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   94篇
  免费   5篇
  国内免费   22篇
儿科学   2篇
妇产科学   6篇
基础医学   7篇
口腔科学   1篇
临床医学   14篇
内科学   2篇
神经病学   26篇
外科学   12篇
综合类   11篇
预防医学   12篇
眼科学   9篇
药学   14篇
中国医学   2篇
肿瘤学   3篇
  2022年   1篇
  2021年   2篇
  2020年   1篇
  2019年   3篇
  2018年   2篇
  2017年   1篇
  2015年   1篇
  2014年   1篇
  2013年   2篇
  2012年   2篇
  2011年   10篇
  2009年   1篇
  2008年   2篇
  2007年   10篇
  2006年   5篇
  2005年   6篇
  2004年   6篇
  2003年   8篇
  2002年   2篇
  2001年   5篇
  2000年   2篇
  1999年   3篇
  1998年   4篇
  1997年   2篇
  1996年   3篇
  1994年   2篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
  1990年   1篇
  1989年   1篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1978年   1篇
  1977年   1篇
  1974年   2篇
  1973年   5篇
  1972年   3篇
  1970年   1篇
  1969年   1篇
  1967年   5篇
  1966年   2篇
  1965年   1篇
排序方式: 共有121条查询结果,搜索用时 15 毫秒
1.
The nucleocapsid (N) protein of SARS-coronavirus (SARS-CoV) is the key protein for the formation of the helical nucleocapsid during virion assembly. This protein is believed to be more conserved than other proteins of the virus, such as spike and membrane glycoprotein. In this study, the N protein of SARS-CoV was expressed in Escherichia coli DHSalpha and identified with pooled sera from patients in the convalescence phase of SARS. A plasmid pCI-N, encoding the full-length N gene of SARS-CoV, was constructed. Expression of the N protein was observed in COS1 cells following transfection with pCI-N. The immune responses induced by intramuscular immunization with pCI-N were evaluated in a murine model. Serum anti-N immunoglobutins and splenocytes proliferative responses against N protein were observed in immunized BALB/c mice. The major immunoglobulin G subclass recognizing N protein was immunoglobulin G2a, and stimulated splenocytes secreted high levels of gamma interferon and IL-2 in response to N protein. More importantly, the immunized mice produced strong delayed-type hypersensitivity (DTH) and CD^8+ CTL responses to N protein.  相似文献   
2.
204 infants with birthweights between 751 and 2000 g and 26-35 weeks gestational age (100 treated and 104 control subjects) were enrolled in a prospective controlled trial of the effectiveness of D-penicillamine (DPA) in the prevention of retinopathy of prematurity (ROP). The two groups did not differ significantly in gestational age, birth weight, Apgar scores, the time of exposure to oxygen and in the incidence of PDA or in the number of exchange transfusions and RBTs. Of the treated infants 29, and of the control infants 34 died before the tenth week of life. These cases were not included in further analysis. Patients were subsequently examined and assessed by two ophthalmologists independently, who did not know which babies were receiving DPA. Six of the 70 surviving control infants and none of the 71 surviving treated infants had ROP stage II or graver. The results suggested that ROP may effectively be prevented with DPA in very low-birth-weight-infants, and that the drug has no serious adverse effects during the neonatal period.  相似文献   
3.
Small moving sensations, so-called moving phosphenes are perceived, when V5, a visual area important for visual motion analysis, is stimulated by transcranial magnetic stimulation (TMS). However, it is still a matter of debate if only V5 takes part in movement perception or other visual areas are also involved in this process. In this study we tested the involvement of V1 in the perception of moving phosphenes by applying transcranial direct current stimulation (tDCS) to this area. tDCS is a non-invasive stimulation technique known to modulate cortical excitability in a polarity-specific manner. Moving and stationary phosphene thresholds (PT) were measured by TMS before, immediately after and 10, 20 and 30 min after the end of 10 min cathodal and anodal tDCS in nine healthy subjects. Reduced PTs were detected immediately and 10 min after the end of anodal tDCS while cathodal stimulation resulted in an opposite effect. Our results show that the excitability shifts induced by V1 stimulation can modulate moving phosphene perception. tDCS elicits transient, but yet reversible effects, thus presenting a promising tool for neuroplasticity research.  相似文献   
4.
Prospective study was performed to measure the changes in calcium metabolism after kidney transplantation. 139 recipients received calcium substitution (1st group) and 81 patients were treated with alfacalcidol (2nd group). Serum Ca, P, Mg, alkaline phosphatase (AP) and intact PTH levels were determined before transplantation and at 1, 3, 6, 12 and 24 months thereafter in the two groups. Femoral and vertebral bone mineral density was measured with bone densitometer at the same period. The serum Ca level elevated and the serum P concentration decreased significantly in both group. The mean serum Mg and AP concentration changed in the normal range after the transplantation. The intact PTH level decreased significantly in both group at 2 years following transplantation. The intact PTH concentration changed from 17.1 pmol/l to 9.3 pmol/l in the 1st group, and it is decreased from 17.7 pmol/l to 7.9 pmol/l in the 2nd group. Bone densitometry showed osteoporosis in both group. At 12 months and at 24 months after kidney transplantation bone mineral density (BMD) of lumbar spine was 90.8% and 86.9% in the 1st group and 85.3% and 81% in the 2nd group. At the same time BMD of the femoral region was 84.4% and 85.5% in the 1st group and 82.0% and 81.3% in the 2nd group. The BMD did not changed significantly in the 1st compared to the 2nd group. During this period osteonecrosis was diagnosed in 6 patients in the 1st group and in 9 cases in the 2nd group. In conclusion, the serum Ca and P levels were in the normal range after kidney transplantation. The alfacalcidol treatment significantly decreased the intact PTH concentration compared to the calcium substitution. Moderate osteopenia was observed in both groups after the transplantation, despite of the administration of alfacalcidol treatment.  相似文献   
5.
Moyamoya disease is a progressive disease which involves the internal carotid arteries and its branches bilaterally. The disease is reported both in adults and in children. Moyamoya disease is frequently seen in Japanese patients having certain human leucocyte antigen (HLA) haplotypes including HLA-Aw24, Bw46 and Bw54. Twin cases are rarely reported in the literature. We hereby present the first Turkish monozygotic twins with moyamoya disease whose HLA haplotypes are A2, A9, B21, Bw22, Bw4, Bw6, Cw3, and DR2, DR4, DRw52, DRw53, Dq7. The patients with advanced disease were given nifedipine and intravenous immunoglobulin (400mg/kg/d for 5 days). During the 11 months of follow-up, the patients were attack free.  相似文献   
6.
计算机程序化的初均速法测定双黄连注射液的稳定性   总被引:2,自引:0,他引:2  
用计算机程序化的初均速法,测定了双黄连溶液中3种主要成分——绿原酸、黄苓甙、连翘甙的活化能及室温贮存期。该方法简便、快速、结果准确。对临床应用有一定价值。  相似文献   
7.
The aim of our study was to test if the electrical stimulation of the prefrontal cortex (PFC) could modify probabilistic classification learning (PCL). Transcranial direct current stimulation (tDCS) was administered to the left prefrontal and to the primary visual cortex of 22 healthy subjects while they performed a PCL task. In this task subjects learned which of two outcomes would occur on each trial after presentation of a particular combination of cues. Ten minutes of anodal, but not cathodal, stimulation improved implicit learning only when the left PFC was stimulated. Our results show that implicit PLC can be modified by weak anodal tDCS, which probably increases neural excitability, as has been shown in the motor and visual cortices previously. Our results suggest that further studies on the facilitation of learning and memory processes by tDCS are warranted.  相似文献   
8.
The authors report a case and treatment of multiple brain abscesses located in the cerebrum and cerebellum combined with subdural empyema. In conjunction with the case report, the authors review the literature on the pathogenesis of brain abscesses and discuss therapeutic strategies concerning the topic. In the case presented, the primary infection persisted in the lung causing subclinical bronchitis. The hemoculture showed evidence of Streptococcus mitis infection. Although the etiological role of this bacterium in meningitis is known, it rarely causes bacterial meningitis without underlying predisposing factors. In their case, the patient was free of the most common predisposing factors such as congenital heart disease or immunodeficiency. Following the 2 month period of latency, a rapid onset of the symptoms of intracranial inflammation could be observed: fever, headache, meningeal symptoms, focal neurological symptoms and coma. They were not able to identify any bacteria in the cerebrospinal fluid; the Streptocossus mitis could be cultivated only from the haemoculture. The cytological analysis of the cerebrospinal fluid showed typical signs of bacterial infection and the cranial Computed Tomography revealed multiple cerebral abscesses. Neurosurgical intervention was not recommended because of the number, localization and size of the focal lesions. The therapy consisted of intravenous administration of 24 x 10(6) IU/die Penicillin and 4 g/die ceftriaxon. For supportive therapy, Mannitol B, 3 mg/die clonazepam and 300 mg/die phenytoin were administered. Corticosteroids were not used during the course of therapy. Two years later the 55 year old female is symptom free and doing well.  相似文献   
9.
白花丹参化学成分的研究   总被引:30,自引:0,他引:30  
从白花丹参(Salvia miltiorrhiza f.alba)中分离出14个二萜醌类化合物,其中2个为新化合物,由光谱分析推定为1,2,15,16-四氢丹参醌(Ⅰ)和丹参醛(Ⅱ);另一个化合物Ⅲ与R0-090680的结构相同。化合物Ⅰ和Ⅲ对淋巴白血病细胞P388均有较强的抑制作用。  相似文献   
10.
目的:观察依达拉奉对深低温保存大鼠断肢再植后出现缺血再灌注损伤时的保护作用。方法:实验于2006-04/11在山东省立医院手足外科低温医学实验室完成。①选取健康成年Wistar大鼠36只,随机分为对照组、冷冻组和依达拉奉组3组,每组12只。②对照组只显露股动静脉而不结扎,其他2组大鼠截断右后肢,对断肢进行深低温冷冻保存处理(自结扎股动静脉至深低温保存约2h)。③1个月后,将冷冻保存的断肢复温、灌洗液洗脱,依达拉奉组所用灌洗液中含依达拉奉0.5mg/kg,行自体肢体回植(自液氮中取出肢体至恢复血供约2h),恢复肢体血供4h后取材,骨骼肌丙二醛含量,超氧化物歧化酶活性以及线粒体ATP酶活性,测定胫前肌含水量,光镜观察各组骨骼肌肌组织的结构改变。结果:36只全部进入结果分析。①骨骼肌丙二醛含量:依达拉奉组低于冷冻组[(10.37±1.25),(15.36±1.28)μmol/g,P<0.01]。②骨骼肌ATP酶和超氧化物歧化酶活性:依达拉奉组高于冷冻组[(206.2±45.2),(72.7±32.5)μkat/g;(83.9±5.2),(70.5±8.0)mkat/g;P均<0.01]。③胫前肌湿/干质量比值:依达拉奉组低于冷冻组(4.89±0.82,6.38±0.63,P<0.01)。④光镜结果显示依达拉奉组骨骼肌损伤程度明显轻于冷冻组。结论:依达拉奉可以降低肢体再灌注后肌肉组织中的氧自由基水平,减轻缺血再灌注对骨骼肌造成的损伤,对缺血再灌注骨骼肌具有保护作用。  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