bluuebunny/crossref_metadata_2025 huggingface dataset:
Paraprotein implicated in hardware failures in nucleic acid testing of blood donors
Authors: Leitch Sophie , Charlewood Richard
Published: November 2019

Background and Objectives

Analyser blockage due to gel formation by paraproteins leading to invalid results is a rare problem in viral nucleic acid testing (NAT) at New Zealand Blood Service (NZBS) despite many blood samples tested without problems from individuals with known paraproteins. This study aimed to identify common factors in samples causing blockages.

Method

Retrospective data were gathered on blood samples known to have blocked analysers at NZBS testing sites. Patients with plasma cell dyscrasia undergoing haematopoietic stem cell (HSC) harvest formed the comparator arm. These patients were identified from registry data of individuals undergoing autologous stem cell transplantation at Auckland City Hospital between 2013 and 2017.

Results

Four individuals were identified as having blocked analysers between 2010 and 2018. A total of 184 HSC transplant patients were identified, with contemporaneous paraprotein levels available for 177 (96%). Patients with intact immunoglobulin subtypes (134, 73%) were further analysed. Of these, 119 patients (65%) also had total protein and globulin levels available. Mean paraprotein (37.5 g/l), total protein (95.3 g/l), globulin levels (51.5 g/l) and proportion of lambda subtype (75%) were higher in the blocker group compared with non‐blocking comparators (4.7 g/l, 66.8 g/l, 27.7 g/l, 36.6% respectively) (P = 0·03, 0·02, 0·007, 0·12). The highest paraprotein and total protein levels from the non‐blocking cohort overlapped with the lowest of the blocker group.

Discussion

High protein levels (paraprotein >20 g/l, total protein >75 g/l) and a trend towards lambda subtype were associated with NAT analyser blockage. The overlap with non‐blocking donor samples suggests factors in addition to protein quantity that are also important.
Connexin‐mediated cell communication in the kidney: A potential therapeutic target for future intervention of diabetic kidney disease?
Authors: Price Gareth W. , Potter Joe A. , Williams Bethany M. , Cliff Chelsy L. , Squires Paul E. , Hills Claire E.
Published: December 2019

The ability of cells to communicate and synchronise their activity is essential for the maintenance of tissue structure, integrity and function. A family of membrane‐bound proteins called connexins are largely responsible for mediating the local transfer of information between cells. Assembled in the cell membrane as a hexameric connexon, they either function as a conduit for paracrine signalling, forming a transmembrane hemi‐channel, or, if aligned with connexons on neighbouring cells, form a continuous aqueous pore or gap junction, which allows for the direct transmission of metabolic and electrical signals. Regulation of connexin synthesis and activity is critical to cellular function, and a number of diseases are attributed to changes in the expression and/or function of these important proteins. A link between hyperglycaemia, connexin expression, altered nucleotide concentrations and impaired function highlights a potential role for connexin‐mediated cell communication in complications of diabetes. In the diabetic kidney, glycaemic injury is the leading cause of end‐stage renal failure, reflecting multiple aetiologies including glomerular hyperfiltration, albuminuria, increased deposition of extracellular matrix and tubulointerstitial fibrosis. Loss of connexin‐mediated cell‐to‐cell communication in diabetic nephropathy may represent an early sign of disease progression, but our understanding of the process remains severely limited. This review focuses on recent evidence demonstrating that glucose‐evoked changes in connexin‐mediated cell communication and associated purinergic signalling may contribute to the pathogenesis of kidney disease in diabetes, highlighting the tantalising potential of targeting these proteins as a novel therapeutic intervention.
Impaired sarcoplasmic reticulum Ca2+ release is the major cause of fatigue‐induced force loss in intact single fibres from human intercostal muscle
Authors: Olsson Karl , Cheng Arthur J. , Al‐Ameri Mamdoh , Wyckelsma Victoria L. , Rullman Eric , Westerblad Håkan , Lanner Johanna T. , Gustafsson Thomas , Bruton Joseph D.
Published: December 2019

Key points

Changes in intramuscular Ca2+ handling contribute to development of fatigue and disease‐related loss of muscle mass and function. To date, no data on human intact living muscle fibres have been described.

We manually dissected intact single fibres from human intercostal muscle and simultaneously measured force and myoplasmic free [Ca2+] at physiological temperature.

Based on their fatigue resistance, two distinct groups of fibres were distinguished: fatigue sensitive and fatigue resistant. Force depression in fatigue and during recovery was due to impaired sarcoplasmic reticulum Ca2+ release in both groups of fibres.

Acidification did not affect force production in unfatigued fibres and did not affect fatigue development in fatigue‐resistant fibres.

The current study provides novel insight into the mechanisms of fatigue in human intercostal muscle.

Changes in intracellular Ca2+ handling of individual skeletal muscle fibres cause a force depression following physical activity and are also implicated in disease‐related loss of function. The relation of intracellular Ca2+ handling with muscle force production and fatigue tolerance is best studied in intact living single fibres that allow continuous measurements of force and myoplasmic free [Ca2+] during repeated contractions. To this end, manual dissections of human intercostal muscle biopsies were performed to isolate intact single fibres. Based on the ability to maintain tetanic force at >40% of the initial value during 500 fatiguing contractions, fibres were classified as either fatigue sensitive or fatigue resistant. Following fatigue all fibres demonstrated a marked reduction in sarcoplasmic reticulum Ca2+ release, while myofibrillar Ca2+ sensitivity was either unaltered or increased. In unfatigued fibres, acidosis caused a reduction in myofibrillar Ca2+ sensitivity that was offset by increased tetanic myoplasmic free [Ca2+] so that force remained unaffected. Acidification did not affect the fatigue tolerance of fatigue‐resistant fibres, whereas uncertainties remain whether or not fatigue‐sensitive fibres were affected. Following fatigue, a prolonged force depression at preferentially low‐frequency stimulation was evident in fatigue‐sensitive fibres and this was caused exclusively by an impaired sarcoplasmic reticulum Ca2+ release. We conclude that impaired sarcoplasmic reticulum Ca2+ release is the predominant mechanism of force depression both in the development of, and recovery from, fatigue in human intercostal muscle.
Interaction of Impact Liquid Drop With Splat in Spray Cooling
Authors: Liang Gangtao , Yu Haibing , Chen Liuzhu , Shen Shengqiang
Published: December 2019

This study investigates the interaction between an impacting liquid drop and a splat generated on a solid prior to impact, focusing mainly on the wave production and propagation on the splat with low impact velocity. Using high-speed video, the wave generation concerning the effects of Weber number is observed and analyzed, including the first wave caused by drop kinematic energy, the secondary and tertiary capillary waves subjected to surface tension. Also, the wave propagation magnitude is discussed, the purpose of which is to provide a suitable method for predicting the wave diameter. Results show that the increasing of Weber number is slightly against the wave propagation, but this effect weakens gradually. The kinematic discontinuity theory devised for crown propagation can be applied to predict the wave propagation magnitude with an excellent agreement, for both the kinematic wave and the capillary wave. In addition, the propagation speed of the wave during the drop-splat interaction is also analyzed.
Experimental Study on Heat Transfer Performance of Pulsating Heat Pipe CPU Radiator
Authors: Shang Fu-Min , Yang Qing-Jing , Liu Jian-Hong
Published: December 2019

According to the characteristics of heat dissipation process and the structural characteristics of traditional heat dissipation device, pulsating heat pipe (PHP) and traditional The pin-finned heat sink are used to simulate the cooling process of CPU, so as to meet the cooling requirements of computer CPU. By comparing the heat transfer perform of the two heat sinks under three conditions: the top wall temperature of the heat sink, the wall temperature of the heat sink and the temperature difference between the inlet and outlet of hot water, it can be found that the heat transfer performance of the PHP radiator is better. The experimental results show that in order to further improve the heat dissipation performance of the computer CPU, the CPU radiator device can be manufactured by the PHP device, and the PHP technology has broad application prospects in electronic heat dissipation.
Investigation of the Thermo-Mechanical Property of Knitting 3D Polyethylene: A Comparative Study
Authors: Zhang Bo , Gao Shan , Liang Yunmin , Li Ji , Mao Peng , Liu Wei , Liu Zhichun
Published: December 2019

Polymers have been widely used due to low cost, light weight, chemical inertness and easy of processing. However, bulk polymers are usually considered as thermal insulators owing to their low thermal conductivity. In this paper, the 3D polyethylene (PE) structure based on knitting method is proposed. We investigate the thermo-mechanical property of 3D PE and make a comparison with the amorphous PE. The results show that the 3D PE has a higher thermal conductivity, elastic modulus, and shear modulus than amorphous PE, which provides a novel perspective on designing high thermal conductivity polymers. In the past decades, although the strain effect on the thermal conductivity of PE has been intensively studied, little research has been focused on the impact of shear. In this work, the thermal conductivity of PE under different shear strain is calculated by molecular dynamics simulation. Unexpectedly, the impact of shear on the amorphous PE and 3D PE is different. For amorphous PE, the average thermal conductivity is insensitive to the shear strain. However, the thermal conductivity of 3D PE can be slightly enhanced when the shear strain is large enough. The underlying mechanism is related to the specific morphology. Our findings can deliver new insights on designing high thermal conductive polymers.
Numerical Analysis of Parametric Effects of Tube-Strip Heat Exchanger for Fuel Cell Vehicles
Authors: Wu Xiaoyu , Zhang Hengyun , Zhu Zhehua , Xu Shen , Deng Yuchen
Published: December 2019

Fuel cell vehicles (FCVs) are facing more severe heat dissipation challenges since the fuel cell stack is required to operate at a lower temperature and thus smaller heat exchanger temperature difference. Thorough analysis of the parametric effects is required to maximize the thermal performance. In this paper, a numerical analysis of the tube-strip heat exchanger is conducted for the targeted application in a high performance passenger FCV. The representative unit cell is used to model the detailed fluid flow and heat transfer at both hot and cold sides in the theoretical framework of volume averaging. Based on the numerical computation over the representative unit cells, the flow, temperature and pressure fields are obtained, which are then utilized to obtain the cell-level heat transfer coefficient between the hot and cold fluids. The obtained heat transfer coefficients are used for the estimation of the heat exchanger thermal performance based on the effectiveness-NTU method. Different air and liquid water flow rates are first examined. Various design parameters such as fin height, fin spacing, fin thickness and fin material are examined through the heat transfer analysis at the unit cell level. Attention is also paid on the improvement of the air-side performance by changing fin shapes to increase the heat transfer coefficient of the heat exchanger. The result shows that the total exchanged heat of the aluminum louvered fin heat exchanger, with fin thickness of 0.06mm, fin height of 5mm and fin spacing of 1mm, can reach 59.24 kW at the liquid flowrate of 120L/min and air velocity of 5m/s.
Heat Transfer Characteristics of Horizontal Nano-Structured Oscillating Heat Pipes
Authors: Hao Tingting , Yu Huiwen , Ma Xuehu , Lan Zhong
Published: December 2019

Working fluid in the oscillating heat pipe (OHP) with low turn number (< 9) positioned in the horizontal heat mode could not easily backflow to the evaporator due to the absence of gravity. In this paper, copper OHP with superhydrophilic nano-structured inner surface by introducing additional capillary force was investigated through the visualization and thermal experiments. OHPs with 6 turns, charged with pure water as the working fluid, were fabricated with copper, and nano-structured inner surface and tested for comparison. Contact angles of water on the copper and superhydrophilic surface were 36.7 and 0 deg. The filling ratio of water was 50%, 65%, and 80%, respectively. Startup performance, thermal resistance, and liquid slug oscillation of OHPs were investigated experimentally at the heat input of 100–380 W. Experimental results showed that OHPs with the superhydrophilic nano-structured surface showed an enhanced heat transfer performance due to the nanostructure-induced capillary action for water in the horizontal direction. The optimum filling ratio was 65% in this work. Dryout was observed in the OHPs with the filling ratio of 50% at the heat input higher than 220 W. At the filling ratio of 80%, the working fluid was accumulated in the adiabatic and condensation section, and the driving force due to the water evaporation in evaporator was not high enough to activate the movements of liquid slugs. Heat transfer performance of OHP with nano-structured surface was higher than that of bare copper surface by introducing the additional capillary force.
Atomistic Modeling of Condensation Over Nano-Structured Surface
Authors: Hasan Mohammad Nasim , Rahman Md. Hafijur , Omar Salauddin , Akhter Chandni
Published: December 2019

Present study has been performed to understand condensation characteristics of argon vapor over nano-structured surface using non equilibrium molecular dynamics (MD) simulation. Main focus of this study is to explore the effect of condensation surface increment due to presence of nano-structure (considering flat surface as reference), solid-liquid interfacial wettability and condensation wall temperature. The simulation domain is a horizontal cuboid system that has two platinum walls at two opposite ends, left wall as the evaporation wall and the right wall as the condensation wall. Liquid argon was placed over the evaporation wall and the rest of the domain was filled with argon vapor. Various platinum nano-structured configurations were used to vary the surface area of the condensation wall. The system is first equilibrated at 90 K for a while and the evaporation of liquid argon is achieved by increasing the evaporation wall temperature at 130 K. The condensation of argon vapor is assumed for two different condensation temperatures such as 90 K and 110 K. The results indicate that condensation improves with condensation surface increment due to presence of nano-structure. Also it shows that the effect of condensation surface increment due to presence of nano-structure is drastically reduced with increasing solid-liquid interfacial wettability. The condensation at 110 K was poor compared to condensation at 90 K. The obtained results has been presented and discussed from macroscopic approach in terms of condensation mass flux, thermodynamic heat flux and time averaged wall heat flux.
Effect Analysis of Various Gradient Particle Size Distribution on Electrical Performance of Anode-Supported SOFCs With Gradient Anode
Authors: Fu Pei , Song Yuansheng , Yang Jian , Wang Qiuwang
Published: December 2019

Gradient particle size anode has shown great potential in improving the electrical performance of anode-supported solid oxide fuel cells (SOFCs). In the present study, a 3-D comprehensive model is established to study the effect of various gradient particle size distribution on the cell electrical performance for the anode microstructure optimization. The effect of homogeneous particle size on the cell performance is studied first. The maximum current density of homogeneous anode SOFC is obtained for the comparison with the electrical performance of gradient anode SOFC. Then the effect of various gradient particle size distribution on the cell molar fraction and polarization losses distribution is analyzed and discussed in detail. Increasing the particle diameter gradient can effectively reduce the anodic concentration overpotential. Decreasing the particle diameter of AFL2 is beneficial to reducing the activation and ohmic overpotentials. On these bases, the comprehensive electrical performances of SOFCs with gradient particle size anode and homogeneous anode are compared to highlight the optimal gradient particle diameter distribution. In the studied cases of the present work, the gradient particle diameter of 0.7 μm, 0.4 μm and 0.1 μm at ASL, AFL1 and AFL2 (Case 3) is the optimal particle size distribution.
Targeting diacylglycerol acyltransferase 2 for the treatment of nonalcoholic steatohepatitis
Authors: Amin Neeta B. , Carvajal-Gonzalez Santos , Purkal Julie , Zhu Tong , Crowley Collin , Perez Sylvie , Chidsey Kristin , Kim Albert M. , Goodwin Bryan
Published: November 2019

Inhibition of DGAT2 reduces steatosis, inflammation, and fibrosis in rodent models of NASH and reduces liver fat in clinical testing.
The Manganese-Responsive Transcriptional Regulator MumR Protects Acinetobacter baumannii from Oxidative Stress
Authors: Green Erin R. , Juttukonda Lillian J. , Skaar Eric P.
Published: November 2019

Acinetobacter baumannii
is an emerging opportunistic pathogen that primarily infects critically ill patients in nosocomial settings. Because of its rapid acquisition of antibiotic resistance, infections caused by
A. baumannii
have become extremely difficult to treat, underlying the importance of identifying new antimicrobial targets for this pathogen. Manganese (Mn) is an essential nutrient metal required for a number of bacterial processes, including the response to oxidative stress.
A MUC16 IgG Binding Activity Selects for a Restricted Subset of IgG Enriched for Certain Simian Immunodeficiency Virus Epitope Specificities
Authors: Schneider Jeffrey R. , Shen Xiaoying , Orlandi Chiara , Nyanhete Tinashe , Sawant Sheetal , Carias Ann M. , Smith Archer D. , Kelleher Neil L. , Veazey Ronald S. , Lewis George K. , Tomaras Georgia D. , Hope Thomas J.
Published: November 2019

Understanding how antibodies are distributed in the mucosal environment is valuable for developing a vaccine to block HIV infection. Here, we study an IgG binding activity in MUC16, potentially representing a new IgG effector function that would concentrate certain antibodies within the glycocalyx to trap pathogens before they can reach the underlying columnar epithelial barriers. These studies reveal that rhesus macaque IgG responses during chronic SIV infection generate increased antibodies that bind MUC16, and interestingly, these MUC16-tethered antibodies are enriched for binding to certain antigens. Therefore, it may be possible to direct HIV vaccine-generated responses to associate with MUC16 and enhance the antibody’s ability to mediate immune exclusion by trapping virions within the glycocalyx and preventing the virus from reaching immune target cells within the mucosa. This concept will ultimately have to be tested in the rhesus macaque model, which is shown here to have MUC16-targeted antigen responses.
Body mass in adolescents with chronic pain: observational study
Authors: Gauntlett-Gilbert Jeremy , Bhat Chandrika , Clinch Jacqui
Published: November 2019

Objective

In a paediatric chronic pain population, to determine whether higher body mass was associated with poorer functioning, mood or treatment outcome.

Design

Cross-sectional study with examination of treatment outcomes.

Setting

Tertiary specialist adolescent pain rehabilitation unit.

Patients

355 adolescents with relatively severe non-malignant chronic pain.

Interventions

Intensive 3-week pain rehabilitation programme.

Main outcome measures

Objective physical measures (walk, sit-to-stand); self-reported functioning and mood

Results

Average body mass index (BMI) in the sample was relatively high (24.2 (SD 5.6)) with 20.5% being classified as obese. However, there were no relationships between body mass and objective physical measures, physical or social functioning, depression or anxiety (all p>0.05). There was a small relationship between higher body mass and greater pain-related fear (r=0.17, p<0.01). Treatment improved all variables (p<0.001) apart from pain intensity. There were no relationships between higher body mass and poorer treatment outcome; in fact, patients with higher BMI showed slightly greater decreases in depression (r=0.12, p<0.05) and pain-specific anxiety (r=0.18, p<0.01) during treatment.

Conclusions

Higher body mass does not worsen functioning, mood or treatment response in adolescents with disabling chronic pain. Childhood obesity and chronic pain are both stigmatised conditions; clinicians should avoid implying that high body mass alone is a causal factor in the struggles of a young person with chronic pain.
Os odontoideum: a rare cause of syncope
Authors: Buntting Christopher Shane , Dower Ashraf , Seghol Haider , Kohan Saeed
Published: November 2019

Syncopal events are a concerning presentation and timely evaluation is warranted. Common aetiologies include cardiac and neurological pathology such as arrhythmias, vertebrobasilar arterial disease and vasovagal syncope. We describe the case of a 65-year-old man who presented to our emergency department with symptoms of vertigo and syncope. He was investigated extensively for both cardiac and neurological causes of his symptoms which returned negative results. An outpatient CT scan demonstrated the presence of Os odontoideum and dynamic instability of the atlantoaxial junction, with presumed dynamic obstruction of the vertebral arterial system. This was successfully managed with a posterior atlantoaxial lateral mass fusion with resolution of syncopal symptoms.
Virtual sports deserve real sports medical attention
Authors: Pereira Ana Monteiro , Brito João , Figueiredo Pedro , Verhagen Evert
Published: December 2019

In recent years, virtual sports or ‘eSports’ have grown exponentially both recreationally and at the professional level. eSports comprise several regulated video games played competitively, using electronic platforms. Some eSports competitions present a structure comparable to traditional sports, and eSports players, even with major skills and mental focus, need preparation and training to thrive. However, little is known about the demands of eSports competitions and continuous training. As the popularity and stakes rise, concerns about the health and emerging risks of eSports participation might arise. Indeed, in the absence of proper descriptive data about the specific characteristics of the eSports population (including factors such as screen time, physical activity, overuse injuries or training environment), effective prevention and care cannot be developed nor provided. Therefore, quality healthcare and prevention strategies are needed. In the current viewpoint, we argue that those involved with Sports Science and Medicine should lead the discussion and reflect on the health effects of eSports participation, providing scientifically-based arguments to better answer to the current eSports professionalism.
Understanding cost data collection tools to improve economic evaluations of health interventions
Authors: Chapel John M , Wang Guijing
Published: December 2019

Micro-costing data collection tools often used in literature include standardized comprehensive templates, targeted questionnaires, activity logs, on-site administrative databases, and direct observation. These tools are not mutually exclusive and are often used in combination. Each tool has unique merits and limitations, and some may be more applicable than others under different circumstances. Proper application of micro-costing tools can produce quality cost estimates and enhance the usefulness of economic evaluations to inform resource allocation decisions. A common method to derive both fixed and variable costs of an intervention involves collecting data from the bottom up for each resource consumed (micro-costing). We scanned economic evaluation literature published in 2008-2018 and identified micro-costing data collection tools used. We categorized the identified tools and discuss their practical applications in an example study of health interventions, including their potential strengths and weaknesses. Sound economic evaluations of health interventions provide valuable information for justifying resource allocation decisions, planning for implementation, and enhancing the sustainability of the interventions. However, the quality of intervention cost estimates is seldom addressed in the literature. Reliable cost data forms the foundation of economic evaluations, and without reliable estimates, evaluation results, such as cost-effectiveness measures, could be misleading. In this project, we identified data collection tools often used to obtain reliable data for estimating costs of interventions that prevent and manage chronic conditions and considered practical applications to promote their use.
Penetrating thoracic wound with cardiac trauma
Authors: McGrath Ciara , Smith Caroline , Meakin Lee B
Published: December 2019

A young male whippet presented in hypovolaemic shock with a penetrating thoracic wound. Point‐of‐care ultrasound documented a moderate volume of pleural effusion and a hyperechoic mass adjacent to the right ventricle suspected to be a haematoma. Thoracic CT confirmed these findings. Following stabilisation, the patient proceeded to theatre and a median sternotomy was performed. A large haematoma was attached to the ventral surface of the right ventricle. The haematoma was removed, and a partial thickness laceration was visualised on the ventral surface of the right ventricular free wall. The defect was repaired with pledgeted mattress sutures. A chest drain was placed and the thorax closed routinely. The patient recovered without complication. This case report describes the importance of considering internal trauma, including cardiac trauma, in patients presenting with a penetrating thoracic injury. It also highlights the importance of emergency stabilisation and utility of point‐of‐care ultrasonography in these patients.
Developing a two-level fire regime zonation system for Canada
Authors: Erni Sandy , Wang Xianli , Taylor Steve , Boulanger Yan , Swystun Tom , Flannigan Mike , Parisien Marc-André
Published: December 2019

Fire regime zonation systems are critical tools for research and management activities. In this study, we develop a hierarchical framework that applies both qualitative and quantitative approaches to create a two-level fire regime zonation system for Canada. The finer scale level, Fire Regime Units (FRUs), was created through a stepwise synthesis of fire regime metrics based on 1970–2016 fire records, environmental attributes such as topographic features and vegetation, literature review, and expert advice. Each of these 60 FRUs exhibits an internal homogeneity in fire regime. As non-contiguous units can show similar patterns in fire-related measurements, we performed a clustering analysis on the FRUs to define 15 broad-scale Fire Regime Types (FRTs). Each type is characterized by a unique set of indices related to fire activity, seasonality, and ignition cause. This two-level fire regime zonation system has a large range of applications (e.g., modeling, gradient analysis) and is flexible enough to be updated with new data or when notable shifts in fire dynamics occur.
Increased trophic position of black bear (Ursus americanus) at the northern fringe of its distribution range
Authors: Bonin Michaël , Dussault Christian , Côté Steeve D.
Published: November 2019

Studies describing the diet of omnivorous species are abundant, but the drivers affecting the balance between animal and plant resources remain unclear. Among those drivers, latitude has been reported to positively correlate with the trophic position of consumers. Using stable isotope analysis, we tested the hypothesis that trophic position of black bears (Ursus americanus Pallas, 1780) is positively correlated with latitude in eastern North America. We sampled 57 bears over a 15° latitudinal gradient in Quebec, Canada, and used stable isotope analysis to assess individual trophic position and metrics of dietary niches. We found a strong positive correlation between trophic position of bears and latitude (r2= 0.76), which persisted throughout seasons. The width of the dietary niche of bears also appeared to follow a latitudinal pattern, even though bears foraging at the southernmost part of the gradient also showed a wide dietary niche. The impact of latitude on the foraging tactic of omnivores fosters our understanding of their capability to deal with contrasting environmental conditions, especially for species whose distribution ranges are expanding due to climate change. The flexibility of black bear foraging tactic likely allows this species to expand its geographical distribution range toward northern habitats.
Duality between Dirac fermions in curved spacetime and optical solitons in non-linear Schrodinger model: magic of $$1+1$$-dimensional bosonization
Authors: Ghosh Subir
Published: November 2019

Bosonization in curved spacetime maps massive Thirring model (self-interacting Dirac fermions) to a generalized Sine–Gordon model, both living in $$1+1$$1+1-dimensional curved spacetime. Applying this duality we have shown that the Thirring model fermion, in non-relativistic limit, gets identified with the soliton of non-linear Scrodinger model with Kerr form of non-linearity. We discuss one particular optical soliton in the latter model and relate it with the Thirring model fermion.
Cyclic parallel hypersurfaces in complex Grassmannians of rank 2
Authors: Lee Hyunjin , Suh Young Jin
Published: November 2019

The object of the paper is to study cyclic parallel hypersurfaces in complex (hyperbolic) two-plane Grassmannians which have a remarkable geometric structure as Hermitian symmetric spaces of rank 2. First, we prove that if the Reeb vector field belongs to the orthogonal complement of the maximal quaternionic subbundle, then the shape operator of a cyclic parallel hypersurface in complex hyperbolic two-plane Grassmannians is Reeb parallel. By using this fact, we classify all cyclic parallel hypersurfaces in complex hyperbolic two-plane Grassmannians with non-vanishing geodesic Reeb flow. Next, we give a non-existence theorem for cyclic Hopf hypersurfaces in complex two-plane Grassmannians.
HETEROGENEOUS EFFECTS OF CREDIT ACCESS ON FORMAL AND INFORMAL FIRM GROWTH: EMPIRICAL EVIDENCE FROM VIETNAM
Authors: LONG TRINH QUANG , MORGAN PETER JOHN , TRAN MINH BINH
Published: November 2019

This paper examines the causal effect of credit access on firm growth (measured by employment growth), using a unique micro-, small-, and medium-sized firm-level data collected every two years in Vietnam from 2005 to 2013. The results obtained from fixed-effects (FE) and FE with instrumental variable estimators show that firms with credit access experience a higher growth than firms without credit access. We also find that access to credit is positively associated with both formal and informal firm growth, but the results for formal firms seem to be driven by some high growth firms (and rapidly shrinking firms). The effect of credit access on firm growth is also heterogeneous by firm size and firm age in both types of firms.
Theoretical investigation of transition metals (subgroup = 8, 9, 10 and 11) substituted (MgO)9 nanotube clusters
Authors: Zhao Zhen , Li Zhi
Published: November 2019

The structures, electronic and magnetic properties of the transition metals (TMs) (subgroup = 8, 9, 10 and 11) substituted [Formula: see text] nanotube clusters have been investigated using first-principles at the PBE functional. The results show that as for the [Formula: see text] clusters, [Formula: see text] atoms and Re atoms prefer to substitute the Mg atoms which occupy the edge position of the [Formula: see text] nanotube clusters, while [Formula: see text] and [Formula: see text] atoms prefer to substitute the Mg atoms which occupy the middle hexagonal ring [Formula: see text] nanotube clusters expect for Re atoms. The [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]O9 clusters are more stable than other TMs-substituted [Formula: see text] nanotube clusters. TM substituting significantly improves the kinetic activity of the [Formula: see text] nanotube clusters. The HOMO and LUMO states display evident hybridization between the TMs [Formula: see text] and O [Formula: see text] band states. A few [Formula: see text] orbital electrons of the TM atoms transfers to O atoms. As for the spins of the [Formula: see text] TM atoms for the ground state [Formula: see text] and [Formula: see text] (subgroup = 8, 9, 10 and 11) clusters, [Formula: see text].
A Symmetrical Multilevel Inverter Topology with Minimal Switch Count and Total Harmonic Distortion
Authors: Janardhan Kavali , Mittal Arvind , Ojha Amit
Published: November 2019

A multilevel inverter (MLI) with reduced number of power devices, especially for the higher output levels, is presented in this paper. The generalized topology for ([Formula: see text]) level MLI is developed with symmetrical isolated dc sources and ([Formula: see text]) number of switches. A five-level MLI is developed with five power switches and then by adding each one additional switch two more levels are added in the output voltage waveform. With the help of lookup table, the working principle of the proposed five-level MLI topology is explained. Sinusoidal pulse width modulation–phase disposition control technique has been used to get a minimal total harmonic distortion (THD). The proposed MLI topology is simulated on the MATLAB platform. The laboratory prototype is developed for five-level MLI, and the experimental results obtained validate the simulation studies. The dSPACE 1104 is used for generating gate pulses in case of experimentation. The output voltage and current THDs obtained are 9.20% and 4.60%, respectively; the harmonics are mitigated more with five-level inverter. The proposed topology is compared with the cascaded H-bridge multilevel inverter.
An Ultra-Low-Power Five-Input Majority Gate in Quantum-Dot Cellular Automata
Authors: Deng Feifei , Xie Guangjun , Wang Shaowei , Cheng Xin , Zhang Yongqiang
Published: November 2019

Quantum-dot cellular automata (QCA) is a highly attractive alternative to CMOS for future digital circuit design, relying on its high-performance and low-power-consumption features. This paper analyzes and compares previously published five-input majority gates. These designs do not perform well in terms of physical properties, especially concerting power consumption. Therefore, an ultra-low-power five-input majority gate in one layer is proposed, which uses a minimum number of cells and smaller area, and achieves the expected highly polarized output compared with previous designs. In order to evaluate its practicability, a new one-bit coplanar full-adder is proposed. The analysis results show that this full-adder performs well compared with existing multilayer and single-layer designs. The number of cells of the proposed design is reduced by 7.14% to get the same area and clock delay compared with the best coplanar full-adder. In addition, its power dissipation is also reduced by 9.28% at 0.5[Formula: see text], 11.09% at 1[Formula: see text] and 12.66% at 1.5[Formula: see text] in terms of average energy dissipation compared with the best single-layer design. QCADesigner tool is used to verify the simulation results of the proposed designs and QCAPro tool is used to evaluate the power dissipation of all considered designs.
EFFECT OF VARIATION IN GRAIN SIZES AND TWINNING DEFORMATION ON CRACK GROWTH BEHAVIOR IN MAGNESIUM ALLOY AZ31
Authors: MORI KEISUKE , MAKABE CHOBIN , INOUE SHIN-ICHI , ANDO SHINJI
Published: November 2019

Push–pull tests of rolled magnesium alloy AZ31 were performed with a side-notch plate specimen to examine the crack growth behavior under negative mean stress conditions in conditions of high humidity. The effects of repetition of compression on crack growth were discussed. The geometry of the fracture surface and the changes in microstructure were related to the crack growth behavior. The crack growth rate varied even when the experimental conditions were the same. When the oxidized powder appeared from the cracked surface, the crack growth rate became lower. That was related to the changes in microstructure while the crack grew with local shear plastic deformation. The variation of crack closure point was related to the local shear plastic deformation.
SLURRY EROSION BEHAVIOR OF HVOF SPRAYED WC-12Co AND Cr3C2-25NiCr COATINGS DEPOSITED ON 16Cr5Ni STAINLESS STEEL
Authors: DU JIN , ZHANG JIANFENG , XIAO JINKUN , ZHANG CHAO
Published: November 2019

Slurry erosion behaviors of HVOF WC-12Co and Cr3C2-25NiCr coatings as well as 16Cr5Ni martensitic stainless steel were investigated in the present paper. Erosion experiments were carried out using slurry with different rotational speeds, particle size and concentration to evaluate their influences on the coatings. It was found that the rotational speed had the most significant influence on WC-12Co coating, whereas the erosion particle size was a more dominant factor for the Cr3C2-25NiCr coating. Nevertheless, the effect of concentration was most important in the case of 16Cr5Ni steel. It is demonstrated that cermet composite coatings could effectively enhance the resistance of slurry erosion, and the WC-12Co coating exhibits a minimum erosion rate compared with the steel and Cr3C2-25NiCr coating. 16Cr5Ni steel and WC-12Co coating showed ductile and brittle mechanisms, respectively, whereas Cr3C2-25NiCr exhibited multiple mechanisms of ductile and brittle, dominantly ductile.
A Human Joint Torque Estimation Method for Elbow Exoskeleton Control
Authors: Li Xinwei , Liu Su , Chang Ying , Li Sujiao , Fan Yuanjie , Yu Hongliu
Published: November 2019

Exoskeleton for motion assistance has obtained more and more attention due to its advantages in rehabilitation and assistance for daily life. This research designed an estimation method of human joint torque by the kinetic human–machine interaction between the operator’s elbow joint torque and the output of exoskeleton. The human elbow joint torque estimation was obtained by back propagation (BP) neural network with physiological and physical input elements including shoulder posture, elbow joint-related muscles activation, elbow joint position, and angular velocity. An elbow-powered exoskeleton was developed to verify the validity of the human elbow joint torque estimation. The average correlation coefficients of estimated and measured three shoulder joint angles are 97.9%, 96.2%, and 98.1%, which show that estimated joint angles are consistent with the measured joint angle. The average root-mean-square error between estimated elbow joint torque and measured values is about 0.143[Formula: see text]N[Formula: see text]m. The experiment results proved that the proposed strategy had good performance in human joint torque estimation.
Joint Position Control Based on Fractional-Order PD and PI Controllers for the Arm of the Humanoid Robot TEO
Authors: Muñoz Jorge , Monje Concepción A. , Casa Santiago Martínez de la , Balaguer Carlos
Published: November 2019

This paper presents a control scheme for the humanoid robot TEO’s elbow joint based on a novel tuning method for fractional-order PD and PI controllers. Due to the graphical nature of the proposed method, a few basic operations are enough to tune the controllers, offering very competitive results compared to classic methods. The experiments show a robust performance of the system to mass changes at the tip of the humanoid arm.
Spatial-spectral identification of abnormal leukocytes based on microscopic hyperspectral imaging technology
Authors: Hu Xueqi , Ou Jiahua , Zhou Mei , Hu Menghan , Sun Li , Qiu Song , Li Qingli , Chu Junhao
Published: November 2019

Screening and diagnosing of abnormal Leukocytes are crucial for the diagnosis of immune diseases and Acute Lymphoblastic Leukemia (ALL). As the deterioration of abnormal leukocytes is mainly due to the changes in the chromatin distribution, which significantly affects the absorption and reflection of light, the spectral feature is proved to be important for leukocytes classification and identification. This paper proposes an accurate identification method for healthy and abnormal leukocytes based on microscopic hyperspectral imaging (HSI) technology which combines the spectral information. The segmentation of nucleus and cytoplasm is obtained by the morphological watershed algorithm. Then, the spectral features are extracted and combined with the spatial features. Based on this, the support vector machine (SVM) is applied for classification of five types of leukocytes and abnormal leukocytes. Compared with different classification methods, the proposed method utilizes spectral features which highlight the differences between healthy leukocytes and abnormal leukocytes, improving the accuracy in the classification and identification of leukocytes. This paper only selects one subtype of ALL for test, and the proposed method can be applied for detection of other leukemia in the future.
Quantum Spin Hall Insulators in Tin Films: Beyond Stanene
Authors: Li Jiaheng , Xu Yong
Published: December 2019

Large-gap quantum spin Hall (QSH) insulators were previously predicted in stanene and its derivatives. Beyond stanene that is the thinnest [Formula: see text]-Sn(111) film, we propose to explore QSH insulators in [Formula: see text]-Sn films with different crystallographic orientations. Our first-principles calculations reveal that the thickness-dependent band gap of [Formula: see text]-Sn(100) and [Formula: see text]-Sn(110) films does not show a monotonic decrease as typically expected by quantum confinement, but displays an oscillating change behavior, an indicative of topological quantum phase transition. While these films are normal insulators in the ultrathin limit, the QSH phase emerges above a critical film thickness of around 10 layers. Remarkably, the QSH insulators are obtainable within a wide thickness range and their energy gaps are sizable (even [Formula: see text][Formula: see text]0.1[Formula: see text]eV), which facilitates experimental realization of the high-temperature QSH effect.
Long Noncoding RNA GATA3-AS1 Promotes Cell Proliferation and Metastasis in Hepatocellular Carcinoma by Suppression of PTEN, CDKN1A, and TP53
Authors: Luo Xuee , Zhou Ning , Wang Le , Zeng Qinghua , Tang Hongying
Published: December 2019

Background. Long noncoding RNAs (lncRNAs) have been known to play important roles in the progression of various types of human cancer. LncRNA GATA3 antisense RNA 1, GATA3-AS1, has been reported to be associated with T-cell development and differentiation. However, the expression pattern and function of GATA3-AS1 in hepatocellular carcinoma (HCC) remain unknown. Methods. Real-time quantitative PCR (RT-qPCR) assay was conducted to detect GATA3-AS1 expression levels in 80 cases of pairs HCC tissues and matched normal tissues. Chi-squared (χ2) test was used to analyze the correlation between GATA3-AS1 expression and clinicopathologic variables. Survival curves were plotted using the Kaplan–Meier method and were compared via the log-rank test. The cell counting kit-8 (CCK-8) and wound scratch assays were applied to detect the effect of GATA3-AS1 knockdown and overexpression on cell growth and migration of HCC. RT-qPCR was performed for the detection of the phosphatase and tensin homolog (PTEN), cyclin-dependent kinase inhibitor 1A (CDKN1A), and tumor protein p53 (TP53) expression in HCC cells after GATA3-AS1 knockdown and overexpression. Results. GATA3-AS1 was significantly upregulated in HCC tissues compared with matched normal tissues. The high expression of GATA3-AS1 was significantly correlated with larger tumor size, advanced TNM stage, and more lymph node metastasis. High GATA3-AS1 expression was markedly correlated with shorter overall survival times of HCC patients. Furthermore, knockdown of GATA3-AS1 obviously inhibited Hep3B and HCCLM3 cell growth and migration, whereas overexpression of GATA3-AS1 had the opposite effects. In addition, GATA3-AS1 knockdown resulted in upregulated expression levels of tumor-suppressive genes, PTEN, CDKN1A, and TP53, in Hep3B and HCCLM3 cells, while restoration of GATA3-AS1 decreased PTEN, CDKN1A, and TP53 expression levels. Conclusion. Our data suggested that GATA3-AS1 promotes cell proliferation and metastasis of HCC by suppression of PTEN, CDKN1A, and TP53.
Exploring the Most Promising Stem Cell Therapy in Liver Failure: A Systematic Review
Authors: AdiwinataPawitan Jeanne
Published: December 2019

Background. Alternative approaches to transplantation for liver failure are needed. One of the alternative approaches is stem cell therapy. However, stem cell therapy in liver failure is not standardized yet, as every centre have their own methods. This systematic review is aimed at compiling and analyzing the various studies that use stem cells to treat liver failure, to get an insight into potential protocols in terms of safety and efficacy by comparing them to controls. Methods. This systematic review was done according to PRISMA guidelines and submitted for registration in PROSPERO (registration number CRD42018106119). All published studies in PubMed/MEDLINE and Cochrane Library, using key words: “human” and “stem cell” AND “liver failure” on 16th June 2018, without time restriction. In addition, relevant articles that are found during full-text search were added. Inclusion criteria included all original articles on stem cell use in humans with liver failure. Data collected included study type, treatment and control number, severity of disease, concomitant therapy, type and source of cells, passage of cells, dose, administration route, repeats, and interval between repeats, outcomes, and adverse events compared to controls. Data were analyzed descriptively to determine the possible causes of adverse reactions, and which protocols gave a satisfactory outcome, in terms of safety and efficacy. Results. There were 25 original articles, i.e., eight case studies and 17 studies with controls. Conclusion. Among the various adult stem cells that were used in human studies, MSCs from the bone marrow or umbilical cord performed better compared to other types of adult stem cells, though no study showed a complete and sustainable performance in the outcome measures. Intravenous (IV) route was equal to invasive route. Fresh or cryopreserved, and autologous or allogeneic MSCs were equally beneficial; and giving too many cells via intraportal or the hepatic artery might be counterproductive.