Anticorrosion Effect of Silicon Nitride and Zirconium Diboride Composite on Ni–P– Zn Electroless Deposition on Mild Steel

Electroless nicked-based deposition on mild steel surface from a nickel–zinc phosphate bath with NiSO4·6H2O, ZnSO4·7H2O, and NaH2PO2·H2O salt in the presence of silicon nitrides and zirconium diboride as additives at a constant time was studied. The structural evolution of electroless deposited mild steel surface was characterized for crystal change formation using a scanning electron microscope (SEM) and elemental quantification done using energydispersive spectroscopy (EDS). The electrochemical corrosion analysis of the deposited mild steel with and without composite additives was analyzed using linear polarization resistance and open circuit potential in both H2SO4 and NaCl solution. From the results, significant presence and the effect of wt% of additives were noticeable on the electroless mild steel surface. Ni–P–Zn in the presence of 10ZrBr2 and 10Si3N4 actively provide an induced weight gain of 0.0974 g and 0.0973 g, respectively. A correspondent, 0.034 g/m2 coating per unit area of zirconium diboride additives, was obtained against 0.030 g/m2 for silicon nitrides. The structural evolution shows proper homogeneous crystal formation and stable packed additive concentrated at the lattices with EDS showing the presence of induced peak. From the corrosion assessment result, electroless deposited mild steel with Ni–P–Zn–10ZrBr2 and Ni–P–Zn– 10Si3N4 with optimum particle concentration shows better corrosion resistance performance with a corrosion rate of 0.5048 mm/year, and 5.1347 mm/year, as against the unadditive deposition with 11.393 mm/year in NaCl solution

Experimental studies and influence of process factor on zinc-nickel based coating on mild steel

Sulphate-rich electrolytic bath containing ZnSO4.7H2O in NiP solution was used to develop coating with Ni-P-Zn matrix under optimised process parameter. The major considerations are to examine the factor variance and the effect of varying time parameter between 10, 15, 20 and 25 min on the developed coating. Wear loss evolution was examined using reciprocating sliding wear tester with a force of 10 N and 20 N. The microhardness behaviour was examined using durascan microhardness tester with diamond indenter. The change in the structural build-up and the corrosion performance trend was observed using a scanning electron microscope enhanced with energy dispersive spectroscopy and potentiodynamic polarisation route. From the result we observe that time-dependant factors impact maximally on the crystal growth which rightly influences the coating hardness performance. For wear performance, the counter with external forces couldn’t penetrate wholly into the lattice of the developed coating due to the resilient formation of stable flakes. The microstructure formation shows stable dispersed crystal build-up and homogeneous growth. An excellent corrosion resistance characteristic was noticed with Ni-P-Zn-25 min matrix

Rapid and Convenient Single-Chain Variable Fragment-Employed Electrochemical C-Reactive Protein Detection System

Although IgG-free immunosensors are in high demand owing to ethical concerns, the development of convenient immunosensors that alternatively integrate recombinantly produced antibody fragments, such as single-chain variable fragments (scFvs), remains challenging. The low affinity of antibody fragments, unlike IgG, caused by monovalent binding to targets often leads to decreased sensitivity. We improved the affinity owing to the bivalent effect by fabricating a bivalent antibody–enzyme complex (AEC) composed of two scFvs and a single glucose dehydrogenase, and developed a rapid and convenient scFv-employed electrochemical detection system for the C-reactive protein (CRP), which is a homopentameric protein biomarker of systemic inflammation. The development of a point-of-care testing (POCT) system is highly desirable; however, no scFv-based CRP-POCT immunosensors have been developed. As expected, the bivalent AEC showed higher affinity than the single scFv and contributed to the high sensitivity of CRP detection. The electrochemical CRP detection using scFv-immobilized magnetic beads and the bivalent AEC as capture and detection antibodies, respectively, was achieved in 20 min without washing steps in human serum and the linear range was 1–10 nM with the limit of detection of 2.9 nM, which has potential to meet the criteria required for POCT application in rapidity, convenience, and hand-held detection devices without employing IgGs

Risk factors for cardiovascular disease in people with idiopathic pulmonary fibrosis: a population-based study

OBJECTIVE: People with idiopathic pulmonary fibrosis (IPF) have been shown to be at an increased risk for cardiovascular (CV) disease, but reasons for this are unknown. The aim of this study was to compare the prevalence of common CV risk factors in people with IPF and the general population and establish the incidence of ischemic heart disease (IHD) and stroke after the diagnosis of IPF, controlling for these risk factors. METHODS: We used data from a large, UK primary care database to identify incident cases of IPF and matched general-population control subjects. We compared the prevalence of risk factors for CV disease and prescription of CV medications in people with IPF (before diagnosis) with control subjects from the general population and assessed the incidence of IHD and stroke in people with IPF (after diagnosis) compared with control subjects. RESULTS: We identified 3,211 cases of IPF and 12,307 control subjects. Patients with IPF were more likely to have a record of hypertension (OR, 1.31; 95% CI, 1.19-1.44), and diabetes (OR, 1.20; 95% CI, 1.07-1.34) compared with control subjects; they were also more likely to have been prescribed several CV drugs. The rate of first-time IHD events was more than twice as high in patients than control subjects (rate ratio, 2.32; 95% CI, 1.85-2.93; P < .001), but the incidence of stroke was only marginally higher (P = .09). Rate ratios for IHD and stroke were not altered substantially after adjusting for CV risk factors. CONCLUSIONS: Several CV risk factors were more prevalent in people with IPF; however, this did not account for the increased rate of IHD in this group of patients

The simple and rapid detection of specific PCR products from bacterial genomes using Zn finger proteins

A novel method of rapid and specific detection of polymerase chain reaction (PCR) products from bacterial genomes using Zn finger proteins was developed. Zn finger proteins are DNA-binding proteins that can sequence specifically recognize PCR products. Since Zn finger proteins can directly detect PCR products without undergoing dehybridization, unlike probe DNA, and can double check the specific PCR amplification and sequence specificity of the PCR products, this novel method would be quick and highly accurate. In this study, we tried to detect Legionella pneumophila using Sp1. It was found that a 49 bp L. pneumophila-specific region containing the Sp1 recognition site is located on the flhA gene of the L. pneumophila genome. We succeeded in specifically detecting PCR products amplified from L. pneumophila in the presence of other bacterial genomes by ELISA, and demonstrated that Sp1 enables the discrimination of L. pneumophila-specific PCR products from others. By fluorescence depolarization measurement, these specific PCR products could be detected within 1 min. These results indicate that the rapid and simple detection of PCR products specific to L. pneumophila using a Zn finger protein was achieved. This methodology can be applied to the detection of other bacteria using various Zn finger proteins that have already been reported

Characterization of different FAD-dependent glucose dehydrogenases for possible use in glucose-based biosensors and biofuel cells

In this study, different flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenases (FADGDHs) were characterized electrochemically after “wiring” them with an osmium redox polymer [Os(4,4′-dimethyl-2,2′-bipyridine)2(PVI)10Cl]+ on graphite electrodes. One tested FADGDH was that recently discovered in Glomerella cingulata (GcGDH), another was the recombinant form expressed in Pichia pastoris (rGcGDH), and the third was a commercially available glycosylated enzyme from Aspergillus sp. (AspGDH). The performance of the Os-polymer “wired” GDHs on graphite electrodes was tested with glucose as the substrate. Optimal operational conditions and analytical characteristics like sensitivity, linear ranges and current density of the different FADGDHs were determined. The performance of all three types of FADGDHs was studied at physiological conditions (pH 7.4). The current densities measured at a 20 mM glucose concentration were 494 ± 17, 370 ± 24, and 389 ± 19 μA cm−2 for GcGDH, rGcGDH, and AspGDH, respectively. The sensitivities towards glucose were 2.16, 1.90, and 1.42 μA mM−1 for GcGDH, rGcGDH, and AspGDH, respectively. Additionally, deglycosylated rGcGDH (dgrGcGDH) was investigated to see whether the reduced glycosylation would have an effect, e.g., a higher current density, which was indeed found. GcGDH/Os-polymer modified electrodes were also used and investigated for their selectivity for a number of different sugars

New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya

Seventeen glass vessels and twenty glass beads recovered from the excavations at the ancient city of Malindi and the archaeological site of Mambrui in Kenya, east Africa were analysed using electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The results show that all of the glass samples are soda-lime-silica glass. They belong to the high alumina -plant ash glass type, characterised by high alumina and relatively low calcium contents, widely distributed in eastern (10th- 16th centuries AD) and southern Africa (13th - 15th centuries AD), Central Asia (9th- 14th centuries AD) and southeast Asia (12th- 13th centuries AD), made with plant ashes and sands. This is an understudied glass type for which previous research has indicated there were three types. When compared with published research on such glasses using Zr, Ti, Ba, Cr, La, Li, Cs, Na2O, MgO and CaO we have identified at least four different compositional groups of v-Na-Al glass: Types A, B, C and D. By comparing the results with contemporary v-Na-Al glass vessels and beads from Central Asia, Africa, and southeast Asia we show that most of the Malindi and Mambrui glass share similar characteristics to the compositions of Mapungubwe Oblate and some of the Madagascar glass beads from southern Africa. They belong to Type A v-Na-Al glass which is characterised by an elevated level of Ti and Ba and a relatively high ratios of Cr/La, relatively low Zr concentrations and low ratios of Zr/ Ti. Differences in Zr, Li, MgO and Na2O concentrations in Type A glass indicates that there are subgroups which might derive from different glass workshop(s) specialising in Type A v- Na-Al glass production. Comparison with the chemical compositions of glass from Ghazni, Afghanistan and Termez, Uzbekistan, and by using lead isotope analysis, we suggest v-Na- Al glass was manufactured in Central Asia and possibly worked into vessels and beads there. Copyright: © 2020 Siu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

A two-component protease in Methylorubrum extorquens with high activity toward the peptide precursor of the redox cofactor pyrroloquinoline quinone

Pyrroloquinoline quinone is a prominent redox cofactor in many prokaryotes, produced from a ribosomally synthesized and post-translationally modified peptide PqqA via a pathway comprising four conserved proteins PqqB?E. These four proteins are now fairly well-characterized and span radical SAM activity (PqqE), aided by a peptide chaperone (PqqD), a dual hydroxylase (PqqB), and an eight-electron, eight-proton oxidase (PqqC). A full description of this pathway has been hampered by a lack of information regarding a protease/peptidase required for the excision of an early, cross-linked di-amino acid precursor to pyrroloquinoline quinone. Herein, we isolated and characterized a two-component heterodimer protein from the ?-proteobacterium Methylobacterium (Methylorubrum) extorquens that can rapidly catalyze cleavage of PqqA into smaller peptides. Using pulldown assays, surface plasmon resonance, and isothermal calorimetry, we demonstrated the formation of a complex PqqF/PqqG, with a K-D of 300 nm. We created a molecular model of the heterodimer by comparison with the Sphingomonas sp. A1 M16B Sph2681/Sph2682 protease. Analysis of time-dependent patterns for the appearance of proteolysis products indicates high specificity of PqqF/PqqG for serine side chains. We hypothesize that PqqF/PqqG initially cleaves between the PqqE/PqqD-generated cross-linked form of PqqA, with nonspecific cellular proteases completing the release of a suitable substrate for the downstream enzyme PqqB. The finding of a protease that specifically targets serine side chains is rare, and we propose that this activity may be useful in proteomic analyses of the large family of proteins that have undergone post-translational phosphorylation at serine.National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [GM118117, GM124002, 1S10OD020062-01

Biologics registers in RA: methodological aspects, current role and future applications

The beginning of the 21st century saw a biopharmaceutical revolution in the treatment of inflammatory rheumatic diseases, particularly rheumatoid arthritis. The fast-evolving use of biologic therapies highlighted the need to develop registers at national and international levels with the aim of collecting long-term data on patient outcomes. Over the past 15 years, many biologics registers have contributed a wealth of data and provided robust and reliable evidence on the use, effectiveness and safety of these therapies. The unavoidable challenges posed by the continuous introduction of new therapies, particularly with regard to understanding their long-term safety, highlights the importance of learning from experience with established biologic therapies. In this Perspectives article, the role of biologics registers in bridging the evidence gap between efficacy in clinical trials and real-world effectiveness is discussed, with a focus on methodological aspects of registers, their unique features and challenges and their role going forward

Prader-Willi syndrome: A primer for clinicians

The advent of sensitive genetic testing modalities for the diagnosis of Prader-Willi syndrome has helped to define not only the phenotypic features of the syndrome associated with the various genotypes but also to anticipate clinical and psychological problems that occur at each stage during the life span. With advances in hormone replacement therapy, particularly growth hormone children born in circumstances where therapy is available are expected to have an improved quality of life as compared to those born prior to growth hormone