Worldwide cohort study of 46, XY differences/disorders of sex development genetic diagnoses: geographic and ethnic differences in variants.

Differences/disorders of sex development (DSDs) in individuals with a 46, XY karyotype are a group of congenital disorders that manifest as male gonadal hypoplasia or abnormalities of the external genitalia. Approximately 50% of patients with 46, XY DSDs cannot obtain a molecular diagnosis. The aims of this paper were to review the most common causative genes and rare genes in patients with 46, XY DSDs, analyze global molecular diagnostic cohorts for the prevalence and geographic distribution of causative genes, and identify the factors affecting cohort detection results. Although the spectrum of genetic variants varies across regions and the severity of the clinical phenotype varies across patients, next-generation sequencing (NGS), the most commonly used detection method, can still reveal genetic variants and aid in diagnosis. A comparison of the detection rates of various sequencing modalities revealed that whole-exome sequencing (WES) facilitates a greater rate of molecular diagnosis of the disease than panel sequencing. Whole-genome sequencing (WGS), third-generation sequencing, and algorithm advancements will contribute to the improvement of detection efficiency. The most commonly mutated genes associated with androgen synthesis and action are AR, SR5A2, and HSD17B3, and the most commonly mutated genes involved in gonadal formation are NR5A1 and MAP3K1. Detection results are affected by differences in enrollment criteria and sequencing technologies.

Perceptions and challenges of online teaching and learning amidst the COVID-19 pandemic in India: a cross-sectional study with dental students and teachers.

BACKGROUND: Online education has emerged as a crucial tool for imparting knowledge and skills to students in the twenty-first century, especially in developing nations like India, which previously relied heavily on traditional teaching methods. METHODS: This study delved into the perceptions and challenges experienced by students and teachers in the context of online education during the COVID-19 pandemic. Data were collected from a sample of 491 dental students and 132 teachers utilizing a cross-sectional research design and an online-validated survey questionnaire. RESULTS: The study's findings revealed significant insights. Internet accessibility emerged as a major impediment for students, with online instruction proving more effective for theoretical subjects compared to practical ones. Although most teachers expressed comfort with online teaching, they highlighted the absence of classroom interaction as a significant challenge. CONCLUSION: This study comprehensively examines the perspectives of both students and teachers regarding online education during the pandemic. The results carry substantial implications for the academic community, underscoring the need to address internet access issues and explore ways to enhance engagement and interaction in online learning environments.

Regional Differences in Diagnosis Journey and Healthcare Utilization: Results from the International Map of Axial Spondyloarthritis (IMAS).

INTRODUCTION: To assess differences in the diagnosis journey and access to care in a large sample of patients with axial spondyloarthritis (axSpA) from around the world, included in the International Map of Axial Spondyloarthritis (IMAS). METHODS: IMAS was a cross-sectional online survey (2017-2022) of 5557 unselected patients with axSpA from 27 countries. Across five worldwide geographic regions, the patient journey until diagnosis and healthcare utilization in the last 12 months prior to survey were evaluated. Univariable and multivariable linear regression was used to analyze factors associated with higher healthcare utilization. RESULTS: Of 5557 participants in IMAS, the diagnosis took an average of 7.4 years, requiring more than two visits to HCPs (77.7% general practitioner and 51.3% rheumatologist), and more than two diagnostic tests [67.5% performed human leukocyte antigen B27 (HLA-B27), 64.2% x-ray, and 59.1% magnetic resonance imaging (MRI) scans]. North America and Europe were the regions with the highest number of healthcare professional (HCP) visits for diagnosis, while the lowest number of visits was in the Asian region. In the previous 12 months, 94.9% (n = 5272) used at least one healthcare resource, with an average of 29 uses per year. The regions with the highest healthcare utilization were Latin America, Europe, and North America. In the multiple linear regression, factors associated with higher number of healthcare utilization were younger age (b =  - 0.311), female gender (b = 7.736), higher disease activity (b = 1.461), poorer mental health (b = 0.624), greater functional limitation (b = 0.300), greater spinal stiffness (b = 1.527), and longer diagnostic delay (b = 0.104). CONCLUSION: The diagnosis of axSpA usually takes more than two visits to HCPs and at least 7 years. After diagnosis, axSpA is associated with frequent healthcare resource use. Younger age, female gender, higher disease activity, poorer mental health, greater functional limitation, greater spinal stiffness, and longer diagnostic delay are associated with higher healthcare utilization. Europe and North America use more HCP visits and diagnostic tests before and after diagnosis than the other regions.

Effects of fuel and driving conditions on particle number emissions of China-VI gasoline vehicles: based on corrections to test results.

The increasing number of vehicles are emitting a large amount of particles into the atmosphere, causing serious harm to the ecological environment and human health. This study conducted the Worldwide Harmonized Light Vehicles Test Cycle (WLTC) to investigate the emission characteristics of particle number (PN) of China-VI gasoline vehicles with different gasoline. The gasoline with lower aromatic hydrocarbons and olefins reduced particulate matter (PM) and PN emissions by 24% and 52% respectively. The average PN emission rate of the four vehicles during the first 300 s (the cold start period) was 7.2 times that of the 300 s-1800s. Additionally, because the particle transmission time and instrument response time, the test results of instantaneous emissions of PN were not synchronized with vehicle specific power (VSP). By calculating the Spearman correlation coefficient between pre-average vehicle specific power (PAVSP) and the test results of PN instantaneous emissions, the delay time was determined as 10s. After the PN emissions results were corrected, the PN emissions were found to be more related to VSP. By analyzing the influence of driving status on emission, this study found that vehicles in acceleration mode increased PN emissions by 76% compared to those in constant speed mode.

Global daily mask use estimation in the pandemic and its post environmental health risks: Analysis based on a validated dynamic mathematical model.

The outbreak of the COVID-19 pandemic led to a sharp increase in disposable surgical mask usage. Discarded masks can release microplastic and cause environmental pollution. Since masks have become a daily necessity for protection against virus infections, it is necessary to review the usage and disposal of masks during the pandemic for future management. In this study, we constructed a dynamic model by introducing related parameters to estimate daily mask usage in 214 countries from January 22, 2020 to July 31, 2022. And we validated the accuracy of our model by establishing a dataset based on published survey data. Our results show that the cumulative mask usage has reached 800 billion worldwide, and the microplastics released from discarded masks due to mismanagement account for 3.27% of global marine microplastic emissions in this period. Furthermore, we illustrated the response relationship between mask usage and the infection rates. We found a marginally significant negative correlation existing between the mean daily per capita mask usage and the rate of cumulative confirmed cases within the range of 25% to 50%. This indicates that if the rate reaches the specified threshold, the preventive effect of masks may become evident.

A global systematic review and meta-analysis on the babesiosis in dogs with special reference to Babesia canis.

BACKGROUND: Canine babesiosis is a clinically significant tick-transmitted disease caused by several species of the intraerythrocytic protozoan parasite Babesia, which result in a wide range of clinical manifestations, from mild, transient infection to serious disease and even death. OBJECTIVES: The current study aimed to estimate the global prevalence and associated risk factors of Babesia in dogs. METHODS: Multiple databases (PubMed, Scopus, ProQuest, Web of Science and Google Scholar) were searched for relevant literature published from January 2000 up to December 2022. The statistical analyses were performed based on the R software (version 3.6) meta-package. RESULTS: Out of 23,864 publications, 229 studies met the inclusion criteria. The pooled prevalence of canine babesiosis was 0.120 (95% CI; 0.097-0.146). The highest pooled prevalence was found in Europe (0.207, 95% CI; 0.097-0.344). Among several species, Babesia canis was the most prevalent parasite (0.216, 95% CI; 0.056-0.441). The highest pooled prevalence of Babesia in dogs was observed in the summer season (0.097, 95% CI; 0.040-0.174). CONCLUSIONS: Regular screening and appropriate control strategies are recommended for the prevention of transmission of tick-borne disease transmission among dogs.

The global prevalence and associated risk factors of Eimeria infection in domestic chickens: A systematic review and meta-analysis.

BACKGROUND: Eimeria is a protozoan parasite that affects poultry, particularly chickens, causing a disease known as coccidiosis. This disease imposes substantial significant economic challenges to the poultry sector. OBJECTIVES: The current study aimed to estimate the global prevalence and associated risk factors of Eimeria in domestic chickens. METHODS: Multiple databases (Scopus, PubMed, ProQuest, Web of Science and Google Scholar) were searched for articles published until June 2023. The pooled prevalence was estimated using a random-effects model with a 95% confidence interval. The statistical analysis was conducted using meta packages in R version (3.6.1). RESULTS: In total, 41 articles fulfilled the eligibility criteria. The global pooled prevalence was 44.3% (36.9%-51.8%) with Eimeria tenella (38.7%, 30.1%-47.7%) as the most prevalent species. The highest pooled prevalence was related to the Western Pacific Region (80.5%, 72.6%-87.3%) and urban areas (44.4%, 36.5%-52.6%). Moreover, areas with humid subtropical climates represent the highest overall prevalence (75.8%, 46.6%-95.9%). CONCLUSION: The necessity for robust and innovative strategies for preventing and managing this disease cannot be overstated. Addressing Eimeria impact is crucial not only for safeguarding poultry health but also for sustaining the economic viability of the poultry industry.

Automatic Classification and Visualization of Text Data on Rare Diseases.

More than 7000 rare diseases affect over 400 million people, posing significant challenges for medical research and healthcare. The integration of precision medicine with artificial intelligence offers promising solutions. This work introduces a classifier developed to discern whether research and news articles pertain to rare or non-rare diseases. Our methodology involves extracting 709 rare disease MeSH terms from Mondo and MeSH to improve rare disease categorization. We evaluate our classifier on abstracts from PubMed/MEDLINE and an expert-annotated news dataset, which includes news articles on four selected rare neurodevelopmental disorders (NDDs)-considered the largest category of rare diseases-from a total of 16 analyzed. We achieved F1 scores of 85% for abstracts and 71% for news articles, demonstrating robustness across both datasets and highlighting the potential of integrating artificial intelligence and ontologies to improve disease classification. Although the results are promising, they also indicate the need for further refinement in managing data heterogeneity. Our classifier improves the identification and categorization of medical information, essential for advancing research, enhancing information access, influencing policy, and supporting personalized treatments. Future work will focus on expanding disease classification to distinguish between attributes such as infectious and hereditary diseases, addressing data heterogeneity, and incorporating multilingual capabilities.

Facilitators and Barriers to Lung Cancer Screening during Long COVID: A Global Systematic Review and Meta-Study Synthesis of Qualitative Research.

Background: Participation in targeted screening reduces lung cancer mortality by 30-60%, but screening is not universally available. Therefore, the study aimed to synthesize the evidence and identify facilitators and barriers to lung cancer screening participation globally. Methods: Two reviewers screened primary studies using qualitative methods published up to February 2023. We used two-phase synthesis consistent with a meta-study methodology to create an interpretation of lung cancer screening decisions grounded in primary studies, carried out a thematic analysis of group themes as specific facilitators and barriers, systematically compared investigations for similarities and differences, and performed meta-synthesis to generate an expanded theory of lung cancer screening participation. We used the Social Ecological Model to organize and interpret the themes: individual, interpersonal, social/cultural, and organizational/structural levels. Results: Fifty-two articles met the final inclusion criteria. Themes identified as facilitating lung cancer screening included prioritizing patient education, quality of communication, and quality of provider-initiated encounter/coordination of care (individual patient and provider level), quality of the patient-provider relationship (interpersonal group), perception of a life's value and purpose (cultural status), quality of tools designed, and care coordination (and organizational level). Themes coded as barriers included low awareness, fear of cancer diagnosis, low perceived benefit, high perceived risk of low-dose computerized tomography, concern about cancer itself, practical obstacle, futility, stigma, lack of family support, COVID-19 fear, disruptions in cancer care due to COVID-19, inadequate knowledge of care providers, shared decision, and inadequate time (individual level), patient misunderstanding, poor rapport, provider recommendation, lack of established relationship, and confusing decision aid tools (interpersonal group), distrust in the service, fatalistic beliefs, and perception of aging (cultural level), and lack of institutional policy, lack of care coordinators, inadequate infrastructure, absence of insurance coverage, and costs (and organizational status). Conclusions: This study identified critical barriers, facilitators, and implications to lung cancer screening participation. Therefore, we employed strategies for a new digital medicine (artificial intelligence) screening method to balance the cost-benefit, "workdays" lost in case of disease, and family hardship, which is essential to improve lung cancer screening uptake.

Best practice guidelines on genetic diagnostics of facioscapulohumeral muscular dystrophy: Update of the 2012 guidelines.

The gold standard for facioscapulohumeral muscular dystrophy (FSHD) genetic diagnostic procedures was published in 2012. With the increasing complexity of the genetics of FSHD1 and 2, the increase of genetic testing centers, and the start of clinical trials for FSHD, it is crucial to provide an update on our knowledge of the genetic features of the FSHD loci and renew the international consensus on the molecular testing recommendations. To this end, members of the FSHD European Trial Network summarized the evidence presented during the 2022 ENMC meeting on Genetic diagnosis, clinical outcome measures, and biomarkers. The working group additionally invited genetic and clinical experts from the USA, India, Japan, Australia, South-Africa, and Brazil to provide a global perspective. Six virtual meetings were organized to reach consensus on the minimal requirements for genetic confirmation of FSHD1 and FSHD2. Here, we present the clinical and genetic features of FSHD, specific features of FSHD1 and FSHD2, pros and cons of established and new technologies (Southern blot in combination with either linear or pulsed-field gel electrophoresis, molecular combing, optical genome mapping, FSHD2 methylation analysis and FSHD2 genotyping), the possibilities and challenges of prenatal testing, including pre-implantation genetic testing, and the minimal requirements and recommendations for genetic confirmation of FSHD1 and FSHD2. This consensus is expected to contribute to current clinical management and trial-readiness for FSHD.

Optimal lymph node dissection for gastric cancer: a narrative review.

The management of gastric cancer has long been debated, particularly the extent of lymph node (LN) dissection required during curative surgery. LN invasion stands out as the most critical prognostic factor in gastric cancer. Historically, Japanese academic societies were the pioneers in defining a classification system for regional gastric LN stations, numbering them from 1 to 16. This classification was later used to differentiate between different types of LN dissection, such as D1, D2 and D3. However, these definitions were often considered too complex to be universally adopted, resulting in wide variations in recommendations from one country to another and making it difficult to compare published studies. In addition, the optimal extent of LN dissection remains uncertain, with initially recommended dissections being extensive but associated with significant morbidity without a clear survival benefit. The aim of this review is to make a case for extending LN dissection based on the existing literature, which includes a comprehensive examination of the current definitions of lymphadenectomy and an analysis of the results of all randomised controlled trials evaluating morbidity, mortality and long-term survival associated with different types of LN dissection. Finally, we provide a summary of the various recommendations issued by organizations such as the Japanese Gastric Research Association, the National Comprehensive Cancer Network, the European Society for Medical Oncology, and the French National Thesaurus of Digestive Oncology.

An atmospheric water harvesting system based on the "Optimal Harvesting Window" design for worldwide water production.

Atmospheric water harvesting (AWH) is a promising solution to the water shortage problem. Current sorption-based AWH (SAWH) systems seldom obtain both wide climatic adaptability and high energy efficiency due to the lack of thermodynamic optimization. To achieve the ideal harvesting circulation in SAWH systems, the "optimal harvesting window" (OHW) design based on thermodynamic analysis was first proposed and validated by our prototype. The "OHW" theory indicates the water production rate and energy efficiency could be improved by properly reducing the adsorption temperature. As the humidity increases, the optimal adsorption temperature should be closer to the dew point of the environment. Experimental results revealed that, loaded with 3 kg widely adopted silica gel, the daily water production could reach 5.76-17.64 L/d with ultrahigh energy efficiency of 0.46-1.5 L/kWh. This prototype could also achieve optimal performance in wide climatic conditions in terms of 13-35 °C and 18%-72% RH. Lastly, the performance of photovoltaic (PV)-driven SAWH was evaluated. Results showed that a 1 m2 PV panel could generate 0.66-2 L water per day in Shanghai throughout the year, the highest in opening literature. Notably, this work introduces a promising concept that can help achieve large-scale, ultra-fast, energy-efficient AWH worldwide.

IHMCIF: An Extension of the PDBx/mmCIF Data Standard for Integrative Structure Determination Methods.

IHMCIF (github.com/ihmwg/IHMCIF) is a data information framework that supports archiving and disseminating macromolecular structures determined by integrative or hybrid modeling (IHM), and making them Findable, Accessible, Interoperable, and Reusable (FAIR). IHMCIF is an extension of the Protein Data Bank Exchange/macromolecular Crystallographic Information Framework (PDBx/mmCIF) that serves as the framework for the Protein Data Bank (PDB) to archive experimentally determined atomic structures of biological macromolecules and their complexes with one another and small molecule ligands (e.g., enzyme cofactors and drugs). IHMCIF serves as the foundational data standard for the PDB-Dev prototype system, developed for archiving and disseminating integrative structures. It utilizes a flexible data representation to describe integrative structures that span multiple spatiotemporal scales and structural states with definitions for restraints from a variety of experimental methods contributing to integrative structural biology. The IHMCIF extension was created with the benefit of considerable community input and recommendations gathered by the Worldwide Protein Data Bank (wwPDB) Task Force for Integrative or Hybrid Methods (wwpdb.org/task/hybrid). Herein, we describe the development of IHMCIF to support evolving methodologies and ongoing advancements in integrative structural biology. Ultimately, IHMCIF will facilitate the unification of PDB-Dev data and tools with the PDB archive so that integrative structures can be archived and disseminated through PDB.

Refining the genomic profiles of North African sheep breeds through meta-analysis of worldwide genomic SNP data.

Introduction: The development of reproducible tools for the rapid genotyping of thousands of genetic markers (SNPs) has promoted cross border collaboration in the study of sheep genetic diversity on a global scale. Methods: In this study, we collected a comprehensive dataset of 239 African and Eurasian sheep breeds genotyped at 37,638 filtered SNP markers, with the aim of understanding the genetic structure of 22 North African (NA) sheep breeds within a global context. Results and discussion: We revealed asubstantial enrichment of the gene pool between the north and south shores of the Mediterranean Sea, which corroborates the importance of the maritime route in the history of livestock. The genetic structure of North African breeds mirrors the differential composition of genetic backgrounds following the breed history. Indeed, Maghrebin sheep stocks constitute a geographically and historically coherent unit with any breed-level genetic distinctness among them due to considerable gene flow. We detected a broad east-west pattern describing the most important trend in NA fat-tailed populations, exhibited by the genetic closeness of Egyptian and Libyan fat-tailed sheep to Middle Eastern breeds rather than Maghrebin ones. A Bayesian FST scan analysis revealed a set of genes with potentially key adaptive roles in lipid metabolism (BMP2, PDGFD VEGFA, TBX15, and WARS2), coat pigmentation (SOX10, PICK1, PDGFRA, MC1R, and MTIF) and horn morphology RXFP2) in Tunisian sheep. The local ancestry method detected a Merino signature in Tunisian Noire de Thibar sheep near the SULF1gene introgressed by Merino's European breeds. This study will contribute to the general picture of worldwide sheep genetic diversity.

Global State of the Art and Science of Childhood Dysphagia: Similarities and Disparities in Burden.

Feeding/swallowing and airway protection are complex functions, essential for survival, and continue to evolve throughout the lifetime. Medical and surgical advances across the globe have improved the long-term survival of medically complex children at the cost of increasing comorbidities, including dysfunctional swallowing (dysphagia). Dysphagia is prominent in children with histories of preterm birth, neurologic and neuromuscular diagnoses, developmental delays, and aerodigestive disorders; and is associated with medical, health, and neurodevelopmental problems; and long-term socioeconomic, caregiver, health system, and social burdens. Despite these survival and population trends, data on global prevalence of childhood dysphagia and associated burdens are limited, and practice variations are common. This article reviews current global population and resource-dependent influences on current trends for children with dysphagia, disparities in the availability and access to specialized multidisciplinary care, and potential impacts on burdens. A patient example will illustrate some questions to be considered and decision-making options in relation to age and development, availability and accessibility to resources, as well as diverse cultures and family values. Precise recognition of feeding/swallowing disorders and follow-up intervention are enhanced by awareness and knowledge of global disparities in resources. Initiatives are needed, which address geographic and economic barriers to providing optimal care to children with dysphagia.

Global Potential Distribution of Invasive Species Pseudococcus viburni (Hemiptera: Pseudococcidae) under Climate Change.

The potential distribution range and management strategies for P. viburni are poorly understood. Based on historical distribution data and environmental factors, the present study predicted the potentially suitable areas for P. viburni spread under different climate change scenarios using MaxEnt (maximum entropy). The results showed that precipitation of the coldest quarter (Bio19), precipitation seasonality (Bio15), and mean temperature of the wettest quarter (Bio8) were the most important environmental factors determining the distribution of P. viburni. Under the current climate conditions, its potential suitable areas are southern China, the whole of Japan, North America (especially the eastern part of the United States), the southwestern part of South America, the Mediterranean coast and most of Europe, the central part of Africa, i.e., the south of the Sahara Desert, and most of the southern coast of Australia. The total area of habitats suitable for this insect pest is predicted to be increased in the future. In order to prevent P. viburni transmission and spread, there is a need to strengthen the monitoring and quarantine measures against this pest at the Southern ports.

Global prevalence of restless legs syndrome among hemodialysis patients: A systematic review and meta-analysis.

OBJECTIVES: Restless legs syndrome (RLS) is a common complaint in patients undergoing hemodialysis (HD). Despite the fact that the estimated prevalence of RLS among HD patients is widely reported, these results varied significantly in the relevant literature. Due to this limitation, the aim of this study was to determine the global prevalence of RLS among HD patients. METHODS: This systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 statement. We searched the electronic databases: Cochrane Library, PubMed, Embase, Web of Science, Scopus, Cumulative Index to Nursing and Allied Health Literature, China Knowledge Resource Integrated Database, Wanfang Database, Chinese Biomedical Database, and Weipu Database. A random effects model was employed to calculate pooled prevalence rates. RESULTS: The global pooled prevalence of RLS in HD patients was 27.2% (95% CI: 24.8-29.7). Stratified analyses demonstrated that included studies with sample size <100 had the highest pooled prevalence of RLS. The prevalence of RLS using clinical interviews and questionnaires was 28.7% (95% CI: 25.2-32.2) and 25.9% (95% CI: 22.8-29.1), respectively. RLS prevalence is higher in females (29.7%, 95% CI: 26.2-33.2) HD patients than in males (23.5%, 95% CI: 20.9-26.0), and the African region has the highest prevalence in the world when the diagnostic criteria were restricted to the 2003 version of International RLS Study Group criteria, the prevalence of RLS was highest (28.9%, 95% CI: 25.9-31.9). CONCLUSION: Our results revealed a high RLS prevalence in HD patients worldwide. However, the prevalence of RLS among HD patients varied significantly based on sample size, data collection method, gender, diagnostic criteria, and geographical region.

Impact of COVID-19 pandemic on a world-wide private ophthalmic practice.

Purpose: To assess the impact of the COVID-19 pandemic on a worldwide private ophthalmic practice. Design: In this retrospective study, we reviewed the 2020 monthly outpatient and surgical volume of refractive, cataract, and retinal disease in Aier Eye clinics/hospitals of different regions, including the United States, Germany, Spain, Italy, and six major cities in China (Wuhan, Beijing, Shanghai, Shenyang, Urumqi and Yili). All of these data were compared to those of the same period of 2019. Results: Overall, during the early stage (2020 January to 2020 April) of COVID-19 outbreak, the outpatient and surgical volume of three main type ocular diseases (refractive, cataract and retinal surgery) showed an obvious reduction and reached the bottom in February in China. The data from the United States, Germany, Spain and Italy revealed the same trend, but the visit count nadir occurred until April, which is consistent with the spread trend of COVID-19 disease around the world. The average change rates of surgery volume (refractive, cataract and retinal surgery) in Chinese centers are 5.59%, -26.38%, 11.76%. The change rates of refractive (REF) and cataract volumes (CAT) in the United States are -8.62% and -10.58%, in Germany are -13.71% and -20.49%, in Spain are 15.35% and 27.97%, in Italy are 30.43% and -22.64%. In addition, the optometry outpatient volumes keep going up since May, with an average increasing rate of 21.18%, ranging from 7.43% to 49.51%. Conclusion: In conclusion, in this global chain of eye care units, the visit volumes of cataract, retinal and refractive changed significantly with the spread of COVID-19 pandemic. Among them, cataract surgery was the most affected sub-specialty, and refractive surgery and optometry volumes showed a potential growth in the near future. Therefore, medical institutions should make corresponding adjustments to the disease diagnosis and treatment strategies.

Microbial diversity in polyextreme salt flats and their potential applications.

Recent geological, hydrochemical, and mineralogical studies performed on hypersaline salt flats have given insights into similar geo-morphologic features on Mars. These salt-encrusted depressions are widely spread across the Earth, where they are characterized by high salt concentrations, intense UV radiation, high evaporation, and low precipitation. Their surfaces are completely dry in summer; intermittent flooding occurs in winter turning them into transitory hypersaline lakes. Thanks to new approaches such as culture-dependent, culture-independent, and metagenomic-based methods, it is important to study microbial life under polyextreme conditions and understand what lives in these dynamic ecosystems and how they function. Regarding these particular features, new halophilic microorganisms have been isolated from some salt flats and identified as excellent producers of primary and secondary metabolites and granules such as halocins, enzymes, carotenoids, polyhydroxyalkanoates, and exopolysaccharides. Additionally, halophilic microorganisms are implemented in heavy metal bioremediation and hypersaline wastewater treatment. As a result, there is a growing interest in the distribution of halophilic microorganisms around the world that can be looked upon as good models to develop sustainable biotechnological processes for all fields. This review provides insights into diversity, ecology, metabolism, and genomics of halophiles in hypersaline salt flats worldwide as well as their potential uses in biotechnology.