全文获取类型
收费全文 | 621篇 |
免费 | 18篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 34篇 |
妇产科学 | 4篇 |
基础医学 | 80篇 |
口腔科学 | 11篇 |
临床医学 | 67篇 |
内科学 | 135篇 |
皮肤病学 | 56篇 |
神经病学 | 17篇 |
特种医学 | 92篇 |
外科学 | 27篇 |
综合类 | 1篇 |
预防医学 | 24篇 |
眼科学 | 10篇 |
药学 | 62篇 |
肿瘤学 | 23篇 |
出版年
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 14篇 |
2012年 | 6篇 |
2011年 | 5篇 |
2010年 | 17篇 |
2009年 | 15篇 |
2008年 | 5篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 7篇 |
2003年 | 7篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 12篇 |
1998年 | 25篇 |
1997年 | 29篇 |
1996年 | 39篇 |
1995年 | 28篇 |
1994年 | 30篇 |
1993年 | 17篇 |
1992年 | 9篇 |
1991年 | 20篇 |
1990年 | 11篇 |
1989年 | 29篇 |
1988年 | 29篇 |
1987年 | 27篇 |
1986年 | 20篇 |
1985年 | 23篇 |
1984年 | 13篇 |
1983年 | 4篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 12篇 |
1979年 | 10篇 |
1978年 | 9篇 |
1977年 | 7篇 |
1976年 | 9篇 |
1975年 | 8篇 |
1974年 | 6篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1969年 | 4篇 |
1968年 | 3篇 |
1966年 | 6篇 |
1958年 | 6篇 |
1956年 | 6篇 |
1955年 | 4篇 |
1954年 | 4篇 |
排序方式: 共有648条查询结果,搜索用时 15 毫秒
41.
TH. B. Twickler G. M. Dallinga-Thie P. M. J. Zelissen H. P. F. Koppeschaar D. W. Erkelens 《Clinical endocrinology》2001,55(1):69-75
BACKGROUND: Premature atherosclerosis is a clinical feature in untreated acromegaly. Increased postprandial lipoprotein remnant levels are associated with premature atherosclerosis. In most studies, remnants have been measured indirectly using retinyl esters (RE) as a chylomicron core label. Remnants can also be directly quantified by immunoseparation using monoclonal antibodies to apolipoprotein (apo) AI and apo B100 to remove nonremnant lipoproteins. Cholesterol is quantified in the remaining apo E-rich remnant fraction (RLP-C). OBJECTIVE: The aim of the present study was to investigate the role of postprandial lipaemia in patients with acromegaly to further define abnormalities leading to increased susceptibility for atherosclerosis. PATIENTS: In a case-control study, the plasma postprandial lipoprotein remnant fraction (RLP-C and RE) were analysed in six patients with active acromegaly [two females, four males; aged 53 +/- 9 years; body mass index (BMI), 29 +/- 4 kg/m2] and in six normolipidaemic control subjects (matched for age, gender, BMI and apo E genotype). They underwent an oral vitamin A fat loading test. RESULTS: Baseline plasma triglycerides (TG) were not significantly different in patients (1.75 +/- 0.71 mM) and controls (1.15 +/- 0.46 mM). Lipoprotein lipase activity was significantly lower in patients than in controls (108 +/- 21 vs. 141 +/- 19 U/l, respectively; P < 0.05). Baseline plasma apo E levels were higher in patients (60.8 +/- 7.9 mg/l) than in controls (48.3 +/- 5.9 mg/l; P < 0.05). No differences were found in the area under the postprandial TG curve (AUC-TG), the incremental AUC-TG (DeltaAUC-TG) and AUC-RE in the Sf < 1000 remnant fraction. However, fasting plasma RLP-C concentrations, isolated by immunoseparation, were increased in patients with active acromegaly (0.41 +/- 0.13 mM) compared to control subjects (0.20 +/- 0.07 mM; P < 0.05). Incremental postprandial RLP-C response (corrected for fasting values) was also significantly elevated in patients (2.14 +/- 1.19 mM/h/l) compared to controls (0.86 +/- 0.34 mM/h/l; P < 0.05). In both groups, the maximal RLP-C concentration was reached between 2 and 4 h. CONCLUSIONS: In conclusion, the atherogenic postprandial remnants, represented by RLP-C, were significantly elevated at baseline and in the postprandial period, whereas the larger-sized remnants, represented by retinyl esters (Sf < 1000), were not different from controls. The disturbances in the postprandial RLP-C response increased the susceptibility for premature atherosclerosis as observed in patients with acromegaly. 相似文献
42.
43.
In a 5-year period, 92 patients with biliary obstruction proximal to the pancreatic segment were evaluated with computed tomography (CT). Seventy-three were judged to have technically optimal studies. Observations of the level of obstruction were compared with data from 50 percutaneous transhepatic cholangiograms; CT data enabled the level of obstruction to be correctly predicted in 46. CT enabled correct prediction of the distribution of obstructing lesions in all 18 patients with intrahepatic obstruction. Forty-four of the 73 patients had pathologic examination of the porta hepatitis. CT findings of obstructing mass and lesser omental nodes resulted in correct prediction of malignancy in 25 (92%) of 27 patients; the absence of such findings enabled correct prediction of benign disease in 13 (77%) of 17 individuals. CT is most valuable as a noninvasive means of planning surgical or radiologic drainage procedures in patients with biliary obstruction. 相似文献
44.
45.
Non-drug related asystole associated with anaesthetic induction 总被引:1,自引:0,他引:1
A patient is presented where routine venepuncture associated with anaesthetic induction resulted in bradycardia and asystole. The case highlights the need for special caution with, and ECG monitoring throughout induction for, patients with a history of syncope. It also demonstrates the need for caution when attributing cardiovascular events during induction to the effect of the induction agents used. 相似文献
46.
TH.J. Postmes J.C. Van Hout G. Saat P. Willems J. Coenegracht 《Clinica chimica acta; international journal of clinical chemistry》1974,50(2):189-195
The serum triiodothyronine (T3) and thyroxine (T4) concentration of healthy persons remains almost constant for at least ten months. Fresh serum and serum frozen for two years were compared. The mean difference in T3 concentration is negligible, only 3 ng/100 ml. The radioimmunoassay has a Between Assay Coefficient of 6.3% and is therefore reliable. Results can be obta 相似文献
47.
目的:为保护濒死心肌提供机会窗口,对比观察经冠脉移植自体骨髓单个核细胞或间充质干细胞后,实验性急性心肌梗死动物心功能变化及心肌组织核转录因子кB、心肌细胞凋亡情况。方法:实验于2005-03/2006-11在河北省人民医院实验中心完成。选用24只雄性冀中白猪,随机数字表法分为4组:正常对照组、模型组、单个核细胞组、间充质干细胞组,6只/组。①24只猪均以盐酸氯胺酮200mg臀部肌肉注射麻醉后,分别于各自右侧股骨抽取骨髓20mL,采用Fercoll法分离获得骨髓单个核细胞,加入胶体金溶液,培养12~16h待用。分离过程中取出含有骨髓单个核细胞成分的细胞层,常规培养传代,每3d换液1次,贴壁生长细胞即为骨髓间充质干细胞,加入胶体金溶液,培养24h待用。②除正常对照组外,其余各组均经导管球囊封闭第一对角支以远的前降支,复制猪急性心肌梗死模型。单个核细胞组、间充质干细胞组均于造模后立即开通前降支,分别经球囊注入预先分离的骨髓单个核细胞6×108个、间充质干细胞6×108个。模型组造模后于梗死1h开通前降支,经球囊注入磷酸盐缓冲液10mL。③各组分别于术前及术后4周经心脏超声检测心功能,取材行病理学检查、心肌组织核转录因子кB的免疫组织化学检测及心肌细胞凋亡检测。结果:24只雄性白猪均进入结果分析。①心功能变化:术前各组左心室收缩末内径、左心室舒张末内径、左心室射血分数、短轴缩短率基本相似。移植术后4周,正常对照组、单个核细胞组、间充质干细胞组左心室舒张末内径均明显低于模型组(F=4.68,P=0.01),左心室射血分数及短轴缩短率均明显高于模型组(F=5.14,P=0.01;F=3.32,P=0.04),各组左心室收缩末内径差异无显著性意义(F=1.64,P=0.21)。②心肌组织病理学改变:电镜下单个核细胞组、间充质干细胞组在梗死边缘区可见有胶体金颗粒的不成熟的心肌细胞,胞质中散在肌丝结构,肌丝排列紊乱不规则。③心肌组织核转录因子кB阳性率表达:与模型组比较,单个核细胞组、间充质干细胞组的梗死边缘区核转录因子кB阳性率明显降低(F=25.59,P=0.0001);正常心肌区核转录因子кB阳性率亦明显降低(F=18.20,P=0.0001)。④心肌细胞凋亡检测结果:与模型组比较,单个核细胞组、间充质干细胞组在心肌梗死区细胞凋亡率均明显降低(F=6.63,P=0.0027),梗死边缘区细胞凋亡率亦明显降低(F=36.07,P=0.0001)。正常心肌区单个核细胞组细胞凋亡率与模型组基本相似(F=9.69,P=0.004),但间充质干细胞组有所降低。⑤心功能与心肌细胞凋亡及心肌组织NF-кB的相关性:急性心肌梗死4周时,左心室射血分数与心肌细胞凋亡、心肌组织核转录因子кB均呈负相关(r=0.613,P=0.001;r=-0.437,P=0.033)。心肌细胞凋亡与心肌组织核转录因子кB呈正相关(r=0.672,P=0.002)。结论:经冠脉移植骨髓单个核细胞和间充质干细胞均可改善实验性急性心肌梗死动物的心功能,与梗死边缘区核转录因子кB表达降低及心肌细胞凋亡减少有关。骨髓单个核细胞移植的促血管增生作用优于间充质干细胞移植。 相似文献
48.
目的:缝隙连接蛋白43对维持心肌细胞的连接通讯功能、电信号传导和正常的节律性收缩起重要作用,其表达和分布的异常是多种室性心律失常的解剖学基础,建立小型猪急性心肌梗死模型.观察自体骨髓间充质干细胞移植后室性心动过速的发生及心肌缝隙连接蛋白43的表达方法:实验于2006-01/2007-01在河北省人民医院导管室完成。①材料:选取8~12月龄小型猪22头,由河北医科大学实验动物中心提供,体质量20~30 kg,随机数字表法分为细胞移植组12头、模型对照组10头.实验过程中对动物的处置符合动物伦理学际准②实验方法:无菌条件下抽取猪双侧股骨骨髓20 mL,percoll法 贴壁法分离培养骨髓间充质干细胞,待细胞生长达75%融合时用胰酶消化传代。将传至第2代细胞加入终浓度为10μmol/L的5-氮胞苷进行诱导,用胶体金标记12 h后继续培养20 d用于移植:两组小型猪均采用球囊堵闭法建立急性心肌梗死模型.心电图监测示相关至少2个导联ST段抬高大于0.2 mV、术后血肌钙蛋白和肌酸磷酸激酶同工酶升高超过正常的两倍为建模成功标准:细胞移植组于造模成功后经OTW球囊于第一对角支远端1 cm处再次阻断血流,注入经胶体金标记的10×10~7个骨髓间充质干细胞。③实验评估:于细胞移植后2 h及4周行电生理程序刺激.观察室性心动过速的发生情况。末次电生理检查后、采用免疫组化染色法检测心肌缝隙连接蛋白43的表达.计算其积分吸光度值。结果:①模型建立指标检测:与术前比较.造模后所有小型猪血肌钙蛋白含量和肌酸磷酸激酶同工酶活性均增高,峰值浓度分别为(21.3±3.6)μg/L和(178.3×41.4)IU/L,术中心电图ST段平均抬高(10.67±1.43)mm.证明急性心肌梗死模型成功建立。②骨髓间充质干细胞移植后室性心动过速的发生情况:与模型对照组诱发出室性心动过速的动物数量比较,术后2 h细胞移植组无明显变化(X~2=0.201,P=0.650),术后4周细胞移植组明显降低(X~2=4.455.P=0.035)。②骨髓间充质干细胞移植后梗死心肌缝隙连接蛋白43的表达:术后4周移植到梗死心肌的骨髓间充质干细胞与宿主心肌生长为一体,移植部位颜色变黑,苏木精-伊红染色示移植细胞的胞浆呈紫红色。细胞移植组心肌梗死区缝隙连接蛋白43积分吸光度值明显高于模型对照组(t=16,82.P=0.00),细胞移植组中未发生室性心动过速小型猪的梗死心肌缝隙连接蛋白43的表达明显高于发生室性心动过速小型猪(t=5.06,P=0.00)。结论:自体骨髓间充质干细胞移植可促进急性心肌梗死猪心肌缝隙连接蛋白43的表达,其表达程度可能与急性心肌梗死室性心动过速的发生有关。 相似文献
49.
A. PIKWER L. BÅÅTH I. PERSTOFT B. DAVIDSON J. ÅKESON 《Acta anaesthesiologica Scandinavica》2009,53(9):1145-1152
Background: Knowledge of the radiographic catheter tip position after central venous cannulation is normally not required for short-term catheter use. Detection of a possible iatrogenic pneumothorax may nevertheless justify routine post-procedure chest X-ray. Our aim was to design a clinical decision rule to select patients for radiographic evaluation after central venous cannulation.
Methods: A total of 2230 catheterizations performed using external jugular, internal jugular or subclavian venous approaches during a 4-year period were included consecutively. Information on patient data and corresponding procedures was recorded prospectively. A post-procedure chest X-ray was obtained after each cannulation.
Results: Thirteen cases (0.58%) of cannulation-associated pneumothorax were identified. The risk of pneumothorax after a technically difficult (1.8%) or subclavian (1.6%) cannulation was significantly higher than after cannulation not considered as difficult (0.37%) or performed using other routes (0.33%). Clinical signs of pneumothorax within 8 h of cannulation were found in all seven patients with pneumothorax requiring specific treatment. A new clinical decision rule for radiographic evaluation after central venous cannulation based on the results of the present study shows that 48% of the post-procedure chest X-rays performed in our patients were clinically redundant.
Conclusion: Clinical symptoms were reported in all patients with pneumothorax requiring specific treatment. Approximately half of the post-procedure chest X-ray controls could be avoided using the proposed clinical decision rule to select patients for radiographic evaluation after central venous cannulation. A large prospective multi-centre study should be carried out to further evaluate this decision rule. 相似文献
Methods: A total of 2230 catheterizations performed using external jugular, internal jugular or subclavian venous approaches during a 4-year period were included consecutively. Information on patient data and corresponding procedures was recorded prospectively. A post-procedure chest X-ray was obtained after each cannulation.
Results: Thirteen cases (0.58%) of cannulation-associated pneumothorax were identified. The risk of pneumothorax after a technically difficult (1.8%) or subclavian (1.6%) cannulation was significantly higher than after cannulation not considered as difficult (0.37%) or performed using other routes (0.33%). Clinical signs of pneumothorax within 8 h of cannulation were found in all seven patients with pneumothorax requiring specific treatment. A new clinical decision rule for radiographic evaluation after central venous cannulation based on the results of the present study shows that 48% of the post-procedure chest X-rays performed in our patients were clinically redundant.
Conclusion: Clinical symptoms were reported in all patients with pneumothorax requiring specific treatment. Approximately half of the post-procedure chest X-ray controls could be avoided using the proposed clinical decision rule to select patients for radiographic evaluation after central venous cannulation. A large prospective multi-centre study should be carried out to further evaluate this decision rule. 相似文献
50.
R Wanitphakdeedecha TH Nguyen TM Chen 《Journal of the European Academy of Dermatology and Venereology》2010,24(4):445-448
Background Appropriate pricing for medical services of not‐for‐profit hospital is necessary. The prices should be fair to the public and should be high enough to cover the operative costs of the organization. Objective The purpose of this study was to determine the cost and unit cost of medical services performed at the Mohs and Dermasurgery Unit (MDU), Department of Dermatology, The University of Texas – MD Anderson Cancer Center, Houston, TX from the healthcare provider’s perspective. Methods MDU costs were retrieved from the Financial Department for fiscal year 2006. The patients’ statistics were acquired from medical records for the same period. Unit cost calculation was based on the official method of hospital accounting. Results The overall unit cost for each patient visit was $673.99 United States dollar (USD). The detailed unit cost of nurse visit, new patient visit, follow‐up visit, consultation, Mohs and non‐Mohs procedure were, respectively, $368.27, $580.09, $477.82, $585.52, $1,086.12 and $858.23 USD. With respect to a Mohs visit, the unit cost per lesion and unit cost per stage were $867.89 and $242.30 USD respectively. Conclusions Results from this retrospective study provide information that may be used for pricing strategy and resource allocation by the administrative board of MDU. 相似文献