全文获取类型
收费全文 | 2921308篇 |
免费 | 239792篇 |
国内免费 | 7265篇 |
专业分类
耳鼻咽喉 | 43166篇 |
儿科学 | 88826篇 |
妇产科学 | 79110篇 |
基础医学 | 412845篇 |
口腔科学 | 84608篇 |
临床医学 | 265869篇 |
内科学 | 566305篇 |
皮肤病学 | 59422篇 |
神经病学 | 244549篇 |
特种医学 | 117066篇 |
外国民族医学 | 1059篇 |
外科学 | 443149篇 |
综合类 | 76704篇 |
现状与发展 | 7篇 |
一般理论 | 1174篇 |
预防医学 | 235846篇 |
眼科学 | 70115篇 |
药学 | 219388篇 |
27篇 | |
中国医学 | 6970篇 |
肿瘤学 | 152160篇 |
出版年
2018年 | 29746篇 |
2016年 | 25490篇 |
2015年 | 29298篇 |
2014年 | 41975篇 |
2013年 | 63133篇 |
2012年 | 85068篇 |
2011年 | 89747篇 |
2010年 | 52955篇 |
2009年 | 50270篇 |
2008年 | 84403篇 |
2007年 | 90219篇 |
2006年 | 90866篇 |
2005年 | 88693篇 |
2004年 | 85423篇 |
2003年 | 82486篇 |
2002年 | 81067篇 |
2001年 | 130571篇 |
2000年 | 135063篇 |
1999年 | 114434篇 |
1998年 | 33872篇 |
1997年 | 30921篇 |
1996年 | 30423篇 |
1995年 | 29405篇 |
1994年 | 27685篇 |
1993年 | 25746篇 |
1992年 | 93219篇 |
1991年 | 89944篇 |
1990年 | 87024篇 |
1989年 | 83806篇 |
1988年 | 78131篇 |
1987年 | 77115篇 |
1986年 | 72935篇 |
1985年 | 69997篇 |
1984年 | 53481篇 |
1983年 | 45731篇 |
1982年 | 28250篇 |
1981年 | 25269篇 |
1980年 | 23773篇 |
1979年 | 51284篇 |
1978年 | 36331篇 |
1977年 | 30603篇 |
1976年 | 28603篇 |
1975年 | 30334篇 |
1974年 | 37521篇 |
1973年 | 35874篇 |
1972年 | 33638篇 |
1971年 | 31079篇 |
1970年 | 29406篇 |
1969年 | 27649篇 |
1968年 | 25151篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
962.
T F Kruger J P Van der Merwe H J Odendaal F S Stander G M Grobler V A Hulme E L Erasmus K Coetzee M L Windt Y Swart 《Suid-Afrikaanse tydskrif vir geneeskunde》1990,77(12):634-636
The results of the in vitro fertilisation programme at Tygerberg Hospital for the period April 1983 to January 1988 are presented. Of the 1117 laparoscopies performed, 825 patients reached the transfer stage. A live-birth rate of 9.3% was achieved. The pregnancy rate after transfer of 4 embryos was 25.9% compared with 15.4% after 2 embryos and 10.8% after 3 embryos (P = less than 0.0001). The multiple pregnancy rate was 2.8% in the group receiving 2 embryos and 11.7% and 10.4% in those receiving 3 and 4 embryos, respectively. Of the 77 successful pregnancies (90 babies), 1 baby died at 34 weeks' gestation as the result of abruptio placentae due to preeclampsia and 1 cot death occurred. The only congenital abnormality encountered was a cleft palate. 相似文献
963.
S.A. GEORGE D.J. BILSLAND N.J. WAINWRIGHT J. FERGUSON 《The British journal of dermatology》1993,128(3):301-305
Despite a widely held belief that the use of emollients prior to broad-band UVB irradiation accelerates clearance of psoriasis, only one single-blind controlled study exists in support of this. No similar study has been carried out with photochemotherapy (PUVA) or narrow-band UVB (311–313 nm) phototherapy. As some emollients absorb UV radiation, and thereby inhibit psoriasis clearance, there is a need to identify emollients suitable for pre-irradiation use. Coconut oil may be useful in this respect. In two randomized groups of patients with chronic plaque psoriasis undergoing either routine PUVA(n=14) or narrow-band UVB phototherapy (n=15), a single-blind controlled (half-body) study was undertaken to assess the died of pre-irradiation application of coconut oil. Patients were given PUVA twice weekly, or TL-01 therapy thrice weekly. The initial UV dose was 70% of previously determined minimal phototoxic (MPD) or minimal erythema doses (MED), with 40% incremental steps at each visit (reduced if adverse effects occurred). Psoriasis severity was scored on each side after every three treatments. No significant acceleration of psoriasis clearance was seen in either group. We do not, therefore, recommend the routine use of emollients prior to PUVA or TL-01 therapy when using near erythemogenic irradiation regimens. 相似文献
964.
Gonadoblastoma, a rare gonadal neoplasm, presents most frequently in phenotypic female or phenotypically male patients with dysgenetic gonads or undescended testes. To date, only 2 cases of gonadoblastoma have been reported in anatomically normal male patients with scrotal testes. Both of these patients presented with testicular masses and germ cell tumors. We report a case of a genotypically and phenotypically normal, fertile man with descended testes who on evaluation for chronic orchialgia had a gonadoblastoma unaccompanied by a germ cell neoplasm. The tumor was nonpalpable and was initially discovered on scrotal ultrasound. 相似文献
965.
J Komen P J Van den Dobbelsteen W J Slierendrecht W B Van Muiswinkel 《Transplantation》1990,49(4):788-793
The fate of skin allografts exchanged among heterozygous and homozygous gynogenetic common carp siblings, and among newly developed inbred strains and F1 hybrids, is described. Heterozygous gynogenetic offspring were produced by fertilizing eggs with UV-irradiated sperm and by treating the resulting zygote with a cold shock (0 degree C, 45 min). The temperature shock causes retention of the second polar body, which allows the eggs to develop into normal diploid fry. Homozygous gynogenetic offspring were similarly produced by using a heat shock (40 degrees C, 2 min), which suppresses the first mitotic division. Skin allografts exchanged among heterozygous gynogenetic carp exhibited prolonged survival, with some allografts (21.8%) surviving for over 28 days. Furthermore, a strong histocompatibility locus was seen to segregate in this group. In contrast, skin allografts exchanged among homozygous gynogenetic siblings were all rejected within 14 days (MST 9.4 days). New homozygous inbred strains, designated JJ and MM, were produced by gynogenetic reproduction of homozygous female carps, while F1 hybrids were produced by crossing of these homozygous females with homozygous male siblings. All grafts exchanged among members of the same strain were permanently accepted. Likewise grafts from homozygous strain members were accepted by fish from the related F1-hybrids, while the reverse grafts were rejected. These results provide evidence for the idea that in the carp histocompatibility genes exist at least one major locus and multiple minor loci, which are codominantly expressed. 相似文献
966.
D. L. Crosby G. A. Rees J. Gill 《Annals of the Royal College of Surgeons of England》1990,72(5):309-312
The current experience of a high dependency unit established 5 years ago for the postoperative care of high-risk patients undergoing surgery is reported. The resource implications and contributions to the safety and quality of post-operative care, particularly pain relief, are described. 相似文献
967.
Clinical experience with immediate breast reconstruction using tissue expansion or transverse rectus abdominis musculocutaneous flaps 总被引:5,自引:0,他引:5
We retrospectively reviewed our experience with immediate breast reconstruction in 103 consecutive patients with stage 0 or I breast carcinoma between May 1983 and April 1988. Two reconstructive techniques were used, that is, either tissue expansion with secondary prosthesis implantation (60%) or transverse rectus abdominis musculocutaneous (TRAM) flap (40%). Chemotherapy was administered in 22% of patients without delay or compromise. The mean length of follow-up is 30 months. The complication rate was equal for both groups (24%) with infection being most common in the group of patients with tissue expansion and partial flap necrosis being most common in the group of patients with TRAM flaps. Aesthetic results were superior with use of the TRAM flap. Our experience concurs with previous reports that documented satisfactory results with immediate breast reconstruction without compromising further therapy. We conclude that although the tissue expansion technique yields acceptable results, the TRAM flap yields superior aesthetic results in terms of both appearance and consistency. 相似文献
968.
Summary This study explores the effects of a calcium-deficient diet on patterns of bone remodeling, and examines regional differences
in the amount of bone lost. Skeletally mature female rabbits (n=6) were fed a calcium-deficient diet (0.10% Ca2+ and 0.50% P) for 14 weeks. A separate group of rabbits (n=4) were fed a maintenance diet (1.2% Ca2+ and 0.45% P). Bone mineral content, serum calcium, and serum phosphorus were measured each week during the experimental period.
Following sacrifice, the L3 vetebra, femoral head, proximal tibial metaphysis, and tibial midshaft were analyzed histomorphometrically. Rabbits had 20%
less vertebral bone after only 14 weeks of a calcium-deficient diet. As in human postmenopausal osteoporosis, bone loss in
calcium-deficient rabbits occurs in the trabecular bone of the lumbar spine before that in the trabecular bone of the lower
extremity. Calcium-deficient diets alone do not lead to increased osteoid volume or thickness. Because bone loss is relatively
rapid and because the pattern of loss is similar in some respects to that found in humans, adult rabbits may provide an attractive
model of calcium deficiency osteoporosis in a skeletally mature mammal in which remodeling is predominant over modeling. 相似文献
969.
T. M. Skerry M.D. M.R.C.V.S. R. Suswillo A. J. El Haj N. N. Ali R. A. Dodds L. E. Lanyon 《Calcified tissue international》1990,46(5):318-326
Summary Previous studies of Alcian blue-induced birefringence in adult avian cortical bone showed that a short period of intermittent
loading rapidly produces an increased level of orientation of proteoglycans within the bone tissue. In the absence of further
loading, this persists for over 24 hours. We have proposed that this phenomenon could provide a means for “capturing” the
effects of transient strains, and so provide a persistent, constantly updated strain-related influence on osteocyte populations
related to the bones' averaged recent strain history, in effect, a “strain memory” in bone tissue. In our present study, we
use the Alcian blue-induced birefringence technique to demonstrate that proteoglycan orientation also occurs after intermittent
loading of both cortical and cancellous mammalian bonein vivo andin vitro. We also show that the change in birefringence is proportional to the magnitude of the applied strain, and that the reorientation
occurs rapidly, reaching a maximal value after only 50 loading cycles. Examination of electron micrographs of bone tissue
after staining with cupromeronic blue allows direct visualization and quantification of the change in proteoglycan orientation
produced by loading. This shows that intermittent loading is associated with a realignment of the proteoglycan protein cores,
bringing them some 5 degrees closer to the direction of collagen fibrils in the bone matrix. 相似文献
970.
Bladder mucosa in urethral reconstructions 总被引:6,自引:0,他引:6