Phase angle
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Energization of thylakoid membranes brings about the acidification of the lumenal aqueous phase, which activates important regulatory mechanisms. Earlier Jajoo and coworkers (2014 FEBS Lett. 588:970) have shown that low pH in isolated plant thylakoid membranes induces changes in the excitation energy distribution between the two photosystems. In order to elucidate the structural background of these changes, we used small-angle neutron scattering on thylakoid membranes exposed to low p(2)H (pD) and show that gradually lowering the p(2)H from 8.0 to 5.0 causes small but well discernible reversible diminishment of the periodic order and the lamellar repeat distance and an increased mosaicity - similar to the effects elicited by light-induced acidification of the lumen. Our data strongly suggest that thylakoids dynamically respond to the membrane energization and actively participate in different regulatory mechanisms.
- MeSH
- fluidita membrány MeSH
- fotosyntéza * MeSH
- fotosystém I (proteinový komplex) metabolismus ultrastruktura MeSH
- fotosystém II (proteinový komplex) metabolismus ultrastruktura MeSH
- hrách setý metabolismus ultrastruktura MeSH
- koncentrace vodíkových iontů MeSH
- listy rostlin metabolismus MeSH
- maloúhlový rozptyl * MeSH
- neutronová difrakce * MeSH
- přenos energie MeSH
- tylakoidy metabolismus ultrastruktura MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Relationship of bioelectrical properties of human body and vertical jump performance is still unexplored, especially in non-athletic population. The aim of this study is to evaluate association of bioelectrical impedance results with mean force and power of the lower limbs in non-athletic young adults, and to evaluate differences between sexes in both bioelectrical impedance results and vertical jump performance. The cross-sectional study included 75 healthy non-athletic college students (40 women and 35 men aged 19-24 years). Whole-body bioelectrical impedance analysis was performed for phase angle and body composition. Force and power of lower limbs were assessed by vertical jump test. There is difference between sexes in both body composition and vertical jump performance. Along to higher content of muscles (47.5% vs 40.5%) and lower content of fat in the body (19.25% vs 28.19%), men also had higher mean force (3691.75 N vs 2351.44 N) and explosive power of the lower limbs (5627.19 W vs 2752.21 W) compared to women. Leg force and power are in correlation with body composition and with phase angle obtained by bioelectrical impedance analysis. Difference between sexes in force and power of the legs persists even after adjustment for body composition.
OBJECTIVE: To characterize the microstructure of two zinc phosphate cement formulations in order to investigate the role of liquid/solid ratio and composition of powder component, on the developed porosity and, consequently, on compressive strength. METHODS: X-ray powder diffraction with the Rietveld method was used to study the phase composition of zinc oxide powder and cements. Powder component and cement microstructure were investigated with scanning electron microscopy. Small angle neutron scattering (SANS) and microfocus X-ray computed tomography (XmCT) were together employed to characterize porosity and microstructure of dental cements. Compressive strength tests were performed to evaluate their mechanical performance. RESULTS: The beneficial effects obtained by the addition of Al, Mg and B to modulate powder reactivity were mitigated by the crystallization of a Zn aluminate phase not involved in the cement setting reaction. Both cements showed spherical pores with a bimodal distribution at the micro/nano-scale. Pores, containing a low density gel-like phase, developed through segregation of liquid during setting. Increasing liquid/solid ratio from 0.378 to 0.571, increased both SANS and XmCT-derived specific surface area (by 56% and 22%, respectively), porosity (XmCT-derived porosity increased from 3.8% to 5.2%), the relative fraction of large pores ≥50μm, decreased compressive strength from 50±3MPa to 39±3MPa, and favored microstructural and compositional inhomogeneities. SIGNIFICANCE: Explain aspects of powder design affecting the setting reaction and, in turn, cement performance, to help in optimizing cement formulation. The mechanism behind development of porosity and specific surface area explains mechanical performance, and processes such as erosion and fluoride release/uptake.
- MeSH
- difrakce rentgenového záření MeSH
- fosforečnany vápenaté MeSH
- kostní cementy MeSH
- maloúhlový rozptyl MeSH
- mikroskopie elektronová rastrovací MeSH
- pevnost v tlaku MeSH
- počítačová rentgenová tomografie * MeSH
- testování materiálů MeSH
- zinkfosfátový cement * MeSH
- zubní cementy * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cílem práce bylo hodnocení výsledků léčby vad Angleovy II.třídy, 1. oddělení u pacientů léčených horním a dolním fixním aparátem s extrakcí dvou horních premolárů. Byly hodnoceny také výsledky léčby 3-8 let po ukoncení aktivní fáze (sejmutí aparátu). Soubor měl 110 pacientů. Výsledky byly hodnoceny na sádrových modelech, zhotovených před léčením (čas T0), po sejmutí aparátu (T1) a v období 3-8 let po ukončení aktivnífáze léčení (T2). Na sádrových modelech bylo hodnoceno: Angleova třída v molárech, vztah ve špičácích, incizální schůdek (OJ), hloubka skusu (OB), délka zubního oblouku, mezišpičáková vzdálenost a velikost stěsnání. Výsledky: po ukončení aktivní fáze léčení (T0-T1) se statisticky významně změnila poloha molárů, špičáků, incizální schůdek hloubka skusu, délka dolního zubního oblouku. V období 3-8 let po sejmutí fixního aparátu (T1-T2) se mírně zvětšila hloubka skusu, mírně se zvětšil incizální schůdek, ale všechny změny byly statisticky nevýznamné.
Treatment results for Angle Class II, Division 1 male lilocclusions are evaluated in patients treated with upper and lower fixed appliance; the therapy involved also extraction of two upper premolars. The treatment results were evaluated also after 3-8 years after the finished active phase (after the removal of fixed appliance). The sample included 110 patients. The results were evaluated in models made prior the commencement of the therapy (time To), after the appliance removal (time T1), and between 3 and 8 years after the active phase ended (time T2). The parameters evaluated were: Angle Class in molars, relationship of canines, overjet (OJ), overbite (OB), length of dental arch, intercanine distance, and the amount of crowding. Results: after the active phase of therapy (To-T1) positions of molars, canines, overjet, overbite, and the length of dental arch changed significantly. In the period of 3-8 years after the appliance was removed (T1T2) only mild increase of overbite and overjet was noticed, however, these changes were statistically insignificant.
Abnormální úhel progrese nohou, tj. abnormální rotace špiček při chůzi, je jednou z patologií, kterou lze odhalit pouhou aspekcí. Jedná se přitom o průvodní jev řady onemocnění, z nichž některá jsou indikována k terapii stélkami. Některé malé, avšak klinicky významné změny, které stélky způsobují, už přitom pouhým okem zachytit nelze. Jejich skutečný efekt tak nemusí být vždy správně interpretován. Cílem studie bylo objektivizovat okamžitý vliv pelot senzomotorických stélek na úhel progrese nohou ve stojné fázi chůzového cyklu u asymptomatických dospělých osob. Celkem u 11 probandů (věk 23,0 ± 3,3 let; výška 174,4 ± 8,4 cm; hmotnost 66,9 ± 6,0 kg) byl pomocí optoelektronického systému Vicon hodnocen úhel progrese nohou při chůzi se základní stélkou bez pelot a s využitím jednotlivých pelot senzomotorických stélek. Výsledky ukázaly, že peloty mohou signifikantně měnit úhel progrese nohou. Retrokapitální peloty při chůzi rotují v porovnání se základní stélkou nohu zevně, mediální kalkaneální pelota rotuje nohu vnitřně.
Abnormal feet progression angle, i.e. abnormal feet rotation during walking, is one of the pathologies which can be revealed by mere visual inspection. It is an epiphenomenon of a series of diseases, some of which are indicated for therapy by insoles. However, some of the small, but clinically significant changes caused by the insoles cannot be captured with the naked eye. Therefore, their actual effect may not always be interpreted properly. The aim of this study was to objectify the immediate effect of bars of sensorimotor insoles on the feet progression angle in the stance phase of the gait cycle in asymptomatic adults. The feet progression angle was assessed during walking with the base sole both with and without the individual bars of sensorimotor insoles, using the Vicon optoelectronic system in 11 subjects altogether (age 23,0 ± 3,3 years, height 174,4 ± 8,4 cm, weight 66,9 ± 6,0 kg). The results show that bars can significantly change the feet progression angle. During walking, retrocapital bars rotate feet outwards in relation to the base sole; calcaneal medial bars rotate feet inwards.
- Klíčová slova
- úhel progrese nohy,
- MeSH
- biomechanika MeSH
- chůze MeSH
- dospělí MeSH
- klinická studie jako téma MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- ortézy nohy (od hlezna dolů) * MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- Publikační typ
- práce podpořená grantem MeSH
A new method providing a relief phase contrast for investigation of microorganisms by optical microscopy used a neutral filter Zeiss NG 10/1 that could be controllably slid at a certain azimuthal angle below the aperture condenser diaphragm of the microscope phase contrast. Two ways of application are described depending on the type of the microscope: (1) in a special holder, and (2) fixed on a rubber ring. The device enabled us to obtain excellent results in the area of both optical microscopy and microphotography. With the microorganisms visualized, a better resolution, higher contrast and a significant 3D effect were obtained; outer morphology and organelles (chloroplasts, nuclei, granules, oil reserve vacuoles, etc.) could also be investigated.
The development of nanomedicines for the treatment of neurodegenerative disorders demands innovative nanoarchitectures for combined loading of multiple neuroprotective compounds. We report dual-drug loaded monoolein-based liquid crystalline architectures designed for the encapsulation of a therapeutic protein and a small molecule antioxidant. Catalase (CAT) is chosen as a metalloprotein, which provides enzymatic defense against oxidative stress caused by reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). Curcumin (CU), solubilized in fish oil, is co-encapsulated as a chosen drug with multiple therapeutic activities, which may favor neuro-regeneration. The prepared self-assembled biomolecular nanoarchitectures are characterized by biological synchrotron small-angle X-ray scattering (BioSAXS) at multiple compositions of the lipid/co-lipid/water phase diagram. Constant fractions of curcumin (an antioxidant) and a PEGylated agent (TPEG1000) are included with regard to the lipid fraction. Stable cubosome architectures are obtained for several ratios of the lipid ingredients monoolein (MO) and fish oil (FO). The impact of catalase on the structural organization of the cubosome nanocarriers is revealed by the variations of the cubic lattice parameters deduced by BioSAXS. The outcome of the cellular uptake of the dual drug-loaded nanocarriers is assessed by performing a bioassay of catalase peroxidatic activity in lysates of nanoparticle-treated differentiated SH-SY5Y human cells. The obtained results reveal the neuroprotective potential of the in vitro studied cubosomes in terms of enhanced peroxidatic activity of the catalase enzyme, which enables the inhibition of H2O2 accumulation in degenerating neuronal cells.
- MeSH
- kapalné krystaly chemie MeSH
- katalasa chemie MeSH
- kurkumin chemie MeSH
- lidé MeSH
- maloúhlový rozptyl MeSH
- nanostruktury chemie MeSH
- peroxid vodíku chemie MeSH
- polyethylenglykoly chemie MeSH
- reaktivní formy kyslíku MeSH
- synchrotrony MeSH
- zobrazování trojrozměrné MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Thermally induced phase separation (TIPS) based methods are widely used for the fabrication of porous scaffolds for tissue engineering and related applications. However, formation of a less-/non-porous layer at the scaffold's outer surface at the air-liquid interface, often known as the skin-effect, restricts the cell infiltration inside the scaffold and therefore limits its efficacy. To this end, we demonstrate a TIPS-based process involving the exposure of the just quenched poly(lactide-co-caprolactone):dioxane phases to the pure dioxane for a short time while still being under the quenching strength, herein after termed as the second quenching (2Q). Scanning electron microscopy, mercury intrusion porosimetry and contact angle analysis revealed a direct correlation between the time of 2Q and the gradual disappearance of the skin, followed by the widening of the outer pores and the formation of the fibrous filaments over the surface, with no effect on the internal pore architecture and the overall porosity of scaffolds. The experiments at various quenching temperatures and polymer concentrations revealed the versatility of 2Q in removing the skin. In addition, the in vitro cell culture studies with the human primary fibroblasts showed that the scaffolds prepared by the TIPS based 2Q process, with the optimal exposure time, resulted in a higher cell seeding and viability in contrast to the scaffolds prepared by the regular TIPS. Thus, TIPS including the 2Q step is a facile, versatile and innovative approach to fabricate the polymer scaffolds with a skin-free and fully open porous surface morphology for achieving a better cell response in tissue engineering and related applications.
- MeSH
- analýza selhání vybavení MeSH
- biokompatibilní materiály chemická syntéza MeSH
- chemická frakcionace metody MeSH
- design vybavení MeSH
- polyestery chemie MeSH
- polymery chemie MeSH
- poréznost MeSH
- povrchové vlastnosti MeSH
- testování materiálů MeSH
- tkáňové inženýrství přístrojové vybavení metody MeSH
- tkáňové podpůrné struktury * MeSH
- vytápění metody MeSH
- změna skupenství MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
