全文获取类型
收费全文 | 1692篇 |
免费 | 102篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 65篇 |
妇产科学 | 20篇 |
基础医学 | 153篇 |
口腔科学 | 52篇 |
临床医学 | 178篇 |
内科学 | 469篇 |
皮肤病学 | 233篇 |
神经病学 | 76篇 |
特种医学 | 105篇 |
外科学 | 145篇 |
综合类 | 15篇 |
预防医学 | 157篇 |
眼科学 | 7篇 |
药学 | 87篇 |
肿瘤学 | 49篇 |
出版年
2021年 | 21篇 |
2020年 | 11篇 |
2019年 | 12篇 |
2018年 | 20篇 |
2017年 | 18篇 |
2016年 | 38篇 |
2015年 | 47篇 |
2014年 | 47篇 |
2013年 | 77篇 |
2012年 | 43篇 |
2011年 | 40篇 |
2010年 | 46篇 |
2009年 | 67篇 |
2008年 | 32篇 |
2007年 | 35篇 |
2006年 | 48篇 |
2005年 | 26篇 |
2004年 | 28篇 |
2003年 | 28篇 |
2002年 | 29篇 |
2001年 | 20篇 |
2000年 | 40篇 |
1999年 | 53篇 |
1998年 | 68篇 |
1997年 | 58篇 |
1996年 | 62篇 |
1995年 | 53篇 |
1994年 | 58篇 |
1993年 | 39篇 |
1992年 | 69篇 |
1991年 | 26篇 |
1990年 | 50篇 |
1989年 | 47篇 |
1988年 | 57篇 |
1987年 | 36篇 |
1986年 | 33篇 |
1985年 | 16篇 |
1984年 | 35篇 |
1983年 | 18篇 |
1982年 | 20篇 |
1981年 | 22篇 |
1980年 | 18篇 |
1978年 | 12篇 |
1977年 | 8篇 |
1976年 | 13篇 |
1975年 | 8篇 |
1973年 | 10篇 |
1971年 | 9篇 |
1966年 | 9篇 |
1964年 | 14篇 |
排序方式: 共有1816条查询结果,搜索用时 187 毫秒
71.
72.
CT‐guided aspiration cytology of advanced silicosis and confirmation of the deposited zeolite nano particles through X ray diffraction: A novel approach
下载免费PDF全文
![点击此处可从《Diagnostic cytopathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Arghya Bandyopadhyay M.D. Kaushik Majumdar M.D. D.N.B. Abhijit Chakraborty PH.D. Partha Mitra PH.D. Subhomoy Nag M.D. 《Diagnostic cytopathology》2016,44(3):246-249
Silicosis is a common occupational lung disease, resulting in fibrotic nodular lesions in the upper lobes of the lung parenchyma. Most of the pneumoconioses are diagnosed on the basis of relevant history and clinico‐radiological correlation. Image‐guided aspiration cytology appears to be poorly yielding and is not usually considered as a diagnostic modality. However, silicosis may sometimes offer a diagnostic challenge because of its radiological resemblance and clinical overlap with pulmonary tuberculosis and neoplastic lesions. We present a unique situation where image‐guided fine needle aspiration cytology (FNAC) has been advised on the basis of nodular upper lobe opacities. The cytology smears revealed hypocellular granular material, while phase contrast and polarized light microscopy highlighted crystalline particles. History of silica dust exposure long back was available after the cytological evaluation, suggesting the diagnosis of pulmonary silicosis. X ray diffraction (XRD) crystallography was also possible on cytology smears, confirming zeolite nano particles of size as small as 40 ? 50 nm as the concerned agent for the first time. Cytological evaluation by phase contrast and polarized light microscopy may be useful for the confirmation of silicosis, supplemented by clinical history and radiological evaluation. XRD on smears may help in determination of chemical nature and particle size. Diagn. Cytopathol. 2016;44:246–249. © 2015 Wiley Periodicals, Inc. 相似文献
73.
An evaluation of the ‘Yaka Ŋarali’’ Tackling Indigenous Smoking program in East Arnhem Land: Yolŋu people and their connection to ŋarali’
下载免费PDF全文
![点击此处可从《Health promotion journal of Australia》网站下载免费的PDF全文](/ch/ext_images/free.gif)
74.
de Andrade e Silva SM Marquezini L Manso AP Garcia FP Carrilho MR Pashley DH Tay FR Carvalho RM 《The journal of adhesive dentistry》2007,9(6):505-512
PURPOSE: To test the effects of sequential application of potassium oxalate gel/adhesive agent on in vitro dentin permeability. MATERIALS AND METHODS: Full crown preparations were made in extracted human molars to expose deep coronal dentin. The roots and pulp were removed and the resulting crown segments were connected to a special device (Flodec) to permit the measurement of the permeability of the specimens before and after treatments. Minimum and maximum permeability were recorded after smear layer and phosphoric acid treatment. A new smear layer was created and the permeability measured after the crowns were bonded with Single Bond (3M ESPE), One-Up Bond F (Tokuyama), and AdheSE (Ivoclar Vivadent), either according to manufacturer's instructions or after treating the acid-etched dentin with a 3 wt% potassium oxalate gel. The results were expressed as a percentage of maximum permeability values. Impressions and epoxy resin replicas from the crown segments were produced for SEM examination. RESULTS: None of the adhesives were able to eliminate the fluid flow through dentin. Two-way ANOVA revealed that the application of potassium oxalate prior to the bonding procedures was the most effective technique in reducingthe dentin permeability (p < 0.05), regardless of the adhesive used. SEM micrographs showed that transudation of dentinal fluid could be identified on the surfaces of all replicas. CONCLUSION: The use of potassium oxalate gel was effective in reducing the permeability of bonded dentin. 相似文献
75.
Arruda VR; Pieneman WC; Reitsma PH; Deutz-Terlouw PP; Annichino-Bizzacchi JM; Briet E; Costa FF 《Blood》1995,86(8):3015-3020
The molecular characterization of the mutations in hemophilia A patients is hampered by the large size of the factor VIII gene and the great heterogeneity of mutations. In this study, we have performed a protocol involving multiplex polymerase chain reaction in which 19 exons were amplified in four different combinations followed by nonradioactive single-strand conformational polymorphism (SSCP) to screen for mutations. Southern blotting was used to detect inversion of the factor VIII gene resulting from recombination between copies of the gene A (F8A) located in intron 22 of the factor VIII gene and two copies close telomeric region of X chromosome. Forty-two hemophilia A patients (21 with severe and 21 with mild-to-moderate disease) were studied. The inversion of factor VIII occurred in 13 of 21 patients affected by severe hemophilia A. One patient showed a large extra band in addition to the three bands observed after Southern blotting with the F8A probe. An abnormal electrophoretic pattern of SSCP was detected in 85% and 50% of the patients affected by mild-to-moderate and severe disease, respectively. Sixteen different mutations were identified. Eleven mutations were novel and comprised 9 point mutations and 2 small deletions. This study shows that the methodology used is safe and rapid and has potential for detecting almost all of the genetic defects of the studied hemophilia A patients. 相似文献
76.
A 45-year-old male patient with Ph-negative chronic myeloid leukemia (CML) had rearranged bcr-3' and bcr-5' gene regions in Southern blot studies when leukemia was diagnosed. During development of terminal blast crisis, successive blood samples showed a progressive decrease in the amount of germline bcr DNA and its complete loss by full blast crisis. There were also increased amounts of rearranged bcr DNA consistent with acquired homozygosity. A similar result was obtained with an IgV lambda probe and indicated homozygosity of a significant part of chromosome 22. The bcr-abl gene complex behaves as a somatic dominant in CML, and we suggest that its acquired homozygosity is a mechanism of bcr-abl amplification similar to duplication of the Ph chromosome commonly found in the blast crisis of CML. 相似文献
77.
78.
Shalender Bhasin MB BS Thomas G. Travison PhD Todd M. Manini PhD Sheena Patel MS Karol M. Pencina PhD Roger A. Fielding PhD Jay M. Magaziner PhD Anne B. Newman MD MPH Douglas P. Kiel MD Cyrus Cooper DM FMedSci Jack M. Guralnik MD PhD Jane A. Cauley Dr.PH Hidenori Arai MD PhD Brian C. Clark PhD Francesco Landi MD PhD Laura A. Schaap PhD Suzette L. Pereira PhD Daniel Rooks PhD Jean Woo MD PhD Linda J. Woodhouse PhD Ellen Binder MD Todd Brown MD Michelle Shardell PhD Quian-Li Xue PhD Ralph B. DʼAgostino Sr PhD Denise Orwig PhD Greg Gorsicki PhD Rosaly Correa-De-Araujo MD PhD Peggy M. Cawthon PhD 《Journal of the American Geriatrics Society》2020,68(7):1410-1418
79.
80.
María N. Pizzi Elisa Franquet Santiago Aguadé-Bruix Begoña Manso Jaume Casaldáliga Gemma Cuberas-Borrós Guillermo Romero-Farina Josep Pinar Joan Castell-Conesa David García-Dorado Jaume Candell-Riera 《Pediatric cardiology》2014,35(2):197-207
The arterial switch operation (ASO) is the preferred technique for correcting transposition of the great arteries, but translocation and reimplantation of the coronary arteries can produce myocardial ischemia. This report aims to describe the authors’ experience with exercise single-photon emission computed tomography (SPECT) used to evaluate myocardial perfusion. Exercise-rest gated-myocardial perfusion SPECT was performed for 69 patients (49 boys; median age, 9 years; 5th percentile [6.4 years] to 95th percentile [15.6 years]), 64 of whom were asymptomatic 9.98 ± 3.20 years after ASO. During exercise testing, the patients reached 9.85 ± 3.05 metabolic equivalents (METs) and a median heart rate of 160 beats per minute (bpm), 5th percentile (106 bpm) to 95th percentile (196 bpm). Whereas 61 patients (88.41 %) had normal myocardial perfusion, 2 patients (2.9 %) had reversible defects, and 6 patients (8.7 %) had fixed defects. All the patients with perioperative ischemic complications (4/4, 100 %) had myocardial perfusion defects, whereas four patients (4/65, 6.15 %) without ischemic complications had abnormal perfusion (p = 0.0005). Age at the time of surgery did not differ significantly (p = 0.234) between the patients with perfusion defects and those with normal study results. No significant difference was observed between the patients who had an A coronary pattern (left coronary artery originating from the left sinus and the right coronary artery originating from the right sinus, n = 47) and those who had a non-A coronary pattern (n = 22) (p = 1). The high rate for normality of exercise myocardial perfusion in our study suggests that myocardial perfusion gated-SPECT should be reserved for patients who have experienced perioperative ischemic complications or those with symptoms, at least during the first 10 years after the surgery. 相似文献