44 research outputs found

    Key performance requirement of future next wireless networks (6G)

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    Given the massive potentials of 5G communication networks and their foreseeable evolution, what should there be in 6G that is not in 5G or its long-term evolution? 6G communication networks are estimated to integrate the terrestrial, aerial, and maritime communications into a forceful network which would be faster, more reliable, and can support a massive number of devices with ultra-low latency requirements. This article presents a complete overview of potential 6G communication networks. The major contribution of this study is to present a broad overview of key performance indicators (KPIs) of 6G networks that cover the latest manufacturing progress in the environment of the principal areas of research application, and challenges

    PCR assembly of synthetic human erythropoietin gene

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    Human erythropoietin (huEPO) is a glycoprotein with important physiological functions, such as erythropoiesis, angiogenesis, and wound healing. A therapeutic protein, huEPO is commonly used to treat patients suffering from renal and non-renal anemia. Recombinant human erythropoietin (rhuEPO) and endogenous huEPO are similar with respect to their biological and chemical properties. In this study, we describe the construction of synthetic huEPO gene to produce rhuEPO. The synthetic huEPO gene was constructed by overlapping oligonucleotides assembly and amplified by polymerase chain reaction (PCR). Twenty oligonucleotide sets, covering the huEPO gene sequence and two newly introduced restriction enzyme sites, were pulled together and amplified using Pfu DNA polymerase to produce the expected DNA products with sizes of ~500bp and ~600bp. The PCR products were ligated into pGEM-T plasmid vector to facilitate DNA sequencing process of the constructed huEPO gene and downstream cloning manipulation. DNA sequence analysis showed correctly assembled oligonucleotide sets, representing the huEPO gene sequence albeit with minor base mutations. Hence, oligonucleotides assembly and PCR amplification provide a convenient and speedy method for the synthesis of huEPO gene without depending on mRNA isolation and reverse transcription or the need to have a genomic library

    Deciphering the complex three-way interaction between the non-integrin laminin receptor, galectin-3 and Neisseria meningitidis

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    The non-integrin laminin receptor (LAMR1/RPSA) and galectin-3 (Gal-3) are multi-functional host molecules with roles in diverse pathological processes, particularly of infectious or oncogenic origins. Using bimolecular fluorescence complementation and confocal imaging, we demonstrate that the two proteins homo- and heterodimerize, and that each isotype forms a distinct cell surface population. We present evidence that the 37 kDa form of LAMR1 (37LRP) is the precursor of the previously described 67 kDa laminin receptor (67LR), whereas the heterodimer represents an entity that is distinct from this molecule. Site-directed mutagenesis confirmed that the single cysteine (C173) of Gal-3 or lysine (K166) of LAMR1 are critical for heterodimerization. Recombinant Gal-3, expressed in normally Gal-3-deficient N2a cells, dimerized with endogenous LAMR1 and led to a significantly increased number of internalized bacteria (Neisseria meningitidis), confirming the role of Gal-3 in bacterial invasion. Contact-dependent cross-linking determined that, in common with LAMR1, Gal-3 binds the meningococcal secretin PilQ, in addition to the major pilin PilE. This study adds significant new mechanistic insights into the bacterial–host cell interaction by clarifying the nature, role and bacterial ligands of LAMR1 and Gal-3 isotypes during colonization

    The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

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    Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

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

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    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

    Electrochemical study of the complexation of methyl yellow with some metal ions as a model for doped poly azo compound

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    The electrochemical behaviour of the complexation of 4- dimethylaminoazobenzene (methyl yellow) with some metal ions has been evaluated using square wave voltammetry. The interactions between the azo compound with metal ions Co 2+, Cd 2+, Rb+, Rh 3+, Ti 3+, Hg 2+, La 3+ and Sc 3+ were measured in phosphate buffer solution at pH 7. The slope obtained from the relationship between diffusion current (Ip) and concentration of azo compound is most steep for Sc 3+ while Rb+ has the least steep slope. This indicates that amongst the metal ions investigated, Sc 3+ has the most interaction with the azo compound

    Solvent effects on n-phthaloyl chitosan polymer: prediction of solubility in different solvents using theoretical calculations

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    The theoretical calculations for different solvents in the gas phase have been evaluated by semi-empirical using (PM3) method and ab initio calculations using both HF/3-21G and DFT/B3LYP/3-21G methods. The physical properties of these solvents were compared between them to choose the best solvent to dissolve the phthalic anhydride-chitosan monomer, (I). These solvents are: dimethylsulfoxide, N,N-dimethyl formamide, tetrahydrofuran, 1,2-ethylene diamine, ethylene-carbonic acid and propylene-carbonic acid. The calculations show that (dimethylsulfoxide, N,N-dimethyl formamide and 1,2-ethylene diamine) are the good solvents to dissolve the phthalic anhydridechitosan monomer, (I). The physical properties of the formation of phthalic anhydride-chitosan monomer, (I), were also calculated, using the parameters: dipole moment, HOMO, LUMO, hardness (η), electronic chemical potential (μ) and global electrophilicity index (�). The results show that the computed geometrical parameters using the (PM3), (HF/3-21G) and (DFT/B3LYP/3-21G) are in good agreement with the experimental and the parameters play an important role to choose the best solvent. The synthesized N-phthaloyl chitosan polymer was also dissolved in many solvents in order to study the effect of solvent experimentally, but only three organic solvents (dimethylsulfoxide, N,N-dimethyl formamide and 1,2-ethylene diamine) were found to be able to dissolve it. These results are in agreement with the theoretical calculations. Finally, these calculations are useful for choosing the best solvent to dissolve the polymer of phthali canhydride-chitosan monomer, (I)

    Quantum Chemical Calculations (QSAR) of antipyrine drug and its Metabolites

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    The electronic properties of antipyrine and its metabolites have been investigated theoretically by the different methods of semi-empirical (AM1, MNDO/3 and PM3) and ab initio at STO-3G level calculations. These metabolites are of much interest due to their biological and medical importance. The charges, HOMO, LUMO, hardness (η), electronic chemical potential (μ) and global electrophilicity index (�) were determined. The metabolites of A4 (according to MNDO/3) and A6 (according to AM1, PM3 and ab initio) have relatively low LUMO-HOMO differences indicating that these compounds would be the most reactive metabolites

    Acid corrosion inhibition of copper by mangrove tannin

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    Purpose – The purpose of this paper is to evaluate the corrosion inhibition potential of mangrove (Rhizopora apiculata) tannin in hydrochloric acid medium on copper with the view of developing a natural corrosion inhibitor. Design/methodology/approach – The mangrove tannin was extracted from the mangrove bark and its anticorrosion potential was studied by weight loss, electrochemical and scanning electron microscopy (SEM) analysis. Findings – It has been found that the mangrove tannin effectively inhibits the corrosion on copper metal in hydrochloric acid solution. The results of the electrochemical and weight loss methods showed that the inhibition efficiency of mangrove tannin increases with increasing its concentration. Inhibition is achieved through the adsorption of tannin molecules onto the copper surface and the adsorption follows the Langmuir adsorption isotherm model. SEM study also supports the adsorption of the inhibitor molecules onto the copper surface. Originality/value – In this paper, mangrove tannin has been studied for the first time as a potential copper corrosion inhibitor in hydrochloric acid medium. The anticorrosion effect of tannin has been proven by standard methods. This natural inhibitor could find use in industries where copper is used as a fabrication metal
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