全文获取类型
收费全文 | 14631篇 |
免费 | 728篇 |
国内免费 | 353篇 |
专业分类
耳鼻咽喉 | 71篇 |
儿科学 | 749篇 |
妇产科学 | 769篇 |
基础医学 | 1088篇 |
口腔科学 | 104篇 |
临床医学 | 1652篇 |
内科学 | 1616篇 |
皮肤病学 | 65篇 |
神经病学 | 671篇 |
特种医学 | 560篇 |
外科学 | 1942篇 |
综合类 | 1873篇 |
预防医学 | 2451篇 |
眼科学 | 154篇 |
药学 | 1196篇 |
12篇 | |
中国医学 | 338篇 |
肿瘤学 | 401篇 |
出版年
2024年 | 17篇 |
2023年 | 219篇 |
2022年 | 464篇 |
2021年 | 638篇 |
2020年 | 519篇 |
2019年 | 544篇 |
2018年 | 490篇 |
2017年 | 486篇 |
2016年 | 508篇 |
2015年 | 476篇 |
2014年 | 1207篇 |
2013年 | 1140篇 |
2012年 | 863篇 |
2011年 | 1079篇 |
2010年 | 808篇 |
2009年 | 768篇 |
2008年 | 810篇 |
2007年 | 686篇 |
2006年 | 552篇 |
2005年 | 491篇 |
2004年 | 365篇 |
2003年 | 320篇 |
2002年 | 277篇 |
2001年 | 227篇 |
2000年 | 201篇 |
1999年 | 165篇 |
1998年 | 157篇 |
1997年 | 141篇 |
1996年 | 117篇 |
1995年 | 101篇 |
1994年 | 87篇 |
1993年 | 61篇 |
1992年 | 71篇 |
1991年 | 65篇 |
1990年 | 51篇 |
1989年 | 58篇 |
1988年 | 30篇 |
1987年 | 40篇 |
1986年 | 35篇 |
1985年 | 51篇 |
1984年 | 69篇 |
1983年 | 26篇 |
1982年 | 58篇 |
1981年 | 22篇 |
1980年 | 20篇 |
1979年 | 22篇 |
1977年 | 21篇 |
1976年 | 20篇 |
1975年 | 12篇 |
1973年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Janet R. Hankin James J. Sloan Ira J. Firestone Joel W. Ager Robert J. Sokol Susan S. Martier Joyce Townsend 《Alcoholism, clinical and experimental research》1993,17(2):428-430
This article presents data on the awareness of the alcohol beverage warning label among a sample of 5,169 inner city African-American gravidas seeking prenatal care. While the label law was implemented in November 1989, a significant increase in knowledge of the label did not occur until March 1990. Women who predominantly consumed wine coolers and beer, and those under age 30 were more likely to know about the label than their counterparts. 相似文献
42.
低分子肝素对不稳定型心绞痛病理生理干预作用的研究 总被引:1,自引:0,他引:1
目的:观察低分子肝素(LMWH)对不稳定型心绞痛((UAP)的临床症状、心电图、血脂以及内皮素(ET)的影响。方法:前瞻性地将84例UAP患者随机分为两组:对照组使用硝酸甘油、倍他乐克、阿司匹林等药物;治疗组(LMWH组)在上述治疗基础上加用LMWH(速避凝)。治疗前后调查临床症状以及心电图改变,抽血测定血脂、红细胞压积、血小板及内皮素水平的变化。结果:两组治疗后,患者心绞痛发作次数、持续时间以及硝酸甘油的用量明显减少,心电图明显改善,且LMWH组优于对照组(P<0.05)。LMWH治疗后,患者HCT、TC、TG及ET较治疗前明显降低(P<0.05)。对照组血浆ET水平无变化。结论:LMWH对UAP患者不仅具有抗凝抗栓作用,而且可以降低血液粘度、保护血管内皮细胞,纠正脂类代谢紊乱状态, 相似文献
43.
Dr. Shosaku Nakahara M.D. Hideaki Itoh M.D. Ryuichi Mibu M.D. Shinichi Ikeda M.D. Yoshihiro Oohata M.D. Kamesaburo Kitano M.D. Yoshihiko Nakamura M.D. 《Diseases of the colon and rectum》1988,31(10):762-766
Anorectal function was evaluated in eight patients who had low anterior resection of the rectum with a low anastomotic line,
using an EEA™ stapler, with determination of function based on periodic manometric studies and clinical symptoms. Immediately following
surgery all patients suffered from frequent bowel actions and soiling. These symptoms improved with time and most patients
could enjoy almost normal daily life by the sixth postoperative month. One month after surgery, anal canal resting pressure
and maximum squeeze pressure were significantly reduced and rectoanal inhibitory reflex was absent; neither showed a distinct
tendency to improve thereafter. Rectal sensation and reservoir capacity, which also were seriously impaired, recovered satisfactorily
by the time of the six-month examination. This suggests that an improvement of clinical symptoms following this operation
is dependent upon the recovery of reservoir capacity and sensation of the neorectum, and that this operative procedure is
a functionally acceptable option for low rectal cancer. 相似文献
44.
Beat M. Jucker Maria L. Barnard Robert G. Shulman 《Alcoholism, clinical and experimental research》1994,18(6):1377-1385
Weight gain efficiency differences previously reported between alcohol-fed rats and their controls were investigated. Additionally, the futile cycling of ethanol proposed to explain such differences was studied by NMR spectroscopy. Male Sprague-Dawley rats were fed a nutritionally adequate diet containing 36% of the calories as alcohol, and their paired controls were fed an isocaloric diet for 1 f weeks to establish conditions of chronic alcohol feeding. Normalized metabolic efficiencies varied significantly during the initial 2-week period (6.86 ± 0.51 vs. 2.83 ± 0.18 g/kcal × 10−2 ) for control and alcohol-fed groups, respectively, and to a lesser extent over the entire feeding period (6.41 ± 0.78 vs. 4.60 ± 0.27 g/kcal × 10−2 ) for control and alcohol-fed groups, respectively. Alcohol-induced weight gain inefficiency in metabolism has previously been studied and explained by a variety of different biochemical and physiological mechanisms. One possible pathway of energy wastage may occur due to ethanol futile cycling from ethanol to acetaldehyde through the microsomal ethanol oxidation system pathway, and simultaneously from acetaldehyde to ethanol via the ADH pathway. This futile cycle represents a net loss of 6 ATP/cycle, corresponding to the loss of two reducing equivalents (NADH and NADPH). 1H NMR spectroscopy was used to test for this cycling in blood extracts after administration of 1,1-2 H2 ethanol. No futile cycling was detected either during the initial 2 weeks of feeding or after the entire feeding period. 相似文献
45.
The records of 1018 patients with low back pain in a tertiary spine referral practice were reviewed. One hundred thirty-nine out of 1018 (13.6%) underwent technetium-99m planar bone scanning as part of their investigation. Seventy-three out of 139 scans (52%) showed increased uptake in some area, but only 27 out of 139 (19.4%) showed increased uptake specifically in the low back. Scans consistently yielded no findings with reference to the back when the prescan diagnosis was spinal stenosis, lumbar pain syndrome, herniated nucleus pulposus, or postlaminectomy syndrome. Some scans gave positive findings in patients with a diagnosis of degenerative disc disease, pseudarthrosis, spondylolisthesis, fracture, infection, metabolic disorder, or tumor. Positive scans were generally obtained early after presentation (within 3 months) and negative scans obtained later (after 6 months), suggesting that clinical suspicion is still the main indication for early scanning. Planar bone scanning was helpful in both diagnosis and therapeutic decisionmaking in many conditions. 相似文献
46.
Summary An anatomical study of the lumbar apophyseal joints was carried out to facilitate recognition of facet joint lesions, which we now examine routinely by percutaneous arthrography. Special attention was given to the configuration of the different compartments of the joint space and to its relationships with the contents of the intervertebral foramen. The abnormalities seen on lumbar facet joint arthrography are very varied; two major groups should be stressed: synovial fringe hypertrophy and pseudodiverticular synovial ectasia. The percutaneous approach to lumbar facet joint arthrography allows it to be used a therapeutic measure, with injection of anti-inflammatory drugs into the joint space, the beneficial effects of which were confirmed in our series. The precision, efficiency and cost-effectiveness of this outpatient technique justify and should encourage its more widespread application in the diagnosis and treatment of low back pain. 相似文献
47.
Christina Frennesson Peter Jakobsson Ulla L. Nilsson 《Documenta ophthalmologica. Advances in ophthalmology》1995,91(1):9-16
A new approach designed to establish the most suitable area for eccentric viewing and to teach and train patients with severe age-related macular degeneration (AMD) to use the eccentric viewing technique is described. Using a computer and video display based system, as well as software written specifically for this purpose, we investigated and trained ten consecutive patients with AMD. The patients were 80.1 ± 5.6 years old, on average. All of them had an absolute central scotoma. Mean visual acuity was 0.035 ± 0.016. After 30 min of testing, instruction and reading on the screen, followed by 2.6 ± 0.69 one-hour training sessions, on average, with the low vision therapist, reading newspaper and book texts with the aid of hyperoculars or aplanatic systems and a very short reading distance, the patients achieved a reading speed of 58.9 ± 19.7 words/min, significantly (p<0.001) higher than the initial speed when reading on the screen, 11.5 ± 4.5 words/min. 相似文献
48.
目的探讨低分子肝素联合辛伐他汀治疗不稳定型心绞痛的疗效。方法将100例不稳定型心绞痛患者随机分为对照组50例和观察组50例。对照组仅采取常规治疗(硝酸酯类、β-受体阻滞剂、钙拮抗剂、阿司匹林等),观察组在常规治疗的基础上加用低分子肝素和辛伐他汀,观察比较各组的疗效。结果观察组总有效率为90.0%,对照组总有效率为60.0%,两组疗效比较差异有显著性意义(P〈0.05)。结论低分子肝素联合辛伐他汀治疗不稳定型心绞痛取得满意的疗效。 相似文献
49.
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
50.
Nixie G. Raymond Johanna T. Dwyer Patricia Nevins Paul Kurtin 《Pediatric nephrology (Berlin, Germany)》1990,4(2):145-151
Children with mild to moderate renal insufficiency may be at an increased risk for developing glomerulosclerosis and subsequent renal failure. Low protein diets (LPD) have been shown to delay the progression of renal insufficiency in laboratory animals and may be of benefit in adult humans. The nutritional costs of a LPD in adults are reportedly minimal. We review the protein and caloric requirements of growing children and discuss the potential harmful effects and benefits of an LPD in this population. We also discuss dietary adherence and the difficulty of designing an LPD for children. We conclude that the protein content of a typical American diet can safely be reduced to, but not below, the recommended daily allowance for protein if diets are carefully planned, patients and their parents extensively counseled, and if dietary supplements are given to help meet the caloric and vitamin-mineral nutrient needs of growing children. In addition, ongoing nutritional assessment, counseling, and frequent monitoring of growth, diet and biochemical indicators of protein status are essential for maintaining the health of these children. 相似文献