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1.
Zusammenfassung 1. Mit Hilfe eines Homogenisators der Type Ultra-Turrax Typ 18/2 wurden Aufteilungen von Bakterienaggregaten in marinen Proben durchgeführt, da die verwandten Kulturverfahren nur in der Lage sind, räumlich voneinander getrennte Bakterien zu erfassen.2. Um die Temperatur der Probe während der Laufzeit des Gerätes nicht in schädliche Bereiche ansteigen zu lassen, ist eine Kühlung durch ein Eis-Wassergemisch notwendig.3. Bei Seewasserproben wurden stark wechselnde Ergebnisse erhalten, die teilweise geringfügig über, teilweise unter dem Ausgangswert lagen.4. Bei küstenfernen Sedimenten wurde nach Homogenisation eine Steigerung der Keimzahl bis auf das 2,3fache erzielt.5. Eine Fischfleischprobe (tiefgefrorener Hering) ergab bis zum 3,6fachen der Ausgangszahl.6. Bei küstennahen Sedimenten, die reich an organischer Substanz waren beziehungsweise bei sich zersetzenden Algen, wurde durch die Behandlung mit dem Ultra-Turrax eine gewaltige Steigerung der mit dem Gußplattenverfahren erfaßbaren Bakterien erreicht. Sie betrug in 4 Versuchsreihen das 31-, 19-, 59- und 119fache der nicht homogenisierten Probe. Im Interesse einer vollständigeren Erfassung der Bakterien wird bei solchen Proben die Anwendung des Ultra-Turrax vorgeschlagen.
The use of the Ultra-Turrax for separation of bacterial aggregates in marine samples
Marine samples were treated with a homogenizer, Type Ultra-Turrax TP 18/2, 24,000 rpm. (Janke & Kunkel, Staufen im Breisgau). In shore sediments rich in organic material, treatment with the Ultra-Turrax resulted in an increase in bacterial numbers (pourplate method) up to 119 times, compared with the results obtained from an untreated sample. The Ultra-Turrax has proven to be a useful tool, separating bacterial aggregates by mechanical effects. In sediment samples taken several miles offshore, there was a constant but only slight increase in the bacterial numbers up to 237 %. Experiments on sea water samples treated with the homogenizer showed varying results, with values occasionally slightly above or slightly below those of the untreated samples.


Herrn Professor Dr.Adolf Bückmann zum 65. Geburtstag in Verehrung gewidmet.  相似文献   

2.
A rapid and simple method for preparing freeze-clamped tissue samples for metabolite determinations is described. Freeze-clamped rat heart tissue samples weighing from 0.8 to 1.0 g were homogenized directly in an Ultra-Turrax homogenizer for 60 s in 3.5 ml of ice-cold 0.6 M HClO4 without pulverizing them in liquid nitrogen. After centrifugation, the pellet was rehomogenized in the Ultra-Turrax homogenizer for 30 s in 1.5 ml of HClO4. Following a further centrifugation the extracts were combined and the pH was adjusted to 7.0 by adding 5 M K2CO3. The neutralized supernatant was used for the desired assays. The analyses of the tissue extracts obtained from isolated perfused rat hearts by the present method give similar results for different kinds of metabolites than those processed according to the previous classical method. Moreover, the values of the various parameters determined from the tissue extracts prepared according to the method described here are similar to the data reported in literature. The method can be readily applied to any other freeze-clamped tissue. The greatest improvement obtained is that the homogenization procedure can be accomplished easily and conveniently in about one-tenth of the time required for the earlier classical method without the time-consuming and unpleasant tissue grinding in liquid nitrogen.  相似文献   

3.
This paper describes an examination of the cell envelope stability opposite to disruption by chemical and physical methods of extremely halophilic bacteria. The following methods of cell treatment were studied: solvent and chelating agents; pressure shearing at several pressures; ultrasonic disintegration for various times; ballistic disintegration; grinding with cold alumina; lysozyme digestion; osmotic shock; and freezing and thawing. The procedure is based on the determination of three cytoplasmic enzymes released by the cell treatment. Menadione reductase was also used as convenient marker enzyme for damage to the permeability barrier. Of all the methods, only pressure shearing and ultrasonic disintegration yielded a crude extract with high halophilic enzyme activities. These procedures are suitable in designing a cell fractionation scheme for halophilic enzyme purifications.  相似文献   

4.
《Plains anthropologist》2013,58(71):57-61
Abstract

In an attempt to discern the quantitative parameters diagnostic of specific load applications (i.e.hard-and soft-hammer percussion and pressure flaking) used in flint knapping, approximately 1,500 experimentally produced flakes were analyzed. Load varieties were recorded during production, flakes were standardized as to plane size through graduated sieves, and weighed and measured for maximum thicknesses. Although the study indicates that hardand soft-hammer percussion do not yield significantly different debitage weights or thicknesses, pressure flakes can be differentiated from percussion spalls on the basis of these variables.  相似文献   

5.
Assessing for the presence of splenomegaly is an important component of the physical examination. Although several methods of palpation and percussion of the spleen have been described, until recently they have not been validated by noninvasive imaging techniques such as ultrasonography, radionuclide scanning, and computed tomography that offer objective means to assess splenomegaly. We review the literature comparing various physical examination techniques with noninvasive imaging modalities and conclude that palpation and percussion of the spleen are complementary but frequently insensitive and that further studies are needed to evaluate the efficacy of specific diagnostic methods.  相似文献   

6.
Summary Seventeen methods of glucose isomerase extraction fromStreptomyces nigrificans 82/20 were tested and compared. Autolysis with lysozyme, X-press disintegration, sonication, and disintegration using Novotny's procedure were the best.  相似文献   

7.
Knowledge of digestion kinetics of solid foods in human stomach, as affected by food processing methods, is critical in establishing processing conditions at the manufacturing stage to achieve desirable release of nutrients in the gastrointestinal tract. The objective of this study was to investigate how roasting affected disintegration and solid release properties of almond in simulated gastric environment. In vitro trials were performed for raw and roasted almonds by using static soaking method and a model stomach system. The changes in sample weight, dry mass, and moisture during the trials were determined. Both compression and penetration tests were used to investigate the texture of almonds with a focus on the influence of absorption of gastric juice. Light microscopy and transmission electronic microscopy were used to study the change in microstructure of the raw and roasted almonds after simulated digestion. The results suggested that the slow disintegration rate and the high amount of swelling of the almonds in the stomach may contribute to their high satiety property. Roasting significantly improved the disintegration rates of almonds and increased loss of solids during simulated digestion, which is well correlated with the decrease in the rigidity of almond samples after absorbing gastric juice. Microstructure of digested almonds showed breakage and breach of cell walls due to acid hydrolysis. Intercellular and intracellular channels formed in almonds during roasting are important for penetration of gastric juice that may facilitate an effective digestion.  相似文献   

8.
Investigation of the effect of disintegrants on the disintegration time and hardness of rapidly disintegrating tablets (RDTs) was carried out using a quality by design (QbD) paradigm. Ascorbic acid, aspirin, and ibuprofen, which have different water solubilities, were chosen as the drug models. Disintegration time and hardness of RDTs were determined and modeled by executing combined optimal design. The generated models were validated and used for further analysis. Sodium starch glycolate, croscarmellose sodium, and crospovidone were found to lengthen disintegration time when utilized at high concentrations. Sodium starch glycolate and crospovidone worked synergistically in aspirin RDTs to decrease disintegration time. Sodium starch glycolate-crospovidone mixtures, as well as croscarmellose sodium-crospovidone mixtures, also decreased disintegration time in ibuprofen RDTs at high compression pressures as compared to the disintegrants used alone. The use of sodium starch glycolate in RDTs with highly water soluble active ingredients like ascorbic acid slowed disintegration, while microcrystalline cellulose and crospovidone drew water into the tablet rapidly and quickened disintegration. Graphical optimization analysis demonstrated that the RDTs with desired disintegration times and hardness can be formulated with a larger area of design space by combining disintegrants at difference compression pressures. QbD was an efficient and effective paradigm in understanding formulation and process parameters and building quality in to RDT formulated systems.KEY WORDS: disintegrants, quality by design, rapidly disintegrating tablets  相似文献   

9.
延边地区和龙石人沟发现的旧石器   总被引:9,自引:3,他引:6  
2004年5月初,在对延边和龙石人沟旧石器遗址的调查中,在山坡台地的黄色亚黏土和含黄色砂质土的角砾层内获得40件黑曜岩石制品,包括石核、石片、细石叶和使用石片、刮削器、雕刻器、琢背小刀等工具。遗址可能属于晚更新世的晚期,即旧石器时代晚期。  相似文献   

10.
大鼠侧位液压冲击脑损伤动物模型的病理生理学观察   总被引:2,自引:0,他引:2  
目的:建立一种重复性好的大鼠分级侧位液压冲击脑损伤模型,为进一步研究外伤性脑损伤的分子机制提供物质基础。方法:雄性SD大鼠,随机分为正常对照组,手术对照组和损伤组损作组接冲击力大小分为轻(100kPa)、中(200kPa)、重(300kPa)3个亚组。实验中由计算机记录冲击时脑承受的压力曲线并描记大鼠血压和心率变化。结果:脑承受的压力曲线与冲击气压呈直线正相关(r=0.985),损伤组大鼠在冲击后  相似文献   

11.
The purpose of the work was to investigate correlation between disintegration and dissolution for immediate release tablets containing a high solubility drug and to identify formulations where disintegration test, instead of the dissolution test, may be used as the acceptance criteria based on International Conference on Harmonization Q6A guidelines. A statistical design of experiments was used to study the effect of filler, binder, disintegrating agent, and tablet hardness on the disintegration and dissolution of verapamil hydrochloride tablets. All formulation variables, i.e., filler, binder, and disintegrating agent, were found to influence tablet dissolution and disintegration, with the filler and disintegrating agent exerting the most significant influence. Slower dissolution was observed with increasing disintegration time when either the filler or the disintegrating agent was kept constant. However, no direct corelationship was observed between the disintegration and dissolution across all formulations due to the interactions between different formulation components. Although all tablets containing sodium carboxymethyl cellulose as the disintegrating agent, disintegrated in less than 3 min, half of them failed to meet the US Pharmacopeia 30 dissolution criteria for the verapamil hydrochloride tablets highlighting the dependence of dissolution process on the formulation components other than the disintegrating agent. The results identified only one formulation as suitable for using the disintegration test, instead of the dissolution test, as drug product acceptance criteria and highlight the need for systematic studies before using the disintegration test, instead of the dissolution test as the drug acceptance criteria. The opinions expressed in this work are only of authors and do not necessarily reflect the policy and statements of the FDA.  相似文献   

12.
The amount of protein produced per m2 by plants cultivated in soil in a greenhouse at three levels of fertilizer application, for c . 10 weeks, was estimated by Kjeldahl analysis of the TCA-insoluble fraction of freeze-dried material. The quantity of protein extractable for production of leaf protein concentrates was determined by Kjeldahl analysis of non-dried but frozen material after disintegration with a meat mincer and an Ultra-Turrax homogenizer, hydraulic pressing and filtration, and protein precipitation by heat (in two steps) or by TCA. The precipitability was also studied by Folin-Ciocalteu determination of protein. The quality of each protein concentrate was studied by determining nitrogen content (Kjeldahl), digestibility by pepsin and by pepsin + pancreatin, nutritive value in Tetrahymena tests, and lysine and methionine content (analysed microbiologically). Twenty-nine species and varieties were investigated. Large differences between species were found in all the properties studied. Protein extractability varied between 5 and 80%, while the extractable protein produced per m2 ranged between 1 and 140 g. The highest digestibility was two to three times greater than the lowest one. In the most digestible species ( Amaranthus caudatus ), 82% of the N of the chloroplastic protein concentrate was digested by pepsin + pancreatin. The Tetrahymena value generally ranged between 40 and 98, whereas casein gave values of about 75. The lysine content always exceeded the FAO minimum. The methionine content of most species varied between 2.0 and 2.2% of the hydrolyzed protein.
Amaranthus caudatus and the Chenopodiaceae investigated were the most suitable species for large-scale production of leaf protein concentrates for human consumption because they gave high yield of extractable protein and high-quality protein concentrates.  相似文献   

13.
The aim of the study is to find an eventual correlation between the presence of Er receptors and epidemiologic (age, domestic anamnesis, weight, menarca) and clinicist factors (cancerous diameter, linfonodes, first symptoms). The presence of receptors is very important for the start of endocrine therapy. In conclusion we can affirm the absence of correlation between the presence of receptors and the factors we considered. The only exception is about the age of patients; very probably because too little number of patients was considered. On the contrary a correlation was observed between receptors and severity of cancerous receptors in neoplastic tissues was obtained with Poffanelli method using an Ultra-Turrax homogenization followed by a centrifugation at 3800 rpm; the separation was achieved with carbon-dextran.  相似文献   

14.
大鼠液压冲击脑损伤热休克蛋白70基因表达的研究   总被引:3,自引:0,他引:3  
目的:观察大鼠侧位液压冲击脑损伤时HSP70的表达分布特点及时序性变化。方法:雄性SD大鼠,给以0.2MPa液压冲击,造成脑损伤,应用免疫组织化学技术观察冲击后不同时间HSP70在脑组织内的表达特点。结果:冲击侧大脑皮层和脑干SHP70阳性神经辊冲击后2h和4h出现,7并逐渐增强直至12h;冲击后4h,冲击侧海马HSP70免疫阳性细胞开始出现,4 ̄12h,海马HSP70免疫阳性细胞数无明显改变。结  相似文献   

15.
We examined the effects of 10 min of lower lateral chest wall percussion with a mechanical percussor or hand clapping in groups of anesthetized, paralyzed, and ventilated supine dogs. Mechanical percussion was applied at 10-16 Hz and caused an esophageal pressure swing (delta Pes) of 10-17 cmH2O. Hand clapping was applied at 4-7 Hz and caused a delta Pes of 6-17 cmH2O. At necropsy there were large reddened areas on the lateral surface of the underlying lung as well as smaller reddened areas on the hilar surfaces of both lungs and on the lateral surface of the opposite lung. These reddened regions were demonstrated to be atelectatic by postmortem lung inflation (which caused the reddened areas to disappear) and by microscopic examination. Despite the atelectasis, gas exchange improved toward the end of the percussion or clapping period. In four dogs that were ventilated for an additional 20 min after percussion, there was a tendency for gas exchange initially to worsen and then to gradually improve.  相似文献   

16.
大鼠液压冲击脑损伤脑干c—jun mRNA表达的定位观察   总被引:2,自引:0,他引:2  
目的:研究大鼠中度侧位液压冲击脑损伤时脑干c-jun mRNA及其表达产物Jun变化规律。方法:雄性SD大鼠,随机分为正常对照组、手术对照组和损伤组。损伤组动物均给以0.2MPa液压冲击脑损伤,按冲击后处死时间不同再分为5min、15min、30min、1h、2h、4h、8h和12h组。应用免疫组织化学和原位杂交方法观察c-jun在脑干的表达。结果:脑冲击后15min-12h,Jun阳性细胞数逐渐增多。冲击后5min,c-jun mRNA表达开始增强,2h表达最强,然后逐渐减弱。结论:侧位液压冲击脑损伤后c-jun在脑干表达迅速增强,持续时间较长。  相似文献   

17.
The aim of this study was to develop benzydamine hydrochloride-loaded orodispersible films using the modification of a solvent casting method. An innovative approach was developed when the drying process of a small-scale production was used based on a heated inert base for casting the film. During this process, two types of film-forming maltodextrins for rapid drug delivery were used. They were plasticized with two different polyols (xylitol and sorbitol). Superdisintegrant Kollidon® CL-F was tested as an excipient that can induce faster disintegration of the prepared films. The influence of the formulation parameters (dextrose equivalent of film-forming maltodextrins, a type of plasticizer, and the presence of superdisintegrant) on the disintegration time, mechanical properties, and moisture content of films was statistically evaluated using a multivariate data analysis. Orodispersible films containing maltodextrin with lower dextrose equivalent value showed better mechanical properties (tensile strength ranged from 886.6?±?30.2 to 1484.2?±?226.9 N cm?2), lower moisture content (0.5?±?0.0 to 1.2?±?0.2%), and shorter disintegration time (17.6?±?2.9 to 27.8?±?2.8 s). Films plasticized with xylitol showed shorter disintegration time (17.6?±?2.9 to 29.2?±?3.8 s) than films containing sorbitol (23.8?±?2.9 to 31.7?±?3.9 s). With the addition of superdisintegrant Kollidon® CL-F, a significant influence on disintegration time was not observed. The modified solvent casting method shows great promise in a small-scale laboratory production of orodispersible films, e.g., in a pharmacy lab.  相似文献   

18.
在打制石器中,软锤法能够更有效地控制石片形态,是古人类认知与技术水平提升的一个重要标志。传统认为,使用软锤法打下的石片具有打击泡散漫、台面处有唇等特征。随着针对性实验的开展,上述石片特征已经不再被认为仅是软锤剥片所致,而是打制过程中如打击角度、背缘角等诸多因素共同作用的结果,通过石片特征区分软、硬锤存在很大争议。本文旨在梳理学术界对软锤法的认知过程和系统实验历史。根据国际上大量的实验可知,目前的实验以燧石、黑曜石为主要石料,根据石片特征区分软、硬锤尚存在很大争议,石片特征的产生可能受锤的质地、石料、打制者、打击角度等多种因素的影响,因此,不宜仅凭个别石片特征判断遗址中存在软锤剥片。在对具体考古材料的技术分析中,需综合考量整个石器打制过程中涉及到的多种因素,有必要建立一个汇集实验数据与遗址出土石片相关特征的数据库,为打制技术与技法分析提供更为丰富的对比材料。  相似文献   

19.
Eighty-nine consecutive patients with suspected intracranial masses were examined by auscultatory percussion in a blind study to assess the sensitivity of the procedure. Each patient underwent computed tomography (CT) of the brain as part of his medical care, and the results were compared with those of auscultatory percussion. Fifty-one of the patients had abnormal CT scans, of whom 44 (86%) had abnormal (positive) findings on auscultatory percussion; seven (13%) yielded false-negative results. Each of the patients with subdural haematomas had distinctly positive findings by auscultatory percussion. Of the 38 patients with normal CT scans, 11 had strokes with hemiparesis, and each had positive findings in the contralateral hemisphere by auscultatory percussion. The remaining 27 patients with normal CT scans were healthy; 25 had normal findings on auscultatory percussion, two (7%) gave false-positive results. Twenty subjects were studied with phonoscopy. Auscultatory percussion is easy to perform and is clinically useful.  相似文献   

20.
In order to increase the availability of the cell bound protein in Scenedesmus algae, mechanical, enzymatic, and chemical methods of degrading the cell wall structure were investigated. Mechanical treatment involved the use of a ball-mill. The algae suspension together with glass beads was milled in a water-cooled chamber equipped with rotating disks. The enzyme tested was a cellulolytic enzyme (Meicelase) and the chemical employed was hydrogen peroxide. In the ball-mill experiments a complete disintegration was achieved ina disintegrator, working with batches. Trails wwere also performed with a continuous disintegrator and the depedence of disintegration on bead size and flow rate was studied. The disintegration determined by microscropic cell count was compared to the increase of the pepsin digestibility. The meicelase treatment caused a slight increase of the pepsin digestibility, as measured after 3 hr pepsin incubation. No increase of the pepsin disgestibility could be detected with hydrogen peroxide treatment. After the ball-mill disintegration 95% of contaminating bacteria were killed and yields of extractable proteins were higher. The capacity of availble continuous ball-mills is such that they could be used on a pilot-plant scale and the energy cost of disintegration would be of the same magnitude as that of separation.  相似文献   

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