• MeSH
• Neoplasms radiotherapy   MeSH
• Nuclear Medicine methods   MeSH
• Radiotherapy methods   MeSH
• Publication type
• Textbook MeSH

• Conspectus
• Učební osnovy. Vyučovací předměty. Učebnice
• Lékařské vědy. Lékařství
• NML Fields
• radiologie, nukleární medicína a zobrazovací metody
• onkologie
• NML Publication type
• kolektivní monografie

• MeSH
• Biochemistry MeSH
• Chemistry MeSH
• Chemistry, Organic MeSH

• Conspectus
• Chemie. Mineralogické vědy
• NML Fields
• chemie, klinická chemie
• NML Publication type
• kolektivní monografie

Localization of sound source azimuth within horizontal plane uses interaural time differences (ITDs) between sounds arriving through the left and right ear. In mammals, ITDs are processed primarily in the medial superior olive (MSO) neurons. These are the first binaural neurons in the auditory pathway. The MSO neurons are notable because they possess high time precision in the range of tens of microseconds. Several theories and experimental studies explain how neurons are able to achieve such precision. In most theories, neuronal coincidence detection processes the ITDs and encodes azimuth in ascending neurons of the auditory pathway using modalities that are more tractable than the ITD. These modalities have been described as firing rate codes, place codes (labeled line codes) and similarly. In this theoretical model it is described how the ITD is processed by coincidence detection and converted into spikes by summing the postsynaptic potentials. Particular postsynaptic conductance functions are used in order to obtain an analytical solution in a closed form. Specifically, postsynaptic response functions are derived from the exponential decay of postsynaptic conductances and the MSO neuron is modeled as a simplified version of the Spike Response Model (SRM0) which uses linear summations of the membrane responses to synaptic inputs. For plausible ratios of time constants, an analytical solution used to describe properties of coincidence detection window is obtained. The parameter space is then explored in the vicinity of the analytical solution. The variation of parameters does not change the solution qualitatively.

• MeSH
• Action Potentials physiology   MeSH
• Humans MeSH
• Sound Localization physiology   MeSH
• Models, Neurological * MeSH
• Nerve Net physiology   MeSH
• Sensory Receptor Cells physiology   MeSH
• Synaptic Transmission physiology   MeSH
• Computer Simulation MeSH
• Auditory Pathways physiology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Six common water-soluble singlet oxygen ((1)O2) photosensitizers - 5,10,15,20-tetrakis(1-methyl-4-pyridinio) porphine (TMPyP), meso-tetrakis(4-sulfonathophenyl)porphine (TPPS4), Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4), eosin Y, rose bengal, and methylene blue - were investigated in terms of their ability to produce delayed fluorescence (DF) in solutions at room temperature. All the photosensitizers dissolved in air-saturated phosphate buffered saline (PBS, pH 7.4) exhibit easily detectable DF, which can be nearly completely quenched by 10 mM NaN3, a specific (1)O2 quencher. The DF kinetics has a biexponential rise-decay character in a microsecond time domain. Therefore, we propose that singlet oxygen-sensitized delayed fluorescence (SOSDF), where the triplet state of a photosensitizer reacts with (1)O2 giving rise to an excited singlet state of the photosensitizer, is the prevailing mechanism. It was confirmed by additional evidence, such as a monoexponential decay of triplet-triplet transient absorption kinetics, dependence of SOSDF kinetics on oxygen concentration, absence of SOSDF in a nitrogen-saturated sample, or the effect of isotopic exchange H2O-D2O. Eosin Y and AlPcS4 show the largest SOSDF quantum yield among the selected photosensitizers, whereas rose bengal possesses the highest ratio of SOSDF intensity to prompt fluorescence intensity. The rate constant for the reaction of triplet state with (1)O2 giving rise to the excited singlet state of photosensitizer was estimated to be ~/>1 × 10(9) M(-1) s(-1). SOSDF kinetics contains information about both triplet and (1)O2 lifetimes and concentrations, which makes it a very useful alternative tool for monitoring photosensitizing and (1)O2 quenching processes, allowing its detection in the visible spectral region, utilizing the photosensitizer itself as a (1)O2 probe. Under our experimental conditions, SOSDF was up to three orders of magnitude more intense than the infrared (1)O2 phosphorescence and by far the most important pathway of DF. SOSDF was also detected in a suspension of 3T3 mouse fibroblast cells, which underlines the importance of SOSDF and its relevance for biological systems.

• MeSH
• 3T3 Cells MeSH
• Spectrometry, Fluorescence MeSH
• Photosensitizing Agents chemistry   MeSH
• Kinetics MeSH
• Hydrogen-Ion Concentration MeSH
• Quantum Theory MeSH
• Mice MeSH
• Singlet Oxygen chemistry   MeSH
• Temperature MeSH
• Water chemistry   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

• MeSH
• Clinical Medicine MeSH
• Oral Hygiene MeSH
• Health Promotion MeSH
• Preventive Dentistry MeSH
• Dental Care MeSH
• Dental Hygienists MeSH
• Dental Prophylaxis MeSH

• Conspectus
• Stomatologie
• NML Fields
• zubní lékařství
• hygiena
• NML Publication type
• kolektivní monografie

• MeSH
• Microbiology MeSH

• Conspectus
• Mikrobiologie
• NML Fields
• mikrobiologie, lékařská mikrobiologie

• MeSH
• Cell Biology MeSH
• Mathematics MeSH
• Molecular Biology MeSH
• Models, Molecular MeSH
• Models, Theoretical MeSH
• Publication type
• Monograph MeSH

• Conspectus
• Matematika
• NML Fields
• přírodní vědy
• cytologie, klinická cytologie
• biologie

• MeSH
• Otolaryngology MeSH
• Publication type
• Periodical MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• otorinolaryngologie