Natural aluminum particles have the core-shell structure.The structure response refers to the mechanical behavior of the aluminum particle structure caused by external influences.The dynamic behavior of the structural...Natural aluminum particles have the core-shell structure.The structure response refers to the mechanical behavior of the aluminum particle structure caused by external influences.The dynamic behavior of the structural response of aluminum core-shell particles before combustion is of great importance for the aluminum powder burning mechanism and its applications.In this paper,an aluminum particle combustion experiment in a detonation environment is conducted and analyzed;the breakage factors of aluminum particles shell in detonation environment are analyzed.The experiment results show that the aluminum particle burns in a gaseous state and condenses into a sub-micron particle cluster.The calculation and simulation demonstrate that the rupture of aluminum particle shell in the detonation environment is mainly caused by the impact of the detonation wave.The detonation wave impacts the aluminum particles,resulting in shell cracking,and due to the shrinkage-expansion of the aluminum core and stripping of the detonation product,the cracked shell is fractured and peeled with the aluminum reacting with the detonation product.展开更多
The combustion mechanism of aluminum particles in a detonation environment characterized by high temperature(in unit 10^(3)K),high pressure(in unit GPa),and high-speed motion(in units km/s)was studied,and a combustion...The combustion mechanism of aluminum particles in a detonation environment characterized by high temperature(in unit 10^(3)K),high pressure(in unit GPa),and high-speed motion(in units km/s)was studied,and a combustion model of the aluminum particles in detonation environment was established.Based on this model,a combustion control equation for aluminum particles in detonation environment was obtained.It can be seen from the control equation that the burning time of aluminum particle is mainly affected by the particle size,system temperature,and diffusion coefficient.The calculation result shows that a higher system temperature,larger diffusion coefficient,and smaller particle size lead to a faster burn rate and shorter burning time for aluminum particles.After considering the particle size distribution characteristics of aluminum powder,the application of the combustion control equation was extended from single aluminum particles to nonuniform aluminum powder,and the calculated time corresponding to the peak burn rate of aluminum powder was in good agreement with the experimental electrical conductivity results.This equation can quantitatively describe the combustion behavior of aluminum powder in different detonation environments and provides technical means for quantitative calculation of the aluminum powder combustion process in detonation environment.展开更多
BACKGROUND The occurrence of Streptococcus pneumoniae-associated hemolytic uremic syndrome(SP-HUS)is increasing.Thomsen-Friedenreich antigen activation is highly involved in the pathogenesis of SP-HUS,and T-antibody-n...BACKGROUND The occurrence of Streptococcus pneumoniae-associated hemolytic uremic syndrome(SP-HUS)is increasing.Thomsen-Friedenreich antigen activation is highly involved in the pathogenesis of SP-HUS,and T-antibody-negative plasma exchange(PE)may be effective in the treatment of severe cases of SP-HUS.CASE SUMMARY We retrospectively reviewed two pediatric patients with SP-HUS.Both clinical features and laboratory examination results of the children were described.Tantibody-negative PE was performed in both cases.Both children made a full recovery after repeated PE and remained well at a 2 year follow-up.CONCLUSION Streptococcal pneumonia continues to be an uncommon but important cause of HUS.The successful treatment of the presented cases suggests that T-antibodynegative PE may benefit patients with SP-HUS.展开更多
Objective To study the changes of lymphocyte subsets and regulatory T cells in peripheral blood of patients with acute leukemia(AL) and its clinical significance.Methods The different levels of peripheral blood lympho...Objective To study the changes of lymphocyte subsets and regulatory T cells in peripheral blood of patients with acute leukemia(AL) and its clinical significance.Methods The different levels of peripheral blood lymphocyte subsets and regulatory T cells of 60 AL patients and 40 normal controls were detected with flow cytometry.Results Compared with the normal controls,the percentages of CD3+ T cells,CD4+ T cells,CD16+CD56+ NK cells and the ratio of CD4+ /CD8+ obviously decreased in newly diagnosed AL group(P <0.05),while their percentages of CD8+ T cells and CD19+ B cells significantly increased(P <0.01).The percentage of CD4+ T cells and the ratio of CD4+ /CD8+ in acute lymphoblastic leukemia(ALL) group were much lower than those in acute myelogenous leukemia(AML) group(P <0.01).Compared with these in control group,the proportions of CD4+ CD25high Treg cells and CD4+ CD25+ T cells in newly diagnosed AL group were significantly increased(P <0.01).Conclusion Cellular immune function is significantly abnormal in patients with AL.Compared with AML patients,ALL patients had poorer cellular immune function.The increased CD4 + CD25high Treg cells might be one of the important reasons of immunosuppression in AL.Detection of lymphocyte subsets and regulatory T cells is of clinical value on the evaluation of therapeutic effect and prognosis in AL patients.展开更多
We investigate the impurity effects on surfaces of a thin film topological insulator, applied by an off-resonant circular polarized light. It is found that the off-resonant driving induces a quantized total Hall condu...We investigate the impurity effects on surfaces of a thin film topological insulator, applied by an off-resonant circular polarized light. It is found that the off-resonant driving induces a quantized total Hall conductivity, when the driving strength is larger than a critical value and the Fermi level lies in the band gap, indicating that our system is converted into the topological phase. We also find that with the increasing disorder strength, the Dirac masses of top and bottom surfaces are renormalized and then fixed to half of their initial values, respectively,which will shrink the widths of the half-integer plateau of anomalous Hall conductivities.展开更多
Background:While combined oral contraceptives (COCs) are commonly used to treat polycystic ovary syndrome (PCOS),comparative data regarding metabolic effects of different progestogens on this patient population a...Background:While combined oral contraceptives (COCs) are commonly used to treat polycystic ovary syndrome (PCOS),comparative data regarding metabolic effects of different progestogens on this patient population are missing.This study aimed to compare the different effects of drospirenone (DRP)-containing COCs with cyproterone acetate (CPA)-containing COCs,combined with metformin and lifestyle modifications in women with PCOS and metabolic disorders.Methods:Ninety-nine women with PCOS and a metabolic disorder between January 2011 and January 2013 were enrolled into this prospective randomized clinical trial.Participants were randomized into two groups such as DRP-containing COCs,and CPA-containing COCs.Participants took COCs cyclically for 6 months,combined with metformin administration (1.5 g/d) and lifestyle modifications (diet and exercise).Clinical measures and biochemical and hormone profiles were compared.Comparisons for continuous variables were evaluated with paired and unpaired Student&#39;s t-tests.The Wilcoxon signed rank test was used when the data were not normally distributed.Analysis of covariance was used to control for age,body mass index (BMI),and baseline data of each analyzed parameter when compared between the two groups.Results:A total of 68 patients have completed the study.The combination regimen of COCs,metformin,and lifestyle modifications in these patients resulted in a significant decrease in BMI,acne,and hirsutism scores when compared to baseline levels in both groups (P 〈 0.05).Blood pressure (BP) was significantly different in the CPA group when compared to baseline (75.14 ± 6.77 mmHg vs.80.70 ± 5.60 mmHg,P 〈 0.01),and after 6 months of treatment,only the change in systolic BP was significantly different between the two groups (4.00 [-6.00,13.00] mmHg vs.-3.50 [-13.00,9.00] mmHg,P =0.009).Fasting glucose,fasting insulin,and homeostasis model assessment-insulin resistance decreased significantly in the DRP group (5.40 ± 0.41 mmol/L vs.5.21 ± 0.32 mmol/L,P =0.041;13.90 [10.50,18.40] μU/ml vs.10.75 [8.60,13.50] μU/ml,P =0.020;3.74 [2.85,4.23] vs.2.55 [1.92,3.40],P =0.008) but did not differ between the two groups.While individual lipid profiles increased in both groups,no statistically significant difference was observed.Conclusions:DRP-containing COCs combined with metformin and lifestyle modifications could better control BP and correct carbohydrate metabolism in women with PCOS and metabolic disorders compared with CPA-containing COCs.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11772058)
文摘Natural aluminum particles have the core-shell structure.The structure response refers to the mechanical behavior of the aluminum particle structure caused by external influences.The dynamic behavior of the structural response of aluminum core-shell particles before combustion is of great importance for the aluminum powder burning mechanism and its applications.In this paper,an aluminum particle combustion experiment in a detonation environment is conducted and analyzed;the breakage factors of aluminum particles shell in detonation environment are analyzed.The experiment results show that the aluminum particle burns in a gaseous state and condenses into a sub-micron particle cluster.The calculation and simulation demonstrate that the rupture of aluminum particle shell in the detonation environment is mainly caused by the impact of the detonation wave.The detonation wave impacts the aluminum particles,resulting in shell cracking,and due to the shrinkage-expansion of the aluminum core and stripping of the detonation product,the cracked shell is fractured and peeled with the aluminum reacting with the detonation product.
基金Project supported by the National Natural Science Foundation of China(Grant No.11772058)。
文摘The combustion mechanism of aluminum particles in a detonation environment characterized by high temperature(in unit 10^(3)K),high pressure(in unit GPa),and high-speed motion(in units km/s)was studied,and a combustion model of the aluminum particles in detonation environment was established.Based on this model,a combustion control equation for aluminum particles in detonation environment was obtained.It can be seen from the control equation that the burning time of aluminum particle is mainly affected by the particle size,system temperature,and diffusion coefficient.The calculation result shows that a higher system temperature,larger diffusion coefficient,and smaller particle size lead to a faster burn rate and shorter burning time for aluminum particles.After considering the particle size distribution characteristics of aluminum powder,the application of the combustion control equation was extended from single aluminum particles to nonuniform aluminum powder,and the calculated time corresponding to the peak burn rate of aluminum powder was in good agreement with the experimental electrical conductivity results.This equation can quantitatively describe the combustion behavior of aluminum powder in different detonation environments and provides technical means for quantitative calculation of the aluminum powder combustion process in detonation environment.
文摘BACKGROUND The occurrence of Streptococcus pneumoniae-associated hemolytic uremic syndrome(SP-HUS)is increasing.Thomsen-Friedenreich antigen activation is highly involved in the pathogenesis of SP-HUS,and T-antibody-negative plasma exchange(PE)may be effective in the treatment of severe cases of SP-HUS.CASE SUMMARY We retrospectively reviewed two pediatric patients with SP-HUS.Both clinical features and laboratory examination results of the children were described.Tantibody-negative PE was performed in both cases.Both children made a full recovery after repeated PE and remained well at a 2 year follow-up.CONCLUSION Streptococcal pneumonia continues to be an uncommon but important cause of HUS.The successful treatment of the presented cases suggests that T-antibodynegative PE may benefit patients with SP-HUS.
文摘Objective To study the changes of lymphocyte subsets and regulatory T cells in peripheral blood of patients with acute leukemia(AL) and its clinical significance.Methods The different levels of peripheral blood lymphocyte subsets and regulatory T cells of 60 AL patients and 40 normal controls were detected with flow cytometry.Results Compared with the normal controls,the percentages of CD3+ T cells,CD4+ T cells,CD16+CD56+ NK cells and the ratio of CD4+ /CD8+ obviously decreased in newly diagnosed AL group(P <0.05),while their percentages of CD8+ T cells and CD19+ B cells significantly increased(P <0.01).The percentage of CD4+ T cells and the ratio of CD4+ /CD8+ in acute lymphoblastic leukemia(ALL) group were much lower than those in acute myelogenous leukemia(AML) group(P <0.01).Compared with these in control group,the proportions of CD4+ CD25high Treg cells and CD4+ CD25+ T cells in newly diagnosed AL group were significantly increased(P <0.01).Conclusion Cellular immune function is significantly abnormal in patients with AL.Compared with AML patients,ALL patients had poorer cellular immune function.The increased CD4 + CD25high Treg cells might be one of the important reasons of immunosuppression in AL.Detection of lymphocyte subsets and regulatory T cells is of clinical value on the evaluation of therapeutic effect and prognosis in AL patients.
基金Supported by the National Key R&D Program of China under Grant No 2017YFA0303203the National Natural Science Foundation of China under Grant Nos 11574217 and 11474149
文摘We investigate the impurity effects on surfaces of a thin film topological insulator, applied by an off-resonant circular polarized light. It is found that the off-resonant driving induces a quantized total Hall conductivity, when the driving strength is larger than a critical value and the Fermi level lies in the band gap, indicating that our system is converted into the topological phase. We also find that with the increasing disorder strength, the Dirac masses of top and bottom surfaces are renormalized and then fixed to half of their initial values, respectively,which will shrink the widths of the half-integer plateau of anomalous Hall conductivities.
文摘Background:While combined oral contraceptives (COCs) are commonly used to treat polycystic ovary syndrome (PCOS),comparative data regarding metabolic effects of different progestogens on this patient population are missing.This study aimed to compare the different effects of drospirenone (DRP)-containing COCs with cyproterone acetate (CPA)-containing COCs,combined with metformin and lifestyle modifications in women with PCOS and metabolic disorders.Methods:Ninety-nine women with PCOS and a metabolic disorder between January 2011 and January 2013 were enrolled into this prospective randomized clinical trial.Participants were randomized into two groups such as DRP-containing COCs,and CPA-containing COCs.Participants took COCs cyclically for 6 months,combined with metformin administration (1.5 g/d) and lifestyle modifications (diet and exercise).Clinical measures and biochemical and hormone profiles were compared.Comparisons for continuous variables were evaluated with paired and unpaired Student&#39;s t-tests.The Wilcoxon signed rank test was used when the data were not normally distributed.Analysis of covariance was used to control for age,body mass index (BMI),and baseline data of each analyzed parameter when compared between the two groups.Results:A total of 68 patients have completed the study.The combination regimen of COCs,metformin,and lifestyle modifications in these patients resulted in a significant decrease in BMI,acne,and hirsutism scores when compared to baseline levels in both groups (P 〈 0.05).Blood pressure (BP) was significantly different in the CPA group when compared to baseline (75.14 ± 6.77 mmHg vs.80.70 ± 5.60 mmHg,P 〈 0.01),and after 6 months of treatment,only the change in systolic BP was significantly different between the two groups (4.00 [-6.00,13.00] mmHg vs.-3.50 [-13.00,9.00] mmHg,P =0.009).Fasting glucose,fasting insulin,and homeostasis model assessment-insulin resistance decreased significantly in the DRP group (5.40 ± 0.41 mmol/L vs.5.21 ± 0.32 mmol/L,P =0.041;13.90 [10.50,18.40] μU/ml vs.10.75 [8.60,13.50] μU/ml,P =0.020;3.74 [2.85,4.23] vs.2.55 [1.92,3.40],P =0.008) but did not differ between the two groups.While individual lipid profiles increased in both groups,no statistically significant difference was observed.Conclusions:DRP-containing COCs combined with metformin and lifestyle modifications could better control BP and correct carbohydrate metabolism in women with PCOS and metabolic disorders compared with CPA-containing COCs.