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The objective of this study was a validation of an optical multiple indicator dilution technique for measuring microvascular exchange parameters in edematous lungs by comparison to conventional radioisotope multiple indicator dilution methods. Six anesthetized dogs were studied at baseline and after alloxan infusion to increase capillary permeability. In addition, 11 isolated, perfused dog lungs were studied at baseline and after edema was created by increasing venous pressure or by infusing alloxan to increase vascular permeability. Increased capillary permeability from alloxan infusion led to increases in most but not all capillary exchange parameters as analyzed by mathematical models and measured by both optical and radioisotope methods. Increased vascular pressure led to increased edema but no significant increases in capillary exchange parameters. Two-way analysis of variance (ANOVA; variations in baseline versus pressure or alloxan and variation in optical versus radioisotope for each transport parameter derived from the mathematical models) indicated few significant differences in capillary exchange parameters between optical and radioisotope measures. Newman-Keuls multiple comparison tests did uncover some variations between a few of the group-mean values derived from optical and radioisotope methods. However, optical and radioisotope parameter measurements were highly correlated for all studies regardless of the mathematical model used for analysis.  相似文献   

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While being shipped to a laboratory, impressions can be exposed to excessive temperatures. This study compared the effects of different time and temperature storage conditions, including temperature extremes of 66 C and -10 C, on the accuracy of addition silicone and polyether impressions. The greatest distortion generally occurred as a result of the 66 C temperature extreme. The authors recommend that impressions be poured in stone according to manufacturers' specifications before being shipped to a dental laboratory.  相似文献   

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BACKGROUND: Case studies from Project IMPROVE, the first randomized controlled trial to evaluate the effectiveness of continuous quality improvement (CQI) in primary care, were subjected to a qualitative analysis. Three questions were addressed: How does change in the health care environment affect a quality improvement (QI) process? How does clinic organization influence a QI process? and What is the impact of a QI process on clinic organization? METHOD: Case studies were conducted in 6 clinics that had been randomly selected from the 22 clinics participating in the IMPROVE intervention. The case study data consisted of observations of CQI team meetings, open-ended interviews with 30 informants (team members plus others in the clinics), interviews with IMPROVE consultants, and documentation from the project. The data were analyzed to identify themes and generate concepts, assess and compare the informants' experiences, and develop a conceptual framework stimulated by research and theory literature. RESULTS: Change and uncertainty in the health care environment both complicated the QI process and motivated participation in improvement. The smaller clinics appeared to have more difficulty with the QI process because of limited resources and lack of compatibility between the QI approach and their clinic organization. Project IMPROVE had two qualitative effects on clinics: increased awareness of preventive services and application of the CQI method to other problems and issues. CONCLUSION: QI initiatives can help clinics adapt to a changing health care environment and create functioning teams or groups that can address a variety of organization problems and tasks. The process should be flexible to accommodate varying organization structures and cultures.  相似文献   

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In recent decades,the demand for cold-rolled steel sheets has remarkably increased. To prevent the sheets from rusting before the manufacturing process,a layer of rust-preventive oil has to be coated on the sheets. In this study,the shipment and storage environments were simulated through a salt spray test and a damp-heat experiment,respectively,and the packaging status of the sheets was imitated by a laminated sheet test. The protection effect of oil on the steel sheet was investigated under the different environmental conditions and oil weights by using electrochemical approaches,scanning electron microscopy( SEM),and X-ray diffraction( XRD) techniques. It was found that chloride ions had more severe effects on the corrosion resistance of the oils than hydrothermal conditions did. This was shown in the sheets with oil weights of 0. 4,0. 9,and 1. 2 g·m~(-2),which were too severely corroded after a four-hour salt spraying test to meet the demands of subsequent processing. However,the sheets showed satisfactory corrosion resistance after a three-week damp-heat experiment with a temperature of 49 ℃ and 95% RH. In addition,it was disclosed that the penetration of the chloride ions determined the protection mechanism of the oil,i. e.,the corrosion resistance was initially enhanced by the increase in the oil content. As long as the chloride ion reached the interface between the oil film and the sheet,the oil distribution became the predominant factor in the protection of the sheet. The corrosion mechanism of the steel sheet was dependent on the stacking style of the sample. When exposed to air,the corrosion product of the sample was rust red with a composition of Fe_2O_3,whereas the black product that is mainly composed of Fe_3O_4 was found on the edge of the laminated sheets,which resulted from the oxygen concentration cell.  相似文献   

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The existence of autonomous system of the biliary ducts local immunity was established. The contents of the antibodies and C3-component complement in intraductal bile in patients with purulent cholangitis (PC) is normalizing during an early postoperative period. In a common biliary duct bile while PC a polymorphonuclear neutrophils are regularly revealed, which restore nitroblue tetrazolium (NBT) diffusely. The NBT test application in PC diagnosis is substantiated.  相似文献   

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We examined the effect of L-dihydroxyphenylalanine (L-DOPA) infusion in vitro upon dopamine (DA) and dihydroxyphenylacetic acid (DOPAC) output from superfused corpus striatum of vehicle and reserpine or tetrabenazine (TBZ) treated male rats. Specifically, we tested the effects of two 20-min infusions of L-DOPA (5 uM) upon DA and DOPAC output (pg/mg/min) in reserpine (5 mg/kg, i.p., 24 hours before sacrifice; n=11), TBZ (30 mg/kg, i.p. 1 hour before sacrifice; n=8) or vehicle (n=21) treated rats. There was an overall significantly higher L-DOPA evoked DA output from the vehicle (12.22+/-1.74) versus reserpine (4.39+/-2.40) (p < 0.05), but not TBZ (9.16+/-2.81) treated rats. In addition, the DA response to the second L-DOPA infusion was significantly increased over that of the first response in the vehicle (9.40+/-2.11 vs. 15.04+/-2.78) (p < 0.05), but not reserpine or TBZ treated rats. The overall DOPAC outputs did not achieve a statistically significant difference among all treatment groups. However, the DOPAC outputs following the second L-DOPA infusion were significantly reduced in reserpine (41.15+/-6.10 vs. 20.27+/-4.54) and TBZ (21.38+/-4.41 vs. 10.87+/-2.36) (both p < 0.05), but not vehicle (28.99+/-4.00 vs. 24.91+/-4.78) treated rats. We conclude that: 1) the storage capacity of DA neurons is one of the important elements involved in affecting L-DOPA's effects upon DA and DOPAC output, 2) the shunting of storage to metabolism may represent a common characteristic in impaired nigrostriatal dopaminergic system, and 3) TBZ may operate differently from reserpine in the nigrostriatal dopaminergic system.  相似文献   

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The main points of a workshop on the place of clinical trials in the memory clinics in France are reproduced schematically. The efficiency of these centres has been tested at the time of the numerous clinical trials performed in France on Alzheimer's disease. In parallel, several difficulties have been pointed out: inhomogeneity of the technical approaches, official role of psychologists in the hospital teams, integration of clinical research to individual care. A particular effort should be oriented towards specific research on the different types of dementia, on early stages, on information for both media and authorities as well as on specific technical and methodological problems.  相似文献   

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Treponema pallidum DNA from even small numbers of organisms was detectable in cerebrospinal fluid (CSF) stored at room temperature or at 4 degrees C for several hours and in CSF subjected to three freeze-thaw cycles. These results suggest that negative PCR results for T. pallidum from patients diagnosed with T. pallidum invasion of the central nervous system are probably not due to the loss of target DNA prior to testing.  相似文献   

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One goal of nursing has always been to improve the quality of health care. This goal has resulted in myriad attempts to evaluate both nurses and nursing care, determine outcomes and goals, establish criteria, and develop measurement tools. Since Derryberry first documented the evaluation of nursing care in 1939, evaluations have focused on the provider, the consumer, the outcomes, and the process of providing care; but all have had as their central purpose the benefit of the client through the improvement of health care. The importance of quality assurance is reflected not only in nursing literature, but also in the recent development of PSROs, Medicaid/Medicare regulations, certification, and mandatory continuing education for health professionals. At the 1978 American Nurses' Association Convention, the House of Delegates pledged "to work aggressively on improving the quality of health care, and that of nursing care in particular, through peer review."  相似文献   

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Methacholine chloride solutions, routinely used for testing bronchial hyperreactivity, have been shown to degrade over time. The data published addressing the optimal conditions for methacholine chloride storage are conflicting and incomplete. This study investigated the effects of a variety of conditions on the stability of methacholine chloride. Methacholine chloride, dissolved in phosphate buffered saline (PBS) or sodium chloride (NaCl) at 50 and 0.39 g x L(-1), was subjected to various light and temperature conditions for 9 months. Methacholine chloride degradation was determined by high performance liquid chromatography, and all solutions underwent bacterial and pH testing. By 9 months, all 50 g x L(-1) solutions of methacholine chloride had degraded by 65+/-0.8%. All 0.39 g x L(-1) solutions in NaCl had degraded by 11.0+/-0.33%. The 0.39 g x L(-1) solutions in PBS which had been frozen, refrigerated or stored at room temperature had degraded by 8.0%, 16.0+/-0.3% and 63.8+/-0.5%, respectively. The pH of methacholine chloride was 7.2 in PBS at 0.39 g x L(-1), 5.8 in PBS at 50 g x L(-1), 3.9 in NaCl at 0.39 and 2.7 in NaCl at 50 g x L(-1). Bacterial contamination was minimal. The results of this study demonstrate that methacholine chloride is more stable at the higher concentration. However, the pH of the more concentrated solutions of methacholine chloride in sodium chloride could cause bronchoconstriction in some subjects. We therefore recommend storing methacholine chloride at 50 g x L(-1) in phosphate-buffered saline.  相似文献   

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The normal flora is typified by the yeast-like fungi Malassezia (Pityrosporum). Successful attempts at treating patients with atopic and seborreic dermatitis, pityriasis versicolor, and psoriasis with antifungicides confirm the involvement of these fungi in the etiology and development of these diseases. In patients with various skin diseases, an immune response to M. furfur is specific. In those with psoriasis, it is characterized by the higher chemoatractant activity of polymorphonuclear leukocytes stimulated by a M. furfur extract and by the immune response of IgG antibodies with immunoreactive proteins having a molecular weight of 100-120 kD. Patients with atopic dermatitis show a hyperimmune IgE-mediated response to M. furfur, with its specific Th2-lymphocytes inducing the atopic cytokines (IL-4, IL-10) that stimulate allergic reactions to other allergens. Those with pityriasis versicolor had impaired keratinocytic pigment exchange due to azelainic acid produced by M. furfur. The cause of transformation of the yeast phase of M. furfur to the mycelial one is presumably to be changes in the composition of fatty acids of the sebaceous glands due to increased androgen concentrations.  相似文献   

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