Diaphragm thickness and stiffness in patients with hyperkyphosis due to osteoporotic vertebral fracture : an ultrasonographic and elastographic study

Purpose: The objective of this study was to evaluate the thickness and stiffness of the diaphragm, using ultrasound (US) and strain elastography (SE) in patients with hyperkyphosis due to osteoporotic vertebral fracture. Material and methods: This prospective and case-control study was conducted between October 2019 and December 2019. Diaphragm thickness, SE, and strain ratio values of patients with hyperkyphosis due to osteoporotic vertebral fracture were compared with those of the control group. Results: There were 42 patients (14 males, 28 females) with a mean age of 81.10 ± 6.3 years in the kyphosis group and 36 subjects (11 males, 25 females) with a mean age of 81.00 ± 5.5 years in the control group. End-inspirium thickness, change level, and thickening ratio of the diaphragm were significantly higher in the control group (p < 0.001 for all). Strain ratio values were significantly higher in the kyphosis group, and the rate of hardest colour code was significantly higher in the control group. The diaphragm thickness at end-inspirium and thickening ratio values correlated positively with the forced expiratory volume in the first second (FEV1, %) and forced vital capacity (FVC, %) values. The strainratio values correlated inversely with the FEV1 (%) and FVC (%) values. The diaphragm thickness at end-inspirium and thickening ratio values correlated inversely with the Cobb values and number of vertebra fractures. A positive correlation was determined between the strain ratio values and the Cobb values and number of vertebra fractures. Conclusions: Ultrasonography is a promising imaging tool to evaluate and quantify the diaphragm function and stiffness in relevant patients

A novel functional conducting polymer: synthesis and application to biomolecule immobilization

WOS: 000310721300027A recently synthesized conducting polymer poly(TBT6-NH2); poly(6-(4,7-di(thiophen-2-yl)-2H-benzo [d][1,2,3]triazol-2-yl)hexan-1-amine) was utilized as a matrix for biomolecule immobilization. After successful electrochemical deposition the polymer poly(TBT6-NH2) on the graphite electrodes, immobilization of choline oxidase (ChO) was carried out. Due to the free amino functional groups of the polymeric structure, ChO molecules were successfully immobilized onto the polymer surface via covalent binding. For this, glutaraldehyde (GA) was used as crosslinker and bifunctional agent. Hence, a robust binding between the support and the protein molecules was achieved. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to monitor the surface morphologies of both the polymer and the bioactive layer and to confirm the binding of the protein. Amperometric measurements were recorded by monitoring oxygen consumption in the presence of choline as the substrate at -0.7 V. The optimized biosensor showed a very good linearity between 0.1 and 10 mM with a 7 s response time and a detection limit (LOD) of 16.8 mu M to choline. Also, kinetic parameters, operational and storage stabilities were determined. Finally, designed system was applied for pesticide detection.TUBATurkish Academy of Sciences; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110T580]This work is partially supported by TUBA and TUBITAK 110T580 grants. METU Central Laboratory is acknowledged for the SEM and XPS analyses

A conducting polymer with benzothiadiazole unit: Cell based biosensing applications and adhesion properties

PubMed ID: 22580479Poly(4,7-di(2,3)-dihydrothienol[3,4-b][1,4]dioxin-5-yl-benzo[1,2,5]thiadiazole) (PBDT) was electrochemically deposited on graphite electrodes and used as a matrix for microbial biosensing studies. Moreover, protein adsorption property of the surface was investigated using bovine serum albumin (BSA). For the biosensor preparation, after electrochemical deposition of the polymeric matrix, Gluconobacter oxydans cells were immobilized on the modified electrode. Glucose was used as the substrate and biosensor response was followed successfully at -0.7. V vs Ag/AgCl due to the respiratory activity of the cells which is directly proportional with the substrate concentration. Characterizations were carried out in terms of several parameters such as operational and storage stabilities and surface morphologies. Finally, the effect of antimicrobial agent on the cell based response was tested. As a matrix, conducting polymers enable the preparation of sensitive and stable electrochemical microbial biosensors. © 2012 Elsevier B.V.This work is partially supported by TUBA grant. Abidin Balan is acknowledged for his valuable helps during the synthesis of the monomer. Appendix A -

Electrochemical Polymerization of (2-Dodecyl-4, 7-di (thiophen-2-yl)-2H-benzo[d][1,2,3] triazole): A Novel Matrix for Biomolecule Immobilization

PubMed ID: 20957699A recently synthesized conducting polymer [poly(2-dodecyl-4,7-di(thiophen-2-yl)-2H-benzo[d][1,2,3]triazole (PTBT)] was tested as a platform for biomolecule immobilization. After electrochemical polymerization of the monomer (TBT) on graphite electrodes, immobilization of glucose oxidase (GOx, ß-D-glucose: oxygen-1-oxidoreductase, EC 1.1.3.4) was carried out. To improve the interactions between the enzyme and hydrophobic alkyl chain on the polymeric structure, GOx and isoleucine (Ile) amino acid were mixed in sodium phosphate buffer (pH 7.0) with a high ionic strength (250 × 10-3 M). The solution is then casted on the polymer film, and the amino groups in the protein structure were crosslinked using glutaraldehyde (GA) as the bifunctional agent. Finally, the surface was covered with a perm-selective membrane. Consequently, cross-linked enzyme crystal (CLEC) like assembles with regular shapes were observed after immobilization. Microscopic techniques such as scanning electron microscopy (SEM) and fluorescence microscopy were used to monitor the surface morphologies of both the polymer and the bioactive layer. Electrochemical responses of the enzyme electrodes were measured by monitoring O2 consumption in the presence of glucose at -0.7 V. The optimized biosensor showed a very good linearity between 0.05 and 2.5 × 10-3 M with a 52 s response time and a detection limit (LOD) of 0.029 × 10-3 M to glucose. Also, kinetic parameters, operational and storage stabilities were determined. Km and Imax values were found as 4.6 × 10-3 M and 2.49 µA, respectively. It was also shown that no activity was lost during operational and storage conditions. Finally, proposed system was applied for glucose biomonitoring during fermentation in yeast culture where HPLC was used as the reference method to verify the data obtained by the proposed biosensor. A newly synthesized conducting polymer [poly(2-dodecyl-4,7-di(thiophen-2-yl)-2H-benzo[d][1,2,3]triazole (PTBT)] as a matrix for biomolecule immobilization was reported here. Glucose oxidase (GOx) was used as the model enzyme to examine the possibility of its immobilization onto PTBT after electrochemical polymerization of TBT on the graphite surface. Microscopic techniques such as scanning electron microscopy (SEM) and fluorescence microscopy were used to monitor the surface morphologies of both the polymer and the bioactive layer. After optimization and characterization studies, designed biosensor was applied for glucose monitoring in yeast culture. © 2010 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim

An amperometric acetylcholine biosensor based on a conducting polymer

WOS: 000321229000015PubMed ID: 23603072An amperometric acetylcholine biosensor was prepared by the generation of the conducting polymer poly(4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzenamine) (poly(SNS-NH2)) on graphite electrodes. For pesticide detection, the enzymes acetylcholinesterase (AChE) and choline oxidase (ChO) were co-immobilized onto the conducting polymer poly(SNS-NH2) films using covalent binding technique. Electrochemical polymerization was carried out using a three-electrode cell configuration via cyclic voltammetry. Characterization of resulting acetylcholine biosensor was done in terms of optimum pH, enzyme loading, range of linear response and shelf-life. Linear range was 0.12-10 mM and shelf-life 4 weeks. Sensitivity was calculated as 2.19 mu A mM(-1) cm(-2). The designed biosensor was tested for the determination of paraoxon-ethyl in spiked tap water samples. The results were compared with a conventional quantification method using HPLC-DAD. Linear correlation of the quantification results with both methods (R-2=0.998) was obtained. (C) 2013 Elsevier B.V. All rights reserved

Synthesis and application of poly-SNS-anchored carboxylic acid: a novel functional matrix for biomolecule conjugation

WOS: 000293694700027Here we report the synthesis of a novel conducting polymer and its properties as an immobilization platform for biosensor application. The conducting polymer has functional groups used for the formation of amide bonding with the enzyme immobilized on the polymer surface. After covalent immobilization of glucose oxidase (GOx) on the polymeric matrix, its application for glucose biosensing was investigated in detail. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements were used to monitor the surface properties of the polymer before and after biomolecule conjugation. The optimized biosensor showed a very good linearity between 0.01 mM and 1.2 mM, a 13 s response time and a detection limit (LOD) of 0.004 mM to glucose. Also, kinetic parameters, operational and storage stabilities were determined. Apparent Michaelis constant (K-m(app)) and I-max values of 1.17 mM and 11.28 mu A, respectively, were obtained.TUBATurkish Academy of Sciences; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110T580]This work is partially supported by TUBA and TUBITAK 110T580 grants. METU Central Laboratory is acknowledged for the SEM images. Merve Yuksel is gratefully acknowledged for her contributions in HPLC applications. Dr Selda Keskin is also gratefully acknowledged for access to the XPS facilities