全文获取类型
收费全文 | 16336篇 |
免费 | 1232篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 161篇 |
儿科学 | 391篇 |
妇产科学 | 349篇 |
基础医学 | 3010篇 |
口腔科学 | 194篇 |
临床医学 | 1761篇 |
内科学 | 3469篇 |
皮肤病学 | 374篇 |
神经病学 | 1293篇 |
特种医学 | 558篇 |
外科学 | 2289篇 |
综合类 | 127篇 |
一般理论 | 5篇 |
预防医学 | 1087篇 |
眼科学 | 203篇 |
药学 | 1341篇 |
中国医学 | 23篇 |
肿瘤学 | 977篇 |
出版年
2023年 | 109篇 |
2022年 | 137篇 |
2021年 | 313篇 |
2020年 | 253篇 |
2019年 | 350篇 |
2018年 | 399篇 |
2017年 | 354篇 |
2016年 | 363篇 |
2015年 | 415篇 |
2014年 | 520篇 |
2013年 | 687篇 |
2012年 | 969篇 |
2011年 | 909篇 |
2010年 | 486篇 |
2009年 | 494篇 |
2008年 | 802篇 |
2007年 | 816篇 |
2006年 | 755篇 |
2005年 | 687篇 |
2004年 | 709篇 |
2003年 | 601篇 |
2002年 | 555篇 |
2001年 | 356篇 |
2000年 | 351篇 |
1999年 | 328篇 |
1998年 | 185篇 |
1997年 | 156篇 |
1996年 | 172篇 |
1995年 | 125篇 |
1994年 | 138篇 |
1993年 | 122篇 |
1992年 | 270篇 |
1991年 | 250篇 |
1990年 | 299篇 |
1989年 | 299篇 |
1988年 | 278篇 |
1987年 | 239篇 |
1986年 | 248篇 |
1985年 | 263篇 |
1984年 | 194篇 |
1983年 | 187篇 |
1982年 | 120篇 |
1981年 | 115篇 |
1979年 | 124篇 |
1978年 | 93篇 |
1977年 | 82篇 |
1976年 | 85篇 |
1975年 | 86篇 |
1974年 | 111篇 |
1973年 | 98篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
71.
Henrik Hein Lauridsen Jan Hartvigsen Claus Manniche Lars Korsholm Niels Grunnet-Nilsson 《European spine journal》2006,15(11):1717-1728
In studies evaluating the efficacy of clinical interventions, it is of paramount importance that the functional outcome measures are responsive to clinically relevant change. Knowledge thereof is in fact essential for the choice of instrument in clinical trials and for clinical decision-making. This article endeavours to investigate the sensitivity, specificity and clinically significant improvement (responsiveness) of the Danish version of the Oswestry disability index (ODI) in two back pain populations. Two hundred and thirty three patients with low back pain (LBP) and/or leg pain completed a questionnaire booklet at baseline and 8 weeks follow-up. Half of the patients were seen in the primary (PrS) and half in the secondary sectors (SeS) of the Danish Health Care System. The booklet contained the Danish version of the ODI, along with the Roland Morris Questionnaire, the LBP Rating Scale, the SF36 (physical function and bodily pain scales) and a global pain rating. At follow-up, a 7-point transition question (TQ) of patient perceived change and a numeric rating scale relating to the importance of the change were included. Responsiveness was operationalised using three strategies: change scores, standardised response means (SRM) and receiver operating characteristic (ROC) analyses. All methods revealed acceptable responsiveness of the ODI in the two patient populations which was comparable to the external instruments. SRM of the ODI change scores at 2 months follow-up was 1.0 for PrS patients and 0.3 for SeS (raw and percentage). A minimum clinically important change (MCID) from baseline score was established at 9 points (71%) for PrS patients and 8 points (27%) for SeS patients using ROC analyses. This was dependable on the baseline entry score with the MCID increasing with 5 points for every 10 points increase in the baseline score. We conclude that the Danish version of the ODI has comparable responsiveness to other commonly used functional status measures and is appropriate for use in low back pain patients receiving conservative care in both the primary and secondary sector. 相似文献
72.
73.
Michael Sørensen M.D. Michael Bachmann Nielsen M.D. Jan Fog Pedersen M.D. Ph.D. John Christiansen M.D. Ph.D. 《Diseases of the colon and rectum》1994,37(2):138-143
PURPOSE: The aim of our study was to investigate internal anal sphincter electromyographic signals. METHODS: Electromyography of the internal anal sphincter was performed with platinum wire electrodes in six healthy volunteers (three males and three females), inserted under endosonographic guidance. Platinum wire electrodes were also inserted into the external anal sphincter. Activity of both the internal and external anal sphincter in a 40-second period was measured. RESULTS: Internal anal sphincter median activity was 22.1 (range, 5.5–67.6) μ V. Slow-wave activity was 47 cycles/minute (range, 34–55 cycles/minute). After inflation of a rectal balloon with air until a constant relaxation of the anal canal was obtained, a decrease in internal anal sphincter activity to 15.9 (1.2–31.3) μV as well as a decrease in slow-wave activity to 34 cycles/minute (range, 27–40 cycles/minute) was found. The original internal anal sphincter EMG was resumed after deflation of the rectal balloon. External anal sphincter median activity was 31 (range, 0.77–18.6)μV. During inflation of the rectal balloon, a reflex increase in external sphincter EMG activity was found. With the rectal balloon fully inflated a part of this increase was still present, 11.0 (1.9–24.6)μV. In some of the subjects, this increased activity was superimposed on the internal anal sphincter recordings as well. During a voluntary squeeze it was not possible to identify internal anal sphincter activity due to activity of the external anal sphincter totally overriding the internal anal sphincter signal. CONCLUSION: Precise EMG recordings from the internal anal sphincter is possible with endosonographic guidance of the electrodes, except during voluntary squeezing of the external anal sphincter. 相似文献
74.
L B Jensen P Vestergaard A P Hermann J Gram P Eiken B Abrahamsen C Brot N Kolthoff O H S?rensen H Beck-Nielsen S Pors Nielsen P Charles L Mosekilde 《Journal of bone and mineral research》2003,18(2):333-342
The aim of this study was to study the influence of hormone replacement therapy (HRT) on weight changes, body composition, and bone mass in early postmenopausal women in a partly randomized comprehensive cohort study design. A total of 2016 women ages 45-58 years from 3 months to 2 years past last menstrual bleeding were included. One thousand were randomly assigned to HRT or no HRT in an open trial, whereas the others were allocated according to their preferences. All were followed for 5 years for body weight, bone mass, and body composition measurements. Body weight increased less over the 5 years in women randomized to HRT (1.94 +/- 4.86 kg) than in women randomized to no HRT (2.57 +/- 4.63, p = 0.046). A similar pattern was seen in the group receiving HRT or not by their own choice. The smaller weight gain in women on HRT was almost entirely caused by a lesser gain in fat. The main determinant of the weight gain was a decline in physical fitness. Women opting for HRT had a significantly lower body weight at inclusion than the other participants, but the results in the self-selected part of the study followed the pattern found in the randomized part. The change in fat mass was the strongest predictor of bone changes in untreated women, whereas the change in lean body mass was the strongest predictor when HRT was given. Body weight increases after the menopause. The gain in weight is related to a decrease in working capacity. HRT is associated with a smaller increase in fat mass after menopause. Fat gain protects against bone loss in untreated women but not in HRT-treated women. The data suggest that women's attitudes to HRT are more positive if they have low body weight, but there is no evidence that the conclusions in this study are skewed by selection bias. 相似文献
75.
A myelodysplastic syndrome (MDS), type 5 (RAEB-t), and systemic mastocytosis affecting the spleen, the splenic lymph nodes, the bone marrow and the liver were diagnosed in a 38-year-old woman. The clinical course was complicated by splenic vein thromboses and iliac artery embolism. The thrombotic episodes might be secondary to mast cell mediator release. A complete remission of the MDS was obtained by allogeneic bone marrow transplantation, but the mastocytosis persisted. Thus, the possibility that the mast cell originates from a common myeloid precursor cell may be questioned. 相似文献
76.
77.
78.
C. Sylvester-Hvid M. Nielsen K. Lamberth G. Røder S. Justesen C. Lundegaard P. Worning H. Thomadsen O. Lund S. Brunak & S. Buus 《Scandinavian journal of immunology》2004,59(6):632-632
An effective SARS vaccine is likely to include components that can induce specific cytotoxic T-cell (CTL) responses. The specificities of such responses are governed by HLA-restricted presentation of SARS-derived peptide epitopes. Exact knowledge of how the immune system handles protein antigens would allow for the identification of such linear sequences directly from genomic/proteomic sequence information. The latter was recently established when a causative coronavirus (SARS CoV) was isolated and full-length sequenced. Here, we have combined advanced bioinformatics and high-throughput immunology to perform an HLA supertype, genome-wide scan for SARS-specific cytotoxic T cell epitopes. The scan includes all nine human HLA supertypes in total covering >99% of all major human populations. For each HLA supertype, we have selected the 15 top candidates for test in biochemical-binding assays. At this time (approximately 6 months after the genome was established), we have tested the majority of the HLA supertypes and identified almost 100 potential vaccine candidates. These should be further validated in SARS survivors and used for vaccine formulation. We suggest that immunobioinformatics may become a fast and valuable tool in rational vaccine design. 相似文献
79.
80.
The aim of the study was to investigate if the stretch reflex of the soleus muscle was useful in quantifying upper motor neuron lesions. The soleus stretch reflex was recorded in 10 healthy subjects and 20 patients with active relapsing-remitting multiple sclerosis and correlated to the number of MRI lesions in cerebrum and clinical scores (expanded disability status scale and regional functional scoring system). The short latency stretch reflex was elicited by rotating the left ankle joint 4 degrees with a rise time in the interval of 40-640 ms. The amplitude of the stretch was larger in multiple sclerosis patients being 88.5 microV in patients and 12.8 microV in controls, P = 0.007. The sensitivity of the stretch reflex expressed as the slope of the best linear fit was increased in MS patients to 2.6 microVs/degree compared with 0.6 microVs/degree (0.1-2.2) in controls, P = 0.009. There was no correlation between amplitude of the stretch reflex and number of MRI lesions (r = -0.03). In conclusion, the soleus stretch reflex might be useful to quantify spasticity but is not useful in detecting dysfunction of upper motor neurons in MS. 相似文献