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排序方式: 共有511条查询结果,搜索用时 929 毫秒
91.
CC Mourani SG Mallat MY Moukarzel CY Akatcherian P Cochat 《Canadian Metallurgical Quarterly》1998,12(9):709-711
Pseudotumor cerebri is a syndrome characterized by intracranial hypertension (intracranial pressure >200 mmH2O) and a normal ventricular system. The diagnosis should be made as early as possible to prevent impairment of vision. Several diseases have been reported in association with pseudotumor cerebri in pediatric patients, and have been occasionally also noted with chronic renal failure, heart and renal transplantation. We report a 7-year-old boy who complained of severe headaches and visual impairment 2 years after hemodialysis for renal hypoplasia. Pseudotumor cerebri was suspected and, despite treatment with corticosteroids, acetazolamide, and lumboperitoneal diversion, visual impairment worsened. Bilateral optic nerve sheath decompression (ONSD) was performed without success and the child completely lost his vision within 2 weeks. He was successfully transplanted 2 months later. Two years post transplantation, the blind child has a normal renal function and school performance. Pseudotumor cerebri must be rapidly suspected in a child with renal failure suffering from headaches and papilledema. Visual loss may progress rapidly and ONSD seems to be the best surgical treatment when medical treatment fails. In this patient renal transplantation was well tolerated, with no deterioration in the neurological status over 2 years of follow-up. 相似文献
92.
93.
Abstract The initiation and the propagation of fatigue cracks and the low cycle fatigue life of a cast cobalt base superalloy was studied at 293K, 973K and 1173K by optical and scanning electron microscopy. A substantial decrease in fatigue life occurred at 973 and 1173K when compared to room temperature life. A time-dependent bulk damage was evidenced at 1173K which was determined by quantitative microscopy for two plastic strain levels. High strain fatigue crack propagation experiments were carried out at room temperature and at 1173K. From these experiments the decrease of the overall fatigue life at high temperature was shown to result from a considerable reduction of the initiation period due to oxidation and also from a significant acceleration of the crack propagation rate in the presence of oxidation and bulk damage. 相似文献
94.
Sprague-Dawley rats received subcutaneous injections of 2,6-dimethylnitrosomorpholine (2,6-DMNM) at 3 different dose levels (1/5, 1/10 or 1/20 LD50) once weekly for life. Up to a 100% rate of tumors of the esophagus was detected in animals which received 1/10 and 1/20 LD50. In addition to tumors of this organ, neoplasms developed at different rates in the lungs and in the liver. 相似文献
95.
Risk of cancer in Finnish children living close to power lines 总被引:1,自引:0,他引:1
PK Verkasalo E Pukkala MY Hongisto JE Valjus PJ J?rvinen KV Heikkil? M Koskenvuo 《Canadian Metallurgical Quarterly》1993,307(6909):895-899
OBJECTIVE: To investigate the risk of cancer in children living close to overhead power lines with magnetic fields of > or = 0.01 microteslas (microT). DESIGN: Cohort study. SETTING: The whole of Finland. SUBJECTS: 68,300 boys and 66,500 girls aged 0-19 years living during 1970-89 within 500 m of overhead power lines of 110-400 kV in magnetic fields calculated to be > or = 0.01 microT. Subjects were identified by record linkages of nationwide registers. MAIN OUTCOME MEASURES: Numbers of observed cases in follow up for cancer and standardised incidence ratios for all cancers and particularly for nervous system tumours, leukaemia, and lymphoma. RESULTS: In the whole cohort 140 cases of cancer were observed (145 expected; standardised incidence ratio 0.97, 95% confidence interval 0.81 to 1.1). No statistically significant increases in all cancers and in leukaemia and lymphoma were found in children at any exposure level. A statistically significant excess of nervous system tumours was found in boys (but not in girls) who were exposed to magnetic fields of > or = 0.20 microT or cumulative exposure of > or = 0.40 microT years. CONCLUSIONS: Residentia magnetic fields of transmission power lines do not constitute a major public health problem regarding childhood cancer. The small numbers do not allow further conclusions about the risk of cancer in stronger magnetic fields. 相似文献
96.
97.
Although the correlation between fibromuscular dysplasia (FMD) and intracranial aneurysm is well established, the combination of FMD with a giant aneurysm is rare. This paper reports a patient with extracranial FMD associated with a giant intracavernous aneurysm compromising the trigeminal and abducens nerve. A review of the literature uncovered only four documented cases of FMD with concurrent giant intracranial aneurysms. The present case adds further weight to the argument for including FMD in the differential diagnosis list when confronted with a patient with a giant intracranial aneurysm. Absence of adequate collaterals in this patient eliminated ligation as a treatment strategy for the aneurysm. 相似文献
98.
Effects of natural blends of garlic and eucalypt essential oils on biogas production of four fibrous feeds at short‐term of incubation in the ruminal anaerobic biosystem
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99.
HM Xu WH Li N Hou SG Zhang HF Li SQ Wang ZY Yu ZJ Li MY Zeng GM Zhu 《Canadian Metallurgical Quarterly》1997,21(9):1013-1022
Thirty-two cases of so-called sclerosing hemangioma of the lung observed by light microscopy were further studied by electron microscopy and/or immunohistochemistry. Three histologic patterns were seen: hemangioma-like, papillary, and solid. The only significant component representing the nature of the lesion is characteristic round cells within the stroma in all these patterns, whereas the surface cells lining the papillary projections or cystic spaces are normal or are hyperplastic bronchioloalveolar cells with a few neuroendocrine cells. Immunohistochemical findings showed that the "stromal cells" (tumor cells) were positive for neuroendocrine markers, namely, chromogranin A (19 of 22 cases), neuron-specific enolase (24 of 24), synaptophysin (six of 10), adrenocorticotropic hormone (14 of 15), growth hormone (14 of 15), calcitonin (11 of 15), and gastrin (11 of 14). Besides, some tumor cells were positive for epithelial membrane antigen (four of four), carcinoembryonic antigen (one of four), and vimentin (one of one). All tumor cells were negative for polyclonal antikeratin antibody (25 cases), AE1 (one case), and AE3 (one case). However, in contrast to the "stromal cells," the surface cells of the cystic spaces stained positively for keratin (25 of 25 cases), AE1 (one of one), AE3 (one of one), epithelial membrance antigen (four of four), and carcinoembryonic antigen (four of four); only a few of them expressed neruoendocrine markers. Both surface and tumor cells were negative for factor VIII-related antigen (25 cases), CD31 (one case), and alpha1-antitrypsin (25 cases). Ten cases further studied by electron microscopy and six examined by ultrastructural morphometry showed that the surface cells were mainly type 2 pneumocytes containing many lamellar bodies in the cytoplasm. Lying among them, neuroendocrine cells were occasionally seen. The stromal tumor cells had no lamellar body, but dense core granules (neurosecretory granules) and microtubules. In six cases, 92.3% (345 of 374) of tumor cells contained neurosecretory granules, which were pleomorphic and 73 to 1056 nm in diameter (mean, 302 nm). Two to 193 (mean, 12) neurosecretory granules were found in each tumor cell. Both immunohistochemical findings and ultrastructural evidence indicate that so-called sclerosing hemangioma of the lung is a benign lesion composed of neoplastic neuroendocrine cells with areas of sclerosis. A suggested name for this tumor is benign neuroendocrine tumor of the lung. The differentiation between this tumor and papillary adenoma, bronchioloalveolar carcinoma, or carcinoid tumor of the lung is discussed. 相似文献
100.
EJ Lee YC Hung MY Lee JJ Yan YT Lee JH Chang GL Chang KC Chung 《Canadian Metallurgical Quarterly》1999,44(1):139-46; discussion 146-7
OBJECTIVE: This study was conducted to evaluate the kinematic response of late fusion results for cervical spine discectomies with and without bone grafting. MATERIALS AND METHODS: Fifteen Barbados Black Belly sheep underwent sham operations (Group A, n = 5), C2-C3 discectomies only (Group B, n = 5), and C2-C3 discectomies with autologous iliac bone grafting (Group C, n = 5). Ten months after surgery, the animals were killed. Fresh ligamentous spines (C1-C5) were subjected to the relevantly applied loads through a loading frame attached to the C1. Each vertebra (from C2 to C4) was attached with a set of three infrared light-emitting diodes to record the spatial location relating to each load application using a Selspot II system (Selcom Selective Electronics, Inc., Valdese, NC). The load-deformation data of the C2-C3 and C3-C4 motion segments were recorded and analyzed for the three groups. RESULTS: At the C2-C3 motion segment, the results indicated that Group B displayed larger motion ranges of rotation and lateral bending loads than did the other two groups. Significantly larger motion ranges of rotation loads were found in Group B than in Group C (P<0.05, for both comparisons). In contrast, Group C had the smallest motion ranges of flexion, lateral bending, and rotation loads. At the C3-C4 motion segment, both groups that had undergone discectomies had a significantly larger motion range of flexion load compared with Group A (P<0.05, for both comparisons). A significant increase in the motion range of right axial rotation was found in Group B (P<0.05), but not in Group C, compared with Group A. Group B exhibited larger motion ranges responding to all six tested loads than did Group C. CONCLUSION: The results indicate that anterior fusion after C2-C3 cervical discectomies, regardless of the presence or absence of bone grafting, decreases the motion range of flexion load at the C2-C3 motion segment, and contrary data were seen at the C3-C4 motion segment. For axial rotation loads, discectomies without bone grafting resulted in increased motion ranges of both C2-C3 and C3-C4 motion segments whereas discectomies with bone grafting did not. The data may have clinical relevance regarding the role of bone grafting in cases of cervical spine disease. 相似文献