bluuebunny/crossref_metadata_2025 huggingface dataset:
Letrozole protects against cadmium-induced inhibition of spermatogenesis via LHCGR and Hsd3b6 to activate testosterone synthesis in mice
Authors: Yao Yao , Wan Yangyang , Shi Xiaoyun , Guo Lan , Jiang Hui , Zhang Xiansheng , Xu Bo , Hua Juan
Published: March 2022

The heavy metal cadmium is proposed to be one of the environmental endocrine disruptors of spermatogenesis. Cadmium-induced inhibition of spermatogenesis is associated with a hormone secretion disorder. Letrozole is an aromatase inhibitor that increases peripheral androgen levels and stimulates spermatogenesis. However, the potential protective effects of letrozole on cadmium-induced reproductive toxicity remain to be elucidated. In this study, male mice were administered CdCl2 (4 mg/kg BW) orally by gavage alone or in combination with letrozole (0.25 mg/kg BW) for 30 days. Cd exposure caused a significant decreases in body weight, sperm count, motility, vitality, and plasma testosterone levels. Histopathological changes revealed extensive vacuolization and decreased spermatozoa in the lumen. However, in the Cd + letrozole group, letrozole treatment compensated for deficits in sperm parameters (count, motility, and vitality) induced by Cd. Letrozole treatment significantly increased serum testosterone levels, which were reduced by Cd. Histopathological studies revealed a systematic array of all germ cells, a preserved basement membrane and relatively less vacuolization. For a mechanistic examination, RNA-seq was used to profile alterations in gene expression in response to letrozole. Compared with that in the Cd-treated group, RNA-Seq analysis showed that 214 genes were differentially expressed in the presence of letrozole. Gene ontology (GO) enrichment analysis and KEGG signaling pathway analysis showed that steroid biosynthetic processes were the processes most affected by letrozole treatment. Furthermore, we found that the expression of the testosterone synthesis-related genes LHCGR (luteinizing hormone/choriogonadotropin receptor) and Hsd3b6 (3 beta- and steroid delta-isomerase 6) was significantly downregulated in Cd‐treated testes, but these genes maintained similar expression levels in letrozole-treated testes as those in the control group. However, the transcription levels of inflammatory cytokines, such as IL-1β and IL-6, and oxidative stress-related genes (Nrf2, Nqo1, and Ho-1) showed no changes. The present study suggests that the potential protective effect of letrozole on Cd-induced reproductive toxicity might be mediated by the upregulation of LHCGR and Hsd3b6, which would beneficially increase testosterone synthesis to achieve optimum protection of sperm quality and spermatogenesis.
Knowledge gaps and national research priorities for COVID-19 in Iran
Authors: Yazdizadeh Bahareh , Ehsani-Chimeh Elham , Zendehdel Kazem , Mobinizadeh Mohammadreza , Mesgarpour Bita , Fakoorfard Zeinab
Published: March 2022

Background

In the present COVID-19 crisis, one of the greatest challenges for research funding at both the international and national level is selecting the best research topic to achieve efficiency and equity in health research and to address the knowledge gap urgently raised due to the event. Despite international recommendations, countries should consider their context-specific situation and define local research priorities. We aimed to exercise a priority-setting activity to identify the knowledge gaps and suggest research priorities in response to the COVID-19 epidemic in Iran.

Methods

First, we tried to identify the contextual knowledge gaps based on an online survey, performing key informant interviews (i.e. health professionals, policy-makers and managers) and media analysis. We also performed a literature review and considered international research priorities for COVID-19. Subsequently, we prepared a list of research questions and challenges to respond to the COVID-19 crisis in Iran using a systems approach. Then we mapped approved COVID-19 research projects in the country to research questions. Finally, we compared the identified research questions (not challenges) with the prioritized research from international organizations and then prioritized them for Iran.

Results

We found risk factors and epidemiological dissemination patterns of the virus and its consequences in an epidemiology domain, implementation of clinical and hygiene in a clinical management domain, genetic studies for targeting prevention and treatment in a candidate treatment and vaccine research and development (R&D) knowledge domain, examination of the manifestations of ethics in society instead of ethics in research in an ethics domain, “care, access and health system” and “public health and participation in response to public health and clinical research” as two sub-domains of a social sciences domain, and finally, no new questions in either the virology, transmission, diagnosis or animal and environmental domain.

Conclusions

In the event of global health crises like COVID-19, prioritization of research questions can be done globally, but some of the research priorities are context-specific and may vary by regional needs. To better manage research resources, researchers must respond to the challenges faced in each country based on its political, economic, social and cultural characteristics, and to make evidence-informed decisions, global knowledge gaps must be customized in each country.
The mechanisms of mutual relationship between malignant hematologic cells and mesenchymal stem cells: Does it contradict the nursing role of mesenchymal stem cells?
Authors: Goodarzi Alireza , Valikhani Mohsen , Amiri Fatemeh , Safari Armita
Published: March 2022

Mesenchymal stem/stromal cells (MSCs) are known as the issue in biology because of some unpredictable characteristics in the different microenvironments especially in their bone marrow niche. MSCs are used in the regenerative medicine because of their unique potentials for trans-differentiation, immunomodulation, and paracrine capacity. But, their pathogenic and pro-survival effects in tumors/cancers including hematologic malignancies are indisputable. MSCs and/or their derivatives might be involved in tumor growth, metastasis and drug resistance in the leukemias. One of important relationship is MSCs and hematologic malignancy-derived cells which affects markedly the outcome of disease. The communication between these two cells may be contact-dependent and/or contact-independent. In this review, we studied the crosstalk between MSCs and malignant hematologic cells which results the final feedback either the progression or suppression of blood cell malignancy.

Graphical abstract
Perceptions of physical activity and sedentary behaviour guidelines among end-users and stakeholders: a systematic review
Authors: Hollman Heather , Updegraff John A. , Lipkus Isaac M. , Rhodes Ryan E.
Published: March 2022

Background

Many of the world’s population, across all age groups and abilities, are not meeting or even aware of internationally recommended physical activity (PA) and sedentary behaviour (SB) guidelines. In order to enhance awareness and uptake, guidelines should be perceived positively by targeted users. The purpose of this study was to review the literature on end-user and stakeholder perceptions of PA and SB guidelines.

Methods

The electronic databases APA PsycInfo, CINAHL, MEDLINE, and SPORTDiscus, using EBSCOhost Research Platform, and Web of Science were searched from inception to June, 2021 with keyword synonyms for “perceptions”, “PA guidelines”, and “SB guidelines”. Studies of any design that collected stakeholder and/or end-user responses to a PA and/or SB guideline were included and assessed for risk of bias. The PA and/or SB guideline could be any type of official form (e.g., national documents, organizational guidelines, expert consensus statements, etc.) from any country, that targets individuals at the regional, provincial/statewide, national, or international level, and includes all types of guidelines (e.g., strength, aerobic, clinical, nonclinical, screen-time, sitting, etc.). Data were extracted and analyzed using thematic synthesis.

Results

After screening 1399 abstracts and applying citation screening, 304 full-texts were retrieved. A total of 31 articles met the inclusion criteria. End-users and stakeholders for PA guidelines across all age groups expressed the need for simplified language with more definitions, relatable examples and imagery, and quantification of PA behaviours. There was concern for the early years and child PA guidelines leading to guilt amongst parents and the SB guidelines, particularly the recommendations to limit screen-time, being unrealistic. General age group PA guidelines were not perceived as usable to populations with differing abilities, clinical conditions, and socioeconomic status. Guidelines that targeted clinical populations, such as persons with multiple sclerosis and persons with spinal cord injury, were well received.

Conclusions

There is a clear need to balance the evidence base with the pragmatic needs of translation and uptake so that the guidelines are not ignored or act as a barrier to actual engagement.
Evaluation of neuroprotective and immunomodulatory properties of mesenchymal stem cells in an ex vivo retinal explant model
Authors: Reboussin Élodie , Buffault Juliette , Brignole-Baudouin Françoise , Réaux-Le Goazigo Annabelle , Riancho Luisa , Olmiere Céline , Sahel José-Alain , Mélik Parsadaniantz Stéphane , Baudouin Christophe
Published: March 2022

Background

Glaucoma is a blinding degenerative neuropathy in which the death of retinal ganglion cells (RGCs) causes progressive loss of visual field and eventually vision. Neuroinflammation appears to be a key event in the progression and spread of this disease. Thus, microglial immunomodulation represents a promising therapeutic approach in which mesenchymal stem cells (MSCs) might play a crucial role. Their neuroprotective and regenerative potentials have already raised hope in animal models. Yet no definitive treatment has been developed, and some safety concerns have been reported in human trials. In the present study, we investigated the neuroprotective and immunomodulatory properties as well as the safety of MSCs in an ex vivo neuroretina explant model.

Methods

Labeled rat bone marrow MSCs were placed in coculture with rat retinal explants after optic nerve axotomy. We analyzed the neuroprotective effect of MSCs on RGC survival by immunofluorescence using RBPMS, Brn3a, and NeuN markers. Gliosis and retinal microglial activation were measured by using GFAP, CD68, and ITGAM mRNA quantification and GFAP, CD68, and Iba1 immunofluorescence stainings. We also analyzed the mRNA expression of both ‘M1’ or classically activated state inflammatory cytokines (TNFα, IL1β, and IL6), and ‘M2’ or alternatively activated state microglial markers (Arginase 1, IL10, CD163, and TNFAIP6).

Results

The number of RGCs was significantly higher in retinal explants cultured with MSCs compared to the control group at Day 7 following the optic nerve axotomy. Retinal explants cultured with MSCs showed a decrease in mRNA markers of gliosis and microglial activations, and immunostainings revealed that GFAP, Iba1, and CD68 were limited to the inner layers of the retina compared to controls in which microglial activation was observed throughout the retina. In addition, MSCs inhibited the M1 phenotype of the microglia. However, edema of the explants was observed in presence of MSCs, with an increase in fibronectin labeling at the surface of the explant corresponding to an epiretinal membrane-like phenotype.

Conclusion

Using an ex vivo neuroretina model, we demonstrated a neuroprotective and immunomodulatory effect of MSCs on RGCs. Unfortunately, the presence of MSCs also led to explant edema and epiretinal membrane formation, as described in human trials. Using the MSC secretome might offer the beneficial effects of MSCs without their potential adverse effects, through paracrine signaling.
Microglial VPS35 deficiency impairs Aβ phagocytosis and Aβ-induced disease-associated microglia, and enhances Aβ associated pathology
Authors: Ren Xiao , Yao Lingling , Wang YongGang , Mei Lin , Xiong Wen-Cheng
Published: March 2022

Background

Vacuolar sorting protein 35 (VPS35), a key component of the retromer, plays an essential role in selectively retrieval of transmembrane proteins from endosomes to trans-Golgi networks. Dysfunctional retromer is a risk factor for neurodegenerative disorders, including Alzheimer’s disease (AD). Microglial VPS35 deficiency is found in AD patients’ brain; however, it remains unclear if and how microglial VPS35-loss contributes to AD development.

Methods

We used mice with VPS35 cKO (conditional knockout) in microglial cells in 5XFAD, an AD mouse model. The AD related brain pathology (Aβ and glial activation), behavior, and phagocytosis of Aβ were accessed by a combination of immunofluorescence staining analyses and neurological behavior tests.

Results

A decrease in learning and memory function, but increases in insoluble, fibrillar, and plaques of β-amyloids (Aβ), dystrophic neurites, and reactive astrocytes are observed in microglial VPS35 deficient 5XFAD mice. Further examining microglial phenotype demonstrates necessity of microglial VPS35 in disease-associated microglia (DAM) development and microglial uptake of Aβ, revealing a tight association of microglial Aβ uptake with DAM development.

Conclusions

Together, these results uncovered a mechanism by which microglial VPS35-deficiency precipitates AD pathology in 5XFAD mice likely by impairing DAM development and DAM mediated Aβ uptake and clearance, and thus accelerating the cognition decline.
Psychometric study of the SF-36v2 in hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE)
Authors: Palao-Ocharan Paola , Prior Nieves , Pérez-Fernández Elia , Caminoa Magdalena ,   DV-HAE-QoL Study Group, Aberer W. , Betschel S. , Bygum A. , Campos R. A. , Csuka D. , Farkas H. , Gómez-Traseira C. , Grumach A. S. , Leibovich I. , Malbran A. , Moldovan D. , Mihaly E. , Obtulowicz K. , Porebski G. , Reshef A. , Staubach P. , Caballero Teresa
Published: March 2022

Background

The generic 36-item Short-Form Health Survey (SF-36v2) has been used to assess health related quality of life in adult patients with hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) even though it has not yet been validated for use in this specific disease.

Objective

This study aims to validate the SF-36v2 for use in adult patients with C1-INH-HAE.

Results

There was a very low item non-response rate (1–3.4%), with a high ceiling effect in 25/35 items and a low floor effect in 3/35 items. A moderate ceiling effect was observed in 5/8 dimensions of the SF-36v2, whereas no floor effect was noticed in any of the dimensions. Internal consistency was good to excellent with Cronbach's alpha coefficient ranging between 0.82 and 0.93 for the different dimensions. Construct validity was good: seven out of the 8 hypotheses defined on clinical criteria were confirmed, discriminant validity assessment showed significant differences among patients with different C1-INH-HAE severity, convergent validity showed a good correlation among the physical and mental component summaries of the SF-36v2 and the HAE-QoL total score (0.45 and 0.64 respectively, P < 0.001). Test–retest reliability was high with intraclass correlation coefficient varying from 0.758 to 0.962. The minimal clinically important difference was calculated by distribution methods and small differences in the domain scores and in the component summaries scores were shown to be meaningful. 

Conclusions

The psychometric properties of the SF-36v2 show it can be a useful tool to assess HRQoL in adult patients with C1-INH-HAE, although with some content validity limitation.

Methods

The psychometric properties of the SF-36v2 were evaluated in an international setting based on responses from 290 adult C1-INH-HAE patients in 11 countries.
Establishing and boosting communication in the European Reference Network for Rare Neurological Diseases (ERN-RND): the impact of offering free educational webinars
Authors: Brunelle Praschberger Alicia , Post Annemarie E. M. , Hermanns Sanja , Graessner Holm
Published: March 2022

Background

Since it first started operating in 2017, the European Reference Network for Rare Neurological Diseases (ERN-RND) implemented a multi-channel communication strategy to effectively reach its target audience: healthcare professionals, patients, researchers, industry representatives and the general public. We first created a website containing useful and up to date information, followed by social media accounts. Here, the analytical data collected about the ERN-RND website and social media channels was compared (Twitter, Facebook, YouTube) during two periods: October 2018 to September 2019, and the year after the ERN-RND free educational webinars were launched: from October 2019 to September 2020. This allowed us to quantify the impact of offering a tangible product (webinars) on the communication strategy.

Results

The analytical data obtained from October 2018 to September 2019 and from October 2019 to September 2020 clearly shows a significant increase in traffic and followers since the launch of the ERN-RND webinars in November 2019. We also created a communication survey which was disseminated between February and June 2021. We collected responses from 61 people: 38 healthcare professionals, 11 scientists, 10 patients (advocates), 2 industry representatives, 1 patient association, 1 charity representative, 1 resident and 1 master student. Most respondents answered “webinars” as the number one reason when asked about which content they look for on the ERN-RND website.

Conclusions

Offering a tangible product—such as the webinars presented in this report—to a specific target group (healthcare professionals) supported our communication strategy by driving traffic to ERN-RND communication channels. It has also successfully tackled ERN-RND’s general aim: by enabling the flow of knowledge on rare neurological and movement disorders to the medical community in hospitals treating patients with these rare and complex conditions, patients ultimately benefit from improved and faster diagnosis, care, and treatment. We aim to set up similar strategies to effectively reach other or the same target groups. For healthcare professionals, organising eConsultations via the Clinical Patient Management System or disseminating standards of care such as diagnostic and therapeutic algorithms as well as clinical practice guidelines might offer potential. For the patient community, organising customised and multilingual webinars could also work.
In-depth biological analysis of alteration in Plasmodium knowlesi-infected red blood cells using a noninvasive optical imaging technique
Authors: Firdaus Moh Egy Rahman , Muh Fauzi , Park Ji-Hoon , Lee Seong-Kyun , Na Sung-Hun , Park Won-Sun , Ha Kwon-Soo , Han Jin-Hee , Han Eun-Taek
Published: March 2022

Background

Imaging techniques are commonly used to understand disease mechanisms and their biological features in the microenvironment of the cell. Many studies have added to our understanding of the biology of the malaria parasite Plasmodium knowlesi from functional in vitro and imaging analysis using serial block-face scanning electron microscopy (SEM). However, sample fixation and metal coating during SEM analysis can alter the parasite membrane.

Methods

In this study, we used noninvasive diffraction optical tomography (DOT), also known as holotomography, to explore the morphological, biochemical, and mechanical alterations of each stage of P. knowlesi-infected red blood cells (RBCs). Each stage of the parasite was synchronized using Nycodenz and magnetic-activated cell sorting (MACS) for P. knowlesi and P. falciparum, respectively. Holotomography was applied to measure individual three-dimensional refractive index tomograms without metal coating, fixation, or additional dye agent.

Results

Distinct profiles were found on the surface area and hemoglobin content of the two parasites. The surface area of P. knowlesi-infected RBCs showed significant expansion, while P. falciparum-infected RBCs did not show any changes compared to uninfected RBCs. In terms of hemoglobin consumption, P. falciparum tended to consume hemoglobin more than P. knowlesi. The observed profile of P. knowlesi-infected RBCs generally showed similar results to other studies, proving that this technique is unbiased.

Conclusions

The observed profile of the surface area and hemoglobin content of malaria infected-RBCs can potentially be used as a diagnostic parameter to distinguish P. knowlesi and P. falciparum infection. In addition, we showed that holotomography could be used to study each Plasmodium species in greater depth, supporting strategies for the development of diagnostic and treatment strategies for malaria.

Graphical Abstract
Development of microsatellite markers for population genetics of biting midges and a potential tool for species identification of Culicoides sonorensis Wirth & Jones
Authors: Shults Phillip , Moran Megan , Blumenfeld Alexander J. , Vargo Edward L. , Cohnstaedt Lee W. , Eyer Pierre-Andre
Published: March 2022

Background

Proper vector surveillance relies on the ability to identify species of interest accurately and efficiently, though this can be difficult in groups containing cryptic species. Culicoides Latreille is a genus of small biting flies responsible for the transmission of numerous pathogens to a multitude of vertebrates. Regarding pathogen transmission, the C. variipennis species complex is of particular interest in North America. Of the six species within this group, only C. sonorensis Wirth & Jones is a proven vector of bluetongue virus and epizootic hemorrhagic disease virus. Unfortunately, subtle morphological differences, cryptic species, and mitonuclear discordance make species identification in the C. variipennis complex challenging. Recently, single-nucleotide polymorphism (SNP) analysis enabled discrimination between the species of this group; however, this demanding approach is not practical for vector surveillance.

Methods

The aim of the current study was to develop a reliable and affordable way of distinguishing between the species within the C. variipennis complex, especially C. sonorensis. Twenty-five putative microsatellite markers were identified using the C. sonorensis genome and tested for amplification within five species of the C. variipennis complex. Machine learning was then used to determine which markers best explain the genetic differentiation between species. This led to the development of a subset of four and seven markers, which were also tested for species differentiation.

Results

A total of 21 microsatellite markers were successfully amplified in the species tested. Clustering analyses of all of these markers recovered the same species-level identification as the previous SNP data. Additionally, the subset of seven markers was equally capable of accurately distinguishing between the members of the C. variipennis complex as the 21 microsatellite markers. Finally, one microsatellite marker (C508) was found to be species-specific, only amplifying in the vector species C. sonorensis among the samples tested.

Conclusions

These microsatellites provide an affordable way to distinguish between the sibling species of the C. variipennis complex and could lead to a better understanding of the species dynamics within this group. Additionally, after further testing, marker C508 may allow for the identification of C. sonorensis with a single-tube assay, potentially providing a powerful new tool for vector surveillance in North America.

Graphical Abstract
Molecular detection of a novel Ancylostoma sp. by whole mtDNA sequence from pangolin Manis javanica
Authors: Tuli Merga Daba , Li Hongyi , Li Song , Zhai Junqiong , Wu Yajiang , Huang Wanyi , Feng Yaoyu , Chen Wu , Yuan Dongjuan
Published: March 2022

Background

Ancylostoma species are hematophagous parasites that cause chronic hemorrhage in various animals and humans. Pangolins, also known as scaly anteaters, are mammals that live in soil environments where they are readily exposed to soil-borne parasitic nematodes. However, only a limited number of helminth species have been identified in this animal host so far.

Methods

Ancylostoma sp. was isolated from a wild pangolin, and the complete mitochondrial (mt) genome of Ancylostoma sp. was obtained by Illumina sequencing of total genomic DNA.

Results

The circular complete mt genome that was assembled had a total length of 13,757 bp and comprised 12 protein-coding genes (PCGs), 22 transfer ribosomal RNAs, two ribosomal RNAs (rRNAs), two non-coding regions and one AT-rich region, but lacked the gene coding for ATPase subunit 8 (atp8). The overall AT content of the mt genome of Ancylostoma sp. was 76%, which is similar to that of other nematodes. The PCGs used two start codons (ATT and TTG) and three stop codons (TAA, TAG, and T). The nucleotide identity of the 12 PCGs ranged from 83.1% to 89.7% and had the highest sequence identity with Ancylostoma caninum among species in the Ancylostomatidae family. Also, the pangolin-derived Ancylostoma sp. lacked repeat sequences in the non-coding regions and in the unique sequence of the short non-coding regions, which differentiated it from other Ancylostoma species. In addition, phylogenetic analyses of 18S rRNA and mtDNA sequences revealed that the Ancylostoma sp. was positioned in a separate branch in the subfamily Ancylostomatinae along with other Ancylostoma species.

Conclusions

The Ancylostoma sp. isolated from a pangolin in this study was identified as a possible new Ancylostoma species. The identification of this Ancylostoma sp. from pangolin enriches our knowledge of the species in the Ancylostomatidae family and provides information that will lead to a better understanding of the taxonomy, diagnostics, and biology of hookworms.

Graphical Abstract
RNA profiling of blood platelets noninvasively differentiates colorectal cancer from healthy donors and noncancerous intestinal diseases: a retrospective cohort study
Authors: Xu Luming , Li Xinbo , Li Xiangchun , Wang Xingyue , Ma Qian , She Dan , Lu Xiaohuan , Zhang Jiao , Yang Qianqian , Lei Shijun , Wang Lin , Wang Zheng
Published: March 2022

Background

The RNA profiles of tumor-educated platelets (TEPs) possess pathological features that could be used for early cancer detection. However, the utility of TEP RNA profiling in detecting early colorectal cancer (CRC) versus noncancerous colorectal diseases has not yet been investigated. This study assesses the diagnostic capacity of TEP RNA profiles in a cohort of patients with CRC and noncancerous diseases.

Methods

Transcriptome sequencing for platelets isolated from 132 patients with CRC at early and late stages and 190 controls consisting of healthy donors and patients with ulcerative disease, Crohn’s disease, polyps, and adenomas was performed and analyzed using binary particle swarm optimization coupled with support vector machine to identify genes that contributed to the classification of CRC patients versus controls. The area under the receiver operating curves (AUROCs) and the accuracy of TEP RNA profiles in CRC diagnosis were assessed.

Results

TEP RNA profiling achieved high performance in distinguishing and staging CRC patients from the controls. Using the swarm intelligence algorithm, the 921 most contributive genes that classified CRC patients from the controls were identified. AUROCs of 0.928 for the training set via leave-one-out cross-validation and 0.92 for the validation set were achieved, both of which were significantly higher than the clinically utilized serum biomarkers: carcinoembryonic antigen and cancer antigen 19-9. Notably, an AUROC of 0.915 in an external validation set was achieved. For predicting different CRC stages, an AUROC of 0.984 was achieved in the training set and 1.000 in the internal validation set.

Conclusions

RNA profiles of TEPs are of potential diagnostic value for identifying early CRC from noncancerous diseases. Prospective studies are needed to validate its clinical relevance.
Rhizophagus intraradices improves arsenic tolerance in Sophora viciifolia Hance
Authors: Zhang Qiaoming , Gong Minggui , Xu Shanshan , Wei Yanan , Yuan Jiangfeng , Chang Qingshan
Published: March 2022

Purpose

Arbuscular mycorrhizal fungi (AMF) are capable of protecting host plants against heavy metal toxicity, whereas rare knowledge has been acquired on the underlying effects of AMF on woody leguminous species under arsenic (As) stress. This study was aimed that whether AMF inoculation improves the As tolerance in Sophora viciifolia (a king of leguminous shrub).

Methods

S. viciifolia seedlings were inoculated with AMF Rhizophagus intraradices, and then the seedlings were grown at three levels (0, 50, and 100 mg As kg−1 soil) of As-polluted soil by performing the potted experiments. The plant growth, photosynthetic parameter, oxidative damage, antioxidant enzyme activities and gene expression of phytochelatin synthase in R. intraradices- and non-inoculated S. davidii seedlings under the different levels of As stress were analyzed.

Result

Compared with non-inoculated S. viciifolia at the identical As level, R. intraradices-inoculated S. viciifolia were higher in the shoot and root dry weight, plant height, root length, photosynthetic rate, stomatal conductance, transpiration rate, maximal photochemical efficiency of PSII photochemistry, actual quantum yield, and photochemical quenching values, while the intercellular CO2 concentration and non-photochemical quenching values were lower. As-induced oxidative stress generating malondialdehyde, hydrogen peroxide and superoxide in the S. viciifolia leaves and roots reduced significantly by R. intraradices inoculation, whereas the activities of antioxidative enzymes (e.g., superoxide dismutase, peroxidase, and catalase) in S. viciifolia leaves and roots were increased by R. intraradices inoculation. Notably, R. intraradices inoculation up-regulated the gene expression of S. viciifolia phytochelatins in the leaves and roots.

Conclusion

These results demonstrated that R. intraradices inoculation enhanced the As tolerance in S. viciifolia seedlings by improving the plant growth, gas exchange, chlorophyll fluorescence, reactive oxygen species, antioxidant enzymes and gene expression of S. viciifolia phytochelatins. The present study verified a multifarious positive role of AMF for woody leguminous species under As stress.
Downlink transmission and channel estimation for cell-free massive MIMO-OFDM with DSDs
Authors: Guo Yunxiang , Fan Zhenqi , Lu An , Wang Pan , Liu Dongjie , Xia Xinjiang , Wang Dongming
Published: March 2022

In a cell-free massive MIMO system, multiple users arrive at multiple access points at separate times, while in an OFDM system, different delays can be equivalent to delay spread differences (DSDs). Since DSDs are not all the same, in the downlink transmission process, it is necessary to consider its impact on transmission techniques, such as channel estimation and downlink precoding. In this paper, aiming at the performance loss caused by DSDs in cell-free massive MIMO-OFDM system, we propose a multi-RB precoding optimization algorithm that maximizes the downlink sum rate. We derive the sum rate maximization problem into an iterative second-order cone programming form to achieve convex approximation. Then, considering the impact of DSDs on the accuracy of cell-free massive MIMO-OFDM channel estimation, we propose a downlink channel estimation method, which jointly uses channel state information reference signal and demodulation reference signal. The simulation results show that the proposed multi-RB optimal precoding can effectively improve the downlink sum rate, and the proposed downlink channel estimation can obtain accurate multi-RB frequency-domain channel parameters.
Blockchain localization spoofing detection based on fuzzy AHP in IoT systems
Authors: Lv Wenzhe , Qiu Xuesong , Meng Luoming
Published: March 2022

Location spoof detection is a major component of location proofing mechanisms in internet of things (IoT), and it is significant for the system to assess the trustworthiness of the location data associated with the user. Unlike the work that employs physical layer features, we interest in building the infrastructure for a solution to establish location spoofing detection capabilities in blockchain-based IoT systems. In detail, at the node and the mobile trajectory level, we create an IoT system for evaluating the trustworthiness of location proofs with blockchain location system features. A blockchain-based multilayer fuzzy hierarchical analysis process (AHP) evaluation method is contemplated to detect location spoofing in the IoT system. Simulation results indicate the proposed method has a superior performance and provides a basis for the trustworthiness assessment of location proofs.
A new iterative approximation scheme for Reich–Suzuki-type nonexpansive operators with an application
Authors: Ofem Austine Efut , Işık Hüseyin , Ali Faeem , Ahmad Junaid
Published: March 2022

In this article, we propose a faster iterative scheme, called the AH iterative scheme, for approximating fixed points of contractive-like mappings and Reich–Suzuki-type nonexpansive mappings. We show that the AH iterative scheme converges faster than a number of existing iterative schemes for contractive-like mappings. The $w^{2}$

w
2

-stability result of the new iterative scheme is established and a supportive example is provided to illustrate the notion of $w^{2}$

w
2

-stability. Then, we prove weak and several strong convergence results of our new iterative scheme for fixed points of Reich–Suzuki-type nonexpansive mappings. Further, we carry out a numerical experiment to illustrate the efficiency of our new iterative scheme. As an application, we use our main result to prove the existence of a solution of a mixed-type nonlinear integral equation. An illustrative example to validate the result in our application is also given. Our results extend and generalize several related results in the existing literature.
Resistant starch (RS), a novel endogenous inert marker for detecting glucose absorption of small intestine with sweeteners administration in mice
Authors: Wu Yaran , Cai Lei , Xie Xingzi , Yang Shuying , Shi Qing , Jia Hongzhe , Gu Xuqiang , Deng Jingmin , Shi Mingzhao , Chen Qiuping , Cao Shaoqian , Cai Shuangfeng
Published: March 2022

Resistant starch could be degraded by the fermentation of colonic microorganisms in the large intestine of mammals, but not in the small intestine. In this study, we established a novel strategy by using resistant starch as an endogenous marker to determine the glucose absorption of the small intestine of laboratory animals. By optimization of the classical enzymatic method of starch measurement, the demand for the sample weight was reduced by 90%. Moreover, the amount of resistant starch in normal feed was detectable without any extra addition. The value of small intestine glucose absorption of mice was similar when using resistant starch and titanium dioxide as inert markers. The fermentation of resistant starch by intestinal microorganisms in the small intestine was demonstrated not disturbing the detection of glucose absorption significantly. Artificial sweeteners exposed ICR mice showed different glucose absorption which indicated, first, resistant starch can be used as a novel endogenous marker in the small intestine of small animals; second, although glucose tolerance did not change in mice after short-term exposure to artificial sweeteners, there were significant changes in glucose absorption associated with it; third, the short-term exposure resulted in no significant change in glucose tolerance.
Buprenorphine/naloxone access for people with opioid use disorder in correctional facilities: taking steps to support knowledge translation
Authors: Regenstreif Lori , Sadik Marina , Beaulieu Erin , Bodkin Claire , Kiefer Lori , Guenter Dale , Lee Patsy W. P. , Kouyoumdjian Fiona G.
Published: March 2022

People with opioid use disorders are overrepresented in correctional facilities, and are at high risk of opioid overdose. Despite the fact that buprenorphine/naloxone is the first line treatment for people with opioid use disorder, there are often institutional, clinical, and logistical barriers to buprenorphine/naloxone initiation in correctional facilities. Guided by the knowledge-to-action framework, this knowledge translation project focused on synthesizing knowledge and developing a tool for buprenorphine/naloxone initiation that was tailored to correctional facilities, including jails. This information and tool can be used to support buprenorphine/naloxone access for people in correctional facilities, in parallel with other efforts to address barriers to treatment initiation in correctional facilities.
Mental health, learning behaviour and perceived fatigue among university students during the COVID-19 outbreak: a cross-sectional multicentric study in the UAE
Authors: Mosleh Sultan M. , Shudifat Raed M. , Dalky Heyam F. , Almalik Mona M. , Alnajar Malek K.
Published: March 2022

Background

The rapid shift to online education due to COVID-19 quarantine challenged students’ ability to accept pure online learning without negative consequences for their physical, emotional and mental health. Some educational institutions introduced new strategies to reduce the psychosocial burden associated with online learning during home confinement. Thus, the primary aims were to determine the consequences of COVID-19 for the psychological well-being and fatigue levels of higher education students and to explore the effects of a new academic assessment approach in reducing home confinement stress.

Method

A cross-sectional online survey was conducted among students, from 30 August to 30 September 2020, of 7 disciplines in all 16 higher colleges of technology in the United Arab Emirates (UAE). The Mental Well-being and Learning Behaviours Scale and the modified Copenhagen Burnout Inventory were used to evaluate students’ psychological well-being and fatigue levels. A Welch t-test and Welch ANOVA were performed to determine the differences in perceived psychological well-being associated with students’ characteristics. Second, Kruskal_Wallis and Mann_Whitney were performed to determine the differences in fatigue level based on students’ characteristics.

Results

One thousand four hundred students participated. The majority were female (78.5%) and aged from 21–25 years (58.1%). Around 14% of respondents were married with children. Nearly 40% were satisfied with the new assessment approach introduced during the COVID pandemic and 45.5% perceived it as having reduced their home confinement stress. The mean psychological distress score of 3.00 (SD ± 0.71) indicates a moderate impact of COVID-19 on psychological well-being. Students’ psychological distress was positively correlated with fatigue level (0.256, p < 0.001) and negatively correlated with the perceived impact of the new assessment approach on student lifestyle (− 0.133, p < 0.001), physical health (− 0.149, p < 0.001) and coping with stress (− 0.125, p < 0.001). Male students experienced significantly lower fatigue and better psychological well-being than female students.

Conclusion

The study reveals that new assessment approaches which emerged during home confinement reduced students’ perception of stress and of impaired lifestyle. However, students still had a considerable burden of psychological distress, requiring further preventive measures to maintain their psychological well-being during future outbreak events. Educational institutions should consider additional strategies to improve students’ preparedness for online teaching, which could help maintain their psychological well-being.
Alternative migratory strategies related to life history differences in the Walleye (Sander vitreus)
Authors: McKee Graydon , Hornsby Rachael L. , Fischer Friedrich , Dunlop Erin S. , Mackereth Robert , Pratt Thomas C. , Rennie Michael
Published: March 2022

Background

While Pace of Life Syndrome predicts behavioural differences between individuals with differential growth and survival, testing these predictions in nature is challenging due to difficulties with measuring individual behaviour in the field. However, recent advances in acoustic telemetry technology have facilitated measurements of individual behaviour at scales not previously possible in aquatic ecosystems.

Methods

Using a Walleye (Sander vitreus) population inhabiting Black Bay, Lake Superior, we examine whether life history characteristics differ between more and less mobile individuals as predicted by Pace of Life Syndrome. We tracked the movement of 192 individuals from 2016 to 2019 using an acoustic telemetry study, relating patterns in annual migratory behaviour to individual growth, and seasonal changes in optimal thermal-optical habitat.

Results

We observed two consistent movement patterns in our study population—migratory individuals left Black Bay during late summer to early fall before returning to the bay, whereas residents remained within the bay year-round. The average maximum length of migrant Walleye was 5.5 cm longer than residents, and the sex ratios of Walleye caught during fall surveys was increasingly female-biased towards the mouth of Black Bay, suggesting that a majority of migrants were females. Further, Walleye occupancy outside of Black Bay was positively associated with increasing thermal-optical habitat.

Conclusions

Walleye in Black Bay appear to conform to Pace of Life Syndrome, with migrant individuals gaining increased fitness through increased maximum size, which, given size-dependent fecundity in this species, likely results in greater reproductive success (via greater egg deposition vs. non-migrants). Further, apparent environmental (thermal) controls on migration suggest that migratory Walleye (more so than residents) may be more sensitive to changing environmental conditions (e.g., warming climate) than residents.
Management of COVID-19 vaccines cold chain logistics: a scoping review
Authors: Fahrni Mathumalar Loganathan , Ismail Intan An-Nisaa’ , Refi Dalia Mohammed , Almeman Ahmad , Yaakob Norliana Che , Saman Kamaliah Md , Mansor Nur Farhani , Noordin Noorasmah , Babar Zaheer-Ud-Din
Published: March 2022

Background

Successful mass vaccination programmes are public health achievements of the contemporary world. While pharmaceutical companies are actively developing new vaccines, and demonstrating results of effectiveness and safety profiles, concerns on COVID-19 vaccine management are under-reported. We aimed to synthesise the evidence for efficient cold chain management of COVID vaccines.

Methods

The scoping review’s conduct and reporting were based on the PRISMA–ScR 2018 checklist. We searched from April 2020 to January 2022 for publications in PubMed (LitCovid), Scopus and ScienceDirect. All review stages were pilot-tested to calibrate 2 reviewers. Articles on cold chain logistics and management were included, while publications solely describing COVID vaccines, their development and clinical aspects of the vaccine, were excluded. To capture relevant data, charting was conducted by one reviewer and verified by another. Results were analysed thematically and summarised descriptively in a table and in-text.

Results and discussion

We assessed 6984 potentially relevant citations. We included 14 publications originating from USA (n = 6), India (n = 2), Finland, Spain, Bangladesh, Netherlands, Switzerland and Ethiopia. They were reported as reviews (4), policy or guidance documents (3), experimental studies (2), case reports (2), expert commentary (1), phenomenological study (1), and decision-making trial and evaluation laboratory trial (1). The findings were presented in three themes: (i) regulatory requirements for cold-chain logistics, (ii) packaging and storage, and (iii) transportation and distribution. A conceptual framework emerged linking regulatory requirements, optimal logistics operation and formulation stability as the key to efficient cold chain management. Recommendations were made for improving formulation stability, end-product storage conditions, and incorporating monitoring technologies.

Conclusion

COVID-19 vaccines require special end-to-end supply cold chain requirements, from manufacture, and transportation to warehouses and healthcare facilities. To sustain production, minimise wastage, and for vaccines to reach target populations, an efficient and resilient vaccine supply chain which is assisted by temperature monitoring technologies is imperative.
Global distribution of magnetic ripples and electron density fluctuations as observed by the Swarm satellites on the dayside and their relation to the rainfall estimated by the GSMaP
Authors: Iyemori Toshihiko , Aoyama Tadashi , Yokoyama Yoshihiro
Published: March 2022

In mid- and low-latitude ionospheric F-region on the dayside, magnetic field and electron density (Ne) fluctuations with amplitude smaller than a few nT and 1–2% of Ne, respectively, are commonly observed. Their spatial scale along satellite orbit is around 70–250 km. It is presumed that they are generated by the waves propagated from lower atmosphere. However, the mode of waves (acoustic wave or internal gravity wave) and their source are not yet clear. Among the possible sources, cumulus convection and/or associated rainfall are considered to be the strong candidates for the atmospheric wave generation. We use the rainfall estimated by the hourly Global Satellite Mapping of Precipitation (JAXA/GSMaP) as a proxy of lower atmospheric disturbance as the wave source, and compare the rainfall with the amplitude of magnetic fluctuations (magnetic ripples) and electron density fluctuations observed by the Swarm satellites. The data from April 2014 to July 2020 are used. The global distribution of rainfall estimated by the GSMaP and its seasonal variation have similarities with amplitude distribution of magnetic ripples and electron density fluctuations on the dayside. We calculate the ratio of their magnitude, i.e., amplitude of magnetic ripples or electron density fluctuations in rainfall cases to those in no-rainfall cases. Although the longitudinally averaged ratio is not very large but around 1.1–1.2 in ± 10– ± 50° Apex latitudes, it is clearly larger than 1.0. The ratio increases when the intensity of rainfall (mm/h) increases. These results indicate that a cumulous convection which causes rainfall is one of the main sources of atmospheric waves that produce magnetic ripples and electron density fluctuations commonly observed in the dayside ionosphere. Anticipating acoustic waves as the driver of magnetic ripples and electron density variations, a difference in the generation mechanism of electron density fluctuations from that of magnetic ripples is suggested even if their sources are common.

Graphical abstract
A significant vascular variant in oncologic pancreaticoduodenectomy: the arc of Buhler
Authors: Schumacher L. , Albrecht H. C. , Gretschel S.
Published: March 2022

Background

The arc of Buhler (AOB), a rare anastomosis connecting the superior mesenteric artery (SMA) to the celiac trunk (CA), was found in a patient suffering from an adenocarcinoma of the pancreatic head.

Case presentation

Oncologic pancreaticoduodenectomy required resection of the AOB to achieve complete tumor removal. After an uneventful clinical course in the first days, the patient suffered a severe complication. Due to ischemia of the stomach and spleen, complete resection of the stomach, spleen, and remaining pancreas had to be performed.

Conclusions

The hemodynamic impact of this arterial variant has been discussed mainly for liver perfusion, which remained intact at all times in our case. Because of the serious obstacles mentioned above, we strongly recommend that the presence of AOB be considered in preoperative diagnosis and preservation when possible. If the AOB is likely to be ligated, stenosis of the SMA or CA should be excluded and resolved before surgery.