全文获取类型
收费全文 | 1465篇 |
免费 | 106篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 32篇 |
妇产科学 | 32篇 |
基础医学 | 253篇 |
口腔科学 | 83篇 |
临床医学 | 132篇 |
内科学 | 353篇 |
皮肤病学 | 23篇 |
神经病学 | 176篇 |
特种医学 | 54篇 |
外科学 | 103篇 |
综合类 | 3篇 |
一般理论 | 1篇 |
预防医学 | 96篇 |
眼科学 | 53篇 |
药学 | 77篇 |
中国医学 | 4篇 |
肿瘤学 | 105篇 |
出版年
2023年 | 14篇 |
2022年 | 45篇 |
2021年 | 64篇 |
2020年 | 38篇 |
2019年 | 54篇 |
2018年 | 61篇 |
2017年 | 59篇 |
2016年 | 53篇 |
2015年 | 59篇 |
2014年 | 81篇 |
2013年 | 93篇 |
2012年 | 133篇 |
2011年 | 145篇 |
2010年 | 75篇 |
2009年 | 59篇 |
2008年 | 78篇 |
2007年 | 71篇 |
2006年 | 81篇 |
2005年 | 89篇 |
2004年 | 55篇 |
2003年 | 53篇 |
2002年 | 38篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1585条查询结果,搜索用时 11 毫秒
41.
G Desideri C Kwik-Uribe D Grassi S Necozione L Ghiadoni D Mastroiacovo A Raffaele L Ferri R Bocale MC Lechiara C Marini C Ferri 《Hypertension》2012,60(3):794-801
Flavanol consumption is favorably associated with cognitive function. We tested the hypothesis that dietary flavanols might improve cognitive function in subjects with mild cognitive impairment. We conducted a double-blind, parallel arm study in 90 elderly individuals with mild cognitive impairment randomized to consume once daily for 8 weeks a drink containing ≈990 mg (high flavanols), ≈520 mg (intermediate flavanols), or ≈45 mg (low flavanols) of cocoa flavanols per day. Cognitive function was assessed by Mini Mental State Examination, Trail Making Test A and B, and verbal fluency test. At the end of the follow-up period, Mini Mental State Examination was similar in the 3 treatment groups (P=0.13). The time required to complete Trail Making Test A and Trail Making Test B was significantly (P<0.05) lower in subjects assigned to high flavanols (38.10±10.94 and 104.10±28.73 seconds, respectively) and intermediate flavanols (40.20±11.35 and 115.97±28.35 seconds, respectively) in comparison with those assigned to low flavanols (52.60±17.97 and 139.23±43.02 seconds, respectively). Similarly, verbal fluency test score was significantly (P<0.05) better in subjects assigned to high flavanols in comparison with those assigned to low flavanols (27.50±6.75 versus 22.30±8.09 words per 60 seconds). Insulin resistance, blood pressure, and lipid peroxidation also decreased among subjects in the high-flavanol and intermediate-flavanol groups. Changes of insulin resistance explained ≈40% of composite z score variability through the study period (partial r(2)=0.4013; P<0.0001). To the best of our knowledge, this is the first dietary intervention study demonstrating that the regular consumption of cocoa flavanols might be effective in improving cognitive function in elderly subjects with mild cognitive impairment. This effect appears mediated in part by an improvement in insulin sensitivity. 相似文献
42.
Eduardo D. E. Papa Izo Helber Manes R. Ehrlichmann Claudia Maria Rodrigues Alves Marcia Makdisse Livia N. Matos Jairo Lins Borges Renato D. Lopes Edson Stefanini Antonio Carlos Carvalho 《Clinics (S?o Paulo, Brazil)》2013,68(12):1481-1487
OBJECTIVES:
To correlate the importance of the ankle-brachial index in terms of cardiovascular morbimortality and the extent of coronary arterial disease amongst elderly patients without clinical manifestations of lower limb peripheral arterial disease.METHODS:
We analyzed prospective data from 100 patients over 65 years of age with coronary arterial disease, as confirmed by coronary angiography, and with over 70% stenosis of at least one sub-epicardial coronary artery. We measured the ankle-brachial index immediately after coronary angiography, and a value of <0.9 was used to diagnose peripheral arterial disease.RESULTS:
The patients'' average age was 77.4 years. The most prevalent risk factor was hypertension (96%), and the median late follow-up appointment was 28.9 months. The ankle-brachial index was <0.9 in 47% of the patients, and a low index was more prevalent in patients with multiarterial coronary disease compared to patients with uniarterial disease in the same group. Using a bivariate analysis, only an ankle-brachial index of <0.9 was a strong predictive factor for cardiovascular events, thereby increasing all-cause deaths and fatal and non-fatal acute myocardial infarctions two- to three-fold.CONCLUSION:
In elderly patients with documented coronary disease, a low ankle-brachial index (<0.9) was associated with the severity and extent of coronary arterial disease, and in late follow-up appointments, a low index was correlated with an increase in the occurrence of major cardiovascular events. 相似文献43.
44.
Livia Garavelli Graziella Simonte Simonetta Rosato Anita Wischmeijer Enrico Albertini Elisa Guareschi Caterina Longo Giuseppe Albertini Chiara Gelmini Chiara Greco Stefania Errico Gustavo Savino Marco Pavanello Rudolf Happle Sheila Unger Andrea Superti‐Furga Karl‐Heinz Grzeschik 《American journal of medical genetics. Part A》2013,161(7):1750-1754
45.
Sönke Harder Rainer Podschun Livia Grancicova Christian Mehl Matthias Kern 《Clinical oral investigations》2013,17(4):1135-1142
Objective
Information about the spectrum of microorganisms in the intraimplant cavities of two-piece dental implants is scarce. The purpose of this study was to assess the intraimplant microflora of two-piece dental implants by conventional biochemical testing, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16 s rDNA gene sequencing.Materials and methods
Ten patients (six men and four women; average age?=?66.7 years; age range?=?58–78 years) received 35 two-piece titanium implants carrying ball attachments. Biofilm sampling was performed with sterile microbrushes, and nonadherent microbial samples were obtained by injection and reuptake of predefined volumes of NaCl solution. The samples were cultured and analyzed by conventional biochemical testing, MALDI-TOF MS, and 16 s rDNA gene sequencing.Results
Of the 103 species detected, 27 and 33 were identified only in the biofilm and nonadherent microbial samples, respectively. Forty-three species were identified in both types of samples.Conclusions
Two-piece dental implants harbored a broad spectrum of gram-positive and gram-negative aerobes and anaerobes, especially rods and cocci.Clinical relevance
These findings confirm bacterial translocation from the oral cavity to intraimplant cavities. Microbiological methods as used in this study are necessary to reveal the complete vital microflora of intraimplant cavities. 相似文献46.
Background: Epidemiological studies have shown a higher risk of thyroid cancer among individuals who have a relative with papillary thyroid cancer (PTC) compared to those without a family history. This study evaluated the prevalence of thyroid cancer among subjects with only one first-degree relative (sibling) with PTC who had no palpable nodules, factors predictive of this malignancy, and the characteristics of tumors discovered during ultrasonographic screening. Methods: A total of 757 siblings of 447 patients with apparently sporadic PTC were examined. Nodules were palpable in 34 subjects (excluded). The 723 individuals without palpable abnormalities were submitted to thyroid ultrasonography and comprised the study group. The control group, consisting of 241 volunteers without a family history of thyroid cancer matched for gender and age to the study group, was also submitted to thyroid ultrasonography. All nodules ≥5?mm were examined by fine-needle aspiration cytology. Subjects with benign cytology were not submitted to surgery, whereas the subjects having malignant, suspicious for a malignancy, indeterminate, or inadequate cytology were referred for thyroidectomy. Results: Ultrasonography detected nodules in 303 (41.9%) study subjects. PTC was observed in 5.94% of the 723 subjects studied (8% women and 3.75% men, p=0.017) and in 14.2% of the 303 subjects with nonpalpable nodular disease. In the control group, 80 (33.2%) of the volunteers had nodules. PTC was observed in 1.2% of them and in 3.8% of those with nodular disease. In addition, 7.17% of the 447 patients had siblings with PTC detected only by ultrasonography. Multicentricity of the tumor was the main predictor of the presence of malignancy in siblings of patients with PTC. Twenty-two subjects (3% of those screened) had tumors that were not intrathyroid microcarcinomas (whereas all three tumors detected in controls were intrathyroid microcarcinomas). Screening permitted an earlier diagnosis of the disease when compared to siblings with a spontaneous diagnosis. Conclusions: The present results favor ultrasonographic screening of first-degree relatives of patients with apparently sporadic multicentric PTC, especially among women. 相似文献
47.
Raffaele Manta Marzio Frazzoni Rita Conigliaro Livia Maccio Gianlugi Melotti Emanuele Dabizzi Helga Bertani Mauro Manno Danilo Castellani Vincenzo Villanacci Gabrio Bassotti 《Surgical endoscopy》2013,27(5):1569-1572
Background
SpyGlass® single-operator peroral cholangioscopy appears to be a promising technique to overcome some limitations of conventional peroral cholangioscopy. We aimed to prospectively evaluate the SpyGlass system in a cohort of patients with indeterminate biliary lesions.Methods
Patients with indeterminate strictures or filling defects at endoscopic retrograde cholangiopancreatography (ERCP) were consecutively enrolled. After SpyGlass visual evaluation, targeted biopsies were taken with the SpyBite® and histopathological assessment was made by two experienced gastrointestinal pathologists. SpyBite-targeted biopsy results were evaluated by assessing agreement with surgical specimens and by evaluation of final, clinical follow-up-based diagnosis.Results
Fifty-two patients participated in the study. In 7 cases, definite diagnosis (stones, varices) was made by SpyGlass endoscopic evaluation. In 42 of the remaining 45 cases, material suitable for histopathology assessment was provided by the SpyBite. Overall, a definite diagnosis was made in 49 (7 + 42; 94 %) cases. Agreement of SpyBite biopsy results with surgical specimen diagnosis was found in 38/42 (90 %) cases; sensitivity, specificity, and positive and negative predictive values were 88, 94, 96, and 85 %, respectively. Procedure-related complications consisted of one case of mild cholangitis and one case of mild pancreatitis.Conclusions
In our series, the SpyGlass system allowed adequate biopsy sampling and definite diagnosis with high accuracy in the vast majority of patients with indeterminate biliary lesions. Its use was associated with a low complication rate. Further refinements of the technique are warranted, but the SpyGlass system has the potential to become a diagnostic standard for the assessment of indeterminate biliary lesions. 相似文献48.
Koehler Jana Christina Georgescu Alexandra Livia Weiske Johanna Spangemacher Moritz Burghof Lana Falkai Peter Koutsouleris Nikolaos Tschacher Wolfgang Vogeley Kai Falter-Wagner Christine M. 《Journal of autism and developmental disorders》2022,52(8):3718-3726
Journal of Autism and Developmental Disorders - Reliably diagnosing autism spectrum disorders (ASD) in adulthood poses a challenge to clinicians due to the absence of specific diagnostic markers.... 相似文献
49.
The aim of this paper is to present a new phantom for arc therapy, intensity-modulated radiation therapy (IMRT), and tomotherapy dose distribution measurement in pretreatment verification. The presented phantom is innovative for its use of water as the tissue equivalent material, together with a technical solution specifically designed to support radiographic or radiochromic film and ionization chambers in any desired position. The phantom comprise a Plexiglas container, whose present shape and dimensions offer the possibility to simulate a human torso or abdomen; the container can be filled with water by opening the upper cover. On the internal side of the cover, a set of carbon pipes can support film in the desired coronal, axial, or sagittal planes. At one of the two ends of the phantom, an ionization chamber can be positioned parallel to the rotation axis of the accelerator gantry in all possible positions within a 20 cm diameter cylinder, for film calibration purposes. Inhomogeneities can be inserted into the phantom using the same carbon pipes and plastic sheets used to support film. An example of vertebra-shaped inserts made of bone equivalent material is reported. Radiochromic film can be dipped in water, while radiographic film must be protected to prevent damage. To accomplish this, radiographic film is laminated using a cold laminating film. In order to assess the effects of both the lamination itself and the effects of water on laminated Kodak EDR2 film, the optical density (OD) of conventional, laminated, and laminated film immersed in water and exposed to a range of doses from 0 to 300 cGy were compared. The OD of the three samples receiving the same radiation dose did not present any significant difference, thus proving that laminated EDR2 film can also be used in water. A prerequisite for any dosimetric comparison between planned and measured data is a proper film to plan registration. The solution proposed here is an extrinsic in-plane registration technique using four reference points marked on each film in predefined positions. The four points and the millimeter scales fixed on the carbon pipes that support the film are designed and manufactured so as to transfer onto the film the same reference system used during the planning procedure, thus allowing a straightforward registration. Tests to assess the accuracy of the proposed registration method demonstrate that the distances between measured and intended marker positions, evaluated for coronal, axial, and sagittal planes, were about 1 mm for both anteroposterior and lateral projections. 相似文献
50.
Alvarenga Livia Cardozo Ludmila F. M. F. Da Cruz Beatriz O. Paiva Bruna R. Fouque Denis Mafra Denise 《International urology and nephrology》2022,54(10):2645-2652
International Urology and Nephrology - Recent studies have shed light on the potential role of curcumin in mitigating inflammation in patients with chronic kidney disease (CKD). This study aimed to... 相似文献