全文获取类型
收费全文 | 659篇 |
免费 | 33篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 19篇 |
妇产科学 | 10篇 |
基础医学 | 135篇 |
口腔科学 | 40篇 |
临床医学 | 40篇 |
内科学 | 88篇 |
皮肤病学 | 17篇 |
神经病学 | 71篇 |
特种医学 | 15篇 |
外科学 | 64篇 |
综合类 | 3篇 |
预防医学 | 61篇 |
眼科学 | 11篇 |
药学 | 68篇 |
中国医学 | 4篇 |
肿瘤学 | 43篇 |
出版年
2023年 | 3篇 |
2022年 | 15篇 |
2021年 | 14篇 |
2020年 | 9篇 |
2019年 | 15篇 |
2018年 | 28篇 |
2017年 | 18篇 |
2016年 | 34篇 |
2015年 | 30篇 |
2014年 | 21篇 |
2013年 | 32篇 |
2012年 | 46篇 |
2011年 | 42篇 |
2010年 | 22篇 |
2009年 | 28篇 |
2008年 | 34篇 |
2007年 | 39篇 |
2006年 | 30篇 |
2005年 | 30篇 |
2004年 | 18篇 |
2003年 | 31篇 |
2002年 | 28篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1996年 | 4篇 |
1995年 | 9篇 |
1994年 | 4篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 8篇 |
1986年 | 3篇 |
1982年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1974年 | 2篇 |
1971年 | 2篇 |
1970年 | 4篇 |
1969年 | 1篇 |
1965年 | 2篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1957年 | 1篇 |
1945年 | 1篇 |
1940年 | 2篇 |
1939年 | 2篇 |
1921年 | 2篇 |
排序方式: 共有693条查询结果,搜索用时 421 毫秒
21.
Juliana Giacomazzi BSc MSc PhD Rudinei Luis Correia Edenir Ines Palmero PhD Jorge Francisco Gaspar PhD Marta Almeida MD Catarina Portela MD Suzi Alves Camey PhD Augusta Monteiro MSc Manuela Pinheiro MSc Ana Peixoto MSc Manuel R. Teixeira MD PhD Rui Manuel Reis PhD Patricia Ashton‐Prolla MD PhD 《The breast journal》2014,20(5):534-536
Since the first studies reporting the TP53 p.R337H mutation as founder mutation in Southern and Southeastern Brazil, there has been controversy on its origin. Preliminary analysis of a small subset of Brazilian mutation carriers revealed that the haplotype incided on a Caucasian background. The vast majority of carriers identified today reside in Brazil or, if identified in other countries, are Brazilian immigrants. To our knowledge, the only two exceptions of carriers without a recognizable link with Brazil are two European families, from Portugal and Germany. Haplotype analysis in the Portuguese family revealed the same haplotype identified in Brazilian individuals, but in the German family, a distinct haplotype was found. Knowing that a significant proportion of women with breast cancer (BC) in Southern Brazil are p.R337H carriers, we analyzed p.R337H in a Portuguese cohort of women diagnosed with this disease. Median age at diagnosis among the first 573 patients tested was 60 years and 100 (17.4%) patients had been diagnosed at or under the age of 45 years. Mutation screening failed to identify the mutation in the 573 patients tested. These results are in contrast with the mutation frequency observed in a study including 815 BC‐affected women from Brazil, in which carrier frequencies of 12.1 and 5.1% in pre‐ and postmenopausal women were observed, respectively. These findings suggest that the Brazilian founder mutation p.R337H, the most frequent germline TP53 mutation reported to date, is not a common germline alteration in Portuguese women diagnosed with BC. 相似文献
22.
Angiogenic properties of human immunodeficiency virus type 1 Tat protein. 总被引:12,自引:0,他引:12 下载免费PDF全文
A Albini G Barillari R Benelli R C Gallo B Ensoli 《Proceedings of the National Academy of Sciences of the United States of America》1995,92(11):4838-4842
Extracellular human immunodeficiency virus type 1 (HIV-1) Tat protein promotes growth of spindle cells derived from AIDS-associated Kaposi sarcoma (AIDS-KS), an angioproliferative disease very frequent in HIV-1-infected individuals. Normal vascular cells, progenitors of AIDS-KS cells, proliferate in response to Tat after exposure to inflammatory cytokines, whose levels are augmented in HIV-1-infected individuals and in KS lesions. Here we show that Tat also promotes AIDS-KS and normal vascular cells to migrate and to degrade the basement membrane and stimulates endothelial cell morphogenesis on a matrix substrate. These effects are obtained at picomolar concentrations of exogenous Tat and are promoted by the treatment of the cells with the same inflammatory cytokines stimulating expression of the receptors for Tat, the integrins alpha 5 beta 1 and alpha v beta 3. Thus, under specific circumstances, Tat has angiogenic properties. As Tat and its receptors are present in AIDS-KS lesions, these data may explain some of the mechanisms by which Tat can induce angiogenesis and cooperate in the development of AIDS-KS. 相似文献
23.
Maite Augusta Gil-Ruiz Gil-Esparza Andrés José Alcaraz Romero Alfonso Romero Otero Nuria Gil Villanueva Eva Sanavia Morán Ana Rodríguez Sánchez de la Blanca Jorge Lorente Romero José María Bellón Cano 《Pediatric nephrology (Berlin, Germany)》2014,29(7):1265-1272
Background
Acute renal injury increases risk of death after cardiac surgery. The objective of the study was to evaluate the ability of the pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease (pRIFLE) criteria to characterize the development of postoperative renal damage in children after cardiopulmonary bypass (CPB) and to evaluate the relationship between the severity of kidney injury and mortality, pediatric intensive care unit (PICU) length of stay, and the duration of mechanical ventilation (MV).Methods
In this retrospective study including children undergoing CPB surgery during a 3-year period in the PICU of a tertiary hospital, demographic, clinical, surgery-related, and postoperative clinical data were collected. Kidney damage was assessed with pRIFLE criteria.Results
Four hundred and nine patients were included. Early acute kidney injury (AKI) was found in 82 patients (achieving categories Risk 44; Injury 16; Failure 22). Early AKI was associated with younger age (P?=?0.010), longer CPB, deep hypothermic circulatory arrest (DHCA) use, ICU stay >12 days, MV >4 days, and death (P?<?0.001). Controlling the effect of age, CPB, DHCA use, previous cardiac surgeries, and Risk Adjustment in Congenital Heart Surgery Surgical Severity Score (RACHS-1), early AKI development proved to predict ICU stay >12 days [odds ratio (OR) 3.5; 95 % confidence interval (CI) 1.9–6.5, P?<?0.001)] and need of MV >4 days (OR 5.1; 95 % CI 2.6–10.2, P?<?0.001).Conclusions
Early AKI when evaluated with the pRIFLE criteria can predict prolonged ICU stay, need of prolonged MV, and mortality. 相似文献24.
Rossana Patricia Basso Vanice Rodrigues Poester Jssica Louise Benelli David A. Stevens Melissa Orzechowski Xavier 《Emerging infectious diseases》2022,28(3):721
We evaluated disseminated histoplasmosis (DH) in HIV patients over 10 years in southern Brazil. The incidence was 12 cases/1,000 hospitalizations (2010–2019); the mortality rate was 35%. Tuberculosis frequently obscured the diagnosis of DH. We emphasize the need in our region to suspect and investigate DH using more sensitive methods. 相似文献
25.
26.
Guilherme Gonçalves Maria Augusta Santos João Graça Frade José Saraiva Cunha 《BMC public health》2007,7(1):109
Background
The need for tetanus toxoid decennial booster doses has been questioned by some experts. Several counter arguments have been presented, supporting the maintenance of decennial adult booster doses with tetanus and diphtheria toxoids (adult formulation of the vaccine: Td). This study aimed to evaluate the use of Td in Portuguese adult women under routine conditions. For that purpose we selected a group of women 30+ years of age to which vaccination was recommended. We intended to know if pre-vaccination antibody concentrations were associated with factors as age at first and last vaccination, number of doses and time since last revaccination. We also intended to assess the serological efficacy of Td booster. 相似文献27.
The solitary fibrous tumor (SFT) is a rare mesenquimal neoplasm, found originally in association with the pleura. Recently, SFT was reported in others sites. The extension into adjacent structures is not uncommon. The meningeal involvement by SFT is rare and there has only twenty-six cases been reported previously in the literature. We report a case of a 25 years-old female patient with generalized tonic clonic seizures in the last six years. During the neurologic investigation, a tumor in the left occipital region of the brain was found. The patient underwent an occipital craniotomy with total resection of the tumor. The histopathological and immunohistochemical diagnosis was STF. After three years of follow-up, the patient remains stable, with a normal neurological exam. There is no sign of tumor recidive in the postoperative cranial tomography. We will briefly review the literature about STF. 相似文献
28.
Purpose: To evaluate efficacy of a scleral window between the scleral lake and suprachoroidal space in Deep Sclerectomy, as an alternative way to improve the outflow of aqueous humor. Methods: 8 patients (aged 56-80 years), affected by open angle glaucoma, underwent deep sclerectomy with jaluronic acid implant: a large scleral window (3mmx2mm) was performed in the bed of the scleral lake. Postoperative examinations were per- 相似文献
29.
Rats were given22Na intraperitoneally and the retention of the isotope was determined in whole body and in bone for periods up to 650 days. In contrast to45Ca, which is rapidly taken up by bone and then very slowly released, most of the22Na taken up by bone leaves, with a halftime of 3–5.5 days. However, about 5% of the skeletal burden exhibits a very slow turnover, with a half-time of about 700 days. Since this rate is comparable to that of45Ca, it is concluded that this small fraction of bone Na is an integral part of the crystal structure. Only two of the several experimental procedures which were tried produced a significant effect on bone Na turnover. These were prolonged feeding of a low calcium diet and a change in parathyroid activity. An increase in dietary Na affected the fast component of bone Na turnover, but there was little if any effect on the slow component. Calculations from our data suggest that, in contrast to Ca, the skeleton does not serve a significant reservoir function for the support of extracellular fluid Na. 相似文献
30.
Ferreira PC Amarante JM Rodrigues JM Pinho CJ Cardoso MA Reis JC 《International surgery》2005,90(3):160-166
Tumors of the parotid gland are uncommon. We performed a retrospective study to analyze the clinical, diagnostic, and therapeutic features of a group of patients. We reviewed the clinical and the surgical records of a series of 109 patients who were recommended for surgery because of parotid tumors by the Plastic and Reconstructive Service of S?o Jo?o Hospital, Portugal, between 1990 and 2002. The following parameters were evaluated: age, sex, gland afflicted, symptoms, and duration of symptoms, diagnostic procedures, treatment methods, follow-up, and recurrences. Pleomorphic adenoma was the most common tumor (63.5%). In the majority of cases, fine-needle aspiration cytology was used. Swelling was the most frequent clinical finding. In 68.2%, superficial parotidectomy was performed. There were five cases of permanent facial palsy, and 10 patients developed Frey's syndrome. Recurrent disease was seen in six patients. For the majority of tumors, superficial parotidectomy is an effective treatment with acceptable morbidity. 相似文献