全文获取类型
收费全文 | 604篇 |
免费 | 40篇 |
国内免费 | 14篇 |
专业分类
儿科学 | 36篇 |
妇产科学 | 4篇 |
基础医学 | 29篇 |
口腔科学 | 15篇 |
临床医学 | 114篇 |
内科学 | 101篇 |
皮肤病学 | 4篇 |
神经病学 | 13篇 |
特种医学 | 180篇 |
外科学 | 16篇 |
综合类 | 44篇 |
预防医学 | 38篇 |
眼科学 | 5篇 |
药学 | 24篇 |
1篇 | |
肿瘤学 | 34篇 |
出版年
2022年 | 7篇 |
2021年 | 9篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 8篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 5篇 |
2012年 | 20篇 |
2011年 | 17篇 |
2010年 | 11篇 |
2009年 | 16篇 |
2008年 | 6篇 |
2007年 | 19篇 |
2006年 | 19篇 |
2005年 | 16篇 |
2004年 | 13篇 |
2003年 | 20篇 |
2002年 | 12篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 13篇 |
1998年 | 29篇 |
1997年 | 24篇 |
1996年 | 18篇 |
1995年 | 25篇 |
1994年 | 21篇 |
1993年 | 35篇 |
1992年 | 8篇 |
1991年 | 12篇 |
1990年 | 15篇 |
1989年 | 20篇 |
1988年 | 25篇 |
1987年 | 36篇 |
1986年 | 23篇 |
1985年 | 22篇 |
1984年 | 9篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1981年 | 13篇 |
1980年 | 12篇 |
1979年 | 2篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 7篇 |
1974年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有658条查询结果,搜索用时 15 毫秒
71.
72.
73.
目的 了解不同的心肌保护方法是否对体外循环 (ECC)术后房性心律失常有影响。 方法 将 12只成年杂交犬随机分为两组 ,A组 :6只犬 ,用持续温血心脏停搏液灌注 ;B组 :6只犬 ,用冷晶体心脏停搏液灌注和局部低温。两组动物主动脉阻断时间均为 30分钟。记录术前及术后 1~ 5天 2 4小时动态心电图 ,计算标准化房性心律失常 ,标准化室性心律失常和 2 4小时平均心率。 结果 ECC后两组动物均未出现心房颤动。尽管术后 A组标准化房性心律失常率高于 B组 (P<0 .0 5 ) ,但两组动物术前、术后标准化房性心律失常率无明显变化 ,标准化室性心律失常率亦无明显变化。此外 ,两组动物术后 2 4小时平均心率亦升高 ,且 B组高于 A组 (P<0 .0 5 )。 结论 不同的心肌保护方法对 ECC术后房性心律失常的发生无明显影响。 相似文献
74.
75.
低氧训练对下丘脑-垂体-肾上腺皮质轴内分泌相关激素的影响 总被引:1,自引:0,他引:1
目的:总结低氧训练对下丘脑-垂体-肾上腺皮质轴内分泌相关激素的影响,为科学运动训练提供依据。资料来源:应用计算机检索中国期刊全文数据库1994-01/2006-10的相关文章,检索词"低氧,低氧训练,下丘脑-垂体-肾上腺,激素",并限定文章语言种类为中文。并应用计算机检索美国国立医学图书馆NCBI1980-01/2006-10的相关文章,检索词"Hypoxic Training,organism endocrine system,hormone",并限定文章语言种类为English。资料选择:对资料进行初审,选取低氧训练与下丘脑-垂体-肾上腺分泌的相关激素有关的文献,并作初步分类,同类文献首选近年发表的核心期刊文章。排除重复及综述类文献。资料提炼:共收集到95篇相关文章,其中56篇属于重复及综述类文献,对符合标准38篇文献进行分析整理。资料综合:①高海拔状态下机体对低氧产生应激反应,表现为下丘脑-垂体-肾上腺皮质轴的适应性运转,血中促肾上腺皮质激素浓度增加,以调节机体对应激刺激的适应能力,同时使促肾上腺皮质激素释放因子分泌增加。②高原训练后,睾酮和皮质醇的变化都较明显,其总体变化均趋于降低,睾酮/皮质醇值有升有降,从一定意义上反映了机体的机能状况与疲劳积累程度。③低氧还引起大鼠血浆β-内啡肽浓度升高,可使心房钠尿素增加、前列腺素增加、血管内皮素分泌增加及抑制血管内皮舒张因子的分泌。结论:激素对机体的新陈代谢、生长发育、各种功能活动以及维持内环境稳态等方面发挥重要的调节作用,低氧训练对机体激素的影响一直应该受到人们的关注。 相似文献
76.
77.
Xu Liu PhD Jing Zheng PhD RN Ke Liu PhD RN Judith G. Baggs PhD RN FAAN Jiali Liu PhD RN Yan Wu PhD RN Liming You PhD RN FAAN 《Research in nursing & health》2020,43(1):103-113
Strengthening the nursing workforce is core to health system reform in China. Patient experiences of hospital care have been recognized as important in this endeavor. Studies exploring the relationships between nursing workforce and patient experiences of hospital care, however, are scarce. The aim of this cross-sectional study was to examine the associations between nurse education level, nurse staffing, and hospitalized patients’ experiences of hospital care. Participants were 1,582 nurses responsible for direct care and 1,305 hospitalized patients from 23 hospitals in Guangdong province, China in 2014. Education level of nurses was measured by the proportion of nurses holding a baccalaureate or higher degree. Nurse staffing was measured by the unit nurse-patient ratio. The Hospital Consumer Assessment of Health care Providers and Systems Scale was used to measure patient experiences of hospital care. Structural equation modeling demonstrated that a higher proportion of nurses holding a baccalaureate or higher degree was related directly to better patient perceptions of communication with nurses, responsiveness of nurses, pain management, and physical environment, and related indirectly to overall hospital ratings and recommendation of the hospital. A higher nurse-patient staffing ratio was associated directly with better patient perceptions of communication with nurses, education about new medications given in hospital, and physical environment, and indirectly with overall ratings and recommendation of the hospital. Our findings add new evidence in the Chinese societal context about the relationship between the nursing workforce and patient experiences of hospital care. Upgrading nurse education level and increasing nurse staffing could potentially improve patient experiences of hospital care. 相似文献
78.
79.
Engraftment of bone marrow cells into normal unprepared hosts: effects of 5-fluorouracil and cell cycle status 总被引:2,自引:7,他引:2
Bone marrow from animals treated with 5-fluorouracil (5FU) competes equally with normal marrow when assessed in vivo in an irradiated mouse, but shows markedly defective engraftment when transplanted into noncytoablated hosts. Using Southern Blot analysis and a Y-chromosome specific probe, we determined the level of engraftment of male donor cells in the bone marrow, spleen, and thymus of unprepared female hosts. We have confirmed the defective engraftment of marrow harvested 6 days after 5FU (FU-6) and transplanted into unprepared hosts and shown that this defect is transient; by 35 days after 5FU (FU-35), engraftment has returned to levels seen with normal marrow. FU-6 marrow represents an actively cycling population of stem cells, and we hypothesize that the cycle status of the stem cell may relate to its capacity to engraft in the nonirradiated host. Accordingly, we have evaluated the cycle status of engrafting normal and FU-6 marrow into normal hosts using an in vivo hydroxyurea technique. We have shown that those cells engrafting from normal marrow and over 70% of the cells engrafting from FU-6 marrow were quiescent, demonstrating no killing with hydroxyurea. We have also used fluorescent in situ hybridization (FISH) analysis with a Y-chromosome probe and demonstrated that normal and post-5FU engraftment patterns in peripheral blood were similar to those seen in bone marrow, spleen, and thymus. Altogether these data indicate that cells engrafting in normal, unprepared hosts are dormant, and the defect that occurs after 5FU is concomitant with the induction of these cells to transit the cell cycle. 相似文献
80.
We report the successful long-term engraftment of normal male donor bone marrow (BM) transfused into noncytoablated female mice, challenging the assumption that "niches" need to be created for marrow to engraft. We have used chromosomal banding and Southern blot analysis to identify transplanted male marrow cells, and shown the long-term stability of the chimeric marrows. Balb/C, BDF1, or CBA-J female hosts (no irradiation) received for 5 consecutive days 40 x 10(6) male cells (per day) of the same strain, and repopulation patterns were observed. Parallel studies were performed using tibia/femur equivalents of normal marrow or marrow from Balb/C mice pretreated 6 days previously with 150 mg/kg 5-fluorouracil (5-FU). Chromosome banding techniques showed that 5% to 46% of marrow cells were male 3 to 9 months posttransplant with normal donor marrow. Southern blot analysis, using the pY2 probe, showed continued engraftment at 21 to 25 months posttransplant, ranging from 15% to 42% male engrafted cells in marrow. Normal donor male marrow engrafted significantly better than 5-FU-pretreated male marrow as shown 1 to 12 months posttransplant in non-cytoablated female recipients. Percentages of male engrafted cells in BM ranged from 23% to 78% for recipients of normal donor marrow and from 0.1% to 39% for recipients of 5-FU marrow. Mean engraftment for 6 mice receiving normal marrow was 38%, whereas that for 6 mice receiving post-5-FU marrow was 8%, as assayed 1 to 3 months posttransplant. At 10 to 12 months, mean engraftment for the normal donor group was 46%, compared with 16% for the 5-FU group. The patterns of engraftment with normal and 5-FU marrow were similar for spleen and thymus. These results show that long-term chimerism can be established after transplantation of normal donor marrow to normal nonirradiated host mice and indicate that marrow spaces do not have to be created for successful engraftment. They suggest that transplanted marrow competes equally with host marrow for marrow space. Finally, these data show that post-5-FU Balb/C male marrow is markedly inferior in the repopulation of Balb/C female host marrow, spleen, and thymus, and suggest that this population of cells may not be the ideal population for gene transfer studies. 相似文献