BACKGROUND Hepatocellular carcinoma(HCC)is now the most common primary liver malignancy worldwide,and multiple risk factors attribute to the occurrence and development of HCC.Recently,increasing studies suggest that u...BACKGROUND Hepatocellular carcinoma(HCC)is now the most common primary liver malignancy worldwide,and multiple risk factors attribute to the occurrence and development of HCC.Recently,increasing studies suggest that ubiquitinconjugating enzyme E2T(UBE2T)serves as a promising prognostic factor in human cancers,although the molecular mechanism of UBE2T in HCC remains unclear.AIM To investigate the clinical relevance and role of UBE2T in HCC development.METHODS UBE2T expression in HCC tissues from the TCGA database and its association with patient survival were analyzed.A lentivirus-mediated strategy was used to knock down UBE2T in HCC cells.qRT-PCR and Western blot assays were performed to check the effect of UBE2T silencing in HCC cells.Cell growth in vitro and in vivo was analyzed by multiparametric high-content screening and the xenograft tumorigenicity assay,respectively.Cell cycle distribution and apoptosis were determined by flow cytometry.The genes regulated by UBE2T were profiled by microarray assay.RESULTS UBE2T was overexpressed in HCC tissues compared with paired and non-paired normal tissues.High expression of UBE2T predicted a poor overall survival in HCC patients.In vitro,lentivirus-mediated UBE2T knockdown significantly reduced the viability of both SMMC-7721 and BEL-7404 cells.In vivo,the xenograft tumorigenesis of SMMC-7721 cells was largely attenuated by UBE2T silencing.The cell cycle was arrested at G1/S phase in SMMC-7721 and BEL-7404 cells with UBE2T knockdown.Furthermore,apoptosis was increased by UBE2T knockdown.At the molecular level,numerous genes were dysregulated after UBE2T silencing,including IL-1B,FOSL1,PTGS2,and BMP6.CONCLUSION UBE2T plays an important role in cell cycle progression,apoptosis,and HCC development.展开更多
The physiological and biochemical characteristics of the yeast 3SJ with resistance against three species of postharvest diseases were identified in the pa- per, and the inhibitory effects of the yeast 3SJ on Penicilli...The physiological and biochemical characteristics of the yeast 3SJ with resistance against three species of postharvest diseases were identified in the pa- per, and the inhibitory effects of the yeast 3SJ on Penicillium expansum, Botrytis cinerea and Colletotrichum gloeosporioides during storage period was preliminarily studied. The control effects of the yeast on postharvest diseases caused by P. expansum, B. cinerea and C. gloeosporioides were measured in vivo and in vitro condi- tions. The results showed that the yeast had best control effect against P. expansum and B. cinerea at 20 ~C ; followed by the control effect against C. gloeospori- oides. Inoculation of spore suspension of yeast in apple wound could effectively inhibit rot of apple, while supematant filtrate and sterilized liquid could not inhibit rot of apple. This simultaneously indicated that the action mode of the yeast mainly was nutrition competition. The yeast was conducted traditional classification and identification based on physiological and biochemical characteristics of the yeast, and preliminarily identified to be Kloechera spp. The yeast could survive for at least one month in apple wound at 4 ~C low temperature conditions, with increased amounts. The tolerance to low temperature laid the foundation for application of yeast in low-temperature refrigeration of fruits.展开更多
This paper reviews recent progress in the structural modification and activities on Panax notoginseng saponins(PNS).PNS can not only improve the function of cardio-cerebral system,central nervous system and immune sys...This paper reviews recent progress in the structural modification and activities on Panax notoginseng saponins(PNS).PNS can not only improve the function of cardio-cerebral system,central nervous system and immune system,but also reveal anticancer,anti-aging and anti-oxidation activities.In order to solve the problem of low bioavailability and poor absorbability of PNS in vivo,usually,the researchers modified the structure of PNS with three methods:glycoside cleavage(including acid hydrolysis,sulfation,etc.),biotransformation method(including enzyme hydrolysis,microbial transformation)and combinatorial chemical method.It was found that the structural modification sites of PNS were single,mainly aimed at C-3,C-6 and C-20,which provided a new perspective for the structural modification of PNS.Therefore,structural modification on PNS with high yield and ready availability are significant in the discovery of new active ingredients and industrialization.Derivatives of PNS are applied to research of structure-activity relationship,which is beneficial to the development of new medicines.展开更多
This paper presents a study on how to accommodate wind power into multiple regions,while simultaneously implementing economic and reliable dispatch for multi-area power system operation.The focus is on quantifying the...This paper presents a study on how to accommodate wind power into multiple regions,while simultaneously implementing economic and reliable dispatch for multi-area power system operation.The focus is on quantifying the operational risk brought by wind power uncertainty and at the same time accommodating wind power by coordinating multi-area generation and reserve resources.The reserve requirement of each area is calculated based on two indexes,namely,loss of load probability and wind spillage probability.Then,a generation-reserve cooptimization dispatch model that factors cross-regional wind power accommodation is proposed.The transmission margin and network security constraints of tie-lines are considered to systematically allocate reserve resources for all areas.Finally,optimality condition decomposition is used to decompose the dispatching model to achieve relatively independent regional scheduling,and to get the global optimization result.The reasonableness and effectiveness of the proposed approach is validated by a 6-bus 2-area test system and a 236-bus interconnected system.展开更多
Immunoglobin(Ig)G4-related disease(IgG4-RD)is an immune-mediated fibroinflammatory condition characterized by elevated serum IgG4 levels and multi-organ involvement.The characteristic histological findings of IgG4-RD ...Immunoglobin(Ig)G4-related disease(IgG4-RD)is an immune-mediated fibroinflammatory condition characterized by elevated serum IgG4 levels and multi-organ involvement.The characteristic histological findings of IgG4-RD are dense lymphoplasmacytic infiltration,fibrosis,and massive IgG4 positive plasma cells infiltrating the affected tissues.[1]Previous studies have demonstrated various relapse predictors corresponding to demographic,clinical characteristics,laboratory test results,and treatment agents.However,no study has revealed the risk factors of flares in pathology.This study aimed to ascertain whether the pathological characteristics are related to therapeutic outcomes.展开更多
When integrating the generation of large-scale renewable energy,such as wind and solar energy,the supply and demand sides of the new power system will exhibit high uncertainty.Pumped storage power stations can improve...When integrating the generation of large-scale renewable energy,such as wind and solar energy,the supply and demand sides of the new power system will exhibit high uncertainty.Pumped storage power stations can improve flexible resource supply regulation in the power system,which is the key support and important guarantee for building low-carbon,safe,and efficient new power systems.Limited by the current operation mode and electricity price mechanism,the pumped storage power station cost cannot be effectively recovered,and the value cannot be reasonably compensated,resulting in difficult return on investment,single investment subjects,and notable industry development difficulties.According to the operational requirements of the new power system,combined with the various functions of pumped storage power stations,the value of pumped storage power stations in the new power system was analyzed.Based on the equivalent value substitution principle and system operation simulation,a pumped storage value evaluation method for the new power system was proposed.The new power system operation was simulated considering the dispatching model of wind and photovoltaic power abandonment penalties.Under the same dispatching objectives,the output of various power sources and power generation operating costs with and without pumped storage power stations in the system were compared.From economic,safety,social,and environmental benefit perspectives,a quantitative model of the pumped storage power station value was established,covering seven dimensions:asset investment savings,power generation operating cost reduction,flexible adjustment capability improvement,system resilience enhancement,power outage loss reduction,renewable energy consumption,and emission reduction promotion.Based on the new power system operation and planning data for southern China,the value of typical pumped storage power stations was analyzed,and the results showed that with new power system’s construction and development,the value of pumped storage power stations is increasing,and the value structure is closely related to power grid characteristics.This value evaluation method could provide references for pumped storage investment decisions,subsidy policies,and price mechanisms to fully utilize the role of pumped storage power stations and promote high-quality development of new power systems.展开更多
Dear Editor,The purinergic receptors(P2YRs)are involved in a variety of physiological processes,including proliferation,chemotaxis,cancer metastasis,cardiovascular events,neurodegenerative diseases and aging(Weisman e...Dear Editor,The purinergic receptors(P2YRs)are involved in a variety of physiological processes,including proliferation,chemotaxis,cancer metastasis,cardiovascular events,neurodegenerative diseases and aging(Weisman et al.,2012).Thus far,eight human P2YRs have been characterized and are classified into two subfamilies based on their sequence homology and signal transduction mechanisms,including P2Y1 R-like receptors that signal preferentially through Gq/11 proteins and P2Y12R-like receptors that activate Gi/o proteins(Abbracchio et al.,2006).展开更多
Background: Betel quid chewing has been a major risk factor for oral cancer (OC) in southern China. This study aimed to analyze the scientific publications on the relationship between betel quid chewing and OC and ...Background: Betel quid chewing has been a major risk factor for oral cancer (OC) in southern China. This study aimed to analyze the scientific publications on the relationship between betel quid chewing and OC and construct a model to quantitatively and qualitatively evaluate pertinent publications from 1998 to 2017. Methods: The publications from 1998 to 2017 were retrieved from the Web of Science Core Collection database. Microsoft Excel, Thomson Data Analyzer, VOSviewer, and CiteSpace software were used to analyze the publication outcomes, journals, countries/regions, institutions, authors, research areas, and research frontiers. Results: A total of 788 publications on the relationship between betel quid chewing and OC published until October 25, 2017, were identified. The top 4 related journals were Journal of Oral Pathology Medicine, Oral Oncology, Plos One, and lnternational Journal of Cancer. The top five countries engaged in related research included China, India, the United States, the United Kingdom, and Malaysia. The corresponding disciplines, such as oncology, oral surgery, pathology, environmental and occupational health, and toxicology, were mainly concentrated in three disciplines. The subject ternas squamous cell carcinoma, OC, betel quid, expression, oral submucous fibrosis, India, and p53 ranked first among research hotspots. The burst terms squamous cell carcinoma, OC, betel quid, and expression ranked first in research frontiers. Conclusions: Research in this area emphasized hotspots such as squamous cell carcinoma, OC, oral submucosal fibrosis, betel quid, and tobacco. The annual number of publications steadily decreased from 1998 to 2017, with a lack of a systematic study from interdisciplinary perspectives, inadequate pertinent journals, limited regions with the practice of betel quid chewing, and insufficient participation of researchers, which indicate that as the prevalence of OC increases, particularly in China, research in this area warrants further expansion.展开更多
Objective:The metabolites produced by the gut microbiota are of interest to scientists.The objective of this review was to provide an updated summary of progress regarding the microbiota and their metabolites and infl...Objective:The metabolites produced by the gut microbiota are of interest to scientists.The objective of this review was to provide an updated summary of progress regarding the microbiota and their metabolites and influences on the pathogenesis of inflammatory bowel disease(IBD).Data sources:The author retrieved information from the PubMed database up to January 2018,using various combinations of search terms,including IBD,microbiota,and metabolite.Study selection:Both clinical studies and animal studies of intestinal microbiota and metabolites in IBD were selected.The information explaining the possible pathogenesis of microbiota in IBD was organized.Results:In IBD patients,the biodiversity of feces/mucosa-associated microbiota is decreased,and the probiotic microbiota is also decreased,whereas the pathogenic microbiota are increased.The gut microbiota may be a target for diagnosis and treatment of IBD.Substantial amounts of data support the view that the microbiota and their metabolites play pivotal roles in IBD by affecting intestinal permeability and the immune response.Conclusions:This review highlights the advances in recent gut microbiota research and clarifies the importance of the gut microbiota in IBD pathogenesis.Future research is needed to study the function of altered bacterial community compositions and the roles of metabolites.展开更多
An accurate quantification of the contaminant transport through fractured media is critical for dealing with water-quality related scientific and engineering issues, where the dispersion coefficient is an important an...An accurate quantification of the contaminant transport through fractured media is critical for dealing with water-quality related scientific and engineering issues, where the dispersion coefficient is an important and elusive parameter for the solute transport modeling. Many previous studies show that the dispersion coefficient(D) in the standard advection-dispersion equation(ADE) model can be approximated by D=avλ(where a is the dispersivity), a formula to be revisited systematically in this study by laboratory experiments and model analysis. First, a series of tracer transport experiments in single empty fractures are conducted in cases of different hydraulic gradients. Second, the tracer breakthrough curves are determined by simulations based on the ADE model, to obtain the dispersion coefficients corresponding to various fracture roughnesses and flow velocities. A varying trend of λ is analyzed under different flow conditions. Results show that although the standard ADE model cannot be used to characterize the late-time tailing of the tracer BTCs, likely due to the solute retention, this simple model can simulate most of the solute mass dynamics moving through fractures and may therefore provide information for estimating the dispersion in parsimonious models appropriate for the non-Fickian transport. The following three conclusions are drawn:(1) the peak of the breakthrough curves comes earlier with increasing the roughness, according to the ADE simulation,(2) the value of λ generally decreases as the relative roughness of the fracture increases,(3) the value of λ is approximately equal to 2.0 when the dispersion is dominated by the molecular diffusion in the smooth fracture.展开更多
Deep-subwavelength all-dielectric composite materials are believed to tightly obey the Maxwell Garnett effective medium theory. Here, we demonstrate that the Maxwell Garnett theory could break down due to evanescent f...Deep-subwavelength all-dielectric composite materials are believed to tightly obey the Maxwell Garnett effective medium theory. Here, we demonstrate that the Maxwell Garnett theory could break down due to evanescent fields in deep-subwavelength dielectric structures. By using two-and three-dimensional dielectric composite materials with inhomogeneities at a scale of λ∕100, we show that local evanescent fields generally occur near the dielectric inhomogeneities. When tiny absorptive constituents are placed there, the absorption and transmission of the whole composite will show strong dependence on the positions of the absorptive constituents. The Maxwell Garnett theory fails to predict such position-dependent characteristics because it averages out the evanescent fields. By taking the distribution of the evanescent fields into consideration, we have made a correction to the Maxwell Garnett theory so that the position-dependent characteristics become predictable. We reveal not only the breakdown of the Maxwell Garnett theory, but also a unique phenomenon of "invisible" loss induced by the prohibition of electric fields at deep-subwavelength scales. We believe our work promises a route to control the macroscopic properties of composite materials without changing their composition, which is beyond the traditional Maxwell Garnett theory.展开更多
The Brewster’s law predicts zero reflection of p-polarization on a dielectric surface at a particular angle.However,when loss is introduced into the permittivity of the dielectric,the Brewster condition breaks down a...The Brewster’s law predicts zero reflection of p-polarization on a dielectric surface at a particular angle.However,when loss is introduced into the permittivity of the dielectric,the Brewster condition breaks down and reflection unavoidably appears.In this work,we found an exception to this long-standing dilemma by creating a class of nonmagnetic anisotropic metamaterials,where anomalous Brewster effects with independently tunable absorption and refraction emerge.This loss-independent Brewster effect is bestowed by the extra degrees of freedoms introduced by anisotropy and strictly protected by the reciprocity principle.The bandwidth can cover an extremely wide spectrum from dc to optical frequencies.Two examples of reflectionless Brewster absorbers with different Brewster angles are both demonstrated to achieve large absorbance in a wide spectrum via microwave experiments.Our work extends the scope of Brewster effect to the horizon of nonmagnetic absorptive materials,which promises an unprecedented wide bandwidth for reflectionless absorption with high efficiency.展开更多
文摘BACKGROUND Hepatocellular carcinoma(HCC)is now the most common primary liver malignancy worldwide,and multiple risk factors attribute to the occurrence and development of HCC.Recently,increasing studies suggest that ubiquitinconjugating enzyme E2T(UBE2T)serves as a promising prognostic factor in human cancers,although the molecular mechanism of UBE2T in HCC remains unclear.AIM To investigate the clinical relevance and role of UBE2T in HCC development.METHODS UBE2T expression in HCC tissues from the TCGA database and its association with patient survival were analyzed.A lentivirus-mediated strategy was used to knock down UBE2T in HCC cells.qRT-PCR and Western blot assays were performed to check the effect of UBE2T silencing in HCC cells.Cell growth in vitro and in vivo was analyzed by multiparametric high-content screening and the xenograft tumorigenicity assay,respectively.Cell cycle distribution and apoptosis were determined by flow cytometry.The genes regulated by UBE2T were profiled by microarray assay.RESULTS UBE2T was overexpressed in HCC tissues compared with paired and non-paired normal tissues.High expression of UBE2T predicted a poor overall survival in HCC patients.In vitro,lentivirus-mediated UBE2T knockdown significantly reduced the viability of both SMMC-7721 and BEL-7404 cells.In vivo,the xenograft tumorigenesis of SMMC-7721 cells was largely attenuated by UBE2T silencing.The cell cycle was arrested at G1/S phase in SMMC-7721 and BEL-7404 cells with UBE2T knockdown.Furthermore,apoptosis was increased by UBE2T knockdown.At the molecular level,numerous genes were dysregulated after UBE2T silencing,including IL-1B,FOSL1,PTGS2,and BMP6.CONCLUSION UBE2T plays an important role in cell cycle progression,apoptosis,and HCC development.
基金Supported by The Forth Subject of National Scientific and Technological Support Project ( 2007BA I32B04)
文摘The physiological and biochemical characteristics of the yeast 3SJ with resistance against three species of postharvest diseases were identified in the pa- per, and the inhibitory effects of the yeast 3SJ on Penicillium expansum, Botrytis cinerea and Colletotrichum gloeosporioides during storage period was preliminarily studied. The control effects of the yeast on postharvest diseases caused by P. expansum, B. cinerea and C. gloeosporioides were measured in vivo and in vitro condi- tions. The results showed that the yeast had best control effect against P. expansum and B. cinerea at 20 ~C ; followed by the control effect against C. gloeospori- oides. Inoculation of spore suspension of yeast in apple wound could effectively inhibit rot of apple, while supematant filtrate and sterilized liquid could not inhibit rot of apple. This simultaneously indicated that the action mode of the yeast mainly was nutrition competition. The yeast was conducted traditional classification and identification based on physiological and biochemical characteristics of the yeast, and preliminarily identified to be Kloechera spp. The yeast could survive for at least one month in apple wound at 4 ~C low temperature conditions, with increased amounts. The tolerance to low temperature laid the foundation for application of yeast in low-temperature refrigeration of fruits.
基金Supported by High-level Talent Training Program for Graduate Students of Tibet University(2020-GSP-B014)National Natural Science Foundation of China(81560589)Yunnan Provincial Department of Science and Technology-Kunming Medical University Applied Basic Research Joint Special Fund(2017FE468-001)。
文摘This paper reviews recent progress in the structural modification and activities on Panax notoginseng saponins(PNS).PNS can not only improve the function of cardio-cerebral system,central nervous system and immune system,but also reveal anticancer,anti-aging and anti-oxidation activities.In order to solve the problem of low bioavailability and poor absorbability of PNS in vivo,usually,the researchers modified the structure of PNS with three methods:glycoside cleavage(including acid hydrolysis,sulfation,etc.),biotransformation method(including enzyme hydrolysis,microbial transformation)and combinatorial chemical method.It was found that the structural modification sites of PNS were single,mainly aimed at C-3,C-6 and C-20,which provided a new perspective for the structural modification of PNS.Therefore,structural modification on PNS with high yield and ready availability are significant in the discovery of new active ingredients and industrialization.Derivatives of PNS are applied to research of structure-activity relationship,which is beneficial to the development of new medicines.
基金supported in part by the National Key Research and Development Program(2016YFB0900105)the National Natural Science Foundation of China(51577061)the Management&Consultation Project of SGCC.
文摘This paper presents a study on how to accommodate wind power into multiple regions,while simultaneously implementing economic and reliable dispatch for multi-area power system operation.The focus is on quantifying the operational risk brought by wind power uncertainty and at the same time accommodating wind power by coordinating multi-area generation and reserve resources.The reserve requirement of each area is calculated based on two indexes,namely,loss of load probability and wind spillage probability.Then,a generation-reserve cooptimization dispatch model that factors cross-regional wind power accommodation is proposed.The transmission margin and network security constraints of tie-lines are considered to systematically allocate reserve resources for all areas.Finally,optimality condition decomposition is used to decompose the dispatching model to achieve relatively independent regional scheduling,and to get the global optimization result.The reasonableness and effectiveness of the proposed approach is validated by a 6-bus 2-area test system and a 236-bus interconnected system.
基金This work was supported by grants from the National Natural Science Foundation of China(Nos.81771757,81771780,82071839)the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(No.NWB20203346)+1 种基金Capital’s Funds for Health Improvement and Research(No.2020-2-4017)Beijing Municipal Science and Technology Commission(No.Z201100005520023)。
文摘Immunoglobin(Ig)G4-related disease(IgG4-RD)is an immune-mediated fibroinflammatory condition characterized by elevated serum IgG4 levels and multi-organ involvement.The characteristic histological findings of IgG4-RD are dense lymphoplasmacytic infiltration,fibrosis,and massive IgG4 positive plasma cells infiltrating the affected tissues.[1]Previous studies have demonstrated various relapse predictors corresponding to demographic,clinical characteristics,laboratory test results,and treatment agents.However,no study has revealed the risk factors of flares in pathology.This study aimed to ascertain whether the pathological characteristics are related to therapeutic outcomes.
基金Supported by the Innovation Project of the China Southern Power Grid Co.,Ltd. (020000KK52210005).
文摘When integrating the generation of large-scale renewable energy,such as wind and solar energy,the supply and demand sides of the new power system will exhibit high uncertainty.Pumped storage power stations can improve flexible resource supply regulation in the power system,which is the key support and important guarantee for building low-carbon,safe,and efficient new power systems.Limited by the current operation mode and electricity price mechanism,the pumped storage power station cost cannot be effectively recovered,and the value cannot be reasonably compensated,resulting in difficult return on investment,single investment subjects,and notable industry development difficulties.According to the operational requirements of the new power system,combined with the various functions of pumped storage power stations,the value of pumped storage power stations in the new power system was analyzed.Based on the equivalent value substitution principle and system operation simulation,a pumped storage value evaluation method for the new power system was proposed.The new power system operation was simulated considering the dispatching model of wind and photovoltaic power abandonment penalties.Under the same dispatching objectives,the output of various power sources and power generation operating costs with and without pumped storage power stations in the system were compared.From economic,safety,social,and environmental benefit perspectives,a quantitative model of the pumped storage power station value was established,covering seven dimensions:asset investment savings,power generation operating cost reduction,flexible adjustment capability improvement,system resilience enhancement,power outage loss reduction,renewable energy consumption,and emission reduction promotion.Based on the new power system operation and planning data for southern China,the value of typical pumped storage power stations was analyzed,and the results showed that with new power system’s construction and development,the value of pumped storage power stations is increasing,and the value structure is closely related to power grid characteristics.This value evaluation method could provide references for pumped storage investment decisions,subsidy policies,and price mechanisms to fully utilize the role of pumped storage power stations and promote high-quality development of new power systems.
基金the National Science Foundation of China grants(31825010 and 82121005)National Key R&D Program of China(2018YFA0507000)+1 种基金CAS Strategic Priority Research Program(XDB37030100)Shanghai Pilot Program for Basic Research-Chinese Academy of Sciences,Shanghai Branch(JCYJ-SHFY-2021-008).
文摘Dear Editor,The purinergic receptors(P2YRs)are involved in a variety of physiological processes,including proliferation,chemotaxis,cancer metastasis,cardiovascular events,neurodegenerative diseases and aging(Weisman et al.,2012).Thus far,eight human P2YRs have been characterized and are classified into two subfamilies based on their sequence homology and signal transduction mechanisms,including P2Y1 R-like receptors that signal preferentially through Gq/11 proteins and P2Y12R-like receptors that activate Gi/o proteins(Abbracchio et al.,2006).
文摘Background: Betel quid chewing has been a major risk factor for oral cancer (OC) in southern China. This study aimed to analyze the scientific publications on the relationship between betel quid chewing and OC and construct a model to quantitatively and qualitatively evaluate pertinent publications from 1998 to 2017. Methods: The publications from 1998 to 2017 were retrieved from the Web of Science Core Collection database. Microsoft Excel, Thomson Data Analyzer, VOSviewer, and CiteSpace software were used to analyze the publication outcomes, journals, countries/regions, institutions, authors, research areas, and research frontiers. Results: A total of 788 publications on the relationship between betel quid chewing and OC published until October 25, 2017, were identified. The top 4 related journals were Journal of Oral Pathology Medicine, Oral Oncology, Plos One, and lnternational Journal of Cancer. The top five countries engaged in related research included China, India, the United States, the United Kingdom, and Malaysia. The corresponding disciplines, such as oncology, oral surgery, pathology, environmental and occupational health, and toxicology, were mainly concentrated in three disciplines. The subject ternas squamous cell carcinoma, OC, betel quid, expression, oral submucous fibrosis, India, and p53 ranked first among research hotspots. The burst terms squamous cell carcinoma, OC, betel quid, and expression ranked first in research frontiers. Conclusions: Research in this area emphasized hotspots such as squamous cell carcinoma, OC, oral submucosal fibrosis, betel quid, and tobacco. The annual number of publications steadily decreased from 1998 to 2017, with a lack of a systematic study from interdisciplinary perspectives, inadequate pertinent journals, limited regions with the practice of betel quid chewing, and insufficient participation of researchers, which indicate that as the prevalence of OC increases, particularly in China, research in this area warrants further expansion.
基金grants from the International Science and Technology Cooperation Project of Shanxi(No.2013081066)the Science Foundation of Health and Family Planning Commission of Shanxi Province(Nos.201601014,2017020).
文摘Objective:The metabolites produced by the gut microbiota are of interest to scientists.The objective of this review was to provide an updated summary of progress regarding the microbiota and their metabolites and influences on the pathogenesis of inflammatory bowel disease(IBD).Data sources:The author retrieved information from the PubMed database up to January 2018,using various combinations of search terms,including IBD,microbiota,and metabolite.Study selection:Both clinical studies and animal studies of intestinal microbiota and metabolites in IBD were selected.The information explaining the possible pathogenesis of microbiota in IBD was organized.Results:In IBD patients,the biodiversity of feces/mucosa-associated microbiota is decreased,and the probiotic microbiota is also decreased,whereas the pathogenic microbiota are increased.The gut microbiota may be a target for diagnosis and treatment of IBD.Substantial amounts of data support the view that the microbiota and their metabolites play pivotal roles in IBD by affecting intestinal permeability and the immune response.Conclusions:This review highlights the advances in recent gut microbiota research and clarifies the importance of the gut microbiota in IBD pathogenesis.Future research is needed to study the function of altered bacterial community compositions and the roles of metabolites.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.41831289,41877191 and 41772250)
文摘An accurate quantification of the contaminant transport through fractured media is critical for dealing with water-quality related scientific and engineering issues, where the dispersion coefficient is an important and elusive parameter for the solute transport modeling. Many previous studies show that the dispersion coefficient(D) in the standard advection-dispersion equation(ADE) model can be approximated by D=avλ(where a is the dispersivity), a formula to be revisited systematically in this study by laboratory experiments and model analysis. First, a series of tracer transport experiments in single empty fractures are conducted in cases of different hydraulic gradients. Second, the tracer breakthrough curves are determined by simulations based on the ADE model, to obtain the dispersion coefficients corresponding to various fracture roughnesses and flow velocities. A varying trend of λ is analyzed under different flow conditions. Results show that although the standard ADE model cannot be used to characterize the late-time tailing of the tracer BTCs, likely due to the solute retention, this simple model can simulate most of the solute mass dynamics moving through fractures and may therefore provide information for estimating the dispersion in parsimonious models appropriate for the non-Fickian transport. The following three conclusions are drawn:(1) the peak of the breakthrough curves comes earlier with increasing the roughness, according to the ADE simulation,(2) the value of λ generally decreases as the relative roughness of the fracture increases,(3) the value of λ is approximately equal to 2.0 when the dispersion is dominated by the molecular diffusion in the smooth fracture.
基金National Key Research and Development Program of China(2017YFA0303702)National Natural Science Foundation of China(11704271,11974176,61671314)+1 种基金Natural Science Foundation of Jiangsu Province(BK20170326)Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Deep-subwavelength all-dielectric composite materials are believed to tightly obey the Maxwell Garnett effective medium theory. Here, we demonstrate that the Maxwell Garnett theory could break down due to evanescent fields in deep-subwavelength dielectric structures. By using two-and three-dimensional dielectric composite materials with inhomogeneities at a scale of λ∕100, we show that local evanescent fields generally occur near the dielectric inhomogeneities. When tiny absorptive constituents are placed there, the absorption and transmission of the whole composite will show strong dependence on the positions of the absorptive constituents. The Maxwell Garnett theory fails to predict such position-dependent characteristics because it averages out the evanescent fields. By taking the distribution of the evanescent fields into consideration, we have made a correction to the Maxwell Garnett theory so that the position-dependent characteristics become predictable. We reveal not only the breakdown of the Maxwell Garnett theory, but also a unique phenomenon of "invisible" loss induced by the prohibition of electric fields at deep-subwavelength scales. We believe our work promises a route to control the macroscopic properties of composite materials without changing their composition, which is beyond the traditional Maxwell Garnett theory.
基金Y.L.,R.P.,and M.W.acknowledge support from the National Key R&D Program of China under Grant No.2020YFA0211300,2017YFA0303702National Natural Science Foundation of China under Grant Nos.11974176,11634005,11974177,61975078+3 种基金J.Luo acknowledges support from the National Natural Science Foundation of China under Grant No.11704271Natural Science Foundation of Jiangsu Province under Grant No.BK20170326a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)J.Li acknowledges support from the Research Grants Council of Hong Kong under Grant No.R6015-18.
文摘The Brewster’s law predicts zero reflection of p-polarization on a dielectric surface at a particular angle.However,when loss is introduced into the permittivity of the dielectric,the Brewster condition breaks down and reflection unavoidably appears.In this work,we found an exception to this long-standing dilemma by creating a class of nonmagnetic anisotropic metamaterials,where anomalous Brewster effects with independently tunable absorption and refraction emerge.This loss-independent Brewster effect is bestowed by the extra degrees of freedoms introduced by anisotropy and strictly protected by the reciprocity principle.The bandwidth can cover an extremely wide spectrum from dc to optical frequencies.Two examples of reflectionless Brewster absorbers with different Brewster angles are both demonstrated to achieve large absorbance in a wide spectrum via microwave experiments.Our work extends the scope of Brewster effect to the horizon of nonmagnetic absorptive materials,which promises an unprecedented wide bandwidth for reflectionless absorption with high efficiency.
基金the National Natural Science Foundation of China (NSFC)(Grant Nos.61522103,61501216, and 61372112)the National Science and Technology Major Project (2015ZX03003002-002)+2 种基金the Inter-Governmental Science and Technology Cooperation Project (2016YFE0104600)the IRTSTHN (18IRTSTHN014) the Science and Technology Plan Projects (Openness and Cooperation) of Henan Province (152106000048).