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1.
Environ Sci Technol ; 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32242420

RESUMO

Mercury (Hg) and lead (Pb) accumulation since the Industrial Revolution has been generally observed to increase concurrently in lake sedimentary records around the world. Located downwind during the monsoon season from a rapidly developing South Asia, the Himalayas and Tibetan Plateau are expected to receive direct anthropogenic Hg and Pb loadings, yet the source, pathway and effects of such transport remain poorly known due to logistic challenges in accessing this region. When studying the sediment record from Lake Gokyo (4,750 m a.s.l.) in the Himalayas, we find remarkably different Hg and Pb accumulation trends over the past 260 years. Whereas Hg accumulation has continued to increase since the Industrial Revolution, Pb accumulation peaked during that time and has been decreasing since then. Stable isotope analysis reveals that the decoupling trends between these two elements are due to different sources and pathways of Hg and Pb to the region. Both δ202Hg and Δ199Hg have been increasing since the Industrial Revolution, suggesting that anthropogenic Hg emissions from South Asia have been continuously increasing, and that the Indian monsoon-driven wet deposition of atmospheric Hg is the dominant pathway for Hg accumulation in the sediments. In contrast, analysis of 206Pb/207Pb and 208Pb/207Pb ratios suggests that Pb accumulation in the sediments originates primarily from natural sources, and that the decreasing trend of Pb accumulation is most likely due to a weakening input of atmospheric mineral dust by the westerlies. These decoupling trends highlight the ongoing issue of transboundary Hg transport to the Himalayas and Tibetan Plateau that are source waters for major freshwater systems in Asia, and calls for regional and international collaborations on Hg emission controls in South Asia.

2.
Sci Total Environ ; 721: 137752, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-32182467

RESUMO

Tibetan Plateau (TP) is an important geographical region for investigating the long-range transport of pollutants as limited emission sources exist in this region. In this study, based on analysis of 61 surface samples, we report the spatial distribution and concentrations of BC, Hg, total organic carbon (TOC) and inorganic carbon (IC) in surface sediments of Selin Co, the largest lake in central Tibet. The mean BC and Hg concentrations were 0.62 ± 0.34 mg/g and 32.03 ± 9.88 ng/g (range: 0.03-1.47 mg/g and 13.83-51.81 ng/g respectively), which were lower than the values from other lakes in the Himalayan-Tibetan Plateau (HTP). BC and Hg exhibited similar spatial distribution in the surface sediments. Similarly, the mean TOC and IC were 2.19 ± 1.46% and 3.13 ± 1.07% (range: 0.0007-7.78% and 0.30-5.30% respectively). BC/TOC ratio, as well as char/soot ratio, suggests biomass burning as a major source of BC in the sediments via the influence of long-range transport. The positive correlation between the concentrations of BC and Hg suggests similar emission sources or transport pathway. Concentrations of BC and Hg were higher in fine grain particles (size <~50 µm) which were capable of transport and deposit in the deeper part of the lake, as suggested by a significant relationship between water depth and particle size. This study elucidates the extent of pollution in very recent ages and also could serve as the basis for paleo-environmental studies in future.

3.
Environ Pollut ; 261: 114239, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32114124

RESUMO

This study presents a comprehensive analysis of organic carbon (OC), elemental carbon (EC), and particularly the light absorption characteristics of EC and water-soluble brown carbon (WS-BrC) in total suspended particles in the Kathmandu Valley from April 2013 to January 2018. The mean OC, EC, and water-soluble organic carbon (WSOC) concentrations were 34.8 ± 27.1, 9.9 ± 5.8, and 17.4 ± 12.5 µg m-3, respectively. A clear seasonal variation was observed for all carbonaceous components with higher concentrations occurring during colder months and lower concentrations in the monsoon season. The relatively low OC/EC ratio (3.6 ± 2.0) indicates fossil fuel combustion as the primary source of carbonaceous components. The optical attenuation (ATN) at 632 nm was significantly connected with EC loading (ECS) below 15 µg cm-2 but ceased as ECS increased, reflecting the increased influence of the shadowing effect. The derived average mass absorption cross-section of EC (MACEC) (7.0 ± 4.2 m2 g-1) is comparable to that of freshly emitted EC particles, further attesting that EC was mainly produced from local sources with minimal atmospheric aging processes. Relatively intensive coating with organic aerosols and/or salts (e.g., sulfate, nitrate) was probably the reason for the slightly higher MACEC during the monsoon season, whereas increased biomass burning was a major factor leading to lower MACEC in other seasons. The average MACWS-BrC at 365 nm was 1.4 ± 0.3 m2 g-1 with minimal seasonal variations. In contrast to MACEC, biomass burning was the main reason for a higher MACWS-BrC in the non-monsoon season. The relative light absorption contribution of WS-BrC to EC was 9.9% over the 300-700 nm wavelength range, with a slightly higher ratio (13.6%) in the pre-monsoon season. Therefore, both EC and WS-BrC should be considered in the study of optical properties and radiative forcing of carbonaceous aerosols in this region.

4.
Environ Pollut ; 261: 114144, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32062463

RESUMO

With the recent rapid development of urbanization, atmospheric pollutants such as polycyclic aromatic hydrocarbons (PAHs) have attracted wide attention, particularly in remote regions. The Tibetan Plateau (TP), known as the third pole is adjacent to areas with heavy atmospheric pollution, such as South and East Asia. However, the spatial distribution and sources of PAHs on the TP remain unclear. Thus, we investigated the sources and spatio-temporal distributions of PAHs on the TP by combining aerosol sample data from six sites, including Ngari (NG), Laohugou (LHG), Beiluhe (BLH), Nam Co (NMC), Everest (EV), and Yulong (YL), in 2014 and 2016. The average concentrations of 15 PAHs at the six sites ranged from 3.4 to 15.2 ng m-3, with a decreasing trend from the marginal to inner areas of the plateau. The highest concentration was that in YL in the southeastern part of the TP, with an average of 15.2 ng m-3. The PAH concentrations in NG, NMC, and YL were higher in autumn and winter and lower in summer. High molecular weight PAHs usually exists in the particulate phase whereas tricyclic PAHs can change from particulate to gaseous phase, therefore it can indicate long-range transport. Tricyclic PAHs were the dominant PAHs on the TP (44%-58%), indicating long-range atmospheric transport as the major source of PAHs. Principal component analysis (PCA) and diagnostic ratio analysis showed that biomass and coal combustion were the major sources of PAHs in inland areas of the TP; however, marginal plateau areas were affected by fossil fuel emissions. Compared with levels in Beijing and other urban sites, the toxic equivalent quantity (TEQ) was low (0.36-1.06 ng m-3), suggesting a low risk to human and ecosystem health.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31940147

RESUMO

Total suspended particles (TSP) were collected in Lumbini from April 2013 to March 2016 to better understand the characteristics of carbonaceous aerosol (CA) concentrations, compositions and sources and their light absorption properties in rural region of severe polluted Indo-Gangetic Plain (IGP). Extremely high TSP (203.9 ± 109.6 µg m-3), organic carbon (OC 32.1 ± 21.7 µg m-3), elemental carbon (EC 6.44 ± 3.17 µg m-3) concentrations were observed in Lumbini particularly during winter and post-monsoon seasons, reflecting the combined influences of emission sources and weather conditions. SO42- (7.34 ± 4.39 µg m-3) and Ca2+ (5.46 ± 5.20 µg m-3) were the most dominant anion and cation in TSP. These components were comparable to those observed in urban areas in South and East Asia but significantly higher than those in remote regions over the Himalayas and Tibetan Plateau, suggesting severe air pollution in the study region. Various combustion activities including industry, vehicle emission, and biomass burning are the main reasons for high pollutant concentrations. The variation of OC/EC ratio further suggested that biomass such as agro-residue burning contributed a lot for CA, particularly during the non-monsoon season. The average mass absorption cross-section of EC (MACEC) and water-soluble organic carbon (MACWSOC) were 7.58 ± 3.39 and 1.52 ± 0.41 m2 g-1, respectively, indicating that CA in Lumbini was mainly affected by local emissions. Increased biomass burning decreased MACEC; whereas, it could result in high MACWSOC during the non-monsoon season. Furthermore, dust is one important factor causing higher MACWSOC during the pre-monsoon season.

6.
Expert Rev Gastroenterol Hepatol ; 14(2): 85-92, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31922886

RESUMO

Introduction: In recent years, circular RNAs (circRNAs) have emerged in the field of RNA research and their biological functions are now being gradually identified. circRNAs are divided into three categories: exonic circular RNAs (ecircRNAs), exon-intron circular RNAs (EIciRNAs), and intronic circular RNAs (ciRNAs). The circular structure of circRNAs confers unique biological characteristics upon them, such as enhanced stability over linear RNAs.Areas covered: circRNAs function to competitively bind with microRNAs (miRNAs) and proteins, participate in protein coding, regulate transcription, and form pseudogenes after reverse transcription. In gastric cancer, the circRNA-miRNA-mRNA axis is the most studied mechanisms underlying gastric cancer occurrence and development. Some specific and sensitive circRNAs, such as hsa_circ_102958, hsa_circ_0000520, and hsa_circ_0001017 may have potential diagnostic potential in early-stage gastric cancer. Abnormal expression of some circRNAs, including circ-LMTK2, circ-PSMC3, and circ-DLST are associated with the development of gastric cancer. Other circRNAs, such as hsa_circ_0001368, circ-ZFR, and circ-ERBB2, may also play important roles in gastric cancer treatment.Expert opinion: Exploring the roles of circRNAs in gastric cancer occurrence and development will help us to elucidate the functions of circRNAs and develop potential tools for early diagnosis and effective treatment of gastric cancer.

7.
Environ Pollut ; 256: 113432, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31662270

RESUMO

The concentration and isotopic composition of mercury (Hg) were studied in frozen soils along a southwest-northeast transect over the Himalaya-Tibet. Soil total Hg (HgT) concentrations were significantly higher in the southern slopes (72 ±â€¯54 ng g-1, 2SD, n = 21) than those in the northern slopes (43 ±â€¯26 ng g-1, 2SD, n = 10) of Himalaya-Tibet. No significant relationship was observed between HgT concentrations and soil organic carbon (SOC), indicating that the HgT variation was not governed by SOC. Soil from the southern slopes showed significantly negative mean δ202Hg (-0.53 ±â€¯0.50‰, 2SD, n = 21) relative to those from the northern slopes (-0.12 ±â€¯0.40‰, 2SD, n = 10). The δ202Hg values of the southern slopes are more similar to South Asian anthropogenic Hg emissions. A significant correlation between 1/HgT and δ202Hg was observed in all the soil samples, further suggesting a mixing of Hg from South Asian anthropogenic emissions and natural geochemical background. Large ranges of Δ199Hg (-0.45 and 0.24‰) were observed in frozen soils. Most of soil samples displayed negative Δ199Hg values, implying they mainly received Hg from gaseous Hg(0) deposition. A few samples had slightly positive odd-MIF, indicating precipitation-sourced Hg was more prevalent than gaseous Hg(0) in certain areas. The spatial distribution patterns of HgT concentrations and Hg isotopes indicated that Himalaya-Tibet, even its northern part, may have been influenced by transboundary atmospheric Hg pollution from South Asia.


Assuntos
Monitoramento Ambiental , Mercúrio/análise , Poluentes do Solo/análise , Ásia , Carbono , Gases , Isótopos , Isótopos de Mercúrio/análise , Solo/química , Tibet
8.
Sci Total Environ ; 708: 135226, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31806346

RESUMO

The Qinghai-Tibet Plateau glaciers are an important carrier of mercury (Hg). With global warming, Hg enters into the downstream ecosystem in the melt waters, threatening human health and ecosystem security in the region. Methylmercury (MeHg), which has higher toxicity than Hg itself, is converted from inorganic Hg. However, little is known about the process of Hg methylation and, in particular, microbial Hg methylation in high altitude mountain glaciers. We combined Hg speciation measurements and metagenomic analysis of 6 sample types from the terminus of Laohugou No.12 glacier to elucidate potential microbially mediated Hg methylation. We found higher Hg concentrations in supraglacial cryoconite (SC) and dusty layer (DL) samples which contain considerable debris and dust. In addition, MeHg concentrations were highest in some of these SC and DL samples. Bacterial hgcA Hg methylation genes were present in all samples except supraglacial ice but were of highest abundance in SC and DL. This suggested that microbial Hg methylation is most likely to occur in SC and DL. There were 8 phyla of potential Hg methylation microorganisms, but 37% of the sequences could not be classified into any known genus. Most of the hgcA sequences were closely related to sequences from previously reported Hg methylating genera within the Deltaproteobacteria and Firmicutes, but the common Hg methylating Methanomicrobia were absent in glacial samples.

9.
Pathol Res Pract ; 216(1): 152763, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31810586

RESUMO

Gastric cancer (GC) is an aggressive malignancy that seriously threatens human health. Accumulating studies have shown that circular RNAs (circRNAs) can be used as diagnostic biomarkers and promising therapeutic targets with significant clinical implications. However, the roles of circRNAs in GC remain largely elusive. In this study, hsa_circ_0000419 levels in GC cell lines, tissues and plasma were detected, and their clinicopathological correlation was analyzed. Receiver operating characteristic (ROC) curve and Kaplan-Meier survival curve were established for its clinical values evaluation. Potential biological functions were further predicted and annotated by bioinformatics analysis. Hsa_circ_0000419 levels were significantly decreased in GC cell lines, cancer tissues and plasma from GC patients. GC tissues hsa_circ_0000419 levels were associated with cell differentiation, Borrmann type, overall survival and disease-free survival, whereas plasma hsa_circ_0000419 were significantly correlated with tumor stage, lymphatic and distal metastasis, venous and perineural invasion. Plasma hsa_circ_0000419 exists in exosomes and maintain good stability. Bioinformatics analysis showed that hsa_circ_0000419 involved in gastric tumorigenesis and progression via its interaction with microRNAs. Collectively, our study suggests that hsa_circ_0000419 is a novel biomarker for GC screening as well as an important indicator for prognostic estimation of patients with advanced GC.

10.
Sci Total Environ ; 708: 135127, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31787283

RESUMO

Permafrost on the Qinghai-Tibetan Plateau (QTP) has been degrading in the past decades. While the degradation may mobilize previously protected material from the permafrost profile, little is known about the stocks and stability of mercury (Hg) in the QTP permafrost. Here we measured total soil Hg in 265 samples from 15 permafrost cores ranging from 3 to 18 m depth, and 45 active layer (AL) soil samples from different land cover types on the QTP. Approximately 21.7 Gg of Hg was stored in surficial permafrost (0-3 m), with 16.58 Gg of Hg was stored in the active layer. Results from six permafrost collapse areas showed that much of the thawed Hg is mobile, with decreases in total Hg mass of 17.6-30.9% for the AL (top 30 cm) in comparison with non-thermokarst surfaces. We conclude that the QTP permafrost region has a large mercury pool, and the stored mercury is sensitive to permafrost degradation.

11.
Dis Markers ; 2019: 2624586, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827632

RESUMO

Background: Gastric cancer (GC) has a poor prognosis due to the lack of ideal tumor markers. Circular RNAs (circRNAs) are a novel type of noncoding RNA related to the occurrence of GC. Among our research, we investigated the role of hsa_circ_0005556 in GC. Materials and Methods: The expression of hsa_circ_0005556 of 100 paired GC tissues and adjacent normal tissues was detected using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). A receiver operating characteristic (ROC) curve was established to evaluate the diagnostic value of hsa_circ_0005556. The correlation between the expression of hsa_circ_0005556 and corresponding clinicopathological characteristic was explored. Results: hsa_circ_0005556 was significantly downregulated in GC tissues contrasted with adjacent normal tissues (n = 100, p < 0.001). The areas under the ROC curve (AUC) of hsa_circ_0005556 were up to 0.773, while 64% sensitivity and 82% specificity, respectively. Moreover, its expression levels were significantly associated with differentiation (p = 0.001), TNM stage (p = 0.013), and lymphatic metastasis (p = 0.039). GC patients of high hsa_circ_0005556 levels had a longer overall survival (OS) than those of the low group (p = 0.047). Conclusion: hsa_circ_0005556 is a potential biomarker for GC, which may guide judgment of the indication of endoscopic treatment for early gastric cancer (EGC).

12.
J Clin Lab Anal ; : e23080, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31721300

RESUMO

BACKGROUND: Gastric cancer (GC) is one of the global mortality diseases and has a poor prognosis due to the lack of ideal tumor biomarkers. Circular RNAs (circRNAs) are an abundant kind of endogenous RNAs that recently are found play a crucial role in the cancer occurrence and development. Nevertheless, little is known with regard to the diagnostic values of these circRNAs for GC. In this article of research, we investigated the role of hsa_circ_0067582 in clinical diagnosis of GC. MATERIALS AND METHODS: We used divergent primers, and the expression levels of hsa_circ_0067582 in 93 fresh GC tissues and paired adjacent normal tissues from surgical patients were detected using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Then, a receiver operating characteristic (ROC) curve was established to assess the diagnostic significance of hsa_circ_0067582. The relationship between expression of hsa_circ_0067582 and clinicopathological factors of patients was made further explored. RESULTS: Hsa_circ_0067582 levels were significantly decreased in GC tissues contrasted with adjacent normal tissues (n = 93, P < .001). After that, we discovered that it was evidently downregulated in 81.7% (76/93) GC tissues. The area under the ROC curve (AUC) of hsa_circ_0067582 was up to 0.6937, the sensitivity was 66.67%, and the specificity was 61.29%. Moreover, the hsa_circ_0067582 levels were obviously associated with tumor diameter (P = .002) and carbohydrate antigen 19-9 (CA19-9, P = .01). Meanwhile, after operation, low-level group of hsa_circ_0067582 of GC patients was associated with better prognosis. CONCLUSION: Our data imply that hsa_circ_000067582 may be a potential biomarker for GC diagnosis and prognosis evaluation.

13.
Sci Rep ; 9(1): 16864, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31728020

RESUMO

Various nickel and magnesium dual-doped LiNixMg0.08Mn1.92-xO4 (x ≤ 0.15) were synthesized via a modified solid-state combustion method. All as-prepared samples show typical spinel phase with a well-defined polyhedron morphology. The Ni-Mg dual-doping obviously decreases the lattice parameter that gives rise to the lattice contraction. Owing to the synergistic merits of metal ions co-doping, the optimized LiNi0.03Mg0.08Mn1.89O4 delivers high initial capacity of 115.9 and 92.9 mAh·g-1, whilst retains 77.1 and 69.7 mAh·g-1 after 1000 cycles at 1 C and high current rate of 20 C, respectively. Even at 10 C and 55 °C, the LiNi0.03Mg0.08Mn1.89O4 also has a discharge capacity of 92.2 mAh·g-1 and endures 500 cycles long-term life. Such excellent results are contributed to the fast Li+ diffusion and robust structure stability. The anatomical analysis of the 1000 long-cycled LiNi0.03Mg0.08Mn1.89O4 electrode further demonstrates the stable spinel structure via the mitigation of Jahn-Teller effect. Hence, the Ni-Mg co-doping can be a potential strategy to improve the high-rate capability and long cycle properties of cathode materials.

14.
Cancer Med ; 8(17): 7278-7287, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31595711

RESUMO

Circular RNAs (circRNAs) have been increasingly revealed to be desirable biomarkers for some tumors, including hepatocellular carcinoma (HCC). Combined with our previous microarray screening results, we aimed to determine the hsa_circ_0028502 and hsa_circ_0076251 expression features in HCC, analyze the relationship between their expression level and clinical and pathological characteristics, and investigate their diagnostic and prognostic values. Our data demonstrated that the hsa_circ_0028502 and hsa_circ_0076251 levels were considerably lower in HCC tissues than in adjacent paracancerous tissues (P < .001). Further study revealed that hsa_circ_0028502 expression levels were related to tumor node metastasis (TNM) stage (P = .015) and that hsa_circ_0076251 expression levels were related to Barcelona Clinic Liver Cancer (BCLC) stage (P = .038), comorbidity with type 2 diabetes mellitus (P = .023) and the presence of serum HbsAg (P = .044). Furthermore, the degree of expression of both hsa_circ_0028502 and hsa_circ_0076251 increased from HCC to liver cirrhosis (LC) to chronic hepatitis (CH). The receiver operating characteristic (ROC) curve demonstrated that hsa_circ_0028502 and hsa_circ_0076251 could serve as fairly accurate markers to distinguish HCC tissues from CH tissues and LC tissues, as well as distinguishing LC tissues from CH tissues. Cox regression analysis showed that low expression of has_circ_0076251 was associated with unfavorable survival rates in HCC (HR = 0.46; 95% CI = 0.22-0.98; P < .05). These findings implied that hsa_circ_0028502 and hsa_circ_0076251 were potentially valuable biomarkers for HCC diagnosis, whereas hsa_circ_0076251 could be used as a prognostic indicator for HCC.

15.
Cancer Biomark ; 26(4): 403-410, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31640088

RESUMO

Gastric cancer is one of the most common cancers in the world. However, current medical technologies have not identified a reliable method to cure advanced gastric cancer, and early gastric cancer is difficult to diagnose. Therefore, we focused on circular RNAs (circRNAs) that have been proven to be involved in the carcinogenesis of gastric cancer. We first used quantitative reverse transcription-polymerase chain reaction (qRT-PCR) to evaluate the expression levels of hsa_circ_0005654 in 301 tissues, including 122 healthy gastric mucosa samples, 68 paired tissues from early gastric cancer and adjacent nontumor mucosae obtained by submucosal dissection, and 43 chronic gastritis tissues. Then, we analyzed the relationship between the expression levels of hsa_circ_0005654 and the clinicopathological characteristics of patients with early gastric cancer. We ultimately confirmed the clinical diagnostic value of hsa_circ_0005654 through generating receiver operating characteristic (ROC) curves and comparing the areas under the ROC curves (AUCs).Our data revealed that hsa_circ_0005654 was significantly downregulated in early gastric cancer tissues compared with matched normal mucosae (P< 0.001). Meanwhile, the expression levels of hsa_circ_0005654 in early gastric cancer tissues were also obviously lower than those in chronic gastritis tissues (P< 0.001). The AUCs of early gastric cancer tissues vs. paired normal adjacent mucosae, and that of early gastric cancer vs. healthy controls, were 0.927 and 0.924, respectively. These results clearly demonstrated that hsa_circ_0005654 may serve as a new and promising diagnostic biomarker for screening early gastric cancer. The AUC, sensitivity and specificity of hsa_circ_0005654 are significantly higher than those of present gastric cancer associated-biomarkers.

16.
J Colloid Interface Sci ; 555: 64-71, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31376769

RESUMO

The improvements of cyclability and rate capability of lithium ion batteries with spinel LiMn2O4 as cathode are imperative demands for the large-scale practical applications. Herein, a nickel (Ni) and magnesium (Mg) co-doping strategy was employed to synthesize LiNi0.03Mg0.05Mn1.92O4 cathode material via a facile solid-state combustion approach. The effects of the Ni-Mg co-doping on crystalline structure, micromorphology and electrochemical behaviors of the as-prepared LiNi0.03Mg0.05Mn1.92O4 are investigated by a series of physico-chemical characterizations and performance tests at high-rate and elevated-temperature. The resultant LiNi0.03Mg0.05Mn1.92O4 has the intrinsic spinel structure with no any impurities, and exhibits an elevated average valence of manganese in comparison to the pristine LiMn2O4. Owing to the Ni and Mg dual-doped merits, the LiNi0.03Mg0.05Mn1.92O4 sample demonstrates a robust spinel structure and high first discharge specific capacity of 112.3 mAh g-1, whilst undergoing a long cycling of 1000 cycles at 1 C. At a high current rate of 20 C, the capacity of 91.2 mAh g-1 with an excellent retention of 77% is obtained after 1000 cycles. Even at 10 C under 55 °C, an excellent capacity of 97.6 mAh g-1 is also delivered. These results offer a new opportunity for developing high-performance lithium ion batteries with respect to the Ni-Mg co-doping strategy.

17.
Pathol Oncol Res ; 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31432324

RESUMO

Circular RNAs (circRNAs) are an endogenous RNAs with a covalently closed cyclic structure. They have emerged recently as key regulators in the development and progression of human cancers. However, the clinical values of most circRNAs in gastric cancer (GC) are unknown. Hsa_circ_0065149, one of the dysregulated circRNAs in gastric carcinogenesis detected by circRNA microarray, was chose as a targeted circRNA in this study. We firstly enlarged sample size and identified the level changes of hsa_circ_0065149 among four stages of gastric tumorigenesis from healthy gastric mucosa, gastritis, intestinal metaplasia to GC. Then, the potential relationship between hsa_circ_0065149 expression levels and GC patients' clinicopathological factors was investigated. Moreover, the clinical significance of hsa_circ_0065149 in plasma exosomes and gastric juice were explored. Receiver operating characteristic (ROC) curve and Kaplan-Meier survival curve were constructed to evaluate diagnostic and prognostic values. Finally, bioinformatics analysis was performed to excavate the potential functions of hsa_circ_0065149. Hsa_circ_0065149 expression was only significantly down-regulated in gastric cancer, not changed among healthy gastric mucosa and gastritis intestinal metaplasia. Low hsa_circ_0065149 expression levels in GC tissues were significantly associated with tumor diameter (P = 0.034) and perineural invasion (P = 0.037). GC patients with low hsa_circ_0065149 levels had a much longer overall survival than those in high group (P = 0.020). More important, hsa_circ_0065149 levels were significantly decreased in plasma exosomes of early GC patients. As a screening biomarker for early GC, hsa_circ_0065149 in plasma exosomes has higher sensitivity and specificity than traditional clinical biomarkers. Bioinformatics analysis suggest that the abnormal expression of hsa_circ_0065149 may play an important role during gastric carcinogenesis. Those results indicate that hsa_circ_0065149 in exosmoes is an indicator for early GC screening and prognosis prediction.

18.
J Clin Lab Anal ; 33(9): e22984, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31328820

RESUMO

BACKGROUND: Circular RNAs (circRNAs) are a special class of endogenous noncoding RNAs that have numerous biological functions in normal situation and diseases including cancers. However, the clinical significance of circRNAs in gastric cancer (GC) remains largely unknown. Here, we chose two representative circRNAs, hsa_circ_0067582 and hsa_circ_0005758, to investigate their clinical significance in GC patients. METHODS: Using real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), we explored the expression levels of hsa_circ_0067582 and hsa_circ_0005758 in tissues with different stages of gastric tumorigenesis. Then, the relationships between their expression levels and GC patients' clinicopathological factors were further investigated. Receiver operating characteristic (ROC) curves were established for evaluating diagnostic values of hsa_circ_0067582 and hsa_circ_0005758. RESULTS: Compared with healthy control tissues, both hsa_circ_0067582 and hsa_circ_0005758 were significantly decreased in GC tissues. Besides, hsa_circ_0067582 expression was associated with GC patients' tissue CEA level (P <.001) and stages (P = .037); and hsa_circ_0005758 expression was relevant to tissue CEA level (P < .001) and perineural invasion (P = .048). The area under the ROC curve (AUC) of hsa_circ_0067582 was up to 0.671. The cutoff value was set at 10.61, with which the sensitivity and specificity were 55.2% and 75.0%, respectively. Similar to hsa_circ_0005758, the AUC of hsa_circ_0005758 was 0.721. The cutoff value was set at 10.20, with which the sensitivity and specificity were 75.0% and 67.7%, respectively. CONCLUSION: These results showed that both hsa_circ_0067582 and hsa_circ_0005758 may play an important role in gastric carcinogenesis; and they may be potential indicators for GC diagnosis.

19.
Environ Pollut ; 253: 49-60, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302402

RESUMO

Carbonaceous aerosols (CAs) scatter and absorb incident solar radiation in the atmosphere, thereby influencing the regional climate and hydrological cycle, particularly in the Third Pole (TP). Here, we present the characteristics of CAs at 19 observation stations from the Atmospheric Pollution and Cryospheric Change network to obtain a deep understanding of pollutant status in the TP. The organic carbon (OC) and elemental carbon (EC) concentrations decreased noticeably inwards from outside to inland of the TP, consistent with their emission load and also affected by transport process and meteorological condition. Urban areas, such as Kathmandu, Karachi, and Mardan, exhibited extremely high OC and EC concentrations, with low and high values occurring in the monsoon and non-monsoon seasons, respectively. However, remote regions inland the TP (e.g., Nam Co and Ngari) demonstrated much lower OC and EC concentrations. Different seasonal variations were observed between the southern and northern parts of the TP, suggesting differences in the patterns of pollutant sources and in distance from the sources between the two regions. In addition to the influence of long-range transported pollutants from the Indo-Gangetic Plain (IGP), the TP was affected by local emissions (e.g., biomass burning). The OC/EC ratio also suggested that biomass burning was prevalent in the center TP, whereas the marginal sites (e.g., Jomsom, Dhunche, and Laohugou) were affected by fossil fuel combustion from the up-wind regions. The mass absorption cross-section of EC (MACEC) at 632 nm ranged from 6.56 to 14.7 m2 g-1, with an increasing trend from outside to inland of the TP. Urban areas had low MACEC values because such regions were mainly affected by local fresh emissions. In addition, large amount of brown carbon can decrease the MACEC values in cities of South Asia. Remote sites had high MACEC values because of the coating enhancement of aerosols. Influenced by emission, transport process, and weather condition, the CA concentrations and MACEC presented decreasing and increasing trends, respectively, from outside to inland of the TP.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , Ásia , Atmosfera/química , Biomassa , Carbono/análise , Cidades , Clima , Poluição Ambiental , Combustíveis Fósseis , Estações do Ano , Tempo (Meteorologia) , Vento
20.
Dalton Trans ; 48(33): 12459-12465, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31353369

RESUMO

In this work, a novel fluoroaluminate red phosphor of Cs2NaAl3F12:Mn4+ with excellent color purity was fabricated via the introduction of Mn4+ in the octahedral center. The crystal and electronic structures, luminescence properties and optical performances were characterized and investigated in detail. The evidences showed that Cs2NaAl3F12:Mn4+ well-crystallized into a single phase with particulate morphology, and the non-equivalent occupation in Cs2NaAl3F12 resulted in sharp red emissions with improved color purity upon blue light illumination. For solid-state lighting, the optical parameters consisted of the "blue-yellow-red" contributions significantly improved to a high color-rendering index of 88.7 and a low color temperature of 3856 K, indicating the potential use of Cs2NaAl3F12:Mn4+ for warm white light-emitting diode applications.

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