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Preparation and Characterization of Hydroxyapatite Nanopowder Using Sol-Gel Technique for Biomedical Applications
No full textHydroxyapatite (HAp) is extensively studied inorganic bioceramic, which is widely used in various biomedical applications, mainly in orthopedics and dentistry due to its close similarities with chemical composition of natural bone and teeth. The different methods for HAp synthesis are of interest due to its importance and wide utilization in biomedical applications. This paper focuses on the synthesis of HAp using a sol-gel method with chemical reagents (precursors) phosphoric pentoxide and calcium nitrate tetrahydrate, characterization and bioactivity. The prepared HAp powder was sintered at 750°C to improve crystallinity. The developed HAp nanopowders were studied to show the effect of sintering temperature on crystallinity, purity, thermal stability, size, shape and the morphology. The HAp nanoparticles were characterized by X-Ray Diffraction analysis (XRD) for identification of diffractional patterns and mineralogy and the determination of abundance based on measured intensities and areas. Transmission Electron Microscopy (TEM) was conducted to observe the features of very small specimens and used to study the structure and morphology; and Scanning Electron Microscopy (SEM) was employed to check pore geometry, grain morphology; digenetic sequences. Next, Fourier Transform Infrared Spectroscopy (FT-IR) was used to provide fingerprint of a sample for the detection of different chemical functional groups; and Atomic Force Microscopy was utilized for examination of the surface roughness of the coated HAp sensor surfaces before and after Human Bone Morphogenetic Protein 2 BMP-2 was introduced. The adsorption of BMP-2 onto HAp nanoparticles thin layer sensor and was investigated using quartz-crystal microbalance with dissipation (QCM-D), an innovative manner to monitor in-situ adsorption of BMP-2 on HAp
Broad host susceptibility of North American amphibian species to Batrachochytrium salamandrivorans suggests high invasion potential and biodiversity risk
Get PDFBatrachochytrium salamandrivorans (Bsal) is a fungal pathogen of amphibians that is emerging in Europe and could be introduced to North America through international trade or other pathways. To evaluate the risk of Bsal invasion to amphibian biodiversity, we performed dose-response experiments on 35 North American species from 10 families, including larvae from five species. We discovered that Bsal caused infection in 74% and mortality in 35% of species tested. Both salamanders and frogs became infected and developed Bsal chytridiomycosis. Based on our host susceptibility results, environmental suitability conditions for Bsal, and geographic ranges of salamanders in the United States, predicted biodiversity loss is expected to be greatest in the Appalachian Region and along the West Coast. Indices of infection and disease susceptibility suggest that North American amphibian species span a spectrum of vulnerability to Bsal chytridiomycosis and most amphibian communities will include an assemblage of resistant, carrier, and amplification species. Predicted salamander losses could exceed 80 species in the United States and 140 species in North America
Study on Tomato Pollen Heat Tolerance Using Proteomics and Artificial Intelligence
No full textTomato (Solanum lycopersicum) is a major vegetable species worldwide. The most suitable temperature for growing tomatoes is between 21/29ºC (night/day). Among all the physiological responses, the development of male gametophyte is the most sensitive process to temperatures. Elevated temperature beyond the optimal range, typically 10-15ºC higher, during heat stress conditions negatively affect tomato plants, leading to a decline in pollen quality, viability and low levels of fruit sets. This research focuses to find the HS-induced proteomes in pollen mother cell and microspore of two different varieties of tomatoes, Black Vernissage and Micro-Tom exposed to high heat of 35-39ºC/25-27ºC (day/night) for 15 days. The non-heat-treated tomato plants were kept at 22-25ºC. The flower bud containing pollen mother cell and micropore were embedded in OCT compound and cryo-sectioned into 20uM thickness. The tissues were collected into capture cap using the Laser capture microdissection (LCM). The extracted protein was TMT labeled and peptides were identified with LC-MS/MS. The proteomes revealed that in a high heat of 38ºC, family of HSP and peptidase activity were upregulated as a tolerance mechanism. Proteins related to ribosomal and translation activity were repressed. At a temperature of 32ºC, the viability of BV was significantly higher compared to MT. Additionally, BV produced fruits with seeds, whereas MT did not exhibit any seed development. These observations strongly indicate that BV has a greater heat tolerance than MT. However, it is important to note that at an even higher temperature of 38ºC, the viability of pollen decreased in both tomato varieties
Fabrication of Antimicrobial Packaging Materials Using Natural Polymers by Coaxial Electrospray
No full textThe development of packaging materials with antimicrobial properties is of great importance to extend product shelf-life and reduce the risk of foodborne illness. In the current study, the coaxial electrospray technique was applied to encapsulate nanoparticles using natural polymers, namely potato starch and water-soluble yellow mustard mucilage (WSM). Emulsions were prepared as the core material by mixing essential oils (thymol: carvacrol at the ratio of 1:1), starch and WSM solution, and starch-WSM solution was prepared as the shell material. The core-shell structured nanoparticles were obtained by coaxial electrospray. The resultant nanoparticles were evaluated on their morphology, particle size, encapsulation efficiency, releasing kinetics, and antimicrobial properties. Scanning electron microscopy (SEM) was used for morphology and size analysis. The results have indicated that the particles are sphere-shaped with the size ranging from 548 nm to 1435 nm. The encapsulation efficiency is 84.17 ± 0.04%. Compared to the nanoparticles without the shell layer by regular electrospray, the releasing kinetics has demonstrated a significantly slower release pattern at the first several hours after dissolving in water, with only 12.84% of the total essential oils released during the first 7 h. The antimicrobial efficacy of the packaging materials was evaluated against Escherichia coli, Staphylococcus aureus, Salmonella dublin, and Pseudomonas fluorescen. The results have indicated that the nanoparticles exhibited significant antimicrobial activity against the tested strains. The results have confirmed that the shell of the nanoparticles can significantly provide additional protection over the essential oil and can modulate the release pattern of the core materials over time. The fabricated particles were further evaluated on their effect on product quality attributes using grape tomatoes. The results showed that the particles can effectively extend grape tomatoes’ shelf life by reducing water loss, delaying the textured softness and color change along with time. Further studies would be carried out to study the effect of varied shell composition and thickness on the release pattern of the antimicrobial agents
Sense of Belonging: Impact of HBCU Living Learning Communities on University Retention
No full textThis research investigated the pivotal role of Living Learning Communities (LLCs) within a public Historically Black Colleges and Universities (HBCUs) institution in the southeast region within the United States in fostering a sense of belonging among students and its subsequent influence on the university retention rate for freshman students. A mixed-methods approach was used to gather participant data for this study. An online survey was used to collect quantitative data. The target population was 2022-2023 freshman who did not return for the fall. Most of the 18–20-year-old participants were African American (n = 100, 98%). In addition, seven students of the 100 survey respondents participated in a focus group. The survey included Likert-scale questions to assess agreement or disagreement with statements regarding the factors of interest (feeling of belonging, involvement, intent to stay at the institution). In addition, students participated in a focus group to discuss how living-learning communities have affected their sense of belonging and university retention. The findings of this study contributed valuable knowledge to the disciplines of university retention, sense of belonging, and the design of intentional living-learning communities for freshman students at HBCUs. Thus, recommendations are made for HBCUs to engage in and develop Living Learning Communities (LLCs) in regard to retention measures, concentrating on personalized programming that promotes belonging, academic assistance, mentoring, and mental health