全文获取类型
收费全文 | 2048242篇 |
免费 | 148025篇 |
国内免费 | 3128篇 |
专业分类
耳鼻咽喉 | 29345篇 |
儿科学 | 62226篇 |
妇产科学 | 57286篇 |
基础医学 | 295071篇 |
口腔科学 | 59654篇 |
临床医学 | 175787篇 |
内科学 | 400849篇 |
皮肤病学 | 42735篇 |
神经病学 | 159403篇 |
特种医学 | 80419篇 |
外国民族医学 | 438篇 |
外科学 | 324299篇 |
综合类 | 41587篇 |
现状与发展 | 2篇 |
一般理论 | 510篇 |
预防医学 | 144543篇 |
眼科学 | 47321篇 |
药学 | 158227篇 |
3篇 | |
中国医学 | 4302篇 |
肿瘤学 | 115388篇 |
出版年
2018年 | 19108篇 |
2016年 | 16343篇 |
2015年 | 18846篇 |
2014年 | 25820篇 |
2013年 | 38820篇 |
2012年 | 53221篇 |
2011年 | 56543篇 |
2010年 | 33525篇 |
2009年 | 31771篇 |
2008年 | 55086篇 |
2007年 | 59052篇 |
2006年 | 60116篇 |
2005年 | 58586篇 |
2004年 | 56581篇 |
2003年 | 54690篇 |
2002年 | 53846篇 |
2001年 | 102492篇 |
2000年 | 105729篇 |
1999年 | 89199篇 |
1998年 | 23159篇 |
1997年 | 20592篇 |
1996年 | 20811篇 |
1995年 | 19524篇 |
1994年 | 18397篇 |
1993年 | 17009篇 |
1992年 | 70291篇 |
1991年 | 68320篇 |
1990年 | 66881篇 |
1989年 | 65126篇 |
1988年 | 60289篇 |
1987年 | 58822篇 |
1986年 | 55682篇 |
1985年 | 53194篇 |
1984年 | 38897篇 |
1983年 | 33471篇 |
1982年 | 18835篇 |
1981年 | 16566篇 |
1979年 | 35894篇 |
1978年 | 24808篇 |
1977年 | 21422篇 |
1976年 | 19564篇 |
1975年 | 21504篇 |
1974年 | 25662篇 |
1973年 | 24441篇 |
1972年 | 23343篇 |
1971年 | 21855篇 |
1970年 | 20526篇 |
1969年 | 19665篇 |
1968年 | 18241篇 |
1967年 | 16129篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
Addison's disease is rarely caused by metastatic cancer. We report a unique case of hypoadrenalism owing to metastatic transitional cell carcinoma of the bladder. The relevant literature is reviewed. 相似文献
922.
In a previous study, we described a new method [3] to measure Na reabsorption by each segment of the human nephron independently. Reabsorption was expressed as equivalent volumes of solute-free water (CH2O) generated by the loop of Henle (CH2O-HL) and by the distal tubule (CH2O-DT), and dissipated by back diffusion (BD) across collecting ducts (CH2O-BD). These data were obtained during maximal water diuresis (MWD). The present study was undertaken to calculate CH2O-HL by experiments performed during maximal antidiuresis (MA). For this purpose, a new theoretical approach was devised, described by algebraic equations which allowed calculations of segmental transport during MA alone, where only CH2O-HL could be calculated independently. The study was performed on 14 normal volunteers who were studied twice by clearance measurements, firstly during MWD and again during MA. In each experiment, clearance periods were performed during baseline conditions and during the administration of furosemide (0.7 mg/kg bolus injection followed by 0.06 mg/kg/min maintenance infusion). From the values measured during either condition, segmental reabsorption was calculated. During MWD, CH2O-HL averaged 19.4 + 10.4, during MA 20.4 + 8.0 ml/min/GFR X 100; p greater than 0.05. The paired measurements were significantly correlated (r = 0.80; p less than 0.01). These data demonstrate that CH2O-HL obtained with the original theory is a reproducible result that can be confirmed with independent measurements obtained during different experimental conditions. Thus, measurements of segmental Na transport in the human nephron are feasible and can contribute important informations on disease states. 相似文献
923.
Uptake of iodine-123 MIBG by pheochromocytomas, paragangliomas, and neuroblastomas: a histopathological comparison 总被引:2,自引:0,他引:2
J Bomanji D A Levison W D Flatman T Horne P M Bouloux G Ross K E Britton G M Besser 《Journal of nuclear medicine》1987,28(6):973-978
The percentage uptake of [123I]metaiodobenzylguanidine (MIBG) by tumors of the paraganglion system is compared with the number of neurosecretory granules (assessed by both light and electron microscopy) in the subsequently resected tumors in six patients. Iodine-123 MIBG was injected intravenously; the tumor uptake of [123I]MIBG varied between 0.001% and 0.14% of the injected dose per gram of tumor tissue at 22 hr. The number of neurosecretory granules in tissue sections was scored on a scale of I-III. A direct proportional correlation was found between the percentage uptake of [123I]MIBG by the tumor and the number of neurosecretory granules in the tissue sections but not with plasma or urinary catecholamines. This technique for imaging reflects the storage status of the tumor better than plasma and urinary catecholamine measurements. 相似文献
924.
Up to now two abnormal nephrographic patterns have been described as a result of arterial hypotension as an adverse response to urographic contrast material. We would like to describe a third pattern. 相似文献
925.
926.
927.
(E)-5-(2-Bromovinyl)-2'-deoxyuridine (1; BrVUdR) inhibits the replication of herpes simplex virus type 1 (HSV-1) and of varicella-zoster virus (VZV) in vitro at concentrations of 0.01 to 0.23 mumol/l, whereas herpes simplex virus type 2 (HSV-2) is influenced only at 5.5 to 27 mumol/l. In comparison to some classical and newly developed antiherpetics, i. e. 5-iodo-2'-desoxyuridine (2; idoxuridine, IDU), 9-beta-D-arabinofuranosyladenine (4; vidarabine Ara-A), 9-(2-hydroxyethoxymethyl) guanine (5; acyclovir, ACV) and 2'-fluoro-5-iodo-1-beta-D-aracytosine (6;FIAC) the following order of decreasing activity was found:1 greater than 6 greater than 5 greater than 2 greater than 4 (against HSV-1) and 6 greater than 2 greater than 5 greater than 1 greater than 4 (against HSV-2). The high selectivity of the antiviral effect of BrVUdR towards HSV-1 and TZV is based on the fact, that proliferation of different mammalian cell lines is inhibited by 50% only at concentrations as high as 90 to 170 mumol/l, resulting in a therapeutical index of 1000 to 10,000. Successful treatment of an HSV-1 encephalitis in mice as well as an HSV-1 keratitis of rabbits confirmed the efficiency of 1 in experimental animal infections. No toxic side effects in both local and systemic applications were observed. Promising data from cell culture and animal experiments recommend 1 as a potential candidate for the local and systemic treatment of HSV-1 and VZV infections in man. 相似文献
928.
929.
Several antisera specific to neuropeptides of vertebrates were applied to sections of the earthworm Eisenia fetida Sav. Some of them were able to reveal specific neurones of the supraoesophageal ganglion: h-GHRF, CRF, Leu- and Met-enkephalin, dynorphin, substance P, CCK-8, and CCK-8S. A map of different areas or nuclei was established in the brain, taking position of reactive cells into account. Four symmetrically paired nuclei and one mediodorsal nucleus were identified and plotted. There is generally no characteristic modification correlated with maturation of the worms. However, the reaction against anti-Leu-enkephalin differs significantly according to age of Eisenia in nucleus No. 1 and particularly in nuclei No. 2 where one cell group presents specific reactivity on and after puberty. Moreover, the successive application of two antisera to the same sections after elution showed no coexistence of substances in a single neurone. By comparison with these vertebrate peptide-like containing nerve cells, the assay to anti-5-HT showed only a few reactive aminergic neurones. An attempt of correlation of cellular types with reactive perikarya is started. 相似文献
930.