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   3937篇
  免费   271篇
  国内免费   6篇
耳鼻咽喉   13篇
儿科学   154篇
妇产科学   59篇
基础医学   682篇
口腔科学   110篇
临床医学   330篇
内科学   1025篇
皮肤病学   51篇
神经病学   235篇
特种医学   113篇
外科学   474篇
综合类   14篇
预防医学   164篇
眼科学   95篇
药学   296篇
中国医学   21篇
肿瘤学   378篇
  2023年   39篇
  2022年   51篇
  2021年   90篇
  2020年   41篇
  2019年   59篇
  2018年   74篇
  2017年   56篇
  2016年   81篇
  2015年   101篇
  2014年   103篇
  2013年   144篇
  2012年   262篇
  2011年   253篇
  2010年   151篇
  2009年   131篇
  2008年   205篇
  2007年   222篇
  2006年   221篇
  2005年   221篇
  2004年   206篇
  2003年   180篇
  2002年   188篇
  2001年   102篇
  2000年   88篇
  1999年   79篇
  1998年   45篇
  1997年   28篇
  1996年   36篇
  1995年   33篇
  1994年   23篇
  1993年   26篇
  1992年   74篇
  1991年   70篇
  1990年   48篇
  1989年   37篇
  1988年   39篇
  1987年   44篇
  1986年   37篇
  1985年   41篇
  1984年   19篇
  1983年   17篇
  1979年   31篇
  1978年   10篇
  1977年   11篇
  1974年   12篇
  1973年   11篇
  1971年   11篇
  1969年   17篇
  1968年   13篇
  1967年   11篇
排序方式: 共有4214条查询结果,搜索用时 22 毫秒
91.
Adeno-associated virus (AAV) vector system has several useful advantages with regard to in vitro and in vivo gene transfer. However, their usages have been limited by cumbersome and labor-intensive vector production in the traditional method. To overcome limitations in AAV production, in this report, we explored the possibility of generating AAV packaging cell line, 293T R/C.VA.E2A.E4. cells, by using lentivirus-mediated transduction of Rep/Cap gene of AAV-2, VA RNA, E2A, and E4 genes of Ad5 into 293T cells. In packaging cell lines, it is important that supply of the AAV vector can be stably performed for long time. We showed that the 293T R/C.VA.E2A.E4. cells have stably maintained the transduced components after more than 10 passages and yielded high-titer AAV vectors, and the titer of AAV vectors did not decline even if culture of the packaging cells was continued for long time. The Rep/Cap and E4 gene products caused no remarkable cytotoxicity. The 293T R/C.VA.E2A.E4. cells might be able to tolerate the Rep/Cap and E4 gene products, or have less copy numbers of the Rep/Cap and E4 genes than the traditional method. Moreover, we showed that the AAV vectors derived from 293T R/C.VA.E2A.E4. cells infected the primary human CD34+ haematopoietic progenitor cells with high efficiency (50-70%). In the 293T R/C.VA.E2A.E4. cells, the AAV vectors can be generated by the transfection of one AAV vector plasmid, and large-scale AAV production can be easily achieved. It is important that cumbersome, variable, and costly transfection is avoided.  相似文献   
92.
93.
Hypertension contributes to the occurrence and progression of cardiovascular diseases. The angiotensin II type 1 receptor blocker telmisartan is reported to activate the peroxisome proliferator-activated receptor gamma and improve insulin sensitivity. We investigated the effects of telmisartan treatment on visceral fat, serum adiponectin and vascular inflammation markers in Japanese hypertensive patients. This was an open-label, non-controlled study. Twenty-eight essential hypertensive patients (22 men and 6 women; age 60.6+/-1.9 years; body mass index [BMI] 25.5+/-0.6 kg/m(2)) participated. Fat area was assessed with computerized tomography. All the subjects were started on telmisartan 40 mg/day, which was increased to 80 mg/day to achieve the blood pressure target of less than 130/80 mmHg. We assessed the visceral and subcutaneous fat areas, serum adiponectin levels, and vascular inflammation markers at baseline and 24 weeks of telmisartan treatment. There were significant reductions in visceral fat area (from 103.1+/-7.9 to 93.3+/-8.4 cm(2), p<0.01) and pulse wave velocity (from 1,706+/-52 to 1,587+/-51 cm/s, p<0.01) at 24 weeks. In contrast, significant increases in serum high-density lipoprotein cholesterol (from 5.06+/-0.15 to 5.32+/-0.13 mmol/L, p<0.05) and adiponectin levels (from 8.27+/-0.76 to 9.13+/-0.81 microg/mL, p<0.05) were observed. Also, there were reductions in the interleukin-6 level (from 2.26+/-0.27 to 1.60+/-0.14 pg/mL, p<0.01). We also conducted these investigations in male subjects alone and similar findings were obtained for all of these parameters. In conclusion, telmisartan treatment was associated with an improvement of vascular inflammation, reductions in visceral fat and increases in serum adiponectin.  相似文献   
94.
95.
96.
The management of LSRS is a crucial problem to ensure a sufficient PV flow during pediatric LT. Although several techniques have been indicated to solve this problem, a more appropriate approach to LSRS is still needed in pediatric LT. We herein present a modified surgical approach to the ligation of LSRS via the left side of the IVC for a nine‐month‐old boy with severe portal hypertension and a history of Kasai portoenterostomy. LSRS was identified and exposed through the left side of the IVC and the dorsal surface of the pancreas from the superior side of the body of the pancreas. The post‐operative course was uneventful with an excellent PV flow. The central approach for the ligation of LSRS is worth considering as an alternative procedure for a patient with collateral vessels and a history of multiple laparotomies.  相似文献   
97.
98.
PC is produced in the liver and inhibits blood coagulation by catalyzing active factors V and VIII. PC deficiency causes abnormal blood clotting that is difficult to regulate by anticoagulative treatments. Four reports of PC deficiency treated with LTx have been published; however, no report of DLT as a therapy for PC deficiency is available. We describe a case of a 23‐month‐old girl who received DLT for compound heterozygous PC deficiency. Her PC activity was below 5%. She developed intracranial lesion and frequent refractory purpura fulminans. Both her parents had heterozygous mutations of PC genes and were excluded as living donors. Furthermore, she was a low priority on the waiting list of deceased‐donor transplantation. We performed living DLT using the liver from a patient with MSUD. Activated PC concentrate safely supported the perioperative period. After DLT, she maintained normal PC activities and BCAA levels. This is the first case of PC deficiency successfully treated by living DLT with MSUD. We propose that DLT using liver from patients with MSUD is a treatment option for PC deficiency.  相似文献   
99.
Taurine neurons and their dendrites and axons were visualized in the mammalian cerebellum by autoradiography, after in vivo injections of [3H]taurine directly into the cerebellar cortex or deep cerebellar nuclei, and by immunocytochemistry at the light- and electron-microscope levels with antibodies against cysteine-sulfinic acid decarboxylase (CSADCase; L-cysteine-sulfinate carboxylyase, EC 4.1.1.29). Uptake and sequestration of [3H]taurine labeled numerous Purkinje cell somata, primary dendrites, and axons; many granule cell somata, dendrites, and parallel fibers; stellate, basket, and Golgi cells; the larger neurons in all deep cerebellar nuclei; the largest neurons in the lateral vestibular nucleus; and, more rarely, Purkinje cell axonal terminals in the neuropil. The label at all sites was diminished by preinjection into the cerebellum of hypotaurine, p-chloromercuriphenylsulfonic acid, or β-alanine, and was virtually eliminated by strychnine. Immunocytochemical labeling with polyclonal antibodies directed against CSADCase, the enzyme responsible for the synthesis of hypotaurine from cysteine sulfinic acid and taurine from cysteic acid, had a similar distribution. In electron micrographs, immunoreactivity within Purkinje cell somata and dendrites was localized to the Golgi apparatus, the inner plasma membrane, and condensed nonmembranous foci (120 nm in diameter) marked by clumps of peroxidase reaction product. Large Nissl bodies were usually not CSADCase immunoreactive. Numerous immunoreactive granule cells, dendrites, and parallel fibers were recognized. Pretreatment of the animals with colchicine increased the intensity of CSADCase immunoreactivity but did not change the number or distribution of labeled cells. These experiments indicate that taurine is synthesized and involved in a specific uptake process by cerebellar neurons. Neuroglial cells do not synthesize taurine but some neuroglia take up [3H]taurine. These findings call for a reexamination of the physiological function of taurine in the cerebellum. A hypothesis is proposed that taurine may be involved in the regulation of calcium, in dendritic spike generation, and in the inhibition of impulse propagation in major Purkinje cell dendrites.  相似文献   
100.
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