Caffeine is an important functional component in tea,which has the effect of excitement and nerve stimulation,but excessive intake can cause insomnia and dysphoria.Therefore,the production of tea with low-caffeine con...Caffeine is an important functional component in tea,which has the effect of excitement and nerve stimulation,but excessive intake can cause insomnia and dysphoria.Therefore,the production of tea with low-caffeine content can meet the consumption needs of certain people.Here,in addition to the previous alleles of the tea caffeine synthase(TCS1)gene,a new allele(TCS1h)from tea germplasms was identified.Results of in vitro activity analysis showed that TCS1h had both theobromine synthase(TS)and caffeine synthase(CS)activities.Site-directed mutagenesis experiments of TCS1a,TCS1c,and TCS1h demonstrated that apart from the 225th amino acid residue,the 269th amino acid also determined the CS activity.GUS histochemical analysis and dual-luciferase assay indicated the low promoter activity of TCS1e and TCS1f.In parallel,insertion and deletion mutations in large fragments of alleles and experiments of site-directed mutagenesis identified a key cis-acting element(G-box).Furthermore,it was found that the contents of purine alkaloids were related to the expression of corresponding functional genes and alleles,and the absence or presence and level of gene expression determined the content of purine alkaloids in tea plants to a certain extent.In summary,we concluded TCS1 alleles into three types with different functions and proposed a strategy to effectively enhance low-caffeine tea germplasms in breeding practices.This research provided an applicable technical avenue for accelerating the cultivation of specific low-caffeine tea plants.展开更多
We investigate the structural,static magnetic and damping properties in two Mn-deficient magnetic Weyl semimetal Co-Mn-Ga(CMG) alloy films,i.e.,Co_(55)Mn_(18)Ga_(27)(CMG1) and Co_(50)Mn_(18)Ga_(32)(CMG2),which were ep...We investigate the structural,static magnetic and damping properties in two Mn-deficient magnetic Weyl semimetal Co-Mn-Ga(CMG) alloy films,i.e.,Co_(55)Mn_(18)Ga_(27)(CMG1) and Co_(50)Mn_(18)Ga_(32)(CMG2),which were epitaxially grown on MgO(001) substrates.CMG1 has a mixing phase of B2and L21,larger saturation magnetization(M_(s) ~760 emu/cm^(3)),stronger in-plane magnetic anisotropy.CMG2 has an almost pure B2phase,smaller M_(s)(~330 emu/cm^(3)),negligible in-plane magnetic anisotropy.Time-resolved magneto-optical Kerr effect results unambiguously demonstrate an obvious perpendicular standing spin wave(PSSW) mode in addition to the Kittel mode for both of the CMG films.The intrinsic damping constant is about 0.0055 and 0.015 for CMG1 and CMG2,respectively,which are both significantly larger than that of the stoichiometric CMG(i.e.,Co_(2)MnGa)film reported previously.In combination with the first-principles calculations,the intrinsic damping properties of the Mn-deficient CMG films can be well explained by considering the increase of density of states at the Fermi level,reduction of M_(s),and excitation of the PSSW mode.These findings provide a new clue to tuning the magnetic damping of the magnetic Weyl semimetal film through slight off-stoichiometry.展开更多
A teaching strategy is a method, which can help students to gain knowledge, deliver information, and improve their learning. Different learning environments, such as clinical teaching, online teaching, and face-to-fac...A teaching strategy is a method, which can help students to gain knowledge, deliver information, and improve their learning. Different learning environments, such as clinical teaching, online teaching, and face-to-face traditional learning environments, require different teaching strategies for students. Choosing teaching strategies for a course is very important for nurse educators because various factors should be taken into account to make students meet the learning outcomes. The use of modern technologies in teaching strategies can improve students’ competencies and confidences. The purpose of this article is to create a toolbox integrating ten teaching strategies that can be used in different teaching environments.展开更多
Single-cell transcriptomics has been fully embraced in plant biological research and is revolutionizing our understanding of plant growth,development,and responses to external stimuli.However,single-cell tran-scriptom...Single-cell transcriptomics has been fully embraced in plant biological research and is revolutionizing our understanding of plant growth,development,and responses to external stimuli.However,single-cell tran-scriptomic data analysis in plants is not trivial,given that there is currently no end-to-end solution and that integration of various bioinformatics tools involves a large number of required dependencies.Here,we pre-sent scPlant,a versatile framework for exploring plant single-cell atlases with minimuminput data provided by users.The scPlant pipeline is implemented with numerous functions for diverse analytical tasks,ranging from basic data processing to advanced demands such as cell-type annotation and deconvolution,trajec-tory inference,cross-species data integration,and cell-type-specific gene regulatory network construc-tion.In addition,a variety of visualization tools are bundled in a built-in Shiny application,enabling explo-ration of single-cell transcriptomic data on the fly.展开更多
The combustion and explosion characteristics of lithium-ion battery vent gas is a key factor in determining the fire hazard of lithium-ion batteries.Investigating the combustion and explosion hazards of lithium-ion ba...The combustion and explosion characteristics of lithium-ion battery vent gas is a key factor in determining the fire hazard of lithium-ion batteries.Investigating the combustion and explosion hazards of lithium-ion batteries vent gas can provide guidance for rescue and protection in explosion accidents in energy storage stations and new energy vehicles,thereby promoting the application and development of lithium-ion batteries.Based on this understanding and combined with previous research on gas production from lithium-ion batteries,this article conducted a study on the combustion and explosion risks of vent gas from thermal runaway of 18650 LFP batteries with different states of charge(SOCs).The explosion limit of mixed gases affected by carbon dioxide inert gas is calculated through the“elimination”method,and the Chemkin-Pro software is used to numerically simulate the laminar flame speed and adiabatic flame temperature of the battery vent gas.And the concentration of free radicals and sensitivity coefficients of major elementary reactions in the system are analyzed to comprehensively evaluate the combustion explosion hazard of battery vent gas.The study found that the 100%SOC battery has the lowest explosion limit of the vent gas.The inhibitory elementary reaction sensitivity coefficient in the reaction system is lower and the concentration of free radicals is higher.Therefore,it has the maximum laminar flame speed and adiabatic flame temperature.The combustion and explosion hazard of battery vent gas increases with the increase of SOC,and the risk of explosion is the greatest and most harmful when SOC reaches 100%.However,the related hazards decrease to varying degrees with overcharging of the battery.This article provides a feasible method for analyzing the combustion mechanism of vent gas from lithium-ion batteries,revealing the impact of SOC on the hazardousness of battery vent gas.It provides references for the safety of storage and transportation of lithium-ion batteries,safety protection of energy storage stations,and the selection of related fire extinguishing agents.展开更多
A new class of RNA regulatory genes known as microRNAs(miRNAs)has been found to introduce a whole new layer of gene regulation in eukaryotes.The intensive studies of the past several years have demonstrated that miRNA...A new class of RNA regulatory genes known as microRNAs(miRNAs)has been found to introduce a whole new layer of gene regulation in eukaryotes.The intensive studies of the past several years have demonstrated that miRNAs are not only found intracellularly,but are also detectable outside cells,including in various body fluids(e.g.serum,plasma,saliva,urine and milk).This phenomenon raises questions about the biological function of such extracellular miRNAs.Substantial amounts of extracellular miRNAs are enclosed in small membranous vesicles(e.g.exosomes,shedding vesicles and apoptotic bodies)or packaged with RNA-binding proteins(e.g.high-density lipoprotein,Argonaute 2 and nucleophosmin 1).These miRNAs may function as secreted signaling molecules to influence the recipient cell phenotypes.Furthermore,secreted extracellular miRNAs may reflect molecular changes in the cells from which they are derived and can therefore potentially serve as diagnostic indicators of disease.Several studies also point to the potential application of siRNA/miRNA delivery as a new therapeutic strategy for treating diseases.In this review,we summarize what is known about the mechanism of miRNA secretion.In addition,we describe the pathophysiological roles of secreted miRNAs and their clinical potential as diagnostic biomarkers and therapeutic drugs.We believe that miRNA transfer between cells will have a significant impact on biological research in the coming years.展开更多
Tumor-associated macrophages(TAMs)mostly exhibit M2-like(alternatively activated)properties and play posi-tive roles in angiogenesis and tumorigenesis.Vascular en-dothelial growth factor(VEGF)is a key angiogenic facto...Tumor-associated macrophages(TAMs)mostly exhibit M2-like(alternatively activated)properties and play posi-tive roles in angiogenesis and tumorigenesis.Vascular en-dothelial growth factor(VEGF)is a key angiogenic factor.During tumor development,TAMs secrete VEGF and other factors to promote angiogenesis;thus,anti-treatment against TAMs and VEGF can repress cancer development,which has been demonstrated in clinical trials and on an experimental level.In the present work,we show that miR-150 is an oncomir because of its promotional effect on VEGF.MiR-150 targets TAMs to up-regulate their secre-tion of VEGF in vitro.With the utilization of cell-derived vesicles,named microvesicles(MVs),we transferred an-tisense RNA targeted to miR-150 into mice and found that the neutralization of miR-150 down-regulates miR-150 and VEGF levels in vivo and attenuates angiogenesis.There-fore,we proposed the therapeutic potential of neutralizing miR-150 to treat cancer and demonstrated a novel,natu-ral,microvesicle-based method for the transfer of nucleic acids.展开更多
Osteosarcoma is the most common primary sarcoma of bone, and it is a leading cause of cancer death among adolescents and young adults. However, the molecular mechanism underlying osteosarcoma carcinogenesis remains po...Osteosarcoma is the most common primary sarcoma of bone, and it is a leading cause of cancer death among adolescents and young adults. However, the molecular mechanism underlying osteosarcoma carcinogenesis remains poorly understood. Recently, cyclin-dependent kinase 6 (CDK6) was identified as an important onco- gene. We found that CDK6 protein level, rather than CDK6 mRNA level, is much higher in osteosarcoma tissues than in normal adjacent tissues, which indicates a post-transcriptional mechanism involved in CDK6 regulation in osteosarcoma. MiRNAs are small non- coding RNAs that repress gene expression at the post- transcriptional level and have widely been shown to play important roles in many human cancers. In this study, we investigated the role of miR-29b as a novel regulator of CDK6 using bioinformatics methods. We demon- strated that CDK6 can be downregulated by miR-29b via binding to the 3'-UTR region in osteosarcoma cells. Furthermore, we identified an inverse correlation between miR-29b and CDK6 protein levels in osteosar- coma tissues. Finally, we examined the function of miR- 29b-driven repression of CDK6 expression in osteosarcoma cells. The results revealed that miR-29b acts as a tumor suppressor of osteosarcoma by targeting CDK6 in the proliferation and migration processes. Taken together, our results highlight an important role for miR-29b in the regulation of CDK6 in osteosarcoma and may open new avenues for future osteosarcoma therapies.展开更多
Colostrum provides essential nutrients and immunologically active factors that are beneficial to newborns.Our previous work demonstrated that milk contains large amounts of miRNA that is largely stored in milk-derived...Colostrum provides essential nutrients and immunologically active factors that are beneficial to newborns.Our previous work demonstrated that milk contains large amounts of miRNA that is largely stored in milk-derived microvesicles(MVs).In the present study,we found that the MVs from colostrum contain signifi cantly higher levels of several immune-related miRNAs.We hypothesized that the colostrum MVs may transfer the immune-related miR-NAs into cells,which contribute to its immune modulatory feature.We isolated colostrum MVs by ultracentrifugation and demonstrated several immune modulation features associated with miRNAs.We also provide evidence that the physical structure of milk-derived MVs is essential for transfer miRNAs and following immune modulation effect.Moreover,we found that colostrum powder-derived MVs also contains higher levels of immune-related miRNAs that display similar immune modulation effects.Taken together,these results show that MV-containing immunerelated miRNAs may be a novel mechanism by which co-lostrum modulates body immune response.展开更多
The identification of important nodes in a power grid has considerable benefits for safety. Power networks vary in many aspects, such as scale and structure. An index system can hardly cover all the information in var...The identification of important nodes in a power grid has considerable benefits for safety. Power networks vary in many aspects, such as scale and structure. An index system can hardly cover all the information in various situations. Therefore, the efficiency of traditional methods using an index system is case-dependent and not universal. To solve this problem, an artificial intelligence based method is proposed for evaluating power grid node importance. First, using a network embedding approach, a feature extraction method is designed for power grid nodes, considering their structural and electrical information. Then, for a specific power network, steady-state and node fault transient simulations under various operation modes are performed to establish the sample set. The sample set can reflect the relationship between the node features and the corresponding importance. Finally, a support vector regression model is trained based on the optimized sample set for the later online use of importance evaluation. A case study demonstrates that the proposed method can effectively evaluate node importance for a power grid based on the information learned from the samples. Compared with traditional methods using an index system, the proposed method can avoid some possible bias. In addition, a particular sample set for each specific power network can be established under this artificial intelligence based framework, meeting the demand of universality.展开更多
Programmed cell death 4 (PDCD4) is a RNA-binding protein that acts as a tumor suppressor in many cancer types, including colorectal cancer (CRC). During CRC carcinogenesis, PDCD4 protein levels remarkably decrease...Programmed cell death 4 (PDCD4) is a RNA-binding protein that acts as a tumor suppressor in many cancer types, including colorectal cancer (CRC). During CRC carcinogenesis, PDCD4 protein levels remarkably decrease, but the underlying molecular mechanism for decreased PDCD4 expression is not fully understood. In this study, we performed bioinformatics analysis to identify miRNAs that potentially target PDCD4. We demonstrated miR-181b as a direct regulator of PDCD4. We further showed that activation of IL6/STAT3 signaling pathway increased miR-181b expression and conse- quently resulted in downregulation of PDCD4 in CRC cells. In addition, we investigated the biological effects of PDCD4 inhibition by miR-181b both in vitro and in vivo and found that miR-181b could promote cell proliferation and migration and suppress apoptosis in CRC cells and accelerate tumor growth in xenograft mice, potentially through targeting PDCD4. Taken toge- ther, this study highlights an oncomiR role for miR-181b in regulating PDCD4 in CRC and suggests that miR-181b may be a novel molecular therapeutic target for CRC.展开更多
The mechanism underlying T cell-mediated fulminant hepatitis is not fully understood. In this study, we investigated whether myeloid derived suppressor cells (MDSCs) could prevent the concanavalin A (ConA)- induce...The mechanism underlying T cell-mediated fulminant hepatitis is not fully understood. In this study, we investigated whether myeloid derived suppressor cells (MDSCs) could prevent the concanavalin A (ConA)- induced hepatitis through suppressing T cell proliferation. We observed an increase in the frequencies of MDSCs in mouse spleen and liver at early stage of ConA treatment, implicating that the MDSCs might be involved in the initial resistance of mice against ConA- mediated inflammation. Subpopulation analysis showed that the MDSCs in liver of ConA-induced mice were mainly granulocytic MDSCs. Adoptive transfer of the bone marrow-derived MDSCs into ConA-treated mice showed that the MDSCs migrated into the liver and spleen where they suppressed T cell proliferation through ROS pathway. In addition, the frequencies of MDSCs in mice were also significantly increased by the treatment with immune suppressor glucocorticoids. Transfer of MDSCs into the regulatory T cell (Treg)- depleted mice showed that the protective effect of MDSCs on ConA-induced hepatitis is Treg-independent. In conclusion, our results demonstrate that MDSCs possess a direct protective role in T cell-mediated hepatitis, and increasing the frequency of MDSCs by either adoptive transfer or glucocorticoid treatment represents a potential cell-based therapeutic strategy for the acute inflammatory disease.展开更多
MTUS1 (microtubule-associated tumor suppressor 1) has been identified that can function as a tumor sup- pressor gene in many malignant tumors. However, the function and mechanisms underlying the regulation of MTUS1 ...MTUS1 (microtubule-associated tumor suppressor 1) has been identified that can function as a tumor sup- pressor gene in many malignant tumors. However, the function and mechanisms underlying the regulation of MTUS1 are unclear. In the present study, we reported that miR-19a and miR-19b (miR-19a/b) promote prolifer- ation and migration of lung cancer cells by targeting MTUS1. First, MTUS1 was proved to function as a tumor suppressor in lung cancer and was linked to cell prolif- eration and migration promotion. Second, an inverse correlation between miR-19a/b expression and MTUS1 mRNA/protein expression was noted in human lung cancer tissues. Third, MTUS1 was appraised as a direct target of miR-19a/b by bioinformatics analysis. Fourth, direct MTUS1 regulation by miR-19a/b in lung cancer cells was experimentally affirmed by cell transfection assay and luciferase reporter assay. Finally, miR-19a/b were shown to cooperatively repress MTUS1 expression and synergistically regulate MTUS1 expression to pro- mote lung cancer cell proliferation and migration. In conclusion, our findings have provided the first cluesregarding the roles of miR-19a/b, which appear to func- tion as oncomirs in lung cancer by downregulating MTUSI.展开更多
Ophiocordyceps sinensis is well known as a traditional Chinese medicine and has widely been used for over 2,000 years to stimulate immune system, decrease blood pressure and to inhibit tumor growth. While miRNAs are i...Ophiocordyceps sinensis is well known as a traditional Chinese medicine and has widely been used for over 2,000 years to stimulate immune system, decrease blood pressure and to inhibit tumor growth. While miRNAs are increasingly recognized for their roles in post-transcriptional regulation of gene expression in animals and plants, miRNAs in fungi were less studied until the discovery of microRNA-like RNA(milRNA). High-throughput sequencing and bioinformatics approaches were used to identify conserved and novel milRNAs in O. sinensis. 40 conserved milRNAs were identified, while 23 pre-miRNA candidates encoding 31 novel milRNAs were predicted. Furthermore, the potential target genes of milRNAs in human were predicted and gene ontology analysis was applied to these genes. Enrichment analysis of GO-represented biological process showed that target genes of both conserved and novel milRNAs are involved in development, metabolic and immune processes, indicating the potential roles of milRNAs of O. sinensis in pharmacological effects as health food and traditional Chinese medicine. This study is the first report on genome-wide analysis of milRNAs in O. sinensis and it provides a useful resource to further study the potential roles of milRNAs as active components of O. sinensis in health food or traditional Chinese medicine.展开更多
基金supported by the National Natural Science Foundation of China(31670685)Zhejiang Provincial Natural Science Foundation of China(LZ22C160008)+2 种基金Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(2021C02067)to J.-Q.J.the Chinese Academy of Agricultural Sciences through the Agricultural Science and Technology Innovation Program(CAASASTIP-2021-TRICAAS)the China Agricultural Research System of MOF and MARA(CARS-19)to L.C.,the Zhejiang Provincial Natural Science Foundation of China(LQ20C160010)to J.-D.C.
文摘Caffeine is an important functional component in tea,which has the effect of excitement and nerve stimulation,but excessive intake can cause insomnia and dysphoria.Therefore,the production of tea with low-caffeine content can meet the consumption needs of certain people.Here,in addition to the previous alleles of the tea caffeine synthase(TCS1)gene,a new allele(TCS1h)from tea germplasms was identified.Results of in vitro activity analysis showed that TCS1h had both theobromine synthase(TS)and caffeine synthase(CS)activities.Site-directed mutagenesis experiments of TCS1a,TCS1c,and TCS1h demonstrated that apart from the 225th amino acid residue,the 269th amino acid also determined the CS activity.GUS histochemical analysis and dual-luciferase assay indicated the low promoter activity of TCS1e and TCS1f.In parallel,insertion and deletion mutations in large fragments of alleles and experiments of site-directed mutagenesis identified a key cis-acting element(G-box).Furthermore,it was found that the contents of purine alkaloids were related to the expression of corresponding functional genes and alleles,and the absence or presence and level of gene expression determined the content of purine alkaloids in tea plants to a certain extent.In summary,we concluded TCS1 alleles into three types with different functions and proposed a strategy to effectively enhance low-caffeine tea germplasms in breeding practices.This research provided an applicable technical avenue for accelerating the cultivation of specific low-caffeine tea plants.
基金supported by the National Key R&D Program of China (Grant Nos.2022YFA1403602 and 2021YFB3601600)the National Natural Science Foundation of China (Grant Nos.51971109,U22A20117,51771053,52001169,11874199,12104216,and 12241403)the Natural Science Foundation of Jiangsu Province of China (Grant No.BK20200307)。
文摘We investigate the structural,static magnetic and damping properties in two Mn-deficient magnetic Weyl semimetal Co-Mn-Ga(CMG) alloy films,i.e.,Co_(55)Mn_(18)Ga_(27)(CMG1) and Co_(50)Mn_(18)Ga_(32)(CMG2),which were epitaxially grown on MgO(001) substrates.CMG1 has a mixing phase of B2and L21,larger saturation magnetization(M_(s) ~760 emu/cm^(3)),stronger in-plane magnetic anisotropy.CMG2 has an almost pure B2phase,smaller M_(s)(~330 emu/cm^(3)),negligible in-plane magnetic anisotropy.Time-resolved magneto-optical Kerr effect results unambiguously demonstrate an obvious perpendicular standing spin wave(PSSW) mode in addition to the Kittel mode for both of the CMG films.The intrinsic damping constant is about 0.0055 and 0.015 for CMG1 and CMG2,respectively,which are both significantly larger than that of the stoichiometric CMG(i.e.,Co_(2)MnGa)film reported previously.In combination with the first-principles calculations,the intrinsic damping properties of the Mn-deficient CMG films can be well explained by considering the increase of density of states at the Fermi level,reduction of M_(s),and excitation of the PSSW mode.These findings provide a new clue to tuning the magnetic damping of the magnetic Weyl semimetal film through slight off-stoichiometry.
基金Acknowledgments We thank Drs Fengyong Liu and Sheng Luan at UC Berkeley, USA, for their discussion and help with the writing of the manuscript. This work was supported by grants from the National Natural Science Foundation of China (no. 30225037, 30471991, 30570731), National Basic Research Program of China (973 Program) (no. 2006CB503909, 2004CB518603), the "111" Project, and the Natural Science Foundation of Jiangsu Province (no. BK2004082, BK2006714).
基金This work was supported by grants from the National Natural Science Foundation of China (30225037, 30471991, 30570731), the 973 Program of China (2006CB503909, 2004CB518603), the "111" Project, and the Natural Science Foundation of Jiangsu Province (BK2004082, BIC2006714).
基金Supplementary information is linked to the online version of the paper on the Cell Research website. Acknowledgments We thank Yun Luo, Jia Jia and Dr Yun Xu at Nanjing University, Nanjing, China, for their scientific discussions and experimental assistance. This work was supported by grants from the National Natural Science Foundation of China (Nos. 30871195, 90813035, 30890044), the National Basic Research Program of China (Nos. 2006CB503909, 2004CB518603), the "111" Project, the Hi-Tech Research and Development Program of China (No. 2006AA02A112,), and the Natural Science Foundation of Jiangsu Province (Nos. BK2004082, BK2006714, BK2008021).
基金This work was supported by grants from the National Natural Science Foundation of China (No. 30225037, 30400538, 30471991,30570731);the 973 Program of China (No. 2006CB503909, 2004CB518603);the "111" Project, and the Natural Science Foundation of Jiangsu Province (No. BK2004082, BK2006714).
文摘A teaching strategy is a method, which can help students to gain knowledge, deliver information, and improve their learning. Different learning environments, such as clinical teaching, online teaching, and face-to-face traditional learning environments, require different teaching strategies for students. Choosing teaching strategies for a course is very important for nurse educators because various factors should be taken into account to make students meet the learning outcomes. The use of modern technologies in teaching strategies can improve students’ competencies and confidences. The purpose of this article is to create a toolbox integrating ten teaching strategies that can be used in different teaching environments.
基金supported by the National Natural Science Foundation of China(no.32070656)the Nanjing University Deng Feng Scholars Program.
文摘Single-cell transcriptomics has been fully embraced in plant biological research and is revolutionizing our understanding of plant growth,development,and responses to external stimuli.However,single-cell tran-scriptomic data analysis in plants is not trivial,given that there is currently no end-to-end solution and that integration of various bioinformatics tools involves a large number of required dependencies.Here,we pre-sent scPlant,a versatile framework for exploring plant single-cell atlases with minimuminput data provided by users.The scPlant pipeline is implemented with numerous functions for diverse analytical tasks,ranging from basic data processing to advanced demands such as cell-type annotation and deconvolution,trajec-tory inference,cross-species data integration,and cell-type-specific gene regulatory network construc-tion.In addition,a variety of visualization tools are bundled in a built-in Shiny application,enabling explo-ration of single-cell transcriptomic data on the fly.
基金supported by the National Natural Science Foundation of China(52106284)the Natural Science Foundation of Hebei Province(B2021507001)support of Project to Promote Innovation in Doctoral Research at CPPU(BSKY202302).
文摘The combustion and explosion characteristics of lithium-ion battery vent gas is a key factor in determining the fire hazard of lithium-ion batteries.Investigating the combustion and explosion hazards of lithium-ion batteries vent gas can provide guidance for rescue and protection in explosion accidents in energy storage stations and new energy vehicles,thereby promoting the application and development of lithium-ion batteries.Based on this understanding and combined with previous research on gas production from lithium-ion batteries,this article conducted a study on the combustion and explosion risks of vent gas from thermal runaway of 18650 LFP batteries with different states of charge(SOCs).The explosion limit of mixed gases affected by carbon dioxide inert gas is calculated through the“elimination”method,and the Chemkin-Pro software is used to numerically simulate the laminar flame speed and adiabatic flame temperature of the battery vent gas.And the concentration of free radicals and sensitivity coefficients of major elementary reactions in the system are analyzed to comprehensively evaluate the combustion explosion hazard of battery vent gas.The study found that the 100%SOC battery has the lowest explosion limit of the vent gas.The inhibitory elementary reaction sensitivity coefficient in the reaction system is lower and the concentration of free radicals is higher.Therefore,it has the maximum laminar flame speed and adiabatic flame temperature.The combustion and explosion hazard of battery vent gas increases with the increase of SOC,and the risk of explosion is the greatest and most harmful when SOC reaches 100%.However,the related hazards decrease to varying degrees with overcharging of the battery.This article provides a feasible method for analyzing the combustion mechanism of vent gas from lithium-ion batteries,revealing the impact of SOC on the hazardousness of battery vent gas.It provides references for the safety of storage and transportation of lithium-ion batteries,safety protection of energy storage stations,and the selection of related fire extinguishing agents.
基金by grants from the National Natural Science Foundation of China(Nos.90813035,81101330,81171661,30890044,30772484,30725008,30890032,31071232,31000323,90608010,and J1103512)the Natural Science Foundation of Jiangsu Province(No.BK2011013)the Fundamental Research Funds for the Central Universities(No.1107020839).
文摘A new class of RNA regulatory genes known as microRNAs(miRNAs)has been found to introduce a whole new layer of gene regulation in eukaryotes.The intensive studies of the past several years have demonstrated that miRNAs are not only found intracellularly,but are also detectable outside cells,including in various body fluids(e.g.serum,plasma,saliva,urine and milk).This phenomenon raises questions about the biological function of such extracellular miRNAs.Substantial amounts of extracellular miRNAs are enclosed in small membranous vesicles(e.g.exosomes,shedding vesicles and apoptotic bodies)or packaged with RNA-binding proteins(e.g.high-density lipoprotein,Argonaute 2 and nucleophosmin 1).These miRNAs may function as secreted signaling molecules to influence the recipient cell phenotypes.Furthermore,secreted extracellular miRNAs may reflect molecular changes in the cells from which they are derived and can therefore potentially serve as diagnostic indicators of disease.Several studies also point to the potential application of siRNA/miRNA delivery as a new therapeutic strategy for treating diseases.In this review,we summarize what is known about the mechanism of miRNA secretion.In addition,we describe the pathophysiological roles of secreted miRNAs and their clinical potential as diagnostic biomarkers and therapeutic drugs.We believe that miRNA transfer between cells will have a significant impact on biological research in the coming years.
基金This work was supported by grants from the National Basic Research Program(973 Program)(No.2014CB542300)the National Natural Science Foundation of China(Grant Nos.31200969,31200874,81101330,31271378,and 81250044)+2 种基金the National Science Fund for Distinguished Young Scholars(81025019)the Natural Science Foun-dation of Jiangsu Province(BK2011013 and BK2012014)the Research Fund for the Doctoral Program of Higher Education of China(20120091120044).
文摘Tumor-associated macrophages(TAMs)mostly exhibit M2-like(alternatively activated)properties and play posi-tive roles in angiogenesis and tumorigenesis.Vascular en-dothelial growth factor(VEGF)is a key angiogenic factor.During tumor development,TAMs secrete VEGF and other factors to promote angiogenesis;thus,anti-treatment against TAMs and VEGF can repress cancer development,which has been demonstrated in clinical trials and on an experimental level.In the present work,we show that miR-150 is an oncomir because of its promotional effect on VEGF.MiR-150 targets TAMs to up-regulate their secre-tion of VEGF in vitro.With the utilization of cell-derived vesicles,named microvesicles(MVs),we transferred an-tisense RNA targeted to miR-150 into mice and found that the neutralization of miR-150 down-regulates miR-150 and VEGF levels in vivo and attenuates angiogenesis.There-fore,we proposed the therapeutic potential of neutralizing miR-150 to treat cancer and demonstrated a novel,natu-ral,microvesicle-based method for the transfer of nucleic acids.
文摘Osteosarcoma is the most common primary sarcoma of bone, and it is a leading cause of cancer death among adolescents and young adults. However, the molecular mechanism underlying osteosarcoma carcinogenesis remains poorly understood. Recently, cyclin-dependent kinase 6 (CDK6) was identified as an important onco- gene. We found that CDK6 protein level, rather than CDK6 mRNA level, is much higher in osteosarcoma tissues than in normal adjacent tissues, which indicates a post-transcriptional mechanism involved in CDK6 regulation in osteosarcoma. MiRNAs are small non- coding RNAs that repress gene expression at the post- transcriptional level and have widely been shown to play important roles in many human cancers. In this study, we investigated the role of miR-29b as a novel regulator of CDK6 using bioinformatics methods. We demon- strated that CDK6 can be downregulated by miR-29b via binding to the 3'-UTR region in osteosarcoma cells. Furthermore, we identified an inverse correlation between miR-29b and CDK6 protein levels in osteosar- coma tissues. Finally, we examined the function of miR- 29b-driven repression of CDK6 expression in osteosarcoma cells. The results revealed that miR-29b acts as a tumor suppressor of osteosarcoma by targeting CDK6 in the proliferation and migration processes. Taken together, our results highlight an important role for miR-29b in the regulation of CDK6 in osteosarcoma and may open new avenues for future osteosarcoma therapies.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.30988003,31071232,3100032331000478 and 90608010)the National Basic Research Program(973 Program)(No.2011CB504803).
文摘Colostrum provides essential nutrients and immunologically active factors that are beneficial to newborns.Our previous work demonstrated that milk contains large amounts of miRNA that is largely stored in milk-derived microvesicles(MVs).In the present study,we found that the MVs from colostrum contain signifi cantly higher levels of several immune-related miRNAs.We hypothesized that the colostrum MVs may transfer the immune-related miR-NAs into cells,which contribute to its immune modulatory feature.We isolated colostrum MVs by ultracentrifugation and demonstrated several immune modulation features associated with miRNAs.We also provide evidence that the physical structure of milk-derived MVs is essential for transfer miRNAs and following immune modulation effect.Moreover,we found that colostrum powder-derived MVs also contains higher levels of immune-related miRNAs that display similar immune modulation effects.Taken together,these results show that MV-containing immunerelated miRNAs may be a novel mechanism by which co-lostrum modulates body immune response.
文摘The identification of important nodes in a power grid has considerable benefits for safety. Power networks vary in many aspects, such as scale and structure. An index system can hardly cover all the information in various situations. Therefore, the efficiency of traditional methods using an index system is case-dependent and not universal. To solve this problem, an artificial intelligence based method is proposed for evaluating power grid node importance. First, using a network embedding approach, a feature extraction method is designed for power grid nodes, considering their structural and electrical information. Then, for a specific power network, steady-state and node fault transient simulations under various operation modes are performed to establish the sample set. The sample set can reflect the relationship between the node features and the corresponding importance. Finally, a support vector regression model is trained based on the optimized sample set for the later online use of importance evaluation. A case study demonstrates that the proposed method can effectively evaluate node importance for a power grid based on the information learned from the samples. Compared with traditional methods using an index system, the proposed method can avoid some possible bias. In addition, a particular sample set for each specific power network can be established under this artificial intelligence based framework, meeting the demand of universality.
文摘Programmed cell death 4 (PDCD4) is a RNA-binding protein that acts as a tumor suppressor in many cancer types, including colorectal cancer (CRC). During CRC carcinogenesis, PDCD4 protein levels remarkably decrease, but the underlying molecular mechanism for decreased PDCD4 expression is not fully understood. In this study, we performed bioinformatics analysis to identify miRNAs that potentially target PDCD4. We demonstrated miR-181b as a direct regulator of PDCD4. We further showed that activation of IL6/STAT3 signaling pathway increased miR-181b expression and conse- quently resulted in downregulation of PDCD4 in CRC cells. In addition, we investigated the biological effects of PDCD4 inhibition by miR-181b both in vitro and in vivo and found that miR-181b could promote cell proliferation and migration and suppress apoptosis in CRC cells and accelerate tumor growth in xenograft mice, potentially through targeting PDCD4. Taken toge- ther, this study highlights an oncomiR role for miR-181b in regulating PDCD4 in CRC and suggests that miR-181b may be a novel molecular therapeutic target for CRC.
基金ACKNOWLEDGEMENTS This work was supported by grants from the National Basic Research Program (973 Program) (Nos. 2012CB517603 and 2011CB504803), the National Natural Science Foundation of China (Grant No. 31301061), the Natural Science Foundation of Jiangsu Province (No. BK2011013 and BK20130564), and the Specialized Research Fund for the Doctoral Program of Higher Education (20130091120037).
文摘The mechanism underlying T cell-mediated fulminant hepatitis is not fully understood. In this study, we investigated whether myeloid derived suppressor cells (MDSCs) could prevent the concanavalin A (ConA)- induced hepatitis through suppressing T cell proliferation. We observed an increase in the frequencies of MDSCs in mouse spleen and liver at early stage of ConA treatment, implicating that the MDSCs might be involved in the initial resistance of mice against ConA- mediated inflammation. Subpopulation analysis showed that the MDSCs in liver of ConA-induced mice were mainly granulocytic MDSCs. Adoptive transfer of the bone marrow-derived MDSCs into ConA-treated mice showed that the MDSCs migrated into the liver and spleen where they suppressed T cell proliferation through ROS pathway. In addition, the frequencies of MDSCs in mice were also significantly increased by the treatment with immune suppressor glucocorticoids. Transfer of MDSCs into the regulatory T cell (Treg)- depleted mice showed that the protective effect of MDSCs on ConA-induced hepatitis is Treg-independent. In conclusion, our results demonstrate that MDSCs possess a direct protective role in T cell-mediated hepatitis, and increasing the frequency of MDSCs by either adoptive transfer or glucocorticoid treatment represents a potential cell-based therapeutic strategy for the acute inflammatory disease.
文摘MTUS1 (microtubule-associated tumor suppressor 1) has been identified that can function as a tumor sup- pressor gene in many malignant tumors. However, the function and mechanisms underlying the regulation of MTUS1 are unclear. In the present study, we reported that miR-19a and miR-19b (miR-19a/b) promote prolifer- ation and migration of lung cancer cells by targeting MTUS1. First, MTUS1 was proved to function as a tumor suppressor in lung cancer and was linked to cell prolif- eration and migration promotion. Second, an inverse correlation between miR-19a/b expression and MTUS1 mRNA/protein expression was noted in human lung cancer tissues. Third, MTUS1 was appraised as a direct target of miR-19a/b by bioinformatics analysis. Fourth, direct MTUS1 regulation by miR-19a/b in lung cancer cells was experimentally affirmed by cell transfection assay and luciferase reporter assay. Finally, miR-19a/b were shown to cooperatively repress MTUS1 expression and synergistically regulate MTUS1 expression to pro- mote lung cancer cell proliferation and migration. In conclusion, our findings have provided the first cluesregarding the roles of miR-19a/b, which appear to func- tion as oncomirs in lung cancer by downregulating MTUSI.
基金supported by the National Basic Research Program of China (2014CB542300)the National Natural Science Foundation of China (81602697)+1 种基金the Natural Science Foundation of Jiangsu Province (BE2016737) the Fundamental Research Funds for the Central Universities (020814380070)
文摘Ophiocordyceps sinensis is well known as a traditional Chinese medicine and has widely been used for over 2,000 years to stimulate immune system, decrease blood pressure and to inhibit tumor growth. While miRNAs are increasingly recognized for their roles in post-transcriptional regulation of gene expression in animals and plants, miRNAs in fungi were less studied until the discovery of microRNA-like RNA(milRNA). High-throughput sequencing and bioinformatics approaches were used to identify conserved and novel milRNAs in O. sinensis. 40 conserved milRNAs were identified, while 23 pre-miRNA candidates encoding 31 novel milRNAs were predicted. Furthermore, the potential target genes of milRNAs in human were predicted and gene ontology analysis was applied to these genes. Enrichment analysis of GO-represented biological process showed that target genes of both conserved and novel milRNAs are involved in development, metabolic and immune processes, indicating the potential roles of milRNAs of O. sinensis in pharmacological effects as health food and traditional Chinese medicine. This study is the first report on genome-wide analysis of milRNAs in O. sinensis and it provides a useful resource to further study the potential roles of milRNAs as active components of O. sinensis in health food or traditional Chinese medicine.