全文获取类型
收费全文 | 15966篇 |
免费 | 940篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 125篇 |
儿科学 | 471篇 |
妇产科学 | 288篇 |
基础医学 | 3094篇 |
口腔科学 | 200篇 |
临床医学 | 1542篇 |
内科学 | 3402篇 |
皮肤病学 | 381篇 |
神经病学 | 1290篇 |
特种医学 | 648篇 |
外科学 | 2215篇 |
综合类 | 64篇 |
预防医学 | 840篇 |
眼科学 | 258篇 |
药学 | 1002篇 |
中国医学 | 36篇 |
肿瘤学 | 1075篇 |
出版年
2023年 | 81篇 |
2022年 | 85篇 |
2021年 | 288篇 |
2020年 | 188篇 |
2019年 | 285篇 |
2018年 | 476篇 |
2017年 | 304篇 |
2016年 | 374篇 |
2015年 | 411篇 |
2014年 | 509篇 |
2013年 | 654篇 |
2012年 | 1203篇 |
2011年 | 1182篇 |
2010年 | 588篇 |
2009年 | 461篇 |
2008年 | 973篇 |
2007年 | 997篇 |
2006年 | 941篇 |
2005年 | 935篇 |
2004年 | 856篇 |
2003年 | 763篇 |
2002年 | 714篇 |
2001年 | 239篇 |
2000年 | 190篇 |
1999年 | 187篇 |
1998年 | 51篇 |
1997年 | 47篇 |
1994年 | 42篇 |
1992年 | 79篇 |
1991年 | 87篇 |
1990年 | 95篇 |
1989年 | 110篇 |
1988年 | 85篇 |
1987年 | 86篇 |
1986年 | 78篇 |
1985年 | 65篇 |
1984年 | 61篇 |
1979年 | 69篇 |
1978年 | 51篇 |
1974年 | 54篇 |
1973年 | 48篇 |
1936年 | 54篇 |
1934年 | 43篇 |
1933年 | 63篇 |
1932年 | 66篇 |
1931年 | 63篇 |
1930年 | 52篇 |
1929年 | 45篇 |
1928年 | 52篇 |
1927年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 765 毫秒
11.
12.
13.
14.
Background
Chronic plantar heel pain (CPHP) is one of the most common musculoskeletal disorders of the foot, yet its aetiology is poorly understood. The purpose of this study was to examine the association between CPHP and a number of commonly hypothesised causative factors. 相似文献15.
Céline Chipoy Martine Berreur Séverine Couillaud Gilbert Pradal Fran?ois Vallette Caroline Colombeix Fran?oise Rédini Dominique Heymann Frédéric Blanchard 《Journal of bone and mineral research》2004,19(11):1850-1861
The effects of OSM on proliferation and differentiation of osteosarcoma and nontransformed osteoblasts were analyzed. OSM downregulates osteoblast markers but induces the glial fibrillary acidic protein by the combined activation of PKCdelta and STAT3, offering new lines of therapeutic investigations. INTRODUCTION: Oncostatin M (OSM) is a multifunctional cytokine of the interleukin-6 family implicated in embryonic development, differentiation, inflammation, and regeneration of various tissues, mainly the liver, bone, and the central nervous and hematopoietic systems. One particularity of OSM relies on its growth inhibitory and pro-differentiating effects on a variety of tumor cell lines such as melanoma, providing arguments for a therapeutic application of OSM. The objective of this study was to analyze the effects of OSM on osteosarcoma cell lines proliferation and differentiation. MATERIALS AND METHODS: Proliferation was analyzed by 3H thymidine incorporation. Differentiation was analyzed by semiquantitative RT-PCR and immunocytochemistry for various markers. Alizarin red S staining was used to evaluate bone nodule formation. Morphological changes were studied by confocal and electron microscopy. Western blotting, kinases inhibitors, and dominant negative STAT3 were used to identified the signaling pathways implicated. RESULTS: OSM inhibits the growth of rat osteosarcoma cell lines as well as normal osteoblasts, in correlation with induction of the cyclin-dependent kinases inhibitor p21WAF1. However, OSM reduces osteoblast markers such as alkaline phosphatase, osteocalcin, and bone sialoprotein, leading to strong inhibition of mineralized nodule formation. This inhibitory effect is restricted to mature osteoblasts and differentiated osteosarcoma because OSM effectively stimulates osteoblast markers and bone nodule formation in early, but not late, bone marrow mesenchymal stem cell (BMSC) cultures. In osteosarcoma cells or BMSC, OSM induces expression of the glial fibrillary acidic protein (GFAP) as well as morphological and ultrastructural changes, for example, elongated shape and bundles of microfilaments in cell processes. Rottlerin (PKCdelta inhibitor), and to a lesser degree UO126 (MEK/ERK inhibitor), prevents the loss of osteoblastic markers by OSM, whereas dominant negative STAT3 prevents GFAP induction. CONCLUSIONS: These results highlight the particular gene expression profile of OSM-treated osteosarcoma cells and BMSCs, suggesting either a osteocytic or a glial-like phenotype. Together with the implication of PKCdelta, ERK1/2, and STAT3, these results offer new lines of investigations for neural cell transplantation and osteosarcoma therapy. 相似文献
16.
Detection of the center of the hip joint in computer-assisted surgery: an evaluation study of the Surgetics algorithm. 总被引:4,自引:0,他引:4
Eric Stindel Daniel Gil Jean-Louis Briard Philippe Merloz Frédéric Dubrana Christian Lefevre 《Computer aided surgery》2005,10(3):133-139
OBJECTIVE: The aim of this paper is to assess the accuracy of an algorithm implemented by PRAXIM in the SURGETICS navigation station for detection of the hip center. This study will assess the robustness and accuracy of the algorithm in various clinical situations such as those involving non-sphericity of the femoral head, motion of the pelvis during hip center detection, and restricted range of motion. MATERIALS AND METHODS: The localization of the hip center, based on kinematics, relies on the recording of n successive positions of the femoral rigid body in the localizer reference system during a passive circumduction motion of the hip joint. Therefore, the shape of the clouds of points acquired may vary from one acquisition to the next. To allow a comprehensive study of the consequences of these variations for hip center detection, we developed a simulator to generate numerous clouds of points. Results given subsequently for each test are the values of the difference between the femoral mechanical axis computed with C(c), the computed hip center, and the same axis computed with C(o), the reference hip center. RESULTS: Test 1: Sensitivity to noise. The errors ranged from 3.33 E - 12 (SD 3.29E - 12) for a noise of 0 mm to 8.18E - 1 (SD - 7.05E - 1) for a noise of 15 mm. Test 2: Sensitivity to the shape of the acquisition motion. All trajectories gave an error < 1 degrees . Test 3: Sensitivity to restricted range of motion. No value > 1 degrees was found during this test. Test 4: Sensitivity to the distance between two points of the cloud. No value > 0.5 degrees was found during this test. Test 5: Sensitivity to the number of points included in the cloud. No value > 1 degrees was found during this test. CONCLUSIONS: The Surgetics algorithm is robust to noise, can compensate for pelvic motion, and can be used even in the case of restricted range of motion. 相似文献
17.
Z. Janczewski L. Bablok A. Smith M. Czaplicki S. Fr⇂cki 《International urology and nephrology》1990,22(2):161-165
Changes in semen parameters are presented for 4708 patients treated for infertility. The largest group comprised patients
with oligoasthenozoospermia of various grades (57.7%). Improvement in the seminal state was noted in 70.3%. The percentage
of achieved normospermia increased proportionally to the initial semen state. Pregnancy rate also increased proportionally
to the initial seminal state.
Among the patients' wives 20.4% conceived: 28.2% of these pregnancies had occurred after having achieved normospermia, while
in 71.8% the seminal states were still below the accepted normal values. 相似文献
18.
Drug related hospital admissions 总被引:13,自引:0,他引:13
J. Hallas B. Harvald J. Worm J. Beck-Nielsen L. F. Gram E. Grodum N. Damsbo J. Schou H. Kromann-Andersen F. Frølund 《European journal of clinical pharmacology》1993,45(3):199-203
Summary As part of a high-intensity monitoring study of drug events as the cause of admission to departments of internal medicine, the effect of an educational intervention programme was studied. Two departments were included, one specialising in geriatrics and one that received patients by non-selected referral. The series consisted of 607 consecutive admissions studied before and 703 after the intervention. The drug events considered were adverse drug reactions and dose-related therapeutic failures, mainly due to non-compliance.A modest, statistically non-significant decrease in drug related hospital admissions (DRH) was seen, from 14% before to 13% after the intervention period. However, DRHs classified as definitely avoidable showed the significant decrease of 83%.There was no apparent relationship between the topics selected for the intervention programme and changes in the pattern of DRHs. No relationship between alterations in sales data and hospital admissions caused by a given drug could be demonstrated. A blinded external evaluation of case abstracts did not disclose any significant shift in the investigators' assessments.The intervention may have had an non-specific effect on avoidable DRHs. 相似文献
19.
Dany Anglicheau Alexandre Lautrette Catherine Scieux Martin Flamant Frédéric Morinet Christophe Legendre 《Nephrology, dialysis, transplantation》2003,18(8):1654-1656
BACKGROUND: Routine cytomegalovirus (CMV)-pp65 antigenaemia monitoring shows that some patients will develop pp65 antigenaemia during valaciclovir prophylaxis or after cessation of treatment. The aim of this pilot study was to evaluate the safety and efficacy of lowering immunosuppression in kidney transplant recipients who exhibit mildly symptomatic CMV infections while on valaciclovir prophylaxis. METHODS: We selected 12 patients who experienced mildly symptomatic CMV infections defined as a positive CMV-pp65 antigenaemia test associated with either neutropenia, asthenia or arthralgia, but no fever. All of them received prophylaxis with valaciclovir for at least 3 months. Testing for CMV-pp65 antigenaemia was performed weekly for 6 months. RESULTS: The mildly symptomatic infections occurred at a median interval of 69 days after transplantation-during prophylaxis in eight cases and after valaciclovir discontinuation in the other four cases. All of them were effectively managed by lowering immunosuppressive therapy, leading to the disappearance of symptoms and CMV antigenaemia reduction. No immunological complication or recurrence of CMV infection or disease was noted. I.v. ganciclovir never became necessary. CONCLUSION: The mildly symptomatic CMV infections occurring in valaciclovir-treated patients may be managed efficiently and without immunologic complication by lowering immunosuppressive therapy. 相似文献
20.
Lamine Abdennour Paola Sanchez-Pea Damien Galanaud Vincent Navarro Nicolas Weiss Louis Puybasset 《Neuropsychiatric Disease and Treatment》2007,3(5):695-702
As for the majority of antiepileptic drugs, encephalopathy, manifested by transient somnolence, mood and motor disorders, is a possible side-effect. To our knowledge, there is little information about gabapentin-induced coma. We report a third case of gabapentin-induced coma where magnetic resonance-spectrometry was performed in diagnosis assessment. 相似文献