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1.
为了对比分析对比增强能谱乳腺X线摄影(contrast enhanced specral mammography,CESM)与全视野数字化乳腺X线摄影(full-field digital mammography,FFDM)在致密型乳腺疾病中的诊断价值,回顾性分析了2017年3月~2018年12月在我院乳腺外科就诊并经病理证实的137例患者。所有患者乳腺纤维腺体均为致密型,且在一周内行FFDM和CESM两种检查,以病理结果为金标准,计算了两种检查方法诊断致密型乳腺疾病的敏感度、特异度、阳性预测值、阴性预测值和准确率,采用卡方检验比较了FFDM与CESM在致密型乳腺疾病中的诊断效能。结果显示,137例患者经病理证实共检出140个病灶,其中良性病灶105个、恶性病灶35个。CESM诊断致密型乳腺疾病的特异度、阳性预测率和准确率均高于FFDM(P<0.05)。总之,与FFDM比较,CESM对致密型乳腺疾病的诊断效能较高。  相似文献   

2.
本研究探讨3.0T磁共振成像(MRI)结合X线钼靶诊断乳腺恶性肿瘤的价值。采用回顾性研究方法,选取乳腺肿块患者110例162个病灶,给予3.0T MRI及X线钼靶检查。经病理确诊为恶性病变101个;恶性病灶形态不规则、边缘毛刺、时间-信号强度曲线(TIC)类型Ⅲ型和早期增强率≥60%比例明显高于良性病灶(P<0.05),而分叶状比例和表观扩散系数(ADC)值明显低于良性病变(P<0.05);恶性病变X线钼靶表现:形态不规则、钙化、结构不对称和大导管征比例明显高于良性病变(P<0.05);MRI联合X线钼靶诊断乳腺恶性病变的灵敏性、准确性和阴性预测值明显高于MRI诊断(P<0.05)。3.0T MRI检查结合X线钼靶诊断乳腺恶性肿瘤有较好的价值。  相似文献   

3.
本研究的目的是探讨超声和钼靶X线检查在更年期女性乳腺微小肿块诊断中的价值。选取乳腺微小肿块更年期女性患者115例,其中良性与恶性病变分别为79例和36例。患者均进行超声和钼靶X线检查,分析两种方法的图像特征及诊断价值。恶性病变超声图像边缘不光滑、有微钙化、纵横比>0.8比例、钼靶微小钙化比例明显高于良性病变(P<0.05);超声诊断恶性病变的灵敏性、准确性和阴性预测值明显高于钼靶X线检查(P<0.05)。直径1~2 cm恶性病灶钼靶诊断准确性明显高于直径<1 cm恶性病灶(P<0.05);直径<1 cm恶性病灶时,超声诊断准确性明显高于钼靶X线检查(P<0.05)。超声在更年期女性乳腺微小肿块诊断中的价值优于钼靶X线检查,尤其在直径<1 cm病灶中。  相似文献   

4.
本文研究了一些钼络合物的X光电子能谱,测定了钼3d电子的结合能(E_b),并讨论了钼的氧化态和桥连原子对此的影响。  相似文献   

5.
含硫氮的螯合树脂及其金属螯合物的X—光电子能谱研究   总被引:1,自引:0,他引:1  
螯合树脂的合成及其对各种金属离子的吸附性能研究已有大量文献报道。螯合树脂由于对某些金属离子具有优良的吸附选择性,以及其他优点现已广泛应用于金属的富集与分  相似文献   

6.
本文叙述了用X射线光电子能谱(XPS)表征棉纤维的表面特性,比较了不同方法处理的棉纤维的表面改性。还讨论了等离子体对棉纤维的润湿性和脱脂作用机理。实验表明:刻蚀、氧化、分裂和接枝含氧基团是低温氧等离子体对棉纤维表面的主要作用。  相似文献   

7.
用角分布X射线光电子能谱(XPS)测试和样品原位加热相结合的方法研究了阴离子是对甲苯磺酸根的电生导电聚吡咯的化学和聚集态结构.其结果表明聚吡咯表面约几个原子层内原子的相对浓度依下述次序递减:C>O>S>N;导电聚吡咯中的氮原子至少有吡咯氮和氧化态氮两种;在200℃加热以后聚合物链不受影响,但阴离子向表面迁移,同时氧化态氮大大减少.  相似文献   

8.
本文制备了一系列不同碘含量的板状碘溴化银微晶(微晶大小约为3微米)。运用扫描透射电镜和X射线能谱仪(EDS)对单个微晶进行了分析和研究,半定量地测定了碘离子在板状微晶中的面分布;运用扫描俄歇微区棵针(SAM)和二次电子像、离子溅射剥层技术对微晶进行了表面及其纵深的碘离子的点分析,根据EDS和SAM的结果,可以得到板状碘溴化银微晶中的碘离子的空间分布。实验结果表明在板状缺溴化银微晶中,在其中心部位的碘含量最高;越靠近横向边缘的位置,碘含量越低。且在制备碘溴化银微晶时,如果pAg值较高,将会使在制备早期加入的碘离子通过不断的重结晶向微晶表面扩散,得到的微晶不是夹心结构的碘溴化银微晶。  相似文献   

9.
为解决X射线荧光测量过程中的仪器刻度和校正难题,通过理论研究并运用蒙特卡洛方法对X射线荧光仪进行建模,得到了X射线探测器能谱响曲线。结果表明:模拟的X射线探测器能谱响应全谱与实测情况基本一致,而主成份谱线则高度一致,特征峰半高宽相对误差均在5%以内。方法为X射线荧光测量的仪器刻度和校正提供重要的研究信息,不仅为元素分析工作节省大量人力物力,也为无标样X射线荧光分析提供了有力的理论支撑。方法也可用于X射线荧光分析过程中的其他研究领域。  相似文献   

10.
利用X射线光电子能谱(XPS)和聚焦离子束(FIB)技术,实现对FeCrAl合金涂层在1200℃水蒸气环境下氧化行为的研究.XPS和FIB法可以检测和观测到材料随深度变化的界面层、化学态和真实结构等信息,具有直观、且信息丰富(含量、化学态及形貌)等优点.为方法在更广泛的材料体系内的应用提供理论和实践基础.  相似文献   

11.
Low contrast and noisy photographic pictures can be considerably improved by image-processing techniques. Techniques like histogram equalisation produce high-contrast images but often fail to preserve the colour texture information. To overcome this deficiency, a contrast-enhancement approach has been devised, using virtual contrast image fusion (in Haar wavelet domain). This technique has been evaluated by a study of the optical textures of nano-dispersed decyloxybenzoic acid with small quantities of Fe3O4 and ZnO added.  相似文献   

12.
高分辨阿达玛变换显微光谱成像系统研究   总被引:2,自引:0,他引:2  
阿达玛变换(HT)是一种多通道的光谱调制技术,基于这一原理,研制了一种显微光谱成像系统.通过光学设计,除可以获得微小试样(如单个细胞)的光谱以外,还可以对试样进行分光谱成像,得到分辨率为256×256像素的256级灰度图像.通过对两种不同荧光发射波长的CdSe/ZnS量子点进行的分光谱成像测试表明,本系统具有良好的分光谱成像能力,可以对具有复杂光谱的物质针对其某一特定成分进行成像.  相似文献   

13.
表面增强拉曼光谱(SERS)的广泛应用源于优良的基底,目前主要局限在粗糙贵金属及胶体纳米颗粒材料.而半导体的光谱高稳定性和再现性,使其成为制备SERS基底的新型材料,但对于其SERS增强机理的研究仍存在极大挑战.本工作以典型的形貌新颖、尺寸均一的扫帚状n型纳米半导体ZnO为SERS基底材料,通过调节激发光的波长和选用具有不同对位取代基的对硝基苯硫酚(PNTP)、苯硫酚(TP)、对氨基苯硫酚(PATP)为探针分子,系统地研究了纳米ZnO的SERS增强行为,估算了其表面增强因子(EF),分离了化学增强作用中非共振增强效应和电荷转移效应对SERS的贡献.研究表明三种分子在不同激发光作用下的增强因子为10至35,其中PNTP分子约10倍的增强主要来自于因吸附而造成极化率变化的非共振增强效应,TP和PATP分子20~35倍的增强则是由非共振增强效应与光子驱动电荷转移效应共同作用所致,光子能量越高,SERS增强效应越强.且因分子与ZnO间电荷转移的速率较慢导致ZnO表面电荷转移增强效应较贵金属低1~2个数量级.本研究结果为新型半导体SERS基底的制备及调控提供了新思路.  相似文献   

14.
The emissive properties of fluorophores in aggregated state are important for the development of bio-sensors or bio-imaging reagents. So three water-soluble TPE derivatives with different lengths of side chains have been synthesized and we investigated the effects of side chains on aggregation-induced emission (AIE) properties in the aggregated states. The results indicate that side chains on the fluorophores play a pivotal role in their emission in aggregated state mediated by heparin or solid state, because the coplanarity of these TPE derivatives was affected by side chains. The rates of radiative decay kf and non-radiative decay knr have been obtained through the quantum yields and lifetime, and a larger kf and smaller knr were present for compound TPE-C4N, suggesting that the aggregated TPE-C4N should posses the most remarkable fluorescent property.  相似文献   

15.
硒素营养对麦芽质量指标的影响   总被引:1,自引:0,他引:1  
大麦在制麦过程中的溶解对麦芽质量、啤酒的酿造以及成品啤酒的质量有重要的影响。本文利用生物转化技术,以微量元素硒作为制麦添加剂,以提高麦芽质量。本实验中,浸麦采用第一次浸6h以下采用浸二断四的工艺,浸水时每小时换水一次,一直通风,当浸麦度达40%~42%时,用硒溶液处理1h。发芽前两天每天补水两次,后期促进其凋萎。焙燥过程中前期低温大风量排湿,中期合理稳步升温,后期严格控制焙焦温度,使整个过程稳定。测定制得的成品麦芽的糖化力、α-AN、无水浸出率、色度等质量指标。发现硒对麦芽的质量有一定的影响。  相似文献   

16.
本支通过对Si_(29)无规网络原子簇模型的CNDO计算,探讨了非晶硅(a-Si)结构短程序对其电子态密度(DOS)分布的影响。结果表明,在与实验原子径向分布函数(RDF)基本相同的条件下,a-Si模型中的键角和二面角是影响电子态密度分布的主要参数。  相似文献   

17.
介绍了中国科学技术大学化学实验教学中心在实验助教培训和管理方面所开展的举措,从助教申请及培训流程、教学方法与技巧、考核制度、奖励措施等方面展开论述,分析了实验助教在本科实验教学中的作用,以及目前实验助教制度中存在的一些问题和解决方法。  相似文献   

18.
张博  郭玉鹏  魏士刚 《化学教育》2022,43(14):74-77
实验室的日常管理水平直接反映了高校实验室管理的水平,也潜移默化地影响着实验教学的质量。为做好化学国家级实验教学示范中心的可持续性发展,详细介绍了吉林大学化学国家级实验教学示范中心在人员、设备、材料、环境和操作规程等精细化管理过程中所做的有别于其他学校的工作以及取得的良好效果,为实验室管理细节创新和促进实验教学质量提高积累了宝贵的经验。  相似文献   

19.
Today, the most significant challenge encountered by food manufacturers is degradation in the food quality during storage, which is countered by expensive packing, which causes enormous monetary and environmental costs. Edible packaging is a potential alternative for protecting food quality and improving shelf life by delaying microbial growth and providing moisture and gas barrier properties. For the first time, the current article reports the preparation of the new films from Ditriterpenoids and Secomeliacins isolated from Melia azedarach (Dharek) Azadirachta indica plants to protect the quality of fruits. After evaluating these films, their mechanical, specific respirational, coating crystal elongation, elastic, water vapor transmission rate (WVTR), film thickness, and nanoindentation test properties are applied to apple fruit for several storage periods: 0, 3, 6, 9 days. The fruits were evaluated for postharvest quality by screening several essential phytochemical, physiological responses under film coating and storage conditions. It was observed that prepared films were highly active during storage periods. Coated fruits showed improved quality due to the protection of the film, which lowered the transmission rate and enhanced the diffusion rate, followed by an increase in the shelf life. The coating crystals were higher in Film-5 and lower activity in untreated films. It was observed that the application of films through dipping was a simple technique at a laboratory scale, whereas extrusion and spraying were preferred on a commercial scale. The phytochemicals screening of treated fruits during the storage period showed that a maximum of eight important bioactive compounds were present in fruits after the treatment of films. It was resolved that new active films (1–5) were helpful in the effective maintenance of fruit quality and all essential compounds during storage periods. It was concluded that these films could be helpful for fruits growers and the processing industry to maintain fruit quality during the storage period as a new emerging technology.  相似文献   

20.
Surfactants are commonly used to increase the solubility of poorly water soluble drugs but the interactions between drug and surfactant can be complex and quantitative relationships can be hard to derive. One approach is to quantify the thermodynamics of interaction and relate these parameters to known solubility or dissolution rate enhancement data. Isothermal titration calorimetry (ITC) was used to measure the enthalpy and free energy of transfer of a model drug (simvastatin) to a number of surfactant (SDS, HTAB, SDCH and Brij 35) micelles. These data were then compared with the solubility enhancements determined for each surfactant using HPLC assays. As expected, there was correlation between the free energy of transfer for the drug to each surfactant and the solubility enhancement of that surfactant. Although the data set is limited, the results suggest that ITC screening of a range of surfactants against a poorly water soluble drug may allow the selection of the best potential solubilising surfactants.  相似文献   

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