bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterisation of underwater operational sound of a tidal stream turbine
Authors: Risch Denise , van Geel Nienke , Gillespie Douglas , Wilson Ben
Published: April 2020

The underwater sound emitted during the operation of the Atlantis AR1500 turbine, a 1.5 MW three bladed horizontal axis tidal-stream turbine, was measured in the Pentland Firth, Scotland. Most sound was concentrated in the lower frequencies, ranging from 50 to 1000 Hz. Within 20 m of the turbine, third-octave band sound pressure levels were elevated by up to 40 dB relative to ambient conditions. In comparison, ambient noise at these frequencies fluctuated by about 5–10 dB between different tidal states. At the maximum recording distance of 2300 m from the turbine, median sound pressure levels when the turbine was operational were still over 5 dB higher than ambient noise levels alone. A higher frequency, tonal signal was observed at 20 000 Hz. This signal component appears at a constant level whenever the turbine is operational and did not change with turbine rotation rate. It is most likely produced by the turbine's generator. This study highlights the importance of empirical measurements of turbine underwater sound. It illustrates the utility and challenges of using drifting hydrophone systems to spatially map operational turbine signal levels with reduced flow noise artefacts when recording in high flow environments.
Mechanisms of OCT4-SOX2 motif readout on nucleosomes
Authors: Michael Alicia K. , Grand Ralph S. , Isbel Luke , Cavadini Simone , Kozicka Zuzanna , Kempf Georg , Bunker Richard D. , Schenk Andreas D. , Graff-Meyer Alexandra , Pathare Ganesh R. , Weiss Joscha , Matsumoto Syota , Burger Lukas , Schübeler Dirk , Thomä Nicolas H.
Published: April 2020

Engaging the nucleosome

Cell identity is defined by gene expression patterns that are established through the binding of specific transcription factors. However, nucleosomal units limit access of transcription factors to specific DNA motifs within the mammalian genome. To study how transcription factors bind such chromatinized, nucleosome-embedded motifs, Michael
et al.
focused on the pluripotency factors OCT4 and SOX2. They systematically quantified the relative affinities of these factors at different motif positions throughout the nucleosome, enabling structure determination of OCT4-SOX2–bound nucleosomes by cryo–electron microscopy. OCT4 and SOX2 bound cooperatively to strengthen DNA-binding affinity and resulted in DNA distortions that destabilized the nucleosome. This analysis reveals position-dependent binding modes that were validated in vivo, providing insights on how transcription factors read out chromatinized motifs.

Science
, this issue p.
1460
Against pandemic research exceptionalism
Authors: London Alex John , Kimmelman Jonathan
Published: April 2020

Crises are no excuse for lowering scientific standards
Innate Lymphoid Cells Are Required for Endometrial Resistance toChlamydia trachomatisInfection
Authors: Xu Hong , Su Xin , Zhao Yujie , Tang Lingli , Chen Jianlin , Zhong Guangming
Published: April 2020

In some women, sexually transmittedChlamydia trachomatismay ascend to infect the endometrium, leading to pelvic inflammatory disease. To identify endometrial innate immune components that interact withChlamydia, we introducedC. trachomatisinto mouse endometrium via transcervical inoculation and compared the infectious yields in mice with and without immunodeficiency. LiveC. trachomatisrecovered from vaginal swabs or endometrial tissues peaked on day 3 and then declined in all mice with or without deficiency in adaptive immunity, indicating a critical role for innate immunity in endometrial control ofC. trachomatisinfection.
ATP Binding as a Key Target for Control of the Chemotaxis Kinase
Authors: Jun Se-Young , Pan Wenlin , Hazelbauer Gerald L.
Published: April 2020

In bacterial chemotaxis, chemoreceptors in signaling complexes modulate the activity of two-component histidine kinase CheA in response to chemical stimuli. CheA catalyzes phosphoryl transfer from ATP to a histidinyl residue of its P1 domain. That phosphoryl group is transferred to two response regulators. Receptor control is almost exclusively at autophosphorylation, but the aspect of enzyme action on which that control acts is unclear. We investigated this by a kinetic analysis of activated kinase in signaling complexes. We found that phosphoryl transfer from ATP to P1 is an ordered sequential reaction in which the binding of ATP to CheA is the necessary first step; the second substrate, the CheA P1 domain, binds only to an ATP-occupied enzyme; and phosphorylated P1 is released prior to the second product, namely, ADP. We confirmed the crucial features of this kinetically deduced ordered mechanism by assaying P1 binding to the enzyme. In the absence of a bound nucleotide, there was no physiologically significant binding, but the enzyme occupied with a nonhydrolyzable ATP analog bound P1. Previous structural and computational analyses indicated that ATP binding creates the P1-binding site by ordering the “ATP lid.” This process identifies the structural basis for the ordered kinetic mechanism. Recent mathematical modeling of kinetic data identified ATP binding as a focus of receptor-mediated kinase control. The ordered kinetic mechanism provides the biochemical logic of that control. We conclude that chemoreceptors modulate kinase by controlling ATP binding. Structural similarities among two-component kinases, particularly the ATP lid, suggest that ordered mechanisms and control of ATP binding are general features of two-component signaling.

IMPORTANCE Our work provides important new insights into the action of the chemotaxis signaling kinase CheA by identifying the kinetic mechanism of its autophosphorylation as an ordered sequential reaction, in which the required first step is binding of ATP. These insights provide a framework for integrating previous kinetic, mathematical modeling, structural, simulation, and docking observations to conclude that chemoreceptors control the activity of the chemotaxis kinase by regulating binding of the autophosphorylation substrate ATP. Previously observed conformational changes in the ATP lid of the enzyme active site provide a structural basis for the ordered mechanism. Such lids are characteristic of two-component histidine kinases in general, suggesting that ordered sequential mechanisms and regulation by controlling ATP binding are common features of these kinases.
Interactions between DksA and Stress-Responsive Alternative Sigma Factors Control Inorganic Polyphosphate Accumulation in Escherichia coli
Authors: Gray Michael J.
Published: April 2020

Inorganic polyphosphate (polyP) is an evolutionarily ancient, widely conserved biopolymer required for stress resistance and pathogenesis in diverse bacteria, but we do not understand how its synthesis is regulated. In this work, I gained new insights into this process by characterizing the role of the transcriptional regulator DksA in polyP regulation in
Escherichia coli
and identifying previously unknown links between polyP synthesis and the stress-responsive alternative sigma factors FliA, RpoN, and RpoE.
Sterility Testing for Cellular Therapies: What Is the Role of the Clinical Microbiology Laboratory?
Authors: Gebo James E. T. , Lau Anna F.
Published: April 2020

Sterility testing of cellular therapy products along with the associated environmental monitoring requirements for aseptic facilities, including compounding pharmacies, continues to impact clinical microbiology laboratories, as evidenced by the numerous discussions recurring on American Society for Microbiology Division C and ClinMicroNet listservs. This minireview provides an overview of this complex field of current good manufacturing practices (cGMP) based on biopharmaceutical industry standards and summarizes the compendial and alternative rapid microbial test methods available for product sterility and
Mycoplasma
testing.
The influence of wave power on bedrock sea-cliff erosion in the Hawaiian Islands
Authors: Huppert Kimberly L. , Perron J. Taylor , Ashton Andrew D.
Published: April 2020

Waves erode sea cliffs by various mechanisms, but the influence of wave power on bedrock coastal erosion has not been well quantified, making it difficult to predict how rocky coasts evolve in different environments. Volcanic ocean islands offer a unique opportunity to examine the influence of waves on bedrock coastal erosion because many islands have relatively homogeneous bedrock, well-constrained initial topography, and considerable differences in wave power between shorelines that face different directions and wave regimes. We used lava-flow ages and the morphology of coastal profiles on Maui, Kaho‘olawe, and the Big Island of Hawai‘i (USA) to estimate sea-cliff retreat rates at 11 sites that experience nearly eightfold differences in incident wave power. Using a range of possible sea-level histories that incorporate different trends of subsidence due to volcanic loading, we modeled the evolution of each coastal profile since its formation (12 ka to 1.4 Ma) to find the regionally consistent relative sea-level history and the site-specific sea-cliff retreat rates that best reproduce observed coastal profiles. We found a best-fit relative sea-level history prescribed by an effective elastic lithosphere thickness of 30 km, consistent with estimates from observations of total deflection beneath the Hawaiian Ridge. This suggests that coastal profiles may retain a decipherable record of sea-level change. Comparing the best-fit sea-cliff retreat rates to mean annual wave power at each site, which we calculated from 30 yr hindcast wave data, we found a positive relationship between wave power and sea-cliff erosion, consistent with theoretical predictions and measurements on unlithified coastal bluffs. These comparisons provide field evidence that bedrock coastal erosion scales with wave power, offering a basis for modeling rocky coast evolution in different wave climates.
Cambridge experience in spontaneous bone regeneration after traumatic segmental bone defect: a case series and review of literature
Authors: Abdulkarim Ali , Hu Shu Yang , Walker Brendon R , Krkovic Matija
Published: April 2020

High-energy traumatic long bone defects are some of the most challenging to reconstruct. Although cases of spontaneous bone regeneration in these defects have been reported, we are aware of no management guidelines or recommendations for when spontaneous bone regeneration should be considered a viable management option. We aim to identify how certain patient characteristics and surgical factors may help predict spontaneous bone regeneration. A total of 26 cases with traumatic segmental defects were treated at our institution, with eight cases (30.8%) undergoing spontaneous regeneration. We discuss four in detail. Six (75%) reported a degree of periosteal preservation, four (50%) were associated with traumatic brain injury and none were complicated by infection. The average time to spontaneous bone regeneration was 2.06 months. According to our cases, patients with favourable characteristics may benefit from delaying surgical treatment by 6 weeks to monitor for any signs of spontaneous bone formation.
Malignant peripheral nerve sheath tumour of thyroid: a diagnostic dilemma
Authors: Danish Muhammad Hassan , Wasif Muhammad , Ud Din Nasir , Awan Muhammad Sohail
Published: April 2020

Malignant peripheral nerve sheath tumours of thyroid are rare entities that can present a diagnostic dilemma. We present the case of a patient who presented with neck mass with a history of multiple neck surgeries and airway compression. The patient’s previous histopathology was mistaken for Riedel’s thyroiditis in an outside hospital, which delayed appropriate treatment leading to suffering on part of the patient and frustration on part of the physician. We emphasise that rare malignancies should be considered in rapidly growing neck masses that are causing airway compression, and histopathology of such tumours should be reported by expert pathologists.
Non-invasive monitoring of pharmacodynamics during the skin wound healing process using multimodal optical microscopy
Authors: Rico-Jimenez Jose , Lee Jang Hyuk , Alex Aneesh , Musaad Salma , Chaney Eric , Barkalifa Ronit , Spillman Jr Darold R , Olson Eric , Adams David , Marjanovic Marina , Arp Zane , Boppart Stephen A
Published: April 2020

Objective

Impaired diabetic wound healing is one of the serious complications associated with diabetes. In patients with diabetes, this impairment is characterized by several physiological abnormalities such as metabolic changes, reduced collagen production, and diminished angiogenesis. We designed and developed a multimodal optical imaging system that can longitudinally monitor formation of new blood vessels, metabolic changes, and collagen deposition in a non-invasive, label-free manner.

Research design and methods

The closure of a skin wound in (db/db) mice, which presents delayed wound healing pathologically similar to conditions in human type 2 diabetes mellitus, was non-invasively followed using the custom-built multimodal microscope. In this microscope, optical coherence tomography angiography was used for studying neovascularization, fluorescence lifetime imaging microscopy for nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) assessment, fluorescence intensity changes of NAD(P)H and flavin adenine dinucleotide (FAD) cofactors for evaluating metabolic changes, and second harmonic generation microscopy for analyzing collagen deposition and organization. The animals were separated into four groups: control, placebo, low concentration (LC), and high concentration (HC) treatment. Images of the wound and surrounding areas were acquired at different time points during a 28-day period.

Results

Various physiological changes measured using the optical imaging modalities at different phases of wound healing were compared. A statistically significant improvement in the functional relationship between angiogenesis, metabolism, and structural integrity was observed in the HC group.

Conclusions

This study demonstrated the capability of multimodal optical imaging to non-invasively monitor various physiological aspects of the wound healing process, and thus become a promising tool in the development of better diagnostic, treatment, and monitoring strategies for diabetic wound care.
Association of fasting plasma glucose variability with gestational diabetes mellitus: a nationwide population-based cohort study
Authors: Kim Jung A , Kim Jinsil , Roh Eun , Hong So-hyeon , Lee You-Bin , Baik Sei Hyun , Choi Kyung Mook , Noh Eunjin , Hwang Soon Young , Cho Geum Joon , Yoo Hye Jin
Published: April 2020

Objective

Long-term glycemic variability has recently been recognized as another risk factor for future adverse health outcomes. We aimed to evaluate the risk of gestational diabetes mellitus (GDM) according to the prepregnancy long-term fasting plasma glucose (FPG) variability.

Research design and methods

A total of 164 053 women who delivered their first baby between January 1, 2012 and December 31, 2015, were selected from the Korean National Health Insurance data. All women underwent at least three national health screening examinations, and the last examination should be conducted within 2 years before their first delivery. GDM was defined as the presence of more than four times of claim of GDM (International Classification of Disease, 10th Revision (ICD-10) O24.4 and O24.9) or prescription of insulin under the ICD-code of GDM. FPG variability was assessed by variability independent of the mean (FPG-VIM), coefficient of variation, SD, and average successive variability.

Results

Among the 164 053 women, GDM developed in 6627 (4.04%). Those in the higher quartiles of FPG-VIM showed a stepwise increased risk of GDM. In fully adjusted model, the ORs for GDM was 1.22 (95% CI 1.14 to 1.31) in women with the highest FPG-VIM quartile compared with those in the lowest quartile. The risk for GDM requiring insulin therapy was 48% increase in women in the highest quartile of FPG-VIM compared with those in the lowest quartile, while that for GDM not requiring insulin therapy was 19% increase. The association between high FPG variability and the risk of GDM was intensified in the obese and aged more than 35 years women.

Conclusions

Increased FPG variability in the prepregnancy state is associated with the risk of GDM independent of confounding factors. Therefore, prepregnancy FPG variability might be a surrogate marker of the risk of GDM.
Discovery of plasma biomarkers for predicting the severity of coronary artery atherosclerosis by quantitative proteomics
Authors: Ku Eu Jeong , Cho Kyung-Cho , Lim Cheong , Kang Jeong Won , Oh Jae Won , Choi Yu Ri , Park Jong-Moon , Han Na-Young , Oh Jong Jin , Oh Tae Jung , Jang Hak Chul , Lee Hookeun , Kim Kwang Pyo , Choi Sung Hee
Published: April 2020

Introduction

Cardiovascular disease (CVD) in patients with diabetes is the leading cause of death. Finding early biomarkers for detecting asymptomatic patients with CVD can improve survival. Recently, plasma proteomics—targeted selected reaction monitoring/multiple reaction monitoring analyses (MRM)—has emerged as highly specific and sensitive tools compared with classic ELISA methods. The objective was to identify differentially regulated proteins according to the severity of the coronary artery atherosclerosis.

Research design and methods

A discovery cohort, a verification cohort and a validation cohort consisted of 18, 53, and 228 subjects, respectively. The grade of coronary artery stenosis was defined as a percentage of luminal stenosis of the major coronary arteries. Participants were divided into six groups, depending on the presence of diabetes and the grade of coronary artery stenosis. Two mass spectrometric approaches were employed: (1) conventional shotgun liquid chromatography tandem mass spectrometry for a discovery and (2) quantitative MRM for verification and validation. An analysis of the covariance was used to examine the biomarkers’ predictivity beyond conventional cardiovascular risks.

Results

A total of 1349 different proteins were identified from a discovery cohort. We selected 52 proteins based on the tandem mass tag quantitative analysis then summarized as follows: chemokine (C-X-C motif) ligand 7 (CXCL7), apolipoprotein C-II (APOC2), human lipopolysaccharide-binding protein (LBP) and dedicator of cytokinesis 2 (DOCK2) in diabetes; CXCL7, APOC2, LBP, complement 4A (C4A), vitamin D-binding protein (VTDB) and laminin β1 subunit in non-diabetes. Analysis of covariance showed that APOC2, DOCK2, CXCL7 and VTDB were upregulated and C4A was downregulated in patients with diabetes showing severe coronary artery stenosis. LBP and VTDB were downregulated in patients without diabetes, showing severe coronary artery stenosis.

Conclusion

We identified significant associations between circulating APOC2, C4A, CXCL7, DOCK2, LBP and VTDB levels and the degree of coronary artery stenosis using the MRM technique.
Assessment of the quality, content and perceived utility of local maternity guidelines in hospitals in England implementing the saving babies’ lives care bundle to reduce stillbirth
Authors: Lau Yu Zhen , Widdows Kate , Roberts Stephen A , Khizar Sheher , Stephen Gillian L , Rauf Saima , Heazell Alexander E P
Published: April 2020

Introduction

The UK Department of Health have targeted a reduction in stillbirth by 50% by 2025; to achieve this, the first version of the Saving Babies’ Lives Care Bundle (SBLCB) was developed by NHS England in 2016 to improve four key areas of antenatal and intrapartum care. Clinical practice guidelines are a key means by which quality improvement initiatives are disseminated to front-line staff.

Methods

Seventy-five clinical practice guidelines covering the four areas of antenatal and intrapartum care in the first version of SBLCB were obtained from 19 maternity providers. The content and quality of guidelines were evaluated using the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool. Maternity health professionals in participating organisations were invited to participate in an anonymous survey to determine perceptions toward and experiences of the use of clinical practice guidelines using a series of Likert scales.

Results

Unit guidelines showed considerable variation in quality with median scores of 50%–58%. Only 4 (5.6%) guidelines were recommended for use in clinical practice without modifications, 54 (75.0%) were recommended for use subject to modifications and 12 (16.7%) were not recommended for use. The lowest scoring domains were ‘rigour of development’, ‘stakeholder involvement’ and ‘applicability’. A significant minority of unit guidelines omitted recommendations from national guidelines. The majority of staff believed that clinical practice guidelines standardised and improved the quality of care but over 30% had insufficient time to use them and 24% stated they were unable to implement recommendations.

Conclusion

To successfully implement initiatives such as the SBLCB change is needed to local clinical practice guidelines to reduce variation in quality and to ensure they are consistent with national recommendations . In addition, to improve clinical practice, adequate time and resources need to be in place to deliver and evaluate care recommended in the SBLCB.
Recommendations for control and prevention of infections for pediatric orthopedics during the epidemic period of COVID-19
Authors: Wu Chunxing , Zhang Zhiqiang , Mo Yueqiang , Wang Dahui , Ning Bo , Xu Ping , Song Jun , Pei Xinhong , Ni Xiaoyan , Zheng Yiming , Xia Tian , Jing Yanhui , Sun Wanlin , Meng Junrong , Qian Chuang
Published: April 2020

The outbreak of Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged and spread rapidly throughout the world. As of February 29, 2020, 79 389 cases of COVID-19 have been reported, and the outbreak is linked to 2838 deaths. The population is generally susceptible to the disease, and differences in incubation periods after infection exist among individuals. These two aspects of COVID-19 pose significant challenges to pediatric orthopedic diagnosis and treatment. As a dedicated center for managing pediatric cases of SARS-CoV-2 in Shanghai, our hospital has mobilized all branches and departments to undertake joint actions for scientific prevention and control, precise countermeasure and comprehensive anti-epidemic efforts. Combined with our experience, we have consulted the relevant national regulations and the latest research advances and have formulated the prevention and control measures of SARS-CoV-2 infection, including outpatient, emergency, inpatient and surgical cares, for clinical practices of pediatric orthopedics according to the physicochemical properties of SARS-CoV-2. It may serve as practical references and recommendations for managing SARS-CoV-2 infection in other pediatric specialties and in other hospitals.
A comparative study of floor accelerations of different structural systems with lead-rubber-bearing (LRB) isolators
Authors: Özuygur Ali Ruzi
Published: April 2020

Seismic base isolation technique has been successfully used to protect structural as well as nonstructural components from the damaging effects of earthquakes by reducing floor accelerations and inter-story drifts for many decades. The level of floor acceleration is a key issue in the protection of acceleration-sensitive nonstructural components. The intensity of floor acceleration varies depending on the vibration characteristics of the structural system. Furthermore, the viscous damping devices sometimes are used to improve the performance of the superstructure as well as the base isolation system. The characteristics of the ground motions are also influential in the performance of the viscous damping devices. In this paper, the floor acceleration performance of seismically isolated buildings with different lateral load resisting systems such as moment resisting frame, dual system, moment resisting frame plus viscous wall dampers, and dual system plus viscous wall dampers is investigated under near-fault and far-fault earthquake ground motions. Moreover, the effectiveness of supplemental viscous damping devices equipped in parallel with lead-rubber-bearing isolators is studied. It is inferred from the study that the most effective way of reducing floor accelerations is to provide more rigidity to the superstructure. Utilizing supplemental viscous dampers along with lead-rubber-bearing isolators having about 20% of effective damping ratio is meaningless or harmful in relation to floor acceleration and base shear.
Isotopic niche of the American pika (Ochotona princeps) through space and time
Authors: Westover M.L. , Lizewski K.A. , Klingler K.B. , Smith F.A.
Published: April 2020

Anthropogenic climate change is influencing the ecology and distribution of animals. The American pika (Ochotona princeps (Richardson, 1828)) is considered a model species for studying the effects of climate on small alpine mammals and has experienced local extirpation across its range. Using stable isotope analysis of two seasonal molts and bone collagen, we characterize the isotopic carbon and nitrogen niche of pika populations across their range and through time. We find pika isotopic diet to be stable across both time and space compared with other animals and considering the geographic and environmental extent of their range. We find that climatic, not geographic, factors explain part of the isotopic variation across their range. Both δ13C and δ15N from the fall-onset molt decrease with relative humidity of the environment and δ15N values from bone collagen increase with temperature and precipitation. We find a small but significant seasonal difference in δ13C, which could be explained by microbial enrichment of cached haypiles. We establish a baseline of pika isotopic diet and patterns related to climate across their range. We conclude that differences in isotopic signature between pika populations likely reflect the physiology of their forage plants in different environmental conditions.
A molecular assessment of infectious agents carried by Atlantic salmon at sea and in three eastern Canadian rivers, including aquaculture escapees and North American and European origin wild stocks
Authors: Teffer Amy K. , Carr Jonathan , Tabata Amy , Schulze Angela , Bradbury Ian , Deschamps Denise , Gillis Carole-Anne , Brunsdon Eric B. , Mordecai Gideon , Miller Kristina M.
Published: April 2020

Infectious agents are key components of animal ecology and drivers of host population dynamics. Knowledge of their diversity and transmission in the wild is necessary for the management and conservation of host species like Atlantic salmon ( Salmo salar). Although pathogen exchange can occur throughout the salmon life cycle, evidence is lacking to support transmission during population mixing at sea or between farmed and wild salmon due to aquaculture exposure. We tested these hypotheses using a molecular approach that identified infectious agents and transmission potential among sub-adult Atlantic salmon at marine feeding areas and adults in three eastern Canadian rivers with varying aquaculture influence. We used high-throughput qPCR to quantify infection profiles and next generation sequencing to measure genomic variation among viral isolates. We identified 14 agents, including five not yet described as occurring in Eastern Canada. Phylogenetic analysis of piscine orthoreovirus showed homology between isolates from European and North American origin fish at sea, supporting the hypothesis of intercontinental transmission. We found no evidence to support aquaculture influence on wild adult infections, which varied relative to environmental conditions, life stage, and host origin. Our findings identify research opportunities regarding pathogen transmission and biological significance for wild Atlantic salmon populations.
The role of the third body in the fretting wear of 690 alloy
Authors: Mi Xue , Bai Xiao-Ming , Tang Pan , Xie Hai , Peng Jin-Fang , Zhu Min-Hao
Published: April 2020

In this work, to investigate the role of the third body in the fretting behavior of 690 alloy, the fretting capabilities of 690 alloy against 405 stainless steel have been performed under various experimental conditions. The testing normal force and temperature varied from 10 N to 40 N and from room-temperature (RT) to [Formula: see text]C, respectively, at 5 Hz and 200 [Formula: see text]m. The results demonstrated that the profile shape of wear scar was dependent on the action of the wear particles. Three typical profile shapes were examined in this work: “U” shape, “W” shape and “M” shape. The balance of the formation and ejection of wear particles led to a steady value of the coefficient of friction (COF) and friction energy.
Regulation of different ratios of Sr doping and O vacancies on the magnetic properties of anatase TiO2
Authors: Chen Meixu , Hou Qingyu , Guan Yuqin , Xu Zhenchao , Xia Danyang
Published: April 2020

Theoretical calculations on the effects of different Sr-doped ratios and oxygen vacancy concentrations on the magnetic mechanism of anatase TiO2 are rarely reported. For this problem, generalized gradient approximation (GGA) plane wave ultra-soft pseudopotential [Formula: see text]U based on the spin density functional theory framework was adopted in this work. The effect of different Sr doping ratios and O vacancy concentrations on the magnetic properties of anatase TiO2 was studied by first principles. Results show that Sr replaces Ti and O vacancies at different Sr:V[Formula: see text] ratios (1:0, 1:1, 1:2, 2:1 and 2:2), the doping system is magnetic when the Sr:V[Formula: see text] ratio is 1:2. The systems with Sr[Formula: see text]:V[Formula: see text] ratios of 1:0 and 2:1 are nonmagnetic, whereas those with 1:1, 1:2, and 2:2 Sr[Formula: see text]:V[Formula: see text] ratios are magnetic. Regardless of whether or not Sr replaces Ti and O vacancies or interstitial Sr and O vacancies in different ratios of anatase TiO2, the effect of magnetic switching can be achieved by adjusting the concentration. In this study, the largest magnetic moment of Ti[Formula: see text]Sr[Formula: see text]O[Formula: see text] system is obtained at Sr[Formula: see text]:V[Formula: see text] ratio of 2:2. The Curie temperature of the doping system is above room-temperature, and the doping system produces 100% electron spin polarizability and is half-metallized. These features are valuable to the design and preparation of novel dilute magnetic semiconductors with spin-electron injection sources. The main magnetic sources of the Ti[Formula: see text]Sr[Formula: see text]O[Formula: see text] system are the holes generated by doped Sr and O vacancy complexes, which cause the spin polarization double exchange of Ti-3d electron orbitals and O-2p electron orbits near O vacancies. This result is consistent with the average field approximation and dual exchange mechanism theories.
Selection of intense spectral region and attosecond pulse from X2+ by using chirp-delay effect
Authors: Liu Hui , Liu Hang , Ford Cheryl
Published: April 2020

A potential scheme to obtain intense harmonic spectra from X[Formula: see text] ([Formula: see text] and T) has been studied by using chirped-delay effect and half-cycle pulse. First, for the shorter pulse duration case, the main contributions of harmonic spectra of H[Formula: see text] and T[Formula: see text] are both coming from the falling part of laser field. While, for the longer pulse duration case, the rising and falling parts of laser field play the main role in harmonic spectra of H[Formula: see text] and T[Formula: see text], respectively. Second, according to the changed law of harmonic yields of H[Formula: see text] and T[Formula: see text] and by properly introducing the chirp-delay effect at some specific timing, the intense harmonic emission peak (HEP) can be obtained from both H[Formula: see text] and T[Formula: see text]. Third, with the help of the half-cycle pulse, the selected HEP can be further extended, showing the intense and broad spectral continua. Finally, by Fourier transformation of some harmonics on the spectral continua, the intense attosecond pulses with durations of 35 as can be produced.
The nonlinear diffusion reaction dynamical system with quadratic and cubic nonlinearities with analytical investigations
Authors: Seadawy Aly R. , Iqbal Mujahid , Lu Dianchen
Published: April 2020

Our aim in this research work is to formulate the exact traveling and solitary wave solutions of nonlinear diffusion reaction (DR) equation with quadratic and cubic nonlinearities by implementing the new technique which is a modified mathematical method. We have investigated the density independent nonlinear diffusion equation with convective flux term. As a result, we have found a variety of new exact traveling and solitary wave solutions in the form of dark solitons, bright solitons, combined dark-bright solitons, traveling wave, periodic wave solutions and we also represent the physical structure of the obtained solutions by two- and three-dimensional graphics by using the Mathematica software. This work proves the power, reliability and fruitfulness of this new technique.
Diving deep: understanding the genetic components of hypoxia tolerance in marine mammals
Authors: Hindle Allyson G.
Published: April 2020

Marine mammals have highly specialized physiology, exhibited in many species by extreme breath-holding capabilities that allow deep dives and extended submergence. Cardiovascular control and cell-level hypoxia tolerance are key features of this phenotype. Identifying genomic signatures tied to physiology will be valuable in understanding these natural model species, which may generate translational opportunities to human diseases arising from hypoxic stress or tissue injury. Genomic analyses have now been conducted in dolphins, river dolphins, minke whales, bowhead whales, and polar bears, with multispecies studies exploring evolutionary signals across marine mammal lineages, encompassing extinct and extant divers. Single-species genome studies for sirenians do not yet exist. Extant marine mammals arose in three lineages from separate aquatic recolonizations. Their physiological specializations, along with these independent origins create an interesting case to examine convergent evolution. Although molecular mechanisms of hypoxia tolerance are not universally apparent across marine mammal genomic studies, altered evolutionary rates have been identified for genes linked to oxygen binding and transport (e.g., MB, HBA, and HBB), blood pressure control (e.g., endothelin pathway genes), and cell protection in multiple species. Despite convergent phenotypes across clades, instances of identical molecular convergence have been uncommon. Given the inherent logistical and regulatory difficulties associated with functional genetic experiments in marine mammals, several avenues of further investigation are suggested to enable validation of candidate genes for hypoxia tolerance: leveraging phylogeny to better understand convergent phenotypes; ontogenic studies to identify regulation of key genes underlying the elite, adult, hypoxia-tolerant physiology; and cell culture manipulations to understand gene function.
Cumulative Effect of Cardiovascular Risk Factors on Regulation of AMPK/SIRT1-PGC-1α-SIRT3 Pathway in the Human Erectile Tissue
Authors: Pereira Andressa S. , Gouveia Alexandra M. , Tomada Nuno , Rodrigues Adriana R. , Neves Delminda
Published: April 2020

Cardiovascular disease risk factors (CVDRF), especially diabetes mellitus (DM), disrupt oxidative stress response. This condition underlies endothelial dysfunction, early manifested in men as erectile dysfunction. The current study is aimed at elucidating the impact of CVDRF in the oxidation responsive AMPK/SIRT1-PGC-1α-SIRT3 pathway and related miRNAs in the human corpus cavernosum. Human penile tissue fragments from individuals submitted to programmed urological surgeries (n=27), aged 43-63 years, were clustered depending on the presence of CVDRF; the control group included samples from patients without CVDRF, and groups A and B included samples from patients with DM and additional CVDRF, totalizing ≤2 CVDRF (group A) and ≥3 CVDRF (group B). Dual-immunolabelling of SIRT3, SOD2, or GPX1 with α-actin in tissue sections was carried out. The assessment of expression levels of NOX1, phospho-AMPKα, total AMPKα, SIRT1, PGC-1α, SIRT3, SOD2, and GPX1 was performed by western blotting and of miR-200a, miR-34a, miR-421, and miR-206 by real-time PCR. Phospho-AMPKα and SIRT3 expression was found significantly increased in group B relative to other groups, suggesting a marked influence of CVDRF, additional to DM, in the regulation of these enzymes. NOX1 was also increased in group B relative to controls. Only an increasing tendency was observed in the phospho-AMPKα/total AMPKα ratio, SIRT1, and PGC-1α expression in groups A and B when compared with controls. Concerning antioxidant enzymes, GPX1 expression was found incremented in group A, but SOD2 expression was decreased in groups A and B, comparative with controls. Group B presented significantly diminished levels of miR-421 and miR-200a, but only a decreasing trend on miR-34 and miR-206 expression was observed. Taken together, our findings demonstrated that besides DM, additional CVDRF presented a cumulative effect in the cellular response to oxidative unbalance, contributing to AMPK/SIRT1-PGC-1α-SIRT3 pathway activation. SOD2, a major mitochondrial antioxidant defence, did not follow the same variation.
Fixed Points, Symmetries, and Bounds for Basins of Attraction of Complex Trigonometric Functions
Authors: Bray Kasey , Dwyer Jerry , Barnard Roger W. , Williams G. Brock
Published: April 2020

The dynamical systems of trigonometric functions are explored, with a focus on tz=tanz and the fractal image created by iterating the Newton map, Ftz, of  tz. The basins of attraction created from iterating  Ftz are analyzed, and some bounds are determined for the primary basins of attraction. We further prove x- and y-axis symmetry of the Newton map and explore the nature of the fractal images.
The Regulatory Effects of mTOR Complexes in the Differentiation and Function of CD4+T Cell Subsets
Authors: Wang Peng , Zhang Qian , Tan Liang , Xu Yanan , Xie Xubiao , Zhao Yong
Published: April 2020

T cells are an important part of the adaptive immune system and play critical roles in the elimination of various pathogens. T cells could differentiate into distinct cellular subsets under different extracellular signals and then play different roles in maintaining host homeostasis and defense. The mechanistic target of rapamycin (mTOR) is a conserved intracellular serine/threonine kinase which belongs to the phosphoinositide 3-kinase- (PI3K-) related kinase family. The mTOR signaling pathway is closely involved in a variety of cell biological processes, including cell growth and cell metabolism, by senses and integrates various environmental cues. Recent studies showed that mTOR including mTORC1 and mTORC2 is closely involved in the development of T cell subpopulations such as Th1, Th2, Th9, Th17, follicular helper T cells (Tfh), and Treg cells through distinctive pathways. We herein mainly focused on the recent progress in understanding the roles of mTOR in regulating the development and differentiation of CD4+T cell subsets.
Numerical Simulation of Mixed‐Mode Fatigue Crack Growth for Compact Tension Shear Specimen
Authors: Fageehi Yahya Ali , Alshoaibi Abdulnaser M.
Published: April 2020

This work concentrates on the fracture behaviour of the compact tension specimen under mixed‐mode loading, and numerical investigation using ANSYS Mechanical APDL 19.2 finite element program with different modes of mix angles is carried out. The prediction of mixed‐mode fatigue life under constant amplitude fatigue loading for the compact tension shear specimen (CTS) is employed using Paris’ law model for two different loading angles with agreement to the experimental results. The predicted values of ΔKeq were compared with the experimental and analytical data for various models. Depending on the analysis, the findings of the present study show consistency with the results achieved with similar models of predicting the equivalent stress intensity factor. In addition, the direction of crack growth derived from the analysis was observed to follow the same trend of the literature experimental results.
An Improved Anonymous Authentication Protocol for Wearable Health Monitoring Systems
Authors: Mo Jiaqing , Shen Wei , Pan Weisheng
Published: April 2020

Wearable health monitoring system (WHMS), which helps medical professionals to collect patients’ healthcare data and provides diagnosis via mobile devices, has become increasingly popular thanks to the significant advances in the wireless sensor network. Because health data are privacy-related, they should be protected from illegal access when transmitted over a public wireless channel. Recently, Jiang et al. presented a two-factor authentication protocol on quadratic residues with fuzzy verifier for WHMS. However, we observe that their scheme is vulnerable to known session special temporary information (KSSTI) attack, privileged insider attack, and denial-of-service (DoS) attack. To defeat these weaknesses, we propose an improved two-factor authentication and key agreement scheme for WHMS. Through rigorous formal proofs under the random oracle model and comprehensive informal security analysis, we demonstrate that the improved scheme overcomes the disadvantages of Jiang et al.’s protocol and withstands possible known attacks. In addition, comparisons with several relevant protocols show that the proposed scheme achieves more security features and has suitable efficiency. Thus, our scheme is a reasonable authentication solution for WHMS.
Around the Lipschitz Summation Formula
Authors: Li Wenbin , Li Hongyu , Mehta Jay
Published: April 2020

Boundary behavior of important functions has been an object of intensive research since the time of Riemann. Kurokawa, Kurokawa-Koyama, and Chapman studied the boundary behavior of generalized Eisenstein series which falls into this category. The underlying principle is the use of the Lipschitz summation formula. Our purpose is to show that it is a form of the functional equation for the Lipschitz–Lerch transcendent (and in the long run, it is equivalent to that for the Riemann zeta-function) and that this being indeed a boundary function of the Hurwitz–Lerch zeta-function, one can extract essential information. We also elucidate the relation between Ramanujan’s formula and automorphy of Eisenstein series.
Assessment of the Level of Pain Intensity and the Level of Anxiety Treated as State and Trait in Patients with Osteoarthritis of the Limbs
Authors: Kuciel-Lewandowska Jadwiga , Kasperczak Michał , Lewandowski Łukasz B. , Paprocka-Borowicz Małgorzata
Published: April 2020

Introduction. Osteoarthritis of the musculoskeletal system is accompanied with chronic pain which is the main factor in mood lowering, causing anxiety. Rehabilitation conducted in the framework of spa therapy and outpatient care aims at eliminating or reducing pain and improving physical fitness. Pain relief is an expected phenomenon because it improves the quality of life. Aim of the study. The aim of the study was to evaluate the effect of rehabilitation in the spa and in outpatient clinic on the level of pain and anxiety in patients with degenerative joints and disc disease. Material and methods. The study included a comprehensive treatment conducted in the spa and in outpatient clinic. Observation included 120 persons with disorders of the musculoskeletal system treated in the spa Przerzeczyn-Zdrój. The second group of patients was treated in the rehabilitation clinic. The examinations were performed before and after treatment. The scope of the observations included self-evaluation of anxiety treated as a state and a trait, the level of intensity of pain, medical history, and sociodemographic background interview. In the observations, there were VAS scale and State Trait Anxiety Inventory STAI used. Result. As a result of the spa therapy and therapy performed in an outpatient clinic, there was an improvement in lowering the level of pain and anxiety noted. Conclusions. 1. Spa therapy and treatment performed in an outpatient clinic reduce the level of pain and anxiety in patients with degenerative disease of the musculoskeletal system. 2. It was found that the therapy conducted in the spa was more effective in lowering the level of pain and anxiety. This trial is registered with NCT03405350.
Research on the Optimization Design of Abnormal Flip Buckets
Authors: Wang Liang-ze-nan , Su Chao
Published: April 2020

This study constructs an optimization model to address ski-jump energy dissipation problems in different reservoir environments. The multiobjective genetic algorithm is herein applied as the calculation method. In the process of changing the ski-jump flow model, the runoff of ski-jump flow is changed (especially the abnormal flip bucket). Water flow might go from having a single falling point to multiple falling points. Optimization is only performed after the stabilization of the fall of the water because the fall of the water from the starting point to the ground is not stable over a short period. Only a stable flow can reduce the computation time for optimization. The optimal overflow width and height of the flip bucket were calculated through optimal computation, which can minimize the scouring force of the water flow as it falls to the ground. The results obtained provide theoretical references for practical engineering and reduce the potential safety hazards. The energy in flip buckets following the optimization of the water flow can be fully dissipated, creating an ecosystem where water can flow unobstructed. Guiding a water flow to water-deficient areas is of great significance in ensuring the long-term protection of environments and ecosystems.
Abnormal Peripheral Neutrophil Transcriptome in Newly Diagnosed Type 2 Diabetes Patients
Authors: Lin Qiuqiu , Zhou Wenzhi , Wang Yanfei , Huang Juan , Hui Xiaoyan , Zhou Zhiguang , Xiao Yang
Published: April 2020

Aim. There are increasing evidence demonstrating that neutrophil-mediated inflammation plays a role in the etiology of type 2 diabetes. However, the molecular mechanisms by which neutrophils contribute to type 2 diabetes remain largely unknown. The aim of the present work was to identify possible changes in circulating neutrophils to better elucidate neutrophil involvement in human type 2 diabetes.Methods. Patients newly diagnosed with type 2 diabetes (n=5) and age- and sex-matched healthy controls (n=5) were recruited. Neutrophils were purified from type 2 diabetes patients and controls, and RNA sequencing (RNA-seq) was used for comprehensive transcriptome analysis. Differentially expressed genes (DEGs) were screened, and Gene Ontology (GO) and KEGG pathway enrichment analyses were performed. Real-time polymerase chain reaction (qPCR) was used for validation in external samples of type 2 diabetes patients (n=8) and healthy controls (n=8).Results. Gene expression analysis showed that, compared with neutrophils from healthy controls, there were 1990 upregulated DEGs and 1314 downregulated DEGs in neutrophils from type 2 diabetes patients. GO analysis demonstrated that the DEGs were mainly involved in myeloid leukocyte activation, T cell activation, adaptive immunity, and cytokine production. The top 20 enriched KEGG pathways included the cytokine-cytokine receptor interaction pathway, NF-κB signaling pathway, cell adhesion molecules, and chemokine signaling pathway. Furthermore, qPCR of genes related to neutrophil activation revealed that the expression of SELL, SELP, CXCR1, and S100A8 was significantly increased in neutrophils from type 2 diabetes patients compared with that in neutrophils from controls.Conclusions. Our study reveals an abnormal activation of circulating neutrophils at the transcriptome level in type 2 diabetes patients. These findings suggest a potential involvement of neutrophil dysfunction in the pathologic process of type 2 diabetes and provide insight into potential therapeutic targets for type 2 diabetes.