Two challenges in the management of Acute Respiratory Distress Syndrome are the difficulty in diagnosing cyclical atelectasis, and in individualising mechanical ventilation therapy in real-time. Commercial optical oxygen sensors can detect [Formula: see text] oscillations associated with cyclical atelectasis, but are not accurate at saturation levels below 90%, and contain a toxic fluorophore. We present a computer-controlled test rig, together with an in-house constructed ultra-rapid sensor to test the limitations of these sensors when exposed to rapidly changing [Formula: see text] in blood in vitro. We tested the sensors' responses to simulated respiratory rates between 10 and 60 breaths per minute. Our sensor was able to detect the whole amplitude of the imposed [Formula: see text] oscillations, even at the highest respiratory rate. We also examined our sensor's resistance to clot formation by continuous in vivo deployment in non-heparinised flowing animal blood for 24h, after which no adsorption of organic material on the sensor's surface was detectable by scanning electron microscopy.
- MeSH
- Analysis of Variance MeSH
- Pulmonary Atelectasis blood MeSH
- Biological Clocks MeSH
- Blood Coagulation physiology MeSH
- Blood Pressure physiology MeSH
- Oxygen blood MeSH
- Microscopy, Electron, Scanning MeSH
- Partial Pressure MeSH
- Computer Simulation * MeSH
- In Vitro Techniques MeSH
- Fiber Optic Technology * MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Vlivem biomechanických silových účinků působících na kostní struktury vznikají ve tkáních stavy napjatosti a stavy přetvoření. Anabolické účinky zatěžované kostní tkáně jsou ovlivněny frekvencemi zatížení. Mechanický přenos cyklických silových a deformačních účinků zahrnuje také komplex interakcí mezi smykovými silami vyvozenými tokem extracelulární tekutiny na povrchu příslušné buňky. Cyklické zatěžování kostí stimuluje formace nové kostní tkáně prostřednictvím řady senzorů. Cyklické změny napjatostně deformačních stavů a pulzní toky kapalin v intercelulární síti kanálků a lakun osteocytů mohou být indukovány externím elektronicky regulovaným budičem – elektronickým distrakčním fixátorem (EDF). Dynamické účinky EDF stimulují distrakční osteogenezi (desmogenezi). Prodlužování dlouhých kostí prostřednictvím EDF je regulováno postupným protahováním svalku mezi kostními fragmenty a oscilacemi. Definované velikosti oscilací, iniciované softwarově naprogramovanými silami/ posuny, účinně regulují rychlost remodelace, nárůst únosnosti tkáně a vývoj elastických a viskoelastických vlastností nové kostní tkáně. Aktivita zatěžování může být také softwarově přerušena a programovaně modulována. EDF reguluje délku a doby distrakce, frekvence oscilací a velikosti amplitud (výkmitů). EDF je efektivním klinickým nástrojem pro softwarem regulované stimulace osteogeneze. Presentovaný distrakční fixátor (EDF) je tč. prvním elektronicky řízeným distrakčním fixátorem (prolongátorem) na světě. Jeho předností je schopnost stimulovat remodelaci a regulovat osifikační fázi během distrakcí, prolongovat asymetricky nebo symetricky zkrácené dlouhé kosti dětí/dospělých a přispět k odstranění některých deformit dlouhých kostí u dětí nebo u dospělých
Biomechanical loading affects bone structures. The anabolic effects of cyclic biomechanical loading on bone tissue are influenced by the frequency of loading. Mechanotransduction appears to involve a complex interaction between extracellular fluid shear forces and cellular mechanics. Bone cells are activated by both the cyclic fluid shear stresses and transported ions/molecules in fluid flow. The cyclic loading stimulates new bone formation through (for example) integrin linkages and ion channels. Cyclic stress/strain changes in bone and the cyclic fluid flow in intercellular networks can be induced by the dynamic electronic fixative (EDF). The dynamic effects of EDF stimulate the distraction osteogenesis (desmogenesis). Increasing the rate or frequency by which dynamic loading is applied greatly improves bone tissue mechanosensitivity, possibly due to loading-induced extracellular fluid forces around bone cells, that serve as mechanosensors. The elongation of long bones by EDF is accompanied by the gradual stretching and/or oscillations of the callus between bone fragments. Defined microoscilations of callus between bone fragments initiated by predetermined external force effects very efficiently regulate the healing velocity, the corticalisation – the rise of load bearing tissue structures and the development of elastic and viscoelastic properties of new bone tissue. The active load cycles can be interrupted by the defined tranquillity also. EDF regulates both strain frequencies and amplitude modulations also. EDF presents the effective clinical tool for software regulated osteogenic stimulations within the callus. The presented distraction fixator was originally the first electronically controlled distraction fixation apparatus in the world. Its advantage is the ability to stimulate and regulate the corticalisation of the callus during distraction, to asymmetrically or symmetrically elongate shortened long bones of children/adults and to contribute to the elimination of some deformities of long bones in children or in adul
- Keywords
- prolongátor, stimulace kortikalizace, novotvorba kostní tkáně, distrakce dlouhých kostí, elektronicky regulované oscilace,
- MeSH
- Biomechanical Phenomena * MeSH
- Time Factors MeSH
- Equipment Design MeSH
- Child MeSH
- Adult MeSH
- Electrical Equipment and Supplies * MeSH
- Extracellular Fluid physiology MeSH
- Physical Stimulation methods MeSH
- Ion Transport physiology MeSH
- Bone and Bones physiology metabolism MeSH
- Bony Callus physiology MeSH
- Humans MeSH
- Osteocytes physiology MeSH
- Osteogenesis, Distraction * methods instrumentation utilization MeSH
- Bone Lengthening * methods MeSH
- Bone Remodeling physiology MeSH
- Software MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Previously suggested antioxidant mechanisms for mitochondria-targeted plastoquinone SkQ1 included: i) ion-pairing of cationic SkQ1+ with free fatty acid anions resulting in uncoupling; ii) SkQ1H2 ability to interact with lipoperoxyl radical; iii) interference with electron flow at the inner ubiquinone (Q) binding site of Complex III (Qi), involving the reduction of SkQ1 to SkQ1H2 by ubiquinol. We elucidated SkQ1 antioxidant properties by confocal fluorescence semi-quantification of mitochondrial superoxide (Jm) and cytosolic H2O2 (Jc) release rates in HepG2 cells. Only in glycolytic cells, SkQ1 prevented the rotenone-induced enhancement of Jm and Jc but not basal releases without rotenone. The effect ceased in glutaminolytic aglycemic cells, in which the redox parameter NAD(P)H/FAD increased after rotenone in contrast to its decrease in glycolytic cells. Autofluorescence decay indicated decreased NADPH/NADH ratios with rotenone in both metabolic modes. SkQ1 did not increase cell respiration and diminished Jm established high by antimycin or myxothiazol but not by stigmatellin. The revealed SkQ1 antioxidant modes reflect its reduction to SkQ1H2 at Complex I IQ or Complex III Qi site. Both reductions diminish electron diversions to oxygen thus attenuating superoxide formation. Resulting SkQ1H2 oxidizes back to SkQ1at the second (flavin) Complex I site, previously indicated for MitoQ10. Regeneration proceeds only at lower NAD(P)H/FAD in glycolytic cells. In contrast, cyclic SkQ1 reduction/SkQ1H2 oxidation does not substantiate antioxidant activity in intact cells in the absence of oxidative stress (neither pro-oxidant activity, representing a great advantage). A targeted delivery to oxidative-stressed tissues is suggested for the effective antioxidant therapy based on SkQ1.
- MeSH
- Antimycin A analogs & derivatives pharmacology MeSH
- Antioxidants pharmacology MeSH
- Hep G2 Cells MeSH
- Flavin-Adenine Dinucleotide metabolism MeSH
- Glycolysis MeSH
- Humans MeSH
- Methacrylates pharmacology MeSH
- Mitochondria drug effects metabolism MeSH
- NAD metabolism MeSH
- Oxidation-Reduction MeSH
- Oxidative Stress MeSH
- Oxidative Phosphorylation * MeSH
- Plastoquinone analogs & derivatives pharmacology MeSH
- Polyenes pharmacology MeSH
- Electron Transport Complex I metabolism MeSH
- Electron Transport Complex III metabolism MeSH
- Rotenone pharmacology MeSH
- Superoxides metabolism MeSH
- Thiazoles pharmacology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Magnetic resonance spectroscopic imaging (MRSI) involves a huge number of spectra to be processed and analyzed. Several tools enabling MRSI data processing have been developed and widely used. However, the processing programs primarily focus on sophisticated spectra processing and offer limited support for the analysis of the calculated spectroscopic maps. In this paper the jSIPRO (java Spectroscopic Imaging PROcessing) program is presented, which is a java-based graphical interface enabling post-processing, viewing, analysis and result reporting of MRSI data. Interactive graphical processing as well as protocol controlled batch processing are available in jSIPRO. jSIPRO does not contain a built-in fitting program. Instead, it makes use of fitting programs from third parties and manages the data flows. Currently, automatic spectra processing using LCModel, TARQUIN and jMRUI programs are supported. Concentration and error values, fitted spectra, metabolite images and various parametric maps can be viewed for each calculated dataset. Metabolite images can be exported in the DICOM format either for archiving purposes or for the use in neurosurgery navigation systems.
- MeSH
- Electronic Data Processing statistics & numerical data MeSH
- Fourier Analysis MeSH
- Functional Neuroimaging statistics & numerical data MeSH
- Humans MeSH
- Magnetic Resonance Imaging statistics & numerical data MeSH
- Brain metabolism pathology MeSH
- Programming Languages MeSH
- Software * MeSH
- Imaging, Three-Dimensional MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Cold acclimation modifies the photosynthetic machinery and enables plants to survive at sub-zero temperatures, whereas in warm habitats, many species suffer even at non-freezing temperatures. We have measured chlorophyll a fluorescence (ChlF) and CO2 assimilation to investigate the effects of cold acclimation, and of low temperatures, on a cold-sensitive Arabidopsis thaliana accession C24. Upon excitation with low intensity (40 µmol photons m- 2 s- 1) ~ 620 nm light, slow (minute range) ChlF transients, at ~ 22 °C, showed two waves in the SMT phase (S, semi steady-state; M, maximum; T, terminal steady-state), whereas CO2 assimilation showed a linear increase with time. Low-temperature treatment (down to - 1.5 °C) strongly modulated the SMT phase and stimulated a peak in the CO2 assimilation induction curve. We show that the SMT phase, at ~ 22 °C, was abolished when measured under high actinic irradiance, or when 3-(3, 4-dichlorophenyl)-1, 1- dimethylurea (DCMU, an inhibitor of electron flow) or methyl viologen (MV, a Photosystem I (PSI) electron acceptor) was added to the system. Our data suggest that stimulation of the SMT wave, at low temperatures, has multiple reasons, which may include changes in both photochemical and biochemical reactions leading to modulations in non-photochemical quenching (NPQ) of the excited state of Chl, "state transitions," as well as changes in the rate of cyclic electron flow through PSI. Further, we suggest that cold acclimation, in accession C24, promotes "state transition" and protects photosystems by preventing high excitation pressure during low-temperature exposure.
... -- Chapter 5 -- Steps of Glycolysis Figure 5.2 7 -- The Steps of the Krebs Cycle Figure 5.7 8 -- Electron ... ... 11.4 45 -- The Mechanism of the Action of T3 on the Target Cells Figure 11.5 45 -- The Function of Cyclic ... ... 14.9 77 -- The Renin-Angiotensin-Aldosterone System Figure 14.10 78 -- Relationships Between Blood Flow ... ... Regions and Structures of the Stomach Figure 18.5 Structure of an Intestinal Villus Figure 18.13 -- Flow ... ... -- The Inverse Relationship Between Insulin and Glucagon Secretion and Action Figure 19.9 115 -- Cyclic ...
5th ed. vii, 131 s. : převážně barev. il. 28 cm
- MeSH
- Physiological Phenomena MeSH
- Physiology MeSH
- Publication type
- Pictorial Work MeSH
- Conspectus
- Fyziologie člověka a srovnávací fyziologie
- NML Fields
- fyziologie
- NML Publication type
- učebnice vysokých škol
... - Glycolysis 102 -- Lactic Acid Pathway 103 -- Aerobic Respiration 106 -- The Krebs Cycle 106 -- Electron ... ... 397 -- Physical Laws Describing Blood Flow 397 -- Extrinsic Regulation of Blood Flow 399 -- Paracrine ... ... Regulation of Blood Flow 400 -- Intrinsic Regulation of Blood Flow 401 -- Blood Flow to the Heart and ... ... Skeletal -- Muscles 402 -- Aerobic Requirements of the Heart 402 -- Regulation of Coronary Blood Flow ... ... 404 -- Blood Flow to the Brain and -- Skin 406 -- Cerebral Circulation 406 -- Cutaneous Blood Flow 408 ...
5th ed. xx, 704 s. : il.
... Directing Their Own Synthesis 4 -- Self-replicating Molecules Undergo Natural Selection 6 -- Information Flows ... ... Cells Can Be Seen in a Phase-Contrast or Differential-Interference-Contrast Microscope 146 -- The Electron ... ... and Freeze-Etch Electron Microscopy -- Provide Novel Views of the Cell 152 -- Individual Macromolecules ... ... Transport from ATP Synthesis 508 -- Respiratory Control Normally Restrains the Electron -- Flow Through ... ... AMP and Calcium Ions as Second Messengers 743 -- Cyclic AMP Activates Intracellular Protein Kinases ...
xxxix, 1146 s. : il., tab. ; 28 cm
- MeSH
- Cell Biology MeSH
- Molecular Biology MeSH
- Publication type
- Monograph MeSH
- Conspectus
- Biochemie. Molekulární biologie. Biofyzika
- NML Fields
- biologie
- cytologie, klinická cytologie
... Covalent Bonds and Noncovalent -- Interactions 32 -- The Electronic Structure of an Atom Determines the ... ... -- Number and Geometry of Covalent Bonds It Can Make 33 -- CONTENTS -- XV -- Electrons May Be Shared ... ... to -- Proton Pumping 493 -- Electrons Flow from FADH2 and NADH to 02 Through Four Multiprotein Complexes ... ... 494 -- Reduction Potentials of Electron Carriers Favor -- Electron Flow from NADH to 02 499 -- Experiments ... ... Electron Flow Through PSI Generates a -- Proton-Motive Force but No NADPH or 02 522 -- Relative Activities ...
6th ed. xxxvii, 1150 s. : il., tab. ; 29 cm
- MeSH
- Cell Biology MeSH
- Molecular Biology MeSH
- Publication type
- Monograph MeSH
- Conspectus
- Biochemie. Molekulární biologie. Biofyzika
- NML Fields
- biologie
- cytologie, klinická cytologie
... Protein Structure and Function 41 -- Chapter 4 Exploring Proteins 77 -- Chapter § RIMA, DNA, and the Flow ... ... Two Single Strands of DNÁ Combine to Form a Double Helix -- 1.1.3 RNA is an Intermediate in the Flow ... ... A 1.14-Volt Potential Difference Between NADH and 02 Drives Electron Transport Through the Chain and ... ... Favors the Formation of a Proton Gradient 496 -- 18.2.3 Electrons Can Be Transferred Between Groups ... ... Electron Flow Through Photosystem I -- Leads to the Production of ATP Instead of NADPH 541 -- 19.4.3 ...
5th ed. xvii, 974 s. : il., tab., grafy ; 32 cm
