Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigate...Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigated to improve the selective conversion of siderite to magnetite and CO,enriching the theoretical system of green SMR using siderite as a reductant.According to the gas products analyses,the peak value of the reaction rate increased with increasing temperature,and its curves presented the feature of an early peak and long tail.The mechanism function of the siderite pyrolysis was the contraction sphere model(R_(3)):f(α)=3(1−α)2/3;E_(α)was 46.4653 kJ/mol;A was 0.5938 s^(−1);the kinetics equation was k=0.5938exp[−46.4653/(RT)].The in-situ HT-XRD results indicated that siderite was converted into magnetite and wüstite that exhibited a good crystallinity in SMR under a N_(2) atmosphere.At 620℃,the saturation magnetization(M_(s)),remanence magnetization(Mr),and coercivity(Hc)of the product peaked at 53.63×10^(-3)A·m^(2)/g,10.23×10^(-3)A·m^(2)/g,and 12.40×10^(3)A/m,respectively.Meanwhile,the initial particles with a smooth surface were transformed into particles with a porous and loose structure in the roasting process,which would contribute to reducing the grinding cost.展开更多
Alkaline anions,include CO3^2–,HCO3^–,Al(OH)4^–,OH^–,continuously released from bauxite residue(BR),will cause a potential disastrous impact on surrounding environment.The composition variation of alkaline anions,...Alkaline anions,include CO3^2–,HCO3^–,Al(OH)4^–,OH^–,continuously released from bauxite residue(BR),will cause a potential disastrous impact on surrounding environment.The composition variation of alkaline anions,alkaline phase transformation pathway,and micro-morphological transition characteristics during the gypsum addition were investigated in an attempt to understand alkalinity stabilization behavior.Results demonstrated that alkaline anions stabilization degree in leachates can reach approximately 96.29%,whilst pH and alkalinity were reduced from 10.47 to 8.15,47.39 mmol/L to 2 mmol/L,respectively.During the alkalinity stabilization,chemical regulation behavior plays significant role in driving the co-precipitation reaction among the critical alkaline anions(CO3^2–,HCO3^–,Al(OH)4^–,OH^–),with calcium carbonate(CaCO3))being the most prevalent among the transformed alkaline phases.In addition,XRD and SEM-EDX analyses of the solid phase revealed that physical immobilization behavior would also influence the stability of soluble alkali and chemical bonded alkali due to released Ca^2+from gypsum which aggregated the clay particles and stabilized them into coarse particles with a blocky structure.These findings will be beneficial for effectively regulating strong alkalinity of BR.展开更多
Given the limited spontaneous repair that follows cartilage injury, demand is growing for tissue engi- neering approaches for cartilage regeneration. There are two major applications for tissue-engineered cartilage. O...Given the limited spontaneous repair that follows cartilage injury, demand is growing for tissue engi- neering approaches for cartilage regeneration. There are two major applications for tissue-engineered cartilage. One is in orthopedic surgery, in which the engineered cartilage is usually used to repair cartilage defects or loss in an articular joint or meniscus in order to restore the joint function. The other is for head and neck reconstruction, in which the engineered cartilage is usually applied to repair cartilage defects or loss in an auricle, trachea, nose, larynx, or eyelid. The challenges faced by the engineered car- tilage for one application are quite different from those faced by the engineered cartilage for the other application. As a result, the emphases of the engineering strategies to generate cartilage are usually quite different for each application. The statuses of preclinical animal investigations and of the clinical translation of engineered cartilage are also at different levels for each application. The aim of this review is to provide an opinion piece on the challenges, current developments, and future directions for cartilage engineering for both applications.展开更多
Objective.To study expression and localiza tion of Smad4protein,the common-mediator Smad,which is one of intracellular signaling molecules of transforming growth factor-afamily,in rat t estis during postnatal developm...Objective.To study expression and localiza tion of Smad4protein,the common-mediator Smad,which is one of intracellular signaling molecules of transforming growth factor-afamily,in rat t estis during postnatal development.Methods.In this study,whole testes were co llected from S.D rats aged3days,7days,14days and28days,and adult respe ctively.We examined the cellular localization and developmental change of Smad 4in rat testis by immunohistochemical ABC method with glucose oxidase-DAB-nic kel enhancement technique;the quantitative analysis of the immunostaining by t he image analysis system;the Smads pro-teins coexistence in the adult rat test is by the double immune staining for CD14-Smad4and Smad2-Smad4;the prote in expression of Smad during rat testicular development by means of Western blo ts.Results.The protein of Smad4was present in rats from3days of age to adul thood,and the im-munolocalization was exclusively localized to the cytoplasm o f Leydig cells with negative nuclei in the in-terstitial tissue at any time po int.No expression was detected in germ cells.The result of image and sta-tis tical analysis showed that generally,there was a tendency that the expression o f Smad4in the testes increased gradually with the rats developing maturation.C onclusion.Our data provide direct evidence for the molecular mechanism of TGF-aaction in rat testes during postnatal development and spermatogenesis of ra ts.展开更多
HuPBLSCID mice were used to explore how they would response to human tumor cells of 80llMLC.Living 80llMLC cells appeared to be fetal to the the mice due to the production of human TNF- The hupBL-SCID mice did not gen...HuPBLSCID mice were used to explore how they would response to human tumor cells of 80llMLC.Living 80llMLC cells appeared to be fetal to the the mice due to the production of human TNF- The hupBL-SCID mice did not generate any noticeable amount of specific human immunoglobulin either by single immunization with living 801/MLC cells or by repeated immunization with irradiated 80llMLC cells. Our preliminary experiments with huPBL-SCID mice showed that such chimeras would be a very useful models for tumor immunological researches.展开更多
Objective: To investigate the effect of cytokines (TNF-α,IFN-γ and IL-6) on the expression of sodium-iodide symporter(NIS)gene in breast cancer cell(MCF-7). Methods:The breast cancer cell was cultureds with negativ...Objective: To investigate the effect of cytokines (TNF-α,IFN-γ and IL-6) on the expression of sodium-iodide symporter(NIS)gene in breast cancer cell(MCF-7). Methods:The breast cancer cell was cultureds with negative control culture or culture with different concentrations of cytokines for 72 h.NIS gene mRNA in breast cancer cells cultured was determined by reverse transcriptase-polymerase chain reaction(RT-PCR). Results:Expression of sodium-iodide symporter mRNA can be found decreasing along with increasing the concentration of cytokine dose-dependently. Conclusion: Cytokine may play a role in iodide-uptake modulating in breast cancer cells by their effect on NIS gene expression.展开更多
Animal nutrition is one of the most important limiting factors in animal production, especially in ruminants, providing proteins being the main constraint, due to the limited availability and high cost of protein sour...Animal nutrition is one of the most important limiting factors in animal production, especially in ruminants, providing proteins being the main constraint, due to the limited availability and high cost of protein sources (oilseed meals). Currently in the dam "El lnfiernillo" in Michoacan Mexico, has a large population of devil fish (Pterygoplichthys spp.), which is an economic and ecological problem, because it is not consumed by humans and causes pollution to be discarded directly into the environment. For that reason the objective of this study was to evaluate the use of silage acid devil fish (SADF) in fattening beef cattle as a protein supplement. SADF is defined as a product semi-liquid or pasty mixed with formic acid, which leads to a decrease in pH to near 4.0. Used 18 young bulls (Bos taurus × Bos indicus) for 60 days with a starting weight of 278.9 ± 51.2 kg, housed in individual pens with food and water ad libitum were randomly assigned to three treatments with different levels of inclusion SADF (0%, 12% and 18%). They were weighed to the beginning of the experiment and later every 30 days, previous fasting of 24 hours. To determine the food consumption, weigh every day the offered food and the surplus. There were no significant differences (P 〈 0.05) among treatments with different levels of inclusion of SADF with respect to daily weight gain, with values of 952 ± 324, 927 ±322 and 854 ± 307 g/day, respectively. The dry matter intake (DMI) was 8.9, 9.3 and 7.7 kg/day to 0%, 12% and 18% of SADF, respectively. In the same values for feed conversion were 9.34, 10.03 and 9.01 kg DMI/kg of weigh live, and carcass yield of 60.6%, 60.3% and 58.5%, respectively. It is concluded that fish silage acid devil is an excellent alternative in feeding beef cattle as a protein supplement.展开更多
The thermodynamics,kinetics,phase transformation,and microstructure evolution of vanadium-bearing stone coal during suspension roasting were systematically investigated.Thermodynamic calculations showed that the carbo...The thermodynamics,kinetics,phase transformation,and microstructure evolution of vanadium-bearing stone coal during suspension roasting were systematically investigated.Thermodynamic calculations showed that the carbon in the stone coal burned and produced CO_(2) in sufficient oxygen during roasting.The mass loss of stone coal mainly occurred within the temperature range from 600 to 840℃,and the thermal decomposition reaction rate increased to the peak at approximately 700℃.Verified by the Flynn−Wall−Ozawa(FWO)and Kissinger−Akahira−Sunose(KAS)methods,the thermal decomposition reaction of stone coal was described by the Ginstling−Brounshtein equation.The apparent activation energy and pre-exponential factors were 136.09 kJ/mol and 12.40 s^(−1),respectively.The illite in stone coal lost hydroxyl groups and produced dehydrated illite at 650℃,and the structure of sericite was gradually destroyed.The surface of stone coal became rough and irregular as the temperature increased.Severe sintering occurred at the roasting temperature of 850℃.展开更多
Cricket is widely recognized in Indonesia especially in Java island, and commonly kept by village farmers for food and feed. In general, crickets has very short life cycle (60-70 d), with three weeks of laying perio...Cricket is widely recognized in Indonesia especially in Java island, and commonly kept by village farmers for food and feed. In general, crickets has very short life cycle (60-70 d), with three weeks of laying period and egg production within the range of 200-1,500 eggs/female. The female has capability for multiple mating with several males and therefore produces more fertile eggs. Serial studies including experiments on laboratory and field observation of local crickets had been conducted to evaluate the farming practices and reproductive performance of three local species (Gryllus spp., Gryllus mitratus and Gryllus testaceus) which were given local feeds--Manihot esculenta and Carica papaya leaves. The experiment was conducted in randomized block design with feed as the treatments and species as the block. Cliring crickets (G. mitratus) fed with M. esculenta leaves revealed the highest total egg production (1,478.22 eggs), with daily egg production of 32.85 eggs/d, the longest laying period (45 d), the lowest feed intake (0.28 g/head) and feed conversion (0.93 mg/egg), compared to Cendawang crickets (G. testaceus) and Gryllus spp.. The revenue and cost (R/C) ratio was 1.4, indicating that small scale cricket enterprise could offer significant profit and could be chosen as an alternative activities for earning regular income.展开更多
Recent deep sequencing surveys of mammalian genomes have unexpectedly revealed pervasive and complex transcription and identified tens of thousands of RNA transcripts that do not code for proteins. These non-coding RN...Recent deep sequencing surveys of mammalian genomes have unexpectedly revealed pervasive and complex transcription and identified tens of thousands of RNA transcripts that do not code for proteins. These non-coding RNAs(nc RNAs) highlight the central role of RNA in gene regulation. nc RNAs are arbitrarily divided into two main groups: The first includes small RNAs, such as mi RNAs, pi RNAs, and endogenous si RNAs, that usually range from 20 to 30 nt, while the second group includes long non-coding RNAs(lnc RNAs), which are typically more than 200 nt in length. These nc RNAs were initially thought to merely regulate gene expression at the post-transcriptional level, but recent studies have indicated that nc RNAs, especially lnc RNAs, are extensively associated with diverse chromatin remodeling complexes and target them to specific genomic loci to alter DNA methylation or histone status. These findings suggest an emerging theme of nc RNAs in epigenetic regulation. In this review, we discuss the wide spectrum of nc RNAs in the regulation of DNA methylation and chromatin state, as well as the key questions that needs to be investigated and acknowledging the elegant design of these intriguing macromolecules.展开更多
Epithelial–mesenchymal transition(EMT) is a complex nonlinear biological process that plays essential roles in fundamental biological processes such as embryogenesis, wounding healing, tissue regeneration,and cancer ...Epithelial–mesenchymal transition(EMT) is a complex nonlinear biological process that plays essential roles in fundamental biological processes such as embryogenesis, wounding healing, tissue regeneration,and cancer metastasis. A hallmark of EMT is the switch-like behavior during state transition, which is characteristic of phase transitions. Hence, detecting the tipping point just before mesenchymal state transition is critical for understanding molecular mechanism of EMT. Through dynamic network biomarkers(DNB) model, a DNB group with 37 genes was identified which can provide the early-warning signals of EMT. Particularly, we found that two DNB genes, i.e., SMAD7 and SERPINE1 promoted EMT by switching their regulatory network which was further validated by biological experiments. Survival analyses revealed that SMAD7 and SERPINE1 as DNB genes further acted as prognostic biomarkers for lung adenocarcinoma.展开更多
As an essential component of proteins and genetic material for all organisms, nitrogen(N) is one of the major limiting factors that control the dynamics, biodiversity and functioning of lacustrine wetlands, in which i...As an essential component of proteins and genetic material for all organisms, nitrogen(N) is one of the major limiting factors that control the dynamics, biodiversity and functioning of lacustrine wetlands, in which intensified N biogeochemical activities take place. Reactive N loaded into wetland ecosystems has been doubled due to various human activities, including industrial, agricultural activities and urbanization. The main driving mechanisms of N transport and transformation in lacustrine wetlands are categorized to pushing forces and pulling forces in this study. Geomorphology, wetland age, N concentrations, and temperature are the main pushing forces(passive forces); whereas water table variation, oxygen concentration, other elements availability, oxidation-reduction potential(Eh) and p H, and microorganisms are the predominant pulling forces(active forces). The direction and kinetic energy of reactions are determined by pulling forces and then are stimulated by pushing forces. These two types of forces are analyzed and discussed separately. Based on the analysis of driving mechanisms, possible solutions to wetland N pollutions are proposed at individual, regional and global scales, respectively. Additional research needs are addressed to obtain a thorough understanding of N transport and transformations in wetlands and to reduce detrimental impacts of excessive N on such fragile ecosystems.展开更多
The stress response of amorphous polymers in the glass transition region shows apparent temperature and rate dependence.With increasing loading rate,amorphous polymers also exhibit a clear ductile-brittle transition o...The stress response of amorphous polymers in the glass transition region shows apparent temperature and rate dependence.With increasing loading rate,amorphous polymers also exhibit a clear ductile-brittle transition of tensile failure.The rate-dependent behaviors originate from intrinsic relaxations,ranging from perturbation of molecular bonds between polymer segments to reptation of polymer chains.In this work,we develop a constitutive model that incorporates segmental and chain dynamics into the deformation of bond and polymer networks,respectively.The dynamic scission of polymer chains is also incorporated into the theoretical framework to describe the damage evolution and ultimate failure of polymers.A comparison between theoretical predictions and experiments shows that the present model is able to simultaneously capture the observed rate-dependent features,including the transition from glassy state to rubbery state,strain hardening,and failure threshold.展开更多
基金Projects(51874071,52022019,51734005)supported by the National Natural Science Foundation of ChinaProject(161045)supported by the Fok Ying Tung Education Foundation for Yong Teachers in the Higher Education Institutions of China。
文摘Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigated to improve the selective conversion of siderite to magnetite and CO,enriching the theoretical system of green SMR using siderite as a reductant.According to the gas products analyses,the peak value of the reaction rate increased with increasing temperature,and its curves presented the feature of an early peak and long tail.The mechanism function of the siderite pyrolysis was the contraction sphere model(R_(3)):f(α)=3(1−α)2/3;E_(α)was 46.4653 kJ/mol;A was 0.5938 s^(−1);the kinetics equation was k=0.5938exp[−46.4653/(RT)].The in-situ HT-XRD results indicated that siderite was converted into magnetite and wüstite that exhibited a good crystallinity in SMR under a N_(2) atmosphere.At 620℃,the saturation magnetization(M_(s)),remanence magnetization(Mr),and coercivity(Hc)of the product peaked at 53.63×10^(-3)A·m^(2)/g,10.23×10^(-3)A·m^(2)/g,and 12.40×10^(3)A/m,respectively.Meanwhile,the initial particles with a smooth surface were transformed into particles with a porous and loose structure in the roasting process,which would contribute to reducing the grinding cost.
基金Project(41877511)supported by the National Natural Science Foundation of ChinaProject(201509048)supported by the Environmental Protection’s Special Scientific Research for the Chinese Public Welfare Industry,China
文摘Alkaline anions,include CO3^2–,HCO3^–,Al(OH)4^–,OH^–,continuously released from bauxite residue(BR),will cause a potential disastrous impact on surrounding environment.The composition variation of alkaline anions,alkaline phase transformation pathway,and micro-morphological transition characteristics during the gypsum addition were investigated in an attempt to understand alkalinity stabilization behavior.Results demonstrated that alkaline anions stabilization degree in leachates can reach approximately 96.29%,whilst pH and alkalinity were reduced from 10.47 to 8.15,47.39 mmol/L to 2 mmol/L,respectively.During the alkalinity stabilization,chemical regulation behavior plays significant role in driving the co-precipitation reaction among the critical alkaline anions(CO3^2–,HCO3^–,Al(OH)4^–,OH^–),with calcium carbonate(CaCO3))being the most prevalent among the transformed alkaline phases.In addition,XRD and SEM-EDX analyses of the solid phase revealed that physical immobilization behavior would also influence the stability of soluble alkali and chemical bonded alkali due to released Ca^2+from gypsum which aggregated the clay particles and stabilized them into coarse particles with a blocky structure.These findings will be beneficial for effectively regulating strong alkalinity of BR.
文摘Given the limited spontaneous repair that follows cartilage injury, demand is growing for tissue engi- neering approaches for cartilage regeneration. There are two major applications for tissue-engineered cartilage. One is in orthopedic surgery, in which the engineered cartilage is usually used to repair cartilage defects or loss in an articular joint or meniscus in order to restore the joint function. The other is for head and neck reconstruction, in which the engineered cartilage is usually applied to repair cartilage defects or loss in an auricle, trachea, nose, larynx, or eyelid. The challenges faced by the engineered car- tilage for one application are quite different from those faced by the engineered cartilage for the other application. As a result, the emphases of the engineering strategies to generate cartilage are usually quite different for each application. The statuses of preclinical animal investigations and of the clinical translation of engineered cartilage are also at different levels for each application. The aim of this review is to provide an opinion piece on the challenges, current developments, and future directions for cartilage engineering for both applications.
文摘Objective.To study expression and localiza tion of Smad4protein,the common-mediator Smad,which is one of intracellular signaling molecules of transforming growth factor-afamily,in rat t estis during postnatal development.Methods.In this study,whole testes were co llected from S.D rats aged3days,7days,14days and28days,and adult respe ctively.We examined the cellular localization and developmental change of Smad 4in rat testis by immunohistochemical ABC method with glucose oxidase-DAB-nic kel enhancement technique;the quantitative analysis of the immunostaining by t he image analysis system;the Smads pro-teins coexistence in the adult rat test is by the double immune staining for CD14-Smad4and Smad2-Smad4;the prote in expression of Smad during rat testicular development by means of Western blo ts.Results.The protein of Smad4was present in rats from3days of age to adul thood,and the im-munolocalization was exclusively localized to the cytoplasm o f Leydig cells with negative nuclei in the in-terstitial tissue at any time po int.No expression was detected in germ cells.The result of image and sta-tis tical analysis showed that generally,there was a tendency that the expression o f Smad4in the testes increased gradually with the rats developing maturation.C onclusion.Our data provide direct evidence for the molecular mechanism of TGF-aaction in rat testes during postnatal development and spermatogenesis of ra ts.
文摘HuPBLSCID mice were used to explore how they would response to human tumor cells of 80llMLC.Living 80llMLC cells appeared to be fetal to the the mice due to the production of human TNF- The hupBL-SCID mice did not generate any noticeable amount of specific human immunoglobulin either by single immunization with living 801/MLC cells or by repeated immunization with irradiated 80llMLC cells. Our preliminary experiments with huPBL-SCID mice showed that such chimeras would be a very useful models for tumor immunological researches.
文摘Objective: To investigate the effect of cytokines (TNF-α,IFN-γ and IL-6) on the expression of sodium-iodide symporter(NIS)gene in breast cancer cell(MCF-7). Methods:The breast cancer cell was cultureds with negative control culture or culture with different concentrations of cytokines for 72 h.NIS gene mRNA in breast cancer cells cultured was determined by reverse transcriptase-polymerase chain reaction(RT-PCR). Results:Expression of sodium-iodide symporter mRNA can be found decreasing along with increasing the concentration of cytokine dose-dependently. Conclusion: Cytokine may play a role in iodide-uptake modulating in breast cancer cells by their effect on NIS gene expression.
文摘Animal nutrition is one of the most important limiting factors in animal production, especially in ruminants, providing proteins being the main constraint, due to the limited availability and high cost of protein sources (oilseed meals). Currently in the dam "El lnfiernillo" in Michoacan Mexico, has a large population of devil fish (Pterygoplichthys spp.), which is an economic and ecological problem, because it is not consumed by humans and causes pollution to be discarded directly into the environment. For that reason the objective of this study was to evaluate the use of silage acid devil fish (SADF) in fattening beef cattle as a protein supplement. SADF is defined as a product semi-liquid or pasty mixed with formic acid, which leads to a decrease in pH to near 4.0. Used 18 young bulls (Bos taurus × Bos indicus) for 60 days with a starting weight of 278.9 ± 51.2 kg, housed in individual pens with food and water ad libitum were randomly assigned to three treatments with different levels of inclusion SADF (0%, 12% and 18%). They were weighed to the beginning of the experiment and later every 30 days, previous fasting of 24 hours. To determine the food consumption, weigh every day the offered food and the surplus. There were no significant differences (P 〈 0.05) among treatments with different levels of inclusion of SADF with respect to daily weight gain, with values of 952 ± 324, 927 ±322 and 854 ± 307 g/day, respectively. The dry matter intake (DMI) was 8.9, 9.3 and 7.7 kg/day to 0%, 12% and 18% of SADF, respectively. In the same values for feed conversion were 9.34, 10.03 and 9.01 kg DMI/kg of weigh live, and carcass yield of 60.6%, 60.3% and 58.5%, respectively. It is concluded that fish silage acid devil is an excellent alternative in feeding beef cattle as a protein supplement.
基金the Fundamental Research Funds for the Central Universities of China(No.N2101023).
文摘The thermodynamics,kinetics,phase transformation,and microstructure evolution of vanadium-bearing stone coal during suspension roasting were systematically investigated.Thermodynamic calculations showed that the carbon in the stone coal burned and produced CO_(2) in sufficient oxygen during roasting.The mass loss of stone coal mainly occurred within the temperature range from 600 to 840℃,and the thermal decomposition reaction rate increased to the peak at approximately 700℃.Verified by the Flynn−Wall−Ozawa(FWO)and Kissinger−Akahira−Sunose(KAS)methods,the thermal decomposition reaction of stone coal was described by the Ginstling−Brounshtein equation.The apparent activation energy and pre-exponential factors were 136.09 kJ/mol and 12.40 s^(−1),respectively.The illite in stone coal lost hydroxyl groups and produced dehydrated illite at 650℃,and the structure of sericite was gradually destroyed.The surface of stone coal became rough and irregular as the temperature increased.Severe sintering occurred at the roasting temperature of 850℃.
文摘Cricket is widely recognized in Indonesia especially in Java island, and commonly kept by village farmers for food and feed. In general, crickets has very short life cycle (60-70 d), with three weeks of laying period and egg production within the range of 200-1,500 eggs/female. The female has capability for multiple mating with several males and therefore produces more fertile eggs. Serial studies including experiments on laboratory and field observation of local crickets had been conducted to evaluate the farming practices and reproductive performance of three local species (Gryllus spp., Gryllus mitratus and Gryllus testaceus) which were given local feeds--Manihot esculenta and Carica papaya leaves. The experiment was conducted in randomized block design with feed as the treatments and species as the block. Cliring crickets (G. mitratus) fed with M. esculenta leaves revealed the highest total egg production (1,478.22 eggs), with daily egg production of 32.85 eggs/d, the longest laying period (45 d), the lowest feed intake (0.28 g/head) and feed conversion (0.93 mg/egg), compared to Cendawang crickets (G. testaceus) and Gryllus spp.. The revenue and cost (R/C) ratio was 1.4, indicating that small scale cricket enterprise could offer significant profit and could be chosen as an alternative activities for earning regular income.
文摘Recent deep sequencing surveys of mammalian genomes have unexpectedly revealed pervasive and complex transcription and identified tens of thousands of RNA transcripts that do not code for proteins. These non-coding RNAs(nc RNAs) highlight the central role of RNA in gene regulation. nc RNAs are arbitrarily divided into two main groups: The first includes small RNAs, such as mi RNAs, pi RNAs, and endogenous si RNAs, that usually range from 20 to 30 nt, while the second group includes long non-coding RNAs(lnc RNAs), which are typically more than 200 nt in length. These nc RNAs were initially thought to merely regulate gene expression at the post-transcriptional level, but recent studies have indicated that nc RNAs, especially lnc RNAs, are extensively associated with diverse chromatin remodeling complexes and target them to specific genomic loci to alter DNA methylation or histone status. These findings suggest an emerging theme of nc RNAs in epigenetic regulation. In this review, we discuss the wide spectrum of nc RNAs in the regulation of DNA methylation and chromatin state, as well as the key questions that needs to be investigated and acknowledging the elegant design of these intriguing macromolecules.
基金supported by the National Key Research and Development Program of China (2017YFA0505500)the National Natural Science Foundation of China (31930022, 31771476, 61773196)+5 种基金Shanghai Municipal Science and Technology Major Project (2017SHZDZX01)Key Project of Zhangjiang National Innovation Demonstration Zone Special Development Fund (ZJ2018ZD-013)Ministry of Science and Technology Project (2017YFC0907505)Guangdong Provincial Key Laboratory Funds (2017B030301018, 2019B030301001)Shenzhen Research Funds (JCYJ20170307104535585, ZDSYS20140509142721429)Shenzhen Peacock Plan (KQTD2016053117035204)
文摘Epithelial–mesenchymal transition(EMT) is a complex nonlinear biological process that plays essential roles in fundamental biological processes such as embryogenesis, wounding healing, tissue regeneration,and cancer metastasis. A hallmark of EMT is the switch-like behavior during state transition, which is characteristic of phase transitions. Hence, detecting the tipping point just before mesenchymal state transition is critical for understanding molecular mechanism of EMT. Through dynamic network biomarkers(DNB) model, a DNB group with 37 genes was identified which can provide the early-warning signals of EMT. Particularly, we found that two DNB genes, i.e., SMAD7 and SERPINE1 promoted EMT by switching their regulatory network which was further validated by biological experiments. Survival analyses revealed that SMAD7 and SERPINE1 as DNB genes further acted as prognostic biomarkers for lung adenocarcinoma.
基金the National Natural Science Foundation of China (Grant No. 41272249)Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20110072110020)
文摘As an essential component of proteins and genetic material for all organisms, nitrogen(N) is one of the major limiting factors that control the dynamics, biodiversity and functioning of lacustrine wetlands, in which intensified N biogeochemical activities take place. Reactive N loaded into wetland ecosystems has been doubled due to various human activities, including industrial, agricultural activities and urbanization. The main driving mechanisms of N transport and transformation in lacustrine wetlands are categorized to pushing forces and pulling forces in this study. Geomorphology, wetland age, N concentrations, and temperature are the main pushing forces(passive forces); whereas water table variation, oxygen concentration, other elements availability, oxidation-reduction potential(Eh) and p H, and microorganisms are the predominant pulling forces(active forces). The direction and kinetic energy of reactions are determined by pulling forces and then are stimulated by pushing forces. These two types of forces are analyzed and discussed separately. Based on the analysis of driving mechanisms, possible solutions to wetland N pollutions are proposed at individual, regional and global scales, respectively. Additional research needs are addressed to obtain a thorough understanding of N transport and transformations in wetlands and to reduce detrimental impacts of excessive N on such fragile ecosystems.
基金supported by the National Natural Science Foundation of China(Grant Nos.12022204,12002302 and 12072316)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ21A020008)the Fundamental Research Funds of Zhejiang Sci-Tech University(Grant No.2021Q039).
文摘The stress response of amorphous polymers in the glass transition region shows apparent temperature and rate dependence.With increasing loading rate,amorphous polymers also exhibit a clear ductile-brittle transition of tensile failure.The rate-dependent behaviors originate from intrinsic relaxations,ranging from perturbation of molecular bonds between polymer segments to reptation of polymer chains.In this work,we develop a constitutive model that incorporates segmental and chain dynamics into the deformation of bond and polymer networks,respectively.The dynamic scission of polymer chains is also incorporated into the theoretical framework to describe the damage evolution and ultimate failure of polymers.A comparison between theoretical predictions and experiments shows that the present model is able to simultaneously capture the observed rate-dependent features,including the transition from glassy state to rubbery state,strain hardening,and failure threshold.