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   80736篇
  免费   8051篇
  国内免费   5724篇
耳鼻咽喉   644篇
儿科学   967篇
妇产科学   1136篇
基础医学   8973篇
口腔科学   1400篇
临床医学   10124篇
内科学   11984篇
皮肤病学   801篇
神经病学   4061篇
特种医学   2856篇
外国民族医学   37篇
外科学   8369篇
综合类   14366篇
现状与发展   29篇
一般理论   8篇
预防医学   6082篇
眼科学   1924篇
药学   8732篇
  64篇
中国医学   4651篇
肿瘤学   7303篇
  2024年   252篇
  2023年   1112篇
  2022年   2818篇
  2021年   3655篇
  2020年   2906篇
  2019年   2553篇
  2018年   2669篇
  2017年   2610篇
  2016年   2379篇
  2015年   3623篇
  2014年   4416篇
  2013年   4245篇
  2012年   6146篇
  2011年   6409篇
  2010年   4355篇
  2009年   3606篇
  2008年   4467篇
  2007年   4514篇
  2006年   4148篇
  2005年   4057篇
  2004年   3178篇
  2003年   3364篇
  2002年   2824篇
  2001年   2259篇
  2000年   1969篇
  1999年   1834篇
  1998年   1081篇
  1997年   1124篇
  1996年   784篇
  1995年   747篇
  1994年   683篇
  1993年   455篇
  1992年   477篇
  1991年   475篇
  1990年   410篇
  1989年   347篇
  1988年   288篇
  1987年   270篇
  1986年   238篇
  1985年   184篇
  1984年   122篇
  1983年   103篇
  1982年   45篇
  1981年   56篇
  1980年   33篇
  1979年   44篇
  1978年   31篇
  1977年   29篇
  1976年   25篇
  1973年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
(续)亥寝鸣云鼓,寅兴漱玉津。妖邪难犯己,精气自全身。在这一节里,孙思邈郑重提出了两条养生的具体措施“:鸣云鼓”和“潄玉津”,并且指出了它们与正常睡眠和祛邪防病、保精全神的关系。何谓“鸣云鼓”?就是叩齿。何时鸣云鼓?孙氏也明确规定了时间“,亥”时,即夜晚的21~23时。在《千金方》中,孙氏还提出过早晨叩齿的方法,曰“:每旦以一撮盐纳口中,以暖水含,揩牙及叩击百遍,为之不绝,不过五日,口齿即牢密”。可见,孙氏对叩齿与护齿的关系看得是很重的。叩齿何益?用现代的话说,它可以增强牙齿的力量和防病、抗病能力,促进牙周组织及根尖组织…  相似文献   
62.
BACKGROUND: This study investigated the utility of the alveolar - arterial oxygen pressure difference (AaDO (2)) in predicting the short-term prognosis of acute pulmonary embolism (PE). METHODS AND RESULTS: This study retrospectively enrolled 114 consecutive patients with acute PE, diagnosed by either spiral computed tomography or high probability ventilation - perfusion lung scans. During the first 24 h of admission, all patients had initial artery blood gas collected under room air. Patient exclusion criteria were chronic lung disease, septic emboli, and moderate and low probability lung scans. Patients were assigned to 2 groups based on either 30-day death or a 30-day composite event. Receiver operating characteristic analyses was used to determine the AaDO(2) cut-off value for predicting primary and composite endpoints. Statistical analysis demonstrated significant differences in AaDO(2) between the 30-day composite endpoint group and the 30-day composite event-free survival group (p=0.012). The AaDO(2) had a strong trend between the 30-day death group and the survival group (p=0.062). The best cut-off value for AaDO(2) was 53 mmHg and using this, the positive predictive value for 30-day death was 25% and the negative predictive value was 92%. For the 30-day composite endpoint, the positive predictive value for AaDO(2) was 35%, and the negative predictive value was 84%. In this study, thrombocytopenia was also an indicator of poor prognosis for patients with acute PE. CONCLUSION: The AaDO(2) measurement is a highly useful and simple measurement for predicting short-term prognosis in patients with acute PE. It has high negative predictive value and moderate positive predictive value for 30-day death and 30-day composite event. Aggressive thrombolytic treatment strategies should be considered for patients with an initial poor prognostic parameter (ie, AaDO(2) >or=53 mmHg).  相似文献   
63.
We report a patient with a posterior inferior cerebellar artery (PICA) aneurysm and an incidental facial nerve schwannoma at the cerebellopontine angle (CPA). A 46-year-old woman presented with the sudden onset of a severe headache, nausea, and vomiting. She had no other abnormal neurological symptoms and signs. Computed tomography (CT) showed hemorrhage in the fourth ventricle. Cerebral angiography demonstrated an aneurysm arising from the tonsillomedullary segment of the left PICA. A facial nerve schwannoma was incidentally found as the aneurysm was being clipped. The aneurysm was clipped via a left transcondylar approach. Subsequently, the schwannoma (2 x 3 x 2 mm) was resected from the facial nerve fascicles, and the facial nerve was preserved. Postoperatively, the patient developed mild to moderate dysfunction of the facial nerve (House-Brackmann grade III [H-B III]) but her hearing was intact. Both a facial nerve schwannoma involving the CPA and an aneurysm involving the PICA can be managed through the transcondylar approach. An asymptomatic facial nerve schwannoma can be resected safely with minimal facial nerve dysfunction.  相似文献   
64.
目的:观察局部光化学疗法(Psoralen plus UVA,PUVA)治疗儿童白癜风的临床疗效及安全性.方法:采用小型UVA灯(电压220V,电流0.34A,功率25.4w,主波峰长36 5nm,辐照度为1 070uw/cm2)治疗56例白癜风患儿,30次为一个疗程,共观察3个疗程.结果:第一疗程、第二疗程及第三疗程结束后临床显效率分别达39.29%、48.21%和5 5.36%,未发现明显不良反应,其中病程短、局限性及面颈部白癜风患儿疗效佳.结论:局部PUVA治疗儿童白癜风安全、有效、不良反应小,小型UVA灯具有疗效好、治疗方便的优点.  相似文献   
65.
目的 探讨西藏地区农、牧民生活习俗与包囊虫病的关系。方法 自制问卷对 7个县 2 40个家庭 163 1名成员与包囊虫感染有关的生活习俗进行调查分析。结果 饭前便后洗手的人仅有 16 1%,餐具一般都用天然水洗 ,大部家庭用天然绵羊绒擦洗茶具。大多数人都喝过河溪水 ,池塘水 ,人人都吃半生不熟的肉 ,半数以上的吃生肉和生血肠 ,绝大多数人喝未经消毒的鲜牛、羊奶。 10 0 %家庭养狗 ,所有人员与狗、羊、牛、马接触密切。包囊虫病人占调查人数 0 43 %( 7/ 163 1) ,有典型症状者占 0 67%( 11/ 163 1)。结论 当地居民感染包囊虫与不良生活习俗有关  相似文献   
66.
BACKGROUND AND PURPOSE: The potential risk of prolongation of treatment time in cervical cancer has been reported for many low-dose rate (LDR) studies, with an estimated loss of local control ranging from 0.3 to 1.6% per day of treatment prolongation. Since the treatment schedule for fractionated high-dose rate intracavitary brachytherapy (HDRICB) is not directly comparable with that for low-dose rate studies, this report aims to evaluate the adverse effect of treatment prolongation specifically for cervical cancer treated with HDRICB. MATERIAL AND METHODS: From September 1992 to December 1997, 257 patients diagnosed with uterine cervical cancer (35 Ib, 26 IIa, 122 IIb, 10 IIIa, 57 IIIb, 7 IVa), who underwent external radiotherapy combined with between two and four courses of HDRICB and a minimum of 3 years of follow-up (median 57 months), were analyzed. Treatment consisted of irradiation of the whole pelvis with 44-45 Gy consisting of 22-25 fractions by 5 weeks, with the dose boosted to 54-58 Gy (with central shielding) for patients diagnosed as FIGO stage IIb-IVa bilateral parametrial disease. HDRICB was performed using an Ir-192 remote afterloading technique at 1-week intervals. The standard prescribed dose for each course of HDRICB was 7.2 Gy to point A for three insertions (before July 1995), or 6.0 Gy to point A for four insertions (after July 1995). Total prescribed point A doses (external beam radiotherapy+HDRICB) ranged from 58 to 71.6 Gy (median, 65.6 Gy) for stage IB-IIA, while analogous dosage for larger lesions (stage IIb-IVa) ranged from 59 to 75.6 Gy (median, 65.6 Gy). Kaplan-Meier and multivariate analyses were used to test the effect of treatment time on pelvic control rate (PCR) and cause-specific survival (CSS) at 5 years. RESULTS: Median treatment time was 63 days. For all stages of disease, the 5-year CSS and PCR were significantly different comparing treatment times of less than and greater than or equal to 63 days [83% and 65% (P=0.004], 93% and 83% (P=0.02), respectively]. These associations were also significant for stage Ib/IIa [97% and 79% (P=0.01), and 100% and 87% (P=0.02), respectively), but not for stage IIb [75% and 72% (P=0.79), and 93% and 87% (P=0.83), respectively] or stage III [66% and 49% (P=0.2), and 83% and 72% (P=0.21), respectively]. Multivariate analysis identified three prognostic factors for CSS, stage (P<0.001), tumor response to external RT (P=0.001), and overall treatment time (OTT; P=0.006). Prognostic factors for pelvic failure were stage (P<0.001), tumor response to external RT (P=0.001), and OTT (P=0.03). Prolongation of treatment time resulted in a daily decrease in pelvic control rate of 0.67% overall, and 0.43% for stage Ib-IIa, 0.57% for stage IIb, and 0.73% for stage III patients. CONCLUSION: Analysis of the data from the current study demonstrates that the adverse effect of treatment prolongation was observed later in the treatment course for the high-dose rate (HDR) series compared to the LDR analog, however, treatment-time prolongation still negatively influenced the cause-specific survival and pelvic control rate for both dosage groups.  相似文献   
67.
Opioid tolerance and opioid-induced hyperalgesia are conditions that negatively affect pain management. Tolerance is defined as a state of adaptation in which exposure to a drug induces changes that result in a decrease of the drug's effects over time. Opioid-induced hyperalgesia occurs when prolonged administration of opioids results in a paradoxic increase in atypical pain that appears to be unrelated to the original nociceptive stimulus. Complex intracellular neural mechanisms, including opioid receptor desensitization and down-regulation, are believed to be major mechanisms underlying opioid tolerance. Pain facilitatory mechanisms in the central nervous system are known to contribute to opioid-induced hyperalgesia. Recent research indicates that there may be overlap in the two conditions. This article reviews known and hypothesized pathophysiologic mechanisms surrounding these phenomena and the clinical implications for pain management nurses.  相似文献   
68.
近30年来糖尿病患病率在多数欧美和亚洲国家中迅速增高。糖尿病心血管并发症是糖尿病患者的主要死亡原因,其发生机制不甚明了。糖尿病有关的代谢因素增加循环和组织中氧化和糖化蛋白或脂蛋白的水平和氧化应激性。这些改变可引起动脉粥样硬化,凝血因子和血小板活性增高,纤溶活性  相似文献   
69.
肠道T细胞淋巴瘤临床分析   总被引:1,自引:0,他引:1  
本文总结报告了3例肠道T细胞淋巴瘤(intestinal T-cell lymphoma,ITCL)的诊治资料,并结合文献复习,发现IT—CL多见于中年男性,以腹痛、血便、发热、体质量下降为主要症状,治疗效果差,预后不良。病理改变以肠道溃疡形成为特点,溃疡形态呈多形性、多灶性、不规则,镜下瘤细胞明显异型、弥漫性浸润,中至大细胞多见。肿瘤细胞呈T细胞表型。ITCL临床少见,缺乏特异性临床表现,极易误诊。故临床医师应重视对ITCL临床病理特征、免疫表型和基因型的研究,注意识别,促其早期诊治。  相似文献   
70.
浅谈健康教育中的护理风险管理   总被引:3,自引:0,他引:3  
沈佩娟 《护理研究》2006,20(3):729-730
健康教育作为临床护理中的重要内容,对病人的疾病转归有重要作用。而任何医疗护理行为都是具有超过各种服务之上的高科技行为的组合活动,具有高风险性,健康教育同样存在一定的风险性。所以,我们应提高风险意识,加强风险管理,将风险降低至最低限度。  相似文献   
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