首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   66篇
  免费   11篇
  国内免费   13篇
  2023年   2篇
  2021年   3篇
  2020年   3篇
  2018年   3篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   4篇
  2013年   6篇
  2012年   6篇
  2011年   1篇
  2010年   2篇
  2009年   2篇
  2008年   9篇
  2007年   4篇
  2006年   3篇
  2005年   5篇
  2004年   4篇
  2002年   4篇
  2001年   6篇
  2000年   5篇
  1999年   2篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1989年   1篇
  1988年   1篇
  1985年   3篇
  1984年   1篇
  1982年   1篇
  1975年   1篇
排序方式: 共有90条查询结果,搜索用时 15 毫秒
41.
庆大霉素单克隆抗体的制备及试剂盒的配制   总被引:1,自引:0,他引:1  
目的建立庆大霉素直接竞争酶联免疫吸附分析方法。方法应用戊二醛法制备庆大霉素完全抗原,通过杂交瘤技术筛选分泌特异性庆大霉素抗体的杂交瘤细胞株,并建立庆大霉素竞争酶联免疫吸附分析检测方法。结果获得3株能稳定分泌庆大霉素单克隆抗体的杂交瘤细胞株,建立了庆大霉素竞争酶联免疫吸附分析检测方法,该方法操作简单具有良好的线性、特异性和精密度;庆大霉素质量浓度在1.5625~50.0000 ng/mL范围内,呈现良好的线性,r2=0.9913,50%抑制浓度为(IC50)为7.37 ng/mL,检测限(LOD)为1.54 ng/mL,该试剂盒与链霉素等8种药物无交叉反应。结论获得3株能稳定分泌庆大霉素单克隆抗体的杂交瘤细胞株,研制的庆大霉素竞争ELISA检测试剂盒具有良好的线性、特异性和精密度。  相似文献   
42.
目的:对比肺大泡并自发性气胸患者经单孔与三孔胸腔镜治疗后的临床疗效。方法:回顾性分析2016年6月~2019年4月期间我院收治的93例肺大泡并自发性气胸患者的临床资料,根据手术方式的不同将其分为单孔组(n=45,单孔胸腔镜治疗)和三孔组(n=48,三孔胸腔镜治疗),比较两组患者围术期指标、视觉疼痛模拟量表(VAS)评分、并发症、血气分析指标、肺功能指标。结果:单孔组住院时间短于三孔组,出血量少于三孔组(P<0.05);两组手术时间、术后引流量比较无差异(P>0.05)。两组术后并发症发生率比较无差异(P>0.05)。两组患者术后3d血氧分压(PaO2)较术前升高,且单孔组较三孔组高(P<0.05);两组患者术后3d二氧化碳分压(PaCO2)较术前降低,且单孔组低于三孔组(P<0.05)。两组患者术后3d第一秒用力呼吸容积(FEV1)较术前升高,肺总量(TLC)及肺残气量(RV)较术前降低(P<0.05),但组间比较无统计学差异(P>0.05)。两组患者术后1d、术后2d、术后3d VAS评分呈先升高后降低趋势,且单孔组低于三孔组(P<0.05)。结论:与三孔胸腔镜治疗相比,单孔胸腔镜治疗肺大泡并自发性气胸,可有效减少术中出血量,减轻疼痛,促进患者恢复,同时还可改善血气指标,安全性较好。  相似文献   
43.

Background

Recently, mist saunas have been used in the home as a new bathing style in Japan. However, there are still few reports on the effects of bathing methods on recovery from muscle fatigue. Furthermore, the effect of mist sauna bathing on human physiological function has not yet been revealed. Therefore, we measured the physiological effects of bathing methods including the mist sauna on recovery from muscle fatigue.

Methods

The bathing methods studied included four conditions: full immersion bath, shower, mist sauna, and no bathing as a control. Ten men participated in this study. The participants completed four consecutive sessions: a 30-min rest period, a 10-min all out elbow flexion task period, a 10-min bathing period, and a 10-min recovery period. We evaluated the mean power frequency (MNF) of the electromyogram (EMG), rectal temperature (Tre), skin temperature (Tsk), skin blood flow (SBF), concentration of oxygenated hemoglobin (O2Hb), and subjective evaluation.

Results

We found that the MNF under the full immersion bath condition was significantly higher than those under the other conditions. Furthermore, Tre, SBF, and O2Hb under the full immersion bath condition were significantly higher than under the other conditions.

Conclusions

Following the results for the full immersion bath condition, the SBF and O2Hb of the mist sauna condition were significantly higher than those for the shower and no bathing conditions. These results suggest that full immersion bath and mist sauna are effective in facilitating recovery from muscle fatigue.  相似文献   
44.
H Shen  X Li  L Meng  Y Ni  G Wang  W Dong  J Du 《Gene》2012,509(1):173-177
PET/CT (Positron Emission Tomography-Computed Tomography) is an advanced diagnostic imaging device that combines both PET and an X-ray CT. This study evaluates the effects of PET/CT on detecting primary tumors and metastases, and looks at the therapeutic effect of minimally invasive surgery on esophageal cancer patients. Eighty patients with esophageal cancer were enrolled in the study between January, 2004 and December, 2007, who were randomly divided into two groups of 40, one of which was treated with hand-video-assisted thoracoscopy surgery (HVATS) esophagectomy and one of which was treated with conventional surgery. All patients underwent a PET/CT scan 2-3weeks before their operation, and their cervical, thoracic and upper abdominal lymph nodes were biopsied. All the primary esophageal lesions showed high FDG uptake. The maximum standardized uptake value (SUV) was 3.78-25.64 (11.73±5.32), while the mean SUV was 3.65=16.92 (9.12±4.37). Using 2.5 as the SUV standard, all esophageal lesions were detected by PET/CT image. Of the 80 patients, 53 had lymph nodal metastases, with a total of 142 metastatic lymph nodes, which showed high FDG uptake. The maximum SUV was 2.77-14.63 (7.98±3.25), and the mean SUV was 2.31-12.84 (5.34±3.19). The visual analysis from the PET/CT scan showed a sensitivity of 86.62%, a specificity of 95.85%, a positive predictive value of 93.89%, a negative predictive value of 90.69% and an accuracy of 91.94%. The PET/CT scan showed a high sensitivity and specificity in detecting primary esophageal cancer and lymph nodal metastases. The mean post-surgery life expectancies for patients undergoing HVATS and conventional surgery are 27.93months and 28.05months, respectively. The two groups showed no statistically significant difference. We thus conclude that PET/CT combined with HVATS is a new choice for esophageal carcinoma patients.  相似文献   
45.
Our objectives were to standarize the procedure needed to reproduce a similar surgical scene which a pediatric surgeon would face on repairing a Bochdalek hernia in newborns and to define the optimal time period for hernia development that achieve a realistic surgical scenario with minimimal animal suffering. Twenty New Zealand white rabbits weighing 3–3.5 kg were divided into four groups depending on the time frame since hernia creation to thoracoscopic repair: 48 h, 72 h, 96 h and 30 days. Bochdalek trigono was identified and procedures for hernia creation and thoracoscopic repair were standarized. Blood was collected for hematology (red blood cells, white blood cells, platelets, hemoglobin and hematocrit), biochemistry (blood urea nitrogen, creatinine, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and creatine kinase) and gas analysis (arterial blood pH, partial pressure of oxygen, partial pressure of carbón dioxide, oxygen saturation and bicarbonate) at baseline and before the surgial repairment. Glucocorticoid metabolites concentration in faeces was measured. Thoracoscopy video recordings were evaluated by six pediatric surgeons and rated from 0 to 10 according to similarities with congenital diaphragmatic hernia in newborn and with its thoracoscopic approach. Statistical methods included the analysis of variance, and comparisons between groups were followed by a post-hoc Tukey’s test. Fourty -eight h showed to be the optimal time frame to obtain a diaphragmatic hernia similar to newborn scenario from a surgical point of view with minimal stress for the animals.  相似文献   
46.
Medium composition and culture conditions for the bleaching stable alkaline protease production by Aspergillus clavatus ES1 were optimized. Two statistical methods were used. Plackett-Burman design was applied to find the key ingredients and conditions for the best yield. Response surface methodology (RSM) including full factorial design was used to determine the optimal concentrations and conditions. Results indicated that Mirabilis jalapa tubers powder (MJTP), culture temperature, and initial medium pH had significant effects on the production. Under the proposed optimized conditions, the protease experimental yield (770.66 U/ml) closely matched the yield predicted by the statistical model (749.94 U/ml) with R (2)=0.98. The optimum operating conditions obtained from the RSM were MJTP concentration of 10 g/l, pH 8.0, and temperature of 30 degrees C, Sardinella heads and viscera flour (SHVF) and other salts were used at low level. The medium optimization contributed an about 14.0-fold higher yield than that of the unoptimized medium (starch 5 g/l, yeast extract 2 g/l, temperature 30 degrees C, and pH 6.0; 56 U/ml). More interestingly, the optimization was carried out with the by-product sources, which may result in cost-effective production of alkaline protease by the strain.  相似文献   
47.
Ming K  Rosenbaum PR 《Biometrics》2000,56(1):118-124
In observational studies that match several controls to each treated subject, substantially greater bias reduction is possible if the number of controls is not fixed but rather is allowed to vary from one matched set to another. In certain cases, matching with a fixed number of controls may remove only 50% of the bias in a covariate, whereas matching with a variable number of controls may remove 90% of the bias, even though both control groups have the same number of controls in total. An example of matching in a study of surgical mortality is discussed in detail.  相似文献   
48.
49.
Invasive exotic plants can persist and successfully spread within ecosystems and negatively affect the recruitment of native species. The exotic invasive Ailanthus altissima and the native Robinia pseudoacacia are frequently found in disturbed sites and exhibit similar growth and reproductive characteristics, yet each has distinct functional roles such as allelopathy and nitrogen fixation, respectively. A four-month full additive series in the greenhouse was used to analyze the intraspecific and interspecific interference between these two species. In the greenhouse experiment, the inverse of the mean total biomass (g) response per plant for each species was regressed on the density of each species and revealed that the performance of the plants was significantly reduced by interspecific interference and not by intraspecific interference (p < 0.05). Other biomass traits such as root dry weight, shoot dry weight, stem dry weight, and leaf dry weight were also negatively affected by interspecific interference. Competition indices such as Relative Yield Total and Relative Crowding Coefficient suggested that A. altissima was the better competitor in mixed plantings. Ailanthus altissima consistently produced a larger above ground and below ground relative yield while R. pseudoacacia generated a larger aboveground relative yield in high density mixed species pots.  相似文献   
50.
“741杨”扦插苗耐阴性的研究   总被引:8,自引:0,他引:8       下载免费PDF全文
 用黑色遮阴网遮光,研究了741杨嫩枝扦插苗的耐阴性。共设置全日照(对照)、全日照的24.5%、7.5%和2.5%等4种光量。研究了光强对叶生长、叶解剖构造、叶绿素含量、光-光合曲线、新梢生长和生物量等指标。结果表明,741杨是一种喜光树种,在全日照下生长,其生物量等多项指标都高于各种遮光处理。741杨对24.5%光量有较强的适应补偿能力,其单片叶面积、新梢生长率、叶绿素含量、叶柄长度等都超过对照,但生物量还是低于对照34.4%。7.5%光量处理已接近741杨的耐阴极限。741杨扦插苗不能长期在2.5%的光量下生活。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号