Controlled Release of Drugs FromHydrogel Based Matrices Systems: Experiments and Modeling

Hydrogels are materials largely used in the formulation of pharmaceuticals since, in principle, they could produce a release system of zero-order kinetics, which is of great therapeutic interest. In this paper, a model was proposed for the description of the main transport phenomena involved in the drug release process from hydrogel matrices (water diffusion, polymer swelling, drug diffusion and polymer dissolution); the model predictions are successfully compared with a large set of experimental data, obtained working with matrices systems based on HPMC (Hydroxy Propyl Methyl Cellulose). The proposed model was found able to reproduce main features of the observed phenomena, it can thus be adopted for prediction of the performances of drug release systems from hydrogel matrices

Controlled Release of Drugs FromHydrogel Based Matrices Systems: Experiments and Modeling

Hydrogels are materials largely used in the formulation of pharmaceuticals since, in principle, they could produce a release system of zero-order kinetics, which is of great therapeutic interest. In this paper, a model was proposed for the description of the main transport phenomena involved in the drug release process from hydrogel matrices (water diffusion, polymer swelling, drug diffusion and polymer dissolution); the model predictions are successfully compared with a large set of experimental data, obtained working with matrices systems based on HPMC (Hydroxy Propyl Methyl Cellulose). The proposed model was found able to reproduce main features of the observed phenomena, it can thus be adopted for prediction of the performances of drug release systems from hydrogel matrices

Controlled Release of Drugs fromMicroparticles Produced by Ultrasonic Assisted Atomization Based on Biocompatible Polymers

Microencapsulation of active molecules in biocompatible polymers is a matter of great interest in pharmaceutical sciences. Ultrasonic assisted atomization as a new technique to produce microencapsulated systems seems to offer several advantages (low level of mechanical stress in materials, reduced energy request, reduced apparatuses size) with respect to more conventional techniques. In this work, fine drug-loaded particles were produced by ionic reticulation of droplets obtained by ultrasonic atomization of biopolymers solutions. The particles were then characterized in terms of morphology and drug release kinetics. Data were used to estimate the PNMS (Polymeric Network Mesh-Size) with the aims of clarifying its role in controlled drug release, and analyzing its relationships with material and process parameters. For materials and operative conditions investigated, the calculated PNMS was found consistent with a fast release of drugs of small molecular size

Controlled Release of Drugs fromMicroparticles Produced by Ultrasonic Assisted Atomization Based on Biocompatible Polymers

Microencapsulation of active molecules in biocompatible polymers is a matter of great interest in pharmaceutical sciences. Ultrasonic assisted atomization as a new technique to produce microencapsulated systems seems to offer several advantages (low level of mechanical stress in materials, reduced energy request, reduced apparatuses size) with respect to more conventional techniques. In this work, fine drug-loaded particles were produced by ionic reticulation of droplets obtained by ultrasonic atomization of biopolymers solutions. The particles were then characterized in terms of morphology and drug release kinetics. Data were used to estimate the PNMS (Polymeric Network Mesh-Size) with the aims of clarifying its role in controlled drug release, and analyzing its relationships with material and process parameters. For materials and operative conditions investigated, the calculated PNMS was found consistent with a fast release of drugs of small molecular size

Mitotic and meiotic polyploidization in lily hybrids for transferring Botrytis resistance

In an effort to transfer Botrytis resistance from Oriental lilies to Asiatic hybrids (Lilium, 2n=2x=24) we made a large number of F1 hybrids between these two distantly related species. Because these species belong to two different taxonomic sections, the F1 hybrids were totally sterile and could not be directly used in breeding. Therefore, two approaches were used for utilizing the F1 hybrids. First, the somatic chromosome number of the F1s was doubled by treating with oryzalin that resulted in allotetraploids (mitotic doubling). These allotetraploids were used for crossing with the parents. Second, 2n gametes were used directly for crossing with the parents for producing sexual polyploids (meiotic doubling). The two types of BC1 progenies were monitored for resistance against Botrytis elliptica through a ¿leaf tip test¿. Disease severity was evaluated on a nominal scale, ranging from 1 resistant (no lesions) to 6 (a high degree of necrosis with mycelium or even spores). In both populations the resistance varied from very susceptible to highly resistant. However, the occurrence of transgression of resistance, meaning that the degree of resistance in some seedlings exceeded that of the parent, was higher in meiotically doubled polyploids as compared to those derived from mitotic doubling. This was explained from the fact that the typical allotetraploids produce uniformly a single genotype of 2x gametes containing both parental genomes because of autosyndetic pairing so that there is no scope for genetic variation. On the contrary, in the case of meiotic polyploids intergenomic recombination occurs between the alien chromosomes that could lead to considerable amount of genetic variation. This phenomenon might be an explanation for the observed transgression of Botrytis resistance in the meiotic polyploid progenies

Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub

The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)\u2014a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3�6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55 of the global rise in mean BMI from 1985 to 2017�and more than 80 in some low- and middle-income regions�was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing�and in some countries reversal�of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories. © 2019, The Author(s)

Preliminary Validation of a Numerical Code for Heat Transfer Simulations,

A great number of heat transfer problems can be treated as transient heat transport phenomena within a body, often semi-infinite or symmetric in some directions, and in these cases a one-dimensional treatise is enough. Dielectric/microwave heating of cylinder and fast cooling of thin slabs are common examples. A numerical code was developed to simulate heat transfer phenomena in variable conditions. Model equations were based on transient one-dimensional energy balance. Moreover, the different kinds of energy source terms, and the different kinds of boundary conditions can be implemented in the model. Aim of this communication is a preliminary validation of the numerical code, by comparison with several analytical solutions of the heat transfer problems coming from literature. The validation has been carried out, and here results are shown and briefly discussed. 10.1007/s00231-002-0341-