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Effect of high-altitude Exposure on the Heart

Cardiology Discovery 2023年第1期3卷 48-53页

作者： Lan Huang Institute of Cardiovascular Diseases of People’s Liberation Army Department of CardiologySecond Affiliated HospitalThird Military Medical University(Army Medical University)Chongqing 400037China

high altitude brings a great physiological change in human beings,both during short-term exposure and in lifelong residents,especially in the cardiovascular *** notably induces pulmonary vasoconstriction,thus resulting in a moderate increase in pulmonary arterial *** inhabitants exhibit lower pulmonary pressure and better exercise capacity than lowlanders during short-term high-altitude *** ascent to high altitude without adequate acclimatization can cause high-altitude pulmonary edema in susceptible individuals,with a rapid increase in pulmonary *** output increases initially following acute high-altitude exposure and returns to normal as at sea level after a few days of *** volumes at high altitude change consistently with decreases in plasma *** ventricular systolic function is enhanced after acute high-altitude exposure and during chronic ***,there are controversies on whether right ventricular systolic function is preserved or decreases after high-altitude exposure,probably due to variable hypoxic pulmonary *** altitude induces altered ventricular diastolic ***,a new perspective has emerged,whereby ventricular intrinsic relaxation is not impaired,as assessed by untwisting through speckle-tracking *** hypoxic pulmonary hypertension probably induced right ventricular dilation and hypertrophy,and even right heart failure,described as high-altitude heart *** to lower altitude should be the best treatment for them,and potential pharmacological agents majorly focus on the inhabitation of pulmonary vasoconstriction,such as phosphodiesterase-5 inhibitors and endothelin receptor *** on the risks of high-altitude exposure for patients with previous cardiovascular diseases is limited,and thus they should be prudent when ascending to high *** randomized large-scale studies are need

关键词： altitude high-altitude exposure Hypoxia Cardiac function Pulmonary hypertension

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Correlation of vascular endothelial growth factor to permeability of blood-brain barrier and brain edema during high-altitude exposure

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Neural Regeneration Research 2009年第10期4卷 775-779页

作者： Qiquan Zhou Chang'e Liu Jing Wang Yunli Wang Bo Zhou Department of high altitude Disease College of High Altitude Military Medicine Third Military Medical University of Chinese PLA Chongqing 400038 China Key Laboratory of high altitude Medicine Ministry of Education and Key Laboratory of High Altitude Physiology and High Altitude Disease of Chinese PLA Chongqing 400038 China Department of Animal Science College of Basic Medicine Third Military Medical University of Chinese PLA Chongqing 400038 China Department of Pathology and Pathophysiology Chengdu Medical College Chengdu 610083 Sichuan Province China Clinical Laboratory the25 Hospital of Chinese PLA Jiuquan 735000 Gansu Province China

BACKGROUND： Many studies have evaluated the role of vascular endothelial growth factor （VEGF） in traumatic brain edema and hemorrhagic brain edema. OBJECTIVE： To observe the effects of VEGF expression on permeability of the blood-brain barrier （BBB） during high-altitude and hypoxia exposure, and to investigate the correlation between VEGF expression and BBB permeability with regard to Evans blue staining and brain edema during high-altitude exposure. DESIGN, TIME AND SETTING： The randomized, controlled, animal study was performed at the Tanggula Etape, Central Laboratory of Chengdu Medical College, and Central Laboratory of General Hospital of Chengdu Military Area Command of Chinese PLA, China, from July 2003 to November 2004. MATERIALS： Quantitative RT-PCR kit （Sigma, USA）, VEGF ELISA kit （Biosource, USA）, and Evans blue （Jingchun, China） were acquired for this study. METHODS： A total of 180 Wistar rats were equally and randomly assigned to 15 groups： low-altitude （500 m）, middle-altitude （2 880 m）, high-altitude （4 200 m）, super-high-altitude （5 000 m）, 1,3, 5, 7, 9, 11, 13, 15, 17, 19, and 21 days of super high-altitude exposure. Wistar rats were exposed to various altitude gradients to establish a hypoxia model. MAIN OUTCOME MEASURES： Brain water content was calculated according to the wet-to-dry weight ratio. BBB permeability to Evans blue was determined by colorimetric method. VEGF mRNA and protein levels in brain tissues were detected using RT-PCR and double-antibody sandwich ELISA. RESULTS： Brain water content, BBB permeability to Evans blue, and VEGF mRNA and protein levels in brain tissues increased with increasing altitude and prolonged exposure to altitude. The greatest increase was determined on day 9 upon ascending 5 000 m. Simultaneously, VEGF expression positively correlated to BBB permeability of Evans blue and brain water content （r = 0.975, 0.917, P〈 0.01）. CONCLUSION： Increased VEGF protein and mRNA expression was responsible for increased BBB p

关键词： high-altitude blood-brain barrier permeability vascular endothelial growth factor

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A GIS-aided response model of high-altitude permafrost to global change

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Science China Earth Sciences 1999年第1期42卷 72-79页

作者：李新程国栋

Two models are used to simulate the high-altitude permafrost distribution on the Qinghai-Xizang Plateau. The two models are the 'altitude model', a Gaussian distribution function used to describe the latitudinal zonation of permafrost based on the three-dimensional rules of high-altitude permafrost, and the 'frost number model', a dimensionless ratio defined by manipulation of freezing and thawing degree-day sums. The results show that the 'altitude model' can simulate the high-altitude permafrost distribution under present climate conditions accurately. Given the essential hypotheses and using the GCM scenarios from HADCM2, the 'altitude model' is used for predicting the permafrost distribution change on the Qinghai-Xizang Plateau. The results show that the permafrost on the plateau will not change significantly during 20—50 a, the percentage of the total disappeared area will not be over 19%. However, by the year 2099, if the air temperature increases by an average of 2.91℃ on the plateau, the

关键词： high-altitude permafrost global change response model GIS.

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Effects of host identity on the gut microbiota:A comparative study on three microtinae species

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Animal Models and Experimental Medicine 2024年第2期7卷 98-105页

作者： Zhen Yao Wenli Zhao Baohong Tang Qinghua Li Zhenlong Wang School of Life Sciences Zhengzhou UniversityZhengzhouHenan ProvinceP.R.China

Background:Gut microbiota exert an immense effect on host health and host environmental ***,the composition and structure of gut microbiota are determined by the environment and host genetic ***,the relative contribution of the environment and host genetic factors toward shaping the structure of gut microbiota has been poorly ***:In this study,we characterized the fecal microbial communities of the closely related voles Neodon fuscus,Lasiopodomys brandtii,and *** after caged feeding in the laboratory for 6 months,through high-throughput sequencing and bioinformatics ***:The results of pairwise comparisons of *** *** and *** *** revealed significant differences in bacterial diversity and composition after *** 991 same operational taxonomic units(OTUs)were shared in three voles,there were 362,291,and 303 species-specific OTUs in ***,***,and ***,*** relative abundances of Proteobacteria and Prevotella,which are reported to be enriched in high-altitude populations,were significantly higher in high-altitude *** than in low-altitude *** after ***,which produce various digestive enzymes for energy metabolism,and Spirochaetes,which can degrade cellulose,were found in higher abundance in subterranean *** than that in *** which dwells on the earth ***:Our findings showed that some components of gut microbiota still maintained dominance even when different host species are reared under the same environmental conditions,suggesting that these bacteria are substantially influenced by host factors.

关键词： gut microbiota high-altitude Lasiopodomys brandtii Neodon fuscus

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Industrial Poverty Alleviation Model in Southwestern high-altitude Mountainous Areas of China——A Case Study of Industrial Poverty Alleviation of Xueshan Township in Luquan County of Yunnan Province through Planting Codonopsis pilosula

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Asian Agricultural Research 2019年第3期11卷 48-54页

作者： Zisheng YANG Renyi YANG Yanbo HE Chonghui LU En ZHU Yaohan PI Mingxin WU Ying XIONG Targeted Poverty Alleviation and Development Institute Yunnan University of Finance and Economics Office of Rural Work Leading Group of Kunming Municipal Committee of the Communist Party of China People's Government of Xueshan Township Luquan County

Due to the severe restrictions of natural conditions and ecological environment,high-altitude mountainous areas usually become the " hard bones" in the battle against poverty. Xueshan Township,Luquan Yi and Miao Autonomous County of Yunnan Province,located in the alpine valley of Jinsha River,is a major township with wide and deep poverty,and the incidence of poverty is up to 45. 00%. In recent years,Xueshan Township has insisted on the battle against poverty,made effort to develop the Codonopsis pilosula industry,and successfully developed a road to poverty alleviation through C. pilosula industry,and formed a unique industrial poverty alleviation model by the end of 2018,the incidence of poverty dropped to 0. 74%. Based on field survey and interview,this paper analyzes and summarizes the specific practices,main results,practical experience and promotion and application measures of the poverty alleviation model of C. pilosula planting industry in Xueshan Township,in the hope of providing certain reference for the targeted poverty alleviation in similar areas in Yunnan Province and other provinces of China.

关键词： high-altitude mountainous areas Industrial poverty alleviation Chinese herbal medicine planting Codonopsis pilosula Model Xueshan Township of Luquan County

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Impact of atmospheric ionization by delayed radiation from highaltitude nuclear explosions on radio communication

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Nuclear Science and Techniques 2019年第12期30卷 58-64页

作者： Heng Xu Jian-Ming Ouyang Shang-Wu Wang Yun Liu Xu Sun College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073China College of Physics and Micro Electronic Hunan UniversityChangsha 410006China College of Electronics Science National University of Defense TechnologyChangsha 410073China

In this study,we investigated the motion,shape,and delayed radiation intensity of a radioactive cloud by establishing a volume-source model of delayed radiation after high-altitude nuclear ***,the spatial distribution of electron number density at different moments on the north side of the explosion point generated by delayed γ-rays and delayed β-rays from the radioactive cloud under the influence of the geomagnetic field was calculated by solving chemical reaction kinetics *** impact of radio communication in the different frequency bands on the process of atmospheric ionization was also *** numerical results of the high-altitude nuclear explosion (120 km high and with a 1 megaton equivalent at 40°N latitude) indicated that the peak of electron number density ionized delayed γ-rays is located at a height of approximately 100 km and that of electron number density ionized delayed β-rays is about 90 km *** 1 min of explosion,the radio communication in the medium frequency (MF) and high-frequency (HF)bands was completely interrupted,and the energy attenuation of the radio wave in the very high-frequency (VHF)band was extremely *** minutes later,the VHF radio communication was basically restored,but the energy attenuation in the HF band was still *** 30 min,theVHF radio communication returned to normal,but its influence on the HF and MF radio communication continued.

关键词： high-altitude nuclear explosions Delayed radiation Ionization effect Radio communication

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Modeling turbulent transport effects on kernel formation and ?ame propagation in an ignition process

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Chinese Journal of Aeronautics 2019年第4期32卷 895-905页

作者： Linghan KONG Zhuyin REN Lingyun HOU School of Aerospace Engineering Tsinghua University

Reliable relighting is crucial for advanced low-emission aero-engine combustors. For forced ignition under highly-turbulent conditions, eddies of sizes being smaller than the flame kernel can affect its formation through penetrating and modifying the kernel structure. In this study, a one-dimensional model for small-scale turbulence on kernel formation is developed through the incorporation of turbulence-induced diffusion in governing equations. With given flow conditions,the spatial and time-dependent turbulent diffusivity is modeled using the idea of residual eddy viscosity. One-dimensional spherical flames of premixed pre-vaporized n-dodecane/air mixtures under high-altitude conditions are simulated to investigate the effects of turbulence. It is revealed that the range of the equivalence ratio for successful turbulent ignition is much narrower than that for laminar ignition. The range decreases with an increased turbulent intensity, and this effect is more pronounced for a low spark energy. In addition, turbulent transport has more pronounced effects on rich mixtures. An analysis on energy budget and species profiles shows that turbulence-induced diffusion enhances the heat loss at the very beginning of the kernel formation process that could lead to ignition failure. After the flame kernel is established, turbulent transport broadens the flame front, enhances the heat release rate, and thereafter increases the flame propagation speed.

关键词： Flame kernel Flame propagation high-altitude ignition Kernel formation probability Turbulence-induced diffusion

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Adaptation of mammals to hypoxia

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Animal Models and Experimental Medicine 2021年第4期4卷 311-318页

作者： Fang Li Zhenglei Qiao Qijiao Duan Eviatar Nevo College of Life Sciences and Technology Mudanjiang Normal UniversityMudanjiangChina College of Natural Resources and Environment South China Agriculture UniversityGuangzhouChina Institute of Evolution University of HaifaHaifaIsrael

Oxygen plays a pivotal role in the metabolism and activities of ***,oxygen is restricted in some environments-subterranean burrow systems or habitats at high altitude or deep in the ocean-and this could exert hypoxic stresses such as oxidative damage on organisms living in these *** order to cope with these stresses,organisms have evolved specific strategies to adapt to hypoxia,including changes in physiology,gene expression regulation,and genetic ***,we review how mammals have adapted to the three high-altitude plateaus of the world,the limited oxygen dissolved in deep water habitats,and underground tunnels,with the aim of better understanding the adaptation of mammals to hypoxia.

关键词： hemoglobin high-altitude hypoxia marine mammals subterranean mammals

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Actinic prurigo of the lip: Two case reports

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World Journal of Clinical Cases 2014年第8期2卷 385-390页

作者： Ana MO Miranda Thiago M Ferrari Juliana T Werneck Arley Silva Junior Karin S Cunha Eliane P Dias Department of Pathology Federal Fluminense UniversityNiteroiRio de Janeiro 24220-008Brazil

Actinic prurigo is a photodermatosis that can affect the skin, conjunctiva and lips. It is caused by an abnormal reaction to sunlight and is more common in high-altitude living people, mainly in indigenous descendants. The diagnosis of actinic prurigo can be challenging, mainly when lip lesions are the only manifestation, which is not a common clinical presentation. The aim of this article is to report two cases of actinic prurigo showing only lip lesions. The patients were Afro-American and were unaware of possible Indian ancestry. Clinical exam, photographs, videoroscopy examination and biopsy were performed, and the diagnosis of actinic prurigo was established. Topical corticosteroid and lip balm with ultraviolet protection were prescribed with excellent results. The relevance of this report is to show that although some patients may not demonstrate the classical clinical presentation of actinic prurigo, the associated clinical and histological exams are determinants for the correct diagnosis and successful treatment of this disease.

关键词： Actinic prurigo Follicular cheilitis Photodermatosis high-altitude Lip diseases

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