全文获取类型
收费全文 | 7714篇 |
免费 | 433篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 95篇 |
儿科学 | 151篇 |
妇产科学 | 45篇 |
基础医学 | 1026篇 |
口腔科学 | 141篇 |
临床医学 | 589篇 |
内科学 | 2036篇 |
皮肤病学 | 127篇 |
神经病学 | 482篇 |
特种医学 | 386篇 |
外科学 | 1376篇 |
综合类 | 23篇 |
一般理论 | 1篇 |
预防医学 | 314篇 |
眼科学 | 81篇 |
药学 | 388篇 |
中国医学 | 14篇 |
肿瘤学 | 925篇 |
出版年
2023年 | 88篇 |
2022年 | 152篇 |
2021年 | 280篇 |
2020年 | 158篇 |
2019年 | 219篇 |
2018年 | 246篇 |
2017年 | 168篇 |
2016年 | 222篇 |
2015年 | 185篇 |
2014年 | 269篇 |
2013年 | 310篇 |
2012年 | 446篇 |
2011年 | 512篇 |
2010年 | 278篇 |
2009年 | 199篇 |
2008年 | 324篇 |
2007年 | 384篇 |
2006年 | 363篇 |
2005年 | 349篇 |
2004年 | 342篇 |
2003年 | 283篇 |
2002年 | 320篇 |
2001年 | 183篇 |
2000年 | 201篇 |
1999年 | 201篇 |
1998年 | 57篇 |
1997年 | 55篇 |
1996年 | 38篇 |
1995年 | 41篇 |
1994年 | 46篇 |
1993年 | 39篇 |
1992年 | 125篇 |
1991年 | 111篇 |
1990年 | 114篇 |
1989年 | 103篇 |
1988年 | 99篇 |
1987年 | 88篇 |
1986年 | 74篇 |
1985年 | 66篇 |
1984年 | 61篇 |
1983年 | 42篇 |
1982年 | 26篇 |
1981年 | 21篇 |
1980年 | 21篇 |
1979年 | 41篇 |
1978年 | 19篇 |
1977年 | 30篇 |
1975年 | 24篇 |
1972年 | 18篇 |
1969年 | 18篇 |
排序方式: 共有8200条查询结果,搜索用时 15 毫秒
71.
Su M Tokairin T Nishikawa Y Yoshioka T Takahashi O Watanabe H Doi Y Omori Y Yoshioka T Sageshima M Tanaka T Enomoto K 《Pathology international》2002,52(2):158-163
A rare case of rapidly growing osteosarcoma that developed in the uterine corpus of a 62-year-old woman is presented. The tumor occupied almost the entire pelvic cavity and extended into the abdominal cavity, with marked involvement of the intestines. Histopathologically, the tumor was composed of an osteoblastic component, accompanied by conspicuous bone formation, and a fibroblastic component. The tumor cells were positive for vimentin and osteocalcin, as well as desmin, alpha-smooth muscle actin and muscle-specific actin, but negative for h-caldesmon. The results indicated myofibroblastic differentiation in a part of the tumor. A review of 14 reported cases and our case of uterine osteosarcoma revealed that this tumor has a biologically aggressive nature, although its histopathological and immunohistochemical features are similar to those of osteosarcomas in soft tissue and bone. As the prognosis of patients with this tumor is poor, it is of importance to differentiate this tumor from other types of tumors arising from the uterine corpus. 相似文献
72.
Susumu Matsukuma Masateru Doi Masatoshi Suzuki Kazuya Ikegawa Kimiya Sato Noriyuki Kuwabara 《Pathology international》1997,47(11):789-793
A unique case of duodenal stromal tumor In a 51-year-old man is reported. The tumor histologically showed spindle cell proliferation and numerous eosinophilic globules. Most globules were composed of tangled 45 nm thick fibrils, which were ultrastructurally Identical to 'skelnoid fibers'. The presence of glycogen granules in the tumor cells and the Immunoreactivity for α-smooth muscle actin suggested smooth muscle differentiation. Focal ultrastructural findings also supported the smooth muscle nature of this tumor. There were no immunohistochemical and ultra-structural features indicating neural differentiation. In previous studies, the presence of such 'skeinoid fibers' was suggested to be a histological marker for neural differentiation in gastrointestinal stromal tumor. However, the findings In the present case suggest that numerous 'skeinoid fibers' can be Identified in duodenal stromal tumor with smooth muscle differentiation, although this condition may be rare. 相似文献
73.
Itoh K Naganawa Y Matsuzawa F Aikawa S Doi H Sasagasako N Yamada T Kira J Kobayashi T Pshezhetsky AV Sakuraba H 《Journal of human genetics》2002,47(1):29-37
Three novel missense mutations in the human lysosomal sialidase gene causing amino acid substitutions (P80L, W240R, and P316S)
in the coding region were identified in two Japanese sialidosis patients. One patient with a severe, congenital form of type
2 sialidosis was a compound heterozygote for 239C-to-T (P80L) and 718T-to-C (W240R). The other patient with a mild juvenile-onset
phenotype (type 1) was a homozygote for the base substitution of 946C-to-T (P316S). None of these mutant cDNA products showed
enzymatic activity toward an artificial substrate when coexpressed in galactosialidosis fibroblastic cells together with protective
protein/cathepsin A (PPCA). All mutants showed a reticular immunofluorescence distribution when coexpressed with the PPCA gene in COS-1 cells, suggesting that the gene products were retained in the endoplasmic reticulum/Golgi area or rapidly degraded
in the lysosomes. Homology modeling of the structural changes introduced by the mutations predicted that the P80L and P316S
transversions cause large conformational changes including the active site residues responsible for binding the sialic acid
carboxylate group. The W240R substitution was deduced to influence the molecular surface structure of a limited region of
the constructed models, which was also influenced by previously identified V217M and G243R transversions.
Received: Stptember 21, 2001 / Accepted: November 2, 2001 相似文献
74.
Sputum cytology was performed in 179 cases of squamous-cell carcinoma of the lung; 134 cases were diagnosed as positive. There were no significant differences in diagnostic accuracy of sputum cytology between tumors sizes. In cases with tumors extending proximally into the main, lobar, or segmental bronchi, the diagnostic accuracy of sputum cytology was significantly higher than in cases where the proximal invasion of tumor was limited to the peripheral bronchi. In cases with tumors 3 cm or less in diameter, when tumors extended proximally into main, lobar, or segmental bronchi, the diagnostic accuracy of sputum cytology was significantly higher than in cases with tumors extending proximally into subsegmental or subsubsegmental bronchi. In peripherally located squamous-cell carcinoma, in cases in which the tumor arose in subsegmental or subsubsegmental bronchi, carcinoma could be detected by sputum cytology even when it was roentgenographically occult. 相似文献
75.
Hattori S Sakuma K Wakutani Y Wada K Shimoda M Urakami K Kowa H Nakashima K 《Neuroscience letters》2004,368(3):319-322
Early onset familial Alzheimer's disease with spastic paraparesis (FAD-SP) has been associated with mutations of the presenilin 1 gene (PSEN1). We report a pedigree of FAD-SP due to a novel missense mutation of PSEN1 (Y154N). The symptoms of the proband were characterized by presenile dementia in her 40s, preceded by spastic paraparesis in her 30s, whereas the mother of the proband presented with spastic paraparesis in her 40s, followed by symptoms of dementia in her mid 60s. The mutation was found only in the proband, and not in a normal family member, normal Japanese control subjects, patients with sporadic Alzheimer's disease or patients with familial spastic paraparesis without dementia. Thus, Y154N is a novel PSEN1 mutation responsible for FAD-SP of Japanese origin. 相似文献
76.
F Juji H Takashima M Suko M Doi T Takaishi H Okudaira K Ito T Miyamoto 《Arerugī》1990,39(11):1515-1522
A 17 years old girl experienced an anaphylactic reaction of urticaria, dyspnea, syncope and hypotension while riding a bicycle 55 minutes after eating shellfish Lapas shellfish which was a-like Sulculus Supertexta (SS). She recovered within several hours after the emergency treatment. Another attack occurred 3 months later while she was running with a dog 30 minutes after eating shellfish (Turbo Cornutus; TC). RAST scores were 4 for Lapas and 2 for TC. RAST inhibition test by ELISA showed a high crose-reaction between keyhole limpet hemocyanin (KLH) and Lapas, and between KLH and TC, while the cross reaction between Lapas and TC was low. Gel chromatography with sephacryl G-200 revealed that both Lapas and TC had several allergens with different molecules which were detected by ELISA. Exercise challenge produced an immediate fall of FEV1 and a significant increase in plasma histamine levels for 45 minutes. 相似文献
77.
Ji-Youn Jung Akira Yasoshima Junzo Saegusa Hiroyuki Nakayama Kunio Doi 《Experimental and toxicologic pathology》2003,54(4):265-271
Mast cells are one of the major effector cells in the pathogenesis of allergic diseases such as contact dermatitis. In the present study, ultrastructural features of mast cells in contact dermatitis were examined. Namely, the ear of IQI/Jic mice was topically applied with picryl chloride (PCL) at 4 (1st), 11 (2nd), 18 (3rd) and 25 days (4th) after the sensitization with PCL to the abdominal skin. The changes in the ear swelling responses, total serum IgE levels and histology including mast cell numbers were similar to those of previous reports by our research group (Ikeda et al. 2000; Jung et al. 2001). Ultrastructurally, after the 1st application, a close spacial relationship between mast cells and neutrophils and phagocytosis of mast cell granules by neutrophils were observed. Mast cells generally contained non-fused swollen granules filled with altered contents with low electron density and showed an extrusion of membrane-free granules through membrane pores. In addition, interestingly, a few mast cells secreted membrane-bound granules into the dermis without leaving cell membrane damage. After the 4th application when the number of mast cells prominently increased and the total serum IgE level was greatly elevated, in addition to mast cells showing typical anaphylactic degranulation, many mast cells probably in the recovery process from degranulation and several immature mast cells characterized by well-developed Golgi apparatus, many ribosomes and a few electron-dense secretory granules in the peripheral cytoplasm were also observed at the same time. The present results clarified the ultrastructural features of mast cells in the course of PCL-induced contact dermatitis in IQI/Jic mice. 相似文献
78.
Ichiro Yamadori Makoto Motoi Kazuhiko Hayashi Akira Tsutsumi Katsuo Ogawa Kenji Doi Kazuo Hamaya 《Pathology international》1984,34(2):459-469
Two cases of disseminated infection caused by Mycobacterium intracellulare were reported and discussed. In the first case, the patient was a fifty-seven-year-old male who complained of general fatigue, weight loss, and fever. Biopsy of the right inguinal lymph nodes and the liver revealed infiltration by histiocytes engulfing many acid-fast bacilli. At autopsy an egg-sized abscess was found is the region of the right Iliac lymph nodes. Histological examination showed histiocytic infiltration in the abscess wall, neighboring lymph nodes, liver, and spleen. In the second case, the patient was a four-year-old boy, who had persistent fever and splenomegaly. Splenectomy was performed and histological examination of the spleen revealed multiple nodular infiltration by swollen histiocytes with many acid-fast bacilli in their cytoplasm. The bone marrow aspirates and liver tissue obtained in the necropsy also showed many histiocytes containing many acid-fast bacilli. The authors emphasized the importance of paying special attention to atypical mycobacteriosis in feverish patients having lesions with a proliferation of histiocytes. 相似文献
79.
The protease genes of Bacillus subtilis. 总被引:2,自引:0,他引:2
80.
An association of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and common carotid atherosclerosis 总被引:3,自引:0,他引:3
Kawamoto R Kohara K Tabara Y Miki T Doi T Tokunaga H Konishi I 《Journal of human genetics》2001,46(9):506-510
Plasma homocysteine (Hcy) concentration has been shown to be influenced by a mutation in the gene coding methylenetetrahydrofolate
reductase (MTHFR). Although plasma Hcy is related to atherosclerotic disorders, conflicting results have been reported about
the association between MTHFR gene polymorphism and sclerotic lesions of the common carotid arteries. The effect of age–gene interaction on carotid arterial
remodeling was investigated in elderly subjects with several risk factors for atherosclerosis. We evaluated sclerotic lesions
of the common carotid arteries by ultrasonography in 326 patients (mean age ± standard deviation, 73 ± 12 years) and studied
relations among the known risk factors for atherosclerosis, including MTHFR gene polymorphism and its interactions with age and sex. Of the 326 subjects studied, 136 had MTHFR genotype CC, 136 genotype CT, and 54 genotype TT. The three groups did not differ with respect to background factors such as age, history of cigarette smoking, blood pressure,
lipids or uric acid, or in the incidence of atherosclerotic diseases. Spearman's rank correlation revealed a significant relationship
between gender, age, Brinkman index, systolic blood pressure, triglycerides, HDL-cholesterol (HDL-C), uric acid, and MTHFR gene polymorphism. Multiple regression analysis using intima-media complex thickness (IMT) as a criterion variable and risk
factors, including MTHFR gene polymorphism as explanatory variables showed that MTHFR gene polymorphism (P = 0.039) was a significant independent explanatory variable for IMT, along with gender (male) (P < 0.001), age (P < 0.001), systolic blood pressure (SBP) (P = 0.047), total cholesterol (T-C) (P < 0.001), and HDL-C (P < 0.001). Furthermore, a general linear model analysis revealed that interaction between age and MTHFR gene polymorphism was significantly associated with IMT, independently of age, SBP, T-C, and HDL-C in male subjects. However,
age–gene interaction was not observed in female subjects. The findings of the present study confirm an association between
MTHFR gene polymorphism and common carotid atherosclerosis in the Japanese population and further support the role of risk factor–gene
interaction in common carotid atherosclerosis.
Received: May 14, 2001 / Accepted: June 8, 2001 相似文献