bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prevalence of Anti-HBc Antibodies among HBsAg Negative Individuals and Its Association with Occult Hepatitis B
Authors: Madhavan Anitha , Sachu Arun , Balakrishnan Anu Kumar , Balakrishnan Sobha , Vasudevapanicker Jayalakshmi 
Published: May 2021

Abstract
Introduction Hepatitis B virus (HBV) infection is an endemic in many Asian countries, and among the major routes of transmission, transfusion is the one that should be prevented. Occult HBV infection (OBI) is defined as the presence of HBV DNA in the absence of detectable HBsAg, with or without anti-HBV antibodies. The aim of this study was to detect the prevalence of anti-HBc total antibodies among the HB surface antigen (HBsAg) negative individuals by way of enzyme-linked immunosorbent assay (ELISA), and detect the presence of HBV DNA among the anti-HBc seropositives by polymerase chain reaction (PCR). Anti-HBs among the HBV DNA positives were also found out by enzyme-linked fluorescent assay (ELFA).
Materials and Methods A total of 910 serum samples was subjected to initial screening for HBsAg by MERILISA HBsAg ELISA kits. The anti-HB core (HBc) total antibody titer was evaluated using MONOLISA ELISA (Biorad) kits. If found negative, the samples were discarded. If found positive, the samples underwent HBV DNA testing by nested PCR. Antibody to hepatitis B surface antigen (anti-HBs) was calculated among the DNA positives by ELFA.
Results A total of 133 samples were positive for anti-HBC total antibody, resulting in an overall prevalence of 14.6%. Overall prevalence of HBV DNA among the anti-HBc seropositives was 2.2%.
Conclusion Among the three HBV DNA positive patients, two belonged to the preoperative screening group, which is an alarming situation. Screening of blood for HBsAg has reduced the incidence of posttransfusion hepatitis, but HBV still remains the major source of transfusion transmitted infection in India.
Infective Endocarditis Caused by C. sordellii: The First Case Report from India
Authors: Chaudhry Rama , Bahadur Tej , Sagar Tanu , Agrawal Sonu Kumari , Arif Nazneen , Choudhary Shiv K. , Verma Nishant 
Published: May 2021

Abstract
Clostridium sordellii is a gram-positive anaerobic bacteria most commonly isolated from skin and soft tissue infection, penetrating injurious and intravenous drug abusers. The exotoxins produced by the bacteria are associated with toxic shock syndrome. We report here a first case of infective endocarditis due to C. sordellii from a female patient with ventricular septal defect from India.
Infectious Myelopathies
Authors: Anand Pria 
Published: May 2021

AbstractIn the setting of both globalization and increasing use of immunosuppressive therapy, infectious myelopathies are an important cause of morbidity worldwide. Clinical spinal cord syndromes related to infection are varied, including transverse myelitis, acute flaccid paralysis related to anterior horn cell involvement, spinal cord compression, chronic spastic paraparesis, and myeloradiculitis. Causative pathogens include viruses, parasites, pyogenic and atypical bacteria, and fungi. The epidemiology, clinical characteristics, diagnosis, and treatment of selected organisms will be discussed in this article.
Metabolic and Toxic Myelopathies
Authors: Slama Michaël C. C. , Berkowitz Aaron L. 
Published: May 2021

AbstractMetabolic and toxic causes of myelopathy form a heterogeneous group of disorders. In this review, we discuss the causes of metabolic and toxic myelopathies with respect to clinical presentation, pathophysiology, diagnostic testing, treatment, and prognosis. This review is organized by temporal course (hyperacute, acute, subacute, and chronic) and etiology (e.g., nutritional deficiency, toxic exposure). Broadly, the myelopathies associated with dietary toxins (neurolathyrism, konzo) and decompression sickness present suddenly (hyperacute). The myelopathies associated with heroin use and electrical injury present over hours to days (acutely). Most nutritional deficiencies (cobalamin, folate, copper) and toxic substances (nitrous oxide, zinc, organophosphates, clioquinol) cause a myelopathy of subacute onset. Vitamin E deficiency and hepatic myelopathy cause a chronic myelopathy. Radiation- and intrathecal chemotherapy-induced myelopathy can cause a transient and/or a progressive syndrome. For many metabolic and toxic causes of myelopathy, clinical deficits may stabilize or improve with rapid identification and treatment. Familiarity with these disorders is therefore essential.
Photochemistry of NH2NO2 and implications for chemistry in the atmosphere
Authors: Esposito Vincent J. , Trabelsi Tarek , Francisco Joseph S. 
Published: May 2021

Recent studies have indicated that nitramide (NH2NO2) may be formed more plentifully in the atmosphere than previously thought, while also being a missing source of the greenhouse gas nitrous oxide (N2O) via catalyzed isomerization. To validate the importance of NH2NO2 in the Earth’s atmosphere, the ground and first electronic excited states of NH2NO2 were characterized and its photochemistry was investigated using multireference and coupled cluster methods. NH2NO2 is non-planar and of singlet multiplicity in the ground state while exhibiting large out-of-plane rotation in the triplet first excited state. One-dimensional cuts of the adiabatic potential energy surface calculated using the MRCI+Q method show low-lying singlet electronic states with minima in their potential along the N–N and N–O bond coordinates. Due to vertical excitation energies in the 225–180 nm region, photochemical processes will not compete in the troposphere, causing N2O production to be the predicted major removal process of NH2NO2. In the upper atmosphere, photodissociation to form NH2NO + O (3P) is suggested to be a major photochemical removal pathway.
Influence of saturable absorber parameters on the operation regimes of a dumbbell-shaped thulium fibre laser
Authors: Zverev A.D. , Kamynin V.A. , Trikshev A.I. , Kovtun E.Yu. , Arutyunyan N.R. , Mastin A.A. , Ryabochkina P.A. , Obraztsova E.D. , Tsvetkov V.B. 
Published: May 2021

Abstract
The influence of saturable absorber parameters on the operation regimes of a dumbbell-shaped thulium fibre laser is studied. As saturable absorbers, polymer films with nanotubes characterised by different transmission coefficients in the saturated and unsaturated states are used. The operation of lasers with absorbers of different configurations used to obtain stable Q-switching and mode-locking regimes in the spectral range 1930 – 1960 nm is demonstrated. The average output power in the single-pulse mode-locking regime is 3.5 mW at a pulse repetition rate of 8.4 MHz and a pulse duration of 1.08 ps.
Investigation of the transition at a wavelength of 506 nm, intended for deep cooling of thulium atoms
Authors: Provorchenko D.I. , Tregubov D.O. , Mishin D.A. , Golovizin A.A. , Fedorova E.S. , Khabarova K.Yu. , Sorokin V.N. , Kolachevsky N.N. 
Published: May 2021

Abstract
A scheme is proposed for the third stage of laser cooling of thulium atoms at a wavelength of 506.2 nm, and a system for stabilising the laser radiation frequency is described, which provides the required characteristics. The transition

at a wavelength of 506.2 nm is detected in a magneto-optical trap with the employment of the developed laser setup. The value of hyperfine splitting of the transition upper level is measured, and the single-dimension cooling at this wavelength is observed for the first time.
Analysis of uncertainties of a cold-ytterbium atomic frequency standard using operational parameters of its optical lattice
Authors: Semenko A.V. , Belotelov G.S. , Sutyrin D.V. , Slyusarev S.N. , Yudin V.I. , Taichenachev A.V. , Ovsiannikov V.D. , Pal’chikov V.G. 
Published: May 2021

Abstract
We have assessed the effect of optical lattice laser field parameters (polarisation, intensity, and wavelength) of a cold-ytterbium atomic frequency standard on the systematic uncertainty of precision clock transition frequency measurements. The spectrum and polarisation of the laser field of the lattice have been investigated in detail directly in the spatial region of interaction of cold ytterbium atoms with the laser field. The Stark shift of the clock transition in the vicinity of the magic wavelength of the laser has been estimated as a function of the experimentally measured laser field intensity in the dipole approximation. The estimates have been used to calculate the residual systematic uncertainty in the light shift of the optical lattice laser frequency.
Heterodera glycines (soybean cyst nematode).
Authors: Hunt David 
Published: May 2021

Abstract

The soybean cyst nematode H. glycines is a known major pest of soybean in regions of the USA particularly semi-arid areas. The nematode has now been found as a pest of soybean outside the USA in Argentina, Brazil, Colombia, China, Egypt, Indonesia, Iran, Italy, Japan, Korea, Paraguay and the former Soviet Union. Other hosts include Phaseolus beans. It can survive in a semi-dried state and is easily spread in soil or on plant material. It is a pest in temperate areas and does not develop below 15°C or above 33°C. Once introduced, the populations of the nematode can rapidly increase as it will complete 6-7 generations per growing season.
Magnetic coupling across the antiferromagnetic–antiferromagnetic interface
Authors: Jena Bibhuti Bhusan , Kar Arunava , Barman Sukanta , Mandal Suman , Menon Krishnakumar S R 
Published: May 2021

Abstract
We investigate the magnetic coupling across the antiferromagnetic–antiferromagnetic (AFM–AFM) interface for the prototypical CoO-NiO bilayer system where the bulk Néel temperature (T
N
) of NiO is higher than that of CoO. Using the temperature-dependent exchange-scattered electron intensities from the surface AFM lattice, the surface T
N
of CoO was estimated as a function of the CoO/NiO film thicknesses. Our results show that the surface T
N
of CoO layers is enhanced significantly from its bulk T
N
value and approaching the T
N
of the NiO layers, as the thickness of the CoO layers is reduced to the monolayer limit. Thus, thinner CoO layers are found to have higher T
N
than thicker layers on NiO, contrasting with the expected finite-size behavior. In addition to the short-range magnetic exchange coupling at the CoO-NiO interface, we observe the existence of a longer-range magnetic coupling across the interface, mediated by the magnetic correlations. Thus, the magnetic proximity effect is attributed to a combination of a short-range and a weaker long-range magnetic coupling, explaining the long AFM order propagation length in AFM–AFM superlattices and bilayers. Further, our results indicate a new approach to tune the AFM Néel temperature by varying the individual layer thickness of the bilayer system through the magnetic proximity effect.
Bloch oscillations at room temperature in graphene/h-BN electrostatic superlattices
Authors: Dragoman M , Dinescu A , Dragoman D , Comanescu Florin 
Published: May 2021

Abstract
In this manuscript, we report the fabrication and the measurements of Bloch oscillations at room temperature in electrostatic graphene/h-BN superlattices. The electrostatic superlattice consists of an array of tilted metallic electrodes deposited over graphene monolayer/h-BN monolayer grown on 2 inch wafers of doped Si/SiO2. We show the formation of minibands at room temperature, negative differential resistance and the evidence of Bloch oscillations. The experimental results are sustained by numerical modelling of these 2D superlattices. The experimental results are sustained by numerical modelling of these 2D superlattices. At room temperature, we have measured a period of Bloch oscillations of 55 meV which corresponds to a frequency of 13 THz.
Core−shell NiSe/Ni(OH)2 with NiSe nanorods and Ni(OH)2 nanosheets as battery-type electrode for hybrid supercapacitors
Authors: He Leqiu , Wang Yan , Guo Yajie , Li Guobing , Zhang Xubin , Cai Wangfeng 
Published: May 2021

Abstract
Novel core−shell nanostructure electrodes benefit from the excellent properties of their constituent materials, as well as the synergy between them. However, it is challenging to fabricate such structures efficiently. In this study, NiSe nanorods were fabricated using Ni foam as the conductive substrate and reactant via a one-step hydrothermal process, and Ni(OH)2 nanosheets were coated on the surface of the nanorods via one-step electrodeposition. The effect of the structure and morphology on the properties of the material was explored using scanning electron microscopy, x-ray diffraction, and electrochemical technology. The obtained core−shell NiSe/Ni(OH)2 exhibited an areal capacity of 1.89 mAh cm−2 at a current density of 5 mA cm−2. The assembled NiSe/Ni(OH)2//AC hybrid supercapacitor exhibited excellent energy and power densities, indicating that NiSe/Ni(OH)2 has great potential for use as a battery-type electrode in energy storage systems.
Low n electromagnetic modes in spherical tokamaks
Authors: Chowdhury J , McMillan B F 
Published: May 2021

Abstract
The performance of spherical tokamak reactors depends on plasma β, and an upper limit is set by long-wavelength kinetic ballooning modes (KBMs). We examine how these modes become unstable in spherical-tokamak reactor relevant plasmas, which may contain significant fast-ion pressure. In a series of numerically generated equilibria of increasing β, the KBM becomes unstable at sufficiently high plasma β, and for such cases, it is also significantly unstable even in the long-wavelength limit. The β threshold for the KBMs is similar to the ideal Magnetohydrodynamics (MHD) threshold, and in cases without fast ions, their frequencies are as predicted by diamagnetic-drift stabilised MHD. To isolate and explore the KBMs, simulations are performed where the pressure gradient is entirely due to the density profile, or entirely due to the temperature profile; the resulting KBMs have similar properties in the long-wavelength regime. The introduction of energetic ions restricts the KBMs to longer wavelengths, and reduces the β threshold somewhat; for parameter regimes of current-day devices, this is such long wavelength that a global analysis would become necessary. Mode frequencies in plasmas with a significant fast particle population are seen to be controlled by fast particle precession frequencies.
Three-dimensional coherent x-ray diffraction imaging of ferroelastic domains in single CsPbBr3 perovskite nanoparticles
Authors: Dzhigaev D , Zhang Z , Marçal L A B , Sala S , Björling A , Mikkelsen A , Wallentin J 
Published: May 2021

Abstract
Metal halide perovskites attract significant interest due to their remarkable performance in optoelectronic devices. However, the gap in understanding the relationship between their nanoscale structure and properties limits their application towards novel devices. In this work, twinned ferroelastic domains in single 500 nm CsPbBr3 particles are studied with 3D Bragg coherent x-ray diffraction imaging. A preferential double-domain structure is revealed in four identical particles, with one domain oriented along the [110] and the other along the [002] direction. The particles exhibit similar scattering volume ratios of 0.12 ± 0.026 between twin phases, suggesting the possibility of a deterministic formation process. The domains exhibit a difference in lattice tilt of 0.59 degrees, in excellent agreement with calculations of the lattice mismatch at the (112) twin boundary. These results provide important insights both for the fundamental understanding of ferroelastic nanoscale materials and for the performance improvement of perovskite-based devices. Moreover, this work paves the way towards real-time imaging of the domain dynamics in ferroic systems.
Inclusion–exclusion principle for open quantum systems with bosonic bath
Authors: Yang Siyao , Cai Zhenning , Lu Jianfeng 
Published: May 2021

Abstract
We present two fast algorithms which apply inclusion–exclusion principle to sum over the bosonic diagrams in bare diagrammatic quantum Monte Carlo and inchworm Monte Carlo method, respectively. In the case of inchworm Monte Carlo, the proposed fast algorithm gives an extension to the work [2018 Inclusion–exclusion principle for many-body diagrammatics Phys. Rev. B 98 115152] from fermionic to bosonic systems. We prove that the proposed fast algorithms reduce the computational complexity from double factorial to exponential. Numerical experiments are carried out to verify the theoretical results and to compare the efficiency of the methods.
A bird’s eye perspective of the measurement of oxygen reduction reaction in gas diffusion electrode half-cell set-ups for Pt electrocatalysts in acidic media
Authors: Loukrakpam Rameshwori , Ferreira Gomes Bruna , Kottakkat Tintula , Roth Christina 
Published: May 2021

Abstract
Reliable electrochemical testing protocols assessing the catalytic performance of novel materials, such as the rotating disk electrode method to determine the oxygen reduction reaction activity, play an essential role in the knowledge-based design of tailored electrocatalysts. However, these techniques are unable to accurately predict the performance of the developed electrocatalysts in membrane electrode assemblies (MEAs) which are ultimately used in full fuel cell measurements. Half-cell tests of gas diffusion electrodes have been shown to be a good compromise, with economical use of electrocatalysts while also mimicking the three-phase boundary in MEA during the presence of humidified reactant gas. In this review, we aim for a bird’s eye view of the set-ups already reported, how the testing protocols differ and how the protocols can be unified for a more consistent performance evaluation.
External validation of the Hospital Frailty Risk Score in France
Authors: Gilbert Thomas , Cordier Quentin , Polazzi Stéphanie , Bonnefoy Marc , Keeble Eilìs , Street Andrew , Conroy Simon , Duclos Antoine 
Published: May 2021

AbstractBackgroundThe Hospital Frailty Risk Score (HFRS) has made it possible internationally to identify subgroups of patients with characteristics of frailty from routinely collected hospital data.ObjectiveTo externally validate the HFRS in France.DesignA retrospective analysis of the French medical information database.Setting743 hospitals in Metropolitan France.SubjectsAll patients aged 75 years or older hospitalised as an emergency in 2017 (n = 1,042,234).MethodsThe HFRS was calculated for each patient based on the index stay and hospitalisations over the preceding 2 years. Main outcome measures were 30-day in-patient mortality, length of stay (LOS) &gt;10 days and 30-day readmissions. Mixed logistic regression models were used to investigate the association between outcomes and HFRS score.ResultsPatients with high HFRS risk were associated with increased risk of mortality and prolonged LOS (adjusted odds ratio [aOR] = 1.38 [1.35–1.42] and 3.27 [3.22–3.32], c-statistics = 0.676 and 0.684, respectively), while it appeared less predictive of readmissions (aOR = 1.00 [0.98–1.02], c-statistic = 0.600). Model calibration was excellent. Restricting the score to data prior to index admission reduced discrimination of HFRS substantially.ConclusionsHFRS can be used in France to determine risks of 30-day in-patient mortality and prolonged LOS, but not 30-day readmissions. Trial registration: Reference ID on clinicaltrials.gov: ID: NCT03905629.
The Association Between Cytomegalovirus and Disability by Race/Ethnicity and Sex: Results From the Health and Retirement Study
Authors: Duchowny Kate A , Noppert Grace A 
Published: May 2021

Abstract
Recent studies have documented a decline in the overall prevalence of disability in the United States; however, racial/ethnic and sex disparities continue to persist. Cytomegalovirus (CMV) infection, a socially patterned exposure, may be a key mechanism in understanding these previously documented disparities. Using data from a nationally representative study, the 2016 Health and Retirement Study, we employed Poisson log-binomial models to estimate the prevalence of disability in a comparison of CMV-seropositive and -seronegative adults and investigated effect modification by race/ethnicity and sex. Among the 9,029 participants (55% women; mean age = 67.4 years), 63% were CMV-seropositive and 15% were disabled. CMV seropositivity was highest among non-Hispanic Black (88%) and Hispanic (92%) adults as compared with non-Hispanic White adults (57%). We found evidence for effect modification in the association between CMV and disability by sex but not race/ethnicity. While the 95% confidence intervals in the fully adjusted models included the null value, in comparison with seronegative women, our results suggest a greater prevalence of disability among CMV-seropositive women (prevalence ratio = 1.16, 95% confidence interval: 0.97, 1.38) but not among men (prevalence ratio = 0.85, 95% confidence interval: 0.69, 1.06). Results provide initial support for the hypothesis that CMV may be an important determinant of sex disparities in disability.
Cardiac risk stratification in emergency resection for colonic tumours
Authors: Bass G A , Forssten M , Pourlotfi A , Ahl Hulme R , Cao Y , Matthiessen P , Mohseni S 
Published: May 2021

Abstract

Background
Despite advances in perioperative care, the postoperative mortality rate after emergency oncological colonic resection remains high. Risk stratification may allow targeted perioperative optimization and cardiac risk stratification. This study aimed to test the hypothesis that the Revised Cardiac Risk Index (RCRI), a user-friendly tool, could identify patients who would benefit most from perioperative cardiac risk mitigation.

Methods
Patients who underwent emergency resection for colonic cancer from 2007 to 2017 and registered in the Swedish Colorectal Cancer Registry (SCRCR) were analysed retrospectively. These patients were cross-referenced by social security number to the Swedish National Board of Health and Welfare data set, a government registry of mortality, and co-morbidity data. RCRI scores were calculated for each patient and correlated with 90-day postoperative mortality risk, using Poisson regression with robust error of variance.

Results
Some 5703 patients met the study inclusion criteria. A linear increase in crude 90-day postoperative mortality was detected with increasing RCRI score (37.3 versus 11.3 per cent for RCRI 4 or more versus RCRI 1; P &lt; 0.001). The adjusted 90-day all-cause mortality risk was also significantly increased (RCRI 4 or more versus RCRI 1: adjusted incidence rate ratio 2.07, 95 per cent c.i. 1.49 to 2.89; P &lt; 0.001).

Conclusion
This study documented an association between increasing cardiac risk and 90-day postoperative mortality. Those undergoing emergency colorectal surgery for cancer with a raised RCRI score should be considered high-risk patients who would most likely benefit from enhanced postoperative monitoring and critical care expertise.