Comparison of the molecular weight distribution of gelatin fractions by size-exclusion chromatography and light scattering

Commercial gelatin is a heterogeneous proteinaceous product with a broad range of molecular weights. The use of gelatin to prepare insoluble nanoparticles depends largely on the presence of high molecular weight fractions that can be separated by size-exclusion chromatography. The purpose of this study was to determine the molecular fractions of gelatins from three commercial types (B225, B60 and A60), measure their molecular weight and compare these with data obtained from an absolute light scattering method. The mean molecular weight of the gelatins decreased in the order B225 > B60 > A60. All samples were polydisperse, with fractions varying from 2 MDa. Each sample was divided into eight fractions based on the molecular weight distribution and using a paired t-test the two methods were shown to be in substantial agreement. The light scattering method would appear to provide an absolute quality control procedure for commercial gelatin, depending on its application and requirements.peer-reviewe

Ethyl 2-(4-carb­oxy­benzyl­idene)-7-methyl-3-oxo-5-phenyl-2,3-dihydro-5H-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate–N,N-dimethyl­formamide (1/1)

In the title compound, C24H20N2O5S·C3H7NO, a benzene ring is positioned axially to the pyrimidine ring, which adopts a twist-boat conformation, and is inclined to its mean plane by 85.36 (7)°. In the crystal, inter­molecular C—H⋯O inter­actions result in centrosymmetric head-to-head dimers with an R 2 2(14) graph-set motif along the b axis. Pairs of C—H⋯O and O—H⋯O hydrogen bonds form centrosymmetric head-to-head dimers about inversion centres, corresponding to an R 2 2(7) graph-set motif along the a axis

A review of studies investigating the dielectric properties of biological tissues for application in hyperthermia and microwave thermal ablation

Heating of biological tissues beyond 40 C has become an established method of treating a number of diseases, most notably tumours, where hyperthermia and thermal ablation are important modalities. In some interventions, tissue temperatures reached can even go beyond 100 C, and demand precise knowledge of tissue dielectric properties and how these vary with frequency and temperature in order to facilitate accurate computational simulations for preclinical planning. This paper reviews the available literature concerning dielectric properties of biological tissues and their temperature dependence, focusing on the frequencies of 915 MHz and 2.45 GHz, at which most of the studies reviewed investigate predominantly liver tissue. In this review a comparative analysis of the results obtained by different research groups are presented in the different studies is also made, indicating possible limiting factors in the different studies. These studies propose a number of different models which could be used to describe temperature dependence. Due to the prevalence of liver investigations, it would be ideal to conduct further studies on different biological tissues.peer-reviewe

Bis{N-[bis­(pyrrolidin-1-yl)phosphor­yl]-2,2,2-trichloro­acetamide}di­nitrato­dioxidouranium(VI)

The crystal structure of the title compound, [U(NO3)2O2(C10H17Cl3N3O2P)2], is composed of centrosymmetric [UO2(L)2(NO3)2] mol­ecules {L is N-[bis­(pyrrolidin-1-yl)phosphor­yl]-2,2,2-trichloro­acetamide, C10H17Cl3N3O2P}. The UVI ion, located on an inversion center, is eight-coordinated with axial oxido ligands and six equatorial oxygen atoms of the phosphoryl and nitrate groups in a slightly distorted hexa­gonal-bipyramidal geometry. One of the pyrrolidine fragments in the ligand is disordered over two conformation (occupancy ratio 0.58:0.42). Intra­molecular N—H⋯O hydrogen bonds between the amine and nitrate groups are found

(2,2′-Bipyridine)bis­(triphenyl­phosphine)copper(I) nitrate chloro­form solvate hemihydrate

In the title compound, [Cu(C10H8N2)(C18H15P)2]NO2·CHCl3·0.5H2O, the Cu atom is tetra­hedrally coordinated by a bidentate 2,2′-bipyridine ligand and two PPh3 ligands. The Cu—N and Cu—P distances are similar to those observed in similar compounds. The range of coordination angles shows a moderate distortion from ideal tetra­hedral geometry. The bipyridine ligand is twisted [14.2 (4)°] about the ring–ring C—C bond. The nitrate anion and the water and chloro­form mol­ecules of solvation are disordered. In the crystal structure, there are O(water)—H⋯O(nitrate), C—H⋯O(water) and C—H⋯O(nitrate) hydrogen bonds

1-Methyl-3-(4-chloro­benzo­yl)imidazo[1,2-a]pyridin-1-ium-2-olate

In the mol­ecule of the title compound, C15H11ClN2O2, the nine-membered heterobicycle is approximately planar [largest deviation from least-squares plane = 0.012 (2) Å] and forms a dihedral angle of 51.14 (8)° with the plane of the 4-chloro­phenyl group. There is a non-classical intra­molecular hydrogen bond between the pyridine α-H atom and the O atom of the benzoyl group. The crystal structure is stabilized by weak C—H⋯O and C—H⋯Cl inter­actions involving the ‘olate’ O atom and the Cl atom attached to the benzoyl group as acceptors

The non-linear evolution of magnetic flux ropes: 3. effects of dissipation

International audienceWe study the evolution (expansion or oscillation) of cylindrically symmetric magnetic flux ropes when the energy dissipation is due to a drag force proportional to the product of the plasma density and the radial speed of expansion. The problem is reduced to a single, second-order, ordinary differential equation for a damped, non-linear oscillator. Motivated by recent work on the interplanetary medium and the solar corona, we consider polytropes whose index, ?, may be less than unity. Numerical analysis shows that, in contrast to the small-amplitude case, large-amplitude oscillations are quasi-periodic with frequencies substantially higher than those of undamped oscillators. The asymptotic behaviour described by the momentum equation is determined by a balance between the drag force and the gradient of the gas pressure, leading to a velocity of expansion of the flux rope which may be expressed as (1/2?)r/t, where r is the radial coordinate and t is the time. In the absence of a drag force, we found in earlier work that the evolution depends both on the polytropic index and on a dimensionless parameter, ?. Parameter ? was found to have a critical value above which oscillations are impossible, and below which they can exist only for energies less than a certain energy threshold. In the presence of a drag force, the concept of a critical ? remains valid, and when ? is above critical, the oscillatory mode disappears altogether. Furthermore, critical ? remains dependent only on ? and is, in particular, independent of the normalized drag coefficient, ?*. Below critical ?, however, the energy required for the flux rope to escape to infinity depends not only on ? (as in the conservative force case) but also on ?*. This work indicates how under certain conditions a small change in the viscous drag coefficient or the initial energy may alter the evolution drastically. It is thus important to determine ?* and ? from observations

5,5′-Bis[(trimethyl­silyl)meth­yl]-2,2′-bipyridine

The mol­ecule of the title compound, C18H28N2Si2, occupies a special position on an inversion centre. The Si—CH2—C(ipso) plane is approximately orthogonal to the plane of the pyridine rings, the corresponding dihedral angle being 82.0 (2)°

“An investigation of Malta’s evolution in global value chains and the implications for sustainable development”

This research presents an investigation into the development of FDI manufacturing companies and the business of their logistics partners within a host economy state and the evolvement of the host economy state itself. The gathered data provided information to satisfy the aim of this study to understand what makes a host state attractive to multinational enterprises in their global value chains, the state’s development policy and the implications for sustainable development, the so-called ‘triple bottom line’ of economy, society and environment. To accomplish this task, a range of literature is evaluated to acquire a foundation of knowledge and to explore possible extant scholarship on the investigated elements within this study. This exploratory research is underpinned by an interpretive epistemology and a qualitative case study approach with a plan to collect and analyse evidence (Flick, 2009). The research was conducted in Malta. Open-ended interviews were held with high ranking representatives of FDI case study companies and logistics service providers; and with key informants within government and non-government institutions and agencies and academia at the national level. All participants’ responses provide experiences and perceptions representing their everyday context and the real-life situations of their practices, policies and interactions, with implications for sustainability. The provided primary data were collected between 2017 and 2018. Emerging topics from the data at every stage have been discussed with the participants. This research is a longitudinal study, including a historical background for the underlying and developmental aspects and highlights implications for global value chain policies, regional development policies, sustainable economic growth, institutionalism and co-evolution, providing a contribution to theory and practice