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Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes 被引量:8
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作者 Gustavo F Gonzales 《Asian Journal of Andrology》 SCIE CAS CSCD 2013年第3期368-374,共7页
Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl-1〈haemoglobin (Hb)≤21 gdl-1) and others with excessive er... Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl-1〈haemoglobin (Hb)≤21 gdl-1) and others with excessive erythrocytosis (EE) (Hb〉21 g dl-1). Elevated haemoglobin values (EE) are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate (DH EAS) to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Lower 17beta-HSD activity via A4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the A5-pathway. Currently, there are various situations in which people live (human biodiversity) with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process. 展开更多
关键词 chronic mountain sickness DHEA HAEMOGLOBIN high altitudes MEN OESTRADIOL women
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Prevalence of Congenital Heart Disease at Extremely High Altitudes in Tibet and the Establishment of a New Free Treatment Model 被引量:1
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作者 Shuting Chang Guanzhao Zhang +14 位作者 Nengjun Sun Xinpeng Yuan Qingting Wang Lin Zhu Feiyue Zhang Yu Xiu Yang Dong Yonghong Chen Zhanpeng Zhao Xiao Liu Qiang Shao Xiaofeng Xu Anshun Wang Mengjiao Li Bo Li 《Congenital Heart Disease》 SCIE 2022年第6期709-716,共8页
Background: This study aimed to illustrate the prevalence of CHD by screening children in extremely high-altitudeareas (over 4000 m to even 5000 m above sea level) and explore an aid model for early diagnosis and trea... Background: This study aimed to illustrate the prevalence of CHD by screening children in extremely high-altitudeareas (over 4000 m to even 5000 m above sea level) and explore an aid model for early diagnosis and treatmentfor the Tibetan population. Methods: A total of 2242 students from different schools in Ngamring County,Xigaze City, Tibet from September 2019 to September 2020 were selected for screening. The students were examinedthrough the inquiry of their current medical history and family history, cardiac auscultation and a physicalexamination, in order to screen out the suspected cases of CHD, and then the suspected cases were confirmed bycardiac color ultrasound examinations. After that, positive patients were be transferred to Shandong Province forfree treatment. Results: The prevalence of CHD among children in Ngamring County was 3.70% (83 cases),which is the highest incidence rate ever reported. The most common type of CHD was patent ductus arteriosus(PDA), accounting for 55.42% of the total number of cases screened, followed by atrial septal defect (ASD) andventricular septal defect (VSD), accounting for 28.92% and 12.05%, respectively. The prevalence of CHD in childrenat high altitude was significantly higher than that in children at low altitude. The children with CHD weretransferred to Shandong Province for surgery, the operations were successful and their recoveries went well.Conclusions: The results show that high altitude is closely related to the prevalence of CHD, and the incidencein Ngamring County is much higher than that in previous reports. 展开更多
关键词 TIBET high altitude CHD free treatment model
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Study on Skin Care Efficacy of the Active Ingredients in Camellia Japonica Flowers at High and Low Altitudes
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作者 Cao Yimiao Gao Hongqi +1 位作者 Gao Cong Deng Quanzhi 《China Detergent & Cosmetics》 CAS 2024年第1期76-80,共5页
The active ingredients of Camellia japonica flowers(CJF)at high and low altitudes,as well as their skin care efficacy were compared.The dried red CJF at high and low altitudes were ultrasonically extracted with 70%eth... The active ingredients of Camellia japonica flowers(CJF)at high and low altitudes,as well as their skin care efficacy were compared.The dried red CJF at high and low altitudes were ultrasonically extracted with 70%ethanol,and these extracts were concentrated and then diluted to a constant volume.The content of total flavonoids,total polyphenols and total proteins was tested and analyzed.In addition,DPPH free radical scavenging,inhibition of the formation of advanced glycation end products,and inhibitory activity against elastase was measured to compare their skin care efficacy in anti-oxidation,anti-glycation,anti-wrinkling and firming.The results showed that,based on the dry weight of CJF,the content of total flavonoids and total proteins of the CJF at high altitude was approximately 1.5 times of the CJF at low altitude,while the content of total polyphenols was approximately 2.4 times that of the CJF at low altitude.The skin care efficacy of CJF at high altitude was significantly better than that of the CJF at low altitude.This work could provide theoretical basis for the selection and application of Camellia japonica flowers in the field of cosmetics. 展开更多
关键词 camellia japonica flowers at high and low altitudes active ingredients skin care efficacy
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Effect of dissolved-oxygen on the flotation behavior of pyrite at high altitude area
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作者 Yan Miao Guangke Ye Guofan Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第10期2148-2158,共11页
With the continuous development of mineral resources to high altitude areas,the study of sulfide ore flotation in unconventional systems has been emphasized.There is a consensus that moderate oxidation of sulfide ore ... With the continuous development of mineral resources to high altitude areas,the study of sulfide ore flotation in unconventional systems has been emphasized.There is a consensus that moderate oxidation of sulfide ore is beneficial to flotation,but the specific suitable dissolved oxygen value is inconclusive,and there are few studies on sulfide ore flotation under low dissolved oxygen environment at high altitude.In this paper,we designed and assembled an atmosphere simulation flotation equipment to simulate the flotation of pyrite at high altitude by controlling the partial pressure of N_(2)/O_(2) and dissolved oxygen under atmospheric conditions.X-ray photoelectron spec-troscopy(XPS),atomic force microscope(AFM),Fourier transform infrared spectrometer(FT-IR),UV-vis spectrophotometer,zeta po-tential,and contact angle measurements were used to reveal the effects of surface oxidation and agent adsorption on pyrite at high altitude(4600 m dissolved oxygen(DO)=4.0 mg/L).The results of pure mineral flotation indicated that the high altitude and low dissolved oxy-gen environment is favorable for pyrite flotation.Contact angle measurements and XPS analysis showed that the high altitude atmosphere nslows down the oxidation of pyrite surface,facilitates S_(n)^(2-)/S^(0) production and enhances surface hydrophobicity.Electrochemical calcula-tions and zeta potential analysis showed that the influence of atmosphere on the form of pyrite adsorption is small,and the different atmo-spheric conditions are consistent with dixanthogen electrochemical adsorption,with lower Zeta potential under high altitude atmosphere and significant potential shift after sodium isobutyl xanthate(SIBX)adsorption.The results of FT-IR,UV-vis,and AFM analysis showed that SIBX adsorbed more on the surface of pyrite under high altitude atmosphere and adsorbed on the surface in a mesh structure com-posed of column/block.The results of the experimental study revealed the reasons for the easy flotation of sulfide ores at high altitude with less collector dosage,and confirmed that the combined DO-pH regulation is beneficial to achieve more efficient flotation of pyrite. 展开更多
关键词 high altitude DISSOLVED-OXYGEN PYRITE FLOTATION OXIDATION
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Modification of streamer-to-leader transition model based on radial thermal expansion in the sphere-plane gap discharge at high altitude
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作者 耿江海 林果 +3 位作者 王平 丁玉剑 丁杨 俞华 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第1期42-49,共8页
Historically,streamer-to-leader transition studies mainly focused on the rod-plane gap and low altitude analysis,with limited attention paid to the sphere-plane gap at high altitude analysis.In this work,sphere-plane ... Historically,streamer-to-leader transition studies mainly focused on the rod-plane gap and low altitude analysis,with limited attention paid to the sphere-plane gap at high altitude analysis.In this work,sphere-plane gap discharge tests were carried out under the gap distance of 5 m at the Qinghai Ultra High Voltage(UHV)test base at an altitude of 2200 m.The experiments measured the physical parameters such as the discharge current,electric field intensity and instantaneous optical power.The duration of the dark period and the critical charge of streamer-toleader transition were obtained at high altitude.Based on radial thermal expansion of the streamer stem,we established a modified streamer-to-leader transition model of the sphere-plane gap discharge at high altitude,and calculated the stem temperature,stem radii and the duration of streamer-to-leader transition.Compared with the measured duration of sphere-plane electrode discharge at an altitude of 2200 m,the error rate of the modified model was 0.94%,while the classical model was 6.97%,demonstrating the effectiveness of the modified model.From the comparisons and analysis,several suggestions are proposed to improve the numerical model for further quantitative investigations of the leader inception. 展开更多
关键词 streamer-to-leader transition model high altitude streamer stem convective diffusion radial thermal expansion
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The cardiovascular system at high altitude:A bibliometric and visualization analysis
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作者 Mao-Lin Zhao Zhong-Jie Lu +6 位作者 Li Yang Sheng Ding Feng Gao Yuan-Zhang Liu Xue-Lin Yang Xia Li Si-Yi He 《World Journal of Cardiology》 2024年第4期199-214,共16页
BACKGROUND When exposed to high-altitude environments,the cardiovascular system undergoes various changes,the performance and mechanisms of which remain controversial.AIM To summarize the latest research advancements ... BACKGROUND When exposed to high-altitude environments,the cardiovascular system undergoes various changes,the performance and mechanisms of which remain controversial.AIM To summarize the latest research advancements and hot research points in the cardiovascular system at high altitude by conducting a bibliometric and visualization analysis.METHODS The literature was systematically retrieved and filtered using the Web of Science Core Collection of Science Citation Index Expanded.A visualization analysis of the identified publications was conducted employing CiteSpace and VOSviewer.RESULTS A total of 1674 publications were included in the study,with an observed annual increase in the number of publications spanning from 1990 to 2022.The United States of America emerged as the predominant contributor,while Universidad Peruana Cayetano Heredia stood out as the institution with the highest publication output.Notably,Jean-Paul Richalet demonstrated the highest productivity among researchers focusing on the cardiovascular system at high altitude.Furthermore,Peter Bärtsch emerged as the author with the highest number of cited articles.Keyword analysis identified hypoxia,exercise,acclimatization,acute and chronic mountain sickness,pulmonary hypertension,metabolism,and echocardiography as the primary research hot research points and emerging directions in the study of the cardiovascular system at high altitude.CONCLUSION Over the past 32 years,research on the cardiovascular system in high-altitude regions has been steadily increasing.Future research in this field may focus on areas such as hypoxia adaptation,metabolism,and cardiopulmonary exercise.Strengthening interdisciplinary and multi-team collaborations will facilitate further exploration of the pathophysiological mechanisms underlying cardiovascular changes in high-altitude environments and provide a theoretical basis for standardized disease diagnosis and treatment. 展开更多
关键词 Cardiovascular system high altitude HYPOXIA Bibliometric analysis VISUALIZATION
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Accuracy of FreeStyle Libre flash glucose monitoring in patients with type 2 diabetes who migrated from highlands to plains
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作者 Zeng-Mei Sun Yuan-Ze Du +11 位作者 Su-Yuan Wang Shu-Yao Sun Yan Ye Xue-Ping Sun Ming-Xia Li Hua He Wun-Chun Long Cheng-Hui Zhang Xuan-Yu Yao Wu-Yi Fan Ling Wang Yun-Hong Wu 《World Journal of Diabetes》 SCIE 2024年第6期1254-1262,共9页
BACKGROUND The FreeStyle Libre flash glucose monitoring(FGM)system entered the Chinese market in 2017 to complement the self-monitoring of blood glucose.Due to its increased usage in clinics,the number of studies inve... BACKGROUND The FreeStyle Libre flash glucose monitoring(FGM)system entered the Chinese market in 2017 to complement the self-monitoring of blood glucose.Due to its increased usage in clinics,the number of studies investigating its accuracy has increased.However,its accuracy has not been investigated in highland populations in China.AIM To evaluate measurements recorded using the FreeStyle Libre FGM system compared with capillary blood glucose measured using the enzyme electrode method in patients with type 2 diabetes(T2D)who had migrated within 3 mo from highlands to plains.METHODS Overall,68 patients with T2D,selected from those who had recently migrated from highlands to plains(within 3 mo),were hospitalized at the Department of Endocrinology from August to October 2017 and underwent continuous glucose monitoring(CGM)with the FreeStyle Libre FGM system for 14 d.Throughout the study period,fingertip capillary blood glucose was measured daily using the enzyme electrode method(Super GL,China),and blood glucose levels were read from the scanning probe during fasting and 2 h after all three meals.Moreover,the time interval between reading the data from the scanning probe and collecting fingertip capillary blood was controlled to<5 min.The accuracy of the FGM system was evaluated according to the CGM guidelines.Subsequently,the factors influencing the mean absolute relative difference(MARD)of this system were analyzed by a multiple linear regression method.RESULTS Pearson’s correlation analysis showed that the fingertip and scanned glucose levels were positively correlated(R=0.86,P=0.00).The aggregated MARD of scanned glucose was 14.28±13.40%.Parker's error analysis showed that 99.30%of the data pairs were located in areas A and B.According to the probe wear time of the FreeStyle Libre FGM system,MARD_(1 d) and MARD_(2-14 d) were 16.55%and 14.35%,respectively(t=1.23,P=0.22).Multiple stepwise regression analysis showed that MARD did not correlate with blood glucose when the largest amplitude of glycemic excursion(LAGE)was<5.80 mmol/L but negatively correlated with blood glucose when the LAGE was≥5.80 mmol/L.CONCLUSION The FreeStyle Libre FGM system has good accuracy in patients with T2D who had recently migrated from highlands to plains.This system might be ideal for avoiding the effects of high hematocrit on blood glucose monitoring in populations that recently migrated to plains.MARD is mainly influenced by glucose levels and fluctuations,and the accuracy of the system is higher when the blood glucose fluctuation is small.In case of higher blood glucose level fluctuations,deviation in the scanned glucose levels is the highest at extremely low blood glucose levels. 展开更多
关键词 Type 2 diabetes Flash glucose monitoring ACCURACY Continuous glucose monitor high altitude
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A novel point source oxygen supply method for sleeping environment improvement at high altitudes 被引量:2
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作者 Yanfeng Liu Zhiyuan Song +1 位作者 Cong Song Dengjia Wang 《Building Simulation》 SCIE EI CSCD 2021年第6期1843-1860,共18页
The hypoxic environment at high altitudes causes various sleep disorders.Diffuse oxygen enrichment is an effective way to alleviate sleep disorders and improve the built environment in high altitude areas.In this stud... The hypoxic environment at high altitudes causes various sleep disorders.Diffuse oxygen enrichment is an effective way to alleviate sleep disorders and improve the built environment in high altitude areas.In this study,a novel point source local diffuse oxygen supply method was proposed to improve the sleeping oxygen environment.The oxygen supply performance was investigated by the computational fluid dynamics(CFD)method including the oxygen concentration and air velocity distributions.A sleeping experiment was conducted on the plateau to validate the CFD model.The occupied zone including the inhalation zone and the active zone was defined.The results showed that the oxygen concentration showed a rapid rise,then decreased slowly,and finally tended to be stable.The oxygen concentration after stabilization was remarkably influenced by indoor ventilation rate.The sleeping environment’s improvement was examined considering the oxygen enrichment efficiency,uniformity,stability and human comfort demand.The optimal strategies were recommended with a ventilation rate of 1 air change per hour,supplied oxygen concentration of 90%;and jet distance of 0.50 m.The study contributes to improving the oxygen environment and human sleep quality in an effective and energy-saving approach to the sustainable development of buildings in high altitude areas. 展开更多
关键词 oxygen supply indoor airflow built environment CFD method high altitudes
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Thermal comfort in winter incorporating solar radiation effects at high altitudes and performance of improved passive solar design-Case of Lhasa 被引量:2
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作者 Lingjiang Huang Jian Kang 《Building Simulation》 SCIE EI CSCD 2021年第6期1633-1650,共18页
The solar incidence on an indoor environment and its occupants has significant impacts on indoor thermal comfort.It can bring favorable passive solar heating and can result in undesired overheating(even in winter).Thi... The solar incidence on an indoor environment and its occupants has significant impacts on indoor thermal comfort.It can bring favorable passive solar heating and can result in undesired overheating(even in winter).This problem becomes more critical for high altitudes with high intensity of solar irradiance,while received limited attention.In this study,we explored the specific overheating and rising thermal discomfort in winter in Lhasa as a typical location of a cold climate at high altitudes.First,we evaluated the thermal comfort incorporating solar radiation effect in winter by field measurements.Subsequently,we investigated local occupant adaptive responses(considering the impact of direct solar irradiance).This was followed by a simulation study of assessment of annual based thermal comfort and the effect on energy-saving potential by current solar adjustment.Finally,we discussed winter shading design for high altitudes for both solar shading and passive solar use at high altitudes,and evaluated thermal mass shading with solar louvers in terms of indoor environment control.The results reveal that considerable indoor overheating occurs during the whole winter season instead of summer in Lhasa,with over two-thirds of daytime beyond the comfort range.Further,various adaptive behaviors are adopted by occupants in response to overheating due to the solar radiation.Moreover,it is found that the energy-saving potential might be overestimated by 1.9 times with current window to wall ratio requirements in local design standards and building codes due to the thermal adaption by drawing curtains.The developed thermal mass shading is efficient in achieving an improved indoor thermal environment by reducing overheating time to an average of 62.2% during the winter and a corresponding increase of comfort time. 展开更多
关键词 thermal comfort OVERHEATING passive solar design high altitude TIBET solar shading
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Distribution characteristics of indoor oxygen concentration under natural ventilation in oxygen-enriched buildings at high altitudes
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作者 Cong Song Tingting Zhao +1 位作者 Yanfeng Liu Dengjia Wang 《Building Simulation》 SCIE EI CSCD 2021年第6期1823-1841,共19页
Diffuse oxygen supply is an important means to improve the indoor oxygen environment of buildings and ensure physiological and psychological health of immigrants in plateau areas.Existing research on oxygen enrichment... Diffuse oxygen supply is an important means to improve the indoor oxygen environment of buildings and ensure physiological and psychological health of immigrants in plateau areas.Existing research on oxygen enrichment strategies at high altitudes has mainly focused on confined spaces under mechanical ventilation,with few studies on the distribution of indoor oxygen concentration under natural ventilation in actual buildings.This study used a verified computational fluid dynamics(CFD)method to investigate the indoor oxygen distribution with practical consideration of natural ventilation at high altitudes.The results showed that the oxygen distribution under wind-driven natural ventilation was more nonuniform than that under buoyancy-driven natural ventilation,with the ratio of local oxygen concentration to overall-mean oxygen concentration,the k value,between 0.8 and 1.3 under wind-driven natural ventilation and between 0.9 and 1.1 under buoyancy-driven natural ventilation.The effects of meteorological condition and oxygen source position on indoor spatial oxygen distribution characteristics were explored with careful examination in human occupied zone under lying,sitting and standing postures.The results can provide implications for effective and energy saving design of indoor oxygen supply system in plateau buildings. 展开更多
关键词 high altitude indoor environment-oxygen concentration distribution natural ventilation oxygen enrichment
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Proteomic Analysis of the Small Intestine Reveals Adaptive Strategies for Energy Restriction of Phrynocephalus vlangalii at High Altitude
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作者 Yangyang ZHAO Cui YANG +4 位作者 Yongxing HE Yue QI Shuhui CAO Xue BIAN Wei ZHAO 《Asian Herpetological Research》 SCIE CSCD 2023年第2期167-174,共8页
The environmental characteristics of hypothermia and hypoxia exert great selective pressure on the energy metabolism of high-altitude animals,especially the ectotherms.Current research on energy-limited adaptation of ... The environmental characteristics of hypothermia and hypoxia exert great selective pressure on the energy metabolism of high-altitude animals,especially the ectotherms.Current research on energy-limited adaptation of high-altitude ectotherms has focused on energy expenditures.However,the mechanisms of increasing energy intake in high-altitude ectotherms have been studied rarely.In order to investigate the adaptation mechanism of the small intestine,the key part of energy acquisition for animals,to energy limitation at high altitude in ectotherms,the gut proteins of Phrynocephalus vlangalii from high-and low-altitude populations were compared using label free proteomics.GO enrichment and KEGG pathway analysis showed that proteins associated with energy intake,such as those involved in oxidation-reduction processes,glutathione metabolism,oxidoreductase activity,cofactor binding,catalytic activity and metabolic pathways,were significantly up-regulated in high-altitude populations;while proteins associated with energy expenditure,such as immune responses and processes,membrane attack complexes,natural killer pathway and other immune-related processes,were significantly down-regulated in expression. 展开更多
关键词 energy intake energy limitation high altitude label-free proteomic analysis lipid metabolism Phrynocephalus vlangalii
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基于高空平台的边缘计算卸载:网络、算法和展望
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作者 孙恩昌 李梦思 +2 位作者 何若兰 张卉 张延华 《北京工业大学学报》 CAS CSCD 北大核心 2024年第3期348-361,共14页
高空平台(high altitude platform,HAP)技术与多接入边缘计算(multi-access edge computing,MEC)技术的结合将MEC服务器部署区域由地面扩展到空中,打破传统地面MEC网络的局限性,为用户提供无处不在的计算卸载服务。针对基于HAP的MEC卸... 高空平台(high altitude platform,HAP)技术与多接入边缘计算(multi-access edge computing,MEC)技术的结合将MEC服务器部署区域由地面扩展到空中,打破传统地面MEC网络的局限性,为用户提供无处不在的计算卸载服务。针对基于HAP的MEC卸载研究进行综述,首先,从HAP计算节点的优势、网络组成部分、网络结构、主要挑战及其应对技术4个方面分析基于HAP的MEC网络;其次,分别从图论、博弈论、机器学习、联邦学习等理论的角度对基于HAP的MEC卸载算法进行横向分析和纵向对比;最后,指出基于HAP的MEC卸载技术目前存在的问题,并对该技术的未来研究方向进行展望。 展开更多
关键词 高空平台(high altitude platform HAP) 多接入边缘计算(multi-access edge computing MEC) 计算卸载 图论 博弈论 机器学习
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High Altitude Adaptation and Phylogenetic Analysis of Tibetan Horse Based on the Mitochondrial Genome 被引量:9
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作者 徐树青 洛桑江白 +7 位作者 华桑 何健 阿叁次仁 王威 童晓梅 梁羽 汪建 郑晓光 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第8期720-729,共10页
To investigate genetic mechanisms of high altitude adaptations of animals living in the Tibetan Plateau, three mitochondrial genomes (mt-genome) of Tibetan horses living in Naqu (4,500 m) of Tibetan, Zhongdian (3... To investigate genetic mechanisms of high altitude adaptations of animals living in the Tibetan Plateau, three mitochondrial genomes (mt-genome) of Tibetan horses living in Naqu (4,500 m) of Tibetan, Zhongdian (3,300 m) and Deqin (3,100 m) of Yunnan province were sequenced. The structures and lengths of these three mt-genomes are similar to the Cheju horse, which is related to Tibetan horses, but little shorter than the Swedish horse. The pair-wise identity of these three horses on nucleotide level is more than 99.3%. When the gene encoding the mitochondrial protein of Tibetan horses was analyzed, we found that NADH6 has higher non-synonymous mutation rate in all of three Tibetan horses. This implies that NADH6 may play a role in Tibetan horses' high altitude adaptation. NADH6 is one of the subunits of the complex I in the respiratory chain. Furthermore, 7 D-loop sequences of Tibetan horse from different areas were sequenced, and the phylogeny tree was constructed to study the origin and evolutionary history of Tibetan horses. The result showed that the genetic diverse was high among Tibetan horses. All of Tibetan horses from Naqu were clustered into one clade, and Tibetan horses from Zhongdian and Deqin were clustered into others clades. The first molecular evidence of Tibetan horses indicated in this study is that Tibetan horse population might have multiple origins. 展开更多
关键词 Tibetan horses mitochondrial genome high altitude adaptation NADH6 PHYLOGENY
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Satellite and high altitude platform-based inter-vehicle communications in vast and desolate areas 被引量:1
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作者 林元乖 王琳 沈连丰 《Journal of Southeast University(English Edition)》 EI CAS 2012年第2期135-139,共5页
In order to solve the problem of inter-vehicle communication (IVC) in vast and desolate areas such as the desert and the Gobi, two vehicle network models are proposed. One is based on satellite communication and the... In order to solve the problem of inter-vehicle communication (IVC) in vast and desolate areas such as the desert and the Gobi, two vehicle network models are proposed. One is based on satellite communication and the other is based on high altitude platform ( HAP ) communication. The system outline and networking modes of the two models are described. In the satellite communication based model, all the vehicles are equipped with vehicle-bone satellite communication on the move terminals and the communication signals between vehicles are forwarded by satellite. In the high altitude platform-based model, the HAPs are equipped with base station facilities to form aerial base stations, and vehicles can communicate with each other via common terrestrial mobile communication devices. Some key parameters such as path loss, link loss and system capacity are also computed. The analysis shows that both the two models can satisfy the requirement of IVC in the descriptive environment. 展开更多
关键词 inter-vehicle communication satellite communication high altitude platform communication terrestrial mobile communication device system capacity
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High-altitude gastrointestinal bleeding:An observation in Qinghai-Tibetan railroad construction workers on Mountain Tanggula 被引量:28
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作者 Tian-Yi Wu Shou-Quan Ding +6 位作者 Jin-Liang Liu Jian-Hou Jia Rui-Chen Dai Dong-Chun Zhu Bao-Zhu Liang De-Tang Qi Yong-Fu Sun 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第5期774-780,共7页
AIM: To investigate the gastrointestinal bleeding (GIB) in people from lowland to high altitude and in workers on Mountain Tanggula and its causes as well as treatment and prophylaxis.METHODS: From 2001 to October 200... AIM: To investigate the gastrointestinal bleeding (GIB) in people from lowland to high altitude and in workers on Mountain Tanggula and its causes as well as treatment and prophylaxis.METHODS: From 2001 to October 2003, we studied GIB in 13 502 workers constructing the railroad on Mountain Tanggula which is 4905 m above the sea level. The incidence of GIB in workers at different altitudes was recorded. Endoscopy was performed when the workers evacuated to Golmud (2808 m) and Xining (2261 m). The available data on altitude GIB were analyzed.RESULTS: The overall incidence of GIB was 0.49% in 13 502 workers. The incidence increased with increasing altitude. The onset of symptoms in most patients was within three weeks after arrival at high altitude. Bleeding manifested as hematemesis, melaena or hematochezia, and might be occult. Endoscopic examination showed that the causes of altitude GIB included hemorrhage gastritis, gastric ulcer, duodenal ulcer, and gastric erosion. Experimental studies suggested that acute gastric mucosal lesion (AGML) could be induced by hypoxic and cold stress, which might be the pathogenesis of altitude GIB. Those who consumed large amount of alcohol, aspirin or dexamethasone were at a higher risk of developing GIB. Persons who previously suffered from peptic ulcer or high-altitude polycythemia were also at risk of developing GIB. Early diagnosis, evacuation, and treatment led to early recovery. CONCLUSION: GIB is a potentially life threatening disease, if it is not treated promptly and effectively. Early diagnosis, treatment and evacuation lead to an early recovery. Death due to altitude GIB can be avoided if early symptoms and signs are recognized. 展开更多
关键词 high altitude Gastrointestinal bleeding Hypoxic stress Acute gastric mucosal lesion Risk factors
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Over-starvation aggravates intestinal injury and promotes bacterial and endotoxin translocation under high-altitude hypoxic environment 被引量:16
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作者 Qi-Quan Zhou Ding-Zhou Yang +3 位作者 Yong-Jun Luo Su-Zhi Li Fu-Yu Liu Guan-Song Wang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第12期1584-1593,共10页
AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobari... AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln. 展开更多
关键词 high altitude HYPOXIA STARVATION Intestinal mucosal injury Bacterial translocation ENDOTOXIN GLUTAMINE
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ANTI-HYPOXIA AND ANTI-OXIDATION EFFECTS OF AMINOPHYLLINE ON HUMAN WITH ACUTE HIGH-ALTITUDE EXPOSURE 被引量:8
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作者 Bo Yang Guang-yi Wang +3 位作者 Bin Chen Rong-bin Qin Si Lang Zha Xi Lian Chen 《Chinese Medical Sciences Journal》 CAS CSCD 2007年第1期62-65,共4页
Objective To investigate the anti-hypoxia and anti-oxidation effects of aminophylline on human with acute high- altitude exposure. Mothoda Totally 100 young male army members newly recruited from Sichuan province (4... Objective To investigate the anti-hypoxia and anti-oxidation effects of aminophylline on human with acute high- altitude exposure. Mothoda Totally 100 young male army members newly recruited from Sichuan province (400 meters above sea level) were enrolled. They were randomly divided into two groups: 50 in aminophylline group (A group) and 50 in control group ( C group). A group and C group orally took aminophylline and placebo respectively for 10 days, 7 days before entering Lhasa (3 658 meters above sea level) by air and 3 days after it. Several parameters were measured at three time points: before drug taken, 7 days after drug taken, and 3 days after ascending high altitude. These parameters included serum levels of nitric oxide (NO), superoxide dismutase (SOD), catalase (CAT), hydrogen dioxide (H2O2), lactic acid (LA), as well as arterial oxygen saturation (SO2), arterial oxygen partial pressure (PaO2), and arterial carbon dioxide partial pressure (PaCO2). Statistical analysis was conducted to compare the difference between two groups with Stata 7.0 software system. Results There were no statistical differences between groups in hypoxia and oxidation indicators before and after drug taken in plain area. Three days after ascending high altitude, the serum levels of SOD, CAT, H202, LA, PaCO2 increased in both groups, yet to a much larger degree in C group than A group (P 〈0. 01 ) ; and NO, SO2 , PaO2 decreased more markedly in C group ( P 〈 0. 05 for NO, P 〈 0. 0001 for SO2 and PaO2 ). Conclusion Aminophylline has significant anti-hypoxia and anti-oxidation effects at high altitude. 展开更多
关键词 AMINOPHYLLINE high altitude ANTI-HYPOXIA ANTI-OXIDATION
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Endothelial Nitric Oxide Synthase Gene Polymorphisms Associated with Susceptibility to High Altitude Pulmonary Edema in Chinese Railway Construction Workers at Qinghai-Tibet over 4500 Meters above Sea Level 被引量:9
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作者 Yu-jing Sun Ming-wu Fang +17 位作者 Wen-quan Niu Guang-ping Li Jing-liang Liu Shou-quan Ding Ying Xu Guo-shu Yu Jian-qun Dong Yun-jun Pan Guang-xue Yu Hui-cheng Sun Zhong-hou Jia Jun Liu Xiao-ming Wang Qin Si Qi-xia Wu Wen-yu Zhou Tong-chun Zhu Chang-chun Qiu 《Chinese Medical Sciences Journal》 CAS CSCD 2010年第4期215-221,共7页
Objective To examine whether the polymorphisms of endothelial nitric oxide synthase (eNOS) gene are associated with the susceptibility to high altitude pulmonary edema (HAPE) in Chinese railway construction workers at... Objective To examine whether the polymorphisms of endothelial nitric oxide synthase (eNOS) gene are associated with the susceptibility to high altitude pulmonary edema (HAPE) in Chinese railway construction workers at Qinghai-Tibet where the altitude is over 4 500 m above sea level. Methods A case-control study was conducted including 149 HAPE patients in the construction workers and 160 healthy controls randomly recruited from their co-workers, matching the patients in ethnicity, age, sex, lifestyle, and working conditions. Three polymorphisms of eNOS gene, T-786C in promoter, 894G/T in exon 7, and 27bp variable number tandem repeat (VNTR) in intron 4, were genotyped using polymerase chain reaction (PCR) and confirmed with DNA sequencing. Results The frequencies of 894T allele and heterozygous G/T of the 894G/T variant were significantly higher in HAPE patients group than in the control group (P=0.0028 and P=0.0047, respectively). However, the frequencies of the T-786C in promoter and the 27bp VNTR in intron 4 were not significantly different between the two groups. Haplotypic analysis revealed that the frequencies of two haplotypes (H3,T-T-b, b indicates 5 repeats of 27 bp VNTR; H6, C-G-a, a indicates 4 repeats of 27 bp VNTR) were significantly higher in HAPE patients (both P<0.0001). On the contrary, the frequencies of H1 (T-G-b) and H2 (T-G-a) were lower in HAPE patients than in healthy controls (both P<0.001). Conclusions Two haplotypes (T-T-b and C-G-a) may be strongly associated with susceptibility to HAPE. Compared with the individual alleles of eNOS gene, the interaction of multiple genetic markers within a haplotype may be a major determinant for the susceptibility to HAPE. 展开更多
关键词 high altitude pulmonary edema nitric oxide synthase gene polymorphism HAPLOTYPE
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EP300 contributes to high-altitude adaptation in Tibetans by regulating nitric oxide production 被引量:4
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作者 Wang-Shan Zheng Yao-Xi He +26 位作者 Chao-Ying Cui Ouzhuluobu Dejiquzong Yi Peng Cai-Juan Bai Duojizhuoma Gonggalanzi Bianba Baimakangzhuo Yong-Yue Pan Qula Kangmin Cirenyangji Baimayangji Wei GUO Yangla Hui Zhang Xiao-Ming Zhang Yong-Bo Guo Shu-Hua Xu Hua Chen Sheng-Guo Zhao Yuan Cai Shi-Ming Liu Tian-Yi Wu Xue-Bin Qi Bing Su 《Zoological Research》 CAS CSCD 2017年第3期163-170,共8页
The genetic adaptation of Tibetans to high altitude hypoxia likely involves a group of genes in the hypoxic pathway, as suggested by earlier studies. To test the adaptive role of the previously reported candidate gene... The genetic adaptation of Tibetans to high altitude hypoxia likely involves a group of genes in the hypoxic pathway, as suggested by earlier studies. To test the adaptive role of the previously reported candidate gene EP300 (histone acetyltransferase p300), we conducted resequencing of a 108.9 kb gene region of EP300 in 80 unrelated Tibetans. The allele-frequency and haplotype-based neutrality tests detected signals of positive Darwinian selection on EP300 in Tibetans, with a group of variants showing allelic divergence between Tibetans and lowland reference populations, including Han Chinese, Europeans, and Africans. Functional prediction suggested the involvement of multiple EP300 variants in gene expression regulation. More importantly, genetic association tests in 226 Tibetans indicated significant correlation of the adaptive EP300 variants with blood nitric oxide (NO) concentration. Collectively, we propose that EP300 harbors adaptive variants in Tibetans, which might contribute to high-altitude adaptation through regulating NO production. 展开更多
关键词 Tibetans high altitude HYPOXIA EP300 Genetic adaptation Nitric oxide
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Correlation between blood pressure changes and AMS, sleeping quality and exercise upon high-altitude exposure in young Chinese men 被引量:6
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作者 Yang Liu Ji-Hang Zhang +6 位作者 Xu-Bin Gao Xiao-Jing Wu Jie Yu Jian-Fei Chen Shi-Zhu Bian Xiao-Han Ding Lan Huang 《Journal of Medical Colleges of PLA(China)》 CAS 2014年第2期89-97,共9页
Background: Excessive elevation of arterial blood pressure(BP) at high altitude can be detrimental to our health due to acute mountain sickness(AMS) or some AMS symptoms. This prospective and observational study aimed... Background: Excessive elevation of arterial blood pressure(BP) at high altitude can be detrimental to our health due to acute mountain sickness(AMS) or some AMS symptoms. This prospective and observational study aimed to elucidate blood pressure changes induced by exposure to high-altitude hypoxia and the relationships of these changes with AMS prevalence, AMS severity, sleep quality and exercise condition in healthy young men.Methods: A prospective observational study was performed in 931 male young adults exposed to high altitude at 3,700 m(Lhasa) from low altitude(LA, 500 m). Blood pressure measurement and AMS symptom questionnaires were performed at LA and on day 1, 3, 5, and 7 of exposure to high altitude. Lake Louise criteria were used to diagnose AMS. Likewise, the Athens Insomnia Scale(AIS) and the Epworth Sleepiness Scale(ESS) were filled out at LA and on day 1, 3, and 7 of exposure to high altitude.Results: After acute exposure to 3,700 m, diastolic blood pressure(DBP) and mean arterial blood pressure(MABP) rose gradually and continually(P【0.05). Analysis showed a relationship with AMS for only MABP(P【0.05) but not for SBP and DBP(P】0.05). Poor sleeping quality was generally associated with higher SBP or DBP at high altitude, although inconsistent results were obtained at different time(P【0.05). SBP and Pulse BP increased noticeably after high-altitude exercise(P【0.05).Conclusions: Our data demonstrate notable blood pressure changes under exposure to different high-altitude conditions: 1) BP increased over time. 2) Higher BP generally accompanied poor sleeping quality and higher incidence of AMS. 3) SBP and Pulse BP were higher after high-altitude exercise. Therefore, we should put more effort into monitoring BP after exposure to high altitude in order to guard against excessive increases in BP. 展开更多
关键词 arterial blood pressure changes high altitude acute mountain sickness sleep quality EXERCISE
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