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   7374篇
  免费   423篇
  国内免费   71篇
耳鼻咽喉   85篇
儿科学   168篇
妇产科学   81篇
基础医学   970篇
口腔科学   86篇
临床医学   485篇
内科学   1986篇
皮肤病学   78篇
神经病学   559篇
特种医学   277篇
外科学   1389篇
综合类   22篇
预防医学   207篇
眼科学   151篇
药学   391篇
中国医学   4篇
肿瘤学   929篇
  2023年   44篇
  2022年   102篇
  2021年   230篇
  2020年   133篇
  2019年   178篇
  2018年   245篇
  2017年   172篇
  2016年   217篇
  2015年   225篇
  2014年   263篇
  2013年   342篇
  2012年   537篇
  2011年   509篇
  2010年   309篇
  2009年   250篇
  2008年   413篇
  2007年   358篇
  2006年   401篇
  2005年   387篇
  2004年   350篇
  2003年   404篇
  2002年   381篇
  2001年   133篇
  2000年   130篇
  1999年   115篇
  1998年   95篇
  1997年   92篇
  1996年   72篇
  1995年   67篇
  1994年   43篇
  1993年   47篇
  1992年   75篇
  1991年   68篇
  1990年   60篇
  1989年   53篇
  1988年   50篇
  1987年   40篇
  1986年   37篇
  1985年   25篇
  1984年   25篇
  1983年   26篇
  1982年   16篇
  1981年   13篇
  1980年   14篇
  1979年   13篇
  1978年   12篇
  1975年   9篇
  1973年   8篇
  1967年   11篇
  1966年   13篇
排序方式: 共有7868条查询结果,搜索用时 15 毫秒
1.
2.
3.
Two cultivars of Japanese parsley were harvested in different seasons; their antioxidant capacities were evaluated by oxygen radical absorbance capacity (ORAC) methods, and the contents of hydrophilic and lipophilic antioxidants were compared. Japanese parsley possessed potent antioxidant capacities both in hydrophilic and lipophilic extracts when evaluated by ORAC methods. LC/MS/MS analyses revealed that chlorogenic acid and four kinds of quercetin glycosides were major antioxidants in the hydrophilic extract. Lutein was the main contributor to the antioxidant capacity of the lipophilic extract. Antioxidant capacities of the hydrophilic extracts of both cultivars tended to be higher in winter because of the increase in the contents of chlorogenic acid and quercetin glycosides. An obvious trend in the lipophilic antioxidant capacities or lutein contents was not observed irrespective of the cultivar.  相似文献   
4.
A Bochdalek hernia (BH) is a congenital abnormality with incomplete closure of the diaphragm. It is usually manifested in infants but rarely in adults. Here, we report an adult patient with gastric volvulus and giant BH that were safely repaired by endoscopic reduction and elective laparoscopic surgery, respectively. A 79-year-old woman presented with left upper abdominal pain but no history of trauma. CT revealed a giant BH with gastric volvulus. After emergency endoscopic reduction of the volvulus, elective laparoscopic repair of the BH was performed. The 8 × 8-cm defect was repaired with interrupted nonabsorbable sutures and a mesh. The patient's postoperative course was uneventful, and no complications or recurrence were observed in the 6 months that followed.  相似文献   
5.
Context: We sought to describe our experience with the Hybrid Assistive Limb® (HAL®) for active knee extension and voluntary ambulation with remaining muscle activity in a patient with complete paraplegia after spinal cord injury.

Findings: A 30-year-old man with complete paraplegia used the HAL® for 1 month (10 sessions) using his remaining muscle activity, including hip flexor and upper limb activity. Electromyography was used to evaluate muscle activity of the gluteus maximus, tensor fascia lata, quadriceps femoris, and hamstring muscles in synchronization with the Vicon motion capture system. A HAL® session included a knee extension session with the hip flexor and voluntary gait with upper limb activity. After using the HAL® for one month, the patient’s manual muscle hip flexor scores improved from 1/5 to 2/5 for the right and from 2/5 to 3/5 for the left knee, and from 0/5 to 1/5 for the extension of both knees.

Conclusion/clinical relevance: Knee extension sessions with HAL®, and hip flexor and upper-limb-triggered HAL® ambulation seem a safe and feasible option in a patient with complete paraplegia due to spinal cord injury.  相似文献   

6.
7.
Severe myoclonic epilepsy (SMEI) or Dravet syndrome is caused by mutations of the SCN1A gene that encodes voltage-gated sodium channel alpha-1 subunit. Recently, we generated and characterized a knock-in (KI) mice with an SCN1A nonsense mutation that appeared in three independent SMEI patients. The SCN1A-KI mice well reproduced the SMEI disease phenotypes. Both homozygous and heterozygous knock-in mice developed epileptic seizures within the first postnatal month. In heterozygous knock-in mice, trains of evoked action potentials in inhibitory neurons exhibited pronounced spike amplitude decrement late in the burst but not in pyramidal neurons. We further showed that in wild-type mice the Nav1.1 protein is expressed dominantly in axons and moderately in somata of parbalbumin (PV) – positive inhibitory interneurons. Our immunohistochemical observations of the Nav1.1 are clearly distinct to the previous studies, and our findings has corrected the view of the Nav1.1 protein distribution. The data indicate that Nav1.1 plays critical roles in the spike output from PV interneurons and further, that the specifically altered function of these inhibitory circuits may contribute to epileptic seizures in the mice. These information should contribute to the understanding of molecular pathomechanism of SMEI and to develop its effective therapies.  相似文献   
8.
BACKGROUND: Food protein-induced enterocolitis syndrome (FPIES) is a severe, cell-mediated food allergy in which digestive symptoms such as severe vomiting and diarrhea are induced by cow's milk and/or soy protein in infants. Generally, a food-specific IgE is not detected, and FPIES may be caused by inadvertent exposure to allergenic foods. CASE SUMMARY: The patient in our case was a male infant in whom vomiting had been induced by ingestion of a cow's milk-based formula and bloody diarrhea had been caused by ingestion of breast milk during the neonatal period. Accidental ingestion of a new and extensively hydrolyzed casein/whey formula, MA-mi, caused watery diarrhea at 8 months of age, and FPIES was diagnosed based on these symptoms. In antigen-specific lymphocyte stimulation tests, New MA-1 was negative, but MA-mi and cow's milk antigens were positive. The only causative antigens were derived from cow's milk, and the symptoms were not induced by another extensively hydrolyzed casein formula, New MA-1. The patient grew and developed normally thereafter, and no symptoms were induced by solid food during the course of the condition. DISCUSSION: MA-mi is likely to be used increasingly for allergic infants, but it is not necessarily a substitute for other hydrolyzed milk formulae in all cases, and care should be taken regarding its use and possible misuse.  相似文献   
9.
Background In cases of synchronous colorectal hepatic metastases, the primary colorectal cancer strongly influences on the metastases. Our treatment policy has been to conduct hepatic resection for the metastases at an interval of 3 months after colorectal resection. We examined the appropriateness of interval hepatic resection for synchronous hepatic metastasis. Materials and methods The subjects were 164 patients who underwent resection of hepatic metastasis of colorectal cancer (synchronous, 70 patients; metachronous, 94 patients). Background factors for hepatic metastasis and postoperative results were compared for synchronous and metachronous cases. Results The cumulative survival rate for 164 patients at 3, 5, and 10 years postoperatively was 71.9%, 51.8%, and 36.6%, and the post-resection recurrence rate in remnant livers was 26.8%. Interval resection for synchronous hepatic metastases was conducted in 49 cases after a mean interval of 131 days. No difference was seen in postoperative outcome between synchronous and metachronous cases. Conclusion The outcome was similarly favorable in cases of synchronous hepatic metastasis and in cases of metachronous metastasis. Delaying resection allows accurate understanding of the number and location of hepatic metastases, and is beneficial in determining candidates for surgery and in selecting surgical procedure.  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