Exploring Astronautical Dentistry: A Review

The Human body reacts differently in different environment(s). With development in the field of astronomy, long distance trip to another planet is now possible. These trips require humans to stay in zero gravity conditions for a long time. Simulated microgravity is the best way to assess the physiologic changes in near zero gravity conditions, as it is not always possible to conduct scientific experiments in space. The purpose of this review is to determine the effects of zero gravity on oral cavity

Dynamic characterization of cellulose nanofibrils in sheared and extended semi-dilute dispersions

New materials made through controlled assembly of dispersed cellulose nanofibrils (CNF) has the potential to develop into biobased competitors to some of the highest performing materials today. The performance of these new cellulose materials depends on how easily CNF alignment can be controlled with hydrodynamic forces, which are always in competition with a different process driving the system towards isotropy, called rotary diffusion. In this work, we present a flow-stop experiment using polarized optical microscopy (POM) to study the rotary diffusion of CNF dispersions in process relevant flows and concentrations. This is combined with small angle X-ray scattering (SAXS) experiments to analyze the true orientation distribution function (ODF) of the flowing fibrils. It is found that the rotary diffusion process of CNF occurs at multiple time scales, where the fastest scale seems to be dependent on the deformation history of the dispersion before the stop. At the same time, the hypothesis that rotary diffusion is dependent on the initial ODF does not hold as the same distribution can result in different diffusion time scales. The rotary diffusion is found to be faster in flows dominated by shear compared to pure extensional flows. Furthermore, the experimental setup can be used to quickly characterize the dynamic properties of flowing CNF and thus aid in determining the quality of the dispersion and its usability in material processes.Comment: 45 pages, 13 figure

Physico-chemical properties based differential toxicity of graphene oxide/reduced graphene oxide in human lung cells mediated through oxidative stress

Goraphene derivatives (GD) are currently being evaluated for technological and biomedical applications owing to their unique physico-chemical properties over other carbon allotrope such as carbon nanotubes (CNTs). But, the possible association of their properties with underlying in vitro effects have not fully examined. Here, we assessed the comparative interaction of three GD - graphene oxide (GO), thermally reduced GO (TRGO) and chemically reduced GO (CRGO), which significantly differ in their lateral size and functional groups density, with phenotypically different human lung cells; bronchial epithelial cells (BEAS-2B) and alveolar epithelial cells (A549). The cellular studies demonstrate that GD significantly ineternalize and induce oxidative stress mediated cytotoxicity in both cells. The toxicity intensity was in line with the reduced lateral size and increased functional groups revealed more toxicity potential of TRGO and GO respectively. Further, A549 cells showed more susceptibility than BEAS-2B which reflected cell type dependent differential cellular response. Molecular studies revealed that GD induced differential cell death mechanism which was efficiently prevented by their respective inhibitors. This is prior study to the best of our knowledge involving TRGO for its safety evaluation which provided invaluable information and new opportunities for GD based biomedical applications

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Sustainable Architecture in Terms of Building Materials

Building materials are the single unit cell of a building and thus are the essential part of construction techniques. It encloses the spaces in a building or acts as an envelope for spaces in architecture. In today’s scenario sustainable architecture is at its pace. Sustainable architecture does not only mean to plant trees or using vernacular materials, but it also means to use eco- friendly building materials since building materials are the first and most important part of a building. Life of a building is dependent on the material being used in that building. Therefore, selection of an eco-friendly material is a rapid step towards sustainable and eco-friendly built environment. Now what material could be ecofriendly? Truly saying materials that result in a more sustainable and affordable construction complying with the comfort standards required today can be termed as eco-friendly materials. So, rather making environment sustainable we could use materials that are sustainable, affordable, low energy consumption and can be recycled or reused easily. This paper deals with how green building materials can sustain our environment by reducing its impact on our mother earth, that could lessen the amount of environmental degradation, have consumes less energy, can be re-used in a building itself and the comparison between other man-made materials and their energy consumption that are presently in use

GLASS : AS A GREEN BUILDING MATERIAL

Glass is a versatile crystalline solid material having many uses in building industry. Silica is the main constituent of glass. But sometimes it is to be added with sodium potassium carbonate to bring down melting point. Green building material means a material that is eco-friendly and resource efficient. Hence glass acts as green building material due to its various properties such as transparency, insulating property, does not gets easily affected by atmosphere, it refracts or transmits light and is strong and durable. This paper deals with the justification that glass which produces non-renewable and harmful waste can still be a green building material i.e. it can be resource efficient and eco-friendly material

Erratum: Physico-chemical properties based differential toxicity of graphene oxide/reduced graphene oxide in human lung cells mediated through oxidative stress (vol 6, 39548, 2017)

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Dynamics of step-emulsification: From a single to a collection of emulsion droplet generators

International audienceMicrofluidics has proven to be an efficient tool for making fine and calibrated emulsion droplets. The parallelization of drop makers is required for producing large amounts. Here, we investigate the generation of emulsion drops along a series of shallow microchannels emerging in a deep one, in other words the step-emulsification process. The dynamics of a single drop maker is first characterized as a function of interfacial tension and viscosities of both phases. The characteristic time scale of drop formation, namely, the necking time that finally sets drop size, is shown to be principally governed by the outer phase viscosity to interfacial tension ratio with a minor correction linked to the viscosity ratio. The step emulsification process experiences a transition of fragmentation regime where both the necking time and drop size suddenly raise. This transition, that corresponds to a critical period of drop formation and thus defines a maximum production rate of small droplets, is observed to be ruled by the viscosity ratio of the two phases. When drops are produced along an array of microchannels with a cross flow of the continuous phase, a configuration comparable to a one-dimensional membrane having rectangular pores, a drop boundary layer develops along the drop generators. In the small drop regime, the local dynamics of drop formation is shown to be independent on the emulsion cross flow. Moreover, we note that the development of the drop boundary layer is even beneficial to homogenize drop size along the production line. On the other hand, in the large drop regime, drop collision can trigger fragmentation and thus lead to size polydispersity