全文获取类型
收费全文 | 2048篇 |
免费 | 148篇 |
国内免费 | 97篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 89篇 |
妇产科学 | 82篇 |
基础医学 | 262篇 |
口腔科学 | 41篇 |
临床医学 | 305篇 |
内科学 | 358篇 |
皮肤病学 | 31篇 |
神经病学 | 94篇 |
特种医学 | 137篇 |
外科学 | 248篇 |
综合类 | 80篇 |
预防医学 | 225篇 |
眼科学 | 19篇 |
药学 | 171篇 |
中国医学 | 2篇 |
肿瘤学 | 145篇 |
出版年
2023年 | 16篇 |
2021年 | 28篇 |
2020年 | 24篇 |
2019年 | 34篇 |
2018年 | 43篇 |
2017年 | 30篇 |
2016年 | 34篇 |
2015年 | 29篇 |
2014年 | 31篇 |
2013年 | 68篇 |
2012年 | 92篇 |
2011年 | 91篇 |
2010年 | 78篇 |
2009年 | 65篇 |
2008年 | 78篇 |
2007年 | 123篇 |
2006年 | 80篇 |
2005年 | 70篇 |
2004年 | 64篇 |
2003年 | 66篇 |
2002年 | 55篇 |
2001年 | 46篇 |
2000年 | 38篇 |
1999年 | 49篇 |
1998年 | 59篇 |
1997年 | 51篇 |
1996年 | 43篇 |
1995年 | 40篇 |
1994年 | 38篇 |
1993年 | 43篇 |
1992年 | 39篇 |
1991年 | 42篇 |
1990年 | 36篇 |
1989年 | 56篇 |
1988年 | 54篇 |
1987年 | 40篇 |
1986年 | 48篇 |
1985年 | 57篇 |
1984年 | 38篇 |
1983年 | 26篇 |
1982年 | 23篇 |
1980年 | 19篇 |
1979年 | 16篇 |
1978年 | 13篇 |
1975年 | 12篇 |
1974年 | 19篇 |
1973年 | 12篇 |
1972年 | 13篇 |
1971年 | 12篇 |
1969年 | 12篇 |
排序方式: 共有2293条查询结果,搜索用时 31 毫秒
1.
顺铂聚乳酸微球的药物释放特性及肝动脉栓塞研究 总被引:5,自引:0,他引:5
对顺铂聚乳酸微球进行了体外药物释放和家犬肝动脉栓塞研究。该微球粒径范围为50~200μm,平均粒径为115.76±35.94μm,顺铂含量为37.16%(W/W);体外药物释放机制符合Higuchi方程;肝动脉栓塞后8h,肝组织顺铂浓度高达21.55±12.18μg/g,明显高于肝动脉灌注顺铂组:3.16±0.09μg/g(P<0.05);肝动脉栓塞组的顺铂血浓峰值、各取血点浓度及曲线下面积AUC皆低于肝动脉灌注顺铂组。可望达到提高栓塞部位的药物疗效,降低全身毒副反应的作用。 相似文献
2.
R J Aitken 《British medical bulletin》1990,46(3):654-674
Our understanding of the causes of male infertility and our ability to develop an appropriate range of diagnostic tests are both dependent upon a knowledge of the cellular mechanisms responsible for the regulation of human sperm function. This review examines the intra- and extracellular factors regulating four separate components of human sperm function: sperm transport, sperm-egg recognition, the acrosome reaction and sperm-oocyte fusion. Within each of these areas the fundamental nature of the process, the control mechanisms involved, the availability of appropriate diagnostic tests and the relationship with human infertility have been considered. 相似文献
3.
PC Chamyal A Mehta SL Ojha JR Bhardwaj 《Indian journal of otolaryngology and head and neck surgery》1991,43(1):26-27
Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed. 相似文献
4.
R. Alan Aitken Michael C. Bibby John A. Double Andrea L. Laws Robert B. Ritchie David W. J. Wilson 《Archiv der Pharmazie》1997,330(7):215-224
A range of 18 derivatives of flavone-8-acetic acid (FAA) with substituents on the 2-phenyl group have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. There was no clear-cut relationship between in vitro and in vivo activity but the activity in each situation was found to be very sensitive to the precise substitution pattern with closely related isomers giving widely different activities. Some of the compounds, notably 10b,cj , and r , were active in vivo and these require further studies in order to evaluate their potential for development. 相似文献
5.
BACKGROUND: Many patients with asthma or chronic obstructive pulmonary diseaseuse their medication inhalers incorrectly. General practitioners,pharmacists and other health care providers do not always havethe opportunity to instruct patients in correct inhaler technique. OBJECTIVE: To find out whether the inhaler technique and respiratory symptomsof patients can be improved after instruction by practice assistants. METHODS: Single blind, randomized intervention study in which 48 patientswho had been using a dry powder inhaler for at least one monthtook part. Their inhaler technique was videotaped on two visitswith a two-week interval between visits. The inhaler techniqueon the videos was subsequently scored by two experts on ninecriteria. At both visits the patients completed a questionnaireabout their respiratory symptoms. After the first video, 25patients were randomly chosen to receive instruction from oneof six practice assistants who had followed a one evening courseabout inhaler instruction, and who had been issued an instruction-set. RESULTS: The patients who received instruction had a significantly greaterreduction in number of mistakes at the second visit than thepatients who did not (P = 0.01). The instructed patients alsoreported less dyspnoea at the second visit (P = 0.03). No effectof instruction was found on wheezing, cough and sputum production. CONCLUSION: The inhaler technique of patients can be improved significantlyby the instruction of patients by trained practice assistants,possibly resulting in less dyspnoea. Keywords. Administration-inhalation, obstructive lung diseases, airways symptoms, patient-education, general practice. 相似文献
6.
P G Mattison R C Aitken R J Prescott 《Archives of physical medicine and rehabilitation》1992,73(10):926-929
The Edinburgh Rehabilitation Status Scale (ERSS) was applied to 129 attenders at a day center for physical disability. All of the attenders had significant neurological impairment dating from birth or from infancy. Fifty-nine of the subjects (46%) had been diagnosed on conventional grounds as having mental handicap as well as physical disability. ERSS scores were compared with Barthel Index scores in all subjects and with PULSES profile in 50 subjects (27 physical disability alone, 23 combined with mental handicap). The ERSS scores clearly demonstrated significant differences in the level of disablement between the two groups in all four subscales as well as in total scores; the Barthel scores showed differences in self-care and total scores, and, to a lesser extent, in mobility. PULSES failed to differentiate the groups except in one of its subscales. The ERSS is a sensitive index of overall function and is useful in highlighting the additive effect of mental handicap and physical disability, a difference which may not be apparent when other assessment scales are used. 相似文献
7.
Kinnison ML; Perler BA; Kaufman SL; Mitchell SE; Kadir S; Williams GM; White RI Jr 《Radiology》1986,160(3):727-730
In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications. 相似文献
8.
A synchronous occurrence of large bowel adenocarcinoma and extragenital malignant mixed mesodermal tumour (MMMT) is reported. This case represents the sixth extragenital MMMT reported in the literature. 相似文献
9.
Digital radiography of subtle pulmonary abnormalities: an ROC study of the effect of pixel size on observer performance 总被引:3,自引:0,他引:3
Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy. 相似文献
10.
Serial doxycycline and metronidazole in prevention of recurrent periodontitis in high-risk patients.
The efficacy of metronidazole and doxycycline in preventing recurrent periodontitis was studied in 23 patients. After treatment in the previous 7 months with either bimonthly scaling and 3 weeks of systemic doxycycline (11 subjects) or scaling and placebo (12 subjects), patients were monitored for recurrent periodontitis and were scaled every 2 months. When either a periodontal abscess or greater than 2 mm loss of gingival attachment was observed, metronidazole was administered (250 mg every 8 hours) for 10 days. In the placebo plus metronidazole group, 5 patients (42%) exhibited recurrent periodontitis after the metronidazole regimen compared with only one (9%) in the doxycycline plus metronidazole group (P less than 0.096). Subgingival plaque samples at study and healthy control sites were screened for the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, and Fusobacterium nucleatum by immunofluorescence and for spirochetes using Ryu's stain. Presence/absence analysis of the sum of scores of the 6 individual pathogens demonstrated large reductions (P less than 0.005) in the frequency of detection of pathogens in the former doxycycline compared with the placebo plus metronidazole group at both study and control sites before and one month after metronidazole. By 7 months after metronidazole, there was no detectable difference between groups. These results indicate that prevention of recurrent periodontitis with metronidazole may be enhanced by previous treatment with doxycycline. 相似文献