• MeSH
• chemie MeSH
• matematika MeSH

• Konspekt
• Chemie. Mineralogické vědy
• Učební osnovy. Vyučovací předměty. Učebnice
• NLK Obory
• chemie, klinická chemie
• NLK Publikační typ
• učebnice vysokých škol

• Klíčová slova
• chemické výpočty,
• MeSH
• biochemie výchova   MeSH
• chemie výchova   MeSH

• Konspekt
• Chemie. Mineralogické vědy
• NLK Obory
• chemie, klinická chemie
• biochemie
• NLK Publikační typ
• učebnice vysokých škol

• MeSH
• biochemie MeSH

• Konspekt
• Biochemie. Molekulární biologie. Biofyzika
• NLK Obory
• biochemie
• NLK Publikační typ
• učebnice vysokých škol

• Publikační typ
• abstrakt z konference MeSH

• Publikační typ
• abstrakty MeSH

• Publikační typ
• abstrakty MeSH

Biosensors consist of a biological entity that recognizes the target analyte and the transducer that translates the biorecognition event into an electrical signal. The use of biological materials as recognizing elements imparts to biosensors the ability to specifically respond to the analyte of interest, distinguishing it from structurally similar compounds. Amperometric biosensors are based on measurements of the electric current resulting from the oxidation or reduction of an electroactive species, by keeping a constant potential at the working electrode. Enzymes can be immobilized in a thin layer on the transducer surface. Besides the reactive layer or membrane many biosensors contain one or several inner or outer membranes with different functions. The protective inner membrane may decrease the influence of interfering species. The outer membrane serves as a diffusion-limiting barrier to the enzyme substrate. Biosensors are considered biocompatible if their implantation does not affect normal functioning of the host medium and, vice versa, the host medium does not materially affect their normal operation. The present review focuses on the immobilisation techniques and preparation and utilization of protective inner and outer diffusionlimiting membranes of amperometric biosensors.

• MeSH
• biosenzitivní techniky metody   přístrojové vybavení   MeSH
• chemické techniky analytické metody   MeSH
• financování organizované MeSH

Nearly monodispersed superparamagnetic maghemite nanoparticles (15-20nm) were prepared by a one-step thermal decomposition of iron(II) acetate in air at 400 degrees C. The presented synthetic route is simple, cost effective and allows to prepare the high-quality superparamagnetic particles in a large scale. The as-prepared particles were exploited for the development of magnetic nanocomposites with the possible applicability in medicine and biochemistry. For the purposes of the MRI diagnostics, the maghemite particles were simply dispersed in the bentonite matrix. The resulting nanocomposite represents very effective and cheap oral negative contrast agent for MRI of the gastrointestinal tract and reveals excellent contrast properties, fully comparable with those obtained for commercial contrast material. The results of the clinical research of this maghemite-bentonite contrast agent for imaging of the small bowel are discussed. For biochemical applications, the primary functionalization of the prepared maghemite nanoparticles with chitosan was performed. In this way, a highly efficient magnetic carrier for protein immobilization was obtained as demonstrated by conjugating thermostable raffinose-modified trypsin (RMT) using glutaraldehyde. The covalent conjugation resulted in a further increase in trypsin thermostability (T(50)=61 degrees C) and elimination of its autolysis. Consequently, the immobilization of RMT allowed fast in-solution digestion of proteins and their identification by MALDI-TOF mass spectrometry.

• MeSH
• difrakce rentgenového záření MeSH
• enzymy imobilizované MeSH
• financování organizované MeSH
• gastrointestinální trakt patologie   MeSH
• kontrastní látky MeSH
• magnetická rezonanční tomografie MeSH
• mikroskopie elektronová rastrovací MeSH
• transmisní elektronová mikroskopie MeSH
• trypsin MeSH
• železité sloučeniny MeSH

• MeSH
• alfa-amylasy analýza   izolace a purifikace   MeSH
• amylasy izolace a purifikace   metabolismus   MeSH

Inhibition of porcine pancreas and human saliva alpha-amylase (EC 3.2.1.1) by sanguinarine and chelerythrine was studied. The inhibition of alpha-amylase was assayed using a biosensor method which utilises a flow system equipped with a peroxide electrode. 250 microM sanguinarine and 250 microM chelerythrine cause complete inhibition of 1.9 nkat alpha-amylase from porcine pancreas. The same concentration of sanguinarine and chelerythrine caused 23.9% and 7.5% inhibition, respectively, of 1.9 nkat alpha-amylase from human saliva. Mixed type and partially reversible inhibition was found for both alpha-amylases treated with either alkaloid.

• MeSH
• alfa-amylasy antagonisté a inhibitory   metabolismus   MeSH
• alkaloidy farmakologie   metabolismus   MeSH
• biosenzitivní techniky MeSH
• časové faktory MeSH
• fenantridiny farmakologie   metabolismus   MeSH
• financování organizované MeSH
• inhibitory enzymů farmakologie   MeSH
• kinetika MeSH
• lidé MeSH
• prasata MeSH
• stabilita enzymů MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH