全文获取类型
收费全文 | 44338篇 |
免费 | 2260篇 |
国内免费 | 270篇 |
专业分类
耳鼻咽喉 | 266篇 |
儿科学 | 915篇 |
妇产科学 | 558篇 |
基础医学 | 5618篇 |
口腔科学 | 1083篇 |
临床医学 | 2958篇 |
内科学 | 11451篇 |
皮肤病学 | 764篇 |
神经病学 | 3566篇 |
特种医学 | 1926篇 |
外科学 | 7315篇 |
综合类 | 172篇 |
预防医学 | 1163篇 |
眼科学 | 710篇 |
药学 | 3153篇 |
中国医学 | 92篇 |
肿瘤学 | 5158篇 |
出版年
2023年 | 242篇 |
2022年 | 409篇 |
2021年 | 935篇 |
2020年 | 497篇 |
2019年 | 763篇 |
2018年 | 909篇 |
2017年 | 703篇 |
2016年 | 918篇 |
2015年 | 951篇 |
2014年 | 1311篇 |
2013年 | 1506篇 |
2012年 | 2374篇 |
2011年 | 2700篇 |
2010年 | 1442篇 |
2009年 | 1286篇 |
2008年 | 2260篇 |
2007年 | 2462篇 |
2006年 | 2437篇 |
2005年 | 2462篇 |
2004年 | 2360篇 |
2003年 | 2303篇 |
2002年 | 2297篇 |
2001年 | 1143篇 |
2000年 | 1100篇 |
1999年 | 1136篇 |
1998年 | 608篇 |
1997年 | 496篇 |
1996年 | 467篇 |
1995年 | 374篇 |
1994年 | 342篇 |
1993年 | 316篇 |
1992年 | 766篇 |
1991年 | 672篇 |
1990年 | 685篇 |
1989年 | 648篇 |
1988年 | 560篇 |
1987年 | 492篇 |
1986年 | 486篇 |
1985年 | 435篇 |
1984年 | 313篇 |
1983年 | 261篇 |
1982年 | 118篇 |
1981年 | 122篇 |
1980年 | 110篇 |
1979年 | 249篇 |
1978年 | 157篇 |
1977年 | 142篇 |
1975年 | 109篇 |
1972年 | 112篇 |
1971年 | 106篇 |
排序方式: 共有10000条查询结果,搜索用时 86 毫秒
121.
K Nishi M Yamada D Morishita Y Nakamura Y Murata M Fujioka S Muramoto S Murakami K Sasaki M Yasui 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(7):904-908
A rare case of a 25-year-old man with pulmonary aspergillosis is reported. Pulmonary bulla and eosinophilic pneumonia in the right upper lobe were diagnosed by chest roentgenogram and transbronchial lung biopsy. Because the patient developed infective bullae during steroid therapy, we performed transcutaneous thoracic drainage and right upper lobectomy. The resected lung tissue contained numerous hyphae of Aspergillus. Around the hyphae of Aspergillus, granulomatous reaction and eosinophilic infiltration were observed. Antibodies against Aspergillus were detected in the serum of the patient. The number of peripheral blood eosinophils decreased after right upper lobectomy. These findings suggest that pulmonary bullae and eosinophilic pneumonia may be a rare manifestation of pulmonary aspergillosis. 相似文献
122.
Five latissimus dorsi musculocutaneous flaps (LD flap) were used for reconstruction with prostheses after resection of tumors between 1984 and 1991 in our hospital. Bony structures were reconstructed with prostheses and in three cases autoclaved autobone grafts were also needed. The prostheses and adjacent grafts were then wrapped by the LD flaps. Tumor sites included one humerus, two thighs, and two knees. All but one case healed primarily. The sole case of infection was successfully treated with debridement and irrigation. Due to the LD flaps' plentiful blood supply, we believe infection of the prosthetics can be avoided and good clinical results can be achieved using the flap with autoclaved autograft prosthetic composite reconstruction. © 1994 Wiley-Liss, Inc. 相似文献
123.
124.
125.
Hiroyuki Kumamoto Nobuhiro Takahashi Kiyoshi Ooya 《Journal of oral pathology & medicine》2004,33(6):360-367
BACKGROUND: To clarify the roles of rat sarcoma (Ras)/mitogen-activated protein kinase (MAPK) signaling pathway in oncogenesis and cytodifferentiation of odontogenic tumors, K-Ras gene status and expression of Ras, Raf1, MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK)1, and ERK1/2 proteins were analyzed in ameloblastomas as well as in tooth germs. METHODS: Paraffin sections of 10 tooth germs and 46 benign and 6 malignant ameloblastomas were examined immunohistochemically for the expression of K-Ras, Raf1, MEK1, and ERK1/2. Frozen tissue samples of 22 benign ameloblastomas and 1 malignant (metastasizing) ameloblastoma were analyzed by direct DNA sequencing to detect K-Ras gene alteration. RESULTS: Immunohistochemical reactivity for K-Ras, Raf1, MEK1, and ERK1/2 was detected in both normal and neoplastic odontogenic epithelium, and these molecules were reactive chiefly with odontogenic epithelial cells neighboring the basement membrane. Plexiform ameloblastomas showed slightly stronger expression of these Ras/MAPK signaling molecules than follicular ameloblastomas. Keratinizing cells and granular cells showed decreased reactivity for the signaling molecules. Basal cell ameloblastomas showed slightly stronger reactivity for the signaling molecules than did the other subtypes. K-Ras immunoreactivity in malignant ameloblastomas was lower than that in dental lamina of tooth germs. Direct DNA sequencing showed a GGT to GCT point mutation at codon 12 of K-Ras gene in one ameloblastoma. Conclusion: Expression of K-Ras, Raf1, MEK1, and ERK1/2 in tooth germs and ameloblastomas suggests that Ras/MAPK signaling pathway functions to regulate cell proliferation and differentiation in both normal and neoplastic odontogenic epithelium. K-Ras gene status implied that K-Ras mutations might play a minor role in oncogenesis of odontogenic epithelium. 相似文献
126.
tsFT20 cells derived from a mouse mammary carcinoma cell line, FM3A, which has temperature-sensitive DNA polymerase alpha activity (Y. Murakami, H. Yasuda, H. Miyazawa, F. Hanaoka, and M. Yamada, Proc. Natl. Acad. Sci. USA, 82:1761-1765, 1985) were rapidly committed to death after temperature upshift to 39 degrees C. tsFT20 cells synchronized in S phase were more sensitive to the restrictive temperature than exponentially growing cells. In order to gain insight into the processes from the interruption of DNA synthesis to cell death, we analyzed chromosome aberrations induced in tsFT20 cells which had been incubated for 2 or 4 h at the restrictive temperature and then cultured at the permissive temperature. The majority of metaphase cells showed extensive chromosome aberrations such as chromatid gaps, breaks, and exchanges; chromosome pulverizations; their mixed types; and ring chromosomes. Analyses with the use of cell synchronization and autoradiography revealed that chromosome aberrations were induced only in the cells which synthesized DNA during incubation at 39 degrees C. We classified the chromosome aberrations into five types: gap or break type; exchange type; pulverization type; complex type; and ring type. The temporal order of the appearance of these types of chromosome aberrations was found to be the above described order. It was further found that cycloheximide dramatically repressed the induction of chromosome aberrations, and metaphases with many chromosome aberrations exhibited a large number of sister chromatid exchanges. These results indicate that abnormal cessation of DNA replication in tsFT20 cells at the restrictive temperature due to the inactivation of DNA polymerase alpha results in cell death via induction of double-strand breaks which lead to chromosome aberrations as well as sister chromatid exchanges. 相似文献
127.
K Yamada Y Ushio T Hayakawa N Arita T Y Huang M Nagatani N Yamada H Mogami 《Cancer research》1987,47(8):2123-2128
To assess the rationale of intraarterial (i.a.) 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea chemotherapy, distribution of 14C-labeled 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)- 3-nitrosourea in rat glioma was studied after i.a. or i.v. infusion. Immediately after infusion, the tumor located in the hemisphere of intracarotid infusion received 4.6-fold higher radioactivity than the tumor located contralaterally to intracarotid infusion and 2.8-fold higher radioactivity than i.v. infusion. The difference was kept up to 30 min after i.a. infusion. Autoradiographic observation indicated rather uniform distribution of the tracer in the central portion of i.a. infusion. However, in the periphery of i.a. infusion, distribution of the tracer was nonhomogenous. The results indicate that i.a. 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea chemotherapy is useful when the tumor has high blood flow and is located in the center of an infused area. 相似文献
128.
K Takaori T Takeda H Yamada K Miura T Yukimura F Ikemoto K Yamamoto 《Japanese circulation journal》1988,52(11):1346-1350
Plasma immunoreactive renin was measured by sandwich radioimmunoassay, under various physiological and pathological conditions. Enzymatic activities of active renin and trypsin-activatable inactive renin were also measured. There was a significant correlation between plasma immunoreactive renin concentration (IRRC) and total (active plus inactive) renin concentration, as estimated by enzymatic activity. In plasma from normotensive volunteers and hypertensive patients, the IRRC were 279 +/- 37 pg/ml and 268 +/- 29 pg/ml, respectively. After the intravenous injection of furosemide, the plasma IRRC in normotensive volunteers increased significantly. IRRC was significantly higher in plasma from juvenile diabetics than in plasma from age-matched disease-free children. Thus, renin secretion in children with diabetes mellitus is increased. 相似文献
129.
130.
Radiotherapy was applied to 14 esophageal carcinomas with respiratory tract fistulas using various treatment regimens. Closure of the fistulas was observed in four cases after irradiation at a daily dose of 1.5 Gy. The period of closure was transient in two cases but long-term in the other two. One long-term closure case underwent low-dose rate telecobalt therapy (LDRT)(1 Gy per hour, 7 Gy per day; a total dose of 28 Gy) as a boost. His cancer has been well controlled and he is still alive without recurrence at 74 months after fistula formation. 相似文献