全文获取类型
收费全文 | 43764篇 |
免费 | 2215篇 |
国内免费 | 227篇 |
专业分类
耳鼻咽喉 | 555篇 |
儿科学 | 819篇 |
妇产科学 | 485篇 |
基础医学 | 5266篇 |
口腔科学 | 1437篇 |
临床医学 | 2942篇 |
内科学 | 10395篇 |
皮肤病学 | 819篇 |
神经病学 | 4088篇 |
特种医学 | 2088篇 |
外国民族医学 | 1篇 |
外科学 | 7152篇 |
综合类 | 160篇 |
现状与发展 | 1篇 |
一般理论 | 7篇 |
预防医学 | 1317篇 |
眼科学 | 882篇 |
药学 | 2747篇 |
中国医学 | 96篇 |
肿瘤学 | 4949篇 |
出版年
2023年 | 235篇 |
2022年 | 451篇 |
2021年 | 779篇 |
2020年 | 458篇 |
2019年 | 596篇 |
2018年 | 782篇 |
2017年 | 647篇 |
2016年 | 825篇 |
2015年 | 785篇 |
2014年 | 1079篇 |
2013年 | 1297篇 |
2012年 | 2070篇 |
2011年 | 2182篇 |
2010年 | 1365篇 |
2009年 | 1169篇 |
2008年 | 1998篇 |
2007年 | 2227篇 |
2006年 | 2052篇 |
2005年 | 2053篇 |
2004年 | 2033篇 |
2003年 | 1942篇 |
2002年 | 1965篇 |
2001年 | 1415篇 |
2000年 | 1497篇 |
1999年 | 1372篇 |
1998年 | 609篇 |
1997年 | 478篇 |
1996年 | 440篇 |
1995年 | 376篇 |
1994年 | 374篇 |
1993年 | 330篇 |
1992年 | 1046篇 |
1991年 | 882篇 |
1990年 | 836篇 |
1989年 | 831篇 |
1988年 | 782篇 |
1987年 | 784篇 |
1986年 | 685篇 |
1985年 | 640篇 |
1984年 | 445篇 |
1983年 | 366篇 |
1982年 | 157篇 |
1979年 | 305篇 |
1978年 | 209篇 |
1977年 | 188篇 |
1974年 | 194篇 |
1973年 | 167篇 |
1972年 | 164篇 |
1971年 | 186篇 |
1969年 | 183篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
The precise course and termination levels of the corticospinal tract (CST) in the cat were studied using the anterograde transport of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP). Following injection of WGA-HRP into the pericruciate (sensorimotor) cortex on one side, we observed the precise caudal termination levels of the CST fibers in the lateral and ventral funiculi. Simultaneously, the bilateral CSTs descending through the dorsal funiculus of the spinal cord were identified. Anterogradely labeled CST fibers within the lateral and ventral funiculi were observed bilaterally to reach the level of the third sacral (S3) spinal segment, which is lower than that ever described. The lowest level of the CST fibers within the dorsal funiculus, however, reached the level of the first sacral (S1) spinal segment. In conclusion, this study demonstrates that, in the cat, there exist 6 different CSTs (crossed and uncrossed lateral, ventral, dorsal) and that the termination levels of the lateral and ventral CSTs are much lower than those described in previous reports. 相似文献
44.
M Nakayama Y Takahashi H Itoh K Kamiya M Shiratsuchi G Otani 《The Journal of antibiotics》1989,42(11):1535-1540
Two antifungal antibiotics maniwamycins A and B were isolated from the culture broth of a strain of actinomycetes, which were classified as Streptomyces prasinopilosus. These antibiotics were isolated by resin absorption and extraction with EtOAc and purified by column chromatography. Both antibiotics were found to be new azoxy substances from their physico-chemical properties. They showed broad antifungal spectra. 相似文献
45.
Kazuhiko Yanai Tatsuo Ido Kiichi Ishiwata Jun Hatazawa Toshihiro Takahashi Ren Iwata Taiju Matsuzawa 《European journal of nuclear medicine and molecular imaging》1986,12(3):141-146
The endogenous hallucinogen, N,N-dimethyltryptamine (DMT), was labeled with carbon-11 and its regional distribution in rat brain studied. [11C]DMT showed higher accumulation in the cerebral cortex, caudate putamen, and amygdaloid nuclei. Studies of the subcellular distribution of [11C]DMT revealed the specific localization in the fractions enriched with serotonin receptors only when a very low dose was injected into rats. The proportions of the radioactivity in receptor-rich fractions were greatly enhanced by pretreatment with the monoamine oxidase inhibitor, pargyline. Specific binding of [11C]DMT to serotonin receptors in dog brain was demonstrated by a positron emission tomographic study in which 5-methoxy-N,N-dimethyltryptamine caused approximately 20% displacement of the radioligand from the receptors. 相似文献
46.
Tatsurou Tanaka Yasuhiro Morimoto Hiroshi Takano Kazuhiro Tominaga Shinji Kito Sachiko Okabe Tetsu Takahashi Jin-ichi Fukuda Takeshi Ohba 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2005,100(5):609-613
OBJECTIVE: To evaluate a proposed technique for the 3-dimensional (3D) detection of hemangiomas, including vascular malformation and their feeding arteries, in the head and neck. The new technique combines phase-contrast magnetic resonance angiography (PCMRA) without contrast medium and 3D fast asymmetric spin-echo (FASE) sequences. METHODS: The technique was applied to 3 patients having hemangiomas in the head and neck region. In 1 patient the image obtained with the proposed technique was compared to that obtained by standard contrast angiography. RESULTS: In all 3 patients, the 3D presence of the hemangiomas and the feeding arteries were well defined in images created by the proposed technique. Additionally, the characterization of the hemangioma's 3D structure and distribution of the feeding arteries coincided with those observed using contrast angiography in the case for which contrast angiography was also performed. CONCLUSIONS: Preliminary experience shows that the proposed technique combining 3D-FASE and 3D-PCMRA is useful to visualize both the 3D structure of hemangiomas and to identify the 3D distribution of the feeding arteries without using contrast medium. 相似文献
47.
48.
Yukinori Sakao Toru Sakuragi Yuji Takeda Masafumi Natsuaki Tsuyoshi Itoh 《General thoracic and cardiovascular surgery》2003,51(10):537-540
We experienced a rare case of giant cell tumor (GCT) arising in the 5th rib involving the 5th vertebral body and transverse process. A 57-year-old man presented with a well-defined mass in the left thoracic cavity on chest x ray examination. Chest computed tomography showed a heterogeneous 7cm-diameter mass originating in the posterior segment of the left 5th rib. The tumor had spread to the 5th thoracic vertebra destroying the left half of the body and transverse process. Magnetic resonance imaging showed a heterogeneous-intensity mass involving the 4th to 6th ribs. A radical excision of the tumor followed by a 50 Gy radiotherapy was performed after embolization of the feeding arteries. The pathological diagnosis was a GCT. The patient remains well without evidence of recurrence for 6 years following surgery. The present case is only the 14th case of GCT arising in the rib to have been reported in Japan. 相似文献
49.
Hidenobu Takahashi Masahiko Harada Tetsushi Ito Harubumi Kato 《Annals of thoracic and cardiovascular surgery》2007,13(3):191-194
Lymphoepithelioma is a lymphocyte-rich, poorly differentiated and non-keratinizing squamous cell carcinoma of the nasopharynx. Tumors arising outside the nasopharynx are rare and are designated as lymphoepithelioma-like carcinomas (LELCs). This is the third reported case of LELC of the trachea. A 27-year-old woman was referred to our hospital on suspicion of bronchial asthma on August 2000. A polypoid tumor of the cervical trachea was recognized on neck X-ray, neck computed tomography (CT) scan, and fiberoptic bronchoscopy. The protruding tumor was resected endoscopically by an electrosurgical snare. Histological and immunohistochemical examinations demonstrated large irregular polygonal cells extending in an islet or trabecular pattern among lymphoid stroma. These polygonal cells showed non-keratinization, atypia and prominent nucleoli. In situ hybridization showed these cells were infected with the Epstein-Barr (EB) virus. The infiltrating lymphocytes consisted of both T-and B-lymphocytes with no atypia. Thus the tumor was diagnosed as LELC. Blood examination revealed a past EB viral infection. Sphenoid resection of the tracheal cartilaginous portion was performed for residual tumor. We gave 50 Gy postoperative radiation, and she has been disease free in the 6-year follow-up period. 相似文献
50.
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