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991.
Nuclear magnetic resonance (NMR) proton density images of the human brain have been made by the FONAR method. Spin-lattice relaxation times, T1, of water hydrogen protons have been determined at random positions within frontal and temporal regions of the human brain. The primary purpose of this ongoing research is to accumulate a large data base of normal T1 values for water protons in normal human brain tissue. Our experience to data includes 31 measurements on 18 volunteer subjects, and the mean value ± standard deviation is 215 ± 42 msec. In addition, two metastatic lesions of the brain were studied and found to have T1 values longer than those for normal brain tissue. 相似文献
992.
Izumi M Tsuruta O Kajihara Y Yazawa S Yuasa H Hashimoto H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(10):3032-3038
5-Thio-L-fucose-containing trisaccharide H-type II was synthesized. The 3',4'-O-isopropylidene-2-azido-2-deoxylactoside derivative, which was prepared from lactose by azidonitration of lactal, was used as a starting material. By regio- and stereoselective 5-thio-L-fucosylation of the 6,6'-dibenzoate 5 with 5-thiofucosyl trichloroacetimidate 6 and subsequent deprotection gave the 5-thio-L-fucose-containing H-type II 1. Conformational analysis of the 5-thio-L-fucose-containing H-type II and the native H-type II was carried out through NOESY experiments. The observed NOE values between N-acetylglucosamine and galactose, and galactose and fucose were same for these two trisaccharides. However, NOE values between fucose and N-acetylglucosamine were significantly different. Binding of the 5-thio-L-fucose-containing H-type II to lectins and antibodies were in some case stronger and in some case weaker than those of the native trisaccharide. 相似文献
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995.
Alkaline phosphatase (ALP) was encapsulated in gellan-chitosan polyion complex (PIC) capsules using a convenient procedure. The recovery of ALP was about 50% when the capsules were prepared by dropping a solution of ALP and gellan mixture (ALP/gellan) into a chitosan solution. When p-nitrophenyl phosphate (p-NPP) and 5-bromo-4-chloro-3-indolyl phosphate (BCIP) were incubated with ALP/gellan-chitosan capsules as substrates for ALP, the transparent colorless capsules changed to yellow and blue, respectively. The encapsulation of ALP into the PIC capsules was also confirmed by SDS-PAGE and immunoblot analyses. The ALP and polypeptides of more than 30 kDa remained without release even after incubation at 4 degrees C for 14 d. The biochemical properties of the encapsulated ALP activity were similar to those of the intact enzyme. When the solution containing p-NPP was loaded on a column packed with ALP/gellan-chitosan capsules at 27 degrees C, approximately 75% of p-NPP was hydrolyzed by passing through the column. No significant leakage of ALP was observed during the procedure, indicating that the capsules were resistant to pressure in the chromatographic operation. Furthermore, 70% of the hydrolytic activity of the packed capsules remained after storage at 4 degrees C for one month. These results suggest that the polyion complex capsules could be useful materials for protein fixation without chemical modification. [Diagram: see text] Encapsulation of ALP into PIC capsules and the morphological changes seen in the absence of the ALP substrate and in the presence of p-NPP and BICP. 相似文献
996.
光电精确制导战术武器的发展 总被引:4,自引:0,他引:4
本文简述光电精确制导技术武器发展的基本特征,探讨新一代自动寻的精确制导战术武器发展的趋势和技术途径,分析精确制导战术武器的关键技术。 相似文献
997.
首次报道了应用PerfusionG蛋白亲和色谱法快速测定人体生长激素与抗体免疫反应活性和摩尔配比的方法。这一新方法与传统的免疫测试技术相比较,具有快速、易于自动化操作和低劳动强度的优点。 相似文献
998.
Two simple sample preparation methods for the speciation analysis of triphenyltin and butyltin compounds in marine biotissues, using tetramethylammonium hydroxide (TMAH) solubilization and enzymic hydrolysis, have been developed and compared with conventional acid digestion. Derivatization was carried out in situ using sodium tetraethylborate (NaBEt4) without prior separation of the analytes from the tissue matrix. Separation and detection was performed using capillary gas chromatography (GC) coupled to microwave-induced plasma atomic emission spectrometry (MIP AE) allowing detection limits of 2 ng g?1 (as tin) to be reached. The accuracy of the presented methods was demonstrated by the analysis of a fish reference material (NIES No. 11). the necessity for sample clean-up is discussed and examples of the analysis of mussel tissue are shown. 相似文献
999.
On MR lymphography, a new approach to the lung hilar and mediastinal nodes was developed in an animal model. Five rabbits were made to inhale iron colloid (cideferron) that was nebulized to aerosol. Two days after inhalation of the agent, the mediastinal lymph nodes decreased in signal on SE 2000/30 and SE 2000/60 images and proved to have iron on histological evaluation, whereas the popliteal nodes did not have any iron. Experimental results indicate that inhalational administration can deliver the agent to the pulmonary lymphatic system and has the potential of lung hilar and mediastinal MR lymphography. 相似文献
1000.