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1.
Nat Commun ; 11(1): 4928, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004791

RESUMO

High-altitude adaptation of Tibetans represents a remarkable case of natural selection during recent human evolution. Previous genome-wide scans found many non-coding variants under selection, suggesting a pressing need to understand the functional role of non-coding regulatory elements (REs). Here, we generate time courses of paired ATAC-seq and RNA-seq data on cultured HUVECs under hypoxic and normoxic conditions. We further develop a variant interpretation methodology (vPECA) to identify active selected REs (ASREs) and associated regulatory network. We discover three causal SNPs of EPAS1, the key adaptive gene for Tibetans. These SNPs decrease the accessibility of ASREs with weakened binding strength of relevant TFs, and cooperatively down-regulate EPAS1 expression. We further construct the downstream network of EPAS1, elucidating its roles in hypoxic response and angiogenesis. Collectively, we provide a systematic approach to interpret phenotype-associated noncoding variants in proper cell types and relevant dynamic conditions, to model their impact on gene regulation.


Assuntos
Aclimatação/genética , Cromatina/metabolismo , Grupos Étnicos/genética , Redes Reguladoras de Genes , Modelos Genéticos , Altitude , Doença da Altitude/etnologia , Doença da Altitude/genética , Doença da Altitude/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Hipóxia Celular/genética , Células Cultivadas , Cromatina/genética , Sequenciamento de Cromatina por Imunoprecipitação , Resistência à Doença/genética , Feminino , Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Oxigênio/metabolismo , Polimorfismo de Nucleotídeo Único , Gravidez , Cultura Primária de Células , RNA-Seq , Elementos Reguladores de Transcrição/genética , Seleção Genética , Tibet/etnologia , Fatores de Transcrição/metabolismo , Sequenciamento Completo do Genoma
2.
Zootaxa ; 4802(1): zootaxa.4802.1.7, 2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-33056635

RESUMO

Only three species of the genus Belisana Thorell, 1898, were recorded from Tibet, China, before the current study. In this study, four new Belisana species from Tibet are described: Belisana medog sp. nov. (male), Belisana muruo sp. nov. (male, female), Belisana xigaze sp. nov. (male, female), and Belisana zham sp. nov. (male, female). The female of Belisana gyirong Zhang, Zhu Song, 2006 is reported for the first time.


Assuntos
Aranhas , Animais , China , Feminino , Masculino , Tibet
3.
Nat Commun ; 11(1): 5085, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033250

RESUMO

Tibetan wheat is grown under environmental constraints at high-altitude conditions, but its underlying adaptation mechanism remains unknown. Here, we present a draft genome sequence of a Tibetan semi-wild wheat (Triticum aestivum ssp. tibetanum Shao) accession Zang1817 and re-sequence 245 wheat accessions, including world-wide wheat landraces, cultivars as well as Tibetan landraces. We demonstrate that high-altitude environments can trigger extensive reshaping of wheat genomes, and also uncover that Tibetan wheat accessions accumulate high-altitude adapted haplotypes of related genes in response to harsh environmental constraints. Moreover, we find that Tibetan semi-wild wheat is a feral form of Tibetan landrace, and identify two associated loci, including a 0.8-Mb deletion region containing Brt1/2 homologs and a genomic region with TaQ-5A gene, responsible for rachis brittleness during the de-domestication episode. Our study provides confident evidence to support the hypothesis that Tibetan semi-wild wheat is de-domesticated from local landraces, in response to high-altitude extremes.


Assuntos
Adaptação Fisiológica , Altitude , Triticum/fisiologia , Adaptação Fisiológica/genética , Domesticação , Ecótipo , Genoma de Planta , Geografia , Metagenômica , Fenótipo , Análise de Componente Principal , Tibet , Triticum/genética
4.
J Environ Radioact ; 222: 106325, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32892899

RESUMO

The current spatial distribution of the risk of terrestrial gamma radiation in China were investigated by using spatial interpolation. And the driving factors influence on the terrestrial gamma radiation dose (TGRD) distribution were identified using the geographic detector, a new statistical method based on the nonlinear hypothesis. The results showed that the values of TGRD were range from 60 to 195 nGy h-1 with the average of 86.5 nGy h-1, and the higher values were recorded in Qingahi-Tibet Plateau, which were all within the range of background value in China. In addition, the radiological indices, ELCR (Excess Lifetime Cancer Risk), TGRD and AEDE (Annual Effective Dose Equivalent) were also within the acceptable range of values by risk assessment. The results by use of the geographic detector showed that sunshine duration, atmosphere pressure, altitude, and rainfall condition have closely related to the TGRD distribution. In addition, these meteorological factors and altitude had more impact on TGRD than the air pollution-related factors. Our study can provide useful information on studying the influence mechanism of the TGRD distribution, the variability of the natural terrestrial gamma radiation in China, and exposure data for risk assessment from low dose chronic exposures.


Assuntos
Raios gama , Monitoramento de Radiação , Poluentes Radioativos do Solo , Radiação de Fundo , China , Doses de Radiação , Medição de Risco , Tibet
5.
J Environ Sci (China) ; 97: 169-179, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32933732

RESUMO

Total contents of metals in soil and sediments on the Tibetan Plateau of China have been widely analyzed, but existing information is insufficient to effectively evaluate metal ecological risk because of a lack of metal bioavailability data. In this study, distribution, potential risk, mobility and bioavailability of metals in sediments of Lake Yamdrok Basin in Tibet of China were explored by combined use of total digestion, sequential extraction and the diffusive gradient in thin-films (DGT). Average concentrations of Cr, Ni, Cu, Zn, As, Cd and Pb in surface sediments were 31.25, 30.31, 22.00, 45.04, 31.32, 0.13 and 13.39 mg/kg, respectively. Higher levels of metals were found near the inflowing rivers. Residual form was dominant in Cr, Ni, Zn, Cd and Pb, and reducible form was dominant in As and Cd. Metals in surface sediments showed a low enrichment degree overall, but Cd and As had higher ecological risk levels than the other metals. Furthermore, there was a larger average proportion of exchangeable form of As (20.4%) and Cd (9.0%) than the other metals (1.7%-3.3%), implying their higher mobility and release risk. Average DGT-labile concentrations of Cr, Ni, Cu, Zn, As, Cd and Pb were 0.5, 4.5, 0.7, 25.1, 60.0, 0.22 and 1.0 µg/L, respectively. The DGT-labile As was significantly correlated with extractable As forms (p< 0.01), suggesting that extractable As in sediments acts as a "mobile pool" for bioavailable As. These results suggest potential risks of As and Cd, especially As, deserve further attention in Lake Yamdrok Basin.


Assuntos
Metais Pesados/análise , Poluentes Químicos da Água/análise , Disponibilidade Biológica , China , Monitoramento Ambiental , Sedimentos Geológicos , Lagos , Medição de Risco , Tibet
6.
Environ Monit Assess ; 192(10): 663, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32989603

RESUMO

Reflecting on the change in the global biodiversity pattern, the Tibetan Plateau, considered to be a "natural laboratory" for analyzing environmental change in China and around the world, has suffered profound changes in the vegetation ecosystem. This study introduces the gravity center model and geographical detectors to examine and discuss the spatial-temporal change pattern and the driving mechanism behind vegetation net primary production (NPP) in the Qinghai-Tibet Plateau from the year 2000 to 2015 while also quantitatively classifying the relative roles incorporated in the NPP change process. The study found that (1) from 2000 to 2015, the annual average NPP of the Tibetan Plateau demonstrated a declining trend from southeast to northwest. (2) The gravity center of vegetation NPP on the Qinghai-Tibet Plateau seems to have shifted eastward in the past 16 years, indicating that the level of vegetation NPP in the east depicts a greater increment and growth rate than the west. (3) In the arid regions, temperature and rainfall appear as the dominant factors for vegetation NPP, while slope and aspect parameters have constantly assumed dominancy for the same in the tropical rainforest-monsoon ecological zone in southeastern Tibet. (4) The structure of vegetation NPP exhibits an interaction between human and natural factors, which enhances the influence of single factors. (5) Considering the global ecological change and related human activities, certain differences are observed in the dominant and interaction factors for different study periods and ecological subregions in the Qinghai-Tibet Plateau. The research results could prove conclusive for vegetation ecological protection in the Qinghai-Tibet plateau.


Assuntos
Mudança Climática , Ecossistema , China , Monitoramento Ambiental , Atividades Humanas , Humanos , Modelos Teóricos , Tibet
7.
Environ Pollut ; 266(Pt 1): 115401, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32829172

RESUMO

Contamination by polycyclic aromatic hydrocarbons (PAHs) has been observed at high elevation environments; however, the occurrence and spatial variation of PAHs in alpine lakes of China is not well understood. We measured 15 priority PAHs in the sediments of Lake Qinghai in the Qinghai-Tibet Plateau, and assessed their distribution, source, and ecological risks. The total PAH concentration ranged from 30.4 to 125.2 ng g-1. Low molecular weight PAHs were dominant in the sediments, suggesting a local source for the emissions. Sediment sites closer to local settlements and rivers had higher concentration of PAHs. The concentration of PAHs was significantly correlated with pH, probably as a result of the high salinity of the lake, while it was not significantly correlated with organic matter content. Molecular diagnostic ratio analysis indicated that PAHs were derived mainly from coal and biomass combustion. Specifically, the positive matrix factorization model showed that petrogenic sources, vehicular emissions, biomass combustion, and coal combustion contributed for 11.6, 16.3, 23.6, and 48.5% of the PAHs, respectively. The risk quotient method was used to assess ecological risk of PAHs individually. The results indicate that indeno[1,2,3-cd]pyrene, benzo[b]fluoranthene, benzo[a]pyrene, phenanthrene, and anthracene would produce moderate ecological risks in 5, 20, 65, 100, and 100% of the sediment sites, respectively, while the other 10 PAH homologues would scarcely produce any serious ecological risk. We used the hierarchical Archimedean copula integral assessment model to evaluate the integral risk of PAHs. The result showed that 10, 40, and 50% of the sediment sites belong to mid-high, low, and mid-low risk levels, respectively. The current concentration and risk levels of PAHs in this study might be used as a baseline to assess the influence of future anthropogenic activities.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Sedimentos Geológicos , Lagos , Medição de Risco , Tibet
8.
Science ; 369(6503): 493, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32732403
9.
Science ; 369(6503): 578-581, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32732426

RESUMO

Understanding how alpine biotas formed in response to historical environmental change may improve our ability to predict and mitigate the threats to alpine species posed by global warming. In the world's richest temperate alpine flora, that of the Tibet-Himalaya-Hengduan region, phylogenetic reconstructions of biome and geographic range evolution show that extant lineages emerged by the early Oligocene and diversified first in the Hengduan Mountains. By the early to middle Miocene, accelerated diversification and colonization of adjacent regions were likely driven jointly by mountain building and intensification of the Asian monsoon. The alpine flora of the Hengduan Mountains has continuously existed far longer than any other alpine flora on Earth and illustrates how modern biotas have been shaped by past geological and climatic events.


Assuntos
Biodiversidade , Plantas , Chuva , Vento , Mudança Climática , Tibet
10.
Sci Total Environ ; 747: 141358, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-32771793

RESUMO

While the composition and diversity of soil microbial communities play a central and essential role in biogeochemical cycling of nutrients, they are known to be shaped by the physical and chemical properties of soils and various environmental factors. This study investigated the composition and diversity of microbial communities in 48 samples of seasonally frozen soils collected from 16 sites in an alpine wetland region (Lhasa River basin) and an alpine forest region (Nyang River basin) on the Tibetan Plateau using high-throughput sequencing that targeted the V3-V4 region of 16S rRNA gene. The dominant soil microbial phyla included Proteobacteria, Acidobacteria, and Actinobacteria in the alpine wetland and alpine forest ecosystems, and no significant difference was observed for their microbial composition. Linear discriminant analysis Effect Size (LEfSe) analysis showed that significant enrichment of Hymenobacteraceae and Cytophagales (belonging to Bacteroidetes) existed in the alpine wetland soils, while the alpine forest soils were enriched with Alphaproteobacteria (belonging to Proteobacteria), suggesting that these species could be potential biomarkers for alpine wetland and alpine forest ecosystems. Results of redundancy analysis (RDA) suggest that the microbial community diversity and abundance in the seasonally frozen soils on the Tibetan Plateau were mainly related to the total potassium in the alpine wetland ecosystem, and available potassium and soil moisture in the alpine forest ecosystem, respectively. In addition, function prediction analysis by Tax4Fun revealed the existence of potential functional pathways involved in human diseases in all soil samples. These results provide insights on the structure and function of soil microbial communities in the alpine wetland and alpine forest ecosystems on the Tibetan Plateau, while the potential risk to human health from the pathogenic microbes in the seasonally frozen soils deserves attention.


Assuntos
Microbiota , Solo , Florestas , RNA Ribossômico 16S/genética , Microbiologia do Solo , Tibet , Áreas Alagadas
11.
PLoS One ; 15(8): e0237652, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841272

RESUMO

EV-B93 is a novel serotype within the Enterovirus B species and is uncommon worldwide. Currently, only one full-length genomic sequence (the prototype strain) has been deposited in the GenBank database. In this study, three EV-B93 were identified, including one from an acute flaccid paralysis (AFP) patient (named 99052/XZ/CHN/1999, hereafter XZ99052) and two from healthy children (named 99096/XZ/CHN/1999 and 99167/XZ/CHN/1999, hereafter XZ99096 and XZ99167, respectively) from Tibet in 1999 during the polio eradication program. The identity between the nucleotide and amino acid sequences of the Tibet EV-B93 strain and the EV-B93 prototype strain is 83.2%-83.4% and 96.8%-96.9%, respectively. The Tibet EV-B93 strain was found to have greater nucleotide sequence identity in the P3 region to another enterovirus EV-B107 as per a phylogenetic tree analysis, which revealed that recombination occurred. Seroepidemiology data showed that EV-B93 has not produced an epidemic in Tibet and there may be susceptible individuals. The three Tibet EV-B93 strains are temperature-resistant with prognosticative virulence, suggesting the possibility of a potential large-scale outbreak of EV-B93. The analyzed EV-B93 strains enrich our knowledge about this serotype and provide valuable information on global EV-B93 molecular epidemiology. What is more, they permit the appraisal of the serotype's potential public health impact and aid in understanding the role of recombination events in the evolution of enteroviruses.


Assuntos
Enterovirus Humano B/genética , Infecções por Enterovirus/virologia , Genoma Viral/genética , Paralisia/virologia , Pré-Escolar , Surtos de Doenças/prevenção & controle , Enterovirus Humano B/isolamento & purificação , Enterovirus Humano B/patogenicidade , Infecções por Enterovirus/epidemiologia , Fezes/virologia , Feminino , Humanos , Lactente , Masculino , Tipagem Molecular , Paralisia/epidemiologia , Filogenia , RNA Viral/genética , Recombinação Genética , Análise de Sequência de RNA , Estudos Soroepidemiológicos , Tibet/epidemiologia
12.
J Environ Manage ; 271: 111034, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778314

RESUMO

As the largest carbon emitter in the world, China faces great pressure to fulfill the temperature control targets, i.e., 2 °C and 1.5 °C, proposed in the Paris Agreement. Thus, selecting a development path that could both meet the temperature targets and economic growth is essential and worth investigating. We propose an optimization model to analyze China's carbon dioxide emission paths from 2010 to 2050 in three scenarios, namely baseline, and 1.5 °C and 2 °C target scenarios. The marginal cost of carbon abatement in China's 30 provinces (excluding Hong Kong, Macao, Taiwan, and Tibet) were also calculated using the quadratic directional distance function model, and the quotas of carbon dioxide emission among provinces were allocated. Carbon dioxide emission peak will occur in 2040 under the 2 °C target scenario and in 2030 under the 1.5 °C target scenario. The marginal cost of carbon abatement to achieve the 1.5 °C goal is approximately 1.6 times more expensive than the 2 °C goal. We suggest to implement emission reduction policies in the Eastern coastal areas of China and to allocate greater carbon dioxide emission quotas in under-developed areas in the Central and Western regions. Provincial quota allocation may also help to balance regional development and achieve the mutually beneficial goal of economic growth and carbon emission reduction in China. Our findings provide practical guidance on achieving carbon dioxide emission reduction and critical enlightenments on policymaking.


Assuntos
Dióxido de Carbono/análise , China , Hong Kong , Macau , Paris , Taiwan , Temperatura , Tibet
13.
Environ Pollut ; 265(Pt B): 115079, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806461

RESUMO

Soils, especially permafrost in the Arctic and the Tibetan Plateau, are one of the largest reservoirs of mercury (Hg) in the global environment. The Hg concentration in the grassland soils over the Tibetan Plateau and its driving factors have been less studied. This study analyzes soil total mercury (STHg) concentrations and its vertical distribution in grassland soil samples collected from the Tibetan Plateau. We adopt a nested-grid high-resolution GEOS-Chem model to simulate atmospheric Hg deposition. The relationship between STHg and soil organic carbon (SOC), as well as atmospheric deposition, are explored. Our results show that the STHg concentrations in the Tibetan Plateau are 19.8 ± 12.2 ng/g. The concentrations are higher in the south and lower in the north in the Tibetan Plateau, consistent with the previous results. Our model shows that the average deposition flux of Hg is 3.3 µg m-2 yr-1, with 57% contributed by dry deposition of elemental mercury (Hg0), followed by dry (19%) and wet (24%) deposition of divalent mercury. We calculate the Hg to carbon ratio (RHg:C) as 5.6 ± 6.5 µg Hg/g C, and the estimated STHg is 86.6 ± 101.2 Gg in alpine grasslands in the Tibetan Plateau. We find a positive relationship between STHg and SOC in the Tibetan Plateau (r2 = 0.36) and a similar positive relationship between STHg and atmospheric total Hg deposition (r2 = 0.24). A multiple linear regression involving both variables better model the observed STHg (r2 = 0.42). We conclude that SOC and atmospheric deposition influence STHg simultaneously in this region. The data provides information to quantify the size of the soil Hg pool in the Tibetan Plateau further, which has important implications for the Hg cycles in the permafrost regions as well as on the global scale.


Assuntos
Mercúrio/análise , Pergelissolo , Carbono , Monitoramento Ambiental , Pradaria , Solo , Tibet
14.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(4): 1406-1409, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32798434

RESUMO

OBJECTIVE: To explore the possible etiological factors of iron overload through detecting plasma hepcidin level of adult males at Tibet plateau. METHODS: 81 Tibetan male adult patients hospitalized in our department during January 2017 - December 2018 were selected, and divided into iron overload group and non-iron overload group. The difference in serum ferritin, serum iron, total iron binding capacity, hemoglobin, HBSAg, ALT, AST, albumin, creatinine and hepcidin of patients in each group were tested. To analyze the differences between groups. The regression analysis was applied to analyze the relationship between laboratory index and hepcidin. RESULTS: The plasma hepcidin of iron overload group was significantly higher than that of the non-iron overload group [93.69 (65.57-133.92) ng/ml vs 63.93 (40.01-90.65) ng/ml] (P=0.005). And there was a positive correlation between plasma hepcidin and ferritin (ß=0.03 ng/ml,95%CI 0.01-0.05) (P<0.01) and BMI (ß=5.71 ng/ml,95%CI 0.54-10.88) (P<0.05). CONCLUSION: Iron overload at Tibet plateau can not be attributed to hepcidin deficiency in Tibetan adult male patients. Iron metabolism disorders in Tibetan population may be associated with metabolic syndrome.


Assuntos
Sobrecarga de Ferro , Ferro , Adulto , Ferritinas , Hepcidinas , Humanos , Masculino , Tibet
15.
Int J Syst Evol Microbiol ; 70(8): 4683-4690, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32692642

RESUMO

Four novel strains (592T, S592, MF47T and SMF47) were isolated from Tibetan antelopes (Pantholops hodgsonii) and plateau pikas (Ochotona curzoniae), respectively. The cells were aerobic, non-motile, Gram-stain- and catalase-positive, rod-shaped bacteria. The 16S rRNA gene sequences of the four strains showed highest similarities to Aeromicrobium fastidiosum DSM 10552T (98.1, 98.6, 98.7 and 98.7 %, respectively), and the phylogenetic analyses based on 16S rRNA gene and genomic sequences indicated that strains 592T and MF47T represent two novel species. The four isolates produced acid from l-rhamnose, d-xylose and cellobiose, but were unable to reduce nitrate. The DNA G+C contents of strains 592T and MF47T were 70.3 and 69.8 mol%, respectively. The digital DNA-DNA hybridization value between strains 592T and MF47T was 32.6 %, lower than the threshold of 70 %, indicating they belong to different species. The four strains' genomes displayed less than 24.6 % DNA-DNA relatedness with all available genomes of the genus Aeromicrobium in the NCBI database, including Aeromicrobium fastidiosum NBRC 14897T and Aeromicrobium ginsengisoli JCM 14732T. The major fatty acids of the four strains were C18 : 1 ω9c and C18 : 0 10-methyl, and the main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. The predominant respiratory quinones were MK-9(H4) and MK-8(H4). The cell-wall peptidoglycan contained ll-diaminopimelic acid. Based on these genotypic, phenotypic and biochemical analyses, it is proposed that the four unidentified bacteria be classified as two novel species, Aeromicrobium chenweiae sp. nov. and Aeromicrobium yanjiei sp. nov. The type strains are 592T (=CGMCC1.16526T=DSM 106289T) and MF47T (=CGMCC 1.17444T=JCM 33790T), respectively.


Assuntos
Actinobacteria/classificação , Antílopes/microbiologia , Lagomorpha/microbiologia , Filogenia , Actinobacteria/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Fezes/microbiologia , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Tibet , Vitamina K 2/análogos & derivados , Vitamina K 2/química
16.
Environ Pollut ; 266(Pt 1): 115221, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32698057

RESUMO

As a well-known toxic element, antimony occurred in a wide range of concentrations in the geothermal waters discharging from Rehai and Daggyai, two representative hydrothermal areas in the Yunnan-Sichuan-Tibet Geothermal Province of China. Antimony speciation in different types of the hot springs in Rehai and Daggyai varied greatly as well, and tri- and tetrathioantimonate were detected in most neutral to alkaline Rehai hot springs. Neutral to alkaline pH, high sulfide concentrations, and high sulfide to antimony ratios were the critical factors promoting the formation of thioantimonates. The fact that no thioantimonates were detected in neutral to alkaline Daggyai hot springs is attributed to high concentrations of coexistent arsenic capable of inhibiting the thiolation of oxyantimony anions, because thioantimonates are kinetically more labile than thioarsenates. Upon discharge of the hot springs, both total aqueous antimony and arsenic decreased rapidly and substantially via immobilization to the sediments in the spring vents and their outflow channels. Some of the common iron-bearing minerals in the spring sediments, like pyrite and goethite, are known sinks for antimony and arsenic. Yet, an interesting difference was observed with antimony and iron contents in the sediment samples showing a significant correlation that was lacking for arsenic and iron contents. The explanation might be that for arsenic, sorption affinities are known to vary significantly with aqueous arsenic speciation and mineral phases. Typically, thiolation increases, and oxidation decreases arsenic mobility. Sorption experiments for antimony conducted in the present study, in contrast, showed that different antimony species were comparably sorbed to pyrite over a wide range of initial antimony concentrations and to goethite at relatively low initial antimony concentrations (but still covering the concentration range of antimony in common natural waters), so neither thiolation nor oxidation contributed significantly to the mobility of antimony in the hot springs investigated in this study.


Assuntos
Arsênico/análise , Fontes Termais , Antimônio , China , Sulfetos/análise , Tibet
17.
Sci Total Environ ; 744: 140612, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32711302

RESUMO

Increased nitrogen (N) deposition can affect ecosystem processes and thus influence plant eco-physiological processes in grasslands. However, how N deposition affects eco-physiological processes of leguminous and non-leguminous forbs in alpine grasslands is understudied. A long-term field experiment using a range of simulated N deposition rates (0, 8, 24, 40, 56, and 72 kg N ha-1 year-1) was established to examine the effects of N deposition on various eco-physiological parameters in leguminous and non-leguminous forbs in an alpine meadow of the Qinghai-Tibetan Plateau. We found that the responses of leguminous and non-leguminous forbs to simulated N deposition varied. Net photosynthetic rate of leguminous and non-leguminous forbs exhibited different response patterns, but chronic increases in simulated N deposition rates may lead to negative effects in both functional groups. Neither functional group responded differently in aboveground biomass under the highest N addition level (72 kg N ha-1 year-1) compared to the control. Differences in aboveground biomass of leguminous forbs were observed at intermediate N levels. Short-term simulated N deposition significantly promoted N uptake of both functional groups. In leguminous forbs, simulated N deposition affected net photosynthetic rates (PN) and aboveground biomass (AGB) mainly via stomatal conductance (gs), water use efficiency (WUE), and plant N uptake. In non-leguminous forbs, simulated N deposition affected PN and AGB mainly through WUE and plant N uptake. Our findings suggest that leguminous and non-leguminous forbs have differential response mechanisms to N deposition, and compared with non-leguminous forbs, leguminous forbs are more sensitive to continuing increased N deposition. The obvious decline trend in photosynthetic capacity in leguminous forbs is likely to exacerbate the already divergent ecological processes between leguminous and non-leguminous forbs. More importantly, these changes are likely to alter the future composition, function, and stability of alpine meadow ecosystems.


Assuntos
Fabaceae , Fenômenos Fisiológicos , Biomassa , Ecossistema , Pradaria , Solo , Tibet
18.
Zhongguo Zhong Yao Za Zhi ; 45(11): 2708-2713, 2020 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-32627507

RESUMO

Appropriate producing areas can guarantee the quality of Tibetan medicine, but research on the suitable ecological factors and suitable producing areas of Tibetan medicinal plants is scarce. This paper used the Geographic Information System for Global Medicinal Plants(GMPGIS) to analyze the ecological suitability of Tibetan medicinal plants nationwide. For the first time, the range of ecological factors and main soil types of Tibetan medicinal plants were extracted, such as the average annual temperature-19.4-24.2 ℃, annual average precipitation 17-4 088 mm, annual average sunshine 124.2-171.6 W·m~(-2). The main soil types were black calcareous soil, thin layer soil, chestnut soil and so on. Based on 337 sampling points, the largest ecological similarity area of Tibetan medicine across the country was obtained through ecological similarity analysis. In addition to Tibet and Qinghai provinces and Tibetan Autonomous Prefectures in Sichuan, Gansu, and Yunnan provinces, Jiuquan city and Linxia county in Gansu province, Panzhihua and Ya'an in Sichuan province, and Xinjiang, Inner Mongolia, and Shanxi provinces also had larger suitable cultivation areas. In addition, by analyzing the current situation of Tibetan medicine industry, the research pointed out that there were some problems such as unreasonable development and utilization of resources, lack of standards and norms, weak basic research and imperfect industrial system, and made corresponding countermeasures for sustainable development of resources, formulation of standards and specifications, promotion of medicine through science and technology, expansion of domestic and foreign markets, etc. This study provided the basis for guiding the rational layout of production bases, introduction and breeding of plant Tibetan medicine nationwide, laying the foundation for the scientific and standardized production of high-quality Tibetan medicine, clarifying the development direction of Tibetan medicine industry, and providing ideas for the development strategy of Tibetan medicine and other national medicine industry.


Assuntos
Desenvolvimento Industrial , Medicina Tradicional Tibetana , China , Solo , Tibet
19.
Medicine (Baltimore) ; 99(29): e21133, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32702866

RESUMO

The aim of the study is to discuss the risk factor of right heart failure (RHF) especially the association of iron deficiency with RHF in Tibetan children who live in high altitude area. In this retrospective study, we collected the data of Tibetan children from January 2011 to December 2018 in our hospital. The patients included in the study had the following data: age, gender, ferritin, echocardiography, hemoglobin, C-reaction protein, and altitude of residence. According to whether RHF was diagnosed, the patients were divided into RHF group and non-RHF group. Totally 133 patients were included with 59 in RHF group and 74 in non-RHF group. In single factor analysis, age (P = .008), altitude of residence (P < .001), ferritin (P < .001), and pulmonary arterial systolic pressure (P < .001) showed significant difference between the 2 groups. Binary logistic regression was performed to further identify the association of the clinical factors with RHF. Higher pulmonary arterial systolic pressure (odds ratio: 29.303, 95% confidence interval: 5.249-163.589, P < .001) and lower ferritin level (odds ratio: 5.849, 95% confidence interval: 1.585-21.593, P = .008) were independent risk factors associated with RHF. In receiver-operating characteristic curve, the optimal cutoff value of ferritin level was 14.6 µg/L with the sensitivity of 81.4% and specificity of 89.2%. As continuous variable, the correlation between ferritin and RHF was not certain (P = .281). Due to the possibility that iron deficiency be a risk factor of RHF in Tibetan children, prevention and treatment of iron deficiency might be a potential way in reducing the incidence of RHF in this high altitude area.


Assuntos
Altitude , Anemia Ferropriva/complicações , Insuficiência Cardíaca/etiologia , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/fisiopatologia , Proteína C-Reativa/análise , Distribuição de Qui-Quadrado , Ecocardiografia/métodos , Ecocardiografia/estatística & dados numéricos , Feminino , Ferritinas/análise , Ferritinas/sangue , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/fisiopatologia , Hemoglobinas/análise , Humanos , Lactente , Modelos Logísticos , Masculino , Estudos Retrospectivos , Tibet/epidemiologia , Disfunção Ventricular Direita/sangue , Disfunção Ventricular Direita/epidemiologia , Disfunção Ventricular Direita/etiologia
20.
Environ Pollut ; 266(Pt 2): 115217, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32707351

RESUMO

Domestic consumption of biomass fuels has been found as a leading source of polycyclic aromatic hydrocarbons (PAHs) in pristine regions. The biomass ashes would serve as both source and vector for PAHs, which may threaten residents' health. However, research focusing on the behaviors of waste biomass ashes acting as emission resources of PAHs is still lacking. In present study, occurrence and fate of PAHs released from disposal biomass ashes in the Tibetan Plateau were investigated by evaluating their patterns and levels in soils at different distances from the Lhasa landfill. Concentrations of 16 PAHs averaged at 1009 ng/g dry weight and 103 ng/g dry weight in landfill cover soils and surrounding soils, respectively. The spatial distributions of PAHs evidenced the local source of biomass ashes in landfill, while the fractionations of PAHs in soils profiles emphasized the post-deposal leaching. Since PAH compositions altered significantly during their transport and sequestration, the rectification factors were suggested to adjust the source diagnostic ratios. In study area, the emission flux of PAHs from waste biomass ashes to soils was 0.93 ton/year; extended to the Tibetan Plateau, the flux was estimated to be 13.1-32.5 ton/year. This study confirmed that waste biomass ashes would represent significant contributions of PAH emissions in this pristine region, which might remarkably exacerbate the total emissions of PAHs in Tibet by more than 25%.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Biomassa , China , Monitoramento Ambiental , Solo , Tibet
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