Positive Darwinian selection is a driving force for the diversification of terpenoid biosynthesis in the genus Oryza

Background: Terpenoids constitute the largest class of secondary metabolites made by plants and display vast chemical diversity among and within species. Terpene synthases (TPSs) are the pivotal enzymes for terpenoid biosynthesis that create the basic carbon skeletons of this class. Functional divergence of paralogous and orthologous TPS genes is a major mechanism for the diversification of terpenoid biosynthesis. However, little is known about the evolutionary forces that have shaped the evolution of plant TPS genes leading to terpenoid diversity. Results: The orthologs of Oryza Terpene Synthase 1 (OryzaTPS1), a rice terpene synthase gene involved in indirect defense against insects in Oryza sativa, were cloned from six additional Oryza species. In vitro biochemical analysis showed that the enzymes encoded by these OryzaTPS1 genes functioned either as (E)-β-caryophyllene synthases (ECS), or (E)-β-caryophyllene & germacrene A synthases (EGS), or germacrene D & germacrene A synthases (DAS). Because the orthologs of OryzaTPS1 in maize and sorghum function as ECS, the ECS activity was inferred to be ancestral. Molecular evolutionary detected the signature of positive Darwinian selection in five codon substitutions in the evolution from ECS to DAS. Homology-based structure modeling and the biochemical analysis of laboratory-generated protein variants validated the contribution of the five positively selected sites to functional divergence of OryzaTPS1. The changes in the in vitro product spectra of OryzaTPS1 proteins also correlated closely to the changes in in vivoblends of volatile terpenes released from insect-damaged rice plants. Conclusions: In this study, we found that positive Darwinian selection is a driving force for the functional divergence of OryzaTPS1. This finding suggests that the diverged sesquiterpene blend produced by the Oryza species containing DASmay be adaptive, likely in the attraction of the natural enemies of insect herbivores

SIRT1 is a regulator of autophagy: Implications in gastric cancer progression and treatment

AbstractSilent mating type information regulation 1 (SIRT1) is implicated in tumorigenesis through its effect on autophagy. In gastric cancer (GC), SIRT1 is a marker for prognosis and is involved in cell invasion, proliferation, epithelial-mesenchymal transition (EMT) and drug resistance. Autophagy can function as a cell-survival mechanism or lead to cell death during the genesis and treatment of GC. This functionality is determined by factors including the stage of the tumor, cellular context and stress levels. Interestingly, SIRT1 can regulate autophagy through the deacetylation of autophagy-related genes (ATGs) and mediators of autophagy. Taken together, these findings support the need for continued research efforts to understand the mechanisms mediating the development of gastric cancer and unveil new strategies to eradicate this disease

Role of export industries on ozone pollution and its precursors in China

This study seeks to estimate how global supply chain relocates emissions of tropospheric ozone precursors and its impacts in shaping ozone formation. Here we show that goods produced in China for foreign markets lead to an increase of domestic non-methane volatile organic compounds (NMVOCs) emissions by 3.5 million tons in 2013; about 13% of the national total or, equivalent to half of emissions from European Union. Production for export increases concentration of NMVOCs (including some carcinogenic species) and peak ozone levels by 20–30% and 6–15% respectively, in the coastal areas. It contributes to an estimated 16,889 (3,839–30,663, 95% CI) premature deaths annually combining the effects of NMVOCs and ozone, but could be reduced by nearly 40% by closing the technology gap between China and EU. Export demand also alters the emission ratios between NMVOCs and nitrogen oxides and hence the ozone chemistry in the east and south coast

Estimation Study of the Residual Stress Redistribution in Crack Propagation Process Based on Hull - Rimmer Theory

The redistribution of residual stress appears with the propagation of internal crack or damage, which also has an influence on the fatigue life of structure. A prediction model of residual stress redistribution is raised based on the Hull - Rimmer theory. And the quantitative expression between crack length, initiation crack location, initial distribution of residual stress and redistribution stress is achieved. Then the residual stres of crack tip and the redistribution stress of three instances are predicted, which also compared with the test results. It can be found from the comparison that the prediction results are basically same with the test results. Therefore, the prediction model of residual stress redistribution based on Hull-Rimmer theory can be well used for the precise prediction of residual stress redistribution in the crack propagation process

Estimation Study of the Residual Stress Redistribution in Crack Propagation Process Based on Hull - Rimmer Theory

The redistribution of residual stress appears with the propagation of internal crack or damage, which also has an influence on the fatigue life of structure. A prediction model of residual stress redistribution is raised based on the Hull - Rimmer theory. And the quantitative expression between crack length, initiation crack location, initial distribution of residual stress and redistribution stress is achieved. Then the residual stres of crack tip and the redistribution stress of three instances are predicted, which also compared with the test results. It can be found from the comparison that the prediction results are basically same with the test results. Therefore, the prediction model of residual stress redistribution based on Hull-Rimmer theory can be well used for the precise prediction of residual stress redistribution in the crack propagation process

Segmentation of Brain Tissues from Magnetic Resonance Images Using Adaptively Regularized Kernel-Based Fuzzy C-Means Clustering

An adaptively regularized kernel-based fuzzy C-means clustering framework is proposed for segmentation of brain magnetic resonance images. The framework can be in the form of three algorithms for the local average grayscale being replaced by the grayscale of the average filter, median filter, and devised weighted images, respectively. The algorithms employ the heterogeneity of grayscales in the neighborhood and exploit this measure for local contextual information and replace the standard Euclidean distance with Gaussian radial basis kernel functions. The main advantages are adaptiveness to local context, enhanced robustness to preserve image details, independence of clustering parameters, and decreased computational costs. The algorithms have been validated against both synthetic and clinical magnetic resonance images with different types and levels of noises and compared with 6 recent soft clustering algorithms. Experimental results show that the proposed algorithms are superior in preserving image details and segmentation accuracy while maintaining a low computational complexity

Systematic analysis of safety profile for darunavir and its boosted agents using data mining in the FDA Adverse Event Reporting System database

Abstract This current investigation was aimed to generate signals for adverse events (AEs) of darunavir-containing agents by data mining using the US Food and Drug Administration Adverse Event Reporting System (FAERS). All AE reports for darunavir, darunavir/ritonavir, or darunavir/cobicistat between July 2006 and December 2019 were identified. The reporting Odds Ratio (ROR), proportional reporting ratio (PRR), and Bayesian confidence propagation neural network (BCPNN) were used to detect the risk signals. A suspicious signal was generated only if the results of the three algorithms were all positive. A total of 10,756 reports were identified commonly observed in hepatobiliary, endocrine, cardiovascular, musculoskeletal, gastrointestinal, metabolic, and nutrition system. 40 suspicious signals were generated, and therein 20 signals were not included in the label. Severe high signals (i.e. progressive extraocular muscle paralysis, acute pancreatitis, exfoliative dermatitis, acquired lipodystrophy and mitochondrial toxicity) were identified. In pregnant women, umbilical cord abnormality, fetal growth restriction, low birth weight, stillbirth, premature rupture of membranes, premature birth and spontaneous abortion showed positive signals. Darunavir and its boosted agents induced AEs in various organs/tissues, and were shown to be possibly associated with multiple adverse pregnant conditions. This study highlighted some novel and severe AEs of darunavir which need to be monitored prospectively

Environmental Controls to Soil Heavy Metal Pollution Vary at Multiple Scales in a Highly Urbanizing Region in Southern China

Natural and anthropogenic activities affect soil heavy metal pollution at different spatial scales. Quantifying the spatial variability of soil pollution and its driving forces at different scales is essential for pollution mitigation opportunities. This study applied a multivariate factorial kriging technique to investigate the spatial variability of soil heavy metal pollution and its relationship with environmental factors at multiple scales in a highly urbanized area of Guangzhou, South China. We collected 318 topsoil samples and used five types of environmental factors for the attribution analysis. By factorial kriging, we decomposed the total variance of soil pollution into a nugget effect, a short-range (3 km) variance and a long-range (12 km) variance. The distribution of patches with a high soil pollution level was scattered in the eastern and northwestern parts of the study domain at a short-range scale, while they were more clustered at a long-range scale. The correlations between the soil pollution and environmental factors were either enhanced or counteracted across the three distinct scales. The predictors of soil heavy metal pollution changed from the soil physiochemical properties to anthropogenic dominated factors with the studied scale increase. Our study results suggest that the soil physiochemical properties were a good proxy to soil pollution across the scales. Improving the soil physiochemical properties such as increasing the soil organic matter is essentially effective across scales while restoring vegetation around pollutant sources as a nature-based solution at a large scale would be beneficial for alleviating local soil pollution

RETRACTED: Haplotype diversity and phylogenetic characteristics for Guanzhong Han population from Northwest China via 38 Y‐STRs using Yfiler™ Platinum Amplification System

Abstract Background For better application in human forensic cases and population genetics research, it is imperative to investigate the genetic characteristics of Guanzhong Han population using enhanced Y‐chromosomal short tandem repeats (Y‐STR) detecting system with higher discriminating power than previous ones. Methods In this study, 38 Y‐STRs were profiled in 430 unrelated Chinese Han male individuals from Guanzhong region of Shaanxi Province, Northwest China, using the Yfiler™ Platinum PCR Amplification Kit. Haplotype frequencies and forensic parameters were calculated. Comprehensive population comparisons with geographically/ethnically different populations in China and other worldwide countries were performed. Results A total of 422 different haplotypes were observed with the overall haplotype diversity (HD), discriminatory power (DC) and haplotype match probability (HMP) were 0.9999, 0.9814, and 0.0024, respectively. Guanzhong Han showed genetically affinity with Han ethnicity from Shanxi and Henan provinces, while far distant from Tibetan populations. Conclusion This study offered a unique insight into Guanzhong Han population, the 38 Y‐STRs included in the the Yfiler™ Platinum system are highly polymorphic and informative and can be used for forensic practice and human genetic research