全文获取类型
收费全文 | 985篇 |
免费 | 78篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 60篇 |
妇产科学 | 11篇 |
基础医学 | 123篇 |
口腔科学 | 32篇 |
临床医学 | 114篇 |
内科学 | 198篇 |
皮肤病学 | 35篇 |
神经病学 | 27篇 |
特种医学 | 142篇 |
外科学 | 58篇 |
综合类 | 37篇 |
预防医学 | 45篇 |
眼科学 | 125篇 |
药学 | 45篇 |
中国医学 | 2篇 |
肿瘤学 | 19篇 |
出版年
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 13篇 |
2020年 | 15篇 |
2019年 | 21篇 |
2018年 | 14篇 |
2017年 | 21篇 |
2016年 | 20篇 |
2015年 | 32篇 |
2014年 | 33篇 |
2013年 | 38篇 |
2012年 | 23篇 |
2011年 | 22篇 |
2010年 | 54篇 |
2009年 | 40篇 |
2008年 | 24篇 |
2007年 | 39篇 |
2006年 | 30篇 |
2005年 | 33篇 |
2004年 | 19篇 |
2003年 | 19篇 |
2002年 | 18篇 |
2001年 | 15篇 |
2000年 | 18篇 |
1999年 | 20篇 |
1998年 | 48篇 |
1997年 | 43篇 |
1996年 | 39篇 |
1995年 | 28篇 |
1994年 | 40篇 |
1993年 | 31篇 |
1992年 | 10篇 |
1991年 | 13篇 |
1990年 | 11篇 |
1989年 | 27篇 |
1988年 | 21篇 |
1987年 | 23篇 |
1986年 | 16篇 |
1985年 | 17篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 10篇 |
1980年 | 14篇 |
1978年 | 5篇 |
1977年 | 15篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1972年 | 4篇 |
1956年 | 3篇 |
排序方式: 共有1078条查询结果,搜索用时 15 毫秒
91.
ELISE JALIL PIERRE Le FRANC RÉAL LEBEAU FRANCK MOLIN PAOLO COSTI TERESA KÚS 《Pacing and clinical electrophysiology : PACE》1998,21(3):528-535
The composition of the excitable gap (EG) in common atrial flutter (AFI) was determined before and during infusion of procainamide (PA) in 9 patients (6 men and 3 women; age 70 ± 7 years). The EG was determined by introducing a premature stimulus after every 20th AFI complex detected using a quadripolar electrode catheter placed just above the tricuspid valve. Diastole was scanned in 2- to 4-ms decrements to the atrial effective refractory period (ERP). The relationship between the coupling interval and the return cycle length (CL) determined a reset-response curve (RRC), which described the EG. PA (15 mg/kg) was administered during AFl over 30 minutes and RRC was repeated at maximum AFI CL. PA prolonged AF1 CL from 227 ± 29 to 296 ± 62 ms (P < 0.01) but did not terminate AFI. ERP during AFl prolonged from 169 ± 24 to 219 ± 41 ms (P < 0.01). Control EG was 57 ± 16 ms or 25%± 6% of AFl CL and on PA EG was 77 ± 30 ms (P = 0.01), which was still 26%± 7% of the CL. Without drug, RRC was mixed in eight cases demonstrating an EG composed of fully excitable tissue (10 ± 4 ms or 19%± 10% of the EG) and partially refractory tissue (48 ± 18 ms), PA did not change the duration of the fully excitable region (13 ± 10 ms or 19%± 15% of EG). Peak PA plasma concentration was 47 ± 20 μmol/L. PA prolonged AFI CL, ERP, and EG duration but did not change the proportion of AFI CL occupied by the EG. The persistence of fully excitable tissue at the head of the wavefront in the presence of PA may largely explain its inefficacy in the acute termination of common AFl. 相似文献
92.
93.
94.
胶原海绵复合新生大鼠原代心肌细胞构建工程化心肌组织 总被引:2,自引:2,他引:2
目的:探索以胶原海绵为支架、新生大鼠原代心肌细胞为种子细胞,于体外构建工程化心肌组织的方法。方法:实验于2005-12/2006-11在解放军第四军医大学西京医院心内科实验室完成。Ⅰ型胶原海绵剪切成方形片状(2.0cm×1.4cm×0.2cm),经60Co照射消毒,于DMEM培养液中水化1h左右。另取1d龄SD大鼠心脏,剪成小碎块,然后用2.5g/L胰蛋白酶于37℃中消化,吸取上清至含胎牛血清的DMEM中,重复消化四五次,用差速贴壁法除去大部分成纤维细胞,将细胞沉淀用DMEM培养液以2×109L-1的密度悬浮备用。将上述的心肌细胞悬液1mL缓慢滴注于玻璃模型中的胶原海绵上,然后置于细胞培养中培养。肉眼及显微镜主要观察工程化心肌组织在培养期间的自发收缩情况,包括收缩的部位、强度、频率、一致性以及收缩随时间变化的情况。苏木精-伊红染色观察工程化心肌组织内胶原纤维的变化,细胞形态,胞核的形状及细胞之间的连接。免疫组织化学染色和透射电镜观察工程化心肌组织片的形态和功能。结果:①细胞接种于胶原海绵上1d后,细胞/胶原复合物的凝胶化过程基本完毕,体积保持恒定,维持至培养结束,第3天细胞/胶原复合物局部出现点片状自发收缩,第5天整个细胞/胶原复合物出现同步化自发收缩,收缩频率61~199次/min。2周后37.5%的工程化心肌组织的自发收缩活动减弱,但75%的工程化心肌组织的自发收缩活动持续至培养结束。②苏木精-伊红染色、免疫组织化学染色和透射电子显微镜显示,工程化心肌组织内细胞间连接广泛存在,细胞多呈纵向分布,胞核呈长圆形,胞浆内α-肌节肌动蛋白阳性,胞内肌原纤维排列整齐,可见到心肌特异性的肌小节结构和Z线,多数细胞具有分化的心肌细胞表型。结论:用新生大鼠原代心肌细胞为种子细胞、以Ⅰ型胶原海绵为支架材料,构建出的工程化心肌组织,于体外可长时间持续自发收缩,该细胞/胶原复合物的形态结构与生理功能均类似于成熟大鼠心肌组织。 相似文献
95.
Taipale Joonas Mikhailova Alexandra Ojamo Matti Nättinen Janika Väätäinen Saku Gissler Mika Koskinen Seppo Rissanen Harri Sainio Päivi Uusitalo Hannu 《Quality of life research》2019,28(12):3225-3236
Quality of Life Research - The impact of visual acuity (VA) on Health-Related Quality of Life (HRQoL) and the cross-sectional and longitudinal differences in HRQoL during the 11-year follow-up were... 相似文献
96.
Maria HBM Lopes PhD Carlos AL D'Ancona PhD Neli RS Ortega PhD Paulo SP Silveira PhD Anna C Faleiros‐Martins PhD Heimar F Marin PhD 《International Journal of Urological Nursing》2016,10(3):146-153
Lower urinary tract dysfunctions (LUTD) restrict quality of life, resulting in decreased work productivity and emotional well‐being. However, most people are not diagnosed because they do not seek medical treatment. In addition, some facilities do not adequately train health professionals in the evaluation, diagnosis and treatment of these conditions. The study's objective was to develop a decision support system modelled on fuzzy logic that defines LUTD using the terminology of the International Continence Society. This methodological study aimed to develop a model that uses the maximum–minimum composition (max–min) of fuzzy relations that can perform differential diagnoses of LUTD. The model was tested in 100 cases (50 men and 50 women), and the data were obtained from medical records containing the clinical data and results of urodynamic studies. All medical records were reviewed by a specialist in urology. The model was capable of determining a diagnosis in full (62%) or partial (36%) agreement with the medical report. Agreement between the model and the medical report was excellent (kappa = 0·98, p ? 0·001, CI = 0·88–1) or substantial (kappa = 0·53, p ? 0·001, CI = 0·45–0·60), considering overestimative accordance (where accordance is assumed when at least one diagnosis is equal) and underestimative accordance (where accordance is assumed when all diagnoses are equal), respectively. The proposed model based on the max–min composition of fuzzy relationships is very simple and performed well. However, more tests are recommended before the model is used as a decision support system. 相似文献
97.
Samar AL‐EMADI Mohammed HAMMOUDEH Nagui ABDULWAHAB 《International journal of rheumatic diseases》2007,10(2):156-159
Pyomyositis is a primary infection of the striated muscles. We describe the clinical and imaging features of pyomyositis in two patients, one diabetic and the other immunocompetent. Treatment with incision, drainage and antibiotics was successful and resulted in full recovery. Increased awareness, especially in immuno‐competent patients, should lead to earlier diagnosis, correct treatment and a better outcome. 相似文献
98.
David C Lee Patricia P Campbell Vicente Gilsanz Tishya AL Wren 《Journal of bone and mineral research》2009,24(8):1398-1403
Because DXA is a projection technique, anterior–posterior (AP) measurements of the spine include the posterior elements and the vertebral body. This may be a disadvantage because the posterior elements likely contribute little to vertebral fracture resistance. This study used QCT to quantify the impact of the posterior elements in DXA AP spine measures. We examined 574 subjects (294 females and 280 males), age 6–25 yr, with DXA and QCT. QCT measures were calculated for the cancellous bone region and for the vertebral body including and excluding the posterior elements. DXA data were analyzed for the entire L3 vertebra and for a 10‐mm slice corresponding to the QCT scan region. BMC and BMD were determined and compared using Pearson's correlation. The posterior elements accounted for 51.4 ± 4.2% of the total BMC, with a significant difference between males (49.9 ± 4.0%) and females (52.8 ± 3.9%, p < 0.001). This percentage increased with age in younger subjects of both sexes (p < 0.001) but was relatively consistent after age 17 for males and 16 for females (p > 0.10). DXA areal BMD and QCT volumetric BMD correlated strongly for the whole vertebra including the posterior elements (R = 0.83), with BMC measures showing a stronger relationship (R = 0.93). Relationships were weaker when excluding the posterior elements. We conclude that DXA BMC provides a measure of bone that is most consistent with QCT and that the contribution of the posterior elements is consistent in young subjects after sexual maturity. 相似文献
99.
100.
Miia Turpeinen Ari Tolonen Christophe Chesne André Guillouzo Jouko Uusitalo Olavi Pelkonen 《Toxicology in vitro》2009,23(4):748-753
Practically all human hepatocyte cell lines are deficient in major cytochrome P450 (CYP)-related enzyme activities, making them unrepresentative of in vivo hepatocytes. We have used the recently developed HepaRG cell line to determine the spectrum of most important CYP enzyme activities involved in xenobiotic metabolism (CYP1A1/2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4) and the effect of the prototypical CYP-inducer phenobarbital and a panel of known CYP-selective inhibitors on these activities. Comparison of these activities was carried out with two human primary hepatocyte populations. We show that excluding CYP2A6 and CYP2E1, HepaRG cells express high functional levels of most of the major xenobiotic metabolising CYPs. These activities were found to be selectively inhibited and induced by prototypical CYP-selective inhibitors and inducer at comparable levels to primary hepatocytes. In conclusion, HepaRG cells may be a promising cell line for various applications, which currently employ hepatic subcellular preparations or cultured primary hepatocytes. 相似文献