全文获取类型
收费全文 | 1923篇 |
免费 | 115篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 51篇 |
妇产科学 | 30篇 |
基础医学 | 211篇 |
口腔科学 | 180篇 |
临床医学 | 124篇 |
内科学 | 361篇 |
皮肤病学 | 49篇 |
神经病学 | 86篇 |
特种医学 | 127篇 |
外科学 | 193篇 |
综合类 | 15篇 |
预防医学 | 274篇 |
眼科学 | 10篇 |
药学 | 218篇 |
中国医学 | 41篇 |
肿瘤学 | 81篇 |
出版年
2023年 | 14篇 |
2022年 | 24篇 |
2021年 | 44篇 |
2020年 | 33篇 |
2019年 | 50篇 |
2018年 | 61篇 |
2017年 | 54篇 |
2016年 | 57篇 |
2015年 | 65篇 |
2014年 | 91篇 |
2013年 | 104篇 |
2012年 | 122篇 |
2011年 | 129篇 |
2010年 | 101篇 |
2009年 | 76篇 |
2008年 | 114篇 |
2007年 | 104篇 |
2006年 | 94篇 |
2005年 | 72篇 |
2004年 | 78篇 |
2003年 | 62篇 |
2002年 | 43篇 |
2001年 | 32篇 |
2000年 | 20篇 |
1999年 | 30篇 |
1998年 | 36篇 |
1997年 | 34篇 |
1996年 | 32篇 |
1995年 | 26篇 |
1994年 | 28篇 |
1993年 | 20篇 |
1992年 | 14篇 |
1991年 | 11篇 |
1990年 | 12篇 |
1989年 | 20篇 |
1988年 | 20篇 |
1987年 | 11篇 |
1986年 | 19篇 |
1985年 | 16篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 13篇 |
1981年 | 9篇 |
1980年 | 5篇 |
1978年 | 4篇 |
1975年 | 6篇 |
1970年 | 5篇 |
1967年 | 3篇 |
1966年 | 4篇 |
1964年 | 3篇 |
排序方式: 共有2059条查询结果,搜索用时 15 毫秒
61.
Christiane Mariotini-Moura Matheus Silva e Bastos Felipe Freitas de Castro Mellina Lanna Trindade Raphael de Souza Vasconcellos Myrian Augusta Araújo Neves-do-Valle Bernardo Pereira Moreira Ramon de Freitas Santos Claudia Miranda de Oliveira Luana Celina Seraphim Cunha Xênia Macedo Souto Gustavo Costa Bressan Abelardo Silva-Júnior Munira Muhammad Abdel Baqui Maria Terezinha Bahia Márcia Rogéria de Almeida José Roberto Meyer-Fernandes Juliana Lopes Rangel Fietto 《Acta tropica》2014
Previous work has suggested that Trypanosoma cruzi diphosphohydrolase 1 (TcNTPDase-1) may be involved in the infection of mammalian cells and serve as a potential target for rational drug design. In this work, we produced recombinant TcNTPDase-1 and evaluated its nucleotidase activity, cellular localization and role in parasite adhesion to mammalian host cells. TcNTPDase-1 was able to utilize a broad range of triphosphate and diphosphate nucleosides. The enzyme's Km for ATP (0.096 mM) suggested a capability to influence the host's ATP-dependent purinergic signaling. The use of specific polyclonal antibodies allowed us to confirm the presence of TcNTPDase-1 at the surface of parasites by confocal and electron microscopy. In addition, electron microscopy revealed that TcNTPDase-1 was also found in the flagellum, flagellum insertion region, kinetoplast, nucleus and intracellular vesicles. The presence of this enzyme in the flagellum insertion region and vesicles suggests that it may have a role in nutrient acquisition, and the widespread distribution of TcNTPDase-1 within the parasite suggests that it may be involved in other biological process. Adhesion assays using anti-TcNTPDase-1 polyclonal antibodies as a blocker or purified recombinant TcNTPDase-1 as a competitor revealed that the enzyme has a role in parasite–host cell adhesion. These data open new frontiers to future studies on this specific parasite–host interaction and other unknown functions of TcNTPDase-1 related to its ubiquitous localization. 相似文献
63.
Igor Bastos Polonio Milena Marques Pagliareli Acencio Rogério Pazetti Francine Maria de Almeida Bárbara Soares da Silva Karina Aparecida Bonifácio Pereira Rogério Souza 《Jornal brasileiro de pneumologia》2014,40(4):421-424
We assessed the effects of lodenafil on hemodynamics and inflammation in the rat
model of monocrotaline-induced pulmonary hypertension (PH). Thirty male
Sprague-Dawley rats were randomly divided into three groups: control; monocrotaline
(experimental model); and lodenafil (experimental model followed by lodenafil
treatment, p.o., 5 mg/kg daily for 28 days) Mean pulmonary artery pressure (mPAP) was
obtained by right heart catheterization. We investigated right ventricular
hypertrophy (RVH) and IL-1 levels in lung fragments. The number of cases of RVH was
significantly higher in the monocrotaline group than in the lodenafil and control
groups, as were mPAP and IL-1 levels. We conclude that lodenafil can prevent
monocrotaline-induced PH, RVH, and inflammation. 相似文献
64.
Silvana Neves Ferraz de Assun??o Carla Hilário da Cunha Daltro Ney Christian Boa Sorte Hugo da Costa Ribeiro Júnior Maria de Lourdes Bastos Cleriston Farias Queiroz Ant?nio Carlos Moreira Lemos 《Jornal brasileiro de pneumologia》2014,40(2):134-141
OBJECTIVE:
To describe lung function findings in overweight children and adolescents without respiratory disease.METHODS:
This was a cross-sectional study involving male and female overweight children and adolescents in the 8-18 year age bracket, without respiratory disease. All of the participants underwent anthropometric assessment, chest X-ray, pulse oximetry, spirometry, and lung volume measurements. Individuals with respiratory disease were excluded, as were those who were smokers, those with abnormal chest X-rays, and those with an SpO2 = 92%. Waist circumference was measured in centimeters. The body mass index-for-age Z score for boys and girls was used in order to classify the individuals as overweight, obese, or severely obese. Lung function variables were expressed in percentage of the predicted value and were correlated with the anthropometric indices.RESULTS:
We included 59 individuals (30 males and 29 females). The mean age was 11.7 ± 2.7 years. Lung function was normal in 21 individuals (35.6%). Of the 38 remaining individuals, 19 (32.2%), 15 (25.4%), and 4 (6.7%) presented with obstructive, restrictive, and mixed ventilatory disorder, respectively. The bronchodilator response was positive in 15 individuals (25.4%), and TLC measurements revealed that all of the individuals with reduced VC had restrictive ventilatory disorder. There were significant negative correlations between the anthropometric indices and the Tiffeneau index in the individuals with mixed ventilatory disorder.CONCLUSIONS:
Lung function was abnormal in approximately 65% of the individuals evaluated here, all of whom were overweight. Obstructive ventilatory disorder and positive bronchodilator response predominated. 相似文献65.
66.
67.
PO Ajiboye OA Abiodun MF Tunde-Ayinmode OIN Buhari EO Sanya KW Wahab 《African health sciences》2013,13(3):624-631
Back ground
Stroke produces a wide range of mental and emotional disorders. Neuropsychiatric complications associated with stroke may have negative effects on the social functioning, overall quality of life and the recovery of motor functioning of stroke survivors.Objective
To determine the prevalence and nature of psychiatric morbidity among stroke patients attending neurology outpatient clinic of the University of Ilorin Teaching Hospital (UITH), Ilorin-Nigeria.Methods
All patients with stroke aged 18 years and above at an outpatient neurology clinic in Ilorin, Nigeria were assessed for mental and emotional disorders using the Schedule for Clinical Assessment in Neuropsychiatry (SCAN) over one year (March 2009 to February 2010).Results
Overall prevalence of psychiatric morbidity was 36.0% (30/83) among 83 patients who constituted the study population. Specific diagnoses recorded were depression (19.2%), generalised anxiety disorder (9.6%), harmful alcohol use (2.4%); dementia, somatoform disorder, phobia and delusional disorder each had a prevalence of 1.2%. Clinical and sociodemographic variables were not significantly associated with psychiatric morbidity.Conclusion
Psychiatric disorders are often associated with stroke. Identifying and treating stroke patients with these psychiatric co-morbidities could thus help to improve the overall quality of life of these patients. 相似文献68.
Joyce Pinho Bezerra Ariane de Siqueira Amanda Gonçalves Pires Marcelo Rocha Marques Poliana Mendes Duarte Marta Ferreira Bastos 《Journal of periodontology》2013,84(6):839-849
Background: The aim of this study is to evaluate the effects of caffeine and/or estrogen deficiency on ligature‐induced bone loss (BL), trabecular bone area (TBA), and postextraction bone healing (BH). Methods: Rats were assigned into one of the following groups (15 each): 1) control = non‐ingestion of caffeine/sham surgery; 2) caffeine = ingestion of caffeine/sham surgery); 3) ovariectomized (OVX) = non‐ingestion of caffeine/ovariectomy; or 4) caffeine/OVX = ingestion of caffeine/ovariectomy. The rats were under caffeine administration for 65 days and/or estrogen deficiency for 51 days. On day 21 after ovariectomy, one first mandibular molar received a ligature and the contralateral tooth was not ligated. The first maxillary molars were extracted 8 days before sacrifice. BL, TBA, the positive cells for tartrate‐resistant acid phosphatase (TRAP), receptor activator of nuclear factor‐κB ligand (RANKL), and osteoprotegerin (OPG) were analyzed in the furcation area of mandibular molars. Histometric BH and gene expression of bone morphogenetic protein (BMP)‐2, BMP‐7, osteopontin, and bone sialoprotein were evaluated in alveolar sockets. Results: The caffeine group presented the greatest BL and the OVX group the highest number of TRAP‐positive (TRAP+) cells around ligated teeth (P <0.05). The control group presented higher TBA and BH than the other groups (P <0.05). All test groups presented higher RANKL/OPG+ cells than the control group around ligated/unligated teeth. The OVX and caffeine/OVX groups presented a greater number of TRAP+ cells around unligated teeth than the control group (P <0.05). There were no differences among groups for gene expression (P >0.05). Conclusions: Caffeine increased BL in ligated teeth. Caffeine and/or estrogen deficiency decreased TBA in the unligated teeth and reduced BH after tooth extraction. 相似文献
69.
70.