bluuebunny/crossref_metadata_2025 huggingface dataset:
Linear Epitope Binding Patterns of Grass Pollen-Specific Antibodies in Allergy and in Response to Allergen-Specific Immunotherapy
Authors: Thörnqvist Linnea , Sjöberg Ronald , Greiff Lennart , van Hage Marianne , Ohlin Mats
Published: March 2022

Allergic diseases affect many individuals world-wide and are dependent on the interaction between allergens and antibodies of the IgE isotype. Allergen-specific immunotherapy (AIT) can alter the development of the disease, e.g., through induction of allergen-specific IgG that block allergen-IgE interactions. The knowledge of epitopes recognized by allergy-causing and protective antibodies are limited. Therefore, we developed an allergome-wide peptide microarray, aiming to track linear epitope binding patterns in allergic diseases and during AIT. Here, we focused on immune responses to grass pollen allergens and found that such epitopes were commonly recognized before initiation of AIT and that AIT commonly resulted in increased antibody production against additional epitopes already after 1 year of treatment. The linear epitope binding patterns were highly individual, both for subjects subjected to and for individuals not subjected to AIT. Still, antibodies against some linear epitopes were commonly developed during AIT. For example, the two rigid domains found in grass pollen group 5 allergens have previously been associated to a diversity of discontinuous epitopes. Here, we present evidence that also the flexible linker, connecting these domains, contains regions of linear epitopes against which antibodies are developed during AIT. We also describe some commonly recognized linear epitopes on Phl p 2 and suggest how antibodies against these epitopes may contribute to or prevent allergy in relation to a well-defined stereotyped/public IgE response against the same allergen. Finally, we identify epitopes that induce cross-reactive antibodies, but also antibodies that exclusively bind one of two highly similar variants of a linear epitope. Our findings highlight the complexity of antibody recognition of linear epitopes, with respect to both the studied individuals and the examined allergens. We expect that many of the findings in this study can be generalized also to discontinuous epitopes and that allergen peptide microarrays provide an important tool for enhancing the understanding of allergen-specific antibodies in allergic disease and during AIT.
Genetic Stability and Fitness of Aedes aegypti Red-Eye Genetic Sexing Strains With Pakistani Genomic Background for Sterile Insect Technique Applications
Authors: Misbah-ul-Haq Muhammad , Carvalho Danilo O. , Duran De La Fuente Lucia , Augustinos Antonios A. , Bourtzis Kostas
Published: March 2022

The mosquito speciesAedes aegyptiis the primary transmitter of viruses that cause endemic diseases like dengue in Pakistan. It is also a cause of other vector-borne diseases like yellow fever, Zika fever, and chikungunya, which significantly impact human health worldwide. In the absence of efficient vaccines (except for yellow fever) or drugs, vector control methods, such as the sterile insect technique (SIT), have been proposed as additional tools for the management of these diseases. Mosquito SIT programs are based on the release of sterile males and it is important female releases to be ideally zero or to be kept at a minimum, since females are the ones that bite, blood-feed and transmit pathogens. Recently, anAe. aegyptigenetic sexing strain (GSS), with and without a recombination-suppressing inversion (Inv35), was developed using the eye color as a selectable marker, with males having black eyes and females red eyes. In the present study, we introgressed the sexing features and the Inv35 of theAe. aegyptired-eye GSS into the Pakistani genomic background aiming to their future use for SIT applications in the country. Both introgressed strains, the Red-eye GSS-PAK and the Red-eye GSS/Inv35-PAK, were evaluated in respect to their genetic stability and biological quality by assessing parameters like recombination rate, fecundity, fertility, pupal and adult recovery, time of development, pupal weight, survival, and flight ability in comparison with a wild Pakistani population (PAK). The results suggest that the sexing features and the recombination suppression properties of Inv35 were not affected after their introgression into the local genomic background; however, some biological traits of the two newly constructed strains were affected, positively or negatively, suggesting that a thorough quality control analysis should be performed after the introgression of a GSS into a new genomic background prior to its use in SIT field trials or applications. The importance of using GSS with local genomic background for SIT applications againstAedes aegyptiis also discussed.
Production of Potyvirus-Derived Nanoparticles Decorated with a Nanobody in Biofactory Plants
Authors: Martí Maricarmen , Merwaiss Fernando , Butković Anamarija , Daròs José-Antonio
Published: March 2022

Viral nanoparticles (VNPs) have recently attracted attention for their use as building blocks for novel materials to support a range of functions of potential interest in nanotechnology and medicine. Viral capsids are ideal for presenting small epitopes by inserting them at an appropriate site on the selected coat protein (CP). VNPs presenting antibodies on their surfaces are considered highly promising tools for therapeutic and diagnostic purposes. Due to their size, nanobodies are an interesting alternative to classic antibodies for surface presentation. Nanobodies are the variable domains of heavy-chain (VHH) antibodies from animals belonging to the family Camelidae, which have several properties that make them attractive therapeutic molecules, such as their small size, simple structure, and high affinity and specificity. In this work, we have produced genetically encoded VNPs derived from two different potyviruses—the largest group of RNA viruses that infect plants—decorated with nanobodies. We have created a VNP derived from zucchini yellow mosaic virus (ZYMV) decorated with a nanobody against the green fluorescent protein (GFP) in zucchini (Cucurbita pepo) plants. As reported for other viruses, the expression of ZYMV-derived VNPs decorated with this nanobody was only made possible by including a picornavirus 2A splicing peptide between the fused proteins, which resulted in a mixed population of unmodified and decorated CPs. We have also produced tobacco etch virus (TEV)-derived VNPs in Nicotiana benthamiana plants decorated with the same nanobody against GFP. Strikingly, in this case, VNPs could be assembled by direct fusion of the nanobody to the viral CP with no 2A splicing involved, likely resulting in fully decorated VNPs. For both expression systems, correct assembly and purification of the recombinant VNPs was confirmed by transmission electron microscope; the functionality of the CP-fused nanobody was assessed by western blot and binding assays. In sum, here we report the production of genetically encoded plant-derived VNPs decorated with a nanobody. This system may be an attractive alternative for the sustainable production in plants of nanobody-containing nanomaterials for diagnostic and therapeutic purposes.
Cellular Chitchatting: Exploring the Role of Exosomes as Cardiovascular Risk Factors
Authors: Germena Giulia , Zelarayán Laura Cecilia , Hinkel Rabea
Published: March 2022

Exosomes are small bi-lipid membranous vesicles (30–150 nm) containing different biological material such as proteins, lipids and nucleic acid. These small vesicles, inducing a cell to cell signaling pathway, are able to mediate multidirectional crosstalk to maintain homeostasis or modulate disease processes. With their various contents, exosomes sort and transfer specific information from their origin to a recipient cell, from a tissue or organ in the close proximity or at distance, generating an intra-inter tissue or organ communication. In the last decade exosomes have been identified in multiple organs and fluids under different pathological conditions. In particular, while the content and the abundance of exosome is now a diagnostic marker for cardiovascular diseases, their role in context-specific physiological and pathophysiological conditions in the cardiovascular system remains largely unknown. We summarize here the current knowledge on the role of exosomes as mediators of cardiovascular diseases in several pathophysiological conditions such as atherosclerosis and diabetes. In addition, we describe evidence of intercellular connection among multiple cell type (cardiac, vasculature, immune cells) as well as the challenge of their in vivo analysis.
Molecular Switches—Tools for Imparting Control in Drug Delivery Systems
Authors: Fitzmaurice Owen , Bartkowski Michał , Giordani Silvia
Published: March 2022

Cancer is a globally prevalent cause of premature mortality. Of growing interest is the development of novel anticancer therapies and the optimisation of associated risks. Major issues presently facing conventional anticancer therapies include systemic toxicity, poor solubility, membrane permeability, and multidrug resistance Nanocarriers have been employed to address these issues. Nanocarriers encapsulate anticancer drugs, enabling them to bypass biological barriers and minimise their adverse side effects. These drug delivery systems offer extensive benefits as they can be modified to gravitate towards specific environmental conditions. To further enhance the safety and efficacy of these drug carriers, modern developments have included incorporating a molecular switching mechanism into their structure. These molecular switches are responsive to endogenous and exogenous stimuli and may undergo reversible and repeatable conformational changes when activated. The incorporation of molecular switches can, therefore, impart stimuli-responsive drug-release control on a DDS. These stimuli can then be manipulated to offer precise dosage control over the drug release at a specific target site. This review discusses recent developments in the design of DDSs incorporating light and pH-responsive molecular switches as drug release controllers.
Central-to-Folding Chirality Control: Asymmetric Synthesis of Multilayer 3D Targets With Electron-Deficient Bridges
Authors: Jin Shengzhou , Wang Jia-Ying , Tang Yao , Rouh Hossein , Zhang Sai , Xu Ting , Wang Yu , Yuan Qingkai , Chen Daixiang , Unruh Daniel , Li Guigen
Published: March 2022

New multilayer 3D chiral molecules have been designed and synthesized asymmetrically through the strategy of center-to-multilayer folding chirality control and double Suzuki couplings. Individual diastereoisomers were readily obtained and separated via flash column chromatography. The key diastereoisomer was further converted into corresponding enantiomers. These enantiomers possess electron-deficient aromatic bridges layered with top and bottom aromatic scaffolds. X-ray structural analysis has unambiguously confirmed the configuration, and intermolecular packing results in regular planar patterns in solid crystals. The synthesis was achieved in a total of ten steps starting from commercially available starting materials.
The Cellular and Molecular Interaction Between Erythrocytes and Plasmodium falciparum Merozoites
Authors: Molina-Franky Jessica , Patarroyo Manuel Elkin , Kalkum Markus , Patarroyo Manuel Alfonso
Published: March 2022

Plasmodium falciparum is the most lethal human malaria parasite, partly due to its genetic variability and ability to use multiple invasion routes via its binding to host cell surface receptors. The parasite extensively modifies infected red blood cell architecture to promote its survival which leads to increased cell membrane rigidity, adhesiveness and permeability. Merozoites are initially released from infected hepatocytes and efficiently enter red blood cells in a well-orchestrated process that involves specific interactions between parasite ligands and erythrocyte receptors; symptoms of the disease occur during the life-cycle’s blood stage due to capillary blockage and massive erythrocyte lysis. Several studies have focused on elucidating molecular merozoite/erythrocyte interactions and host cell modifications; however, further in-depth analysis is required for understanding the parasite’s biology and thus provide the fundamental tools for developing prophylactic or therapeutic alternatives to mitigate or eliminate Plasmodium falciparum-related malaria. This review focuses on the cellular and molecular events during Plasmodium falciparum merozoite invasion of red blood cells and the alterations that occur in an erythrocyte once it has become infected.
Gut Microbiome Signature Are Correlated With Bone Mineral Density Alterations in the Chinese Elders
Authors: Wang Yangyang , Gao Xiaoguang , Lv Jing , Zeng Yuhong , Li Qingmei , Wang Liping , Zhang Yuanyuan , Gao Wenjie , Wang Jihan
Published: March 2022

Objective

Osteoporosis (OP), clinically featured with a low bone mineral density (BMD) and high risk of bone fracture, has become a major risk factor of disability and death in the elders, especially in postmenopausal women. The gut microbiome (GM) is thought to be implicated in bone metabolism. Herein, we clarified the composition signature and gene functional profile of GM in older people with normal and low BMD.

Design and Methods

A total of 455 participants underwent the BMD measurement and biochemical detection. GM analysis was further performed on 113 cases of postmenopausal women and men aged over 50, including both 16S rRNA and metagenomic sequencing.

Results

Generally, the BMD value was significantly lower in the older age groups, especially in the postmenopausal women. Consistently, we observed obvious vitamin D deficiency or insufficiency in females (compared to the male, P < 0.0001). The results from 16S rRNA sequencing revealed higher numbers of OTUs and diversity indexes in females than in males. The abundance in composition of Firmicutes and Clostridiales were correlated with the BMD values in females. LEfSe analysis discovered several enriched bacteria taxons in OP and normal control (NC) subgroups. A positive correlation between the number of genes and BMD values was observed in females based on metagenomic sequencing analysis. Furthermore, we identified the connecting modules among the GM composition – gene functional signature – BMD value/T score in both females and males.

Conclusions

This study provides evidences upon which to understand the mechanisms of the effects of GM on bone health, consequently revealing the physiology status and potential diagnostic/therapeutic targets based on GM for OP and postmenopausal osteoporosis (PMOP). Besides, the status of vitamin D deficiency or insufficiency need to be concerned and improved in the Chinese people.
The Role and Place of Sign Language in Deaf Youth's Access to Literacy: Contributions of a Cross-Review of ASL-English and LSF-French Research
Authors: Beaujard Laurence , Perini Marie
Published: March 2022

In this mini-review, we investigate the role sign language (SL) might play in the development of deaf learners' reading skills. Since Stokoe's recognition, in the 1960s, of American Sign Language (ASL) as a language in its own right, the ASL has been progressively included in the research on the development of reading in the deaf, but with different statuses. Two contrasting paradigms can thus be identified in the literature. The first considers that sign language (SL) plays an indirect role in the development of reading skills. In line with the dominant psycholinguistic model of reading acquisition in hearing children, the authors consider that deaf children must first develop phonological representations in order to learn to read, like their hearing peers. For the authors of the second paradigm, SL plays a direct and central role in deaf children's access to reading as long as an appropriate visual (rather than phonological) mediation is made between the SL and the written language. We propose to present an overview of studies in both paradigms, in the American and French contexts. Then, we defend the idea of a “deaf norm”, operating both in SL structuring and in information processing in general, justifying the central position that SL must have in any learning by deaf people. We will conclude by outlining some promising avenues for teaching reading to deaf learners.
“Tonga”: A Novel Toolbox for Straightforward Bioimage Analysis
Authors: Ritchie Alexandra , Laitinen Suvi , Katajisto Pekka , Englund Johanna I.
Published: March 2022

Techniques to acquire and analyze biological images are central to life science. However, the workflow downstream of imaging can be complex and involve several tools, leading to creation of very specialized scripts and pipelines that are difficult to reproduce by other users. Although many commercial and open-source software are available, non-expert users are often challenged by a knowledge gap in setting up analysis pipelines and selecting correct tools for extracting data from images. Moreover, a significant share of everyday image analysis requires simple tools, such as precise segmentation, cell counting, and recording of fluorescent intensities. Hence, there is a need for user-friendly platforms for everyday image analysis that do not require extensive prior knowledge on bioimage analysis or coding. We set out to create a bioimage analysis software that has a straightforward interface and covers common analysis tasks such as object segmentation and analysis, in a practical, reproducible, and modular fashion. We envision our software being useful for analysis of cultured cells, histological sections, and high-content data.
Single-Cell Sequencing of Immune Cells in Human Aortic Dissection Tissue Provides Insights Into Immune Cell Heterogeneity
Authors: Liu Yifan , Zou Lingwei , Tang Hanfei , Li Jie , Liu Hao , Jiang Xiaolang , Jiang Baohong , Dong Zhihui , Fu Weiguo
Published: March 2022

Background

Inflammation plays an important role in the progression of sporadic aortic dissection (AD). Immune cells, especially macrophages, infiltrate the aorta and secrete inflammatory cytokines and matrix metalloproteinases to cause degradation of the extracellular matrix, thereby contributing to the pathogenesis of AD. However, the cellular heterogeneity within these immune cells has not been fully characterized.

Methods

We used single-cell RNA sequencing to profile the transcriptomes of all immune cells in AD tissue and normal aorta. Using magnetic-activated cell sorting gating on CD45, we obtained a higher resolution identification of the immune cell subsets in the aorta.

Results

We observed significant differences in the proportion of major immune cell subpopulations between AD and normal aorta tissues. Macrophages accounted for a higher percentage in the normal aorta, while the proportions of T cells, B cells and natural killer (NK) cells were all increased in AD tissues. Macrophage clusters that expanded in AD tissues originated primarily from circulating monocytes and expressed genes encoding proinflammatory cytokines and molecules involved in tissue repair. T and NK cells in AD tissues exhibited enhanced cytotoxic properties. A cluster of CD4+ T cells that had expanded in AD tissues was Th17-like and might contribute to the pathogenesis of AD. Cell–cell interaction analysis highlighted the increased communication between macrophages and T cells, which primarily regulated the costimulation of T cells.

Conclusions

Our study provides a comprehensive characterization of immune cells in the dissected aorta with an emphasis on the role of macrophages and T cells. The information from our study improves our understanding of immune mechanisms in AD formation and helps to identify additional useful targets for early diagnosis or therapy of AD.
Machine Learning Approaches for Predicting Hypertension and Its Associated Factors Using Population-Level Data From Three South Asian Countries
Authors: Islam Sheikh Mohammed Shariful , Talukder Ashis , Awal Md. Abdul , Siddiqui Md. Muhammad Umer , Ahamad Md. Martuza , Ahammed Benojir , Rawal Lal B. , Alizadehsani Roohallah , Abawajy Jemal , Laranjo Liliana , Chow Clara K. , Maddison Ralph
Published: March 2022

Background

Hypertension is the most common modifiable risk factor for cardiovascular diseases in South Asia. Machine learning (ML) models have been shown to outperform clinical risk predictions compared to statistical methods, but studies using ML to predict hypertension at the population level are lacking. This study used ML approaches in a dataset of three South Asian countries to predict hypertension and its associated factors and compared the model's performances.

Methods

We conducted a retrospective study using ML analyses to detect hypertension using population-based surveys. We created a single dataset by harmonizing individual-level data from the most recent nationally representative Demographic and Health Survey in Bangladesh, Nepal, and India. The variables included blood pressure (BP), sociodemographic and economic factors, height, weight, hemoglobin, and random blood glucose. Hypertension was defined based on JNC-7 criteria. We applied six common ML-based classifiers: decision tree (DT), random forest (RF), gradient boosting machine (GBM), extreme gradient boosting (XGBoost), logistic regression (LR), and linear discriminant analysis (LDA) to predict hypertension and its risk factors.

Results

Of the 8,18,603 participants, 82,748 (10.11%) had hypertension. ML models showed that significant factors for hypertension were age and BMI. Ever measured BP, education, taking medicine to lower BP, and doctor's perception of high BP was also significant but comparatively lower than age and BMI. XGBoost, GBM, LR, and LDA showed the highest accuracy score of 90%, RF and DT achieved 89 and 83%, respectively, to predict hypertension. DT achieved the precision value of 91%, and the rest performed with 90%. XGBoost, GBM, LR, and LDA achieved a recall value of 100%, RF scored 99%, and DT scored 90%. In F1-score, XGBoost, GBM, LR, and LDA scored 95%, while RF scored 94%, and DT scored 90%. All the algorithms performed with good and small log loss values <6%.

Conclusion

ML models performed well to predict hypertension and its associated factors in South Asians. When employed on an open-source platform, these models are scalable to millions of people and might help individuals self-screen for hypertension at an early stage. Future studies incorporating biochemical markers are needed to improve the ML algorithms and evaluate them in real life.
Impact of the COVID-19 Pandemic on ST-Elevation Myocardial Infarction Management in Hunan Province, China: A Multi-Center Observational Study
Authors: Tang Liang , Wang Zhao-jun , Hu Xin-qun , Fang Zhen-fei , Zheng Zhao-fen , Zeng Jian-ping , Jiang Lu-ping , Ouyang Fan , Liu Chang-hui , Zeng Gao-feng , Guo Yong-hong , Zhou Sheng-hua
Published: March 2022

Background

This study aimed to investigate the impact of the COVID-19 pandemic on ST-segment elevation myocardial infarction (STEMI) care in China.

Methods

We conducted a multicenter, retrospective cohort study in Hunan province (adjacent to the epidemic center), China. Consecutive patients presenting with STEMI within 12 h of symptom onset and receiving primary percutaneous coronary intervention, pharmaco-invasive strategy and only thrombolytic treatment, were enrolled from January 23, 2020 to April 8, 2020 (COVID-19 era group). The same data were also collected for the equivalent period of 2019 (pre-COVID-19 era group).

Results

A total of 610 patients with STEMI (COVID-19 era group n = 286, pre-COVID-19 era group n = 324) were included. There was a decline in the number of STEMI admissions by 10.5% and STEMI-related PCI procedures by 12.7% in 2020 compared with the equivalent period of 2019. The key time intervals including time from symptom onset to first medical contact, symptom onset to door, door-to-balloon, symptom onset to balloon and symptom onset to thrombolysis showed no significant difference between these two groups. There were no significant differences for in-hospital death and major adverse cardiovascular events between these two groups.

Conclusion

During the COVID-19 pandemic outbreak in China, we observed a decline in the number of STEMI admissions and STEMI-related PCI procedures. However, the key quality indicators of STEMI care were not significantly affected. Restructuring health services during the COVID-19 pandemic has not significantly adversely influenced the in-hospital outcomes.
Thrombosis and Inflammation—A Dynamic Interplay and the Role of Glycosaminoglycans and Activated Protein C
Authors: Kohli Shrey , Shahzad Khurrum , Jouppila Annukka , Holthöfer Harry , Isermann Berend , Lassila Riitta
Published: March 2022

Hemostasis, thrombosis, and inflammation are tightly interconnected processes which may give rise to thrombo-inflammation, involved in infectious and non-infectious acute and chronic diseases, including cardiovascular diseases (CVD). Traditionally, due to its hemostatic role, blood coagulation is isolated from the inflammation, and its critical contribution in the progressing CVD is underrated, until the full occlusion of a critical vessel occurs. Underlying vascular injury exposes extracellular matrix to deposit platelets and inflammatory cells. Platelets being key effector cells, bridge all the three key processes (hemostasis, thrombosis, and inflammation) associated with thrombo-inflammation. Under physiological conditions, platelets remain in an inert state despite the proximity to the endothelium and other cells which are decorated with glycosaminoglycan (GAG)-rich glycocalyx (GAGs). A pathological insult to the endothelium results in an imbalanced blood coagulation system hallmarked by increased thrombin generation due to losses of anticoagulant and cytoprotective mechanisms, i.e., the endothelial GAGs enhancing antithrombin, tissue factor pathway-inhibitor (TFPI) and thrombomodulin-protein C system. Moreover, the loss of GAGs promotes the release of mediators, such as von Willebrand factor (VWF), platelet factor 4 (PF4), and P-selectin, both locally on vascular surfaces and to circulation, further enhancing the adhesion of platelets to the affected sites. Platelet-neutrophil interaction and formation of neutrophil extracellular traps foster thrombo-inflammatory mechanisms exacerbating the cardiovascular disease course. Therefore, therapies which not only target the clotting mechanisms but simultaneously or independently convey potent cytoprotective effects hemming the inflammatory mechanisms are expected to provide clinical benefits. In this regard, we review the cytoprotective protease activated protein C (aPC) and its strong anti-inflammatory effects thereby preventing the ensuing thrombotic complications in CVD. Furthermore, restoring GAG-like vasculo-protection, such as providing heparin-proteoglycan mimetics to improve regulation of platelet and coagulation activity and to suppress of endothelial perturbance and leukocyte-derived pro-inflammatory cytokines, may provide a path to alleviate thrombo-inflammatory disorders in the future. The vascular tissue-modeled heparin proteoglycan mimic, antiplatelet and anticoagulant compound (APAC), dual antiplatelet and anticoagulant, is an injury-targeting and locally acting arterial antithrombotic which downplays collagen- and thrombin-induced and complement-induced activation and protects from organ injury.
Strengthening Health Systems Using Innovative Digital Health Technologies in Africa
Authors: Ibeneme Sunny , Karamagi Humphrey , Muneene Derrick , Goswami Kajali , Chisaka Noel , Okeibunor Joseph
Published: March 2022

While effective health systems are needed to advance Universal Health Coverage and actualize the health Sustainable Development Goals, information system verticalization remains a challenge among African health systems. Most investments are vertical, partner-driven and program-specific with limited system-wide impacts. Poor linkages exist amongst different solutions as they are not designed to capture robust data across multiple programmatic areas. To address these challenges, the World Health Organization Africa Regional Office has proposed the adoption of a Digital Health Platform (DHP) to streamline different solutions to a cohesive whole. The DHP presents a pragmatic approach of bringing multiple platforms together using recognized standards to create a national infostructure, which bridges information solutions toward healthy and sustainable outcomes. It has capacities to curate accurate, high fidelity and timely data feedback loops needed to strengthen and continuously improve program delivery, monitoring, management, and informed decision-making at every level of the health system regardless of location. This paper contributes to the ongoing regional conversations on the need to harness innovative digital solutions to improve healthcare delivery in Africa.
The Effects of Freeze–Thaw Cycles on Methane Emissions From Peat Soils of a High-Altitude Peatland
Authors: Yang Zao , Zhu Dan , Liu Liangfeng , Liu Xinwei , Chen Huai
Published: March 2022

The Qinghai– Tibet Plateau (QTP), which embodies the largest area of permafrost at mid–low altitudes of the world, has been experiencing rapid permafrost degradation and changes in freeze–thaw processes for the past decades. However, the responses and potential feedbacks of the methane flux from peatlands on the QTP to changing freeze–thaw cycles (FTCs) remain unknown. In this study, we collected peat soils from the Zoîgé peatlands, the largest peatland complex on the QTP, to examine methane emissions under simulated diurnal FTC scenarios. In incubation experiments of 15 days, two freeze–thaw temperature ranges of −5 to 4°C (mild) and −15 to 4°C (intense) were applied to two sets of peat soil samples, and each of them was characterized by 100% or 80% maximum water holding capacity (MWHC). The results showed that the peak of methane emission from the peat soil occurred after the first freeze–thaw cycle (FTC1), with the highest reaching a value of 0.103 mg kg soil−1·h−1. Generally, the cumulative methane emissions were elevated by FTCs, and relative higher rates of methane emissions were found for the 2nd FTC to the 15th FTC, compared with those from low-altitude peatlands. Methane emissions were significantly correlated to the export of dissolved organic carbon (DOC) and the activities of β-D-cellobiosidase and phenol oxidase in various freeze–thaw conditions. This study highlights the importance of FTCs in stimulating methane emissions and implies that methane emissions during FTCs from high-altitude peatlands would increase under a warmer climate in the future.
Fractal Characteristics and Energy Dissipation of Granite After High-Temperature Treatment Based on SHPB Experiment
Authors: Liu Lei , Wang Yuan , An Huaming
Published: March 2022

In deep mining and high-concentration nuclear waste storage engineering, the surrounding rocks may be subjected to the combined action of high-temperature fire and impact load. In this study, the fracture morphology and the energy dissipation of granite following high-temperature treatment at 25–800°C were analyzed using the split Hopkinson pressure bar (SHPB) device. The fracture characteristics and the dynamic mechanical properties of granite were determined. The energy dissipation of granite specimens affected by high temperatures in the SHPB experiment was also analyzed. When the temperature of the impact rate was less than 200°C, the fragmentation degree, transmitted energy, and dissipated energy of granite increased with an increase in temperature. When the temperature was higher than 200°C, the change law was opposite. A strong linear correlation existed among the fragmentation, fractal dimension, and energy consumption density of granite at different impact rates after high-temperature treatment. Moreover, a strong quadratic correlation existed between the damage factors and temperature. When the temperature was less than 200°C, the damage factor decreased with the increase in temperature. When the temperature was higher than 200°C, the change law was opposite, which corresponded with the influence law of temperature on dynamic compressive strength. Scanning electron microscopy and X-ray diffraction analyses were conducted to study the fracture modes and mineral composition changes in the granites. A quantitative relationship existed between macro- and meso-properties. The results could provide theoretical basis for the design of underground engineering structures, post-disaster assessment, and rehabilitation activities.
Austrian Students’ Perceptions of Social Distancing and Their Emotional Experiences During Distance Learning Due to the COVID-19 Pandemic
Authors: Heidrich Franziska , Pozas Marcela , Letzel Verena , Lindner Katharina-Theresa , Schneider Christoph , Schwab Susanne
Published: March 2022

The COVID-19 pandemic has led to far-reaching changes in various aspects of students’ lives. In the particular case of the educational field, classroom teaching was drastically shifted to a distance learning format. Consequently, students needed to deal with a completely different everyday school life. Learning was carried out online, which implied that students could not see some of their regular, important social contacts such as teachers, classmates or friends. It is already proven that such social distancing measures had impacts on students’ emotional experiences during the lockdown. Following a mixed-methods concurrent single-phase design, this study examined students’ perceptions of social distancing and their emotional experiences during the first school lockdown in Austria. Data from an online survey (n = 263 students) and from qualitative interviews (n = 56 students) were analyzed. The results show that distance learning drastically reduced interaction among students and between students and their teachers. Furthermore, the results indicate negative emotional experiences due to less social contact, increased learning pressures, and less structure. However, findings revealed that students also experience and perceived positive emotional experiences during distance learning because of more freedom, autonomy, and to some extent, less performance pressure. Based on the findings, the present study discusses possible perspectives on how to support students during and after distance learning, as well as further lines of research.
Single-Dose Versus Multiple-Dose GnRH Agonist for Luteal-Phase Support in Women Undergoing IVF/ICSI Cycles: A Network Meta-Analysis of Randomized Controlled Trials
Authors: Liu Yang , Wu Yanzhi , Pan Zhengmei , Jiang Fangjie , Lu Youhui , Meng Yushi
Published: March 2022

Background

Although gonadotropin-releasing hormone (GnRH) agonist has been introduced as a beneficial luteal phase support (LPS), the optimal strategy of GnRH agonist remains unclear. This network meta-analysis was therefore performed to determine the comparative efficacy and safety of multiple-dose versus single-dose GnRH agonist protocol for LPS in patients undergoing IVF/ICSI cycles.

Methods

We searched relevant studies in PubMed, Embase and the Cochrane Registry of Controlled Trials (CENTRAL) from their inception util to September 2021. Live birth, clinical pregnancy rate, multiple pregnancy rate, and clinical abortion rate was evaluated. Pairwise and network meta-analysis were conducted using RevMan and ADDIS based on random-effects model, respectively. Moreover, the prioritization of protocols based on ranking probabilities for different outcomes were performed.

Results

Sixteen RCTs met our eligibility criteria. Pairwise meta-analysis showed that multiple-dose protocol of GnRH agonist was effective for increasing live birth rate (OR 1.80, 95% CI 1.15 to 2.83, p=0.01) and clinical pregnancy rate (OR 1.89, 95% CI 1.01 to 3.56, p=0.05) as well as decreasing clinical abortion rate (OR 0.55, 95% CI 0.34 to 0.90, p=0.02). Meanwhile, single-dose protocol of GnRH agonist was effective for increasing clinical pregnancy rate (OR 1.45, 95% CI 1.11 to 1.89, p=0.007) and multiple pregnancy rate (OR 2.55, 95% CI 1.12 to 5.78, p=0.03). However, network meta-analysis only confirmed that multiple-dose protocol of GnRH agonist was the best efficacious strategy for live birth rate (OR 2.04, 95% CrI 1.19 to 3.93) and clinical pregnancy rate (OR 2.10, 95% CrI 1.26 to 3.54).

Conclusion

Based on the results of NMA, multiple-dose protocol may be the optimal strategy for patients undergoing IVF/ICSI cycles owing to its advantage in increasing live birth and clinical pregnancy rate. Moreover, single-dose protocol may be the optimal strategy for improving multiple pregnancy rate. However, with the limitations, more RCTs are required to confirm our findings.
Surgical Treatment of Obesity. Special Mention to Roux-en-Y Gastric Bypass and Vertical Gastrectomy
Authors: Luesma María José , Fernando José , Cantarero Irene , Lucea Pilar , Santander Sonia
Published: March 2022

Introduction

The prevalence of obesity has increased exponentially in recent decades, being one of the diseases that most affects global health. It is a chronic disease associated with multiple comorbidities, which lead to a decrease in life expectancy and quality of life. It requires a multidisciplinary approach by a specialized medical team. Obesity can be treated with conservative or with surgical treatments that will depend on the characteristics of the patient.

Objective/Methodology

The referenced surgery can be performed using different surgical techniques that are analyzed in the present work through an exhaustive narrative bibliographic review in the PubMed and Cochrane databases, as well as in UpToDate.

Results

Currently, those most used are restrictive techniques, specifically vertical gastrectomy and mixed techniques, with gastric bypass being the “gold standard”.

Conclusions

In order to choose one technique or another, the characteristics of each patient and the experience of the surgical team must be taken into account.
Stochastic Steady-State Security Assessment for Power System Operation by Chance Constrained Optimal Power Flow-Based Load Shedding
Authors: Zhou Xinyu , Jiang Yingying , Yang Chen , Xu Dan , Tang Junjie , Xie Kaigui
Published: March 2022

The operational uncertainty of the power system is significantly increased by the high penetration of renewable energy and diversification of load behavior, which have aroused the novel research on stochastic steady-state security assessment (SSSA) urgently when the operational condition gets worse and contingency happens more frequently. First of all, a novel contingency analysis model has been proposed based on chance constrained optimal power flow (CCOPF) in this work, which is able to give a comprehensive consideration on conventional generator outage, uncertainty of system operation and load shedding of interruptible loads (ILs). Moreover, the proposed model is very practical and can be solved much efficiently by an iteration method so that the purpose of secure system operation after contingency can be better realized. Second, to further enhance the steady-state security of the system, a novel pricing method for ILs has been developed here. In addition, a composite contingency ranking index has been also established to reflect the severity of generator outage more accurately. Finally, extensive study results based on a modified IEEE-39 test system have demonstrated the validity of the proposed model, which can hold a good balance amongst security, economy, controllability, and maneuverability.
Stochastic and Iterative Based Optimization for Enhancing Dynamic Performance of Interconnected Power System With Hybrid Energy Storage
Authors: Sivadanam Niveditha , Bhookya Nagu , Maheswarapu Sydulu
Published: March 2022

With the growing dominance of inverter-based resources (IBRs), the synchronous inertia of the interconnected power systems (IPSs) is affected. The increase in IBRs results in a decrease in the system inertia. The decrease in inertia impacts the initial rate of decline of the frequency. Thus, there is a need for faster frequency response requirements to enhance the dynamic performance of the IPS. With the massive penetration of the plug-in hybrid electric vehicles (PHEVs) into expanding smart cities, PHEVs can act as controllable loads which support the inertial response of the system in a rapid manner. This gives a scope to monitor a large amount of EV operational data to ensure reliable operation considering extensive penetration of EVs. This study proposes a stochastic and iterative based optimization for a two-area interconnected power system (IPS) coupled with a hybrid energy storage system (HESS). The HESS uses 10,000 plug-in hybrid electric vehicles (PHEVs) in each area and a superconducting magnetic energy storage (SMES) device to aid load frequency control (LFC). The 10,000 PHEVs would contribute to massive operational data, which needs to be considered while studying the IPS dynamic performance. Here, we investigated two discrete tie lines: HVDC links parallel to the alternating current (AC) tie line and a virtual synchronous power-based (VSP)-HVDC link parallel to the AC tie line. The controller’s optimal parameters are recorded using two meta-heuristic algorithms, that is, particle swarm optimization (PSO) and biogeography-based optimization (BBO) along with simultaneous coordinated tuning of secondary controller and storage units. Results are taken both in the presence and absence of a HESS with two types of tie links. The analysis is performed with typical load changes and sensitivity analysis scenarios for an accurate record of variations in the outcomes. Thus, the proposed BBO-based LFC tracks the supply and demand variations, ensuring precision and accuracy, indicating improved IPS dynamic performance in smart cities.
Modeling Study on Oil Particle Filtration Performance of a Composite Coalescing Filter
Authors: Lyu Le , Zhang Jun , Xu ChengWei
Published: March 2022

The traditional theoretical model is not suitable for the simulation of the oil particle filtration process of a composite filter due to its huge difference in fiber diameter. In this paper, the concept of fiber dispersion σ was introduced into a mathematical model for describing the dynamic filtration process of a composite filter. The results show that the model is in good agreement with the experimental data. As the packing density is constant, the higher the fiber dispersion, the better performance is. In addition, the effect of different factors on the efficiency of different mechanisms was discussed. For fine particles (<0.1 μm), diffusion is the dominant mechanism. For coarse particles (>1 μm), the inertia impaction mechanism dominates the filtration efficiency. The fiber diameter has a significant effect on the inertia impaction mechanism. The single-fiber efficiency by inertia impaction mechanism is obviously affected by filtration velocity. The packing density has an effect on all mechanisms except for the diffusion mechanism. Moreover, such a model would contribute to an accurate prediction of the dynamic filtration performance of composite filters with polydisperse fiber diameter and improve performance by adjusting parameters reasonably.
Endangered Dracaena ombet Population in the Red Sea Hills, Sudan, Recovers After Abrupt Change
Authors: Andersen Gidske L. , Krzywinski Knut , Talib Mohammed , Musa Mohammed A. M.
Published: March 2022

The endangered and endemic Nubian dragon blood tree, Dracaena ombet, has been feared extirpated from core distribution areas in the Red Sea Hills, Sudan, after reported mass death events in the 20th century. Populations of dragon tree species are generally reported to be in decline, with a noticeable lack of recruitment and possible poor resilience. Rare recruitment events are, however, normal for species with remnant population dynamics, and when eventually occurring, such events can restore seemingly degraded populations. In response to recently reported observations of dracaena saplings in a historically core distribution area of the Red Sea Hills, we assess the status of this long-lived arboreal species. We describe a current realized niche, investigate a potential range shift by comparing the spatial distribution of saplings and older individuals, and assess population recovery based on pre-disturbance system identity derived from qualitative, historical observations. We document a beginning recovery of the dracaena population in the study area. Around half of the mapped population are individuals in the sapling stage, and they are in good health. Its current realized niche is described by higher altitudes, steeper slopes, more concave landscape forms and east-facing aspects compared to areas where dracaena individuals are absent. However, for the new generation of dracaena saplings we find signs of a leaning range shift where saplings are shifted towards higher altitudes near the mist-influenced escarpment. A full collapse and eventual extirpation of the endangered Dracaena ombet population may at best be averted, or at least delayed in the study area. Our resilience analysis indicates that a full recovery will be a slow process due to the inherent natural climate variability of arid lands, only allowing sporadic regeneration. Considering this species’ information legacy, saplings seem to be well equipped to survive such variability, but perhaps within a restricted safe operating space. Conservation measures should therefore be taken to secure the survival of the new generation along with broader spatial scale studies to confirm whether our findings reflect a regional phenomenon.
Relevance of Nutrient-Sensing in the Pathogenesis of Trichophyton rubrum and Trichophyton interdigitale
Authors: Cruz Aline H. S. , Santos Rodrigo S. , Martins Maíra P. , Peres Nalu T. A. , Trevisan Glauce L. , Mendes Niege S. , Martinez-Rossi Nilce M. , Rossi Antonio
Published: March 2022

The growth and development of organisms depend on nutrient availability. Dermatophytes must sense nutrient levels and adapt to the host environment to colonize human and animal keratinized tissues. Owing to the clinical importance of the Trichophyton genus, this study compared the expression profile of genes involved in metabolism, cell cycle control, and proteases in two Trichophyton species, Trichophyton rubrum, and Trichophyton interdigitale, in response to nutrients and environmental pH. In addition, we evaluated the activity of enzymes in the tricarboxylic acid, glyoxylate, and methylcitrate cycles. Moreover, the effects of interruption of the transcription factor pacC on T. interdigitale in the same conditions as for the wild-type strain were determined. Our analyses revealed specific responses in each species to the nutritional and pH variation. An improved adaptation of T. interdigitale to keratin was observed, compared with that of T. rubrum. T. rubrum growth in buffered keratin media indicated pH 8.0 as an optimal pH condition for metabolic activity, which differed from that for T. interdigitale. Tricarboxylic acid components in T. rubrum showed increased enzymatic activity and transcript accumulation. In T. interdigitale, a higher activity of enzymes in glyoxylate and methylcitrate cycles was observed, with no direct correlation to the transcriptional profile. T. interdigitale fungal metabolism suggests the requirement of anaplerotic pathways in the late cultivation period. The identified differences between T. rubrum and T. interdigitale may represent determinants for adaptation to the host and the incidence of infection with each species.