the quotient of any even theta constants associated with a given non-hyperelliptic curve in terms of geometry of the curve. In order to apply the method, we work out non-hyperelliptic curves of genus 4, in particular, such curves lying on a singular quadric, which arise from del Pezzo surfaces of degree 1. Indeed, we obtain a complete level 2 structure of the curves by studying their theta characteristic divisors via exceptional divisors of the del Pezzo surfaces as the structure is required for the method.
Impaired Alanine Transport or Exposure to d-Cycloserine Increases the Susceptibility of MRSA to β-lactam Antibiotics
Authors: Gallagher Laura A , Shears Rebecca K , Fingleton Claire , Alvarez Laura , Waters Elaine M , Clarke Jenny , Bricio-Moreno Laura , Campbell Christopher , Yadav Akhilesh K , Razvi Fareha , O’Neill Eoghan , O’Neill Alex J , Cava Felipe , Fey Paul D , Kadioglu Aras , O’Gara James P 
Published: October 2019

AbstractProlonging the clinical effectiveness of β-lactams, which remain first-line antibiotics for many infections, is an important part of efforts to address antimicrobial resistance. We report here that inactivation of the predicted d-cycloserine (DCS) transporter gene cycA resensitized methicillin-resistant Staphylococcus aureus (MRSA) to β-lactam antibiotics. The cycA mutation also resulted in hypersusceptibility to DCS, an alanine analogue antibiotic that inhibits alanine racemase and d-alanine ligase required for d-alanine incorporation into cell wall peptidoglycan. Alanine transport was impaired in the cycA mutant, and this correlated with increased susceptibility to oxacillin and DCS. The cycA mutation or exposure to DCS were both associated with the accumulation of muropeptides with tripeptide stems lacking the terminal d-ala-d-ala and reduced peptidoglycan cross-linking, prompting us to investigate synergism between β-lactams and DCS. DCS resensitized MRSA to β-lactams in vitro and significantly enhanced MRSA eradication by oxacillin in a mouse bacteremia model. These findings reveal alanine transport as a new therapeutic target to enhance the susceptibility of MRSA to β-lactam antibiotics.
AKINβ1, a regulatory subunit of SnRK1, regulates organic acid metabolism and acts as a global regulator of genes involved in carbon, lipid and nitrogen metabolism
Authors: Wang You , Wang Liping , Micallef Barry J , Tetlow Ian J , Mullen Robert T , Feil Regina , Lunn John E , Emes Michael J 
Published: October 2019

Abstract
The Sucrose Non-fermenting-1-Related Protein Kinase 1 (SnRK1) is a highly conserved heterotrimeric protein kinase in plants. It possesses a catalytic subunit (α) and two regulatory subunits (β and γ). The effects of altered expression of AKINβ1 on carbohydrate metabolism and gene expression in leaves were investigated in an Arabidopsis T-DNA insertion mutant. The contents of key intermediates in the tricarboxylic acid (TCA) cycle of the mutant leaves were markedly reduced throughout the diurnal cycle, coupled with a decrease in measurable respiration rate. Compared to wild-type, 2485 genes and 188 genes were expressed differentially in leaves of the akinβ1 mutant in response to light and darkness respectively. Among these, several genes exhibited very substantial decreases in expression. Notably, expression of particular isoforms of multigene families involved in malate and lipid metabolism, and nitrate uptake showed decreases of 40-240 fold during the light period, but not during darkness. The subcellular localization of AKINβ1 and the regulatory function of N-myristoylation on the subcellular localization of AKINβ1 were investigated, showing that AKINβ1 localizes to Golgi. A model is hypothesized to explain the effects of AKINβ1 on metabolism and gene expression in Arabidopsis.
PolyASite 2.0: a consolidated atlas of polyadenylation sites from 3′ end sequencing
Authors: Herrmann Christina J , Schmidt Ralf , Kanitz Alexander , Artimo Panu , Gruber Andreas J , Zavolan Mihaela 
Published: October 2019

Abstract
Generated by 3′ end cleavage and polyadenylation at alternative polyadenylation (poly(A)) sites, alternative terminal exons account for much of the variation between human transcript isoforms. More than a dozen protocols have been developed so far for capturing and sequencing RNA 3′ ends from a variety of cell types and species. In previous studies, we have used these data to uncover novel regulatory signals and cell type-specific isoforms. Here we present an update of the PolyASite (https://polyasite.unibas.ch) resource of poly(A) sites, constructed from publicly available human, mouse and worm 3′ end sequencing datasets by enforcing uniform quality measures, including the flagging of putative internal priming sites. Through integrated processing of all data, we identified and clustered sites that are closely spaced and share polyadenylation signals, as these are likely the result of stochastic variations in processing. For each cluster, we identified the representative - most frequently processed - site and estimated the relative use in the transcriptome across all samples. We have established a modern web portal for efficient finding, exploration and export of data. Database generation is fully automated, greatly facilitating incorporation of new datasets and the updating of underlying genome resources.
Entangled: Evangelicals and Gangs in El Salvador
Authors: Offutt Stephen 
Published: October 2019

Abstractow are the two most ubiquitous community-based organizations in poor Salvadoran neighborhoods—gangs and evangelical churches—connected? Most studies concur with the Brenneman/Wolseth thesis, which states that evangelical churches uniquely provide people with a pathway out of gangs. This article argues that such dynamics are a relatively small subset of a broad range of interactions between evangelicals and gangs. Data from the Religion, Global Poverty, and International Development study, collected in a mid-sized Salvadoran city from 2014 to 2018, show that: (1) family networks link evangelicals and gangs; (2) evangelicals and gangs share community governance; (3) gangs infiltrate congregations; and (4) evangelical ideas and networks penetrate gang life. These findings indicate that the widely accepted “haven” perspective of evangelicals in Latin America is insufficient to explain current empirical complexities. An “entanglement” framework is thus introduced, which may be relevant to evangelicals’ relationships to contemporary Latin American society more broadly.
30-Day Postoperative Morbidity and Readmission Following Revision Anterior Cervical Discectomy and Fusion (ACDF)
Authors: Malik Azeem T. , Khan Safdar N. , Kim Jeffery , Yu Elizabeth 
Published: October 2019

Study Design:
This was a retrospective cohort study.

Objective:
To analyze risk factors associated with 30-day adverse outcomes and readmissions after revision anterior cervical discectomy and fusion (ACDF).

Summary of Background Data:
No current literature has evaluated the risk factors associated with adverse outcomes after revision ACDF.

Methods:
The 2012–2016 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried using Current Procedural Terminology codes for ACDF (22551, 22554, and 63075) combined with Current Procedural Terminology codes 22830 (exploration of spinal fusion) or 22855 (removal of anterior instrumentation) to identify revision cases. Patients undergoing concurrent posterior cervical spine surgery and/or corpectomies were excluded from the analysis. A total of 1140 patients were retrieved for analysis.

Results:
Out of a total of 1140 patients, 51 (4.5%) experienced at least 1 any adverse event, with 40 (3.5%) experiencing a severe adverse event, and 17 (1.5%) experiencing a minor adverse event. A 30-day readmission rate was 3.4% (N=39) after a revision ACDF. On multivariate analysis, any adverse events were significantly associated with male sex [odds ratio (OR), 1.98], 2-level versus 1-level fusion (OR, 2.05), and a length of stay (LOS)>1 day (OR, 7.70). Severe adverse events were independently associated with male sex (OR, 2.85), smoking (OR, 0.33), 2-level versus 1-level fusion (OR, 2.03), and LOS>1 day (OR, 7.28). LOS>1 day was the only significant factor associated with an minor adverse event (OR, 14.65) and readmission within 30 days (OR, 2.67).

Conclusions:
Using a national surgical database, the study is the first of its kind to report rates and risk factors associated with adverse outcomes after ACDFs. Providers should understand the need of preoperative risk stratification in these patients to reduce the risk of experiencing adverse outcomes.

Level of Evidence:
Level III—retrospective.