全文获取类型
收费全文 | 1492838篇 |
免费 | 96911篇 |
国内免费 | 3326篇 |
专业分类
耳鼻咽喉 | 21897篇 |
儿科学 | 46114篇 |
妇产科学 | 43410篇 |
基础医学 | 207692篇 |
口腔科学 | 44679篇 |
临床医学 | 124935篇 |
内科学 | 289589篇 |
皮肤病学 | 33718篇 |
神经病学 | 115465篇 |
特种医学 | 62422篇 |
外国民族医学 | 517篇 |
外科学 | 231783篇 |
综合类 | 32006篇 |
现状与发展 | 6篇 |
一般理论 | 438篇 |
预防医学 | 106052篇 |
眼科学 | 34958篇 |
药学 | 110555篇 |
6篇 | |
中国医学 | 3113篇 |
肿瘤学 | 83720篇 |
出版年
2018年 | 14955篇 |
2017年 | 13122篇 |
2016年 | 13466篇 |
2015年 | 16244篇 |
2014年 | 20475篇 |
2013年 | 28169篇 |
2012年 | 41493篇 |
2011年 | 38823篇 |
2010年 | 22600篇 |
2009年 | 23551篇 |
2008年 | 35234篇 |
2007年 | 38959篇 |
2006年 | 39731篇 |
2005年 | 46007篇 |
2004年 | 46513篇 |
2003年 | 41357篇 |
2002年 | 36395篇 |
2001年 | 66491篇 |
2000年 | 66453篇 |
1999年 | 59251篇 |
1998年 | 15057篇 |
1997年 | 13666篇 |
1996年 | 13190篇 |
1995年 | 12486篇 |
1992年 | 47576篇 |
1991年 | 46377篇 |
1990年 | 45872篇 |
1989年 | 44636篇 |
1988年 | 41643篇 |
1987年 | 41057篇 |
1986年 | 39313篇 |
1985年 | 36999篇 |
1984年 | 27527篇 |
1983年 | 23219篇 |
1982年 | 13417篇 |
1981年 | 12157篇 |
1979年 | 26825篇 |
1978年 | 18865篇 |
1977年 | 16157篇 |
1976年 | 14617篇 |
1975年 | 17175篇 |
1974年 | 20549篇 |
1973年 | 19748篇 |
1972年 | 18954篇 |
1971年 | 17968篇 |
1970年 | 17002篇 |
1969年 | 16361篇 |
1968年 | 15329篇 |
1967年 | 13835篇 |
1966年 | 12888篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
991.
992.
C. COLETTE M. C. GOUTTEBEL† L. H. MONNIER B. SAINT-AUBERT† H. JOYEUX† 《European journal of clinical investigation》1986,16(4):271-276
Seventeen patients who had undergone extensive small bowel resection were studied for calcium absorption (FACa) and plasma vitamin D metabolites. FACa was measured by a double radio-tracer technique and expressed as percentage of total oral dose. FACa was decreased compared with controls (34%, range: 3-46 v 65%, range: 57-73, P less than 0.01). A positive correlation (r = 0.49, P = 0.05) was found between FACa and the remaining length of small bowel (SBL). As wide variations in both SBL and duration after surgery were observed among the seventeen investigated patients, we were led to individualize less heterogeneous subgroups of patients. Better correlations were found when the patients were divided into two subgroups according to whether the time interval between the resection and the investigation was shorter (r = 0.75, n = 11, P less than 0.02) or longer (r = 0.89, n = 6, P = 0.05) than 2 years. In thirteen patients who had a SBL shorter than 100 cm, a positive correlation was observed between FACa and the time interval after surgery (months): r = 0.65, P less than 0.05. Plasma 1,25 (OH)2D was markedly reduced in the whole group (31 pmol l-1, range: 8-108) compared with controls (103 pmol-1, range: 59-134, P less than 0.01). The present study shows that in extensively small bowel resected patients, calcium absorption is reduced, the alteration being dependent both on the length of the remnant small bowel and on the time after surgery.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
993.
J Syrj?nen M Iivanainen M Kallio H Somer V V Valtonen 《Annals of clinical research》1986,18(4):191-194
Three different pathogenic mechanisms are apparent for paraparesis in association with a bacterial infection: a spinal cord compression caused by either an epidural abscess or a vertebral collapse due to spondylitis, an ischaemic spinal cord lesion as a result of septic thromboembolus in abdominal aorta, and a nonspecific, probably immunological, cause in association with reactive polyarthritis. An example of each of these mechanisms is described by means of case histories. 相似文献
994.
Limb-salvage treatment versus amputation for osteosarcoma of the distal end of the femur 总被引:14,自引:0,他引:14
M A Simon M A Aschliman N Thomas H J Mankin 《The Journal of bone and joint surgery. American volume》1986,68(9):1331-1337
A retrospective multi-institutional study of 227 patients with osteosarcoma of the distal end of the femur was done to compare rates of local recurrence, metastasis, and survival. Three cohorts of patients who had had either a limb-sparing procedure, an above-the-knee amputation, or disarticulation of the hip were compared. The results revealed prevalences of eight of seventy-three, nine of 115, and zero of thirty-nine as to local recurrence; forty-three of seventy-three, sixty-five of 115, and twenty-one of thirty-nine as to metastasis; and thirty-three of seventy-three, forty-eight of 115, and eighteen of thirty-nine as to death. Of the seventeen patients who had a local recurrence, sixteen died. In the limb-salvage group, eighteen patients required amputation, because of local recurrence in eight and other local complications in ten. The Kaplan-Meier estimates of the percentage of patients who survived and the percentage of patients without recurrent disease showed no difference among the three surgical groups (Mantel-Cox test statistic: p = 0.8) after a median length of follow-up of five and one-half years. Various covariant adjusted estimates yielded similar results. For the entire group of patients, the rate of continuously disease-free survival was 42 per cent, and the over-all rate of survival was 55 per cent at five years. It appears that, compared with above-the-knee amputation or disarticulation of the hip, the use of a limb-salvage procedure for osteosarcoma of the distal end of the femur did not shorten the disease-free interval or compromise long-term survival. 相似文献
995.
Autocrine growth and tumorigenicity of interleukin 2-dependent helper T cells transfected with IL-2 gene 总被引:15,自引:5,他引:10 下载免费PDF全文
We introduced a mouse IL-2 cDNA expression vector into an IL-2-dependent mouse helper T cell line HT-2. Transfected cells secreted substantial amounts of IL-2, to which they themselves responded by proliferating without further requirement for exogenous IL-2. The proliferation was a direct function of the cell density and was inhibitable by antibodies against IL-2 or IL-2-R, indicating the autocrine nature of the proliferation. Those producing higher amounts of IL-2 were found to be tumorigenic when inoculated into nude mice. The latency period of tumor development correlated inversely with the level of IL-2 secreted. Tumor cells proliferated in vitro in an IL-2 autocrine fashion indistinguishable from that of the inoculated cells. We thus provide evidence that the aberrant activation of the IL-2 autocrine circuit can lead T cells to malignant transformation. 相似文献
996.
T Schaub H M Dittrich A Antoniadis P Wolff P Gutjahr 《R?ntgen-Bl?tter; Zeitschrift für R?ntgen-Technik und medizinisch-wissenschaftliche Photographie》1986,39(10):287-290
Spinal Ewing's sarcomas are rare and cause problems in differential diagnosis. The radiologic, nuclear medicine and CT findings in two children with histologically proven Ewing's sarcoma are presented and problems in differential diagnosis discussed. Biopsy should be done early. 相似文献
997.
998.
A comparative study of the tissue-destroying effect of the laser and electrocoagulation 总被引:1,自引:0,他引:1
The effect of the laser on compact, glandular tissue at the dosage employed for the local palliative treatment of tumors, can largely be mimicked with the aid of high-frequency current (HF-current), applied with the aid of an electro-hydro-thermo-probe: The experiments described in the present study were performed on the livers of 70 male Wistar rats. The laser was applied for 2 seconds at an output of 80 J at a distance to the tissue of 0.5 cm. In the first stage, in the acute experiment, the effect of the HF-current was matched to that of the laser by varying the modulated and unmodulated current components. It was found that the depths of penetration into the tissue at the given laser settings could be achieved with modulated HF-current (so-called coagulation current) at an output of more than 72 watts (equipment setting K 10) coagulation being performed for 10 seconds. The admixture of modulated HF-current (so-called cutting current) reduces the depth of penetration into the tissue. In the first 5 days, the depth of penetration increases after both laser irradiation and HF-coagulation, by a factor of 2 to 3. With respect to the depths of penetration (DP), the scatter ranges, and the histological changes, no difference is to be seen between laser and HF lesions: Laser DP = 5.7 mm (confidence range: 4.4-7.0 mm); HF DP (equipment setting K 10) = 4.8 mm (confidence range: 3.6-5.4 mm).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
999.
E.P. WALKER P.H. BUTLER J.W. PICKERING W.A. DAY R. FRASER C.N. VAN HALEWYN 《The British journal of dermatology》1989,121(2):217-223
We report histological changes in four patients with port wine stains treated with 578 nm yellow light from a high power copper vapour laser. Histology showed that selective damage occurred to the ectatic blood-vessels in the dermis, without haemorrhage and damage to non-vascular structures, and without scarring. The initial damage to the overlying epidermis was not permanent, and the damaged ectatic vessels returned to normal size or were completely necrosed and replaced by collagen. 相似文献
1000.
Summary: Three chromosomal rearrangements: a balanced reciprocal translocation, t(14;10) (q22;q13), a Y-autosome translocation, t(Y;16) (q11;p13) and a deleted Y chromosome, Yq- were detected among 100 infertile men. The autosomal translocation, associated with oligozoospermia was found to be familial with various effects on the female carriers and the proband's father. The patients with the chromosome Y abberations were found to be azoospermic and might have lost the genes necessary for normal sperma-togenesis.
Zusammenfassung: Unter 100 infertilen Männern wurden drei Chromosomenneuan-ordnungen entdeckt: eine balancierte reziproke Translokation, t(14;10) (q22;q13), eine Y-autosome Translokation, t(Y;16) (q11;p13) und eine Deletion des Y-Chromosoms, Yq-. Die autosomale Translokation bei Oligozoospermie zeigte sich familiär mit verschiedenen Auswirkungen bei den weiblichen Überträgern und dem Vater des Probanden. Die Patien-ten mit chromosomalen Y-Aberrational wiesen eine Azoospermie auf und scheinen die zur normalen Spermatogenese notwendigen Gene verloren zu haben. 相似文献
Zusammenfassung: Unter 100 infertilen Männern wurden drei Chromosomenneuan-ordnungen entdeckt: eine balancierte reziproke Translokation, t(14;10) (q22;q13), eine Y-autosome Translokation, t(Y;16) (q11;p13) und eine Deletion des Y-Chromosoms, Yq-. Die autosomale Translokation bei Oligozoospermie zeigte sich familiär mit verschiedenen Auswirkungen bei den weiblichen Überträgern und dem Vater des Probanden. Die Patien-ten mit chromosomalen Y-Aberrational wiesen eine Azoospermie auf und scheinen die zur normalen Spermatogenese notwendigen Gene verloren zu haben. 相似文献