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   15951篇
  免费   863篇
  国内免费   414篇
耳鼻咽喉   737篇
儿科学   830篇
妇产科学   123篇
基础医学   828篇
口腔科学   152篇
临床医学   1725篇
内科学   2668篇
皮肤病学   32篇
神经病学   129篇
特种医学   950篇
外国民族医学   2篇
外科学   4005篇
综合类   2323篇
预防医学   400篇
眼科学   407篇
药学   943篇
  4篇
中国医学   612篇
肿瘤学   358篇
  2024年   27篇
  2023年   219篇
  2022年   363篇
  2021年   540篇
  2020年   517篇
  2019年   503篇
  2018年   528篇
  2017年   463篇
  2016年   554篇
  2015年   528篇
  2014年   1075篇
  2013年   944篇
  2012年   876篇
  2011年   1078篇
  2010年   898篇
  2009年   872篇
  2008年   843篇
  2007年   925篇
  2006年   750篇
  2005年   625篇
  2004年   552篇
  2003年   451篇
  2002年   397篇
  2001年   333篇
  2000年   284篇
  1999年   242篇
  1998年   210篇
  1997年   198篇
  1996年   159篇
  1995年   162篇
  1994年   108篇
  1993年   97篇
  1992年   102篇
  1991年   79篇
  1990年   86篇
  1989年   74篇
  1988年   79篇
  1987年   50篇
  1986年   55篇
  1985年   65篇
  1984年   72篇
  1983年   39篇
  1982年   48篇
  1981年   37篇
  1980年   33篇
  1979年   28篇
  1978年   15篇
  1977年   12篇
  1976年   15篇
  1973年   6篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
51.
In the neonate, chronic unilateral ureteral obstruction (UUO) reduces renal blood flow (RBF) of the ipsilateral kidney and increases RBF of the opposite kidney. To determine whether renal nerves mediate or modulate these responses complete left UUO in the neonatal rat was used as a model of severe obstructive uropathy, and was compared with sham-operated controls. At 24–28 days of age, animals underwent left or right mechanical renal denervation or left sham renal denervation. One week after denervation, animals were anesthetized and blood pressure and heart reate were measured. Cardiac output and RBF were determined by the radioactive microsphere technique. UUO increased blood pressure and heart rate, and decreased RBF in the obstructed kidney, regardless of denervation. While left UUO increased RBF to the intact opposite kidney in rats with left renal denervation, this was attenuated by right renal denervation. Thus, in the neonatal rat, UUO modulates systemic renal hemodynamics, possibly through activation of the renin-angiotensin system. While renal nerves do not mediate the vasoconstriction of the obstructed kidney, renal nerves modulate vascular tone of the kidney contralateral to UUO.  相似文献   
52.
We present two cases in which complication of a Meckel's diverticulum were dealt with, and in one case diagnosed using the laparoscope. One was a large bleeding diverticulum containing ectopic gastric mucosa, with the diagnosis suggested preoperatively, confirmed laparoscopically, and the pathology resected extracorporeally. The second was a partial intermittent small-bowel obstruction due to torsion around the mesodiverticular band, diagnosed and resected via the laparoscope. The literature of Meckel's diverticula and complications is reviewed, with open and laparoscopic treatment options. Although uncommon, many cases of Meckel's diverticulum may be quite suitable for laparoscopic diagnosis and treatment.  相似文献   
53.
Summary The objective of this study was to evaluate the effect of two non-steroid anti-inflammatory drugs, indomethacin and metamizole, on ureteral peristalsis during acute occlusion similar to the situation in renal colic. In 12 pentobarbital anesthetized sheep, both ureters were cannulated and the frequency of ureteral contractions, urine flow, mean ureteral pressure and blood pressure were recorded during 10-min control and i.v. drug administration periods. Both indomethacin (1–2 mg/kg) and metamizole (60–120 mg/kg) showed a dose dependent reduction in peristaltic frequency without reduction of the mean pressure. In addition, the pressure amplitude of the peristaltic waves was also lowered, particularly with indomethacin. Only indomethacin reduced the urine flow. Arterial blood pressure was elevated by both drugs, particularly after the first dose of indomethacin. It can be concluded that indomethacin and metamizole reduce ureteral peristaltic frequency, probably blocking the impulse transmission at the ureteropelvic junction.For the partial fulfillment of a Master's degree in Pharmacology  相似文献   
54.
采用窥视下尿道内切开术治疗尿道狭窄或闭锁53例,其中48例治疗成功。狭窄闭锁段≤3cm者,单纯冷刀切开即可;>3cm者,冷刀切开后需加电刀切除疤痕组织,扩大尿道,尿道内皮管植入。36例患者术后随访1~8年(平均4年6个月),27例排尿通畅,尿流率和性功能正常。本文就操作要点和并发症防治等进行了详细讨论。  相似文献   
55.
Ureteropelvic junction obstruction was noted in a newborn male infant with acro-pectoro-renal field defect. To our knowledge, this association has not previously been reported. Ultrasonography of the urinary tract should be performed on all children with aplasia of the pectoralis major muscle.  相似文献   
56.
第Ⅲ段肝管空肠吻合解除肝门部胆管恶性梗阻   总被引:6,自引:0,他引:6  
肝门部胆管恶性梗阻的治疗仍然十分困难。若不解除胆道梗阻,病人很快因肝细胞功能衰竭而死亡。由于肿瘤在肝门部侵润性生长,直接经肝门的手术往往不可能实现。1980~1993年间,我们采用第Ⅲ段肝管空肠吻合术姑息治疗28例肝门部胆管恶性梗阻的黄疸病人。24例为肝门部胆管癌,2例为胆囊癌,2例为胃癌肝门部淋巴结转移。术后19例病人恢复顺利;5例发生并发症,4例病人手术后死亡。24例存活病人中,19例黄疸完全消退3月以上,手术有效率为79%。4例黄疸再次出现,2例因胆管炎需要入院治疗。作者认为:第Ⅲ段肝管空肠吻合术能有效解除不能切除的肝门部恶性肿瘤病人的胆道梗阻。  相似文献   
57.
女性膀胱颈部梗阻的诊断与治疗   总被引:17,自引:0,他引:17  
为探讨女性膀胱颈部梗阻的病因、诊断及治疗方法。总结1981年5月~1996年6月收治女性膀胱颈部梗阻病例32例。29例经手术治疗,其中2例行膀胱颈YV成形术,27例经尿道膀胱颈部后唇切除术,效果满意。结果认为,女性膀胱颈部梗阻病因为纤维组织增生和慢性炎症所致;尿流率检查是客观评价排尿状况的指标;膀胱镜检查为可靠的诊断手段;经尿道膀胱颈部后唇切除为有效的治疗方法。  相似文献   
58.
1. The authors investigated the effect of two extrahepatic cholestasis models (one by bile duct ligation and the other by choledocho-jugular fistula) on the hepatic clearance of horseradish peroxidase in male Sprague-Dawley rats divided into four groups. 2. In groups A (n = 5 rats) and B (n = 5), bile duct ligation was performed, while a choledocho-jugular fistula was created in groups C (n = 5) and D (n= 7). A 10 mg intravenous bolus of horseradish peroxidase was injected after 24 h (groups A and C), 48 h (groups B and D) or 1 h (Group E; five sham-operated rats). Serum and bile samples were then serially collected for 2 h. 3. In all groups, serum horseradish peroxidase levels increased soon after injection and then rapidly decreased, the curves being similar. Biliary excretion increased for 30 min and then slowly decreased. The highest horseradish peroxidase biliary concentrations and outputs were found in Group B followed by Group A; both groups had significantly higher levels than Group E. No difference was found between horseradish peroxidase biliary excretion of groups C and D and that of sham-operated rats. 4. When each group was considered separately, sampling times correlated with the corresponding ratios of bile/ plasma HRP. Significant differences were found between the relative slopes of groups A, B and E, but not between those of groups C, D and E. 5. In conclusion, bile duct obstruction greatly affects the plasma-bile transfer of fluid phase markers, such as horseradish peroxidase, while single retention, caused by choledocho-jugular fistula, has no influence. The increased biliary hyperpressure related to the duration of cholestasis may account for the degree of horseradish peroxidase transfer which, in turn, probably depends on an enhanced paracellular passage.  相似文献   
59.
Paediatric dacryocystorhinostomy   总被引:1,自引:0,他引:1  
Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease.  相似文献   
60.
目的 :探讨改良泪道探通术注入素高捷疗眼膏治疗泪道阻塞的临床效果。方法 :用 7~ 9号腰脊穿刺针针头去尖 ,磨光后制成改良空管式泪道探针。为慢性泪囊炎 98例、10 2眼探通泪道后沿空管注入素高捷疗眼膏 ,使之布满泪道内壁 ,尽快修复探通的泪道内皮 ,达到扩张疏通的目的。以同一疾病 84例、85眼为对照组 ,以 1~ 3号银质泪道扩张针扩通泪道 ,留针 15min ,隔日 1次 ,共扩张 2~ 3次 ,扩张后用 0 .2 5 %氯氟液冲洗。结果 :术后随访 3个月 ,观察组治愈率为 97.0 5 %,对照组治愈率为 9.4 1%,差异有高度显著性 (P<0 .0 1)。 结论 :用改良的泪道探针探通泪道后注入素高捷疗眼膏 ,促使泪道修复 ,是治疗泪道阻塞或狭窄的有效方法。  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