全文获取类型
收费全文 | 6127篇 |
免费 | 346篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 135篇 |
妇产科学 | 73篇 |
基础医学 | 883篇 |
口腔科学 | 354篇 |
临床医学 | 535篇 |
内科学 | 1332篇 |
皮肤病学 | 164篇 |
神经病学 | 453篇 |
特种医学 | 418篇 |
外科学 | 677篇 |
综合类 | 38篇 |
一般理论 | 1篇 |
预防医学 | 595篇 |
眼科学 | 62篇 |
药学 | 498篇 |
中国医学 | 34篇 |
肿瘤学 | 233篇 |
出版年
2023年 | 55篇 |
2022年 | 125篇 |
2021年 | 175篇 |
2020年 | 134篇 |
2019年 | 138篇 |
2018年 | 200篇 |
2017年 | 139篇 |
2016年 | 154篇 |
2015年 | 182篇 |
2014年 | 241篇 |
2013年 | 331篇 |
2012年 | 454篇 |
2011年 | 462篇 |
2010年 | 241篇 |
2009年 | 278篇 |
2008年 | 347篇 |
2007年 | 363篇 |
2006年 | 306篇 |
2005年 | 240篇 |
2004年 | 184篇 |
2003年 | 178篇 |
2002年 | 174篇 |
2001年 | 131篇 |
2000年 | 122篇 |
1999年 | 97篇 |
1998年 | 101篇 |
1997年 | 102篇 |
1996年 | 112篇 |
1995年 | 78篇 |
1994年 | 72篇 |
1993年 | 61篇 |
1992年 | 37篇 |
1991年 | 29篇 |
1990年 | 38篇 |
1989年 | 46篇 |
1988年 | 43篇 |
1987年 | 47篇 |
1986年 | 58篇 |
1985年 | 46篇 |
1984年 | 15篇 |
1983年 | 18篇 |
1982年 | 21篇 |
1981年 | 12篇 |
1980年 | 16篇 |
1979年 | 16篇 |
1978年 | 18篇 |
1977年 | 15篇 |
1976年 | 18篇 |
1975年 | 17篇 |
1969年 | 20篇 |
排序方式: 共有6550条查询结果,搜索用时 15 毫秒
31.
OBJECTIVE: The ketogenic diet is a high-fat, low-protein, low-carbohydrate diet developed in the 1920s for the treatment of children with difficult to control seizures. Despite advances in both the pharmacotherapy and the surgery of epilepsy, many children continue to have difficult-to-control seizures. This prospective study sought to determine the ketogenic diet's effectiveness and tolerability in children refractory to today's medications. METHODS: One hundred fifty consecutive children, ages 1 to 16 years, virtually all of whom continued to have more than two seizures per week despite adequate therapy with at least two anticonvulsant medications, were prospectively enrolled in this study, treated with the ketogenic diet, and followed for a minimum of 1 year. Seizure frequency was tabulated from patients' daily seizure calendars and seizure reduction calculated as percentage of baseline frequency. Adverse events and reasons for diet discontinuation were recorded. RESULTS: The children (mean age, 5.3 years), averaged 410 seizures per month before the diet, despite an exposure to a mean of 6.2 antiepileptic medications. Three months after diet initiation, 83% of those starting remained on the diet and 34% had >90% decrease in seizures. At 6 months, 71% still remained on the diet and 32% had a >90% decrease in seizures. At 1 year, 55% remained on the diet and 27% had a >90% decrease in seizure frequency. Most of those discontinuing the diet did so because it was either insufficiently effective or too restrictive. Seven percent stopped because of intercurrent illness. CONCLUSIONS: The ketogenic diet should be considered as alternative therapy for children with difficult-to-control seizures. It is more effective than many of the new anticonvulsant medications and is well tolerated by children and families when it is effective. 相似文献
32.
33.
Teixeira AB Etchebehere CS Carvalho DC Sousa MC Santos AO Lima MC Ramos CD Camargo EE 《Clinical nuclear medicine》2000,25(6):484
A 47-year-old woman with adenocarcinoma of the right breast had bone scintigraphy with Tc-99m MDP. Bone imaging did not show any metastases. However, a large area of increased tracer uptake was seen extending from the abdomen to the pelvis. Abdominal ultrasound revealed a large solid and heterogeneous mass, measuring 18 x 11 x 14.3 cm, that originated in an empty uterus. A biopsy of the surgical specimen showed a leiomyoma of the uterus. 相似文献
34.
35.
Bernardo L. Teixeira Joo Cabral Andr Marques-Pinto Fernando Vila Joaquim Lindoro Avelino Fraga 《Canadian Urological Association journal》2022,16(5):E267
IntroductionWe aimed to compare the rate of postoperative infection and drug-resistant organism (DRO) before and during the COVID-19 pandemic in urology departments.MethodsA retrospective cohort study was carried out. Data from all elective surgical procedures carried out in two urology departments between April and June 2018 and the homologous period in 2020 were collected. Main outcomes were the number of postoperative infections during the pandemic and the number of DROs. Sample size was calculated based on a 50% relative reduction of infections during the pandemic. Variables were compared by Chi-squared test, and multivariable logistic regression was used to estimate predictors.ResultsA total of 698 patients undergoing elective surgery were included. The postoperative infection rate during the pre-pandemic period was of 14.1% compared to 12.1% during the pandemic (p=0.494). DROs were lower during the pandemic (92.3% vs. 52.4%, p=0.002). The pandemic period was the main predictor for reduced multidrug-resistant isolates, with an odds ratio of 0.10 (p=0.010, 95% confidence interval 0.016–0.57).ConclusionsPostoperative infection rates were not significantly reduced during the COVID-19 pandemic, despite the adoption of enhanced infection preventive measures. There was, however, a decrease in the rate of DROs during this period, suggesting a secondary benefit to enhanced infection prevention practices adopted during the COVID-19 era. 相似文献
36.
Thiago A Teixeira Yasmin C Oliveira Felipe S Bernardes Esper G Kallas Amaro N Duarte-Neto Sandro C Esteves Jo?l R Drevet Jorge Hallak 《Asian journal of andrology》2021,(4):335-347
Viral infections have haunted humankind since times immemorial.Overpopulation,globalization,and extensive deforestation have created an ideal environment for a ... 相似文献
37.
Grance SR Teixeira MA Leite RS Guimarães EB de Siqueira JM de Oliveira Filiu WF de Souza Vasconcelos SB do Carmo Vieira M 《Journal of ethnopharmacology》2008,117(1):28-33
AIM OF THE STUDY: This investigation evaluated the effect of a hydroethanolic extract of Baccharis trimera on pregnant Wistar rats, once the plant is well-known consumed in pregnancy and little is known on its potentially toxic effects on pregnant women. MATERIAL AND METHODS: Thirty-five female rats were distributed into three groups. Those in treatments 1 and 2 were given 8.4 mg/kg of the extract orally from gestational day (GD) 1 to 19 and from GD 6 to 15, respectively, whereas those in the control group received distilled water orally from GD 1 to 19. Body weights were recorded on GD 1, 6, 15, and 20. On GD 20 animals were anesthetized, blood samples were collected and maternal livers, kidneys, and spleens were weighed and processed for histological studies. RESULTS: No clinical signs of maternal toxicity and no changes in hematological parameters were observed. Urea levels and kidney weights differed significantly between animals receiving treatment 1 and controls. Histopathological alterations were found in kidneys and livers in both treatment groups. CONCLUSIONS: The hydroethanolic extract of Baccharis trimera administered to pregnant rats at 8.4 mg/kg was toxic to maternal kidney and liver cells, although such alterations are reversible once administration is discontinued. 相似文献
38.
Cabrita S Rodrigues H Abreu R Martins M Teixeira L Marques C Mota F de Oliveira CF 《European journal of gynaecological oncology》2008,29(2):135-137
PURPOSE OF INVESTIGATION: Magnetic resonance imaging (MRI) has emerged as an important imaging modality in the evaluation of the extension of endometrial carcinoma which is essential in planning treatment and predicting prognosis. This study aimed to assess the value of MRI in the preoperative staging of endometrial carcinoma. METHODS: We included in this study 162 patients with a histological diagnosis of endometrial carcinoma who underwent MRI pelvic imaging and surgical staging. MRI images were compared with pathological findings to measure MRI's sensitivity, specificity, positive and negative predictive values and diagnostic accuracy in what concerns myometrial, cervical and lymph node invasion. RESULTS: MRI differentiation of deep myometrial invasion from superficial disease agreed with pathological findings in 77% of cases, with a sensitivity of 83%, a specificity of 72% and a diagnostic accuracy of 77%. Concerning cervical invasion, MRI had a sensitivity, specificity and diagnostic accuracy of 42%, 92%, 81% respectively. In assessing lymph node invasion, MRI presented a sensitivity of just 17%, a specificity of 99% and a diagnostic accuracy of 89%. CONCLUSION: Our study confirmed the high accuracy of MRI imaging in assessing myometrial and cervical invasion in endometrial carcinoma. When evaluating lymph node invasion, micrometastases are responsible for the low sensitivy of MRI. 相似文献
39.