1,053 research outputs found
A microangiographic study of the effect of hyperthermia on the rabbit bladder
A model was used to study the effect of hyperthermia on a normal tissue. The model selected was the rabbit bladder and the end point measured was the changes in the micro-vasculature of the bladder wall. It was already demonstrated clinically that hot water bladder infusions produce regression in bladder tumors
Ultra-slow cratonic denudation in Finland since 1.5 Ga indicated by tiered unconformities and impact structures
Self-consistent modeling of the energetic storm particle event of November 10, 2012
It is thought that solar energetic ions associated with
coronal/interplanetary shock waves are accelerated to high energies by the
diffusive shock acceleration mechanism. For this mechanism to be efficient,
intense magnetic turbulence is needed in the vicinity of the shock. The
enhanced turbulence upstream of the shock can be produced self-consistently by
the accelerated particles themselves via streaming instability. Comparisons of
quasi-linear-theory-based particle acceleration models that include this
process with observations have not been fully successful so far, which has
motivated the development of acceleration models of a different nature. The aim
of this work is to test how well our self-consistent quasi-linear SOLar
Particle Acceleration in Coronal Shocks (SOLPACS) simulation code, developed
earlier to simulate proton acceleration in coronal shocks, models the particle
foreshock region. We applied SOLPACS to model the energetic storm particle
(ESP) event observed by the STEREO A spacecraft on November 10, 2012. In the
simulations, all but one main input parameter of SOLPACS are fixed by the
in-situ plasma measurements from the spacecraft. By comparing a simulated
proton energy spectrum at the shock with the observed one, we were able to fix
the last simulation input parameter related to the efficiency of particle
injection to the acceleration process. A subsequent comparison of simulated
proton time-intensity profiles in a number of energy channels with the observed
ones shows a very good correspondence throughout the upstream region
Size-dependent filling effect of crystalline celluloses in structural engineering of composite oleogels
Oleogels are a class of solid-fat mimetics that contain a large fraction of oil. Most of these materials have low stiffness and poor oil-binding capacity at commercially viable concentrations, which limits their application in the food and cosmetic industries. To improve their mechanical behavior, we exploited the concepts of particulate-filled materials by developing oil-continuous monoglyceride composites reinforced with crystalline cellulose of various sizes. Cellulose was used as the reinforcing filler material due to its strength, biodegradability, and abundance. The composites gradually stiffened and became more brittle with a progressive increase of the cellulose weight fraction as the maximum packing fraction of fillers approached. This was manifested as an increase in the viscoelastic moduli and yield stress, consistent with the size of the filler. Based on differential scanning calorimetry, X-ray diffraction, X-ray scattering analyses, and microscopic analyses, the inert surface of crystalline celluloses provided a solid substrate for the crystallization of monoglycerides, favoring the lamellar stacking of monoglyceride molecules during the composite oleogel formation regardless of the cellulose size. The present study suggests that cellulose is a suitable bio-based filler material to obtain mechanically strong oleogels suitable for high-shear applications e.g., in food and pharmaceutical industries.Peer reviewe
Highly selective recovery of Ni(II) in neutral and acidic media using a novel Ni(II)-ion imprinted polymer
In this work, an original ion-imprinted polymer (IIP) was synthetized for the highly selective removal of Ni(II) ions in neutral and acidic media. First a novel functional monomer (AMP-MMA) was synthetized through the amidation of 2-(aminomethyl)pyridine (AMP) with methacryloylchloride. Following Ni(II)/AMP-MMA complex formation study, the Ni(II)-IIP was produced via inverse suspension polymerization (DMSO in mineral oil) and characterized with solid state 13C CPMAS NMR, FT-IR, SEM and nitrogen adsorption/desorption experiments. The Ni(II)-IIP was then used in solid-phase extraction of Ni(II) exploring a wide range of pH (from neutral to strongly acidic solution), several initial concentrations of Ni(II) (from 0.02 to 1 g/L), and the presence of competitive ions (Co(II), Cu(II), Cd(II), Mn(II), and Mg(II)). The maximum Ni(II) adsorption capacity at pH 2 and pH 7 reached values of 138.9 mg/g and 169.5 mg/g, that are among the best reported in literature. The selectivity coefficients toward Cd(II), Mn(II), Co(II), Mg(II) and Cu(II) are also very high, with values up to 38.6, 32.9, 25.2, 23.1 and 15.0, respectively. The Ni(II)-IIP showed good reusability of up to 5 cycles both with acidic and basic Ni(II) eluents.Peer reviewe
Tail reconnection in the global magnetospheric context : Vlasiator first results
The key dynamics of the magnetotail have been researched for decades and have been associated with either three-dimensional (3-D) plasma instabilities and/or magnetic reconnection. We apply a global hybrid-Vlasov code, Vlasiator, to simulate reconnection self-consistently in the ion kinetic scales in the noon-midnight meridional plane, including both dayside and nightside reconnection regions within the same simulation box. Our simulation represents a numerical experiment, which turns off the 3-D instabilities but models ion-scale reconnection physically accurately in 2-D. We demonstrate that many known tail dynamics are present in the simulation without a full description of 3-D instabilities or without the detailed description of the electrons. While multiple reconnection sites can coexist in the plasma sheet, one reconnection point can start a global reconfiguration process, in which magnetic field lines become detached and a plasmoid is released. As the simulation run features temporally steady solar wind input, this global reconfiguration is not associated with sudden changes in the solar wind. Further, we show that lobe density variations originating from dayside reconnection may play an important role in stabilising tail reconnection.Peer reviewe
Molecular analysis of two novel missense mutations in the GDF5 proregion that reduce protein activity and are associated with brachydactyly type C
Growth and differentiation factor 5 (GDF5) plays a central role in bone and cartilage development by regulating the proliferation and differentiation of chondrogenic tissue. GDF5 is synthesized as a preproprotein. The biological function of the proregion comprising 354 residues is undefined. We identified two families with a heterozygosity for the novel missense mutations p.T201P or p.L263P located in the proregion of GDF5. The patients presented with dominant brachydactyly type C characterized by the shortening of skeletal elements in the distal extremities. Both mutations gave rise to decreased biological activity in in vitro analyses. The variants reduced the GDF5-induced activation of SMAD signaling by the GDF5 receptors BMPR1A and BMPR1B. Ectopic expression in micromass cultures yielded relatively low protein levels of the variants and showed diminished chondrogenic activity as compared to wild-type GDF5. Interestingly, stimulation of micromass cells with recombinant human proGDF5(T201P) and proGDF5(L263P) revealed their reduced chondrogenic potential compared to the wild-type protein. Limited proteolysis of the mutant recombinant proproteins resulted in a fragment pattern profoundly different from wild-type proGDF5. Modeling of a part of the GDF5 proregion into the known three-dimensional structure of TGFbeta1 latency-associated peptide revealed that the homologous positions of both mutations are conserved regions that may be important for the folding of the mature protein or the assembly of dimeric protein complexes. We hypothesize that the missense mutations p.T201P and p.L263P interfere with the protein structure and thereby reduce the amount of fully processed, biologically active GDF5, finally causing the clinical loss of function phenotype
Combined and single effects of pesticide carbaryl and toxic Microcystis aeruginosa on the life history of Daphnia pulicaria
The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different, sub-lethal concentrations (chronic exposure). In order to determine the actual carbaryl concentrations in the water LC–MS/MS was used. For analyses of the cyanotoxin concentration in Daphnia’s body enzyme-linked immunosorbent assay (ELISA) was used. Individual daphnids were cultured in a flow-through system under constant light (16 h of light: 8 h of dark), temperature (20°C), and food conditions (Scenedesmus obliquus, 1 mg of C l−1). The results showed that in the treatments with carbaryl egg numbers per female did not differ significantly from controls, but the mortality of newborns increased significantly. Increasing microcystin concentrations significantly delayed maturation, reduced size at first reproduction, number of eggs, and newborns. The interaction between carbaryl and Microcystis was highly significant. Animals matured later and at a smaller size than in controls. The number of eggs per female was reduced as well. Moreover, combined stressors caused frequent premature delivery of offspring with body deformations such as dented carapax or an undeveloped heart. This effect is concluded to be synergistic and could not be predicted from the effects of the single stressors.
Wood lignocellulosic stabilizers : effect of their characteristics on stability and rheological properties of emulsions
Lignocellulosic materials from the forest industry have shown potential to be used as sustainable hydrocolloids to stabilize emulsions for many applications in life science and chemical industries. However, the effect of wood species and recovery method on the product’s properties and ability to stabilize emulsions of isolated lignocellulosic compounds is not well understood. Hemicelluloses, abundant lignocellulosic side stream, exhibit differences in their water solubility, anionic character, lignin content, and degree of acetylation. Here, we explored stability and rheological properties of model emulsions (5% hexadecane and 1% stabilizer, w/w) stabilized by different grades of sprucewood galactoglucomannan (GGM) and birchwood glucuronoxylan (GX) hemicelluloses. The results were compared to known soluble, insoluble, charged, and non-charged cellulosic stabilizers, namely methyl cellulose (MC), carboxymethyl cellulose (CMC), anionic- and nonionic-cellulose nanocrystals (aCNC and dCNC). The results showed that GX emulsions were highly stable compared to GGM emulsions, and that deacetylation and lignin removal markedly reduced emulsion stability of GGM. Carboxymethylation to increase anionic characters enhanced the emulsion stabilization capacity of GGM, but not that of GX. Investigating flow behaviors of emulsions indicated that hemicelluloses primarily stabilize emulsions by adsorption of insoluble particles, as their flow behaviors were similar to those of cellulose nanocrystals rather than those of soluble celluloses. Understanding the impact of the variations in composition and properties of hemicellulose stabilizers to stabilize emulsions allows tailoring of their recovery processes to obtain desirable hydrocolloids for different applications.Peer reviewe
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