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1.
Mesophasic proliposomal system for levonorgestrel was developed and evaluated both in vitro and in vivo. The vesicles were mostly unilamellar, however, few vesicles were multilamellar which budded off spontaneously upon hydration. The release of drug from this system adhered to zero order kinetics. The effect of alcohols and volatile oils on transdermal flux was investigated. The flux was found to be the highest for alcohol, and followed by that for lemon oil. The in vivo studies indicate the requirement for a loading dose, since, a significant lag phase was observed before the therapeutic levels were reached. This system was, however, superior to the PEG-based ointment system which was employed as the control formulation. The results demonstrate the potential of proliposomal system for efficacious transdermal delivery of hydrophobic drugs.  相似文献   
2.
Bactericidal effect of the Nd:YAG laser in in vitro root canals   总被引:1,自引:0,他引:1  
The spatio-temporal patterns of neural activity evoked by electrical stimuli to the antennal nerve (AN) in male cockroach antennal lobes (ALs) in vivo were analyzed by optical imaging using a voltage-sensitive dye. The response pattern was initially a depolarization on the AN and subsequently a depolarization followed by a hyperpolarization on the whole area of macroglomerulus (MG) and a part of ordinary glomerulus (OG). It was suggested by the pharmacological results that the depolarizing responses on the AL consist of both a presynaptic response, representing synchronous compound action potentials from the AN, and a postsynaptic response, representing synchronous compound excitatory postsynaptic potentials and action potentials from neurites of AL neurons, and that the inhibitory responses of GABAergic local interneurons in the AN are different in time course from that in the AL.  相似文献   
3.
OBJECTIVE: The purpose of this study was to determine what factors beyond relevance influence a clinician's decision to choose to read one journal article over another in satisfying an information need. DESIGN: Seventeen health care providers were interviewed and then surveyed regarding the characteristics of key articles (those they would not want to miss). On a Likert scale, the clinicians graded forty-two characteristics for importance in the decision process. Relevance was assumed and not at issue. SETTING: The study took place in an academic health science center. SUBJECTS: The subjects were seventeen clinicians, all with patient care responsibilities. There were four internists, four surgeons, three family practitioners, three pediatricians, two psychiatrists, and one clinical psychologist. RESULTS: Factors beyond relevance that most often influenced the decision process pertained to methodological rigor, authors and their institutional affiliations, document types, and population studied. CONCLUSIONS: Among the clinicians surveyed, factors beyond topicality influenced judgments as to what constitutes an important article. The emphasis respondents gave to certain attributes is echoed in other published work and highlights the need for more intensive investigation of these non-subject indicators as search parameters. Improved searching capabilities might well lead to a significant reduction in the clinician's information overload.  相似文献   
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In renal cell carcinoma (RCC), single members of the Wnt/β-catenin signaling cascade were recently identified to contribute to cancer progression. However, the role of Wnt1, one of the key ligands in β-catenin regulation, is currently unknown in RCC. Therefore, alterations of the Wnt1/β-catenin axis in clear cell RCC (ccRCC) were examined with regard to clinicopathology, overall survival (OS) and cancer specific survival (CSS). Corresponding ccRCCs and benign renal tissue were analyzed in 278 patients for Wnt1 and β-catenin expression by immunohistochemistry in tissue microarrays. Expression scores, including intensity and percentage of stained cells, were compared between normal kidney and ccRCCs. Data was categorized according to mean expression scores and correlated to tumor and patients’ characteristics. Survival was analyzed according to the Kaplan-Meier and log-rank test. Univariable and multivariable Cox proportional hazard regression models were used to explore the independent prognostic value of Wnt1 and β-catenin. In ccRCCs, high Wnt1 was associated with increased tumor diameter, stage and vascular invasion (p ≤ 0.02). High membranous β-catenin was associated with advanced stage, vascular invasion and tumor necrosis (p ≤ 0.01). Higher diameter, stage, node involvement, grade, vascular invasion and sarcomatoid differentiation (p ≤ 0.01) were found in patients with high cytoplasmic β-catenin. Patients with a high cytoplasmic β-catenin had a significantly reduced OS (hazard ratio (HR) 1.75) and CSS (HR 2.26), which was not independently associated with OS and CSS after adjustment in the multivariable model. Increased ccRCC aggressiveness was reflected by an altered Wnt1/β-catenin signaling. Cytoplasmic β-catenin was identified as the most promising candidate associated with unfavorable clinicopathology and impaired survival. Nevertheless, the shift of membranous β-catenin to the cytoplasm with a subsequently increased nuclear expression, as shown for other malignancies, could not be demonstrated to be present in ccRCC.  相似文献   
6.
This work deals with the formulation of a three-dimensional crystallographic time-incremental lifetime rule for face-centered cubic (fcc) single crystals used for gas-turbine blade applications. The damage contribution rate of each slip system to the total damage is governed by the current values of the resolved shear stress and the slip rate on the corresponding slip system. The damage rule is combined with a crystallographic viscoplastic deformation model. For the nickel-base single-crystal superalloy CMSX4 at 950 °C, various strain- and stress-controlled uniaxial cyclic tests with and without hold-times can be described for different crystal orientations by one set of material parameters. For verification, simulation results for a single-crystal specimen with a notch have been compared with corresponding experimental results. The predicted lifetime is within the factor of two of the measured one.  相似文献   
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OBJECTIVE: To evaluate the prevalence of H. pylori antibodies in mentally and physically handicapped adults living together in a long-term care facility. METHODS: One hundred twenty-two institutionalized subjects from six living areas were compared to a normal representative Caucasian population obtained by random sampling from the urban population area of Melbourne. Serum samples from 1977 and 1989 from 122 subjects were tested for H. pylori antibody by an ELISA technique. The data were analyzed by Student's t test, chi 2 test and logistic regression. RESULTS: Ninety-two of the 122 subjects (75%) from whom sera was collected in 1989 were seropositive for H. pylori, compared with only 23% in age- and sex-matched control subjects (p < 0.0001). The prevalence of H. pylori antibodies in 1977 was 34% (42/122). Of the remaining 80 seronegative subjects, 51 (61.4%) converted to became positive in the 12-yr interval. The annual seroconversion rate was 7.4%, with an average of 4.25 newly positive subjects each year. The prevalence of H. pylori in 1989 was significantly higher than in 1977 after adjustment for age (odds ratio 2.39, 95% CI 1.1-5.3, p = 0.03). CONCLUSIONS: H. pylori antibodies are significantly more prevalent in institutionalized adults compared with controls from the general population. These data support the hypothesis that H. pylori is acquired by either fecal-oral or oral-oral transmission.  相似文献   
9.
Meteorological satellites provide a unique opportunity to obtain thermodynamic profiles in regions of the globe that do not have a dense meteorological upper-air station network, such as South America. Temperature and mixing ratio profiles were retrieved every hour with a spatial resolution of 10 km over South America from July 2007 to February 2009 using radiances from the Geostationary Operational Environmental Satellite 10 (GOES-10). The GOES-10 retrieval algorithm for thermodynamic profiles was developed by the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) in the USA, so some adjustments had to be made for its application on South America, such as the construction of a new covariance matrix. In this context, the scientific focus of this research was the construction of a new covariance matrix adapted to the meteorological conditions in South America. In addition, the algorithm results were validated by the use of the original and the new covariance matrices. The variables validated were air temperature, mixing ratio vertical profiles and total precipitable water (TPW). The data set used comprised a total of 1100 radiosonde observations recorded in the tropical region of South America at 00:00 and 12:00 Universal Time Clock (UTC), as well as thermodynamic profiles from 12 h forecasts from the Centre for Weather Forecast and Climate Studies's (CPTEC's) Global Model, used as a first guess, and upwelling radiances of 18 infrared channels from GOES-10 for the period from July to November 2007. In general, the results indicated that with the regionalization of the covariance matrix, the algorithm performed better retrievals than with that of the original matrix. The greatest improvements were found in the mixing ratio profiles and in the values of the TPW. These results could be associated with the presence of the Amazon rainforest, which incorporated a greater amount of moisture into the new covariance matrix than the previous had the previous one.  相似文献   
10.
The temperature dependence of the cyclic behavior of IN 738 LC was studied. Cyclic iso- and non-isothermal tests were performed with proportional and non-proportional tension/torsion strain paths. It was shown that maximum and minimum stress values measured in isothermal strain controlled tests correspond quite well with results of non-isothermal tests. Thermal-mechanical constitutive equations based on the viscoplastic Chaboche model were used to describe the non-isothermal stress-strain behavior.  相似文献   
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