BACKGROUND Colonization with Helicobacter pylori(H.pylori)has a strong correlation with gastric cancer,and the virulence factor CagA is implicated in carcinogenesis.Studies have been conducted using medicinal plants w...BACKGROUND Colonization with Helicobacter pylori(H.pylori)has a strong correlation with gastric cancer,and the virulence factor CagA is implicated in carcinogenesis.Studies have been conducted using medicinal plants with the aim of eliminating the pathogen;however,the possibility of blocking H.pylori-induced cell differentiation to prevent the onset and/or progression of tumors has not been addressed.This type of study is expensive and time-consuming,requiring in vitro and/or in vivo tests,which can be solved using bioinformatics.Therefore,prospective computational analyses were conducted to assess the feasibility of interaction between phenolic compounds from medicinal plants and the CagA oncoprotein.AIM To perform a computational prospecting of the interactions between phenolic compounds from medicinal plants and the CagA oncoprotein of H.pylori.METHODS In this in silico study,the structures of the phenolic compounds(ligands)kaempferol,myricetin,quercetin,ponciretin(flavonoids),and chlorogenic acid(phenolic acid)were selected from the PubChem database.These phenolic compounds were chosen based on previous studies that suggested medicinal plants as non-drug treatments to eliminate H.pylori infection.The three-dimensional structure model of the CagA oncoprotein of H.pylori(receptor)was obtained through molecular modeling using computational tools from the I-Tasser platform,employing the threading methodology.The primary sequence of CagA was sourced from GenBank(BAK52797.1).A screening was conducted to identify binding sites in the structure of the CagA oncoprotein that could potentially interact with the ligands,utilizing the GRaSP online platform.Both the ligands and receptor were prepared for molecular docking using AutoDock Tools 4(ADT)software,and the simulations were carried out using a combination of ADT and AutoDock Vina v.1.2.0 software.Two sets of simulations were performed:One involving the central region of CagA with phenolic compounds,and another involving the carboxy-terminus region of CagA with phenolic compounds.The receptor-ligand complexes were then analyzed using PyMol and BIOVIA Discovery Studio software.RESULTS The structure model obtained for the CagA oncoprotein exhibited high quality(C-score=0.09)and was validated using parameters from the MolProbity platform.The GRaSP online platform identified 24 residues(phenylalanine and leucine)as potential binding sites on the CagA oncoprotein.Molecular docking simulations were conducted with the three-dimensional model of the CagA oncoprotein.No complexes were observed in the simulations between the carboxy-terminus region of CagA and the phenolic compounds;however,all phenolic compounds interacted with the central region of the oncoprotein.Phenolic compounds and CagA exhibited significant affinity energy(-7.9 to-9.1 kcal/mol):CagA/kaempferol formed 28 chemical bonds,CagA/myricetin formed 18 chemical bonds,CagA/quercetin formed 16 chemical bonds,CagA/ponciretin formed 13 chemical bonds,and CagA/chlorogenic acid formed 17 chemical bonds.Although none of the phenolic compounds directly bound to the amino acid residues of the K-Xn-R-X-R membrane binding motif,all of them bound to residues,mostly positively or negatively charged,located near this region.CONCLUSION In silico,the tested phenolic compounds formed stable complexes with CagA.Therefore,they could be tested in vitro and/or in vivo to validate the findings,and to assess interference in CagA/cellular target interactions and in the oncogenic differentiation of gastric cells.展开更多
While the region of western Guangxi-southeastern Yunan, China, is known and considered prospective for manganese deposits, carrying out prospectivity mapping in this region is challenging due to the diversity of geolo...While the region of western Guangxi-southeastern Yunan, China, is known and considered prospective for manganese deposits, carrying out prospectivity mapping in this region is challenging due to the diversity of geological factors, the complexity of geological process and the asymmetry of geo-information. In this work, the manganese potential mapping for further exploration targeting is implemented via spatial analysis and modal-adaptive prospectivity modeling. On the basis of targeting criteria developed by the mineral system approach, the spatial analysis is leveraged to extract the predictor variables to identify features of the geological process. Specifically, a metallogenic field analysis approach is proposed to extract metallogenic information that quantifies the regional impacts of the synsedimentary faults and sedimentary basins. In the integration of the extracted predictor variables, a modal-adaptive prospectivity model is built, which allows to adapt different data availability and geological process. The resulting prospective areas of high potential not only correspond to the areas of known manganese deposits but also provide a number of favorable targets in the region for future mineral exploration.展开更多
In this paper, the backdrop and significance of the research of germ-remaining rice whitener firstly were expatiated. Then, the study progress in China and overseas was summarized. Lastly, the research prospect of thi...In this paper, the backdrop and significance of the research of germ-remaining rice whitener firstly were expatiated. Then, the study progress in China and overseas was summarized. Lastly, the research prospect of this kind of whitener in China was analyzed. It is hoped that it can coach the design of germ-remaining rice whitener.展开更多
Application and promotion of biodegradable plastic film in modern agricultural production construction have become trend and direction of agricultural development.As important production material,biodegradable plastic...Application and promotion of biodegradable plastic film in modern agricultural production construction have become trend and direction of agricultural development.As important production material,biodegradable plastic film not only effectively changes agricultural production mode but also effectively decreases environmental pollution.Accompanied by degradation of new material,upgrading of optimizing process,and infiltration and blending of science and technology in new plastics industry,new biodegradable plastic films have been developed and popularized effectively and rapidly.In this paper,starting from development situation and prospect of degradable plastic film in China,natural-based biodegradable plastics,petroleum-based biodegradable plastics and biological-based biodegradable plastics are introduced in detail from basic material of plastics.The advantages and disadvantages of additive biodegradable film and fully biodegradable film are scientifically analyzed,and seasonal and periodic characteristics of biodegradable plastic film industry are elaborated.Moreover,disadvantages of biodegradable plastic film industry development are explored from technical barrier,brand and channel barriers,and talent barrier.Finally,development trend of biodegradable plastic film industry in China is predicted and analyzed scientifically.The research could provide guidance for the development of biodegradable plastic film industry in China ,research of biodegradable plastic film technology,and demonstration and extension of biodegradable plastic film application.展开更多
China is lack of bromine and potassium seriously.Oilfield brines is the headline goal of bromine and potassium resources exploration.Applicants grab 24oilfield brines samples from various wells of Ordovician
Background: The temporal relationship between hepatitis B virus (HBV) mutations and hepatocellular carcinoma (HCC) remains unclear. Methods: We conducted a meta-analysis including cohort and nested case-control ...Background: The temporal relationship between hepatitis B virus (HBV) mutations and hepatocellular carcinoma (HCC) remains unclear. Methods: We conducted a meta-analysis including cohort and nested case-control studies to prospectively examine the HCC risk associated with common variants of HBV in the PreS, Enhancer Ⅱ, basal core promoter (BCP) and precore regions. Pertinent studies were identified by searching PubMed, Web of Science and the Chinese Biological Medicine databases through to November 2014. Study-specific risk estimates were combined using fixed or random effects models depending on whether significant heterogeneity was detected. Results: Twenty prospective studies were identified, which included 8 cohort and 12 nested case-control studies. There was an increased risk of HCC associated with any PreS mutations with a pooled relative risk (RR) of 3.82 [95% confidence interval (CI): 2.59-5.61]. The pooled-RR for PreS deletion was 3.98 (95% CI: 2.28-6.95), which was higher than that of PreS2 start codon mutation (pooled-RR=2.63, 95% CI: 1.30-5.34). C1653T in Enhancer Ⅱ was significantly associated with HCC risk (pooled-RR=l.83; 95% CI: 1.21-2.76). For mutations in BCP, statistically significant pooled-RRs of HCC were obtained for T1753V (pooled- RR=2.09; 95% CI: 1.49-2.94) and AI762T/G1764A double mutations (pooled-RR=3.11; 95% CI: 2.08- 4.64). No statistically significant association with HCC risk was observed for G1896A in the precore region (pooled-RR=0.77; 95% CI: 0.47-1.26). Conclusions: This study demonstrated that PreS mutations, C1653T, T1753V, and A1762T/G1764A, were associated with an increased risk of HCC. Clinical practices concerning the HCC risk prediction and diagnosis may wish to focus on patients with these mutations.展开更多
The discovery of Gonghe County Haergeng tungsten polymetallic deposit is one of the most important tungsten deposits discovered in Qinghai Province in recent years.It has important theoretical and practicalsignificanc...The discovery of Gonghe County Haergeng tungsten polymetallic deposit is one of the most important tungsten deposits discovered in Qinghai Province in recent years.It has important theoretical and practicalsignificance.1 Regional geological background The research area lies in the northwest edge of展开更多
By combing 20 documents of the Central Committee on the historical evolution of rural development policies since 1982, we hold that historical evolution has undergone reforms, adjustments, modernization developments a...By combing 20 documents of the Central Committee on the historical evolution of rural development policies since 1982, we hold that historical evolution has undergone reforms, adjustments, modernization developments and new ideas, and the path of reform experienced economic recovery, industrial nurturing agriculture, agriculture modernization and rural revitalization. The study found that: farmers' income has always been the focus of attention; agricultural production has shifted from total demand to green ecology; urban and rural resource elements are not well-organized, resulting in internal contradictions. The implementation of the rural revitalization strategy is an important measure to fundamentally solve the rural development problems in the new era.展开更多
Owing to the far-reaching environmental consequences of agriculture and food systems,such as their contribution to climate change,there is an urgent need to reduce their impact.International and national governments s...Owing to the far-reaching environmental consequences of agriculture and food systems,such as their contribution to climate change,there is an urgent need to reduce their impact.International and national governments set sustainability targets and implement corresponding measures.Nevertheless,critics of the globalized system claim that a territorial administrative scale is better suited to address sustainability issues.Yet,at the subnational level,local authorities rarely apply a systemic environmental assessment to enhance their action plans.This paper employs a territorial life cycle assessment methodology to improve local environmental agri-food planning.The objective is to identify significant direct and indirect environmental hotspots,their origins,and formulate effective mitigation strategies.The methodology is applied to the administrative department of Finistere,a strategic agricultural region in North-Western France.Multiple environmental criteria including climate change,fossil resource scarcity,toxicity,and land use are modeled.The findings reveal that the primary environmental hotspots of the studied local food system arise from indirect sources,such as livestock feed or diesel consumption.Livestock reduction and organic farming conversion emerge as the most environmentally efficient strategies,resulting in a 25%decrease in the climate change indicator.However,the overall modeled impact reduction is insufficient following national objectives and remains limited for the land use indicator.These results highlight the innovative application of life cycle assessment led at a local level,offering insights for the further advancement of systematic and prospective local agri-food assessment.Additionally,they provide guidance for local authorities to enhance the sustainability of planning strategies.展开更多
背景:非编码RNA作为一类不编码蛋白质的RNA分子,在细胞调控中发挥关键作用。同时,间充质干细胞具有多向分化潜能,对组织修复和再生至关重要。近年来,研究者们对非编码RNA在调控间充质干细胞功能中的作用展开了深入探讨。目的:通过文献...背景:非编码RNA作为一类不编码蛋白质的RNA分子,在细胞调控中发挥关键作用。同时,间充质干细胞具有多向分化潜能,对组织修复和再生至关重要。近年来,研究者们对非编码RNA在调控间充质干细胞功能中的作用展开了深入探讨。目的:通过文献计量学分析方法系统地了解非编码RNA与间充质干细胞相关研究的发展趋势与关键领域。方法:从Web of Science核心合集1990年至今的科学引文索引扩展获取非编码RNA与间充质干细胞相关研究的文献数据,运用VOSviewer和Cite Space计量学软件对年份、国家或地区、研究机构、被引文献和关键词进行发文量、聚类、被引频次、突增性和中介中心性进行分析,揭示该研究领域的知识基础及前沿热点。结果与结论:(1)最终纳入5348篇文献,发表在1997-2021年,相关文献呈现明显的增长趋势,尽管在2022年略有减少,其发文量仍保持较高水平,中国在该领域的研究中占据主导地位,其中上海交通大学为最活跃的机构。(2)对被引文献分析发现,高突增性、高中介中心性、高被引的文献主要与微小RNA、细胞外囊泡和骨代谢等内容相关,这些文献构成了非编码RNA与间充质干细胞研究领域的重要知识基础。(3)对关键词进行突增性分析发现,至今保持高突增性的关键词包括外泌体、环状RNA、细胞外囊泡和损伤。(4)对关键词进行聚类演变分析,发文量仍保持增长趋势的关键词聚类包括:肿瘤微环境、骨关节炎、氧化应激和细胞外囊泡,这些关键词反映了目前以及未来该领域的研究热点。(5)文章结果不仅展示了非编码RNA与间充质干细胞研究领域的研究态势,更重要的是有望为研究人员提供潜在的方向和启示。展开更多
China was formed by amalgamation of several small continental blocks (cratons), micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its ow...China was formed by amalgamation of several small continental blocks (cratons), micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its own specific characteristics; therefore the tectonic environments of China's marine and continental saline basins and salt, and potash, forming environment have some specific characteristics: multiple phases of salt formation, difference in salt, forming ages, migration and concentration of salt, forming processes and diversity of component materials, as well as small sizes of marine saline basins and great changes of saline basins in the late stage and occurrence of abundant liquid mineral resources. The nature of the tectonic basement exerted a key controlling effect on the formation of potash basins. The stable tectonic region was favorable for potash concentration in a quasi, stable region, and quasi, and the quasi-stable region was favorable for salt concentration and potash formation in a local stable tectonic region. Most China's major ancient saline basins occur in "quasi, cratons (continental block)"; especially all the marine saline basins occur in continental blocks with the Precambrian basement. These regions are the key ones for potash search. Most relatively large, scale soluble salt deposits are developed in relatively stable continental nuclei. According to the characteristics of the tectonic domains where China's salt, forming basins are located, the North China, Yangtze and Tarim, Qaidam salt minerogenetic domains and the northern Qiangtang, western Yunnan salt minerogenetic belt may be distinguished. Their salt and potash prospects will be discussed separately.展开更多
Landsat 8 Oli,ASTER,and Sentinel 2A satellite images processing was used to map geological formations,lineaments and hydrothermal alteration minerals in the Aouli inlier,as a case study to illustrate the application o...Landsat 8 Oli,ASTER,and Sentinel 2A satellite images processing was used to map geological formations,lineaments and hydrothermal alteration minerals in the Aouli inlier,as a case study to illustrate the application of digital images processing and Geographic Information System(GIS)in geological mapping and mining prospecting.Principal Component Analysis(PCA)applied to the Landsat images allowed good lithological discrimination and contributed to the updating of available geological maps.The Automatic lineament extraction from Sentinel images revealed the main tectonic structures affecting Aouli inlier.The ratio bands(b5+b7)/b6 and the false color composite(b4/b6,b2/b1,b3/b2)allowed the hydrothermal alteration minerals mapping from Aster images.Combined with available geological data and field observations,the satellite derived data were integrated and analyzed in a GIS software to establish mining prospecting guides.The results showed that the anomaly zones are intimately linked to NNE-SSW and NW-SE oriented faults and to highly fractured areas developing argillic and Fe rich alterations.Verified via field survey,this approach was successfully applied to the Aouli inlier to rapidly target potential areas to be explored in the tactical phase.This provides a model for future prospecting efforts for similar mineral deposits in other areas.展开更多
With deep mining of coal mines, prospecting multilayer water-filled goaf has become a new content that results from geophysical exploration in coalfields. The central loop transient electromagnetic (TEM) method is f...With deep mining of coal mines, prospecting multilayer water-filled goaf has become a new content that results from geophysical exploration in coalfields. The central loop transient electromagnetic (TEM) method is favorable for prospecting conductive layers because of the coupling relationship between its field structure and formation. However, the shielding effect of conductive overburden would not only require a longer observation time when prospecting the same depth but also weaken the anomalous response of underlying layers. Through direct time domain numerical simulation and horizontal layered earth forward modeling, this paper estimates the length of observation time required to prospect the target, and the distinguishable criterion of multilayer water-filled goal is presented with observation error according to the effect of noise on observation data. The observed emf curves from Dazigou Coal Mine, Shanxi Province can distinguish multilayer water-filled goaf. In quantitative inversion interpretation of observed curves, using electric logging data as initial parameters restrains the equivalence caused by coal formation thin layers. The deduced three-layer and two-layer water-filled goals are confirmed by the drilling hole. The result suggests that when observation time is long enough and with the anomalous situation of underlying layers being greater than the observation error, the use of the central loop TEM method to orosoect a multilaver water-filled goaf is feasible.展开更多
The Varzaghan district at the northwestern margin of the Urumieh–Dokhtar magmatic arc, is considered a promising area for the exploration of porphyry Cu deposits in Iran. In this study we identified mono-and multi-el...The Varzaghan district at the northwestern margin of the Urumieh–Dokhtar magmatic arc, is considered a promising area for the exploration of porphyry Cu deposits in Iran. In this study we identified mono-and multi-element geochemical anomalies associated with Cu–Au–Mo–Bi mineralization in the central parts of the Varzaghan district by applying the concentration–area fractal method. After mono-element geochemical investigations, principal component analysis was applied to ten selected elements in order to acquire a multi-element geochemical signature based on the mineralization-related component. Quantitative comparisons of the obtained fractal-based populations were carried out in accordance with known Cu occurrences using Student's t-values. Then,significant mono-and multi-element geochemical layers were separately combined with related geologic and structural layers to generate prospectivity models, using the fuzzy GAMMA approach. For quantitative evaluation of the effectiveness of different geochemical signatures in final prospectivity models, a prediction-area plot was adapted. The results show that the multi-element geochemical signature of principal component one(PC1) is more effective than mono-element layers in delimiting exploration targets related to porphyry Cu deposits.展开更多
An increasing number of tunnels are being constructed with tunnel-boring machines (TBMs) due to the increased efficiency and shorter completion time resulting from their use. However, when a TBM encoun- ters adverse...An increasing number of tunnels are being constructed with tunnel-boring machines (TBMs) due to the increased efficiency and shorter completion time resulting from their use. However, when a TBM encoun- ters adverse geological conditions in the course of tunnel construction (e.g., karst caves, faults, or frac- tured zones), disasters such as water and mud inrush, collapse, or machine blockage may result, and may severely imperil construction safety. Therefore, the advance detection of adverse geology and water-bearing conditions in front of the tunnel face is of great importance. This paper uses the TBM tun- neling of the water conveyance project from Songhua River as a case study in order to propose a compre- hensive forward geological prospecting technical system that is suitable for TBM tunnel construction under complicated geological conditions. By combining geological analysis with forward geological prospecting using a three-dimensional (3D) induced polarization method and a 3D seismic method, a comprehensive forward geological prospecting technical system can accurately forecast water inrush geo-hazards or faults in front of the TBM tunnel face. In this way, disasters such as water and mud inrush, collapse, or machine blockage can be avoided. This prospecting technical system also has reference value for carrying out the forward prospecting of adverse geology for potential TBM tunneling and for ensuring that a TBM can work efficiently.展开更多
文摘BACKGROUND Colonization with Helicobacter pylori(H.pylori)has a strong correlation with gastric cancer,and the virulence factor CagA is implicated in carcinogenesis.Studies have been conducted using medicinal plants with the aim of eliminating the pathogen;however,the possibility of blocking H.pylori-induced cell differentiation to prevent the onset and/or progression of tumors has not been addressed.This type of study is expensive and time-consuming,requiring in vitro and/or in vivo tests,which can be solved using bioinformatics.Therefore,prospective computational analyses were conducted to assess the feasibility of interaction between phenolic compounds from medicinal plants and the CagA oncoprotein.AIM To perform a computational prospecting of the interactions between phenolic compounds from medicinal plants and the CagA oncoprotein of H.pylori.METHODS In this in silico study,the structures of the phenolic compounds(ligands)kaempferol,myricetin,quercetin,ponciretin(flavonoids),and chlorogenic acid(phenolic acid)were selected from the PubChem database.These phenolic compounds were chosen based on previous studies that suggested medicinal plants as non-drug treatments to eliminate H.pylori infection.The three-dimensional structure model of the CagA oncoprotein of H.pylori(receptor)was obtained through molecular modeling using computational tools from the I-Tasser platform,employing the threading methodology.The primary sequence of CagA was sourced from GenBank(BAK52797.1).A screening was conducted to identify binding sites in the structure of the CagA oncoprotein that could potentially interact with the ligands,utilizing the GRaSP online platform.Both the ligands and receptor were prepared for molecular docking using AutoDock Tools 4(ADT)software,and the simulations were carried out using a combination of ADT and AutoDock Vina v.1.2.0 software.Two sets of simulations were performed:One involving the central region of CagA with phenolic compounds,and another involving the carboxy-terminus region of CagA with phenolic compounds.The receptor-ligand complexes were then analyzed using PyMol and BIOVIA Discovery Studio software.RESULTS The structure model obtained for the CagA oncoprotein exhibited high quality(C-score=0.09)and was validated using parameters from the MolProbity platform.The GRaSP online platform identified 24 residues(phenylalanine and leucine)as potential binding sites on the CagA oncoprotein.Molecular docking simulations were conducted with the three-dimensional model of the CagA oncoprotein.No complexes were observed in the simulations between the carboxy-terminus region of CagA and the phenolic compounds;however,all phenolic compounds interacted with the central region of the oncoprotein.Phenolic compounds and CagA exhibited significant affinity energy(-7.9 to-9.1 kcal/mol):CagA/kaempferol formed 28 chemical bonds,CagA/myricetin formed 18 chemical bonds,CagA/quercetin formed 16 chemical bonds,CagA/ponciretin formed 13 chemical bonds,and CagA/chlorogenic acid formed 17 chemical bonds.Although none of the phenolic compounds directly bound to the amino acid residues of the K-Xn-R-X-R membrane binding motif,all of them bound to residues,mostly positively or negatively charged,located near this region.CONCLUSION In silico,the tested phenolic compounds formed stable complexes with CagA.Therefore,they could be tested in vitro and/or in vivo to validate the findings,and to assess interference in CagA/cellular target interactions and in the oncogenic differentiation of gastric cells.
基金Project(2017YFC0601503)supported by the National Key R&D Program of ChinaProjects(41772349,41972309,41472301,41772348)supported by the National Natural Science Foundation of China。
文摘While the region of western Guangxi-southeastern Yunan, China, is known and considered prospective for manganese deposits, carrying out prospectivity mapping in this region is challenging due to the diversity of geological factors, the complexity of geological process and the asymmetry of geo-information. In this work, the manganese potential mapping for further exploration targeting is implemented via spatial analysis and modal-adaptive prospectivity modeling. On the basis of targeting criteria developed by the mineral system approach, the spatial analysis is leveraged to extract the predictor variables to identify features of the geological process. Specifically, a metallogenic field analysis approach is proposed to extract metallogenic information that quantifies the regional impacts of the synsedimentary faults and sedimentary basins. In the integration of the extracted predictor variables, a modal-adaptive prospectivity model is built, which allows to adapt different data availability and geological process. The resulting prospective areas of high potential not only correspond to the areas of known manganese deposits but also provide a number of favorable targets in the region for future mineral exploration.
文摘In this paper, the backdrop and significance of the research of germ-remaining rice whitener firstly were expatiated. Then, the study progress in China and overseas was summarized. Lastly, the research prospect of this kind of whitener in China was analyzed. It is hoped that it can coach the design of germ-remaining rice whitener.
基金Supported by Project from Science and Technology Department of Tibet Autonomous Region[XZ2018ZR G-59(Z)]Project of "Young Scholars in Western China" of Chinese Academy of Sciences——"Assessment on Effects of Environmental-friendly Plastic Film Covering on Growth Indicators of Major Crops and Environment in Tibet at High-altitude Region"
文摘Application and promotion of biodegradable plastic film in modern agricultural production construction have become trend and direction of agricultural development.As important production material,biodegradable plastic film not only effectively changes agricultural production mode but also effectively decreases environmental pollution.Accompanied by degradation of new material,upgrading of optimizing process,and infiltration and blending of science and technology in new plastics industry,new biodegradable plastic films have been developed and popularized effectively and rapidly.In this paper,starting from development situation and prospect of degradable plastic film in China,natural-based biodegradable plastics,petroleum-based biodegradable plastics and biological-based biodegradable plastics are introduced in detail from basic material of plastics.The advantages and disadvantages of additive biodegradable film and fully biodegradable film are scientifically analyzed,and seasonal and periodic characteristics of biodegradable plastic film industry are elaborated.Moreover,disadvantages of biodegradable plastic film industry development are explored from technical barrier,brand and channel barriers,and talent barrier.Finally,development trend of biodegradable plastic film industry in China is predicted and analyzed scientifically.The research could provide guidance for the development of biodegradable plastic film industry in China ,research of biodegradable plastic film technology,and demonstration and extension of biodegradable plastic film application.
基金supported by Geological survey project (Project Number: 12120113078500)
文摘China is lack of bromine and potassium seriously.Oilfield brines is the headline goal of bromine and potassium resources exploration.Applicants grab 24oilfield brines samples from various wells of Ordovician
基金supported by the fund of the National Key Basic Research Program "973 project" (2015CB554000)grants from the State Key Project Specialized for Infectious Diseases of China(2008ZX10002015 and 2012ZX10002008-002)
文摘Background: The temporal relationship between hepatitis B virus (HBV) mutations and hepatocellular carcinoma (HCC) remains unclear. Methods: We conducted a meta-analysis including cohort and nested case-control studies to prospectively examine the HCC risk associated with common variants of HBV in the PreS, Enhancer Ⅱ, basal core promoter (BCP) and precore regions. Pertinent studies were identified by searching PubMed, Web of Science and the Chinese Biological Medicine databases through to November 2014. Study-specific risk estimates were combined using fixed or random effects models depending on whether significant heterogeneity was detected. Results: Twenty prospective studies were identified, which included 8 cohort and 12 nested case-control studies. There was an increased risk of HCC associated with any PreS mutations with a pooled relative risk (RR) of 3.82 [95% confidence interval (CI): 2.59-5.61]. The pooled-RR for PreS deletion was 3.98 (95% CI: 2.28-6.95), which was higher than that of PreS2 start codon mutation (pooled-RR=2.63, 95% CI: 1.30-5.34). C1653T in Enhancer Ⅱ was significantly associated with HCC risk (pooled-RR=l.83; 95% CI: 1.21-2.76). For mutations in BCP, statistically significant pooled-RRs of HCC were obtained for T1753V (pooled- RR=2.09; 95% CI: 1.49-2.94) and AI762T/G1764A double mutations (pooled-RR=3.11; 95% CI: 2.08- 4.64). No statistically significant association with HCC risk was observed for G1896A in the precore region (pooled-RR=0.77; 95% CI: 0.47-1.26). Conclusions: This study demonstrated that PreS mutations, C1653T, T1753V, and A1762T/G1764A, were associated with an increased risk of HCC. Clinical practices concerning the HCC risk prediction and diagnosis may wish to focus on patients with these mutations.
文摘The discovery of Gonghe County Haergeng tungsten polymetallic deposit is one of the most important tungsten deposits discovered in Qinghai Province in recent years.It has important theoretical and practicalsignificance.1 Regional geological background The research area lies in the northwest edge of
文摘By combing 20 documents of the Central Committee on the historical evolution of rural development policies since 1982, we hold that historical evolution has undergone reforms, adjustments, modernization developments and new ideas, and the path of reform experienced economic recovery, industrial nurturing agriculture, agriculture modernization and rural revitalization. The study found that: farmers' income has always been the focus of attention; agricultural production has shifted from total demand to green ecology; urban and rural resource elements are not well-organized, resulting in internal contradictions. The implementation of the rural revitalization strategy is an important measure to fundamentally solve the rural development problems in the new era.
文摘Owing to the far-reaching environmental consequences of agriculture and food systems,such as their contribution to climate change,there is an urgent need to reduce their impact.International and national governments set sustainability targets and implement corresponding measures.Nevertheless,critics of the globalized system claim that a territorial administrative scale is better suited to address sustainability issues.Yet,at the subnational level,local authorities rarely apply a systemic environmental assessment to enhance their action plans.This paper employs a territorial life cycle assessment methodology to improve local environmental agri-food planning.The objective is to identify significant direct and indirect environmental hotspots,their origins,and formulate effective mitigation strategies.The methodology is applied to the administrative department of Finistere,a strategic agricultural region in North-Western France.Multiple environmental criteria including climate change,fossil resource scarcity,toxicity,and land use are modeled.The findings reveal that the primary environmental hotspots of the studied local food system arise from indirect sources,such as livestock feed or diesel consumption.Livestock reduction and organic farming conversion emerge as the most environmentally efficient strategies,resulting in a 25%decrease in the climate change indicator.However,the overall modeled impact reduction is insufficient following national objectives and remains limited for the land use indicator.These results highlight the innovative application of life cycle assessment led at a local level,offering insights for the further advancement of systematic and prospective local agri-food assessment.Additionally,they provide guidance for local authorities to enhance the sustainability of planning strategies.
文摘背景:非编码RNA作为一类不编码蛋白质的RNA分子,在细胞调控中发挥关键作用。同时,间充质干细胞具有多向分化潜能,对组织修复和再生至关重要。近年来,研究者们对非编码RNA在调控间充质干细胞功能中的作用展开了深入探讨。目的:通过文献计量学分析方法系统地了解非编码RNA与间充质干细胞相关研究的发展趋势与关键领域。方法:从Web of Science核心合集1990年至今的科学引文索引扩展获取非编码RNA与间充质干细胞相关研究的文献数据,运用VOSviewer和Cite Space计量学软件对年份、国家或地区、研究机构、被引文献和关键词进行发文量、聚类、被引频次、突增性和中介中心性进行分析,揭示该研究领域的知识基础及前沿热点。结果与结论:(1)最终纳入5348篇文献,发表在1997-2021年,相关文献呈现明显的增长趋势,尽管在2022年略有减少,其发文量仍保持较高水平,中国在该领域的研究中占据主导地位,其中上海交通大学为最活跃的机构。(2)对被引文献分析发现,高突增性、高中介中心性、高被引的文献主要与微小RNA、细胞外囊泡和骨代谢等内容相关,这些文献构成了非编码RNA与间充质干细胞研究领域的重要知识基础。(3)对关键词进行突增性分析发现,至今保持高突增性的关键词包括外泌体、环状RNA、细胞外囊泡和损伤。(4)对关键词进行聚类演变分析,发文量仍保持增长趋势的关键词聚类包括:肿瘤微环境、骨关节炎、氧化应激和细胞外囊泡,这些关键词反映了目前以及未来该领域的研究热点。(5)文章结果不仅展示了非编码RNA与间充质干细胞研究领域的研究态势,更重要的是有望为研究人员提供潜在的方向和启示。
基金supported by projects of China Geological Survey(grants 1212010918025 and 1212010011810)National Natural Science Foundation of China and joint foundation(grants 40531002 and U0833601)
文摘China was formed by amalgamation of several small continental blocks (cratons), micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its own specific characteristics; therefore the tectonic environments of China's marine and continental saline basins and salt, and potash, forming environment have some specific characteristics: multiple phases of salt formation, difference in salt, forming ages, migration and concentration of salt, forming processes and diversity of component materials, as well as small sizes of marine saline basins and great changes of saline basins in the late stage and occurrence of abundant liquid mineral resources. The nature of the tectonic basement exerted a key controlling effect on the formation of potash basins. The stable tectonic region was favorable for potash concentration in a quasi, stable region, and quasi, and the quasi-stable region was favorable for salt concentration and potash formation in a local stable tectonic region. Most China's major ancient saline basins occur in "quasi, cratons (continental block)"; especially all the marine saline basins occur in continental blocks with the Precambrian basement. These regions are the key ones for potash search. Most relatively large, scale soluble salt deposits are developed in relatively stable continental nuclei. According to the characteristics of the tectonic domains where China's salt, forming basins are located, the North China, Yangtze and Tarim, Qaidam salt minerogenetic domains and the northern Qiangtang, western Yunnan salt minerogenetic belt may be distinguished. Their salt and potash prospects will be discussed separately.
文摘Landsat 8 Oli,ASTER,and Sentinel 2A satellite images processing was used to map geological formations,lineaments and hydrothermal alteration minerals in the Aouli inlier,as a case study to illustrate the application of digital images processing and Geographic Information System(GIS)in geological mapping and mining prospecting.Principal Component Analysis(PCA)applied to the Landsat images allowed good lithological discrimination and contributed to the updating of available geological maps.The Automatic lineament extraction from Sentinel images revealed the main tectonic structures affecting Aouli inlier.The ratio bands(b5+b7)/b6 and the false color composite(b4/b6,b2/b1,b3/b2)allowed the hydrothermal alteration minerals mapping from Aster images.Combined with available geological data and field observations,the satellite derived data were integrated and analyzed in a GIS software to establish mining prospecting guides.The results showed that the anomaly zones are intimately linked to NNE-SSW and NW-SE oriented faults and to highly fractured areas developing argillic and Fe rich alterations.Verified via field survey,this approach was successfully applied to the Aouli inlier to rapidly target potential areas to be explored in the tactical phase.This provides a model for future prospecting efforts for similar mineral deposits in other areas.
基金supported by the National Science Foundation of China(No.41374129)Science and Technology Project of Shanxi Province(No.20100321066)Research and Development Project of National Major Scientifi c Research Equipment(No.ZDYZ2012-1-05-04)
文摘With deep mining of coal mines, prospecting multilayer water-filled goaf has become a new content that results from geophysical exploration in coalfields. The central loop transient electromagnetic (TEM) method is favorable for prospecting conductive layers because of the coupling relationship between its field structure and formation. However, the shielding effect of conductive overburden would not only require a longer observation time when prospecting the same depth but also weaken the anomalous response of underlying layers. Through direct time domain numerical simulation and horizontal layered earth forward modeling, this paper estimates the length of observation time required to prospect the target, and the distinguishable criterion of multilayer water-filled goal is presented with observation error according to the effect of noise on observation data. The observed emf curves from Dazigou Coal Mine, Shanxi Province can distinguish multilayer water-filled goaf. In quantitative inversion interpretation of observed curves, using electric logging data as initial parameters restrains the equivalence caused by coal formation thin layers. The deduced three-layer and two-layer water-filled goals are confirmed by the drilling hole. The result suggests that when observation time is long enough and with the anomalous situation of underlying layers being greater than the observation error, the use of the central loop TEM method to orosoect a multilaver water-filled goaf is feasible.
文摘The Varzaghan district at the northwestern margin of the Urumieh–Dokhtar magmatic arc, is considered a promising area for the exploration of porphyry Cu deposits in Iran. In this study we identified mono-and multi-element geochemical anomalies associated with Cu–Au–Mo–Bi mineralization in the central parts of the Varzaghan district by applying the concentration–area fractal method. After mono-element geochemical investigations, principal component analysis was applied to ten selected elements in order to acquire a multi-element geochemical signature based on the mineralization-related component. Quantitative comparisons of the obtained fractal-based populations were carried out in accordance with known Cu occurrences using Student's t-values. Then,significant mono-and multi-element geochemical layers were separately combined with related geologic and structural layers to generate prospectivity models, using the fuzzy GAMMA approach. For quantitative evaluation of the effectiveness of different geochemical signatures in final prospectivity models, a prediction-area plot was adapted. The results show that the multi-element geochemical signature of principal component one(PC1) is more effective than mono-element layers in delimiting exploration targets related to porphyry Cu deposits.
文摘An increasing number of tunnels are being constructed with tunnel-boring machines (TBMs) due to the increased efficiency and shorter completion time resulting from their use. However, when a TBM encoun- ters adverse geological conditions in the course of tunnel construction (e.g., karst caves, faults, or frac- tured zones), disasters such as water and mud inrush, collapse, or machine blockage may result, and may severely imperil construction safety. Therefore, the advance detection of adverse geology and water-bearing conditions in front of the tunnel face is of great importance. This paper uses the TBM tun- neling of the water conveyance project from Songhua River as a case study in order to propose a compre- hensive forward geological prospecting technical system that is suitable for TBM tunnel construction under complicated geological conditions. By combining geological analysis with forward geological prospecting using a three-dimensional (3D) induced polarization method and a 3D seismic method, a comprehensive forward geological prospecting technical system can accurately forecast water inrush geo-hazards or faults in front of the TBM tunnel face. In this way, disasters such as water and mud inrush, collapse, or machine blockage can be avoided. This prospecting technical system also has reference value for carrying out the forward prospecting of adverse geology for potential TBM tunneling and for ensuring that a TBM can work efficiently.