全文获取类型
收费全文 | 6841篇 |
免费 | 322篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 107篇 |
儿科学 | 165篇 |
妇产科学 | 64篇 |
基础医学 | 908篇 |
口腔科学 | 101篇 |
临床医学 | 479篇 |
内科学 | 1778篇 |
皮肤病学 | 168篇 |
神经病学 | 640篇 |
特种医学 | 240篇 |
外科学 | 869篇 |
综合类 | 18篇 |
预防医学 | 290篇 |
眼科学 | 51篇 |
药学 | 591篇 |
中国医学 | 3篇 |
肿瘤学 | 727篇 |
出版年
2023年 | 33篇 |
2022年 | 54篇 |
2021年 | 93篇 |
2020年 | 66篇 |
2019年 | 92篇 |
2018年 | 111篇 |
2017年 | 96篇 |
2016年 | 103篇 |
2015年 | 101篇 |
2014年 | 124篇 |
2013年 | 165篇 |
2012年 | 301篇 |
2011年 | 290篇 |
2010年 | 148篇 |
2009年 | 135篇 |
2008年 | 276篇 |
2007年 | 279篇 |
2006年 | 318篇 |
2005年 | 303篇 |
2004年 | 315篇 |
2003年 | 293篇 |
2002年 | 334篇 |
2001年 | 278篇 |
2000年 | 291篇 |
1999年 | 318篇 |
1998年 | 104篇 |
1997年 | 90篇 |
1996年 | 95篇 |
1995年 | 82篇 |
1994年 | 79篇 |
1993年 | 55篇 |
1992年 | 177篇 |
1991年 | 178篇 |
1990年 | 140篇 |
1989年 | 155篇 |
1988年 | 180篇 |
1987年 | 137篇 |
1986年 | 123篇 |
1985年 | 122篇 |
1984年 | 74篇 |
1983年 | 45篇 |
1982年 | 30篇 |
1981年 | 29篇 |
1980年 | 21篇 |
1979年 | 59篇 |
1978年 | 45篇 |
1977年 | 28篇 |
1975年 | 32篇 |
1971年 | 21篇 |
1969年 | 24篇 |
排序方式: 共有7199条查询结果,搜索用时 31 毫秒
141.
We have organized skull base surgery teams with otolaryngologists, neurosurgeons and plastic surgeons since 1993 and managed frontal skull base malignancies by a combined transbasal and transfacial approach. However, in the maneuvers, several problems are yet to be solved in minimizing tumor recurrence and postoperative complications. We have recently developed a microscopic en-bloc resection method assisted by an endoscope, and VFOT flap (vascularized frontal outer table flap) for the reconstruction on the frontal skull base. The VFOT flap can be elevated simultaneously with bifrontal craniotomy. The pedicled calvarian bone is split, and the frontal outer table with the pericranium is placed on the frontal base defect caused by the tumor resections. Those procedures seem to be useful for skull base surgery, and easy to perform for neurosurgeons. 相似文献
142.
Ishida H Koyama I Sawada T Murakami T Utsumi K Sannomiya A Tsuji K Tojimbara T Nakajima I Tanabe K Fuchinoue S Yamaguchi Y Toma H Agishi T 《Transplantation》2000,69(1):59-63
BACKGROUND: In organ transplantation, the grafts must be carefully monitored, but it is often difficult to make a quick and accurate diagnosis of unusual changes. Extensive research has failed to identify a useful marker for rejection. We investigated the clinical utility of sialyl Lewis(X) (CD15s) monitoring in 17 renal transplant patients with acute rejection. METHODS: The expression of CD15s on peripheral lymphocytes was examined using flow cytometry in renal transplant recipients with rejection (n=17), without rejection (n=23), recipients infected with cytomegalovirus (n=7), recipients with other diseases (n=7), and healthy volunteers (n=18). CD15s expression was compared with histological findings, and was also examined before and after steroid pulse therapy to investigate the effects of steroids on CD15s antigen expression on the surface of the peripheral lymphocytes. RESULTS: CD15s was strongly expressed in all patients with rejection, but was not expressed in any of the patients without rejection or in any healthy volunteers. Histologically, cell infiltration into the rejected graft was moderate or severe in all patients with strong expression of CD15s. In contrast, no or only mild infiltration was observed in patients with weak expression of CD15s. In addition, 14 of 17 patients (14/17, 82%) with strong CD15s expression improved upon administration of steroid pulse therapy, although there was no benefit from steroids in any of the patients with weak expression of CD15s. CONCLUSIONS: The CD15s antigen is expressed strongly on the peripheral lymphocytes at the time of rejection. It is interesting that the efficacy of steroid therapy in the patients with elevated creatinine could be predicted by CD15s expression on the peripheral lymphocytes before graft biopsy. There have been only few reports showing the relationship between CD markers and the efficacy of the treatment in patients with elevated creatinine. We report that the detection of CD15s on the peripheral lymphocytes by flow cytometry was an easy, helpful, and noninvasive means for the diagnosis and treatment of patients with elevated creatinine after renal transplantation. 相似文献
143.
144.
Yamamoto M Morita K Tomita Y Tsuji K Kawamura K Maeda H 《The Kurume medical journal》2000,47(4):285-290
This study investigated whether or not P300 components are influenced by emotional affect such as sadness and pleasure in twenty healthy subjects and whether or not the P300 effects of facial affect stimuli are influenced by auditory and visual stimulus modalities. Written informed consent was taken from each subject before the study. Each subject was asked to stare at a simple picture of a facial expression (crying or smiling faces) during the auditory and visual oddball tasks. P300 amplitude and area were significantly larger when viewing a crying face (sadness) than a smiling face (pleasure) under both conditions with auditory and visual stimulus. P300 latency was significantly longer while viewing sadness than while viewing pleasure only with auditory stimuli. Reaction time was not changed by facial stimuli. Amplitude and area of P300 were significantly larger in women than men in their modalities, but the effects of facial affect on P300 amplitude and area in women were similar to those in men. These results suggest that amplitude and area of P300 with both modalities recorded while viewing sadness may induce larger attentional resource than pleasure. Gender was a less potent influence of facial expression on P300 parameters. The influence of facial emotion may be important to investigate the recognition processes of subjects. 相似文献
145.
Clara cell 10 kDa protein (CC10) has been thought to be fairly specific to Clara cells and a major secretory protein that
is both synthesized and released from Clara cells. In the present study, morphometric analyses of the immunohistochemical
expression of CC10 were carried out on the bronchioles of human neonates with congenital diaphragmatic hernia (CDH) and then
compared with morphometric analyses from a gestationally and postnatally age-matched control group in order to clarify the
immaturity of Clara cells in CDH lungs. No difference was found in CC10 expression between the affected side and the unaffected
side of the lungs in the CDH group. However, compared with the lungs of the control group, the CDH group showed a significant
decrease in CC10 expression, namely, the ratio of CC10-positive cells per bronchiole, per unit perimeter of bronchiole, and
per unit bronchiolar surface area. These results suggest that in the lungs of CDH cases, a possible delay in either functional
maturation or the development of CC10 synthesis by the bronchioles may exist, and this retardation of functional maturation
of the airway is also considered to play a role in the postnatal respiratory insufficiency observed in CDH patients.
Accepted: 25 February 1998 相似文献
146.
Takahashi A Ohnishi K Tsuji K Matsumoto H Aoki H Wang X Tamamoto T Yukawa O Furusawa Y Ejima Y Tachibana A Ohnishi T 《International journal of radiation biology》2000,76(3):335-341
PURPOSE: There have been no reports about the effects of heavy-ion beams on the expression of the WAF1 gene, although ionizing radiation such as y-rays and X-rays is well known to induce WAF1 (p21/CIP1/sdi1) gene expression in a p53-dependent manner. In the present study, it was examined whether WAF1 accumulation was induced after carbon-ion (C-) beam or alpha-particle irradiation in four glioblastoma cell lines. MATERIALS AND METHODS: A colony assay for radiosensitivity and Western blot analysis of WAF1 were applied to two human glioblastoma cell lines, A-172 bearing wild-type p53 (wtp53) and T98G bearing mutated p53 (mp53). A-172/neo and A-172/mp53 were transfected with a control vector (containing only a neo selection marker) and a mp53 expression vector respectively. RESULTS: The amount of WAF1 increased markedly after X-ray irradiation in A-172 and A-172/neo cells but not in T98G and A-172/mp53 cells. The level of WAF1 reached a plateau at 3-10 h after X-ray irradiation at 5 Gy in A-172 and A-172/neo cells. Likewise, the levels of WAF1 in A-172 and A-172/neo cells reached a plateau at 3-10 h and 6-24 h after C-beam (3.0 Gy) and alpha-particle (4.5 Gy) irradiation respectively. The amount of WAF1 increased markedly in a dose-dependent manner 10 h after X-ray, C-beam or alpha-particle irradiation in A-172 and A-172/neo cells but not in T98G or A-172/mp53 cells. In addition, cell survival assay showed that these cell lines were most sensitive to C-beams, less sensitive to alpha-particles and least sensitive to X-rays at 10% survival. There was no difference in sensitivity among these cell lines against C-beam and alpha-particle irradiation whereas wtp53 cells (A-172 and A-172/neo) were more sensitive to X-rays than mp53 cells (A-172/mp53 and T98G). CONCLUSIONS: These results indicate that C-beams and alpha-particles induce p53-dependent WAF1 accumulation as well as is the case with X-rays, suggesting that WAF1 protein accumulation may not contribute to cell killing. 相似文献
147.
148.
149.
150.
Hitoshi Ishida Akira Nozawa Haruo Nukaya Lesley Rhodes Paul McNabb Patrick T Holland Kuniro Tsuji 《Toxicon》2004,43(6):701-712
We examined metabolism of PbTxs in New Zealand cockle, Austrovenus (A.) stutchburyi, and greenshell mussel, Perna (P.) canaliculus, by means of liquid chromatography coupled with tandem mass spectrometry. PbTx-2, PbTx-3 and BTX-B5 were detected in Karenia (K.) brevis culture medium in the ratio of ca. 50:2:5. The amounts of PbTx-3 and BTX-B5 were greatly increased in both seawater and shellfish exposed to K. brevis cultures or supernatant prepared by disruption of K. brevis under appropriate condition, while those of PbTx-2 were decreased. Some PbTx-2 was present in P. canaliculus, but not in A. stutchburyi. Low levels of BTX-B1 were detected in A. stutchburyi, but not P. canaliculus. Levels of PbTx-3 and BTX-B5 were highest immediately after exposure and then declined rapidly in both shellfish. BTX-B1 increased in concentration after exposure, and was then gradually eliminated from A. stutchburyi. Three successive exposures of A. stutchburyi to K. brevis cultures resulted in similar initial levels of PbTx-3 and BTX-B5, while BTX-B1 accumulated after each dose. In P. canaliculus, initial levels of PbTx-3 were similar, while PbTx-2 and BTX-B5 accumulated after each dose. PbTx-3 and BTX-B5 are proposed to be suitable markers for monitoring shellfish toxicity after a red tide event. 相似文献