全文获取类型
收费全文 | 16732篇 |
免费 | 767篇 |
国内免费 | 141篇 |
专业分类
耳鼻咽喉 | 124篇 |
儿科学 | 379篇 |
妇产科学 | 162篇 |
基础医学 | 1732篇 |
口腔科学 | 538篇 |
临床医学 | 902篇 |
内科学 | 4377篇 |
皮肤病学 | 203篇 |
神经病学 | 1340篇 |
特种医学 | 687篇 |
外科学 | 3389篇 |
综合类 | 49篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 463篇 |
眼科学 | 355篇 |
药学 | 964篇 |
中国医学 | 35篇 |
肿瘤学 | 1939篇 |
出版年
2023年 | 98篇 |
2022年 | 210篇 |
2021年 | 339篇 |
2020年 | 180篇 |
2019年 | 251篇 |
2018年 | 325篇 |
2017年 | 250篇 |
2016年 | 338篇 |
2015年 | 352篇 |
2014年 | 485篇 |
2013年 | 559篇 |
2012年 | 888篇 |
2011年 | 985篇 |
2010年 | 633篇 |
2009年 | 565篇 |
2008年 | 947篇 |
2007年 | 1001篇 |
2006年 | 899篇 |
2005年 | 946篇 |
2004年 | 934篇 |
2003年 | 904篇 |
2002年 | 852篇 |
2001年 | 426篇 |
2000年 | 420篇 |
1999年 | 353篇 |
1998年 | 261篇 |
1997年 | 189篇 |
1996年 | 167篇 |
1995年 | 140篇 |
1994年 | 143篇 |
1993年 | 137篇 |
1992年 | 266篇 |
1991年 | 212篇 |
1990年 | 207篇 |
1989年 | 229篇 |
1988年 | 167篇 |
1987年 | 164篇 |
1986年 | 154篇 |
1985年 | 157篇 |
1984年 | 105篇 |
1983年 | 104篇 |
1982年 | 44篇 |
1979年 | 59篇 |
1978年 | 45篇 |
1977年 | 51篇 |
1974年 | 38篇 |
1972年 | 45篇 |
1970年 | 39篇 |
1969年 | 41篇 |
1968年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Suzuki Hisamitsu; Ota Kazuo; Ohno Ryuzo; Masaoka Toru; Shibata Hirotoshi; Kimura Ikuro; Amaki Ichita; Miura Yasusada; Uzuka Yoshiro; Kawato Masafumi; Shirakawa Shigeru; Hirota Yutaka; Maekawa Tadashi; lmai Kuniyuki; Takaku Fumimaro; Shimoyama Masanori; Kitahara Takeshi; Oguro Masao; Kozuru Mitsuo; Kawagoe Hiroya; Nakamura Toru; Yamada Kazumasa 《Japanese journal of clinical oncology》1989,19(4):338-347
Patients with acute (2,569) and chronic (957) leukemia diagnosedat 19 institutes took part in the study on the "MultidisciplinaryTreatment of Leukemia" between 1971 and 1985 and were investigatedretrospectively. By dividing the 15 years into three five-yearperiods, we were able to compare patient ratios in the differentperiods. The proportions of acute to chronic leukemia casesshowed no obvious change; however, the proportions of casesdiagnosed as acute lymphocytic leukemia in acute leukemia showeda significant increase. The main chemotherapeutic drugs usedduring the three time periods were cytarabine or its analogues,the anthracyclines, 6-mercaputopurine and prednisolone, againstacute myelogenous leukemia, and the vinca alkaloids, prednisoloneand the anthracyclines against acute lymphocytic leukemia. Therate of complete remission from acute myelogenous leukemia mademarked progress, from 45.1% during 19711975 to 62.3%during 19811985, but that of acute lymphocytic leukemiashowed no significant progress, being 65% during 19711975and 69.7% during 19811985. The durations of remission,however, and the survival times for patients with acute lymphocyticleukemia, as well as for those with acute myelogenous leukemia,became significantly longer over the three periods. Median survivaltimes from chronic myelocytic leukemia were 3740 mo inall three periods, showing no progress. There was a better prognosisin cases of chronic myelocytic leukemia with, than without,Philadelphia chromosome. Except for a low incidence of chroniclymphocytic leukemia in Japan, adult leukemia patients' characteristicsand prognoses seem to be almost the same in Japan as in theU.S.A. and Europe. 相似文献
82.
Recent data have shown the existence of specific changes in mRNAs in thyroid carcinomas. It has not been clarified, however, why these changes clearly distinguish benign tissues from carcinomas, while genomic alternation such as mutations in the RAS or P53 genes do not. Further, the widely believed hypothesis, multi-step carcinogenesis, does not explain some clinical and experimental evidence of thyroid carcinomas. Considering these facts, we propose a new idea for thyroid carcinogenesis called "germ-cell carcinogenesis", in which cancer cells are derived from the remnant of fetal thyroid germ cells(thyroblasts) instead of normal thyroid follicular cells. Utilizing such mRNAs, we have established a new method for preoperative molecular-based diagnosis of thyroid carcinomas, Aspiration Biopsy Nucleic Acid Diagnosis(ABND). ABND allows us to perform preoperative nucleic acid analyses of the tumors by extracting RNAs or DNAs from tumor cells obtained by fine needle aspiration biopsies(FNABs). Pathological diagnosis of thyroid follicular carcinoma is quite difficult, and the establishment of preoperative molecular-based diagnosis of follicular carcinoma has been long expected. We found that quantification of the trefoil factor 3(TFF3)/galectin-3 mRNA ratio in thyroid tumor cells is a useful tool for distinction between follicular adenomas and carcinomas. Because ABND can be performed without any severe invasion to the patients, in the near future, when more reliable systems of quantitative RNA analysis have been developed, ABND will probably become one of the standard tests for preoperative diagnosis of thyroid carcinoma. 相似文献
83.
Characterization of htAKR, a novel gene product in the aldo-keto reductase family specifically expressed in human testis 总被引:1,自引:0,他引:1
Azuma Y Nishinaka T Ushijima S Soh J Katsuyama M Lu HP Kawata M Yabe-Nishimura C Miki T 《Molecular human reproduction》2004,10(7):527-533
In human testis, expression of a novel member of the aldo-keto reductase family was identified. Based on its testis-specific expression, we termed this protein human testis aldo-keto reductase (htAKR). In addition to four major isoforms, the existence of multiple alternatively spliced products of htAKR was detected using RT-PCR followed by nested PCR. htAKR was a homologue of mouse liver keto-reductase, AKR1E1, with close similarity in their genomic organizations. htAKR4, the longest isoform, was expressed as a non-fused native form. It exhibited a limited activity toward 9,10-phenanthrenequinone, while no activity toward the steroids or prostaglandins was demonstrated. Using the laser capture microdissection technique and RT-PCR, expression of htAKR was detected in testicular germ cells as well as in interstitial cells. The levels of htAKR mRNA in the tissues obtained from seminoma were much lower than those in normal testes. A significant decline in the htAKR expression was observed when NEC8, a cell line originated from a human testicular germ cell tumour, was exposed to phorbol 12-myristate 13-acetate or 5alpha-dihydrotestosterone. These results indicate that the expression of htAKR, down-regulated in the testicular tumour, is possibly controlled by mitogenic and hormonal signals. 相似文献
84.
DNA mediated immunization with encoding the nucleoprotein gene of porcine transmissible gastroenteritis virus 总被引:19,自引:0,他引:19
Liu C Kokuho T Kubota T Watanabe S Inumaru S Yokomizo Y Onodera T 《Virus research》2001,80(1-2):75-82
The immune response to a naked plasmid DNA encoding the nucleoprotein (N protein) of porcine transmissible gastroenteritis virus (TGEV) was investigated in this study. A complementary DNA of the entire N gene was amplified by RT-PCR, and inserted into a mammalian expression vector (pcDNA3.1) to construct a recombinant plasmid (pcDNA/N). To evaluate the immunogenicity of the construct, BALB/c mice were intramuscularly immunized with different doses (50, 100 and 200 μg/mouse) of pcDNA/N twice at a 5-week interval. An optimal antibody response was achieved with 100 μg of pcDNA/N. The response lasted at least 11 weeks after primary immunization. By western blotting analysis, the antibodies specifically recognized a 47 kDa protein corresponding to the viral N protein, but they did not reveal neutralizing activity against infectious TGEV in vitro. Immunoglobulin G2a was predominant among these antibodies, which was indicative of Th1 type cell activation in pcDNA/N immunized mice. Moreover, spleen cells from these mice showed stronger immune responses than those from live vaccine or parental vector immunized mice. These results suggest that the construct can elicit both humoral and cell-mediated immune (CMI) responses against TGEV N protein in mice. 相似文献
85.
H. Fujiwara M. Emi H. Nagai T. Nishimura N. Konishi Y. Kubota T. Ichikawa S. Takahashi T. Shuin T. Habuchi O. Ogawa K. Inoue M. H. Skolnick J. Swensen N. J. Camp S. V. Tavtigian 《Journal of human genetics》2002,47(12):0641-0648
The recently identified prostate cancer susceptibility gene ELAC2 (HPC2) harbors two common missense variants, a serine to leucine substitution at residue 217 (Leu217) and an alanine to threonine
substitution at residue 541 (Thr541). We genotyped the two variants in a Japanese cohort consisting of 350 prostate cancer
patients 242 male population controls, and 114 male low-risk controls. Both missense alleles, Leu217 and Thr541, were carried
at higher frequency in Japanese patients than in the controls (Leu217, P = 0.0012; Thr541, P = 0.0145), and the odds ratios associated with carrying these sequence variants were higher in Japanese than in Caucasians.
Although the Leu217 and Thr541 variants of ELAC2 are less common in Japanese than in Caucasians, both variants confer significantly increased risk of prostate cancer in Japanese.
Carriage of these variants was not associated with age at diagnosis, tumor stage, or tumor grade in these Japanese prostate
cancer patients. The allele-specific pattern of risk observed in Japanese and familial Caucasian patients was qualitatively
similar; however, the magnitude of that risk was considerably greater in Japanese than in Caucasians.
Received: September 3, 2002 / Accepted: October 2, 2002 相似文献
86.
Kiyoshi Kasai Toru Kameya Takashi Okuda Paul I. Terasaki Yuichi Iwaki 《Virchows Archiv : an international journal of pathology》1987,410(3):253-261
Summary In order to explore the relationship between the expression of cancer-associated glycolipids such as sialylated Lex (SLEX) and sialylated Lea (SLEA) and the histological subtypes of lung cancers, 30 cases of small cell carcinoma (SCC) and 47 cases of non-small cell carcinoma (non-SCC) were examined immunohistochemically using monoclonal antibodies reacting with SLEX and SLEA. The forty-seven cases of non-SCC included 20 cases of adenocarcinoma, 20 of squamous cell carcinoma and 7 of large cell carcinoma. Tumour cells of most non-SCCs expressed SLEX and SLEA. In adenocarcinomas, the number of tumour cells having SLEX and SLEA was more than that of squamous cell carcinomas, large cell carcinomas and SCC. In SCC, 14 of the 30 cases were found to be positive for both antigens. Although the cancer cells of 11 cases of 17 intermediate cell type SCC had both antigens, the cells of only 3 of 13 oat cell tumours expressed SLEX and SLEA. The present study shows that SLEX and SLEA are useful markers for lung adenocarcinomas, that most cases of intermediate cell type of SCCs have characteristics similar to non-SCC but that many oat cell tumours lack them. 相似文献
87.
Furukawa H Doh-ura K Sasaki K Iwaki T 《Laboratory investigation; a journal of technical methods and pathology》2004,84(7):828-835
Prion protein (PrP) is known to accumulate in some non-neuronal tissues under conditions unrelated to prion diseases. The biochemical and biological nature of such accumulated PrP molecules, however, has not been fully evaluated. In this study, we established experimental myopathy in hamsters by long-term administration of chloroquine, and we examined the nature of the PrP molecules that accumulated. PrP accumulation was immunohistochemically demonstrated in autophagic vacuoles in degenerated muscle fibers, and this was accompanied by the accumulation of other molecules related to the neuropathogenesis of prion diseases such as clathrin, cathepsin B, heparan sulfate, and apolipoprotein J. Accumulated PrP molecules were partially insoluble in detergent solution and were slightly less sensitive to proteinase K digestion than normal cellular PrP. Muscle homogenates containing these PrP molecules did not cause disease in inoculated hamsters. The findings indicate that the PrP molecules that accumulated in muscle fibers have distinct biochemical and biological properties. Therefore, experimental chloroquine myopathy is a novel and useful model to investigate the mechanism of deposition of PrP in non-neuronal tissues and might provide new insights in the pathogenesis of prion diseases. 相似文献
88.
Repair of infarcted myocardium mediated by transplanted bone marrow-derived CD34+ stem cells in a nonhuman primate model 总被引:6,自引:0,他引:6
Yoshioka T Ageyama N Shibata H Yasu T Misawa Y Takeuchi K Matsui K Yamamoto K Terao K Shimada K Ikeda U Ozawa K Hanazono Y 《Stem cells (Dayton, Ohio)》2005,23(3):355-364
Rodent and human clinical studies have shown that transplantation of bone marrow stem cells to the ischemic myocardium results in improved cardiac function. In this study, cynomolgus monkey acute myocardial infarction was generated by ligating the left anterior descending artery, and autologous CD34(+) cells were transplanted to the peri-ischemic zone. To track the in vivo fate of transplanted cells, CD34(+) cells were genetically marked with green fluorescent protein (GFP) using a lentivirus vector before transplantation (marking efficiency, 41% on average). The group receiving cells (n = 4) demonstrated improved regional blood flow and cardiac function compared with the saline-treated group (n =4) at 2 weeks after transplant. However, very few transplanted cell-derived, GFP-positive cells were found incorporated into the vascular structure, and GFP-positive cardiomyocytes were not detected in the repaired tissue. On the other hand, cultured CD34(+) cells were found to secrete vascular endothelial growth factor (VEGF), and the in vivo regional VEGF levels showed a significant increase after the transplantation. These results suggest that the improvement is not the result of generation of transplanted cell-derived endothelial cells or cardiomyocytes; and raise the possibility that angiogenic cytokines secreted from transplanted cells potentiate angiogenic activity of endogenous cells. 相似文献
89.
Tanigaki K Han H Yamamoto N Tashiro K Ikegawa M Kuroda K Suzuki A Nakano T Honjo T 《Nature immunology》2002,3(5):443-450
RBP-J is a key mediator of Notch signaling that regulates cell fate determination in various lineages. To investigate the function of Notch-RBP-J in mature B cell differentiation, we generated mice that selectively lacked B cell RBP-J expression using conditional mutagenesis. Absence of RBP-J led to the loss of marginal zone B (MZB) cells with a concomitant increase in follicular B cells; in contrast, B1 cells in the peritoneal cavity were unaffected. Lack of RBP-J caused no defects in B cells maintenance, survival, plasma cell differentiation or activation. It is therefore likely that Notch-RBP-J signaling regulates the lineage commitment of mature B cells into follicular versus MZB cells. In addition, in mice with RBP-J-deficient B cells, had no obvious changes in immunoglobulin production in response to Ficoll, lipopolysaccharide or chicken gammaglobulin. In contrast, these mice exhibited increased mortality rates after blood-borne bacterial infection, which indicates that MZB cells play pivotal roles in the clearance of these bacteria. 相似文献
90.
K Takebayashi Y Fujioka K Nagashima T Nagakawa M Kubota 《Acta pathologica japonica》1989,39(12):810-813
A fibrous pseudotumor of the testis from a 46-year-old man was examined histologically and immunohistochemically. The tumor, situated in the tunica vaginalis, appeared as multiple round nodules up to 2 cm in diameter, and was composed largely of fibrous tissue with scanty inflammatory cell infiltration. Besides mesothelial cells covering part of the tumor, foci of piled-up cells were found among the fibrous tumor tissue. The cells in the foci were spindle and polygonal in shape, and contained oval nuclei. Immunohistochemically, these cells were positive for vimentin and keratin, but negative for CEA. Similar features have been found in pleural mesothelioma, supporting the concept that testicular fibrous pseudotumor could represent neoplastic growth of the mesothelium of the tunica vaginalis. 相似文献