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Effect of Different Implant Abutment Materials and Their Surface Characteristics on Human Gingival Fibroblasts Growth
No full textStatement of problem: soft tissue attachment to the implant abutment has been regarded as an essential but absent or poorly formed barrier compared to one in natural teeth. Fibroblasts are an important part of this soft tissue barrier in natural dentition. This study focuses on newer additively manufactured biomaterials and their effect on human gingival fibroblasts growth.
Purpose: The purpose of the study is to analyze fibroblast growth and compare it to the surface roughness and water contact angle of the different biomaterials.
Material and methods: two conventionally milled materials, zirconia (MZr) and titanium (MTi) were compared to new additively manufactured silica nitride (AMSN) and zirconia (AMZR). Surface roughness (n=3) and water contact angle (n=10) were measured for the discs. Discs were then prepared for cell culture. Cell growth (n=7) was measured at 24, 48 and 72 hours using CCK-8. After 72 hours cells were fixed, and morphology of cells was seen through SEM. In addition, analysis of collagen type I, Vinculin and phalloidin using confocal-immunofluorescence staining was done. The Kruskal Wallis test was conducted for inter group and intra group comparison. The significance level was set at p < 0.05.
Results: Kruskal Wallis showed a significant difference in growth of cells on experimental discs compared to the positive control. The cell growth drastically reduced on 2nd day on all the materials. On day 3, growth is seen on AMZR and AMSN samples. Bonferroni correction shows significant difference in cell growth between AMSN, AMZR and blank control. Cell growth on Milled zirconia and titanium group did not have much statistical difference.
Conclusions: results show that at 24 hours, fibroblasts have a better affinity towards the MTi and AMZR compared to MZr and AMSN, though it is not significantly different. At 72 hours, AMZR and AMSN have shown cell growth significantly more than the blank
Protective Imperative, Quickenings Collected
No full textThis publication may contain explicit sexual literary descriptions and/or artistic depictions.Includes two zines: "Protective Imperative, a Stargate SG1 Sentinel Slash Zine (J/B & J/D)", and "Quickenings 1 & 2, a Slash 'Highlander' Zine with Dark Overtones." Half of the stories are Sentinel crossed with Stargate and half of the stories are Highlander
Gas Perfusion through Porous Non-Hydrophobic and Hydrophobic Surfaces for Friction Drag Reduction in Turbulent Channel Flows
No full textFriction drag reduction (FDR) in liquid flows can be achieved by bubble injection, air layer creation, polymer injection, and super-hydrophobic coatings. Prior research that conducted experiments by injecting gas through slot injectors shows that FDR has poor downstream persistence unless air layers are formed. High pumping costs are inevitable for these air layers as all the air is lost downstream. Polymer injection works well if attention is given to its pumping, but costs are high. For the fourth method, super-hydrophobic coatings, the loss of the trapped air pockets from the super-hydrophobic surfaces in turbulent flows may cause a significant drag increase. To overcome the above limitations and obtain improved FDR in turbulent flows, a novel method of gas perfusion through porous surfaces is investigated. FDR by such a method is measured on a flat-plate test model in two types of turbulent flows. In fully-developed turbulent flow, the wall shear stress is measured via the streamwise pressure gradient at channel-height-based Reynolds numbers to 76000; in turbulent-boundary-layer flow, the total wall shear stress is measured by a load cell apparatus at downstream-distance-based Reynolds numbers to 8.2 million. Air is perfused through two porous media with and without hydrophobic treatment. The morphology results of bubbly flow show that gas perfusion occurs nearly uniformly along the entire surface and a portion of the bubbles remain near the wall at the furthest downstream location. Thus, the downstream persistence appears not to be an issue with this technique. In the fully-developed flow, a maximum FDR of 5���10% is obtained under low injection rates on all four surfaces (Refractron Ceramic and Maryland Porous ��� treated and untreated), and drag increases significantly under high injection rates. In the turbulent-boundary-layer flow, however, the highest %FDR is usually measured with maximum airflow on Maryland porous material. A total drag reduction of typically 10���25% is achieved on the untreated surface and about 20���30% on the hydrophobic surface. This synergistic effect between the surface hydrophobicity and gas perfusion is promoted under higher injection rates and lower flow speeds. Additionally, data collapse of %FDR could be achieved with respect to the nominal bubble-layer thickness
Economic Indicators of the College Station - Bryan MSA, November 2024
No full textThe Business-Cycle Index increased 0.2% from August 2024 to September 2024. The local unemployment rate remained steady at 3.2% in September 2024 compared to August 2024. Local nonfarm employment decreased by 0.1% from August 2024 to September 2024. Inflation-adjusted taxable sales decreased by 2% from August 2024 to September 2024. Cumulative inflation-adjusted Texas state tax revenues for fiscal year 2024 surpassed fiscal year 2019 by 12.6%. Tax revenues were actually 3.4% lower in fiscal year 2024 compared with fiscal year 2023
