The influences of the free volume and the termperature on the damping property of chlorinated isoprene-isobutylene rubber (CIIR) were first investigated by positron annihilation lifetime spectroscopy (PALS), dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC), respectively. From the variations of ortho-positronium (o-Ps) lifetimes as a function of temperature, two transition temperatures can be observed, i.e., Tg and TB. We found that there exists a pre-rubbery state between the glass transition temperature Tg and TB. The DMA results indicate that the tan delta peak of CIIR has a very broad temperature distribution because of the existence of a liquid-liquid transition (Tll). The temperature dependence of the average free volume size can be linearly fitted below Tg and above TB, respectively. It is very interesting that the difference spectrum of the free volume size between the results fitted by two lines (below Tg and above TB) and experimental data is very similar to the dynamic mechanical spectrum of CIIR. In order to clarify the damping mechanics, the Williams-Landel-Ferry (WLF) equation based on free volume theory has been successfully used to establish a direct quantificational relationship between the free volume and the damping property, which indicates that the free volume plays an important role in determining the damping property.
Degradable bone cement has superior osteoconductive and plasticity and is commonly used to treat defects over critical-size. Magnesium gallate metal-organic frameworks (MOFs) (Mg-MOF), with antibacterial and anti-inflammatory properties, are doped...
To expand the applications of glow discharge microplasma into biological analysis, an innovative ambient ion source for mass spectrometry, microplasma probe desorption/ionization mass spectrometry (MPPDI-MS), has been developed and demonstrated. Electrodes and a sampling tube were creatively combined using a stainless steel syringe needle, and efficient methods of introduction for biological samples in solid, liquid, and gaseous phases like phospholipid and amino acids were specially designed. Based on the active species generated by glow discharge plasma, simplified protonated spectra were obtained without extra solvent spray assistance. The method is easy to operate and versatile and especially has the ability to distinguish the isomeric compounds of ketone and aldehyde. Quantitative results of this method for different biological samples in different phases were also performed well. It was proved that with further improvement, this sensitive and selective analysis using MPPDI-MS with minimal invasiveness will be an ingenious tool in disease diagnosis and single-cell detections in the future.
Numerous studies have investigated the utility of calretinin in differentiating malignant mesothelioma (MM) from metastatic carcinoma (MC) in serous effusions. However, the results remain controversial. The aim of this study is to determine the overall accuracy of calretinin in serous effusions for MM through a meta-analysis of published studies. Publications addressing the accuracy of calretinin in the diagnosis of MM were selected from the Medline (Ovid), PubMed, the Cochrane Library Database and the Web of Science. Data from selected studies were pooled to yield summary sensitivity, specificity, positive and negative likelihood ratio (LR), diagnostic odds ratio (DOR), and receiver operating characteristic (SROC) curve. Statistical analysis was performed by Meta-Disc 1.4 and STATA 12.0 softwares. 18 studies met the inclusion criteria and the summary estimating for calretinin in the diagnosis of MM were: sensitivity 0.91 (95%CI: 0.87–0.94), specificity 0.96 (95%CI: 0.95–0.96), positive likelihood ratio (PLR) 14.42 (95%CI: 7.92–26.26), negative likelihood ratio (NLR) 0.1 (95%CI: 0.05–0.2) and diagnostic odds ratio 163.03 (95%CI: 54.62–486.63). The SROC curve indicated that the maximum joint sensitivity and specificity (Q-value) was 0.92; the area under the curve was 0.97. Our findings suggest that calretinin may be a useful diagnostic tool for confirming MM in serous effusions.
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