全文获取类型
收费全文 | 9327篇 |
免费 | 501篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 175篇 |
妇产科学 | 73篇 |
基础医学 | 1159篇 |
口腔科学 | 323篇 |
临床医学 | 612篇 |
内科学 | 2297篇 |
皮肤病学 | 306篇 |
神经病学 | 652篇 |
特种医学 | 318篇 |
外科学 | 1367篇 |
综合类 | 38篇 |
预防医学 | 425篇 |
眼科学 | 187篇 |
药学 | 925篇 |
中国医学 | 23篇 |
肿瘤学 | 924篇 |
出版年
2023年 | 51篇 |
2022年 | 101篇 |
2021年 | 167篇 |
2020年 | 94篇 |
2019年 | 127篇 |
2018年 | 173篇 |
2017年 | 131篇 |
2016年 | 158篇 |
2015年 | 146篇 |
2014年 | 218篇 |
2013年 | 283篇 |
2012年 | 406篇 |
2011年 | 477篇 |
2010年 | 260篇 |
2009年 | 241篇 |
2008年 | 419篇 |
2007年 | 458篇 |
2006年 | 478篇 |
2005年 | 505篇 |
2004年 | 452篇 |
2003年 | 478篇 |
2002年 | 457篇 |
2001年 | 303篇 |
2000年 | 346篇 |
1999年 | 289篇 |
1998年 | 105篇 |
1997年 | 94篇 |
1996年 | 99篇 |
1995年 | 74篇 |
1994年 | 70篇 |
1993年 | 61篇 |
1992年 | 191篇 |
1991年 | 171篇 |
1990年 | 165篇 |
1989年 | 172篇 |
1988年 | 162篇 |
1987年 | 149篇 |
1986年 | 136篇 |
1985年 | 130篇 |
1984年 | 102篇 |
1983年 | 81篇 |
1981年 | 40篇 |
1979年 | 60篇 |
1978年 | 47篇 |
1977年 | 49篇 |
1973年 | 49篇 |
1972年 | 42篇 |
1971年 | 42篇 |
1969年 | 50篇 |
1968年 | 53篇 |
排序方式: 共有9872条查询结果,搜索用时 31 毫秒
81.
Yamazaki K 《Virchows Archiv : an international journal of pathology》2003,442(1):77-81
A 56-year-old Japanese man underwent total gastrectomy with lymph-node dissection for a gastric tumor. In the oral rim of the excised large ulcerated tumor, a small nodular mass demonstrated a unique histology of a carcinosarcoma composed of more than three distinctive components. A major part of the large ulcerated tumor tissue consisted of conventional tubular adenocarcinoma, with the coincidental focal distribution of solid cell nests of poorly differentiated or neuroendocrine cell (small cell) carcinoma. Sarcoma cells were another of the constituents of the small nodular tumor with atypical spindle-shaped cells. All the excised lymph-node metastasis demonstrated the histology of tubular adenocarcinoma. In the sarcoma cells, many of the lineage-specific immunohistochemical markers were negative. Only vimentin was positive. Electron microscopy revealed that the neuroendocrine cell carcinoma contained cells with abundant small aggregations of neurosecretory-type granules in their cellular cytoplasm. Primitive cellular junctions and incomplete basal lamina were seen in the sarcoma cells. No transitional or hybrid-type cells were seen between carcinoma and sarcoma cells. The interfaces between the cancer cell nests and the proliferation of sarcoma cells are clearly discerned. It was speculated that the unique histology of carcinosarcoma might have progressed from the conventional type of pre-existing advanced tubular adenocarcinoma. 相似文献
82.
Yasuni Nakanuma Goroku Ohta Haruo Takeshita Yoshikiyo Yamazaki Kenji Doishita Masaru Shimizu 《Pathology international》1983,33(6):1095-1104
Intrahepatic biliary tree with either florid duct lesions or a moderate to severe degree of the duct loss in four livers with chronic hepatic diseases other than primary biliary cirrhosis were studied with histometric and serial section observations. Florid duct lesions, distributed segmentally in the liver, were found in one case with incomplete septal cirrhosis and one case with idiopathic portal hypertension. The florid duct lesions including marked plasma cell infiltration and occasional periductal granulomas, were not associated with any bile duct loss in the two cases. The duct lesions were reversible in one case during a long clinical course. On the other hand, a moderate to severe bile duct loss with biliary epithelial degeneration and necrosis was associated with no or little periductal inflammatory cell infiltration in one other case with chronic intrahepatic cholestasis, probably drug-induced, and in one case with idiopathic portal hypertension. Although florid duct lesions and bile duct loss were important diagnostic features of primary biliary cirrhosis, one of them was observed to develop independently in severely diseased livers, not consistent with a diagnosis of primary biliary cirrhosis, sclerosing cholangitis or intrahepatic bile duct paucity syndrome. 相似文献
83.
J Miyauchi M Mukai K Yamazaki I Kiso S Higashi S Hori 《Acta pathologica japonica》1987,37(8):1347-1355
A patient who had disseminated vascular tumors involving the bilateral ovaries, bilateral lungs and pleura, pericardium, and mediastinum is reported. The tumors were histologically of the capillary, and partly the cavernous, type of hemangioma. However, endothelial cell growth was prominent in some areas, especially in the lung, and the histology of the lung tumor resembled epithelioid hemangioendothelioma or intravascular bronchiolo-alveolar tumor (IVBAT). In the endocardium of the right atrium, an endothelial tumorous projection was observed, and there were tiny foci of tumor cell nests in the abdominal venous wall. Small lymphangiomas were also found in the subcapsular region of the spleen. These findings suggest that there had been an abnormal proliferation of systemic endothelial cells and that tumors of endothelial cell origin with diverse histological patterns developed with this condition as a background. The autopsy finding of fibrin thrombi in multiple organs as well as laboratory data including thrombocytopenia suggest that this case belongs to the "Kasabach-Merritt syndrome." 相似文献
84.
Kazuko Sukegawa Shunji Tomatsu Toshiyuki Fukao Hideki Iwata Xiang-Qian Song Yukiji Yamada Seiji Fukuda Kouji Isogai Tadao Orii 《Human mutation》1995,6(2):136-143
Mucopolysaccharidosis type II (Hunter disease) is a lysosomal storage disorder caused by a deficiency of the enzyme iduronate-2-sulfatase. Varied clinical phenotypes of this disease have been described. To identify mutations in individual patients and to examine possible correlations between mutations and clinical phenotypes, we analyzed the iduronate-2-sulfatase gene in Japanese patients with different clinical phenotypes. Five missense mutations, S333L (severe), R468Q (severe), R468L (severe), W337R (intermediate), R48P (mild), and three nonsense mutations, W345X (severe), R443X (intermediate), Q531X (mild), were identified by the RT-PCR method. Transient expression in the enzyme-deficient fibroblasts revealed that all five missense mutant enzymes were synthesized as the normal-size precursor (73 kD), and the nonsense mutant enzymes were synthesized as truncated ones (W345X:54 kD, R443X:59 kD, and Q531X:69 kD), although stable mature enzymes (45–56 kD) were not detected by Western blot analysis. Further more, expression of the eight mutant cDNAs resulted in severe reductions of iduronate-2-sulfatase enzyme activity in comparison with a normal cDNA. © 1995 Wiley-Liss, Inc. 相似文献
85.
Satoru Takahashi Tomoyuki Shirai Kumiko Ogawa Katsumi Imaida Chikao Yamazaki Akira Ito Kazuo Masuko Nobuyuki Ito 《Pathology international》1993,43(11):674-682
Step-sections of 96 whole kidneys from 50 chronic hemodialysis patients were subjected to a histopathological and quantitative investigation with regard to the development of renal neoplastic lesions. The range of hemodialysis duration was from 1 to 222 months. A total of 349 renal cell adenomas were found in 41 cases (82%). They were commonly multiple and present bilaterally. Renal cell carcinomas were evident in four cases (8%), with hemodialysis durations of 54, 57, 112 and 222 months. The incidence of adenomas increased in a hemodialysis duration-dependent manner, indicating a high risk of renal cell tumor development in chronic hemodialysis patients. Furthermore, acquired cystic disease of the kidney (ACDK) was also observed in 12 cases (24.0%), where the mean hemodialysis period was 143.4 ± 48.0 months. This value was significantly longer than that of non-ACDK cases (P < 0.001). There was, however, no clear relationship between the appearance of ACDK and renal cell tumors. The present results underline the necessity for attention to possible neoplasia of the kidney in patients on long-term hemodialysis. 相似文献
86.
87.
A bacterial lectinlike substance, which is considered to participate in the adherence of Eikenella corrodens to various host cells, was purified from E. corrodens cells. The substance was extracted in 1% Triton X-100 with sonication from the cell envelope of E. corrodens 1073 and partially purified by galactosamine affinity chromatography and gel filtration chromatography based on its hemagglutination (HA) activity. The lectinlike substance was purified about 256-fold as evaluated by its specific HA activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the partially purified lectinlike substance (PPL) produced a single protein band of large molecular weight when it was applied to the gel without the addition of beta-mercaptoethanol and heating. Chemical analysis showed that PPL contained 14.4 micrograms of hexose per 100 micrograms of protein and that it did not contain muramic acid, glucosamine, or 2,6-diaminopimelic acid, which are characteristic of peptidoglycans. The HA activity of PPL was inhibited by EDTA but restored by adding Ca2+. The HA activity was remarkably inhibited by sugars containing N-acetyl-D-galactosamine and D-galactose. These results indicate that the lectinlike substance on the E. corrodens cells is an essential factor for the adherence to host cells. 相似文献
88.
Liver cell membrane antibody detected by protein A and isolated rabbit liver plasma membrane in sera of patients with chronic liver diseases 总被引:1,自引:1,他引:1 下载免费PDF全文
G Toda Y Ikeda N Hashimoto M Yamazaki M Torii H Oka 《Clinical and experimental immunology》1983,54(3):661-670
Using the plasma membrane fraction isolated from rabbit liver (RLPM), we detected non-species specific IgG antibody against liver cell surface membrane in the sera from the patients with chronic liver diseases. The sea were treated with dithiothreitol and iodoacetamide, and absorbed with sufficient amount of actin isolated from rabbit striated muscles. The antibody was detected by incubation of RLPM with the treated and absorbed sera and subsequent determination of IgG bound to RLPM by 125I-staphylococcal protein A. It was found mainly in the patients with autoimmune hepatitis (12 of 28) and liver cirrhosis (eight of 24). It occurred more frequently in HBsAg negative liver cirrhosis than in HBsAg positive forms (six of 13 vs two of 11). The frequency of the antibody was low in chronic hepatitis except autoimmune hepatitis, and primary biliary cirrhosis. Thus the antibody against RLPM was an immunological marker of autoimmune hepatitis and HBsAg negative liver cirrhosis. The occurrence did not correlate with those of anti-smooth muscle antibody, anti-nuclear antibody and anti-mitochondrial antibody. In two cases of autoimmune hepatitis, the antibody against RLPM decreased with clinical improvement induced by corticosteroids. 相似文献
89.
Tanaka E Nakamura T Nagashima A Yamazaki K Ohashi N Tsuchihashi H Misawa S 《Journal of chromatography. B, Biomedical sciences and applications》2001,759(2):361-366
In the present study, small volumes of plasma were used for the measurement of bromvalerylurea (BVU), its metabolite, 3-methylbutyrylurea (MVU), and bromide in carbon tetrachloride (CCl4)-treated rats by HPLC-UV and energy dispersive X-ray spectrometry. A liquid-liquid extraction system was also investigated. BVU and MVU were extracted from 100 microl plasma samples in a single-step involving deproteination with 1 M hydrochloric acid using ethenzamide as internal standard. Samples were separated by HPLC in an acetonitrile-8 mM potassium dihydrogenphosphate buffer (35:65, v/v) mobile phase at a flow-rate of 0.4 ml/min on a 15 cm octadecylsilyl column at room temperature. Analytes were detected at a wavelength of 210 nm. The limits of quantitation for BVU, MVU and bromide are 0.1, 0.1 and 50 microg/ml, respectively. The intra-day accuracies over the range of concentrations were 95.8 to 121.1%, 97.2 to 119.7% and 96.2 to 105.8% for BVU, MVU and bromide, respectively. The inter-day accuracies were 97.7 to 115.1%, 98.3 to 111.6% and 98.3 to 102.9% for BVU, MVU and bromide, respectively. The absolute recoveries using tert.-butyl methyl ether are 96-98% for BVU and 95-98% for MVU. The decline in the plasma concentrations of BVU in olive oil-treated rats fitted a one-compartment model and the plasma MVU level reached a peak at around 1.5-2 h and then decreased gradually. The elimination of BVU in CCl4 (1 ml/kg)-treated rats was delayed and MVU production was less than that in the olive oil-treated group. However, there was no difference in the plasma levels of bromide between CCl4-treated rats and control rats. rights reserved. 相似文献
90.
Mitochondrial cytochrome b genes (cyt b) of 40 strains of Cryptococcus neoformans were partially sequenced to determine the genetic relations. With the exception of the type strain of C. neoformans var. neoformans, all strains contained introns in their sequences. Analysis of 386 bp of coding sequence from each strain under investigation revealed a total of 27 (6.99%) variable nucleotide sites and categorized isolates of C. neoformans into nine cyt b types. C. neoformans var. gattii included cyt b types I to V, and C. neoformans var. neoformans comprised types VI to IX. cyt b types were correlated with serotypes. All strains with cyt b types I, IV, and V were serotype B. All other strains except IFM 5878 (serotype B) with cyt b types II and III were serotype C. Serotype D strains had cyt b types VI and IX, and serotype A strains were cyt b type VIII. Of four serotype AD strains, one was cyt b type VII and the remaining three were type VIII. The phylogenetic tree based on deduced amino acid sequences divided the strains only into C. neoformans var. neoformans and C. neoformans var. gattii. These results indicate that cyt b sequences are effective for DNA typing as well as phylogenetic analysis of C. neoformans. 相似文献