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991.
992.
Blood flow is a critical parameter for obtaining satisfactory temperature distributions during clinical hyperthermia. This study examines the changes in blood flow distribution in normal porcine skeletal muscle before, during and after a period of regional microwave hyperthermia. The baseline blood flow distribution during general anaesthesia and after the insertion of the thermal probes was established independently in order to isolate the changes due to hyperthermia. General anaesthesia alone and thermocouple insertion during anesthesia had no significant effect on the muscle blood flow distribution. Regional microwave heating generated a non-uniform blood flow distribution which was a function of the tissue temperature distribution. Blood flow was greater in those tissues samples in which higher temperatures were recorded and less in those sampled further from the applicators peak SAR (Specific Absorption Rate). The increase in blood flow appears to be primarily a local phenomenon. Although muscle blood flow may be considered to be uniform prior to heating, this does not hold during hyperthermia treatment. Therefore, the non-uniform nature of the blood distribution during heating should be incorporated into any practical bioheat transfer model. 相似文献
993.
994.
E. M. Telles J. C. S. Moraes A. Scalabrin D. Pereira G. Carelli C. A. Massa A. Moretti F. Strumia 《Journal of Infrared, Millimeter and Terahertz Waves》1995,16(12):2233-2248
We used a Stark-Optoacoustic cell and hybrid waveguide resonators to perform an Infrared and Far Infrared Stark Spectroscopy study on some transitions of13CD3OH. Different behaviours of the transitions in the presence of a d.c. electric field were observed. The Stark splittings of six FIR laser lines ranging from 34 to 136 MHz/kVcm?1 were determined. The analysis of the behaviour of the IR and FIR transitions in the presence of the external electric fields gives important and exclusive information on the levels involved in the transitions. 相似文献
995.
996.
D Schmidt P Wischmeyer I Leuschner E Sprenger E Langenau D von Schweinitz D Harms 《Canadian Metallurgical Quarterly》1993,72(10):2914-2919
BACKGROUND: In several types of tumors, including hepatocellular carcinoma, prognosis could be correlated with DNA ploidy. Few studies have been performed on hepatoblastoma with contradictory results. METHODS: Twenty-nine cases of nonpretreated hepatoblastoma were studied with flow cytometry and image cytometry for DNA index and proliferation index using paraffin-embedded tissue. RESULTS: Twenty-three (79.9%) tumors were diploid, and 6 (20.7%) were aneuploid (hyperdiploid). Patients with diploid tumors were younger than those with aneuploid tumors. With regard to stage, diploid tumors were almost equally distributed among stages (tumor, lymph node metastases, distant metastases), whereas aneuploid tumors tended to occur in higher stages (tumor, lymph node metastases, distant metastases). Diploid tumors had clearly a better prognosis than aneuploid tumors, although the difference was not statistically significant (flow cytometry, P = 0.06; image cytometry, P = 0.16). A more favorable prognosis was also noted for hepatoblastomas with low-proliferation index (< or = 7%), but the difference from tumors with high-proliferation index (> 7%) again was not statistically significant (P = 0.16). CONCLUSIONS: Although no statistically significant differences in prognosis between hepatoblastomas with diploid and aneuploid DNA content, respectively, were found, there is a clear tendency that diploid hepatoblastomas behave more favorably. The same is true for hepatoblastomas with low-proliferation index. 相似文献
997.
998.
J. M. Kremer A. A. Shabana G. E. O. Widera 《International journal for numerical methods in engineering》1993,36(1):17-42
This investigation concerns itself with the computer implementation of the dynamic formulation of thin laminated composite plates consisting of layers of orthotropic laminae that undergo large arbitrary rigid body displacements and small elastic deformations. A finite element preprocessor computer program is developed to automatically generate the invariants of the laminae, which may have arbitrary orientations. The laminae invariants are then used to obtain the invariants of the elements and the composite laminated plate. The consistent and lumped mass formulations of the invariants of motion of composite plates are compared and it is concluded that the two methods are comparable, if a fine enough finite element mesh is used. The structure of the dynamic equations of motion, based on the formulation presented in Part I of this paper, is examined. Non-linear centrifugal and Coriolis forces arising as the result of the finite rotations of the laminae are defined, and the solution schemes of the resulting non-linear differential equations of motion are discussed. Numerical examples illustrating the differences between homogeneous isotropic and laminated composite plates are presented. An RSSR (Revolute-Spherical-Spherical-Revolute) mechanism is used in the numerical examples, with the coupler modelled as a laminated plate flexible body. It is found that the inertia of the plate contributed greatly to the transverse deformation. The effects of laminae orientation is also investigated. 相似文献
999.
Bladder psoas hitch is an surgical technique which, in very complicated cases, like repeated failures of vesico-ureteral re-implants or undiversions, allow us to bridge the shortness of the ureter and obtain a good vesico-ureteral reimplant. The surgical maneuver is described and several of the 11 cases operated by this technique are commented. The results are presented. 相似文献
1000.
OBJECTIVE: To compare the efficacy and toxicity of three patient-controlled analgesia (PCA) morphine regimens. DESIGN: A prospective, randomized, pilot study of three PCA morphine regimens: (1) 1 mg with 6-minute lockout (n = 10), (2) 2 mg with 12-minute lockout (n = 12), and (3) 2 mg with 20-minute lockout (n = 12). SETTING: Large teaching institution. PARTICIPANTS: Thirty-four patients undergoing cholecystectomy or hysterectomy. MAIN OUTCOME MEASURES: Pain scores (0 = no pain, 1 = mild pain, 2 = moderate pain, 3 = severe pain), sedation scores, analgesic consumption, and patient attempts (patient activation of PCA device) and injections (doses actually delivered) were evaluated using analysis of covariance. Distribution of pain and sedation scores and adverse effects were assessed using Fisher's exact test. RESULTS: Data on 24 patients were evaluable. Six patients withdrew for poor pain control (2 in group 1, 1 in group 2, and 3 in group 3). Three other patients withdrew because of adverse effects and 1 withdrew because of pump problems. Mean morphine consumption did not differ significantly among the groups. Distribution of pain and sedation scores and the number of patients with nausea were similar across treatment groups. The mean injection to attempt ratio was significantly smaller in group 3 (0.71 +/- 0.11) compared with groups 1 and 2 (0.9 +/- 0.06 and 0.83 +/- 0.09, respectively; p = 0.001). Adverse events occurred similarly among treatment groups. CONCLUSIONS: No significant differences in the efficacy or toxicity of the three morphine PCA regimens were identified. 相似文献