Synthesis, Characterization, and Size Control of Zinc Sulfide Nanoparticles Capped by Polyethylene Glycol

Zinc sulfide nanoparticles were synthesized with controllable size via chemical precipitation. highresolution transmission electron microscopy (HRTEM) and X-ray powder diffraction (XRD) showed that the samples were grown with the cubic phase; the particle size was varied by varying the molar ratios of zinc chloride and sodium sulfide in the presence of poly(ethylene glycol). The optical band gap was calculated on the basis of ultraviolet-visible spectroscopy (UV-VIS) and ranged from 4.13 eV to 4.31 eV depending on the particle size. Surface passivation and adsorption of poly(ethylene glycol) on the nanoparticles was explained on the basis of Fourier transform infrared measurements (FTIR)

Synthesis and Spectroscopic Studies of Copper Selenide Nanoparticles

Copper selenide nanoparticles were synthesized using solvothermal route at different temperatures using ethylenediamine as a solvent. The study of the molecular structure by FTIR spectroscopy indicated that the cupper complex with ethylenediamine through the nitrogen atom was formed when the sample prepared at 140 °C. The cupper selenide nanoparticles were formed at temperatures 160, 170 and 200 °C. The X-ray diffraction data revealed that, all samples exhibit crystalline nature and the particle size depends on the temperature. At the same time transmission electron microscope was used in studying of the morphology and particle size. The particle size estimated by XRD and TEM was consistent and the two in nanorange. The obtained results reveal that the CuSe nanoparticles were formed with particle size 13, 15 and 21 nm at temperatures 160, 170 and 200 °C respectively

Size-Tailored Physicochemical Properties of Monodisperse Polystyrene Nanoparticles and the Nanocomposites Made Thereof

The latex monodisperse polystyrene (PS) colloids are important for different advanced applications (e.g. in coating, biotechnology etc.). However, the size dependency of their structural properties that impacts the characteristics of the nanocomposites composed thereof is largely unknown. Here, monodisperse PS nanoparticles (MPNPs) are synthesized via emulsion polymerization in five sizes (50, 150, 300, 350, and 450 nm). The size of the PS MPNPs is tailored by controlling the reaction time, temperature, and amount of surfactant and initiator. The correlation between the particle size and structural properties of the PS MPNPs is established by different thermomechanical and optical characterizations. The smaller particles (50 and 150 nm) show a lower glass transition (Tg) and thermal decomposition temperature and a lower Raman peak intensity. Yet, they trigger a higher IR absorption, thanks to a larger surface area. When incorporated in a polyvinyl alcohol (PVA) matrix, the smaller particles impart the resulting nanocomposite a higher tensile strength, and elastic and storage moduli. Whereas, they decline the elongation and loss factor. The very few examples of the MPNPs incorporated polymeric nanocomposites have been unstudied from this perspective. Thus, these tangible knowledge can profit scalable production of this kind of nanocomposite materials for different applications in a cost/energy efficient manner.Peer reviewe

Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function

Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes

The Effect of Using Herbal Extracts as Irrigant Solution in Disinfecting Root Canals of Endodontically Treated Teeth: A Narrative Review

Objectives: The use of herbal medicine continues to grow worldwide in all fields including dentistry. The constant use of chemical products in the root canal treatment process has prompted researchers to look for herbal alternatives due to the side effects and the relatively high resistant microbial strains available in the root canal that can contribute to the refractory infection. Therefore, the aim of this narrative review is to evaluate the effectiveness of using selected herbal extracts in disinfecting the root canals and removing the smear layer of the endodontically treated teeth. Design: Systematic search from 1999-2019 was performed using four electronic databases. The level of evidence of eligible studies was assessed using Critical Appraisal Skills Programme and Cochrane risk of bias tools. Results: A total of 44 eligible experimental studies that assessed aloe vera, turmeric, Peganum harmala, green tea, garlic and chamomile extracts were retrieved electronically. Potent disinfectant properties provided by the herbal extract of the six selected plants were demonstrated. Among these herbal extracts, garlic and chamomile extracts were found to have better properties in removing the smear layer from the root canal compared to the other herbal extracts. Conclusion: The results of the present review support the use of the examined herbal extracts in disinfecting the root canal; however, these findings need to be assessed clinically to determine the possibility of using herbal products as a successful alternative for chemical products within the process of root canal treatment

Clinical oral microbiology: A view of the road ahead

‘There’s none so blind as those that will not see.’ With almost daily headlines describing novel and re-emerging challenges in healthcare related to infection prevention and antimicrobial resistance, it is quite extraordinary that there are currently only four clinical oral microbiologists in UK consultant posts, and no trainees. Given the backdrop of increasing antimicrobial resistance, and a drive towards optimal diagnosis, surveillance and management of infection in all others areas of healthcare, how has this situation arisen? More importantly, can it be remedied? If so, how? </jats:p