全文获取类型
收费全文 | 6260篇 |
免费 | 290篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 74篇 |
儿科学 | 68篇 |
妇产科学 | 72篇 |
基础医学 | 782篇 |
口腔科学 | 118篇 |
临床医学 | 339篇 |
内科学 | 1682篇 |
皮肤病学 | 117篇 |
神经病学 | 639篇 |
特种医学 | 292篇 |
外科学 | 1092篇 |
综合类 | 25篇 |
预防医学 | 110篇 |
眼科学 | 41篇 |
药学 | 448篇 |
中国医学 | 8篇 |
肿瘤学 | 680篇 |
出版年
2023年 | 47篇 |
2022年 | 74篇 |
2021年 | 169篇 |
2020年 | 74篇 |
2019年 | 95篇 |
2018年 | 144篇 |
2017年 | 91篇 |
2016年 | 136篇 |
2015年 | 130篇 |
2014年 | 208篇 |
2013年 | 218篇 |
2012年 | 341篇 |
2011年 | 377篇 |
2010年 | 249篇 |
2009年 | 191篇 |
2008年 | 287篇 |
2007年 | 357篇 |
2006年 | 374篇 |
2005年 | 342篇 |
2004年 | 357篇 |
2003年 | 368篇 |
2002年 | 377篇 |
2001年 | 132篇 |
2000年 | 137篇 |
1999年 | 131篇 |
1998年 | 77篇 |
1997年 | 95篇 |
1996年 | 86篇 |
1995年 | 64篇 |
1994年 | 56篇 |
1993年 | 52篇 |
1992年 | 105篇 |
1991年 | 72篇 |
1990年 | 56篇 |
1989年 | 70篇 |
1988年 | 48篇 |
1987年 | 52篇 |
1986年 | 55篇 |
1985年 | 53篇 |
1984年 | 32篇 |
1983年 | 28篇 |
1982年 | 20篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1979年 | 30篇 |
1978年 | 16篇 |
1977年 | 10篇 |
1975年 | 10篇 |
1973年 | 8篇 |
1968年 | 9篇 |
排序方式: 共有6587条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Mitsuhiro Tozaki Kunihiko Fukuda Masafumi Suzuki 《Magnetic resonance in medical sciences》2006,5(3):137-146
PURPOSE: The purpose of this study was to assess the relationship between the amount of scirrhous component in invasive ductal carcinoma and its MR characteristics. MATERIALS AND METHODS: We retrospectively reviewed 71 consecutive patients with invasive ductal carcinoma smaller than 25 mm (average, 16.6 mm) in diameter. The scirrhous component was defined as invasive foci in small clusters of cancer cells showing desmoplasia. Invasive ductal carcinoma was subclassified into 3 groups in accordance with the amount of the scirrhous component (scirrhous component degree; SCD): SCD I (scirrhous component less than 20%), SCD II (intermediate), and SCD III (more than 80%). Dynamic magnetic resonance (MR) imaging was performed using volumetric interpolated sequence. Prior to dynamic study, T2*-weighted first-pass perfusion images were obtained before, during, and after bolus injection of 0.1 mmol Gd-DTPA/kg. RESULTS: Twenty-eight lesions were classified as SCD I, 14 as SCD II, and 29 as SCD III. Mass margin and signal intensity loss in the perfusion study were significantly different among the 3 SCD groups (P<0.001). The kinetic patterns were significantly different among the 3 SCD groups (P=0.04), and between SCD I/II and SCD III (P=0.03). The presence of enhancing internal septations was significantly different between SCD I/II and SCD III carcinomas (P=0.05). Central enhancement was only observed in SCD I carcinoma (4%; 3/71). CONCLUSION: The histological predominance of the scirrhous component in invasive ductal carcinoma may be one explanation for the differences in morphologic and kinetic patterns on MR imaging. 相似文献
6.
7.
Active production of anti-human T-lymphotropic virus type I (HTLV-I) IgM antibody in HTLV-I-associated myelopathy 总被引:2,自引:0,他引:2
Kunihiko Nagasato Tatsufumi Nakamura Ohishi Kiyosumi Kohji Shibayama Masakatsu Motomura Ichinose Katsuhiro Mitsuhiro Tsujihata Shigenobu Nagataki 《Journal of neuroimmunology》1991,32(2):105-109
We investigated the presence of anti-human T-lymphotropic virus type I (HTLV-I) IgM in sera and cerebrospinal fluid from patients with HTLV-I-associated myelopathy (HAM) by Western blot analysis. Analyses of 36 serum samples revealed that most patients (31/36; 86.1%) had anti-HTLV-I IgM, whereas only four of 23 (17.4%) HTLV-I carriers had it. In studies of cerebrospinal fluid, anti-HTLV-I IgM was detected in 24 of 36 (66.7%) HAM patients, whereas none was detected in nine HTLV-I carriers. The differences were statistically significant (p less than 0.01). These results suggest that persistent active replication of HTLV-I occurs in the central nervous system as well as in the peripheral blood of HAM patients, and may contribute to the development of HAM. 相似文献
8.
Changes in central dopaminergic systems with the expression of Shh or GDNF in mice perinatally exposed to bisphenol-A. 总被引:1,自引:0,他引:1
Kazuya Miyagawa Minoru Narita Michiko Narita Keiichi Niikura Hisahiko Akama Yuri Tsurukawa Tsutomu Suzuki 《Nihon shinkei seishin yakurigaku zasshi》2007,27(2):69-75
In the previous study, we reported that exposure to bisphenol-A induced the potentiation of dopamine receptor functions in the mouse limbic area, resulting in supersensitivity to methamphetamine-induced pharmacological actions. The present study was undertaken to investigate whether prenatal exposure to bisphenol-A could produce morphological change in dopaminergic neuron and the pattern of expression of genes regulating the dopaminergic neuron development. Here we found that prenatal and neonatal exposures to bisphenol-A increased the tyrosine hydroxylase- and dopamine transporter-like immunoreactivities in the adult mouse limbic area. The present molecular biological study shows that chronic bisphenol-A treatment produced a significant decrease in the dopaminergic neuron development factors, sonic hedgehog and glial cell line-derived neurotrophic factor, which were also decreased by prenatal exposure to bisphenol-A. These results suggest that chronic exposure to bisphenol-A could disrupt the dopaminergic neurotransmission in the process of dopaminergic neuron development. 相似文献
9.
H Iwanami M Saitoh K Narita M Tachibana K Hasegawa M Sakonzi E Tuboi 《Kyobu geka. The Japanese journal of thoracic surgery》1990,43(3):211-214
Of 200 lung cancer lesions resected in our hospital, there were 15 cases (7.5%) with middle lobe origin. The histological types were adenocarcinoma in 13 patients (4 patients with alveolar cell carcinoma), squamous cell carcinoma in one and large cell carcinoma in one. These patients were classified into two groups according to the type of operation they received and each group was evaluated. Group I (resection of the middle lobe) included 8 patients. Each one of Stage IIIB and Stage IV received the operation to improve their symptoms. The six patients of Stage I received only middle lobectomy as absolute curable cases. Group II (resection of the middle and lower lobes) included 7 patients, who had preoperative diagnosis of stage III. Two of them were postoperatively found to be cases of Stage I and Stage II. Although it was still short-term, the follow-up evaluation proved that these patients survived without local recurrence and distant metastasis, except for two with pleural dissemination and one with cerebral metastasis, who had received lobectomy as palliative operation. No difference was observed between the two groups receiving different types of operation. 相似文献
10.
Yukinobu Nakaseko Kentaro Nabeshima Kazuhisa Kinoshita & Mitsuhiro Yanagida 《Genes to cells : devoted to molecular & cellular mechanisms》1996,1(7):633-644
Background : Fission yeast microtubule associating protein (MAP) p93Dis1 functions for sister chromatid separation: dis1 mutants fail to separate chromosomes, while the spindle elongates but without cyclin destruction. p93Dis1 localizes along microtubules in interphase cytoplasm, but shifts to the spindle pole body (SPB) and spindle microtubules upon the entry into mitosis. In this study, regions of p93Dis1 were dissected to examine their role.
Results : Nitrocellulose filter blotting shows that recombinant Dis1 binds to bovine brain microtubules in vitro . A basic central region rich in S, T and P is essential for this association. However, the whole p93Dis1 with N- and C-termini containing a conserved repeat motif and heptad repeats, respectively, is necessary for normal microtubule association in vivo . The N-truncated region also binds to microtubules but only to the portions near the SPBs. Overproduction phenotypes indicate that p93Dis1 greatly affects spindle formation and cell morphogenesis. The central region is essential but, by itself, not sufficient for generating such effects.
Conclusions : We propose that p93Dis1 consists of three regions which carry distinct properties for localization: the N-region for cell cycle dependent localization, the central region for direct microtubule association, and the C-region for SPB and nuclear localization. The essential role of p93Dis1 is carried out in the C-region, while the N-region acts as a regulator. 相似文献
Results : Nitrocellulose filter blotting shows that recombinant Dis1 binds to bovine brain microtubules in vitro . A basic central region rich in S, T and P is essential for this association. However, the whole p93
Conclusions : We propose that p93