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1.
Behav Sci (Basel) ; 14(3)2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38540468

RESUMO

Positive psychology has attracted increasing attention from many scholars worldwide. There is a considerable body of knowledge on the relationship between optimism and subjective well-being (SWB). However, their mediation mechanism has not been fully studied, and most of the current conclusions were formulated within the context of Western culture, with a limited number of empirical studies specifically targeting Chinese people. Based on the theories of self-regulation and stress coping, our research aimed to validate the association between optimism and SWB among Chinese adults and further investigate the mediating effect of positive and negative coping in this relationship. In Study 1, using a national dataset from the Chinese General Social Survey (N = 12,582), we captured the direct positive relationship between optimism and SWB. In Study 2, taking a cross-sectional study (N = 272), we found the mediating effect of positive and negative coping in the relationship between optimism and SWB according to correlation and regression analysis. In Study 3, taking a cross-lagged study (N = 343), we reverified the results of Study 2 and found negative coping no longer played a role as a mediator after accounting for the factors of social desirability and state anxiety in the analysis. These findings are worthwhile for paying attention to Chinese people's optimistic traits and the pathways to improving their subjective well-being using different coping behaviors.

2.
Environ Pollut ; 346: 123498, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38342433

RESUMO

Heavy metals present a substantial threat to both the environment and human health. Considering the delicate ecological equilibrium of the Tibetan Plateau (TP) and its heightened susceptibility to anthropogenic impacts, scholarly attention has progressively turned toward the examination of heavy metal pollution within the plateau's environment. In this study, we conducted a comprehensive analysis of various heavy metals (As, Cr, Co, Ni, Cu, Mo, Cd, Pb, and Sb), utilizing topsoil samples collected from the TP during the period of 2018-2021. Additionally, snow and cryoconite samples obtained from TP glaciers during the same timeframe were also subjected to analysis. The results indicate elevated concentrations of total heavy metals in the eastern and western TP (328.7 µg/g), as opposed to the central and southern TP (145.7 µg/g). Most heavy metals exhibit a consistent spatial distribution pattern. High Enrichment Factors (EFs) and Geoaccumulation Index (Igeo) values for As and Cd suggest their enrichment in TP topsoil. Receptor modeling identified three primary sources of heavy metals within the topsoil: industrial sources (42.3%), inherent natural sources within the surface soil (20.6%), and vehicular emissions (14.2%). Substantial differences in heavy metal concentrations and spatial distribution were observed between the topsoil and the glacial snow-cryoconite matrix. The prominent presence of Sb in the snow-cryoconite matrix, in contrast to its low abundance in the topsoil, indicates distinct source influences of long-range transported materials between the two environments. Our inference suggests that the influence of heavy metals from distant pollutants undergo mixing and dilution in the topsoil due to the presence of local indigenous heavy metals, although such influence is notably observed on the glacier surface of the TP. Consequently, this underscores the significant impact of long-range transported sources on heavy metals, surpassing the influence of local TP soils, to the alpine glaciers and even other atmospheric sediments in Tibetan Plateau.


Assuntos
Metais Pesados , Poluentes do Solo , Humanos , Tibet , Camada de Gelo , Cádmio/análise , Monitoramento Ambiental/métodos , Metais Pesados/análise , Solo , Poluentes do Solo/análise , China , Medição de Risco
3.
Eur J Med Chem ; 267: 116156, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38295687

RESUMO

Murine double minute 2 (MDM2) and homologous protein murine double minute X (MDMX) are p53 negative regulators that perform significant driving effects in tumorigenesis, and targeting these oncoproteins has became an efficient strategy in treating cancers. However, the definite antitumor activity and significance ordering of each protein in MDM family is still unclear due to the similar structure and complicated regulation. Herein, we identified two G-rich sequences (G1 and G5) located in the promoter that could assemble the G-quadruplex to respectively inhibit and promote the transcription of the MDM2 and MDMX. Based on this target, we designed and synthesized a novel G-quadruplex ligand A3f and achieved the differentiated regulation of MDM protein. In triple-negative breast cancer (TNBC) cells, A3f could induce MDM2-dependent proliferation arrest and exhibit additive therapeutic effect with MDMX inhibitors. Overall, this study provided a novel strategy to regulate the transcription of MDM genes by targeting certain G-rich sequences, and discovered an active antitumor molecule for use in TNBC treatment.


Assuntos
Proteínas Proto-Oncogênicas c-mdm2 , Neoplasias de Mama Triplo Negativas , Humanos , Camundongos , Animais , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteínas Proto-Oncogênicas , Proteínas Nucleares/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Proteínas de Ciclo Celular/metabolismo , Proteína Supressora de Tumor p53/metabolismo
4.
Sci Total Environ ; 912: 168768, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38029980

RESUMO

Lithium isotope is one of the most promising indicators for the study of continental silicate weathering, and lithium concentrations and its isotopic compositions in earth surface can provide a better understanding of the geochemical behavior and isotopic fractionation during weathering and erosion. This work focused on the composition and distribution of Li isotope in cryoconite deposited on various glacier areas in a large range of the Tibetan Plateau and surroundings, as well as its implications for cryoconite dust provenances. Results showed that δ7Li in cryoconite varied within the same order of magnitude (-2.14 ‰-7.74 ‰), which is characterized by geographic distribution of higher δ7Li value of cryoconite in northern glaciers (e.g. Yuzhufeng Glacier), and lower δ7Li value in southern glaciers. In comparison with other global materials, the cryoconite dust shows a lighter δ7Li isotopic composition due to constraints of climatic conditions and land surface weathering intensity. Compared with dust materials in the surrounding Asian dust sources (e.g. large deserts and Gobi), we find that, the primary sources of Li isotope in cryoconite of the northern locations were from both local dust/soils of the TP surface and the surrounding large deserts. Moreover, the products of anthropogenic activities (e.g. coal-burning) may also influence the isotopic composition of the cryoconite dust, and Li isotope may serve as potential tracers of anthropogenic source activities. Therefore, this work provides a complete view of the composition and distribution of Lithium isotopes in cryoconite from various glacier areas of the Tibetan Plateau, and the research significance of its transport processes and source constraints of Li isotopes in cryoconite is proposed.

5.
Small ; : e2305083, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38009483

RESUMO

Zero-dimensional (0D) organic metal halides comprising heterogeneous metal cations in single phase can achieve multiple luminous emissions enabling them toward multifunctional light-emitting applications. Herein, A novel single crystal of (C8 H20 N)4 SbMnCl9 containing two luminescent centers of [SbCl5 ]2- pentahedrons and [MnCl4 ]2- tetrahedrons is reported. The large distance between Sb-Sb, Mn-Mn, and Sb-Mn as well as theory calculation indicate negligible interaction between individual centers, thus endowing (C8 H20 N)4 SbMnCl9 with excitation-dependable and efficient luminescence. Under near-UV excitation, only orange emission originates from self-trapped excitons recombination in [SbCl5 ]2- pentahedron occurs with photoluminescence quantum yield (PLQY) of 91.5%. Under blue-light excitation, only green emission originating from 4 T1 -6 A1 transition of Mn2+ in [MnCl4 ]2- tetrahedrons occurs with PLQY of 66.8%. Interestingly, upon X-ray illumination, both emissions can be fully achieved due to the high-energy photon absorption. Consequently, (C8 H20 N)4 SbMnCl9 is employed as phosphors to fabricate white light-emitting diodes optically pumped by n-UV chip and blue-chip thanks to its excitation-dependable property. Moreover, it also shows promising performance as X-ray scintillator with low detection limit of 60.79 nGyair S-1 , steady-state light yield ≈54% of commerical scintillaotr LuAG:Ce, high resolution of 13.5 lp mm-1 for X-ray imaging. This work presents a new structural design to fabricate 0D hybrids with multicolor emissions.

6.
J Oleo Sci ; 72(8): 755-765, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37532566

RESUMO

This study compared the effect of five different adsorbents (activated clay, activated carbon, attapulgite clay, bentonite, diatomite) on the levels of nutrients, harmful substance retention, and decolorization in rice bran oil. Among the adsorbents tested, activated carbon displayed the highest decolorization efficiency (82.90%) and adsorption effect on 3,4-benzopyrene (BaP, 89.53%) and 3-monochloropropane-1,2-diol ester (41.55%), whereas activated clay had the highest oryzanol retention percentages (85.98%) and affordability. Activated carbon and activated clay were therefore selected as composite decolorizing agents. Based on single-factor and Box-Behnken response surface tests, the optimal conditions for decolorization efficiency (97.08%), oryzanol retention (89.62%), sterol retention (90.16%), vitamin E retention (79.91%), and benzo(a)pyrene adsorption percentages (95.98%) were determined to be achieved by using a 5% (w/w) composite decolorant (activated clay:activated carbon=5:1), at a temperature of 116℃, with an incubation time of 33 min. This study provides evidence to support the efficacy of compound decolorants, which may have practical use in large-scale industrial applications of edible oil decolorization during refinement.


Assuntos
Carvão Vegetal , Óleo de Farelo de Arroz , Argila , Valor Nutritivo
7.
Ecotoxicol Environ Saf ; 263: 115271, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37473703

RESUMO

Toxic and major elements, such as As and Fe, in watersheds can significantly impact the surrounding water environment and ecosystem. Thus, in this study, we conducted an investigation into the origins and spatial distribution of typical toxic trace elements (As and Mn) and crustal major elements (Al, Fe, and Ti) in suspended particulate matter (SPM) across various glacial watersheds located at different elevations in the northeastern Tibetan Plateau (NETP) from June to July in 2017. The results revealed that the mean value of each element followed the order of abundance in the samples, with Al having the highest mean value at 21307 µg/L, followed by Fe at 13366 µg/L, Ti at 1520 µg/L, Mn at 245 µg/L, and As at 66.6 µg/L. Moreover, our study identified high content of these elements from the Dabanshan Snowpack, Laohugou Glacier No.12, and Yuzhufeng Glacier in the upper reaches of the basin, which were found to be 9.9, 10.2, and 19.4 times higher, respectively, than that of the upper reaches of the Heihe River. We found that As and Mn exhibited clear indications of anthropogenic influence on a local and regional scale. The calculated enrichment factor (EF) demonstrated a significant As enrichment (EF>100) in the Qiyi and Lenglongling Glaciers, possibly resulting in the release of upstream glacier melt and anthropogenic-derived As deposition. Our findings suggested that the upstream region was primarily linked to glacier meltwater discharge. In contrast, the middle and lower reaches of the basin exhibited a more pronounced influence from local human activities. Based on the findings, the water environment of the glacier watershed appears to be in good condition overall. However, the presence of elevated levels of As element in the water system can be traced back to both anthropogenic and natural factors. As a result, ensuring the safety of the water supply for nearby residents is a matter of utmost concern. This study provides a comprehensive examination of hydrochemical variations and the overall water environment of high-altitude glacier basins in the NETP, offering valuable insights into the topic.


Assuntos
Oligoelementos , Humanos , Tibet , Oligoelementos/análise , Ecossistema , Material Particulado , Água/química , Monitoramento Ambiental/métodos
8.
Sci Total Environ ; 890: 164234, 2023 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-37230341

RESUMO

Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs) are significant components of persistent organic pollutants (POPs) and pose a threat to both ecosystems and human health. To explore their spatial distribution, origins, and risk assessment, we collected 25 glacial meltwater and downstream river water samples in the eastern Tibetan Plateau (including the Qilian Mountains in the northeast) during the summer of 2022 (June-July). Our results showed that ∑PAHs and ∑PCBs were present in a wide range from ND-1380 ng/L and ND-1421 ng/L, respectively. Compared to other studies worldwide, the ∑PAHs and ∑PCBs in the Hengduan Mountains were at high levels. The PAHs and PCBs mainly consisted of low-molecular-weight homologs, including Ace, Flu, Phe, and PCB52. Phe was the primary component of PAHs. Glacial meltwater samples generally exhibited low concentration of PAHs and PCB52, whereas downstream river water samples typically showed high concentration of PAHs and PCB52. We attributed this characteristic to the influence of pollutants physicochemical properties, altitude effect, long-range transport (LRT), and local environmental conditions. In the eastern Tibetan Plateau glacier basin (especially in the Hailuogou watersheds), the concentration of PAHs and PCB52 in runoff generally increased with decreasing elevation. We believe that the primary factor affecting the concentration of PAHs and PCB52 in the region is the difference in local human activity inputs from various altitudes. The composition characteristics of PAHs and PCBs suggested that incomplete coal combustion and coking discharge mainly caused PAHs, while the combustion of coal and charcoal and the release of capacitors primarily caused PCBs. We assessed the carcinogenic risk of PAHs and PCBs in the glacier basin of the TP and found that the potential threat of PAHs was stronger than that of PCBs. Overall, this study provides new insights into the ecological security of water resources in eastern Tibetan Plateau. It is significant for controlling PAHs and PCBs emissions, assessing the ecological environment of the glacier watershed, and regional human health.


Assuntos
Bifenilos Policlorados , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Humanos , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Tibet , Ecossistema , Água , Medição de Risco , Carvão Mineral , Monitoramento Ambiental , Poluentes Químicos da Água/análise
9.
Front Psychol ; 14: 1072344, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36949915

RESUMO

The extant literature has accumulated enormous knowledge on personality prediction from digital records on social networking sites (e.g., photo selfies). However, little is known about how short video selfies reflect their owner's personality and how people judge others' personalities from short video selfies. Taking short video selfies is very popular today; many people are willing to share their short video selfies with others. Based on the lens model theory, it is expected that one's personality is associated with short video selfies. By analyzing 177 Chinese TikTok (Douyin in China) users' short video selfies and their Big Five personalities, it showed that specific cues in short video selfies related to agreeableness, conscientiousness, neuroticism, and openness. But only extraversion could be predicted by short video selfies accurately. This study is the first to reveal personality-related cues in short video selfies and has practical implications for both short video platforms and their users.

10.
Soc Psychol Personal Sci ; 14(2): 207-217, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36741803

RESUMO

Building on the benign violation theory and self-construal theory, we conducted four studies to examine how culture and social distance would influence humor appreciation, sharing, and production. Study 1 found that Chinese participants appreciated and intended to share a joke involving distant others more than that involving close others. They also generated funnier titles for a joke involving distant others than close others. Studies 2a and 2b compared Chinese and Americans using various types of jokes, replicating the social distance effect among Chinese but finding little effect of social distance among Americans. In Study 3, interdependence-primed participants generated more humorous titles for a joke involving distant than close others, whereas independence-primed participants showed no effect of social distance. The research provides further support to the benign violation theory from a cultural perspective and has important implications for cross-cultural communications.

11.
Environ Pollut ; 317: 120824, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36493938

RESUMO

Atom ratio between 235U and 238U is often used as an indicator of U contamination as the isotopic signature of products generated by the nuclear and military industry significantly vary from the natural isotopic ratio of U. In this study, surface soils and glaciers samples were collected in the Tibetan Plateau (TP) and its surrounding areas and analyzed for U isotopic composition. Results show that the 235U/238U atom ratios in the surface soils of the TP ranges from 0.007122 to 0.007615, with an average value of 0.007378 ± 0.00011; while in the snow/ice dust from high-altitude glaciers it ranges from 0.007254 to 0.007687, with an average value of 0.007345 ± 0.000128. These ratios are slightly higher than the typical crustal value, indicating that the TP was affected by an anthropogenic input of 235U, especially in its northeast and southwest sectors. The variability of our results suggests that the spatial distribution of this contamination is not uniform, pointing to differences in the potential sources and transmission paths of radioactive particles. Combining the knowledge of past tests and activities conducted in the geographic areas around the TP with the knowledge of prevailing winds, we hypothesize that the observed 235U contamination in the TP surface soils and glaciers may have originated mainly from the previous nuclear related activities in surrounding areas (e.g., north Gobi Desert and South Asia). In addition, the horizontal and vertical wind field around the Tibetan Plateau, as well as the atmospheric aerosol optical thickness data also demonstrated the possible transport paths of the radionuclides, that is, originated from in northern Gobi desert and South Asia and reached the TP crossing the Himalayas.


Assuntos
Monitoramento Ambiental , Camada de Gelo , Tibet , Monitoramento Ambiental/métodos , Vento , Radioisótopos
12.
Behav Sci (Basel) ; 12(5)2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35621445

RESUMO

Moral observer-licensing happens when observers condone actors' morally questionable conduct due to the actors' history of moral behaviors. In four studies (N = 808), we investigated this phenomenon in the context of cyberspace and its contributing factors and boundary conditions. The pilot study determined what participants perceived as typically moral and immoral behaviors in cyberspace. Then, in Study 1, participants condemned a story character's online immoral behavior less often when they were informed of the character's prior online moral behavior than when they were not, which indicates moral observer-licensing in cyberspace. Study 2 confirmed the presence of moral observer-licensing in cyberspace and further demonstrated that a character's prior moral or immoral behavior online respectively reduces or intensifies the perceived negativity of the character's subsequent immoral behavior. Finally, Study 3 showed that participants who identified with the victim in a hypothetical scenario showed less forgiveness and more condemnation of a character's immoral behavior than those who identified with the perpetrator or the bystander. These findings are of theoretical and practical significance for our understanding of cyber ethics.

13.
Sci Total Environ ; 825: 153946, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35189209

RESUMO

Iron (Fe) is an essential micronutrient in glacial ecosystems and modulates global biogeochemical cycles. To find out the deposition concentration, multiple origins and release form of iron in various glacier areas of central Asia, this study investigated the total Fe (TFe) and dissolved-Fe (dFe, diameter < 0.45 or <0.2 µm) deposition in glaciers and snowpack of northeast Tibetan Plateau, based on snow and meltwater sampling in ablation period of 2014-2017. The composition and concentration of dFe in the samples were measured, and the spatial distribution and temporal variations of dFe in glacial surface snow and meltwater runoff were investigated. Results showed that average TFe and dFe contents exhibited a generally heterogeneous geographic distribution that varied from north to south. The northern locations in eastern Tianshan Mountains (e.g. Miaoergou Glacier) showed the highest TFe and dFe values, followed by Yuzhufeng Glacier of eastern Kunlun Mountains, whereas the Qilian Mountains locations displayed relatively lower TFe and dFe contents spanning a wide range. Based on the good correlation between TFe and dFe, we infer that aeolian dust and anthropogenic aerosols, and their chemical interactions are likely the important origins for dFe deposition. In meltwater runoff the peak values of dFe release flux appeared in July, with maximum appeared earlier (the early of July) than TFe (the end of July). Moreover, the annual dFe release flux from Laohugou glacier terminus meltwater runoff is estimated to be 1740 kg yr-1 (with 9256 kg yr-1 for TFe), and meltwater showed higher mean concentration of dFe than that of glacier snowpack. We also provided a conceptual framework showing the multiple origins and transport dynamics of dissolved Fe along the atmosphere-glacier-meltwater runoff path. Compared to Fe release in other global glacier/ice-sheet, the TP glacier is an important potential dFe reservoir and may have a profound effect on regional downstream ecosystem through Fe biochemistry cycle.


Assuntos
Ecossistema , Camada de Gelo , Monitoramento Ambiental/métodos , Camada de Gelo/química , Ferro , Tibet
14.
Environ Sci Technol ; 55(14): 10121-10132, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34227802

RESUMO

Large areas of arid regions in the Tibetan Plateau (TP) are undergoing desertification and subsequent aeolian emission and transport. The contribution of TP soils to the atmospheric aerosol burden in Asia and elsewhere is not known. Here, we use Hf, Nd, and Sr isotopes to distinguish the TP from other Asian dust-producing regions and compare the signatures to sediments in major dust sink regions. We found that the Hf-Nd-Sr isotopes of TP soils showed unique spatial signatures. From north to south, 87Sr/86Sr ratios gradually increased, while εNd and εHf values gradually decreased; from west to east, 87Sr/86Sr and εHf gradually increased, while εNd changed indistinctly. The Hf-Nd-Sr isotopic compositions of TP soils were controlled by four geographic isotope regions: the northern, southern, western, and eastern TP. Compared with Asian large deserts, the TP showed a unique isotopic composition, which together exhibited a significant spatial change across Asia. Compared to dust isotopes in prominent sink areas, we found that the TP is an important dust source to eastern TP glaciers, the Chinese Loess Plateau, South China Sea, Japan, and Greenland. This study provides clear isotopic evidence that the TP is a major aeolian contributor in the Northern Hemisphere and may have important implications for the global aeolian cycle.


Assuntos
Poeira , Monitoramento Ambiental , Aerossóis , Poeira/análise , Camada de Gelo , Tibet
15.
Ecotoxicol Environ Saf ; 207: 111228, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32890952

RESUMO

Atmospheric heavy metals have important environmental and health threats. To investigate atmospheric deposition and contamination of heavy metal elements in the glaciers of the eastern Tibetan Plateau (ETP), we collected the surface snow (cryoconites) samples in the Lenglongling Glacier (LG), the Gannan Snowpack (GS), the Dagu Glacier (DG), the Hailuogou Glacier (HG) and Yulong Snow-mountain Glacier (YG) in summer 2017. Samples were analyzed for concentrations and enrichment factors (EFs) of Al and trace elements (Pb, Co, Cd, Ba, Mn, Ga, Sc, V, Zn, Cr, Ni, Cu, Rb, Sb, Cs, As, Mo, Li) using inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that the concentrations and EFs of heavy metals (e.g. Sb, Cu, Cr, Ni, As, Mo) were generally high value in YG, GS and LG, while were relatively low value in DG and HG, implying that ETP glaciers may have been affected by atmospheric anthropogenic pollutants deposition to varying degrees. Comparing the heavy metal concentrations in the glaciers with those in the precipitation of middle/eastern China cities and also the South Asian cities, we find that the glacial heavy metal concentrations were generally low level, though the anthropogenic pollutants were still significantly enriched. Taking the spatial distribution of As and Ni concentration/EFs in the glaciers and surrounding urban precipitation as an example, we find that the heavy metal pollutants were probably transported to the glaciers through three routes from the surrounding densely populated area of Asia. The MODIS AOD and NCEP/NCAR wind vector also demonstrated that the atmospheric pollutants originated from anthropogenic emissions of urban areas of both South Asia, and northwest and east China, mainly caused by the large scale atmospheric circulation (e.g. the South Asian Monsoon, westerlies and Eastern Asian Summer Monsoon). Therefore, control of these potential pollution emission sources of the surrounding densely populated areas in Asia could be important to ETP glaciers in future perspectives.


Assuntos
Monitoramento Ambiental , Camada de Gelo/química , Metais Pesados/análise , China , Poluição Ambiental/análise , Estações do Ano , Neve/química , Tibet , Oligoelementos/análise , Vento
17.
Environ Pollut ; 261: 114114, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32062097

RESUMO

This study employs the grain size distributions and the concentrations and isotopic compositions of Sr, Nd, and Pb in the precipitation samples collected from the Laohugou Glacier (LHG) in northeastern Tibetan Plateau (TP) during August 2014-2015 to investigate seasonal variability in the insoluble precipitation particle sources. Fine dust particle (0.57-27 µm) depositions dominated in autumn and winter, whereas both fine and coarse dust particle (27-100 µm) depositions were found in spring and summer. Furthermore, the concentrations of Sr, Nd, and Pb also varied seasonally-the highest and lowest Sr and Nd concentrations were recorded in spring and autumn, respectively, whereas the highest and lowest Pb concentrations were recorded in winter and summer, respectively. The Sr and Nd isotopes revealed that the dust in the winter precipitation originated predominately from the Taklimakan Desert and that in spring originated from the Badain Jaran and Qaidam deserts. The precipitation residues in summer were derived from a complex mixture of dust sources from the Gobi and other large deserts in northwest China. Autumn residues were predominately sourced from local soil near the LHG as well as from the Qaidam Basin and the northern TP surface soil. The Taklimakan, long suspected as a major source of long-range transported dust, was an insignificant contributor to the precipitation over LHG during spring, summer, and autumn. Further, the Pb isotopic ratios indicated a primary impact of anthropogenic pollutants for most part of the year (except spring). Meteorological data and the MODIS AOD model are in good agreement with the results from the analyses of the Sr, Nd, and Pb isotopes for the LHG particle source, and further clarify the source regions. Thus, this study thus provides new evidence on the seasonal variability of the sources of the residual particles in remote glaciers in Central Asia.


Assuntos
Poluentes Atmosféricos/análise , Camada de Gelo , China , Monitoramento Ambiental , Estações do Ano , Tibet
18.
Sci Total Environ ; 689: 754-764, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31280157

RESUMO

To investigate the large-scale trace element deposition and anthropogenic pollution in mountain glaciers of the northeastern Tibetan Plateau (TP) and its surrounding regions, we analyzed Al and 13 trace elements (As, Cd, Co, Cr, Cs, Cu, Mn, Mo, Ni, Pb, Sb, V, and Zn) in glacier snowpacks collected at the Yuzhufeng, Laohugou No.12, and Qiyi glaciers (YG, LG12, and QG, respectively) in the northeastern TP as well as in the Miaoergou Glacier (MG) in the eastern Tianshan Mountains in June 2017. The concentrations and enrichment factors (EFs) of most trace elements (e.g., As, Cd, Co, Cr, Cu, Ni, and Sb) showed that the largest value appeared in the MG, followed by LG12, and the lowest value appeared in the QG, thereby implying a decreasing influence of anthropogenic emissions on these elements from the west (MG) to the east (QG). The YG inversely exhibited high concentrations but low EFs for As, Cd, Co, Cr, Cs, Cu, Pb, and Sb. Compared to the surrounding regions of the southern and western TP (e.g., NamCo, Mt. Everest, and Pamirs), Japan, and Kathmandu, the trace element concentrations were relatively higher at the YG and MG but relatively lower at the LG12 and QG. The spatial distribution characteristics of trace elements (e.g., Pb and Sb) exhibited a gradually decreasing concentration from west to east in the Tianshan Mountains, and from south to north in the TP, implying two potential transport routes of atmospheric pollutants from Central and South Asia to the northeastern TP. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) backward trajectory model and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations/Cloud-Aerosol Lidar with Orthogonal Polarization (CALIPSO/CALIOP) data reflected that these trace elements in the MG, LG12, and QG predominately originated from the western and surrounding areas, whereas in the YG they were mainly derived from a local source and South Asia through long-distance transport.

19.
Environ Sci Technol ; 53(12): 6632-6639, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31117527

RESUMO

Cryoconite is a granular aggregate, comprised of both mineral and biological material, and known to accumulate atmospheric contaminants. In this study, cryoconite was sampled from seven high-elevation glaciers in Western China to investigate the spatial and altitudinal patterns of atmospheric mercury (Hg) accumulation in the cryoconite. The results show that total Hg (HgT) concentrations in cryoconite were significant with relatively higher Hg accumulation in the southern glaciers (66.0 ± 29.3 ng g-1), monsoon-influenced regions, than those in the northern glaciers (42.5 ± 20.7 ng g-1), westerlies-influenced regions. The altitudinal profile indicates that HgT concentrations in the northern glaciers decrease significantly with altitude, while those in the southern glaciers generally increase toward higher elevations. Unexpectedly high accumulation of methyl-Hg (MeHg) with an average of 1.0 ± 0.4 ng g-1 was also detected in the cryoconite samples, revealing the surface of cryoconite could act as a potential site for Hg methylation in alpine environments. Our preliminary estimate suggests a storage of ∼34.3 ± 17.4 and 0.65 ± 0.28 kg of HgT and MeHg from a single year of formation process in the glacier cryoconite. Therefore, glacier cryoconite could play an important role in Hg storage and transformation, which may result in downstream effects on glacier-fed ecosystems under climate warming scenario.


Assuntos
Camada de Gelo , Mercúrio , China , Ecossistema
20.
Korean J Radiol ; 20(4): 641-648, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30887746

RESUMO

OBJECTIVE: The purpose of this study was to investigate whether three-dimensional (3D) magnetic resonance imaging could improve diagnostic accuracy for suspected posterior ligamentous complex (PLC) disruption. MATERIALS AND METHODS: We used 20 freshly harvested goat spine samples with 60 segments and intact surrounding soft tissue. The animals were aged 1-1.5 years and consisted of 8 males and 12 females, which were sexually mature but had not reached adult weights. We created a paraspinal contusion model by percutaneously injecting 10 mL saline into each side of the interspinous ligament (ISL). All segments underwent T2-weighted sagittal and coronal short inversion time inversion recovery (STIR) scans as well as coronal and sagittal 3D proton density-weighted spectrally selective inversion recovery (3D-PDW-SPIR) scans acquired at 1.5T. Following scanning, some ISLs were cut and then the segments were re-scanned using the same magnetic resonance (MR) techniques. Two radiologists independently assessed the MR images, and the reliability of ISL tear interpretation was assessed using the kappa coefficient. The chi-square test was used to compare the diagnostic accuracy of images obtained using the different MR techniques. RESULTS: The interobserver reliability for detecting ISL disruption was high for all imaging techniques (0.776-0.949). The sensitivity, specificity, and diagnostic accuracy of the coronal 3D-PDW-SPIR technique for detecting ISL tears were 100, 96.9, and 97.9%, respectively, which were significantly higher than those of the sagittal STIR (p = 0.000), coronal STIR (p = 0.000), and sagittal 3D-PDW-SPIR (p = 0.001) techniques. CONCLUSION: Compared to other MR methods, coronal 3D-PDW-SPIR provides a more accurate diagnosis of ISL disruption. Adding coronal 3D-PDW-SPIR to a routine MR protocol may help to identify PLC disruptions in cases with nearby contusion.


Assuntos
Imageamento por Ressonância Magnética/métodos , Traumatismos da Coluna Vertebral/diagnóstico , Animais , Modelos Animais de Doenças , Feminino , Cabras , Imageamento Tridimensional , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Traumatismos da Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/diagnóstico por imagem
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