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   9163篇
  免费   893篇
  国内免费   200篇
耳鼻咽喉   177篇
儿科学   46篇
妇产科学   109篇
基础医学   186篇
口腔科学   187篇
临床医学   1520篇
内科学   768篇
皮肤病学   29篇
神经病学   194篇
特种医学   160篇
外国民族医学   5篇
外科学   3518篇
综合类   1416篇
预防医学   267篇
眼科学   261篇
药学   494篇
  21篇
中国医学   286篇
肿瘤学   612篇
  2024年   36篇
  2023年   240篇
  2022年   399篇
  2021年   547篇
  2020年   546篇
  2019年   466篇
  2018年   459篇
  2017年   434篇
  2016年   408篇
  2015年   354篇
  2014年   617篇
  2013年   583篇
  2012年   433篇
  2011年   501篇
  2010年   324篇
  2009年   317篇
  2008年   341篇
  2007年   312篇
  2006年   320篇
  2005年   309篇
  2004年   261篇
  2003年   239篇
  2002年   184篇
  2001年   192篇
  2000年   147篇
  1999年   146篇
  1998年   122篇
  1997年   117篇
  1996年   118篇
  1995年   89篇
  1994年   88篇
  1993年   74篇
  1992年   58篇
  1991年   67篇
  1990年   56篇
  1989年   49篇
  1988年   35篇
  1987年   35篇
  1986年   39篇
  1985年   36篇
  1984年   24篇
  1983年   19篇
  1982年   35篇
  1981年   22篇
  1980年   12篇
  1979年   15篇
  1978年   13篇
  1977年   10篇
  1976年   4篇
  1975年   4篇
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
101.
102.
103.
BackgroundTo evaluate to what degree preoperative urine white blood cell (WBC) and urine nitrite (NIT) values are predictive of postoperative infections following percutaneous nephrolithotomy (PCNL).MethodsA systematic literature search was performed of the PubMed, Embase, Cochrane Library, Wanfang Data, National Knowledge Infrastructure (CNKI), and China Science and Technology Journal Database (CSTJ or VIP) online databases to identify relevant studies that examined the predictive value of urine WBC or NIT as risk factors for post-PCNL infection, and the search was finished on February 28, 2020. Two independent reviewers screened the relevant studies, extracted necessary data from the eligible case-control studies (CCS), and assessed the quality of included studies through the Newcastle-Ottawa scale (NOS). RevMan 5.3 software and the Stata 16.0 software were used to complete the statistical analysis of data. Results are expressed as odds ratio (OR) with 95% confidence intervals (CIs).ResultsAccording to the statistical analysis of 12 eligible studies involving 6113 patients, positive urine WBC (WBC+: OR =3.86, 95% CI: 3.03–4.91, P<0.001) and positive NIT (NIT+: OR =7.81, 95% CI: 5.44–11.21, P<0.001) in preoperative tests were identified as independent risk factors for postoperative infections following PCNL.ConclusionsIn summary, as risk factors for postoperative infections, the presence of preoperative urine WBC+ and NIT+ should be evaluated as part of clinical procedure, in order to reduce infections of PCNL.  相似文献   
104.
Summary The pharmacokinetics of 9-amino-1,2,3,4-tetrahydroacridine; tacrine, THA, was studied after intravenous administration and following the first and last oral doses of a seven week clinical trial involving 8 patients with amyotrophic lateral sclerosis, ALS. Two surgical patients given intravenous THA for reversal of postoperative sedation were also included. Plasma concentration of THA and in some cases the metabolite, 1-hydroxy-THA, were assayed using a selective and sensitive method with high performance liquid chromatography.After an intravenous dose of 30 mg THA, the plasma concentrations were fitted to a two-compartment model. Plasma clearance showed a threefold interindividual variation with a mean of 2.42 l·h–1. Volume of distribution, V varied 100–680 l with a mean of 349 l. The plasma half-lives of distribution and elimination were 1.8 and 98.2 min, respectively. Oral bioavailability showed large interindividual differences and ranged 6–36% in the four subjects studied.After seven weeks treatment with oral THA, plasma concentrations immediately prior to medication were below 10 ng/ml in three patients and above 100 ng/ml in two patients. At the same occasion the plasma metabolite concentrations considerably exceeded those of THA. THA medication was associated with side effects in the majority of the patients.  相似文献   
105.
颅咽管瘤切除术后常见并发症的处理   总被引:2,自引:0,他引:2  
目的:研究颅咽管瘤术后的常见并发症及其相应的防治措施。方法:分析110例颅咽管瘤手术后所出现的各种并发症,探讨其产生的原因并总结临床处理过程中的体会。结果:颅咽管瘤切除术后并发症的发生与肿瘤切除程度和术中垂体柄、下丘脑等的受损状况有关。尿崩、高热、水电解质平衡失调和癫痫是颅咽管瘤术后最常见的并发症,其发生率分别为79.1%、47.3%、88.2%和17.3%。结论;耐心细致的术中显微外科操作和严格规范化的术后管理对降低颅咽管瘤术后病残率,提高其术后生存率具有十分重要的临床意义。  相似文献   
106.
目的比较硬膜外阻滞复合全身麻醉或单纯全身麻醉对上腹部和胸腔内手术病人术后肺功能和肺部并发症的影响。方法24名伴有中度术后肺部并发症危险的慢阻肺病人,接受上腹部或胸腔内手术,随机分成单纯全身麻醉(GA组)和硬膜外阻滞复合全身麻醉(Epi-Ga组)两组。术后采用VRS法评定镇痛效果。根据临床症状和体征、X线胸片、血气分析和床旁肺功能测定评估是否发生肺部并发症。术前1d和术后3d内评估和记录上述指标。结果术毕,GA组病人平均(34±16)min苏醒,(67±22)min拔除气管导管;Epi-Ga组苏醒时间和拔管时间分别为(12±4)和(32±12)min。术后第1天和第2天,Epi-Ga组病人术后镇痛效果明显优于GA组(P<0.01)。术后第1天,Epi-Ga组病人的FVC、FEV1/FVC%和FEF25%-75%下降不如GA组显著(P<0.05)。GA组有4例需要纤维支气管镜协助吸痰,而Epi-Ga组则无一例需要。两组病人术后肺炎、肺不张、支气管痉挛和呼吸衰竭的发生率无显著差异。结论局麻药加阿片类药物硬膜外自控镇痛使病人术后更加舒适,且能够改善病人术后肺功能。尽管两组病人术后肺部并发症无明显差异,但硬膜外阻滞复合全身麻醉以及术后硬膜外自控镇痛确实能够方便慢阻肺病人的术后管理。  相似文献   
107.
Vomiting is a common, unpleasant aftermath of tonsillectomy in children. Intraoperative intravenous ondansetron (OND) reduces vomiting after this operation. Our doubleblind, placebocontrolled, randomized investigation studied the effect of the oral form of OND on vomiting after outpatient tonsillectomy in children. We studied 233 healthy children age 2–14 yr undergoing elective tonsillectomy. Subjects were given placebo (PLAC) or OND 0.1 mg · kg?1 rounded off to the nearest 2 mg one hr before surgery. Anaesthesia was induced with either propofol or halothane/N2O. Vecuronium 0.1 mg · kg?1 was administered at the discretion of the anaesthetist. Anaesthesia was maintained with halothane/N2O, 50 μg · kg?1 midazolam iv and 1–1.5 mg · kg?1 codeine im. At the end of surgery, residual neuromuscular blockade was reversed with neostigmine and atropine. All episodes of inhospital emesis were recorded by nursing staff. Rescue antiemetics in the hospital were 1 mg · kg?1 dimenhydrinate ivfor vomiting × 2 and 50 μg · kg?1 droperidol iv for vomiting × 4. Parents kept a diary of emesis after discharge. Postoperative pain was treated with morphine, codeine and/or acetaminophen. The two groups were similar with respect to demographic data, induction technique and anaesthesia time. Oral OND (n = 109) reduced postoperative emesis from 54% to 39%, P < 0.05. This effect was most dramatic inhospital, where 10% of the OND-patients and 30% of the PLAC-group vomited, P < 0.05. The OND-subjects required fewer rescue antiemetics, 7% vs 17%, P < 0.05. In conclusion, oral ondansetron decreased the incidence of vomiting after outpatient tonsillectomy in children.  相似文献   
108.
目的:回顾29 例髓母细胞瘤术后放疗,对影响生存情况的因素进行分析。方法:手术后病理证实的29例髓母细胞瘤,先行卡氮芥(BCNU)化疗,再行60钴常规分割照射:全脑剂量(DT)22~40 Gy;原发病灶追加DT15~22 Gy;全脊髓轴DT25~35 Gy。结果:1、3、5、8 年生存率分别为89.6% (26/29)、55.2% (16/29)、30.4% (7/23)、25.0% (4/16)。结论:病人生存期长短与手术切除范围、术后接受放疗时间、放射剂量及是否行化疗有关。  相似文献   
109.
报告3例头颈部恶性肿瘤颈部转移累及颈动脉,术中保留预动脉,术后4~6d颈动脉破裂大出血。分析原因为伤口感染和颈动脉已被肿瘤浸润所致,提示受肿瘤侵犯的颈动脉不宜保留。  相似文献   
110.
BACKGROUND: Although patient-controlled analgesia (PCA) with morphine provides a high degree of satisfactory postoperative analgesia in children, it is often associated with a high incidence of postoperative nausea and vomiting (PONV). Our aim in this study was to evaluate the prophylactic effect of dixyrazine, a phenothiazine with proven anti-emetic properties. METHODS: The incidence of nausea and vomiting was studied in 60 children using PCA after major surgery. The patients were randomised to receive either dixyrazine 0.25 mg kg-1 or placebo on the induction of anaesthesia in a double-blind, placebo-controlled design. The anaesthetic technique was standardised. The PCA pump was programmed to deliver bolus doses of morphine of 20 micrograms kg-1 with a continuous background infusion of 8-10 micrograms kg-1 h-1. Nausea, vomiting, sedation and pain scores were noted every 3 h for a period of 24 h. RESULTS: The morphine consumption of morphine was the same in both groups. During the stay in the recovery room the incidence of vomiting was 3% in the dixyrazine group compared to 30% in the placebo group (P < 0.05). On the ward, 57% versus 83% of the children vomited (P < 0.05). Rescue antiemetics were significantly lower, 30%, in the dixyrazine group compared to 60% in the placebo group (P < 0.05). Higher sedation scores were recorded for the dixyrazine group in the recovery room. No other adverse effects were found. CONCLUSION: A significant number of children using PCA with morphine after major surgery experience PONV. Although prophylactic dixyrazine reduces the incidence and severity of vomiting, the incidence still remains high.  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