全文获取类型
收费全文 | 3100篇 |
免费 | 225篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 48篇 |
妇产科学 | 49篇 |
基础医学 | 371篇 |
口腔科学 | 52篇 |
临床医学 | 197篇 |
内科学 | 605篇 |
皮肤病学 | 138篇 |
神经病学 | 145篇 |
特种医学 | 44篇 |
外科学 | 562篇 |
综合类 | 279篇 |
预防医学 | 176篇 |
眼科学 | 36篇 |
药学 | 297篇 |
中国医学 | 61篇 |
肿瘤学 | 313篇 |
出版年
2024年 | 7篇 |
2023年 | 56篇 |
2022年 | 89篇 |
2021年 | 138篇 |
2020年 | 101篇 |
2019年 | 217篇 |
2018年 | 175篇 |
2017年 | 115篇 |
2016年 | 81篇 |
2015年 | 93篇 |
2014年 | 180篇 |
2013年 | 164篇 |
2012年 | 119篇 |
2011年 | 179篇 |
2010年 | 140篇 |
2009年 | 164篇 |
2008年 | 137篇 |
2007年 | 141篇 |
2006年 | 141篇 |
2005年 | 106篇 |
2004年 | 88篇 |
2003年 | 93篇 |
2002年 | 54篇 |
2001年 | 62篇 |
2000年 | 46篇 |
1999年 | 35篇 |
1998年 | 30篇 |
1997年 | 28篇 |
1996年 | 23篇 |
1995年 | 23篇 |
1994年 | 15篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1988年 | 8篇 |
1987年 | 8篇 |
1986年 | 9篇 |
1985年 | 21篇 |
1984年 | 49篇 |
1983年 | 29篇 |
1982年 | 42篇 |
1981年 | 30篇 |
1980年 | 26篇 |
1979年 | 22篇 |
1978年 | 18篇 |
1977年 | 6篇 |
1976年 | 16篇 |
1975年 | 17篇 |
1974年 | 9篇 |
1973年 | 7篇 |
排序方式: 共有3400条查询结果,搜索用时 31 毫秒
21.
弓形虫主要表膜P30抗原的免疫保护作用研究 总被引:2,自引:0,他引:2
目的 研究弓形虫主要表膜P30抗原免疫小鼠所诱导的免疫性保护作用及免疫保护机制。方法 将单克隆抗体免疫亲和层析分离纯化的P30抗原免疫C57BL/6纯系小鼠,然后用弓形虫RH株速殖子和Fukaya株包衰攻击感染,观察P30抗原免疫对急性弓形虫感染鼠死亡时间及慢性感染鼠脑内包囊形成的影响,同时对感染后不同时间鼠血清特异性抗体水平、IL-2及IFN-r细胞因子水平和脾T淋巴细胞亚群动态变化进行了测试分析。结果 显示P30抗原免疫可在一定程度上延长感染小鼠的存活时间,减少脑内包囊的形成数量,增强小鼠抵抗急慢性弓形虫感染的能力。在感染后不同时期免疫鼠血清中特异性抗休还清瘃IFN-r、IL-2水平均高于同期对照鼠,而且免疫鼠脾CD4^ t CD8^ T淋纠细胞尤其是CD8^ 细胞的数量在感染早期升高较快,至感染后4周达高峰,两者的比值随感染时间的延长而逐渐下降。结论 P30抗原免疫对感染小鼠具有明显的保护作用,是细胞免疫和体液免疫共同作用的结果,尤其是细胞免疫可能发挥着更为重要的作用。 相似文献
22.
目的构建弓形虫主要表面抗原P30基因的原核表达载体并在E.coli中进行表达.方法采用定向克隆的方法,将PCR扩增得到的P30片段,插入原核表达质粒pBV220上,转化大肠杆菌DH5α感受态细胞,于氨苄LB培养平板上筛选阳性克隆,经过酶切及PCR扩增鉴定重组子.将含阳性重组子pBV220-P30的工程菌经温度诱导表达,SDS-PAGE电泳及免疫印迹分析.结果成功构建了pBV2200-P300重组质粒;SDS-PAGE电泳及Western-blot显示表达P30非融合蛋白的分子量为29kD,且能被弓形虫高免鼠血清识别.结论从弓形虫基因组DNA中获取P30基因,并成功构建了pBV220-P30重组质粒,诱导表达了P30非融合蛋白.对弓形虫病基因疫苗研制奠定了基础. 相似文献
23.
Hantavirus can cause panphilic infection in hu-man beings and proliferate especially in such impor-tantimmune organs and cells,as liver,spleen,bonemarrow,lymph nodes,thymus,lymphocyte and soon,thusresulting in immunity disturbance.CD30 is atransmembrane glycoprotein,belonging to the TNF/NGF receptor superfamily.In recent years,the bio-logical significance of CD30 elicited greatconcern.Theclose relationship between the expression of CD30antigen and theactivation and function of T cellssug-… 相似文献
24.
25.
26.
27.
brahim Deniz Canbeyli Meri rpar Birhan Okta Mehmet oban 《Acta orthopaedica et traumatologica turcica》2021,55(1):16
ObjectiveThis study aimed to evaluate the possible effects of surgical procedures on mortality and to identify the possible risk factors for mortality in the management of geriatric hip fractures.MethodsA total of 191 patients (105 women and 86 men; mean age 82.26±9.681 [60–108] years) with AO/OTA 31A2.2 intertrochanteric fractures and treated with sliding hip screw, proximal femoral nail, or hemiarthroplasty were included in this retrospective cohort study. The treatment type was decided by the responsible surgeon according to the patients’ pre-injury activity level, bone quality, and features of the fracture. Age, sex, type of fracture, type of surgery performed, American society of anesthesiology (ASA) grade, type of anesthesia, time to surgery, type of physical therapy, length of hospital stay, and number of comorbidities were documented. We evaluated the 30-day and 1-year mortality of patients treated with sliding hip screw (SHS), proximal femoral nail antirotation (PFN-A), or hemiarthroplasty and identified the possible risk factors for mortality.ResultsA total of 49 patients underwent SHS, 58 underwent PFN-A, and 84 underwent hemiarthroplasty. Of these, 2 patients with SHS, 2 with PFN-A, and 11 with hemiarthroplasty died within 30 days after surgery, whereas 7 patients with SHS, 15 with PFN-A, and 23 with hemiarthroplasty died 1 year after surgery. The 30-day and 1-year overall mortality rates were 7.9% and 23.6%, respectively. Both the 30-day and 1-year mortality risks were higher in patients undergoing hemiarthroplasty than in patients undergoing SHS (p=0.068 versus 0.058). The 30-day mortality was higher in patients receiving general anesthesia than in those receiving combined spinal and epidural anesthesia (p=0.009). The 1-year mortality risk was higher in patients with ASA grade 4 than in those with grade 1 and 2 (p=0.045). Advanced age (p=0.022) and male sex (p=0.007) were also found to be the risk factors for 1-year mortality.ConclusionWe demonstrated that higher ASA grade, male sex, general anesthesia, and hemiarthroplasty procedures are associated with higher mortality rates in elderly patients with hip fractures. Thus, we highly recommend orthopedic surgeons to consider all these factors in the management of intertrochanteric hip fractures in the geriatric population.Level of EvidenceLevel IV, Prognostic Study 相似文献
28.
目的 制备抗弓形虫主要表膜P30抗原单克隆抗体(Mc-Ab)半进行鉴定,为弓形虫病的诊断、抗原的提纯及亚单位疫苗的研制等提供可靠依据。方法 用RH株弓形虫速殖子膜抗原为免疫BALB/C小鼠,取其脾细胞与小鼠SP2/0骨髓瘤细胞融合,筛选出能够稳定分泌高滴度抗P30抗原McAb杂交瘤细胞株,并测定Mc-Ab免疫球蛋白亚类和单抗效价,用IFAT进行单抗识别的抗原定们,并通过SDS-PAGE和Weste 相似文献
29.
An echovirus 30 outbreak with a high meningitis attack rate among children and household members at four day-care centers 总被引:2,自引:0,他引:2
U.C. Vieth M. Kunzelmann S. Diedrich H. Timm A. Ammon O. Lyytikäinen L.R. Petersen 《European journal of epidemiology》1999,15(7):655-658
Echovirus 30 (E 30) outbreaks in defined cohorts have rarely been reported. In June 1996, an outbreak of E 30 occurred in four day-care centers (DCCs) in neighboring villages in Germany. A retrospective cohort study of DCC children, employees and household members was done to determine the extent of the outbreak and risk factors for illness. Forty-two percent (39/92) of DCC children, 13% (30/228) of their household members, 5% (1/19) of employees and 2% (1/49) of household members of employees were ill. Onsets occurred over 31 days. Thirteen percent (12/92) of DCC children had meningitis. In only one of 16 households with multiple family members ill, illness in a family member preceeded that of the DCC child. Household members of ill DCC children were 15 times more likely to report illness than those of non-ill DCC children. We conclude that this outbreak was associated with a very high incidence of meningitis, the outbreak began in the DCCs and then spread to household members, and that household members of ill children compared to those of non-ill children were much more likely to report illness. 相似文献
30.
The focus of the paper is to describe how to present data from studies on health-related quality of life (H-QoL) in a way that is simple and clinically relevant. Data from a longitudinal study of patients with advanced stages of cervix cancer are used. One hundred and eighteen patients filled out questionnaires (including EORTC QLQ-C30) 7 times over a period of 2 years. The following issues are considered: (1) The use of a panel for an initial overview of data. (2) The visual difference between using mean and median values. (3) Box-whisker plots to illustrate the variability of the data. (4) The effect of combining categorical data into fewer categories. (5) Individual patient profiles showing the wide variability among patients. (6) A table showing the change of scores over a one-year period. (7) “Prognostic plots” dividing the initial scores and the following scores. (8) Plotting changes over time. (9) Illustration of the impact of non-random drop-out. (10) The effect of drop-out for the patients who fill out two sequential assessments. (11) The use of healthy controls to help answer the question “what is normal?”. 相似文献