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   4191篇
  免费   233篇
  国内免费   40篇
耳鼻咽喉   18篇
儿科学   196篇
妇产科学   78篇
基础医学   545篇
口腔科学   67篇
临床医学   246篇
内科学   963篇
皮肤病学   39篇
神经病学   267篇
特种医学   164篇
外科学   837篇
综合类   18篇
预防医学   74篇
眼科学   137篇
药学   379篇
中国医学   32篇
肿瘤学   404篇
  2023年   18篇
  2022年   39篇
  2021年   104篇
  2020年   49篇
  2019年   79篇
  2018年   113篇
  2017年   89篇
  2016年   104篇
  2015年   122篇
  2014年   150篇
  2013年   167篇
  2012年   227篇
  2011年   277篇
  2010年   151篇
  2009年   151篇
  2008年   247篇
  2007年   268篇
  2006年   244篇
  2005年   257篇
  2004年   285篇
  2003年   225篇
  2002年   235篇
  2001年   81篇
  2000年   89篇
  1999年   64篇
  1998年   40篇
  1997年   40篇
  1996年   39篇
  1995年   43篇
  1994年   29篇
  1993年   13篇
  1992年   39篇
  1991年   39篇
  1990年   35篇
  1989年   34篇
  1988年   26篇
  1987年   29篇
  1986年   39篇
  1985年   41篇
  1984年   13篇
  1983年   24篇
  1982年   12篇
  1981年   8篇
  1979年   12篇
  1978年   6篇
  1977年   8篇
  1976年   11篇
  1974年   8篇
  1973年   6篇
  1972年   6篇
排序方式: 共有4464条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
One diagnostic criterion for metabolic syndrome is obesity from the accumulation of visceral fat; others include abdominal circumference and area of visceral fat as measured by computed tomography (CT) at the umbilical level. We evaluated visceral fat using frequency-selective excitation magnetic resonance (MR) imaging SPAIR (spectral attenuation with inversion recovery) water suppression THRIVE (3D T1-high resolution isotropic volume examination). Fifty of 70 slices with 2-mm interval were used to render and measure volume of visceral fat ranging within 10 cm of the umbilicus; the area of visceral fat at the umbilical level was also measured. Imaging was completed using breath hold within 14 s. Image processing was easier than using CT.  相似文献   
5.
Congenital absence of the portal vein (CAPV) is a rare malformation of the splanchnic venous system. Although CAPV is usually detected in the pediatric age group, our patient was a 35-year-old woman. She had been diagnosed with CAPV in 1996 when she was 27 years old. In 1998, she was placed on hemodialysis due to chronic renal failure. After several episodes of encephalopathy in 2002, liver transplantation (LT) was recommended to her and her family. Since there was no suitable living donor candidate, she was put on the waiting list for a deceased donor liver transplant in Japan. In 2004, her ammonia level increased to around 300 microg/dl, and she went into a coma lasting for three days. After recovering from this event, she underwent a living domino transplantation using a whole liver donated by a familial amyloid polyneuropathy (FAP) patient. Her portal vein, which had drained directly into the inferior vena cava (IVC), was transected together with a cuff of the IVC wall and anastomosed to the graft liver portal vein in an end-to-end fashion. In conclusion, liver transplantation proved to be a safe and effective way to save this patient and improve her quality of life.  相似文献   
6.
The endogenous hallucinogen, N,N-dimethyltryptamine (DMT), was labeled with carbon-11 and its regional distribution in rat brain studied. [11C]DMT showed higher accumulation in the cerebral cortex, caudate putamen, and amygdaloid nuclei. Studies of the subcellular distribution of [11C]DMT revealed the specific localization in the fractions enriched with serotonin receptors only when a very low dose was injected into rats. The proportions of the radioactivity in receptor-rich fractions were greatly enhanced by pretreatment with the monoamine oxidase inhibitor, pargyline. Specific binding of [11C]DMT to serotonin receptors in dog brain was demonstrated by a positron emission tomographic study in which 5-methoxy-N,N-dimethyltryptamine caused approximately 20% displacement of the radioligand from the receptors.  相似文献   
7.
The role of several hippocampal innervations in the sensitivity to barbital-induced narcosis was studied in selected mice strains. The outbred and inbred mouse strains HS/Ibg, SABRA/HUC, C57BL, CBA/LAC, and BALB/c were tested for barbital-induced sleep (315 mg/kg). The relatively short sleeping HS/Ibg (HS) and the longest sleeping BALE/c (BALE) were chosen for further investigation. Cholinergic (ACh), serotonergic (5-HT), and noradrenergic (NE) innervations were studied in HS strain; whereas BALE, which possesses both an unusually high sensitivity to barbital and unique NE innervations in the cortex and hippocampus, was employed in a detailed study of the NE innervations. Transplantation of embryonic NE cells from the mouse embryo into the hippocampus of adult HS mice increased barbital narcosis by 65% (p < 0.05), whereas transplantation of 5-HT cells decreased barbital narcosis by 54% (p < 0.001). Transplantation of ACh cells had no significant effect on barbital-induced narcosis. BALB mice were subjected to NE cell transplantation into the hippocampus and cortex. Similarly to HS, BALB receiving NE transplants into their hippocampus slept 34% longer than control after barbital challenge (p < 0.025). Noradrenergic cell transplantation into frontal cortex had no effect on barbital sleep. The results suggest that (a) enhancement by neural grafting of the NE innervation to the hippocampus accentuates and enhancement of the 5-HT innervations attenuates the sensitivity to barbital narcosis, whereas ACh innervations have no effect on the sensitivity to barbital narcosis, and (b) the unusually high sensitivity of BALB mice to barbital may not be related to its unique NE innervations.  相似文献   
8.
T Takemoto  H Yanai 《Gan no rinsho》1986,32(10):1077-1081
It is obvious that surgical resection is a superior therapy for gastric cancer. In this sense, endoscopic therapy could be regarded as an orphan in this field. However, in the combination of endoscopic therapy and ultrasonic endoscopy, endoscopic therapy for gastric cancer should be acknowledged to be equal to surgical therapy. We have treated early gastric cancer by means of endoscopical photocoagulation using a Nd-YAG laser, particularly in inoperable cases due to other complication or old age. Forty-seven lesions found in 41 patients have so far been photocoagulation and followed up. By this treatment, cancer cells disappeared in 42 out of 47 lesions, although 2 cases died of other diseases and recurrence was experienced in 3 cases. In addition to photocoagulation therapy using a laser, we have recently developed a large-biopsy technique called strip biopsy in order to get sufficient tissue for diagnosis in comparison with bite biopsy. By this method, we are able to resect the full thickness of the mucosa including the submucosal layer up to a size of about 4 cm, without any severe complication such as hemorrhage and perforation. We succeeded in resecting the early gastric cancer in 34 lesion in 31 patients. The combination therapy of endoscopical photocoagulation and strip biopsy seems to be reasonable for the therapy of early gastric cancer.  相似文献   
9.
Chondroid syringoma of the vulva is an extremely rare tumor. Of the previously reported cases, only one was clinically malignant. The authors describe a case of chondroid syringoma of the right labium majus from which arose a papillary adenocarcinoma. A right inguinal lymph node was replaced with metastatic adenocarcinoma.  相似文献   
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