全文获取类型
收费全文 | 2025篇 |
免费 | 150篇 |
国内免费 | 63篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 145篇 |
妇产科学 | 79篇 |
基础医学 | 262篇 |
口腔科学 | 46篇 |
临床医学 | 164篇 |
内科学 | 314篇 |
皮肤病学 | 44篇 |
神经病学 | 104篇 |
特种医学 | 312篇 |
外科学 | 241篇 |
综合类 | 69篇 |
预防医学 | 118篇 |
眼科学 | 13篇 |
药学 | 183篇 |
肿瘤学 | 107篇 |
出版年
2022年 | 10篇 |
2021年 | 17篇 |
2020年 | 10篇 |
2019年 | 19篇 |
2018年 | 35篇 |
2017年 | 16篇 |
2016年 | 23篇 |
2015年 | 32篇 |
2014年 | 46篇 |
2013年 | 53篇 |
2012年 | 59篇 |
2011年 | 70篇 |
2010年 | 46篇 |
2009年 | 51篇 |
2008年 | 54篇 |
2007年 | 96篇 |
2006年 | 55篇 |
2005年 | 67篇 |
2004年 | 58篇 |
2003年 | 57篇 |
2002年 | 51篇 |
2001年 | 68篇 |
2000年 | 68篇 |
1999年 | 66篇 |
1998年 | 71篇 |
1997年 | 81篇 |
1996年 | 77篇 |
1995年 | 83篇 |
1994年 | 53篇 |
1993年 | 64篇 |
1992年 | 49篇 |
1991年 | 52篇 |
1990年 | 52篇 |
1989年 | 89篇 |
1988年 | 64篇 |
1987年 | 52篇 |
1986年 | 48篇 |
1985年 | 53篇 |
1984年 | 25篇 |
1983年 | 20篇 |
1982年 | 25篇 |
1981年 | 26篇 |
1980年 | 24篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1977年 | 17篇 |
1976年 | 15篇 |
1975年 | 8篇 |
1973年 | 5篇 |
1969年 | 4篇 |
排序方式: 共有2238条查询结果,搜索用时 15 毫秒
31.
背景/目的:术前通过血管影像学检查对拟行肝移植术的儿童进行评价存在很大的差异。采用二维多普勒超声扫描(US)、磁共振血管造影术(M R A)和常规血管造影术评价血管变化范围。作者通过比较术前的血管成像结果和术中所见,从而确定这些检查的精确度和有效性。方法:将37例接受尸体 相似文献
32.
Zhao P Cao J Zhao LJ Qin ZL Ke JS Pan W Ren H Yu JG Qi ZT 《第二军医大学学报》2006,27(5):506-506
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
33.
千层塔中三萜成分的研究 总被引:5,自引:0,他引:5
前曾报道自千层塔[Huperzia serrata Thunb.(Trev)=Lycopodium serratum Thunb(Trev.)]中分得具有胆碱酯酶抑制活性的新生物碱——石杉碱甲、石杉碱乙、甲基石杉碱乙及已知生物碱8-deoxyserratinine,serratinine,lycodoline及lycoclavine。为进一步阐明该植物的化学成分,我们对其三萜成分进行了研究。从浙江安吉产的千层塔植物中分到六个石松三萜,其中一个为新化合物,经下述方法推定为serratenediol-21-acetate(Ⅰ)。另五 相似文献
34.
本文报道我国西南产麻黄——丽江麻黄Ephedra likiangensis Florin、匍枝丽江麻黄E.likiangensis f.mairei(Florin)C.Y.Cheng、藏麻黄E.saxatilis Royle ex Florin、山岭麻黄E.gerardiana Wall、垫状山岭麻黄E.gerardiana Var.congesta C.Y.Cheng、矮麻黄E.minuta Florin和异株矮麻黄E.minuta var.dioeca C.Y.Cheng,以及形态组织特征较特殊的宁夏产斑子麻黄E.lepidosperma C.Y.Cheng、新疆产窄膜麻黄E.lomatolepis Schrenk,西藏产西藏中麻黄E.intermedia var.tibetica Stapf的生药形态组织学研究结果。并根据对国产麻黄的生药形态组织学的系统研究结果,分别编写了各种国产麻黄(包括13种3变种1变型)的生药性状和生药显微特征检索表。 相似文献
35.
36.
37.
Stringer M Brooks PM King K Biesecker B 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》2007,36(6):624-635
New evidence has prompted changes in our national cardiopulmonary resuscitation guidelines for both neonates and adult patients. The purpose of this article is to provide an overview of the changes recommended by the American Heart Association, Academy of American Pediatrics, and the American College of Obstetrics and Gynecology. In addition, a strategy for implementing these guidelines into practice is suggested. 相似文献
38.
Amanda Reiff Metz Matthew Bauer Chelsey Epperly Ginger Stringer Kristen E. Marshall Lindsey Martin Webb Molly Hetherington-Rauth Shannon R. Matzinger Sarah Elizabeth Totten Emily A. Travanty Kristen M. Good Alexis Burakoff 《Emerging infectious diseases》2022,28(8):1551
A COVID-19 outbreak occurred among Cameron Peak Fire responders in Colorado, USA, during August 2020–January 2021. The Cameron Peak Fire was the largest recorded wildfire in Colorado history, lasting August–December 2020. At least 6,123 responders were involved, including 1,260 firefighters in 63 crews who mobilized to the fire camps. A total of 79 COVID-19 cases were identified among responders, and 273 close contacts were quarantined. State and local public health investigated the outbreak and coordinated with wildfire management teams to prevent disease spread. We performed whole-genome sequencing and applied social network analysis to visualize clusters and transmission dynamics. Phylogenetic analysis identified 8 lineages among sequenced specimens, implying multiple introductions. Social network analysis identified spread between and within crews. Strategies such as implementing symptom screening and testing of arriving responders, educating responders about overlapping symptoms of smoke inhalation and COVID-19, improving physical distancing of crews, and encouraging vaccinations are recommended. 相似文献
39.
Ortiz-Alvarez O; Cabral D; Prendiville JS; Stringer D; Petty RE; Malleson PN 《Rheumatology (Oxford, England)》1997,36(2):280-284
Two children are reported in whom intestinal pseudo-obstruction was the
initial manifestation of systemic sclerosis. Gastrointestinal symptoms and
skin changes resolved or improved in both children following treatment with
prednisone and penicillamine (case 1) or methotrexate (case 2), although
radiological changes of the gastrointestinal tract persisted at 3 and 2 yr
of follow-up, respectively.
相似文献
40.
Universal nevirapine upon presentation in labor to prevent mother-to-child HIV transmission in high prevalence settings 总被引:1,自引:0,他引:1
Stringer JS Sinkala M Goldenberg RL Kumwenda R Acosta EP Aldrovandi GM Stout JP Vermund SH 《AIDS (London, England)》2004,18(6):939-943
OBJECTIVE: To assess the uptake of and adherence to nevirapine to prevent mother-to-child HIV transmission among women of unknown HIV serostatus presenting in labor. We also assessed preliminary efficacy of the approach. DESIGN: Women of unknown HIV serostatus presenting in labor were offered single-dose nevirapine in a prospective cohort study. Two additional contemporaneous comparison populations were also studied. METHODS: We measured uptake by counting the number of women that accepted enrollment when offered. We measured adherence with cord blood nevirapine assay. We measured preliminary efficacy with HIV DNA polymerase chain reaction of infant blood spots at 4-6 weeks of life. RESULTS: Of 1591 women approached in labor, 634 (40%) took up the intervention and received nevirapine, of whom 185 (29%) were HIV infected. Of 179 cord blood specimens from HIV-exposed infants that could be evaluated, 178 (99.4%) had nevirapine detected. This was higher than the 73 of 98 (74%) adherence rate observed in a comparison cohort in which women self-administered nevirapine before presenting to the labor ward (P < 0.001). Of 145 available infant specimens, 17 (11.7%) showed evidence of infection at 4-6 weeks, compared with 12 of 60 (20%) infants born immediately prior to study commencement whose HIV-infected mothers did not receive nevirapine (P < 0.05). CONCLUSIONS: Nevirapine without HIV testing upon presentation in labor was accepted by two-fifths of women. Because therapy is directly observed, adherence is nearly perfect. Labor ward dosing to enhance nevirapine coverage should be considered as an adjunct to antenatal nevirapine administration for prevention of mother-to-child transmission of HIV. 相似文献