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   1706篇
  免费   56篇
  国内免费   8篇
耳鼻咽喉   45篇
儿科学   31篇
妇产科学   14篇
基础医学   295篇
口腔科学   52篇
临床医学   97篇
内科学   351篇
皮肤病学   42篇
神经病学   118篇
特种医学   51篇
外科学   231篇
综合类   14篇
预防医学   26篇
眼科学   17篇
药学   209篇
中国医学   7篇
肿瘤学   170篇
  2023年   3篇
  2022年   9篇
  2021年   22篇
  2020年   9篇
  2019年   7篇
  2018年   17篇
  2017年   10篇
  2016年   9篇
  2015年   23篇
  2014年   17篇
  2013年   29篇
  2012年   47篇
  2011年   64篇
  2010年   29篇
  2009年   31篇
  2008年   58篇
  2007年   75篇
  2006年   79篇
  2005年   89篇
  2004年   80篇
  2003年   90篇
  2002年   90篇
  2001年   85篇
  2000年   92篇
  1999年   76篇
  1998年   20篇
  1997年   19篇
  1996年   15篇
  1995年   27篇
  1994年   18篇
  1993年   19篇
  1992年   62篇
  1991年   61篇
  1990年   48篇
  1989年   51篇
  1988年   43篇
  1987年   38篇
  1986年   30篇
  1985年   41篇
  1984年   37篇
  1983年   25篇
  1982年   12篇
  1981年   5篇
  1980年   5篇
  1979年   22篇
  1978年   9篇
  1977年   6篇
  1976年   6篇
  1975年   2篇
  1966年   3篇
排序方式: 共有1770条查询结果,搜索用时 15 毫秒
81.
A male infant with benign hemangiopericytoma of the right atrium is reported. His chief complaint was acute respiratory distress secondary to bloody pericardial effusion. Although the entire mass could not be removed surgically, there was no recurrence of cardiac tamponade or growth of the residual mass during a follow-up period of 3 years. This patient is, to our knowledge, the youngest one with primary cardiac hemangiopericytoma so far reported.  相似文献   
82.
83.
Reduction of cisplatin ototoxicity by fosfomycin in animal model   总被引:1,自引:0,他引:1  
The protective effect of fosfomycin against cisplatin-induced ototoxicity was studied in rats. Sixty-four Fischer rats were injected intravenously with daily doses of 1, 2, 5, and 10 mg/kg of cisplatin with or without 300 mg/kg of fosfomycin for a varying period from 1 to 10 days. The total dose of 10 mg/kg of cisplatin was given equally in all animals. Inner ear damage appeared to be more reduced histopathologically in animals given both cisplatin and fosfomycin than in animals given cisplatin alone. Similarly, renal damage appeared to be reduced histopathologically and functionally by the combined administration of cisplatin and fosfomycin.  相似文献   
84.
The Chediak-Higashi syndrome (CHS) is a rare, autosomal-recessively inherited disease characterized by giant cytoplasmic granules in neutrophils, monocytes and lymphocytes. It has been reported that a lymphoma-like illness develops in the accelerated phase of the syndrome and that early death ensues. Treatment of CHS has not been established, particularly when the accelerated phase develops. We treated a 15-year-old boy, who had entered into the accelerated phase, with high-dose intravenous gammaglobulin. The treatment was beneficial in the management of accelerated phase of CHS.  相似文献   
85.
86.
We reported successful laparoscopic fundoplication in 2 pediatric cases with VPS and discuss the safety and feasibility of the procedure. Case 1: A 13-year-old girl with VPS underwent laparoscopic fundoplication. Case 2: a 9-year-old boy with VPS underwent laparoscopic fundoplication. In both cases, laparoscopic Nissen fundoplication was performed with a standard five-port technique with a low pressure of a pneumoperitoneum. The VPS system had no effect on port layout and intraabdominal manipulation and no adverse complications were observed in either case. The effect of a pneumoperitoneum in the VPS system remains controversial, however, the author emphasized that advanced laparoscopic surgery can be performed safely with creating a low pressure of a pneumoperitoneum.  相似文献   
87.
The effect of the intake of 200 g of grapefruit pulp (corresponding to one grapefruit) on the pharmacokinetics of the calcium antagonists nifedipine (NF) and nisoldipine (NS) were investigated in 8 healthy Japanese male volunteers. A crossover design was used for the study: group I did not ingest any grapefruit (control group); group II ingested grapefruit 1 h after drug administration; and group III ingested grapefruit 1 h before drug administration. The intake of grapefruit pulp increased the plasma concentrations of both NF and NS, an effect that has previously been reported with grapefruit juice. The increase was most marked when grapefruit was eaten before drug administration. For both NF and NS, subjects who ingested grapefruit 1 h before drug administration exhibited a greater Cmax and AUC0-24 than did subjects in the control group. For NF, the Cmax was 1.4 times higher and the AUC0-24 1.3 times larger in group III than in group I. For NS, the Cmax was 1.5 times higher and the AUC0-24 1.3 times larger in group III than in group I. The increase in the AUC0-24 was significant for both drugs (p < 0.05). The finding that the ratios of Cmax and AUC0-24 for unchanged drug and metabolites did not vary greatly among the three groups for either drug suggests that the increase in serum concentration produced by grapefruit intake may be due to other factors than an inhibitory effect on drug metabolism. Also, the increases in Cmax and AUC0-24 of NS produced by grapefruit intake were smaller than those produced by grapefruit juice intake, indicating that grapefruit pulp and juice have different effects on the pharmacokinetics.  相似文献   
88.
Cerebrovascular white matter lesions represent an age-related neurodegenerative condition that appears as a hyperintense signal on magnetic resonance images. These lesions are frequently observed in aging, hypertension and cerebrovascular disease, and are responsible for cognitive decline and gait disorders in the elderly population. In humans, cerebrovascular white matter lesions are accompanied by apoptosis of oligodendroglia, and have been thought to be caused by chronic cerebral ischemia. In the present study, we tested whether chronic cerebral hypoperfusion induces white matter lesions and apoptosis of oligodendroglia in the rat. Doppler flow meter analysis revealed an immediate reduction of cerebral blood flow ranging from 30% to 40% of that before operation; this remained at 52–64% between 7 and 30 days after operation. Transferrin-immunoreactive oligodendroglia decreased in number and the myelin became degenerated in the medial corpus callosum at 7 days and thereafter. Using the TUNEL method, the number of cells showing DNA fragmentation increased three- to eightfold between 3 and 30 days post-surgery compared to sham-operated animals. Double labeling with TUNEL and immunohistochemistry for markers of either astroglia or oligodendroglia showed that DNA fragmentation occurred in both of these glia. Messenger RNA for caspase-3 increased approximately twofold versus the sham-operated rats between 1 and 30 days post-surgery. Immunohistochemistry revealed up-regulation of caspase-3 in the oligodendroglia of the white matter, and also in the astroglia and neurons of the gray matter. Molecules involved in apoptotic signaling such as TNF- and Bax were also up-regulated in glial cells. These results indicate that chronic cerebral hypoperfusion induces white matter degeneration in association with DNA fragmentation in oligodendroglia.  相似文献   
89.
During influenza epidemics in Japan, the number of children with acute encephalopathies and encephalitis has recently increased. Although the pathophysiologies remain unclear, there is usually brain edema with evidence of damage to the blood-brain-barrier (BBB). We investigated the glial reaction and apoptosis in brains of eight such cases comprising two of acute necrotizing encephalopathy and six of influenza encephalopathy, and compared the results with those in five control brains. Apoptosis, evidenced by chromatin condensation and fragmentation in hematoxylin sections, in situ end labeling of fragmented DNA (TUNEL) and DNA laddering, was observed in neurons and glial cells in four brains with influenza encephalopathy. In the TUNEL-positive brains, the increase in microglia was greater than in the TUNEL-negative brains. Immunoreactivity for active-caspase 3, demonstrated by immunohistochemistry, and the overexpression of a caspase-cleaved fragment of poly(ADP-ribose) polymerase, demonstrated by Western blotting, indicated that activation of caspase 3 is involved in the apoptotic pathway in the brains of influenza encephalopathy cases. Apoptosis or specific pathological processes that cause apoptosis may give rise to aggravated encephalopathy.  相似文献   
90.
Resolution of a leg ulcer after hysterectomy for huge uterine myoma   总被引:1,自引:0,他引:1  
Venous ulcers are the most common type of leg ulcers, accounting for 80% to 90% of cases. We report a large, therapy-resistant ulcer present for three months on the right leg of a 44-year-old woman who also had a huge uterine myoma. Without any other treatment, the leg ulcer regressed spontaneously three months after a hysterectomy for the uterine myoma that had been demonstrated in a CT image to be compressing the right common iliac vein in the pelvis. Uterine myoma can become the cause of venous insufficiency of the leg, when it is big enough to disturb the blood circulation in the pelvis in individuals who have incompetent perforating veins.  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