We demonstrated the electrochemical detection of procyanidins in peanut skin, which is often a waste product of the food industry, using a carbon nanotube electrode. Procyanidins, the main ingredients of peanut skin, are oligomers of catechin or epicatechin; therefore, they have various forms such as dimers, trimers, and a different number of linkages between monomers. Quantification using traditional high-performance liquid chromatography-mass spectroscopy (HPLC-MS) is tedious, because many peaks can be traced.
View Article and Find Full Text PDFTo encourage and guide antimicrobial stewardship team (AST) activity and promote appropriate antibiotic use, we studied the impact of day of the week on the initiation and discontinuation of antibiotic administration. This was a multicenter observational study conducted at 8 Japanese hospitals from April 1 to September 30, 2019, targeting patients who underwent treatment with broad-spectrum antibiotics, such as anti-methicillin-resistant Staphylococcus aureus agents and anti-pseudomonal agents. We compared the weekly numbers of initiations and discontinuations of antibiotic prescription on each day of the week or on the days after a holiday.
View Article and Find Full Text PDFLegionella is a rare cause of mild encephalitis/encephalopathy with reversible splenial lesion, which should be considered in patients with risk factors. Brain magnetic resonance imaging (MRI) and legionella urinary antigen test can help the diagnosis since cerebrospinal fluid (CSF) can be normal.
View Article and Find Full Text PDFThis study reports on the electrochemical analysis of coffee extractions at different roasting levels by using a carbon nanotube (CNT) electrode. The roasting levels, ranging from 1 (low) to 6 (high), were determined according to the roasting time after fixing the roasting temperature. Level 1 roasting resulted in light roasted beans and level 6 in dark roasted ones.
View Article and Find Full Text PDFHerein, an electrochemical method is presented for the detection of curcumin in food using a carbon nanotube (CNT)-carboxymethylcellulose (CMC) electrode. The CNT-CMC electrode exhibited ideal characteristics for curcumin detection, namely, a high response current and adequate peak separation toward curcumin oxidation. Cyclic voltammetry revealed two oxidation peaks.
View Article and Find Full Text PDFThe detection of uric acid in blood and urine is clinically important in terms of suitable diagnosis and self-healthcare. An amperometric thin film biosensor composed of carbon nanotube and uricase enzyme is presented. The CNT is successfully dispersed in aqueous solution with carboxymethylcellulose surfactant.
View Article and Find Full Text PDFThe authors wish to make the following erratum to this paper [...
View Article and Find Full Text PDFSince the intake of quercetin glucosides has healthy benefits, the analysis of quercetin glucosides in food is useful. The electrochemical determination of individual quercetin glucosides (quercetin-3-glucoside (Q3G), quercetin-4'-glucoside (Q4'G), and quercetin-3,4'-diglucoside (Q34'G)) in food is carried out. For the detection of quercetin glucosides, a long-length carbon nanotube electrode offers attractive properties such as well-defined current peaks, high sensitivity, and high reproducibility.
View Article and Find Full Text PDFIt has been shown that the faradic current at an electrode grafted with molecularly imprinted polymer (MIP) is sensitive to the specific target molecule used as the template. This phenomenon is applicable to sensors with very high selectivity, but the sensing mechanism is still a black box. We investigated the size sensitivity of nanoparticles of molecularly imprinted polymers (MIP-NPs) to a specific interaction for determination of the mechanism of the gate effect and its feasibility for new applications.
View Article and Find Full Text PDFAn electrochemical analysis of polyphenols (theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B), theaflavin-3,3'-digallate (TF3), and epigallocatechingallate (EGCG)) in a black tea infusion is demonstrated. The characterization of each polyphenol in a solution containing only a single type of polyphenol for a redox reaction at the CNT electrode with cyclic voltammetry (CV) was conducted. The oxidation peak at around +0.
View Article and Find Full Text PDFWe demonstrate the electrochemical quantification of individual catechins (epicatechin, EC; epigallocatechin, EGC; epicatechingallate, ECG; and epigallocatechingallate, EGCG) in a green tea infusion without a separation process nor any adsorption complication. In the detection of catechins, long-length carbon nanotube (CNT)-carboxymethylcellulose (CMC) thin-film electrodes have attractive properties, such as well-defined current peaks, high reproducibility from sample to sample, high repeatability, and low background current. Cyclic voltammograms (CVs) for real green tea, which is mainly composed of a mixture of the four catechins, are produced by the sum of those catechins.
View Article and Find Full Text PDFDirect and mediated electron transfer (DET and MET) in enzyme electrodes with a novel flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) from fungi are compared for the first time. DET is achieved by placing a single-walled carbon nanotube (CNT) between GDH and a flat gold electrode where the CNT is close to FAD within the distance for DET. MET is induced by using a free electron transfer mediator, potassium hexacyanoferrate, and shuttles electrons from FAD to the gold electrode.
View Article and Find Full Text PDFHeparin, a highly sulfated glycosaminoglycan, is an important biomaterial having biological and therapeutic functionalities such as anticoagulation, regeneration, and protein stabilization. This study addresses a label-free quartz crystal microbalance (QCM) biosensor for heparin detection based on a macromolecularly imprinted polymer (MIP) as an artificial recognition element. We demonstrate the novel strategy for MIP in the form of thin film on a gold (Au) electrode with the plasma-induced graft polymerization (PIP) technique.
View Article and Find Full Text PDFSome patients do not inform healthcare professionals of adverse drug reactions (ADRs) because they fear termination of aggressive medication therapies. Preferences for aggressive medication therapies may differ between patients and pharmacists. The goal of this study was to estimate whether pharmacists were able to accurately assess patient preference for aggressive medication therapies with potentially stronger ADRs.
View Article and Find Full Text PDFFlavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase (GDH) was identified and cloned from thermophilic filamentous fungi using the homology cloning method. A direct electron transfer bioanode composed of FAD-GDH and a single-walled carbon nanotube was produced. Enzymes from thermophilic microorganisms generally have low activity at ambient temperature; however, the FAD-GDH bioanode exhibits a large anodic current due to the enzymatic reaction (1 mA cm) at ambient temperature.
View Article and Find Full Text PDFSimultaneous electrochemical determination of nicotinamide adenine dinucleotide (NADH) and ascorbic acid (AA) at a carbon nanotube electrode is presented. The discrimination of NADH and AA is conducted with the difference of peak potential by differential pulse voltammetry. Two well-distinguished anodic peaks, +0.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2015
An electrochemical enzyme biosensor with electronically type-sorted (metallic and semiconducting) single-walled carbon nanotubes (SWNTs) for use in aqueous media is presented. This research investigates how the electronic types of SWNTs influence the amperometric response of enzyme biosensors. To conduct a clear evaluation, a simple layer-by-layer process based on a plasma-polymerized nano thin film (PPF) was adopted because a PPF is an inactive matrix that can form a well-defined nanostructure composed of SWNTs and enzyme.
View Article and Find Full Text PDFWe report on a novel fabrication approach of amperometric biosensor based on multilayer films containing carbon nanotubes (CNT), a nano-thin plasma-polymerized film (PPF), electron transfer mediator phenothiazine (PT), and enzyme glucose dehydrogenase (GDH). The configuration of the electrochemical electrode is sequentially composed of sputtered gold, acetonitrile PPF, PT, GDH, and acetonitrile PPF (denoted as PPF/GDH/PT/CNT/PPF/Au). First PPF deposited on Au acts as a permselective membrane and as a scaffold for CNT layer formation.
View Article and Find Full Text PDFWe report a novel approach to fabrication of an amperometric biosensor with an enzyme, a plasma-polymerized film (PPF), and carbon nanotubes (CNTs). The CNTs were grown directly on an island-patterned Co/Ti/Cr layer on a glass substrate by microwave plasma enhanced chemical vapor deposition. The as-grown CNTs were subsequently treated by nitrogen plasma, which changed the surface from hydrophobic to hydrophilic in order to obtain an electrochemical contact between the CNTs and enzymes.
View Article and Find Full Text PDFObjective: • To evaluate virtual cavernoscopy as a diagnostic tool in erectile dysfunction.
Patients And Methods: • Forty patients who visited our hospital for investigation of erectile dysfunction underwent cavernosography using three-dimensional (3D)-computed tomography (CT). • Virtual cavernoscopic images were reconstructed from 3D-CT data.
Objective: • To examine the feasibility of three-dimensional (3D) CT cavernosography in the diagnosis of corporal veno-occlusive dysfunction.
Patients And Methods: • The subjects were 55 patients who had failed to respond to phosphodiesterase type 5 inhibitors. We performed pharmacodynamic infusion cavernosometry and cavernosography, using 60 mg papaverine hydrochloride.
Bone metastases occur in more than one-third of patients with advanced lung cancer and are difficult to treat. We showed previously the therapeutic effect of a third-generation bisphosphonate, minodronate, and anti-parathyroid hormone-related protein (PTHrP) neutralizing antibody on bone metastases induced by the human small cell lung cancer cell line, SBC-5, in natural killer cell-depleted severe combined immunodeficient mice. The purpose of our current study was to examine the effect of the combination of PTHrP antibody and zoledronic acid, which has been approved to treat bone metastases, against bone metastases produced by SBC-5 cells expressing PTHrP.
View Article and Find Full Text PDFPlatinum is the key drug in current treatment of ovarian cancer. The overall survival rate of patients with advanced ovarian cancer has improved. Recently, therapy-related myelodysplastic syndrome(T-MDS)and therapy-related leukemia( TRL)have been reported with increasing frequency in the literature.
View Article and Find Full Text PDFA novel design is described for an amperometric biosensor based on NAD(P)-dependent glucose dehydrogenase (GDH) combined with a plasma-polymerized thin film (PPF). The GDH is sandwiched between several nanometer thick acetonitrile PPFs on a sputtered gold electrode (PPF/GDH/PPF/Au). The lower PPF layer plays the role as an interface between enzyme and electrode because it is extremely thin, adheres well to the substrate (electrode), has a flat surface and a highly-crosslinked network structure, and is hydrophilic in nature.
View Article and Find Full Text PDFObjective: To clarify the physiological effects of aldosterone on human penile corpus cavernosum (hPCC) tissue, as aldosterone has a wider physiological action than just the maintenance of electrolyte balance, and there are mineralocorticoid receptors, i.e. aldosterone receptors, in hPCC tissue.
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