Indian Summer Monsoon variations and competing influences between hemispheres since ~35 ka recorded in Tengchongqinghai Lake, southwest China

The southwestern Yunnan Province of China, which is located at the southeastern margin of the Tibetan Plateau and close to Bay of Bengal, is significantly influenced by the Indian Summer Monsoon (ISM). In this study, we reconstruct proxies for the ISM from 35 to 1 ka through detailed analysis of grain-size distribution, geochemical composition and environmental magnetism from a 7.96 m sediment core from Tengchongqinghai Lake, Yunnan Province, China. Globally recognized, abrupt climatic events, including Heinrich Events 0–3 (H0−H3) and the Bølling-Allerød (B/A) warm period are identified in most of our proxies, and the long-term trend is consistent with other published records such as stalagmite oxygen isotopes (δ18O) from Sangxing Cave. Northern Hemisphere (NH) temperature, which is influenced by NH solar insolation, is commonly suggested to play a dominant role in controlling the ISM. A comparison of our record with the δ18O variations of ice cores from Greenland and Antarctica, a sea surface temperature (SST) record from the Bay of Bengal, and summer solar insolation at 25°N latitude demonstrates that the general pattern of ISM change does follow variations in summer insolation; however, the ISM lags summer insolation by thousands of years. While the ISM fluctuations are highly correlated with NH temperature on shorter timescales (centennial-millennial), the gradually weakened ISM from 22.5 ka until the Last Glacial Maximum (LGM) indicates a close relationship with the rise of Southern Hemisphere (SH) temperature and the relatively cold background of the SH. Our record expands on the findings of ISM records from Heqing paleolake basin in southwestern China and the Arabian Sea sediments, suggesting that the NH and SH have a competitive influence on ISM by controlling the cross-equatorial pressure gradient. This relationship means that when NH temperatures are relatively high, it has a stronger influence on the ISM than SH influences. In contrast, when the SH temperature is relatively low, it has a dominant influence on ISM. In addition, we speculate that the change of SH temperature not only influences the cross-equatorial pressure gradient directly, but also likely modulates the circulation system of ocean energy by influencing the Atlantic Meridional Overturning Circulation (AMOC)

Methodological Quality Assessment of Meta-Analyses and Systematic Reviews of Probiotics in Inflammatory Bowel Disease and Pouchitis.

Probiotics are widely used for the induction and maintenance of remission in inflammatory bowel disease (IBD) and pouchitis. There are a large number of meta-analyses (MAs)/ systematic reviews (SRs) on this subject, the methodological quality of which has not been evaluated.This study aimed to evaluate the methodological quality of and summarize the evidence obtained from MAs/SRs of probiotic treatments for IBD and pouchitis patients.The PubMed, EMBASE, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases were searched to identify Chinese and English language MAs/SRs of the use of probiotics for IBD and pouchitis. The Assessment of Multiple Systematic Reviews (AMSTAR) scale was used to assess the methodological quality of the studies.A total of 36 MAs/SRs were evaluated. The AMSTAR scores of the included studies ranged from 1 to 10, and the average score was 5.81. According to the Canadian Agency for Drugs and Technologies in Health, 4 articles were classified as high quality, 24 articles were classified as moderate quality, and 8 articles were classified as low quality. Most of the MAs/SRs suggested that probiotics had potential benefits for patients with ulcerative colitis (UC), but failed to show effectiveness in the induction and maintenance of remission in Crohn's disease (CD). The probiotic preparation VSL#3 may play a beneficial role in pouchitis.The overall methodological quality of the current MAs/SRs in the field of probiotics for IBD and pouchitis was found to be low to moderate. More MAs/SRs of high quality are required to support using probiotics to treat IBD and pouchitis

Use of the enhanced frog embryo teratogenesis assay-Xenopus (FETAX) to determine chemically-induced phenotypic effects

The frog embryo teratogenesis assay-Xenopus (FETAX) is an established method for the evaluation of the developmental toxicities of chemicals. To develop an enhanced FETAX that is appropriate for common environmental contaminants, we exposed Xenopus tropicalis embryos to eight compounds, including tributyltin, triphenyltin, CdCl2, pyraclostrobin, picoxystrobin, coumoxystrobin, all-trans-retinoic acid and 9-cis-retinoic acid. Multiple malformations were induced in embryos particularly following exposure to tributyltin, triphenyltin and pyraclostrobin at environmentally relevant concentrations. Based on the range of observed malformations, we proposed a phenotypic assessment method with 20 phenotypes and a 0–5 scoring system. This derived index exhibited concentration-dependent relationships for all of the chemicals tested. Furthermore, the phenotype profiles were characteristic of the different tested chemicals. Our results indicate that malformation phenotypes can be quantitatively integrated with the primary endpoints in conventional FETAX assessments to allow for increased sensitivity and measurement of quantitative effects and to provide indicative mechanistic information for each tested chemical

Current status and future perspectives of microplastic pollution in typical cryospheric regions

The cryosphere is the term used to describe the frozen areas of the Earth, including all forms of snow and ice, which are primarily influenced by anthropogenic pollutants through atmospheric transport. In this review, we described the current status of newly emergent pollutant-microplastics-in the snow and ice of typical cryospheric regions (e.g., Arctic, Antarctic, Alps, Tibetan Plateau, and Andes), discussed their transport pathways, and provided perspectives for future research. A brief summary of snow and ice sampling, pretreatment, and the identification of microplastics in cryospheric regions suggested that standard procedures were inadequate and urgently required improvement. Microplastics were widely distributed in snow and ice across the typical cryospheric regions, indicating the ubiquitous distribution of microplastics in such environments. However, the abundance, size distribution, shape, and polymer composition of the microplastics in snow and ice showed significant differences. Sea ice was especially important for the temporal storage, transport, and release of microplastics in the Arctic and Antarctic. Microplastics in land snow cover and mountain glaciers emphasized the importance of atmospheric transport in the transferal of microplastics to cryospheric regions. In particular, the non-polar cryospheric regions (e.g., Tibetan Plateau, Andes, or Alps) were highlighted as important receptors of mid-latitude emissions of microplastics, which might indicate a future climatic risk considering the ability of microplastics to absorb radiation and accelerate the melting of snow. Microplastics retrieved from mountain glacier ice cores may also provide new insights into the historical variations of anthropogenic pollutants. The potential impact of microplastics in snow and ice on the carbon cycle and the climatic risk needs to be further addressed in the future

Flowchart of the review search and identification.

<p>Flowchart of the review search and identification.</p

Methodological quality of the included MAs/SRs.

<p>Methodological quality of the included MAs/SRs.</p

Conclusions and the number of RCTs and patients included in each MA/SR and the AMSTAR score.

<p>Conclusions and the number of RCTs and patients included in each MA/SR and the AMSTAR score.</p

Enhanced Cell Survival of Gastric Cancer Cells By a Novel Gene URG4

Upregulated gene 4 (URG4), a novel gene located on 7 chromosome (7p13), was found to contribute to hepatocarcinogenesis. However, the role of URG4 in the gastric carcinogenesis still remains unclear. In the present study, URG4 was found by immunohistochemistry to be upregulated in human gastric cancer tissues compared with matched adjacent nonneoplastic tissues. The proliferating cell nuclear antigen index is higher in gastric cancer tissues with high URG4 expression than in those with low URG4 expression. The growth of GES-1 cells, which are immortalized human gastric epithelial mucosa cells with baseline URG4 expression, was accelerated by URG4 induction. Downregulation of URG4 through URG4 small interfering RNA (siRNA) in SGC7901 and MKN28 cells, which had high endogenous URG4 expression, suppressed cell proliferation in both of these cells. URG4-siRNA also inhibited the proliferation of SGC7901 and MKN28 cells in soft agar and tumor formation in nude mice. Overexpression of URG4 in GES cells upregulated cyclin D1, whereas repression of URG4 in SGC7901 and MKN28 cells downregulated cyclin D1. The data suggested that URG4 played an important role in the development of human gastric cancer by regulating the expression of cyclin D1 and might be used as a potential therapeutic target for gastric cancer

MiR-199a Regulates Cell Proliferation and Survival by Targeting FZD7

<div><p>A growing amount of evidence indicates that miRNAs are important regulators of multiple cellular processes and, when expressed aberrantly in different types of cancer such as hepatocellular carcinoma (HCC), play significant roles in tumorigenesis and progression. Aberrant expression of miR-199a-5p (also called miR-199a) was found to contribute to carcinogenesis in different types of cancer, including HCC. However, the precise molecular mechanism is not yet fully understood. The present study showed that miR-199a is frequently down-regulated in HCC tissues and cells. Importantly, lower expression of miR-199a was significantly correlated with the malignant potential and poor prognosis of HCC, and restoration of miR-199a in HCC cells led to inhibition of the cell proliferation and cell cycle <i>in vitro</i> and <i>in vivo</i>. Furthermore, Frizzled type 7 receptor (FZD7), the most important Wnt receptor involved in cancer development and progression, was identified as a functional target of miR-199a. In addition, these findings were further strengthened by results showing that expression of FZD7 was inversely correlated with miR-199a in both HCC tissues and cells and that over-expression of miR-199a could significantly down-regulate the expression of genes downstream of FZD7, including β-catenin, Jun, Cyclin D1 and Myc. In conclusion, these findings not only help us to better elucidate the molecular mechanisms of hepatocarcinogenesis from a fresh perspective but also provide a new theoretical basis to further investigate miR-199a as a potential biomarker and a promising approach for HCC treatment.</p></div