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排序方式: 共有850条查询结果,搜索用时 15 毫秒
91.
RP Dirks ST Van Genesen JJ KrUse L Jorissen NH Lubsen 《Canadian Metallurgical Quarterly》1998,66(2):267-269
A pregnant patient at 38 weeks' gestation developed symptoms of local anaesthetic toxicity following intravenous regional anaesthesia (IVRA) for hand surgery, using a standard dose of lignocaine. Reports suggest that a number of factors, both physiological and pharmacological, combine to increase the likelihood of local anaesthetic (LA) toxicity in pregnancy despite employment of a conventional "safe" IVRA technique. It is suggested that for IVRA, pregnant patients are premedicated with a benzodiazepine, the tourniquet time is increased and the concentration of LA is decreased to reduce the risks of LA toxicity. 相似文献
92.
Pattern Analysis and Applications - It is common to view people in real applications walking in arbitrary directions, holding items, or wearing heavy coats. These factors are challenges in... 相似文献
93.
Dung TH Lee SR Han SD Kim SJ Ju YM Kim MS Yoo H 《Journal of nanoscience and nanotechnology》2007,7(11):3695-3699
Antisense oligonucleotide loaded chitosan nanoparticles were prepared and the release of oligonucleotide from chitosan-TPP/oligonucleotide nanoparticles was investigated. Morphological property, zeta potential and particle size of the prepared chitosan/oligonucleotide nanoparticles were investigated using Field Emission-Scanning Electron Microscope (FE-SEM) and particle size analyzer. The interaction between chitosan and oligonucleotide was confirmed by using capillary zone electrophoresis (CZE), and the released oligonucleotides were determined by spectrophotometric method. Oligonucleotides formed the complexes with chitosan with a unique morphological property. The release of oligonucleotides from nanoparticles was dependent on loading methods and pH conditions. Chitosan/oligomer-TPP nanoparticles, which was prepared by adding TPP after the formation of chitosan/oligonucleotide complex, showed the lowest release percent of oligonucleotides with 41.3% at pH 7.0 among the loading methods. The percent release of oligonucleotide from oligonucleotide loaded chitosan nanoparticle at pH 10 was higher than the one in acidic condition (pH 5.0). The released oligonucleotides from chitosan/oligonucleotide nanoparticles were stable enough for 12 h under the 20% saliva solution. Our results suggest that the sustained release of oligonucleotide from chitosan nanoparticles may be suitable for the local therapeutic application in periodontal diseases. 相似文献
94.
NH Mendelson A Bourque K Wilkening KR Anderson JC Watkins 《Canadian Metallurgical Quarterly》1999,181(2):600-609
The swimming motions of cells within Bacillus subtilis colonies, as well as the associated fluid flows, were analyzed from video films produced during colony growth and expansion on wet agar surfaces. Individual cells in very wet dense populations moved at rates between 76 and 116 microm/s. Swimming cells were organized into patterns of whirls, each approximately 1,000 microm2, and jets of about 95 by 12 microm. Whirls and jets were short-lived, lasting only about 0.25 s. Patterns within given areas constantly repeated with a periodicity of approximately 1 s. Whirls of a given direction became disorganized and then re-formed, usually into whirls moving in the opposite direction. Pattern elements were also organized with respect to one another in the colony. Neighboring whirls usually turned in opposite directions. This correlation decreased as a function of distance between whirls. Fluid flows associated with whirls and jets were measured by observing the movement of marker latex spheres added to colonies. The average velocity of markers traveling in whirls was 19 microm/s, whereas those traveling in jets moved at 27 microm/s. The paths followed by markers were aligned with the direction of cell motion, suggesting that cells create flows moving with them into whirls and along jets. When colonies became dry, swimming motions ceased except in regions close to the periphery and in isolated islands where cells traveled in slow whirls at about 4 microm/s. The addition of water resulted in immediate though transient rapid swimming (> 80 microm/s) in characteristic whirl and jet patterns. The rate of swimming decreased to 13 microm/s within 2 min, however, as the water diffused into the agar. Organized swimming patterns were nevertheless preserved throughout this period. These findings show that cell swimming in colonies is highly organized. 相似文献
95.
96.
The radiation initiated grafting of N-vinylpyrrolidone (NVP) onto poly(tetrafluoroethylene–hexafluoropropylene–vinylidene fluoride) (TFB) films has been investigated using a direct radiation technique. Different solvents were used for diluting the monomer, and it was found that dioxane is suitable for this grafting system. The influence of other grafting parameters, such as inhibitor, monomer concentration and dose rate, on the rate and yield of grafting was studied. The dependence of the grafting rate on the monomer concentration was found to be of the 1.1 order. Some physicochemical properties, such as swelling, thermal behaviour, mechanical and electrical conductivity, were investigated. A study was made to gain a better understanding of the observed water uptake using IR spectroscopy and scanning electron microscope (SEM) analysis. The possibility of some practical uses, e.g. removal of heavy metals from solution by grafted membranes was investigated. © 1999 Society of Chemical Industry 相似文献
97.
Macrophages from lepromatous leprosy patients specifically show reduced protein synthesis in the presence of M. leprae. They also produce, as a result of interaction with M. leprae, factor(s) that reduce protein synthesis in normal macrophages as well as block lymphocyte transformation in normal leukocyte cultures in the presence of M. leprae as the antigen. These observations implicate a defective macrophage system in lepromatous leprosy patients. 相似文献
98.
The motion of a single, spherical particle, released at different radial positions at the inlet of the entrance region of a straight circular laminar flow tube (Re = 260), was studied theoretically. Radial migration of the particle, either toward the tube center or toward the tube wall, was predicted. Based on the hypothesis that the particle experienced a lift force which was produced by the vorticity in the boundary layer and a velocity difference between the center of the suspended particle and the fluid medium, an inertia-vorticity fluid dynamic model was formulated to analyze the particle radial motions. Computational flow dynamics (CFD) solutions obtained from a 9.8 mm diameter tube model included the resulting particle loci for three particle radii (a = 0.1 cm, 0.085 cm, 0.050 cm), with the particle entry at various radial positions. The computation also covered a range of different particle entry speeds. The results showed that the particle migrates toward the tube center if it lags behind the medium in the core region; otherwise, it migrates toward the tube wall. Additional flow experiments were conducted in a circular (2R = 10.2 mm), 300 mm long straight tube. A small polystyrene sphere (2a = 1.72 mm, density rho p = 1.014 g.cm-3) was released at the inlet (X = 0, eta/R = 0.48) with two dimesionless release velocities (omega p = 0, and omega p > 1.0). The recorded particle traces agree well with the computational model. 相似文献
99.
M Packer WS Colucci JD Sackner-Bernstein CS Liang DA Goldscher I Freeman ML Kukin V Kinhal JE Udelson M Klapholz SS Gottlieb D Pearle RJ Cody JJ Gregory NE Kantrowitz TH LeJemtel ST Young MA Lukas NH Shusterman 《Canadian Metallurgical Quarterly》1996,94(11):2793-2799
BACKGROUND: Carvedilol has improved the symptomatic status of patients with moderate to severe heart failure in single-center studies, but its clinical effects have not been evaluated in large, multicenter trials. METHODS AND RESULTS: We enrolled 278 patients with moderate to severe heart failure (6-minute walk distance, 150 to 450 m) and a left ventricular ejection fraction < or = 0.35 at 31 centers. After an open-label, run-in period, each patient was randomly assigned (double-blind) to either placebo (n = 145) or carvedilol (n = 133; target dose, 25 to 50 mg BID) for 6 months, while background therapy with digoxin, diuretics, and an ACE inhibitor remained constant. Compared with placebo, patients in the carvedilol group had a greater frequency of symptomatic improvement and lower risk of clinical deterioration, as evaluated by changes in the NYHA functional class (P = .014) or by a global assessment of progress judged either by the patient (P = .002) or by the physician (P < .001). In addition, treatment with carvedilol was associated with a significant increase in ejection fraction (P < .001) and a significant decrease in the combined risk of morbidity and mortality (P = .029). In contrast, carvedilol therapy had little effect on indirect measures of patient benefit, including changes in exercise tolerance or quality-of-life scores. The effects of the drug were similar in patients with ischemic heart disease or idiopathic dilated cardiomyopathy as the cause of heart failure. CONCLUSIONS: These findings indicate that, in addition to its favorable effects on survival, carvedilol produces important clinical benefits in patients with moderate to severe heart failure treated with digoxin, diuretics, and an ACE inhibitor. 相似文献
100.
Stroke in children is rare. No really good studies of the incidence are available, an estimate, however, is 2-3/100,000 children per year. In this paper we discuss the pathophysiology and the many different causes of stroke in children. In many of the cases more than one prothrombotic condition exists. If the cause is not obvious an extensive programme of examinations is recommended. This is important not only in order to give the best individual treatment, but also necessary in order to decide whether the stroke has a genetic cause. Initially, the treatment is symptomatic, attaching importance to achieving good perfusion of the cerebrum and lowering the energy consumption of the cerebrum. The rational treatment might be prompt reperfusion by thrombolytic medicine: this regime has been tried in adults, but as yet no consensus about this treatment modality exists. In some cases causal treatment is possible. If the stroke has a genetic cause genetic consultation is important and prenatal investigations might be possible. Overall, the mortality in stroke in children is about 25%. About 25% will live without any sequelae and approximately 50% of the children will disabled to a greater or lesser extent. 相似文献