用简便方法计算．
5.93-3.8+1.07&&&&&&&&&
8.75-（3.75+0.64）
38.67-2.18-11.67&&&&&&
56.23-2.73-6.23-7.27
28.3+17.6-8.3+2.4&&&&
1.75+4.67+2.25．
（1）5.93-3.8+1.07=（5.93+1.07）-3.8=7-3.8=3.2；（2）8.75-（3.75+0.64）=8.75-3.75-0.64=5-0.64=4.36；（3）38.67-2.18-11.67&&&&&&=（38.67-11.67）-2.18&&&=27-...
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（1）（3）（5）（6）运用加法交换律与结合律简算．（2）运用减法的性质简算．（4）运用加法交换律与结合律以及减法的性质简算．
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中性粒细胞在骨髓间充质干细胞治疗D-氨基半乳糖诱导急性肝衰竭大鼠中的作用
目的 观察骨髓间充质干细胞(MSCs)移植对D-氨基半乳糖(D-GalN)诱导SD大鼠急性肝衰竭模型的治疗作用并探索中性粒细胞在其中的机制关联. 方法 将39只雄性SD大鼠分为4组:对照组(n=8,腹腔注射等渗盐水)、模型组(n=10,腹腔注射D-GalN)、溶剂组(n=9,腹腔注射D-GalN后2h尾静脉注射等渗盐水)及治疗组(n=12,腹腔注射D-GalN后2h尾静脉注射MSCs).建立D-GalN诱导急性肝衰竭模型后24 h处死大鼠,分别收集血液及肝脏组织,检测血清丙氨酸氨基转移酶、天冬氨酸氨基转移酶和总胆红素,血液分析大鼠外周血中性粒细胞数量及比率,免疫荧光检测肝脏中性粒细胞标志物Ly6g表达水平,髓过氧化物酶(MPO)试剂盒检测肝脏MPO活性,RT-PCR检测肝脏组织炎性因子及趋化因子肿瘤坏死因子α、白细胞介素1β、干扰素γ、白细胞介素10、CXC趋化因子配体1、CXC趋化因子配体2的mRNA水平;另将64只雄性SD大鼠随机分组后连续7d观察各组大鼠生存率.两两组间比较应用独立样本t检验(经Levene方差齐性检验,当P＜0.05时,采用校正t检验);大鼠生存分析采用两两比较的Logrank检验. 结果 D-GalN诱导的急性肝衰竭SD大鼠24 h后反映肝功能的生物化学指标显著升高[丙氨酸氨基转移酶:(2 884.1±541.0)U/L与(45.4±11.0)U/L,P＜0.001;天冬氨酸氨基转移酶:(3 634.9±755.9) U/L与(143.9±23.7)U/L,P＜0.001;总胆红素:(44.4±8.4)μmmol/L与(0.9±0.2)μmmol/L,P＜0.001];外周血中性粒细胞数量与比率大幅上升[数量:(4.7±1.1)×109与(1.4±0.4)×109,P＜ 0.001;比率:44.9％±8.0％与18.3％±4.4％,P＜0.001);肝脏组织中性粒细胞大量聚集,MPO活性[(4.72±1.09) U/g与(1.13±0.24) U/g,P＜ 0.001]、炎性因子及趋化因子均明显增多.MSCs移植较模型组可有效改善急性肝衰竭大鼠肝功能[丙氨酸氨基转移酶:(1 823.9±389.2) U/L与(2 884.1±541.0)U/L,P＜0.001;天冬氨酸氨基转移酶:(2 173.0±567.3) U/L与(3 634.9±755.9) U/L,P＜ 0.001;总胆红素:(30.9±6.5)μ mmol/L与(44.4±8.4)μmmol/L,P＜0.001]并提高其生存率(50.0％与12.5％,P=0.023).同时,外周血中性粒细胞数量与比率明显降低[数量:(3.5±1.0)×109与(4.7±1.1)×109,P=0.012;比率:35.9％±8.9％与44.9％±8.0％,P=0.021],肝脏内中性粒细胞数量显著减少,MPO活性下降[(3.52±1.03)与(4.72±1.09) U/g,P=0.040],且炎性因子及趋化因子表达受到抑制(肿瘤坏死因子α:2.458±0.762与3.778±1.046,P=0.005;白细胞介素1 β:2.498±0.547与4.065±0.953,P=0.002;干扰素γ:3.977±1.039与5.418±1.255,P=0.025;白细胞介素10:6.056±1.542与3.368±0.952,P=0.001;CXC趋化因子配体1:7.988±1.911与10.366±1.239,P=0.010;CXC趋化因子配体2:3.441±1.005与4.847±1.113,P=0.019).结论 MSCs移植对D-GalN诱导的急性肝衰竭大鼠有治疗作用,该过程伴随外周血及肝脏中性粒细胞的聚集减少与活性降低,炎性因子与趋化因子可能参与调控两者的机制联系.
Abstract：
Objective To investigate the therapeutic effect of bone marrow mesenchymal stromal cell (BMSC) transplantation on D-galactosamine-induced acute liver failure in Sprague-Dawley (SD) rats,as well as the mechanism of neutrophils in this process.Methods A total of 39 male SD rats were divided into control group (8 rats,intraperitoneal injection of isotonic saline),model group (10 rats,intraperitoneal injection of D-galactosamine),solvent group (9 rats,tail vein injection of isotonic saline at 2 hours after intraperitoneal injection of D-galactosamine),and treatment group (12 rats,tail vein injection of MSCs at 2 hours after intraperitoneal injection of D-galactosamine).The rats were sacrificed at 24 hours after the model of D-galactosamine-induced acute liver failure was established,and the blood and liver tissue were harvested.The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and total bilirubin (TBil) were measured,and blood analysis was performed to measure the number and percentage of neutrophils in peripheral blood.Immunofluorescence assay was used to measure the expression of the neutrophil marker Ly6g in the liver,the myeloperoxidase (MPO) kit was used to measure the activity of MPO in liver,and RT-PCR was used to measure the mRNA expression of inflammatory cytokines and chemokines in the liver,i.e.,tumor necrosis factor-α (TNF-α),interleukin-1β (IL-1β),interferon-γ (IFN-γ),interleukin-10 (IL-10),CXC chemokine ligand 1 (CXCL1),and CXC chemokine ligand 2 (CXCL2).Another 64 male SD rats were randomly divided into groups,and the survival rates of rats in each group were observed for 7 days.The independent samples t-test was used for comparison between any two groups (Levene homogeneity test of variance,and the corrected t-test was used for a P value of ＜ 0.05),and the log-rank test was used for comparison of survival rates between any two groups.Results At 24 hours after acute liver failure was induced by D-galactosamine in the SD rats,there were significant increases in the liver function parameters (ALT:7;541.0 U/L vs 45.4±11.0 U/L,P ＜ 0.001;AST:7;755.9 U/L vs 143.9±23.7 U/L,P ＜ 0.001;TBil:44.4±8.4 μmmol/L vs 0.9±0.2 μmmol/L,P ＜ 0.001) and the number and percentage of peripheral blood neutrophils [number:(4.7±1.1)×109 vs (1.4±0.4)× 109,P ＜0.001;percentage:44.9％±8.0％ vs 18.3％±4.4％,P ＜ 0.001].A large number of neutrophils aggregated in the liver tissue,and there were significant increases in the MPO activity (4.72±1.09 U/g vs 1.13±0.24 U/g,P ＜ 0.001),inflammatory cytokines,pared with the model group,the treatment group showed significant improvements in liver function (ALT:1 823.9a389.2 U/L vs 2 884.1±541.0 U/L,P ＜ 0.001;AST:7;567.3U/L vs 7;755.9 U/L,P ＜ 0.001;TBil:30.9±6.5 μmmol/L vs 44.4±8.4 μmmol/L,P ＜ 0.001) and survival rate (50％ vs 12.5％,P=0.023).Meanwhile,the treatment group also showed significant reductions in the number and percentage of peripheral blood neutrophils [number:(3.5±1.0)× 109 vs (4.7±1.1)×109,P =0.012;percentage:35.9％±8.9％ vs 44.9％±8.0％,P =0.021],number of neutrophils in the liver,and MPO activity (3.52±1.03 U/g vs 4.72±1.09 U/g,P =0.040),as well as significantly inhibited expression of inflammatory cytokines and chemokines (TNF-α:2.458±0.762 vs 3.778±1.046,P =0.005;IL-1β:2.498±0.547 vs 4.065 ± 0.953,P =0.002;IFN-γ:3.977±1.039 vs 5.418±1.255,P =0.025;IL-10:6.056±1.542 vs 3.368±0.952,P=0.001;CXCL1:7.988±1.911 vs 10.366±1.239,P =0.010;CXCL2:3.441±1.005 vs 4.847±1.113,P=0.019).Conclusion BMSC transplantation has a therapeutic effect on D-galactosamine-induced acute liver failure in rats,and this process is accompanied by reduced aggregation and activity of neutrophils in peripheral blood and liver.Inflammatory cytokines and chemokines may be involved in the mechanism of regulation of these two aspects.
Shi Xiaolei
Zhang Zhiheng
Ma Hucheng
Yuan Xianwen
Ding Yitao
作者单位：
210008,南京大学医学院附属鼓楼医院
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基金项目：
国家自然科学基金，江苏省自然科学基金，National Natural Science Foundation of China，Natural Science Foundation of Jiangsu Province
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