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1.
Summary A group of 8 pupils born in 1962 and a group of 8 future teachers between 25 and 40 years of age, were submitted in 1975 to two types of tests in the presence of environment noises at various levels (45 to 75 dBA), in order to assess the influence of this nuisance on the pedagogic efficiency. The results show a nocivity threshold for the pupils at around 55 dBA and for the teachers at around 65 dBA. Furthermore, backward pupils suffer more in this context from the interference of noise than the advanced ones.  相似文献   

2.
Summary The exogenous release of glutamate has been successfully studied in the cochlear nucleus of guinea-pigs after physiological sound stimulation of the ear (frequency 2000–20,000 Hz at 100 dBA).Acknowledgments. This study was supported by grants from the Swedish Medical Research Council (B80-12X-05666-01) and Torsten Söderbergs och Ragnar Söderbergs stiftelser.  相似文献   

3.
Summary Polygraphic monitoring of several physiological variables was done throughout an experiment investigating the effects of caffeine on mental performance. The experiment started with a mental maze learning task. Then the subjects were given the test beverages according to the group design (CC group (N=16)300 mg caffeine in decaffeinated coffee, DC group (N=16): decaffeinated coffee, WW group (N=8): warm water, and NB group (N=8): no beverage). The experiment continued with a letter cancellation task which was followed by a second mental maze learning task. The caffeine treated subjects differed from the other groups by increased regularity of letter cancellation performance, as indicated by decreases in intraindividual variance. They also differed from the other groups by a slight but significant acrodermal vasoconstriction. No intergroup differences were obtained for mental maze learning, heart rate, respiration, muscle tension, and skin conductance. The results suggest therefore that the drug at this dose level improves behavioral routine and speed rather than cognitive functions and that the vegetative side effects are minimal.  相似文献   

4.
目的对噬菌体D29的免疫原性及安全性进行评价。方法将BALB/C小鼠随机分为噬菌体D29滴鼻暴露组(剂量9×10^8PFU)、噬菌体D29皮下注射组(剂量9×10^8PFU),phagebuffer滴鼻组、phagebuffer皮下注射组、生理盐水滴鼻组、生理盐水皮下注射组、空白对照组,每组动物第一周第一天、第三天暴露一次,以后每周第一天暴露一次,共暴露6周。观察暴露期间噬菌体中和抗体的动态变化、暴露6周后血清中IL-2、IL-4、IL-12、IFN-1、TNF-α和NO的含量及CD4/CD8比例变化,小鼠碳粒廓清率变化、在饲养过程中各组动物的进食量以及活动、体重、生存情况,以及暴露结束后解剖取得脏器作病理学比较。结果D29滴鼻暴露组在第7天即产生低效价的中和抗体,第14天抗体效价下降,第28天之后不能检测到中和抗体,D29皮下注射组中和抗体从第7天开始产生,第21天上升,之后趋于稳定,其余组均无中和抗体产生。各组小鼠血清中细胞因子、CIM/CD8比例、碳粒廓清率以及饲养过程中各组动物的进食量以及活动、体重、生存情况均无明显差异。病理学上各实验组脏器除脾脏外均有轻微充血、水肿表现。结论D29具有抗原特性,可刺激机体产生中和抗体,但不会对机体的安全产生威胁。  相似文献   

5.
目的观察围术期不同时点应用帕瑞昔布对子宫切除术患者术后镇痛的不同效果。方法选择年龄25~50岁,体重45~80kg的ASA Ⅰ-Ⅱ级择期行经腹子宫切除术患者60例,分为帕瑞昔布术前组(PR组)、帕瑞昔布术后组(PO组)、对照组(CO组),每组20例。PR组在麻醉诱导前给予帕瑞昔布40 mg;PO组在关腹前30 min给予帕瑞昔布40 mg;CO组在麻醉诱导前和关腹前30min分别给予相同容积的生理盐水。分别在术后2 h、4 h、8 h、12 h、24 h、48 h进行痛觉评分,并记录各个时点曲马多的使用量、PCIA按压次数,以及出现的不良反应。结果与CO组相比,PR组和PO组术后8 h、12 h、24 h、48 h的VAS评分降低,相应时间点的曲马多用量减少(P0.05)。PR组术后24 h、48 h PCIA按压次数减少(P0.01),术后24 h镇痛满意度提高(P0.05)。PR组、PO组两组间在术后曲马多用量、PCIA按压次数、VAS评分及24 h镇痛满意度比较,差异无统计学意义。三组患者术后不良反应主要是恶心呕吐,未发现严重不良反应,三组间差异无统计学意义。结论术前或术毕时单次静脉注射帕瑞昔布40 mg,均可以减轻术后疼痛,减少曲马多的使用量,提高病人满意度,但不能减少恶心呕吐发生率。术前静脉给予帕瑞昔布未发现超前镇痛效果。  相似文献   

6.
目的通过观察链霉素诱导的2型糖尿病大鼠模型肾脏功能的变化,以探讨此种模型是否适用于糖尿病肾损害的研究。方法采用链脲佐菌素(streptozotocin,STZ)辅以高脂饮食建立2型糖尿病大鼠模型,筛选造模成功的大鼠为糖尿病组,并与正常大鼠比较,造模后8周观察两组大鼠血糖、血尿素氮(blood urea nitrogen,BUN)、血肌酐(creatinine,CR)、血糖基化终末产物(Advanced glycation end products,AGE)、尿微量白蛋白、肾重指数的变化以及AGE受体(Receptor of AGE,RAGE)、蛋白激酶C(protein kinase C,PKC)、蛋白激酶A(protein kinase A,PKA)在肾脏的表达变化。结果糖尿病组的血糖、血尿素氮、血肌酐、血AGE、尿微量白蛋白以及肾重指数均明显高于正常组(P0.05),RAGE、PKC的mRNA以及蛋白表达水平均较正常组高(P0.05),PKA的mRNA和蛋白表达水平则较正常组低(P0.05)。结论 STZ诱导的2型糖尿病大鼠模型在造模后第8周肾脏功能存在明显的损害,并且导致肾脏损害的上游重要介质RAGE、PKC、PKA在第8周都有着明显的变化。此种模型能够用于糖尿病肾损害的研究,并且是观察中早期糖尿病肾病的较好的模型。  相似文献   

7.
C Kamei  M Mio  K Tasaka 《Experientia》1983,39(9):1025-1026
Studies of the analgesic effect of tripeptide-beta-phenethylamides are described, and their structure-activity relationship is discussed. SD-25, which has a methyl group at R2, and a hydroxymethyl group at R3 of beta-phenethylamide, was the most potent one of the 8 analogs tested.  相似文献   

8.
目的研究Roux-en-Y胃旁路术对2型糖尿病大鼠肾脏非对称性二甲基精氨酸(ADMA)代谢的影响。方法 40只SD大鼠,随机分为正常对照组(NC组,n=8)和糖尿病模型组(32只)。糖尿病模型组成模30只,随机分为糖尿病对照组(DC组,n=8)、糖尿病假手术组(DSO组,n=8)及糖尿病手术组(DO,n=14),DO组行胃旁路术,DSO组行胃窦十二指肠离断原位吻合。检测术前、术后1、2、4、8周血胰高血糖素样肽(GLP-1)水平,测定术前、术后8周空腹血糖(FBG),肾脏ADMA、血尿素氮(BUN)、肌酐(Cr)、一氧化氮(NO)水平,一氧化氮合酶(NOS)活性;检测蛋白质精氨酸甲基转移酶1(PRMT1)mRNA及二甲基精氨酸二甲胺水解酶1(DDAH1)mRNA,PRMT1蛋白表达水平,PAS染色观察肾脏组织学变化。结果随着手术时间延长,D0组GLP-1水平增加,其余各组无明显变化(P0.05),术后8周,DC和DSO组较DO组和NC组FBG、BUN、Cr、ADMA水平,PRMT1mRNA和蛋白表达水平均明显升高(P0.05),NO、NOS、水平、DDAH1的mRNA表达明显降低(P0.05);PAS染色示DC组和DSO组肾小球基质沉积,阳性染色物增多,余无明显变化。结论 2型糖尿病肾脏组织中的ADMA升高;胃旁路术促进ADMA代谢,改善了肾功能。  相似文献   

9.
6 groups each of 5 adult rams were subjected in light controlled pens to a pretreatment of normal variations in daylength during May and June. Then one group followed the normal daylength and the other five different "skeleton photoperiods" of 8 hrs of light per day consisting of: 7 hrs continuous light (7 L) + 1 hr light (1 L) situated at different times of the dark period (D) according to groups. Blood samples were taken once each week and hourly during one 24 hr period in June, July and September. Peripheral plasma testosterone measured by radio-immunoassay was used as an index of testicular activity. There was increase in the level of testosterone resuting from a rise in the number of peak release during the 24 hrs. In the different light treatments tested, only the treatment (7L+9D+1L)+7D) stimulated testosterone secretion with the pattern of testosterone of this group being similar to that of the control group. This indicates that there exists a photosensitive phase at 16 to 17 hrs after the beginning of the principal light (the subjective dawn).  相似文献   

10.
Summary The quantitative study of whole liver DNA and liver nuclei DNA at various ages, and the simultaneous study of oxygen uptake shows the following facts:(1) The rate of oxygen consumption to the fresh weight or to the DNA or to diploid chromosomes group is the same for the adult or the young aged 8 days. The values of oxygen consumption calculated for one cell or for one nucleus (taking notice of the fact that the mean level of liver nuclei DNA varies with the age) at 8 days is only the half of the adult value. Even at two months the value is 20% lower than in the adult.(2) In older animals there is a decrease of oxygen uptake which is more noticeable on a cellular scale than with the classical rate to fresh or dry weight. We affirm the fact that the diminution of the oxygen uptake of each cell is compensated by the increase of the number of cells.  相似文献   

11.
目的探讨外源性干细胞因子(SCF)能否改善糖尿病胃轻瘫(DGP)大鼠胃窦Cajal细胞(ICC)的异常病变。方法sD大鼠随机分为实验组和对照组,实验组腹腔注射链脲佐菌素(STZ)50mg/kg并高糖高脂饲料不规律喂养构建DGP模型,对照组腹腔注射等量生理盐水并普通饲料规律喂养。成模后随机分为糖尿病组(DM组)、糖尿病+外源性干细胞因子治疗组(DM+SCF组);DM+SCF纽腹腔注射SCF0.4ug/(kg·d),共15天,对照组和DM纽每天腹腔注射等量的磷酸盐缓冲液(pH=7.4)。RT-PCR、Wester Dblot检测胃窦组织中SCF及c—kit的mRNA及蛋白表达;免疫组化、透射电镜观察胃窦组织中Cajal细胞的变化。结果DM组大鼠胃窦组织SCF及c—kit的mRNA及蛋白表达下降,Cajal细胞数量减少,细胞内线粒体肿胀、内质网扩张;予外源性SCF干预后,胃窦组织中SCF及C—kjf的mRNA及蛋白表达上调,caial细胞数量增多、超微结构明显改善。结论外源性SCF能在一定程度上改善或逆转糖尿病胃轻瘫大鼠胃窦Cajal细胞的异常病变:  相似文献   

12.
The emphasis placed on electron transfer in connection with oxidation reactions has often resulted in these processes being considered as a group apart from the main class of chemical reactions. Although some oxidations, for example certain exchange reactions between ions in solution, can be reasonably described as electron transfer processes, there are very many other oxidations, whose mechanisms are much better described in the familiar terms of modern organic chemistry.The use of isotopes as tracers has shown, that many oxidations proceed with transfer of atoms or groups from oxidant to reductant andvice versa; the use of the kinetic isotope effect has shown that such transfer is seldom an incidental process, but is almost always a part of the slow step of the reaction. In this paper, oxidations involving the transfer of such species as oxygen atoms, hydride ions, hydrogen atoms, chlorine atoms, and hydroxyl radicals are discussed in terms of mechanism. An attempt is made to show that a graded series of mechanisms is possible ranging from what appear to be pure electron transfer processes at one end to certain atom transfer processes at the other. The latter group belong, in fact, in the familiar realm of ordinary chemical raactions, in which strong bonds are being broken and formed in the activated complex.Contribution from Department of Chemistry, University of British Columbia, Vancouver. — Presented at the Organic Chemistry Symposium of the Chemical Institute of Canada, Ottawa, Dec. 8–9, 1958.  相似文献   

13.
目的 探讨外源性细胞色素c (Cytc)对脓毒症小鼠心肌TGF-β1和Smad1/5/8的作用及影响.方法 雄性昆明小鼠78只,随机分为假手术组( Sham)、脓毒症组(CLP)、细胞色素C处理组(T).CLP组和T组用盲肠结扎穿孔法造模,Sham组仅开腹翻动盲肠.24 h造模成功后,T组经尾静脉注射外源性Cyt c(20 mg/kg)、Sham组和CLP组分别经尾静脉注射150(1生理盐水.30 min后以0、6h、12 h点取材,每个时间点5只小鼠,测左心室收缩压(LVSP)、左心室舒张末期压(LVEDP)、左室内压力变化最大上升和下降速率(LV±dp/dt-max);取心肌组织分别做组织学检查、RT-PCR和Western-Blot检测TGF-β1和Smad1/5/8蛋白的表达;24h点留取电镜标本,余下的小鼠观察生存率.结果 与CLP组比较,T组一般情况好转,生存率提高,病理学改善;LVSP、LVEDP和LV±dp/dt-max提高(P<0.05);各组TGF-β1和Smad1/5/8蛋白均有表达,CLP组表达明显增加,经外源性Cytc干预后蛋白表达减少,CLP组与其它组比较差别有统计学意义(P<0.05).结论 外源性Cytc逆转脓毒症小鼠心肌线粒体功能抑制和心肌抑制,改善心功能.  相似文献   

14.
目的 观察GlideScope视频喉镜经口气管插管和经鼻气管插管的声门暴露情况、插管时间和血流动力学变化. 方法 在全身麻醉下行择期手术的患者200例,ASA Ⅰ~Ⅱ级,分为经口气管插管组和经鼻气管插管组.观察记录两组患者喉部显露分级、气管插管时间、气管插管前后的心率、血压,计算各时间点的收缩压-心率乘积(RPP). 结果 使用GlideScope视频喉镜喉部显露分级为Ⅰ级和Ⅱ级的比例高达98%;经口插管组和经鼻插管组的插管时间分别为(43.3±9.8)s和(57.9±13.3)S,两组比较有显著差异;经口插管组的患者在气管插管时和气管插管后1~2 min内的心率、血压和RPP较麻醉诱导前显著升高,经鼻插管组的患者在气管插管后1 min时的心率和RPP较麻醉诱导前显著升高. 结论 使用GlideScope视频喉镜可改善喉部显露分级,经口气管插管所需的时间少于经鼻气管插管,而血流动力学变化强于经鼻气管插管.  相似文献   

15.
To determine the long-term effects of prolonged and intensive treatment with an anticonceptive steroid, 60 female Wistar rats were given 1 mg/kg/day Enidrel (norethynodrel plus ethinyl estradiol 3-methyl-ether) by gastric sound for 60 days. The animals were divided into 2 groups and were placed with males for 10 days. Group 1 continued to recieve Enidrel through mating to the 15th day of gestation; Group 2 received no further treatment. General behavior and weight of the animals was unchanged when compared with controls. There were profound disturbances in the estrous cycle, but couplings and number of impregnations were normal in both groups. Most of the females in Group 1 aborted normal fetuses between Gestation Days 8 and 15; those in Groups 2 continued to term. Group 1 animals were remated and siblings of the 1st generation were crossed. The animals were fertile and the ne onates developed normally. It is concluded that Enidrel had no effect on morphogenesis and no masculinization effect on the hypophyso-hypothalamic system, as evidenced by the normal sexual behavior and fertility of the females.  相似文献   

16.
Evangelista Torricelli (1608-1647) is perhaps best known for being the most gifted of Galileo’s pupils, and for his works based on indivisibles, especially his stunning cubature of an infinite hyperboloid. Scattered among Torricelli’s writings, we find numerous traces of the philosophy of mathematics underlying his mathematical practice. Though virtually neglected by historians and philosophers alike, these traces reveal that Torricelli’s mathematical practice was informed by an original philosophy of mathematics. The latter was dashed with strains of Thomistic metaphysics and theology. Torricelli’s philosophy of mathematics emphasized mathematical constructs as human-made beings of reason, yet mathematical truths as divine decrees, which upon being discovered by the mathematician ‘appropriate eternity’. In this paper, I reconstruct Torricelli’s philosophy of mathematics—which I label radical mathematical Thomism—placing it in the context of Thomistic patterns of thought.  相似文献   

17.
In contrast to the laboratory Rat, the Rat (Rattus rattus) of Guadeloupe is a favorable host for the life cycle of S. mansoni: the parasite population is maintained at a high level (between 8 and 16% in this host until the 16th week and reproduces normally). The evolution of the parasitose is marked, shortly after the 8th week, by a transfer of schistosomes from the liver to the lungs.  相似文献   

18.
Encystment, which at a temperature of 15°C is photoperiodically controlled inGonyaulax polyedra, can also be induced by a decrease of temperature, from 20 to 10 or 8°C in the absence of photoperiodic signals. The cyst-inducing capacity of the decrease in temperature depends on the circadian phase: in constant light, the maximum of sensitivity was found at the beginning of subjective night. In a light/dark cycle, however, cyst formation was reduced during dark phase, indicating that light is required for the process of encystment. A similar light dependence was seen in the effect of the physiologically occurring cyst inducer 5-methoxytryptamine, but not in the encystment response to the protonophores monensin and nigericin.  相似文献   

19.
Following an injection of 3H-5 HT in the neostriatum of the Rat, the tracer is transported by axoplasmic retrograde flow to the cell groups containing mono-aminergic neurons which are known or thought to have afferences to this structure: substantia nigra, dopaminergic group A 8 and n. raphe dorsalis.  相似文献   

20.
G-protein-coupled receptors (GPCRs) can constitute complexes with non-GPCR integral membrane proteins, while such interaction has not been demonstrated at a single molecule level so far. We here investigated the potential interaction between the thyrotropin receptor (TSHR) and the monocarboxylate transporter 8 (MCT8), a member of the major facilitator superfamily (MFS), using fluorescence cross-correlation spectroscopy (FCCS). Both the proteins are expressed endogenously on the basolateral plasma membrane of the thyrocytes and are involved in stimulation of thyroid hormone production and release. Indeed, we demonstrate strong interaction between both the proteins which causes a suppressed activation of Gq/11 by TSH-stimulated TSHR. Thus, we provide not only evidence for a novel interaction between the TSHR and MCT8, but could also prove this interaction on a single molecule level. Moreover, this interaction forces biased signaling at the TSHR. These results are of general interest for both the GPCR and the MFS research fields.  相似文献   

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