全文获取类型
收费全文 | 6736篇 |
免费 | 484篇 |
国内免费 | 71篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 189篇 |
妇产科学 | 169篇 |
基础医学 | 832篇 |
口腔科学 | 232篇 |
临床医学 | 627篇 |
内科学 | 1405篇 |
皮肤病学 | 90篇 |
神经病学 | 554篇 |
特种医学 | 179篇 |
外科学 | 1036篇 |
综合类 | 216篇 |
一般理论 | 5篇 |
预防医学 | 462篇 |
眼科学 | 289篇 |
药学 | 359篇 |
中国医学 | 71篇 |
肿瘤学 | 508篇 |
出版年
2023年 | 57篇 |
2022年 | 92篇 |
2021年 | 178篇 |
2020年 | 131篇 |
2019年 | 190篇 |
2018年 | 200篇 |
2017年 | 163篇 |
2016年 | 198篇 |
2015年 | 231篇 |
2014年 | 281篇 |
2013年 | 297篇 |
2012年 | 435篇 |
2011年 | 499篇 |
2010年 | 337篇 |
2009年 | 231篇 |
2008年 | 346篇 |
2007年 | 373篇 |
2006年 | 408篇 |
2005年 | 338篇 |
2004年 | 347篇 |
2003年 | 324篇 |
2002年 | 258篇 |
2001年 | 186篇 |
2000年 | 167篇 |
1999年 | 126篇 |
1998年 | 52篇 |
1997年 | 34篇 |
1996年 | 33篇 |
1995年 | 18篇 |
1994年 | 18篇 |
1993年 | 12篇 |
1992年 | 47篇 |
1991年 | 54篇 |
1990年 | 58篇 |
1989年 | 56篇 |
1988年 | 53篇 |
1987年 | 53篇 |
1986年 | 46篇 |
1985年 | 54篇 |
1984年 | 41篇 |
1983年 | 30篇 |
1982年 | 24篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 25篇 |
1978年 | 16篇 |
1977年 | 17篇 |
1976年 | 14篇 |
1974年 | 14篇 |
1971年 | 14篇 |
排序方式: 共有7291条查询结果,搜索用时 0 毫秒
91.
Lucie Sosvorová Petra Mikšátková Marie Bičíková Nataša Kaňová Oldřich Lapčík 《Food and chemical toxicology》2012
Dietary supplements used by women during menopause are usually based on plant extracts containing isoflavonoids, daidzein and genistein. Genistein is a known inhibitor of many enzymes, including thyroid peroxidase (TPO). In the thyroid follicle, genistein acts as its alternate substrate for the formation of genistein iodinated derivatives. The aim of this study was to search for daidzein- and genistein-iodinated derivatives in urine of isoflavonoid-supplemented women. Additionally, selected phytoestrogens, steroid and thyroid hormones before and after three months of phytoestrogen supplementation were estimated. Urinary levels of free phytoestrogen increased significantly after therapy. They ranged between 0.3–1600, 0.6–670 and 0–206 nmol/L for daidzein, genistein and S-equol, respectively. Monoiodinated derivatives of genistein were observed (0–504 pmol/L) in 60% of the investigated samples. Steroid and thyroid hormone levels were within the normal range and were not significantly altered. The presence of monoiodinated derivates in human urine confirmed that genistein and daidzein may enter human thyroid follicles and influence TPO. Since the levels of the free thyroid hormones were not affected, we propose that the use of phytoestrogen dietary supplements is not associated with the development of thyroid-gland disorders in subjects with adequate iodine intake. 相似文献
92.
Singapore Indian Eye Study‐2: methodology and impact of migration on systemic and eye outcomes 下载免费PDF全文
93.
Altitude and childhood growth 总被引:2,自引:0,他引:2
To assess the possible influence of altitude on childhood growth in the United States, we used data collected by the Centers for Disease Control Pediatric Nutrition. Surveillance System from eight mountain states to determine the height and weight status of children aged 5 years or younger enrolled in various public health programs between 1982 and 1984. The mean birth weight, height-for-age, weight-for-age, and weight-for-height indicators were found to decline significantly with increasing altitude, starting at an elevation greater than 1500 m (p less than 0.001, ANOVA). The reduction in growth was observed for all age groups and all birth weight groups studied. Part of the observed reduction in growth could be attributed to the lower birth weight of children born at higher altitude. However, the reduced growth status persisted after controlling for birth weight, suggesting the presence of an extrauterine growth retardation effect related to altitude. 相似文献
94.
OBJECTIVE: To evaluate expectation and knowledge on obstetric ultrasound examination in the first and second trimester in a Chinese population. METHOD: A cross-sectional survey was conducted in a university obstetric clinic in Hong Kong. Chinese pregnant women who underwent the first trimester early scan sessions, or the second trimester anomaly scan sessions were invited to complete a self-administered questionnaire, which contained items on their knowledge, expectation, and sociodemographic characteristics. RESULTS: In all 276 eligible pregnant women (117 in the first trimester and 159 in the second trimester) were recruited. Although 249 women (90.2%) claimed they understood the indication of the ultrasound examination, only 93 of them were correct (33.7%). The median perceived overall-detection rate for structural abnormalities was 66.5%. Living in Hong Kong for more than 7 years was significantly associated with higher knowledge level and expectation from ultrasound examination. Attaining tertiary education level was also significantly associated with higher knowledge level. Over 90% of the pregnant women studied wished to know the fetal gender from the anomaly scan examination. CONCLUSION: Knowledge of Chinese pregnant women on ultrasound was generally unsatisfactory. Understanding their limitation of knowledge and expectations helps to devise appropriate education in the local setting. 相似文献
95.
褪黑素鼻粘膜吸收规律的研究 总被引:1,自引:1,他引:1
目的 :研究褪黑素鼻粘膜吸收规律。方法 :观察褪黑素在大鼠鼻腔洗出液中的稳定性 ,在此基础上 ,以大鼠在体鼻循环为实验模型 ,研究褪黑素鼻粘膜吸收规律。 结果 :褪黑素在鼻粘膜洗出液中稳定性良好 ,在鼻粘膜吸收符合一级动力学方程 ,褪黑素鼻粘膜吸收常数不随药物浓度发生变化。结论 :褪黑素在鼻粘膜的吸收机制为被动扩散 ,其在鼻粘膜平均吸收速率常数为 1.0 5 4× 10 -2 min-1 相似文献
96.
营养与食品卫生教研室在学校深化教育改革倡导下,为提高预防医学专业学生综合素质和培养创新思维,将科研课题精心设计并移植到第二课堂教学中,依托学院开展的“预防论坛”形式积极参与打擂。该次有益的尝试为医学生提前介入科学研究,提高对科研的认知,培养高素质科研专才起到了积极作用。 相似文献
97.
Wei Ling Tay Tze Tec Chong Sze Ling Chan Hao Yun Yap Kiang Hiong Tay Marcus Eng Hock Ong Edward Tieng Chek Choke Tjun Yip Tang 《Singapore medical journal》2022,63(2):79
INTRODUCTIONPercutaneous transluminal angioplasty (PTA) is commonly used to treat patients with chronic limb-threatening ischaemia (CLTI). This study aimed to examine the mortality and functional outcomes of patients with CLTI who predominantly had diabetes mellitus in a multi-ethnic Asian population in Singapore.METHODSPatients with CLTI who underwent PTA between January 2015 and March 2017 at the Vascular Unit at Singapore General Hospital, Singapore, were studied. Primary outcome measures were 30-day unplanned readmission, two-year major lower extremity amputation (LEA), mortality rates, and ambulation status at one, six and 12 months.RESULTSA total of 221 procedures were performed on 207 patients, of whom 184 (88.9%) were diabetics. The one-, six- and 12-month mortality rate was 7.7%, 16.4% and 21.7%, respectively. The two-year LEA rate was 30.0%. At six and 12 months, only 96 (46.4%) and 93 (44.9%) patients were ambulant, respectively. Multivariate analysis revealed that preoperative ambulatory status, haemoglobin, Wound Ischaemia and foot Infection (WIfI) score, and end-stage renal failure (ESRF) were independent predictors of one-year ambulatory status. Predictors of mortality at one, six and 12 months were ESRF, preoperative albumin level, impaired functional status and employment status.CONCLUSIONPTA for CLTI was associated with low one-year mortality and two-year LEA rates but did not significantly improve ambulation status. ESRF and hypoalbuminaemia were independent predictors of mortality. ESRF/CKD and WIfI score were independent predictors of loss of ambulation at six months and one year. We need better risk stratification for patients with CLTI to decide between initial revascularisation and an immediate LEA policy. 相似文献
98.
Adri Ramírez Mena Ndeye Fatou Ngom Judicaël Tine Kine Ndiaye Louise Fortes Ousseynou Ndiaye Maguette Fall Assietou Gaye Daye Ka Moussa Seydi Gilles Wandeler 《Viruses》2022,14(8)
Hepatitis B virus (HBV) infection is the first cause of liver cirrhosis and cancer in West Africa. Although the exposure to additional environmental and infectious risk factors may lead to the faster progression of liver disease, few large-scale studies have evaluated the determinants of HBV-related liver fibrosis in the region. We used transient elastography to evaluate the prevalence of liver fibrosis and assessed the association between HBV markers and significant liver fibrosis in a cohort of people living with HBV in Dakar, Senegal. The prevalence of significant liver fibrosis was 12.5% (95% confidence interval [CI] 9.6%–15.9%) among 471 people with HBV mono-infection (pwHBV) and 6.4% (95% CI 2.6%–12.7%) in 110 people with HIV/HBV co-infection (pwHIV/HBV) on tenofovir-containing antiretroviral therapy (p = 0.07). An HBV viral load > 2000 IU/mL was found in 133 (28.3%) pwHBV and 5 (4.7%) pwHIV/HBV, and was associated with significant liver fibrosis (adjusted odds ratio (aOR) 1.95, 95% CI 1.04–3.66). Male participants (aOR 4.32, 95% CI 2.01–8.96) and those with elevated ALT (aOR 4.32, 95% CI 2.01–8.96) were especially at risk of having significant liver fibrosis. Our study shows that people with an HBV viral load above 2000 IU/mL have a two-fold increase in the risk of liver fibrosis and may have to be considered for antiviral therapy, independent of other disease parameters. 相似文献
99.
100.