全文获取类型
收费全文 | 12760篇 |
免费 | 642篇 |
国内免费 | 87篇 |
学科分类
医药卫生 | 13489篇 |
出版年
2023年 | 77篇 |
2022年 | 101篇 |
2021年 | 311篇 |
2020年 | 149篇 |
2019年 | 212篇 |
2018年 | 267篇 |
2017年 | 214篇 |
2016年 | 286篇 |
2015年 | 279篇 |
2014年 | 309篇 |
2013年 | 369篇 |
2012年 | 617篇 |
2011年 | 681篇 |
2010年 | 461篇 |
2009年 | 327篇 |
2008年 | 554篇 |
2007年 | 609篇 |
2006年 | 602篇 |
2005年 | 593篇 |
2004年 | 565篇 |
2003年 | 549篇 |
2002年 | 567篇 |
2001年 | 412篇 |
2000年 | 352篇 |
1999年 | 367篇 |
1998年 | 157篇 |
1997年 | 122篇 |
1996年 | 121篇 |
1995年 | 89篇 |
1994年 | 89篇 |
1993年 | 103篇 |
1992年 | 283篇 |
1991年 | 217篇 |
1990年 | 187篇 |
1989年 | 230篇 |
1988年 | 186篇 |
1987年 | 226篇 |
1986年 | 188篇 |
1985年 | 186篇 |
1984年 | 135篇 |
1983年 | 114篇 |
1979年 | 122篇 |
1978年 | 59篇 |
1975年 | 59篇 |
1974年 | 72篇 |
1973年 | 57篇 |
1972年 | 57篇 |
1970年 | 74篇 |
1968年 | 64篇 |
1967年 | 61篇 |
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
11.
A case of Ullrich disease was presented. The patient was a 3-year-old girl with torticollis, generalized muscle weakness and acroatonia since birth. High-arched palate, protruded calcaneus, and mild contracture of proximal joints were also recognized. Intellectual development was normal. Serum level of CPK was slightly increased. In histological and histochemical examinations of quadriceps femoris muscle, proliferated connective tissue, marked variation in the muscle fiber diameter, and a lot of degenerated and regenerated fibers were recognized. Minimal injury easily causes subcutaneous hemorrhage, but no abnormality was found in the structure of collagen. 相似文献
12.
13.
Yasuo Kikuchi Naoji Kubota Kazushi Maruo Yasuo Goto 《Macromolecular chemistry and physics.》1987,188(11):2631-2642
Water-insoluble polyelectrolyte complexes (PEC) were prepared by mixing methyl glycol chitosan (MGC, 1 ) and [2-(diethylamino)ethyl]dextran (EA, 2 ) with poly(potassium vinyl sulfate) (PVSK, 3 ) in aqueous solution at various hydrogen ion concentrations. Elemental analyses, IR spectroscopy, and solubilities of PEC reveal that PEC differ in molecular structure and properties according to pH. It seems that the degree of dissociation and the conformation of MGC, EA, and PVSK change with pH. PEC membranes were made by casting from solutions of all kinds of PEC, and transport phenomena through the membrane of PEC prepared in 4 wt.-% HCl solution were investigated under various conditions. The driving force of the transport depends on the membrance potential, Donnan potential, and diffusion potential, according to measurements of the transport ratio of Na+ and the electric potential difference between the left- and right-hand side of the membrane. Moreover, the permeability of K+ is higher than that of Na+. 相似文献
14.
15.
Madoka Minoguchi Nobuyuki Yanagawa Chisato Ishikawa Junpei Sasajima Mitsuru Goto Miho Okamoto Yoshinori Saito Masanori Murakami Yutaka Orii Toru Yaosaka 《Nihon Shokakibyo Gakkai zasshi》2007,104(7):1082-1087
Pancreatic metastasis of malignant melanoma is rarely diagnosed while the patient is alive. We report a case of metastatic melanoma of the pancreas in a 35-year-old woman presenting with a solid mass of the pancreas. Her past medical history included a radical hysterectomy 2 years previously for malignant melanoma of the vagina. Twelve months later, lung metastasis was also resected. EUS-guided fine needle aspiration (EUS-FNA) identified that the pancreatic tumor was histologically and immunohistochemically identical to the surgical specimen of her lung neoplasm. Imaging studies including US, CT, and MRI have limited value to distinguish the tumors from primary ductal adenocarcinoma. EUS-FNA can provide tissue diagnosis from pancreatic masses, specifically when other modalities have failed. 相似文献
16.
17.
18.
19.
20.
Kazumichi Yamada Satoshi Goto Taro Oyama Makoto Yoshikawa Shinji Nagahiro Yukitaka Ushio 《Acta neuropathologica》1995,89(2):172-177
The present study concerns the vulnerability of striatal interneurons immunopositive for the Ca2+-binding protein calretinin to ischemic neuronal injury. An immunohistochemical study was carried out on the striata of rats which had undergone transient middle cerebral artery occlusion. Two weeks after the ischemia, there was a marked reduction in the number of calretinin-positive neurons in the ipsilateral ischemic lesion, although the striatal interneurons positive for parvalbumin, which are a neuronal population distinct from the calretinin-immunoreactive cells in the striatum, were spared in the insulted areas. The present data indicate that the striatal calretinin-positive neurons are less resistant to transient ischemia, suggesting that there may exist vulnerability differences among the striatal interneurons in ischemia-induced neuronal injury. 相似文献