A kinetic model of MTO process over the SAPO-34 catalyst considering the effect of water and coke deposition has been proposed.The model takes into account three steps of the MTO reaction in which the products cover 5...A kinetic model of MTO process over the SAPO-34 catalyst considering the effect of water and coke deposition has been proposed.The model takes into account three steps of the MTO reaction in which the products cover 5 lumped components.The water in the feed not only reduces the concentration of methanol but also alleviates the deactivation of SAPO-34 catalyst.The kinetic parameters have been estimated by the least square method.It has been proved that the calculated values in the kinetic model are in good agreement with the experimental values.展开更多
AIM: To study the effect of mobilized peripheral blood autologous CD34 positive(CD34+) cell infusion in patients with non-viral decompensated cirrhosis.METHODS: Cirrhotic patients of non-viral etiology were divided in...AIM: To study the effect of mobilized peripheral blood autologous CD34 positive(CD34+) cell infusion in patients with non-viral decompensated cirrhosis.METHODS: Cirrhotic patients of non-viral etiology were divided into 2 groups based on their willingness to be listed for deceased donor liver transplant(DDLT)(control, n = 23) or to receive autologous CD34+ cell infusion through the hepatic artery(study group, n= 22). Patients in the study group were admitted to hospital and received granulocyte colony stimulating factor injections 520 μg/d for 3 consecutive days to mobilize CD34+ cells from the bone marrow. On day 4,leukapheresis was done and CD34+ cells were isolated using CliniMAC magnetic cell sorter. The isolated CD34+ cells were infused into the hepatic artery under radiological guidance. The patients were discharged within 48 h. The control group received standard of care treatment for liver cirrhosis and were worked up for DDLT as per protocol of the institute. Both groups were followed up every week for 4 wk and then every month for 3 mo.RESULTS: In the control and the study group, the cause of cirrhosis was cryptogenic in 18(78.2%) and16(72.72%) and alcohol related in 5(21.7%) and6(27.27%), respectively. The mean day 3 cell count(cells/μL) was 27.00 ± 20.43 with a viability of 81.84± 11.99%. and purity of 80%-90%. Primary end point analysis revealed that at 4 wk, the mean serum albumin in the study group increased significantly(2.83± 0.36 vs 2.43 ± 0.42, P = 0.001) when compared with controls. This improvement in albumin was,however, not sustained at 3 mo. However, at the end of3 mo there was a statistically significant improvement in serum creatinine in the study group(0.96 ± 0.33 vs 1.42 ± 0.70, P = 0.01) which translated into a significant improvement in the Model for End-Stage Liver Disease score(15.75 ± 5.13 vs 19.94 ± 6.68,P = 0.04). On statistical analysis of secondary end points, the transplant free survival at the end of 1 mo and 3 mo did not show any significant difference(P =0.60) when compared to the control group. There was no improvement in aspartate transaminase, alanine transaminase, and bilirubin at any point in the study population. There was no mortality benefit in the study group. The procedure was safe with no procedural or treatment related complications.CONCLUSION: Autologous CD 34+ cell infusion is safe and effectively improves liver function in the short term and may serve as a bridge to liver transplantation.展开更多
BACKGROUND Although expression of interleukin(IL)-34 is upregulated in active ulcerative colitis(UC),the molecular function and underlying mechanism are largely unclear.AIM To investigate the function of IL-34 in acut...BACKGROUND Although expression of interleukin(IL)-34 is upregulated in active ulcerative colitis(UC),the molecular function and underlying mechanism are largely unclear.AIM To investigate the function of IL-34 in acute colitis,in a wound healing model and in colitis-associated cancer in IL-34-deficient mice.METHODS Colitis was induced by administration of dextran sodium sulfate(DSS),and carcinogenesis was induced by azoxymethane(AOM).Whether the impact of IL-34 on colitis was dependent on macrophages was validated by depletion of macrophages in a murine model.The association between IL-34 expression and epithelial proliferation was studied in patients with active UC.RESULTS IL-34 deficiency aggravated murine colitis in acute colitis and in wound healing phase.The effect of IL-34 on experimental colitis was not dependent on macrophage differentiation and polarization.IL-34-deficient mice developed more tumors than wild-type mice following administration of AOM and DSS.No significant difference was shown in degree of cellular differentiation in tumors between wild-type and IL-34-deficient mice.IL-34 was dramatically increased in the active UC patients as previously reported.More importantly,expression of IL-34 was positively correlated with epithelial cell proliferation in patients with UC.CONCLUSION IL-34 deficiency exacerbates colonic inflammation and accelerates colitis-associated carcinogenesis in mice.It might be served as a potential therapeutic target in UC.展开更多
A moderate stress such as cold water swimming can raise the tolerance of the body to potentially injurious events. However, little is known about the mechanism of beneficial effects induced by moderate stress. In this...A moderate stress such as cold water swimming can raise the tolerance of the body to potentially injurious events. However, little is known about the mechanism of beneficial effects induced by moderate stress. In this study, we used a classic rat model of traumatic brain injury to test the hypothesis that cold water swimming preconditioning improved the recovery of cognitive functions and explored the mechanisms. Results showed that after traumatic brain injury, pre-conditioned rats（cold water swimming for 3 minutes at 4℃） spent a significantly higher percent of times in the goal quadrant of cold water swim, and escape latencies were shorter than for non-pretreated rats. The number of circulating endothelial progenitor cells was significantly higher in pre-conditioned rats than those without pretreatment at 0, 3, 6 and 24 hours after traumatic brain injury. Immunohistochemical staining and Von Willebrand factor staining demonstrated that the number of CD34~＋ stem cells and new blood vessels in the injured hippocampus tissue increased significantly in pre-conditioned rats. These data suggest that pretreatment with cold water swimming could promote the proliferation of endothelial progenitor cells and angiogenesis in the peripheral blood and hippocampus. It also ameliorated cognitive deficits caused by experimental traumatic brain injury.展开更多
The tumor suppressor p53 is at the hub of the cellular DNA damage response network.P53-dependent cell fate decision is inseparable from p53 dynamics.A type of non-coding microRNA miR-34 has the function of enhancing p...The tumor suppressor p53 is at the hub of the cellular DNA damage response network.P53-dependent cell fate decision is inseparable from p53 dynamics.A type of non-coding microRNA miR-34 has the function of enhancing p53 content.An intriguing question arises:How does miR-34 affect p53 kinetics?To address this question,we reconstruct a p53 signal transduction network model containing miR-34.Some experimental phenomena of p53 pulses are reproduced to explain the rationality of the model.The method of numerical bifurcation is used to investigate the effect of miR-34 on p53 kinetics.We point out that appropriate or higher miR-34 transcription rates can prevent DNA-damaged cell proliferation by causing p53 oscillation or high steady-state kinetic behavior,respectively.However,the lack of miR-34 synthesis ability will induce p53 to remain at a low level,and cells cannot respond correctly to DNA damage.These results are well in line with the anti-cancer role of miR-34.Our work sheds light on how miR-34 carries out its tumor-suppressive function from tuning p53 dynamic aspect.展开更多
Thermax 700 thermo gravimetric analysis （TGA） instrument is introduced for the investigation of the reaction and deactivation kinetics of Methanol-to-Olefins （MTO） process with SAPO-34 catalyst.By the use of a spe...Thermax 700 thermo gravimetric analysis （TGA） instrument is introduced for the investigation of the reaction and deactivation kinetics of Methanol-to-Olefins （MTO） process with SAPO-34 catalyst.By the use of a special sample basket,the TGA instrument can be viewed as a plug flow fixed-bed reactor,while the weight change of SAPO-34 during reaction can be recorded online.Kinetic data are acquired in the temperature range of 648.2？748.2 K and space velocities of 7.08？35.91 h^-1 （WHSV）.Catalyst activity is expressed with average coke content,and selectivity for different products is related as a function of coke content and temperature.Methane is also introduced into the lumping kinetic model,and power exponent function with first-order reaction is adopted for model deduction.Exponential function is tested to give the best fit for catalyst activity and product selectivity with the highest correlation coefficient.The nicely agreed results between experimental and calculated data suggest that the overall kinetic model would be meaningful in both product distribution prediction and reactor simulation.展开更多
In this paper, a characteristic model based longitudinal control design for the trans-aerosphere vehicle X-34 in its transonic and hypersonic climbing phase is proposed. The design is based on the dynamic characterist...In this paper, a characteristic model based longitudinal control design for the trans-aerosphere vehicle X-34 in its transonic and hypersonic climbing phase is proposed. The design is based on the dynamic characteristics of the vehicle and the curves it is to track in this climbing phase. Through a detailed analysis of the aerodynamics and vehicle dynamics during this climbing phase, an explicit description of the tracking curve for the flight path angle is derived. On the basis of this tracking curve, the tracking curves for the two short-period variables, the angle of attack and the pitch rate, are designed. An all-coefficient adaptive controller is then designed, based on the characteristic modeling, to cause these two short-period variables to follow their respective tracking curves. The proposed design does not require multiple working points, making the design procedure simple. Numerical simulation is performed to validate the performance of the controller. The simulation results indicate that the resulting control law ensures that the vehicle climbs up successfully under the restrictions on the pitch angle and overloading.展开更多
文摘A kinetic model of MTO process over the SAPO-34 catalyst considering the effect of water and coke deposition has been proposed.The model takes into account three steps of the MTO reaction in which the products cover 5 lumped components.The water in the feed not only reduces the concentration of methanol but also alleviates the deactivation of SAPO-34 catalyst.The kinetic parameters have been estimated by the least square method.It has been proved that the calculated values in the kinetic model are in good agreement with the experimental values.
基金Supported by Grants from Asian Healthcare Foundation
文摘AIM: To study the effect of mobilized peripheral blood autologous CD34 positive(CD34+) cell infusion in patients with non-viral decompensated cirrhosis.METHODS: Cirrhotic patients of non-viral etiology were divided into 2 groups based on their willingness to be listed for deceased donor liver transplant(DDLT)(control, n = 23) or to receive autologous CD34+ cell infusion through the hepatic artery(study group, n= 22). Patients in the study group were admitted to hospital and received granulocyte colony stimulating factor injections 520 μg/d for 3 consecutive days to mobilize CD34+ cells from the bone marrow. On day 4,leukapheresis was done and CD34+ cells were isolated using CliniMAC magnetic cell sorter. The isolated CD34+ cells were infused into the hepatic artery under radiological guidance. The patients were discharged within 48 h. The control group received standard of care treatment for liver cirrhosis and were worked up for DDLT as per protocol of the institute. Both groups were followed up every week for 4 wk and then every month for 3 mo.RESULTS: In the control and the study group, the cause of cirrhosis was cryptogenic in 18(78.2%) and16(72.72%) and alcohol related in 5(21.7%) and6(27.27%), respectively. The mean day 3 cell count(cells/μL) was 27.00 ± 20.43 with a viability of 81.84± 11.99%. and purity of 80%-90%. Primary end point analysis revealed that at 4 wk, the mean serum albumin in the study group increased significantly(2.83± 0.36 vs 2.43 ± 0.42, P = 0.001) when compared with controls. This improvement in albumin was,however, not sustained at 3 mo. However, at the end of3 mo there was a statistically significant improvement in serum creatinine in the study group(0.96 ± 0.33 vs 1.42 ± 0.70, P = 0.01) which translated into a significant improvement in the Model for End-Stage Liver Disease score(15.75 ± 5.13 vs 19.94 ± 6.68,P = 0.04). On statistical analysis of secondary end points, the transplant free survival at the end of 1 mo and 3 mo did not show any significant difference(P =0.60) when compared to the control group. There was no improvement in aspartate transaminase, alanine transaminase, and bilirubin at any point in the study population. There was no mortality benefit in the study group. The procedure was safe with no procedural or treatment related complications.CONCLUSION: Autologous CD 34+ cell infusion is safe and effectively improves liver function in the short term and may serve as a bridge to liver transplantation.
基金the Science and Technology Bureau,No.MS22018007Six Peak Talents in Jiangsu Province,No.YY-177+4 种基金Project of Jiangsu Province Youth Medical Talent Development,No.QNRC2016400 and No.QNRC2016697Project of Nantong Youth Medical Talent Development,No.05Youth Fund of the National Natural Science Foundation of China,No.82000497Youth Fund of the Natural Science Foundation of Jiangsu Province,No.BK20200965Scientific Research Fund of Nantong Health Commission,No.MB2020037.
文摘BACKGROUND Although expression of interleukin(IL)-34 is upregulated in active ulcerative colitis(UC),the molecular function and underlying mechanism are largely unclear.AIM To investigate the function of IL-34 in acute colitis,in a wound healing model and in colitis-associated cancer in IL-34-deficient mice.METHODS Colitis was induced by administration of dextran sodium sulfate(DSS),and carcinogenesis was induced by azoxymethane(AOM).Whether the impact of IL-34 on colitis was dependent on macrophages was validated by depletion of macrophages in a murine model.The association between IL-34 expression and epithelial proliferation was studied in patients with active UC.RESULTS IL-34 deficiency aggravated murine colitis in acute colitis and in wound healing phase.The effect of IL-34 on experimental colitis was not dependent on macrophage differentiation and polarization.IL-34-deficient mice developed more tumors than wild-type mice following administration of AOM and DSS.No significant difference was shown in degree of cellular differentiation in tumors between wild-type and IL-34-deficient mice.IL-34 was dramatically increased in the active UC patients as previously reported.More importantly,expression of IL-34 was positively correlated with epithelial cell proliferation in patients with UC.CONCLUSION IL-34 deficiency exacerbates colonic inflammation and accelerates colitis-associated carcinogenesis in mice.It might be served as a potential therapeutic target in UC.
基金supported by a grant from the Incubation Project of Natural Science Foundation of Tianjin Medical University General Hospital in China,No.303071901401the Natural Science Foundation of Tianjin of China,No.13JCZDJC30800the National Natural Science Foundation of China,No.81271361 and 81330029
文摘A moderate stress such as cold water swimming can raise the tolerance of the body to potentially injurious events. However, little is known about the mechanism of beneficial effects induced by moderate stress. In this study, we used a classic rat model of traumatic brain injury to test the hypothesis that cold water swimming preconditioning improved the recovery of cognitive functions and explored the mechanisms. Results showed that after traumatic brain injury, pre-conditioned rats（cold water swimming for 3 minutes at 4℃） spent a significantly higher percent of times in the goal quadrant of cold water swim, and escape latencies were shorter than for non-pretreated rats. The number of circulating endothelial progenitor cells was significantly higher in pre-conditioned rats than those without pretreatment at 0, 3, 6 and 24 hours after traumatic brain injury. Immunohistochemical staining and Von Willebrand factor staining demonstrated that the number of CD34~＋ stem cells and new blood vessels in the injured hippocampus tissue increased significantly in pre-conditioned rats. These data suggest that pretreatment with cold water swimming could promote the proliferation of endothelial progenitor cells and angiogenesis in the peripheral blood and hippocampus. It also ameliorated cognitive deficits caused by experimental traumatic brain injury.
基金supported by the National Natural Science Foundation of China under Grant No.11762011.
文摘The tumor suppressor p53 is at the hub of the cellular DNA damage response network.P53-dependent cell fate decision is inseparable from p53 dynamics.A type of non-coding microRNA miR-34 has the function of enhancing p53 content.An intriguing question arises:How does miR-34 affect p53 kinetics?To address this question,we reconstruct a p53 signal transduction network model containing miR-34.Some experimental phenomena of p53 pulses are reproduced to explain the rationality of the model.The method of numerical bifurcation is used to investigate the effect of miR-34 on p53 kinetics.We point out that appropriate or higher miR-34 transcription rates can prevent DNA-damaged cell proliferation by causing p53 oscillation or high steady-state kinetic behavior,respectively.However,the lack of miR-34 synthesis ability will induce p53 to remain at a low level,and cells cannot respond correctly to DNA damage.These results are well in line with the anti-cancer role of miR-34.Our work sheds light on how miR-34 carries out its tumor-suppressive function from tuning p53 dynamic aspect.
文摘Thermax 700 thermo gravimetric analysis （TGA） instrument is introduced for the investigation of the reaction and deactivation kinetics of Methanol-to-Olefins （MTO） process with SAPO-34 catalyst.By the use of a special sample basket,the TGA instrument can be viewed as a plug flow fixed-bed reactor,while the weight change of SAPO-34 during reaction can be recorded online.Kinetic data are acquired in the temperature range of 648.2？748.2 K and space velocities of 7.08？35.91 h^-1 （WHSV）.Catalyst activity is expressed with average coke content,and selectivity for different products is related as a function of coke content and temperature.Methane is also introduced into the lumping kinetic model,and power exponent function with first-order reaction is adopted for model deduction.Exponential function is tested to give the best fit for catalyst activity and product selectivity with the highest correlation coefficient.The nicely agreed results between experimental and calculated data suggest that the overall kinetic model would be meaningful in both product distribution prediction and reactor simulation.
基金Supported in part by the National Natural Science Foundation of China (Grant Nos. 90405017, 60736023, 60704014)in part by China Postdoctoral Funds (Grant No. 20060400415)in part by a Cheung Kong Professorship at Shanghai Jiao Tong University
文摘In this paper, a characteristic model based longitudinal control design for the trans-aerosphere vehicle X-34 in its transonic and hypersonic climbing phase is proposed. The design is based on the dynamic characteristics of the vehicle and the curves it is to track in this climbing phase. Through a detailed analysis of the aerodynamics and vehicle dynamics during this climbing phase, an explicit description of the tracking curve for the flight path angle is derived. On the basis of this tracking curve, the tracking curves for the two short-period variables, the angle of attack and the pitch rate, are designed. An all-coefficient adaptive controller is then designed, based on the characteristic modeling, to cause these two short-period variables to follow their respective tracking curves. The proposed design does not require multiple working points, making the design procedure simple. Numerical simulation is performed to validate the performance of the controller. The simulation results indicate that the resulting control law ensures that the vehicle climbs up successfully under the restrictions on the pitch angle and overloading.
