全文获取类型
收费全文 | 1401篇 |
免费 | 75篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 18篇 |
妇产科学 | 29篇 |
基础医学 | 115篇 |
口腔科学 | 14篇 |
临床医学 | 124篇 |
内科学 | 147篇 |
皮肤病学 | 5篇 |
神经病学 | 33篇 |
特种医学 | 32篇 |
外科学 | 206篇 |
综合类 | 248篇 |
预防医学 | 163篇 |
眼科学 | 1篇 |
药学 | 165篇 |
中国医学 | 43篇 |
肿瘤学 | 147篇 |
出版年
2023年 | 12篇 |
2022年 | 41篇 |
2021年 | 52篇 |
2020年 | 42篇 |
2019年 | 40篇 |
2018年 | 45篇 |
2017年 | 44篇 |
2016年 | 53篇 |
2015年 | 44篇 |
2014年 | 109篇 |
2013年 | 89篇 |
2012年 | 98篇 |
2011年 | 93篇 |
2010年 | 67篇 |
2009年 | 64篇 |
2008年 | 54篇 |
2007年 | 54篇 |
2006年 | 54篇 |
2005年 | 40篇 |
2004年 | 39篇 |
2003年 | 34篇 |
2002年 | 23篇 |
2001年 | 25篇 |
2000年 | 32篇 |
1999年 | 18篇 |
1998年 | 16篇 |
1997年 | 12篇 |
1996年 | 22篇 |
1995年 | 26篇 |
1994年 | 18篇 |
1993年 | 13篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1986年 | 4篇 |
1985年 | 12篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 15篇 |
1980年 | 2篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1970年 | 2篇 |
排序方式: 共有1493条查询结果,搜索用时 15 毫秒
11.
Gastric cancer etiology: a biochemical hypothesis. 总被引:1,自引:0,他引:1
We have proposed a two-stage biochemical model for the etiology of "intestinal" gastric cancer. The model postulates that the gastric mucosal barrier is biochemically pierced as a result of chemical interactions between the mucoproteins and mucopolysaccharides of the barrier and ingested polysaccharrides (starches). This would allow the growth of gastric flora which could produce carcinogenic nitrosamines and/or nitrosamides. Observational and experimental evidence in favor of the model is provided. The model suggests various research initiatives, the results of which might provide the basis for biochemical and physiological methods for the prevention and/or treatment of gastric cancer. Various ways in which the model may be tested are also noted. 相似文献
12.
The effect of chronic subcutaneous administration of lead acetate was studied in female rabbits. The low-dose group (15 animals) received three times a week 0.10–0.20 g/kg body weight and the high-dose group (15 animals) 0.80–1.20 g/kg. The control group received the vehicle only. Concentrations of lead in blood in the low-dose group increased to ca. 400 g/l after 70 days and in the high-dose group to ca. 900 g/l after 110 days. After 7.5 months eight animals of each group were sacrificed. The remaining rabbits were kept for an additional 4 months without treatment. Blood lead concentrations decreased with a half-time of 60–70 days. During exposure the gain in body weight was lower in the high-dose group than in the control group and the low-dose group. The high-dose group developed slight anaemia and low MCV, MCH and MCHC, and basophilic stippling of erythrocytes. These effects disappeared during recovery. ALAD activity in erythrocytes was very low during exposure in both exposed groups and did not reach control values during recovery. During exposure the concentrations of ZPP and ALA-U increased, but only ALA-U returned to normal during recovery. No other effects of lead on the composition of the urine were observed. No effects were observed on plasma urea and creatinine concentrations. In the highdose group the concentration of ALAD in the liver decreased by 30%. During recovery this effect was no longer present. No effects were seen in cytochrome P-450 content or cytochrome P-450-dependent enzyme activities. Lead was mainly stored in bones, but some also in serveral soft tissues. After recovery the concentrations in soft tissues decreased to a variable degree. In the high-dose group the relative weights of heart and liver increased. These effects disappeared during recovery. At 400 g lead/l blood no adverse effects were observed that did occur at the high dose level.Part 2, dealing with the histopathology and (electron) microscopy of the kidneys is in preparation 相似文献
13.
Alvarez L Peris P Bedini JL Parés A Monegal A Guañabens N Mas E Aibar C Ballesta AM 《Calcified tissue international》1999,64(4):301-303
Serum tartrate-resistant acid phosphatase (TRAcP) activity is considered to be a biochemical marker of bone resorption. Recently,
a lack of specificity of collagen-related markers for assessing bone turnover has been observed in patients with chronic liver
disease. Thus, it could be of great interest to determine serum TRAcP activity in such patients. However, nonspecificity of
the analytical reaction could occur when hemolyzed, lipemic, or icteric specimens are analyzed. Therefore, we have studied
the interference caused by bilirubin in the measurement of serum TRAcP activity using the Hillmann method. The interference
was assessed in two pools of serum containing different bilirubin concentrations but with similar total AcP levels. Mixing
proportional parts of the two pools, 10 samples were also obtained. Serum activities of total AcP and TRAcP, and the concentration
of bilirubin were measured in the 10 samples. Both the actual and the expected values obtained by theoretical calculations
were compared. Serum bilirubin values of 2.4 mg/dl showed a negative interference of 15% in the determination of serum TRAcP
activity, whereas values of bilirubin higher than 10 mg/dl interfered totally with the measurement of serum TRAcP. Bilirubin
did not interfere with the total AcP determination. This study clearly shows the interference of bilirubin in the determination
of serum TRAcP. This finding should be considered when bone metabolism disorders are evaluated in jaundiced patients.
Received: 6 April 1998 / Accepted: 1 October 1998 相似文献
14.
地砷病患者部分生化指标的测定 总被引:2,自引:0,他引:2
对病区地砷病、非地砷病患者及对照组居民体内的部分生化指标进行了检测。结果表明,地砷病患者血清中的GPT活性、UN和SA含量明显高于对照组,LDH及GSHPx活性明显降低;病区非地砷病患者LDH活性、SA含量明显升高,GSHPx活性明显降低,其它各组及各指标与对照组相比无显著差异。相关分析显示,病区病人组及非病人组血中SA含量与各自尿砷水平呈正相关(r=050,r=046),GSHPx与尿砷呈负相关(r=-051,r=-048)。提示,SA和GSHPx可作为砷中毒的早期诊断指标。砷可能对接砷居民肝功、肾功产生一定影响。 相似文献
15.
目的研究西藏小型猪早期生长发育的规律。方法对本基地F1代西藏小型猪的体重、体长、胸围、体高、体温、呼吸频率、心率及血液生理生化指标进行了测定。结果西藏小型猪体型小,生长性能稳定,生长速度与原产地西藏小型猪基本一致;西藏小型猪的体温、呼吸次数和心率与原产地西藏小型猪相近,且雌雄之间差异不显著(P>0.05);F1代雌雄间除嗜碱性粒细胞、单核细胞数和尿素氮外其他指标也基本一致,大部分指标与人接近。结论由于西藏小型猪体型小、生长性能稳定,血液生理生化值与人类相近,因而是理想的医学研究用实验动物。 相似文献
16.
生化检查对人工髋关节感染的诊断价值 总被引:7,自引:1,他引:7
目的评价翻修术前生化检查对人工髋关节感染的诊断价值。方法对145例人工髋关节翻修患者进行回顾性分析,分别以血沉(ESR)和C-反应蛋白(CRP)作为诊断标准对人工髋关节感染进行诊断,并与“金标准”的诊断结果进行比较分析。结果血沉和CRP诊断人工髋关节感染的灵敏度分别为57.89%、68.42%,特异度分别为85.71%、88.89%,阳性预测值分别为37.93%、48.15%,阴性预测值分别为93.10%、94.92%,准确度分别为20.00、18.62,Youden指数分别为0.44、0.57。结论血沉和CRP作为人工髋关节翻修术前的常规检查,对人工髋关节感染的诊断具有筛选价值;两者结合起互补作用,可以增加诊断的准确性。 相似文献
17.
结合生化指标及影像医学,可以鉴别黄疸的原因和分类,从而提示在隐性黄疸和肝细胞性黄疸方面,茵陈蒿汤疗效显著,而在严重的梗阻性黄疸中,芮陈蒿汤退黄效果不佳. 相似文献
18.
蚯蚓在医药保健方面的综合利用研究 总被引:21,自引:1,他引:21
对中药蚯蚓进行现代生物技术处理,可同时得到四个有药用价值的组分,大分子组分具有一定的抗癌作用;中等分子组分具有溶性活性;小分子组分富含氨基酸及多种矿质元素和微量元素;另外还可得到一个可治疗烧、烫伤的组分.对其主要组分进行了基础生化特性及药用价值研究.这四个组分均可进一步开发为药品或保健品.蚯蚓进行综合利用,能科学、合理和有效地利用生物资源,充分发挥其各组分的药用价值. 相似文献
19.
20.
目的 探讨SD大鼠血液学指标和血清生化学指标的参考值.方法 收集3个批次雌雄共586只大鼠的17项血液学、血清生化学指标进行统计分析.结果 17项指标的平均值及其95%参考值范围的性别差异无显著性;RBC在不同批次的雌雄鼠之间无显著性差异(P>0.05).雌鼠WBC、AST的测定值批间差异有显著性(P<0.05),雄鼠批间差异无显著性.雄鼠ALB、TG的测定值批间差异有显著性(P<0.05),雌鼠批间差异无显著性.结论 SD大鼠亚慢性经口(试验前)17项血液学和血清生化学指标参考值与文献报道一致;并且雌雄鼠可以合并计算. 相似文献