全文获取类型
收费全文 | 14906篇 |
免费 | 952篇 |
国内免费 | 223篇 |
专业分类
耳鼻咽喉 | 221篇 |
儿科学 | 121篇 |
妇产科学 | 151篇 |
基础医学 | 2466篇 |
口腔科学 | 275篇 |
临床医学 | 1411篇 |
内科学 | 2798篇 |
皮肤病学 | 490篇 |
神经病学 | 1058篇 |
特种医学 | 1265篇 |
外科学 | 1775篇 |
综合类 | 48篇 |
一般理论 | 3篇 |
预防医学 | 487篇 |
眼科学 | 236篇 |
药学 | 1830篇 |
中国医学 | 268篇 |
肿瘤学 | 1178篇 |
出版年
2024年 | 8篇 |
2023年 | 126篇 |
2022年 | 470篇 |
2021年 | 658篇 |
2020年 | 310篇 |
2019年 | 464篇 |
2018年 | 550篇 |
2017年 | 462篇 |
2016年 | 644篇 |
2015年 | 861篇 |
2014年 | 1009篇 |
2013年 | 1090篇 |
2012年 | 1464篇 |
2011年 | 1489篇 |
2010年 | 887篇 |
2009年 | 672篇 |
2008年 | 879篇 |
2007年 | 842篇 |
2006年 | 689篇 |
2005年 | 635篇 |
2004年 | 555篇 |
2003年 | 402篇 |
2002年 | 314篇 |
2001年 | 168篇 |
2000年 | 136篇 |
1999年 | 79篇 |
1998年 | 45篇 |
1997年 | 29篇 |
1996年 | 24篇 |
1995年 | 11篇 |
1994年 | 12篇 |
1993年 | 7篇 |
1992年 | 22篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1983年 | 3篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1974年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
AIMS: Voiding diary duration may be related to patient compliance and burden. To test this hypothesis, we evaluated patient compliance and burden. METHODS: Between January and July 2002, we prospectively evaluated 162 patients (57 males and 105 females, mean age 53.0, range 20-81 years) with stress urinary incontinence or lower urinary tract symptoms. At the initial visit, all patients underwent a detailed clinical evaluation including an International Prostate Symptom Score (I-PSS) assessment and were randomly requested to complete 2-day, 3-day, or 7-day voiding diaries (the three study groups). At the second visit, a simple self-administered questionnaire was completed by all patients. The questionnaire included 11 items on subject demographics and voiding diary-keeping. RESULTS: No significant differences were found in either the accuracy of diary-keeping or the daily average number of omissions when the three groups were compared. However, as the diary duration increased, the mean burden scores increased (P = 0.005), and the mean preferred duration of the diary in the 7-day group was significantly higher than that of the 2-day or 3-day groups (P < 0.001). After categorizing patients into two groups according to the degree of patient burden, members of the group with a greater perceived burden were found to have a significantly higher I-PSS quality of life score (P = 0.045) and to have kept a diary for a longer time (P = 0.038). CONCLUSIONS: Our results suggest that keeping a diary for 7 days may increase patient burden and thus, we recommend that the 7-day diary should be reduced to cover fewer days. 相似文献
992.
993.
A 39-year-old man presented with urinary retention and lower abdominal discomfort at our hospital, and a computed tomography scan showed a huge cystic mass posterior to the urinary bladder. During surgical exploration, a mass superior to the prostate in the region of the left seminal vesicle was found. Histologically, the tumor was characterized by cystically dilated or slit-like glands mixed in a densely cellular stroma with pleomorphism and resembled those of phyllodes tumor of the breast or prostate. The glandular epithelium within the tumor showed focal lipofuscin pigment and negative staining for prostate specific antigen (PSA). The stromal cells showed positive immunoreactivity for vimentin and CD34, and focal positive reactions for desmin and alpha-smooth muscle actin. Mitosis was present 0 to 1 per 10 high power fields of magnification in the stromal cells. Approximately 20% of the stromal cells were positive for progesterone receptor. The patient is alive with no evidence of disease 12 months after surgery. Mixed epithelial-stromal tumors of the seminal vesicle are extremely rare. A combination of stromal cellularity, atypia and mitosis might be used for the histological grading, and a prostatic origin might be excluded by the location of the primary lesion itself and by the failure to show PSA. 相似文献
994.
A composite material consisting of poly(epsilon-caprolactone) (PCL) and silica was prepared and evaluated as a bioactive bone substitute. The composite was synthesized by the co-condensation of tetraethyl orthosilicate and PCL and end-capped with triethoxysilane (Si-PCL). The as-prepared specimens were subjected to an initial heat treatment of 2 days at 60 degrees C, followed by further heat-treatments at 100 degrees C, 150 degrees C, and 200 degrees C for 24 h. The tensile mechanical properties of the heat-treated specimens were determined, and additional specimens were exposed to a simulated body fluid (SBF) for different periods of time. The SBF exposure led to the deposition of a layer of apatite crystals on the surface of the composites. It was found that increasing the second heat-treatment temperature produced an increase in tensile strength and Young's modulus of the composite but a decrease in the initial rate of apatite formation. These phenomena are explained in terms of the condensation reaction that takes place between the silanol groups in the silica and Si-PCL as the heat-treatment temperature is increased. 相似文献
995.
MCL-1 expression in B-cell non-Hodgkin's lymphomas 总被引:13,自引:0,他引:13
Cho-Vega JH Rassidakis GZ Admirand JH Oyarzo M Ramalingam P Paraguya A McDonnell TJ Amin HM Medeiros LJ 《Human pathology》2004,35(9):1095-1100
996.
997.
Park HS Lee JH Jeong EJ Koh SE Park TK Jang WJ Park KH Kim BJ Kook YH Lee SH 《Journal of clinical microbiology》2004,42(3):1270-1273
The nucleotide sequences of the groEL genes, the flagellin genes, and the 16S rRNA genes from 22 reference strains of Borrelia were compared. groEL sequence analysis is useful not only in interspecies differentiation but also in intraspecies differentiation of Borrelia afzelii and Borrelia garinii isolates. 相似文献
998.
Imaging findings of secondary hepatic lymphoma have been reported as variable, ranging from single or multiple small nodules to diffuse infiltrative tumor patterns. We hear present a rare case report concerning aggressive B cells, secondary Burkitt's lymphoma in non-AIDS demonstrating a surprising periportal lymphoma infiltration, without upper abdominal lymphadenopathy or splenomegaly on the sonography and CT scans. Clinically, the case was characterized by atypical and highly aggressive course, with the patient presenting an abruptly developed obstructive jaundice with rapidly deteriorating hepatic function that could be indicative of cholestatic hepatitis, which differs in its clinical manifestations from hepatic lymphoma without functional deterioration in respect of its non-tissue destructive growth pattern. We suggest that hepatic lymphoma can sometimes be consistent with periportal infiltrating homogeneous mass, with no lymphadenopathy or splenomegaly on the imaging examination, with a predictable aggressive clinical course of the disease and poor prognosis. 相似文献
999.
Altered expression of KCNK9 in colorectal cancers 总被引:3,自引:0,他引:3
Kim CJ Cho YG Jeong SW Kim YS Kim SY Nam SW Lee SH Yoo NJ Lee JY Park WS 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2004,112(9):588-594
K(+) channels have been reported to be involved in the proliferation of many types of cells, including some human carcinoma and tumor cell lines. KCNK9, a TASK channel, is amplified and overexpressed in several types of human cancer. In the present study, we examined the expression and somatic mutations of KCNK9 in 124 colorectal cancers by immunohistochemistry using tissue microarray and PCR-SSCP. Immunopositivity was observed in 57 (46.0%) of 124 colorectal cancers. Clinically, KCNK9 was immunopositive in 4 (30.7%) of 13 cases which were stage A, 26 (55.3%) of 47 which were stage B, 23 (41.1%) of 56 which were stage C, and 4 (50%) of 8 which were stage D. Statistically, KCNK9 protein expression was not related to tumor stage (Bartholomew test, p>0.05) and lymph node metastasis (Chi-Square test, p=0.8338). In the mutation study of the KCNK9 gene, we found only one sequence variation (ACG-->ACC, Thr-->Thr) at codon 170 both in corresponding normal and tumor DNAs. These results indicate that overexpression rather than mutation of the KCNK9 gene may contribute to the development of colorectal cancers and suggest that the development of KCNK9-targeted agents may provide new possibilities in the treatment of colorectal cancer. 相似文献
1000.
Jeong E Chung IF Miyano S 《Genome informatics. International Conference on Genome Informatics》2004,15(1):105-116
Identification of the most putative RNA-interacting residues in protein is an important and challenging problem in a field of molecular recognition. Structural analysis of protein-RNA complexes reveals a strong correlation between interaction residues and their structure. Building on this viewpoint, we have developed a neural network predictor to correctly identify residues involved in protein-RNA interactions from protein sequence and its structural information. The system has been exhaustedly cross-validated with various strategies differing in input encoding, amount of input information, and network architectures. In addition, we have evaluated performance among functional subsets of complexes. Finally, to reflect the properties of protein-RNA complexes in our dataset, two kinds of post-processing method are adopted. The experimental result shows that our system yields not-trivial performance although the residues in interaction sites are too scarce. 相似文献