Detailed structural elucidation of polyesters and acrylates using Fourier transform mass spectrometry

The detailed structural characterization of complex polymer architectures, like copolymers and polymer mixtures, by mass spectrometry presents a challenge. Even though soft ionization analyses revolutionized the characterization of large molecules and provided a means for determining the polymer’s molecular weight distribution, polydispersity, and end groups, full microstructure elucidation and monomer sequencing by soft ionization alone is not possible. The combination of high-resolution Fourier transform mass spectrometry (FTMS) and tandem mass spectrometry (MSn) provides a powerful analytical tool for addressing these challenges. This tool was used in our work to separate and identify the products of polymerization between 12-hydroxystearic acid (HSA) and stearic acid (SA), to provide precise information about the exact location of caprolactones on the Tris(2-hydroxyethyl)isocyanurate (THEIC) molecule, and to sequence a glycidyl methacrylate/methyl methacrylate (GMA/MMA) copolymer. The results highlight the value of ultrahigh resolution and tandem mass spectrometry for fine structural characterization and sequencing of polymers

Reliability, Validity and Factor Structure of the 12-Item General Health Questionnaire among General Population

AIM: The aim of the study is to analyze the internal consistency; validity and factor structure of the twelve item General Health Questionnaire for the Macedonian general population.MATERIAL AND METHODS: Data came from nationally representative sample of 1603 randomly selected Macedonians all aged 18 years or older.RESULTS: The mean GHQ score in the general sample was found to be 7.9 (SD = 4.3). The results revealed a higher GHQ score among women (M = 8.91, SD = 4.5) compared to men (M = 6.89; SD = 4.2). The participants from the rural areas obtained a lower GHQ score (M = 7.55, SD = 3.8) compared to participants coming from the urban areas (M = 9.37, SD = 4.1). The principal component analysis with oblique rotation (direct oblimin) with maximum likelihood procedure solution was performed and the results yielded a three factor solution which jointly accounted for 57.17% of the total variance: Factor I named social management (items 1, 3, 4, 6, 7 and 8); Factor II stress (items 2, 5 and 9) and Factor III named self-confidence (items 10, 11 and 12). Its factor structure is in line with representative research from other population groups.CONCLUSION: The GHQ-12 can be used effectively for assessment of the overall psychological well-being and detection of non-psychotic psychiatric problems among the Macedonian population

Multifunctional Cotton Impregnated with Multilayer Chitosan/Lignin Nanocoating and Ag Nanoparticles

he demand for clothes with antimicrobial and UV protective properties is continually growing. In an attempt to develop a simple and efficient treatment for cotton fabrics, layer-by-layer deposition of chitosan and magnesium lignosulfonate followed by in situ synthesis of Ag nanoparticles (NPs) was performed. Magnesium lignosulfonate acts as a stabilizing agent and UV blocker while NaBH4 is applied as a reducing agent. The influence of the number of bilayers (4 and 12) and the initial concentration of AgNO3 solution (10 mM and 20 mM) on UV protection factor (UPF) and antimicrobial activity against Gram-negative bacteria Escherichia coli, Grampositive bacteria Staphylococcus aureus and yeast Candida albicans was studied. The presence of nanocoating on the surface of cotton fabric is confirmed by FTIR and XPS analyses. XPS and FESEM analyses reveal a successful synthesis of Ag NPs on the surface of cotton fibers with an average dimension of 35 nm. A four bilayer coating is sufficient to reach maximum 50+ UV protection. Maximum reduction of all investigated microorganisms is achieved with 12 bilayers and application of 20 mM AgNO3 solution

Computed Tomography Imaging of Primary Lung Cancer in Mice Using a Liposomal-Iodinated Contrast Agent

To investigate the utility of a liposomal-iodinated nanoparticle contrast agent and computed tomography (CT) imaging for characterization of primary nodules in genetically engineered mouse models of non-small cell lung cancer.Primary lung cancers with mutations in K-ras alone (Kras(LA1)) or in combination with p53 (LSL-Kras(G12D);p53(FL/FL)) were generated. A liposomal-iodine contrast agent containing 120 mg Iodine/mL was administered systemically at a dose of 16 µl/gm body weight. Longitudinal micro-CT imaging with cardio-respiratory gating was performed pre-contrast and at 0 hr, day 3, and day 7 post-contrast administration. CT-derived nodule sizes were used to assess tumor growth. Signal attenuation was measured in individual nodules to study dynamic enhancement of lung nodules.A good correlation was seen between volume and diameter-based assessment of nodules (R(2)>0.8) for both lung cancer models. The LSL-Kras(G12D);p53(FL/FL) model showed rapid growth as demonstrated by systemically higher volume changes compared to the lung nodules in Kras(LA1) mice (p<0.05). Early phase imaging using the nanoparticle contrast agent enabled visualization of nodule blood supply. Delayed-phase imaging demonstrated significant differential signal enhancement in the lung nodules of LSL-Kras(G12D);p53(FL/FL) mice compared to nodules in Kras(LA1) mice (p<0.05) indicating higher uptake and accumulation of the nanoparticle contrast agent in rapidly growing nodules.The nanoparticle iodinated contrast agent enabled visualization of blood supply to the nodules during the early-phase imaging. Delayed-phase imaging enabled characterization of slow growing and rapidly growing nodules based on signal enhancement. The use of this agent could facilitate early detection and diagnosis of pulmonary lesions as well as have implications on treatment response and monitoring

Pressure effects on CO2-laser coincidences with ethene and ammonia investigated by photoacoustic detection

Carbon dioxide laser coincidences were investigated by photoacoustic detection at laser lines 10P(28) and 9P(28) with ethene and at 10P(20) and 10P(16) with ammonia. The intensities of coincidences were measured as a function of pressure of a buffer gas (dry air) and pure gas. The intensities of two ammonia coincidences show an inversion with pressure. A method of eliminating all pressure effects other than those of spectral nature from the PA signal was introduced. This enabled deriving the pressure broadening coefficients of the coinciding absorption lines. (C) 1998 Published by Elsevier Science B.V

An architecture for computer-aided detection and radiologic measurement of lung nodules in clinical trials

Computer tomography (CT) imaging plays an important role in cancer detection and quantitative assessment in clinical trials. High-resolution imaging studies on large cohorts of patients generate vast data sets, which are infeasible to analyze through manual interpretation. In this article we describe a comprehensive architecture for computer-aided detection (CAD) and surveillance on lung nodules in CT images. Central to this architecture are the analytic components: an automated nodule detection system, nodule tracking capabilities and volume measurement, which are integrated within a data management system that includes mechanisms for receiving and archiving images, a database for storing quantitative nodule measurements and visualization, and reporting tools. We describe two studies to evaluate CAD technology within this architecture, and the potential application in large clinical trials. The first study involves performance assessment of an automated nodule detection system and its ability to increase radiologist sensitivity when used to provide a second opinion. The second study investigates nodule volume measurements on CT made using a semi-automated technique and shows that volumetric analysis yields significantly different tumor response classifications than a 2D diameter approach. These studies demonstrate the potential of automated CAD tools to assist in quantitative image analysis for clinical trials