全文获取类型
收费全文 | 1008篇 |
免费 | 102篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 74篇 |
妇产科学 | 31篇 |
基础医学 | 105篇 |
口腔科学 | 36篇 |
临床医学 | 166篇 |
内科学 | 213篇 |
皮肤病学 | 27篇 |
神经病学 | 49篇 |
特种医学 | 156篇 |
外科学 | 70篇 |
综合类 | 25篇 |
预防医学 | 63篇 |
眼科学 | 12篇 |
药学 | 59篇 |
1篇 | |
中国医学 | 12篇 |
肿瘤学 | 51篇 |
出版年
2023年 | 2篇 |
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 22篇 |
2017年 | 23篇 |
2016年 | 26篇 |
2015年 | 29篇 |
2014年 | 39篇 |
2013年 | 42篇 |
2012年 | 19篇 |
2011年 | 29篇 |
2010年 | 43篇 |
2009年 | 68篇 |
2008年 | 28篇 |
2007年 | 47篇 |
2006年 | 20篇 |
2005年 | 27篇 |
2004年 | 12篇 |
2003年 | 15篇 |
2002年 | 12篇 |
2001年 | 22篇 |
2000年 | 14篇 |
1999年 | 24篇 |
1998年 | 74篇 |
1997年 | 82篇 |
1996年 | 58篇 |
1995年 | 51篇 |
1994年 | 37篇 |
1993年 | 43篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 12篇 |
1989年 | 26篇 |
1988年 | 22篇 |
1987年 | 27篇 |
1986年 | 14篇 |
1985年 | 17篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1978年 | 5篇 |
1977年 | 11篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1934年 | 1篇 |
1931年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有1156条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
LP Ham F Andrasik RC Packard CM Bundrick 《Cephalalgia : an international journal of headache》1994,14(2):118-126
In this study, the psychological functioning of patients with chronic post-traumatic headache (PTH), chronic combination headache and chronic low back pain without headache, whose time of onset was similar, and a matched group of controls was investigated. The Symptom Checklist 90-Revised (SCL-90-R), State-Trait Anger Expression Inventory (STAXI), State-Trait Anxiety Inventory, Form Y (STAI-Y), and Beck Depression Inventory (BDI) were used to assess the degree of psychopathology. A MANOVA test indicated highly significant differences between groups. In general, the pain groups fell along a continuum with PTH subjects demonstrating the highest elevations, back pain subjects demonstrating the next highest elevations, and combination subjects demonstrating fewer elevations. A cluster analysis indicated that findings were best classified into four clusters, but no one pain diagnosis predominated in any cluster. Eighty-nine percent of controls were assigned to clusters 1 or 2, which revealed essentially normal scores on all tests. It is suggested that while chronic pain patients demonstrate more psychopathology than non-pain controls, a variety of coping styles exists within each pain group independent of diagnostic categorization. 相似文献
105.
N-甲基-D-天冬氨酸受体在缺氧缺血性脑损伤新生大鼠脑海马中的远期表达 总被引:1,自引:0,他引:1
目的:观察新生大鼠缺氧缺血性脑损伤后,海马发育过程中N-甲基-D-天冬氨酸受体的远期表达变化。方法:实验于2006-03/06在解放军第三军医大学新桥医院中心实验室完成。选用新生7日龄SD大鼠72只,按随机数字表法分为缺氧缺血性脑损伤组和假手术组,每组36只。各组又分为生后15d(n=6)、22d(n=6)、29d(n=6)、36d(n=12)及43d(n=6)5个时相点。①参照Rice法通过结扎7日龄大鼠左侧颈总动脉,吸入氧气体积分数为0.08的氮氧混合气,制成缺氧缺血性脑损伤模型,出现自发或夹尾左旋则证明模型制作成功。假手术组仅切开颈部皮肤,暴露左侧颈总动脉。②应用免疫组织化学法检测缺氧缺血后不同时点两组大鼠脑海马CA1区N-甲基-D-天冬氨酸受体NR1亚单位的表达(n=6),测量平均灰度值,灰度值越低,蛋白表达越强;生后36d时相点大鼠(n=6)利用Morris水迷宫测定学习记忆能力;最后应用电镜观察生后36d大鼠海马突触结构。结果:72只大鼠,全部进入结果分析,无脱失。①生后22-43d缺氧缺血性脑损伤组大鼠(缺氧缺血后15-36d)脑海马CA1区NR1平均灰度值分别为167.69±6.48,174.57±4.81,179.30±5.92,176.50±5.93,均显著高于同日龄假手术组148.96±4.91,151.17±6.37,152.06±9.86,156.32±6.86(P均<0.01)。②Morris水迷宫实验中,缺氧缺血性脑损伤组大鼠逃避潜伏期显著长于假手术组(48.87±9.47)s,(11.97±2.20)s,(P<0.01);原平台象限游泳距离/总游泳距离的百分比显著低于假手术组(14.45±3.85)%,(62.20±8.74)%(P<0.01)。③生后36d(缺氧缺血后29d),透射电镜下缺氧缺血性脑损伤组大鼠患侧海马突触后膜致密物较假手术组明显减少。结论:新生大鼠缺氧缺血性脑损伤后期存在海马N-甲基-D-天冬氨酸受体的表达下调,可能对大鼠远期空间学习记忆产生一定影响。 相似文献
106.
范春明 《中国组织工程研究与临床康复》2007,11(24):4806-4809
目的:分析胚胎干细胞和胚胎生殖细胞的生物学特性、体外培养条件、周围微环境对其增殖分化的影响,了解胚胎干细胞和胚胎生殖细胞的关系和应用前景。方法:应用计算机检索万方数据库2000/2007有关生殖细胞、胚胎干细胞、胚胎生殖细胞的相关研究文章,检索词:生殖细胞,胚胎干细胞,胚胎生殖细胞,并限定文章语言种类为中文;同时应用计算机检索PUBMED2000/2006相关文章,检索词:Germ Cells,Primordial germ cells,Embryonic stem cells,Embryonic Germ Cells,限定文章语言种类为“English”。对资料进行初审,纳入标准为有关生殖细胞、胚胎干细胞、胚胎生殖细胞的生物学特性、体外培养及生长抑制因子的作用等相关文章,并查找全文。主要选择基础研究类文章,无论有无对照组均纳入。结果:共检索到相关文章59篇,排除比较陈旧的文章,最后纳入38篇进行总结分析。胚胎干细胞与胚胎生殖细胞分别从附置前早期胚胎内细胞团和早期胎儿生殖嵴原始生殖细胞分离克隆出来,均具有自我更新、无限增殖能力及多向分化潜能,在体外培养条件下可保持稳定的二倍体核型,诱导分化后可形成3种胚胎生殖层。饲养层细胞是人胚胎生殖细胞体外培养的必要条件,常用饲养层细胞有鼠STO细胞系、鼠胚胎成纤维细胞,体外生长所需主要细胞因子包括干细胞生长因子、碱性成纤维细胞生长因子和白血病抑制因子,然而只要在培养基中加入鼠成纤维细胞的上清液和碱性成纤维细胞生长因子,胚胎干细胞可在无饲养层的条件下进行体外培养。结论:胚胎干细胞和胚胎生殖细胞具有相似的增殖特性,一定条件下可以分化为包括生殖细胞在内的所有功能细胞,并可相互转变,在胚胎发育、基因治疗、药物筛选、新药开发、生殖医学及人类疾病的移植治疗中具有广泛的应用前景。 相似文献
107.
The midwifery art has emphasised the uniqueness of human beings throughout its Nordic history. The educated Nordic midwife has in the last decade celebrated several hundred years of memories. This article studies how the key ideas of the midwifery art and patterns of ideas become evident in the zeitgeist from the beginning of the 19th century to the millennium in the Nordic countries. The legacy and pattern of ideas of the art of midwifery are interpreted in relation to the texts of the selected historical sources and based on Ricoeur's phenomenological-hermeneutic approach to the text and further to the dedication of understanding and interpretation. The historical sources refer to unprinted primary sources from historical archives and printed secondary and tertiary sources. The patterns of ideas include a tripartite whole: the true cultivation of the head, the philosophy and aesthetics of the hand, the strength of the heart and the drive of calling. These ideas open for unique visions and attest to the evident in modern midwives. Today's midwives have academic training with examinations, and the education is based on scientific evidence. The midwife profession is authorised by the state and supervised by the authorities. 相似文献
108.
109.
Expression of bcl-xL can confer a multidrug resistance phenotype 总被引:14,自引:3,他引:14
It has been suggested that genes that regulate apoptotic cell death may play an important role in determining the sensitivity of tumor cells to chemotherapy. We have recently cloned a member of the bcl-2 family, bcl- x. To test whether bcl-XL expression affects the sensitivity of tumor cells to chemotherapy, we have created stable cell lines overexpressing bcl-XL and have tested these cells for resistance to cell death induced by metabolic inhibitors and chemotherapeutic agents. Bcl-XL expression dramatically reduces the cytotoxicity of bleomycin, cisplatin, etoposide, vincristine, hygromycin B, and mycophenolic acid for up to 4 days in culture. Bcl-XL does not prevent cells from undergoing cell cycle arrest in response to these drugs, but rather prevents treated cells from undergoing apoptosis. Cell-cycle analysis on cells treated with the chemotherapeutic agents bleomycin, cisplatin, etoposide, and vincristine, show that the drugs cause growth arrest in different positions within the cell cycle. Bcl-XL expressing cells treated with chemotherapeutic drugs retain their proliferative ability after the drugs are removed. Interestingly, vincristine-treated cells expressing bcl-XL become polyploid after drug removal. These data show that bcl-XL protects cells from a wide variety of apoptotic stimuli, acts in multiple positions within the cell cycle, and confers a multidrug resistance phenotype. The ability of bcl-XL to prevent apoptotic cell death in response to chemotherapy-induced DNA damage and cell-cycle arrest may contribute to the accumulation of chromosomal aberrations within tumors. The expression of bcl-XL in tumor cells is likely to be an important indicator of chemotherapeutic efficacy. 相似文献
110.
Randomized, Controlled Trial of Inhaled Budesonide as an Adjunct to Oral Prednisone in Acute Asthma 总被引:1,自引:2,他引:1
Lillian Sung MD Martin H. Osmond MD CM Terry P. Klassen MD 《Academic emergency medicine》1998,5(3):209-213
Objective: To compare the clinical effect of nebulized budesonide with placebo in acute pediatric asthma.
Methods: A randomized, controlled, double-blind trial with parallel design was used in the ED of a tertiary care children's hospital. Children aged 6 months to 18 years with a moderate to severe exacerbation of asthma [Pulmonary Index Score (PIS) ≥5 or ≤11 after a salbutamol nebulization of 0.15 mg/kg] were eligible. All patients received prednisone 1 mg/kg orally and nebulized salbutamol (0.15 mg/kg) every 30 minutes for 3 doses and then every hour for 4 hours. The intervention was 2 mg (4 mL) of nebulized budesonide or 4 mL of nebulized normal saline.
Results: Baseline characteristics were comparable in the budesonide group ( n = 24) and in the placebo group ( n - 20). There were no significant differences in the primary outcome measure (PIS) between the 2 groups. However, the PIS at 1 hour had a tendency to be lower in the budesonide group (median = 5) as compared with the placebo group (median = 6; p = 0.07). Survival analysis of release/discharge from the ED/hospital showed a more rapid rate in the budesonide group as compared with the placebo group (p = 0.02). No adverse effects were seen.
Conclusion: Although these preliminary results suggest that nebulized budesonide may be an effective adjunct to oral prednisone in the management of moderate to severe asthma exacerbations, a larger trial will be required before the widespread use of inhaled budesonide in acute asthma can be advocated. 相似文献
Methods: A randomized, controlled, double-blind trial with parallel design was used in the ED of a tertiary care children's hospital. Children aged 6 months to 18 years with a moderate to severe exacerbation of asthma [Pulmonary Index Score (PIS) ≥5 or ≤11 after a salbutamol nebulization of 0.15 mg/kg] were eligible. All patients received prednisone 1 mg/kg orally and nebulized salbutamol (0.15 mg/kg) every 30 minutes for 3 doses and then every hour for 4 hours. The intervention was 2 mg (4 mL) of nebulized budesonide or 4 mL of nebulized normal saline.
Results: Baseline characteristics were comparable in the budesonide group ( n = 24) and in the placebo group ( n - 20). There were no significant differences in the primary outcome measure (PIS) between the 2 groups. However, the PIS at 1 hour had a tendency to be lower in the budesonide group (median = 5) as compared with the placebo group (median = 6; p = 0.07). Survival analysis of release/discharge from the ED/hospital showed a more rapid rate in the budesonide group as compared with the placebo group (p = 0.02). No adverse effects were seen.
Conclusion: Although these preliminary results suggest that nebulized budesonide may be an effective adjunct to oral prednisone in the management of moderate to severe asthma exacerbations, a larger trial will be required before the widespread use of inhaled budesonide in acute asthma can be advocated. 相似文献