全文获取类型
收费全文 | 1421229篇 |
免费 | 100054篇 |
国内免费 | 3386篇 |
专业分类
耳鼻咽喉 | 20773篇 |
儿科学 | 42259篇 |
妇产科学 | 39892篇 |
基础医学 | 198124篇 |
口腔科学 | 41887篇 |
临床医学 | 121198篇 |
内科学 | 280743篇 |
皮肤病学 | 31591篇 |
神经病学 | 114482篇 |
特种医学 | 57163篇 |
外国民族医学 | 436篇 |
外科学 | 222438篇 |
综合类 | 31750篇 |
现状与发展 | 6篇 |
一般理论 | 628篇 |
预防医学 | 97980篇 |
眼科学 | 33004篇 |
药学 | 105325篇 |
4篇 | |
中国医学 | 3112篇 |
肿瘤学 | 81874篇 |
出版年
2018年 | 14698篇 |
2017年 | 11644篇 |
2016年 | 12833篇 |
2015年 | 14410篇 |
2014年 | 20182篇 |
2013年 | 29710篇 |
2012年 | 39814篇 |
2011年 | 41619篇 |
2010年 | 24524篇 |
2009年 | 23509篇 |
2008年 | 39144篇 |
2007年 | 42083篇 |
2006年 | 42529篇 |
2005年 | 41141篇 |
2004年 | 39729篇 |
2003年 | 38308篇 |
2002年 | 37409篇 |
2001年 | 64165篇 |
2000年 | 65742篇 |
1999年 | 55986篇 |
1998年 | 15467篇 |
1997年 | 14082篇 |
1996年 | 13440篇 |
1995年 | 12728篇 |
1994年 | 11854篇 |
1992年 | 43072篇 |
1991年 | 41565篇 |
1990年 | 40816篇 |
1989年 | 39796篇 |
1988年 | 37212篇 |
1987年 | 36630篇 |
1986年 | 35152篇 |
1985年 | 33362篇 |
1984年 | 25130篇 |
1983年 | 21317篇 |
1982年 | 12952篇 |
1981年 | 11860篇 |
1979年 | 24051篇 |
1978年 | 17231篇 |
1977年 | 14989篇 |
1976年 | 13492篇 |
1975年 | 15378篇 |
1974年 | 18191篇 |
1973年 | 17648篇 |
1972年 | 16884篇 |
1971年 | 15794篇 |
1970年 | 14973篇 |
1969年 | 14388篇 |
1968年 | 13503篇 |
1967年 | 12043篇 |
排序方式: 共有10000条查询结果,搜索用时 68 毫秒
991.
Chretien Marie Francoise; Lebouvier Brigitte; Denis Alain; Chappard Daniel 《Human reproduction (Oxford, England)》1998,13(10):2767-2771
A cytomorphometric analysis of superficial vaginal cells inwomen in three groups of different types of hormonal concentrationwas made. There were 15 women in each group. Group I was studiedduring a natural cycle, group II under oral contraceptive therapyand group III during an in-vitro fertilization (IVF) stimulationprotocol. Morphometric parameters were measured on an imageanalyser. The area, perimeter and several form factors weremeasured separately for nuclei and cytoplasm. The nucleus:cytoplasmicratio was also determined. The cytoplasmic area was significantlyreduced in group II and was associated with a statisticallysignificant reduction of the nuclear area. The nucleus:cytoplasmicratio appeared significantly increased in group II and reducedin group III. Low oestradiol impregnation obtained with an oralminidosed contraceptive interfered with vaginal cell maturation.High oestradiol concentrations obtained during IVF protocolsinduced marked nuclear pycnosis but did not induce supra-physiologicalcell enlargement. Maximal cell size is genetically regulatedaccording to Driesch's law of volume invariance and hormonalover-stimulation has no effect on cell size. The nucleus:cytoplasmicratio appears to be a powerful parameter reflecting the oppositeeffects of hormones on cell compartments. 相似文献
992.
993.
I. Celebi S. Tekgül H. A. Özen I. Özgü D. Remzi 《International urology and nephrology》1995,27(2):183-187
Bilateral germ cell tumours of the testis are rare but a rise in their incidence is expected since with the new therapeutic
possibilities a significant improvement in prognosis has been achieved even in patients with advanced metastatic spread. Of
the 210 patients treated for malignent germ cell tumours at our Department, six (2.9%) developed a contralateral testicular
tumour. All patients had metachronous tumours and the second tumours occurred after an interval ranging between 1 and 22 years.
The epidemiology, histology, diagnosis, therapy and prognosis are discussed, and the significance of regular self-examination
of the remaining testis in patients with testicular tumour is emphasized. 相似文献
994.
995.
996.
997.
998.
999.
A P Jones A Sofat C H Davis S Denton N T Gurusinghe 《British journal of neurosurgery》1990,4(3):193-197
The high cost of commercial CT-compatible stereotactic frames has restricted the availability of CT-guided stereotaxy for many neurosurgical centres. However, many of these centres do possess the standard stereotactic frames for projection radiography, of which the old type Leksell frame is probably the most common. We have devised a simple and low-cost modification to an old Leksell frame to allow CT-guided stereotaxy. The nature of the modifications allow complete freedom of positioning of the frame relative to the CT scanner and coordinate transformations can be performed simply and effectively. The modified frame has been used successfully for some 18 months and the modification has now been performed at two centres in the North West Regional Health Authority. We hope this modification will allow many other centres to embark on CT-guided stereotaxy. 相似文献
1000.
Hydrosyringomyelia associated with a Chiari I malformation in children and adolescents 总被引:3,自引:0,他引:3
The clinical presentation, radiological features, and results of surgical treatment were analyzed in 17 cases of hydrosyringomyelia associated with a Chiari malformation, in children and adolescents younger than 20 years of age. The initial symptoms were a skeletal abnormality (71%), such as scoliosis (11 patients) or pes cavus (1 patient), pain or numbness (24%), and motor weakness (6%). Frequently seen signs on admission were sensory deficit (100%), scoliosis (85%), muscle weakness (64%), muscle atrophy (35%), and lower cranial nerve palsy (35%). The characteristic neurological findings were unilateral sensory and motor deficits (65%) with decreased or absent deep tendon reflexes on the same side. The localization of the syrinx on the axial section varied according to the level, even in the same patient. In 11 patients with unilateral sensory disturbances or unilateral sensory and motor deficits, the syrinx was located in the region corresponding to the posterolateral portion on the same side as that of sensory disturbance at the cervical or thoracic level. On the other hand, in 6 patients with bilateral sensory and motor deficits, the syrinx was located in the central portion and extended into the posterolateral portion of the more affected side. A syringosubarachnoid shunt was placed in 16 patients, foramen magnum decompression without closure of the obex was performed in 1 patient, ventriculoperitoneal shunt in 1 patient, terminal syringostomy in 1 patient, and foramen magnum decompression with terminal syringostomy in 1 patient. In 15 of 17 patients (88%), the neurological symptoms improved after an average follow-up of 4 years and 1 month. We think that as a surgical treatment, placement of a syringosubarachnoid shunt is effective. 相似文献