首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   535篇
  免费   3篇
综合类   1篇
化学工业   3篇
机械仪表   1篇
能源动力   1篇
轻工业   6篇
石油天然气   1篇
无线电   2篇
一般工业技术   4篇
冶金工业   518篇
原子能技术   1篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2016年   1篇
  2013年   2篇
  2012年   1篇
  2011年   1篇
  2009年   2篇
  2008年   1篇
  2007年   1篇
  2006年   3篇
  2005年   2篇
  2003年   2篇
  2002年   4篇
  2000年   1篇
  1999年   16篇
  1998年   152篇
  1997年   91篇
  1996年   76篇
  1995年   31篇
  1994年   29篇
  1993年   33篇
  1992年   5篇
  1991年   6篇
  1990年   6篇
  1989年   6篇
  1988年   8篇
  1987年   5篇
  1986年   3篇
  1985年   6篇
  1983年   1篇
  1982年   3篇
  1981年   2篇
  1980年   5篇
  1977年   12篇
  1976年   17篇
  1973年   1篇
排序方式: 共有538条查询结果,搜索用时 15 毫秒
381.
382.
200 mg/m2 methotrexate given intravenously in a running drip for 6 h has been used as an initial adjuvant therapy in 38 patients with advanced head and neck cancer. The response rate is as high as 80%, with 21% achieving complete remission. Histologically, specimens were tumor free in 3 patients. Toxicity in 38 patients included leukopenia (4), mucositis (6) and diarrhea (1). This particular dose of methotrexate appears to be safe and usually does not need leucovorin rescue. Also, when given as initial treatment, it is effective in reduction of tumor bulk. A prolonged randomized trial is essential to determine its role in improving long-term survival.  相似文献   
383.
384.
A new compound, 4-isothiocyanato-4'-nitrodiphenylamine (C.9333-Go/CGP 4540), was tried in 39 hospitalized patients with hookworm infection, using several treatment schedules. At effective dose schedules (125 mg X 3 given 4-hourly; 250 mg X 3, 8-hourly; 1,000 mg X 3, 12-hourly), the egg reduction was 96% to 100%; the zero egg-counts were confirmed by coproculture for larvae. The compound was very well tolerated. Transient and mild side effects--giddiness, diarrhea and sweating--were observed in only three patients. No toxic effects were seen as judged by serial organ function tests, except a transient and mild asymptomatic elevation of transaminases in one patient.  相似文献   
385.
Seventy tibial shaft fractures treated by intramedullary nailing using two different techniques were compared. The first group (35 cases) was treated with a Herzog intramedullary nail following hand reaming and minimal traction. The second group (35 cases) had a Grosse and Kempf or AO nail inserted following power reaming and skeletal traction. Fracture patterns were similar in both groups. In the hand-reamed group, the mean time to union was 15.2 weeks with two delayed unions and no non-unions. In the power-reamed group, the mean time to union was 19.9 weeks with 10 delayed unions and two non-unions. These differences were statistically significant. Complications in the hand-reamed group included a Sudecks atrophy and one mal-union. In the power-reamed group, there were three transient foot drops, two compartment syndromes and one pulmonary embolus. This difference was not statistically significant. Our findings suggest that surgical technique has an important effect on the healing rates of nailed tibial shaft fractures. When intramedullary nailing is performed, minimal reaming is required and skeletal traction should be avoided if possible.  相似文献   
386.
Translocations and deletions of the short arm of chromosome 12 [t(12p) and del(12p)] are common recurring abnormalities in a broad spectrum of hematologic malignant diseases. We studied 20 patients and one cell line whose cells contained 12p13 translocations and/or 12p deletions using fluorescence in situ hybridization (FISH) with phage, plasmid, and cosmid probes that we previously mapped and ordered on 12p12-13. FISH analysis showed that the 12p13 translocation breakpoints were clustered between two cosmids, D12S133 and D12S142, in 11 of 12 patients and in one cell line. FISH analysis of 11 patients with deletions demonstrated that the deletions were interstitial rather than terminal and that the distal part of 12p12, including the GDI-D4 gene and D12S54 marker, was deleted in all 11 patients. Moreover, FISH analysis showed that cells from 3 of these patients contained both a del(12p) and a 12p13 translocation and that the affected regions of these rearrangements appeared to overlap. We identified three yeast artificial chromosome (YAC) clones that span all the 12p13 translocation breakpoints mapped between D12S133 and D12S142. They have inserts of human DNA between 1.39 and 1.67 Mb. Because the region between D12S133 and D12S142 also represents the telomeric border of the smallest commonly deleted region of 12p, we also studied patients with a del(12p) using these YACs. The smallest YAC, 964c10, was deleted in 8 of 9 patients studied. In the other patient, the YAC labeled the del(12p) chromosome more weakly than the normal chromosome 12, suggesting that a part of the YAC was deleted. Thus, most 12p13 translocation breakpoints were clustered within the sequences contained in the 1.39 Mb YAC and this YAC appears to include the telomeric border of the smallest commonly deleted region. Whether the same gene is involved in both the translocations and deletions is presently unknown.  相似文献   
387.
388.
Serology has been a fundamental tool to prevent post-transfusional infection with human immunodeficiency virus (HIV) and for epidemiological surveys, the first step to attempt control of the pandemia. Enzyme immunoassay is in widespread use. Nevertheless, simpler methods are needed in many countries, where laboratory facilities and trained personnel are limited, and HIV prevalence is high. The evaluation of a simple and noninstrumented HIV antibody test is presented here. The test employs synthetic antigens of HIV-1 and HIV-2 attached to the teeth of a polystyrene comb, which fit into the wells of standard microtiter plates where samples are diluted. Captured antibodies are developed with colloidal gold-labeled Protein A. Three seroconversion panels plus 662 samples were tested, including HIV-1 and HIV-2-infected individuals, normal blood donors, and a noninfected baby born to a seroreactive mother. When compared with enzyme-linked immunosorbent assay (ELISA) and Western blot, the dipstick showed 100% sensitivity and 98.7% specificity. The simplicity of result evaluations and excellent reagent stability make the dipstick suitable for small blood banks and for epidemiological surveys.  相似文献   
389.
390.
Alterations in core lipid composition of lipoproteins in noninsulin-dependent diabetes mellitus (NIDDM) patients have suggested that the heteroexchange of neutral lipids between HDL and the apo B-containing lipoproteins may be enhanced. For this reason, we studied cholesteryl ester transfer (CET) in ten sulfonylurea-treated patients with stable NIDDM. CET measured in all NIDDM subjects with an assay of mass transfer was significantly greater than that of controls at 1 and 2 h (P < 0.001); the transfer of radiolabeled CE also was increased in a subset of four of the NIDDM group (NIDDM k = 0.21 +/- 0.04 vs. control k = 0.10 +/- 0.05; P < 0.05). A weak correlation was demonstrable between the mass of CE transferred at 1 h and diabetic control expressed as plasma fructosamine (r = 0.58, P < 0.09). To characterize this disturbance in CET further, the donor (HDL + VHDL) and acceptor (VLDL + LDL) lipoprotein fractions were isolated by ultracentrifugation at d 1.063 g/ml from NIDDM and control plasma and a series of recombination experiments were performed. Combining NIDDM acceptor with control donor fractions that contained HDL and CETP and not the combination of NIDDM donor and control acceptor lipoproteins resulted in an accelerated CET response identical to that observed in NIDDM whole plasma. This observation indicated that the abnormality in CET in NIDDM was associated with the VLDL + LDL fraction.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号