Improved peroxide biosensor based on Horseradish Peroxidase/Carbon Nanotube on a thiol-modified gold electrode

A new 3-dimensional (3D) network of crosslinked Horseradish Peroxidase/Carbon Nanotube (HRP/CNT) on a thiol-modified Au surface has been described in order to build up the effective electrical wiring of the enzyme units with the electrode. The synthesized 3D HRP/CNT network has been characterized with cyclic voltammetry and amperometry which results the establishment of direct electron transfer between the redox active unit of HRP and the Au surface. Electrochemical measurements reveal that the high biological activity and stability is exhibited by the immobilized HRP and a quasi-reversible redox peak of the redox centre of HRP was observed at about −0.355 and −0.275 V vs. Ag/AgCl. The electron transfer rate constant, KS and electron transfer co-efficient α were found as 0.57 s−1 and 0.42, respectively. Excellent electrocatalytic activity for the reduction of H2O2 was exhibited by the developed biosensor. The proposed biosensor modified with HRP/CNT 3D network displays a broader linear range and a lower detection limit for H2O2 determination. The linear range is from 1.0 × 10−7 to 1.2 × 10−4 M with a detection limit of 2.2.0 × 10−8 M at 3 σ. The Michaelies–Menten constant Kapp M value is estimated to be 0.19 mM. Moreover, this biosensor exhibits very high sensitivity, good reproducibility and long-time stability

High Sensitive C-reactive Protein for Prediction of Cardiovascular Risk Level in Patients with Metabolic Syndrome in Sulaimania-Iraq

Background and objective: Metabolic syndrome is a group of characteristics, which include obesity, high blood pressure, elevated blood sugar levels, and high triglycerides (fat-like substances in the blood). Having a combination of these characteristics increases the risk of developing type 2 diabetes and heart disease. People with central obesity have an increased risk for developing metabolic syndrome, type 2 diabetes, and cardiovascular disease. However, a substantial number of obese individuals have no other cardiovascular risk factors, besides their obesity. C-reactive protein (CRP) is an acute phase protein produced predominantly by hepatocytes under the influence of cytokines such as IL -6 and TNF-α. Determination of hs-CRP was carried out in this study to discriminate between centrally obese people with and without metabolic syndrome. Patients and Methods: One hundred and forty subject with central obesity aged 20-70 years underwent a physical examination and laboratory assays to determine the presence of metabolic syndrome (NCEP ATP III criteria). The subjects were categorized into metabolic syndrome and non -metabolic syndrome group to decide whether CRP has an impact on the development of metabolic syndrome, and further subdivision have made to sub classify them to five sub-groups according to the existence of components of metabolic syndrome. Results: Mean hs-CRP levels were significantly higher in individuals with central obesity with metabolic syndrome (n = 101; 72.1%) compared to individuals with central obesity without metabolic syndrome (3.64 mg/L versus 1.75 mg/L (IQR 1.25-2.24); p < 0.0001). Mean hs-CRP levels increased with increasing number of metabolic syndrome components present. In univariable linear regression analyses, hs-CRP was significantly correlated positively with body mass index, waist circumference, and atherogenic index, while a significant negative correlations was found with HDL-C level. All the obese participants were at risk of cardiovascular events. Conclusions: The degree of central obesity (waist circumference) and BMI seemed to be the main determinant of an increased hs-CRP level. Serum hs-CRP was significantly correlated with the presence of metabolic syndrome; strong relationship between serum hs-CRP and various features of metabolic syndrome. The addition of serum hs-CRP to the present definition of the metabolic syndrome may help to identify patients at high risk for future cardiovascular disease. Keywords: Abdominal obesity, Metabolic syndrome, High sensitive C-reactive protein

Intelligent intrusion detection in external communication systems for autonomous vehicles

Self-driving vehicles are known to be vulnerable to different types of attacks due to the type of communication systems which are utilized in these vehicles. These vehicles are becoming more reliant on external communication through vehicular ad hoc networks. However, these networks contribute new threats to self-driving vehicles which lead to potentially significant problems in autonomous systems. These communication systems potentially open self-driving vehicles to malicious attacks like the common Sybil attacks, black hole, Denial of Service, wormhole attacks and grey hole attacks. In this paper, an intelligent protection mechanism is proposed, which was created to secure external communications for self-driving and semi-autonomous cars. The protection mechanism is based on the Proportional Overlapping Scores method, which allows to decrease the number of features found in the Kyoto benchmark dataset. This hybrid detection system uses Back Propagation neural networks to detect Denial of Service (DoS), a common type of attack in vehicular ad hoc networks. The results from our experiment revealed that the proposed intrusion detection has the ability to identify malicious vehicles in self-driving and even in semi-autonomous vehicles

Perempuan terpasung: gejolak cinta di balik cadar

479 hlm, ; 20 cm

Interlaboratory Comparison of Hydrogen-Deuterium Exchange Mass Spectrometry Measurements of the Fab fragment of NISTmAb

Hydrogen–deuterium exchange mass spectrometry (HDX-MS) is an established, powerful tool for investigating protein–ligand interactions, protein folding, and protein dynamics. However, HDX-MS is still an emergent tool for quality control of biopharmaceuticals and for establishing dynamic similarity between a biosimilar and an innovator therapeutic. Because industry will conduct quality control and similarity measurements over a product lifetime and in multiple locations, an understanding of HDX-MS reproducibility is critical. To determine the reproducibility of continuous-labeling, bottom-up HDX-MS measurements, the present interlaboratory comparison project evaluated deuterium uptake data from the Fab fragment of NISTmAb reference material (PDB: 5K8A) from 15 laboratories. Laboratories reported ∼89 800 centroid measurements for 430 proteolytic peptide sequences of the Fab fragment (∼78 900 centroids), giving ∼100% coverage, and ∼10 900 centroid measurements for 77 peptide sequences of the Fc fragment. Nearly half of peptide sequences are unique to the reporting laboratory, and only two sequences are reported by all laboratories. The majority of the laboratories (87%) exhibited centroid mass laboratory repeatability precisions of ⟨sLab⟩ ≤ (0.15 ± 0.01) Da (1σx̅). All laboratories achieved ⟨sLab⟩ ≤ 0.4 Da. For immersions of protein at THDX = (3.6 to 25) °C and for D2O exchange times of tHDX = (30 s to 4 h) the reproducibility of back-exchange corrected, deuterium uptake measurements for the 15 laboratories is σreproducibility15 Laboratories(tHDX) = (9.0 ± 0.9) % (1σ). A nine laboratory cohort that immersed samples at THDX = 25 °C exhibited reproducibility of σreproducibility25C cohort(tHDX) = (6.5 ± 0.6) % for back-exchange corrected, deuterium uptake measurements