全文获取类型
收费全文 | 900175篇 |
免费 | 62311篇 |
国内免费 | 2333篇 |
专业分类
耳鼻咽喉 | 12475篇 |
儿科学 | 28681篇 |
妇产科学 | 26151篇 |
基础医学 | 126637篇 |
口腔科学 | 24747篇 |
临床医学 | 74782篇 |
内科学 | 183255篇 |
皮肤病学 | 18988篇 |
神经病学 | 71407篇 |
特种医学 | 36449篇 |
外国民族医学 | 336篇 |
外科学 | 142204篇 |
综合类 | 19031篇 |
一般理论 | 247篇 |
预防医学 | 64569篇 |
眼科学 | 20092篇 |
药学 | 63850篇 |
中国医学 | 1799篇 |
肿瘤学 | 49119篇 |
出版年
2018年 | 9062篇 |
2017年 | 7170篇 |
2016年 | 7681篇 |
2015年 | 8732篇 |
2014年 | 12369篇 |
2013年 | 19226篇 |
2012年 | 25670篇 |
2011年 | 27285篇 |
2010年 | 16588篇 |
2009年 | 15798篇 |
2008年 | 26147篇 |
2007年 | 27752篇 |
2006年 | 27940篇 |
2005年 | 27473篇 |
2004年 | 26310篇 |
2003年 | 25479篇 |
2002年 | 25071篇 |
2001年 | 41372篇 |
2000年 | 42564篇 |
1999年 | 36276篇 |
1998年 | 9969篇 |
1997年 | 9150篇 |
1996年 | 9084篇 |
1995年 | 8446篇 |
1994年 | 8085篇 |
1993年 | 7585篇 |
1992年 | 28203篇 |
1991年 | 26988篇 |
1990年 | 26416篇 |
1989年 | 25350篇 |
1988年 | 23561篇 |
1987年 | 23177篇 |
1986年 | 22254篇 |
1985年 | 21158篇 |
1984年 | 15812篇 |
1983年 | 13484篇 |
1982年 | 8094篇 |
1979年 | 14590篇 |
1978年 | 10211篇 |
1977年 | 8628篇 |
1976年 | 8151篇 |
1975年 | 8967篇 |
1974年 | 10700篇 |
1973年 | 10182篇 |
1972年 | 9662篇 |
1971年 | 8917篇 |
1970年 | 8584篇 |
1969年 | 8026篇 |
1968年 | 7684篇 |
1967年 | 7087篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
982.
Malignant angioendotheliosis involving the nervous system: support for a lymphoid origin of the neoplastic cells. 总被引:1,自引:1,他引:0 下载免费PDF全文
S E Daniel P Rudge F Scaravilli 《Journal of neurology, neurosurgery, and psychiatry》1987,50(9):1173-1177
The clinical and post mortem findings of a case of malignant angioendotheliosis are described. The patient presented with neurological signs attributable to repeated episodes of cerebral and spinal cord infarction. Histological examination showed multifocal intravascular proliferation of mononuclear cells. Immunocytochemical characterisation of these neoplastic cells supports the recent suggestion that this disease represents an unusual form of intravascular lymphoma, which appears to show a predilection for blood vessels of the nervous system. 相似文献
983.
The subacute sclerosing panencephalitis is one of the few child dementiae. An eight cases study is the opportunity of analysing the clinical, electrical and evolutive particularities of this very serious prognosis disease. The circumstantial comment of a thirteen-year-followed-case illustrates the clinical features, the electrical evolution, and the late C.T. scan aspects. 相似文献
984.
Comparison of trichloroethylene and enflurane as adjuncts to nitrous oxide and relaxant anaesthesia 总被引:1,自引:0,他引:1
Forty women who underwent gynaecological surgery were randomly allocated to receive trichloroethylene, enflurane, or enflurane plus fentanyl as adjuncts to nitrous oxide/relaxant anaesthesia with controlled ventilation. No serious cardiac dysrhythmias were seen in any group. Each patient was observed postoperatively for 4 hours by a nurse blind to the technique used, and questioned at 24 hours by a similarly blinded anaesthetist. Recovery after trichloroethylene was not significantly prolonged although postoperative analgesia by visual analogue was better, opiate analgesia was required less frequently and there was less nausea and vomiting than in either of the enflurane groups. We argue for the continued use of trichloroethylene by this technique, because it costs one hundred times less than enflurane and because of the potential morbidity of the postoperative opiate dosage required after enflurane. 相似文献
985.
986.
987.
988.
Postnatal development of the chemosensitivity of rat cerebellar Purkinje cells to excitatory amino acids. An in vitro study 总被引:5,自引:0,他引:5
In vitro sagittal slices of immature rat cerebellum were used to study the development of the sensitivity of Purkinje cells (PCs) to L-aspartate (L-Asp), L-glutamate (L-Glu) and related derivatives. As early as postnatal day 0 all PCs already displayed clear excitatory responses to short iontophoretic applications of L-Asp, L-Glu and quisqualate while in the same conditions no effect of N-methyl-D,L-aspartate (NMDLA) was detected. By postnatal day 5, i.e. after the onset of the synaptogenesis, the sensitivity of PCs to L-Asp, L-Glu and quisqualate significantly increased up to values similar to those recorded in adult rat cerebellum and surprisingly nearly all (87%) the recorded cells now also displayed excitatory responses to NMDLA. Although this sensitivity of PCs to NMDLA was significantly lower than that observed with the other drugs, it persisted until the end of the first postnatal month when the adult type of connectivity is already well established but at this stage only 30 per cent of the tested cells were still sensitive to the agonist. During this period, excitatory responses elicited by NMDLA were selectively antagonized by 2-amino-5-phosphonovalerate (2-APV), suggesting that during postnatal development, NMDA receptor types are transiently expressed on PCs membranes since in the adult, NMDLA no longer had an excitatory effect. Instead, this drug now exerted a preferential antagonistic action on the excitatory response elicited by L-Asp. Also in the adult, no major changes occurred in the sensitivity of PCs to L-Asp, L-Glu and quisqualate when these drugs were ejected at a dendritic site whereas, when ejected at the somatic level, the sensitivity of the cell appeared 2-3 times lower. 相似文献
989.
A V Pinto V F Ferreira R S Capella B Gilbert M C Pinto J S da Silva 《Transactions of the Royal Society of Tropical Medicine and Hygiene》1987,81(4):609-610
Accidental transmission of Chagas disease to man by blood transfusion is a serious problem in Latin America. This paper describes the testing of several naphthoquinones, some of which were active against blood trypomastigotes in vitro at 4 degrees C and might therefore warrant further study for preventing transmission of Chagas disease by blood transfusion. 相似文献
990.
Localized primary (AL) amyloid tumor of the breast. Cytologic, histologic, immunocytochemical and ultrastructural observations 总被引:2,自引:0,他引:2
J F Silverman D J Dabbs H T Norris W J Pories J Legier S Kay 《The American journal of surgical pathology》1986,10(8):539-545
Two examples of localized primary amyloid tumor of the breast are presented, including one patient with metachronous bilateral lesions. Our findings and review of the literature indicate that this rare lesion occurs predominantly in elderly females and can be mammographically and clinically confused with carcinoma. Fine-needle aspiration biopsy can be a useful procedure to make a preliminary diagnosis. Congo red staining with prior potassium permanganate incubation confirmed the AL type of amyloid in our two cases; this might be the predominant type in the localized form involving the breast. Immunofluorescence studies demonstrated IgA, with kappa and lambda light-chain deposition within the amyloid foci in one case, and intracytoplasmic IgG with both light chains within plasma cells and amyloid deposits of the second case. Ultrastructural examination of one of the cases showed characteristic findings of straight, nonbranching fibrils of 4-9 nm, diagnostic of amyloid. From our findings and a review of the literature, we conclude that amyloid tumors of the breast can occur in three separate settings: secondary amyloidosis, systemic or multiple myeloma associated amyloidosis, and as a localized primary type having a benign course. 相似文献