Influence of the Surface Enhancement on the Flow Boiling Heat Transfer in a Minichannel

This paper presents results concerning flow boiling heat transfer in three parallel vertically oriented and asymmetrically heated rectangular minichannels. Each minichannel was 1.7 mm deep, 16 mm wide, and 180 mm long. The heated element for Fluorinert FC-72 flowing in the minichannels was a thin foil. Infrared thermography was used to determine changes in the temperature on the outer smooth side of the foil. Two-phase flow patterns were observed through a glass pane. The heated surfaces in contact with the fluid in the minichannels differed in roughness. In one minichannel the surface was smooth. In the other two, the surface was enhanced. Two types of surface enhancement were analyzed: a surface with unevenly distributed minicavities and a surface coated with metallic powder applied by soldering. This paper analyzes the effects of the microstructured heated surface on the heat transfer coefficient. The results are presented as: relationships between the heat transfer coefficient and the vapor quality, boiling curves and two-phase flow images. The experimental data obtained for the two types of enhanced surfaces was compared with the results recorded for the smooth surface. The highest local values of the heat transfer coefficient were reported for the enhanced foil with minicavities.     

Changes of amino acid and fatty acid profile in freshwater fish after smoking

Three freshwater fishes: common carp, rainbow trout and northern pike were chosen for the evaluation of amino acid and fatty acid composition—fresh and after smoking. Smoking led to the increase in almost all amino acids, with the highest amount of EAA in common carp. This process led also to the enhancement in the level of SFA and the decrease in PUFA/SFA ratio in fishes. PI values were lower after this process for all fishes. HH ratio was also decreased (except for northern pike), while AI and TI were enhanced in all smoked samples.

Practical applications

Fish and fish products consumption (especially freshwater) is still insufficient despite their proven health‐promoting properties. Because of the susceptibility of fish to perish, their preservation becomes a necessity. Smoking is one of the oldest food processing methods in the world. It imparts a characteristic color and flavor of the product. This process influences also on chemical composition of muscle protein and fat. Thus, the aim of this study was to investigate changes in amino acids composition and fatty acids profile in common carp, rainbow trout and northern pike, as a result of smoking. It is very important to increase consumer knowledge concerned on the species being the most suitable for traditional preservation method, taking into consideration the retaining of beneficial fish compounds.     

Calculations of Flow Boiling Heat Transfer in a Minichannel Based on Liquid Crystal and Infrared Thermography Data

ABSTRACT

This paper analyzes results concerning flow boiling heat transfer in two parallel, asymmetrically heated vertical minichannels. The heating element for FC-72 Fluorinert flowing in the minichannels was a thin foil with an enhanced surface on the side in contact with the fluid. In one minichannel, changes in the temperature on the smooth side of the foil were monitored using liquid crystal thermography. Changes in the temperature on the outer surface of the glass in one minichannel and on the foil in the other minichannel were observed using infrared thermography. The heat transfer coefficient at the foil–fluid interface was calculated on the basis of one- and two-dimensional heat transfer models. In the two-dimensional method, the distribution of temperature on the enhanced side of the foil was determined by solving the inverse heat conduction problem. The governing equations were solved using the finite-element method combined with the Trefftz functions used as shape functions. The temperature measurement points were located at the boundary nodes of elements. Local values of the heat transfer coefficient calculated with the one- and two-dimensional models were analyzed in the function of the distance from the minichannel inlet. The values obtained with the two models were similar.     

SB203580—A Potent p38 MAPK Inhibitor Reduces the Profibrotic Bronchial Fibroblasts Transition Associated with Asthma

Subepithelial fibrosis is a component of the remodeling observed in the bronchial wall of patients diagnosed with asthma. In this process, human bronchial fibroblasts (HBFs) drive the fibroblast-to-myofibroblast transition (FMT) in response to transforming growth factor-β₁ (TGF-β₁), which activates the canonical Smad-dependent signaling. However, the pleiotropic properties of TGF-β₁ also promote the activation of non-canonical signaling pathways which can affect the FMT. In this study we investigated the effect of p38 mitogen-activated protein kinase (MAPK) inhibition by SB203580 on the FMT potential of HBFs derived from asthmatic patients using immunocytofluorescence, real-time PCR and Western blotting methods. Our results demonstrate for the first time the strong effect of p38 MAPK inhibition on the TGF-β₁-induced FMT potential throughout the strong attenuation of myofibroblast-related markers: α-smooth muscle actin (α-SMA), collagen I, fibronectin and connexin 43 in HBFs. We suggest the pleiotropic mechanism of SB203580 on FMT impairment in HBF populations by the diminishing of TGF-β/Smad signaling activation and disturbances in the actin cytoskeleton architecture along with the maturation of focal adhesion sites. These observations justify future research on the role of p38 kinase in FMT efficiency and bronchial wall remodeling in asthma.     

Silica functionalized by pyridinecarboximidamides as a novel sorbent of heavy metals ions

ABSTRACT

Two novel sorbents, obtained as a result of surface modification of silica gel for the Cu(II), Co(II) and Ni(II) removal from aqueous solutions were proposed. For the modification, 3-chloropropyltrimethoxysilane, N’-hydroxy-N,N-dioctylpyridine-3-carboximidamide and N’-hydroxy-N,N-dioctylpyridine-4-carboximidamides were used. A series of basic tests on the sorption of Cu(II), Co(II) and Ni(II) were carried out and the presented results indicated that the novel sorbents were able to remove all tested metals ions from the aqueous solutions, and the removal efficiency was dependent on the functionalised agent structure, dosage, metal ions concentration and pH. The Langmuir model also assumed that a monolayer sorption occurred.     

Perisomatic Inhibition and Its Relation to Epilepsy and to Synchrony Generation in the Human Neocortex

Inhibitory neurons innervating the perisomatic region of cortical excitatory principal cells are known to control the emergence of several physiological and pathological synchronous events, including epileptic interictal spikes. In humans, little is known about their role in synchrony generation, although their changes in epilepsy have been thoroughly investigated. This paper demonstraits how parvalbumin (PV)- and type 1 cannabinoid receptor (CB1R)-positive perisomatic interneurons innervate pyramidal cell bodies, and their role in synchronous population events spontaneously emerging in the human epileptic and non-epileptic neocortex, in vitro. Quantitative electron microscopy showed that the overall, PV+ and CB1R+ somatic inhibitory inputs remained unchanged in focal cortical epilepsy. On the contrary, the size of PV-stained synapses increased, and their number decreased in epileptic samples, in synchrony generating regions. Pharmacology demonstrated—in conjunction with the electron microscopy—that although both perisomatic cell types participate, PV+ cells have stronger influence on the generation of population activity in epileptic samples. The somatic inhibitory input of neocortical pyramidal cells remained almost intact in epilepsy, but the larger and consequently more efficient somatic synapses might account for a higher synchrony in this neuron population. This, together with epileptic hyperexcitability, might make a cortical region predisposed to generate or participate in hypersynchronous events.     

Dysregulated Autophagy and Mitophagy in a Mouse Model of Duchenne Muscular Dystrophy Remain Unchanged Following Heme Oxygenase-1 Knockout

Dysregulation of autophagy may contribute to the progression of various muscle diseases, including Duchenne muscular dystrophy (DMD). Heme oxygenase-1 (HO-1, encoded by Hmox1), a heme-degrading enzyme, may alleviate symptoms of DMD, inter alia, through anti-inflammatory properties. In the present study, we determined the role of HO-1 in the regulation of autophagy and mitophagy in mdx animals, a commonly used mouse model of the disease. In the gastrocnemius of 6-week-old DMD mice, the mRNA level of mitophagy markers: Bnip3 and Pink1, as well as autophagy regulators, e.g., Becn1, Map1lc3b, Sqstm1, and Atg7, was decreased. In the dystrophic diaphragm, changes in the latter were less prominent. In older, 12-week-old dystrophic mice, diminished expressions of Pink1 and Sqstm1 with upregulation of Atg5, Atg7, and Lamp1 was depicted. Interestingly, we demonstrated higher protein levels of autophagy regulator, LC3, in dystrophic muscles. Although the lack of Hmox1 in mdx mice influenced blood cell count and the abundance of profibrotic proteins, no striking differences in mRNA and protein levels of autophagy and mitophagy markers were found. In conclusion, we demonstrated complex, tissue, and age-dependent dysregulation of mitophagic and autophagic markers in DMD mice, which are not affected by the additional lack of Hmox1.     

Alteration of the Early Development Environment by Maternal Diet and the Occurrence of Autistic-like Phenotypes in Rat Offspring

Epidemiological and preclinical studies suggest that maternal obesity increases the risk of autism spectrum disorder (ASD) in offspring. Here, we assessed the effects of exposure to modified maternal diets limited to pregnancy and lactation on brain development and behavior in rat offspring of both sexes. Among the studied diets, a maternal high-fat diet (HFD) disturbed the expression of ASD-related genes (Cacna1d, Nlgn3, and Shank1) and proteins (SHANK1 and TAOK2) in the prefrontal cortex of male offspring during adolescence. In addition, a maternal high-fat diet induced epigenetic changes by increasing cortical global DNA methylation and the expression of miR-423 and miR-494. As well as the molecular changes, behavioral studies have shown male-specific disturbances in social interaction and an increase in repetitive behavior during adolescence. Most of the observed changes disappeared in adulthood. In conclusion, we demonstrated the contribution of a maternal HFD to the predisposition to an ASD-like phenotype in male adolescent offspring, while a protective effect occurred in females.     

Tissue Transglutaminase Knock-Out Preadipocytes and Beige Cells of Epididymal Fat Origin Possess Decreased Mitochondrial Functions Required for Thermogenesis

Beige adipocytes with thermogenic function are activated during cold exposure in white adipose tissue through the process of browning. These cells, similar to brown adipocytes, dissipate stored chemical energy in the form of heat with the help of uncoupling protein 1 (UCP1). Recently, we have shown that tissue transglutaminase (TG2) knock-out mice have decreased cold tolerance in parallel with lower utilization of their epididymal adipose tissue and reduced browning. To learn more about the thermogenic function of this fat depot, we isolated preadipocytes from the epididymal adipose tissue of wild-type and TG2 knock-out mice and differentiated them in the beige direction. Although differentiation of TG2 knock-out preadipocytes is phenotypically similar to the wild-type cells, the mitochondria of the knock-out beige cells have multiple impairments including an altered electron transport system generating lower electrochemical potential difference, reduced oxygen consumption, lower UCP1 protein content, and a higher portion of fragmented mitochondria. Most of these differences are present in preadipocytes as well, and the differentiation process cannot overcome the functional disadvantages completely. TG2 knock-out beige adipocytes produce more iodothyronine deiodinase 3 (DIO3) which may inactivate thyroid hormones required for the establishment of optimal mitochondrial function. The TG2 knock-out preadipocytes and beige cells are both hypometabolic as compared with the wild-type controls which may also be explained by the lower expression of solute carrier proteins SLC25A45, SLC25A47, and SLC25A42 which transport acylcarnitine, Co-A, and amino acids into the mitochondrial matrix. As a consequence, the mitochondria in TG2 knock-out beige adipocytes probably cannot reach the energy-producing threshold required for normal thermogenic functions, which may contribute to the decreased cold tolerance of TG2 knock-out mice.