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31.
Josef Pitha Stefan Zawadzki Barbara A. Hughes 《Macromolecular chemistry and physics.》1982,183(4):781-788
Copolymerization of acrylamide with allyl glycidyl ether yielded water soluble polymers containing an epoxy group; addition of a crosslinking agent, N,N′-methylenebis(acrylamide), to the copolymerization mixtures resulted in the formation of similar though water insoluble polymers. Condensation of a potent beta-adrenergic antagonist Alm? H, which contains a reactive amino group, with a polymer containing an epoxy group yeilded a pharmacologically active polymer. The polymer containing the epoxy group was also converted, by reaction with sodium thiosulfate and subsequent reduction, into a mecapto groups containing polymer which was also water soluble. The latter polymer was converted by condensation with a beta-adrenergic antagonist Alm? COCH2Br, which contains a reactive bromoacetamido group, into a pharmacologically active polymer. 相似文献
32.
33.
Dr. Josef Schramek Dr. Paul Hegedüs 《Journal of molecular medicine (Berlin, Germany)》1935,14(7):237-238
Ohne Zusammenfassung 相似文献
34.
Fast implementation of the single scatter simulation algorithm and its use in iterative image reconstruction of PET data 总被引:1,自引:0,他引:1
In positron emission tomography (PET), scatter correction is usually performed prior to image reconstruction using a more or less exact model of the scatter processes. These models require estimates of the true activity and object density distributions of the imaged object. The problem is that these estimates are computed from measured data and, therefore, already contain scattered events. The purpose of this work was to overcome this problem by incorporating scatter characteristics directly into the process of iterative image reconstruction. This could be achieved by an optimized implementation of the single scatter simulation (SSS) algorithm, which results in a significant speed-up of the scatter estimation procedure. The scatter simulation was then included in the forward projection step of maximum likelihood image reconstruction. The results demonstrate that this approach leads to a more exact estimation of the scatter component which cannot be obtained by a simple sequential data processing strategy. 相似文献
35.
Ferrer I Kapfhammer JP Hindelang C Kemp S Troffer-Charlier N Broccoli V Callyzot N Mooyer P Selhorst J Vreken P Wanders RJ Mandel JL Pujol A 《Human molecular genetics》2005,14(23):3565-3577
ATP-binding cassette (ABC) transporters facilitate unidirectional translocation of chemically diverse substances, ranging from peptides to lipids, across cell or organelle membranes. In peroxisomes, a subfamily of four ABC transporters (ABCD1 to ABCD4) has been related to fatty acid transport, because patients with mutations in ABCD1 (ALD gene) suffer from X-linked adrenoleukodystrophy (X-ALD), a disease characterized by an accumulation of very-long-chain fatty acids (VLCFAs). Inactivation in the mouse of the abcd1 gene leads to a late-onset neurodegenerative condition, comparable to the late-onset form of X-ALD [Pujol, A., Hindelang, C., Callizot, N., Bartsch, U., Schachner, M. and Mandel, J.L. (2002) Late onset neurological phenotype of the X-ALD gene inactivation in mice: a mouse model for adrenomyeloneuropathy. Hum. Mol. Genet., 11, 499-505.]. In the present work, we have generated and characterized a mouse deficient for abcd2, the closest paralog to abcd1. The main pathological feature in abcd2-/- mice is a late-onset cerebellar and sensory ataxia, with loss of cerebellar Purkinje cells and dorsal root ganglia cell degeneration, correlating with accumulation of VLCFAs in the latter cellular population. Axonal degeneration was present in dorsal and ventral columns in spinal cord. We have identified mitochondrial, Golgi and endoplasmic reticulum damage as the underlying pathological mechanism, thus providing evidence of a disturbed organelle cross-talk, which may be at the origin of the pathological cascade. 相似文献
36.
Bukac J 《Acta medica (Hradec Králové). Supplementum Universitas Carolina, Facultas Medica Hradec Králové》2004,47(2):123-124
We prefer to use a spreadsheet program when teaching statistics. We have written several programs to cover the methods students use. The input data are typed in the spreadsheet MS Excel, we mark the data, and the program creates an output table. The outputs are both in Czech and English, they contain the basic results useful for students, various alternatives, test criteria, acceptance regions, and p-values. Since the programs are user-friendly, they make it easier on students. 相似文献
37.
Two inbred strains of rats, derived from the Roman High Avoidance and Roman Low Avoidance selection lines, were tested for performance on the two-way active avoidance task which had been used during selection. Both inbred strains rapidly acquired the avoidance response and showed nearly perfect avoidance from trial 40 through trial 50. Probably, genes responsible for the low avoidance performance in the RLA strain disappeared during inbreeding. 相似文献
38.
Human defensins 总被引:7,自引:0,他引:7
Schneider JJ Unholzer A Schaller M Schäfer-Korting M Korting HC 《Journal of molecular medicine (Berlin, Germany)》2005,83(8):587-595
Antimicrobial peptides are small, cationic, amphiphilic peptides of 12–50 amino acids with microbicidal activity against both bacteria and fungi. The eukaryotic antimicrobial peptides may be divided into four distinct groups according to their structural features: cysteine-free -helices, extended cysteine-free -helices with a predominance of one or two amino acids, loop structures with one intramolecular disulfide bond, and -sheet structures which are stabilised by two or three intramolecular disulfide bonds. Mammalian defensins are part of the last-mentioned group. The mammalian defensins can be subdivided into three main classes according to their structural differences: the -defensins, -defensins and the recently described -defensins. Mammalian -defensins are predominantly found in neutrophils and in small intestinal Paneth cells, whereas mammalian -defensins have been isolated from both leukocytes and epithelial cells. Recently, two novel human -defensins, human beta-defensin-3 (HBD-3), and human beta-defensin-4 (HBD-4) have been discovered. Similar to HBD-1 and HBD-2, HBD-3 has microbicidal activity towards the Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli) and the yeasts Candida albicans and Malassezia furfur. In addition, HBD-3 kills Gram-positive bacteria such as Streptococcus pyogenes or Staphylococcus aureus, including multi-resistant S. aureus strains, and even vancomycin-resistant Enterococcus faecium. In contrast to HBD-1 and HBD-2, significant expression of HBD-3 has been demonstrated in non-epithelial tissues, such as leukocytes, heart and skeletal muscle. HBD-4 is expressed in certain epithelia and in neutrophils. Its bactericidal activity against P. aeruginosa is stronger than that of the other known -defensins. Here we present an overview of human antimicrobial peptides with some emphasis on their antifungal properties.J.J. Schneider and A. Unholzer contributed equally to this work 相似文献
39.
Manfred Heckmann Franz Parzefall Josef Dudel 《Pflügers Archiv : European journal of physiology》1996,432(6):1023-1029
Outside-out patches from wild-type Drosophila larval muscle were exposed briefly to L-Glutamate (Glu) using a piezo-driven application system. Glu in concentrations of 0.1 to 30 mM was applied and the responses to repeated applications of a given concentration were averaged. The peak current, î, and the current rise time, tr, from 0.1 î to 0.9 î were determined from the averages. Half-maximum activation of the channels was reached with ≈ 2 mM Glu. î increased proportional to the power n = 3.5 to n = 5.8 (average of four experiments, n = 4.4) for Glu concentrations between 0.3 and 0.5 mM. tr increased from ≈ 0.2 ms at 10 mM Glu to a value of ≈ 3.5 ms at 0.2 mM Glu. A linear reaction scheme with five binding steps preceding the channel-opening conformational change is proposed as the kinetic mechanism of channel activation and investigated in computer simulations. A set of rate constants assuming the same affinity for each binding site is found to describe the data better than one assuming positive cooperativity. The results are very similar to those for Glu-gated channels of crayfish and locust muscle, which is evidence for a common kinetic mechanism of these channels. 相似文献
40.