Construction of Land Resource Security System for Core Grain Production Region in Henan Province

To solve the contradiction between supply and demand of land, the con- struction of land resource security guarantee system is an important part to coordi- nate the economic development and cultivated land protection in the core grain pro- duction region. Based on the deep analysis on the land resources characteristics and problems using the combined method of literature review method with qualita- tive and quantitative analysis, we constructed the land resource security system for different categories according to the land use principles of optimization, intensivism, improvement, and overall planning, and proposed the corresponding supporting mea- sures. The results showed that controlling the new increase, promoting the reclama- tion and improvement of land are the basis for land resource security, clearing the idle, improving the utilization rate of stock are the core of the efficient use of land resources, and establishing a unified urban and rural construction land market is the key to promoting the economical and intensive utilization of land resources, provid- ing scientific basis for the sustainable utilization of land resources in the core grain production regions.

Experimental investigation on pyrolysis products and pore structure characteristics of organic-rich shale heated by supercritical carbon dioxide

The efficient pyrolysis and conversion of organic matter in organic-rich shale,as well as the effective recovery of pyrolysis shale oil and gas,play a vital role in alleviating energy pressure.The state of carbon dioxide(CO_(2))in the pyrolysis environment of shale reservoirs is the supercritical state.Its unique supercritical fluid properties not only effectively heat organic matter,displace pyrolysis products and change shale pore structure,but also achieve carbon storage to a certain extent.Shale samples were made into powder and three sizes of cores,and nitrogen(N_(2))and supercritical carbon dioxide(ScCO_(2))pyrolysis experiments were performed at different final pyrolysis temperatures.The properties and mineral characteristics of the pyrolysis products were studied based on gas chromatography analysis,Xray diffraction tests,and mass spectrometry analysis.Besides,the pore structure characteristics at different regions of cores before and after pyrolysis were analyzed using N_(2) adsorption tests to clarify the impact of fracturing degree on the pyrolysis effect.The results indicate that the optimal pyrolysis temperature of Longkou shale is about 430℃.Compared with N_(2),the oil yield of ScCO_(2) pyrolysis is higher.The pyrolysis oil obtained by ScCO_(2) extraction has more intermediate fractions and higher relative molecular weight.The ScCO_(2) can effectively improve the pore diameter of shale and its effect is better than that of N_(2).The micropores are produced in shale after pyrolysis,and the macropores only are generated in ScCO_(2) pyrolysis environments with temperatures greater than 430℃.The pore structure has different development characteristics at different pyrolysis temperatures,which are mainly affected by the pressure holding of volatile matter and products blocking.Compared to the surface of the core,the pore development effect inside the core is better.With the decrease in core size,the pore diameter,specific surface area,and pore volume of cores all increase after pyrolysis.

Mutations in pre-core and basic core promoter regions of hepatitis B virus in chronic hepatitis B patients

AIM: To investigate the frequency of mutations in pre-core (pre-C) and basic core promoter (BCP) regions of hepatitis B virus (HBV) from Shanxi Province, and the association between mutations and disease related indexes.METHODS: One hundred chronic hepatitis B patients treated at Shanxi Province Hospital of Traditional Chinese Medicine were included in this study. PCR-reverse dot blot hybridization and mismatch amplification mutation assay (MAMA)-PCR were used to detect the mutations in the HBV pre-C and BCP regions. HBV DNA content and liver function were compared between patients with mutant HBV pre-C and BCP loci and those with wild-type loci. The consistency between PCR-reverse dot blot hybridization and MAMA-PCR for detecting mutations in the HBV pre-C and BCP regions was assessed.RESULTS: Of the 100 serum samples detected, 9.38% had single mutations in the pre-C region, 29.17% had single mutations in the BCP region, 41.67% had mutations in both BCP and pre-C regions, and 19.79% had wild-type loci. The rates of BCP and pre-C mutations were 65.7% and 34.3%, respectively, in hepatitis B e antigen (HBeAg) positive patients, and 84.6% and 96.2%, respectively, in HBeAg negative patients. The rate of pre-C mutations was significantly higher in HBeAg negative patients than in HBeAg positive patients (χ2 = 26.62, P = 0.00), but there was no significant difference in the distribution of mutations in the BCP region between HBeAg positive and negative patients (χ2 = 2.43, P = 0.12). The presence of mutations in the pre-C (Wilcoxon W = 1802.5, P = 0.00) and BCP regions (Wilcoxon W = 2906.5, P = 0.00) was more common in patients with low HBV DNA content. Both AST and GGT were significantly higher in patients with mutant pre-C and BCP loci than in those with wild-type loci (P < 0.05). PCR-reverse dot blot hybridization and MAMA-PCR for detection of mutations in the BCP and pre-C regions had good consistency, and the Kappa values obtained were 0.91 and 0.58, respectively.CONCLUSION: HBeAg negative patients tend to have HBV pre-C mutations. However, these mutations do not cause increased DNA copies, but associate with damage of liver function.

Mutations in hepatitis B virus core regions correlate with hepatocellular injury in Chinese patients with chronic hepatitis B

AIM: To elucidate the relationship between the frequency of core mutations and the clinical activity of hepatitis B virus (HBV)-related liver disease and to characterize the amino acid changes in the core region of HBV.METHODS: We studied 17 Chinese patients with chronic hepatitis B according to their clinical courses and patterns of the entire core region of HBV.RESULTS: Amino acid changes often appeared in the HBV core region of the HBV gene in patients with high values of alanine aminotransferase (ALT) or with the seroconversion from HbeAg to anti-HBe. The HBV core region with amino acid changes had high frequency sites that corresponded to HLA Ⅰ/Ⅱ restricted recognition epitopes reported by some investigators.CONCLUSION: The core amino acid changes of this study occur due to influence of host immune system. The presence of mutations in the HBV core region seems to be important for predicting the clinical activity of hepatitis B in Chinese patients.

Review on hepatitis B virus precore/core promoter mutations and their correlation with genotypes and liver disease severity

Of 350 million people worldwide are chronically infected with hepatitis B virus(HBV)and are at risk of developing cirrhosis and hepatocellular carcinoma(HCC)later in life.HBV is the most diverse DNA virus,and its genome is composed of four open reading frames:Presurface antigen/surface antigen gene(preS/S),precore/core gene(preC/C),polymerase gene(P),and theχgene(χ).HBV produces quasispecies naturally or in response to antiviral agents because of the absence of proofreading activity amid reverse transcription and a high replication rate.The virus has 10 genotypes(A to J)with different geographical distributions.There are various HBV mutations in the HBV genome,including preC/C mutations,preS/S mutations,P gene mutations,andχgene mutations.The core promoter region plays a vital part in the replication,morphogenesis and pathogenesis of the virus.The precore region also plays a crucial role in viral replication.Both core promoter and precore mutations rescue the virus from host immune surveillance and result in the formation of mutated strains that may have altered pathogenicity.preC/C mutations are associated with liver disease progression.Precore mutations stop hepatitis B e antigen(HBeAg)production and basal core promoter mutations downregulate HBeAg production.Mutations in the basal core promoter are also associated with increased HBV replication and an increased incidence of advanced liver diseases such as cirrhosis and HCC.The emergence of antiviral-resistant mutations is the main reason for treatment failure.This review focuses mainly on preC/C promoter mutations and their correlation with genotypes and liver disease severity.Thorough perception and knowledge of HBV genetic variety and mutants could be vital to discover techniques for the prognosis and control of HBV infection.

THE LABORATORY OF ICE CORE AND COLD REGIONS ENVIRONMENT

Affiliation unit: Lanzhou Institute of Glaciology and Cold Regions Environment, CAS Brief history: The Laboratory of Ice Core and Cold Regions Environment (LICCRE) was formally approved to open domestically and internationally by Chinese Academy of Sciences in April 1997. It is attached to the Lanzhou Institute of Glaciology and Geocryology, CAS.

Dissecting Psychiatric Heterogeneity and Comorbidity with Core Region-Based Machine Learning

Machine learning approaches are increasingly being applied to neuroimaging data from patients with psychiatric disorders to extract brain-based features for diagnosis and prognosis.The goal of this review is to discuss recent practices for evaluating machine learning applications to obsessive-compulsive and related disorders and to advance a novel strategy of building machine learning models based on a set of core brain regions for better performance,interpretability,and generalizability.Specifically,we argue that a core set of co-altered brain regions(namely‘core regions’)comprising areas central to the underlying psychopathology enables the efficient construction of a predictive model to identify distinct symptom dimensions/clusters in individual patients.Hypothesis-driven and data-driven approaches are further introduced showing how core regions are identified from the entire brain.We demonstrate a broadly applicable roadmap for leveraging this core set-based strategy to accelerate the pursuit of neuroimaging-based markers for diagnosis and prognosis in a variety of psychiatric disorders.

STRUCTURE IN THE PRECORE REGION OF HEPATITIS B CORE GENE AFFECTING ITS EXPRESSION IN E.coil

Restriction fragments of HBV-DNA, cleaved by endonuclease HhaI,containing HBcAg gene were trimmed by BAL-31 exonuclease to remove different lengths of the precore sequence.They were inserted into plasmid pUR222 at EcoRI site through synthetic linker ligation. Transformants in E.coli BMH7118 showing different levels of HBcAg gene expression were screened and analyzed for their nucleotide sequences in the junction region both by Maxam and Gilbert's chemical degradation method and by M13 chain termination method. Results of sequence analysis of different transformants revealed a partial palindromic (loop and stem) structure, at -7 to -35 nucleotide with regard to ATG of the HBcAg gene as position +1, which has dramatic effect on the level of expression of the inserted gene using the same promoter,SD sequence and identical N-terminus.The amount of HBcAg synthesized differed from 9% in the high expressing plasmid to less than 0.01% of the total cell proteins in the low expressing transformants.The findings were compared to results obtained by other workers in studies of HBcAg expression in procaryotes and their significance in the expression of eucaryotic genes in procaryotic cells were discussed.