bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship of Ganciclovir Therapeutic Drug Monitoring with Clinical Efficacy and Patient Safety
Authors: Ritchie Brianne M. , Barreto Jason N. , Barreto Erin F. , Crow Stacy A. , Dierkhising Ross A. , Jannetto Paul J. , Tosh Pritish K. , Razonable Raymund R.
Published: January 2019

The clinical utility of ganciclovir therapeutic drug monitoring (TDM) is unknown. We retrospectively analyzed adult patients treated for cytomegalovirus (CMV) infection with ganciclovir with TDM between 2005 and 2015.
A Rapid Unraveling of the Activity and Antibiotic Susceptibility of Mycobacteria
Authors: Mustazzolu A. , Venturelli L. , Dinarelli S. , Brown K. , Floto R. A. , Dietler G. , Fattorini L. , Kasas S. , Girasole M. , Longo G.
Published: January 2019

The development of antibiotic-resistant bacteria is a worldwide health-related emergency that calls for new tools to study the bacterial metabolism and to obtain fast diagnoses. Indeed, the conventional analysis time scale is too long and affects our ability to fight infections.
Rufomycin Targets ClpC1 Proteolysis in Mycobacterium tuberculosis and M. abscessus
Authors: Choules Mary P. , Wolf Nina M. , Lee Hyun , Anderson Jeffrey R. , Grzelak Edyta M. , Wang Yuehong , Ma Rui , Gao Wei , McAlpine James B. , Jin Ying-Yu , Cheng Jinhua , Lee Hanki , Suh Joo-Won , Duc Nguyen Minh , Paik Seungwha , Choe Jin Ho , Jo Eun-Kyeong , Chang Chulhun L. , Lee Jong Seok , Jaki Birgit U. , Pauli Guido F. , Franzblau Scott G. , Cho Sanghyun
Published: January 2019

ClpC1 is an emerging new target for the treatment of
Mycobacterium tuberculosis
infections, and several cyclic peptides (ecumicin, cyclomarin A, and lassomycin) are known to act on this target. This study identified another group of peptides, the rufomycins (RUFs), as bactericidal to
M. tuberculosis
through the inhibition of ClpC1 and subsequent modulation of protein degradation of intracellular proteins.
Indole-2-Carboxamides Are Active against
Mycobacterium abscessus
in a Mouse Model of Acute Infection
Authors: Pandya Amit N. , Prathipati Pavan K. , Hegde Pooja , Li Wei , Graham Kyle F. , Mandal Subhra , Drescher Kristen M. , Destache Christopher J. , Ordway Diane , Jackson Mary , North E. Jeffrey
Published: January 2019

Nontuberculous mycobacteria (NTM) pathogens particularly infect patients with structural lung disorders. We previously reported novel indole-2-carboxamides (ICs) that are active against a wide panel of NTM pathogens.
The Glucocorticoid Receptor (GR) Stimulates Herpes Simplex Virus 1 Productive Infection, in Part Because the Infected Cell Protein 0 (ICP0) Promoter Is Cooperatively Transactivated by the GR and Krüppel-Like Transcription Factor 15
Authors: Ostler Jeffery B. , Harrison Kelly S. , Schroeder Kayla , Thunuguntla Prasanth , Jones Clinton
Published: January 2019

The ability of herpes simplex virus 1 (HSV-1) to periodically reactivate from latency results in virus transmission and recurrent disease. The incidence of reactivation from latency is increased by chronic or acute stress. Stress increases the levels of corticosteroids, which bind and activate the glucocorticoid receptor (GR). Since GR activation is an immediate early response to stress, we tested whether the GR influences productive infection and the promoter that drives infected cell protein 0 (ICP0) expression. Pretreatment of cells with a GR-specific antagonist (CORT-108297) significantly reduced virus replication. Although the GR had little effect on ICP0 promoter activity alone, the Krüppel-like transcription factor 15 (KLF15) cooperated with the GR to stimulate promoter activity in transfected cells. In transfected or infected cells, the GR and KLF15 occupied ICP0 sequences important for transactivation. Collectively, these studies provide insight into how stress can directly stimulate productive infection and viral gene expression.
The Prodigal Compound: Return of Ribosyl 1,5-Bisphosphate as an Important Player in Metabolism
Authors: Hove-Jensen Bjarne , Brodersen Ditlev E. , Manav M. Cemre
Published: January 2019

Ribosyl 1,5-bisphosphate (PRibP) was discovered 65 years ago and was believed to be an important intermediate in ribonucleotide metabolism, a role immediately taken over by its “big brother” phosphoribosyldiphosphate. Only recently has PRibP come back into focus as an important player in the metabolism of ribonucleotides with the discovery of the pentose bisphosphate pathway that comprises, among others, the intermediates PRibP and ribulose 1,5-bisphosphate (cf.
Draft Genome Sequences of Seven
Chryseobacterium
Type Strains
Authors: Matu Andisiwe , Lum Nde Adeline , Oosthuizen Lize , Hitzeroth Arina , Badenhorst Moira , Duba Lebogang , Gidaga Mphumzi , Klinck Johan , Kriek Ina-Maré , Lekoma Palesa June , Nel Lynette , dos Ramos Sérgio Mendes , Rossouw Jacques , Salomane Nicolaas , Segone Neo , Serobe Shiela , Tiyani Tarsisius , Hugo Celia J. , Newman Jeffrey D.
Published: January 2019

In an honors course on “Omics Sciences,” draft genome sequences of
Chryseobacterium elymi
KCTC 22547
T
,
Chryseobacterium flavum
KCTC 12877
T
,
Chryseobacterium hispanicum
KCTC 22104
T
,
Chryseobacterium lathyri
KCTC 22544
T
, “
Candidatus
Chryseobacterium massiliae” CCUG 51329
T
,
Chryseobacterium piscium
CCUG 51923
T
, and
Chryseobacterium rhizosphaerae
KCTC 22548
T
were generated to facilitate phylogenomic comparisons within the genus.
International variation in radiation dose for computed tomography examinations: prospective cohort study
Authors: Smith-Bindman Rebecca , Wang Yifei , Chu Philip , Chung Robert , Einstein Andrew J , Balcombe Jonathan , Cocker Mary , Das Marcos , Delman Bradley N , Flynn Michael , Gould Robert , Lee Ryan K , Nelson Thomas R , Schindera Sebastian , Seibert Anthony , Starkey Jay , Suntharalingam Saravanabavaan , Wetter Axel , Wildberger Joachim E , Miglioretti Diana L
Published: January 2019

Objective

To determine patient, institution, and machine characteristics that contribute to variation in radiation doses used for computed tomography (CT).

Design

Prospective cohort study.

Setting

Data were assembled and analyzed from the University of California San Francisco CT International Dose Registry.

Participants

Standardized data from over 2.0 million CT examinations of adults who underwent CT between November 2015 and August 2017 from 151 institutions, across seven countries (Switzerland, Netherlands, Germany, United Kingdom, United States, Israel, and Japan).

Main outcome measures

Mean effective doses and proportions of high dose examinations for abdomen, chest, combined chest and abdomen, and head CT were determined by patient characteristics (sex, age, and size), type of institution (trauma center, care provision 24 hours per day and seven days per week, academic, private), institutional practice volume, machine factors (manufacturer, model), country, and how scanners were used, before and after adjustment for patient characteristics, using hierarchical linear and logistic regression. High dose examinations were defined as CT scans with doses above the 75th percentile defined during a baseline period.

Results

The mean effective dose and proportion of high dose examinations varied substantially across institutions. The doses varied modestly (10-30%) by type of institution and machine characteristics after adjusting for patient characteristics. By contrast, even after adjusting for patient characteristics, wide variations in radiation doses across countries persisted, with a fourfold range in mean effective dose for abdomen CT examinations (7.0-25.7 mSv) and a 17-fold range in proportion of high dose examinations (4-69%). Similar variation across countries was observed for chest (mean effective dose 1.7-6.4 mSv, proportion of high dose examinations 1-26%) and combined chest and abdomen CT (10.0-37.9 mSv, 2-78%). Doses for head CT varied less (1.4-1.9 mSv, 8-27%). In multivariable models, the dose variation across countries was primarily attributable to institutional decisions regarding technical parameters (that is, how the scanners were used).

Conclusions

CT protocols and radiation doses vary greatly across countries and are primarily attributable to local choices regarding technical parameters, rather than patient, institution, or machine characteristics. These findings suggest that the optimization of doses to a consistent standard should be possible.

Study registration

Clinicaltrials.gov
NCT03000751
.
Relation betweenChlamydia trachomatisinfection and pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility in a Dutch cohort of women previously tested for chlamydia in a chlamydia screening trial
Authors: Hoenderboom Bernice M , van Benthem Birgit H B , van Bergen Jan E A M , Dukers-Muijrers Nicole H T M , Götz Hannelore M , Hoebe Christian J P A , Hogewoning Arjan A , Land Jolande A , van der Sande Marianne A B , Morré Servaas A , van den Broek Ingrid V F
Published: January 2019

Objectives

A better understanding ofChlamydia trachomatisinfection (chlamydia)–related sequelae can provide a framework for effective chlamydia control strategies. The objective of this study was to estimate risks and risk factors of pelvic inflammatory disease (PID), ectopic pregnancy and tubal factor infertility (TFI) with a follow-up time of up until 8 years in women previously tested for chlamydia in the Chlamydia Screening Implementation study (CSI) and participating in the Netherlands Chlamydia Cohort Study (NECCST).

Methods

Women who participated in the CSI 2008–2011 (n=13 498) were invited in 2015–2016 for NECCST. Chlamydia positive was defined as a positive CSI-PCR test, positive chlamydia serology and/or self-reported infection (time dependent). Data on PID, ectopic pregnancy and TFI were collected by self-completed questionnaires. Incidence rates and HRs were compared between chlamydia-positive and chlamydia-negative women corrected for confounders.

Results

Of 5704 women included, 29.5% (95% CI 28.3 to 30.7) were chlamydia positive. The incidence rate of PID was 1.8 per 1000 person-years (py) (1.6 to 2.2) overall, 4.4 per 1000 py (3.3 to 5.7) among chlamydia positives compared with 1.4 per 1000 py (1.1 to 1.7) for chlamydia negatives. For TFI, this was 0.4 per 1000 py (0.3 to 0.5) overall, 1.3 per 1000 py (0.8 to 2.1) and 0.2 per 1000 py (0.1 to 0.4) among chlamydia positives and negatives, respectively. And for ectopic pregnancy, this was 0.6 per 1000 py (0.5 to 0.8) overall, 0.8 per 1000 py (0.4 to 1.5) and 0.6 per 1000 py (0.4 to 0.8) for chlamydia negatives. Among chlamydia-positive women, the strongest risk factor for PID was symptomatic versus asymptomatic infection (adjusted HR 2.88, 1.4 to 4.5) and for TFI age <20 versus >24 years at first infection (HR 4.35, 1.1 to 16.8).

Conclusion

We found a considerably higher risk for PID and TFI in chlamydia-positive women, but the incidence for ectopic pregnancy was comparable between chlamydia-positive and chlamydia-negative women. Overall, the incidence rates of sequelae remained low.

Trial registration

NTR-5597.
Numerical investigation of coupled arc and electrode for GTAW with a longitudinal electromagnetic field
Authors: Zhang Xiaohong , Chen Jingqing , Zhang Kang , Ma Pengzhao , Chen Hui
Published: January 2019

Due to the good conductivity of ions and free electrons in the arc column, arc plasma possesses a remarkable magnetic controllability. Thus, a new technique of electromagnetic stirring has been developed which is of great interest during welding process by applying superimposed external magnetic field. However, few researches have focused on arc behavior with a coupled electrode under a magnetic field. In this paper, a three-dimensional plasma arc model coupled cathode was developed, and the distributions of current density, electric potential, magnetic field, pressure, velocity and temperature of plasma arc were obtained by solving the conservation equations of momentum, mass and energy coupled Maxwell’s equations. By applying finite volume method, when the intensity of applied electromagnetic field exceeded a threshold value, it reveals that arc contraction near cathode and arc divergence near anode are induced resulting in mutation phenomenon. The distributions of arc temperature and pressure deviate from the axis of tungsten and exhibit a bimodal shape. This is distinctly different from that of the free arc under natural combustion condition. In addition, the maximum velocity of the plasma flow appears on both sides of the arc symmetry axis. Moreover, arc plasma presents a behavior of heavy reflow and eddy, and a low-temperature area and a negative pressure zone appear in the central axis of arc plasma.
X-Ray Free-Electron Lasers for the Structure and Dynamics of Macromolecules
Authors: Chapman Henry N.
Published: January 2019

X-ray free-electron lasers provide femtosecond-duration pulses of hard X-rays with a peak brightness approximately one billion times greater than is available at synchrotron radiation facilities. One motivation for the development of such X-ray sources was the proposal to obtain structures of macromolecules, macromolecular complexes, and virus particles, without the need for crystallization, through diffraction measurements of single noncrystalline objects. Initial explorations of this idea and of outrunning radiation damage with femtosecond pulses led to the development of serial crystallography and the ability to obtain high-resolution structures of small crystals without the need for cryogenic cooling. This technique allows the understanding of conformational dynamics and enzymatics and the resolution of intermediate states in reactions over timescales of 100 fs to minutes. The promise of more photons per atom recorded in a diffraction pattern than electrons per atom contributing to an electron micrograph may enable diffraction measurements of single molecules, although challenges remain.
Molecular Fitness Landscapes from High-Coverage Sequence Profiling
Authors: Blanco Celia , Janzen Evan , Pressman Abe , Saha Ranajay , Chen Irene A.
Published: January 2019

The function of fitness (or molecular activity) in the space of all possible sequences is known as the fitness landscape. Evolution is a random walk on the fitness landscape, with a bias toward climbing hills. Mapping the topography of real fitness landscapes is fundamental to understanding evolution, but previous efforts were hampered by the difficulty of obtaining large, quantitative data sets. The accessibility of high-throughput sequencing (HTS) has transformed this study, enabling large-scale enumeration of fitness for many mutants and even complete sequence spaces in some cases. We review the progress of high-throughput studies in mapping molecular fitness landscapes, both in vitro and in vivo, as well as opportunities for future research. Such studies are rapidly growing in number. HTS is expected to have a profound effect on the understanding of real molecular fitness landscapes.
Toward Autonomy in Sub-Gram Terrestrial Robots
Authors: St. Pierre Ryan , Bergbreiter Sarah
Published: January 2019

Research toward small, autonomous, and mobile robots is inspired by both the insects we see around us and numerous applications, from inspection of jet engines and civil infrastructure to medical procedures. When comparing existing robots at small scales with their biological counterparts, the capability for autonomous operation is a glaring contrast. This review describes the state of the art in robotics at sub-gram scales along with the progress toward autonomy in power, mobility, and control at these small sizes. Metrics are described to both quantify the performance of existing sub-gram robots (e.g., speed and cost of transport) and define a more quantitative path toward autonomy (e.g., mass-specific run time and traversal probability). These metrics from existing robots are also compared with those of insects to identify significant performance gaps and highlight important areas for future study.
Racism and Health: Evidence and Needed Research
Authors: Williams David R. , Lawrence Jourdyn A. , Davis Brigette A.
Published: January 2019

In recent decades, there has been remarkable growth in scientific research examining the multiple ways in which racism can adversely affect health. This interest has been driven in part by the striking persistence of racial/ethnic inequities in health and the empirical evidence that indicates that socioeconomic factors alone do not account for racial/ethnic inequities in health. Racism is considered a fundamental cause of adverse health outcomes for racial/ethnic minorities and racial/ethnic inequities in health. This article provides an overview of the evidence linking the primary domains of racism—structural racism, cultural racism, and individual-level discrimination—to mental and physical health outcomes. For each mechanism, we describe key findings and identify priorities for future research. We also discuss evidence for interventions to reduce racism and describe research needed to advance knowledge in this area.
Interventions to Support Behavioral Self-Management of Chronic Diseases
Authors: Allegrante John P. , Wells Martin T. , Peterson Janey C.
Published: January 2019

A majority of the US adult population has one or more chronic conditions that require medical intervention and long-term self-management. Such conditions are among the 10 leading causes of mortality; an estimated 86% of the nation's $2.7 trillion in annual health care expenditures goes toward their treatment and management. Patient self-management of chronic diseases is increasingly essential to improve health behaviors, health outcomes, and quality of life and, in some cases, has demonstrated effectiveness for reducing health care utilization and the societal cost burden of chronic conditions. This review synthesizes the current state of the science of chronic disease self-management interventions and the evidence for their effectiveness, especially when applied with a systematic application of theories or models that account for a wide range of influences on behavior. Our analysis of selected outcomes from randomized controlled trials of chronic disease self-management interventions contained in 10 Cochrane systematic reviews provides additional evidence to demonstrate that self-management can improve quality of life and reduce utilization across several conditions.
The Economic Case for the Prevention of Mental Illness
Authors: McDaid David , Park A-La , Wahlbeck Kristian
Published: January 2019

Poor mental health has profound economic consequences. Given the burden of poor mental health, the economic case for preventing mental illness and promoting better mental health may be very strong, but too often prevention attracts little attention and few resources. This article describes the potential role that can be played by economic evidence alongside experimental trials and observational studies, or through modeling, to substantiate the need for increased investment in prevention. It illustrates areas of action across the life course where there is already a good economic case. It also suggests some further areas of substantive public health concern, with promising effectiveness evidence, that may benefit from economic analysis. Financial and economic barriers to implementation are then presented, and strategies to address the barriers and increase investment in the prevention of mental illness are suggested.
Intestinal TGR5 agonism improves hepatic steatosis and insulin sensitivity in Western diet-fed mice
Authors: Finn Patricia D. , Rodriguez David , Kohler Jill , Jiang Zhengfeng , Wan Sindy , Blanco Erick , King Andrew J. , Chen Tao , Bell Noah , Dragoli Dean , Jacobs Jeffrey W. , Jain Rakesh , Leadbetter Michael , Siegel Matthew , Carreras Christopher W. , Koo-McCoy Samantha , Shaw Karen , Le Cathy , Vanegas Sandra , Hsu I-Hsin , Kozuka Kenji , Okamoto Keiko , Caldwell Jeremy S. , Lewis Jason G.
Published: January 2019

Takeda G protein-coupled receptor 5 (TGR5) agonists induce systemic release of glucagon-like peptides (GLPs) from intestinal L cells, a potentially therapeutic action against metabolic diseases such as nonalcoholic steatohepatitis (NASH), nonalcoholic fatty liver disease (NAFLD), and Type 2 diabetes. Historically, TGR5 agonist use has been hindered by side effects, including inhibition of gallbladder emptying. Here, we characterize RDX8940, a novel, orally administered TGR5 agonist designed to have minimal systemic effects and investigate its activity in mice fed a Western diet, a model of NAFLD and mild insulin resistance. Agonist activity, binding selectivity, toxicity, solubility, and permeability of RDX8940 were characterized in standard in vitro models. RDX8940 pharmacokinetics and effects on GLP secretion, insulin sensitivity, and liver steatosis were assessed in C57BL/6 mice fed normal or Western diet chow and given single or repeated doses of RDX8940 or vehicle, with or without dipeptidyl peptidase-4 (DPP4) inhibitors. Gallbladder effects were assessed in CD-1 mice fed normal chow and given RDX8940 or a systemic TGR5 agonist or vehicle. Our results showed that RDX8940 is minimally systemic, potent, and selective, and induces incretin (GLP-1, GLP-2, and peptide YY) secretion. RDX8940-induced increases in plasma active GLP-1 (aGLP-1) levels were enhanced by repeated dosing and by coadministration of DPP4 inhibitors. RDX8940 increased hepatic exposure to aGLP-1 without requiring coadministration of a DPP4 inhibitor. In mice fed a Western diet, RDX8940 improved liver steatosis and insulin sensitivity. Unlike systemic TGR5 agonists, RDX8940 did not inhibit gallbladder emptying. These results indicate that RDX8940 may have therapeutic potential in patients with NAFLD/NASH.

NEW & NOTEWORTHY Takeda G protein-coupled receptor 5 (TGR5) agonists have potential as a treatment for nonalcoholic steatohepatitis and nonalcoholic fatty liver disease (NAFLD) but have until now been associated with undesirable side effects associated with systemic TGR5 agonism, including blockade of gallbladder emptying. We demonstrate that RDX8940, a potent, selective, minimally systemic oral TGR5 agonist, improves liver steatosis and insulin sensitivity in a mouse model of NAFLD and does not inhibit gallbladder emptying in mice.
Soft drink consumption during and following exercise in the heat elevates biomarkers of acute kidney injury
Authors: Chapman Christopher L. , Johnson Blair D. , Sackett James R. , Parker Mark D. , Schlader Zachary J.
Published: January 2019

The purpose of this study was to test the hypothesis that consuming a soft drink (i.e., a high-fructose, caffeinated beverage) during and following exercise in the heat elevates biomarkers of acute kidney injury (AKI) in humans. Twelve healthy adults drank 2 liters of an assigned beverage during 4 h of exercise in the heat [35.1 (0.1)°C, 61 (5)% relative humidity] in counterbalanced soft drink and water trials, and ≥1 liter of the same beverage after leaving the laboratory. Stage 1 AKI (i.e., increased serum creatinine ≥0.30 mg/dl) was detected at postexercise in 75% of participants in the Soft Drink trial compared with 8% in Water trial ( P = 0.02). Furthermore, urinary neutrophil gelatinase-associated lipocalin (NGAL), a biomarker of AKI, was higher during an overnight collection period after the Soft Drink trial compared with Water in both absolute concentration [6 (4) ng/dl vs. 5 (4) ng/dl, P < 0.04] and after correcting for urine flow rate [6 (7) (ng/dl)/(ml/min) vs. 4 (4) (ng/dl)/(ml/min), P = 0.03]. Changes in serum uric acid from preexercise were greater in the Soft Drink trial than the Water trial at postexercise ( P < 0.01) and 24 h ( P = 0.05). There were greater increases from preexercise in serum copeptin, a stable marker of vasopressin, at postexercise in the Soft Drink trial ( P < 0.02) than the Water trial. These findings indicate that consuming a soft drink during and following exercise in the heat induces AKI, likely via vasopressin-mediated mechanisms.
Significance of epimuscular myofascial force transmission under passive muscle conditions
Authors: Maas Huub
Published: January 2019

In the past 20 yr, force transmission via connective tissue linkages at the muscle belly surface, called epimuscular myofascial force transmission, has been studied extensively. In this article, the effects of epimuscular linkages under passive muscle conditions are reviewed. Several animal studies that included direct (invasive) measurements of force transmission have shown that different connective tissue structures serve as an epimuscular pathway and that these tissues have sufficient stiffness, especially at supraphysiological muscle lengths and relative positions, to transmit substantial passive forces (up to 15% of active optimal force). Exact values of lumped tissue stiffness for different connective tissue structures have not yet been estimated. Experiments using various imaging techniques (ultrasound, MRI, shear wave elastography) have yielded some, but weak, evidence of epimuscular myofascial force transmission for passive muscles in humans. At this point, the functional consequences of epimuscular pathways for muscle and joint mechanics in the intact body are still unknown. Potentially, however, these pathways may affect sensory feedback and, thereby, neuromuscular control. In addition, altered epimuscular force transmission in pathological conditions may also contribute to changes in passive range of joint motion.
A Review on the Nonpharmacological Therapy of Traditional Chinese Medicine with Antihypertensive Effects
Authors: Fan Hua , Lu Feng , Yang Ailing , Dong Yidan , Liu Ping , Wang Youhua
Published: January 2019

Hypertension is a global health concern. Although the pharmacological treatment has obvious antihypertensive effects, there are still some limitations on management of hypertension by drug therapy alone. In recent years, the nonpharmacological therapy of traditional Chinese medicine (TCM) has gradually become an important mean to help the prevention and treatment of hypertension in some Eastern countries. In this review, the nonpharmacological TCM therapies, including acupuncture, tuina, Tai Chi, and auricular-plaster, are covered along with the mechanism.
Application of the Principles of Green Chemistry for the Development of a New and Sensitive Method for Analysis of Ertapenem Sodium by Capillary Electrophoresis
Authors: Pedroso Tahisa Marcela , Schepdael Ann Van , Salgado Hérida Regina Nunes
Published: January 2019

An innovative method is validated for the analysis of ertapenem sodium by capillary electrophoresis using potassium phosphate buffer 10 mM pH 7 and 15 kV voltage, in the concentration range of 70 to 120 μg mL−1. Ertapenem had a migration time of 3.15 minutes and the linearity curve was y = 2281.7 x - 24495 with a R2 = 0.9994. Thus, we propose a routine analysis method that meets the principles of green analytical chemistry for the routine analysis of ertapenem sodium by capillary electrophoresis.
A Study on the Dynamic Transmission Law of Spiral Drum Cutting Coal Rock Based on ANSYS/LS‐DYNA Simulation
Authors: Zhao Lijuan , Liu Hongmei , Zhou Wenchao
Published: January 2019

The ANSYS/LS‐DYNA software has been used in this paper to establish the coal rock coupling model. A dynamic simulation of the cutting process was used to analyze the variation of the load. Based on the dynamic analysis of the coal and rock that were cut by the spiral drum, the stress cloud diagram of the coupled model of the spiral drum and the coal and the plastic domain evolution law of the coal and the rock were obtained from the coal to the rock. The time history curves of the parameters, such as the stress and strain of the drum and the pick, were obtained, and the stress distribution of the spiral drum during the working process was ascertained. The results showed that when the spiral drum cuts the interface between the coal and the rock, the coal and the rock collapsed and the working load fluctuated. Changing the traction speed in order to change the rotational speed of the drum had a more obvious effect on the load and the stress on the drum. Through the use of simulation, the stress distribution cloud diagram of the drum was obtained. The study has shown that the stress on the end plate was significantly higher than that on the cutting blade. The maximum stress acting on the alloy head was 1209.26 MPa. This study has provided a basis for the design and optimization of the drum with regard to reliability.
Vibration Control of an Axially Moving System with Restricted Input
Authors: Zhao Zhijia , Ma Yonghao , Liu Guiyun , Zhu Dachang , Wen Guilin
Published: January 2019

In this study, we consider the global stabilization of an axially moving system under the condition of input saturation nonlinearity and external perturbation. Based on Lyapunov redesign method, observer backstepping, and high‐gain observers, an output feedback control strategy with an auxiliary system is constructed to eliminate the input saturation constraint effect and suppress the string system vibration, and a boundary disturbance observer is exploited to cope with the external disturbance. The stability of the controlled system is analyzed and proven based on Lyapunov stability without simplifying or discretizing the infinite dimensional dynamics. The presented simulation results show the effectiveness of the derived control.
Same Fuzzy Logic Controller for Two-Wheeled Mobile Robot Navigation in Strange Environments
Authors: Aouf Awatef , Boussaid Lotfi , Sakly Anis
Published: January 2019

For any mobile device, the ability to navigate smoothly in its environment is of paramount importance, which justifies researchers’ continuous work on designing new techniques to reach this goal. In this work, we briefly present a description of a hard work on designing a Same Fuzzy Logic Controller (S.F.L.C.) of the two reactive behaviors of the mobile robot, namely, “go to goal obstacle avoidance” and “wall following,” in order to solve its navigation problems. This new technique allows an optimal motion planning in terms of path length and travelling time; it is meant to avoid collisions with convex and concave obstacles and to achieve the shortest path followed by the mobile robot. The efficiency of employing the proposed navigational controller is validated when compared to the results from other intelligent approaches; its qualities make of it an efficient alternative method for solving the path planning problem of the mobile robot.
Impact of Defocus and High-Order Aberrations on Light Disturbance Measurements
Authors: Amorim-de-Sousa A. , Macedo-de-Araújo R. , Fernandes P. , Queirós A. , González-Méijome J. M.
Published: January 2019

Purpose. To evaluate the impact of different levels of positive and negative defocus on light disturbance (LD) measures and to understand how high-order aberrations (HOAs) and topographic quality parameters may influence the perception of photic phenomena.Methods. Thirty young healthy subjects (21 females and 9 males) attended this cross-sectional study. LD was evaluated with the light distortion analyzer (LDA) in natural accommodative and cycloplegic conditions with positive and negative induced defocus of 1.00D. HOAs were taken for a natural mesopic (without cycloplegia) and for fixed 5 mm (with cycloplegia) pupil size. The impact of corneal morphological parameters (SAI, SRI, and Q-value) in LD was also investigated.Results. Positive and negative induced defocus of 1.00D significantly increased the size of LD (p<0.010, Wilcoxon signed rank test) but not its irregularity index. Spherical-like HOAs were associated with the size of LD, while coma-like and total-like HOAs were associated with LD irregularity. Our results showed that SRI was significantly correlated with the size of the disturbance area (r=0.519,p=0.003, Spearman correlation) and SAI with both size (r=0.502,p=0.005, Spearman correlation) and irregularity (r=0.371,p=0.044, Spearman correlation). However, no correlation between the Q-value and LD parameters was found.Conclusions. The uncorrected positive and negative refractive errors might increase the size of the LD, such as the spherical-like HOAs, SAI, and SRI, instead of asphericity. Coma-like and total-like HOAs and SAI may influence the perception of irregularities in the LD shape. These results might have an impact on postrefractive surgery visual performance that should be investigated.
Two‐Dimensional Direction‐of‐Arrival Estimation of Noncircular Signals in Coprime Planar Array with High Degree of Freedom
Authors: Xu Haiyun , Wang Daming , Lin Size , Ba Bin , Zhang Yankui
Published: January 2019

In estimating the two‐dimensional (2D) direction‐of‐arrival (DOA) using a coprime planar array, there are problems of the limited degree of freedom (DOF) and high complexity caused by the spectral peak search. We utilize the time‐domain characteristics of signals and present a high DOF algorithm with low complexity based on the noncircular signals. The paper first analyzes the covariance matrix and ellipse covariance matrix of the received signals, vectorizes these matrices, and then constructs the received data of a virtual uniform rectangular array (URA). 2D spatial smoothing processing is applied to calculate the covariance of the virtual URA. Finally, the paper presents an algorithm using 2D multiple signal classification and an improved algorithm using unitary estimating signal parameters via rotational invariance techniques, where the latter solves the closed‐form solutions of DOAs replacing the spectral peak search to reduce the complexity. The simulation experiments demonstrate that the proposed algorithms obtain the high DOF and enable to estimate the underdetermined signals. Furthermore, both two proposed algorithms can acquire the high accuracy.
Low-Dose Ibutilide Combined with Catheter Ablation of Persistent Atrial Fibrillation: Procedural Impact and Clinical Outcome
Authors: Sun Xue-Rong , Tian Ying , Shah Ashok , Yin Xian-Dong , Shi Liang , Wang Yan-Jiang , Liu Xiao-Qing , Hocini Meleze , Haissaguerre Michel , Yang Xin-Chun , Liu Xing-Peng
Published: January 2019

Background. In patients with persistent atrial fibrillation (AF), the procedural and clinical outcomes of ablation combined with infusion of antiarrhythmic drug are unknown. Objectives. To determine the impact of low-dose ibutilide after circumferential pulmonary vein isolation (CPVI) and/or left atrial (LA) substrate modification on acute procedural and clinical outcome of persistent AF. Methods. In a prospective cohort of 135 consecutive patients with persistent AF, intravenous 0.25 mg ibutilide was administered 3 days before the procedure and intraprocedurally, if required, after CPVI and/or additional LA substrate modification of sites with continuous, rapid or fractionated, and low-voltage (0.05–0.3 mv) atrial activity. Results. Persistent AF was terminated by CPVI alone (n=15) or CPVI + ibutilide (n=32) in 47 (34.8%) patients (CPVI responders). Additional LA substrate modification without (n=33) or with subsequent administration of 0.25 mg ibutilide (n=19) terminated AF in another 52 (38.5%) patients (substrate modification responders). Sinus rhythm was restored by electrical cardioversion in the remaining 36 (26.7%) patients (nonresponders). The mean LA substrate ablation time was 14 ± 6 minutes. At follow-up of 24 ± 10 months, the rates of freedom from atrial tachyarrhythmias among the responders in CPVI and substrate modification groups were mutually comparable (66.0% and 69.2%) and higher than among the nonresponders (36.1%; P<0.01). Among the responders, there was no difference in clinical outcome between patients whose persistent AF was terminated without or with low-dose ibutilide. Conclusion. Administration of low-dose ibutilide during ablation of persistent AF may allow select patients wherein substrate ablation is not or minimally required to optimize procedural and clinical outcomes.
Adaptive Fuzzy-Based Energy and Delay-Aware Routing Protocol for a Heterogeneous Sensor Network
Authors: Mothku Sai Krishna , Rout Rashmi Ranjan
Published: January 2019

In a heterogeneous sensor actor network, packet loss may occur due to bad link quality, overflow of buffer, and low energy levels. Retransmission of the lost packets leads to more energy consumption and delay. Ensuring data reliability and minimum delay requirement while improving energy efficiency are challenging issues in a resource-constrained heterogeneous sensor actor network. In this paper, a fuzzy-based delay and energy-aware intelligent routing mechanism has been proposed to select efficient routes. In the proposed mechanism, routing decisions are taken using a fuzzy logic system by considering network resources, such as residual energy, quality of link, available buffer size, and distance (proximity). In a network, a node with higher residual energy, higher free available buffer, good link quality, and close distance (proximity) gets opportunity to become a next hop node in a routing path. Furthermore, network performance has been analyzed with various network states. Simulation has been carried out using Network Simulator 3 by considering performance metrics, such as delay, number of retransmissions, energy consumption, lifetime, and network stability of the network.
Neural Personalized Ranking via Poisson Factor Model for Item Recommendation
Authors: Yu Yonghong , Zhang Li , Wang Can , Gao Rong , Zhao Weibin , Jiang Jing
Published: January 2019

Recommender systems have become indispensable for online services since they alleviate the information overload problem for users. Some work has been proposed to support the personalized recommendation by utilizing collaborative filtering to learn the latent user and item representations from implicit interactions between users and items. However, most of existing methods simplify the implicit frequency feedback to binary values, which make collaborative filtering unable to accurately learn the latent user and item features. Moreover, the traditional collaborating filtering methods generally use the linear functions to model the interactions between latent features. The expressiveness of linear functions may not be sufficient to capture the complex structure of users’ interactions and degrades the performance of those recommender systems. In this paper, we propose a neural personalized ranking model for collaborative filtering with the implicit frequency feedback. The proposed method integrates the ranking‐based poisson factor model into the neural networks. Specifically, we firstly develop a ranking‐based poisson factor model, which combines the poisson factor model and the Bayesian personalized ranking. This model adopts a pair‐wise learning method to learn the rankings of uses’ preferences between items. After that, we propose a neural personalized ranking model on top of the ranking‐based poisson factor model, named NRPFM, to capture the complex structure of user‐item interactions. NRPFM applies the ranking‐based poisson factor model on neural networks, which endows the linear ranking‐based poisson factor model with a high level of nonlinearities. Experimental results on two real‐world datasets show that our proposed method compares favorably with the state‐of‐the‐art recommendation algorithms.
Thermoplastic Rubber (TPR) Modified by a Silane Coupling Agent and Its Influence on the Mechanical Properties of Oil Well Cement Pastes
Authors: Song Jianjian , Xu Mingbiao , Liu Weihong , Wang Xiaoliang , Xu Peng , Huang Feng , Pan Yonggong
Published: January 2019

The surface hydrophilicity of thermoplastic rubber (TPR) is poor, and the effect of using it directly in oil well cement is not good. TPR was modified by different silane coupling agents, and the hydrophilicity of the modified TPR was studied by Fourier-transform infrared (FT-IR) spectroscopy and dispersion stability photography. The application effect of modified TPR in oil well cement slurry was also evaluated. The fracture surface morphology of TPR cement stone was observed by macrophotography and scanning electron microscopy (SEM). The results demonstrated that the hydrophilicity of TPR particles was improved after modification with silane coupling agent 3-methacryloxypropyltrimethoxysilane (KH570), and its application effect in cement slurry was excellent. Compared with the pure cement paste, the compressive strength of the cement paste with addition of TPR modified by KH570 was reduced, but the flexural strength and impact strength of the cement paste were effectively enhanced. Moreover, the modified TPR greatly improved the deformation capacity and decreased the elastic modulus of the cement paste. The modified TPR particles formed a plastic polymer network structure in the cement stone and penetrated the cement hydration products, filling in the cement paste to form a flexible structural center. Thus, it improved the mechanical properties and reduced the brittleness of cement paste.
Maternal Perceptions of Self-Weight and Child Weight May Influence Milk Choice of Participants in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)
Authors: Kim Loan P. , Mallo Nelly
Published: January 2019

Objective. To examine the association between maternal perceptions of self-weight and child weight status and milk consumption behavior of Hispanic WIC participants. Methods. Mixed methods design with phone survey (n=529) and one-on-one interviews (n=35). Demographic characteristics, Chi-square, and thematic analyses were conducted. Results. More than half of overweight mothers misperceived their own weight status as well as those of their children. Mothers who perceived their child to be overweight were more likely to make a healthier food choice for their family, namely, choosing reduced-fat milk instead of whole milk. Qualitative interviews revealed a cultural preference for larger size children, and mothers defined healthy weight for their child as a function of (1) the child’s ability to be as active as other children their age, regardless of child’s BMI, and (2) the pediatrician’s opinion of the child’s weight status. Conclusions. Maternal perception of self-weight and child weight status seems to guide milk choices. Mothers may have some level of recognition of overweight in themselves and their child, thus adopting healthier milk choices. Culturally related perceptions should be considered when designing obesity prevention strategies, and the role of a pediatrician cannot be understated when developing obesity prevention programs for Hispanic families.
Kinetic pH Titration to Predict the Acid and Hydrothermal Conditions for the Hydrolysis of Disaccharides: Use of a Microcapillary System
Authors: Shimanouchi Toshinori , Mano Ryota , Yoshioka Yu , Fukuda Ayaka , Park Kyung-Min , Kimura Yukitaka
Published: January 2019

The hydrolysis of disaccharides was conducted using a microcapillary system under hydrothermal conditions (up to 190°C at 10 MPa and pH 4–11). The hydrolysis reaction showed a sigmoidal progression with time, especially under alkaline conditions. Analysis using a kinetic model yielded the reaction induction period. The specific pH value (pHamb) at the induction time, which is the pH value corresponding to the progression of disaccharide hydrolysis, was peculiar to each disaccharide. Finally, the calculation of the electron density around the oxygen atom of the glycosidic bond between saccharides was found to roughly predict the pHamb value required for the progression of hydrolysis.
Acupuncture Enhances Communication between Cortices with Damaged White Matters in Poststroke Motor Impairment
Authors: Han Xiao , Bai Lijun , Sun Chuanzhu , Niu Xuan , Ning Yanzhe , Chen Zhen , Li Yingying , Li Kuangshi , Lyu Diyang , Fu Caihong , Cui Fangyuan , Chen Zhengguang , Tan Zhongjian , Tang Lixin , Zou Yihuai
Published: January 2019

Stroke is a leading cause of motor disability. Acupuncture is an effective therapeutic strategy for poststroke motor impairment. However, its mechanism is still elusive. Twenty-two stroke patients having a right-hemispheric subcortical infarct and 22 matched healthy controls were recruited to undergo diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) scanning. The resting-state fMRI was implemented before and after needling at GB34 (Yanglingquan). The stroke patients presented a substantially reduced fractional anisotropy value in the right superior longitudinal fasciculus (SLF), corticospinal tract, and corpus callosum. The structural integrity of the frontoparietal part of the SLF (SLF-FP) correlated with the motor scores of lower limbs in stroke patients. This corticocortical association bundle originated from the premotor cortex (PM) and the adjacent supplementary motor area (SMA), known as secondary motor areas, and terminated in the supramarginal gyrus (SMG). After acupuncture intervention, the corresponding functional connectivity between the PM/SMA and SMG was enhanced in stroke patients compared with healthy controls. These findings suggested that the integrity of the SLF is a potential neuroimaging biomarker for motor disability of lower limbs following a stroke. Acupuncture could increase the communication between the cortices connected by the impaired white matter tracts, implying the neural mechanism underlying the acupuncture intervention.
Nodes Availability Analysis of NB-IoT Based Heterogeneous Wireless Sensor Networks under Malware Infection
Authors: Wu Xiaojun , Cao Qiying , Jin Juan , Li Yuanjie , Zhang Hong
Published: January 2019

The Narrowband Internet of Things (NB-IoT) is a main stream technology based on mobile communication system. The combination of NB-IoT and WSNs can active the application of WSNs. In order to evaluate the influence of node heterogeneity on malware propagation in NB-IoT based Heterogeneous Wireless Sensor Networks, we propose a node heterogeneity model based on node distribution and vulnerability differences, which can be used to analyze the availability of nodes. We then establish the node state transition model by epidemic theory and Markov chain. Further, we obtain the dynamic equations of the transition between nodes and the calculation formula of node availability. The simulation result is that when the degree of node is small and the node vulnerability function is a power function, the node availability is the highest; when the degree of node is large and the node vulnerability function satisfies the exponential function and the power function, the node availability is high. Therefore, when constructing a NBIOT-HWSNs network, node protection is implemented according to the degree of node, so that when the node vulnerability function satisfies the power function, all nodes can maintain high availability, thus making the entire network more stable.