全文获取类型
收费全文 | 1751篇 |
免费 | 77篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 28篇 |
妇产科学 | 53篇 |
基础医学 | 146篇 |
口腔科学 | 24篇 |
临床医学 | 206篇 |
内科学 | 428篇 |
皮肤病学 | 13篇 |
神经病学 | 97篇 |
特种医学 | 82篇 |
外科学 | 385篇 |
综合类 | 8篇 |
一般理论 | 4篇 |
预防医学 | 55篇 |
眼科学 | 44篇 |
药学 | 55篇 |
中国医学 | 1篇 |
肿瘤学 | 163篇 |
出版年
2023年 | 17篇 |
2022年 | 28篇 |
2021年 | 44篇 |
2020年 | 27篇 |
2019年 | 45篇 |
2018年 | 51篇 |
2017年 | 43篇 |
2016年 | 56篇 |
2015年 | 57篇 |
2014年 | 107篇 |
2013年 | 109篇 |
2012年 | 177篇 |
2011年 | 155篇 |
2010年 | 108篇 |
2009年 | 76篇 |
2008年 | 164篇 |
2007年 | 136篇 |
2006年 | 112篇 |
2005年 | 95篇 |
2004年 | 94篇 |
2003年 | 55篇 |
2002年 | 53篇 |
2001年 | 10篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
排序方式: 共有1849条查询结果,搜索用时 15 毫秒
1.
Evaluation of the thyroid nodule. 总被引:3,自引:0,他引:3
BACKGROUND: Thyroid nodules are common, yet treatment modalities range from observation to surgical resection. Because thyroid nodules are frequently found incidentally during routine physical examination or imaging performed for another reason, physicians from a diverse range of specialties encounter thyroid nodules. Clinical decision making depends on proper evaluation of the thyroid nodule. METHODS: The current literature was reviewed and synthesized. RESULTS: Current evidence allows the formulation of recommendations and a general algorithm for evaluating the incidental thyroid nodule. CONCLUSIONS: Only a small percentage of thyroid nodules require surgical management. Diagnosis and treatment selection require a risk stratification by history, physical examination, and ancillary tests. Nodules causing airway compression or those at high risk for carcinoma should prompt evaluation for surgical treatment. In nodules larger than 1 cm, fine-needle aspiration biopsy is central to the evaluation as it is accurate, low risk, and cost effective. Subcentimeter nodules, often found incidentally on imaging obtained for another purpose, can usually be evaluated by ultrasonography. Other laboratory and imaging evaluations have specific and more limited roles. An algorithm for the evaluation of the thyroid nodule is presented. 相似文献
2.
3.
Greg Reynolds Martin Wilson Andrew Peet Theodoros N Arvanitis 《Magnetic resonance in medicine》2006,56(6):1211-1219
The quantitation of metabolite concentrations from in vitro NMR spectra is hampered by the sensitivity of peak positions to experimental conditions. The quantitation methods currently available are generally labor intensive and cannot readily be automated. Here, an algorithm is presented for the automatic time domain analysis of high-resolution NMR spectra. The TARQUIN algorithm uses a set of basis functions obtained by quantum mechanical simulation using predetermined parameters. Each basis function is optimized by subdividing it into a set of signals from magnetically equivalent spins and varying the simulated chemical shifts of each of these groups to match the signal undergoing analysis. A novel approach to the standard multidimensional minimization problem is introduced based on evaluating the fit resulting from different permutations of possible chemical shifts, obtained from one-dimensional searches. Results are presented from the analysis of (1)H proton magic angle spinning spectra of cell lines illustrating the robustness of the method in a typical application. Simulation was used to investigate the biggest peak shifts that can be tolerated. 相似文献
4.
5.
Norma A. Vavatsi Sophia A. Kouidou Paraschos N. Geleris Christos Tachmatzidis Theodoros Gikas Demetrios K. Tsifodimos Antonios C. Trakatellis 《Clinical genetics》1995,47(1):22-26
Restriction fragment length polymorphisms (RFLPs) at the apolipoprotein AI-CIII-AIV gene cluster and their association with coronary artery disease (CAD) and lipid levels were studied in a Northern Greek population. Ninety-five patients with CAD and fifty-four normal controls, angio-graphically proven, were included in this study. Using genomic hybridization techniques, three polymorphic restriction sites were identified at this locus: the PstI at the 3' end of the apoAI gene, the SacI at the 3' non-coding region of the apoCIII gene and the PvuII at the intergenic region between the apoCIII-AIV genes. The rare allele (P2) arising from the absence of the PstI restriction site was observed with a significantly higher frequency (p<0.01) in patients compared to normals (0.11 vs 0.02). In contrast, the rare allele for the SacI polymorphic site had a similar distribution among patients and controls (0.12 vs 0.16). The same was observed for the PvuII RFLP (0.04 vs 0.05). Correlation of lipid and apolipoprotein AI levels with the three RFLPs revealed no significant association, although apo AI and HDL were lower in patients with the P2 allele. Thus, in this Greek population, only the PstI polymorphism, among the polymorphic restriction sites examined, appears to be associated with CAD. 相似文献
6.
Alexandros Drivalos Georgios Emmanouil Maria Gavriatopoulou Evangelos Terpos Theodoros N. Sergentanis Theodora Psaltopoulou 《Urologic oncology》2021,39(4):221-232
Background: The prompt identification of patients with poor prognosis is essential in order to improve the treatment outcomes in prostate cancer (CaP); as a novel approach, several molecular markers, including integrins, have been discussed as prognostic biomarkers. Our aim was to comprehensively examine aberrant expression of integrins in correlation with clinicopathological features and prognosis in CaP by synthesizing all available evidence, in a systematic review and meta-analysis. Methods: A systematic review and meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Scientific literature databases (Pubmed, Embase, and Scopus) were systematically searched until May 10, 2020. Random-effects (DerSimonian-Laird) models were used to estimate pooled odds ratios (ORs) for cross-sectional correlations with clinicopathological characteristics and relative risks for longitudinal associations with prognosis. Results: Fourteen studies were included with a total number of 3,194 CaP cases examined (13 cross-sectional and four longitudinal cohort study arms). Correlation of low expression of α6 (pooled OR = 0.10, 95% confidence interval [CI]: 0.04–0.28, P < 0.001) and β1 (pooled OR = 0.45; 95% CI: 0.21–1.00, P = 0.049) integrin with high Gleason score was noted. A borderline trend between reduced expression of α6 integrin and an advanced clinical stage of CaP (pooled OR = 0.48; 95% CI: 0.22-1.03, P = 0.06) was observed. No associations with biochemical recurrence and survival were documented. Conclusions: Evidence on the association of low expression of integrins α6 and β1 and more advanced CaP exist, whereas significant results on survival were not documented; further studies are warranted. 相似文献
7.
George T Theodoros MT Chiu E Krapivensky N Hokin A Tiller JW 《The Australian and New Zealand journal of psychiatry》1999,33(6):889-895
OBJECTIVES: The aim of this study is to evaluate the efficacy and tolerability of sertraline in patients with major depression who have failed to respond to an adequate trial of moclobemide. METHOD: Sixty-three patients with major depression who had discontinued moclobemide within the last 6 weeks due to lack of efficacy were recruited from multiple psychiatric services in Victoria and Queensland. After a wash-out period, patients were treated with sertraline 50 mg once daily for 4 weeks. If there was an insufficient response, the dose was titrated upwards to a maximum of 200 mg/day, with 2 weeks at each dosage level. By the end of the study, patients had received a fixed dose of sertraline for 8 weeks. The main outcome measures were the 17-item Hamilton Rating Scale for Depression (HAMD) and Clinical Global Impression (CGI) scales. Secondary outcome measures included the Montgomery-Asberg Depression Rating Scale (MADRS) and Beck Depression Inventory (BDI). RESULTS: Of the 62 intention-to-treat patients enrolled, 48 (77%) responded to sertraline (i.e. experienced > or =50% reduction in HAMD total score from baseline and had a final HAMD score of < or =17). Fifty-four (87%) patients were at least 'minimally improved' on the CGI scale. There were also significant improvements in mean total MADRS and BDI scores. Sertraline was well tolerated. Adverse events were reported by 84% of patients, but only 5% withdrew due to adverse events. CONCLUSIONS: This study shows that patients with major depression who have failed to respond to moclobemide can generally be treated successfully with sertraline. 相似文献
8.
Marco Herling George Z Rassidakis L Jeffrey Medeiros Theodoros P Vassilakopoulos Kay-Oliver Kliche Gianpaolo Nadali Simonetta Viviani Valeria Bonfante Roberto Giardini Marco Chilosi Christos Kittas Alessandro M Gianni Gianni Bonadonna Giovanni Pizzolo Gerassimos A Pangalis Fernando Cabanillas Andreas H Sarris 《Clinical cancer research》2003,9(6):2114-2120
PURPOSE: EBV-latent membrane protein-1 (LMP-1) is often expressed in Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin's lymphoma (cHL), but its clinical significance is controversial. We correlated LMP-1 with presenting features, including serum interleukin 10 levels and clinical outcome. EXPERIMENTAL DESIGN: Patients were eligible if they had biopsy-proven cHL, were untreated, HIV-1 negative, and had available archival tissue. LMP-1 expression was determined by immunohistochemistry. RESULTS: We identified 577 patients with cHL with a median age of 30 years, 55% of whom were male. LMP-1 was expressed in HRS cells of 124 patients (21%) and was detected in 78 of 461 (17%) patients with nodular sclerosis compared with 44 of 112 (39%) with mixed cellularity (P < 0.001 by Fisher's exact test). Patients with tumors with LMP-1-positive HRS cells had higher serum interleukin 10 levels (P = 0.009 by Mann-Whitney test). For the 303 patients treated with doxorubicin, bleomycin, vinblastine, and dacarbazine or equivalent regimens, the 5-year failure-free survival (FFS) for those with LMP-1-positive tumors was 74% compared with 81% for those with LMP-1-negative tumors (P = 0.23, by log-rank test). Overall survival (OS) at 5 years for patients with LMP-1-positive tumors was 90 versus 91% for patients with LMP-1-negative tumors (P = 0.8 by log-rank test). Expression of LMP-1 was not associated with different FFS and OS in patients treated with other regimens or with radiotherapy alone. CONCLUSIONS: LMP-1 was expressed by HRS cells in 21% of cHL and correlated with mixed cellularity type and higher serum interleukin 10 levels. The presence of LMP-1 was not associated with FFS or OS in uniformly treated patients. 相似文献
9.
Leptin is an adipocyte-secreted hormone which plays a key role in energy homeostasis.
Recent “proof of concept” studies involving leptin administration to humans support its
critical role in regulating energy homeostasis, neuroendocrine and immune function as well
as insulin resistance in states of energy/ caloric deprivation. Moreover, interventional
studies in leptin deficient children and observational studies in normal girls and boys
support a role for leptin as a permissive factor for the initiation of puberty in
children. The potential clinical usefulness of leptin in several disease states in
children and adolescents, including hypothalamic amenorrhea, eating disorders and
syndromes of insulin resistance is still under investigation. 相似文献
10.
Mary Feng Siavash Jabbari Alexander Lin Carol R Bradford Douglas B Chepeha Theodoros N Teknos Francis P Worden Christina Tsien Matthew J Schipper Gregory T Wolf Laura A Dawson Avraham Eisbruch 《Radiotherapy and oncology》2005,77(1):32-38
BACKGROUND AND PURPOSE: Predictive factors for local-regional (LR) failures after parotid-sparing, Intensity modulated (IMRT) or 3D conformal radiotherapy for head and neck (HN) cancers were assessed. PATIENTS AND METHODS: One hundred and fifty-eight patients with mostly stages III-IV HN squamous cell carcinoma underwent curative bilateral neck irradiation aimed at sparing the parotid glands. Patient, tumor, and treatment factors were analyzed as predictive factors for LR failure. RESULTS: Twenty-three patients had LR recurrence (19 in-field and four marginal). No differences were found in the doses delivered to the PTVs of patients with or without in-field recurrences. In univariate analysis, tumor site was highly predictive for LR failure in both postoperative and definitive RT patients. In postoperative RT patients, pathologic tumor size, margin status, extracapsular extension (ECE) and number of lymph node metastases, were also significantly predictive. Multivariate analysis showed tumor site (oropharynx vs. other sites) to be a significant predictor in all patients, and involved margins and number of involved lymph nodes in postoperative patients. CONCLUSIONS: Clinical rather than dosimetric factors predicted for LR failures in this series, and were similar to those reported following standard RT. These factors may aid in the selection of patients for studies of treatment intensification using IMRT. 相似文献