Effect of Silica Powder Addition on Mechanical Properties of Polymer Laminate Composite

In this study laminate composites were prepared, one was reinforced with three layers of kevlar fibers at (Vf = 17.89%) and the second was reinforced with hybrid laminate with sequence of layers (Kevlar-Glass-kevlar (KGK)) at (Vf = 15.3%), samples were tested before and after silica addition at volume fraction (3%). Tests were (tensile, flexural, impact, hardness, and optical microscope), hand lay-up technique used to prepare samples. Matrix was unsaturated polyester resin. Results showed that mechanical properties (tensile strength, flexural strength, and fracture toughness) decreased after silica addition from (190 MPa, 610 MPa, 35.6 MPa.m1/2 ) to (100.5 MPa, 212MPa, 27.7 MPa.m1/2 ) respectively for composite reinforced with three layers of Kevlar fibers at (Vf = 17.89%) and from (175.5 MPa, 387 MPa, 32.36 MPa.m1/2 ) to (67.6 MPa, 210 MPa, 23 MPa.m1/2 ) respectively for laminate composite with layers (Kevlar-Glass-Kevlar (KGK)) at (Vf = 15.3%). Hardness increased after addition of silica from (79.25 to 81.2) for composite with three layers of Kevlar fibers at (Vf = 17.89%) and from (80 to 82.3) for composite with layers (Kevlar-Glass-Kevlar (KGK)). Optical microscope showed that layers were distributed in matrix and addition of silica leads to delamination of composite after using flexural test

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Beef production from Sudanese cattle fed diets based on agroindustrial by-products : trials in private feedlots

In IDL-663

Identification of Potential Drug Targets and Prediction of the Potential Impact of High Risk Non Synonymous Single Nucleotide Polymorphism in SARS-CoV-2 3C like Proteinase (3CLpro): A Computational Approach

On January 2020, a new coronavirus (officially named SARS-CoV-2) was associated with alarming outbreak of a pneumonia-like illness, which was later named by the WHO as COVID-19, originating from Wuhan City, China. Although many clinical studies involving antiviral and immunomodulatory drug treatments for SARS-CoV-2 all without reported results, no approved drugs have been found to effectively inhibit the virus so far. Full genome sequencing of the virus was done, and uploaded to be freely available for the world scientists to explore. A promising target for SARS-CoV-2 drug design is a chymotrypsin-like cysteine protease (3CLpro), a main protease responsible for the replication and maturation of functional proteins in the life cycle of the SARS coronavirus. Here we aim to explore SARS-CoV-2 3CLpro as possible drug targets based on ligand- protein interactions. In addition, ADME properties of the ligands were also analyzed to predict their drug likeliness. The results revealed Out of 9 ligands, 8 ligands (JFM, X77, RZG, HWH, T8A, 0EN, PEPTIDE and DMS) showed best ADME properties. These findings suggest that these ligands can be used as potential molecules for developing potent inhibitors against SARS-CoV-2 3CLpro, which could be helpful in inhibiting the propagation of the COVID-19. Furthermore, 10 potential amino acids residues were recognized as potential drug binding site (THR25, HIS41, GLY143, SER144, CYS145, MET165, GLU166, GLN189, ASP295 and ARG298). All those amino acid residues were subjected to missense SNP analysis were recognized to affect the structure and function of the protein. These characteristics provide them the promising to be target sites for the fresh generation inhibitors to work with and overcome drug resistance. These findings would be beneficial for the drug development for inhibiting SARS-CoV-2 3CLpro hence assisting the pharmacogenomics effort to manage the infection. of SARS-CoV-2