Effects of emergency/nonemergency cervical cerclage on the vaginal microbiome of pregnant women with cervical incompetence.

Background: Evaluation of the therapeutic effects of cerclage on preterm birth (PTB) caused by cervical incompetence remains challenging. The vaginal microbiome is associated with preterm births. Thus, this study aimed to analyse the vaginal microbiota of patients with cervical incompetence, explore the relationship between the composition of the vaginal microbiota before cervical cerclage and at term delivery, and assess the effect of cervical cerclage on the vaginal microbiota. Methods: Patients (n = 30) underwent cerclage performed by the same surgical team. Vaginal swabs were obtained pre-surgery and seven days post-surgery. A gestational age-matched cohort of healthy pregnant women (n = 20) (no particular abnormality during pregnancy, delivery at term) was used as the control group and sampled during a comparable pregnancy. All collected vaginal swabs were analysed by 16S rRNA gene sequencing. Results: When comparing the healthy control and cervical cerclage groups, the enriched microorganism in the healthy controls was G. Scardovia, and the enriched microorganism of the cerclage was G. Streptococcus. α diversity was significantly increased in patients who received cerclage with preterm delivery compared with those with full-term delivery, and the enriched microorganism was F. Enterococcus. A comparison before and after nonemergency cerclage suggested that the enriched microorganisms were G. Lactobacillus and F. Lactobacillaceae before surgery. After nonemergency cerclage, the enriched microorganisms were F. Enterobacteriaceae and C. Gammaproteobacteria. Vaginal microbiota diversity significantly increased, and the proportion of women with Lactobacillus spp.-depleted microbiomes increased after emergency cerclage. Significant differences in ß diversity were found between the groups. Before the emergency cerclage, the enriched microorganisms were G. Lactobacillus, O. Alteromonadales, and P. Firmicutes. After emergency cerclage, the enriched microorganisms were P. Actinobacteria, C. Actinobacteria, P. Proteobacteria, F. Bifidobacteriaceae, O. Bifidobacteriales, G. Gardnerella, and G. Veillonella. Conclusion: Cerclage (particularly emergency cerclage) may alter the vaginal microbiota by increasing microbiota diversity, decreasing vaginal Lactobacillus abundance, and increasing the abundance of pathogenic bacteria that are not conducive to pregnancy maintenance, thereby affecting surgical efficacy. Therefore, the role of the vaginal microbiome should be considered when developing treatment strategies for pregnant women with cervical incompetence. Clinical trial registration: https://www.chictr.org.cn, identifier ChiCTR2100046305.

Ancient Great Wall building materials reveal environmental changes associated with oases in northwestern China.

Plant materials used in the construction of segments and beacon towers of the ancient Great Wall in northwestern China contain untapped potential for revealing local paleoclimatic and environmental conditions. For the first time, we characterize the molecular preservation and stable carbon and nitrogen isotope compositions of AMS-dated common reeds (Phragmites) collected from ancient Great Wall fascines in today's Gansu and Xinjiang using a combination of chromatographic techniques and isotope analyses. Our molecular data, along with Scanning Electron Microscopy, demonstrate excellent preservation of these ancient reeds, which were harvested from nearby habitats during periods of significant expansion of Imperial China when climate conditions sustained sizeable oases in the region. Stable isotope data capture differential rates of environmental change along the eastern margin of the Tarim Basin since the Han Dynasty (170 BC), implying that significant surface-water hydrological changes occurred only after the Song Dynasty (1160 AD) due to regional climate change. This study reveals the wealth of environmental and climate information obtainable from these site-specific organic building materials and establishes the foundation for further applications of advanced molecular, biochemical, and isotopic technologies to study these common and widely-distributed organic archaeological materials.

The microRNA-210/Casp8ap2 Axis Alleviates Hypoxia-Induced Myocardial Injury by Regulating Apoptosis and Autophagy.

Coronary heart disease (CHD) is a serious condition comprising atherosclerosis-mediated ischaemic and hypoxic myocardial injury. This study aimed to investigate the mechanism of the miR-210/Casp8ap2 signalling pathway in hypoxic myocardial cells. mRNA and protein expression levels were determined by quantitative real-time PCR and western blotting, respectively. MTT was used to evaluate cell survival, and flow cytometry was used to assess apoptosis and the cell cycle distribution. The interaction between miR-210 and -Casp8ap2 was detected by dual-luciferase reporter assay. As a result, overexpression of miR-210 significantly inhibited apoptosis and reduced the proportion of cells in G1 phase. Moreover, miR-210 suppressed autophagy by upregulating p62 levels and reducing the LC3-II/I ratio in hypoxic cardiomyocytes. miR-210 regulated apoptosis and autophagy by directly targeting Casp8ap2. Furthermore, the expression levels of Casp8ap2, Cleaved caspase 8, Cleaved caspase 3and Beclin-1 were all decreased in response to miR-210. In short, our results suggest that miR-210 exerts anti-apoptotic and anti-autophagic effects in hypoxic cardiomyocytes, which alleviates myocardial injury in response to hypoxia.

800-kyr land temperature variations modulated by vegetation changes on Chinese Loess Plateau.

The complicity of long-term land surface temperature (LST) changes has been under investigated and less understood, hindering our understanding of the history and mechanism of terrestrial climate change. Here, we report the longest (800 thousand years) LSTs based on distributions of soil fossil bacterial glycerol dialkyl glycerol tetraethers preserved in well-dated loess-paleosol sequences at the center of the Chinese Loess Plateau. We have found a previously-unrecognized increasing early and prolonged warming pattern toward the northwestern plateau at the onset of the past seven deglaciations, corresponding to the decrease in vegetation coverage, suggesting underlying surface vegetation or lack of has played an important role in regulating LSTs, superimposed on the fundamental global glacial-interglacial changes. Our results support that LSTs in semi-humid and semi-arid regions with little vegetation will be more sensitive to the anticipated global temperature rise, while improving vegetation coverage would reduce LSTs and thus ecological impacts.

Carbon and hydrogen isotope fractionation under continuous light: implications for paleoenvironmental interpretations of the High Arctic during Paleogene warming.

The effect of low intensity continuous light, e.g., in the High Arctic summer, on plant carbon and hydrogen isotope fractionations is unknown. We conducted greenhouse experiments to test the impact of light quantity and duration on both carbon and hydrogen isotope compositions of three deciduous conifers whose fossil counterparts were components of Paleogene Arctic floras: Metasequoia glyptostroboides, Taxodium distichum, and Larix laricina. We found that plant leaf bulk carbon isotopic values of the examined species were 1.75-4.63 per thousand more negative under continuous light (CL) than under diurnal light (DL). Hydrogen isotope values of leaf n-alkanes under continuous light conditions revealed a D-enriched hydrogen isotope composition of up to 40 per thousand higher than in diurnal light conditions. The isotope offsets between the two light regimes is explained by a higher ratio of intercellular to atmospheric CO(2) concentration (C (i)/C (a)) and more water loss for plants under continuous light conditions during a 24-h transpiration cycle. Apparent hydrogen isotope fractionations between source water and individual lipids (epsilon(lipid-water)) range from -62 per thousand (Metasequoia C(27) and C(29)) to -87 per thousand (Larix C(29)) in leaves under continuous light. We applied these hydrogen fractionation factors to hydrogen isotope compositions of in situ n-alkanes from well-preserved Paleogene deciduous conifer fossils from the Arctic region to estimate the deltaD value in ancient precipitation. Precipitation in the summer growing season yielded a deltaD of -186 per thousand for late Paleocene, -157 per thousand for early middle Eocene, and -182 per thousand for late middle Eocene. We propose that high-latitude summer precipitation in this region was supplemented by moisture derived from regionally recycled transpiration of the polar forests that grew during the Paleogene warming.

Archaefructus--angiosperm precursor or specialized early angiosperm?

With molecular analyses indicating that angiosperms are not closely related to any other extant seed plant group, information from fossils might provide the only basis for reconstructing their origin. Therefore the description of a new Early Cretaceous angiosperm, Archaefructus, placed as the sister of all extant angiosperms, has created much debate and optimism. However, we question both the interpretation and the analysis of Archaefructus, concluding that it might be a crown-group angiosperm specialized for aquatic habit rather than a more primitive relative.