A centrifugal compressor usually operates with low isentropic efficiency and a terrible stable operating range, resulting from the complex impeller flow structure companied with the intense interaction among the impel...A centrifugal compressor usually operates with low isentropic efficiency and a terrible stable operating range, resulting from the complex impeller flow structure companied with the intense interaction among the impeller and the diffuser downstream. In many studies, the potential of centrifugal compressor tandem-impeller configurations for improving the compressor has been demonstrated. Whereas, compared with the convincing results on the tandem-designed axial compressors, the results on tandem impellers are limited and contradictory. Very little insight has been provided into the flow mechanisms inside tandem impellers, which is considered to be the primary reason for the confusion in tandem impeller design and application. Tandem impellers are expected to exhibit a totally different behavior due to the intense aerodynamic interaction between the inducer and the exducer, which substantially contributes to the flow structure and the compressor performance change. In the present study, a numerical study of a highly-loaded centrifugal compressor with various tandem designs was conducted to explore the inducer/exducer matching characteristics and the underlying flow mechanism inside tandem impellers. Two tandem impeller design parameters, namely, the inducer/exducer clocking fraction and the axial gap(overlap), were considered in the tandem impeller design process. The tandem impeller was also compared to the existing conventional impeller which the tandem impeller was redesigned for. The results demonstrated that the tandem-designed impeller can improve the centrifugal compressor stage performance and intense inducer/exducer interaction can be observed with changes in the clocking fraction and the axial gap(overlap). The tandem impeller performance is sensitive to changes in axial gap(overlap) when the suction side of the exducer blade is circumferentially close to the inducer blade. The fundamental reason for the performance variation in the inducer and the exducer lies in the inducer pressure change in the blade trailing edge that is determined by the Kutta condition. Additionally, the correlation between the tandem impeller slip effect and the discharge flow quality should be emphasized in the inducer/exducer gap jet analysis, in which the jet injection angle and the Coanda effect of the exducer suction surface critically affect the discharge flow characteristics.展开更多
Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells en...Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells encounter various obstacles,including limited tissue sources,invasive acquisition methods,cellular heterogeneity,purification challenges,cellular senescence,and diminished pluripotency and proliferation over successive passages.In this study,we used induced pluripotent stem cell-derived mesenchymal stem cells,known for their self-renewal capacity,multilineage differentiation potential,and immunomodulatory characteristics.We used induced pluripotent stem cell-derived mesenchymal stem cells in conjunction with acellular nerve allografts to address a 10 mm-long defect in a rat model of sciatic nerve injury.Our findings reveal that induced pluripotent stem cell-derived mesenchymal stem cells exhibit survival for up to 17 days in a rat model of peripheral nerve injury with acellular nerve allograft transplantation.Furthermore,the combination of acellular nerve allograft and induced pluripotent stem cell-derived mesenchymal stem cells significantly accelerates the regeneration of injured axons and improves behavioral function recovery in rats.Additionally,our in vivo and in vitro experiments indicate that induced pluripotent stem cell-derived mesenchymal stem cells play a pivotal role in promoting neovascularization.Collectively,our results suggest the potential of acellular nerve allografts with induced pluripotent stem cell-derived mesenchymal stem cells to augment nerve regeneration in rats,offering promising therapeutic strategies for clinical translation.展开更多
The plant immunity inducer, amino-oligosaccharin, has remarkable effects in disease resistance, cold tolerance, growth promotion, yield increase and quality improvement. This paper introduced the action mechanism of a...The plant immunity inducer, amino-oligosaccharin, has remarkable effects in disease resistance, cold tolerance, growth promotion, yield increase and quality improvement. This paper introduced the action mechanism of amino-oligosaccharin, its main application effects on crops and application techniques. In 2013-2014, ex- periments were conducted on a variety of crops at multiple locations by Xinjiang Corps as well as popularization and application in 2013-2014, and it was shown by the popularization and application that the application of amino-oligosaccharin could promote plant growth, reduce the incidence of crop diseases and improve crop yield and product quality.展开更多
To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature ...To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature water as working fluid.The pressure fluctuations near the tip region were collected,and the cavity structures under various conditions were documented by a high-speed camera.It is found that large tip clearance distinctly reduces both the non-cavitation and cavitation performance.Three cavitation instabilities,super-synchronous rotating cavitation,synchronous rotating cavitation and cavitation surge have been carefully identified through combination of cross-correlation analysis of pressure signals and visualization results.Large tip clearance displays a remarkable stabilization effect on pressure fluctuation,cavitation surge totally disappears,and the range of occurrence of synchronous rotating cavitation becomes smaller for the large tip clearance,whereas super-synchronous rotating cavitation only occurs in the large tip clearance.The cavitation areas are smaller at large tip clearance,while the flow channels are more seriously choked when cavitation occurs heavily in comparison with those at small tip clearance,which may be responsible for the worse cavitation performance.展开更多
The objective of this paper is to investigate the effect of water temperature on cavitation characteristics in a turbopump inducer,a series of experiments at different temperatures have been conducted in a newly devel...The objective of this paper is to investigate the effect of water temperature on cavitation characteristics in a turbopump inducer,a series of experiments at different temperatures have been conducted in a newly developed visualization test facility.It is found that higher temperature shows little influence on the non-cavitation performance and breakdown characteristic in the investigated range.The relationship between cavitation development and pressure fluctuation has been discussed in detail.Higher temperature displays a remarkable stabilization effect on the cavitation excited pressure.In particular,the inception cavitation numbers of both the super-synchronous rotating cavitation and synchronous rotating cavitation are decreased at higher temperatures,and the corresponding frequencies are not affected,while the amplitudes are distinctly reduced,and the occurrence range of synchronous rotating cavitation is significantly narrowed.A generalized RayleighPlesset equation has been employed to account for the thermal effect on the bubble development,which may provide a deep insight in understanding the experimental results.Thermal effect is found to act as a remarkable dissipation mechanism to suppress the bubble growth,smooth the collapse.In particular,the excited pressure during collapse is smaller at higher temperatures,which may lead to the stabilization effect of high temperature in this study.展开更多
Uric acid is the end product of purine catabolism and its plasma levels are maintained below its maximum solubility in water(6–7 mg/dl).The plasma levels are tightly regulated as the balance between the rate of produ...Uric acid is the end product of purine catabolism and its plasma levels are maintained below its maximum solubility in water(6–7 mg/dl).The plasma levels are tightly regulated as the balance between the rate of production and the rate of excretion,the latter occurring in urine(kidney),bile(liver)and feces(intestinal tract).Reabsorption in kidney is also an important component of this process.Both excretion and reabsorption are mediated by specific transporters.Disruption of the balance between production and excretion leads to hyperuricemia,which increases the risk of uric acid crystallization as monosodium urate with subsequent deposition of the crystals in joints causing gouty arthritis.Loss-of-function mutations in the transporters that mediate uric acid excretion are associated with gout.The ATP-Binding Cassette exporter ABCG2 is important in uric acid excretion at all three sites:kidney(urine),liver(bile),and intestine(feces).Mutations in this transporter cause gout and these mutations occur at significant prevalence in general population.However,mutations that are most prevalent result only in partial loss of transport function.Therefore,if the expression of these partially defective transporters could be induced,the increased number of the transporter molecules would compensate for the mutation-associated decrease in transport function and hence increase uric acid excretion.As such,pharmacologic agents with ability to induce the expression of ABCG2 represent potentially a novel class of drugs for treatment of gouty arthritis.展开更多
Pestalotiopsis sp. J63, producing a high activity of laccase, is a new marine-derived fungus isolated from the oceanic sediment of the East China Sea. Since the marine environment is oligotrophic nutrient, marine deri...Pestalotiopsis sp. J63, producing a high activity of laccase, is a new marine-derived fungus isolated from the oceanic sediment of the East China Sea. Since the marine environment is oligotrophic nutrient, marine derived fungi may use small amount of nutrients to grow and produce laccases. Agricultural residues that are mainly composed of lignin, cellulose and hemicellulose are difficult to be degraded and few microbes can take them as substrates, so they are considered as oligotrophic nutrient and have the potential to be used to produce value added products. In this study, the ability of Pestalotiopsis sp. J63 to use agricultural residues to produce laccases was tested in the submerged fermentation. The combination of 3 g·L 1maltose and 20 g·L 1rice straw was the best carbon sources and 8 g·L 1ammonium sulfate was the best nitrogen source under the condition without inducers. The effects of five inducers, the feeding time and concentration of inducer on laccase production were investigated.Adding 0.09 mmol·L 1phenol after 24 h of incubation led to high laccase activity(5089 U·L 1), while with 0.09mmol·L 1phenol in the medium and wheat bran as the nitrogen source, the laccase activity could reach 5791.7U·L 1. Native-PAGE results showed that two laccase isozymes were present in the cultures. One existed in both induced and non-induced culture filtrates, while the other was only found in the fermentation with the addition of phenol, guaiacol and veratryl alcohol.展开更多
An experiment for rocket engine inducer cavitating flow is conducted on a new experimental platform.The experiment platform,using water as working medium,can be used to investigate the steady and unsteady flows of cav...An experiment for rocket engine inducer cavitating flow is conducted on a new experimental platform.The experiment platform,using water as working medium,can be used to investigate the steady and unsteady flows of cavitating and noncavitating turbopumps.The experimental platform is designed as a flexible and versatile apparatus for any kind of fluid dynamic phenomena relating to high performance liquid rocket engine turbopumps.Design details for the platform is introduced.Various extend of cavitation images and dynamic pressure impulse are obtained,which provides a reference for cavitating flow study in rocket engine inducer.展开更多
Genetically engineered transgenic animals and plants have proven to be extremely useful for analyzing biochemical and developmental processes.Promoters responding to chemical inducers will be powerful tools for basic ...Genetically engineered transgenic animals and plants have proven to be extremely useful for analyzing biochemical and developmental processes.Promoters responding to chemical inducers will be powerful tools for basic research in molecular biology and biotechnological applications.Various chemical inducible systems based on activation and inactivation of the target gene had been described.The transfer of regulatory elements from prokaryotes,insects,and mammals has opened new avenues to construct chemically inducible promoters that differ in their ability to regulate the temporal and spatial expression patterns,and this will dramatically increase the application of transgenic technology.This review provides an overview on regulation of gene expression,promoter activating systems,promoter inactivation systems,inducible gene over expression,and inducible anti suppression.展开更多
In order to evaluate the effects of the short blade locations on the anti-cavitation performance of the splittel bladed inducer and the pump, 5 inducers with different short blade locations are designed, Cavitation si...In order to evaluate the effects of the short blade locations on the anti-cavitation performance of the splittel bladed inducer and the pump, 5 inducers with different short blade locations are designed, Cavitation simulatior and experimental tests of the pumps with these inducers are carried out. The algebraic slip mixture model in th CFX software is adopted for cavitation simulation. The results show that there is a vortex at the inlet of the indu（ er. Asymmetric cavitation on the inducer and on the impeller is observed. The analysis shows that the short blad locations have a minor effect on the internal flow field in the inducer and on the external performance of th pump, but have a significant effect on the anti-cavitation performance. It is suggested that the inducer shoul be designed appropriately. The present simulations found an optimal inducer with better anti-cavitatio performance.展开更多
Many physiological effects of natural antioxidants, their extracts or their major active components, have been reported in recent decades. Most of these compounds are characterized by a phenolic structure, similar to ...Many physiological effects of natural antioxidants, their extracts or their major active components, have been reported in recent decades. Most of these compounds are characterized by a phenolic structure, similar to that of o-tocopherol, and present antioxidant properties that have been demonstrated both in vitro and in vivo. Polyphenors may increase the capacity of endogenous antioxidant defences and modulate the cellular redox state. Changes in the cellular redox state may have wide-ranging consequences for cellular growth and differentiation. The majority of in vitro and in vivo studies conducted so far have attributed the protective effect of bioactive polyphenols to their chemical reactivity toward free radicals and their capacity to prevent the oxidation of important intracellular components. However, in recent years a possible novel aspect inthe mode of action of these compounds has been suggested; that is, the ultimate stimulation of the heme oxygenase-1 （HO-1） pathway is likely to account for the established and powerful antioxidant/anti-inflammatory properties of these polyphenols. The products of the HO-catalyzed reaction, particularly carbon mon- oxide （CO） and biliverdin/bilirubin have been shown to exert protective effects in several organs against oxidative and other noxious stimuli. In this context, it is interesting to note that induction of HO-1 expression by means of natural compounds contributes to protection against liver damage in various experimental models. The focus of this review is on the significance of targeted induction of HO-1 as a potential therapeutic strategy to protect the liver against various stressors in several pathological conditions.展开更多
Fungal laccases are industrially important inducible enzymes extensively used in the delignification of lignocellulosics,detoxification of environmental wastes and decolorization of textile dyes.The discovery of new i...Fungal laccases are industrially important inducible enzymes extensively used in the delignification of lignocellulosics,detoxification of environmental wastes and decolorization of textile dyes.The discovery of new inducers is crucial for laccase productivity by filamentous fungi.In this study,a novel laccase-producing strain S8 from a bambusicolous fungus Shiraia bambusicola was identified by using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate)as laccase secretion indicator and native polyacrylamide gel electrophoresis.The corresponding full-length cDNA of laccase was cloned and characterized.The effect of lanthanum(LaCl_(3))on extracellular laccase activity was tested at the concentration from 0.2 to 2.0 g/L and at different addition time(day 1-4)in the mycelium culture.In the presence of 1.0 g/L La^(3+)at the beginning of the mycelium cultures,the highest laccase activity(2.7×10^(4)U/L)is reached after 10 days of cultivation,about tenfold higher compared with non-induced cultures.La^(3+)is shown to be a very strong inducer for fungal laccase activity with no inhibitory effect on fungal growth at the optimized concentration.In vivo,La^(3+)added to the mycelium culture not only promotes a continuous and high expression of laccase gene(lcc1),but also induces a rapid generation of signaling molecules including reactive oxygen species(ROS)and nitric oxygen(NO).Both the NO donor sodium nitroprusside(SNP)and exogenous hydrogen peroxide(H_(2)O_(2))potentiate La^(3+)-induced laccase activity and increase membrane permeability of hyphal cells.Moreover,the scavengers such as 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide(cPTIO)for NO and vitamin C for ROS suppress the induction.These results suggest that these signals can mediate La^(3+)-induced laccase biosynthesis and its secretion.Our study provides a basis for understanding the induction mechanism of La^(3+)on laccase and a practical strategy for enhanced fungal laccase production.展开更多
Ether extrilcls of 1693 Chinesc medicinal herbs and plilnts from 268 families werestudied for the induction of Epstcin-Barr viral (EBV ) early antigcn (EA ) expression in theRaji cell line. Fifty-two from 18 families ...Ether extrilcls of 1693 Chinesc medicinal herbs and plilnts from 268 families werestudied for the induction of Epstcin-Barr viral (EBV ) early antigcn (EA ) expression in theRaji cell line. Fifty-two from 18 families were found to have inducing activity. Twenty-fiveand seven of them were from Euphorbiaccae and Thymclaeaceae, respectively. Some ofthem, such as Croton tiglium, Euphorbia kansui, Daphnc genkwa, Wikstrocmia chamacdaphen, Wikstroemia indica, Prunus mandshurica Koehne and Achyranthes bidentata arecommonly used drugs. The significance of these herbs in the activation of EBV in vivo andtheir relation to the development of nasopharyngeal carcinoma were discussed.展开更多
AIEgens can serve as an effective platform for the construction of photosensitizer-based immunogenic cell death(ICD)inducers.To date,several mitochondria or endoplasmic reticulum(ER)-targeted aggregationinduced emissi...AIEgens can serve as an effective platform for the construction of photosensitizer-based immunogenic cell death(ICD)inducers.To date,several mitochondria or endoplasmic reticulum(ER)-targeted aggregationinduced emission(AIE)molecules have been developed and have evoked massive ICD in cells.However,due to the complex physicochemical environment in cells,these small AIE molecules cannot maintain a stable aggregate state,which not only affects the fluorescence intensity of the photosensitizer but also decreases the generation of reactive oxygen species(ROS),and thus reducing the effect of the photosensitizer to elicit ICD.AIEgen-based nanomicelles,which maintain a stable micellar structure,can prevent defects of AIE molecules in photodynamic therapy(PDT)applications.Therefore,in this study,a mitochondria-targeted AIE nanophotosensitizer was synthesized and used as a highly potent ICD inducer for vaccine preparation and tumor prevention.展开更多
[Objective] The aim was to analyze the differences in haploid induction rates of different inducers. [Method] Six maize inducers with purple spot and purple color were selected as the male parents to pollinate six inb...[Objective] The aim was to analyze the differences in haploid induction rates of different inducers. [Method] Six maize inducers with purple spot and purple color were selected as the male parents to pollinate six inbred lines. [Result] The mean haploid induction rates were significantly different among the inducers: KMS-3 >WY-1 >PR-2 >YP-13 >KMS-2 >KMS-1. The haploid induction rates of the different hybrid materials were significantly different: K410 >105A >103A >104A >107A >D271 >106A>L73>N21>KZ58. [Conclusion] The haploid inducer line PR-2, which had high haploid induction rate and low variation coefficient, was an elite haploid inducer.展开更多
In this research, centrifugal pump unit was analysed to study the effects of using inducers on its performance. Hydraulic tests were done to obtain the optimum hydraulic performance before and after using inducer. Two...In this research, centrifugal pump unit was analysed to study the effects of using inducers on its performance. Hydraulic tests were done to obtain the optimum hydraulic performance before and after using inducer. Two types of inducers were used in this work （axial, helical）. For this purpose, a test rig was specially designed with a pump system to investigate the parameters under consideration. Plots （H-Q） curves, （B.P.-Q） curves and （q-Q） curves were used to show the effect of pump performance with and without inducers. The present study introduces a simulation of centrifugal pump performance in conjunction with inducers using CFD （Computational Fluid Dynamics）, to compare it with experimentally observed values. The model investigates the impact of using inducers on the head and flow of the pump. The results of the CFD model and experimental are correlated well. Furthermore, the results help the decision makers of the pumps for future developments in pump performance assuring safe and reliable running condition of the water pumps. Also it may be used for more applications of larger head and flow pumps.展开更多
The defining neuropathological feature of Parkinson＇s disease （PD） is the loss of nigrostriatal dopaminergic （DA） projections. This results in striatal dopamine levels and a biochemical reduction of movement diso...The defining neuropathological feature of Parkinson＇s disease （PD） is the loss of nigrostriatal dopaminergic （DA） projections. This results in striatal dopamine levels and a biochemical reduction of movement disorders, such as a tremor at rest, rigidity of the limbs, bradykinesia, and postural instability （Kim et al., 2011; Kim et al., 2012; Burke and O＇Malley, 2013; Leem et al., 2014; Namet al., 2014）.展开更多
The expression of endothelial nitric oxide synthase traffic inducer （NOSTRIN） in the placenta of the patients with pregnancy induced hypertension （PIH） was detected and its role in the pathogenesis of PIH was stud...The expression of endothelial nitric oxide synthase traffic inducer （NOSTRIN） in the placenta of the patients with pregnancy induced hypertension （PIH） was detected and its role in the pathogenesis of PIH was studied. The pathological changes in placental vessels were observed by HE staining. NO2-/NO3- , the stable metabolic end products of NO, was measured with nitrate reductase. The eNOS activity in placental tissues was assayed by spectrophotometry. Western blot analysis was applied to detect NOSTRIN expression. The incidence of thickening and fibronoid necrosis of placental vessels was significantly higher in women with PIH than in the normal group （P〈 0.01）. The levels of placental NO2-/NO3- in PIH patients （27. 53±7.48 μmol/mg） were significantly lower than in normal group （54. 27±9.53 μmol/mg, P〈0.01）. The activity of eNOS was significantly decreased in PIH group （12. 826±3.61 U/mg） as compared with that in normal group （21. 72±3.83 U/mg, P〈0.01）. Western blot analysis revealed that both groups expressed 58 kD NOSTRIN, but the protein level was significantly higher in women with PIH than in the normal group （P〈0.01）. A significant negative correlation existed between the expression of NOSTRIN protein and the activity of eNOS in placental tissue of women with PIH （r=-0.57, P〈0.01）. It was concluded that the level of NOSTRIN expression in placenta of women with PIH was increased, which may play an important role in the pathogenesis of PIH.展开更多
Objective:To study the combined therapeutic effects of cytotoxic agent and differentiation-inducer on human gas tric carcinoma celll line SGC-7901 in vitro. Methods: The combined therapeutic effects of all-trans retin...Objective:To study the combined therapeutic effects of cytotoxic agent and differentiation-inducer on human gas tric carcinoma celll line SGC-7901 in vitro. Methods: The combined therapeutic effects of all-trans retinoic acid (ATRA), interferon a (IFNa)and fluorouracil (5-Fu) on gastric carcinoma cell line ax 7901 were observed when one of the 3, the combination of any 2 of the 3 and combination of all the 3 were administered respectively. The morphological and functional changes of gastric carcinoma cells were studied with MTT assay, flow cytometry, image analysis and determination of CEA content in the culture medium of the cells. Results: The cytostatic rate was increased as shown by the decrease of the rate of colony formation of the cells on culture disc when one agent, the combination of 2 agents and the combination of the 3 were administered progressively. The cells were relatively accumulated in the phase of G0/G1 and synthesis of DNA in he cells was inhibited.The malignant phenotype of the cells disappeared gradually while the characteristics of matUre cells were in creased. Meanwhile, CEA Level in the culture medium was decreased progressively. Apoptosis of the cells was oborved and a large amount of apoptotic apoptotic were found. Conclusion: The administration of the 3 agents in combination result in signif icant inhibition on proliferation, inducing of differention and promotion of apoptosis of gastric caxcinoma cells. The combina tion of cytotoxic agent and differention-inducer exerts significant inhibition on gastric carcinoma cells in vitro.展开更多
BACKGROUND： Recent studies have demonstrated that tumor necrosis factor-like weak inducer of apoptosis （TWEAK） participates in brain edema. However, it is unclear whether blood-brain barrier （BBB） disruption is a...BACKGROUND： Recent studies have demonstrated that tumor necrosis factor-like weak inducer of apoptosis （TWEAK） participates in brain edema. However, it is unclear whether blood-brain barrier （BBB） disruption is associated with TWEAK during the process of brain edema OBJECTIVE： To investigate the effects of TWEAK on BBB permeability in brain edema. DESIGN, TIME AND SETTING： An immunohistochemical observation, randomized, controlled animal experiment was performed at the Laboratory of Neurosurgical Anatomy, Xiangya Medical College, Central South University ＆ Central Laboratory, Third Xiangya Hospital, Central South University between January 2006 and December 2007. MATERIALS： A total of 48 adult Wistar rats were randomly divided into three groups： normal control （n = 8）, sham-operated （n = 8）, and ischemia/reperfusion （n = 32）. Rats from the ischemia/reperfusion group were randomly assigned to four subgroups according to different time points, i.e., 2 hours of ischemia followed by 6 hours （n = 8）, 12 hours （n = 8）, 1 day （n = 8）, or 12 days （n = 8） of reperfusion. METHODS： Focal cerebral ischemia/reperfusion injury was induced by middle cerebral artery occlusion （MCAO） using the suture method in rats from the ischemia/reperfusion group. Thread was introduced at a depth of 17-19 mm. Rats in the sham-operated group were subjected to experimental procedures similar to the ischemia/reperfusion group; however, the introducing depth of thread was 10 mm. The normal control group was not given any intervention. MAIN OUTCOME MEASURES： TWEAK expression was examined by immunohistochemistry; brain water content on the ischemic side was calculated as the ratio of dry to wet tissue weight; BBB permeability was measured by Evans blue extravasation. RESULTS： A total of eight rats died prior to and after surgery and an additional eight rats were randomly entered into the study. Thus 48 rats were included in the final analysis. In the ischemia/reperfusion group, TWEAK-positive cells were present in the ischemic penumbra surrounding the lamellar necrotic region in the fight cerebral hemisphere at 6 hours reperfusion and increased thereafter; by 2 days reperfusion they had reached a peak level, which was significantly higher than the sham-operated and normal control groups （P 〈 0.05）. At 6 hours reperfusion, both brain water content and Evans blue extravasation showed the same tendency for change as TWEAK expression. Pearson correlation analysis results revealed that the degree of TWEAK expression was positively correlated with brain water content （r = 0.892, P 〈 0.05）. CONCLUSION： The present results confirmed that TWEAK was involved in BBB disruption and participated in brain edema following cerebral ischemia.展开更多
基金financial support from the National Natural Science Foundation of China(Project No.51876022,No.51836008)is greatly appreciated。
文摘A centrifugal compressor usually operates with low isentropic efficiency and a terrible stable operating range, resulting from the complex impeller flow structure companied with the intense interaction among the impeller and the diffuser downstream. In many studies, the potential of centrifugal compressor tandem-impeller configurations for improving the compressor has been demonstrated. Whereas, compared with the convincing results on the tandem-designed axial compressors, the results on tandem impellers are limited and contradictory. Very little insight has been provided into the flow mechanisms inside tandem impellers, which is considered to be the primary reason for the confusion in tandem impeller design and application. Tandem impellers are expected to exhibit a totally different behavior due to the intense aerodynamic interaction between the inducer and the exducer, which substantially contributes to the flow structure and the compressor performance change. In the present study, a numerical study of a highly-loaded centrifugal compressor with various tandem designs was conducted to explore the inducer/exducer matching characteristics and the underlying flow mechanism inside tandem impellers. Two tandem impeller design parameters, namely, the inducer/exducer clocking fraction and the axial gap(overlap), were considered in the tandem impeller design process. The tandem impeller was also compared to the existing conventional impeller which the tandem impeller was redesigned for. The results demonstrated that the tandem-designed impeller can improve the centrifugal compressor stage performance and intense inducer/exducer interaction can be observed with changes in the clocking fraction and the axial gap(overlap). The tandem impeller performance is sensitive to changes in axial gap(overlap) when the suction side of the exducer blade is circumferentially close to the inducer blade. The fundamental reason for the performance variation in the inducer and the exducer lies in the inducer pressure change in the blade trailing edge that is determined by the Kutta condition. Additionally, the correlation between the tandem impeller slip effect and the discharge flow quality should be emphasized in the inducer/exducer gap jet analysis, in which the jet injection angle and the Coanda effect of the exducer suction surface critically affect the discharge flow characteristics.
基金supported by the National Natural Science Foundation of China,No.32171356(to YW)Self-Support Research Projects of Shihezi University,No.ZZZC2021105(to WJ)+1 种基金Capital Medical University Natural Science Cultivation Fund,No.PYZ23044(to FQM)Beijing Municipal Natural Science Foundation,No.7244410(to JHD)。
文摘Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells encounter various obstacles,including limited tissue sources,invasive acquisition methods,cellular heterogeneity,purification challenges,cellular senescence,and diminished pluripotency and proliferation over successive passages.In this study,we used induced pluripotent stem cell-derived mesenchymal stem cells,known for their self-renewal capacity,multilineage differentiation potential,and immunomodulatory characteristics.We used induced pluripotent stem cell-derived mesenchymal stem cells in conjunction with acellular nerve allografts to address a 10 mm-long defect in a rat model of sciatic nerve injury.Our findings reveal that induced pluripotent stem cell-derived mesenchymal stem cells exhibit survival for up to 17 days in a rat model of peripheral nerve injury with acellular nerve allograft transplantation.Furthermore,the combination of acellular nerve allograft and induced pluripotent stem cell-derived mesenchymal stem cells significantly accelerates the regeneration of injured axons and improves behavioral function recovery in rats.Additionally,our in vivo and in vitro experiments indicate that induced pluripotent stem cell-derived mesenchymal stem cells play a pivotal role in promoting neovascularization.Collectively,our results suggest the potential of acellular nerve allografts with induced pluripotent stem cell-derived mesenchymal stem cells to augment nerve regeneration in rats,offering promising therapeutic strategies for clinical translation.
文摘The plant immunity inducer, amino-oligosaccharin, has remarkable effects in disease resistance, cold tolerance, growth promotion, yield increase and quality improvement. This paper introduced the action mechanism of amino-oligosaccharin, its main application effects on crops and application techniques. In 2013-2014, ex- periments were conducted on a variety of crops at multiple locations by Xinjiang Corps as well as popularization and application in 2013-2014, and it was shown by the popularization and application that the application of amino-oligosaccharin could promote plant growth, reduce the incidence of crop diseases and improve crop yield and product quality.
基金supported by the National Basic Research Program of China(No.613321)。
文摘To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature water as working fluid.The pressure fluctuations near the tip region were collected,and the cavity structures under various conditions were documented by a high-speed camera.It is found that large tip clearance distinctly reduces both the non-cavitation and cavitation performance.Three cavitation instabilities,super-synchronous rotating cavitation,synchronous rotating cavitation and cavitation surge have been carefully identified through combination of cross-correlation analysis of pressure signals and visualization results.Large tip clearance displays a remarkable stabilization effect on pressure fluctuation,cavitation surge totally disappears,and the range of occurrence of synchronous rotating cavitation becomes smaller for the large tip clearance,whereas super-synchronous rotating cavitation only occurs in the large tip clearance.The cavitation areas are smaller at large tip clearance,while the flow channels are more seriously choked when cavitation occurs heavily in comparison with those at small tip clearance,which may be responsible for the worse cavitation performance.
文摘The objective of this paper is to investigate the effect of water temperature on cavitation characteristics in a turbopump inducer,a series of experiments at different temperatures have been conducted in a newly developed visualization test facility.It is found that higher temperature shows little influence on the non-cavitation performance and breakdown characteristic in the investigated range.The relationship between cavitation development and pressure fluctuation has been discussed in detail.Higher temperature displays a remarkable stabilization effect on the cavitation excited pressure.In particular,the inception cavitation numbers of both the super-synchronous rotating cavitation and synchronous rotating cavitation are decreased at higher temperatures,and the corresponding frequencies are not affected,while the amplitudes are distinctly reduced,and the occurrence range of synchronous rotating cavitation is significantly narrowed.A generalized RayleighPlesset equation has been employed to account for the thermal effect on the bubble development,which may provide a deep insight in understanding the experimental results.Thermal effect is found to act as a remarkable dissipation mechanism to suppress the bubble growth,smooth the collapse.In particular,the excited pressure during collapse is smaller at higher temperatures,which may lead to the stabilization effect of high temperature in this study.
基金This work was supported by the National Institutes of Health grant R41 AR074854the Welch Endowed Chair in Biochemistry,Grant No.BI-0028,at Texas Tech University Health Sciences Center.
文摘Uric acid is the end product of purine catabolism and its plasma levels are maintained below its maximum solubility in water(6–7 mg/dl).The plasma levels are tightly regulated as the balance between the rate of production and the rate of excretion,the latter occurring in urine(kidney),bile(liver)and feces(intestinal tract).Reabsorption in kidney is also an important component of this process.Both excretion and reabsorption are mediated by specific transporters.Disruption of the balance between production and excretion leads to hyperuricemia,which increases the risk of uric acid crystallization as monosodium urate with subsequent deposition of the crystals in joints causing gouty arthritis.Loss-of-function mutations in the transporters that mediate uric acid excretion are associated with gout.The ATP-Binding Cassette exporter ABCG2 is important in uric acid excretion at all three sites:kidney(urine),liver(bile),and intestine(feces).Mutations in this transporter cause gout and these mutations occur at significant prevalence in general population.However,mutations that are most prevalent result only in partial loss of transport function.Therefore,if the expression of these partially defective transporters could be induced,the increased number of the transporter molecules would compensate for the mutation-associated decrease in transport function and hence increase uric acid excretion.As such,pharmacologic agents with ability to induce the expression of ABCG2 represent potentially a novel class of drugs for treatment of gouty arthritis.
基金Supported by the National Natural Science Foundation of China （21036005） and Scientific and Technology Plan of Zhejiang Province （2011C33016）.
文摘Pestalotiopsis sp. J63, producing a high activity of laccase, is a new marine-derived fungus isolated from the oceanic sediment of the East China Sea. Since the marine environment is oligotrophic nutrient, marine derived fungi may use small amount of nutrients to grow and produce laccases. Agricultural residues that are mainly composed of lignin, cellulose and hemicellulose are difficult to be degraded and few microbes can take them as substrates, so they are considered as oligotrophic nutrient and have the potential to be used to produce value added products. In this study, the ability of Pestalotiopsis sp. J63 to use agricultural residues to produce laccases was tested in the submerged fermentation. The combination of 3 g·L 1maltose and 20 g·L 1rice straw was the best carbon sources and 8 g·L 1ammonium sulfate was the best nitrogen source under the condition without inducers. The effects of five inducers, the feeding time and concentration of inducer on laccase production were investigated.Adding 0.09 mmol·L 1phenol after 24 h of incubation led to high laccase activity(5089 U·L 1), while with 0.09mmol·L 1phenol in the medium and wheat bran as the nitrogen source, the laccase activity could reach 5791.7U·L 1. Native-PAGE results showed that two laccase isozymes were present in the cultures. One existed in both induced and non-induced culture filtrates, while the other was only found in the fermentation with the addition of phenol, guaiacol and veratryl alcohol.
文摘An experiment for rocket engine inducer cavitating flow is conducted on a new experimental platform.The experiment platform,using water as working medium,can be used to investigate the steady and unsteady flows of cavitating and noncavitating turbopumps.The experimental platform is designed as a flexible and versatile apparatus for any kind of fluid dynamic phenomena relating to high performance liquid rocket engine turbopumps.Design details for the platform is introduced.Various extend of cavitation images and dynamic pressure impulse are obtained,which provides a reference for cavitating flow study in rocket engine inducer.
文摘Genetically engineered transgenic animals and plants have proven to be extremely useful for analyzing biochemical and developmental processes.Promoters responding to chemical inducers will be powerful tools for basic research in molecular biology and biotechnological applications.Various chemical inducible systems based on activation and inactivation of the target gene had been described.The transfer of regulatory elements from prokaryotes,insects,and mammals has opened new avenues to construct chemically inducible promoters that differ in their ability to regulate the temporal and spatial expression patterns,and this will dramatically increase the application of transgenic technology.This review provides an overview on regulation of gene expression,promoter activating systems,promoter inactivation systems,inducible gene over expression,and inducible anti suppression.
基金Supported by the National Natural Science Foundation of China(51406185,51276172)the China Scholarship Council Project in 2012(201208330325)+1 种基金the Third Level 151 Talent Project in Zhejiang Provincethe Professional Leader Leading Project in 2013(lj2013005)
文摘In order to evaluate the effects of the short blade locations on the anti-cavitation performance of the splittel bladed inducer and the pump, 5 inducers with different short blade locations are designed, Cavitation simulatior and experimental tests of the pumps with these inducers are carried out. The algebraic slip mixture model in th CFX software is adopted for cavitation simulation. The results show that there is a vortex at the inlet of the indu（ er. Asymmetric cavitation on the inducer and on the impeller is observed. The analysis shows that the short blad locations have a minor effect on the internal flow field in the inducer and on the external performance of th pump, but have a significant effect on the anti-cavitation performance. It is suggested that the inducer shoul be designed appropriately. The present simulations found an optimal inducer with better anti-cavitatio performance.
基金Grants (ex 60%) from MURST (Ministero dell’ Università e della Ricerca Scientifica e Tecnologica),Rome,Italy
文摘Many physiological effects of natural antioxidants, their extracts or their major active components, have been reported in recent decades. Most of these compounds are characterized by a phenolic structure, similar to that of o-tocopherol, and present antioxidant properties that have been demonstrated both in vitro and in vivo. Polyphenors may increase the capacity of endogenous antioxidant defences and modulate the cellular redox state. Changes in the cellular redox state may have wide-ranging consequences for cellular growth and differentiation. The majority of in vitro and in vivo studies conducted so far have attributed the protective effect of bioactive polyphenols to their chemical reactivity toward free radicals and their capacity to prevent the oxidation of important intracellular components. However, in recent years a possible novel aspect inthe mode of action of these compounds has been suggested; that is, the ultimate stimulation of the heme oxygenase-1 （HO-1） pathway is likely to account for the established and powerful antioxidant/anti-inflammatory properties of these polyphenols. The products of the HO-catalyzed reaction, particularly carbon mon- oxide （CO） and biliverdin/bilirubin have been shown to exert protective effects in several organs against oxidative and other noxious stimuli. In this context, it is interesting to note that induction of HO-1 expression by means of natural compounds contributes to protection against liver damage in various experimental models. The focus of this review is on the significance of targeted induction of HO-1 as a potential therapeutic strategy to protect the liver against various stressors in several pathological conditions.
基金Project supported by the National Natural Science Foundation of China(82073955,81773696)the Priority Academic Program Development of the Jiangsu Higher Education Institutes(PAPD)。
文摘Fungal laccases are industrially important inducible enzymes extensively used in the delignification of lignocellulosics,detoxification of environmental wastes and decolorization of textile dyes.The discovery of new inducers is crucial for laccase productivity by filamentous fungi.In this study,a novel laccase-producing strain S8 from a bambusicolous fungus Shiraia bambusicola was identified by using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate)as laccase secretion indicator and native polyacrylamide gel electrophoresis.The corresponding full-length cDNA of laccase was cloned and characterized.The effect of lanthanum(LaCl_(3))on extracellular laccase activity was tested at the concentration from 0.2 to 2.0 g/L and at different addition time(day 1-4)in the mycelium culture.In the presence of 1.0 g/L La^(3+)at the beginning of the mycelium cultures,the highest laccase activity(2.7×10^(4)U/L)is reached after 10 days of cultivation,about tenfold higher compared with non-induced cultures.La^(3+)is shown to be a very strong inducer for fungal laccase activity with no inhibitory effect on fungal growth at the optimized concentration.In vivo,La^(3+)added to the mycelium culture not only promotes a continuous and high expression of laccase gene(lcc1),but also induces a rapid generation of signaling molecules including reactive oxygen species(ROS)and nitric oxygen(NO).Both the NO donor sodium nitroprusside(SNP)and exogenous hydrogen peroxide(H_(2)O_(2))potentiate La^(3+)-induced laccase activity and increase membrane permeability of hyphal cells.Moreover,the scavengers such as 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide(cPTIO)for NO and vitamin C for ROS suppress the induction.These results suggest that these signals can mediate La^(3+)-induced laccase biosynthesis and its secretion.Our study provides a basis for understanding the induction mechanism of La^(3+)on laccase and a practical strategy for enhanced fungal laccase production.
文摘Ether extrilcls of 1693 Chinesc medicinal herbs and plilnts from 268 families werestudied for the induction of Epstcin-Barr viral (EBV ) early antigcn (EA ) expression in theRaji cell line. Fifty-two from 18 families were found to have inducing activity. Twenty-fiveand seven of them were from Euphorbiaccae and Thymclaeaceae, respectively. Some ofthem, such as Croton tiglium, Euphorbia kansui, Daphnc genkwa, Wikstrocmia chamacdaphen, Wikstroemia indica, Prunus mandshurica Koehne and Achyranthes bidentata arecommonly used drugs. The significance of these herbs in the activation of EBV in vivo andtheir relation to the development of nasopharyngeal carcinoma were discussed.
基金supported by the National Natural Science Foundation of China(Nos.52173137 and 51873163).
文摘AIEgens can serve as an effective platform for the construction of photosensitizer-based immunogenic cell death(ICD)inducers.To date,several mitochondria or endoplasmic reticulum(ER)-targeted aggregationinduced emission(AIE)molecules have been developed and have evoked massive ICD in cells.However,due to the complex physicochemical environment in cells,these small AIE molecules cannot maintain a stable aggregate state,which not only affects the fluorescence intensity of the photosensitizer but also decreases the generation of reactive oxygen species(ROS),and thus reducing the effect of the photosensitizer to elicit ICD.AIEgen-based nanomicelles,which maintain a stable micellar structure,can prevent defects of AIE molecules in photodynamic therapy(PDT)applications.Therefore,in this study,a mitochondria-targeted AIE nanophotosensitizer was synthesized and used as a highly potent ICD inducer for vaccine preparation and tumor prevention.
基金Supported by Key Program for International S&T Cooperation Projects of China(2011DFR30840)National Key Technology Research and Development Program of Harbin(2007AA6BE047)
文摘[Objective] The aim was to analyze the differences in haploid induction rates of different inducers. [Method] Six maize inducers with purple spot and purple color were selected as the male parents to pollinate six inbred lines. [Result] The mean haploid induction rates were significantly different among the inducers: KMS-3 >WY-1 >PR-2 >YP-13 >KMS-2 >KMS-1. The haploid induction rates of the different hybrid materials were significantly different: K410 >105A >103A >104A >107A >D271 >106A>L73>N21>KZ58. [Conclusion] The haploid inducer line PR-2, which had high haploid induction rate and low variation coefficient, was an elite haploid inducer.
文摘In this research, centrifugal pump unit was analysed to study the effects of using inducers on its performance. Hydraulic tests were done to obtain the optimum hydraulic performance before and after using inducer. Two types of inducers were used in this work （axial, helical）. For this purpose, a test rig was specially designed with a pump system to investigate the parameters under consideration. Plots （H-Q） curves, （B.P.-Q） curves and （q-Q） curves were used to show the effect of pump performance with and without inducers. The present study introduces a simulation of centrifugal pump performance in conjunction with inducers using CFD （Computational Fluid Dynamics）, to compare it with experimentally observed values. The model investigates the impact of using inducers on the head and flow of the pump. The results of the CFD model and experimental are correlated well. Furthermore, the results help the decision makers of the pumps for future developments in pump performance assuring safe and reliable running condition of the water pumps. Also it may be used for more applications of larger head and flow pumps.
文摘The defining neuropathological feature of Parkinson＇s disease （PD） is the loss of nigrostriatal dopaminergic （DA） projections. This results in striatal dopamine levels and a biochemical reduction of movement disorders, such as a tremor at rest, rigidity of the limbs, bradykinesia, and postural instability （Kim et al., 2011; Kim et al., 2012; Burke and O＇Malley, 2013; Leem et al., 2014; Namet al., 2014）.
文摘The expression of endothelial nitric oxide synthase traffic inducer （NOSTRIN） in the placenta of the patients with pregnancy induced hypertension （PIH） was detected and its role in the pathogenesis of PIH was studied. The pathological changes in placental vessels were observed by HE staining. NO2-/NO3- , the stable metabolic end products of NO, was measured with nitrate reductase. The eNOS activity in placental tissues was assayed by spectrophotometry. Western blot analysis was applied to detect NOSTRIN expression. The incidence of thickening and fibronoid necrosis of placental vessels was significantly higher in women with PIH than in the normal group （P〈 0.01）. The levels of placental NO2-/NO3- in PIH patients （27. 53±7.48 μmol/mg） were significantly lower than in normal group （54. 27±9.53 μmol/mg, P〈0.01）. The activity of eNOS was significantly decreased in PIH group （12. 826±3.61 U/mg） as compared with that in normal group （21. 72±3.83 U/mg, P〈0.01）. Western blot analysis revealed that both groups expressed 58 kD NOSTRIN, but the protein level was significantly higher in women with PIH than in the normal group （P〈0.01）. A significant negative correlation existed between the expression of NOSTRIN protein and the activity of eNOS in placental tissue of women with PIH （r=-0.57, P〈0.01）. It was concluded that the level of NOSTRIN expression in placenta of women with PIH was increased, which may play an important role in the pathogenesis of PIH.
文摘Objective:To study the combined therapeutic effects of cytotoxic agent and differentiation-inducer on human gas tric carcinoma celll line SGC-7901 in vitro. Methods: The combined therapeutic effects of all-trans retinoic acid (ATRA), interferon a (IFNa)and fluorouracil (5-Fu) on gastric carcinoma cell line ax 7901 were observed when one of the 3, the combination of any 2 of the 3 and combination of all the 3 were administered respectively. The morphological and functional changes of gastric carcinoma cells were studied with MTT assay, flow cytometry, image analysis and determination of CEA content in the culture medium of the cells. Results: The cytostatic rate was increased as shown by the decrease of the rate of colony formation of the cells on culture disc when one agent, the combination of 2 agents and the combination of the 3 were administered progressively. The cells were relatively accumulated in the phase of G0/G1 and synthesis of DNA in he cells was inhibited.The malignant phenotype of the cells disappeared gradually while the characteristics of matUre cells were in creased. Meanwhile, CEA Level in the culture medium was decreased progressively. Apoptosis of the cells was oborved and a large amount of apoptotic apoptotic were found. Conclusion: The administration of the 3 agents in combination result in signif icant inhibition on proliferation, inducing of differention and promotion of apoptosis of gastric caxcinoma cells. The combina tion of cytotoxic agent and differention-inducer exerts significant inhibition on gastric carcinoma cells in vitro.
文摘BACKGROUND： Recent studies have demonstrated that tumor necrosis factor-like weak inducer of apoptosis （TWEAK） participates in brain edema. However, it is unclear whether blood-brain barrier （BBB） disruption is associated with TWEAK during the process of brain edema OBJECTIVE： To investigate the effects of TWEAK on BBB permeability in brain edema. DESIGN, TIME AND SETTING： An immunohistochemical observation, randomized, controlled animal experiment was performed at the Laboratory of Neurosurgical Anatomy, Xiangya Medical College, Central South University ＆ Central Laboratory, Third Xiangya Hospital, Central South University between January 2006 and December 2007. MATERIALS： A total of 48 adult Wistar rats were randomly divided into three groups： normal control （n = 8）, sham-operated （n = 8）, and ischemia/reperfusion （n = 32）. Rats from the ischemia/reperfusion group were randomly assigned to four subgroups according to different time points, i.e., 2 hours of ischemia followed by 6 hours （n = 8）, 12 hours （n = 8）, 1 day （n = 8）, or 12 days （n = 8） of reperfusion. METHODS： Focal cerebral ischemia/reperfusion injury was induced by middle cerebral artery occlusion （MCAO） using the suture method in rats from the ischemia/reperfusion group. Thread was introduced at a depth of 17-19 mm. Rats in the sham-operated group were subjected to experimental procedures similar to the ischemia/reperfusion group; however, the introducing depth of thread was 10 mm. The normal control group was not given any intervention. MAIN OUTCOME MEASURES： TWEAK expression was examined by immunohistochemistry; brain water content on the ischemic side was calculated as the ratio of dry to wet tissue weight; BBB permeability was measured by Evans blue extravasation. RESULTS： A total of eight rats died prior to and after surgery and an additional eight rats were randomly entered into the study. Thus 48 rats were included in the final analysis. In the ischemia/reperfusion group, TWEAK-positive cells were present in the ischemic penumbra surrounding the lamellar necrotic region in the fight cerebral hemisphere at 6 hours reperfusion and increased thereafter; by 2 days reperfusion they had reached a peak level, which was significantly higher than the sham-operated and normal control groups （P 〈 0.05）. At 6 hours reperfusion, both brain water content and Evans blue extravasation showed the same tendency for change as TWEAK expression. Pearson correlation analysis results revealed that the degree of TWEAK expression was positively correlated with brain water content （r = 0.892, P 〈 0.05）. CONCLUSION： The present results confirmed that TWEAK was involved in BBB disruption and participated in brain edema following cerebral ischemia.
