bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ability self‐concepts and parental support may protect adolescents when they experience low support from their math teachers
Authors: Lee Glona , Simpkins Sandra D. 
Published: February 2021

ABSTRACTIntroductionExperiencing low support from teachers can be associated with low academic achievement. Nonetheless, individual‐ (i.e., ability self‐concepts) and contextual‐level (i.e., parental support) protective factors may help adolescents to display academic resilience. This study examined whether high school students’ math ability self‐concepts and parental support can mitigate the possible negative association between perceived low math teacher support and their math achievement.MethodCorrelational data were drawn from the High School Longitudinal Study (N = 14,580, Mage = 17.42 in 11th grade, 51% female), a nationally representative study of high school students in the U.S. The measures of protective factors (i.e., math ability self‐concepts and parental support) were obtained from the surveys administered to students and parents in 9th grade. Students’ perceived teacher support and their math achievement score were measured in 11th grade. A series of linear regression analyses were estimated to test our hypotheses.Results & ConclusionsPerceived low teacher support was negatively associated with adolescents’ math achievement. Adolescents’ math ability self‐concepts were directly and positively associated with their math achievement. The interaction between perceived low teacher support and ability self‐concepts in predicting adolescents’ achievement varied by parental support. The association between perceived low teacher support and adolescents’ math achievement was not statistically significant when adolescents were high on one of the protective factors. That is, high parental support may be protective for adolescents with low math ability self‐concepts. This study highlights the interaction between adolescents’ academic motivation and parental support in demonstrating resilience to perceived low teacher support.
Computational Screening of Phase-Separating Proteins
Authors: Shen Boyan , Chen Zhaoming , Yu Chunyu , Chen Taoyu , Shi Minglei , Li Tingting 
Published: February 2021

AbstractPhase separation is an important mechanism that mediates the compartmentalization of proteins in cells. Proteins that can undergo phase separation in cells share certain typical sequence features, like intrinsically disordered regions (IDRs) and multiple modular domains. Sequence-based analysis tools are commonly used in the screening of these proteins. However, current phase separation predictors are mostly designed for IDR-containing proteins, thus inevitably overlook the phase-separating proteins with relatively low IDR content. Features other than amino acid sequence could provide crucial information for identifying possible phase-separating proteins: protein–protein interaction (PPI) networks show multivalent interactions that underlie phase separation process; post-translational modifications (PTMs) are crucial in the regulation of phase separation behavior; spherical structures revealed in immunofluorescence (IF)images indicate condensed droplets formed by phase-separating proteins, distinguishing these proteins from non-phase-separating proteins. Here, we summarize the sequence-based tools for predicting phase-separating proteins and highlight the importance of incorporating PPIs, PTMs, and IF images into phase separation prediction in future studies.
Neurological complications in children with infective endocarditis
Authors: AlBassri Tala , Sheikho Maha , Chaikhouni Farah , Al Habshan Fahad , Kabbani Mohamed S. 
Published: February 2021

Background and Objective:
Despite improvement in medical management, infective endocarditis (IE) remains a serious disease that may affect children with and without preexisting cardiac conditions with significant morbidity and mortality. Neurological complications of IE represent the worst with guarded prognosis. The aim of this study is to describe the incidence, etiology, characteristics, risk factors, and outcome of children with neurological complications associated with IE.

Material and methods:
A retrospective cohort study was conducted from 2009 to 2019 where all pediatric patients who fulfilled the modified Duke criteria for IE were included. We divided the cases into 2 groups: IE with neurological complications and IE without neurological complications control group. We compared the two groups statistically and analyzed the results.

Results:
We identified 31 (17 male, 14 female) patients with IE. Neurological complications occurred in 7/31 (23%) patients, mainly in the form of a stroke. Gram-positive microbes were the main causative agents for IE (52%) followed by gram-negative (14%), then fungal organisms (3%). Univariate analysis identified the following risk factors for neurological complications: lower body weight, higher C- reactive protein (CRP) level, and left-sided valvular lesions with P values of (0.0003, 0.0001, and 0.04), respectively.
Although mortality was higher in the neurological complications group, it was 43% in comparison to 21% in the control group and it did not reach statistical significance (P = .49). Large vegetation size (more than 10 mm) was seen in 57% of patients with neurological complications as compared to 16% in the control group (P = .052).

Conclusion:
Neurological complications occurred in almost a quarter of children with IE. Possible risk factors include lower body weight, left-sided valvular lesion, and higher levels of inflammatory markers (CRP). Stroke was the most common neurological complication encountered with possible increased risk of mortality.
Usability of fluorescence angiography with indocyanine green in the surgical management of penetrating abdominal trauma: A case series
Authors: Osterkamp Jens T.F. , Patel Mohamed Q. , Steyn Elmin , Svendsen Lars-Bo , Forgan Tim , Achiam Michael P. 
Published: February 2021

ABSTRACT

Background:
The surgical management of penetrating abdominal trauma can be challenging, and despite improvements in diagnostics and treatment, mortality and morbidity rates remain high. Intraoperative fluorescence angiography with indocyanine green (ICG-FA) is currently implemented in many elective surgical settings. However, there are few data regarding the usability of ICG-FA in emergency surgery, and to our knowledge, ICG-FA has not been evaluated in penetrating abdominal trauma. Hence, our objective was to determine the feasibility and usability of ICG-FA in surgical management of penetrating abdominal trauma.

Materials and methods:
A total of 20 patients undergoing emergency laparotomy for penetrating abdominal trauma were included. The usability of ICG-FA was evaluated using the System Usability Scale (SUS®). The intraoperative macroscopic assessment was compared with that using ICG-FA, and any influence of ICG-FA on surgical management was documented.

Results:
The ICG-FA was completed in all cases and rendered a “good” median SUS® score of 68.8 (interquartile range, 60.6–82.5) by first-time users. The use of ICG-FA influenced surgical management in 14 cases (70%). In six of those cases, ICG-FA significantly changed surgical management. There were no postoperative complications related to surgical management.

Conclusion:
ICG-FA proved useable and relevant in the setting of penetrating abdominal trauma. Although this was only a small case series, the study showed that ICG-FA could substantially influence surgical management of penetrating abdominal trauma, adding considerable patient benefit.

Highlights
Local anesthetic added to spinal anesthesia; does it stabilize stress hormones after inguinal herniorrhaphy? A randomised controlled trial
Authors: Ghafoor Leila , Razavizadeh Mohammad Reza , Hajian Abbas 
Published: February 2021

ABSTRACT

Background:
Elective inguinal hernia repair is a common minor surgery. Early postoperative mobilization without inflammatory related complication is desired.

Methods:
In this randomized controlled trial study 48 adult males were enrolled who experienced elective inguinal hernia repair under spinal anesthesia. Subjects were categorized in 2 groups with equal 24 members in each including patients received local anesthetic (2 mg kg−1 of bupivacaine 0.5%) in addition to spinal anesthesia and controlled who had spinal anesthetic with local placebo injection. Plasma cortisol and prolactin concentration were obtained 1 h before and 3 h after operation. To evaluate severity of postoperative pain the visual analogue scale(VAS) was applied. We also measured the total dosage of analgesic requirement among patients.

Results:
Data showed that spinal anesthesia alone was followed by increasing plasma concentration of either cortisol or prolactin postoperatively (P < 0.01). Findings according to investigate severity of pain implied on that local anesthesia could make more postoperative comfort for patients with inguinal herniorrhaphy(P < 0.001). Therefore, analgesic requirement in patients who were equipped by additional local anesthesia also decreased(P < 0.001).

Conclusions:
We concluded that adding local anesthetic to basic spinal anesthesia during inguinal herniorrhaphy could induce to either lower stress hormones plasma concentration or decrease pain and need for analgesic postoperatively.
Efficacy and safety of systematic corticosteroids among severe COVID-19 patients: a systematic review and meta-analysis of randomized controlled trials
Authors: Ma Shaolei , Xu Changsheng , Liu Shijiang , Sun Xiaodi , Li Renqi , Mao Mingjie , Feng Shanwu , Wang Xian 
Published: February 2021

AbstractThe benefits and harms of corticosteroids for patients with severe coronavirus disease 2019 (COVID-19) remain unclear. We systematically searched PubMed, Embase, and Cochrane Central Register of Controlled Trials from December 31, 2019 to October 1, 2020 to identify randomized controlled trials (RCTs) that evaluated corticosteroids in severe COVID-19 patients. The primary outcome was all-cause mortality at the longest follow-up. Secondary outcomes included a composite disease progression (progression to intubation, ventilation, extracorporeal membrane oxygenation, ICU transfer, or death among those not ventilated at enrollment) and incidence of serious adverse events. A random-effects model was applied to calculate risk ratio (RR) with 95% confidence intervals (CIs). We used the Grading of Recommendations Assessment, Development, and Evaluation approach to evaluate the certainty of the evidence. Seven RCTs involving 6250 patients were included, of which the Randomized Evaluation of COVID-19 Therapy (RECOVERY) trial comprised nearly 78% of all included subjects. Results showed that corticosteroids were associated with a decreased all-cause mortality (27.3 vs. 31.1%; RR: 0.85; 95% CI: 0.73–0.99;P = 0.04; low-certainty evidence). Trial sequential analysis suggested that more trials were still required to confirm the results. However, such survival benefit was absent if RECOVERY trial was excluded (RR: 0.83; 95% CI: 0.65–1.06;P = 0.13). Furthermore, corticosteroids decreased the occurrence of composite disease progression (30.6 vs. 33.3%; RR: 0.77; 95% CI: 0.64–0.92;P = 0.005), but not increased the incidence of serious adverse events (3.5 vs. 3.4%; RR: 1.16; 95% CI: 0.39–3.43;P = 0.79).
Gulf of Mexico blue hole harbors high levels of novel microbial lineages
Authors: Patin N V , Dietrich Z A , Stancil A , Quinan M , Beckler J S , Hall E R , Culter J , Smith C G , Taillefert M , Stewart F J 
Published: February 2021

Abstract
Exploration of oxygen-depleted marine environments has consistently revealed novel microbial taxa and metabolic capabilities that expand our understanding of microbial evolution and ecology. Marine blue holes are shallow karst formations characterized by low oxygen and high organic matter content. They are logistically challenging to sample, and thus our understanding of their biogeochemistry and microbial ecology is limited. We present a metagenomic and geochemical characterization of Amberjack Hole on the Florida continental shelf (Gulf of Mexico). Dissolved oxygen became depleted at the hole’s rim (32 m water depth), remained low but detectable in an intermediate hypoxic zone (40–75 m), and then increased to a secondary peak before falling below detection in the bottom layer (80–110 m), concomitant with increases in nutrients, dissolved iron, and a series of sequentially more reduced sulfur species. Microbial communities in the bottom layer contained heretofore undocumented levels of the recently discovered phylum Woesearchaeota (up to 58% of the community), along with lineages in the bacterial Candidate Phyla Radiation (CPR). Thirty-one high-quality metagenome-assembled genomes (MAGs) showed extensive biochemical capabilities for sulfur and nitrogen cycling, as well as for resisting and respiring arsenic. One uncharacterized gene associated with a CPR lineage differentiated hypoxic from anoxic zone communities. Overall, microbial communities and geochemical profiles were stable across two sampling dates in the spring and fall of 2019. The blue hole habitat is a natural marine laboratory that provides opportunities for sampling taxa with under-characterized but potentially important roles in redox-stratified microbial processes.
Integrating single-molecule FRET and biomolecular simulations to study diverse interactions between nucleic acids and proteins
Authors: Sanders Joshua C. , Holmstrom Erik D. 
Published: February 2021

AbstractThe conformations of biological macromolecules are intimately related to their cellular functions. Conveniently, the well-characterized dipole–dipole distance-dependence of Förster resonance energy transfer (FRET) makes it possible to measure and monitor the nanoscale spatial dimensions of these conformations using fluorescence spectroscopy. For this reason, FRET is often used in conjunction with single-molecule detection to study a wide range of conformationally dynamic biochemical processes. Written for those not yet familiar with the subject, this review aims to introduce biochemists to the methodology associated with single-molecule FRET, with a particular emphasis on how it can be combined with biomolecular simulations to study diverse interactions between nucleic acids and proteins. In the first section, we highlight several conceptual and practical considerations related to this integrative approach. In the second section, we review a few recent research efforts wherein various combinations of single-molecule FRET and biomolecular simulations were used to study the structural and dynamic properties of biochemical systems involving different types of nucleic acids (e.g., DNA and RNA) and proteins (e.g., folded and disordered).
Digital system for frequency regulation and stabilisation of a four-frequency Zeeman laser gyroscope
Authors: Varenik A.I. , Gorshkov V.N. , Grushin M.E. , Ivanov M.A. , Kolbas Yu.Yu. , Savelyev I.I. 
Published: February 2021

Abstract
We report the results of theoretical and experimental studies of a digital system for regulating and stabilising the frequency of a four-frequency Zeeman laser gyroscope (ZLG), in which generation occurs simultaneously on two longitudinal modes with orthogonal circular polarisations; therefore, four light waves propagate in the optical ring resonator. In contrast to a two-frequency Zeeman laser gyroscope, a four-frequency ZLG does not use the intensity modulation signal of one of the light waves, which appears when an alternating magnetic field is applied to the active medium, to analyse the frequency detuning of longitudinal modes from the centre of the active-medium gain contour. At the same time, it is possible to construct a digital perimeter adjustment system (PAS), which allows the resonator perimeter to be adjusted so that the magnetic components of the zero drift of the gyroscope for two longitudinal generation modes are equal and opposite in sign. Due to this, almost complete compensation for the magnetic component of the zero drift of the gyroscope is realised in a four-frequency ZLG. The use of the digital system makes it possible to provide a higher accuracy of the resonator perimeter adjustment than that in a two-frequency ZLG, even with a relatively small bit capacity of the PAS digital-to-analogue conversion (DAC), and to fully take advantage of the capabilities of a four-frequency ZLG to reduce the magnetic sensitivity.
Optoelectronic reference X-band oscillator for radar systems
Authors: Chizh A.L. , Mikitchuk K.B. , Skotorenko I.V. 
Published: February 2021

Abstract
We present the design and results of studying the characteristics of an optoelectronic microwave oscillator in the free-running regime are presented, propose a method for synchronising it with a signal of a highly stable crystal oscillator using a phase-locked loop, and analyse the results of an experimental study on the frequency instability of an optoelectronic microwave reference oscillator. The optoelectronic microwave reference oscillator with optical gain and a 10 GHz oscillation frequency simultaneously provides ultra-low phase noise (less than – 142 dB Hz−1) at a 10 kHz frequency offset from the microwave carrier and a low level of spurs in the oscillation spectrum (no more than – 94 dBc). In this case, the temperature coefficient of the oscillation frequency is determined by the temperature instability of a highly stable crystal oscillator.
Noise conversion in delay-line optoelectronic microwave oscillators
Authors: Chizh A.L. , Mikitchuk K.B. 
Published: February 2021

Abstract
We report the results of theoretical and experimental studies of noise in a delay-line optoelectronic microwave oscillator with optical gain. The effect of various noise sources on the parameters of an optoelectronic microwave oscillator is considered, and, in addition to the noise of its individual components, several linear and nonlinear mechanisms for converting optical carrier noise into microwave signal noise are taken into account. It is shown that, due to the nonlinearity of the energy characteristics of high-power microwave photodiodes in an optoelectronic generator, the low-frequency components of the laser relative intensity noise are converted into microwave signal noise, as a result of which sources of correlated amplitude and phase noise appear in the oscillator loop.
Spontaneous and stimulated emission of thin-film polymer structures in the presence of nitrotoluene vapour
Authors: Berdybaeva Sh.T. , Tel’minov E.N. , Solodova T.A. , Nikonova E.N. , Samsonova L.G. , Kopylova T.N. 
Published: February 2021

Abstract
The features of spontaneous and stimulated emission of polyfluorenes, polyvinylcarbazole, and low-molecular-weight electron-donor compounds incorporated into various materials are studied in the presence of nitrotoluene vapour. Lasing in planar thin-film waveguides is achieved. The dynamics of the lasing spectra of a thin-film optical chemical sensor is presented. It is shown that the response time of the sensor in the lasing regime is 30 s before the lasing intensity decreases by 50% from the initial level.
Nonlinear optical absorption in thin halide perovskite films under femtosecond excitation at wavelengths of 1064 and 532 nm
Authors: Khudyakov D.V. , Ganin D.V. , Lyashedko A.D. , Frolova L.A. , Troshin P.A. , Lobach A.S. 
Published: February 2021

Abstract
The nonlinear optical responses of perovskite films CsPbI2Br, MAPbI3 + 1% PVC, MA0.15FA0.75Cs0.1PbI2.85Br0.15, and MA0.15FA0.75Cs0.1PbI3, irradiated by femtosecond laser pulses with wavelengths of 1064 and 532 nm, are investigated using z-scan measurements. Nonlinear absorption is found to occur in perovskite films irradiated at a wavelength of 1064 nm; the nonlinear absorption coefficient in thin films (45 – 65 nm) greatly exceeds that in thick ones (120 – 350 nm): 524 – 928 and 38 – 50 cm GW−1, respectively. It is shown that the nonlinear absorption saturation intensity for perovskite films depends on the pump pulse duration and increases with pulse shortening. It is also established that the nonlinear absorption coefficient of organometallic perovskite films exceeds that of a film of inorganic perovskite CsPbI2Br. Bleaching of film samples during z-scanning at a wavelength of 532 nm is related to the irreversible photochemical degradation of films exposed to intense light. The kinetics of photochemical bleaching of the films is detected at a wavelength of 532 nm.
Simulation of a two-dimensional laser diode array directly cooled by coolant flow
Authors: Oleshchenko V.A. , Bogatov A.P. , D’yachkov N.V. , Bezotosnyi V.V. 
Published: February 2021

Abstract
We report an analysis of attained output powers of laser diode bars (LDBs) and power densities of two-dimensional laser diode arrays (LDAs). A new LDA design is proposed and its thermal regime is simulated. The cw output power of the proposed LDA consisting of standard cw LDBs (output power 100 W, efficiency 50%, cavity length 2 mm) can reach 5 kW cm−2. The parameters of a coolant flow in the microchannels of the LDA heat sink necessary to achieve such powers are calculated.
SRS of ultrashort laser pulses with nonlinear phase modulation
Authors: Konyashchenko A.V. , Losev L.L. , Pazyuk V.S. 
Published: February 2021

Abstract
The SRS process in the regime of nonlinear phase modulation of laser and Stokes radiation waves is studied experimentally. The effect of the relationship between the laser and Stokes wavelengths on the value of the minimum laser pulse duration, at which an efficient SRS process is possible, is ascertained. The possibility of obtaining maximally broadband Stokes radiation pulses by matching the group velocities of the laser and Stokes pulses is demonstrated.
Atypical symptoms, SARS-CoV-2 test results and immunisation rates in 456 residents from eight nursing homes facing a COVID-19 outbreak
Authors: Blain Hubert , Gamon Lucie , Tuaillon Edouard , Pisoni Amandine , Giacosa Nadia , Albrand Mylène , Miot Stéphanie , Rolland Yves , Picot Marie-Christine , Bousquet Jean 
Published: February 2021

Abstract

Background
Frail older persons may have an atypical presentation of coronavirus disease 2019 (COVID-19). The value of real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) testing for identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nursing homes (NHs) residents is not known.

Objective
To determine whether (i) atypical symptoms may predict rRT-PCR results and (ii) rRT-PCR results may predict immunisation against SARS-CoV-2 in NH residents.

Design
A retrospective longitudinal study.

Setting
Eight NHs with at least 10 rRT-PCR-positive residents.

Subjects
A total of 456 residents.

Methods
Typical and atypical symptoms recorded in residents’ files during the 14 days before and after rRT-PCR testing were analysed. Residents underwent blood testing for IgG-SARS-CoV-2 nucleocapsid protein 6 to 8 weeks after testing. Univariate and multivariate analyses compared symptoms and immunisation rates in rRT-PCR-positive and negative residents.

Results
A total of 161 residents had a positive rRT-PCR (35.3%), 17.4% of whom were asymptomatic before testing. Temperature &gt;37.8°C, oxygen saturation &lt;90%, unexplained anorexia, behavioural change, exhaustion, malaise and falls before testing were independent predictors of a further positive rRT-PCR. Among the rRT-PCR-positive residents, 95.2% developed SARS-CoV-2 antibodies vs 7.6% in the rRT-PCR-negative residents. Among the residents with a negative rRT-PCR, those who developed SARS-CoV-2 antibodies more often had typical or atypical symptoms (P = 0.02 and &lt;0.01, respectively).

Conclusion
This study supports a strategy based on (i) testing residents with typical or unexplained atypical symptoms for an early identification of the first SARS-CoV-2 cases, (ii) rT-PCR testing for identifying COVID-19 residents, (iii) repeated wide-facility testing (including asymptomatic cases) as soon as a resident is tested positive for SARS-CoV-2 and (iv) implementing SARS-CoV-2 infection control measures in rRT-PCR-negative residents when they have unexplained typical or atypical symptoms.