全文获取类型
收费全文 | 465篇 |
免费 | 0篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 6篇 |
能源动力 | 1篇 |
轻工业 | 4篇 |
一般工业技术 | 4篇 |
冶金工业 | 447篇 |
自动化技术 | 2篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2011年 | 1篇 |
2010年 | 1篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 10篇 |
1998年 | 124篇 |
1997年 | 80篇 |
1996年 | 53篇 |
1995年 | 28篇 |
1994年 | 25篇 |
1993年 | 18篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 15篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 19篇 |
1976年 | 28篇 |
1975年 | 1篇 |
排序方式: 共有465条查询结果,搜索用时 31 毫秒
101.
102.
OBJECTIVE: To determine the quality of impressions for crown and bridge work made in general dental practice. DESIGN AND SETTING: All impressions for crown and bridge work which had been sent to four commercial dental laboratories in the UK were assessed by two examiners, each laboratory being visited on two occasions. MATERIALS AND METHODS: 290 cases which had been received by the laboratories on the days of the visits were assessed for a number of factors related to quality. There was no selection or rejection--all impressions received were examined. RESULTS: Flexible plastic trays were used for the majority of working impressions for crown and bridge work in general dental practice (72%), many had been re-used (> 13%), defects in the recording of the prepared teeth were common, and cross infection control was not routine. CONCLUSIONS: Quality standards for impressions for crown and bridge work in general dental practice in the UK are a cause for concern if the sample of cases seen in this study is typical. 相似文献
103.
The purpose of this study was to compare seven skinfold equations with underwater weighing (UWW) for estimating body fat in 39 African American [age: 22.8 +/- 3.6 y (x +/- SD); weight: 59.6 +/- 8.3 kg) and 39 white (age: 22.1 +/- 2.9 y; weight: 61.7 +/- 7.3 kg) women. The hypothesis examined was that the equations would produce more accurate body fat estimates in white women, but would be appropriate for use in African American women. Body fat estimated from two quadratic, three linear, and two logarithmic skinfold equations was compared with body fat estimated from UWW; the same procedures were used to evaluate the results in both African Americans and whites. The data were analyzed by using t tests, analysis of variance, Scheffé's honestly significant difference tests, correlations, error assessments, and agreement. The results showed that total error, SEE, and SD values were larger in the African American women than in the white women and were not within acceptable limits listed in the literature. The correlation coefficients were lower in the African American women than in the white women. Agreement between the skinfold equations and UWW, based on deviations from mean differences, was better in the white women. In conclusion, the skinfold prediction equations evaluated in this study were more variable and produced more error when used in African American women. Therefore, population-specific equations for African American women should be used to estimate body fat because they will probably yield more accurate estimates. 相似文献
104.
S He RP Mason S Hunjan VD Mehta V Arora R Katipally PV Kulkarni PP Antich 《Canadian Metallurgical Quarterly》1998,6(9):1631-1639
Phytochemicals such as indole-3-carbinol (I3C) and sulforaphane are components of cruciferous vegetables which exhibit antitumorigenic activity associated with altered carcinogen metabolism and detoxification. Diindolylmethane (DIM) is a major acid-catalyzed metabolite of I3C formed in the gut that binds to the aryl hydrocarbon receptor (AhR) and treatment of MCF-7 human breast cancer cells with 10-50 microM DIM resulted in rapid formation of the nuclear AhR complex and induction of CYP1A1 gene expression was observed at concentrations >50 microM. Previous studies have demonstrated that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a high affinity AhR ligand, inhibits 17beta-estradiol (E2)-induced responses in MCF-7 cells and growth of E2-dependent 7,12-dimethylbenzanthracene (DMBA)-induced mammary tumors in female Sprague-Dawley rats. Results of this study show that like TCDD, DIM inhibits E2-induced proliferation of MCF-7 cells, reporter gene activity in cells transiently transfected with an E2-responsive plasmid (containing a frog vitellogenin A2 gene promoter insert) and down-regulates the nuclear estrogen receptor. Moreover, DIM (5 mg/kg every other day) also inhibits DMBA-induced mammary tumor growth in Sprague-Dawley rats and this was not accompanied by induction of hepatic CYP1A1-dependent activity. Thus, DIM represents a new class of relatively non-toxic AhR-based antiestrogens that inhibit E2-dependent tumor growth in rodents and current studies are focused on development of analogs for clinical treatment of breast cancer. 相似文献
105.
106.
107.
PV Dicpinigaitis 《Canadian Metallurgical Quarterly》1996,30(11):1242-1245
OBJECTIVE: To determine whether baclofen can suppress the cough induced by angiotensin-converting enzyme (ACE) inhibitors. DESIGN: Prospective, open-label, clinical trial of a 4-week course of low-dose oral baclofen (5 mg tid days 1-7, 10 mg tid days 8-28). SUBJECTS: Seven patients with severe, persistent ACE inhibitor-induced cough. SETTING: University-affiliated teaching hospital. MAIN OUTCOME MEASURES: Study participants kept daily diaries monitoring the frequency of cough during and after completion of baclofen therapy. RESULTS: All subjects demonstrated diminution of cough after initiation of baclofen. Initial improvement was noted by a mean of 4.0 days (range 3-6), and maximal improvement during treatment was achieved by a mean of 10.7 days (range 5-15). In addition, all subjects demonstrated persistent suppression of cough (range 25-74 d) after discontinuation of the study drug. CONCLUSIONS: Low-dose oral baclofen therapy caused a prolonged antitussive effect in all subjects without inducing any adverse reactions. Baclofen may offer an alternative to the discontinuation of ACE inhibitor therapy in patients for whom these drugs are required. 相似文献
108.
F Aghini-Lombardi S Mariotti PV Fosella L Grasso A Pinchera LE Braverman E Martino 《Canadian Metallurgical Quarterly》1993,16(10):823-826
The present report illustrates the clinical and biochemical outcome in two amiodarone iodine-induced thyrotoxicosis (AIIT) patients submitted to plasmapheresis. Amiodarone was discontinued, and treatment with MMI (40 mg/day) was started. In addition, patients were submitted to two sessions of plasma-exchange, with a one-day interval between the two session. In both patients serum total T3 (TT3) and free T3 (FT3) concentrations decreased promptly but in contrast to the serum TT3, FT3 levels remained steadily above the normal range. A similar behaviour was observed for total T4 and free T4 plasma concentrations. Interestingly, a clearcut clinical amelioration was observed in both patients even before a reduction of circulating free thyroid hormone concentrations could be documented. In conclusion, our experience indicates that plasmapheresis may be useful in order to obtain a rapid amelioration of severe clinical picture of thyrotoxicosis, but cannot be considered as a definite therapy in AIIT. It should be considered that plasmapheresis is not devoid of risks and is also a very expensive procedure. 相似文献
109.
Antisera were developed that specifically recognize orphanin FQ/nociceptin, the 17 amino acid peptide reported to be the endogenous ligand for the orphan opioid receptor. Immunocytochemical localizations in rat spinal cord demonstrated that orphanin FQ /nociceptin-immunoreactivity (-ir) was abundant in superficial dorsal horn, lateral spinal nucleus and the region dorsal to the central canal, areas that also exhibit prominent enkephalin-and dynorphin-ir. Orphanin FQ/nociceptin-ir was not affected by dorsal rhizotomy, indicating that in spinal cord the peptide is produced by central rather than primary afferent neurons. thus, the distribution of orphanin FQ/nociceptin-ir appeared in neuronal circuits that parallel those containing enkephalin- and dynorphin-ir, with only modest co-existence of these peptides. 相似文献
110.