Oral glutamine dipeptide or oral glutamine free amino acid reduces burned injury progression in rats

This study was carried out to evaluate the effect of Glutamine, as a dipeptide or a free amino acid form, on the progression of burn injuries in rats. Thirty male Wistar rats were burned with a comb metal plate heated in boiling water (98 °C) for three minutes, creating four rectangular full-thickness burn areas separated by three unburned interspaces (zone of stasis) in both dorsum sides. The animals were randomized into three groups (n=10): saline solution (G1-Control) and treated groups that orally received Glutamine as dipeptide (G2-Dip) or free amino acid (G3-FreeAA). Two and seven days after burn injury, lesions were photographed for unburned interspaces necrosis evolution assessment. Seven days after injury, glutathione seric was measured and histopathological analysis was performed. By photographs, there was a significant reduction in necrosis progression in G3-Free-AA between days two and seven. Histopathological analysis at day 7 showed a significantly higher stasis zone without necrosis and a higher number of fibroblasts in G2-Dip and G3-FreeAA compared with G1-Control. Also, glutathione serum dosage was higher in G2-Dip. The plasmatic glutathione levels were higher in the G2-Dip than the G1-Control, and there was a trend to higher levels in G3-FreeAA. The reduction in histological lesions, greater production of fibroblasts, and greater amounts of glutathione may have benefited the evolution of burn necrosis, which showed greater preservation of interspaces.

Experimental and numerical investigation of metal-polymer riveted joints

This paper presents the modeling and analysis of the joints of metal inserts with polyamide 6 using the injection technique. Based on the conducted experiments, modeling and numerical calculations of joints were carried out for various joint configurations. Metal parts, made of steel grade DC 04, are mechanically locked with polyamide 6 (PA6) with rivets. The mechanical connection with rivets of both elements was achieved by filling the holes in the metal parts in the injection process. As part of the work, mechanical-clamp connections made of steel / PA6 were mechanically tested in a single-axis joint tensile test using appropriate tabs. The main goal was to study and numerically analyze the number of rivets and their location on the metal plate for the strength of the connector. An important element of the work was the modeling process of both the PA6 material behavior and the joint itself. As part of the experimental research, the rivet deformation was also observed using computer thermography with the use of an IR camera. The tests and simulation showed that for the sample, the polymer-metal connected with less than three rivets was destroyed by shear. On the other hand, when the polymer-metal junction was made of three rivets, the jamming mechanism was mainly related to damage to the polymer part. For these joints, the maximum values of the breaking force of the joint were obtained in uniaxial tensile and shear tests where three rivets were used. Similar values were obtained during the numerical calculations performed with the use of Abaqus software.

Room-Temperature Preparation of Ta Ions-Containing Ionic Liquid and its Vapor Deposition toward Ta-Oxide Film Coating

Ta ions-containing solutions, which are brown in color with no precipitation, were successfully prepared through an electroelution process with ionic liquid (IL). An as-delivered Ta metal plate covered with a passivation oxide film could be easily eluted even at room temperature by simply applying an anodic potential of, e.g. +2.2 V vs. Ag in [Bmim][PF6] IL. According to the quantity of electric charge required for oxidation of Ta, most Ta ions in the IL were suggested to be in an oxidation state of +5, which was also confirmed by x-ray photoemission spectroscopy (XPS). Ta ions in IL were found to thermally evaporate together with IL molecules by heating in a vacuum, forming a deposit of the Ta ions-containing IL on a substrate. The Ta concentrations in the deposits were reduced uniquely by about one order of magnitude from those in the original bulk source through the evaporation process under the present conditions. Furthermore, a possibility of the formation of thin film-like Ta oxide from such a Ta ions-containing IL deposit and its bulk droplet prepared on substrates by annealing in air at 1000oC will be discussed.

Visualization of defects in thin metal plates by a scanning airborne ultrasound source technique using guided waves of different frequencies

A scanning airborne ultrasound source technique was developed to overcome the riskiness of laser ultrasound, which uses an ultrasound source that has a fixed sound wave focusing point and thus requires mechanical motion for sound source scanning. Therefore, the measurement time becomes longer. To solve this problem, we have proposed a method of simultaneously exciting many measurement points in the target using focused ultrasound sources of different frequencies. In this paper, we investigated the visualization of defects in a thin metal plate by the scanning elastic wave source technique using an airborne ultrasound source driven at two frequencies. When the testing was performed using two frequencies, either frequency visualized the defects.

Characterization of a metallic interconnect operated in stack during 40,000 hours in SOFC mode

An SOFC stack operated for 40,000 hours has been dismantled offering the opportunity to characterize the metallic interconnect. The metal plate was carefully investigated to define the evolution of the surfaces exposed to the air and to the hydrogen electrodes respectively. The observations of the surfaces reveal the stability of the layers applied on top of the rib at the air side while in the bottom of the channels the protective coating (i.e., Co-Mn base spinel oxide) shows large crystals. The cross section allowed to highlight the formation of a rather homogeneous layer of thermal grown oxide between the metal and the coating. The average thickness of the TGO is around 11 μm. The hydrogen side shows a superficial alteration (due to the interaction with the water vapour) changing from the inlet to the outlet where it seems thinner as if the TGO further reacted by forming volatile compounds. The cross section observations confirmed the presence of a porous TGO with a rather high content of manganese in a Cr-Mn spinel oxide. Several spots testifies the zones of contact with the Ni base contacting layer. The cross section corresponding to such zones highlighted the Ni diffusion in the metal substrate.

Электромагнитные свойства полимерных композитов Li-=SUB=-0.33-=/SUB=-Fe-=SUB=-2.29-=/SUB=-Zn-=SUB=-0.21-=/SUB=-Mn-=SUB=-0.17-=/SUB=-O-=SUB=-4-=/SUB=-/П(ВДФ-ТФЭ) в области частот 100-7000 МГц

The article describes electromagnetic and microwave properties of the polymer composite with the lithium spinel ferrite inclusion of composition Li0.33Fe2.29Zn0.21Mn0.17O4 in the frequency range 100 MHz - 7000 MHz. It is shown that samples with a mass fraction of ferrite 60, 80% have pronounced radio-absorbing properties, measured using the reflection coefficient on a metal plate (return losses). For a composite with 80% ferrite, the minimum return loss was -37.5 dB at 2.71 GHz with an absorption width at -10 dB of 3 GHz. High absorption characteristics are directly related to the use of ferroelectric polymer P(VDF-TFE) as a binder, which is expressed in the combined action of the absorption mechanisms of the magnetic and ferroelectric phases.

Panoramic and periapical radiographs utilization in Disaster Victim Identification (DVI): narrative review

Objectives: The purpose of this narrative review is to discover radiographic images in panoramic and periapical radiographs that are used as identifiers and to compare the use of panoramic and periapical radiographs in identification based on DVI. Review: The databases used in this narrative review are Google Scholar, PubMed, and Science Direct. A total of 1258 search results appeared based on keywords. The search results were selected by title and abstract according to their relevance to the review topic, then results are selected again based on the inclusion and exclusion criteria. Total of 38 literatures were reviewed. This review shows radiographic identifiers used in panoramic radiographs are tooth restorations, crown, Root Canal Treatment (RCT), dental bridge, dental implants, maxillary sinus, rectilinear metal plate, orthodontic brackets, tooth anomaly, and root morphology. The radiographic identifiers used in periapical radiograph are tooth restorations, PSA, tooth anomaly, and root morphology. In this review, 53.8% of the literatures used panoramic radiograph for identification, whereas 46.2% used periapical radiograph. Conclusion: This review concluded that the most used radiographic identifier in panoramic radiograph is tooth restoration (57,1%) whereas in periapical radiograph is RCT (83,3%). Panoramic radiography were used in 53,8% of the literatures in this review, it was used more than periapical radiography.