全文获取类型
收费全文 | 14132篇 |
免费 | 1128篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 102篇 |
儿科学 | 493篇 |
妇产科学 | 303篇 |
基础医学 | 2024篇 |
口腔科学 | 112篇 |
临床医学 | 1918篇 |
内科学 | 2885篇 |
皮肤病学 | 224篇 |
神经病学 | 1407篇 |
特种医学 | 313篇 |
外科学 | 1398篇 |
综合类 | 149篇 |
一般理论 | 20篇 |
预防医学 | 1745篇 |
眼科学 | 166篇 |
药学 | 978篇 |
中国医学 | 16篇 |
肿瘤学 | 1043篇 |
出版年
2024年 | 28篇 |
2023年 | 236篇 |
2022年 | 290篇 |
2021年 | 577篇 |
2020年 | 374篇 |
2019年 | 629篇 |
2018年 | 618篇 |
2017年 | 415篇 |
2016年 | 457篇 |
2015年 | 453篇 |
2014年 | 563篇 |
2013年 | 820篇 |
2012年 | 1227篇 |
2011年 | 1213篇 |
2010年 | 591篇 |
2009年 | 543篇 |
2008年 | 840篇 |
2007年 | 884篇 |
2006年 | 861篇 |
2005年 | 782篇 |
2004年 | 643篇 |
2003年 | 618篇 |
2002年 | 580篇 |
2001年 | 87篇 |
2000年 | 63篇 |
1999年 | 82篇 |
1998年 | 100篇 |
1997年 | 103篇 |
1996年 | 70篇 |
1995年 | 70篇 |
1994年 | 41篇 |
1993年 | 51篇 |
1992年 | 36篇 |
1991年 | 28篇 |
1990年 | 26篇 |
1989年 | 17篇 |
1988年 | 16篇 |
1987年 | 18篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 20篇 |
1983年 | 21篇 |
1982年 | 20篇 |
1981年 | 29篇 |
1980年 | 14篇 |
1979年 | 9篇 |
1978年 | 13篇 |
1977年 | 28篇 |
1976年 | 18篇 |
1972年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Role of group II and group III metabotropic glutamate receptors in spinal cord injury. 总被引:4,自引:0,他引:4
Spinal cord injury (SCI) produces an increase in extracellular excitatory amino acid (EAA) concentrations that results in glutamate receptor-mediated excitotoxic events. An important class of these receptors is the metabotropic glutamate receptors (mGluRs). mGluRs can activate a number of intracellular pathways that increase neuronal excitability and modulate neurotransmission. Group I mGluRs are known to modulate EAA release and the development of chronic central pain (CCP) following SCI; however, the role of group II and III mGluRs remains unclear. To begin evaluating group II and III mGluRs in SCI, we administered the specific agonists for group II, APDC, or group III, L-AP4, by interspinal injection immediately following SCI. Contusion injury was produced at spinal segment T10 with a New York University impactor (12.5-mm drop, 10-g rod 2 mm in diameter) in 30 adult male Sprague-Dawley rats (175-200 g). Evoked and spontaneous behavioral measures of CCP, locomotor recovery, changes in mGluR expression, and amount of spared tissue were examined. Neither APDC nor L-AP4 affected locomotor recovery or the development of thermal hyperalgesia; however, L-AP4 and APDC attenuated changes in mechanical thresholds and changes in exploratory behavior indicative of CCP. APDC- and L-AP4-treated groups had higher expression levels of mGluR2/3 at the epicenter of injury on post contusion day 28; however, there was no difference in the amount of spared tissue between treatment groups. These results demonstrate that treatment with agonists to group II and III mGluRs following SCI affects mechanical responses, exploratory behavior, and mGluR2/3 expression without affecting the amount of tissue spared, suggesting that the level of mGluR expression after SCI may modulate nociceptive responses. 相似文献
23.
Elise Chiffoleau Gaëlle Bériou Patrick Dutartre Claire Usal Jean-Paul Soulillou Maria Cristina Cuturi 《American journal of transplantation》2002,2(8):745-757
A 20-day treatment with LF15-0195, a deoxyspergualine analog, induced long-term heart allograft survival in the rat without signs of chronic rejection. LF15-0195-treated recipients did not develop an anti-donor alloantibody response. Analysis of graft-infiltrating cells, IL10, TNFalpha, IFNgamma mRNA and iNOS protein expression in allografts, 5 days after transplantation, showed that they were markedly decreased in allografts from LF15-0195-treated recipients compared with allografts from untreated recipients. Surprisingly, spleen T cells from LF15-0195 recipients, 5days after grafting, were able to proliferate strongly in vitro, when stimulated with donor cells, but had reduced mRNA expression for IFNy compared with spleen T cells from untreated graft recipients. Furthermore, when T cells from naive animals were stimulated in vitro, using anti-CD3 and anti-CD28, LF15-0195 also increased T-cell proliferation in a dose-dependent fashion: however, these cells expressed less of the Th1 -related cytokines, IFNgamma and IL2, compared with untreated cells, suggesting that LF15-0195 could act on T-cell differentiation. In conclusion, we show here that a short-term treatment with LF15-0195 induced long-term allograft tolerance, decreasing the in situ anti-donor response, and we illustrate evidence for the development of regulatory mechanisms. 相似文献
24.
Augusto Giussani Adeseye M Arogunjo Marie Claire Cantone Federico Tavola Ivan Veronese 《Applied radiation and isotopes》2006,64(6):639-644
The intestinal absorption of molybdenum in healthy human volunteers has been measured by simultaneous oral and intravenous administration of the stable isotopes 95Mo and 96Mo, and the results were analysed using the convolution integral technique. The results showed that molybdenum ingested in liquid form was rapidly and totally absorbed into the circulation under ordinary intake regimes. The rates and extent of absorption were lower for composite meals, and also for increasing levels of administration. This information can be helpful in the application of the new ICRP model of the human alimentary tract. 相似文献
25.
Background: The slitlamp can be used to estimate the anterior chamber depth (ACD). The length of a slit object is increased until the corneal and iris/lens images appear to just touch. Multiplying the just‐touching‐slit‐length (JTSL) by a conversion factor gives an estimate of the ACD as measured by ultrasonography. The purpose of this study was to determine if central corneal thickness (CCT) affects the accuracy of this technique. Methods: The ACD of 50 subjects was measured by A‐scan ultrasonography and estimated by the slitlamp technique. CCT was measured by ultrasonic pachometry. The refractive error was determined subjectively. Results: The average ultrasonographic ACD for all subjects was 3.32 ± 0.65 mm. The average JTSL was 2.46 ± 0.38 mm. The conversion ratio between the ultrasonographic ACD and the average JTSL was 1.35. The predicted ACD using the regression equation of JTSL on the ultrasound anterior chamber depth (USACD) was 3.32 ± 0.54 mm. The corresponding value using the regression equation of JTSL and CCT on USACD was exactly the same, that is, 3.32 ± 0.54 mm. Conclusion: Incorporation of CCT into a regression equation does not improve the accuracy of the Smith technique. 相似文献
26.
27.
Changes in the design of hospital wards have usually been determined by architects and members of the nursing and medical professions, the views and preferences of patients have seldom been sought directly The Hospital Anxiety and Depression scale and the Disturbance Due to Hospital Noise questionnaire were administered to 64 female patients on bay and Nightingale wards together with a questionnaire designed for this study Perceptions of social and physical factors of ward design were examined, and their relationship to psychological well-being and sleep patterns The results show that the bay ward seemed to offer a more favourable environment for patients but some of the disadvantages of bay wards are balanced by better staffing levels and better and more modern facilities Visibility to nurses was lower on the bay ward The Nightingale ward was perceived as significantly noisier than the bay ward and noise levels were significantly correlated to anxiety scores Paradoxically the increase in noise levels appeared to improve the perceived level of privacy on the Nightingale ward Seventy-five per cent of patients were found to prefer the bay ward design, and since neither design appears to have major disadvantages their continued introduction should be encouraged However, recommendations are made concerning the optimizing of patients' well-being within the bay ward setting 相似文献
28.
Acute psychotropic effects of bilateral subthalamic nucleus stimulation and levodopa in Parkinson's disease. 总被引:9,自引:0,他引:9
Aurélie Funkiewiez Claire Ardouin Paul Krack Valérie Fraix Nadège Van Blercom Jing Xie Elena Moro Alim-Louis Benabid Pierre Pollak 《Movement disorders》2003,18(5):524-530
High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves the motor symptoms of Parkinson's disease (PD). Opposite changes in mood, such as mania or depression, have been reported after surgery, but it is not known whether these side effects are specifically related to STN DBS. To learn whether STN DBS also influences the limbic loop, we investigated acute subjective psychotropic effects related to levodopa or bilateral STN DBS. After a median postoperative follow-up of 12 months, 50 PD patients completed the Addiction Research Center Inventory (ARCI), assessing subjective psychotropic effects in four conditions: off-drug/on-stimulation; off-drug/off-stimulation; on-drug/off-stimulation; and on-drug/on-stimulation. Both levodopa and STN DBS improved all the ARCI subscales, indicating subjective feelings of well being, euphoria, increase in motivation, and decrease in fatigue, anxiety, and tension. A suprathreshold dose of levodopa was significantly more effective than STN DBS, using the same electrical parameters as for chronic stimulation, on four of the five ARCI subscales. We concluded that 1) both STN DBS and levodopa have synergistic acute beneficial psychotropic effects in PD, 2) the psychotropic effects of both treatments need to be considered in the long-term management of chronic STN DBS, and 3) the results indicate an involvement of the limbic STN in mood disorders of PD. 相似文献
29.
Balance and recovery from a perturbation are impaired in people with functional ankle instability. 总被引:1,自引:0,他引:1
Claire E Hiller Kathryn M Refshauge Robert D Herbert Sharon L Kilbreath 《Clinical journal of sport medicine》2007,17(4):269-275
OBJECTIVE: To determine if differences in balance and recovery would be found between controls and participants with unilateral or bilateral functional ankle instability (FAI). DESIGN: Cross-Sectional Study. SETTING: University laboratory and Community premises. PARTICIPANTS: Twenty healthy participants(C), 19 participants with unilateral FAI [both the uninjured (UC) and unstable ankle (UI) were included] and 22 participants with bilateral FAI (BI). MAIN OUTCOME MEASURES: Balance was measured in single leg stance as: number of part foot lifts in 30 s; magnitude of medio-lateral ankle movement in two foot positions; and ability to balance on the ball of the foot. Recovery was determined by time to return to baseline medio-lateral ankle movement after a 15 degree inversion perturbation. RESULTS: The controls lifted the foot fewer times than the other three groups [C = 12.7 +/- 1.8 (mean +/- SE) foot lifts, UC = 22.9 +/- 2.5, UI = 25.1 +/- 2.3, and BI = 21.1 +/- 2.2, t-test, P = 0.006] and recovered significantly faster than the unstable ankles [C = 1.53 +/- 0.42 sec (median +/- SE), UI = 2.34 +/- 0.30 sec, BI = 2.15 +/- 0.70 sec, P < 0.02]. With FAI measured by the Cumberland Ankle Instability Tool, the external control group balanced on demi-pointe better than both instability groups (P < 0.05), and recovered quicker than all groups. CONCLUSION: There are differences in balance and recovery between external controls and participants with both unilateral and bilateral FAI but not between the legs of participants with unilateral FAI. 相似文献
30.
Claire Cameron 《Early child development and care》1997,137(1):47-67
A review of the international literature on staffing in childcare centres in five English language countries and Denmark reveals both remarkable similarities and interesting differences in the childcare workforce. The paper compares characteristics of the workforce; their training and professional membership. It also compares conditions of work in each country, including salaries, staff benefits, and features of the working environment such as job satisfaction and staff turnover. Findings indicate that childcare workers tend to be young and female; that a relatively high proportion of untrained staff work in childcare centres; that, except in Denmark, the level of extrinsic benefits is startlingly low. Workers are paid relatively little compared to the average pay for women in their countries but the workforce does not benefit from enhanced conditions of work to compensate for low pay. However, the level of intrinsic satisfaction with the work is high. Caring for children is a satisfying form of employment, even if it offers a limited career structure. 相似文献