全文获取类型
收费全文 | 24394篇 |
免费 | 1287篇 |
国内免费 | 170篇 |
专业分类
耳鼻咽喉 | 275篇 |
儿科学 | 479篇 |
妇产科学 | 315篇 |
基础医学 | 2673篇 |
口腔科学 | 480篇 |
临床医学 | 1656篇 |
内科学 | 6833篇 |
皮肤病学 | 526篇 |
神经病学 | 1917篇 |
特种医学 | 896篇 |
外科学 | 4302篇 |
综合类 | 86篇 |
一般理论 | 1篇 |
预防医学 | 651篇 |
眼科学 | 537篇 |
药学 | 1387篇 |
中国医学 | 53篇 |
肿瘤学 | 2784篇 |
出版年
2024年 | 36篇 |
2023年 | 210篇 |
2022年 | 425篇 |
2021年 | 745篇 |
2020年 | 410篇 |
2019年 | 501篇 |
2018年 | 678篇 |
2017年 | 453篇 |
2016年 | 615篇 |
2015年 | 617篇 |
2014年 | 830篇 |
2013年 | 979篇 |
2012年 | 1559篇 |
2011年 | 1792篇 |
2010年 | 1003篇 |
2009年 | 892篇 |
2008年 | 1461篇 |
2007年 | 1523篇 |
2006年 | 1474篇 |
2005年 | 1511篇 |
2004年 | 1580篇 |
2003年 | 1419篇 |
2002年 | 1323篇 |
2001年 | 346篇 |
2000年 | 308篇 |
1999年 | 339篇 |
1998年 | 282篇 |
1997年 | 255篇 |
1996年 | 190篇 |
1995年 | 158篇 |
1994年 | 170篇 |
1993年 | 131篇 |
1992年 | 174篇 |
1991年 | 155篇 |
1990年 | 140篇 |
1989年 | 125篇 |
1988年 | 132篇 |
1987年 | 124篇 |
1986年 | 118篇 |
1985年 | 87篇 |
1984年 | 86篇 |
1983年 | 58篇 |
1982年 | 45篇 |
1981年 | 33篇 |
1980年 | 27篇 |
1979年 | 40篇 |
1977年 | 30篇 |
1975年 | 37篇 |
1974年 | 29篇 |
1973年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 28 毫秒
81.
Hiroshi Yamada Shizuo Oi Norihiko Tamaki Satoshi Matsumoto Katsuko Sudo 《Child's nervous system》1992,8(7):394-398
Primary aqueductal stenosis is one of the main causes of congenital hydrocephalus in humans and experimental models. The congenitally hydrocephalic rat strain LEW/Jms is one such model. In this report, we describe further detailed histological features of periaqueductal structure, including the posterior commissure, subcommissural organ (SCO), and ependyma, and discuss the changes in these structures in relation to the cause of hydrocephalus. Coronal sections of the aqueduct in normal rats showed that the usual ependyma was absent in the center of the base facing the dorsal side, which was replaced by tall columnar cells. On the other hand, in hydrocephalic rats the ependyma encircled the aqueductal cavity. In midline sagittal sections, normal and hydrocephalic rats showed the SCO, although the SCO in hydrocephalic rats was shorter than in normal rats. There was also a marked difference between normal and hydrocephalic rats in the dorsoventral dimension of the rostral midbrain. In hydrocephalus, this dimension was large in comparison with normal rats. The superior collicular commissure located caudal to the posterior commissure ran along the ventral side of the midbrain in rats with hydrocephalus, and there was a cell-depleted area just dorsal to the superior collicular commissure. The same findings were observed from the 17th day of gestation until the postnatal period. Although the role of the SCO has been widely discussed from the viewpoint of secretory function, the present study indicated that this organ might be involved in the formation of the shape of the aqueduct. 相似文献
82.
83.
Katsumi Kimura Naotaka Fujita Yutaka Noda Go Kobayashi Kei Ito Jun Horaguchi Toshiki Sugawara Osamu Takasawa 《Digestive endoscopy》2004,16(1):54-57
Clinical diagnosis of chronic cholecystitis is made based on diffuse hyperechoic thickening of the gallbladder wall as shown by ultrasonographic examination. We herein report three cases of chronic cholecystitis showing localized hypoechoic thickening of the gallbladder wall that mimicked gallbladder cancer by ultrasonography. Histologically, hypertrophy of the muscularis propria was a common characteristic finding in these three patients. A smooth surface of the inner hypoechoic layer of the thickened wall was considered to be a reliable finding in the differential diagnosis between this type of chronic cholecystitis and gallbladder cancer. 相似文献
84.
85.
Kuniaki Nakahara Satoru Shimizu Satoshi Utsuki Sachio Suzuki Hidehiro Oka Kiyotaka Fujii 《Child's nervous system》2007,23(8):863-865
Objects We evaluated whether the presence of lacunar skull deformity (LSD) with myelomeningocele is a predictive factor for subsequent
hydrocephalus development.
Materials and methods We reviewed the clinical and radiological records of 18 infants with myelomeningocele, divided the patients into groups with
(group A, n=9) and without (group B, n=9) ventriculomegaly at birth and assessed whether the presence of LSD was predictive of the necessity for ventriculoperitoneal
shunt (VPS) placement.
Results LSD was present in five group A patients. All nine group A patients underwent VPS placement. Among the group B patients, five
had LSD; they underwent VPS placement. A significantly higher proportion of those with ventricle enlargement or LSD at birth
required VPS placement (p=0.0001).
Conclusion Adding to the ventriculomegaly at birth, the presence of LSD alerts to the necessity to monitor these infants closely to determine
the necessity for VPS placement. 相似文献
86.
We report a case of primary diffuse leptomeningeal gliomatosis (PDLG) followed up with serial magnetic resonance images (MRI). A 45‐year‐old man manifested with bilateral abducens nerve palsy and meningisms. Repeated MRI revealed diffuse leptomeningeal enhancement throughout the central nervous system without intra‐axial mass accompanied with the dilatation of ventricles and focally enlarged cerebral sulci. Brain biopsies showed a leptomeningeal gliomatosis. The MRI findings described here would contribute to the diagnosis of PDLG among other common diseases diffusely spreading along the leptomeningeal structures. 相似文献
87.
Mitsuru Masaki Tadashi Kuroda Naoki Hosen Hisao Hirota Kazuo Terai Yuichi Oshima Yoshikazu Nakaoka Shoko Sugiyama Ryusuke Kimura Satoshi Yoshihara Manabu Kawakami Norishige Iizuka Yasuhiko Tomita Hiroyasu Ogawa Ichiro Kawase Keiko Yamauchi-Takihara 《Journal of the American Society of Echocardiography》2004,17(4):397-398
A 57-year-old man with a history of renal cell carcinoma presented with presyncope. He underwent nephrectomy years earlier followed by HLA-matched allogeneic peripheral-blood stem-cell transplantation. Echocardiographic investigation revealed a solitary right ventricle mass without contiguous vena caval or right atrial involvement. The mass was pathologically confirmed to be metastatic carcinoma in the right ventricular cavity. This case highlights the need to consider an underlying neoplastic syndrome in patients presenting isolated right ventricle mass by echocardiography. 相似文献
88.
Fumiki Oana Toshiki Homma Hiroo Takeda Akane Matsuzawa Satoshi Akahane Masayuki Isaji Masuo Akahane 《Pharmacological research》2005,52(5):395-400
We aimed to examine the effects of KTO-7924 (beta3-adrenoceptor agonist) on lipid metabolism and mRNA expressions in retroperitoneal white adipose tissue (RP WAT) in obese (fa/fa) Zucker rats using DNA microarray. Oral KTO-7924 for 28 days significantly decreased RP WAT weight, plasma triglyceride, free fatty acid, and insulin, and improved insulin resistance in oral glucose tolerance tests. In RP WAT of KTO-7924-treated rats, DNA microarray analysis revealed specifically enhanced mRNA expressions of uncoupling protein 1 (UCP1) and cytochrome c oxidase subunit VIII-H (COX8H), which are reportedly highly expressed in brown adipose tissue (BAT). Since these mRNA expression levels in RP WAT were significantly lower in obese (fa/fa) Zucker rats than in lean Zucker rats, these genes may be important in lipid metabolism. Our results imply that in obese (fa/fa) Zucker rats, continuous stimulation of beta3-adrenoceptors by KTO-7924 causes BAT-like adipocytes to appear in RP WAT, and improves lipid metabolism. 相似文献
89.
Takashi Ishimori Satoru Nakano Yasutane Mori Reiko Seo Taro Togami Tetsuya Masada Toshiaki Kusuhara Motoomi Ohkawa Seigo Nagao Yuichi Yamashita Satoshi Sugiura 《Magnetic resonance in medical sciences》2007,6(4):225-229
PURPOSE: We assessed the feasibility of utilizing three-dimensional (3D) phase sensitive inversion recovery (IR) images for preoperatively determining deep brain stimulator position. METHODS: We measured geometric distortion with a grid phantom and evaluated images of 3 volunteers to determine optimum imaging parameters for 3D phase sensitive IR. RESULTS: Geometric distortion measured less than 1.0%. Respective inversion and recovery times, which provided high T(1) contrast between the subthalamic nucleus and adjacent tissue, were 200 and 4000 ms. In studies of 3 volunteers and 2 patients, the subthalamic nucleus was clearly depicted in 3D phase sensitive IR images. The measured coordinates of the subthalamic nucleus agreed well with those calculated by conventional estimation from midpoint of the anterior and posterior commissure. CONCLUSION: Three-dimensional phase sensitive inversion recovery was useful in visualizing the subthalamic nucleus for effective deep brain stimulation. 相似文献
90.
Satoshi Suzuki Koji Yasuda Yuji Matsumura Takashi Kondo 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2006,54(5):225-227
We present here a rare case of left-side catamenial pneumothorax, in which endometrial tissue pleura was found on the visceral pleura histologically. A chest roentogenogram confirmed the left pneumothorax, but did not reveal bullae or any associated anomalies, in a 41-year-old woman with three documented episodes of left-side pneumothorax occurring every menstruation. Video-assisted thoracoscopic surgery revealed not only tiny holes in the diaphragm, but also a scattered small brown spots on the visceral pleura. Histological examination of the lung sections revealed the existence of endometrial tissue on the visceral pleura with disrupted pleural elastic fibers. Our case suggests that cyclic erosion of the visceral pleura by the implanted endometrial tissue caused air leakage from the lung, in addition to the most accepted concept that air is aspirated into the thoracic cavity via the abdomen through the acquired fenestration of the diaphragm. 相似文献