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   10412篇
  免费   579篇
  国内免费   101篇
耳鼻咽喉   106篇
儿科学   212篇
妇产科学   109篇
基础医学   1279篇
口腔科学   182篇
临床医学   611篇
内科学   2973篇
皮肤病学   119篇
神经病学   778篇
特种医学   485篇
外科学   1811篇
综合类   40篇
预防医学   321篇
眼科学   161篇
药学   629篇
中国医学   14篇
肿瘤学   1262篇
  2023年   58篇
  2022年   162篇
  2021年   276篇
  2020年   165篇
  2019年   204篇
  2018年   283篇
  2017年   205篇
  2016年   267篇
  2015年   294篇
  2014年   368篇
  2013年   412篇
  2012年   728篇
  2011年   683篇
  2010年   402篇
  2009年   352篇
  2008年   553篇
  2007年   472篇
  2006年   531篇
  2005年   503篇
  2004年   496篇
  2003年   486篇
  2002年   505篇
  2001年   253篇
  2000年   234篇
  1999年   233篇
  1998年   138篇
  1997年   126篇
  1996年   103篇
  1995年   76篇
  1994年   58篇
  1993年   66篇
  1992年   157篇
  1991年   145篇
  1990年   116篇
  1989年   120篇
  1988年   87篇
  1987年   74篇
  1986年   82篇
  1985年   79篇
  1984年   65篇
  1983年   56篇
  1982年   32篇
  1980年   23篇
  1979年   51篇
  1978年   23篇
  1977年   32篇
  1976年   24篇
  1974年   26篇
  1971年   22篇
  1969年   21篇
排序方式: 共有10000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.
A new method for protecting intestinal anastomoses in patients at high risk of anastomotic dehiscence or fistula formation is described herein. This method involves raising a seromuscular flap on a pedicle from the stump of the intestine to be anastomosed. The anastomosis is performed, then covered with the seromuscular flap.  相似文献   
7.
CYP2E1 and ALDH2 Genotypes and Alcohol Dependence in Japanese   总被引:2,自引:0,他引:2  
The genotypes of the CYP2E1 and ALDH2 loci of alcoholic (alcohol dependence) and nonalcoholic (healthy) Japanese were investigated to examine the relationship between the polymorphism of CYP2E1 (C1/C2) and ALDH2 ( ALDH2*1/ALDH2*2 ), and the susceptibility to alcoholism. There was no significant difference in C2 gene frequency between alcoholics (0.19) and nonalcoholics (controls) (0.20), whereas there was a significant difference in ALDH2 allele frequency, suggesting that, in Japanese, the C2 genotype of CYP2E1 may have nothing to do with the risk of developing alcohol dependence. However, the ALDH2*1 allele may influence drinking behavior and the development of alcohol dependence. Furthermore, racial interethnic differences in the frequency of the mutated allele of the CYP2E1 gene (CJ were found, like the ALDH2 gene. Japanese healthy controls showed a significantly higher frequency of the C2 allele than did Swedish healthy controls (0.05; reported by Persson et al., FEBS Lett. 319:207-211,1993).  相似文献   
8.
The presence of cytochrome P-45011 beta in rat brain was studied by immunohistochemistry using polyclonal rabbit antibodies raised against purified bovine adrenocortical P-45011 beta, which is involved in the steroid 11 beta-hydroxylation and glucocorticoid formation. The results showed that cytochrome P-45011 beta immunoreactivity is selectively localized to the tracts of myelinated fibers throughout the brain. The specificity of immunohistochemical stainings with P-45011 beta antibodies was established by control tests including nonimmune rabbit immunoglobulin Gs and P-45011 beta antibodies absorbed with purified antigen. Western immunoblots of homogenates from different brain areas with P-45011 beta antibodies, together with biochemical enzymatic assays for cytochrome P-45011 beta monooxygenase activity in these homogenates, confirmed the selective localization of this enzyme observed with immunohistochemistry. Cytochrome P-45011 beta and 11 beta-hydroxylase activity were detected in a homogenate from the cortical white matter (brain area rich in myelinated fibers) as in that from the rat adrenal, but were not detectable in a homogenate from the cerebral cortex (brain area poor in myelinated fibers). Furthermore, quantitation of the P-45011 beta bands on the immunoblots by the areal density revealed that the cortical white matter contains approximately 1.4 pmol of cytochrome P-45011 beta/mg of tissue protein, the value of which was about one sixth of the corresponding value estimated in the rat adrenal. This relatively high content of cytochrome P-45011 beta was also reflected in a relatively high level of 11 beta-hydroxylase activity measured in a homogenate of this brain area by biochemical enzymatic assays using [4-14C]-11-deoxycorticosterone.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
9.
We report here a 76-year-old male that presented with an immediate allergy to Anisakis following saury intake. Three and a half hours after eating pressed saury sushi, whole-body pomphus appeared including itching, facial dropsical swelling, and dyspnea. Diagnostic tests revealed specific IgE antibodies against anisakis simplex and a skin prick test was positive using an extraction of anisakis simplex. The results of skin prick tests using the body and internal organs of a saury were negative. Based on these results, we diagnosed the case as immediate allergy to Anisakis. Anisakis is parasitic to a diverse array of fish, and it seems rare that eating saury will induce an allergic response because the reported parasitic rate of Anisakis on saury is only 5%. In addition, as tropomyosin is currently considered to be the primary cause of allergies to Anisakis, renewed attention should be paid to other foods for which tropomyosin is also assumed to be a common antigen.  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