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1.
2.
The purpose of the paper is to elucidate the biological effect of benzene on the basis of benzene constitution, quantum chemistry and quantum biology. In addition, we also have examined the toxicological mechanism of benzene in view of action of benzene on energy.  相似文献   

3.
MolecularBasisofTransferofInducedResistanceinPlants*XuWenlian(徐文联),DongHansong(董汉松)+,PanJun(潘军)+,JiangWuling(蒋五玲),LiuAixin(刘爱...  相似文献   

4.
The occurrence of toxic water bloom of cyanobacte-ria algae, widely reported in eutrophic freshwater, hasbeen a serious pollution problem in recent years[1]. Mi-crocystins (MCs), the most common cyanobacteriatoxin with a cyclic heptapeptide structure (Fig…  相似文献   

5.
UltrastructureofHepatopancreasCelsofMacrobrachiumnipponensisWangWeinaWangAnliWeiXuanhuiGuoMingshen(DepartmentofBiology,HebeiU...  相似文献   

6.
Glaciers are extensively developed in the southwest of Tibet and the moraines are widely distributed with large depth. Large-scale debris flows are often reported which blocked rivers and formed dams. In this paper, seven large debris flows in four valleys are discussed, among which five dams developed. 13 sets of experiments have been conducted in laboratory to simulate the formation and failure of the dam. Finally, a model of dam failure is proposed and a formula is established to calculate the flood discharge: Q=kbnnk/TB^-/LG^0.1,where bk is the outlet width of the dam at the original water level, hk the erosive depth, T the time from overflow to final state of failure, the average width of lake; L the length of the lake, and G the total potential energy of the water in the lake.  相似文献   

7.
The orientation between the backbone residues of proteins is defined based on the local configurations and the corresponding preferences are analyzed by statistics.It is found that all the residue pairs have some specific preferences of orientations.The statistical analysis is mainly concen-trated in the orientational distributions for two kinds of groupings of residues based on the hydrophobicity and secondary structural features.The statistics for such two types of groupings shows different orienta-tional preferences.It is found that for the former grouping the orientational preference is rather weak, while for the later a kind of strong orientational pref-erences.This suggests that the formation of local structures and of secondary structures are highly related to the orientational preferences.  相似文献   

8.
9.
completed.□ Lemma2 .2  Suppose H to be a Hilbert spacewith the inner product ( .,.) H and the relativenorm‖·‖H.If{xn}in H weakly converges tox,then there exists a subsequence {xni}satisfyingthatx - 1k ki=1xni H→ 0 ,  k→∞ . The proof can be found in Ref.[9].  Lemma 2 .3  Suppose W* to be a symmetricform on D[W],and W* [u]≤ W1[u]for all u∈D[W].If {un}∈D[W]in H converges W1- weak-ly to u,then it converges W* - weakly to u. The proof can be found in Ref.[8].  Lemma 2 .4…  相似文献   

10.
The indirect release of chemical energy of fuel is investigated, and a new mechanism is proposed to identify the cascade utilization of chemical energy of fuel more clearly. Based on the concept of energy level, the internal phenomenon of the indirect chemical energy release is disclosed, and the equations of energy level describing the utilization of chemical energy and thermal energy during the indirect chemical energy release process are obtained. From theoretical analysis, we find that the superiority of the indirect chemical energy release of fuel comes from the cascade utilization of the fuel's chemical energy. Moreover, the cascade utilization of chemical energy is verified by the investigation of CRGT (chemically recuperated gas turbine). As a result, the thermal exergy obtained from the chemical energy release of fuel increases by 2%?3%. The results obtained here may help a deeper understanding of indirect chemical energy release of fuel and provide a theoretical basis for the synthesis of innovative energy systems.  相似文献   

11.
目的观察重组人Kunitz型蛋白酶抑制剂的变异体(KD/APP var)对实验性大鼠急性坏死性胰腺炎(acutenecrotizing pancreatitis,ANP)的治疗作用。方法采用牛磺胆酸钠逆行注入大鼠胰胆管内诱导ANP模型,观察重组人KD/APPvar大鼠血清淀粉酶(AMS)、脂肪酶(LPS)影响及胰腺组织病理变化。结果与模型组比较,重组人KD/APP var治疗组可明显降低急性胰腺炎大鼠淀粉酶、脂肪酶的活性,且使胰腺的病理变化减轻。结论重组人KD/APP var早期给药可显著减轻胰腺高分泌状态,对大鼠急性胰腺炎具有治疗作用。  相似文献   

12.
Use and effects of liver specific antigen in orthotopic liver transplantations were researched in this study. Group I: syngeneic control (Wistar-to-Wistar); Group II: acute rejection (SD-to-Wistar); Group III: Thymic inoculation of SD rat LSA day 7 before transplantation. The observation of common situation and survival time, rejection grades, NF-KappaB activity of splenocytes and IL-2mRNA expression of grafted liver were used to analyze acute rejection severity and immune state of animals in different groups. The common situation of group I was very well after transplantation and no signs of rejection were found. Recipients of group II lost body weight progressively. All dead within day 9 to day 13 posttransplantation; median survival time was 10.7+/-0.51 days. It was an optimal acute rejection control. As for group III, 5 out of 6 recipients survived for a long time and common situation was remarkably better than that of group II. Its rejection grades were significantly lower than that of group II(P < 0.05). NF-KappaB activity was only detected in group I at day 5 and day 7 after transplantation, whereas high activity of NF-KappaB was detected at all time points in group II and the low NF-KappaB activity detected in group III was significantly lower than that of group II(P < 0.05). No IL-2mRNA expression was detected at any time point in group I, whereas high level expression was detected at all time points in group II and the low level expression only detected at day 3 in group III was significantly lower than that of group II(P < 0.05). Conclusion: LSA is an important transplantation antigen which is involved directly in the immunorejection of liver transplantation. We report here for the first time that intrathymic inoculation of LSA can alleviate the rejection of liver allotransplantation; and that grafts can survive for a long time thereby, thus leading to a novel way to achieve liver transplantation immunotolerance.  相似文献   

13.
摘要: 目的 研究大黄牡丹汤组方( RPDP) 对急性胰腺炎( Acute pancreatitis,AP) 模型大鼠 胰腺腺泡细胞外分泌功 能和腺泡细胞内钙离子浓度( FI) 的影响。方法 SD 大鼠灌胃 RPDP 以制备大黄牡丹汤组方含药血清( RPDP-S) ; SD 大鼠分为假手术组和 AP 模型组,分离胰腺腺泡细胞并与 RPDP-S 共同孵育,测定腺泡细胞淀粉酶分泌水平和 FI 变化。结果 AP 模型大鼠腺泡细胞分泌淀粉酶水平较假手术组显 著升高( P < 0. 05) ,经 RPDP-S 处理的 AP 模 型大鼠腺泡细胞分泌淀粉酶水平显著降低( P < 0. 05) ; FI 随 AP 模型病程延长而升高( P < 0. 05) ,RPDP-S 可抑制 AP 模型大鼠腺泡细胞内 FI 升高( P < 0. 05) 。结论 RPDP 通能抑制 AP 大鼠胰腺腺泡细胞的外分泌功能,抑制腺 泡细胞内钙离子的升高,降低腺泡细胞内 FI 超载。  相似文献   

14.
微生态制剂A对罗非鱼生长及消化酶活性的影响   总被引:6,自引:0,他引:6  
以奥尼罗非鱼为试验对象,考察以枯草芽孢杆菌和紫色非硫光合菌为主要成分制成的微生态制剂A对罗非鱼生长及消化酶活性的影响.结果显示:与对照组相比,饲料中添加微生态制剂A能够降低罗非鱼养殖饵料系数16.91%,体质量提高9.78%;能显著或非常显著地提高罗非鱼胃、肠道和肝脏中的淀粉酶活性(P0.05或P0.01)和脂肪酶活性(P0.05或P0.01);能够显著提高罗非鱼肠道胰蛋白酶的活性(P0.05).可见,微生态制剂A有降低罗非鱼养殖饵料系数和促进生长的作用.  相似文献   

15.
目的 探讨胆囊结石合并急性胰腺炎患者腹腔镜手术时机选择及胆囊结石形成的分子机制.方法 选取行手术治疗的胆囊结石合并急性胰腺炎患者37例,分为早期手术组(发病48h内行腹腔镜下胆囊切除术)16例,延迟手术组(胰腺炎治愈后3~5周)21例,记录术前和术后两组患者血液学指标和手术情况.收集术中切取的胆囊组织(胆固醇结石17例,胆色素结石13例,胆囊息肉7例),RT-PCR检测不同胆囊组织中Cacna1c mRNA的表达量.结果 两组患者手术时间、术中出血量、中转开腹发生率、术后并发症发生率之间比较差异均无统计学意义(P>0.05);早期手术组患者总住院时间短于延迟手术组,差异具有统计学意义(P<0.05).两组患者术前和术后1 d白细胞计数、中性粒细胞比率、血淀粉酶水平之间比较差异无统计学意义(P>0.05);术后3d早期手术组患者白细胞计数和血淀粉酶均恢复到正常水平,明显低于同期延迟手术组,差异具有统计学意义(P<0.05).胆色素结石和胆囊息肉组织中Cacna1c mRNA表达水平均高于胆固醇结石组织,差异具有统计学意义(P<0.01);胆色素结石组织与胆囊息肉组织Cacna1c mRNA表达水平之间差异无统计学意义(P>0.05).结论 胆囊结石合并急性胰腺炎患者发病48 h内行胆囊切除术安全可行,且疗效理想;Cacna1c基因为钙离子通道在不同胆囊结石组织中分布差异的分子基础,在胆固醇结石形成中发挥调控作用.  相似文献   

16.
目的 探讨氢吗啡酮对炎性痛大鼠脊髓ERK1/2信号通路的影响.方法 选择SPF级雄性大鼠30只,随机分为3组,正常组、模型组和氢吗啡酮组;检测各组大鼠热痛阈和机械痛阈;ELISA检测血清中TNF-α、IL-6和IL-10的含量;Western blot检测各组大鼠脊髓中ERK1/2和p-ERK1/2蛋白表达水平;qRT...  相似文献   

17.
实验室循环水养殖系统中,27.5℃条件下,以对照组(添加0%碳水化合物)和处理组(添加12%碳水化合物)的人丁配合饲料喂养南方鲇(Silurus meridionalis Chert)幼鱼(38~42g),在喂养0,2,4周后分别测定实验鱼胃、肠、胰的淀粉酶和蛋白酶活性.结果显示:胃、肠、胰淀粉酶活性在对照组与处理组之间差异均不显著;南方鲇幼鱼的淀粉酶活性的基础水平(未经实验处理的0周)在胃、肠分别为0.073,0.108U/mg,高于某些肉食性鱼类的相应水平;蛋白酶活性在摄人碳水化合物后却产生了明显的变化(卢〈0.05).研究表明:南方鲇幼鱼淀粉酶活性对饲料碳水化合物的变化具有相对保守性,而蛋白酶活性对碳水化合物的变化则表现出明显的反应.本研究提示,南方鲇幼鱼能够利用饲料碳水化合物可能与其淀粉酶活性的基础水平较高有关.  相似文献   

18.
温度和pH对驼背鲈消化酶活力的影响   总被引:2,自引:0,他引:2  
采用酶学分析方法研究了温度和pH对驼背鲈3种主要消化酶(蛋白酶、脂肪酶、淀粉酶)活力的影响。结果表明:在设定的温度和pH范围内,驼背鲈消化酶活力均随着温度和pH的升高呈先升后降的趋势。其中,胃蛋白酶的最适温度为40~45℃,肠、幽门盲囊、肝蛋白酶的最适温度均为40℃;胃脂肪酶的最适温度为35℃,幽门盲囊的最适温度为40~45℃,其他部位均为40℃;胃淀粉酶的最适温度为40℃,其他部位均为35℃。胃蛋白酶的最适pH为3.2,肠、幽门盲囊、肝的最适pH均为8.2;胃、肝脂肪酶的最适pH分别为7.2、8.2,其他部位均为6.2;胃淀粉酶的最适pH为7.2~8.2,其他器官的最适pH均为7.2。各部位在最适温度和pH下,脂肪酶酶活力顺序为肠胃肝幽门盲囊,淀粉酶酶活力顺序为肠幽门盲囊胃肝;蛋白酶在最适温度和pH下的酶活力顺序分别为肠胃肝幽门盲囊、肠胃幽门盲囊肝。  相似文献   

19.
采用酶学分析方法研究了温度和pH值对可口革囊星虫(Phascolosoma esculenta)肠道蛋白酶、淀粉酶、纤维素酶和脂肪酶活力的影响.结果表明:在5~65℃温度范围内,温度显著影响可口革囊星虫肠道中蛋白酶、淀粉酶、纤维素酶和脂肪酶的活力(P<0.01),蛋白酶、淀粉酶、纤维素酶和脂肪酶活力的最适温度分别为50...  相似文献   

20.
Alexopoulou L  Holt AC  Medzhitov R  Flavell RA 《Nature》2001,413(6857):732-738
Toll-like receptors (TLRs) are a family of innate immune-recognition receptors that recognize molecular patterns associated with microbial pathogens, and induce antimicrobial immune responses. Double-stranded RNA (dsRNA) is a molecular pattern associated with viral infection, because it is produced by most viruses at some point during their replication. Here we show that mammalian TLR3 recognizes dsRNA, and that activation of the receptor induces the activation of NF-kappaB and the production of type I interferons (IFNs). TLR3-deficient (TLR3-/-) mice showed reduced responses to polyinosine-polycytidylic acid (poly(I:C)), resistance to the lethal effect of poly(I:C) when sensitized with d-galactosamine (d-GalN), and reduced production of inflammatory cytokines. MyD88 is an adaptor protein that is shared by all the known TLRs. When activated by poly(I:C), TLR3 induces cytokine production through a signalling pathway dependent on MyD88. Moreover, poly(I:C) can induce activation of NF-kappaB and mitogen-activated protein (MAP) kinases independently of MyD88, and cause dendritic cells to mature.  相似文献   

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