全文获取类型
收费全文 | 1558篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 11篇 |
机械仪表 | 1篇 |
轻工业 | 4篇 |
石油天然气 | 2篇 |
无线电 | 4篇 |
一般工业技术 | 5篇 |
冶金工业 | 1512篇 |
自动化技术 | 20篇 |
出版年
2021年 | 1篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2013年 | 8篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2000年 | 2篇 |
1999年 | 40篇 |
1998年 | 480篇 |
1997年 | 262篇 |
1996年 | 184篇 |
1995年 | 103篇 |
1994年 | 68篇 |
1993年 | 117篇 |
1992年 | 6篇 |
1991年 | 12篇 |
1990年 | 9篇 |
1989年 | 19篇 |
1988年 | 14篇 |
1987年 | 15篇 |
1986年 | 14篇 |
1985年 | 9篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 22篇 |
1978年 | 2篇 |
1977年 | 33篇 |
1976年 | 88篇 |
1975年 | 3篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1955年 | 2篇 |
排序方式: 共有1559条查询结果,搜索用时 0 毫秒
61.
This paper is intended to provide an overview of different endodontic applications in guided tissue regeneration. It is our expectation that using these techniques, where applicable, will increase endodontic surgical success. We have described six different clinical conditions including external resorption, root perforation, dehiscence, palatal grooves, oblique root fractures, and large periapical lesions. We believe the use of guided tissue regeneration techniques will allow us to predictably treat teeth that otherwise might be extracted. 相似文献
62.
63.
PR Franken P Dendale F De Geeter D Demoor A Bossuyt P Block 《Canadian Metallurgical Quarterly》1996,37(5):718-722
We determined the predictive value of combined beta-methyl iodophenyl pentadecanoic acid (BMIPP) and sestamibi scintigraphy for the functional outcome after myocardial infarction and compared the value of this approach with dobutamine echocardiography. METHODS: Rest BMIPP, rest sestamibi and low-dose dobutamine echocardiographic studies were obtained in 18 patients 4 to 10 days after infarction (mean 6.7 +/- 2.0 days). Six months later, a rest echocardiographic study was performed to assess functional outcome. RESULTS: Wall motion improved in 27/33 segments (82%) which showed mismatching but not in 19/21 segments (90%) with matched defects (p < 0.001). The accuracy of combined BMIPP and sestamibi SPECT in predicting segmental functional outcome was higher (85%) than that of sestamibi uptake alone (77%). Wall motion improved in 16/20 segments (80%) showing contractile reserve and not in 21/34 segments (63%) with the negative dobutamine test, giving an accuracy of 69% for dobutamine echocardiography. Combination of the two techniques resulted in higher positive (94%) and negative predictive values (94%). CONCLUSION: Mismatching of BMIPP and sestamibi uptake is predictive for long-term functional recovery after acute myocardial infarction. In contrast, segments with matched defects contain only scar tissue. Combined BMIPP and sestamibi scintigraphy offers increased accuracy compared to dobutamine echocardiography. 相似文献
64.
65.
66.
67.
The metabolic effects of protein malnutrition on growth and development of the exocrine pancreas are largely unknown. The aim of the present study was to evaluate the effects of protein malnutrition on pancreatic protein and DNA synthesis during postnatal development. Rat dams and their offspring were fed a protein-deficient diet (6% casein) or a control diet (25% casein) during gestation, lactation and after weaning. Pancreatic protein and DNA synthesis were measured in vitro at postnatal ages 1, 3, 10, 23, 36 and 60 days, by assessing [3H]leucine and [3H]thymidine incorporation in freshly isolated acini. Different patterns of protein synthesis were seen in the two groups. At birth, pancreatic protein synthesis was low in both control and malnourished animals. At day 3, protein synthesis in the control acini increased 10-fold while synthesis in acini of the malnourished animal group was only 50% of age-matched control values. No differences in protein synthesis were detected between the control and malnourished groups between 10 and 36 days of age. At 60 days (adulthood), acinar protein synthesis declined in the control-fed rats, but a significant increase was observed in the malnourished animals (p < 0. 0005). At birth, DNA synthesis was high in the acini from both control and malnourished animals. The low-protein diet induced a slight reduction in DNA synthesis at day 3, without altering the general pattern during later stages of development. In conclusion, protein deprivation has variable effects on pancreatic protein and DNA synthesis at different stages of postnatal development. Furthermore, the mechanisms of control within acini appear to be intrinsically regulated. 相似文献
68.
69.
70.
Although a curable malignancy, testis cancer and its treatment have unique associated morbidities that largely affect reproductive dysfunction. In this focused review, the factors that contribute to infertility in men with testis cancer are outlined. The treatment-specific risks to fertility that accompany cancer management are also discussed. Contemporary methods of overcoming infertility in testis cancer patients are addressed, and several exciting and promising experimental approaches to the preservation or restoration of fertility for men with testis cancer are presented. 相似文献