全文获取类型
收费全文 | 763篇 |
免费 | 0篇 |
专业分类
化学工业 | 8篇 |
金属工艺 | 1篇 |
机械仪表 | 3篇 |
建筑科学 | 1篇 |
石油天然气 | 1篇 |
无线电 | 9篇 |
一般工业技术 | 3篇 |
冶金工业 | 732篇 |
自动化技术 | 5篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2016年 | 3篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2008年 | 1篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1999年 | 27篇 |
1998年 | 246篇 |
1997年 | 120篇 |
1996年 | 80篇 |
1995年 | 52篇 |
1994年 | 37篇 |
1993年 | 38篇 |
1992年 | 8篇 |
1991年 | 13篇 |
1990年 | 14篇 |
1989年 | 11篇 |
1988年 | 7篇 |
1987年 | 11篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1978年 | 1篇 |
1977年 | 10篇 |
1976年 | 33篇 |
1975年 | 1篇 |
排序方式: 共有763条查询结果,搜索用时 15 毫秒
71.
M Carrier TK Leung BC Solymoss R Cartier Y Leclerc LC Pelletier 《Canadian Metallurgical Quarterly》1996,61(5):1310-4; discussion 1314-5
BACKGROUND: A prospective, randomized clinical study involving 34 patients undergoing heart transplantation compared myocardial preservation of donor hearts maintained with continuous reperfusion with retrograde warm blood cardioplegia during surgical implantation versus the standard cold topical irrigation. METHODS: Hearts in both groups were arrested with a standard crystalloid solution and maintained in a cold saline solution during transportation. In the retrograde group, cardioplegia was administered through a catheter in the coronary sinus during surgical implantation. An average of 471 +/- 30 mL of hyperkalemic crystalloid solution diluted 1:4 in warm blood from the oxygenator was infused. In the standard group, the heart was kept cold by topical irrigation of cold saline solution and was reperfused only when the ascending aorta was unclamped. RESULTS: Preoperative characteristics of donors and recipients were similar in the two cohorts. Ischemic time average 139 +/- 12 minutes in the retrograde group compared with 130 +/- 11 minutes in the standard group (p = 0.57). Cardiopulmonary bypass time averaged 89 +/- 4 minutes in the retrograde group and 110 +/- 12 minutes in the standard group (p = 0.12). Defibrillation at reperfusion was performed in 4 patients (4/17, 24%) in the retrograde group and 12 patients (12/18, 67%) in the standard group (p = 0.01). There were no deaths in the retrograde group (0/17), whereas in the standard group, 3 patients (3/17) died of early graft failure (p = 0.11). Four early graft failures occurred in the standard group (p = 0.06). Two patients (2/17, 12%) were weaned from bypass with ventricular assist devices in the standard group. The number of subendocardial necrotic cells in the first two weekly endomyocardial biopsy specimens averaged 2.7 +/- 0.8 cells/mm2 in the retrograde group and 5.9 +/- 2.4 cells/mm2 in the standard group (p = 0.12). CONCLUSIONS: Retrograde warm blood reperfusion appears to improve the initial recovery of transplanted hearts. The technique is easy to use and may be a useful approach to graft protection during surgical implantation. 相似文献
72.
The aim of this study was to assess the translational value of the quantitative assay of mutant p53 protein expression as both a prognostic indicator and a tool to determine appropriate therapy in a group of relatively innocuous and morphologically similar soft tissue sarcomas (STSs). Using a quantitative ELISA, we analyzed mutant p53 protein expression in 47 well-differentiated (grade I) STSs from patients treated in our Department of Surgical Oncology. Sixteen of 47 tumors expressed up to 42.6 ng mutant p53 protein/mg total protein. After a mean follow-up of 112 months, 63% of the patients with mutant p53+ tumors but only 16% of the patients with mutant p53- tumors had died (P < 0.01). Mutant p53 expression of >/=4.5 ng predicted even greater reduction in survival. These data show that mutant p53 expression identifies biologically aggressive grade I STSs. This molecular marker should have translational value as a tool to select those patients likely to benefit from aggressive multimodal therapy and intense surveillance. 相似文献
73.
KR Pollard TK Lewellen MS Kaplan DR Haynor RS Miyaoka JF Eary LD Durack 《Canadian Metallurgical Quarterly》1996,37(12):2030-2037
The use of high-dose 131I antibody therapy requires accurate measurement of normal tissue uptake to optimize the therapeutic dose. One of the factors limiting the accuracy of such measurements is scatter and collimator septal penetration. This study evaluated two classes of energy-based scatter corrections for quantitative 131I imaging: window-based and spectrum-fitting. METHODS: The window-based approaches estimate scatter from data in two or three energy windows placed on either side of the 364-keV photopeak using empirical weighting factors. A set of images from spheres in an elliptical phantom were used to evaluate each of the window-based corrections. The spectrum-fitting technique estimates detected scatter at each pixel by fitting the observed energy spectrum with a function that models the photopeak and scatter, and which incorporates the response function of the camera. This technique was evaluated using a set of Rollo phantom images. RESULTS: All of the window-based methods performed significantly better than a single photopeak window (338-389 keV), but the weighting factors were found to depend on the object being imaged. For images contaminated with scatter, the spectrum-fitting method significantly improved quantitation over photopeak windowing. Little difference, however, between any of the methods was observed for images containing small amounts of scatter. CONCLUSION: Most clinical 131I imaging protocols will benefit from qualitative and quantitative improvements provided by the spectrum-fitting scatter correction. The technique offers the practical advantage that it does not require phantom-based calibrations. Finally, our results suggest that septal penetration and scatter in the collimator and other detector-head components are important sources of error in quantitative 131I images. 相似文献
74.
AP Ivanov TK Dzagurova AE Dekonenko PM Baranovski? VI Shervarli EA Tkachenko 《Canadian Metallurgical Quarterly》1996,41(6):263-265
Enzyme immunoassay with biotin-labeled monoclonal antibodies to Puumala virus was used for typing hantavirus antigens. The system is type-specific, that is, it detects Puumala virus only, which was demonstrated by typing 9 hantavirus antigens in infected Vero E5 cells and by epizootological analysis of an HFRS outbreak in the Yegoryevsk district of the Moscow region in November-December 1995. The suggested system may be used as an element of EIA screening of natural samples in analysis of the screening results. 相似文献
75.
Looking for a coronary artery restenosis model closer to human pathology, a protocol of balloon injury/reinjury (plaque of dilatation) in swine coronary artery was designed. Pig coronary arteries (n = 24) were dilated for this study: 12, group 1, once (sacrifice at 10.0 +/- 2.2 weeks); 6, group 2, twice at 2-wk intervals (sacrifice at 5.2 +/- 0.2 wk); 6, group 3, twice at 4-wk intervals (sacrifice at 9.3 +/- 1.9 wk). A single overdilatation resulted in an eccentric neointimal hyperplasia representing half of the wall area (group 1, 45.6 +/- 5.1%). In animals (groups 2 and 3) subjected to redilatation, fracture length, ratio of fracture length to internal elastic lamina (IEL) circumference, and neointimal hyperplasia response were similar to those observed in group 1. In group 3, the shape of the lesion appeared more concentric and the fracture of the IEL more fragmented than in group 1. Although this model of injury/reinjury did not lead to more severe intimal hyperplasia, performing a second angioplasty at the same site did lead to a more concentric intimal response, related to multiple fractures of the IEL. 相似文献
76.
L Cohen FR Hendrickson AJ Lennox TK Kroc MA Hatcher BR Bennett 《Canadian Metallurgical Quarterly》1996,200(3):627-630
PURPOSE: To evaluate neutron irradiation alone and with chemotherapy to treat inoperable pancreatic cancer. MATERIALS AND METHODS: Between 1977 and 1994, 173 patients (60 men, 113 women, aged 43-77 years [mean, 59 years]) with unresectable adenocarcinoma of the exocrine pancreas were treated, 106 with neutron irradiation alone and 67 with concomitant chemotherapy (fluorouracil [5-FU]). At follow-up, which was performed at 2-month intervals until death (range, 4-64 months), clinical status was recorded, noting the presence of overt metastasis and the onset of any major complications. Actuarial (Kaplan-Meier) survival tables were computed for both groups. RESULTS: For neutron irradiation alone and neutron irradiation plus chemotherapy, median survival times were 6 months and 9 months, respectively; actuarial survival rates at 3 years were 0 and 7%, respectively; major reactions (grade 3 or higher [scale of the Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer]) occurred in 19 (18%) and 17 (25%) patients, respectively; and severe complications (grade 4) occurred in five (5%) and four (6%) patients, respectively. Most deaths were due to metastatic disease rather than to failure of local control. CONCLUSIONS: Neutron irradiation obliterated pancreatic adenocarcinoma at the primary site but has no effect on long-term survival. With more effective concomitant chemotherapy to prevent metastasis, local control of pancreatic cancer with neutron irradiation could lead to increased long-term survival. 相似文献
77.
MA Rodríguez-Bigas PH Lee L O'Malley TK Weber O Suh GR Anderson NJ Petrelli 《Canadian Metallurgical Quarterly》1996,39(6):649-653
INTRODUCTION: Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant condition characterized by early age of onset colorectal cancer, right-sided predominance, excess of synchronous and metachronous colonic neoplasms, and extracolonic cancers. The purpose of this study is to report clinical characteristics of HNPCC families in our registry. METHODS: This is a retrospective review of medical records of patients with a significant history of colorectal cancer and interviews with their families. RESULTS: Three hundred one people with cancer in 40 HNPCC families were identified. In 284 of 301 (94 percent) people, 363 cancers were identified. Colorectal cancer only was identified in 182 people (64 percent) and, in conjunction with extracolonic tumors, in another 31 people (11 percent). Extracolonic cancer alone was noted in 71 people (25 percent). Median age at diagnosis of colorectal cancer was 48 (range, 17-92) years. In patients with documented pathology, right-sided tumors predominated (55 percent), synchronous and metachronous tumors were noted in 53 percent, and synchronous of metachronous adenomas were documented in 51 percent of people. Generational anticipation was also noted. CONCLUSION: This study demonstrates and confirms characteristics that have been described in HNPCC. Namely, early age of onset of colorectal cancer, right-sided predominance, multiple synchronous and metachronous neoplasms, increased extracolonic cancers, and generational anticipation. 相似文献
78.
79.
J Barrette R Bellwied P Braun-Munzinger WE Cleland T Cormier G Dadusc G David J Dee O Dietzsch M Fatyga SV Greene JV Germani JR Hall TK Hemmick N Herrmann RW Hogue B Hong K Jayananda D Kraus BS Kumar R Lacasse D Lissauer WJ Llope TW Ludlam R Majka SK Mark JT Mitchell M Muthuswamy E O'Brien C Pruneau FS Rotondo da Silva NC J Simon-Gillo U Sonnadara J Stachel H Takai EM Takagui TG Throwe L Waters C Winter D Wolfe CL Woody N Xu Y Zhang Z Zhang C Zou 《Canadian Metallurgical Quarterly》1995,52(5):2679-2683
80.
CJ Haines TK Chung JR Masarei B Tomlinson JT Lau 《Canadian Metallurgical Quarterly》1995,22(3):219-225
OBJECTIVES: To determine the effect of percutaneous oestrogen replacement therapy on lipoprotein (a) and other plasma lipoproteins. METHODS: Open longitudinal prospective study conducted at the hormone replacement clinic of the Prince of Wales Hospital, New Territories, Hong Kong. Thirty women who had undergone a total abdominal hysterectomy and bilateral salpingo-oophorectomy for benign gynaecological conditions were treated with 1.5 mg of percutaneous 17 beta-oestradiol gel applied daily for a period of 12 consecutive months. Measurements of plasma lipoproteins were made before the commencement of treatment and repeated at 6- and 12-month intervals. RESULTS: There was a significant reduction in the concentrations of Lp(a) during the first 6 months of treatment, with median values falling from 7.87 mg dL-1 to 6.16 mg dL-1 (P = 0.004, 0-6 months). During the second 6 months, the median concentration increased to 9.38 mg dL-1, (P = 0.072, 6-12 months), which did not significantly differ from the baseline level (P = 0.545, 0-12 months). Significant reductions in the concentrations of apoprotein A-I (apo A-I), apoprotein B (apo B), high density lipoprotein cholesterol (HDL-C), and HDL3-C were also present after 6 months (P = 0.043, 0.049, 0.028, 0.013, respectively), but there were no differences between the baseline values of these lipoproteins and those at the completion of the study (P = 0.948, 0.244, 0.839, 0.117 respectively). Drug compliance was maintained throughout the study, with similar mean oestradiol concentrations at 6 and 12 months. CONCLUSIONS: The percutaneous administration of 17 beta-oestradiol has variable short term effects on plasma lipoproteins which are not maintained over a longer duration of treatment. By avoiding the 'first pass' effect on the liver, this method of delivery does not appear to produce the sustained changes in lipoproteins seen with oral treatment. 相似文献