全文获取类型
收费全文 | 5892篇 |
免费 | 480篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 195篇 |
妇产科学 | 198篇 |
基础医学 | 740篇 |
口腔科学 | 296篇 |
临床医学 | 652篇 |
内科学 | 1006篇 |
皮肤病学 | 122篇 |
神经病学 | 467篇 |
特种医学 | 402篇 |
外科学 | 560篇 |
综合类 | 91篇 |
一般理论 | 1篇 |
预防医学 | 576篇 |
眼科学 | 126篇 |
药学 | 538篇 |
1篇 | |
中国医学 | 3篇 |
肿瘤学 | 347篇 |
出版年
2022年 | 40篇 |
2021年 | 72篇 |
2020年 | 49篇 |
2019年 | 84篇 |
2018年 | 85篇 |
2017年 | 86篇 |
2016年 | 92篇 |
2015年 | 104篇 |
2014年 | 130篇 |
2013年 | 178篇 |
2012年 | 234篇 |
2011年 | 266篇 |
2010年 | 170篇 |
2009年 | 147篇 |
2008年 | 263篇 |
2007年 | 288篇 |
2006年 | 261篇 |
2005年 | 259篇 |
2004年 | 218篇 |
2003年 | 252篇 |
2002年 | 241篇 |
2001年 | 178篇 |
2000年 | 151篇 |
1999年 | 177篇 |
1998年 | 96篇 |
1997年 | 80篇 |
1996年 | 84篇 |
1995年 | 61篇 |
1994年 | 91篇 |
1993年 | 60篇 |
1992年 | 104篇 |
1991年 | 101篇 |
1990年 | 91篇 |
1989年 | 127篇 |
1988年 | 116篇 |
1987年 | 112篇 |
1986年 | 107篇 |
1985年 | 111篇 |
1984年 | 73篇 |
1983年 | 73篇 |
1982年 | 69篇 |
1981年 | 44篇 |
1979年 | 61篇 |
1978年 | 62篇 |
1977年 | 47篇 |
1976年 | 56篇 |
1975年 | 47篇 |
1974年 | 41篇 |
1973年 | 43篇 |
1972年 | 41篇 |
排序方式: 共有6383条查询结果,搜索用时 15 毫秒
1.
2.
3.
Effects of poor glucose handling on arterial stiffness and left ventricular mass in normal children.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease. 相似文献
4.
Despite numerous studies of approach- and avoidant mindsets, relatively little research has addressed the impact of such motivational orientations on performance and emotion in a real-time, multi-task setting. A laboratory simulation is reported that examines the influence of an induced approach-centered, an avoidance-centered, and a “neutral” motivational mindset upon multiple aspects of task performance, self-regulatory cognition, and affect. Undergraduate females randomly assigned to one of three mindset conditions performed a simulated automobile drive across one practice and two experimental trials. Dependent measures included divided attention, behavioral indicators of driving “cautiousness” in relatively safe straight roadway sections as well as during more risk-filled driving, multiple aspects of self-regulatory thinking (including self-monitoring, intended effort, and self-administered consequences), and positive and negative affect. Results revealed that the avoidant mindset produced poorer executive attention (i.e., fewer correctly detected divided attention events), more “cautious” driving behavior and reduced performance variability (i.e., greater control) when driving on presumably safe, straight roadway sections, lower self-reports of intended effort, and greater negative affect relative to the approach mindset. Results are intepreted within a self-regulation-centered motivational framework. Implications of the multi-task simulation for the study of normal and disordered adjustment are considered. 相似文献
5.
D Monnier† C Vidal‡ L Martin§ A Danzon¶ F Pelletier† E Puzenat† MP Algros†† D Blanc† R Laurent† PH Humbert† F Aubin† 《Journal of the European Academy of Dermatology and Venereology》2006,20(10):1237-1242
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating. 相似文献
6.
7.
8.
G A Newton 《The Journal of nursing administration》1986,16(5):25-27
What should you do with indigent patients who are ready for discharge but cannot afford the home care services they need? Should you extend their hospital stay? Discharge them and hope for the best? Search for a community agency that will care for them at no cost? To address this dilemma, one hospital developed a health care consortium for the purpose of guaranteeing home care to indigent patients, regardless of their ability to pay. 相似文献
9.
Balanced analgesia (an opioid and a nonsteroidal anti-inflammatory agent) after hysterectomy often leads to better postoperative pain outcomes. Researchers compared post-hysterectomy patients who received balanced analgesia with those who received only morphine patient-controlled analgesia, and their relationship with pain scores, ambulation, and hospital length of stay. 相似文献
10.
Marijuana components suppress induction and cytolytic function of murine cytotoxic T cells in vitro and in vivo. 总被引:3,自引:0,他引:3
T W Klein Y Kawakami C Newton H Friedman 《Journal of toxicology and environmental health》1991,32(4):465-477
Killer lymphocytes play a major role in host defense against tumors and infectious diseases. Previously, we reported that delta-9-tetrahydrocannabinol (THC) and II-hydroxy-delta-9-tetrahydrocannabinol (II-hydroxy-THC) suppressed the cytolytic activity of cultured natural killer (NK) cells. Also, we showed that the drugs appeared to be affecting a stage in the killing process subsequent to the binding of the killer cell to the target cell. In the present report, we have extended these studies to an examination of the effect of cannabinoids on the activity of cytotoxic T lymphocytes (CTLs). The cytolytic activity of CTLs generated by cocultivation with either allospecific stimulators or TNP-modified-self stimulators were suppressed by both THC and II-hydroxy-THC treatment. Allospecific CTLs generated in vivo were also inhibited by an in vitro exposure to either THC or II-hydroxy-THC, and the sensitivity of these cells to drug effects appeared to be greater than the sensitivity of the in vitro generated CTLs. Suppression of cytolytic function by THC and II-hydroxy-THC was maximal after a 4-h drug treatment, suggesting that the drug effects were inducible and therefore required a finite period of time to develop maximally. As seen in previous studies involving NK cells, drug treatment of mature CTLs appears to have little effect on the binding capacity of these cells for the target. However, the maximal killing capacity of the cells and the frequency of CTLs were significantly reduced by drug treatment. In addition to suppressing the cytolytic activity of mature effector CTLs, we also show that drug treatment inhibits both the proliferation of lymphocytes responding to an allogeneic stimulus and the maturation of these lymphocytes to mature CTLs. Similarly, CTL activity developing in vivo could be inhibited by THC injection. These results suggest that CTLs are inhibited by cannabinoids by at least two mechanisms. First, the cytolytic activity of mature killers is suppressed at some point beyond the binding to the target cell. Second, the cannabinoids appear to suppress the normal development of these mature effector cells from less mature precursor cells. 相似文献