β-Sitosterol is a type of phytosterol that occurs naturally in plants.Previous studies have shown that it has anti-oxidant,anti-hyperlipidemic,anti-inflammatory,immunomodulatory,and anti-tumor effects,but it is unkno...β-Sitosterol is a type of phytosterol that occurs naturally in plants.Previous studies have shown that it has anti-oxidant,anti-hyperlipidemic,anti-inflammatory,immunomodulatory,and anti-tumor effects,but it is unknown whetherβ-sitosterol treatment reduces the effects of ischemic stroke.Here we found that,in a mouse model of ischemic stroke induced by middle cerebral artery occlusion,β-sitosterol reduced the volume of cerebral infarction and brain edema,reduced neuronal apoptosis in brain tissue,and alleviated neurological dysfunction;moreover,β-sitosterol increased the activity of oxygen-and glucose-deprived cerebral cortex neurons and reduced apoptosis.Further investigation showed that the neuroprotective effects ofβ-sitosterol may be related to inhibition of endoplasmic reticulum stress caused by intracellular cholesterol accumulation after ischemic stroke.In addition,β-sitosterol showed high affinity for NPC1L1,a key transporter of cholesterol,and antagonized its activity.In conclusion,β-sitosterol may help treat ischemic stroke by inhibiting neuronal intracellular cholesterol overload/endoplasmic reticulum stress/apoptosis signaling pathways.展开更多
Different concentrations of jasmonic acid(JA)and benzothiadiazole(BTH) were sprayed on 2-year-old Rosa rugosa‘Plena’ seedlings. The induced resistance of JA and BTH to Sphaerotheca pannosa(Wallr.) and the changes of...Different concentrations of jasmonic acid(JA)and benzothiadiazole(BTH) were sprayed on 2-year-old Rosa rugosa‘Plena’ seedlings. The induced resistance of JA and BTH to Sphaerotheca pannosa(Wallr.) and the changes of their related physiological indices were investigated. Results showed that JA and BTH treatments had inhibitory impacts on S. pannosa infection. The optimal concentration of JA and BTH was 0.5 mmol/L for the disease-resistance induction of the leaves, its inductive effect was up to 66.36% for BTH and 54.49% for JA. Our results confirmed that exogenous JA and BTH significantly improved R. rugose ‘Plena’ resistance to S. pannosa. When treated with JA and BTH, activities of the three defense enzymes(POD, PPO, and PAL) increased significantly.Contents of total phenolics, flavonoids, and lignin also increased significantly. It is inferred from these results that exogenous JA and BTH could improve the resistance of R.rugose ‘Plena’ to S. pannosa through enhancing activities of the defensive enzymes and accumulation of secondary metabolites in the leaves.展开更多
The traditional fixed-bed reactor design is usually not suitable for the low tube-to-particle diameter ratios(N = D/d b 8) where the local phenomena of channeling near the wall and backflow in the bed are dominant. Th...The traditional fixed-bed reactor design is usually not suitable for the low tube-to-particle diameter ratios(N = D/d b 8) where the local phenomena of channeling near the wall and backflow in the bed are dominant. The recent"solid particle" meshing method is too complicated for mesh generation, especially for non-spherical particles in large random packed beds, which seriously hinders its development. In this work, a novel high-fidelity mesh model is proposed for simulation of fixed bed reactors by combining the immersed boundary and adaptive meshing methods. This method is suitable for different shapes of particles, which ingeniously avoids handling the complex "contact point" problem. Several packed beds with two different shapes of particles are investigated with this model, and the local flow in the bed is simulated without geometrical simplification. The predicted pressure drop across the fixed bed and heat transfer of the single particle are in good agreement with the corresponding empirical relations. Compared with spherical particles, the packed bed packing with pentaphyllous particles has lower pressure drop and better heat/mass transfer performance, and it shows that this method can be used for the screening of particle shapes in a fixed bed.展开更多
A general CFD-PBE(computational fluid dynamics-population balance equation) solver for gas–liquid poly-dispersed flows of both low and high gas volume fractions is developed in OpenFOAM(open-source field operation an...A general CFD-PBE(computational fluid dynamics-population balance equation) solver for gas–liquid poly-dispersed flows of both low and high gas volume fractions is developed in OpenFOAM(open-source field operation and manipulation) in this work. Implementation of this solver in OpenFOAM is illustrated in detail. The PBE is solved with the cell average technique. The coupling between pressure and velocity is dealt with the transient PIMPLE algorithm, which is a merged PISO-SIMPLE(pressure implicit split operator-semi-implicit method for pressure-linked equations) algorithm. Results show generally good agreement with the published experimental data, whereas the modeling precision could be improved further with more sophisticated closure models for interfacial forces, the models for the bubble-induced turbulence and those for bubble coalescence and breakage.The results also indicate that the PBE could be solved out the PIMPLE loop to save much computation time while still preserving the time information on variables. This is important for CFD-PBE modeling of many actual gas–liquid problems, which are commonly high-turbulent flows with intrinsic transient and 3 D characteristics.展开更多
OBJECTIVE The objective of this study was to explore the effect of CDA-2, a selective inhibitor of abnormal methylation enzymes in cancer cells, on the therapeutic efficacy of cytotoxic chemotherapy. METHODS Advanced ...OBJECTIVE The objective of this study was to explore the effect of CDA-2, a selective inhibitor of abnormal methylation enzymes in cancer cells, on the therapeutic efficacy of cytotoxic chemotherapy. METHODS Advanced cancer patients, all of whom had previously undergone chemotherapy, were randomly divided into 2 groups, one receiving chemotherapy only as the control group, and the other receiving CDA-2 in addition to chemotherapy as the combination group. The therapeutic efficacies and the toxic maniestations of the 2 groups were compared based on the WHO criteria. RESULTS Of 454 cancer patients enrolled in phase Ⅲ clinical trials of CDA-2, 80, 188, and 186 were breast cancer, NSCLC, and primary hepatoma patients, respectively. Among them 378 patients completed treatments according to the protocols. The results showed that the overall effective rate of the combination group was 2.6 fold that of the control group, 4.8 fold in the case of breast cancer, 2.3 fold in the case of primary hepatoma, and 2.2 fold in the case of NSCLC. Surprisingly, the combination therapy appeared to work better for stage Ⅳ than stage Ⅲ patients. CDA-2 did not contribute additional toxicity. On the contrary, it reduced toxic manifestations of chemotherapy, particularly regarding white blood cells, nausea and vomiting. CONCLUSION Modulation of abnormal methylation enzymes by CDA-2 is definitely helpful to supplement chemotherapy. It significantly increased the therapeutic efficacy and reduced the toxic manifestation of cytotoxic chemotherapy on breast cancer and NSCLC.展开更多
To study the effect of jasmonates(JAs)on the resistance of economic forest plants to insects,R osa rugosa‘Plena'leaves were treated with 1 mmol/L jasmonic acid(JA),methyl jasmonate(MeJA)and Z-jasmone,then the con...To study the effect of jasmonates(JAs)on the resistance of economic forest plants to insects,R osa rugosa‘Plena'leaves were treated with 1 mmol/L jasmonic acid(JA),methyl jasmonate(MeJA)and Z-jasmone,then the content of tannin and total phenol in leaves and the feeding area of Monolepta hieroglyphica adults on leaves were measured.Changes in the activities of detoxification enzymes in adult M.hieroglyphica that had fed on leaves treated with JAs were also studied.Tannin and total phenol levels in leaves increased significantly after treatment with JAs,and tannin level was 1.36–1.55-fold higher than in the control after treatment with 1 mmol/L MeJA.The total content of phenol in leaves treated with 1.0 mmol/L Z-jasmone increased by 1.33–2.20-fold compared with those of the control.The activities of detoxification enzymes in adults were inhibited to differing degrees:activity of alkaline phosphatase(AKP)first increased,then decreased;the activities of acid phosphatase(ACP),glutathione S-transferases(GSTs)and carboxylesterase(CarE)following treatment with 1 mmol/L MeJA were significantly reduced and were 22%–31%,11%–26%,and 11%–31%lower than those of the control,respectively.Moreover,the feeding area of adult M.hieroglyphica on the leaves treated with JAs was significantly reduced(P<0.05).The feeding area of economic forest R.rugosa‘Plena'leaves treated with 1 mmol/L MeJA decreased by 17%–43%compared with that of the control.Moreover,the decrease in the adult M.hieroglyphica feeding area was highly positively correlated with the content of tannin and positively correlated with the contents of total phenol of economic forest R.rugosa‘Plena'leaves.The reduced feeding area of adult M.hieroglyphica was highly negatively correlated with the activities of AKP and ACP and negatively correlated with those of the GSTs.In conclusion,the use of 1 mmol/L MeJA can noticeably decrease the deleterious effects of adult M.hieroglyphica.展开更多
As an important horticultural plant,the orchid is widely distributed in its natural habitat and faces various environmental stresses,among which nutrient recycling and stress resistance are of great concern.During the...As an important horticultural plant,the orchid is widely distributed in its natural habitat and faces various environmental stresses,among which nutrient recycling and stress resistance are of great concern.During these processes,autophagy is an essential pathway,which is a conserved self-eating process that degrades macromolecular components and recycles cell materials or nutrients during developmental processes or under stress conditions.Two ubiquitin-like systems(UBLs)play a major role in the initiation of autophagy and are associated with two key proteins:ATG8 and ATG12.In this study,we identified and refined the UBL-related genes in orchids and performed phylogenetic reconstruction together with other plant species.We found that the orchid had unique domains in UBL-related genes,indicating potential functional diversification in the ATG8 system in plants.Transcriptome and protein tertiary structure prediction indicated that conserved domains that are vital for the canonical function of ATG12 are incomplete in orchids,in which a novel mechanism of autophagy may have evolved.展开更多
Background Dental implants have been widely used in the last few decades.However,patients with insufficient bone height need reconstructive surgeries before implant insertion.Distraction implant(Dl)has been invented t...Background Dental implants have been widely used in the last few decades.However,patients with insufficient bone height need reconstructive surgeries before implant insertion.Distraction implant(Dl)has been invented to simplify the treatment procedure,but the shortcomings of Dl have limited its clinical use.We introduced biodegradable polyester to a novel Dl,called biodegradable interference distraction implant(BIDI).The purpose of this study was to assess the radiological,histological,and biomechanical properties of BIDI in animal models.Methods BIDIs were manufactured and inserted into the atrophied mandibles of 6 dogs.展开更多
Ganga-Brahmaputra-Meghna(GBM)river basin is the third-largest and one of the most populated river basins in the world.As climate change is affecting most of the hydrometeorological variables across the globe,this stud...Ganga-Brahmaputra-Meghna(GBM)river basin is the third-largest and one of the most populated river basins in the world.As climate change is affecting most of the hydrometeorological variables across the globe,this study investigated the existence of climate change signal in all four climatological seasons in the GBM river basin and assessed the contribution of anthropogenic activities,i.e.,Greenhouse Gases(GHGs)emission in the change.Significant decreasing trends in the monsoon and a small increase in pre-monsoon precipitation were observed.Negligible change was detected in post-monsoon and winter season precipitation.CMIP5 GCMs were used for climate change detection,change point estimation,and attribution studies.Support Vector Machine(SVM)regression method was adopted to downscale GCM variables at the local scale.Monte-Carlo simulation approach was used to detect changes in different seasons.The climate change‘signals’were detectable after the year 1980 using Signal to Noise ratio(SNR)method in the majority of central and north-western regions.The change point was detectable only in annual monsoon precipitation at the basin level.Attribution analysis indicated>50%contribution of anthropogenic activities(GHGs)to annual monsoon precipitation changes.So,there is high confidence that monsoon precipitation in GBM has significantly changed due to anthropogenic activities.Different mitigation and adaption measures are also suggested,which may be adopted to manage the growing demand and water availability in the basin.展开更多
Traditional methods focus on the ultimate bending moment of glulam beams and the fracture failure of materials with defects,which usually depends on empirical parameters.There is no systematic theoretical method to pr...Traditional methods focus on the ultimate bending moment of glulam beams and the fracture failure of materials with defects,which usually depends on empirical parameters.There is no systematic theoretical method to predict the stiffness and shear distribution of glulam beams in elastic-plastic stage,and consequently,the failure of such glulam beams cannot be predicted effectively.To address these issues,an analytical method considering material nonlinearity was proposed for glulam beams,and the calculating equations of deflection and shear stress distribution for different failure modes were established.The proposed method was verified by experiments and numerical models under the corresponding conditions.Results showed that the theoretical calculations were in good agreement with experimental and numerical results,indicating that the equations proposed in this paper were reliable and accurate for such glulam beams with wood material in the elastic-plastic stage ignoring the influence of mechanic properties in radial and tangential directions of wood.Furthermore,the experimental results reported by the previous studies indicated that the method was applicable and could be used as a theoretical reference for predicting the failure of glulam beams.展开更多
Considering the glulam beam-column connection form and the number of bolts,monotonic loading test and finite element analysis was carried out on 9 connection specimens in 3 groups to study the rotational performance a...Considering the glulam beam-column connection form and the number of bolts,monotonic loading test and finite element analysis was carried out on 9 connection specimens in 3 groups to study the rotational performance and failure mode of the connection.The test results revealed that compared with U-shaped connectors,T-shaped connectors can effectively improve the ductility of connections,and the increase in the number of bolts can reduce the initial stiffness and ductility of connections.By theoretical analysis,formulas for calculating the initial stiffness and ultimate moment of connections were deduced.Subsequently,the moment-rotation theoretical model of connections was established based on the formulas,which were validated according to the test data and simulation results.The proposed model can not only improve the current theoretical system of heavy-duty glulam beam-column structure but also provide a theoretical basis for calculating the mechanical properties of the glulam beam-column connection.展开更多
[Objective] This study aimed to investigate the acaricidal lffect of scopo- letin, and provide the biochemical evidences of scopoletin influencus Ca2+-ATPase activity and gene expressions in the Carmine Spider Mite, ...[Objective] This study aimed to investigate the acaricidal lffect of scopo- letin, and provide the biochemical evidences of scopoletin influencus Ca2+-ATPase activity and gene expressions in the Carmine Spider Mite, Tetranych'us cinnabarinus. in increased protein contents; kinetic analysis showed that the catalytic capability of Ca2+-ATPase was significantly reduced by scopoletin. [Conclusion] Scopoletin exhibits a significant inhibitory effect on Ca2+-ATPase, and its acaricidal effect against T. cinnabarinus might be due to the direct inhibition of Ca2+-ATPase.展开更多
Mitogen-activated protein kinases (MAPKs) are important components in signal transduction modules which play crucial roles in regulation of many biological processes in plants. Although genome-wide analysis of MAPK an...Mitogen-activated protein kinases (MAPKs) are important components in signal transduction modules which play crucial roles in regulation of many biological processes in plants. Although genome-wide analysis of MAPK and MAPKK family has been carried out in poplar species, few data about the biological function analysis of this gene family are available to date. In this study, a group C MAPK gene 84KMPK14 was cloned from hybrid poplar (Populus alba × P. glandulosa cv. “84K”). It contained a typical protein kinase domain, a conserved TEY-motif and an atypical conserved common docking (CD) domain. Sequence alignment revealed that 84KMPK14 was the most homologous to Populus trichocarpa PtMPK14. Expression analysis indicated that the transcript of 84KMPK14 in roots and young leaves was higher than that in other tissues. The expression of 84KMPK14 was down-regulated by low or high temperature and was induced by H2O2 significantly. It was suppressed by drought and salinity stresses slightly one hour after treatment and then increased quickly three hours after treatment. These results indicated that 84KMPK14 may be involved in environmental stresses, which provides basis for further characterization of the physiological analysis on this gene.展开更多
Objective:Nanoparticles(NPs)in haze are potentially hazardous to health,which is more severe in the winter.Brown adipose tissue(BAT)plays important roles in obesity,insulin resistance,and diabetes.Though the toxicolog...Objective:Nanoparticles(NPs)in haze are potentially hazardous to health,which is more severe in the winter.Brown adipose tissue(BAT)plays important roles in obesity,insulin resistance,and diabetes.Though the toxicology of NPs has been intensively studied,few studies have been reported on the antagonistic effects between Silicon dioxide(SiO_(2))NPs and cold exposure in brown adipocytes.Materials and methods:We evaluated changes by quantitative real-time reverse-transcriptase polymerase chain reaction(qRT-PCR)on metabolism genes,plasticity genes and the inflammatory responses genes in brown adipocytes in vitro.Results:The expression of adipogenic genes PRDM16,Dio2,PGC-1αand UCP1 was upregulated upon cold exposure(P<0.05),but downregulated by SiO_(2) NPs(P<0.05).The results demonstrated that there was antagonistic effect between SiO_(2) NPs and cold exposure on the plasticity genes and metabolism genes in brown adipocytes,where the main effects of SiO_(2) NPs or cold exposure on the plasticity genes and metabolism genes were significant(P<0.05).Moreover,the levels of interleukin(IL)-1β,IL-6 and tumor necrosis factor(TNF)-αwere upregulated by SiO_(2) NPs or cold exposure(P<0.05).The factorial analysis indicated that there was also antagonistic effect between SiO_(2) NPs and cold exposure on the toxic effects in brown adipocytes,in which the main effects of cold exposure and/or SiO_(2) NPs on the toxic effects were significant(P<0.05).Conclusion:SiO_(2) NPs inhibit the effect of cold exposure on metabolic genes and inflammatory responses genes in brown adipocytes.展开更多
Objective: This paper mainly determined the action modes of extract of Aloe vera L. against Tetranychus cinnabarinus Boisduval. Methods: The different action modes, contact action, repellent, fumigant, and oviposition...Objective: This paper mainly determined the action modes of extract of Aloe vera L. against Tetranychus cinnabarinus Boisduval. Methods: The different action modes, contact action, repellent, fumigant, and oviposition inhibition property of the acetone extract of Aloe vera L. leaf against the carmine spider mite Tetranychus cinnabaribus (Boisduval) (Acarina: Tetranychidae) were investigated at 26°C ± 1°C, 75% - 80% relative humidity, and 14:10 light: day cycle in the laboratory. Results: Based on the established toxicity regression line of the Aloe vera L. acetone extract against female adult mites, the median lethal concentrations (LC50) were 0.836 and 0.167 mg/mL for 48 and 72 h, respectively. With processing time increased, the contact acaricidal activity increased and the repellent activity gradually decreased. The main modes of action of the extract against female adult mites were contact and repellent, and preferable effects were observed on adult mites. These results indicate that A. vera L. extract contains acaricidal and repellent bioactive components that may be useful in future control of the phytophagous mites.展开更多
Objective:Studies have shown that both short-term and long-term cold exposures disturb the biological process.The aim of the present study is to investigate the effects of intermittent cold exposure on proteomic profi...Objective:Studies have shown that both short-term and long-term cold exposures disturb the biological process.The aim of the present study is to investigate the effects of intermittent cold exposure on proteomic profiles in the hypothalamus and pituitary of female Sprague-Dawley(SD)rats.Materials and methods:The rats were exposed to-10°C in a cabin for 4 h per day,and the treatment lasted for 14 days.The comparative label-free LC-MS/MS analysis was performed to investigate the changes of proteomic profiles in the hypothalamus and pituitary.ELISA analysis was used to validate the expression of differential proteins.Results:22 differential proteins in the hypothalamus and 75 differential proteins in the pituitary were identified by the label-free proteomic analysis.Gene ontology annotation and enrichment analysis indicated that cold exposure disrupted protein phosphorylation,filopodium assembly,intracellular protein transport,peripheral nervous system neuron axonogenesis,spinal cord development,Golgi organization,positive regulation of pseudopodium assembly,and cell-cell adhesion.Three proteins(Cdc42,Ptprs,and Setd7)were down-regulated in the cold exposure group.Conclusion:The results indicate that intermittent cold exposure alters the proteomic profiles of hypothalamus and pituitary in female rats.展开更多
The gut microflora is a combination of all microbes in intestine and their microenvironment,and its change can sensitively reflect the relevant response of the body to external environment and remarkably affect body...The gut microflora is a combination of all microbes in intestine and their microenvironment,and its change can sensitively reflect the relevant response of the body to external environment and remarkably affect body's metabolism as well.Recent studies have found that cold exposure affects the body's gut microflora,which can lead to changes in the body's metabolism of glucose and lipid.This review summarizes recent research on the effects of cold exposure on gut microbes and metabolism of glucose and lipid,aiming to provide some new ideas on the approaches and measures for the prevention and treatment of diabetes and obesity.展开更多
The present study aims at improving the ability of the canonical genetic programming algorithm to solve problems, and describes an improved genetic programming (IGP). The proposed method can be described as follows: t...The present study aims at improving the ability of the canonical genetic programming algorithm to solve problems, and describes an improved genetic programming (IGP). The proposed method can be described as follows: the first inves-tigates initializing population, the second investigates reproduction operator, the third investigates crossover operator, and the fourth investigates mutation operation. The IGP is examined in two domains and the results suggest that the IGP is more effective and more efficient than the canonical one applied in different domains.展开更多
In some situations, the accelerated life test on environmental stress for electronic products is not easily implemented due to various restrictions, and thus engineers are lacking of data of the product life test. Con...In some situations, the accelerated life test on environmental stress for electronic products is not easily implemented due to various restrictions, and thus engineers are lacking of data of the product life test. Concerning this problem, environmental life of the printed circuit board(PCB) board is calculated by way of physics of failure. Influences of thermal cycle and vibration on PCB and its components are studied. Based on the analysis of force and stress between components and the PCB board in thermal cycle events and vibration events, four life computing models of pins and soldered dots are established. The miller damage ratio is used to calculate the accumulated damage of a pin or a soldered dot, and then the environment life of the PCB board can be determined by the first failed one. Finally, an example is used to illustrate the models and their calculations.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82104158(to XT),31800887(to LY),31972902(to LY),82001422(to YL)China Postdoctoral Science Foundation,No.2020M683750(to LY)partially by Young Talent Fund of University Association for Science and Technology in Shaanxi Province of China,No.20200307(to LY).
文摘β-Sitosterol is a type of phytosterol that occurs naturally in plants.Previous studies have shown that it has anti-oxidant,anti-hyperlipidemic,anti-inflammatory,immunomodulatory,and anti-tumor effects,but it is unknown whetherβ-sitosterol treatment reduces the effects of ischemic stroke.Here we found that,in a mouse model of ischemic stroke induced by middle cerebral artery occlusion,β-sitosterol reduced the volume of cerebral infarction and brain edema,reduced neuronal apoptosis in brain tissue,and alleviated neurological dysfunction;moreover,β-sitosterol increased the activity of oxygen-and glucose-deprived cerebral cortex neurons and reduced apoptosis.Further investigation showed that the neuroprotective effects ofβ-sitosterol may be related to inhibition of endoplasmic reticulum stress caused by intracellular cholesterol accumulation after ischemic stroke.In addition,β-sitosterol showed high affinity for NPC1L1,a key transporter of cholesterol,and antagonized its activity.In conclusion,β-sitosterol may help treat ischemic stroke by inhibiting neuronal intracellular cholesterol overload/endoplasmic reticulum stress/apoptosis signaling pathways.
基金supported by the Science Foundation of Heilongjiang Province of China(No.QC2014C012)the Fundamental Research Funds for the Central Universities(NO.2572016CA11)
文摘Different concentrations of jasmonic acid(JA)and benzothiadiazole(BTH) were sprayed on 2-year-old Rosa rugosa‘Plena’ seedlings. The induced resistance of JA and BTH to Sphaerotheca pannosa(Wallr.) and the changes of their related physiological indices were investigated. Results showed that JA and BTH treatments had inhibitory impacts on S. pannosa infection. The optimal concentration of JA and BTH was 0.5 mmol/L for the disease-resistance induction of the leaves, its inductive effect was up to 66.36% for BTH and 54.49% for JA. Our results confirmed that exogenous JA and BTH significantly improved R. rugose ‘Plena’ resistance to S. pannosa. When treated with JA and BTH, activities of the three defense enzymes(POD, PPO, and PAL) increased significantly.Contents of total phenolics, flavonoids, and lignin also increased significantly. It is inferred from these results that exogenous JA and BTH could improve the resistance of R.rugose ‘Plena’ to S. pannosa through enhancing activities of the defensive enzymes and accumulation of secondary metabolites in the leaves.
基金Supported by the National Key Research and Development Program(2016YFB0301702)National Natural Science Foundation of China(21490584,21878298,91534105)+2 种基金Major National Scientific Instrument and Equipment Development Project(21427814)Key Research Program of Frontier Sciences of CAS(QYZDJ-SSW-JSC030)Jiangsu National Synergetic Innovation Center for Advanced Materials.
文摘The traditional fixed-bed reactor design is usually not suitable for the low tube-to-particle diameter ratios(N = D/d b 8) where the local phenomena of channeling near the wall and backflow in the bed are dominant. The recent"solid particle" meshing method is too complicated for mesh generation, especially for non-spherical particles in large random packed beds, which seriously hinders its development. In this work, a novel high-fidelity mesh model is proposed for simulation of fixed bed reactors by combining the immersed boundary and adaptive meshing methods. This method is suitable for different shapes of particles, which ingeniously avoids handling the complex "contact point" problem. Several packed beds with two different shapes of particles are investigated with this model, and the local flow in the bed is simulated without geometrical simplification. The predicted pressure drop across the fixed bed and heat transfer of the single particle are in good agreement with the corresponding empirical relations. Compared with spherical particles, the packed bed packing with pentaphyllous particles has lower pressure drop and better heat/mass transfer performance, and it shows that this method can be used for the screening of particle shapes in a fixed bed.
基金Supported by the National Key Research and Development Program(2016YFB0301702)National Natural Science Foundation of China(21776284,21476236)+1 种基金Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-JSC030)Jiangsu National Synergetic Innovation Center for Advanced Materials
文摘A general CFD-PBE(computational fluid dynamics-population balance equation) solver for gas–liquid poly-dispersed flows of both low and high gas volume fractions is developed in OpenFOAM(open-source field operation and manipulation) in this work. Implementation of this solver in OpenFOAM is illustrated in detail. The PBE is solved with the cell average technique. The coupling between pressure and velocity is dealt with the transient PIMPLE algorithm, which is a merged PISO-SIMPLE(pressure implicit split operator-semi-implicit method for pressure-linked equations) algorithm. Results show generally good agreement with the published experimental data, whereas the modeling precision could be improved further with more sophisticated closure models for interfacial forces, the models for the bubble-induced turbulence and those for bubble coalescence and breakage.The results also indicate that the PBE could be solved out the PIMPLE loop to save much computation time while still preserving the time information on variables. This is important for CFD-PBE modeling of many actual gas–liquid problems, which are commonly high-turbulent flows with intrinsic transient and 3 D characteristics.
文摘OBJECTIVE The objective of this study was to explore the effect of CDA-2, a selective inhibitor of abnormal methylation enzymes in cancer cells, on the therapeutic efficacy of cytotoxic chemotherapy. METHODS Advanced cancer patients, all of whom had previously undergone chemotherapy, were randomly divided into 2 groups, one receiving chemotherapy only as the control group, and the other receiving CDA-2 in addition to chemotherapy as the combination group. The therapeutic efficacies and the toxic maniestations of the 2 groups were compared based on the WHO criteria. RESULTS Of 454 cancer patients enrolled in phase Ⅲ clinical trials of CDA-2, 80, 188, and 186 were breast cancer, NSCLC, and primary hepatoma patients, respectively. Among them 378 patients completed treatments according to the protocols. The results showed that the overall effective rate of the combination group was 2.6 fold that of the control group, 4.8 fold in the case of breast cancer, 2.3 fold in the case of primary hepatoma, and 2.2 fold in the case of NSCLC. Surprisingly, the combination therapy appeared to work better for stage Ⅳ than stage Ⅲ patients. CDA-2 did not contribute additional toxicity. On the contrary, it reduced toxic manifestations of chemotherapy, particularly regarding white blood cells, nausea and vomiting. CONCLUSION Modulation of abnormal methylation enzymes by CDA-2 is definitely helpful to supplement chemotherapy. It significantly increased the therapeutic efficacy and reduced the toxic manifestation of cytotoxic chemotherapy on breast cancer and NSCLC.
基金financially by the National Natural Science Foundation of China(No.31800546)the National Key R&D Program of China(No.2018YFC1200400)the Fundamental Research Funds for the Central Universities(No.2572016CA11)。
文摘To study the effect of jasmonates(JAs)on the resistance of economic forest plants to insects,R osa rugosa‘Plena'leaves were treated with 1 mmol/L jasmonic acid(JA),methyl jasmonate(MeJA)and Z-jasmone,then the content of tannin and total phenol in leaves and the feeding area of Monolepta hieroglyphica adults on leaves were measured.Changes in the activities of detoxification enzymes in adult M.hieroglyphica that had fed on leaves treated with JAs were also studied.Tannin and total phenol levels in leaves increased significantly after treatment with JAs,and tannin level was 1.36–1.55-fold higher than in the control after treatment with 1 mmol/L MeJA.The total content of phenol in leaves treated with 1.0 mmol/L Z-jasmone increased by 1.33–2.20-fold compared with those of the control.The activities of detoxification enzymes in adults were inhibited to differing degrees:activity of alkaline phosphatase(AKP)first increased,then decreased;the activities of acid phosphatase(ACP),glutathione S-transferases(GSTs)and carboxylesterase(CarE)following treatment with 1 mmol/L MeJA were significantly reduced and were 22%–31%,11%–26%,and 11%–31%lower than those of the control,respectively.Moreover,the feeding area of adult M.hieroglyphica on the leaves treated with JAs was significantly reduced(P<0.05).The feeding area of economic forest R.rugosa‘Plena'leaves treated with 1 mmol/L MeJA decreased by 17%–43%compared with that of the control.Moreover,the decrease in the adult M.hieroglyphica feeding area was highly positively correlated with the content of tannin and positively correlated with the contents of total phenol of economic forest R.rugosa‘Plena'leaves.The reduced feeding area of adult M.hieroglyphica was highly negatively correlated with the activities of AKP and ACP and negatively correlated with those of the GSTs.In conclusion,the use of 1 mmol/L MeJA can noticeably decrease the deleterious effects of adult M.hieroglyphica.
文摘As an important horticultural plant,the orchid is widely distributed in its natural habitat and faces various environmental stresses,among which nutrient recycling and stress resistance are of great concern.During these processes,autophagy is an essential pathway,which is a conserved self-eating process that degrades macromolecular components and recycles cell materials or nutrients during developmental processes or under stress conditions.Two ubiquitin-like systems(UBLs)play a major role in the initiation of autophagy and are associated with two key proteins:ATG8 and ATG12.In this study,we identified and refined the UBL-related genes in orchids and performed phylogenetic reconstruction together with other plant species.We found that the orchid had unique domains in UBL-related genes,indicating potential functional diversification in the ATG8 system in plants.Transcriptome and protein tertiary structure prediction indicated that conserved domains that are vital for the canonical function of ATG12 are incomplete in orchids,in which a novel mechanism of autophagy may have evolved.
基金supported by the National Natural Science Foundation of China(No. 30900284,No.31100668,and No.31070873)
文摘Background Dental implants have been widely used in the last few decades.However,patients with insufficient bone height need reconstructive surgeries before implant insertion.Distraction implant(Dl)has been invented to simplify the treatment procedure,but the shortcomings of Dl have limited its clinical use.We introduced biodegradable polyester to a novel Dl,called biodegradable interference distraction implant(BIDI).The purpose of this study was to assess the radiological,histological,and biomechanical properties of BIDI in animal models.Methods BIDIs were manufactured and inserted into the atrophied mandibles of 6 dogs.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0208)CAS Pioneer Hundred Talents Program.
文摘Ganga-Brahmaputra-Meghna(GBM)river basin is the third-largest and one of the most populated river basins in the world.As climate change is affecting most of the hydrometeorological variables across the globe,this study investigated the existence of climate change signal in all four climatological seasons in the GBM river basin and assessed the contribution of anthropogenic activities,i.e.,Greenhouse Gases(GHGs)emission in the change.Significant decreasing trends in the monsoon and a small increase in pre-monsoon precipitation were observed.Negligible change was detected in post-monsoon and winter season precipitation.CMIP5 GCMs were used for climate change detection,change point estimation,and attribution studies.Support Vector Machine(SVM)regression method was adopted to downscale GCM variables at the local scale.Monte-Carlo simulation approach was used to detect changes in different seasons.The climate change‘signals’were detectable after the year 1980 using Signal to Noise ratio(SNR)method in the majority of central and north-western regions.The change point was detectable only in annual monsoon precipitation at the basin level.Attribution analysis indicated>50%contribution of anthropogenic activities(GHGs)to annual monsoon precipitation changes.So,there is high confidence that monsoon precipitation in GBM has significantly changed due to anthropogenic activities.Different mitigation and adaption measures are also suggested,which may be adopted to manage the growing demand and water availability in the basin.
基金support from High-Level Natural ScienceFoundation of Hainan Province of China (Grant No. 2019RC055)National Natural Science Foundation ofChina (Grant No. 51808176) and the Project Funded by the National First-Class Disciplines (PNFD).
文摘Traditional methods focus on the ultimate bending moment of glulam beams and the fracture failure of materials with defects,which usually depends on empirical parameters.There is no systematic theoretical method to predict the stiffness and shear distribution of glulam beams in elastic-plastic stage,and consequently,the failure of such glulam beams cannot be predicted effectively.To address these issues,an analytical method considering material nonlinearity was proposed for glulam beams,and the calculating equations of deflection and shear stress distribution for different failure modes were established.The proposed method was verified by experiments and numerical models under the corresponding conditions.Results showed that the theoretical calculations were in good agreement with experimental and numerical results,indicating that the equations proposed in this paper were reliable and accurate for such glulam beams with wood material in the elastic-plastic stage ignoring the influence of mechanic properties in radial and tangential directions of wood.Furthermore,the experimental results reported by the previous studies indicated that the method was applicable and could be used as a theoretical reference for predicting the failure of glulam beams.
基金funded by the National First-class Disciplines(PNFD)High Level Natural Science Foundation of Hainan Province of China(Grant No.2019RC055)Project Supported by the Education Department of Hainan Province(Project No.hnjg2021-13).
文摘Considering the glulam beam-column connection form and the number of bolts,monotonic loading test and finite element analysis was carried out on 9 connection specimens in 3 groups to study the rotational performance and failure mode of the connection.The test results revealed that compared with U-shaped connectors,T-shaped connectors can effectively improve the ductility of connections,and the increase in the number of bolts can reduce the initial stiffness and ductility of connections.By theoretical analysis,formulas for calculating the initial stiffness and ultimate moment of connections were deduced.Subsequently,the moment-rotation theoretical model of connections was established based on the formulas,which were validated according to the test data and simulation results.The proposed model can not only improve the current theoretical system of heavy-duty glulam beam-column structure but also provide a theoretical basis for calculating the mechanical properties of the glulam beam-column connection.
基金Supported by National Natural Science Foundation of China(31272058)Specialized Research Fund for the Doctoral Program of Higher Education(20100182120021)
文摘[Objective] This study aimed to investigate the acaricidal lffect of scopo- letin, and provide the biochemical evidences of scopoletin influencus Ca2+-ATPase activity and gene expressions in the Carmine Spider Mite, Tetranych'us cinnabarinus. in increased protein contents; kinetic analysis showed that the catalytic capability of Ca2+-ATPase was significantly reduced by scopoletin. [Conclusion] Scopoletin exhibits a significant inhibitory effect on Ca2+-ATPase, and its acaricidal effect against T. cinnabarinus might be due to the direct inhibition of Ca2+-ATPase.
文摘Mitogen-activated protein kinases (MAPKs) are important components in signal transduction modules which play crucial roles in regulation of many biological processes in plants. Although genome-wide analysis of MAPK and MAPKK family has been carried out in poplar species, few data about the biological function analysis of this gene family are available to date. In this study, a group C MAPK gene 84KMPK14 was cloned from hybrid poplar (Populus alba × P. glandulosa cv. “84K”). It contained a typical protein kinase domain, a conserved TEY-motif and an atypical conserved common docking (CD) domain. Sequence alignment revealed that 84KMPK14 was the most homologous to Populus trichocarpa PtMPK14. Expression analysis indicated that the transcript of 84KMPK14 in roots and young leaves was higher than that in other tissues. The expression of 84KMPK14 was down-regulated by low or high temperature and was induced by H2O2 significantly. It was suppressed by drought and salinity stresses slightly one hour after treatment and then increased quickly three hours after treatment. These results indicated that 84KMPK14 may be involved in environmental stresses, which provides basis for further characterization of the physiological analysis on this gene.
基金the National Natural Science Foundation of China(No.21707165)the grants of Institute of Environmental and Operational Medicine(BWS17J025,BWS16J0101,WH2017006 and AWS16J022).
文摘Objective:Nanoparticles(NPs)in haze are potentially hazardous to health,which is more severe in the winter.Brown adipose tissue(BAT)plays important roles in obesity,insulin resistance,and diabetes.Though the toxicology of NPs has been intensively studied,few studies have been reported on the antagonistic effects between Silicon dioxide(SiO_(2))NPs and cold exposure in brown adipocytes.Materials and methods:We evaluated changes by quantitative real-time reverse-transcriptase polymerase chain reaction(qRT-PCR)on metabolism genes,plasticity genes and the inflammatory responses genes in brown adipocytes in vitro.Results:The expression of adipogenic genes PRDM16,Dio2,PGC-1αand UCP1 was upregulated upon cold exposure(P<0.05),but downregulated by SiO_(2) NPs(P<0.05).The results demonstrated that there was antagonistic effect between SiO_(2) NPs and cold exposure on the plasticity genes and metabolism genes in brown adipocytes,where the main effects of SiO_(2) NPs or cold exposure on the plasticity genes and metabolism genes were significant(P<0.05).Moreover,the levels of interleukin(IL)-1β,IL-6 and tumor necrosis factor(TNF)-αwere upregulated by SiO_(2) NPs or cold exposure(P<0.05).The factorial analysis indicated that there was also antagonistic effect between SiO_(2) NPs and cold exposure on the toxic effects in brown adipocytes,in which the main effects of cold exposure and/or SiO_(2) NPs on the toxic effects were significant(P<0.05).Conclusion:SiO_(2) NPs inhibit the effect of cold exposure on metabolic genes and inflammatory responses genes in brown adipocytes.
文摘Objective: This paper mainly determined the action modes of extract of Aloe vera L. against Tetranychus cinnabarinus Boisduval. Methods: The different action modes, contact action, repellent, fumigant, and oviposition inhibition property of the acetone extract of Aloe vera L. leaf against the carmine spider mite Tetranychus cinnabaribus (Boisduval) (Acarina: Tetranychidae) were investigated at 26°C ± 1°C, 75% - 80% relative humidity, and 14:10 light: day cycle in the laboratory. Results: Based on the established toxicity regression line of the Aloe vera L. acetone extract against female adult mites, the median lethal concentrations (LC50) were 0.836 and 0.167 mg/mL for 48 and 72 h, respectively. With processing time increased, the contact acaricidal activity increased and the repellent activity gradually decreased. The main modes of action of the extract against female adult mites were contact and repellent, and preferable effects were observed on adult mites. These results indicate that A. vera L. extract contains acaricidal and repellent bioactive components that may be useful in future control of the phytophagous mites.
基金the grants of Tianjin Institute of Environmental and Operational Medicine(BWS17J025).
文摘Objective:Studies have shown that both short-term and long-term cold exposures disturb the biological process.The aim of the present study is to investigate the effects of intermittent cold exposure on proteomic profiles in the hypothalamus and pituitary of female Sprague-Dawley(SD)rats.Materials and methods:The rats were exposed to-10°C in a cabin for 4 h per day,and the treatment lasted for 14 days.The comparative label-free LC-MS/MS analysis was performed to investigate the changes of proteomic profiles in the hypothalamus and pituitary.ELISA analysis was used to validate the expression of differential proteins.Results:22 differential proteins in the hypothalamus and 75 differential proteins in the pituitary were identified by the label-free proteomic analysis.Gene ontology annotation and enrichment analysis indicated that cold exposure disrupted protein phosphorylation,filopodium assembly,intracellular protein transport,peripheral nervous system neuron axonogenesis,spinal cord development,Golgi organization,positive regulation of pseudopodium assembly,and cell-cell adhesion.Three proteins(Cdc42,Ptprs,and Setd7)were down-regulated in the cold exposure group.Conclusion:The results indicate that intermittent cold exposure alters the proteomic profiles of hypothalamus and pituitary in female rats.
文摘The gut microflora is a combination of all microbes in intestine and their microenvironment,and its change can sensitively reflect the relevant response of the body to external environment and remarkably affect body's metabolism as well.Recent studies have found that cold exposure affects the body's gut microflora,which can lead to changes in the body's metabolism of glucose and lipid.This review summarizes recent research on the effects of cold exposure on gut microbes and metabolism of glucose and lipid,aiming to provide some new ideas on the approaches and measures for the prevention and treatment of diabetes and obesity.
文摘The present study aims at improving the ability of the canonical genetic programming algorithm to solve problems, and describes an improved genetic programming (IGP). The proposed method can be described as follows: the first inves-tigates initializing population, the second investigates reproduction operator, the third investigates crossover operator, and the fourth investigates mutation operation. The IGP is examined in two domains and the results suggest that the IGP is more effective and more efficient than the canonical one applied in different domains.
文摘In some situations, the accelerated life test on environmental stress for electronic products is not easily implemented due to various restrictions, and thus engineers are lacking of data of the product life test. Concerning this problem, environmental life of the printed circuit board(PCB) board is calculated by way of physics of failure. Influences of thermal cycle and vibration on PCB and its components are studied. Based on the analysis of force and stress between components and the PCB board in thermal cycle events and vibration events, four life computing models of pins and soldered dots are established. The miller damage ratio is used to calculate the accumulated damage of a pin or a soldered dot, and then the environment life of the PCB board can be determined by the first failed one. Finally, an example is used to illustrate the models and their calculations.