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51.
A new variant design method of mechanical part is proposed based on extensible logic theory, to support design knowledge reuse more efficiently in computer aided conceptual design. In this method, matter-element, event-element and relation-element are used to characterize the feature information, connection constraint relations and topology variant operations of mechanical conceptual structures respectively. Extensible composite-element model of product part is established sequentially based on the above three basic-element models (matter-element, event-element and relation-element). Moreover, five types of variant operations are defined in order to realize structure variations and shape design of mechanical parts. Finally, an example of shaft housing part in grinder component is taken to explain the part variant design process in details, in which the efficiency and effectiveness of this method are illustrated simultaneously.  相似文献   
52.
We have investigated the resistive upper critical field (μ 0 H c2) of the iron-based superconductor SrFe2(As1?x P x )2 (x=0.35, T c~29 K) in pulsed high magnetic fields of up to 52 T. For Hab, $\mu_{0}H_{\mathrm{c}2}^{ab}(T)$ exhibits the Werthamer-Helfand-Hohenberg (WHH) like behavior. While, for Hc, $\mu_{0}H_{\mathrm {c}2}^{c}(T)$ is almost linear against T and exhibits a slightly upward curvature near T c. The anisotropy of μ 0 H c2 decreases from 2.5 near T c to ~1.2 at T=0 K monotonically. Similar isotropic behavior of μ 0 H c2 at low temperatures has also been observed in the Fe1+δ (Te,Se). We demonstrate the results of the two-band analysis for μ 0 H c2(T) on the present sample and discuss the anisotropy of μ 0 H c2 by comparing with those in some kinds of iron-based superconductors.  相似文献   
53.
Cutaneous sarcomas are uncommon tumors presenting many histological types. The diagnosis is based on pathological, immunohistochemical and sometimes ultrastructural studies. The development of cytogenetic and molecular analysis may constitute an additional aid to the diagnosis and classification. Prognosis and therapeutic strategies are established on the basis of various criteria using different types of staging and grading, but these classifications have not yet been standardized. The rarity of cutaneous sarcoma, and the diversity of clinical presentations account for the difficulties of management, which requires a multidisciplinary approach.  相似文献   
54.
Mutations in the transforming growth factor beta type II receptor (TGFbetaRII) gene have been detected in several human cancer types exhibiting microsatellite instability. Using intron primers previously reported for examination of the entire coding region of the TGFbetaRII gene, 29 sporadic gastric cancers were screened with non-radioactive single strand conformation polymorphism and subsequent DNA sequencing analysis. Mutations of the TGFbetaRII gene were detected in three out of 29 tumors (10%). Two cases showed deletions in a polyadenine tract in both alleles and was positively associated with replication error. One case had an insertion of GA dinucleotide sequence in one allele. Mutations of the TGFbetaRII gene were restricted to exon 3 and other coding regions were not affected. Loss of heterozygosity was detected by analyzing a polymorphic site in intron 2. Three out of nine (33%) informative cases, which were all of intestinal type and advanced cases, showed loss of heterozygosity but neither TGFbetaRII mutation nor replication error was found in these cases. Immunoreactivity of TGFbetaRII in tumor tissues was reduced to a different extent in the gastric cancer with genetically abnormal transforming growth factor. Although the numbers studied are small, homozygous (A)10 deletion or loss of heterozygosity of TGFbetaRII is involved in tumorigenesis and progression of at least some part of sporadic gastric cancer.  相似文献   
55.
56.
BACKGROUND/AIM: The outcome after hepatectomy and non-surgical treatment of liver metastases from gastric and colorectal malignancies are reported. METHODOLOGY: Between April 1988 and March 1994, 176 patients with metastatic liver cancer were treated at the First Department of Surgery, Kyoto Prefectural University of Medicine Hospital. RESULTS: All patients received multi-disciplinary treatment, and 51 underwent hepatectomy. The survival after hepatectomy for metastatic liver cancer from a colorectal primary was better than that for gastric cancer. The survival after hepatic arterial infusion (HAI) therapy for metastases from gastric cancer was better than that for colorectal cancer. CONCLUSION: Surgical resection may be the best treatment for liver metastases from colorectal cancer. HAI may be a better option for liver metastases from gastric cancer.  相似文献   
57.
In this study, we investigated the activation of p42 extracellular signal-regulated kinase (ERK2) during renal regeneration after HgCl2-induced acute renal failure (ARF) in rat. ERK2 activation was observed at 5 and 29 hr after HgCl2 injection, respectively. The tyrosine phosphorylation of hepatocyte growth factor receptor (c-MET) occurred between 2.5 and 5 hr after the treatment. On the other hand, the phosphorylation of epidermal growth factor receptor (EGFR) was transiently observed at 29 hr after the injection. The peak of ornithine decarboxylase activity as a marker of G1 phase was at 10 hr, and subsequently the labeling index of proliferating cell nuclear antigen as a marker of S phase increased at 53 hr. These results indicate that the repetitive activation of ERK2 related to the phosphorylation of c-MET and EGFR is required for the renal regeneration in HgCl2-induced ARF of rat.  相似文献   
58.
A case of phacomatosis pigmentovascularis (PPV) in a 6-year-old girl with Sturge-Weber syndrome, pyogenic granuloma, and other complications is described. It is relatively rare that a complete form of Sturge-Weber syndrome was associated with PPV. A review of the literature on PPV, focusing on total number of reported cases and etiological speculations, is presented. To our knowledge, a total of 118 cases of PPV, including the present one, have been reported to date. Regardless of many speculations, the true etiology remains unknown. The average "density" of mast cells (MCs) per mm2 appearing in the central region of the pyogenic granuloma was calculated to be 86.3/mm2 and that in the adjacent nevus flammeus was 37.9/mm2. The "density" of mast cells in pyogenic granuloma separately calculated from ten other cases was 105.5 +/- 28.6/mm2 (mean +/- SD), compared with that in normal skin, 6.85 +/- 4.9/mm2 (n = 20). There was a significant difference between the two, indicating that MCs are closely associated with angiogenesis in pyogenic granuloma.  相似文献   
59.
We measured the activity of mitogen-activated protein (MAP) kinases, enzymes believed to be involved in the pathway for cell proliferation, in rat aortic strips with or without endothelium, and examined effects of angiotensin receptor antagonists, endothelin receptor antagonists and nitric oxide (NO)-related agents. Endothelium removal produced an activation of MAP kinase activity in the strips, whereas the enzyme activity was not affected in the adventitia. The MAP kinase activation was inhibited by either the angiotensin AT1 receptor antagonist losartan or the endothelin ETA receptor antagonist BQ 123. The combination of both antagonists caused an additive inhibition. The angiotensin AT2 receptor antagonist PD 123,319 and the endothelin ETB receptor antagonist BQ 788 did not affect the MAP kinase activation. The NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) caused an activation of MAP kinase in the endothelium-intact aorta and the MAP kinase activation was inhibited by losartan or BQ123. The NO releaser nitroprusside inhibited the MAP kinase activation induced by endothelium removal or angiotensin II. These results suggest that even in isolated arteries, NO of endothelial origin tonically exert MAP kinase-inhibiting effects and endogenous angiotensin II and endothelins in the media are tonically released to cause MAP kinase-stimulating effects in medial smooth muscle.  相似文献   
60.
This study examines the effects of protein kinase inhibitors and activator on angiotensin II-induced DNA synthesis and protein synthesis of rat aortic smooth muscle cells. In quiescent confluent cells, angiotensin II induced a concentration-dependent increase in thymidine incorporation and leucine incorporation. The tyrosine kinase inhibitor genistein caused an inhibition of the angiotensin II-induced DNA synthesis but not of the agent-induced protein synthesis. The protein kinase C inhibitors staurosporine and calphostin C caused an inhibition of the angiotensin II-induced protein synthesis but not of the agent-induced DNA synthesis. The protein kinase C activator phorbol 12-myristate 13-acetate stimulated protein synthesis. Angiotensin II stimulated mitogen-activated protein (MAP) kinases and the angiotensin II-induced MAP kinase activation was inhibited by genistein but not by staurosporine. These findings suggest that angiotensin II-induced DNA synthesis is at least partly mediated via protein-tyrosine phosphorylation and angiotensin II-induced protein synthesis is at least partly mediated by activation of protein kinase C. It seems likely that MAP kinase activation is involved in DNA synthesis but not in protein synthesis induced by angiotensin II.  相似文献   
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