全文获取类型
收费全文 | 4343篇 |
免费 | 260篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 130篇 |
妇产科学 | 117篇 |
基础医学 | 798篇 |
口腔科学 | 145篇 |
临床医学 | 354篇 |
内科学 | 737篇 |
皮肤病学 | 141篇 |
神经病学 | 644篇 |
特种医学 | 152篇 |
外科学 | 417篇 |
综合类 | 22篇 |
一般理论 | 2篇 |
预防医学 | 224篇 |
眼科学 | 75篇 |
药学 | 309篇 |
中国医学 | 2篇 |
肿瘤学 | 310篇 |
出版年
2023年 | 39篇 |
2022年 | 52篇 |
2021年 | 101篇 |
2020年 | 84篇 |
2019年 | 115篇 |
2018年 | 104篇 |
2017年 | 75篇 |
2016年 | 113篇 |
2015年 | 133篇 |
2014年 | 172篇 |
2013年 | 176篇 |
2012年 | 328篇 |
2011年 | 339篇 |
2010年 | 196篇 |
2009年 | 196篇 |
2008年 | 325篇 |
2007年 | 310篇 |
2006年 | 294篇 |
2005年 | 259篇 |
2004年 | 289篇 |
2003年 | 248篇 |
2002年 | 218篇 |
2001年 | 27篇 |
2000年 | 34篇 |
1999年 | 53篇 |
1998年 | 42篇 |
1997年 | 38篇 |
1996年 | 27篇 |
1995年 | 24篇 |
1994年 | 29篇 |
1993年 | 22篇 |
1992年 | 13篇 |
1991年 | 17篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 12篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1979年 | 6篇 |
1977年 | 7篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1972年 | 3篇 |
1960年 | 3篇 |
1939年 | 3篇 |
1936年 | 2篇 |
排序方式: 共有4620条查询结果,搜索用时 15 毫秒
51.
Malte Buchholz Hans A Kestler Andrea Bauer Wolfgang B?ck Bettina Rau Gerhard Leder Wolfgang Kratzer Martin Bommer Aldo Scarpa Martin K Schilling Guido Adler J?rg D Hoheisel Thomas M Gress 《Clinical cancer research》2005,11(22):8048-8054
PURPOSE: Malignant tumors of the pancreas are frequently indistinguishable from inflammatory tumors arising in the context of a chronic pancreatitis with the use of conventional imaging techniques. Thus, cytologic analysis of cells obtained by abdominal ultrasound, computed tomography, or endoscopic ultrasound-guided fine needle aspiration biopsy is required for diagnosis. However, the reliability of cytologic analyses of pancreatic fine needle aspirates remains unsatisfactory, with a diagnostic accuracy of < or =80%. The purpose of the current study was therefore to develop a novel diagnostic approach based on expression profiling of biopsy material using a specialized diagnostic cDNA array. EXPERIMENTAL DESIGN: Previous gene expression profiling studies were reevaluated to design a 558-feature diagnostic array. Minimal amounts of residual material from pancreatic cytology samples as well as surgically resected tumor and control tissue specimens were analyzed using the diagnostic array and a newly developed statistical classification system. RESULTS AND CONCLUSIONS: Our diagnostic approach resulted in 95% accurate differentiation between ductal adenocarcinomas and nonmalignant tumors of the pancreas. The diagnostic array, in conjunction with conventional diagnostic procedures, is thus suitable to significantly improve the reliability of pancreatic cancer diagnostics and can be expected to become a valuable new tool in the routine workup of suspect masses in the pancreas. 相似文献
52.
Occurrence and elimination of cyanobacterial toxins in two Australian drinking water treatment plants. 总被引:3,自引:0,他引:3
In Australian freshwaters, Anabaena circinalis, Microcystis spp. and Cylindrospermopsis raciborskii are the dominant toxic cyanobacteria. Many of these surface waters are used as drinking water resources. Therefore, the National Health and Medical Research Council of Australia set a guideline for MC-LR toxicity equivalents of 1.3 microg/l drinking water. However, due to lack of adequate data, no guideline values for paralytic shellfish poisons (PSPs) (e.g. saxitoxins) or cylindrospermopsin (CYN) have been set. In this spot check, the concentration of microcystins (MCs), PSPs and CYN were determined by ADDA-ELISA, cPPA, HPLC-DAD and/or HPLC-MS/MS, respectively, in two water treatment plants in Queensland/Australia and compared to phytoplankton data collected by Queensland Health, Brisbane. Depending on the predominant cyanobacterial species in a bloom, concentrations of up to 8.0, 17.0 and 1.3 microg/l were found for MCs, PSPs and CYN, respectively. However, only traces (<1.0 microg/l) of these toxins were detected in final water (final product of the drinking water treatment plant) and tap water (household sample). Despite the low concentrations of toxins detected in drinking water, a further reduction of cyanobacterial toxins is recommended to guarantee public safety. 相似文献
53.
54.
Bettina Kuschel Georgia Chenevix-Trench Amanda B Spurdle Xiaoqing Chen John L Hopper Graham G Giles Margret McCredie Jenny Chang-Claude Catherine S Gregory Nick E Day Douglas F Easton Bruce A J Ponder Alison M Dunning Paul D P Pharoah 《Cancer epidemiology, biomarkers & prevention》2005,14(7):1828-1831
A substantial proportion of the familial risk of breast cancer may be due to genetic variants, each contributing a small effect. The protein encoded by ERCC2 is a key enzyme involved in nucleotide excision repair, in which gene defects could lead to cancer prone syndromes such as Xeroderma pigmentosum D. We have examined the association between single nucleotide polymorphisms in the ERCC2 gene and the incidence of invasive breast cancer in three case-control series, with a maximum of 3,634 patients and of 3,340 controls. None of the three single nucleotide polymorphisms were significantly associated with the incidence of breast cancer. 相似文献
55.
56.
Aladr D. Rnaszki Bettina K. Budai Barbara Csongrdy Rbert Stollmayer Krisztina Hagymsi Klra Werling Tams Fodor Anik Folhoffer Ildik Kalina Gabriella Gyri Pl Maurovich-Horvat Pl N. Kaposi 《Medicine》2022,101(33)
We aimed to assess the feasibility of ultrasound-based tissue attenuation imaging (TAI) and tissue scatter distribution imaging (TSI) for quantification of liver steatosis in patients with nonalcoholic fatty liver disease (NAFLD). We prospectively enrolled 101 participants with suspected NAFLD. The TAI and TSI measurements of the liver were performed with a Samsung RS85 Prestige ultrasound system. Based on the magnetic resonance imaging proton density fat fraction (MRI-PDFF), patients were divided into ≤5%, 5–10%, and ≥10% of MRI-PDFF groups. We determined the correlation between TAI, TSI, and MRI-PDFF and used multiple linear regression analysis to identify any association with clinical variables. The diagnostic performance of TAI, TSI was determined based on the area under the receiver operating characteristic curve (AUC). The intraclass correlation coefficient (ICC) was calculated to assess interobserver reliability.Both TAI (rs = 0.78, P < .001) and TSI (rs = 0.68, P < .001) showed significant correlation with MRI-PDFF. TAI overperformed TSI in the detection of both ≥5% MRI-PDFF (AUC = 0.89 vs 0.87) and ≥10% (AUC = 0.93 vs 0.86). MRI-PDFF proved to be an independent predictor of TAI (β = 1.03; P < .001), while both MRI-PDFF (β = 50.9; P < .001) and liver stiffness (β = −0.86; P < .001) were independent predictors of TSI. Interobserver analysis showed excellent reproducibility of TAI (ICC = 0.95) and moderate reproducibility of TSI (ICC = 0.73).TAI and TSI could be used successfully to diagnose and estimate the severity of hepatic steatosis in routine clinical practice. 相似文献
57.
58.
59.
Alvan L. Barach Bettina Garthwaite Colter Rule Timothy R. Talbot John D. Kernan James Babcock George Brown 《The American journal of medicine》1946,1(3):268-290
Nasal inhalation of penicillin aerosol in conjunction with negative pressure in the nasal passages has been described as a treatment for acute and chronic sinusitis. An apparatus which also produces a slight positive pressure in addition to negative pressure during inhalation of penicillin nebulin is reported.A negative pressure in the antra of 50 to 60 mm. Hg has been demonstrated with the procedure used. Washings from the antrum in selected cases revealed that penicillin was introduced following inhalation of 50,000 units of penicillin aerosol in conjunction with repeated negative pressure.Cases of acute paranasal sinusitis are reported in which clinical recovery took place with one to four treatments per day over a period of three days to two weeks. Patients with chronic sinusitis are described in which marked improvement was demonstrated by x-ray and clinically with four treatments daily over a period of twelve days or more. Cases with chronic paranasal sinusitis treated once a day have frequently shown little or no significant benefit. In those patients in whom allergy is a prominent etiological factor less favorable results may be expected. Clinical improvement has been obtained in cases in which both infectious and allergic causal factors were definitely present.Inspection of the tables and case reports illustrates the effect on the course of the disease in individual patients; a summary of the clinical results may be stated as follows, using the combined findings of hospital, home, clinic and office patients: of 122 courses of therapy in 110 patients, marked improvement took place in thirty-nine, moderate in forty-three, slight in seventeen and no improvement in twenty-three.Of sixty-five patients x-rayed before and after treatment, marked or significant improvement was observed in thirty-nine, no improvement in twenty-two and progressive involvement in four.In forty-one patients in whom comparative cultures of the nasal or sputum cultures were available, disappearance of gram-positive organisms found prior to treatment took place in twenty-four. In twenty-five of these cases gram-positive organisms were found after treatment, either as the predominating organisms or in significant numbers.The method of treating sinusitis by penicillin aerosol and negative pressure appears to be a practical procedure that produces little or no discomfort.This report is intended as an exploratory study on the principles, methods and early clinical results of its use rather than as any final appraisal of its value. 相似文献
60.
Real‐world medical costs of antiviral therapy among patients with chronic HCV infection and advanced hepatic fibrosis
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)