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1.
The purpose of this report is to present the deconjugation of bile acids by numbers of strains of bacteria in the small intestine and feces. The small intestinal juice was aseptically aspirated by a double lumen tube with a rubber cover on the tip devised by us ("Fukushima Type 1"). Bile acids were analyzed with thin layer chromatography. The results: 1) Among aerobic bacteria, species of which all of the strains split conjugated bile acids was enterococcus, and most of the strains split were Staphylococcus (S.) epidermidis and Lactobacillus (L.) bifidus. Species of which none of the strains split were Escherichia (E.) coli, E. communior, E. freundii, L. plantarum, L. acidophilus, L. buchneri, L. cellobiosus, L. bulgaricus, S. aureus, Aerobacter aerogenes, Pseudomonas aeruginosa, candida, proteus, serratia, and almost none of the species split was Intermediate coliform bacilli. 2) Among anaerobic bacteria, species of which all of the strains split were Bacteroides (B.) vulgatus, B. thetaiotaomicron, B. uniformis, Corynebacterium (C.) granulosum, C. avidum, Peptostreptococcus (Peptostrept.) putridus, Eubacterium (Eubact.) lentum, Peptococcus (Pept.) grigoroffii, Pept. anaerobius, Veillonella (V.) orbiculus, and most of the strains split were Coryne. diphtheroides, Eubact. parvum, Peptostrept. intermedius. Species of which none of the strains split were Coryne, parvum, Peptostrept. micros, V. alcalescens, V. parvula, Catenabacterium (Catena.) catenaforme, and Catena. filamentosum. 3) All or none, or almost all or none, of the strains of each species tested split conjugated bile acids, and it seems probably that the presence or absence of this ability would be a proper character of eachspecies.  相似文献   

2.
We have investigated the role of the ADP- ribosylation induced by brefeldin A (BFA) in the mechanisms controlling the architecture of the Golgi complex. BFA causes the rapid disassembly of this organelle into a network of tubules, prevents the association of coatomer and other proteins to Golgi membranes, and stimulates the ADP-ribosylation of two cytosolic proteins of 38 and 50 kD (GAPDH and BARS-50; De Matteis, M.A., M. DiGirolamo, A. Colanzi, M. Pallas, G. Di Tullio, L.J. McDonald, J. Moss, G. Santini, S. Bannykh, D. Corda, and A. Luini. 1994. Proc. Natl. Acad. Sci. USA. 91:1114-1118; Di Girolamo, M., M.G. Silletta, M.A. De Matteis, A. Braca, A. Colanzi, D. Pawlak, M.M. Rasenick, A. Luini, and D. Corda. 1995. Proc. Natl. Acad. Sci. USA. 92:7065-7069). To study the role of ADP-ribosylation, this reaction was inhibited by depletion of NAD+ (the ADP-ribose donor) or by using selective pharmacological blockers in permeabilized cells. In NAD+-depleted cells and in the presence of dialized cytosol, BFA detached coat proteins from Golgi membranes with normal potency but failed to alter the organelle's structure. Readdition of NAD+ triggered Golgi disassembly by BFA. This effect of NAD+ was mimicked by the use of pre-ADP- ribosylated cytosol. The further addition of extracts enriched in native BARS-50 abolished the ability of ADP-ribosylated cytosol to support the effect of BFA. Pharmacological blockers of the BFA-dependent ADP-ribosylation (Weigert, R., A. Colanzi, A. Mironov, R. Buccione, C. Cericola, M.G. Sciulli, G. Santini, S. Flati, A. Fusella, J. Donaldson, M. DiGirolamo, D. Corda, M.A. De Matteis, and A. Luini. 1997. J. Biol. Chem. 272:14200-14207) prevented Golgi disassembly by BFA in permeabilized cells. These inhibitors became inactive in the presence of pre-ADP-ribosylated cytosol, and their activity was rescued by supplementing the cytosol with a native BARS-50-enriched fraction. These results indicate that ADP-ribosylation plays a role in the Golgi disassembling activity of BFA, and suggest that the ADP-ribosylated substrates are components of the machinery controlling the structure of the Golgi apparatus.  相似文献   

3.
主要研究了废锂电池酸浸液杂质除杂原理,采取“两段酸浸—中和除Fe、Al—絮凝除F—深度除杂”非萃取除杂工艺。在除杂过程中,由于酸浸液含高浓度Ni、Co、Mn离子,中和剂的种类和浓度将影响Ni、Co、Mn的损失率。通过工艺控制及中和剂调试,选择10%CaCO3作为除Fe、Al、F中和剂,Fe、Al、Cu、F含量可分别从0.20、9.76、0.58、1.66 g/L降至0.01、0.02、0.01、29.86 mg/L,达到三元前驱体溶液杂质标准要求。此时,Ni、Co、Mn的损失率分别仅为0.96%、0.04%、0.01%,均在接受范围之内。  相似文献   

4.
The betagamma subunits of the heterotrimeric GTP-binding proteins (G proteins) that couple heptahelical, plasma membrane-bound receptors to intracellular effector enzymes or ion channels directly regulate several types of effectors, including phospholipase Cbeta and adenylyl cyclase. The beta subunit is made up of two structurally different regions: an N-terminal alpha helix followed by a toroidal structure made up of 7 blades, each of which is a twisted beta sheet composed of four anti-parallel beta strands (Wall, M. A., Coleman, D. E., Lee, E., I?iguez-Lluhi, J. A., Posner, B. A., Gilman, A. G., and Sprang, S. R. (1995) Cell 83, 1047-1058; Lambright, D. G., Sondek, J., Bohm, A., Skiba, N. P., Hamm, H. E., and Sigler, P. B. (1996) Nature 379, 311-319). We have previously shown that sites for activation of PLCbeta2, PLCbeta3, and adenylyl cyclase II overlap on the "top" surface of the propeller, where Galpha also binds (Li, Y., Sternweis, P. M., Charnecki, S., Smith, T. F., Gilman, A. G., Neer, E. J., and Kozasa, T. (1998) J. Biol. Chem. 273, 16265-16272). The present study was undertaken to identify the regions on the side of the torus that might be important for effector interactions. We made mutations in each of the outer beta strands of the G protein beta1 propeller, as well as mutations in the loops that connect the outer strands to the adjacent beta strands. Our results suggest that activation of PLCbeta2 involves residues in the outer strands of blades 2, 6, and 7 of the propeller. We tested three of the mutations that most severely affected PLCbeta2 activity against two forms of adenylyl cyclase (ACI and ACII). Both inhibition of ACI and activation of ACII were unaffected by these mutations, suggesting that if ACI and ACII contact the outer strands, the sites of contact are different from those for PLCbeta2. We propose that distinct sets of contacts along the sides of the propeller will define the specificity of the interaction of betagamma with effectors.  相似文献   

5.
There has been little explanation of herbal medicines by modern medical sciences, including pharmacokinetics, whereas physicians follow empirical indications written in classical literature. Recent reports of herb-induced adverse reactions compelled us to proceed the investigation of a herbal medicine Shosaiko-to (TJ-9) from a pharmacokinetic point of view. To five healthy volunteers, a single 5 g dose of TJ-9, consisting of 7 herbs, was administered. We conducted HPLC analysis of the timed-urine specimens to disclose the type and amount of compounds excreted. Excretion rate-time curves were analyzed individually. Four flavonoids, liquiritigenin, baicalein, wogonin and oroxylin A, were found both in the urine and TJ-9. The glycosides in TJ-9 were absorbed after microflora hydrolysis. Davidigenin, which was not found in TJ-9, was an intestinal metabolite of liquiritigenin. Also, two flavanones, S-dihydrowogonin and S-dihydrooroxylin A, were identified as the metabolites of wogonin and oroxylin A, respectively. Excretion rate-time curves of the flavonoids were divided into three types of structure-dependent absorption, i.e. (1) the fast absorption of herbal-origin aglycons, (2) the moderately-delayed absorption of aglycons derived from herbal glycosides, and (3) markedly-delayed absorption after the molecular transformation of herbal compounds. Individual excretion profiles seemed to depend on microflora activities. Two types of flavanones, S-dihydrowogonin and S-dihydrooroxylin A, were found in a half of the volunteers, suggesting there might be two kinds of volunteers, namely, rapid and poor metabolizers of flavonoids.  相似文献   

6.
Metals which form soluble stable ammine complex cations were extracted by lignite and brown coal by adsorption from ammoniacal solutions of the metal sulfates and carbonates. Known dry weights of the coal were contacted with the solution by agitation in closed polyethylene containers and then separated by filtration. The amount of metals adsorbed was determined from analysis of the solutions before and after contacting. It was found that metal loadings increase with increases in contact time, liquid to solid ratio and with metal concentration at short contact times, but loadings decrease with increases in coal particle size, ammonium ion concentration and with metal concentration at long contact times. Loading is affected only slightly by temperature and excess ammonia. In single contacting high loading is associated with low percentage extraction, and vice-versa, but relatively high values for both loading and extraction were obtained by counter-current contacting. The highest loadings obtained with single contacts, by using favorable combinations of conditions, were 22 pct copper, 15 pct nickel, 17 pct zinc, 31 pct cadmium, 37 pct silver and 13 pct cobalt. Comparative experiments were done with coals from Australia, United States of America, and West Germany. More development of the method is required before meaningful comparison could be made with other hydrometallurgical methods. It is speculated that possible applications could include treatment of ammoniacal solutions derived from sulfide, carbonate and oxide ores, pressure leaching of sulfides, preferential leaching of scrap metal,in situ solution mining and processing of oceanfloor nodules, arid effluent solutions which already contain ammonia. G. V. CULLEN formerly Manager, Institute of Materials Research, Department of Metallurgy, University of Melbourne, Parkville, Victoria, 3052, Australia. N. G. SIVIOUR formerly Senior Research Officer, Institute of Materials Re- search, Department of Metallurgy University of Melbourne. G. M. PEARSON formerly Experimental Officer, Institute of Materials Research, Department of Metallurgy, University of Melbourne.  相似文献   

7.
钴产品生产过程CoCl2净化液和Co(NO3)2净化液中含有大量钴离子,一般采用基体匹配原子吸收光谱法或萃取分离-分光光度法测定其中Cu、Fe、Ni、Cd、Zn、Mn、Ca、Mg、Na、Si、As、S等12种杂质元素。但是此类方法分析时间长、操作繁琐、费用高,而且只能进行单一元素测定。实验提出了采用电感耦合等离子体原子发射光谱法(ICP-AES)测定钴产品生产过程净化液中以上目标元素,在优化的仪器工作条件下,使用内标法有效地克服了基体效应及仪器波动所产生的影响。各元素校准曲线的线性相关系数均大于0.9999;方法检出限为0.00003~0.00026g/L。按照实验方法测定钴产品生产过程CoCl2净化液和Co(NO3)2净化液两个体系中Cu、Fe、Ni、Cd、Zn、Mn、Ca、Mg、Na、Si、As、S,结果的相对标准偏差(RSD,n=11)为2.8%~8.9%,加标回收率为93%~107%。实验方法用于Co光谱分析标准样品中Cu、Fe、Ni、Cd、Zn、Mn、Mg、Si、As的测定,测定值与认定值相一致。  相似文献   

8.
A short review of works by A.V. Elyutin et al. in the field of rare metals is presented. Technologies of the recovery of zirconium, hafnium, tungsten, tantalum, and niobium from various types of secondary raw materials, notably, scrap metal, scrap of refractory materials, wastes and scrap of hard alloys, and obsolete scrap of capacitors, are considered. Possibilities of increasing the purity of these metals by electrolytic refining and electron-beam melting are shown.  相似文献   

9.
Various compounds are known to allosterically modulate the binding of ligands to muscarinic receptors. Most of these compounds have another predominant pharmacological action. Identification of the potent representatives should be useful for the development of allosteric modulators that are specific and highly active. For various reasons, a direct comparison of allosteric potencies on the basis of literature data is difficult. Therefore, a series of compounds was compared with regard to the allosteric delay of the dissociation of N-[3H]methylscopolamine from porcine heart M2 receptors under the following assay conditions: "Na,K,Pi buffer", 4 mM Na2HPO4, 1 mM KH2PO4, pH 7.4, 23 degrees C; "Mg,Tris,Cl,Pi buffer', 50 mM Tris-HCl, 3 mM MgHPO4,pH 7.3, 37 degrees C. Generally, the allosteric potency of the compounds was higher in the Na,K,Pi buffer, compared with the Mg,Tris,Cl,Pi buffer. However, the extent of the potency shift differed, ranging from approximately 2-fold for tacrine to approximately 100-fold for gallamine. The concentration retarding radioligand dissociation to half of the control rate (EC50) served as a measure of allosteric potency. Under both assay conditions, alcuronium was the most potent compound (EC50,Na,K,Pi = 4 nM and EC50,Mg,Tris,Cl,Pi = 55 nM), followed by alkane-bisammonium and bispyridinium compounds containing phthalimido moieties. Gallamine showed intermediate potency (EC50 values of 180 nM and 16,000 nM in Na,K,Pi buffer and Mg,Tris,Cl,Pi buffer, respectively). Obidoxime and hexamethonium, both known to antagonize allosteric actions, revealed submaximal efficacy and low potency (EC50,Na,K,Pi of approximately 100,000 nM). The relevance of these results, regarding the identification of lead structures for the development of new allosteric modulators, is discussed.  相似文献   

10.
Basety is a French semantic database of exemplars of 21 categories of objects, with a typicality index associated with each exemplar. These 21 semantic categories are animals, trees, weapons, buildings, flowers, fruits, insects, instruments of music, games, toys, vegetables, mammals, furnitures, birds, tools, fish, occupation, containers, sports, vehicles, and clothes. Basety was made up with two groups of 18-to-30 years old French participants, a first group of three subgroups of 100 participants producing exemplars for 7 × 3 categories while a second group of 80 participants evaluating membership of these exemplars. Typicality was computed as the number of occurrences of the exemplar within the set of the five exemplars participants were first producing. Cronbach's coefficient of reliability indicates an internally consistent scale and number of exemplars is correlated with membership ratings: the more the participants of the first group produced exemplars, the more the participants of the second group agreed on the degree of membership of these exemplars. BASETY appears to be a consistant and valid database for French semantic research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

11.
火焰原子吸收光谱法测定合金结构钢中铬、锰   总被引:1,自引:0,他引:1  
利用火焰原子吸收光谱法测定合金结构钢中铬、锰,此方法快速、准确、灵敏度高、精密性好,方法简便,并充分反应了现代仪器的高科技分析手段。合金结构钢使用较为广泛,因此利用原于吸收光谱法测定铬、锰,能迅速有效的达到检测目地的需要。本方法改变了以往化学法操作时间长、步骤多、消耗试剂多的弊病,解决了高氯酸氧化铬对人体的危害及对环境的严重污染。通过对各项做条件试验,优选了最佳仪器测试条件。对干扰元素铁、镍抑制铬的吸收,采用硫酸钠做干扰消除剂,彻底消除了干扰,测定数据稳定可靠。经过对标准样品的测定,重复性好,误差小,回收率达到99~102%,效果令人满意。  相似文献   

12.
In Part I of this communication, a technique (LBA) was described which used DNA replication in the evaluation of chromosome variants in man. It was shown that the method was very useful in the detection of variants in D- and G-group chromosomes. Results on pars 3 and 4 were also presented. In Part II, the rest of chromosomes were examined. In the evaluation of qh variants in 1, 9 and 16, the LBA technique proved itself to be a very effective implement. It was practically free of technical variables coherent with C-band technique and, therefore, it was possible to use the size of an euchromatic segment of a chromosome as a reference standard. LBA variants were observed in about 50% of the members of the remaining 12 pairs of chromosomes, i.e., 2, 5, 6, 7, 8, 10, 11, 12, 17, 18, 19, and 20.  相似文献   

13.
Many artists have used the symbol of salt in both religious and profane works, yet very few studies have explored the symbolism of salt as used in works of art. In this study, Panofsky's method has been adopted to evaluate works of art through an organic process articulated into three stages: (1) pre-iconographic, (2) iconographic and (3) iconological. The method was used for (a) religious paintings of the Old and New Testaments and (b) mythological and profane themes. Various salt-cellars were also studied. In particular, the paper examines the following themes: Isaac blessing Jacob, the return of Esau, Samuel consecrating David, the Last Supper, the suppers at Emmaus and at the house of Simon, the birth of St. John the Baptist, the Baptism of Constantine, the prodigal son, Bacchus-Apollo, the nuptial banquet of Love and Psyche, the death of the Cavalier of Celano, the king drinks, the landlord's visit, 'Phitopolis faisant servir des mets en or au roi Pithès', certain still life paintings and various salt-cellars including those of Cellini and Giulio Romano. The paper discusses the works of many artists including Raphael, Leonardo and his school (Boltraffio, Giampietrino, d'Oggiono, Solario), Hendricksz, Corenzio, Jean-Baptiste and Philippe de Champaigne, Damaskinos, Tintoretto, Titian, Romanino, Rubens, Bellini, Bloemaert, Veronese, Sustris, Just of Ghent, Jan Van Hemessen, Poussin, Loir, Giotto, Jordaens, Brueghel and Mimmo Paladino with his enchanted mountain. From the data examined it emerged that salt is a primary iconological presence in various works of art.  相似文献   

14.
We describe a six-channel, all-solid-state, miniaturized fluorescence sensor array for the precise determination of blood analytes for medical diagnostic purposes. The device features superblue LEDs as light sources, GRIN optics, and photodiodes, assembled according to pigtailing procedures (Bruno, A. E.; et al. Trends Anal. Chem. 1994, 13, 190-198). The numerical aperture of the fluorescence optics is 0.46, rendering a collection efficiency of 2.4%. The performance of this instrument has been evaluated in terms of dynamic response, linearity, channel reproducibility, reversibility, long-term drifts, photobleaching of indicator, cross-talk, ionic strength, and selectivity in pH measurements. The responses of the pH sensing membranes were optimized in the physiological range. Responses are linear with typical values of approximately 1.5 V/pH units, with limits of decision of 24 mV, which corresponds to pH resolutions of 0.03 pH unit. Under continuous illumination, using calibration buffers, the sensors display nonstatistical differences within 2 standard deviations over a period of 6 h, and it is shown that, under discontinuous illumination, the membranes can be used in more than 2000 measurements without need of calibration, in contrast to electrochemical sensors which require periodic calibration. After selecting the appropriate combination of LEDs, excitation and emission filters, and sensing membranes, the instrument was used to determine the concentrations of various critical blood analytes in buffer solutions in the various channels. Similar measurements in untreated blood reproduce the reported results.  相似文献   

15.
16.
首先从绿色通信入手, 对网络能量效率的国内外研究现状进行了分析. 在此基础上, 对超密集网络的关键性能指标, 即能量效率的各种定义进行了梳理, 为建模奠定了基础. 其次, 讨论了网络能量效率建模和优化过程中经常使用的4种理论模型: 随机几何、博弈论、最优化理论和分数阶规划. 并综述了能效提升的技术, 包括高能效部署与规划、高能效基站休眠、高能效用户关联、高能效资源管理、高能效传输方式. 最后, 指出未来的可能的技术挑战: 网络能效理论与超密集网络体系架构、超密集小基站高能效覆盖机理、超密集网络的柔性资源匹配机理、移动用户群体行为建模与高能效服务方法. 通过研究超密集网络高能效覆盖机理和柔性资源匹配机理, 为未来无线通信网络建模和分析提供设计依据与技术支撑.   相似文献   

17.
Clinically apparent involvement of the nervous system occurs in a relatively small number of patients with sarcoidosis. The diagnosis of neurosarcoidosis is often difficult and particularly so in patients who lack either pulmonary or systemic manifestations of sarcoidosis. Furthermore, clinical features of neurosarcoidosis are extremely variable. In this series of 37 patients, seen during the last 30 years, cranial nerve palsies occurred in 52%, polyneuritis or polyneuropathy in 24%, meningeal involvement in 24%, muscle disease in 8%, and Guillain-Barré syndrome in 5% of the patients. Other presentations included seizures, brain mass, pituitary/hypothalamic syndrome, and memory loss associated with confusion. The chest radiograph was abnormal in 8 of every 10 patients with neurosarcoidosis. In 18 (85%) of 21 patients, gallium uptake was consistent with the diagnosis of active sarcoidosis. Serum angiotensin-converting enzyme levels were raised in about half of the patients. Cerebrospinal fluid features, including lymphocyte pleocytosis, raised protein levels, and decreased glucose concentration, were of little help. MRI with gadolinium enhancement was the most sensitive diagnostic tool, particularly in patients with meningeal involvement. The ultimate arbiter of the diagnosis of neurosarcoidosis, the presence of noncaseating granulomas in the involved tissue, was not always available. Although corticosteroids are the mainstay of therapy, in this series, 12 patients received chloroquine or hydroxychloroquine. Prognosis of chronic neurosarcoidosis is poor. Six (18%) of 37 patients died of complications related to sarcoidosis.  相似文献   

18.
Noma: a review     
Cancrum oris or noma is a condition not well known in western Europe and North America. It is, however, a relatively common cause of mortality and disability in children of undeveloped areas of Africa, Asia, and South America. This paper describes the experience at Galmi Hospital, in the sub-Saharan region of South Africa in the Niger Republic, with 50 operative patients out of a group of 300 who were referred. An extensive review of the literature is presented describing the epidemiological impact of the disease, the characteristics of the lesions, the pathogenesis, symptoms, sequelae, differential diagnosis, and preoperative preparation. Additionally, we review approaches to anesthesia, methods of reconstruction, and the most common causes of complications and mortality. Numerous photographs illustrating the devastating consequences of this problem are presented.  相似文献   

19.
程祎  王琳  张芳  刘军  陈浩凤  张帆 《冶金分析》2021,41(9):24-33
准确测定钛铁矿中主次元素对提高钛铁矿的选钛技术及有益元素的综合回收具有指导意义。钛铁矿难溶易水解,一般很难实现一次分解多元素同时测定。采用3 mL HF-1 mL HNO3-0.5 mL H2SO4于180 ℃高压密闭消解10 h,用5 mL逆王水180 ℃高压密闭方式溶解盐类5 h,在线引入Rh、Re混合内标,采用标准模式测定Li、Be、Sc、Ti、V、Cr、Mn、Co、Ni、Cu、Zn、Ga、Rb、Sr、Y、Mo、Cd、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、W、Pb、U,动能歧视模式测定Fe、Zr、Nb、La、Ce、Hf、Ta,对于受质谱干扰严重的V、Ni、Cd、Eu、Gd、Tb,通过数学校正方程在线进行校正,建立了电感耦合等离子体质谱法(ICP-MS)测定钛铁矿中39种主次元素的方法。方法校准曲线的相关系数均不小于0.999 6,检出限为0.002~2.4 μg/g,将其应用于钛铁矿成分分析标准物质分析,结果的相对误差(RE)为-10.0%~13.0%,相对标准偏差(RSD,n=12)均不大于3.5%;对主量元素及缺少认定值的元素进行加标回收试验,回收率为96%~104%。采用实验方法对钛铁矿样品进行分析,测得结果的相对标准偏差(RSD,n=12)均不大于4.1%。  相似文献   

20.
Fifty-seven dating couples were studied on a variety of relationship measures. The interrelations among love attitudes and relationship satisfaction were of primary interest. However, for one subsample of couples, sexual attitudes, self-esteem, self-disclosure, commitment, investment, and relationship continuation/termination were also studied. Partners displayed similarity on a variety of measures, including several love attitudes, disclosure, investment, commitment, and relationship satisfaction. Some of the love attitudes were related to satisfaction, but several other measures (e.g., commitment, investment, self-esteem, and self-disclosure) were also important correlates of satisfaction. A follow up of 30 couples at 2 months after initial data collection assessed the variables that differentiated continuing and terminating couples. Implications of this set of results for other theories and for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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