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Frontiers in Physiology 2024The hypoxic chemoreflex and the arterial baroreflex are implicated in the ventilatory response to exercise. It is well known that long-term exercise training increases... (Review)
Review
The hypoxic chemoreflex and the arterial baroreflex are implicated in the ventilatory response to exercise. It is well known that long-term exercise training increases parasympathetic and decreases sympathetic tone, both processes influenced by the arterial baroreflex and hypoxic chemoreflex function. Hypobaric hypoxia (i.e., high altitude [HA]) markedly reduces exercise capacity associated with autonomic reflexes. Indeed, a reduced exercise capacity has been found, paralleled by a baroreflex-related parasympathetic withdrawal and a pronounced chemoreflex potentiation. Additionally, it is well known that the baroreflex and chemoreflex interact, and during activation by hypoxia, the chemoreflex is predominant over the baroreflex. Thus, the baroreflex function impairment may likely facilitate the exercise deterioration through the reduction of parasympathetic tone following acute HA exposure, secondary to the chemoreflex activation. Therefore, the main goal of this review is to describe the main physiological mechanisms controlling baro- and chemoreflex function and their role in exercise capacity during HA exposure.
PubMed: 38895516
DOI: 10.3389/fphys.2024.1422927 -
Mitochondrial DNA. Part B, Resources 2024Prain 1906, a national second-class rare and endangered plant, is reported here for the first time for its complete chloroplast genome. The genome is 153,290 bp in...
Prain 1906, a national second-class rare and endangered plant, is reported here for the first time for its complete chloroplast genome. The genome is 153,290 bp in length, comprising a large single-copy region (LSC, 83,918 bp), a small single-copy region (SSC, 17,740 bp), and two inverted repeat sequences (IRa and IRb, each 25,816 bp). The overall GC content is 38.7%, with the IR region having the highest content (43.1%). The genome is annotated with 112 unique genes, including 4 rRNA genes, 29 tRNA genes, and 79 protein-coding genes. Analysis of codon usage bias reveals that codons ending in A/T account for 96.7% of those with a Relative Synonymous Codon Usage (RSCU) value above 1. This predominance of A/T-ending codons might be indicative of adaptation to high-altitude environments. Phylogenetic analysis reveals a close kinship between and and , indicating that the ancestral groups of these species might have a complex evolutionary history. This study uncovers the genetic characteristics and adaptive evolution of , offering a new perspective in understanding the phylogenetic relationships within the genus. The findings not only provide a solid theoretical foundation for the conservation and sustainable use of this rare and endangered species but also offer significant scientific support for the conservation of biodiversity.
PubMed: 38895507
DOI: 10.1080/23802359.2024.2368208 -
Animals : An Open Access Journal From... May 2024Despite the crucial role of the gut microbiota in different physiological processes occurring in the animal body, reports regarding the gut microbiota of animals...
Despite the crucial role of the gut microbiota in different physiological processes occurring in the animal body, reports regarding the gut microbiota of animals residing in different environmental conditions like high altitude and different climate settings are limited. The Qinghai-Tibetan Plateau is renowned for its extreme climatic conditions that provide an ideal environment for exploring the effects of high altitude and temperature on the microbiota of animals. Yaks have unique oxygen delivery systems and genes related to hypoxic response. Damxung, Nyêmo, and Linzhou counties in Tibet have variable altitudes and temperatures that offer distinct settings for studying yak adaptation to elevated terrains. The results of our study suggest that amplicon sequencing of V3-V4 and internal transcribed spacer 2 (ITS2) regions yielded 13,683 bacterial and 1912 fungal amplicon sequence variants (ASVs). Alpha and beta diversity indicated distinct microbial structures. Dominant bacterial phyla were Firmicutes, Bacteroidota, and Actinobacteriota. Genera UCG-005, Christensenellaceae_R-7_group, and Rikenellaceae_RC9_gut_group were dominant in confined yaks living in Damxung county (DXS) and yaks living in Linzhou county (LZS), whereas UCG-005 prevailed in confined yaks living in Nyêmo county (NMS). The linear discriminant analysis effect size (LEfSe) analysis highlighted genus-level differences. Meta-stat analysis revealed significant shifts in bacterial and fungal community composition in yaks at different high altitudes and temperatures. Bacterial taxonomic analysis revealed that two phyla and 32 genera differed significantly ( < 0.05). Fungal taxonomic analysis revealed that three phyla and four genera differed significantly ( < 0.05). Functional predictions indicated altered metabolic functions, especially in the digestive system of yaks living in NMS. This study reveals significant shifts in yak gut microbiota in response to varying environmental factors, such as altitude and temperature, shedding light on previously unexplored aspects of yak physiology in extreme environments.
PubMed: 38891617
DOI: 10.3390/ani14111570 -
Responses of Soil C, N, P and Enzyme Activities to Biological Soil Crusts in China: A Meta-Analysis.Plants (Basel, Switzerland) May 2024Biological soil crusts (BSCs) are often referred to as the "living skin" of arid regions worldwide. Yet, the combined impact of BSCs on soil carbon (C), nitrogen (N),... (Review)
Review
Biological soil crusts (BSCs) are often referred to as the "living skin" of arid regions worldwide. Yet, the combined impact of BSCs on soil carbon (C), nitrogen (N), phosphorus (P), and enzyme activities remains not fully understood. This study identified, screened and reviewed 71 out of 2856 literature sources to assess the responses of soil C, N, P and enzyme activity to BSCs through a meta-analysis. The results indicated that BSC presence significantly increased soil C, N, P and soil enzyme activity, and this increasing effect was significantly influenced by the types of BSCs. Results from the overall effect showed that soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), total phosphorus (TP), and available phosphorus (AP) increased by 107.88%, 84.52%, 45.43%, 27.46%, and 54.71%, respectively, and four soil enzyme activities (Alkaline Phosphatase, Cellulase, Sucrase, and Urease) increased by 93.65-229.27%. The highest increases in SOC, TN and AN content occurred in the soil covered with lichen crusts and moss crusts, and significant increases in Alkaline Phosphatase and Cellulase were observed in the soil covered with moss crusts and mixed crusts, suggesting that moss crusts can synergistically enhance soil C and N pool and enzyme activity. Additionally, variations in soil C, N, P content, and enzyme activity were observed under different environmental settings, with more pronounced improvements seen in coarse and medium-textured soils compared to fine-textured soils, particularly at a depth of 5 cm from the soil surface. BSCs in desert ecosystems showed more significant increases in SOC, TN, AN, and Alkaline Phosphatase compared to forest and grassland ecosystems. Specifically, BSCs at low altitude (≤500 m) with an annual average rainfall of 0-400 mm and an annual average temperature ≤ 10 °C were the most conducive to improving soil C, N, and P levels. Our results highlight the role of BSCs and their type in increasing soil C, N, P and enzyme activities, with these effects significantly impacted by soil texture, ecosystem type, and climatic conditions. The implications of these findings are crucial for soil enhancement, ecosystem revitalization, windbreak, and sand stabilization efforts in the drylands of China.
PubMed: 38891333
DOI: 10.3390/plants13111525 -
Foods (Basel, Switzerland) May 2024As a significant crop growing all across the world, coffee is mostly produced in the bean belt of our global atlas. Worldwide variations in environmental conditions are... (Review)
Review
As a significant crop growing all across the world, coffee is mostly produced in the bean belt of our global atlas. Worldwide variations in environmental conditions are causing a decline in the yield and quality of coffee varieties. Coffee production is the main emphasis of several traditional breeding techniques. But conventional breeding methods are not sufficient to tackle the problems related to coffee. The field of genomics, which includes transcriptomics, proteomics, and metabolomics, has made great paces in the last ten years. Proteomics is a well-known technique used to enhance the growth, yield, breeding, and quality of different plants under stable and shifting environments. The regulation of specific enzymes, genes, protein expression, modification, translation, and other features played an important role in the enhancement of important plants. However, relatively less research on the proteomics approach for coffee has been published in the last few years. For this reason, some of the most important aspects of proteome profiling for coffee plants have been covered in this review, including growth, the somatic embryo technique, altitude, environmental adoption, drought, and the role that proteins and important enzymes play in the flavor and taste of coffee. This review can aid in the breeding of new cultivars and improve coffee attributes. Furthermore, the present literature can pave the way for proteomics research on coffee.
PubMed: 38890899
DOI: 10.3390/foods13111670 -
Foods (Basel, Switzerland) May 2024Officinal plants are a source of metabolites whose chemical composition depends on pedoclimatic conditions. In this study, the NMR-based approach was applied to...
Officinal plants are a source of metabolites whose chemical composition depends on pedoclimatic conditions. In this study, the NMR-based approach was applied to investigate the impacts of different altitudes and agronomical practices (Land, Mountain Spontaneous, and Organically Grown Ecotypes, namely LSE, MSE, and OE, respectively) on the metabolite profiles of Burdock root, Dandelion root and aerial part, and Lemon balm aerial part. Sugars, amino acids, organic acids, polyphenols, fatty acids, and other metabolites were identified and quantified in all samples. Some metabolites turned out to be tissue-specific markers. Arginine was found in roots, whereas myo-inositol, galactose, glyceroyldigalactose moiety, pheophytin, and chlorophyll were identified in aerial parts. Caftaric and chicoric acids, 3,5 di-caffeoylquinic acid, and chlorogenic and rosmarinic acids were detected in Dandelion, Burdock and Lemon balm, respectively. The metabolite amount changed significantly according to crop, tissue type, and ecotype. All ecotypes of Burdock had the highest contents of amino acids and the lowest contents of organic acids, whereas an opposite trend was observed in Lemon balm. Dandelion parts contained high levels of carbohydrates, except for the MSE aerial part, which showed the highest content of organic acids. The results provided insights into the chemistry of officinal plants, thus supporting nutraceutical-phytopharmaceutical research.
PubMed: 38890870
DOI: 10.3390/foods13111642 -
Animal Models and Experimental Medicine Jun 2024Under hypoxia, exaggerated compensatory responses may lead to acute mountain sickness. The excessive vasodilatory effect of nitric oxide (NO) can lower the hypoxic...
BACKGROUND
Under hypoxia, exaggerated compensatory responses may lead to acute mountain sickness. The excessive vasodilatory effect of nitric oxide (NO) can lower the hypoxic pulmonary vasoconstriction (HPV) and peripheral blood pressure. While NO is catalyzed by various nitric oxide synthase (NOS) isoforms, the regulatory roles of these types in the hemodynamics of pulmonary and systemic circulation in living hypoxic animals remain unclear. Therefore, this study aims to investigate the regulatory effects of different NOS isoforms on pulmonary and systemic circulation in hypoxic rats by employing selective NOS inhibitors and continuously monitoring hemodynamic parameters of both pulmonary and systemic circulation.
METHODS
Forty healthy male Sprague-Dawley (SD) rats were randomly divided into four groups: Control group (N-nitro-D-arginine methyl ester, D-NAME), L-NAME group (non-selective NOS inhibitor, N-nitro-L-arginine methyl ester), AG group (inducible NOS inhibitor group, aminoguanidine), and 7-NI group (neurological NOS inhibitor, 7-nitroindazole). Hemodynamic parameters of rats were monitored for 10 min after inhibitor administration and 5 min after induction of hypoxia [15% O, 2200 m a. sl., 582 mmHg (76.5 kPa), Xining, China] using the real-time dynamic monitoring model for pulmonary and systemic circulation hemodynamics in vivo. Serum NO concentrations and blood gas analysis were measured.
RESULTS
Under normoxia, mean arterial pressure and total peripheral vascular resistance were increased, and ascending aortic blood flow and serum NO concentration were decreased in the L-NAME and AG groups. During hypoxia, pulmonary arterial pressure and pulmonary vascular resistance were significantly increased in the L-NAME and AG groups.
CONCLUSIONS
This compensatory mechanism activated by inducible NOS and endothelial NOS effectively counteracts the pulmonary hemodynamic changes induced by hypoxic stress. It plays a crucial role in alleviating hypoxia-induced pulmonary arterial hypertension.
PubMed: 38888011
DOI: 10.1002/ame2.12453 -
Frontiers in Plant Science 2024(Maxim.) Pascher, a distinctive medicinal plant native to the Qinghai-Tibet Plateau, China, has garnered attention due to increasing market demand. This study explores...
(Maxim.) Pascher, a distinctive medicinal plant native to the Qinghai-Tibet Plateau, China, has garnered attention due to increasing market demand. This study explores the impact of environmental factors on the distribution and levels of active compounds namely anisodamine, anisodine, and atropine within . Our goal was to identify suitable cultivation areas for this plant. This study employs the maximum entropy model to simulate the suitable area of under current conditions and three climate change scenarios during the 2050s and 2070s. The finding revealed that altitude, precipitation in the warmest season (Bio 18), the average annual temperature (Bio 1) exerted significant influences on the distribution of . Among the environmental factors considered, temperature difference between day and night (Bio 2) had the most substantial impact on the distribution of anisodamine, temperature seasonal variation variance (Bio 4) predominantly influenced anisodine distribution, and Bio 1 had the greatest effected on the distribution of atropine. The suitable areas primarily exist in the eastern Qinghai-Tibet Plateau in China, encompassing a total area of 30.78 × 10 km. Under the climate scenarios for the future, the suitable areas exhibit increasing trends of approximately 30.2%, 30.3%, and 39.8% by the 2050s, and 25.1%, 48.8%, and 60.1% by the 2070s. This research would provide theoretical suggestions for the protection, and cultivation management of resources to face the challenge of global climate change.
PubMed: 38887466
DOI: 10.3389/fpls.2024.1369641 -
Nature Communications Jun 2024Although it is well documented that mountains tend to exhibit high biodiversity, how geological processes affect the assemblage of montane floras is a matter of ongoing...
Although it is well documented that mountains tend to exhibit high biodiversity, how geological processes affect the assemblage of montane floras is a matter of ongoing research. Here, we explore landform-specific differences among montane floras based on a dataset comprising 17,576 angiosperm species representing 140 Chinese mountain floras, which we define as the collection of all angiosperm species growing on a specific mountain. Our results show that igneous bedrock (granitic and karst-granitic landforms) is correlated with higher species richness and phylogenetic overdispersion, while the opposite is true for sedimentary bedrock (karst, Danxia, and desert landforms), which is correlated with phylogenetic clustering. Furthermore, we show that landform type was the primary determinant of the assembly of evolutionarily older species within floras, while climate was a greater determinant for younger species. Our study indicates that landform type not only affects montane species richness, but also contributes to the composition of montane floras. To explain the assembly and differentiation of mountain floras, we propose the 'floristic geo-lithology hypothesis', which highlights the role of bedrock and landform processes in montane floristic assembly and provides insights for future research on speciation, migration, and biodiversity in montane regions.
Topics: China; Biodiversity; Phylogeny; Magnoliopsida; Altitude; Geological Phenomena; Ecosystem
PubMed: 38886388
DOI: 10.1038/s41467-024-49522-4 -
Journal of Thoracic Disease May 2024Despite improvements in management, infective endocarditis (IE) is still associated with high mortality and morbidity. The outcome of patients with IE remains unclear in...
Postoperative follow-up of 221 patients with infective endocarditis from Gaoligong mountain area of Yunnan in China: a retrospective, single-center, observational cohort study.
BACKGROUND
Despite improvements in management, infective endocarditis (IE) is still associated with high mortality and morbidity. The outcome of patients with IE remains unclear in high-altitude areas of China. To characterize the epidemiological features and surgical outcomes, a retrospective analysis was conducted to 221 patients diagnosed with IE from a single center. In addition, to assess the prognosis of patients, a multivariate logistic regression model was performed to analyze the affecting risk factors.
METHODS
A retrospective analysis was conducted on the clinical data of 221 patients with IE who underwent surgical treatment at the Department of Cardiac Surgery of Yan'an Hospital Affiliated to Kunming Medical University from January 2013 to December 2019. The analysis evaluated patient demographics, pathogenic bacterial composition, echocardiography results, and surgical treatment outcomes. After a 1-year follow-up period, the mortality rate was statistically analyzed. The patients were divided into two groups based on their survival status: those who survived and those who did not. Relevant factors were compared between the two groups, and a multivariate logistic regression model was used to analyze the risk factors that affect the prognosis of patients with IE.
RESULTS
Out of the 221 patients diagnosed with IE, 164 were male and 57 were female, with an average age of 39.25±14.36 years. The most common underlying heart diseases were bicuspid aortic valve disease (24.9%), congenital heart disease (19.5%), rupture of aortic sinus aneurysm (5.0%) and rheumatic valvular disease (2.3%). The blood culture had a positive rate of 48.42% (107/221), with (29.9%) and (13.1%) being the main specifically pathogenic bacteria identified. Transthoracic echocardiography produced positive results in 89.6% (198/221) of cases. The findings included vegetation formation (100%), valve perforation or tear (21.7%), and perivalvular abscess formation (5.6%). Out of the patients, 174 underwent elective surgery, 47 received emergency surgery, and 11 died within 1 year after surgery, resulting in a mortality rate of 5.0%. However, the death group had longer operation time, cardiopulmonary bypass (CPB) time and higher EuroSCORE II compared to the non-death group (P<0.05). Logistic regression analysis identified preoperative hematocrit decrease, prolonged operation time and CPB time, high New York Heart Association (NYHA) cardiac function grade, and liver diseases as risk factors for 1-year mortality in patients with IE (OR =1.003, 0.000, 1.006, 1.026, 1.624 and 4.746).
CONCLUSIONS
IE primarily affects young and middle-aged men with rheumatic heart valvular disease as the main underlying heart disease and as the main pathogen. Surgical intervention significantly reduces early mortality in IE patients. To improve postoperative prognosis, clinicians should remain vigilant, especially in high-risk groups with preoperative hematocrit, prolonged operation time, and CPB time, high NYHA cardiac function grade, EuroSCORE II, and vegetation formation.
PubMed: 38883629
DOI: 10.21037/jtd-24-470