Degradable starch nanoparticle assisted ethanol precipitation of DNA

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.carbpol.2014.04.007 © 2014. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Precipitation of DNA from a large volume of aqueous solution is an important step in many molecular biology and analytical chemistry experiments. Currently, this is mainly achieved by ethanol precipitation, where a long-term incubation (usually overnight) at low temperature of −20 to −80 °C with high salt concentration is required. This method also requires a large quantity of DNA to form a visible pellet and was tested mainly for double-stranded DNA. To improve DNA precipitation, co-precipitating polymers such as linear polyacrylamide has been used. In this work, we report that starch nanoparticles (SNPs) can achieve convenient DNA precipitation at room temperature with a low salt concentration and short incubation time. This method requires as low as 0.01–0.1% SNPs and can precipitate both single- and double-stranded DNA of various lengths. The effect of salt concentration, pH and the crosslinking density of SNPs has been systematically studied. Compared to other types of precipitating agents, SNPs are highly biocompatible and can be degraded by a common enzyme (amylase). This work suggests a novel application of a bio-based material that is prepared in mass production.Natural Sciences and Engineering Research Council || EcoSynthetix Inc. |

Degradable starch nanoparticle assisted ethanol precipitation of DNA

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.carbpol.2014.04.007 © 2014. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Precipitation of DNA from a large volume of aqueous solution is an important step in many molecular biology and analytical chemistry experiments. Currently, this is mainly achieved by ethanol precipitation, where a long-term incubation (usually overnight) at low temperature of −20 to −80 °C with high salt concentration is required. This method also requires a large quantity of DNA to form a visible pellet and was tested mainly for double-stranded DNA. To improve DNA precipitation, co-precipitating polymers such as linear polyacrylamide has been used. In this work, we report that starch nanoparticles (SNPs) can achieve convenient DNA precipitation at room temperature with a low salt concentration and short incubation time. This method requires as low as 0.01–0.1% SNPs and can precipitate both single- and double-stranded DNA of various lengths. The effect of salt concentration, pH and the crosslinking density of SNPs has been systematically studied. Compared to other types of precipitating agents, SNPs are highly biocompatible and can be degraded by a common enzyme (amylase). This work suggests a novel application of a bio-based material that is prepared in mass production.Natural Sciences and Engineering Research Council || EcoSynthetix Inc. |

Parts-per-Million of Polyethylene Glycol as a Non-Interfering Blocking Agent for Homogeneous Biosensor Development

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Analytical Chemistry copyright © American Chemical Society after peer review and technical editing by publisher. To access the final edited and published work see Liu, B., Huang, P.-J. J., Zhang, X., Wang, F., Pautler, R., Ip, A. C., & Liu, J. (2013). Parts-per-Million of Polyethylene Glycol as a Non-Interfering Blocking Agent for Homogeneous Biosensor Development. Analytical Chemistry, 85(21), 10045–10050. https://doi.org/10.1021/ac4024654Many homogeneous assays are complicated by the adsorption of probe molecules by the surface of reaction vessels, which are often made of polypropylene or polystyrene-based plastics. To solve this problem, many protein and surfactant-based blocking agents are used. However, these blockers may interfere with intended assays by sequestering transition-metal ions, inducing protein denaturing, generating air bubbles or making pores in membranes. Coating surfaces with polyethylene glycol (PEG) through covalent linkages has been proven to be an effective method to minimize protein adsorption. However, this method is more difficult to apply on plastic surfaces and is quite expensive. While unmodified PEG is often considered as a nonadsorbing polymer, in this Technical Note, we report that PEG at very low concentration (ppm level) can still effectively block plastic surfaces. This method works for DNA, protein, and liposome-based assays as long as the molecular weight of PEG is greater than 2000. PEG works because of multivalent hydrophobic interaction from its repeating methylene units. This Technical Note will not only facilitate biosensor development, but also enhance our understanding of the interaction between various molecules and plastic surfaces.University of Waterloo || Canadian Foundation for Innovation || Ontario Ministry of Research & Innovation || Canadian Institutes of Health Research || Natural Sciences and Engineering Research Council |

Association between monosodium glutamate intake and sleep-disordered breathing among Chinese adults with normal body weight

ObjectiveTo assess whether monosodium glutamate (MSG) intake is associated with sleep-disordered breathing (SDB).MethodsData from 1227 Chinese subjects who participated in the Jiangsu Nutrition Study were analyzed. All the participants were examined at two time points (baseline in 2002 and follow-up in 2007). The MSG intake was assessed quantitatively in 2002 and a sleep questionnaire was used to assess snoring and to construct an SDB probability score in 2007. Those within the fifth quintile of the score (highest) were defined as having a high probability of SDB.ResultsThe MSG intake was positively associated with snoring and a high probability of SDB in participants who had a normal body weight but in those who were overweight. A comparison of the extreme quartiles of MSG intake in subjects with a body mass index lower than 23 kg/m² showed an odds ratio of 2.02 (95% confidence interval 1.02-4.00) for snoring and an odds ratio of 3.11 (95% confidence interval 1.10-8.84) for a high probability of SDB. There was a joint effect between MSG and overweight in relation to SDB.ConclusionThe intake of MSG may increase the risk of SDB in Chinese adults with a normal body weight.Zumin Shi, Gary A. Wittert, Baojun Yuan, Yue Dai, Tiffany K. Gill, Gang Hu, Robert Adams, Hui Zuo, Anne W. Taylo

Reference values for respiratory system impedance using impulse oscillometry in healthy preschool children

PurposeThe normal values for lung resistance and lung capacity of children, as determined by impulse oscillometry (IOS), are different for children of different ethnicities. However, reference values there is no available reference value for Korean preschool children have yet to be determined. The aim of the present study was to determine the normal ranges of IOS parameters in Korean preschool children.MethodsA total of 133 healthy Korean preschool children were selected from 639 children (aged 3 to 6 years) who attended kindergarten in Seongnam, Gyeonggi province, Korea. Healthy children were defined according to the European Respiratory Society (ERS) criteria. All subjects underwent lung function tests using IOS. The relationships between IOS value (respiratory resistance (Rrs) and reactance (Xrs) at 5 and 10 Hz and resonance frequency (RF)) and age, height, and weight were analyzed by simple linear and multiple linear regression analyses.ResultsThe IOS success rate was 89.5%, yielding data on 119 children. Linear regression identified height as the best predictor of Rrs and Xrs. Using stepwise multiple linear regressions based on age, height, and weight, we determined regression equations and coefficients of determination (R2) for boys (Rrs5=1.934-0.009×Height, R2=12.1%; Xrs5=0.774+0.006×Height-0.002×Age, R2=20.2% and for girls (Rrs5=2.201-0.012×Height, R2=18.2%; Xrs5=-0.674+0.004×Height, R2=10.5%).ConclusionThis study provides reference values for IOS measurements of normal Korean preschool children. These provide a basis for the diagnosis and monitoring of preschool children with a variety of respiratory diseases

Ferromagnetic transition metal implanted ZnO: a diluted magnetic semiconductor?

Recently theoretical works predict that some semiconductors (e.g. ZnO) doped with magnetic ions are diluted magnetic semiconductors (DMS). In DMS magnetic ions substitute cation sites of the host semiconductor and are coupled by free carriers resulting in ferromagnetism. One of the main obstacles in creating DMS materials is the formation of secondary phases because of the solid-solubility limit of magnetic ions in semiconductor host. In our study transition metal ions were implanted into ZnO single crystals with the peak concentrations of 0.5-10 at.%. We established a correlation between structural and magnetic properties. By synchrotron radiation X-ray diffraction (XRD) secondary phases (Fe, Ni, Co and ferrite nanocrystals) were observed and have been identified as the source for ferromagnetism. Due to their different crystallographic orientation with respect to the host crystal these nanocrystals in some cases are very difficult to be detected by a simple Bragg-Brentano scan. This results in the pitfall of using XRD to exclude secondary phase formation in DMS materials. For comparison, the solubility of Co diluted in ZnO films ranges between 10 and 40 at.% using different growth conditions pulsed laser deposition. Such diluted, Co-doped ZnO films show paramagnetic behaviour. However, only the magnetoresistance of Co-doped ZnO films reveals possible s-d exchange interaction as compared to Co-implanted ZnO single crystals.Comment: 27 pages, 8 figure

Silver coordination compounds with antimicrobial properties

Silver and its compounds have long been known to possess antimicrobial properties. We report here on our observations in this field of research, namely on silver coordination compounds, and in particular polymers, which can be used in the medical field. An overview of the structural diversity of coordination compounds with a particular class of organic ligands is given, together with their properties, with a special focus on antimicrobial activity, solubility and light stability

The Spill-Over Impact of the Novel Coronavirus-19 Pandemic on Medical Care and Disease Outcomes in Non-communicable Diseases: A Narrative Review

OBJECTIVES: The coronavirus-19 (COVID-19) pandemic has claimed more than 5 million lives worldwide by November 2021. Implementation of lockdown measures, reallocation of medical resources, compounded by the reluctance to seek help, makes it exceptionally challenging for people with non-communicable diseases (NCD) to manage their diseases. This review evaluates the spill-over impact of the COVID-19 pandemic on people with NCDs including cardiovascular diseases, cancer, diabetes mellitus, chronic respiratory disease, chronic kidney disease, dementia, mental health disorders, and musculoskeletal disorders. METHODS: Literature published in English was identified from PubMed and medRxiv from January 1, 2019 to November 30, 2020. A total of 119 articles were selected from 6,546 publications found. RESULTS: The reduction of in-person care, screening procedures, delays in diagnosis, treatment, and social distancing policies have unanimously led to undesirable impacts on both physical and psychological health of NCD patients. This is projected to contribute to more excess deaths in the future. CONCLUSION: The spill-over impact of COVID-19 on patients with NCD is just beginning to unravel, extra efforts must be taken for planning the resumption of NCD healthcare services post-pandemic