全文获取类型
收费全文 | 2625篇 |
免费 | 207篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 105篇 |
妇产科学 | 77篇 |
基础医学 | 329篇 |
口腔科学 | 270篇 |
临床医学 | 195篇 |
内科学 | 529篇 |
皮肤病学 | 62篇 |
神经病学 | 211篇 |
特种医学 | 168篇 |
外科学 | 175篇 |
综合类 | 51篇 |
预防医学 | 236篇 |
眼科学 | 136篇 |
药学 | 139篇 |
中国医学 | 26篇 |
肿瘤学 | 104篇 |
出版年
2023年 | 18篇 |
2022年 | 29篇 |
2021年 | 94篇 |
2020年 | 67篇 |
2019年 | 84篇 |
2018年 | 103篇 |
2017年 | 59篇 |
2016年 | 92篇 |
2015年 | 104篇 |
2014年 | 122篇 |
2013年 | 166篇 |
2012年 | 175篇 |
2011年 | 188篇 |
2010年 | 111篇 |
2009年 | 112篇 |
2008年 | 156篇 |
2007年 | 184篇 |
2006年 | 104篇 |
2005年 | 116篇 |
2004年 | 97篇 |
2003年 | 67篇 |
2002年 | 39篇 |
2001年 | 29篇 |
2000年 | 36篇 |
1999年 | 28篇 |
1998年 | 47篇 |
1997年 | 47篇 |
1996年 | 43篇 |
1995年 | 40篇 |
1994年 | 25篇 |
1993年 | 31篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 14篇 |
1989年 | 21篇 |
1988年 | 17篇 |
1987年 | 11篇 |
1986年 | 15篇 |
1985年 | 14篇 |
1984年 | 8篇 |
1983年 | 13篇 |
1982年 | 6篇 |
1981年 | 13篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1974年 | 8篇 |
1968年 | 8篇 |
排序方式: 共有2848条查询结果,搜索用时 703 毫秒
101.
Gabriel S. A. Moreira Edson A. Adriano Marcia R. M. Silva Paulo S. Ceccarelli Antônio A. M. Maia 《Parasitology research》2014,113(5):1703-1711
A new species of myxosporea (Henneguya rotunda n. sp.) was found in the membrane of the gill arch and the fins of Salminus brasiliensis in the Mogi Guaçu River, municipality of Pirassununga, São Paulo state, Brazil. Morphological and morphometric analyses using light microscopy revealed parasites with similar characteristics at both infection sites. The mature spores found infecting the fins had oval spore body with 7.1?±?0.2 μm in length, 5.6?±?0.2 μm in width, 3.7?±?0.1 μm in thickness, 16.4?±?1.2 μm in length of the caudal process, and 23.6?±?1.1 μm in total length of the spore. In a frontal view, the polar capsule was observed to be symmetrical with 3.4?±?0.2 μm in length and 1.8?±?0.1 μm in width. Mature spores contain six to seven turns of the polar filaments. The morphometric data concerning the spores obtained from plasmodia from the membrane of the gill arch were similar to those from the fins. Ultrastructure analysis revealed that the plasmodial wall was formed by a single membrane and had numerous pinocytotic canals connecting the outside of the plasmodia to the ectoplasm zone. Beyond that, various electron-translucent vesicles also were observed at the periphery of the plasmodium. The molecular analyses of the 18S rDNA gene from the spores obtained from the gill arch membrane and fin membrane showed that these sequences shared 100 % similarity. Phylogenetic studies using maximum parsimony and maximum likelihood methods demonstrated the polyphyletic clustering of the myxosporean parasites of characiform fishes. H. rotunda n. sp. clustered as a sister species of Myxobolus pantanalis, also a parasite of S. brasiliensis. 相似文献
102.
Kátia C. Carvalho Beatriz M. Maia Samantha V. Omae Antonio A. Rocha Luiz P. Covizzi José Vassallo Rafael M. Rocha Fernando A. Soares 《Acta histochemica》2014
There is a lack of standardization of a best practice protocol for Phosphatase and Tensin Homolog (PTEN) assessment by immunohistochemistry in anatomic pathology routine practice. We performed immunohistochemistry for 19 antibodies against PTEN, eleven of which were excluded during the standardization step. Immunohistochemistry of the remaining eight antibodies was performed on a Tissue Microarray containing 55 prostate and 40 renal carcinoma samples. Fluorescent in situ hybridization (FISH) was used as reference standard for immunohistochemistry specificity evaluation. Concerning nuclear staining, polyclonal (Cat#22034-1-AP); 6H2.1 mMAb (Cat#ABM-2052), Y184 RabMAb (Cat#NB110-57441) and 217702 mMAb antibodies presented the highest agreement with fluorescent in situ hybridization (p < 0.001 for all) and with regard to cytoplasmic staining, Y184 RabMAb (Cat#NB110-57441); polyclonal (Cat#22034-1-AP) and 217702 mMAb presented the highest agreement (p < 0.001 for all). Our results indicate that several commercially available antibodies do not show reliability of sensitivity and specificity for PTEN evaluation and we propose 6H2.1 mMAb (Cat#ABM-2052) as the antibody of choice for laboratory standardization and best practice in clinical routine, which demonstrated excellent sensitivity for both nuclear and cytoplasmic staining, specificity for PTEN by Western blot and good correlation with PTEN status by FISH with regard to nuclear staining. 相似文献
103.
Yvana Maria Maia de Albuquerque Ana Luiza Magalh?es de Andrade Lima Ana Kelly Lins Marcelo Magalh?es Vera Magalh?es 《Revista do Instituto de Medicina Tropical de S?o Paulo》2014,56(2):139-142
Objective: To assess quantitative real-time polymerase chain reaction
(q-PCR) for the sputum smear diagnosis of pulmonary tuberculosis (PTB) in patients
living with HIV/AIDS with a clinical suspicion of PTB.
Method: This is a prospective study to assess the accuracy of a
diagnostic test, conducted on 140 sputum specimens from 140 patients living with
HIV/AIDS with a clinical suspicion of PTB, attended at two referral hospitals for
people living with HIV/AIDS in the city of Recife, Pernambuco, Brazil. A
Löwenstein-Jensen medium culture and 7H9 broth were used as gold standard.
Results: Of the 140 sputum samples, 47 (33.6%) were positive with the
gold standard. q-PCR was positive in 42 (30%) of the 140 patients. Only one (0.71%)
did not correspond to the culture. The sensitivity, specificity and accuracy of the
q-PCR were 87.2%, 98.9% and 95% respectively. In 39 (93%) of the 42 q-PCR positive
cases, the CT (threshold cycle) was equal to or less than 37.
Conclusion: q-PCR performed on sputum smears from patients living with
HIV/AIDS demonstrated satisfactory sensitivity, specificity and accuracy, and may
therefore be recommended as a method for diagnosing PTB. 相似文献
104.
105.
Kandelaki G Butsashvili M Kalandadze I Iosava M Avaliani N Imnadze P 《Acta tropica》2012,123(1):47-48
Malaria is well known in Georgia since ancient times, causing national disasters with associated significant mortality and economic losses. By 1970 Georgia managed to reach complete and sustained elimination of the disease as a result of comprehensive anti-malaria measures undertaken in the country. However from the mid-1990s, economic collapse following disintegration of Soviet Union causing breakdown of important public health networks including anti-malaria preventive and control infrastructure resulted in gradual increase of malaria cases in the country with a peak of 437 and 474 cases in 2001 and 2002, respectively. From 2000 two major anti-malaria efforts were carried out by National Center for Disease Control and Public Health, WHO and Global Fund to Fight AIDS, tuberculosis and malaria and as result of comprehensive and collaborative work in 2010 the level of zero cases of local mosquito-borne malaria transmission was achieved and the country entered the elimination phase. 相似文献
106.
Bertoldi EG Severo MD Scheffel RS Foppa M de Azevedo MJ Maia AL 《Echocardiography (Mount Kisco, N.Y.)》2012,29(2):E30-E33
Intracardiac metastases of thyroid carcinoma are a rare event. Their incidence is low in large autopsy series, and antemortem diagnosis is even less common. We present the case of a woman with advanced poorly differentiated thyroid carcinoma who had extensive intracardiac metastases. This case highlights the usefulness of echocardiography and magnetic resonance imaging in the diagnosis and differential diagnosis of cardiac metastases. 相似文献
107.
Julio Leonardo Barbosa Pereira Lucas Alverne Freitas de Albuquerque Marcos Dellaretti Gervásio Teles Cardoso de Carvalho Gerival Vieira Jr Vitor Michelstaedter Brochado Austen Venancio Drummond Joyce Espeschit de Morais Leticia Maia Ferreira Paulo Augusto Carvalho Miranda Atos Alves de Sousa 《Clinics (S?o Paulo, Brazil)》2013,68(6):745-749
OBJECTIVE:
Aneurysmal subarachnoid hemorrhage puts patients at high risk for the development of pituitary insufficiency. We evaluated the incidence of pituitary dysfunction in these patients and its correlation with clinical outcome.METHODS:
Pituitary function was tested in 66 consecutive patients in the first 15 days after aneurysmal subarachnoid hemorrhage. The following were measured in all patients: thyroid-stimulating hormone, free thyroxine, triiodothyronine, luteinizing hormone, follicle-stimulating hormone, total testosterone (in males), estradiol (in females), prolactin, serum cortisol, plasma adrenocorticotropic hormone, growth hormone and insulin growth factor.RESULTS:
The endocrine assessment was made at a mean of 7.4 days (standard deviation ±6.6) after subarachnoid hemorrhage. Forty-four (66.7%) female and 22 (33.3%) male patients were evaluated. Thirty-nine patients (59.1%) had some type of pituitary dysfunction. Follicle-stimulating hormone/luteinizing hormone deficiency was the most frequent disorder (34.8%), followed by growth hormone/insulin growth factor (28.7%), adrenocorticotropic hormone (18.1%) and thyroid-stimulating hormone (9%). Seventeen (25.7%) patients showed deficiencies in more than one axis. A greater incidence of hormone deficiency was observed in patients with a Glasgow Coma Scale score ≤13 (t test, p = 0.008), Hunt-Hess grade ≥4 (t test, p<0.001), or Fisher grade 4 (t test, p = 0.039). Hormone deficiency was not significantly associated (p>0.05) with increased hospitalization or clinical outcome.CONCLUSION:
Pituitary dysfunction was identified in a substantial portion of patients with previous aneurysmal subarachnoid hemorrhage, but no association was found between this dysfunction and poor clinical outcome. 相似文献108.
109.
Denise Sá Maia CASSELLI André Luis FARIA-E-SILVA Henrique CASSELLI Luis Roberto Marcondes MARTINS 《Journal of applied oral science : revista FOB》2013,21(1):68-73
Objective:
This study evaluated the effect of the margin location and an adhesive system on the marginal adaptation of composite restorations.Material and Methods:
Class V cavities were prepared in bovine teeth with the gingival margin on the dentin and the incisal margin on the enamel. The cavities were restored with a micro-hybrid composite resin using an etch-and-rinse [Single Bond 2 (SB)] or a self-etching adhesive [Clearfil SE Bond (CL)]. After finishing and polishing the restorations, epoxy replicas were prepared. The marginal adaptation was analyzed using scanning electronic microscopy (SEM, 500 x magnification). The higher gap width in each margin was recorded (T0). After the first evaluation, the samples were submitted to thermal cycling (2,000 cycles of 5ºC±2ºC followed by 55ºC±2ºC - T1) and mechanical cycling (100,000 cycles of 50 kN and 2 Hz - T2). Replicas of samples were rebuilt after each cycling and analyzed under SEM. The data were submitted to Mann-Whitney, Wilcoxon and Friedman testing (a=0.05).Results:
The SB presented higher gaps in the dentin than the enamel, while there was no difference between the substrate for the CL. In the dentin, the CL showed better marginal sealing than the SB. The opposite occurred in the enamel. There were no significant differences between the baseline, thermal and mechanical cycling for any experimental condition.Conclusions:
The outcomes of the present study showed that the adhesive system and margin location have an important effect on the marginal adaptation of composite restorations. 相似文献110.
Rabies is a zoonotic viral disease, transmitted only in mammals. Terrestrial rabies, predominantly transmitted by dogs, is the most important rabies cycle threatening humans. The causative neurotropic virus is a negative-stranded RNA virus of the family Rhabdoviridae, genus Lyssavirus. This genus contains several rabies-related viruses. All variants are known or suspected to cause rabieslike diseases. Transmission occurs by the virus entering through the skin or the mucosa after bites, scratches, or preexisting injuries contaminated by the saliva of an infected mammal. Only 51 human rabies cases that have not been transmitted by animal bites are described. 相似文献