An enantioselective strategy for the synthesis of (+)-brazilin, (-)-brazilein and (+)-brazilide A has been developed. A Lewis acid mediated lactonization established the novel fused bis-lactone core of brazilide A and finalized the first total synthesis of (+)-brazilide A.
The effect of pastureland shelterbelt on aboveground productivity and underground biomass in Siziwang county,Inner Mongolia was studied.The results indicated that the average ratios of the dominant grass species above-ground productivity(Stipa krylovii and Leymus chinensis in 13 grassland plots) to total grassland above-ground productivity decreased orderly in leeward(62.4±5.7%),under forest(36.1%) and windward(28.0±7.4%).The order of average aboveground productivity for windward,cultivated forest land and leeward grasslands was: forest productivity(3873 kg/hm2,including under forest grassland and forest productivity) leeward grasslands(1769±177 kg/hm2)windward grasslands(1588±47 kg/hm2).With increasing distance from cultivated forest to the plots,the aboveground productivity of leeward grasslands increased with increasing the distance(R2=0.97,p0.001),however,the aboveground productivity of windward grasslands didn't show obvious relationship with the distance.The underground biomass was mostly distributed in the 10cm in depth from the earth's surface(about 86%).With increasing distance from cultivated forest to plots,the roots of grass tend to the soil surface.
This chapter presents an analysis of long-term trends of air temperature, precipitation, aridity, the interdecadal features and spatial variation of the main pastoral regions of China based on statistical data on annual temperature and precipitation from 173 meteorological stations from 1951 to 2004. It is established that over the past years, there is a distinct warming trend, with a definite shift to warmer temperatures in the late 1980s. The coldest period was in the 1960s, the warmest period in the middle/late 1990s and the warmest year was 1998. Annual precipitation varies significantly, with a general rising trend but with a relative shortage period of rain/snow in the 1960s/1970s and relatively ample rain/snow in the 1990s and early 21st century. The highest precipitation year was 2003. Finally, the impact of these climatic changes on people, livestock and plants is also analysed.
Cervical cancer has the second-highest incidence and mortality of female malignancy. The major causes of mortality in patients with cervical cancer are invasion and metastasis. The epithelial-mesenchymal transition (EMT) process plays a major role in the acquisition of metastatic potential and motility. Autophagy-related genes (ARGs) are implicated in the EMT process, and autophagy exerts a dual function in EMT management at different phases of tumor progression. However, the role of specific ARGs during the EMT process has not yet been reported in cervical cancer. Based on the data from the Cancer Genome Atlas (TCGA) cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) sequencing database, we performed the prognosis analysis for those ARGs obtained from the Human Autophagy database. ATG5 was identified as the only important harmful marker influencing survival of cervical cancer patients by univariate Cox regression (HR 1.7; 95% CI: 1.0-2.8, p = 0.047), and the 5-years survival rate for the high- and low-ATG5 expression groups was 0.486 (0.375-0.631) and 0.782 (0.708-0.863), respectively. TCGA CESC methylation data showed that eight methylation sites of ATG5 could also be significantly associated with the overall survival (OS) of cervical cancer patients. Single-sample gene-set enrichment and gene functional enrichment results showed that ATG5 was correlated with some cancer-related pathways, such as phagocytosis-related genes, endocytosis-related genes, immune-related genes, EMT score, and some EMT signature-related genes. Next, cell migration and invasion assay and Western blot were applied to detect the function of ATG5 in EMT of cervical cancer. In cervical cancer cells, ATG5 knockdown resulted in attenuation of migration and invasion. The functional study showed that knockdown of ATG5 could reverse EMT process by P-ERK, P-NFκBp65, P-mTOR pathways, and so on. In conclusion, the present study implies that ATG5 was a major contributor to EMT regulation and poor prognosis in cervical cancer.
Two 1,8-naphthyridine derivatives containing methylene, N-(5-methyl-7-((3-oxo-1,3-dihydroisobenzofuran-1-yl)methyl)-1,8-naphthyridin-2-yl)acetamide ( L1 ) and 2-amino-3-((7-amino-4-methyl-1,8-naphthyridin-2-yl)methyl)isoindolin-1-one ( L2 ), as well as a copper(I) complex CuI(L1) 2 ( C1 ) have been synthesized through a non-catalyst C( sp 3 )–H methylenation process and characterized. The structure of C1 has been determined by X-ray diffraction analysis. The spectroscopic properties have been investigated by experimental as well as theoretical studies for all these compounds. The two ligands exhibit similar electronic absorption spectra with λ max at about 340 nm, which can be tentatively assigned to π naph →π naph * transition. The electronic absorption spectra of C1 exhibits at ~335 nm except in n -hexane, which may be assigned tentatively to the intraligand charge transfer transition. The assignment is further supported by density functional theory calculations and cyclic voltammetry.
Human leukocyte antigen G (HLA-G) is a potential checkpoint molecule that plays a key role in cervical carcinogenesis. The purpose of this study was to construct and validate a prognostic risk model to predict the overall survival (OS) of cervical cancer patients, providing a reference for individualized clinical treatment that may lead to better clinical outcomes. HLA-G-driven differentially expressed genes (DEGs) were obtained from two cervical carcinoma cell lines, namely, SiHa and HeLa, with stable overexpression of HLA-G by RNA sequencing (RNA-seq). The biological functions of these HLA-G-driven DEGs were analysed by GO enrichment and KEGG pathway using the "clusterProfiler" package. The protein-protein interactions (PPIs) were assessed using the STRING database. The prognostic relevance of each DEG was evaluated by univariate Cox regression using the TCGA-CESC dataset. After the TCGA-CESC cohort was randomly divided into training set and testing set, and a prognostic risk model was constructed by LASSO and stepwise multivariate Cox regression analysis in training set and validated in testing set or in different types of cervical cancer set. The predictive ability of the prognostic risk model or nomogram was evaluated by a series of bioinformatics methods. A total of 1108 candidate HLA-G-driven DEGs, including 391 upregulated and 717 downregulated genes, were obtained and were enriched mostly in the ErbB pathway, steroid biosynthesis, and MAPK pathway. Then, an HLA-G-driven DEG signature consisting of the eight most important prognostic genes CD46, LGALS9, PGM1, SPRY4, CACNB3, PLIN2, MSMO1, and DAGLB was identified as a key predictor of cervical cancer. Multivariate Cox regression analysis showed that this signature is an independent risk factor for the overall survival of CESC patients. Kaplan-Meier survival analysis showed that the 5-year overall survival rate is 23.0% and 84.6% for the high-risk and low-risk patients, respectively (P<0.001). The receiver operating characteristic (ROC) curve of this prognostic model with an area under the curve (AUC) was 0.896 for 5 years, which was better than that of other clinical traits. This prognostic risk model was also successfully validated in different subtypes of cervical cancer, including the keratinizing squamous cell carcinoma, non-keratinizing squamous cell carcinoma, squamous cell neoplasms, non-squamous cell neoplasms set. Single-sample gene set enrichment (ssGSEA) algorithm and Tumor Immune Dysfunction and Exclusion (TIDE) analysis confirmed that this signature influence tumour microenvironment and immune checkpoint blockade. A nomogram that integrated risk score, age, clinical stage, histological grade, and pathological type was then built to predict the overall survival of CESC patients and evaluated by calibration curves, AUC, concordance index (C-index) and decision curve analysis (DCA). To summarize, we developed and validated a novel prognostic risk model for cervical cancer based on HLA-G-driven DEGs, and the prognostic signature showed great ability in predicting the overall survival of patients with cervical cancer.
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