bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations on Oilwell Cement Strength Response to Ultrasonic Measurements in the Presence of Additives1
Authors: Romanowski Niklas , Ichim Adonis , Teodoriu Catalin
Published: February 2018

Well cements are an important aspect of wellbore integrity and recent investigations focus on describing the cement lifetime using, when possible, nondestructive tests like ultrasonic measurements. However, the original API and ASTM testing standards were based on destructive mechanical testing of cements, leading to the decision to investigate the backward and forward compatibility between ultrasonic measurements and mechanical testing, which makes the subject of this work. Ultrasonic cement measurement became a very popular method to assess the mechanical properties of the cement in a nondestructive manner. Since various measurement systems exist on the market, the development of an accurate reference data base that can be used to calibrate such measurements becomes very important. Two major systems have therefore been compared: the ultrasonic compressive strength, using the ultrasonic pulse velocity (UPV) principle, and the unconfined compressive strength (UCS), using the standard testing frame according to API and ASTM standards. The tests have been performed at different curing times, using both devices, on API Class G cements with bentonite and other additives. This paper presents the results of over 200 experiments that have displayed a different UPV response as a function of the additive content. Cement specific UPV versus UCS correlations were established. Thereby, a new level of accuracy was reached. Moreover, it was observed that after a given curing time, depending on the additive and its concentration, the UPV response is not as sensitive as the results yielded by the UCS method. The outcomes are an important step forward to improve and understand the wellbore integrity.
Rheological Properties and Ignition and Combustion Characteristics of Biochar–Algae–Water Slurry Fuels
Authors: Zhu Mingming , Zhang Zhezi , Liu Pengfei , Zhang Dongke
Published: February 2018

This study examined the rheological properties, ignition, and combustion characteristics of biochar–algae–water (BAW) slurry fuels. A pine sawdust biochar with a median particle size (D50) of approximately 12 μm and algae Chlorella vulgaris in dry powder form with D50 of approximately 19 μm were used. The BAW slurries with a constant solid loading of 40 wt % and algae/biochar ratio varying from 0 to 0.2 by weight were prepared. The apparent viscosity was measured using a Haake VT550 cone-and-plate viscometer. The stability of the slurries was characterized using a “drop rod” method. Ignition and combustion characteristics of the slurries were studied using a suspended single-droplet technique. A single droplet of a slurry fuel with a diameter ranging from 0.5 mm to 1.5 mm was suspended on a silicon carbide fibre and burned in air at 1023 K in an electrically heated tube furnace. The ignition and combustion processes of the droplet were recorded using a CCD camera at 200 fps. The ignition delay time, burnout time, and burning rate were determined. The BAW slurries showed shear-thinning flow behavior. The slurries had higher viscosity and greater stability at higher algae proportion in the solid. The ignition and combustion process of BAW slurries followed the sequence of water evaporation, devolatilization, ignition, and combustion of the solid residue. The combustion of the residual solid was diffusion controlled under the experimental conditions and the burning rates of the BAW slurry droplets ranged from 0.15 to 0.25 mm2 s−1.
Contrasting the Pyrolysis Behavior of Selected Biomass and the Effect of Lignin
Authors: Zhang Zhezi , Zhu Mingming , Hobson Philip , Doherty William , Zhang Dongke
Published: February 2018

This study was aimed at comparing the pyrolysis behavior of several selected biomass samples, namely, pine wood, poplar wood, wheat straw, and sugarcane bagasse, with a particular attention to the effect of lignin. Raw samples were first treated using Soxhlet solvent extraction with a 2:1 (v/v) mixture of toluene/ethanol to remove wax. Lignin was then removed by soaking the dewaxed samples in a 1.0 M sodium chlorite solution at 343 K till the solids became white. Fourier transform infrared (FTIR) spectroscopy analysis was applied to characterize the surface functional groups of the samples. The morphology of the samples before and after delignification treatment was analyzed using scanning electron microscope (SEM). The pyrolysis behavior of the raw and treated biomass samples was studied using a thermogravimetric analyzer (TGA) operating in nitrogen at a constant heating rate of 10 K min−1 from room temperature to the final temperature 823 K. The FTIR and SEM results indicated that lignin can be successfully removed from the raw biomass via the chemical treatment used. As expected, the pyrolysis behavior differed significantly among the various raw biomass samples. However, the pyrolysis behavior of the delignified samples showed almost identical thermal behavior although the temperature associated with the maximum rate of pyrolysis was shifted to a lower temperature regime by ca. 50 K. This suggests that the presence of lignin significantly affected the biomass pyrolysis behavior. Thus, the pyrolysis behavior of the biomass cannot be predicted simply from the individual components without considering their interactions.
Experimental Investigation on Damage Mechanism of Guar Gum Fracturing Fluid to Low-Permeability Reservoir Based on Nuclear Magnetic Resonance
Authors: Guo Tiankui , Gong Facheng , Lin Xin , Lin Qiang , Wang Xiaozhi
Published: February 2018

The damage mechanism of fracturing fluids has always been the hot research topic in the development of low-permeability reservoir with hydraulic fracturing. At present, the research in this area is conducted mostly by the conventional core fluid flow test designed with industrial standards, less in the experiment operated from a microperspective. Against the reservoir cores with different permeability, and based on the results of SEM, mercury injection experiment, and core fluid flow test, this paper uses the technology of nuclear magnetic resonance (NMR) to systematically analyze the degree and rule of water-sensitivity, water-block, and solid-phase adsorption damage resulted from hydroxypropyl guar gum (HPG) and carboxymethyl guar gum (CMG) fracturing fluids, and proposes a comprehensive test method for evaluating the fracturing fluids damage to the reservoir. The test results show that fracturing fluid infiltrating into the core causes the increase of bound water, mobile water retention, and solid-phase macromolecule substance absorption inside the core in varying degrees, decreasing the reservoir permeability. The extent of reservoir water-sensitivity damage is positively correlated with the increment of bound water, and the extent of water-block damage is positively correlated with mobile water retention volume. The adsorption and retention of solid-phase macromolecule substance causes largest loss of core permeability, averaging about 20%, and it is main damage factor of fracturing fluids, the water-sensitivity damage causes 11% of core permeability loss, and the water-block damage causes 7% of loss. As the reservoir permeability doubles, the comprehensive damage resulted from guar gum fracturing fluid decreases by 14%. The comprehensive damage of CMG fracturing fluid to reservoir is 6.6% lower than that of HPG fracturing fluid, and the lower the reservoir permeability, the larger the gap between damage of CMG and HPG fracturing fluids. With the technology of NMR, the objective and accurate evaluation of various damages to reservoir resulted from fracturing fluids is realized, and the corresponding relation between damage mechanism and damage extent is established, which provides reference for research on improvement of fracturing fluid properties and reservoir protection measures.
Effect of CO2 on Heavy Oil Recovery and Physical Properties in Huff-n-Puff Processes Under Reservoir Conditions
Authors: Li Songyan , Li Binfei , Zhang Qiliang , Li Zhaomin , Yang Daoyong
Published: February 2018

In this paper, experimental and numerical techniques have been utilized to quantify heavy oil properties in CO2 huff-n-puff processes under reservoir conditions. Experimentally, fluid properties together with viscosity reduction of heavy oil and interfacial properties between CO2 and heavy oil have been quantified, while five cycles of CO2 huff-n-puff processes have been conducted to determine oil recovery together with component variation of produced and residual oils. Theoretically, numerical simulation has been conducted to analyze the underlying recovery mechanisms associated with the CO2 huff-n-puff processes. CO2 huff-n-puff processes are only effective in the first two cycles under the existing experimental conditions, while the effective sweep range is limited near the wellbore region, resulting in poor oil recovery in the subsequent cycles. As for produced oil, its viscosity, density, resin and asphaltene contents, and molecular weight of asphaltene are reduced, whereas, for the residual oil, they are increased. The asphaltene component in the residual oil shows weak stability compared to that of the produced oil, while the ultimate oil recovery after the fifth CO2 cycle of huff-n-huff processes is measured to be 31.56%.
Mass Customized Design of Cosmetic Masks Using Three-Dimensional Parametric Human Face Models Constructed From Anthropometric Data
Authors: Chu Chih-Hsing , Wang I-Jan
Published: February 2018

Cosmetic mask is a popular skincare product widely accepted by the youth and female. Most cosmetic masks in the current market offer very few sizes to choose from, thus producing misfit masks with reduced wearing comfort and skincare functionality. This paper describes how to realize customized design of cosmetic masks using three-dimensional (3D) parametric face models derived from a large amount of scanned facial data. The parametric models approximate individual faces using a nonlinear regression model controlled by a set of facial parameters easy to be measured. They serve as effective reference geometry to conduct 3D mask design. A prototyping mask design system implementing the parametric modeling method demonstrates the customized design process. The system allows the user to construct the mask shape directly on 3D meshes of a face model by specifying inner and outer boundary curves. An automatic flattening function unfolds the trimmed meshes into a two-dimensional (2D) pattern with a reduced shape distortion. This research enhances the practical value of large-scale anthropometric data by realizing human centric design customization using cosmetic facial mask as an example.
Influence of Poroelasticity of the Surface Layer on the Surface Love Wave Propagation
Authors: El Baroudi Adil
Published: February 2018

This work presents a theoretical method for surface love waves in poroelastic media loaded with a viscous fluid. A complex analytic form of the dispersion equation of surface love waves has been developed using an original resolution based on pressure–displacement formulation. The obtained complex dispersion equation was separated in real and imaginary parts. mathematica software was used to solve the resulting nonlinear system of equations. The effects of surface layer porosity and fluid viscosity on the phase velocity and the wave attenuation dispersion curves are inspected. The numerical solutions show that the wave attenuation and phase velocity variation strongly depend on the fluid viscosity, surface layer porosity, and wave frequency. To validate the original theoretical resolution, the results in literature in the case of an homogeneous isotropic surface layer are used. The results of various investigations on love wave propagation can serve as benchmark solutions in design of fluid viscosity sensors, in nondestructive testing (NDT) and geophysics.
How Concept Selection Tools Impact the Development of Creative Ideas in Engineering Design Education
Authors: Zheng Xuan , Ritter Sarah C. , Miller Scarlett R.
Published: February 2018

Concept selection tools have been heavily integrated into engineering design education in an effort to reduce the risks and uncertainties of early-phase design ideas and aid students in the decision-making process. However, little research has examined the utility of these tools in promoting creative ideas or their impact on student team decision making throughout the conceptual design process. To fill this research gap, the current study was designed to compare the impact of two concept selection tools, the concept selection matrix (CSM) and the tool for assessing semantic creativity (TASC) on the average quality (AQL) and average novelty (ANV) of ideas selected by student teams at several decision points throughout an 8-week project. The results of the study showed that the AQL increased significantly in the detailed design stage, while the ANV did not change. However, this change in idea quality was not significantly impacted by the concept selection tool used, suggesting other factors may impact student decision making and the development of creative ideas. Finally, student teams were found to select ideas ranked highly in concept selection tools only when these ideas met their expectations, indicating that cognitive biases may be significantly impeding decision making.
Optimization and Evaluation of Piperacillin-Tobramycin Combination Dosage Regimens against Pseudomonas aeruginosa for Patients with Altered Pharmacokinetics via the Hollow-Fiber Infection Model and Mechanism-Based Modeling
Authors: Yadav Rajbharan , Rogers Kate E. , Bergen Phillip J. , Bulitta Jürgen B. , Kirkpatrick Carl M. J. , Wallis Steven C. , Paterson David L. , Nation Roger L. , Lipman Jeffrey , Roberts Jason A. , Landersdorfer Cornelia B.
Published: February 2018

Augmented renal clearance (ARC) in critically ill patients can result in suboptimal drug exposures and treatment failure. Combination dosage regimens accounting for ARC have never been optimized and evaluated against
Pseudomonas aeruginosa
by use of the hollow-fiber infection model (HFIM). Using a
P. aeruginosa
isolate from a critically ill patient and static-concentration time-kill experiments (SCTKs), we studied clinically relevant piperacillin and tobramycin concentrations, alone and in combinations, against two inocula (10
5.8
and 10
7.6
CFU/ml) over 72 h. We subsequently evaluated the effects of optimized piperacillin (4 g every 4 h [q4h], given as 0.5-h infusions) plus tobramycin (5 mg/kg of body weight q24h, 7 mg/kg q24h, or 10 mg/kg q48h, given as 0.5-h infusions) regimens on killing and regrowth in the HFIM, simulating a creatinine clearance of 250 ml/min. Mechanism-based modeling was performed in S-ADAPT. In SCTKs, piperacillin plus tobramycin (except combinations with 8 mg/liter tobramycin and against the low inoculum) achieved synergistic killing (≥2 log
10
versus the most active monotherapy at 48 h and 72 h) and prevented regrowth. Piperacillin monotherapy (4 g q4h) in the HFIM provided 2.4-log
10
initial killing followed by regrowth at 24 h and resistance emergence. Tobramycin monotherapies displayed rapid initial killing (≥5 log
10
at 13 h) followed by extensive regrowth. As predicted by mechanism-based modeling, the piperacillin plus tobramycin dosage regimens were synergistic and provided ≥5-log
10
killing with resistance suppression over 8 days in the HFIM. Optimized piperacillin-tobramycin regimens provided significant bacterial killing and suppressed resistance emergence. These regimens appear to be highly promising for effective and early treatment, even in the near-worst-case scenario of ARC.
Elevated Plasma Moxifloxacin Concentrations and
SLCO1B1
g.−11187G>A Polymorphism in Adults with Pulmonary Tuberculosis
Authors: Weiner Marc , Gelfond Jon , Johnson-Pais Teresa L. , Engle Melissa , Peloquin Charles A. , Johnson John L. , Sizemore Erin E. , Mac Kenzie William R.
Published: February 2018

Moxifloxacin exhibits concentration-dependent prolongation of human QTc intervals and bactericidal activity against
Mycobacterium tuberculosis
. However, moxifloxacin plasma concentrations are variable between patients. We evaluated whether human gene polymorphisms affect moxifloxacin plasma concentrations in tuberculosis patients from two geographic regions. We enrolled a convenience sample of 49 adults with drug-sensitive pulmonary tuberculosis from Africa and the United States enrolled in two treatment trials of moxifloxacin as part of multidrug therapy. Pharmacokinetic parameters were evaluated by noncompartmental techniques. Human single-nucleotide polymorphisms of transporter genes were evaluated by analysis of covariance (ANCOVA) on moxifloxacin exposure and the peak (maximum) concentration (
C
max
). The moxifloxacin area under the concentration-time curve from 0 to 24 h (AUC
0–24
) and
C
max
were significantly increased by the drug milligram-per-kilogram dosage and the genotype of variant g.−11187G>A in the
SLCO1B1
gene (rs4149015) but not by geographic region. The median moxifloxacin AUC
0–24
was 46% higher and the median
C
max
was 30% higher in 4 (8%) participants who had the
SLCO1B1
g.−11187 AG genotype than in 45 participants who had the wild-type GG genotype (median AUC
0–24
from the model, 34.4 versus 23.6 μg · h/ml [
P
= 0.005, ANCOVA]; median
C
max
from the model, 3.5 versus 2.7 μg/ml [
P
= 0.009, ANCOVA]). Because moxifloxacin exhibits concentration-dependent prolongation of human QTc intervals and prolonged QTc intervals are associated with cardiac arrhythmia, further study is needed to evaluate the risk associated with the
SLCO1B1
g.−11187G>A variant. (This study has been registered at ClinicalTrials.gov under identifier NCT00164463.)
Complete Genome Sequences of Six
Listeria monocytogenes
Sequence Type 9 Isolates from Meat Processing Plants in Norway
Authors: Fagerlund Annette , Langsrud Solveig , Moen Birgitte , Heir Even , Møretrø Trond
Published: February 2018

Listeria monocytogenes
is a foodborne pathogen that causes the often-fatal disease listeriosis. We present here the complete genome sequences of six
L. monocytogenes
isolates of sequence type 9 (ST9) collected from two different meat processing facilities in Norway. The genomes were assembled using Illumina and Nanopore sequencing data.
Annotated Genome Sequences of 16 Lineage 4
Mycobacterium tuberculosis
Strains from Guatemala
Authors: Saelens Joseph W. , Lau-Bonilla Dalia , Moller Anneliese , Xet-Mull Ana M. , Medina Narda , Guzmán Brenda , Calderón Maylena , Herrera Raúl , Stout Jason E. , Arathoon Eduardo , Samayoa Blanca , Tobin David M.
Published: February 2018

Whole-genome sequencing has resulted in new insights into the phylogeography of
Mycobacterium tuberculosis
. However, only limited genomic data are available from
M. tuberculosis
strains in Guatemala. Here we report 16 complete genomes of clinical strains belonging to the Euro-American lineage 4, the most common lineage found in Guatemala and Central America.
Complete Genome Sequences of Two Vesicular Stomatitis New Jersey Viruses Representing the 2012 U.S. Epidemic Strain and Its Closest Relative Endemic Strain from Southern Mexico
Authors: Velazquez-Salinas Lauro , Pauszek Steven J. , Verdugo-Rodriguez Antonio , Rodriguez Luis L.
Published: February 2018

We report here the complete genome sequences of two vesicular stomatitis New Jersey virus (VSNJV) field strains isolated from epithelial lesions from naturally infected animals in Mexico and the United States. The close phylogenetic relationship of these isolates makes them an ideal model for assessing potential genetic factors linked with the emergence of VSNJV in the United States.
Complete Genome Sequence of the Model Oleaginous Alga
Nannochloropsis gaditana
CCMP1894
Authors: Schwartz Ariel S. , Brown Rob , Ajjawi Imad , McCarren Jay , Atilla Suzan , Bauman Nick , Richardson Toby H.
Published: February 2018

The model oleaginous alga
Nannochloropsis gaditana
was completely sequenced using a combination of optical mapping and next-generation sequencing technologies to generate one of the most complete eukaryotic genomes published to date. The assembled genome is 30.7 Mb long.
Genome Sequences of 12
Pseudomonas lundensis
Strains Isolated from the Lungs of Humans
Authors: Scales Brittan S. , Erb-Downward John R. , Falkowski Nicole R. , LiPuma John J. , Huffnagle Gary B.
Published: February 2018

We report here the first complete genome sequence of a human
Pseudomonas lundensis
isolate, strain AU1044, and the draft genomes of 11 other clinical
P. lundensis
strains, isolated from the lungs of cystic fibrosis patients. The genome of strain AU1044 is 4.81 Mb and encodes seven 16S rRNAs.
High-Quality Complete Genome Sequences of Three Bovine Shiga Toxin-Producing
Escherichia coli
O177:H- (
fliC
H25
) Isolates Harboring Virulent
stx2
and Multiple Plasmids
Authors: Sheng Haiqing , Duan Mingrui , Hunter Samuel S. , Minnich Scott A. , Settles Matthew L. , New Daniel D. , Chase Jennifer R. , Fagnan Matthew W. , Hovde Carolyn J.
Published: February 2018

Shiga toxin-producing
Escherichia coli
(STEC) bacteria are zoonotic pathogens. We report here the high-quality complete genome sequences of three STEC O177:H- (
fliC
H25
) strains, SMN152SH1, SMN013SH2, and SMN197SH3. The assembled genomes consisted of one optical map-verified circular chromosome for each strain, plus two plasmids for SMN013SH2 and three plasmids for SMN152SH1 and SMN197SH3, respectively.
Draft Genome Sequence of
Lactobacillus helveticus
ATCC 12046
Authors: Palomino María Mercedes , Burguener Germán F. , Campos Josefina , Allievi Mariana , Fina-Martin Joaquina , Prado Acosta Mariano , Fernández Do Porto Darío A. , Ruzal Sandra M.
Published: February 2018

Lactobacillus helveticus
is a lactic acid bacterium used traditionally in the dairy industry, especially in the manufacture of cheeses. We present here the 2,141,841-bp draft genome sequence of
L. helveticus
strain ATCC 12046, a potential starter strain for improving cheese production.
HIV-Associated Mycobacterium tuberculosis Bloodstream Infection Is Underdiagnosed by Single Blood Culture
Authors: Barr David A. , Kerkhoff Andrew D. , Schutz Charlotte , Ward Amy M. , Davies Gerry R. , Wilkinson Robert J. , Meintjes Graeme
Published: February 2018

We assessed the additional diagnostic yield for
Mycobacterium tuberculosis
bloodstream infection (BSI) by doing more than one tuberculosis (TB) blood culture from HIV-infected inpatients. In a retrospective analysis of two cohorts based in Cape Town, South Africa, 72/99 (73%) patients with
M. tuberculosis
BSI were identified by the first of two blood cultures during the same admission, with 27/99 (27%; 95% confidence interval [CI], 18 to 36%) testing negative on the first culture but positive on the second. In a prospective evaluation of up to 6 blood cultures over 24 h, 9 of 14 (65%) patients with
M. tuberculosis
BSI had
M. tuberculosis
grow on their first blood culture; 3 more patients (21%) were identified by a second independent blood culture at the same time point, and the remaining 2 were diagnosed only on the 4th and 6th blood cultures. Additional blood cultures increase the yield for
M. tuberculosis
BSI, similar to what is reported for nonmycobacterial BSI.
Interaction of Human Cytomegalovirus Tegument Proteins ppUL35 and ppUL35A with Sorting Nexin 5 Regulates Glycoprotein B (gpUL55) Localization
Authors: Maschkowitz Gregor , Gärtner Sabine , Hofmann-Winkler Heike , Fickenscher Helmut , Winkler Michael
Published: February 2018

Human cytomegalovirus (HCMV) is a widespread human pathogen that causes asymptomatic infection in healthy individuals but poses a serious threat to immunocompromised patients. During the late phase of HCMV infection, the viral capsid is transported to the cytoplasmic viral assembly center (cVAC), where it is enclosed by the tegument protein layer and the viral envelope. The cVAC consists of circularly arranged vesicles from the
trans
-Golgi and endosomal networks. The HCMV gene UL35 encodes ppUL35 and its shorter form, ppUL35A. We have previously shown that the UL35 gene is involved in HCMV assembly, but it is unknown how UL35 proteins regulate viral assembly. Here we show that sorting nexin 5 (SNX5), a component of the retromer and part of the retrograde transport pathway, interacts with UL35 proteins. Expression of wild-type proteins but not mutants defective in SNX5 binding resulted in the cellular redistribution of the cation-independent mannose-6-phosphate receptor (CI-M6PR), indicating that UL35 proteins bind and negatively regulate SNX5 to modulate cellular transport pathways. Furthermore, binding of UL35 proteins to SNX5 was required for efficient viral replication and for transport of the most abundant HCMV glycoprotein B (gB; gpUL55) to the cVAC. These results indicate that ppUL35 and ppUL35A control the localization of the essential gB through the regulation of a retrograde transport pathway. Thus, this work is the first to define a molecular interaction between a tegument protein and a vesicular transport factor to regulate glycoprotein localization.

IMPORTANCE
Human cytomegalovirus is ubiquitously present in the healthy population, but reactivation or reinfection can cause serious, life-threatening infections in immunocompromised patients. For completion of its lytic cycle, human cytomegalovirus induces formation of an assembly center where mature virus particles are formed from multiple viral proteins. Viral glycoproteins use separate vesicular pathways for transport to the assembly center, which are incompletely understood. Our research identified a viral structural protein which affects the localization of one of the major glycoproteins. We could link this change in glycoprotein localization to an interaction of the structural protein with a cellular protein involved in regulation of vesicle transport. This increases our understanding of how the virus intersects into cellular regulatory pathways to enhance its own replication.
Hepatitis C Virus core+1/ARF Protein Modulates the Cyclin D1/pRb Pathway and Promotes Carcinogenesis
Authors: Moustafa Savvina , Karakasiliotis Ioannis , Mavromara Penelope
Published: February 2018

Viruses often encompass overlapping reading frames and unconventional translation mechanisms in order to maximize the output from a minimum genome and to orchestrate their timely gene expression. Hepatitis C virus (HCV) possesses such an unconventional open reading frame (ORF) within the core-coding region, encoding an additional protein, initially designated ARFP, F, or core+1. Two predominant isoforms of core+1/ARFP have been reported, core+1/L, initiating from codon 26, and core+1/S, initiating from codons 85/87 of the polyprotein coding region. The biological significance of core+1/ARFP expression remains elusive. The aim of the present study was to gain insight into the functional and pathological properties of core+1/ARFP through its interaction with the host cell, combining
in vitro
and
in vivo
approaches. Our data provide strong evidence that the core+1/ARFP of HCV-1a stimulates cell proliferation in Huh7-based cell lines expressing either core+1/S or core+1/L isoforms and in transgenic liver disease mouse models expressing core+1/S protein in a liver-specific manner. Both isoforms of core+1/ARFP increase the levels of cyclin D1 and phosphorylated Rb, thus promoting the cell cycle. In addition, core+1/S was found to enhance liver regeneration and oncogenesis in transgenic mice. The induction of the cell cycle together with increased mRNA levels of cell proliferation-related oncogenes in cells expressing the core+1/ARFP proteins argue for an oncogenic potential of these proteins and an important role in HCV-associated pathogenesis.

IMPORTANCE
This study sheds light on the biological importance of a unique HCV protein. We show here that core+1/ARFP of HCV-1a interacts with the host machinery, leading to acceleration of the cell cycle and enhancement of liver carcinogenesis. This pathological mechanism(s) may complement the action of other viral proteins with oncogenic properties, leading to the development of hepatocellular carcinoma. In addition, given that immunological responses to core+1/ARFP have been correlated with liver disease severity in chronic HCV patients, we expect that the present work will assist in clarifying the pathophysiological relevance of this protein as a biomarker of disease progression.
Association between spectral characteristics of paraspinal muscles and functional disability in patients with low back pain: a cohort study
Authors: Chiou Shin-Yi , Koutsos Ermis , Georgiou Pantelis , Strutton Paul H
Published: February 2018

Objectives

Characteristics of muscle activity, represented by surface electromyography (EMG), have revealed differences between patients with low back pain (LBP) and healthy adults; how they relate to functional and clinical parameters remains unclear. The purpose of the current study was to examine the correlation between frequency characteristics of EMG (analysed using continuous wavelet transform (CWT) analysis) and patients’ self-rated score of disability.

Design and setting

This is a case-control study with 15 patients with mechanical LBP without radicular symptoms. Patients were recruited from the orthopaedic clinic at Charing Cross Hospital. Ten healthy adults were recruited from the staff working in the hospital and associated university. Patients completed the Roland-Morris Disability Questionnaire (RMDQ) and bilateral EMG activity was obtained from erector spinae at vertebral levels L4 and T12. Subjects performed three brief maximal voluntary isometric contractions (MVICs) of the back extensors and the torque was measured using a dynamometer. CWT was applied to the EMG signals of each muscle in a 200 ms window centred around the peak torque obtained during the MVICs. The ratio (low/high frequencies) of the energy, the peak power and the frequency of the peak power were calculated for each recording site, averaged and correlated with the individual’s RMDQ score.

Results

Patients had lower peak power (T12 and L4) and lower frequency of the peak power (at T12) than the healthy adults. Additionally, RMDQ positively correlated to the average ratio of energy at T12 (r=0.63; p=0.012), that is, greater self-rated disability corresponded to a dominant distribution of energy in the lower frequencies.

Conclusion

The current findings reveal alterations in EMG profile and its association with self-related back pain disability, suggesting that spectral characteristics of EMG reflect muscle function.
Are efforts to attract graduate applicants to UK medical schools effective in increasing the participation of under-represented socioeconomic groups? A national cohort study
Authors: Kumwenda Ben , Cleland Jennifer , Greatrix Rachel , MacKenzie Rhoda Katharine , Prescott Gordon
Published: February 2018

Introduction

Attracting graduates was recommended as a means of diversifying the UK medical student population. Graduates now make up nearly a quarter of the total medical student population. Research to date has focused on comparing the sociodemographic characteristics of applicants to and/or students on traditional and graduate entry programmes (GEMs), yet GEMs account for only 40% of the graduate medical student population. Thus, we aimed to compare the sociodemographic characteristic and outcomes of graduates and non-graduate applicants across a range of programmes.

Methods

This was an observational study of 117 214 applicants to medicine who took the UK Clinical Aptitude Test (UKCAT) from 2006 to 2014 and who applied to medical school through Universities and Colleges Admissions Service (UCAS). We included applicant demographics, UKCAT total score and offers in our analysis. Applicants were assigned as graduates or non-graduates on the basis of their highest qualification. Multiple logistic regression was used to predict the odds of receiving an offer, after adjusting for confounders.

Results

Irrespective of graduate or non-graduate status, most applicants were from the highest socioeconomic groups and were from a white ethnic background. Receiving an offer was related to gender and ethnicity in both graduates and non-graduates. After adjusting for UKCAT score, the OR of an offer for graduates versus non-graduates was approximately 0.5 (OR=0.48, 95% CI 0.46 to 0.49).

Discussion

Our findings indicate that the aim of diversifying the medical student population on socioeconomic grounds by attracting graduates has been only marginally successful. Graduate applicants from widening access backgrounds are less likely than others to be offered a place at medical school. Different approaches must be considered if medicine is to attract and select more socially diverse applicants.
Left of bang interventions in trauma: some legal implications of military medical prophylaxis
Authors: Liivoja Rain
Published: February 2018

In the context of military medical care, Eisenstein and colleagues have introduced the notion ‘left of bang intervention in trauma’, which refers to interventions administered before trauma to reduce morbidity and mortality after injury. This paper responds to Eisenstein and colleagues’ ethical analysis of such interventions, highlighting the difficulty in distinguishing between purely prophylactic and enhancing interventions. This response also addresses legal issues that arise from left of bang interventions under human rights law and the law of armed conflict, in particular the questions as to whether the consent of service members would need to be obtained and whether the adversary would as a consequence be authorised to resort to more injurious weapons.
Trismus caused by paraneoplastic brainstem encephalitis
Authors: Malek Naveed , Damian Maxwell
Published: February 2018

We discuss the assessment and differential diagnoses of a middle-aged man who presented with trismus, double vision and behavioural problems. MRI scan of the brain was initially normal, but a month later showed high signal in the hippocampal region on fluid attenuated inversion recovery sequence (FLAIR) imaging. We suspected a paraneoplastic brainstem encephalitis because of his smoking history, rapidly progressive symptoms and abnormal brainstem signs. A positron emission tomography-CT scan identified abnormal subcarinal nodes, shown on biopsy to be metastatic small cell lung cancer. He is currently undergoing treatment with chemotherapy and radiotherapy.
A study on the regenerative effect of platelet-rich plasma on experimentally induced hepatic damage in albino rats
Authors: Shoeib Heba Mamdoh , Keshk Walaa Arafa , Foda Abdallah Mahmoud , Abo El Noeman Saad El-Deen Abd Elfatah
Published: February 2018

Hepatic fibrosis is a worldwide health problem with significant morbidity and mortality. Currently, there is no effective therapy for hepatic fibrosis. The present study was aimed to evaluate the possible regenerative effect of platelet-rich plasma (PRP) against thioacetamide (TAA)-induced hepatic damage. Eighty albino rats were included; 40 were used for PRP preparation and 40 were randomly divided into 4 groups: group I (control group); group II (PRP control); group III (TAA-intoxicated by a dose of 200 mg/kg body mass, intraperitoneally, twice weekly for 7 weeks), and group IV (TAA intoxicated + PRP treated). Macrophage inflammatory protein-1α (MIP-1α) and cyclic adenosine monophosphate (cAMP) were immunoassayed in addition to peroxinitrite level, NADPH-quinone oxidoreductase-1 (NQO1) enzyme activity, and liver function. PRP treatment showed significant improvement in hepatic function, and decreased MIP-1α and peroxinitrite levels. Meanwhile, significant increase in NQO1 enzyme activity and cAMP level were observed. The histopathological results confirmed the laboratory results with improvement of hepatic architecture except for some inflammatory cellular infiltrates. This study shows that PRP has the ability to protect against TAA-induced liver damage, possibly by improving redox status, liver histopathological architecture, and disruption of the inflammatory and fibrotic response induced by TAA.
Formulation and Implementation of Nonlinear Integral Equations to Model Neural Dynamics Within the Vertebrate Retina
Authors: Eshraghian Jason K. , Baek Seungbum , Kim Jun-Ho , Iannella Nicolangelo , Cho Kyoungrok , Goo Yong Sook , Iu Herbert H. C. , Kang Sung-Mo , Eshraghian Kamran
Published: February 2018

Existing computational models of the retina often compromise between the biophysical accuracy and a hardware-adaptable methodology of implementation. When compared to the current modes of vision restoration, algorithmic models often contain a greater correlation between stimuli and the affected neural network, but lack physical hardware practicality. Thus, if the present processing methods are adapted to complement very-large-scale circuit design techniques, it is anticipated that it will engender a more feasible approach to the physical construction of the artificial retina. The computational model presented in this research serves to provide a fast and accurate predictive model of the retina, a deeper understanding of neural responses to visual stimulation, and an architecture that can realistically be transformed into a hardware device. Traditionally, implicit (or semi-implicit) ordinary differential equations (OES) have been used for optimal speed and accuracy. We present a novel approach that requires the effective integration of different dynamical time scales within a unified framework of neural responses, where the rod, cone, amacrine, bipolar, and ganglion cells correspond to the implemented pathways. Furthermore, we show that adopting numerical integration can both accelerate retinal pathway simulations by more than 50% when compared with traditional ODE solvers in some cases, and prove to be a more realizable solution for the hardware implementation of predictive retinal models.
Removing instability of inflation in Polonyi–Starobinsky supergravity by adding FI term
Authors: Aldabergenov Yermek , Ketov Sergei V.
Published: February 2018

Polonyi–Starobinsky (PS) supergravity is the [Formula: see text] supergravity model of Starobinsky inflation with spontaneous supersymmetry breaking (after inflation) due to Polonyi superfield, and inflaton belonging to a massive vector supermultiplet. The PS model is used for an explicit realization of the (super-heavy) gravitino dark matter scenario in cosmology. We find a potential instability in this model, and offer a mechanism for its removal by adding a Fayet–Iliopoulos (FI) term.
Three-dimensional axisymmetric sources for Majumdar–Papapetrou type spacetimes
Authors: García-Reyes Gonzalo , Hernández-Gómez Kevin A.
Published: February 2018

From Newtonian potential-density pairs, we construct three-dimensional axisymmetric relativistic sources for a Majumdar–Papapetrou type conformastatic spacetime. As simple examples, we build two families of relativistic thick disks from the first two Miyamoto–Nagai potential-density pairs used in Newtonian gravity to model flat galaxies, and a three-component relativistic model of galaxy (bulge, disk and dark matter halo). We study the equatorial circular motion of test particles around such structures. Also the stability of the orbits is analyzed for radial perturbation using an extension of the Rayleigh criterion. In all examples, the relativistic effects are analyzed and compared with the Newtonian approximation. The models are considered satisfying all the energy conditions.
MULTIVARIATE FACTOR-BASED PROCESSES WITH SATO MARGINS
Authors: MARENA MARINA , ROMEO ANDREA , SEMERARO PATRIZIA
Published: February 2018

We introduce a class of multivariate factor-based processes with the dependence structure of Lévy [Formula: see text]-models and Sato marginal distributions. We focus on variance gamma and normal inverse Gaussian marginal specifications for their analytical tractability and fit properties. We explore if Sato models, whose margins incorporate more realistic moments term structures, preserve the correlation flexibility in fitting option data. Since [Formula: see text]-models incorporate nonlinear dependence, we also investigate the impact of Sato margins on nonlinear dependence and its evolution over time. Further, the relevance of nonlinear dependence in multivariate derivative pricing is examined.
MULTIVARIATE OPTION PRICING MODELS WITH LÉVY AND SATO VG MARGINAL PROCESSES
Authors: GUILLAUME FLORENCE
Published: February 2018

Pricing and hedging of financial instruments whose payoff depends on the joint realization of several underlyings (basket options, spread options, etc.) require multivariate models that are, at the same time, computationally tractable and flexible enough to accommodate the stylized facts of asset returns and of their dependence structure. Among the most popular models one finds models with VG marginals. The aim of this paper is to compare four multivariate models that are characterized by VG laws at unit time and to assess their performance by considering the flexibility they offer to calibrate the dependence structure for fixed marginals.
Full-Scale Tests and Numerical Simulations of Failure Mechanism of Power Transmission Towers
Authors: Tian Li , Guo Liulu , Ma Ruisheng , Gai Xia , Wang Wenming
Published: February 2018

Full-scale tests are conducted to investigate the load-bearing capacity and failure mechanism of power transmission towers subjected to various loading patterns (broken lines, wind and ice). Detailed finite element models of power transmission towers are established based on these experimental prototypes. To capture the member instability, the integral stability coefficients are obtained from different specifications and introduced into a user-defined material model. Subsequently, the failure analysis of power transmission towers is carried out using an explicit algorithm, and good agreement is found in comparison with experimental results. The results show that the proposed procedure is effective in simulating the power transmission tower failure process. The full-scale test and numerical simulation studies can provide a valuable database for the design of power transmission towers subjected to various loads.
Anisotropic compact stars in non-conservative theory of gravity
Authors: Salako Ines G. , Jawad Abdul , Moradpour Hooman
Published: February 2018

We develop anisotropic compact stars in the scenario of non-conservative theory such as Rastall theory. We consider the Krori and Barua static spherically symmetric metrics and find their unknown constants by using the masses and radii of well-known compact stars. We investigate the anisotropic compact star through various physical quantities such as anisotropic behavior, regularity conditions, stability and surface redshift. It is found that the present compact stars are stable and are in the stellar equilibrium form.
Thermoacoustic Behavior of Laminated Composite Curved Panels Using Higher-Order Finite-Boundary Element Model
Authors: Sharma Nitin , Mahapatra Trupti Ranjan , Panda Subrata Kumar
Published: February 2018

A novel higher-order coupled finite-boundary element scheme is presented for the computation of the thermoacoustic responses of the layered panel structure under the harmonic excitation. The thermally pre-stressed vibrating composite panel model is derived mathematically using the higher-order shear deformation mid-plane kinematics. The eigen frequencies and the corresponding vibrational mode shapes are computed via the finite element method using Hamilton’s principle. Similarly, the surrounding medium is modeled via Helmholtz wave equations and solved numerically using the boundary element steps for the computation of the acoustic responses. The frequency and sound radiation output are computed numerically by means of an own computer code prepared in MATLAB environment. To avoid excess thermal loading during analysis, the critical buckling temperature of the composite panel structure is obtained and the range of thermal loading is selected accordingly. The model accuracy is demonstrated through the proper comparison studies of different structural responses (critical buckling temperature, natural frequency and radiated sound power level) of the curved composite panel with the available benchmark solutions. The reliability and the usefulness of the proposed novel scheme have been revealed by solving several numerical illustrations for different lamination schemes, panel geometries including the geometrical parameters.
Analytical and Experimental Investigation of Ballistic Impact on Thin Laminated Composite Plate
Authors: Mohamadipoor Reza , Zamani Ehsan , Pol Mohammad Hossein
Published: February 2018

Penetration of flat-ended cylindrical projectiles into thin laminated composite plates was investigated analytically and experimentally. An analytical modeling was carried out for thin laminated composite plates by developing a new function for deflection by computing Von Karman nonlinear strains and by using the principle of energy balance. During the perforation process, different regions were considered for the plate, such as fracture region, elastic deformation region, delamination region, and undeformed region. The energy absorbed by each region was measured in small time intervals. To validate this model, the ballistic experiment is performed on the thin laminated composite plate near and beyond ballistic limit velocity. The samples were made from plain woven glass/epoxy using a hand lay-up method. In addition to the initial velocity, the residual velocity of the projectile was also measured using two parallel laser curtains. A comparison drawn between analytical and experimental results demonstrated a good consistency in the residual velocity of the projectile. Finally, the distribution of strains along the plate thickness direction over time, the different amounts of absorbed energy of the failure modes, delamination radius, and energy are assessed at near and beyond ballistic limit velocity.
Ovine uteroplacental and fetal metabolism during and after fetal cortisol overexposure in late gestation
Authors: Vaughan O. R. , De Blasio M. J. , Fowden A. L.
Published: February 2018

Cortisol modifies fetal metabolism in preparation for delivery, but whether preterm cortisol exposure programs persisting changes in fetoplacental metabolism remains unknown. This study infused fetal sheep with saline ( n = 36) or cortisol ( n = 27) to raise fetal plasma cortisol to normal prepartum concentrations for 5 days from day 125 of gestation (term: ≈145 days). Fetal uptake and uteroplacental metabolism of glucose, oxygen, and lactate, together with fetal hepatic glucogenic capacity, were measured on the final day of infusion or 5 days later. Cortisol reduced adrenal weight and umbilical glucose uptake during infusion but increased fetal glucose concentrations, hepatic glycogen content, and hepatic glucogenic enzyme activity (fructose-1,6-bisphosphatase and glucose-6-phosphatase) and gene expression ( PC and G6PC) compared with saline infusion. Postcortisol infusion, umbilical glucose uptake, and hepatic glucose-6-phosphatase activity remained low and high, respectively, whereas fetal glucose levels normalized and hepatic glycogen was lower with higher adrenal weights than in controls. Cortisol infusion increased the proportion of total uterine glucose uptake consumed by the uteroplacental tissues, irrespective of age. Placental tracer glucose transport capacity was also increased after, but not during, cortisol infusion, without changes in placental glucose transporter gene expression. Blood lactate concentration and Pco2 were higher, whereas pH and O2 content were lower in cortisol-infused than saline-infused fetuses, although uteroplacental metabolism and fetal uptake of oxygen and lactate were unaltered. The results suggest that preterm cortisol overexposure alters fetoplacental metabolism and adrenal function subsequently with persisting increases in uteroplacental glucose consumption at the expense of the fetal supply.