全文获取类型
收费全文 | 811篇 |
免费 | 0篇 |
专业分类
化学工业 | 4篇 |
轻工业 | 4篇 |
冶金工业 | 801篇 |
自动化技术 | 2篇 |
出版年
2021年 | 1篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2009年 | 1篇 |
2005年 | 2篇 |
2003年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 30篇 |
1998年 | 242篇 |
1997年 | 138篇 |
1996年 | 95篇 |
1995年 | 55篇 |
1994年 | 36篇 |
1993年 | 43篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 7篇 |
1980年 | 11篇 |
1977年 | 20篇 |
1976年 | 53篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有811条查询结果,搜索用时 0 毫秒
151.
152.
This article describes a new computerized local anesthetic injection system for pain control. The core technology of this system is the microprocessor-controlled delivery of anesthetic solution at a constant pressure and controlled volume, regardless of encountered variations in tissue resistance. This fine-tuned, high suffusion flow rate of anesthetic provides a rapid onset of anesthesia for most patients. Traditional block injections and infiltrations as well as palatal injections and periodontal ligament injections are administered with precision, ease, and patient comfort. 相似文献
153.
154.
155.
Immunization is a safe and cost-effective method to protect adult patients against many diseases, including hepatitis B, pneumococcal infections, and influenza. Despite this fact, only 10% to 40% of adults in the United States who would benefit have been immunized. Approximately 62% to 92% of patients who develop a disease preventable by vaccination have visited an outpatient clinic at least once in the 3 years preceding their illness. Efforts to educate providers about immunization guidelines have not increased immunization rates. In this report, we propose using the preanesthesia clinic as an alternative site to screen, identify, and immunize adults at risk. We also discuss three vaccines that could be offered to patients and analyze the efficacy of the vaccines. 相似文献
156.
157.
MN Kweon K Fujihashi Y Wakatsuki T Koga M Yamamoto JR McGhee H Kiyono 《Canadian Metallurgical Quarterly》1999,162(4):1904-1909
CD40 ligand (CD40L) gene-disrupted (CD40L-/-) mice were employed to examine the role of costimulatory signals via CD40L-CD40 interactions in mucosally induced tolerance. CD40L-/- and control (CD40L+/+) mice of the same C57BL/6 x 129/J background were immunized orally with 25 mg of OVA before systemic challenge with OVA in CFA. While CD40L+/+ mice showed reductions in Ag-specific T cell responses including delayed-type hypersensitivity (DTH) and proliferative responses, CD40L-/- mice underwent normal T cell responses. Further, cytokine analysis of splenic CD4+ T cells showed that both Th1-type (e.g., IFN-gamma and IL-2) and Th2-type (e.g., IL-4, IL-5, IL-6, and IL-10) responses were maintained in CD40L-/- mice orally immunized with OVA, whereas these cytokine responses in CD40L+/+ mice were significantly reduced. In addition, splenic CD4+ T cells from CD40L-/- mice orally immunized with OVA provided B cell help in Ag-specific Ab-forming cells when the cells were cultured with naive B cells in the presence of Ag and CD40L-transfected cell lines. In contrast, an identical culture condition containing splenic CD4+ T cells from orally tolerized CD40L+/+ mice did not exhibit helper activity. Taken together, these findings indicate that CD40L and CD40 interactions are essential for the induction of systemic T cell unresponsiveness to orally administered Ag. 相似文献
158.
159.
160.