Polylactic acid (PLA)/Silver-NP/VitaminE bionanocomposite electrospun nanofibers with antibacterial and antioxidant activity

Cataloged from PDF version of article.The antibacterial property of silver nanoparticles (Ag-NPs) and the antioxidant activity of Vitamin E have been combined by incorporation of these two active components within polylactic acid (PLA) nanofibers via electrospinning (PLA/Ag-NP/VitaminE nanofibers). The morphological and structural characterizations of PLA/Ag-NP/VitaminE nanofibers were performed by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy and X-ray diffraction. The average fiber diameter was 140 ± 60 nm, and the size of the Ag-NP was 2.7 ± 1.5 nm. PLA/Ag-NP/VitaminE nanofibers inhibited growth of Escherichia coli, Listeria monocytogenes and Salmonella typhymurium up to 100 %. The amount of released Ag ions from the nanofibers immersed in aqueous solution was determined by Inductively Coupled Plasma Mass Spectrometry, and it has been observed that the release of Ag ions was kept approximately constant after 10 days of immersion. The antioxidant activity of PLA/Ag-NP/VitaminE nanofibers was evaluated according to DPPH (2,2-diphenyl-1-picrylhydrazyl) method and determined as 94 %. The results of the tests on fresh apple and apple juice indicated that the PLA/Ag/VitaminE nanofiber membrane actively reduced the polyphenol oxidase activity. The multifunctional electrospun PLA nanofibers incorporating Ag-NP and Vitamin E may be quite applicable in food packaging due to the extremely large surface area of nanofibers along with antibacterial and antioxidant activities. These materials could find application in food industry as a potential preservative packaging for fruits and juices. © 2014, Springer Science+Business Media Dordrecht

Upper bounds on the first eigenvalue for a diffusion operator via Bakry-\'{E}mery Ricci curvature II

Let $L=\Delta-\nabla\varphi\cdot\nabla$ be a symmetric diffusion operator with an invariant measure $d\mu=e^{-\varphi}dx$ on a complete Riemannian manifold. In this paper we prove Li-Yau gradient estimates for weighted elliptic equations on the complete manifold with $|\nabla \varphi|\leq\theta$ and $\infty$-dimensional Bakry-\'{E}mery Ricci curvature bounded below by some negative constant. Based on this, we give an upper bound on the first eigenvalue of the diffusion operator $L$ on this kind manifold, and thereby generalize a Cheng's result on the Laplacian case (Math. Z., 143 (1975) 289-297).Comment: Final version. The original proof of Theorem 2.1 using Li-Yau gradient estimate method has been moved to the appendix. The new proof is simple and direc

Foot health of Aboriginal and Torres Strait Islander Peoples in regional and rural NSW, Australia

Background: Foot health of Aboriginal and Torres Strait Islander Australians' has not been established. Additionally, studies have shown that there is a lack of engagement of this population with general preventive foot care services. The aim of this study was to establish foot health in Aboriginal and Torres Strait Islander people attending two recently developed, culturally safe podiatry services in rural and regional New South Wales (NSW), Australia. Secondarily the relationship between self-perceived foot health and some medical and demographic characteristics was investigated. Methods: This descriptive cross-sectional study included participants attending the culturally safe foot health care services managed by the University of Newcastle on the Central Coast or in Wellington, both located in NSW, Australia. At the consultation, participants completed the Foot Health Status Questionnaire (FHSQ) with the assistance of an Aboriginal health care worker, underwent basic vascular and neurological screening, and podiatric treatment. Results: A total of 111 Aboriginal and Torres Strait Islander Australians (48 from the Central Coast, and 63 from Wellington) were included. FHSQ scores for pain (75.7 ± 26.8), function (80.2 ± 25.2), footwear (53.9 ± 33.4), and general foot health (62.0 ± 30.9) were generally good, but below the optimal score of 100. The presence of diabetes (n = 39 of 111 participants or 35.1%) was associated with lower levels of self-perceived foot function (r = - 0.20, n = 107, p = 0.04). Conclusion: We found that community-based foot health care services that are culturally safe are utilised by Aboriginal and Torres Strait Islander Peoples not currently at high risk of foot complications. This supports the use of culturally safe foot care services to improve engagement with preventative foot care. Future research should continue to be driven by Aboriginal and Torres Strait Islander Peoples and investigate ways to implement additional screening measures and undertake prospective evaluation of the impact of such services on health related outcomes in these communities. © 2020 The Author(s)

Secondary giant cell glioblastoma in a multiple drug abuser - simple association or ethiopathogenic correlation? Case presentation and literature review

Experimental investigations have shown that drug abuse initiates a cascade of pathophysiological events including toxic and hypoxic-ischemic injury on neurons, microglia and astrocytes, which finally lead to widespread disturbances in the brain. There are many reports about the psychiatric and neurologic effects of multiple drug abuse, but only a few clinical studies reporting possible correlation between recreational illicit drugs and gliomas. In this paper we present the case of a 40 years-old male patient, with a long history (almost ten years) of multiple drug abuse, including cocaine, heroin, marijuana, ethnobotanical drugs and nicotine, who was diagnosed and surgically treated for a supratentorial secondary giant cell glioblastoma (sgcGB) developed in a diffuse astrocytoma NOS. Depending on the type of the illicit drug used by the patient and the moment of life he used them, the morphological features identified in the histological samples of our patient confirmed the gliomagenesis effect of chronic multiple drug abuse, but also its inhibitory effects on tumour cells growth. This was due to the fact that although the tumour was large in size and caused brain sub-falcine herniation, the patient reported the onset of seizures only late in the evolution. In conclusion, the diagnosis of a brain tumour should take into consideration not only patient's clinical and imaging data, but also his lifestyle, especially his addiction to recreational drugs

Release of the national scheme's Aboriginal and Torres Strait Islander health and cultural safety strategy 2020-2025; the impacts for podiatry in Australia : a commentary

Background Developing since colonisation, Australia's healthcare system has dismissed an ongoing and successful First Nations health paradigm in place for 60,000 years. From Captain James Cook documenting 'very old' First Nations Peoples being 'far more happier than we Europeans' and Governor Arthur Phillip naming Manly in admiration of the physical health of Gadigal men of the Eora Nation, to anthropologist Daisy Bates' observation of First Nations Peoples living 'into their eighties' and having a higher life expectancy than Europeans; our healthcare system's shameful cultural safety deficit has allowed for an Aboriginal and Torres Strait Islander child born in Australia today to expect to live 9 years less than a non-Indigenous child. Disproportionately negative healthcare outcomes including early onset diabetes-related foot disease and high rates of lower limb amputation in Aboriginal and Torres Strait Islander Peoples contribute to this gross inequity. Main body In 2020, the Australian Health Practitioner Regulation Authority released the National Scheme's Aboriginal and Torres Strait Islander Health and Cultural Safety Strategy 2020-2025 - empowering all registered health practitioners within Australia to provide health care to Aboriginal and Torres Strait Islander Peoples that is inclusive, respectful and safe, as judged by the recipient of care. This recently released strategy is critically important to the podiatry profession in Australia. As clinicians, researchers and educators we have a collective responsibility to engage with this strategy of cultural safety. This commentary defines cultural safety for podiatry and outlines the components of the strategy in the context of our profession. Discussion considers the impact of the strategy on podiatry. It identifies mechanisms for podiatrists in all settings to facilitate safer practice, thereby advancing healthcare to produce more equitable outcomes. Conclusion Aboriginal and Torres Strait Islander Peoples access health services more frequently and have better health outcomes where provision of care is culturally safe. By engaging with the National Scheme's Aboriginal and Torres Strait Islander Health and Cultural Safety Strategy, all registered podiatrists in Australia can contribute to achieving equity in health outcomes for Aboriginal and Torres Strait Islander Peoples

Antioxidant activity in selected tomato genotypes cultivated in conventional and organic culture systems

The present study is a compilation of results obtained at the Vegetable Research and Development Station Bacau regarding the influence of the culture system on the quantitative and qualitative yield of tomatoes. The present study provides comparative information regarding yield achievements of tomato genotypes cultivated in two different culture systems (conventional and organic), in order to highlight the suitability of the cultivation system. The best yield results were obtained at a density of 30,000 plants per hectare in both culture systems. All studied genotypes resulted in quantitatively superior yield in the conventional system as opposed to the organic system. Another purpose of this study was to determine the difference in antioxidant activity of tomato genotypes cultivated in the ecological and the conventional culture systems. The results indicate the suitability of the tomato to organic cultivation, highlighting the potential of the tomato species to be utilized as a significant source of natural antioxidants, and also the influence of cultivation systems on the accumulation of antioxidant compounds.Keywords: Lycopersicon esculentum, polyphenols, flavones, yieldAfrican Journal of Biotechnology Vol. 12(20), pp. 2884-289

Time-like constant slope surfaces and space-like Bertrand curves in Minkowski 3-space

Defining Lorentzian Sabban frame of the unit speed time-like curves on de Sitter 2-space $\mathbb{S}^{2}_{1}$ and introducing space-like height function on the unit speed time-like curves on $\mathbb{S}^{2}_{1}$, the invariants of the unit speed time-like curves on $\mathbb{S}^{2}_{1}$ and geometric properties of de Sitter evolutes of the unit speed time-like curves on $\mathbb{S}^{2}_{1}$ are studied. A relation between space-like Bertrand curves and helices is obtained. De Sitter Darboux images of space-like Bertrand curves are equal to de Sitter evolutes. The relations between time-like constant slope surfaces lying in the space-like cone and space-like Bertrand curves in Minkowski 3-space $\mathbb{R}^{3}_{1}$ are obtained.Comment: 15 Pages, 2 Figures. Accepted for publication in the Proceedings of the National Academy of Sciences, India Section A: Physical Science

Evaluation Model of the Entrepreneurial Character in EU Countries.

Abstract The evidence of entrepreneurship development as a factor of sustainable growth at national and regional level frequently calls for the interest of theorists and practitioners on identifying and outlining the best conditions and economic essential prerequisites for supporting the entrepreneurial initiatives on the long term. In this context, the objective of the present research is to analyse and measure the entrepreneurial character of the European Union member countries in an integrated manner, by developing an innovative model for proposing specific action lines and objectively evaluating the entrepreneurship development in the investigated states. Our model is based on a synthesis variable of the entrepreneurial national character, which was developed by sequential application of principal component analysis, while the initial variables are from secondary sources with good conceptual representativeness. Depending on the objective relevance of the three model components (cultural, economic and administrative, and entrepreneurial education components), the achieved results confirm the importance of a favourable cultural and economic and administrative background for entrepreneurship development and they reiterate the inefficiency of isolated entrepreneurial education unless supported by good entrepreneurial culture or adequate economic and administrative infrastructure. The case of Romania, in relation with the European Union member countries, is presented in detail

Ti-Zr-Si-Nb nanocrystalline alloys and metallic glasses: Assessment on the structure, thermal stability, corrosion and mechanical properties

The development of novel Ti-based amorphous or \u3b2-phase nanostructured metallic materials could have significant benefits for implant applications, due to improved corrosion and mechanical characteristics (lower Young's modulus, better wear performance, improved fracture toughness) in comparison to the standardized \u3b1+\u3b2 titanium alloys. Moreover, the devitrification phenomenon, occurring during heating, could contribute to lower input power during additive manufacturing technologies. Ti-based alloy ribbons were obtained by melt-spinning, considering the ultra-fast cooling rates this method can provide. The titanium alloys contain in various proportions Zr, Nb, and Si (Ti60Zr10Si15Nb15, Ti64Zr10Si15Nb11, Ti56Zr10Si15Nb19) in various proportions. These elements were chosen due to their reported biological safety, as in the case of Zr and Nb, and the metallic glass-forming ability and biocompatibility of Si. The morphology and chemical composition were analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy, while the structural features (crystallinity, phase attribution after devitrification (after heat treatment)) were assessed by X-ray diffraction. Some of the mechanical properties (hardness, Young's modulus) were assessed by instrumented indentation. The thermal stability and crystallization temperatures were measured by differential thermal analysis. High-intensity exothermal peaks were observed during heating of melt-spun ribbons. The corrosion behavior was assessed by electrocorrosion tests. The results show the potential of these alloys to be used as materials for biomedical applications