28 research outputs found

    Thermophoresis or When Small Objects Meet Temperature Gradient: Numerous Applications

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    This mini review discusses the phenomenon of thermophoresis, also known as the thermophoretic effect. Thermophoretic effect arises from the combination of a temperature gradient and particles of very small dimensions, on the order of magnitude of the mean free path of the molecules of the surrounding gas. Despite being a little-known effect, it is critical to many physical and chemical processes and for characterising the properties of nanostructured materials that could be used in industry for sensing applications. A description and definition of otherwise very similar thermophoresis terms is provided, as well as a brief overview of the literature on this topic, with a focus on research in the twenty-first centur

    Far-infrared spectroscopy of a nanocomposite of polyvinyl alcohol and lead sulfide nanoparticles

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    A nanocomposite consisting of lead sulfide (PbS) nanoparticles (NPs) with average diameter of 26 angstrom, according to absorption threshold shift, and polyvinyl alcohol (PVA) was characterized using far-infrared absorption spectroscopy. The experimental results are consistent with theoretical calculations that include proper mechanical boundary conditions at the nanocrystal-host interface

    First steps towards national radon action plan in Serbia

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    Radon problem has a special attention in many countries in the world and the most of them have established national radon programmes. The radon issues in Serbia have not been approached in a systematic and organized way. Currently, there are many research groups and institutions working in radon field, and it is a good basis to integrate all these activities into a comprehensive national programme to define the strategic objectives and action plan for the next few years. Also, Serbia as a candidate for membership in the EU is obliged to harmonize its legislation, including the field of radiation protection in which the radon issues has an important role. In this report, a brief history of radon research, present status and plans for the future activity on radon issues in Serbia are presented. Regarding the long-term plans, the establishment and implementation of the Radon Action Plan with the primary goal of raising awareness about the harmful effects of public exposure to radon and implementing a set of measures for its reduction. In that sense, the synergy between the national, regional and local organizations responsible for public health and radiation protection must be achieved

    Understanding of interaction (subgroup) analysis in clinical trials

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    Background: When the treatment effect on the outcome of interest is influenced by a baseline/demographic factor, investigators say that an interaction is present. In randomized clinical trials (RCTs), this type of analysis is typically referred to as subgroup analysis. Although interaction (or subgroup) analyses are usually stated as a secondary study objective, it is not uncommon that these results lead to changes in treatment protocols or even modify public health policies. Nonetheless, recent reviews have indicated that their proper assessment, interpretation and reporting remain challenging. Results: Therefore, this article provides an overview of these challenges, to help investigators find the best strategy for application of interaction analyses on binary outcomes in RCTs. Specifically, we discuss the key points of formal interaction testing, including the estimation of both additive and multiplicative interaction effects. We also provide recommendations that, if adhered to, could increase the clarity and the completeness of reports of RCTs. Conclusion: Altogether, this article provides a brief non-statistical guide for clinical investigators on how to perform, interpret and report interaction (subgroup) analyses in RCTs

    Prenatal exposure to non-steroidal anti-inflammatory drugs (NSAIDs) and neurodevelopmental outcomes in children

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    ___Purpose:___ Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used during pregnancy. Findings that prenatal NSAID exposure may affect offspring neurodevelopment have been inconsistent. We investigated the effect of prenatal NSAID exposure on childhood neurodevelopment and explored the susceptibility of our effect estimates to forms of bias via negative exposure, negative outcome, and multi-informant analyses. ___Methods:___ In a cohort of pregnant women (nĀ =Ā 6876), perinatal NSAID use was assessed by prescriptions and self-report. Primary neurodevelopmental outcomes included attention problems using maternal reports at 1Ā½, 3, and 5Ā years. To explore potential systematic biases, we compared estimates from maternally reported attention problems to a teacher's report and a measure of nonverbal intelligence assessed at a clinic visit at age 6Ā years; we also used NSAID use before pregnancy and somatic problems as a ā€œnegativeā€ exposure and outcome, respectively. ___Results:___ Maternal reports suggested that prenatal exposure to NSAIDs was associated with more attention problems at younger ages (eg, at age 3: mean difference in attention problems score: 0.30; 95% CI 0.12, 0.48). However, no strong association with attention problems was found in the teacher report, and a similarly strong association between prenatal NSAID exposure and somatic complaints suggests residual confounding by indication likely remains. Moreover, prenatal exposure to NSAIDs was not associated with an observed measure of IQ (mean difference in IQ score: āˆ’0.32; 95% CI: āˆ’1.82, 1.19). ___Conclusions:___ Jointly, our results suggest that the observed associations between prenatal exposure to NSAIDs and child attention problems reflect systematic biases of a null or small effect

    Management of anaphylaxis due to COVID-19 vaccines in the elderly

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    Older adults, especially men and/or those with diabetes, hypertension, and/or obesity, are prone to severe COVID-19. In some countries, older adults, particularly those residing in nursing homes, have been prioritized to receive COVID-19 vaccines due to high risk of death. In very rare instances, the COVID-19 vaccines can induce anaphylaxis, and the management of anaphylaxis in older people should be considered carefully. An ARIA-EAACI-EuGMS (Allergic Rhinitis and its Impact on Asthma, European Academy of Allergy and Clinical Immunology, and European Geriatric Medicine Society) Working Group has proposed some recommendations for older adults receiving the COVID-19 vaccines. Anaphylaxis to COVID-19 vaccines is extremely rare (from 1 per 100,000 to 5 per million injections). Symptoms are similar in younger and older adults but they tend to be more severe in the older patients. Adrenaline is the mainstay treatment and should be readily available. A flowchart is proposed to manage anaphylaxis in the older patients.Peer reviewe

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Kinetics and mechanism of structural transformations of 2-(5-ethoxycarbonylmethyl-4-oxothiazolidin-2-ylidene)-N-(2-phenylethyl)-ethanamide during heating

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    The kinetics and mechanism of the structural transformation of 2-(5-ethoxycarbonylmethyl-4-oxothiazolidin-2-ylidene)-N-(2-phenylethyl)-ethanamide in non-isothermal conditions were studied by using isoconversion as well as non-isoconversion techniques. It was shown that the crystal, Z-form of compound, was stable in the temperature range from room temperature to melting point, when E-form of compound was formed. This process involves the breaking of crystal structure and the forming of glass material as a new phase, which by cooling forms crystal of the E-form of compound very slowly. The dependences of kinetic parameters on fractional extent conversion were determined indicating a very complex process which involves more than one elementary step, as can be expected for most solid state reactions. The possible mechanism of the process was discussed according to the algorithm concerning the form of these dependences. The evaluation of kinetics parameters and isokinetic relationships were done by combination of model fitting and model-free approach
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