首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21095篇
  免费   1186篇
  国内免费   432篇
耳鼻咽喉   144篇
儿科学   1154篇
妇产科学   1307篇
基础医学   2299篇
口腔科学   169篇
临床医学   1499篇
内科学   3161篇
皮肤病学   206篇
神经病学   2253篇
特种医学   332篇
外国民族医学   3篇
外科学   2568篇
综合类   2666篇
现状与发展   4篇
预防医学   1133篇
眼科学   66篇
药学   2118篇
  12篇
中国医学   720篇
肿瘤学   899篇
  2023年   180篇
  2022年   315篇
  2021年   602篇
  2020年   515篇
  2019年   493篇
  2018年   532篇
  2017年   578篇
  2016年   572篇
  2015年   552篇
  2014年   994篇
  2013年   1314篇
  2012年   908篇
  2011年   1115篇
  2010年   947篇
  2009年   880篇
  2008年   953篇
  2007年   931篇
  2006年   960篇
  2005年   826篇
  2004年   688篇
  2003年   673篇
  2002年   582篇
  2001年   521篇
  2000年   505篇
  1999年   403篇
  1998年   335篇
  1997年   371篇
  1996年   344篇
  1995年   318篇
  1994年   321篇
  1993年   274篇
  1992年   294篇
  1991年   276篇
  1990年   301篇
  1989年   238篇
  1988年   184篇
  1987年   163篇
  1986年   190篇
  1985年   242篇
  1984年   215篇
  1983年   138篇
  1982年   179篇
  1981年   143篇
  1980年   125篇
  1979年   111篇
  1978年   96篇
  1977年   78篇
  1976年   61篇
  1975年   46篇
  1973年   39篇
排序方式: 共有10000条查询结果,搜索用时 593 毫秒
1.
Menopause is generally experienced as a biopsychosocial process involving physiological changes, and influenced by a wide range of psychological, social and cultural factors. The loss of ovarian oestrogen production may cause debilitating symptoms, including hot flushes, night sweats, sleep disturbance, vaginal dryness, dyspareunia, bladder dysfunction, loss of libido, and mood changes. Experience of the menopause transition varies widely between individuals, depending on the age of onset, personal health and wellbeing, social context, environment and culture.Hormone Replacement Therapy (HRT) remains the most effective treatment for the management of vasomotor symptoms and vaginal dryness, but has no proven role in the treatment of chronic diseases of ageing. Treatment should be individualized, and for most healthy women aged 50–59 years the risks of HRT are low. An understanding of the pathophysiology of menopausal symptoms and the risks and benefits of both hormonal and non-hormonal treatments assists in the individual management of patients.  相似文献   
2.
3.
        绝经是一个古老的概念,见诸于文献,最早可以追溯到春秋时期中医的重要文献之一《黄帝内经》。其中,《素问·上古天真论》有这样的描述:“女子二七而天葵至,任脉通,太冲脉盛,月事以时下,故有子……七七任脉虚,太冲脉衰少,天葵竭,地道不通,故形坏而无子也。”绝经是卵巢功能衰竭所造成的一种生命现象,从理论上讲,经过长期的进化的洗礼,人体所有的器官和组织,都是维持人体生命活动不可或缺的重要组成部分。时至今日,在不同的流行病学调查中,女性平均绝经年龄仍保持在50岁左右[1-2],可谓亘古未变,而变化的是人类寿命的延长,2018年北京女性预期寿命已经达84.63岁。 浏览更多请关注本刊微信公众号及当期杂志。  相似文献   
4.
目的:探讨甲状旁腺激素(PTH)对大鼠牵张成骨(DO)过程中ONC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因表达的影响。方法30只雄性大鼠制备大鼠下颌骨DO模型。随机分5组,每组6只。第1组(只有牵张无PTH),术后8周取材,应用HE染色及微CT检测,以确定成骨情况。第2组(有牵张无PTH),第3组(有牵张有PTH),第4组(无牵张有PTH),第5组(对照组:无牵张无PTH)。2、3、4组及对照组术后1周取材,RT-PCR测定ONC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因的表达。结果第1组,新骨形成,骨质充满牵张区,骨质连续,大鼠建模成功。RT-PCR检测结果显示,2、3、4组与对照组比较,OPN、COL1、RUNX2、ALP基因表达有明显提高(P<0.05),其中第3组最为明显。ONC、C-FOS、VEGF基因2、3、4组与对照组比较差异无统计学意义(P>0.05)。结论 PTH在 DO 过程中,间歇性给以 PTH的作用只有在牵张期发挥作用,其对 OPN、COL1、RUNX2、ALP基因表达能够获得理想的协同作用。  相似文献   
5.
6.
7.
Background/objectiveObstructive sleep apnea (OSA) is independently associated with dyslipidemia, a surrogate marker of atherosclerosis. Low-density lipoprotein (LDL)-cholesterol is accepted as a major independent risk factor for cardiovascular disease. However, non-high-density lipoprotein (HDL)-cholesterol is a better marker of atherogenic dyslipidemia and recommended as a target of lipid lowering therapy. We aimed to assess the prevalence of atherogenic dyslipidemia, and relationship between OSA severity and serum LDL-cholesterol and non-HDL cholesterol levels in OSA patients.MethodsWe retrospectively evaluated treatment naïve 2361 subjects admitted to the sleep laboratory of a university hospital for polysomnography. All subjects’ lipid profile including total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and non-HDL-cholesterol were measured.ResultsOut of 2361 patients (mean age 49.6 ± 11.9 years; 68.9% male, apnea-hypopnea index 36.6 ± 28.4/h), 185 (7.8%) had no OSA and 2176 (92.2%) had OSA. Atherogenic dyslipidemia prevalence was high (57–66%) in OSA patients, and especially increased in severe OSA compared to other groups (p < 0.05). Though total and LDL-cholesterol did not differ between those with and without OSA, non-HDL-cholesterol (p = 0.020), and triglycerides (p = 0.001) were higher and HDL-cholesterol levels (p = 0.018) were lower in OSA patients than non-OSA. Non-HDL-cholesterol was significantly correlated with OSA severity (p < 0.001) and hypoxia parameters (p < 0.01), whereas LDL-cholesterol showed no correlation.ConclusionsAtherogenic dyslipidemia is highly prevalent and non-HDL-cholesterol levels are significantly increased, predominantly in severe OSA patients. Non-HDL-cholesterol but not LDL-cholesterol, is significantly correlated with OSA severity and hypoxia parameters. Therefore, it could be better to use non-HDL-cholesterol, which is a guideline recommended target of lipid therapy, as a marker of atherosclerotic cardiovascular risk in OSA patients.  相似文献   
8.
Parathyroid cancer (PC) is a rare malignant tumor which comprises 0.5–5% of patients with primary hyperparathyroidism (PHPT). Most of these cancers are sporadic, although it may also occur as a feature of various genetic syndromes including hyperparathyroidism-jaw tumor syndrome (HPT-JT) and multiple endocrine neoplasia (MEN) types 1 and 2A. Although PC is characterized by high levels of serum ionized calcium (Ca) and parathyroid hormone (PTH), the challenge to the clinician is to distinguish PC from the far more common entities of parathyroid adenoma (PA) or hyperplasia, as there are no specific clinical, biochemical, or radiological characteristic of PC. Complete surgical resection is the only known curative treatment for PC with the surgical approach during initial surgery strongly influencing the outcome. In order to avoid local recurrence, the lesion must be removed en-bloc with clear margins. PC has high recurrence rates of up to 50% but with favorable long-term survival rates (10-year overall survival of 60–70%) due to its slow-growing nature. Most patients die not from tumor burden directly but from uncontrolled severe hypercalcemia. In this article we have updated the information on PC by reviewing the literature over the past 10 years and summarizing the findings of the largest series published in this period.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号