Effect of Standardized Grape Powder Consumption on the Gut Microbiome of Healthy Subjects: A Pilot Study

Grapes provide a rich source of polyphenols and fibers. This study aimed to evaluate the effect of the daily consumption of 46 g of whole grape powder, providing the equivalent of two servings of California table grapes, on the gut microbiome and cholesterol/bile acid metabolism in healthy adults. This study included a 4-week standardization to a low-polyphenol diet, followed by 4 weeks of 46 g of grape powder consumption while continuing the low-polyphenol diet. Compared to the baseline, 4 weeks of grape powder consumption significantly increased the alpha diversity index of the gut microbiome. There was a trend of increasing Verrucomicrobia (p = 0.052) at the phylum level, and a significant increase in Akkermansia was noted. In addition, there was an increase in Flavonifractor and Lachnospiraceae_UCG-010, but a decrease in Bifidobacterium and Dialister at the genus level. Grape powder consumption significantly decreased the total cholesterol by 6.1% and HDL cholesterol by 7.6%. There was also a trend of decreasing LDL cholesterol by 5.9%, and decreasing total bile acid by 40.9%. Blood triglyceride levels and body composition were not changed by grape powder consumption. In conclusion, grape powder consumption significantly modified the gut microbiome and cholesterol/bile acid metabolism.

Computer Simulation of Hydrodynamic and Thermal Processes in DLD Technology

This article deals with the theoretical issues of the formation of a melt pool during the process of direct laser deposition. The shape and size of the pool depends on many parameters, such as the speed and power of the process, the optical and physical properties of the material, and the powder consumption. On the other hand, the influence of the physical processes occurring in the material on one another is significant: for instance, the heating of the powder and the substrate by laser radiation, or the formation of the free surface of the melt, taking into account the Marangoni effect. This paper proposes a model for determining the size of the melt bath, developed in a one-dimensional approximation of the boundary layer flow. The dimensions and profile of the surface and bottom of the melt pool are obtained by solving the problem of convective heat transfer. The influence of the residual temperature from the previous track, as well as the heat from the heated powder of the gas–powder jet, taking into account its spatial distribution, is considered. The simulation of the size and shape of the melt pool, as well as its free surface profile for different alloys, is performed with 316 L steel, Inconel 718 nickel alloy, and VT6 titanium alloy

THE EFFECT OF SALTWATER FISH NANOPARTICLE POWDER CONSUMPTION ON TOOTH ENAMEL DENSITY In Vivo Study of Mice (Mus musculus)

ABSTRACTBackground: Dental caries is rarely found in children who eat saltwater fish. Overfished fish can be used as powder of saltwater fish nanoparticles, which is useful as an alternative material for the prevention of dental caries in dentistry can be used as a powder for saltwater fish nanoparticles, which is useful as an alternative material for preventing dental caries in dentistry. A Cone Beam Computed Tomography (CBCT), commonly known as a μ-CT Scanner, is a device used to quantify the increase in tooth enamel density Purpose: This study aimed to determine the effectiveness of saltwater fish nanoparticle powder consumption on tooth enamel density of Mus musculus. Method This study used an experimental research method with a randomized posttest only control group design. The research subjects were 16 mice taken from 2 pregnant female mice which were divided into two groups, namely the treatment group with 2.17 mg / 0.5 mL of saltwater fish nanoparticle powder and the control group which was given distilled water. Administration was carried out during the intrauterine period until the teeth of the mice grew, then observed the tooth enamel density with CBCT OP 3D Pro (KaVo, Germany). The data obtained were analyzed by Levene and continued with the Independent T-test. Result: The average value of enamel density in mandibular incisors in the treatment group was greater than the control group (p <0.05). Conclusion: Saltwater fish nanoparticle powder can increase tooth enamel density of Mus musculus. Keywords: CBCT, CT nanoparticle powder, saltwater fish, tooth enamel density,

FORMATION OF COMPOSITE METAL-CERAMIC AND METAL-CARBIDE ELECTRIC ARC SPRAYED COATINGS

The paper studies the possibility of forming composite metal-ceramic (Sv-08G2S-О-Al2O3) and metal-carbide (Sv-08G2S-О-TiC) electric arc sprayed coatings using a hardening phase in the form of powder particles in a free form. For this, a modernized cap of the spray head of an EM-14M electric arc spray gun was used, equipped with a unit for continuous powder feed supply. A laboratory batch of samples was obtained in various technological modes of spraying. Microstructures of the deposited coatings are investigated using a scanning electron microscope. It has been established that composite coatings are characterized by a lamellar structure and a rather low porosity from 8 to 12% (depending on the deposition mode and the hardening phase content), and phase particles of different shades are well differentiated in the structure. The phases were identified by their microhardness indicators. It has been established that the microhardness of the metal matrix (Sv-08G2S-О) is 1.88GPa, ceramic Al2O3 particles ‑ 17.1GPa, TiC particles‑ 31GPa. The influence of the technological parameters of spraying, namely: current, voltage and powder consumption on the content of the hardening phase in the structure of the composite electric arc coatings has been investigated. It was found that when using the maximum values of technological parameters (current 160A, voltage 35V and powder consumption 35 g/min), the maximum content of the hardening phase in the coatings is obtained: 10.3% Al2O3 in metal-ceramic and 25.6% TiC in metal-carbide. The significantly higher maximum TiC content in comparison with the Al2O3 content in composite coatings is explained by the high density of carbide and, as a consequence, the increased velocity of these particles in the high-temperature heterophase jet. Experimental studies of the influence of the content of the strengthening phase in composite coatings on their bond strength to the substrate have been carried out. It is shown that the maximum value of the bond strength of metal-ceramic coatings is 30 MPa and corresponds to the Al2O3 content of 8.7%. As for metal-carbide coatings, the maximum bond strength value of 32 MPa was obtained with a carbide phase content of 18.4%. At the same time, the bond strength of the convention coating sprayed of Sv-08G2S-О wire is 26 MPa. An increase in this characteristic for composite coatings is explained by the additional activation of the sprayed surface by unmelted solid particles of Al2O3 and TiC. It is shown that the decrease in bond strength with an increase in Al2O3 content to 10.3%, and TiC to 25.2% is explained by a significant decrease in the actual contact area of the coating with the substrate.

A Novel Method to Measure the Powder Consumption of Dental Air-Polishing Devices

Background: Oral preventive measures should be efficient, minimally invasive, and painless. Air-polishing has this potential. As the efficiency and abrasivity of powders are dependent on the amount of powder projected, a better understanding of this characteristic will help us to determine the most effective and least invasive device. Method: A new laboratory set-up was designed using light diffusion to measure powder consumption with high accuracy due to its high sampling rate, even at short time intervals (<1 s). We tested six different marketed air-polishers of two different working types: Table-top and Handy. Results: All of the devices presented some powder delivery fluctuations. These differences were manufacturer-dependent. The powder delivery stability varied by up to two times, and ranged among the Table-top devices in the following order: E1 < M2 < N2. The mean powder consumption also varied by up to 2.9 times, in the following order: E1 < N2 < M3. All of the Handy devices presented a short treatment time and poor flow regularity, and consumed significantly more powder than the Table-top devices (by approximately +25%). Conclusion: The powder consumption analysis showed distinct differences between the devices. Therefore, the clinical results among the devices cannot be compared, as their working mechanisms are very different.

The Effect of the Laser Incidence Angle in the Surface of L-PBF Processed Parts

The manufacture of multiple parts on the same platform is a common procedure in the Laser Powder Bed Fusion (L-PBF) process. The main advantage is that the entire working volume of the machine is used and a greater number of parts are obtained, thus reducing inert gas volume, raw powder consumption, and manufacturing time. However, one of the main disadvantages of this method is the possible differences in quality and surface finish of the different parts manufactured on the same platform depending on their orientation and location, even if they are manufactured with the same process parameters and raw powder material. Throughout this study, these surface quality differences were studied, focusing on the variation of the surface roughness with the angle of incidence of the laser with respect to the platform. First, a characterization test was carried out to understand the behavior of the laser in the different areas of the platform. Then, the surface roughness, microstructure, and minimum thickness of vertical walls were analyzed in the different areas of the platform. These results were related to the angle of incidence of the laser. As it was observed, the laser is completely perpendicular only in the center of the platform, whilst at the border of the platform, due to the incidence angle, it melts an elliptical area, which affects the roughness and thickness of the manufactured part. The roughness increases from values of Sa = 5.489 μm in the central part of the platform to 27.473 μm at the outer borders while the thickness of the manufactured thin walls increases around 40 μm.