bluuebunny/crossref_metadata_2025 huggingface dataset:
Circular RNA circ_0002984 Promotes Cell Proliferation and Migration by Regulating miR-181b-5p/Vascular Endothelial Growth Factor Axis and PI3K-AKT Signaling Pathway in Oxidized Low-Density Lipoprotein–Treated Vascular Smooth Muscle Cells
Authors: Wang Xichun , Ma Chong , Hou Xiaojun , Zhang Ge , Huang Yueping
Published: December 2021

RNAs (circRNAs) play critical roles in many diseases, including atherosclerosis (AS). However, the role and underlying mechanism of circ_0002984 in AS remain unclear. Vascular smooth muscle cells (VSMCs) treated with oxidized low-density lipoprotein (ox-LDL) were used as a AS cell model. Quantitative real-time polymerase chain reaction was conducted to detect the expression of circ_0002984, miR-181b-5p and vascular endothelial growth factor A (VEGFA). Cell proliferation was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide assay and 5-ethynyl-2′-deoxyuridine assays. Cell migration was assessed using wound healing assay and transwell assay. All protein levels were analyzed by western blot assay. The interaction between miR-181b-5p and circ_0002984 or VEGFA was confirmed by dual-luciferase reporter, RNA Immunoprecipitation, and RNA pull-down assays. Circ_0002984 and VEGFA were overexpressed, and miR-181b-5p was downregulated in serum of AS patients and ox-LDL–stimulated VSMCs. Circ_0002984 silencing inhibited ox-LDL–induced proliferation and migration in VSMCs. MiR-181b-5p was a target of circ_0002984, and miR-181b-5p inhibition counteracted the suppressing effects of circ_0002984 downregulation on proliferation and migration in ox-LDL–stimulated VSMCs. Additionally, VEGFA was a downstream target of miR-181b-5p and VEGFA upregulation abolished the suppressive influence of miR-181b-5p on proliferation and migration in ox-LDL–exposed VSMCs. Furthermore, circ_0002984 depletion blocked phosphatidylinositol 3 kinase-AKT signaling pathway by regulating miR-181b-5p and VEGFA. Circ_0002984 downregulation suppressed cell proliferation and migration by regulating miR-181b-5p/VEGFA axis and phosphatidylinositol 3 kinase-AKT pathway in ox-LDL–stimulated VEGFA, providing a new mechanism for AS pathogenesis.
Predictive Factors for Humoral Response After 2-dose SARS-CoV-2 Vaccine in Solid Organ Transplant Patients
Authors: Marion Olivier , Del Bello Arnaud , Abravanel Florence , Faguer Stanislas , Esposito Laure , Laure Hebral Anne , Bellière Julie , Izopet Jacques , Kamar Nassim
Published: December 2021

Background.

A weak immunogenicity has been reported in solid organ transplant (SOT) recipients after 2 doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. The aim of this retrospective study was to identify the predictive factors for humoral response in SOT patients.

Methods.

Three hundred and ninety-three SOT patients from our center with at least 4 wk of follow-up after 2 doses of mRNA-based vaccine were included in this study. Anti-SARS-Cov-2 spike protein antibodies were assessed before and after vaccination.

Results.

Anti-SARS-CoV-2 antibodies were detected in 34% of the patients: 33.7% of kidney transplant patients, 47.7% of liver transplant patients, and 14.3% of thoracic transplant patients (P = 0.005). Independent predictive factors for humoral response after vaccination were male gender, a longer period between transplantation and vaccination, liver transplant recipients, a higher lymphocyte count at baseline, a higher estimated glomerular filtration rate and receiving the tacrolimus + everolimus ± steroids combination. Conversely, the nondevelopment of anti-SARS-CoV-2 antibodies after vaccination was associated with younger patients, thoracic organ recipients, induction therapy recipients, and tacrolimus + mycophenolic acid ± steroids recipients.

Conclusions.

The immunosuppressive regimen is a modifiable predictive factor for humoral response to SARS-CoV-2 vaccine.
Comparative analyses of clinical features reveal the severity of human adenovirus type 55 and type 7 in acute respiratory tract infections
Authors: Zhu Qing , Chen Shuyan , Gu Li , Qu Jiuxin
Published: December 2021

Introduction. Human adenovirus (HAdV) is an important pathogen in acute respiratory tract infections (ARTIs) and HAdV genotypes are associated with disease severity.

Hypothesis. Comparative analyses of clinical features could reveal the severity of different HAdV genotypes in ARTIs.

Aim. This study aimed to investigate the molecular epidemiology of HAdV infections and explore the correlations between clinical features and HAdV genotypes.

Methodology. A retrospective study was conducted on ARTIs at Beijing Chao-Yang Hospital during the period 2011–2016. A standardized data form was used to record the clinical information. HAdV was detected by FQ-PCR from respiratory specimens, and genotypes were determined by entire hexon gene sequencing.

Results. A total of 8044 samples were collected, of which 296 (3.7 %) were HAdV-positive. Patients ≤44 years old were more likely to be positive for HAdV. There were three peak periods of adenoviral infections, with detection rates of 13.03, 9.39 and 10.38 %, respectively. Six HAdV genotypes (HAdV-55, -7, -3, -14, -50, -2) were identified, with HAdV-55 and HAdV-7 being the most prevalent (50.6 and 21.5 %). Compared with HAdV-7 and other types, patients infected with HAdV-55 had a longer duration of fever (P=0.0428). Infections with HAdV-55 and HAdV-7 were more severe compared to those caused by other types, with higher rates of oxygen therapy and mechanical ventilation (P=0.0172 and P=0.0144). All five deaths were caused by HAdV‐55.

Conclusion. This study describes the epidemiological characteristics of HAdV infections in North China, revealing the higher severity of HAdV-55 and HAdV-7 in ARTIs. Thus, strengthened surveillance of HAdV genotypes is warranted.
Enhanced production of Shiga toxin 1 in enterohaemorrhagic Escherichia coli by oxygen
Authors: Shimizu Takeshi , Onuki Manami , Suzuki Shin , Hirai Shinichiro , Yokoyama Eiji , Matsumoto Akio , Hamabata Takashi
Published: December 2021

Enterohaemorrhagic

Escherichia coli

(EHEC) produces Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2). Although stx1 and stx2 were found within the late operons of the Stx-encoding phages (Stx-phages), stx1 could mainly be transcribed from the stx1 promoter (P
Stx1), which represents the functional operator-binding site (Fur box) for the transcriptional regulator Fur (ferric uptake regulator), upstream of stx1. In this study, we found that the production of Stx1 by EHEC was affected by oxygen concentration. Increased Stx1 production in the presence of oxygen is dependent on Fur, which is an Fe2+-responsive transcription factor. The intracellular Fe2+ pool was lower under microaerobic conditions than under anaerobic conditions, suggesting that lower Fe2+ availability drove the formation of less Fe2+-Fur, less DNA binding to the P
Stx1 region, and an increase in Stx1 production.
Deafferentation of Olfactory Bulb in Subjects Dying with COVID-19
Authors: Tremblay Cécilia , Beach Thomas G. , Intorcia Anthony J. , Walker Jessica E. , Arce Richard A. , Sue Lucia I. , Nelson Courtney M. , Borja Claryssa I. , Suszczewicz Katsuko E. , Cline Madison P. , Hemmingsen Spencer J. , Qiji Sanaria H. , Desforges Marc , Serrano Geidy E.
Published: December 2021

There have been clinical descriptions of diverse neurological effects in COVID-19 disease, involving up to 36% of patients. It appears likely that most of these are not caused by viral brain invasion but by systemic accompaniments of critical illness such as coagulopathy, deleteriously upregulated immune response, autoimmune mechanisms, hypoxia or multiorgan failure. Anosmia or hyposmia is present in a majority of COVID-19 patients, and there is early and severe involvement of the nasopharyngeal mucosa and olfactory epithelium. Preliminary studies by our group have found massive gene expression changes in olfactory bulb, but the magnitude of these changes are not different between subjects with detectable versus non-detectable olfactory bulb SARS-CoV-2 RNA. As spontaneous discharge of olfactory epithelial afferents dictates intra-olfactory bulb neurophysiological activity and connectivity, we hypothesized that olfactory bulb deafferentation during COVID-19 is responsible for a large fraction of our observed olfactory bulb transcriptional changes. As the olfactory marker protein (OMP-1) is a specific marker of olfactory epithelial afferents to the olfactory bulb and is severely depleted in animal model lesions of olfactory epithelium, we quantified OMP-1-immunoreactivity in the olfactory bulb of subjects dying with or without COVID-19. Additionally, we quantified olfactory bulb tyrosine hydroxylase (TH), which is often also reduced after olfactory epithelium lesions, and SNAP-25, a pan-synaptic marker. COVID-19 cases (n = 18) were generally elderly and were not significantly different in age or gender distribution from the non-COVID-19 cases (n = 28). Both COVID-19 and non-COVID-19 cases had a wide range of neuropathological diagnoses. The area occupied by OMP-1 immunoreactivity in COVID-19 cases was significantly less, about 60% of that in control cases but amongst subjects with COVID-19, there was no significant difference between OBT-SARS-CoV-2-PCR-positive and negative cases. There were no significant group differences for TH or SNAP-25, supporting a selective effect for OMP-1. We suggest that olfactory dysfunction, and some of the COVID-19-associated transcriptional changes that we have reported for the olfactory bulb and amygdala, may be due to olfactory bulb deafferentation and subsequent transsynaptic effects. Additionally, animal models of olfactory bulb deafferentation or bulbectomy indicate a possibility for widespread changes in interconnected brain regions, providing a possible substrate for diverse post-acute COVID-19 neurological sequelae.
Engineered ACE2 counteracts vaccine-evading SARS-CoV-2 Omicron variant
Authors: Ikemura Nariko , Taminishi Shunta , Inaba Tohru , Arimori Takao , Motooka Daisuke , Katoh Kazutaka , Kirita Yuhei , Higuchi Yusuke , Li Songling , Suzuki Tatsuya , Itoh Yumi , Ozaki Yuki , Nakamura Shota , Matoba Satoaki , Standley Daron M , Okamoto Toru , Takagi Junichi , Hoshino Atsushi
Published: December 2021

The novel SARS-CoV-2 variant, Omicron (B.1.1.529) contains an unusually high number of mutations (>30) in the spike protein, raising concerns of escape from vaccines, convalescent sera and therapeutic drugs. Here we analyze the alteration of neutralizing titer with Omicron pseudovirus. Sera obtained 3 months after double BNT162b2 vaccination exhibit approximately 18-fold lower neutralization titers against Omicron than parental virus. Convalescent sera from Alpha and Delta patients allow similar levels of breakthrough by Omicron. Domain-wise analysis using chimeric spike revealed that this efficient evasion was primarily achieved by mutations clustered in the receptor-binding domain, but that multiple mutations in the N-terminal domain contributed as well. Omicron escapes a therapeutic cocktail of imdevimab and casirivimab, whereas sotrovimab, which targets a conserved region to avoid viral mutation, remains effective. The ACE2 decoy is another virus-neutralizing drug modality that is free, at least in theory, from complete escape. Deep mutational analysis demonstrated that, indeed, engineered ACE2 prevented escape for each single-residue mutation in the receptor-binding domain, similar to immunized sera. Engineered ACE2 neutralized Omicron comparable to Wuhan and also showed a therapeutic effect against Omicron infection in hamsters and human ACE2 transgenic mice. Like previous SARS-CoV-2 variants, some sarbecoviruses showed high sensitivity against engineered ACE2, confirming the therapeutic value against diverse variants, including those that are yet to emerge.

One Sentence Summary

Omicron, carrying ∼30 mutations in the spike, exhibits effective immune evasion but remains highly susceptible to blockade by engineered ACE2.
Allosteric Determinants of the SARS-CoV-2 Spike Protein Binding with Nanobodies: Examining Mechanisms of Mutational Escape and Sensitivity of the Omicron Variant
Authors: Verkhivker Gennady
Published: December 2021

Structural and biochemical studies have recently revealed a range of rationally engineered nanobodies with efficient neutralizing capacity against SARS-CoV-2 virus and resilience against mutational escape. In this study, we performed a comprehensive computational analysis of the SARS-CoV-2 spike trimer complexes with Nb6, VHH E and bi-paratopic VHH VE nanobodies. We combined atomistic dynamics and collective motions analysis with binding free energy scanning, perturbation-response scanning and network centrality analysis to examine mechanisms of nanobody-induced allosteric modulation and cooperativity in the SARS-CoV-2 spike trimer complexes with these nanobodies. By quantifying energetic and allosteric determinants of the SARS-CoV-2 spike protein binding with nanobodies, we also examined nanobody-induced modulation of escaping mutations and the effect of the Omicron variant on nanobody binding. The mutational scanning analysis supported the notion that E484A mutation can have a significant detrimental effect on nanobody binding and result in Omicron-induced escape from nanobody neutralization. Our findings showed that SARS-CoV-2 spike protein may exploit plasticity of specific allosteric hotspots to generate escape mutants that alter response to binding without compromising activity. The network analysis supported these findings showing that VHH VE nanobody binding can induce long-range couplings between the cryptic binding epitope and ACE2-binding site through a broader ensemble of communication paths that is less dependent on specific mediating centers and therefore may be less sensitive to mutational perturbations of functional residues. The results suggest that binding affinity and long-range communications of the SARS-CoV-2 complexes with nanobodies can be determined by structurally stable regulatory centers and conformationally adaptable hotspots that are allosterically coupled and collectively control resilience to mutational escape.
Machine learning guided design of high affinity ACE2 decoys for SARS-CoV-2 neutralization
Authors: Chan Matthew C. , Chan Kui. K. , Procko Erik , Shukla Diwakar
Published: December 2021

A potential therapeutic candidate for neutralizing SARS-CoV-2 infection is engineering high-affinity soluble ACE2 decoy proteins to compete for binding of the viral spike (S) protein. Previously, a deep mutational scan of ACE2 was performed and has led to the identification of a triple mutant ACE2 variant, named ACE22.v.2.4, that exhibits nanomolar affinity binding to the RBD domain of S. Using a recently developed transfer learning algorithm, TLmutation, we sought to identified other ACE2 variants, namely double mutants, that may exhibit similar binding affinity with decreased mutational load. Upon training a TLmutation model on the effects of single mutations, we identified several ACE2 double mutants that bind to RBD with tighter affinity as compared to the wild type, most notably, L79V;N90D that binds RBD with similar affinity to ACE22.v.2.4. The successful experimental validation of the double mutants demonstrated the use transfer and supervised learning approaches for engineering protein-protein interactions and identifying high affinity ACE2 peptides for targeting SARS-CoV-2.
An empirical evaluation of genotype imputation of ancient DNA
Authors: Ausmees Kristiina , Sanchez-Quinto Federico , Jakobsson Mattias , Nettelblad Carl
Published: December 2021

With capabilities of sequencing ancient DNA to high coverage often limited by sample quality or cost, imputation of missing genotypes presents a possibility to increase power of inference as well as cost-effectiveness for the analysis of ancient data. However, the high degree of uncertainty often associated with ancient DNA poses several methodological challenges, and performance of imputation methods in this context has not been fully explored. To gain further insights, we performed a systematic evaluation of imputation of ancient data using Beagle 4.0 and reference data from phase 3 of the 1000 Genomes project, investigating the effects of coverage, phased reference and study sample size. Making use of five ancient samples with high-coverage data available, we evaluated imputed data with respect to accuracy, reference bias and genetic affinities as captured by PCA. We obtained genotype concordance levels of over 99% for data with 1x coverage, and similar levels of accuracy and reference bias at levels as low as 0.75x. Our findings suggest that using imputed data can be a realistic option for various population genetic analyses even for data in coverage ranges below 1x. We also show that a large and varied phased reference set as well as the inclusion of low- to moderate-coverage ancient samples can increase imputation performance, particularly for rare alleles. In-depth analysis of imputed data with respect to genetic variants and allele frequencies gave further insight into the nature of errors arising during imputation, and can provide practical guidelines for post-processing and validation prior to downstream analysis.
Interferon-induced transmembrane protein 3 (IFITM3) limits lethality of SARS-CoV-2 in mice
Authors: Zani Ashley , Kenney Adam D. , Kawahara Jeffrey , Eddy Adrian C. , Wang Xiao-Liang , KC Mahesh , Lu Mijia , Hemann Emily A. , Li Jianrong , Peeples Mark E. , Hall-Stoodley Luanne , Forero Adriana , Cai Chuanxi , Ma Jianjie , Yount Jacob S.
Published: December 2021

Interferon-induced transmembrane protein 3 (IFITM3) is a host antiviral protein that alters cell membranes to block fusion of viruses. Published reports have identified conflicting pro- and antiviral effects of IFITM3 on SARS-CoV-2 in cultured cells, and its impact on viral pathogenesisin vivoremains unclear. Here, we show that IFITM3 knockout (KO) mice infected with mouse-adapted SARS-CoV-2 experienced extreme weight loss and lethality, while wild type (WT) mice lost minimal weight and recovered. KO mice had higher lung viral titers and increases in lung inflammatory cytokine levels, CD45-positive immune cell infiltration, and histopathology, compared to WT mice. Mechanistically, we observed disseminated viral antigen staining throughout the lung tissue and pulmonary vasculature in KO mice, while staining was observed in confined regions in WT lungs. Global transcriptomic analysis of infected lungs identified upregulation of gene signatures associated with interferons, inflammation, and angiogenesis in KO versus WT animals, highlighting changes in lung gene expression programs that precede severe lung pathology and fatality. Corroborating the protective effect of IFITM3in vivo, K18-hACE2/IFITM3 KO mice infected with non-adapted SARS-CoV-2 showed enhanced, rapid weight loss and early death compared to control mice. Increased heart infection was observed in both mouse models in the absence of IFITM3, indicating that IFITM3 constrains extrapulmonary dissemination of SARS-CoV-2. Our results establish IFITM3 KO mice as a new animal model for studying severe SARS-CoV-2 infection of the lung and cardiovascular system, and overall demonstrate that IFITM3 is protective in SARS-CoV-2 infections of mice.
Seroconversion rate after primary vaccination with two doses of BNT162b2 versus mRNA-1273 in solid organ transplant recipients: a systematic review and meta-analysis
Authors: Verleye Arno , Wijtvliet Veerle , Abrams Steven , Hellemans Rachel , Bougrea Rania , Massart Annick , Pipeleers Lissa , Wissing Karl Martin , De Winter Benedicte Y. , Van Damme Pierre , Abramowicz Daniel , Ledeganck Kristien J.
Published: December 2021

In the general population, the seroconversion rate after primary vaccination with two doses of anti-SARS-CoV-2 mRNA vaccine reaches nearly 100%, with significantly higher antibody titers after mRNA-1273 vaccination compared to BNT162b2 vaccination. Here, we performed a systematic review and meta-analysis to compare the antibody response after two-dose mRNA-1273 versus BNT162b2 vaccination in solid organ transplant (SOT) recipients. A systematic literature research was performed in Pubmed, Web of Science, and the Cochrane library and original research papers were included for a meta-analysis to calculate vaccine-specific seroconversion rates for each of the mRNA vaccines. Next, the pooled relative seroconversion rate was estimated. Six studies that described the development of antibodies against receptor-binding domain (RBD) and/or S1 subunit of the spike protein were eligible for meta-analysis. Two of them also reported antibody titers. The meta-analysis revealed lower seroconversion rates in SOT recipients vaccinated with two doses of BNT162b2 (45.2%; 95% confidence interval (CI) 32.5%-58.3%) than patients vaccinated with two doses of mRNA-1273 (60.4%; 95% CI 47.4%-72.7%. The relative seroconversion rate amounted 0.79 (95% CI 0.71-0.88). This systematic review and meta-analysis indicates that, in SOT recipients, higher seroconversion rates were observed after vaccination with mRNA-1273 compared to BNT162b2.
Identifying mutations in sd1, Pi54 and Pi-ta, and positively selected genes of TN1, the first semidwarf rice in Green Revolution
Authors: Panibe Jerome P. , Wang Long , Lee Yi-Chen , Wang Chang-Sheng , Li Wen-Hsiung
Published: December 2021

Background

Taichung Native 1 (TN1) is the first semidwarf rice cultivar that initiated the Green Revolution. As TN1 is a direct descendant of the Dee-geo-woo-gen cultivar, the source of the sd1 semidwarf gene, the sd1 gene can be defined through TN1. Also, TN1 is susceptible to the blast disease and is described as being drought-tolerant. However, genes related to these characteristics of TN1 are unknown. Our aim was to identify and characterize TN1 genes related to these traits.

Results

Aligning the sd1 of TN1 to Nipponbare sd1, we found a 382-bp deletion including a frameshift mutation. Sanger sequencing validated this deleted region in sd1, and we proposed a model of the sd1 gene that corrects errors in the literature. We also predicted the blast disease resistant (R) genes of TN1. Orthologues of the R genes in Tetep, a well-known resistant cultivar that is commonly used as a donor for breeding new blast resistant cultivars, were then sought in TN1, and if they were present, we looked for mutations. The absence of Pi54, a well-known R gene, in TN1 partially explains why TN1 is more susceptible to blast than Tetep. We also scanned the TN1 genome using the PosiGene software and identified 11 genes deemed to have undergone positive selection. Some of them are associated with drought-resistance and stress response.

Conclusions

We have redefined the deletion of the sd1 gene in TN1, a direct descendant of the Dee-geo-woo-gen cultivar, and have corrected some literature errors. Moreover, we have identified blast resistant genes and positively selected genes, including genes that characterize TN1’s blast susceptibility and abiotic stress response. These new findings increase the potential of using TN1 to breed new rice cultivars.
Two doses of mRNA vaccine elicit cross-neutralizing memory B-cells against SARS-CoV-2 Omicron variant
Authors: Kotaki Ryutaro , Adachi Yu , Moriyama Saya , Onodera Taishi , Fukushi Shuetsu , Nagakura Takaki , Tonouchi Keisuke , Terahara Kazutaka , Sun Lin , Takano Tomohiro , Nishiyama Ayae , Shinkai Masaharu , Oba Kunihiro , Nakamura-Uchiyama Fukumi , Shimizu Hidefumi , Suzuki Tadaki , Matsumura Takayuki , Isogawa Masanori , Takahashi Yoshimasa
Published: December 2021

SARS-CoV-2 Beta and Omicron variants have multiple mutations in the receptor-binding domain (RBD) allowing antibody evasion. Despite the resistance to circulating antibodies in those who received two doses of mRNA vaccine, the third dose prominently recalls cross-neutralizing antibodies with expanded breadth to these variants. Herein, we longitudinally profiled the cellular composition of persistent memory B-cell subsets and their antibody reactivity against these variants following the second vaccine dose. The vaccination elicited a memory B-cell subset with resting phenotype that dominated the other subsets at 4.9 months. Notably, most of the resting memory subset retained the ability to bind the Beta variant, and the memory-derived antibodies cross-neutralized the Beta and Omicron variants at frequencies of 59% and 29%, respectively. The preservation of cross-neutralizing antibody repertoires in the durable memory B-cell subset likely contributes to the prominent recall of cross-neutralizing antibodies following the third dose of the vaccine.

One Sentence Summary

Fully vaccinated individuals preserve cross-neutralizing memory B-cells against the SARS-CoV-2 Omicron variant.
Structure, dynamics, and inhibition of Staphylococcus aureus m1A22-tRNA methyltransferase
Authors: Sweeney Pamela , Crowe Ashleigh , Kumar Abhishek , Raju Dinesh , Krishna Naveen B. , Sutherland Emmajay , Leo Caitlin J. , Fisher Gemma , Lalitha Roopa , Muthuraj Likith , Sigamani Gladstone , Oehler Verena , Synowsky Silvia , Shirran Sally L. , Gloster Tracey M. , Czekster Clarissa M. , Kumar Pravin , da Silva Rafael G.
Published: December 2021

The enzyme m1A22-tRNA methyltransferase (TrmK) catalyses the transfer of a methyl group from SAM to the N1 of adenine 22 in tRNAs. TrmK is essential for Staphylococcus aureus survival during infection, but has no homologue in mammals, making it a promising target for antibiotic development. Here we describe the structural and functional characterisation of S. aureus TrmK. Crystal structures are reported for S. aureus TrmK apoenzyme and in complexes with SAM and SAH. Isothermal titration calorimetry showed that SAM binds to the enzyme with favourable but modest enthalpic and entropic contributions, whereas SAH binding leads to an entropic penalty compensated by a large favourable enthalpic contribution. Molecular dynamics simulations point to specific motions of the C-terminal domain being altered by SAM binding, which might have implications for tRNA recruitment. Activity assays for S. aureus TrmK-catalysed methylation of WT and position 22 mutants of tRNALeu demonstrate that the enzyme requires an adenine at position 22 of the tRNA. Intriguingly, a small RNA hairpin of 18 nucleotides is methylated by TrmK depending on the position of the adenine. In-silico screening of compounds suggested plumbagin as a potential inhibitor of TrmK, which was confirmed by activity measurements. Furthermore, LC-MS indicated the protein was covalently modified by one equivalent of the inhibitor, and proteolytic digestion coupled with LC-MS identified Cys92, in the vicinity of the SAM-binding site, as the sole residue modified. These results these results identify a cryptic binding pocket of S. aureus TrmK and lay the foundation for future structure-based drug discovery.
Graphene Oxide reinforced Agarose-Hydroxyapatite Bioprinted 3-D Scaffolds for Bone Regeneration
Authors: Yadav Umakant , Kumar Shiva
Published: December 2021

Three-dimensional (3D) bioprinting is an emerging technology for fabricating cells, biomaterials and extracellular matrix (ECM) into customized shapes and patterns. Here, we report additive manufacturing to create a customized 3D bioactive constructs for regenerative medicine. We have attempted to emphasize the use of agarose and graphene oxide as a promising material for the conceptualization of bioink unpaid to its unique physicochemical properties. The 3D printed structure is able to regenerating bone tissues and regulates the cellular differentiation without any significant morphological changes. The presence of graphene oxide enhances the osteoinductive behavior of the developed scaffolds, which is further supplemented by encapsulating human mesenchymal stem cells (hMSCs) on the 3D printed scaffolds.

A significant enhanced expression of early osteogenic markers like morphogenetic protein (BMP), Runx-2, collagen-1, osteopontin, osteocalcin as well as mineralized ECM are observed on agarose-hydroxyapatite and graphene oxide 3D printed scaffolds compared to agarose-hydroxyapatite 3D printed scaffolds. Thus, the outcomes of the developed 3D bioprinted scaffolds provide a promising strategy for development of personalized bone grafts for tissue regeneration.
The mediating role of competitive orientation in determining self-construal in unethical decision-making
Authors: Dissanayake D.M. Sachinthanee
Published: December 2021

Purpose

The ethics literature has focused on the influence of self-construal dimensions on unethical decision-making. However, the literature is unclear about why these self-construal dimensions (Independent-self, Relational-self, Collective-self) impact differently on unethical decision-making. Based on the theory of cooperation and competition, this study empirically examines the mediating role of competitive orientation and addresses the theoretically unexplained question of why self-construal dimensions influence differently on unethical decision-making.

Design/methodology/approach

Based on the deductive approach, a quantitative research study was conducted on the Sri Lankan banking industry because there have been many instances of unethical behavior reported in this sector lately. Data were collected from 305 bank branch managers using a structured survey questionnaire.

Findings

The findings revealed that competitive orientation mediates the self-construal dimensions and explained that competitive orientation is one reason why independent-self, relational-self and collective-self influence differently on unethical decision-making.

Originality/value

This paper addresses the unanswered question of why self-construal dimensions relate to unethical decision-making differently.
Work values: a latent class analysis of Korean employees
Authors: Lee Jinju , Lee Yunsoo , Kim Soo Jung , Song Ji Hoon
Published: December 2021

Purpose

The purpose of this study is to identify latent classes of work values that influence the career choices of Korean workers through a person-centred approach. Because work values may be diverse in individuals, investigating the various combinations of those values will help understand individual's decisions to take, maintain and leave a job.

Design/methodology/approach

The authors used a total of 15,103 datasets collected at the national level in South Korea. Data were analyzed by using latent class analysis (LCA); a three-step approach was employed to address classification.

Findings

As the results of this study, Class 3, “seeking balanced work values rather than income,” presented the highest level of job satisfaction, whereas Class 1, “seeking job security and income,” exhibited the lowest.

Originality/value

Employing an assessment tool to identify the distinct combinations of work values that individuals possess and then providing them with appropriate training and development programs and customized Human Resource (HR) policies aligned with the classes will be essential tasks for HRD (Human Resource Development)/HRM (Human Resource Management) practitioners.
Consumer responses to the failure of self-service banking technology: moderating role of failure stability
Authors: Bahri Ammari Nedra , Hsouna Abir , Benabdallah Mounia , Yousaf Anish , Mishra Abhishek
Published: December 2021

Purpose

The purpose of this study is to investigate the impact of dissatisfaction and anger, driven by the failure of the self-service technology of banks, on customers' post-purchase behavioural reactions, such as complaints, negative word-of-mouth (NWOM) and supplier change. The stability of the failure is proposed to moderate these relationships.

Design/methodology/approach

The proposed research model was tested through data collected from an online survey of a Tunisian sample of 300 respondents, using the scenario method.

Findings

The study validates the positive impact of dissatisfaction on anger and negative word-of-mouth, as well as that of anger on complaint behaviour and negative word-of-mouth. The relation between dissatisfaction and negative word-of-mouth is mediated by anger. When the failure is stable, dissatisfied users of the self-service technology seek to enhance their negative word-of-mouth and supplier change. The results also show that the stability of the failure enhances the effect of anger on complaint behaviour.

Practical implications

Banks should invest efforts to accelerate the recovery of services to reduce consumer dissatisfaction and anger and prevent adverse behavioural outcomes. Further, they need to ensure that failures are not repeated, as failure stability activates some otherwise non-significant behavioural outcomes, like supplier change.

Originality/value

Previous works have focused on the impact of dissatisfaction and negative emotions for interpersonal services, but very few works have come to associate dissatisfaction, anger, complaint, negative word-of-mouth and supplier change in an integrative framework for an self-service technology failure.
Female entrepreneurship in emerging and developing countries: a systematic literature review
Authors: Corrêa Victor Silva , Brito Fernanda Regina da Silva , Lima Rosileine Mendonça de , Queiroz Maciel M.
Published: December 2021

Purpose

Despite the increase in female entrepreneurship literature, very few studies exist that systematize the extant literature, especially in emerging and developing countries. This article fills part of this gap; it maps, categorizes and groups the objectives, theoretical approaches and research methods on female entrepreneurship conducted in one or more of the 155 emerging and developing countries.

Design/methodology/approach

A systematic literature review (SLR) was conducted, using Scopus and Web of Science, over a 10-year timeframe (2010–2020). Out of 465 papers, 77 were selected for content analysis.

Findings

Most articles focus on understanding women entrepreneurs' challenges, the factors affecting their entrepreneurial performance and encouraging entrepreneurship. Qualitative research was found to be the predominant approach, while mixed studies appeared less frequently.

Practical implications

This paper sheds light on female entrepreneurship characteristics, including business competence, performance and entrepreneurial orientation. Further, it can help female entrepreneurs to recognize the most relevant aspects regarding performance, the essential driving factors and entrepreneurial motivations, among others.

Originality/value

First, this paper groups the objectives and the theoretical and methodological approaches that guide female entrepreneurship research. Second, it identifies distinct gaps, grouped and explored using unpublished thematic categories. Finally, the authors propose an extensive future research agenda regarding female entrepreneurship in emerging and developing countries.
Market knowledge acquisition and transfer in international SMEs: peculiarities, specifications and linkages to market success
Authors: Siachou Evangelia , Papasolomou Ioanna , Trichina Eleni , Thrassou Alkis
Published: December 2021

Purpose

This paper aims to systematically review and evaluate extant literature on knowledge acquisition and transfer in international small-to-medium enterprises (SMEs) and to identify the requisite types of knowledge acquired and transferred in this context. The research further determines the mechanisms enabling SMEs to process this knowledge, unpacks the benefits of both knowledge acquisition and transfer for international SMEs and links them to the market success.

Design/methodology/approach

The research has conducted a comprehensive systematic review of existing literature on market knowledge acquisition and its transfer, in the context of international SMEs, utilizing peer-reviewed articles published in top tier journals without any custom range of time.

Findings

The search strategy resulted in 37 reviewed academic articles, whose analysis identifies and elucidates on the best practices of knowledge acquisition and transfer in the context of international SMEs; the type of the knowledge acquired and transferred; the form and mechanism of the intersection of these processes; and the benefits gained. The findings, crucially, also identify and illuminate extant research gaps and insufficiencies and develop a comprehensive research agenda for the way forward.

Originality/value

The present study offers a uniquely comprehensive perspective on a topic of diachronic and, currently, rising significance to scholars and practitioners alike. Transcending its descriptive value, though, it further identifies extant knowledge deficiencies, it distils and consolidates critical knowledge and prescribes avenues for research towards the growth and development of international SMEs and born globals.
Market overreaction, firm-specific information and macroeconomic variables in US and Chinese markets during COVID-19
Authors: Loang Ooi Kok , Ahmad Zamri
Published: December 2021

Purpose

This study examines the impact of firm-specific information and macroeconomic variables on market overreaction of US and Chinese winner and loser portfolio before and during COVID-19.

Design/methodology/approach

The firm-specific information includes firm size, volume, volatility, return of asset (ROA), return of equity (ROE), earning per share (EPS) and quick ratio while the macroeconomic variables are export rate, import rate, real GDP, nominal GDP, FDI, IPI and unemployment rate. Besides, one-third of the top performance stocks are categorized as winner portfolio while one-third of lowest performance stocks are categorized as loser portfolio. This study uses AECR to indicate stock return and measure market overreaction. GAECR is used to determine contrarian profit. The data range of pre-COVID-19 is from 1-Jan-2015 to 31-Dec-2019 while the period of COVID-19 is from 1-Jan-2020 to 31-Dec-2020.

Findings

In pre-COVID-19, firm-specific information (volatility, ROA, ROE and EPS) and macroeconomic variables are found to be correlated to stock return in US and Chinese portfolios except Chinese winner portfolio. Nonetheless, the impact of firm-specific information has vanished and macroeconomic variables are significant to stock return in COVID-19. It shows that investors rely on the economic indicators to trade in turbulent period due to emergence of COVID-19 as a disruption in market. Furthermore, US and Chinese portfolios are overreacted during COVID-19. Chinese loser portfolio has higher tendency of overreaction than US loser portfolio while US winner portfolio has higher tendency of overreaction than Chinese winner portfolio.

Originality/value

The results of this study assists academician, practitioners and investors on understanding and create awareness to the existence of market overreaction and the determinants that can cause the phenomenon.
Towards quality primary health care: the dilemma of Community-Based Health Planning and Services (CHPS) in health service provision in Ghana
Authors: Addi Barnabas , Doe Benjamin , Oduro-Ofori Eric
Published: December 2021

Purpose

Over the past two decades, Community-Based Health Planning and Services (CHPS) has been a pragmatic strategy towards universal Primary Health Care (PHC) in Ghana. However, the ability and capacity of these facilities to deliver quality primary health care remain an illusion as they are still crumbling in myriad challenges. These challenges are translated to the poor-quality services provision and low community utilization of CHPS facilities. The study presents a comparative analysis of three communities in the Kassena-Nankana East Municipality, Ghana.

Design/methodology/approach

Using a mixed-method research design, the study gathered and analysed data from 110 households, three community health officers (CHOs) and three community leaders using semi-structured questionnaires and interview guides.

Findings

The findings indicated that the facilities do not have the requisite inputs such as drugs and supplies, logistics, appropriate health personnel, good infrastructure, funding support necessary to deliver quality and appropriate healthcare services that meet the health needs of the communities. For the CHPS to realize their full potentials as PHC facilities, it is required that the needed inputs such as logistics, drugs and appropriate staff are in place to facilitate the activities of CHOs.

Research limitations/implications

Due to the limited number of participants and selection of the study communities, the results may generalization. Also, the researchers acknowledged the inability to interview the district level health officials and the Kassena-Nankana Municipal Assembly during the field visits. This could have provided in-depth knowledge on the findings of this research as well as the validation of the results from the communities' perspective. Several attempts were made to contact and interview district-level authorities which proven futile due to the unavailability of targeted respondents. This resulted in limiting the studies at the community level. However, this limitation does not disprove the findings of this study.

Practical implications

The article implications for planning primary health care strategies include a keen assessment of community health needs and institutional management of primary health care facilities, equip PHC facilities with adequate resources such as drugs and appropriate staffing to provide the health needs of the communities.

Originality/value

The paper fulfils the gap in the literature by providing empirical data on how the challenges of primary health care facilities affected the provision of high quality service and how this can affect community’s use of the facilities.
Power law bond price and yield approximation
Authors: Barber Joel R.
Published: December 2021

Purpose

This paper determines a simple transformation that nearly linearizes the bond price formula. The transformed price can be used to derive a highly accurate approximation of the change in a bond price resulting from a change in interest rates.

Design/methodology/approach

A logarithmic transformation exactly linearizes the price function for a zero coupon bond and a reciprocal transformation exactly linearizes the price function for a perpetuity. A power law transformation combines aspects of both types of transformations and provides a superior approximation of the bond price sensitivity for both short-term and long-term bonds.

Findings

It is demonstrated that the new formula, based on power-law transformation, is a much better approximation than either the traditional duration-convexity approximation and the more recently developed approximations based on logarithmic transformation of the price function.

Originality/value

The new formula will be used by risk managers to perform stress-testing on bond portfolios. The new formula can easily be inverted, making it possible to relate the distribution of prices (which are observable in the market) to the distribution of yields (which are numerical solutions that are not directly observable).
The development of Emirati university students' intercultural sensitivity
Authors: Deveci Tanju , Elgamal Glenda , Dalton David , Langille Donald John
Published: December 2021

Purpose

This study investigated the effects of an intercultural communication (IC) course on Emirati university students' intercultural sensitivity (IS).

Design/methodology/approach

The participants were 89 Emirati students. The course required student involvement in a variety of tasks and activities, both inside and outside the classroom. The development of the students' IS was tracked using two instruments: the Intercultural Sensitivity Scale (ISS) and a reflective writing task.

Findings

The difference between the students' overall pre-test and post-test scores was at a statistically significant level. The data from the reflective writing papers showed that the course developed the students' IS with a particular effect on their awareness of other cultures, barriers to effective communication and self-confidence.

Originality/value

In an increasingly globalized world, the findings of this study highlight the importance of a course designed to enhance university students' IS and therefore intercultural competence. They also indicate the need for more experiential learning to bridge in-class and out-of-class experiences which facilitate the development of students' intercultural competence.
Measurement and inversion strategies for 3‐D resistivity surveys with vector arrays
Authors: Loke Meng Heng , Wilkinson Paul B. , Gance Julien , Malet Jean‐Philippe , Truffert Catherine , Leite Orlando
Published: December 2021

Three‐dimensional geoelectrical surveys are widely used to map the subsurface in areas with complex geology. Field survey methods using the offset pole–dipole and dipole–dipole arrays have been proposed to map large areas efficiently. However, it has been found that negative apparent resistivity values are sometimes encountered in areas with large resistivity contrasts, particularly when large offsets between the current electrodes and potential dipoles are used. The vector array configuration that makes two measurements of the electric field at each station with two potential dipoles at right angles avoids this problem. The combined potential measured at the two dipoles is independent of the orientation the current electrodes to the receiver station. The amplitude of the vector apparent resistivity value is always positive. A commonly used configuration is to lay out the current and potential electrodes along alternating parallel lines. We examine the use of different offsets between the current electrodes and potential dipoles to improve the survey spatial resolution. A new inversion method using both the amplitude and direction of the vector array potentials is described to improve the resolution. Results from the inversion of a synthetic model data set and a field survey over a deep‐seated landslide are shown.
Natural plant fibers obtained from agricultural residue used as an ingredient in food matrixes or packaging materials: A review
Authors: Soleimanian Yasamin , Sanou Ibrahima , Turgeon Sylvie L. , Canizares Diego , Khalloufi Seddik
Published: December 2021

Every year, agrifood activities generate a large amount of plant byproducts, which have a low economical value. However, the valorization of these byproducts can contribute to increasing the intake of dietary fibers and reducing the environmental pollution. This review presents an overview of a wide variety of agricultural wastes applied in the formulation of different food products and sustainable packaging. In general, the incorporation of fibers into bakery, meat, and dairy products was successful, especially at a level of 10% or less. Fibers from a variety of crops improved the consistency, texture, and stability of sauce formulations without affecting sensory quality. In addition, fiber fortification (0.01–6.4%) presented considerable advantages in terms of rheology, texture, melting behavior, and fat replacement of ice cream, but in some cases had a negative impact on color and mouthfeel. In the case of beverages, promising effects on texture, viscosity, stability, and appetite control were obtained by the addition of soluble dietary fibers from grains and fruits with small particle size. Biocomposites used in packaging benefited from reinforcing effects of various plant fiber sources, but the extent of modification depended on the matrix type, fiber pretreatment, and concentration. The information synthesized in this contribution can be used as a tool to screen and select the most promising fiber source, fiber concentration, and pretreatment for specific food applications and sustainable packaging.