bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simplified empirical model to estimate oxygen relaxivity at different magnetic fields
Authors: Bluemke Emma , Stride Eleanor , Bulte Daniel Peter 
Published: October 2021

The change in longitudinal relaxation rate (R1) produced by oxygen has been used as a means of inferring oxygenation levels in magnetic resonance imaging in numerous applications. The relationship between oxygen partial pressure (pO2) and R1 is linear and reproducible, and the slope represents the relaxivity of oxygen (r1Ox) in that material. However, there is considerable variability in the values of r1Ox reported, and they have been shown to vary by field strength and temperature. Therefore, we have compiled 28 reported empirical values of the relaxivity of oxygen as a resource for researchers. Furthermore, we provide an empirical model for estimating the relaxivity of oxygen in water, saline, plasma, and vitreous fluids, accounting for magnetic field strength and temperature. The model agrees well (R2 = 0.93) with the data gathered from the literature for fields ranging from 0.011 to 8.45 T and temperatures of 21‐40 °C. This provides a useful resource for researchers seeking to quantify pO2 in simple fluids in their studies, such as water and saline phantoms, or bodily fluids such as vitreous fluids, cerebrospinal fluids, and amniotic fluids.
Study of dynamic compressive responses of ultra‐high molecular weight polyethylene felt impregnated with shear thickening fluid
Authors: Nayak Prajesh , Ghosh Anup K. , Bhatnagar Naresh 
Published: October 2021

AbstractIn this study, the effect of high strain rate on the dynamic mechanical properties of shear thickening fluid (STF) impregnated felt of ultra‐high molecular weight polyethylene (UHMWPE) was investigated by split‐hopkinson pressure bar. UHMWPE felts are randomly oriented nonwoven fabric that holds each other due to inter‐fiber coupling either by thermal calendaring or mechanical entanglement. Its lower areal density and highly porous structure can be utilized in lightweight ballistic resistance material. The junction points inside its porous structure make it easier to hold abundant STF. Shear thickening fluid was prepared by dispersing 100 nm dry silica powder into polypropylene glycol at 67.5 wt% concentration using probe ultrasonicator at 25°C. Rheological characterization of prepared STF was conducted using MCR702 advanced Anton Paar rheometer. It was done by performing a steady shear rate and thixotropy tests for shear thickening and structural regeneration behavior. In‐house fabricated split‐hopkinson pressure bar setup was used to evaluate dynamic compressive behavior at different strain rates by changing triggering pressure. It was found that STF impregnated felt shows a higher amplitude of strain rate augmentation and energy absorption than a neat felt. The impact energy absorption increases with increasing strain rate. However, the peak stress shows an opposite trend with an increased strain rate in STF impregnated felt.
Differences in the dynamics of the tandem‐SH2 modules of the Syk and ZAP‐70 tyrosine kinases
Authors: Hobbs Helen T. , Shah Neel H. , Badroos Jean M. , Gee Christine L. , Marqusee Susan , Kuriyan John 
Published: October 2021

AbstractThe catalytic activity of Syk‐family tyrosine kinases is regulated by a tandem Src homology 2 module (tSH2 module). In the autoinhibited state, this module adopts a conformation that stabilizes an inactive conformation of the kinase domain. The binding of the tSH2 module to phosphorylated immunoreceptor tyrosine‐based activation motifs necessitates a conformational change, thereby relieving kinase inhibition and promoting activation. We determined the crystal structure of the isolated tSH2 module of Syk and find, in contrast to ZAP‐70, that its conformation more closely resembles that of the peptide‐bound state, rather than the autoinhibited state. Hydrogen–deuterium exchange by mass spectrometry, as well as molecular dynamics simulations, reveal that the dynamics of the tSH2 modules of Syk and ZAP‐70 differ, with most of these differences occurring in the C‐terminal SH2 domain. Our data suggest that the conformational landscapes of the tSH2 modules in Syk and ZAP‐70 have been tuned differently, such that the autoinhibited conformation of the Syk tSH2 module is less stable. This feature of Syk likely contributes to its ability to more readily escape autoinhibition when compared to ZAP‐70, consistent with tighter control of downstream signaling pathways in T cells.
PDB‐101: Educational resources supporting molecular explorations through biology and medicine
Authors: Zardecki Christine , Dutta Shuchismita , Goodsell David S. , Lowe Robert , Voigt Maria , Burley Stephen K. 
Published: October 2021

AbstractThe Protein Data Bank (PDB) archive is a rich source of information in the form of atomic‐level three‐dimensional (3D) structures of biomolecules experimentally determined using macromolecular crystallography, nuclear magnetic resonance (NMR) spectroscopy, and electron microscopy (3DEM). Originally established in 1971 as a resource for protein crystallographers to freely exchange data, today PDB data drive research and education across scientific disciplines. In 2011, the online portal PDB‐101 was launched to support teachers, students, and the general public in PDB archive exploration (pdb101.rcsb.org). Maintained by the Research Collaboratory for Structural Bioinformatics PDB, PDB‐101 aims to help train the next generation of PDB users and to promote the overall importance of structural biology and protein science to nonexperts. Regularly published features include the highly popularMolecule of the Monthseries, 3D model activities, molecular animation videos, and educational curricula. Materials are organized into various categories (Health and Disease, Molecules of Life, Biotech and Nanotech, and Structures and Structure Determination) and searchable by keyword. A biennial health focus frames new resource creation and provides topics for annual video challenges for high school students. Web analytics document that PDB‐101 materials relating to fundamental topics (e.g., hemoglobin, catalase) are highly accessed year‐on‐year. In addition, PDB‐101 materials created in response to topical health matters (e.g., Zika, measles, coronavirus) are well received. PDB‐101 shows how learning about the diverse shapes and functions of PDB structures promotes understanding of all aspects of biology, from the central dogma of biology to health and disease to biological energy.
Determining folding and binding properties of the C‐terminal SH2 domain of SHP2
Authors: Nardella Caterina , Malagrinò Francesca , Pagano Livia , Rinaldo Serena , Gianni Stefano , Toto Angelo 
Published: October 2021

AbstractSH2 domains are a class of protein–protein interaction modules with the function to recognize and bind sequences characterized by the presence of a phosphorylated tyrosine. SHP2 is a protein phosphatase involved in the Ras‐ERK1/2 signaling pathway that possess two SH2 domains, namely, N‐SH2 and C‐SH2, that mediate the interaction of SHP2 with various partners and determine the regulation of its catalytic activity. One of the main interactors of the SH2 domains of SHP2 is Gab2, a scaffolding protein with critical role in determining cell differentiation. Despite their key biological role and the importance of a correct native fold to ensure it, the mechanism of binding of SH2 domains with their ligands and the determinants of their stability have been poorly characterized. In this article, we present a comprehensive kinetic study of the folding of the C‐SH2 domain and the binding mechanism with a peptide mimicking a region of Gab2. Our data, obtained at different pH and ionic strength conditions and supported by site‐directed mutagenesis, highlight the role of electrostatic interactions in the early events of recognition. Interestingly, our results suggest a key role of a highly conserved histidine residue among SH2 family in the interaction with negative charges carried by the phosphotyrosine of Gab2. Moreover, the analysis of the equilibrium and kinetic folding data of C‐SH2 describes a complex mechanism implying a change in rate‐limiting step at high denaturant concentrations. Our data are discussed under the light of previous works on N‐SH2 domain of SHP2 and other SH2 domains.
Guidelines for radiotherapy of nasopharyngeal carcinoma
Authors: Wang Rensheng , Kang Min 
Published: October 2021

AbstractWith the extensive application of intensity‐modulated conformal radiotherapy and the deepening of the concept of comprehensive treatment, the therapeutic effect of nasopharyngeal carcinoma and the quality of life of patients have been significantly improved. However, guidelines for radiotherapy of nasopharyngeal carcinoma in China are in short supply. Dozens of experts from the Radiation Oncology Physicians Branch of the Chinese Medical Doctor Association and the Radiation Oncology Branch of the Chinese Medical Association have developed the publication Guidelines for radiotherapy of nasopharyngeal carcinoma in China after discussion. The guidelines include the epidemiology, diagnosis, clinical stage, treatment principle, and treatment of complications of radiotherapy of nasopharyngeal carcinoma. Importantly, the procedure of radiotherapy for nasopharyngeal carcinoma has been developed, which covers the imaging of nasopharyngeal carcinoma, radiotherapy localization, target area delineation, dose limitation, and plan evaluation. The guidelines will help to realize the homogenization of the diagnosis and treatment of nasopharyngeal carcinoma among radiotherapeutic medical staff in different levels of hospitals in China, thereby improving the overall level of diagnosis and treatment of nasopharyngeal carcinoma in China.
Molecular insights into the differential efflux mechanism of Rv1634 protein, a multidrug transporter of major facilitator superfamily in Mycobacterium tuberculosis
Authors: Singh Garima , Akhter Yusuf 
Published: October 2021

AbstractCurrently, multidrug‐resistant tuberculosis (MDR‐TB) is a public health crisis and a major health security threat globally. In Mycobacterium tuberculosis (Mtb), major facilitator superfamily (MFS) is the largest group of secondary active transporters. Along with the transport of their natural substrates, MFS proteins were involved in a drug efflux mechanism that ultimately lead to resistance against available anti‐TB drugs in Mtb. In the present study, the three‐dimensional structure model of an MFS protein, Rv1634, a probable multidrug transporter from Mtb, was generated using homology modeling. The protein structure model was found in inward‐open conformation having 14 transmembrane helices. In addition, a central transport channel was deduced across the protein, and a single binding pocket was identified halfway through the central cavity by structural alignment with the homologous protein structures. Further, Rv1634 protein was studied based on the differential structural behavior of apo and ligand‐bound forms. All the protein systems were inserted into a phospholipid bilayer to characterize the conformational dynamics of the protein using molecular dynamics (MD) simulations. Detailed analysis of the MD trajectories showed the diverse substrate specificity of the binding pocket for the antibiotics that caused differential movement in the ciprofloxacin and norfloxacin, to which Mtb strains have now become resistant. The expulsion of the drugs outside the bacterial cell occurs through the alternating‐access mechanism of N and C‐terminal domains, which is intriguing and essential to the understanding the drug resistance mechanism in pathogenic bacteria.
Gas chromatography–mass spectrometry of eight aminoindanes: 2‐Aminoindane, N‐methyl‐2‐, 5‐methoxy‐, 5‐methoxy‐6‐methyl‐, 4,5‐methylenedioxy‐, 5,6‐methylenedioxy‐ and 5‐iodo‐2‐aminoindane, and rasagiline
Authors: Rose Amber R. , Staretz Marianne E. , Joshi Monica , Wood Matthew , Brettell Thomas A. 
Published: October 2021

RationaleAminoindanes are one class of many new psychoactive substances that have emerged over the last decade. Analogues of 2‐aminoindane (2‐AI) are being encountered in crime laboratories and analytical data for most aminoindanes are limited. Interpretation and optimization of gas chromatography–mass spectrometry data will enhance reliability in characterizing aminoindanes.MethodsThis study focuses on the electron ionization mass spectrometric fragmentation of eight aminoindane analogues and the gas chromatographic separation of these eight aminoindane analogues using four different column stationary phases, Rxi®‐1Sil MS, Rxi®‐5Sil MS, Rxi®‐35Sil MS, and Rxi®‐624Sil MS. Split injection (25:1) was utilized and each column had the same configuration (30 m × 25 mm × 0.25 μm), with the exception of the Rxi®‐624Sil MS column (30 m × 25 mm ×1.4 μm).ResultsMass spectra showed strong molecular ions for all aminoindanes, except for rasagiline that produced a uniquely abundant [M − 1] ion. Other characteristic fragmentation that was present for all the aminoindanes included indane and indene ions (m/z 115–117), the tropylium ion (m/z 91), and subsequent loss of diene to produce smaller ions that followed: phenyl (m/z 77), cyclopentadienyl (m/z 65), cyclobutadienyl (m/z 51), and cyclopropenyl (m/z 39).ConclusionsSeparation of eight aminoindanes was optimized, and linear retention indices were determined for the compounds on four capillary columns. Based on the retention data, all eight aminoindanes were resolved on an Rxi®‐624Sil MS column. Each aminoindane exhibited unique fragmentation ions in the mass spectra to distinguish between similar analogues. The results of this study will strengthen the analytical profiles of 2‐AI and seven analogues, assisting forensic scientists in their analysis and identification of these substances.
Practical stability for switched affine systems via time‐dependent switching function
Authors: Xu Xiaozeng , Li Yang , Zhang Hongbin , Chen Wei , Zheng Qunxian 
Published: October 2021

AbstractIn this article, the stability analysis of both continuous‐time switched affine systems discrete‐time switched affine systems is addressed via dwell time switching. Since the information of system states is difficult to obtain in the state‐dependent switching function, the time‐dependent switching function is considered to stabilize the switched affine system. The purpose of this article is to design a time‐dependent switching function assuring the state trajectories are globally attracted to an attractive set containing the desired equilibrium point (which is selected from a set of attainable equilibrium points). By constructing discretized Lyapunov function, a set of conditions in the framework of dwell time are designed to guarantee practical stability of the state trajectories. At last, some numerical examples are given to illustrate our method and compare it with the existing results.
Treatment of acute erythroleukaemia with high‐dose cytarabine in a cat with feline leukaemia virus infection
Authors: Park Da Sol , Lee Jongbok , Song Kun‐Ho , Seo Kyoung Won 
Published: October 2021

AbstractErythroleukaemia is a malignant neoplasm of the erythroid lineage that rarely occurs in cats. It is associated with the feline leukaemia virus (FeLV), and owing to the poor prognosis, treatment is rarely reported. A 4‐year‐old female Korean domestic shorthair cat was presented with hyporexia, fever, lethargy, severe anaemia and rubricytosis. An FeLV antigen test was positive, but a subsequent polymerase chain reaction test was negative. Serum biochemistry analysis results were normal, except for slightly elevated alanine aminotransferase. The patient was tentatively diagnosed with acute erythroleukaemia, and single high‐dose (600 mg/m2) cytarabine chemotherapy was administered via constant rate infusion for 12 h a day for 5 days. After the first cytarabine administration, the clinical signs and anaemia improved, though no change was noted to other haematological parameters. The patient died of shock 16 days after the second cytarabine administration; the total survival time after diagnosis was 67 days. Post‐mortem cytological evaluation of bone marrow aspiration revealed that the myeloid/erythroid ratio was 0.49, the erythroid progenitor cells were 64% of all nucleated cells and the blast cells were 84% of the non‐erythroid cells. Histopathology images indicated that the spleen was diffusely expanded by atypical round cells, possibly erythroid precursors. This is the first case report on the prognosis and effects of high‐dose cytarabine chemotherapy for acute feline erythroleukaemia with FeLV infection. Although the clinical signs improved, the treatment was not effective. Further studies on erythroleukaemia chemotherapy protocols are required.
Antimicrobial resistance profiling and burden of resistance genes in zoonotic Salmonella isolated from broiler chicken
Authors: Das Tridip , Rana Eaftekhar Ahmed , Dutta Avijit , Bostami Md. Bayazid , Rahman Mizanur , Deb Probir , Nath Chandan , Barua Himel , Biswas Paritosh Kumar 
Published: October 2021

AbstractBackgroundSalmonella is frequently found in poultry of which only motile serovars have zoonotic significance due to their potential to induce human gastrointestinal infections. Antimicrobial resistance, being a public health concern, the emergence of multidrug‐resistant (MDR) Salmonella serotypes affecting food chain has greater impact worldwide.AimInformation on circulation of zoonotic Salmonella strains in commercial poultry farm level is limited in many parts of the world. This cross‐sectional study was aimed to investigate the zoonotic Salmonella strains circulating in the broiler farm environment with their detailed antimicrobial resistance profiling.MethodsPooled faecal samples were collected randomly from commercial broiler farms of Chattogram district, Bangladesh. Standard bacteriological procedure was followed to isolate Salmonella, and identification was confirmed by genus specific polymerase chain reaction (PCR). After phenotypic characterisation of resistance profile against eight antimicrobials by disc diffusion technique, all strains were screened by PCR for some selected resistance genes.ResultsOut of the 350 samples, Salmonella was isolated and identified from 86 samples. In antimicrobial sensitivity testing, more than 98.8% isolates showed resistance to ampicillin and 94.2% to tetracycline followed by enrofloxacin (56%) and ciprofloxacin (50%). Notably, 94% isolates were found to be MDR. The results of PCR assays revealed that 81.4% of the isolates were carrying the tetA gene, 19.8% the tetB and 10.47% the tetC gene. The prevalence of the isolates bearing the blaTEM, blaCTX‐M and Sul‐I gene were 95.4%, 7.0 % and 37.2 %, respectively.ConclusionThere is a great risk to secure healthy poultry products due to the circulation of these MDR zoonotic Salmonella
Academic Continuity During the Covid-19 Global Health Emergency: Education 4.0 and the Flexible-Digital Model of Tecnologico de Monterrey University in Mexico Supporting Secondary Education
Authors: Molina Arturo , Villegas Beatriz , Ochoa César Pavel , Miranda Jhonattan 
Published: October 2021

AbstractToday, new teaching-learning models, methods, and programs are emerging to guarantee academic continuity in response to the current situation caused by the global health emergency (Covid-19). This work presents how the Flexible-Digital Model of Tecnologico de Monterrey University in Mexico was designed and implemented during this emergency in this institution. This work also addresses the relevant role that technology has taken during this situation, and the concept of Education 4.0 is offered as a framework to model the presented study. Finally, two case studies that were applied at the secondary education level are presented as an example of how higher education is supporting academic continuity at the secondary level.
Supporting Elementary and Secondary Education During the Pandemic: A Case Study from the National Research University Higher School of Economics
Authors: Sergey Kosaretsky , Elena Likhatskikh 
Published: October 2021

AbstractThe COVID-19 pandemic has presented a formidable challenge to the Russian school system. Such global challenges and crises highlight the significance of the National Research University Higher School of Economics (HSE)’s third mission: responsibility for the well-being of the community.As one of the first universities to offer support to elementary and secondary education systems in Russia during the pandemic, the HSE relied on its ability to create new scientific knowledge and make it useful in practice to provide versatile and targeted aid for students, teachers, regional administrators, and parents across the country. There were two main vectors of HSE activity at the time of the pandemic: (1) promoting the development of the Russian education system through research, monitoring, and coordination of scholars and analysts and (2) direct work with secondary and high school stakeholders using contemporary approaches for talent development and digital tools.The pandemic revealed the importance of developing new areas of research and analysis. In line with the first vector, the HSE focused on:

Monitoring and studying the situation and collecting and promoting university and school case studies on organizing work during a pandemic

Leading and participating in professional reflections and discussions regarding experiences and training practices in the context of a lockdown

The institution organized an array of surveys with students, teachers, parents, and representatives from regional and municipal education organizations and analyzed the results as quickly as possible. The main areas of research were problems of educational inequality and digital transformation. Based on the collected data, the Institute of Education managed to publish more than 30 analytical works between April and June of 2020.For the second vector, the HSE developed programs that seek to expand its geographic reach, implement flexible recruitment, and digitize communication with school students. Such programs aimed at:

Training personnel while consulting with administrators and educators on the technological and legal aspects of the work of schools.

Providing online instruction and assistance for students learning software tools and preparing for exams.

Helping parents arrange support for children in the transition to distance learning.

For this period, the HSE quickly and effectively expanded cooperation with schools in Moscow and regions around Russia that the institution developed over the last 15 years. Key current projects working in this direction are:

The HSE School District

The Lyceum Distributed Schools

The Higher Students Academy

The Higher School for Parents
Initiatives to Promote School-Based Mental Health Support by Department of Educational Sciences, University of Education Under Vietnam National University
Authors: Hanh Hoang Phuong , Nam Tran Thanh , Vinh Le Anh 
Published: October 2021

AbstractThis chapter describes a case study of the university’s attempts to support general education institutions through the COVID-19 pandemic crisis. Applying the School-Based Mental Health Collaboration, faculties from the University of Education, Vietnam National University Hanoi took a whole-school approach to promote mental health services for students all over the country via various channels. With multiple training webinars on studying and coping skills during social distancing periods for students, classroom consultation skills for teachers, initiatives from the university attracted remarkable responses from the community. Suggestions to improve the effectiveness and sustainability of the efforts, including digitalization consideration, targeting and effective mobilization of resources, dissemination of learning materials, and long-term planning, are discussed in the last half of the chapter, after reviewing and evaluating their impact and potential.