全文获取类型
收费全文 | 3473篇 |
免费 | 110篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 109篇 |
儿科学 | 44篇 |
妇产科学 | 20篇 |
基础医学 | 648篇 |
口腔科学 | 54篇 |
临床医学 | 174篇 |
内科学 | 627篇 |
皮肤病学 | 149篇 |
神经病学 | 249篇 |
特种医学 | 89篇 |
外科学 | 507篇 |
综合类 | 19篇 |
预防医学 | 54篇 |
眼科学 | 131篇 |
药学 | 347篇 |
中国医学 | 12篇 |
肿瘤学 | 358篇 |
出版年
2023年 | 9篇 |
2022年 | 13篇 |
2021年 | 40篇 |
2020年 | 26篇 |
2019年 | 24篇 |
2018年 | 47篇 |
2017年 | 38篇 |
2016年 | 37篇 |
2015年 | 36篇 |
2014年 | 61篇 |
2013年 | 109篇 |
2012年 | 162篇 |
2011年 | 189篇 |
2010年 | 100篇 |
2009年 | 120篇 |
2008年 | 173篇 |
2007年 | 209篇 |
2006年 | 214篇 |
2005年 | 234篇 |
2004年 | 234篇 |
2003年 | 264篇 |
2002年 | 252篇 |
2001年 | 108篇 |
2000年 | 80篇 |
1999年 | 95篇 |
1998年 | 70篇 |
1997年 | 51篇 |
1996年 | 49篇 |
1995年 | 45篇 |
1994年 | 38篇 |
1993年 | 27篇 |
1992年 | 50篇 |
1991年 | 43篇 |
1990年 | 33篇 |
1989年 | 38篇 |
1988年 | 43篇 |
1987年 | 34篇 |
1986年 | 27篇 |
1985年 | 49篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1982年 | 12篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1965年 | 2篇 |
排序方式: 共有3591条查询结果,搜索用时 12 毫秒
991.
Tamotsu Takeuchi Ichiro Kubonishi Yuji Ohtsuki Isao Miyoshi 《Virchows Archiv : an international journal of pathology》1991,419(2):147-151
Summary A monoclonal antibody, termed K-20, was generated against an anaplastic thymic carcinoma cell line, Ty-82. Subcapsular thymic epithelial cells of the thymus and blood vessels in various organs were shown to react with the K-20 monoclonal antibody by immunohistochemical staining. Immunofluorescent study revealed that various haematopoietic fresh cells and cell lines did not show any significant reactivity with K-20, except for one Epstein-Barr-virus-carrying lymphoma cell line (SP-50B). Western immunoblotting and affinity purification procedure revealed that K-20 was directed to a protein with a molecular weight of 28 kDa. K-20 is unique in its restrictive reactivity with human subcapsular thymic epithelial cells. 相似文献
992.
We studied thein vitro effects of FPL-52694 [5-(2-hydroxypropoxyl)-8-propyl-4-oxo-4H-benzopyran-2-carboxylic acid Na] on histamine release from rat peritoneal mast cells. These cells exposed to ascaris antigen, compound 48/80 or the ionophore A 23187 concentration-dependently released histamine. About a 30–40% histamine release was obtained by 1×10–4 g/ml of antigen, 1×10–7 g/ml of compound 48/80 and A 23187. FPL-52694 (10–9–10–4 g/ml) concentration-dependently inhibited the histamine release from mast cells in response to antigen (1×10–4 g/ml) and compound 48/80 (1×10–7 g/ml), but only slightly inhibited the histamine release induced by A 23187 (1×10–7 g/ml). Similar results were obtained with disodium cromoglycate (DSCG), in the same dose ranges. However, the inhibitory activity of FPL-52694 on histamine release by antigen and compound 48/80 was approximately 10 times more potent than that of DSCG at certain coincentrations. Tachyphylaxis was observed when these two agents were preincubated with mast cells for 10 min. These results show FPL-52694 to be a novel mast cell stabilizer. 相似文献
993.
The effects of γ-irradiation on allograft rejection in the teleost, , were examined at 25°C. The survival of melanophores in the transplanted scale was observed as an index of rejection. Allografts were rejected in non-irradiated fish within 7 days. In the γ-irradiated recipients (2kR), the grafts were rejected more slowly, but still within 20 days. The γ-ray effects, however, disappeared almost completely within 25 days after the irradiation. If the same recipient again received transplants, the secondary response occurred clearly and the melanophores were rejected very rapidly. The secondary response was suppressed by γ-rays if the fish was irradiated just before the second transplantation. Immunologic memory against the first transplants disappeared within 30 days, a period shorter than that of mammals. 相似文献
994.
The membrane (M) proteins of murine coronavirus (MHV) strains have been reported to contain only O-linked oligosaccharides. The predicted O-glycosylation site consisting of four amino acid residues of Ser-Ser-Thr-Thr is located immediately adjacent to the initiator Met and is well conserved among MHV strains investigated so far. We analyzed the nucleotide sequence of a highly virulent strain MHV-2 M-coding region and demonstrated that MHV-2 had a unique amino acid, Asn, at position 2 at the conserved O-glycosylation site. We also demonstrated that this substitution added N-linked glycans to MHV-2 M protein resulting in increment of molecular mass of MHV-2 M protein compared with JHM strain having only O-linked glycans. 相似文献
995.
The bonding behavior of calcite to bone. 总被引:2,自引:0,他引:2
Y Fujita T Yamamuro T Nakamura S Kotani C Ohtsuki T Kokubo 《Journal of biomedical materials research》1991,25(8):991-1003
Plates of calcite (CaCO3) were implanted in rabbit tibiae, and their biocompatibility and bonding ability to bone were studied. The plates were also implanted subfascially in rabbit muscle for 8 weeks, and changes on their surfaces in the body were examined. Contact microradiography and Giemsa surface stain demonstrated direct bonding between calcite and bone without interpositions. The average failure load of the interface between calcite and bone was 4.11 kg, indicating an adequate strength of bonding. However, a Ca-P-rich layer, which formed on the surfaces of other bioactive ceramics in vivo, was not detected by a scanning electron microscope-electron probe x-ray microanalyzer. Scanning electron micrographs of the surface of calcite implanted subfascially for 8 weeks showed marked degradation and a rough surface. However, the surface apatite layer was not detected by thin-film x-ray diffraction analysis and Fourier transform infrared reflection spectroscopy. Calcite is a biodegradable material that bonds to bone without a surface apatite layer. The mechanical bonding provided by the anchoring effect of the newly formed bone into the surface roughness of calcite is considered to be a major factor in calcite-bone bonding. 相似文献
996.
Human neuronal protein 22 (hNP22) is a novel neuron-specific protein featuring numerous motifs previously described in cytoskeleton-associating and signaling proteins. Because previous studies have supported abnormalities in neuronal cytoarchitecture and/or development in the schizophrenia brain, we examined the expression of hNP22 in the anterior cingulate cortex, the hippocampus and the prefrontal cortex of schizophrenic and normal control postmortem brains using high-sensitive immunohistochemistry. Seven schizophrenic and seven age- and sex-matched control brains were examined. The ratio of hNP22-immunopositive cells/total cells was significantly reduced in layer V (p=.020) and layer VI (p=.022) of the anterior cingulate cortex of schizophrenic brain compared with controls. In contrast, there were no significant changes observed in the hippocampus and the prefrontal cortex. These results suggest that altered expression of hNP22 may be associated with modifications in neuronal cytoarchitecture leading to dysregulation of neural signal transduction in the anterior cingulate cortex of the schizophrenia brain. 相似文献
997.
Kurabayashi A Furihata M Matsumoto M Sonobe H Ohtsuki Y Aki M Kuwahara M 《Pathology international》2001,51(8):624-628
Seminoma arising in patients with Klinefelter's syndrome is extremely rare; to our knowledge, only three cases have been reported in the English language literature. We report a case of intrapelvic seminoma in a 39-year-old man with Klinefelter's syndrome. Gross examination revealed that the tumor was a solid and irregular mass measuring 90 mm in diameter. The cut surfaces of this ill-defined tumor were yellow-white with necrotic foci. Histologically, the tumor cells were separated into lobules by branching, fibrous septa containing lymphocytes. In some parts of the tumor, a cord-like arrangement of tumor cells was present. Immunohistochemically, the tumor cells were strongly and diffusely positive for antiplacental alkaline phosphatase antibody along their cytoplasmic membranes, but negative for both chorionic gonadotrophin and alpha-fetoprotein. Based on these findings, we diagnosed this tumor as a seminoma. The testes when examined were found to be atrophic bilaterally, but with no tumor lesions. Chromosomal analysis yielded a 47XXY karyotype, compatible with Klinefelter's syndrome. These findings indicate a case of primary intrapelvic seminoma in Klinefelter's syndrome. The patient underwent intensive radiation therapy postoperatively, and he demonstrated no evidence of recurrence or metastasis during the 13-month period following surgery. 相似文献
998.
A 32-year-old male had a 4-year history of episodes of loss of consciousness. These episodes occurred several seconds after he would turn his head 60 degrees to the left, and had increased in frequency at the time previous to the operation he underwent. MRI revealed a round mass on the right side between the atlas and the axis. Cerebral angiography demonstrated that the right vertebral artery (VA) was occluded at the transverse foramen of the axis with the head rotated toward the left. The left VA was hypoplastic and no posterior communicating artery was visualized. A lateral surgical approach was performed between the left sternocleidomastoid muscle and the internal jugular vein. A yellowish and elastic but hard tumor was found to compress the VA. Postoperative MRI and vertebral angiography revealed neither residual tumor nor stenosis. Although the VA is frequently compressed by cervical tumors, only a few cases have been reported with tumors whose initial symptom was vertebro-basilar insufficiency. On the other hand, symptomatic stenotic change in the VA due to head movement can occur at the atlanto-axial joint and is named "bow hunter's stroke". In this case, flow of the VA was measured with an ultrasonic flowmeter after the tumor was removed. As the flow proved to change little during head rotation, additional decompression procedures such as removal of the transverse processes were judged unnecessary. Intraoperative arterial flow measurement has been found to be quite useful for evaluating the actual effect of surgical procedures. 相似文献
999.
Shin-ichi Miyagawa Ryuji Kamata Koki Matsumoto Ryo-ichi Okamura Hiroshi Maeda 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1991,229(3):281-286
We studied the inhibitory effects of chicken egg-white ovomacroglobulin (ovoM) on keratitis induced by 56000-Da protease (56 KP) of Serratia marcescens and by elastase (PE) and alkaline protease (PAP) of Pseudomonas aeruginosa. The effects of ovoM on the serratial and pseudomonal keratitis in rabbits were also elucidated. In one model, four drops of 56 KP, PE, or PAP (1 mg/ml) were applied to wounded corneas of eight eyes. Thereafter, 80 l ovoM (10 mg/ml) was dropped into four eyes and 0.01 M phosphate-buffed 0.15 M saline (pH 7.4) into the other eyes as a control. The other in vivo test system involved intrastromal injection of S. marcescens or P. aeruginosa, by which each sample (105–107 colony-forming units) mixed with ovoM was injected into one cornea and the other cornea received organisms without ovoM. OvoM completely inhibited the activity of these bacterial proteases in vitro and reduced corneal destruction in experimental keratitis in rabbits. In addition, greatly accelerated wound healing was observed.Part of this work was presented at the 1989 meeting of the Association for Research in Vision and Ophthalmology in Sarasota, Florida
Offprint requests to: H. Maeda 相似文献
1000.
Yoshifuku Nakayama Hiroshi Murayama Hiroshi Iwasaki Shin-ichi Iwanaga Masahiro Kikuchi Seiyo Ikeda Mitsuo Okada Yoshihiko Iizuka Akinori Iwashita 《Pathology international》1997,47(8):557-563
A rare case of carclnosarcoma (sarcomatoid carcinoma) with rhabdomyoblastic and osteoblastic differentlatlon occurrlng in the gastric remnant is reported. A 69-year-old Japanese man who had undergone a partial gastrectomy for a duodenal ulcer 30 years earlier, presented with anemla, eplgastralgia, and an abdominal mass. The diagnosls of gastric carcinosarcoma was made based on the findings of endoscoplc biopsies. The patient was thus scheduled to undergo a surgical operatlon, but he died of respiratory failure. At autopsy, a huge polypoid tumor measurlng 2Ox18times8 cm was located on the greater curvature of the gastric remnant. Microscopically, the tumor conslsted of Intimately mixed tubular adenocarcinoma and heterologous mesenchymal elements contalning rhabdomyosarcoma and osteosarcoma. Between these components, a morphological transition from the adenocarclnoma element to the sarcomatous element was observed. Ultrastructually, rhabdomyoblastlc dlfferentlation was conflrmed In the sarcomatous areas. lmmunocytochemlcal expresslons of epithelial markers includlng epithelial membrane antlgen and cytokeratlns (35bHll and 34bE12) were recognlzed not only in the carclnomatous cells but also In the sarcomatous cells. These findlngs suggest that carclnomatous cells appear to transform Into cells wlth sarcomatous features. 相似文献