There is a cyclical aperture at a certain part of the fiberglass reinforced plastic compound pipeline with a stainless steel pipe as a liner, which becomes the weakness of the conduit. The field of stress and strain o...There is a cyclical aperture at a certain part of the fiberglass reinforced plastic compound pipeline with a stainless steel pipe as a liner, which becomes the weakness of the conduit. The field of stress and strain of the aperture was investigated using the nonliner finite element code Marc. The results of the finite element analysis showed that there were concentrations of stress and strain in the layer of stainless steel at the part of the pipeline where the aperture existed. The method to solve these problems was also discussed.展开更多
With the global warming and climate change in recent years, heat stress has become one of the major abiotic factors constraining production and productivity of crops in many regions around the world. Although the plan...With the global warming and climate change in recent years, heat stress has become one of the major abiotic factors constraining production and productivity of crops in many regions around the world. Although the plants have developed some adaptive behaviors and avoidance mechanisms against heat stress, they will be hurt under extreme high temperature. Exogenous compounds could enhance plant growth and development, antioxidant enzymes activities, chlorophyll and nutrient contents under stress conditions. Meanwhile, application of exogenous compounds sustains physiological and biochemical process and prevents plants from physiological changes under stress conditions. In this review, effects of heat stress upon crops, and the functions of hormones in plant adaptation to heat stress are simply stated. Then, we intend to appraise how various phytohomrnones that are related to plant adaptation to heat stress. The role of abscisic acid(ABA), salicylic acid(SA) and polyamines(putrescine and spermine) under heat stress conditions are mainly discussed.展开更多
Objective: To investigate the effect of Compound Danshen Dripping Pills (CDDP) on oxidative stress after ischemia/reperfusion (I/R) injury in the rat retina. Methods: Adult male SD rats were randomly divided into 3 gr...Objective: To investigate the effect of Compound Danshen Dripping Pills (CDDP) on oxidative stress after ischemia/reperfusion (I/R) injury in the rat retina. Methods: Adult male SD rats were randomly divided into 3 groups: sham (group A), I/R (group B), and I/R plus CDDP (group C). Retinal ischemia/reperfusion injury (RIRI) was introduced by increasing the intraocular pressure (IOP) to 110 mmHg for 60 min via cannulation into the anterior chamber. Right after the insult, CDDP was administered intragastrically (450 mg/kg/d) for 7 days. The levels of malondialdehyde (MDA), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in the retinal tissues were determined on d1 and d7 after the ischemic insult. Results: Following ischemia, the MDA levels in group B and group C were significantly higher than those in group A (p < 0.01). CDDP significantly lowered MDA levels in group C when compared with group B (p < 0.01). The activities of SOD, GSH-Px and CAT were higher in group A than in group B and group C (p < 0.01). CDDP could increase the activities of SOD, GSH-Px and CAT remarkably in group C when compared with group B (p < 0.01). Conclusion: CDDP can protect the retina from I/R injury through reducing oxidative stress, and thus may be a promising method for the treatment of ischemic retinal disorders.展开更多
目的:通过数据挖掘方法探究复方金果胃康散促使胃癌细胞发生铁死亡的作用机制。方法:以复方金果胃康散7种中药(藤梨根、半枝莲、橘红、太子参、白花蛇舌草、黄药子、守宫)为主题词,分别在中国知网、万方数据库以及中药系统药理学数据库...目的:通过数据挖掘方法探究复方金果胃康散促使胃癌细胞发生铁死亡的作用机制。方法:以复方金果胃康散7种中药(藤梨根、半枝莲、橘红、太子参、白花蛇舌草、黄药子、守宫)为主题词,分别在中国知网、万方数据库以及中药系统药理学数据库与分析平台(traditional Chinese medicine systems pharmacology database and analysis platform,TCMSP)检索药物有效成分及对应相关蛋白。运用Excel、计算机R语言基本算法等对有效成分、蛋白等进行分析,构建发挥作用的蛋白与复方金果胃康散中其他蛋白之间的蛋白网络,并分析其作用关系。结果:共得到复方金果胃康散有效成分1814种,蛋白358种;胃癌蛋白23219种;铁死亡蛋白749种,其中铁代谢蛋白180种,氧化应激蛋白595种。共63个核心蛋白组成蛋白组,主要涉及铁代谢和氧化应激两个主要途径,以CYP3A4为代表的11种蛋白只在铁代谢过程起作用;以MAPK8为代表的43种蛋白只作用于氧化应激过程;以CYP1A1为代表的9种蛋白同时作用于铁代谢和氧化应激两个过程。氧化应激主要涉及NOX1、MAPK14等9种分子;铁代谢通路主要涉及细胞色素P4503A4等物质。结论:复方金果胃康散通过诱导肿瘤细胞发生铁死亡对胃癌发挥治疗作用。展开更多
Senescence is a natural, energy-dependent, physiological, developmental and an ecological process that is controlled by the plant’s own genetic program, allowing maximum recovery of nutrients from older organs for th...Senescence is a natural, energy-dependent, physiological, developmental and an ecological process that is controlled by the plant’s own genetic program, allowing maximum recovery of nutrients from older organs for the survival of the plant, as such;it is classified as essential component of the growth and development of plants. In some cases, under one or many environmental stresses, senescence is triggered in plants. Despite many studies in the area, less consideration has been given to plant secondary metabolites, especially the role of VTCs on plant senescence. This review seeks to capture the biosynthesis and signal transduction of VTCs, the physiology of VTCs in plant development and how that is linked to some phytohormones to induce senescence. Much progress has been made in the elucidation of metabolic pathways leading to the biosynthesis of VTCs. In addition to the classical cytosolic mevalonic acid (MVA) pathway from acetyl-CoA, the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, originating from glyceraldehyde-3-phosphate (GAP) and pyruvate, leads to the biosynthesis of isoprenoid precursors, isopentenyl diphosphate and dimethyl allyl diphosphate. VTCs synthesis and emission are believed to be tightly regulated by photosynthetic carbon supply into MEP pathway. Thus, under abiotic stresses such as drought, high salinity, high and low temperature, and low CO2 that directly affect stomatal conductance and ultimately biochemical limitation to photosynthesis, there has been observed induction of VTC synthesis and emissions, reflecting the elicitation of MEP pathway. This reveals the possibility of important function(s) of VTCs in plant defense against stress by mobilizing resources from components of plants and therefore, senescence. Our current understanding of the relationship between environmental responses and senescence mostly comes from the study of senescence response to phytohormones such as abscisic acid, jasmonic acid, ethylene and salicylic acid, which are extensively involved in response to various abiotic and biotic stresses. These stresses affect synthesis and/or signaling pathways of phytohormones to eventually trigger expression of stress-responsive genes, which in turn appears to affect leaf senescence. Comparison of plant response to stresses in relation to patterns of VTCs and phytohormones biosynthesis indicates a considerable crosstalk between these metabolic processes and their signal to plant senescence.展开更多
Abstract The metabolites of tall fescue leaves under normal and drought conditions were analyzed with LC-ESI-MS （ liquid chromatography tandem mass spec- trometry）. A total of 282 metabolites were stably detected in...Abstract The metabolites of tall fescue leaves under normal and drought conditions were analyzed with LC-ESI-MS （ liquid chromatography tandem mass spec- trometry）. A total of 282 metabolites were stably detected in the two groups using OPI.S-DA （orthogonal partial least squares discriminant analysis） method; 148 of which were down-regulated while 134 were up-regulated. After analyzed with MZ-minc software, 10 major metabolites （4 down, 6 up） were identified through searehing public database. Aromatic compounds, 3-p-eoumaroyll, 5-quinolaetone, aromatic free amino acids, styraxin mad methanofuran, were up-regulated ; grease metabolites, methyl 15-hydroperoxy-9Z, 12Z, 16E-octadecatrienoate, 9,12,13-Tri-HOME （10）, 3-oxo-dodecanoic acid, and 13 （S）-HpOTrE acid ester, were down-regulated; piperanine （alkaloids） was down-regulated while Methyl 7-epi-12-hydroxyjasmonate glucoside （indicant） was up-regulated. In a word, aromatic compounds and liquid metabolites may play vital roles in drought-resistant regulation of tall fescue.展开更多
We examined the influence of oral malodor on psychological stress among patients with a chief complaint of oral malodor. A total of 101 patients (40 male and 61 female) who visited our clinic with a chief complaint of...We examined the influence of oral malodor on psychological stress among patients with a chief complaint of oral malodor. A total of 101 patients (40 male and 61 female) who visited our clinic with a chief complaint of oral malodor were included in this study. The primary compounds of oral malodor—volatile sulfur compounds (VSC)—were measured using the Oral ChromaTM instrument. Salivary stress markers, cortisol, and chromogranin A were measured using an enzyme-linked immunosorbent assay (ELISA) kit. The mood was measured using the Profile of Mood States 2nd Edition (POMS2). Among the participants, 60.3% had at least one level above the threshold in the following three markers: hydrogen sulfide, methyl mercaptan, and dimethyl sulfide. The gender distribution was 35 female (57.4%) and 25 male (62.5%). Salivary cortisol levels, a biomarker of stress, did not vary depending on the presence or absence of oral malodor. Chromogranin A levels were higher in the oral malodor female group than in the no oral malodor female group. With respect to the POMS2, regardless of the presence or absence of oral malodor measured using gas chromatography, the participants had higher scores for “Anger-Hostility” and “Fatigue-Inertia”. Analysis by gender showed that “Depression-Dejection” was significantly higher in the oral malodor female group than in the no oral malodor female group. These results suggest that those who are worried about oral malodor have higher psychological stress than those who are not, regardless of the presence or absence of oral malodor measured using gas chromatography.展开更多
Hydraulic calculation of steady uniform flows in trapezoidal compound open channels is studied. Based on the force balance of water in each sub-section, the average velocities of the main channel, side slope, and floo...Hydraulic calculation of steady uniform flows in trapezoidal compound open channels is studied. Based on the force balance of water in each sub-section, the average velocities of the main channel, side slope, and floodplain are derived. The lateral momentum exchanges between the sub-sections are expressed by using the apparent shear stress. To verify the model, seven groups of UK Flood Channel Facility （UK-FCF） measured data with a relative water depth between the floodplain and the main channel varying from 0.057 to 0.4 are used for comparison. The result shows that the calculated velocity is larger than the measured data when the relative water depth is small, while it is less than or close to the measured value in the case of a larger relative water depth. The influence of the apparent shear stress on the calculation of velocity on the floodplain is not obvious, while it is much greater on the main channel. The three-stage model is compared with Liu’s two-stage model, showing that the former can give a better prediction for a three-stage trapezoidal compound channel. Finally, the apparent shear stress is calculated and compared with the measured data. The result shows that the chosen values of the momentum transfer coefficients are appropriate.展开更多
文摘There is a cyclical aperture at a certain part of the fiberglass reinforced plastic compound pipeline with a stainless steel pipe as a liner, which becomes the weakness of the conduit. The field of stress and strain of the aperture was investigated using the nonliner finite element code Marc. The results of the finite element analysis showed that there were concentrations of stress and strain in the layer of stainless steel at the part of the pipeline where the aperture existed. The method to solve these problems was also discussed.
基金Supported by Natural Science Foundation of Hubei Province(2013CFA011)
文摘With the global warming and climate change in recent years, heat stress has become one of the major abiotic factors constraining production and productivity of crops in many regions around the world. Although the plants have developed some adaptive behaviors and avoidance mechanisms against heat stress, they will be hurt under extreme high temperature. Exogenous compounds could enhance plant growth and development, antioxidant enzymes activities, chlorophyll and nutrient contents under stress conditions. Meanwhile, application of exogenous compounds sustains physiological and biochemical process and prevents plants from physiological changes under stress conditions. In this review, effects of heat stress upon crops, and the functions of hormones in plant adaptation to heat stress are simply stated. Then, we intend to appraise how various phytohomrnones that are related to plant adaptation to heat stress. The role of abscisic acid(ABA), salicylic acid(SA) and polyamines(putrescine and spermine) under heat stress conditions are mainly discussed.
文摘Objective: To investigate the effect of Compound Danshen Dripping Pills (CDDP) on oxidative stress after ischemia/reperfusion (I/R) injury in the rat retina. Methods: Adult male SD rats were randomly divided into 3 groups: sham (group A), I/R (group B), and I/R plus CDDP (group C). Retinal ischemia/reperfusion injury (RIRI) was introduced by increasing the intraocular pressure (IOP) to 110 mmHg for 60 min via cannulation into the anterior chamber. Right after the insult, CDDP was administered intragastrically (450 mg/kg/d) for 7 days. The levels of malondialdehyde (MDA), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in the retinal tissues were determined on d1 and d7 after the ischemic insult. Results: Following ischemia, the MDA levels in group B and group C were significantly higher than those in group A (p < 0.01). CDDP significantly lowered MDA levels in group C when compared with group B (p < 0.01). The activities of SOD, GSH-Px and CAT were higher in group A than in group B and group C (p < 0.01). CDDP could increase the activities of SOD, GSH-Px and CAT remarkably in group C when compared with group B (p < 0.01). Conclusion: CDDP can protect the retina from I/R injury through reducing oxidative stress, and thus may be a promising method for the treatment of ischemic retinal disorders.
文摘目的:通过数据挖掘方法探究复方金果胃康散促使胃癌细胞发生铁死亡的作用机制。方法:以复方金果胃康散7种中药(藤梨根、半枝莲、橘红、太子参、白花蛇舌草、黄药子、守宫)为主题词,分别在中国知网、万方数据库以及中药系统药理学数据库与分析平台(traditional Chinese medicine systems pharmacology database and analysis platform,TCMSP)检索药物有效成分及对应相关蛋白。运用Excel、计算机R语言基本算法等对有效成分、蛋白等进行分析,构建发挥作用的蛋白与复方金果胃康散中其他蛋白之间的蛋白网络,并分析其作用关系。结果:共得到复方金果胃康散有效成分1814种,蛋白358种;胃癌蛋白23219种;铁死亡蛋白749种,其中铁代谢蛋白180种,氧化应激蛋白595种。共63个核心蛋白组成蛋白组,主要涉及铁代谢和氧化应激两个主要途径,以CYP3A4为代表的11种蛋白只在铁代谢过程起作用;以MAPK8为代表的43种蛋白只作用于氧化应激过程;以CYP1A1为代表的9种蛋白同时作用于铁代谢和氧化应激两个过程。氧化应激主要涉及NOX1、MAPK14等9种分子;铁代谢通路主要涉及细胞色素P4503A4等物质。结论:复方金果胃康散通过诱导肿瘤细胞发生铁死亡对胃癌发挥治疗作用。
文摘Senescence is a natural, energy-dependent, physiological, developmental and an ecological process that is controlled by the plant’s own genetic program, allowing maximum recovery of nutrients from older organs for the survival of the plant, as such;it is classified as essential component of the growth and development of plants. In some cases, under one or many environmental stresses, senescence is triggered in plants. Despite many studies in the area, less consideration has been given to plant secondary metabolites, especially the role of VTCs on plant senescence. This review seeks to capture the biosynthesis and signal transduction of VTCs, the physiology of VTCs in plant development and how that is linked to some phytohormones to induce senescence. Much progress has been made in the elucidation of metabolic pathways leading to the biosynthesis of VTCs. In addition to the classical cytosolic mevalonic acid (MVA) pathway from acetyl-CoA, the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, originating from glyceraldehyde-3-phosphate (GAP) and pyruvate, leads to the biosynthesis of isoprenoid precursors, isopentenyl diphosphate and dimethyl allyl diphosphate. VTCs synthesis and emission are believed to be tightly regulated by photosynthetic carbon supply into MEP pathway. Thus, under abiotic stresses such as drought, high salinity, high and low temperature, and low CO2 that directly affect stomatal conductance and ultimately biochemical limitation to photosynthesis, there has been observed induction of VTC synthesis and emissions, reflecting the elicitation of MEP pathway. This reveals the possibility of important function(s) of VTCs in plant defense against stress by mobilizing resources from components of plants and therefore, senescence. Our current understanding of the relationship between environmental responses and senescence mostly comes from the study of senescence response to phytohormones such as abscisic acid, jasmonic acid, ethylene and salicylic acid, which are extensively involved in response to various abiotic and biotic stresses. These stresses affect synthesis and/or signaling pathways of phytohormones to eventually trigger expression of stress-responsive genes, which in turn appears to affect leaf senescence. Comparison of plant response to stresses in relation to patterns of VTCs and phytohormones biosynthesis indicates a considerable crosstalk between these metabolic processes and their signal to plant senescence.
基金Supported by Special Foundation of Guizhou Academy of Agriculture Science"Germplasm Innovation and Application of Drought and Heat Resistant Alfalfa"(QNKYYZX[2013]003)Special Breeding Project of Guizhou Agriculture Commission"Cultivation of Flowering-inhibitory Tall Fescue Varieties with RNA Interference Technique"(QNYZZ[2013]012)
文摘Abstract The metabolites of tall fescue leaves under normal and drought conditions were analyzed with LC-ESI-MS （ liquid chromatography tandem mass spec- trometry）. A total of 282 metabolites were stably detected in the two groups using OPI.S-DA （orthogonal partial least squares discriminant analysis） method; 148 of which were down-regulated while 134 were up-regulated. After analyzed with MZ-minc software, 10 major metabolites （4 down, 6 up） were identified through searehing public database. Aromatic compounds, 3-p-eoumaroyll, 5-quinolaetone, aromatic free amino acids, styraxin mad methanofuran, were up-regulated ; grease metabolites, methyl 15-hydroperoxy-9Z, 12Z, 16E-octadecatrienoate, 9,12,13-Tri-HOME （10）, 3-oxo-dodecanoic acid, and 13 （S）-HpOTrE acid ester, were down-regulated; piperanine （alkaloids） was down-regulated while Methyl 7-epi-12-hydroxyjasmonate glucoside （indicant） was up-regulated. In a word, aromatic compounds and liquid metabolites may play vital roles in drought-resistant regulation of tall fescue.
文摘We examined the influence of oral malodor on psychological stress among patients with a chief complaint of oral malodor. A total of 101 patients (40 male and 61 female) who visited our clinic with a chief complaint of oral malodor were included in this study. The primary compounds of oral malodor—volatile sulfur compounds (VSC)—were measured using the Oral ChromaTM instrument. Salivary stress markers, cortisol, and chromogranin A were measured using an enzyme-linked immunosorbent assay (ELISA) kit. The mood was measured using the Profile of Mood States 2nd Edition (POMS2). Among the participants, 60.3% had at least one level above the threshold in the following three markers: hydrogen sulfide, methyl mercaptan, and dimethyl sulfide. The gender distribution was 35 female (57.4%) and 25 male (62.5%). Salivary cortisol levels, a biomarker of stress, did not vary depending on the presence or absence of oral malodor. Chromogranin A levels were higher in the oral malodor female group than in the no oral malodor female group. With respect to the POMS2, regardless of the presence or absence of oral malodor measured using gas chromatography, the participants had higher scores for “Anger-Hostility” and “Fatigue-Inertia”. Analysis by gender showed that “Depression-Dejection” was significantly higher in the oral malodor female group than in the no oral malodor female group. These results suggest that those who are worried about oral malodor have higher psychological stress than those who are not, regardless of the presence or absence of oral malodor measured using gas chromatography.
基金Project supported by the National Natural Science Foundation of China (Nos. 50709025 and50979078)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry
文摘Hydraulic calculation of steady uniform flows in trapezoidal compound open channels is studied. Based on the force balance of water in each sub-section, the average velocities of the main channel, side slope, and floodplain are derived. The lateral momentum exchanges between the sub-sections are expressed by using the apparent shear stress. To verify the model, seven groups of UK Flood Channel Facility （UK-FCF） measured data with a relative water depth between the floodplain and the main channel varying from 0.057 to 0.4 are used for comparison. The result shows that the calculated velocity is larger than the measured data when the relative water depth is small, while it is less than or close to the measured value in the case of a larger relative water depth. The influence of the apparent shear stress on the calculation of velocity on the floodplain is not obvious, while it is much greater on the main channel. The three-stage model is compared with Liu’s two-stage model, showing that the former can give a better prediction for a three-stage trapezoidal compound channel. Finally, the apparent shear stress is calculated and compared with the measured data. The result shows that the chosen values of the momentum transfer coefficients are appropriate.
