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1.
研究分析了大豆连作、轮作土壤微生物区系,发现连作大豆根际土壤真菌富集,以其优势真菌回接大豆.紫青霉菌(Penicilliumpurpurogenum)能强烈抑制大豆生长发育.在实验室条件下分离获得该菌产生的毒素粗结晶,5μg·ml-1水培液中即可观察到大豆根系受害,根毛很少生长;30μg·ml-1水培液中大豆主根褐变严重,侧根几乎不再生长;200μg·ml-1导致一些大豆品种幼苗在2周内死亡这些结果表明,连作大豆土壤中该菌的大量存在及其产生的毒素是大豆连作障碍产生的主要因素.  相似文献   

2.
天竺葵花清除自由基作用的研究   总被引:4,自引:0,他引:4  
用化学发光法研究了天竺葵花粗担液对超氧阴离子自由基(O2)^=和羟自由基(OH)的清除作用,用分光不镀法研究了它对1,1-二苯基-2-苦肼基自由基(DPPH0的清除作用。结果表明,天竺葵花具有很强的清除自由基活性。其粗提物清除O2^-分别为3.5μg/ml(红花),3.0μg/ml(粉花),1.6μg/ml(浅粉花),与茶多酚(IC50=1.1μg/ml)相近,清除OH的IC50分别为5.7μg/  相似文献   

3.
为了解乙型肝炎血源疫苗皮内接种的持久效果,选HBsAg、抗-HBs和抗-HBc均(-)的9~11岁儿童103名,随机分成4组,分别皮内接种1μg×4和3μg×4(均按0,1,2,5月程序)和肌肉接种10μg×3和30μg×3(各按0,1,2月程序)。首针后48月时,1μg、3μg、10μg和30μg组抗-HBs≥10mIU/mI者各为69.2%,80.0%、92.3%和81.8%;GMT则为14.5,79.0,44.8和70.9mIU/ml,3μg×4皮内免疫的近期和远期效果与肌肉组30μg×3相似,宜于某些人群采用  相似文献   

4.
微生态系统中地衣芽孢杆菌消长的研究   总被引:1,自引:1,他引:0  
采用不同接种培养方法,研究了地衣芽孢杆菌在微生态系统的消长状况.结果表明,在健康人体内该菌能迅速增殖,菌数为1.49×108~1.83×108个·g-1,并能较长时间定植下来,30d后菌数为1.27×107~1.51×107个·g-1.在病人体内增殖相对较慢些,菌数为1.40×108~1.67×108个·g-1,30d后菌数为1.15×107~1.31×107个·g-1.在人工模拟微生态系统中,当pH为5.0~9.0,营养物为食物匀浆培养基、牛肉膏蛋白胨培养基时,其菌数为3.05×108、3.42×108个·ml-1.  相似文献   

5.
黑曲霉生产β-葡萄糖苷酶发酵条件的研究产   总被引:1,自引:0,他引:1  
经多项式回归分析,研究了不同浓度N 源、C 源、无机盐等对酶产量的影响,确定出最佳培养基配方为:麸皮4 .9 % ,(NH4)2SO4 0 .4 % ,KH2PO4 0 .29 % ,CaCl2 0 .05 % ,MgSO4·7H2O0 .04 % ,FeSO4·7H2 O5mg·L- 1 ,ZnCl2 1 .4mg·L- 1 ,0 .2 % 油酸钠.并对培养温度、时间、培养基初始pH、通气量、接种量、接种方式等培养条件进行优化,使黑曲霉生产β葡萄糖苷酶的产量由17U·ml- 1 增至21 .3U·ml- 1 .  相似文献   

6.
应用杂交瘤技术获得4株分泌抗小鼠腺病毒(MurineAdenovirusMAd)单克隆抗体细胞株,并对其特性进行分析。经鉴定,它们所分泌的抗体类型均为IgM,腹水效价为10-3~10-6。相对亲和力分别为0.1μg/ml(A9)、0.65μg/ml(Bl)、12.5μg/ml(G4)和23μg/ml(D4)。与其他10种鼠源性病毒均无交叉反应,表明McAb具有良好的特异性。单抗标记FITC后用于人用鼠源性单抗制品及各种传代细胞和原代细胞中MAd检测,获得良好的实验结果。  相似文献   

7.
凤眼莲根分泌物氨基酸对根际肠杆菌属F2细菌降酚的影响   总被引:9,自引:1,他引:8  
研究2种有代表性的凤眼莲(Eichhorniacrassipes)根分泌物Met、Lys对其根际肠杆菌属F2细菌(Enterobactersp.F2)降酚的影响.结果表明,具有正趋化作用的Met的不同浓度对细菌的生长动态、细菌降酚酶活性、细菌降酚效率基本没有影响;而具有负趋化作用的Lys在高浓度(10-2、10-3mol·L-1)下延滞细菌的生长,抑制细菌的降酚酶活性,随着Lys浓度的降低各种抑制作用相应减弱,凤眼莲根分泌物氨基酸作为根际微生态系统的信息流,影响着该系统的降酚功能  相似文献   

8.
观察了hFPIL6/2对6.5Gyγ线照射NIH小鼠第10天造血功能恢复的影响。结果表明:照射小鼠连续4d给予hFPIL6/2250μg·kg-1·d-1,其脾重、CFU-8、骨髓有核细胞数及CM-CFU分别比对照组增加59.0%、278.5%、57.9%和138.2%,统计学处理均有显著差异;对此四项指标的改善也明显优于25μg组。另外,250μg剂量组小鼠外周血象30d的动态观察结果表明,hFPIL6/2不但能明显提高红细胞和血红蛋白的最低值,而且能使血小板的恢复提前。提示hFPIL6/2在促进血小板生成和促进红系造血方面可能具有良好的应用前景。  相似文献   

9.
采用国产链霉亲和素直接包被塑料板孔,生物素标记抗体,建立的竞争酶联免疫吸附试验的方法测定血中地高辛浓度,其测定灵敏度为0.964μg/L最低检测限为0.2251μg/L,测定三份低,中、高浓度的血甭标本,批内变异系数为8.9%、5.9%、2.4%;批间变民系数为15.8%、10.1%、9.2%,测定回收率在89.1-107.22%之间,此法与FPIA方法相关良好。  相似文献   

10.
温特曲霉转富马酸为L—苹果酸的初步研究   总被引:4,自引:0,他引:4  
谢红  高润香 《菌物系统》2000,19(4):547-551
从大量霉菌在选育到一株具有较高富马酸酶活性的温特曲霉(Aspergillus wentii)A5-61。在摇瓶培养条件下,32℃ 96小时,产L-苹果酸达10.49g/100ml,对富马酸的转化率达90.80%。利用菌体细胞,进行酶转化试验,结果表明:1.6g湿菌体接入25ml含富马酸10.0%(用NaOH中和至pH7.0)的转化液中,35℃16-24小时,连续转化三次,分别产生L-苹果酸9.61  相似文献   

11.
《环境昆虫学报》2014,(5):790-804
综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生(宾主共栖和异种共栖)、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌(原生动物、细菌、真菌和放线菌)和外生菌(蚁巢伞菌等)间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用(如纤维素酶)及今后研究物种间的协同进化提供了基础资料。  相似文献   

12.
13.
To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.  相似文献   

14.
New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn2NPSCH2CH2Sa(P-Sa) (Bn = benzyl, 4), Bn2NPSCHCHSa(CH2)3CaH2(P-Sa)(Ca-Sa) (6) and Bn2NP(4-XC6H4OMe)2 (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)2] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl2Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the νCO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The 1JPRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the 1JPSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh3. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh3.  相似文献   

15.
Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.  相似文献   

16.
The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.  相似文献   

17.
Allergic asthma can be precipitated by many factors. For the atopic person, fungus, pollen, dust mites, cockroach antigens, and diesel exhaust are all agents that may trigger an allergic attack. Cytokines and chemokines are integral mediators of fungal asthma. From the earliest time points, they recruit and activate the cells required for the clearance of fungus as well as being critical factors involved in the immunopathology of this disease. In the final analysis, it is clear that these mediators can act to the benefit or the detriment of the host.  相似文献   

18.
19.
The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE2, PGD2, PGF, TXB2 and 6-keto-PGF. In all types studied PGE2 and TXB2 were the major products formed. The identification of PGE2 and TXB2 was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.  相似文献   

20.
Objective: It has recently been demonstrated that, in middle‐aged women, a wide hip circumference is a protective factor for a number of health endpoints in later years. The effect seems to be independent of both overweight and waist circumference. This paper aims to replicate this finding in another population‐based sample consisting of women and men. Research Methods and Procedures: This was a prospective observational study consisting of a random subset of adult Danes. A total of 2987 subjects born in 1922, 1932, 1942, or 1952 and 35, 45, 55, or 65 years of age (at examination in 1987 to 1988) participated in the Danish MONICA (MONItoring trends and determinants of CArdiovascular disease) project, with measurements of height, weight, and hip and waist circumference taken. Through personal identification numbers, incidence of coronary heart disease (CHD) and cardiovascular disease (CVD) until the end of 1998 and all causes of death until 2001 were retrieved from the National Registers of Hospital Discharge. There was an average of 10 years of follow‐up for incidence of CVD and CHD and 13 years of follow‐up for total mortality. Results: Large hip circumference, relative to body size and waist circumference, predicted less incidence of CVD, CHD, and total death in women. This was not the case in men; BMI and waist circumference were the strongest independent predictors. Discussion: A large hip circumference seems to have independent and positive effects on CVD and CHD morbidity and mortality in women, but no protective effect on cardiovascular health in men. However, a borderline significant protective effect on total mortality was observed.  相似文献   

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