67 research outputs found

    Conic deformation of the subglottic mucosa and its impact on the aerodynamics of the airflow over the vocal folds

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    Objective: This study mapped the variation in tissue elasticity of the subglottic mucosa, applied that data to provide initial models of the likely deformation of the mucosa during the myoelastic cycle, and hypothesised as to the impact on the process of phonation. Study Design: 6 donor human larynges were dissected along the sagittal plane to expose the vocal folds and subglottic mucosa. A Linear Skin Rheometer was used to apply a controlled shear force, and the resultant displacement was measured. This data provided a measure of the stress/strain characteristics of the tissue at each anatomical point. A series of measurements were taken at 2mm interval inferior of the vocal folds, and the change in elasticity determined. Results: It was found that the elasticity of the mucosa in the subglottic region increased linearly with distance from the vocal folds in all 12 samples. A simple deformation model indicated that under low pressure conditions the subglottic mucosa will deform to form a cone, which could result in a higher velocity thus amplifying the low pressure effect resulting from the Venturi principle, and could assist in maintaining laminar flow. Conclusions: This study indicated that the deformation of the subglottic mucosa could play a significant role in the delivery of a low pressure air flow over the vocal folds

    Biological activity and applications of natural compounds

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    (This book is a printed edition of the Special Issue Biological Activity and Applications of Natural Compounds that was published in Applied Sciences).Nature represents an amazing source of inspiration since it produces a great diversity of natural compounds selected by evolution, which exhibit multiple biological activities and applications. A large and very active research field is dedicated to identifying biosynthesized compounds, to improve/develop new methodologies to produce/reuse natural compounds and to assess their potential for pharmaceutical, cosmetic and food industries, among others, and also to understand their mechanism of action.info:eu-repo/semantics/publishedVersio

    Applications of sesquiterpene lactones : a review of some potential success cases

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    Sesquiterpene lactones, a vast range of terpenoids isolated from Asteraceae species, exhibit a broad spectrum of biological effects and several of them are already commercially available, such as artemisinin. Here the most recent and impactful results of in vivo, preclinical and clinical studies involving a selection of ten sesquiterpene lactones (alantolactone, arglabin, costunolide, cynaropicrin, helenalin, inuviscolide, lactucin, parthenolide, thapsigargin and tomentosin) are presented and discussed, along with some of their derivatives. In the authors’ opinion, these compounds have been neglected compared to others, although they could be of great use in developing important new pharmaceutical products. The selected sesquiterpenes show promising anticancer and anti-inflammatory effects, acting on various targets. Moreover, they exhibit antifungal, anxiolytic, analgesic, and antitrypanosomal activities. Several studies discussed here clearly show the potential that some of them have in combination therapy, as sensitizing agents to facilitate and enhance the action of drugs in clinical use. The derivatives show greater pharmacological value since they have better pharmacokinetics, stability, potency, and/or selectivity. All these natural terpenoids and their derivatives exhibit properties that invite further research by the scientific community.Portuguese Foundation for Science and Technology; European Commission; QREN; European Commission; COMPETE; cE3c centre (UIDB/00329/2020); LAQV-REQUIMTE (UIDB/50006/2020); QOPNA UID/QUI/00062/2019), Spanish Ministry Science and Research (MINECO RTI2018-094356-B-C21)info:eu-repo/semantics/publishedVersio

    The impact of boron seed priming on seedling establishment, growth, and grain biofortification of mungbean (Vigna radiata L.) in yermosols

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    Boron-deficiency in Yermosols is among the major constraints to mungbean productivity and grain biofortification in Pakistan. However, agronomic strategies such as boron (B) seed priming have potential to improve mungbean yield and grain biofortification. Moreover, deficiency to toxicity range for B is very narrow; therefore, it is pre-requisite to optimize its dose before field evaluation. A wire house experiment was planned out to reconnoiter the impact of seed priming with B on growth and quality of two cultivars of mungbean, i.e., ‘NM-2011’ and ‘NM-2016’. Four different B levels were used as seed priming, i.e., 0.01%, 0.05%, 0.1% and 1.0% B, (borax Na2B4O7.10H2O, 11.5% B) were tested, whereas hydropriming was regarded as control. Seed priming with 0.01% B significantly (p≤0.05) lowered time taken to start germination and time to reach 50% emergence, whereas improved mean emergence time, emergence index, final emergence percentage, number of leaves, dry and fresh weight of root, shoot, and total weight, root length, plant height, chlorophyll contents, number of pods and 100-grain weight, seeds per plant, grain yield per plant, B concentrations in stem and grain, grain protein, carbohydrate and fiber in both cultivars. Boron seed priming proved beneficial under a specific range; however, deficiency (hydropriming) and excess (above 0.01% B) of B were detrimental for mungbean growth and productivity. The cultivar ‘NM-2016’ had significantly (p≤0.05) higher yield due to prominent increase in yield related traits with 0.01% B priming as compared to ‘NM-2011’. In conclusion, B seed priming (0.01% B) seemed a feasible choice for improving mungbean growth, yield related traits and grain-B concentration of mungbean on Yermosols

    Architectural Heterogeneity in Tumors Caused by Differentiation Alters Intratumoral Drug Distribution and Affects Therapeutic Synergy of Antiangiogenic Organoselenium Compound

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    Tumor differentiation enhances morphologic and microvascular heterogeneity fostering hypoxia that retards intratumoral drug delivery, distribution, and compromise therapeutic efficacy. In this study, the influence of tumor biologic heterogeneity on the interaction between cytotoxic chemotherapy and selenium was examined using a panel of human tumor xenografts representing cancers of the head and neck and lung along with tissue microarray analysis of human surgical samples. Tumor differentiation status, microvessel density, interstitial fluid pressure, vascular phenotype, and drug delivery were correlated with the degree of enhancement of chemotherapeutic efficacy by selenium. Marked potentiation of antitumor activity was observed in H69 tumors that exhibited a well-vascularized, poorly differentiated phenotype. In comparison, modulation of chemotherapeutic efficacy by antiangiogenic selenium was generally lower or absent in well-differentiated tumors with multiple avascular hypoxic, differentiated regions. Tumor histomorphologic heterogeneity was found prevalent in the clinical samples studied and represents a primary and critical physiological barrier to chemotherapy

    Analytical hierarchy process as a tool supporting a decision-making for assessment of the risk of transboundary infectious animal disease introduction to the Russian Federation and previously disease-free territories

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    The livestock industry is increasingly taking its place in the economy of the Russian Federation. Its export potential is actively growing. Already, up to 10% of agricultural products are exported to foreign markets. The demand for food steadily increases during crises, which in turn increases the role of the veterinary service, whose tasks include protecting the country’s territory from the introduction of infectious diseases of animals from foreign countries; implementation of measures to prevent and eliminate infectious and other diseases in agricultural, domestic, zoo and other animals, fur-bearing animals, birds, fish and bees, as well as the implementation of plans of the regional veterinary service in the field of animal husbandry. The article assesses the validity of the possibilities and use of modern methods of analyzing and predicting the spread of animal morbidity, identifying cause-and-effect relationships and the extent of the spread of particularly dangerous animal diseases. The authors propose to consider the possibility of using the mathematical method of hierarchy analysis as a scientifically sound decisionmaking support tool when assessing the risk of introducing trans-border infectious animal diseases into previously prosperous territories of the Russian Federation. This approach can be used in the process of choosing the most appropriate alternative from several risk assessment options. The Hierarchy Analysis Method (MAI) is a mathematical tool for a qualitative systematic approach to solving decision-making problems. This method was developed by the American scientist Thomas Lewis Saati in 1970, since then it has been actively developing and widely used in practice. The hierarchy analysis method can be used not only to compare objects, but also to solve more complex management and forecasting tasks

    Bottle house: A case study of transdisciplinary research for tackling global challenges

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    This work was done in collaboration with colleagues from the institute of Engineering sciences and Architecture Research Institute The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Globalisation has brought a number of challenges to the fore, particularly those problems which require collaboration, innovation and capability development between nations. There are some complex issues piquing the attention of researchers with respect to sustainable development, such as, waste management, climate change, and access to amenities, housing or education. Non-Governmental Organisations, Institutions, governments and others working in the field of international development have been grappling with these difficulties for decades. However, it is becoming apparent that many of these difficulties require multifaceted solutions, particularly in Low and Middle Income countries (LMIC) where it is difficult to consolidate gains and fund schemes. Development work can sometimes be disjointed and inefficient, impairing the capability of local communities and inhibiting sustainable and innovative approaches. Transdisciplinary collaboration is reliably a more efficient way of tackling some of the most pertinacious challenges. This paper presents findings from a transdisciplinary research project focussed on developing resources and capacity for the construction of affordable homes in a low income community in Nigeria. The project explored the suitability of using upcycled materials such as plastic bottles and agricultural waste in construction. Using a user-centred, co-creation methodology, a team of experts from the UK and Nigeria worked with local entrepreneurs to build a prototype home. The study explores the functionality of the home and the sustainability of project. The findings demonstrate the benefits of tackling global challenges from a transdisciplinary perspective. This has implications for researchers focused on developing technical solutions for low-income communities

    Synoptic climatology of winter daily temperature extremes in Sapporo, northern Japan

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    Extreme winter daily temperature is an important parameter for determining winter precipitation. This study used a principal component analysis and k-means clustering to characterize the circulation patterns of extreme daily temperatures for 19 winter seasons in Sapporo, Hokkaido, Japan. Climatological anomaly maps were constructed for sea level pressure (SLP) and the 500-hPa geopotential height for the identified minimum (Tmin(10); 239days) and maximum (Tmax(90); 236days) daily temperature extremes. The Tmax(90) SLP anomaly pattern was the opposite (west-east orientation) of the Tmin(10) pattern. The circulation patterns that predominantly contributed to winter rainfall were derived from cyclones over the Sea of Japan via instability created by abundant heat and moisture over the ocean and a strong positive 500-hPa height anomaly over Hokkaido

    Climatological Characteristics of Heavy Rainfall in Northern Pakistan and Atmospheric Blocking over Western Russia

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    Pakistan and northwestern India have frequently experienced severe heavy rainfall events during the boreal summer over the last 50 years including an event in late July and early August 2010 due to a sequence of monsoon surges. This study identified five dominant atmospheric patterns by applying principal component analysis and k-means clustering to a long-term sea level pressure dataset from 1979 to 2014. Two of these five dominant atmospheric patterns corresponded with a high frequency of the persistent atmospheric blocking index and positive sea level pressure over western Russia as well as an adjacent meridional trough ahead of northern Pakistan. In these two groups, a negative sea surface temperature anomaly was apparent over the equatorial mid- to eastern Pacific Ocean. The heavy precipitation periods with high persistent blocking frequency in western Russia as in the 2010 heat wave tended to have 1.2 times larger precipitation intensity compared to the whole of the heavy precipitation periods during the 36 years

    Tailored polyaniline/barium strontium titanate/expanded graphite multiphase composite for efficient radar absorption

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    The present paper reports the synthesis of a high-performance microwave absorbing material using a simple, cost-effective and scalable method by encapsulating barium strontium titanate (BST) and expanded graphite (EG) in a polyaniline (PANI) matrix. One of the formulations (higher content of BST) shows shielding effectiveness due to absorption of more than 50 dB (>99.9999% attenuation) with minimum reflection loss (<= 1 dB) in the Ku-band (12.4-18 GHz) frequency range. Another formulation (higher content of EG) shows a total shielding effectiveness of more than 81 dB with a reflection loss of 10 dB. In order to probe the relationship between the observed shielding response and the electromagnetic attributes, dielectric and permeability parameters have been calculated from the measured scattering parameters (S-11, S-22, S-12, S-21) using the Nicolson-Ross-Weir algorithm. The synthesised formulations were characterized thoroughly using XRD, FTIR, TGA, UV, Raman spectroscopy, SEM and HRTEM
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