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Tytuł:
Plasma membrane Ca2+ -ATPase in excitable and nonexcitable cells.
Autorzy:
Żylińska, Ludmiła
Soszyński, Mirosław
Powiązania:
https://bibliotekanauki.pl/articles/1044284.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
calcium homeostasis
brain
erythrocytes
plasma membrane Ca2+ -ATPase
Opis:
There is a significant number of data confirming that the maintenance of calcium homeostasis in a living cell is a complex, multiregulated process. Calcium efflux from excitable cells (i.e., neurons) occurs through two main systems - an electrochemically driven Na+/Ca2+ exchanger with a low Ca2+ affinity (K0.5 = 10-15 μM), and a plasmalemmal, specific Ca2+-ATPase, with a high Ca2+ affinity (K0.5 < 0.5-1 μM), whereas in nonexcitable cells (i.e., erythrocytes) the calcium pump is the sole system responsible for the extrusion of calcium ions. The plasma membrane Ca2+-ATPase (PMCA) is a ubiquitously expressed protein, and more than 26 transcripts of four PMCA genes are distributed in a tissue specific manner. Differences in the structure and localization of PMCA variants are thought to correlate with specific regulatory properties and may have consequences for proper cellular Ca2+ signaling. The regulatory mechanisms of calcium pump activity have been studied extensively, resulting in a new view of the functioning of this important molecule in the membranes.
Źródło:
Acta Biochimica Polonica; 2000, 47, 3; 529-539
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of benzo(a)pyrene exposure on the ATPase activity and calcium concentration in the hippocampus of neonatal rats
Autorzy:
Yang, Kai
Chen, Chengzhi
Cheng, Shuqun
Cao, Xianqing
Tu, Baijie
Powiązania:
https://bibliotekanauki.pl/articles/2161850.pdf
Data publikacji:
2017-03-30
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
hippocampus
neurodevelopment
ATPase activity
Ca2+ concentration
neonatal rats
Benzo(a)pyrene
Opis:
Objectives To investigate whether postnatal benzo(a)pyrene (B(a)P) exposure caused the impairments on the process of neurodevelopment and the alteration in the calcium medium in the neonatal rats. Material and Methods Eighty neonatal Sprague Dawley (SD) rats were randomly divided into 5 groups (untreated control group, vehicle group, 0.02 mg/kg, 0.2 mg/kg and 2 mg/kg B(a)P-exposed group). Rats were treated with B(a)P by the intragastric administration from postnatal day (PND) 4 to 25. Morris water maze (MWM) was employed to observe the spatial memory of rats. The activity of calcium adenosine triphosphatase (Ca2+-ATPase), sodium-potassium adenosine triphosphatase (Na+-K+-ATPase) and calcium-magnesium adenosine triphosphatase (Ca2+-Mg2+-ATPase) in the hippocampus were detected by commercial kits. Fura-2 pentakis(acetoxymethyl) (Fura-2/AM) probe and reactive oxygen species (ROS) reagent kit were used for measuring the concentration of Ca2+ and ROS in the hippocampus synapse, respectively. Results Rats exposed to B(a)P resulted in the deficits in the spatial memory manifested by the increased escape latency and decreased number of crossing platform and time spent in target quadrant in comparison with the control groups. Benzo(a)pyrene exposure caused the significant decrease in the ATPase activity in the hippocampus and caused Ca2+ overload in the synaptic, besides, the ROS concentration increased significantly which may further induce neurobehavioral impairment of the neonatal rats. Conclusions Our findings suggest that postnatal B(a)P exposure may cause the neurobehavioral impairments in the neonatal rats, which were mediated by the decreased ATPase activity and elevated Ca2+ concentration. Int J Occup Med Environ Health 2017;30(2):203–211
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2017, 30, 2; 203-211
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Regulation of Ca2+ release from internal stores in cardiac and skeletal muscles.
Autorzy:
Wrzosek, Antoni
Powiązania:
https://bibliotekanauki.pl/articles/1044313.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Ca2+-induced Ca2+ release
calcium channels
dihydropyridine receptor
calcium sparks
excitation-contraction coupling
ryanodine receptor
Opis:
It is widely accepted that Ca2+ is released from the sarcoplasmic reticulum by a specialized type of calcium channel, i.e., ryanodine receptor, by the process of Ca2+-induced Ca2+ release. This process is triggered mainly by dihydropyridine receptors, i.e., L-type (long lasting) calcium channels, directly or indirectly interacting with ryanodine receptor. In addition, multiple endogenous and exogenous compounds were found to modulate the activity of both types of calcium channels, ryanodine and dihydropyridine receptors. These compounds, by changing the Ca2+ transport activity of these channels, are able to influence intracellular Ca2+ homeostasis. As a result not only the overall Ca2+ concentration becomes affected but also spatial distribution of this ion in the cell. In cardiac and skeletal muscles the release of Ca2+ from internal stores is triggered by the same transport proteins, although by their specific isoforms. Concomitantly, heart and skeletal muscle specific regulatory mechanisms are different.
Źródło:
Acta Biochimica Polonica; 2000, 47, 3; 705-723
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calcium (Ca2+) expression and intensity in cumulus-oocyte complex (COCs) in Kacang goat after vitrification
Autorzy:
Widjiati, W.
Faizah, Z.
Darsini, N.
Hendrawan, V.F.
Karima, H.N.
Chotimah, C.
Sumitro, S.B.
Yustinasari, L.R.
Kasman, A.A.M.N.
Ntoruru, J.M.
Luqman, E.M.
Powiązania:
https://bibliotekanauki.pl/articles/16539072.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Calcium (Ca2+)
confocal laser scanning microscope
cumulus-oocyte complex (COCs)
food production
Kacang goat
Opis:
The process of vitrification of the cumulus-oocyte complex (COCs) often results in cold shock. When warming, heat shock occurs which can disrupt the balance of intracellular calcium (Ca2+) intensity. Drastic changes in temperature cause Reactive Oxygen Species (ROS), affecting changes on Ca2+ in COCs. The role of calcium is needed for oocyte activation in the fertilization process. The purpose of this study was to measure the expression of Ca2+ and the intensity of Ca2+ in COCs after vitrification. The study was divided into 2 groups, the control group (C) of fresh COCs, and the treatment group (T) of COCs after vitrification. After vitrification for 24 hours, then thawing, the expression of Ca2+ was examined using the Immunocytochemistry (ICC) method and the intensity of calcium (Ca2+) with a Confocal Laser Scanning Microscope (CLSM). The research data obtained were analyzed statistically by T-Test. The results showed that the expression of Ca2+ in the control group (12.00±0.00) was different from the treatment group (0.35±0.79). The intensity of Ca2+ in the control group (1059.43±489.59) was different from the treatment group (568.21±84.31). The conclusion of this study is that cryopreservation affects calcium in COCs; there were differences in the expression and the intensity of Ca2+ between fresh COCs and COCs after vitrification. Ca2+ intensity of COCs after vitrification was concentrated in the nucleus, while in fresh COCs it was concentrated in the cytoplasm.
Źródło:
Polish Journal of Veterinary Sciences; 2022, 25, 1; 19-26
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvement of plant heat tolerance by modification of xanthophyll cycle activity
Autorzy:
Trojak, Magdalena
Skowron, Ernest
Powiązania:
https://bibliotekanauki.pl/articles/1178460.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
ascorbic acid (AsA);
calcium ions (Ca2+)
dithiothreitol (DTT)
heat stress
plant protection products (PPPs)
putrescine (Put)
xanthophyll cycle
Opis:
Plants are sessile organisms hence environmental factors such as excessive light and high air temperature lead to significant reductions of their productivity and quality of gained yield. In fact, scientific and agriculture hubs make lots of efforts to improve crop tolerance to elevated temperature, selecting more tolerant varieties. We analyzed less expensive and highly efficient method to improve resistance of well-known cultivars of crop plant by reversible modification of xanthophyll cycle. It functions as a safety valve to adjust energy transfer and protects fragile structures of photosynthetic machinery from excessive light, especially accompanied by heat or water stress. Efficiency of modified xanthophyll cycle activity was measured after pre-treatment with four, chemically different regulators, with or without light illumination. Analyses were carried out on barley (Hordeum vulgare L.) cv. Zenek treated with ascorbic acid (AsA), dithiothreitol (DTT), putrescine (Put) and calcium ions (Ca2+). To measure the scale of thermal energy dissipation we traced energy transfer absorbed by PSII with PAM chlorophyll fluorescence technique. Results showed clear correlation between AsA (activator of violaxanthin de-epoxidase) treatment and stimulation of the Φ(NPQ) at increased temperature. DTT (inhibitor of violaxanthin de-epoxidase) decreased the cycle activity at 45 °C at the same time increasing its value at 35°C, caused by interaction with other enzymes. Action of Put (hydrogen ions buffer) concerned mainly a non regulated Φ(NO) energy quenching. We noticed that application of Ca(NO3)2 (Ca2+ source for enzyme activity) reduced the Φ(NPQ) at 45 °C and stimulated it at 25 °C. Obtained results confirmed postulated possibility of creating new type of plant protection products (PPPs) able to precisely manage natural mechanisms of heat resistance.
Źródło:
World Scientific News; 2017, 70, 2; 51-70
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Colocalization pattern of cocaine- and amphetamine-regulated transcript peptide and parvalbumin immunoreactivity in the hippocampus proper of the chinchilla
Autorzy:
Szalak, R.
Matysek, M.
Kukula-Koch, W.
Rycerz, K.
Zacharko-Siembida, A.
Arciszewski, M.B.
Powiązania:
https://bibliotekanauki.pl/articles/2087337.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hippocampus
dentate gyrus
CART
PV
Ca2+
memory
chinchilla
Źródło:
Polish Journal of Veterinary Sciences; 2020, 23, 1; 89-96
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photoreceptor guanylate cyclase variants: cGMP production under control.
Autorzy:
Sokal, Izabela
Alekseev, Andrei
Palczewski, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/1043388.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
rhodopsin
photoreceptor cells
guanylate cyclase
Ca2+-binding proteins
guanylate cyclase-activating protein
retina
Opis:
Changes in the Ca2+ concentration are thought to affect many processes, including signal transduction in a vast number of biological systems. However, only in few cases the molecular mechanisms by which Ca2+ mediates its action are as well understood as in phototransduction. In dark-adapted photoreceptor cells, the equilibrium level of cGMP is maintained by two opposing activities, such as phosphodiesterase (PDE) and guanylate cyclase (GC). Upon absorption of photons, rhodopsin-G-protein-mediated activation of PDE leads to a transient decrease in [cGMP] and subsequently to lowering of [Ca2+]. In turn, lower [Ca2+] increases net production of cGMP by stimulation of GC until dark conditions are re-established. This activation of GC is mediated by Ca2+-free forms of Ca2+-binding proteins termed GC-activating proteins (GCAPs). The last decade brought the molecular identification of GCs and GCAPs in the visual system. Recent efforts have been directed toward understanding the properties of GC at the physiological and structural levels. Here, we summarize the recent progress and present a list of topics of ongoing research.
Źródło:
Acta Biochimica Polonica; 2003, 50, 4; 1075-1095
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and SEM/EDS characterisation of porous coatings enriched in magnesium and copper obtained on titanium by PEO with ramp voltage
Autorzy:
Rokosz, Krzysztof
Hryniewicz, Tadeusz
Pietrzak, Kornel
Dudek, Łukasz
Powiązania:
https://bibliotekanauki.pl/articles/1179226.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CP Titanium Grade 2
Micro Arc Oxidation (MAO)
Plasma Electrolytic Oxidation (PEO)
calcium nitrate Mg(NO3)2∙6H2O
linear polarization
ramp voltage
zinc nitrate Ca(NO3)2∙3H2O
Opis:
In the present paper, the SEM and EDS results of porous and enriched in calcium and/or zinc coatings, which were obtained during 3-minute treatments by Plasma Electrolytic Oxidation/ Micro Arc Oxidation processes on CP Titanium Grade 2 at ramp potentials (liner polarization) from 0 up to 650 VDC in electrolytes containing 500 g Mg(NO3)2∙6H2O and/or 500 g Cu(NO3)2∙3H2O in 1 L H3PO4, are reported. It was found that the obtained coatings, dependent on the PEO process conditions, have pores with different shapes and diameters. The Mg/P and Cu/P ratios by atomic concentration are the same and equal to 0.09±0.01 (by wt %) | 0.11±0.01 (by at%) and/or 0.40±0.08 (by wt %) | 0.19±0.04 (by at%), respectively. That may testify the hydroxyapatite-like structures of Mg-Ti-PO43– and/or Cu-Ti-PO43– have been identified to occur.
Źródło:
World Scientific News; 2017, 80; 29-42
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porous PEO coatings on titanium, obtained under DC regime, enriched in magnesium, calcium, zinc, and copper
Autorzy:
Rokosz, Krzysztof
Hryniewicz, Tadeusz
Pietrzak, Kornel
Dudek, Łukasz
Powiązania:
https://bibliotekanauki.pl/articles/1156239.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
plasma electrolytic oxidation (peo)
micro arc oxidation (mao)
cp titanium grade 2
calcium nitrate ca(no3)2•4h2o
magnesium nitrate mg(no3)2∙6h2o
zinc nitrate zn(no3)2∙6h2o
copper nitrate cu(no3)2∙3h2o
Opis:
In the present paper, the analysis of SEM and EDS results of porous and enriched in calcium, magnesium, zinc, copper and phosphorus coatings, obtained during 3-minute treatments performed by Plasma Electrolytic Oxidation (PEO)/Micro Arc Oxidation (MAO) processes on CP Titanium Grade 2, is presented. The PEO process was carried out at DC potentials of 500 VDC, 575 VDC, and 650 VDC in electrolytes containing 125 g Ca(NO3)2•4H2O, and 125 g Mg(NO3)2∙6H2O, and 125 g Zn(NO3)2∙6H2O, and 125 g Cu(NO3)2∙3H2O in 1 L H3PO4. It was found that obtained coatings have pores with different shapes and diameters and/or size/dimentions. The Ca/P, Mg/P, Zn/P, Cu/P, and M/P ratios (M=Ca+Mg+Zn+Cu) were equal to 0.074, 0.046, 0.056, 0.042, and 0.218, respectively. The highest value of each of these ratios was recorded for 650 VDC. It may be concluded that the obtained PEO coatings structures most likely are similar to hydroxyapatite-like structures, in which the Ca2+ may be replaced with Zn2+, Mg2+, Cu2+.
Źródło:
World Scientific News; 2018, 94, 2; 99-114
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SEM and EDS studies of porous coatings enriched in calcium and zinc obtained by PEO with ramp voltage
Autorzy:
Rokosz, Krzysztof
Hryniewicz, Tadeusz
Pietrzak, Kornel
Powiązania:
https://bibliotekanauki.pl/articles/1178366.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CP Titanium Grade 2
Micro Arc Oxidation (MAO)
Plasma Electrolytic Oxidation (PEO)
calcium nitrate Ca(NO3)2∙4H2O
linear polarization
ramp voltage
zinc nitrate Zn(NO3)2∙6H2O
Opis:
In this work, the SEM and EDS results of porous and enriched in calcium or zinc coatings, which were obtained during 3-minute treatments using Plasma Electrolytic Oxidation (Micro Arc Oxidation) processes on CP Titanium Grade 2 at ramp potentials (linear polarization) from 0 up to 650 VDC in electrolytes containing 500 g Ca(NO3)2∙4H2O and/or 500 g Zn(NO3)2∙6H2O in 1 L H3PO4, are presented. It was found that obtained coatings have pores with different shapes and diameters. The Ca/P and Zn/P ratios by atomic concentration are the same and equal to 0.2, what may suggest hydroxyapatite-like structure (M,Ti)x(PO4)y, where M = {Ca, Zn}.
Źródło:
World Scientific News; 2017, 77, 2; 242-255
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SEM and EDS studies of selected porous coatings obtained on titanium by Plasma Electrolytic Oxidation
Autorzy:
Rokosz, Krzysztof
Hryniewicz, Tadeusz
Pietrzak, Kornel
Dudek, Łukasz
Malorny, Winfried
Powiązania:
https://bibliotekanauki.pl/articles/1178480.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CP Titanium Grade 2
Micro Arc Oxidation (MAO)
Plasma Electrolytic Oxidation (PEO)
calcium nitrate Ca(NO3)2∙4H2O
copper nitrate Cu(NO3)2∙3H2O
magnesium nitrate Mg(NO3)2∙6H2O
Opis:
In present work, SEM and EDS results of porous and enriched in calcium, copper, magnesium and phosphorus coatings, which were obtained during 3-minute treatments of Plasma Electrolytic Oxidation PEO (Micro Arc Oxidation MAO) processes on CP Titanium Grade 2 at two potentials, i.e. 500 VDC and 650 VDC, are presented. It was found that the voltage of that process influences the chemical composition of coatings shapes obtained on titanium in electrolytes containing calcium, copper and magnesium nitrates. The pores shapes of PEO coatings formed on titanium in electrolytes containing calcium, copper and magnesium nitrates are presented, too. In addition, it was also noted that with using of higher voltage (here 650 VDC) of PEO treatments, the higher Ca/P, Cu/P and Mg/P ratios were found than those after treatments at 500 VDC.
Źródło:
World Scientific News; 2017, 70, 2; 71-85
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and characterisation of porous, calcium enriched coatings formed on Titanium via Plasma Electrolytic Oxidation
Autorzy:
Rokosz, Krzysztof
Hryniewicz, Tadeusz
Pietrzak, Kornel
Powiązania:
https://bibliotekanauki.pl/articles/1179160.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
85% orthophosphoric acid H3PO4
CP Titanium Grade 2
Micro Arc Oxidation (MAO)
Plasma Electrolytic Oxidation (PEO)
calcium nitrate tetrahydrate Ca(NO3)2∙4H2O
Opis:
The SEM and EDS study results of porous and calcium enriched coatings obtained via Plasma Electrolytic Oxidation (Micro Arc Oxidation) on the Commercial Purity Titanium Grade 2 samples, at three potentials 450 VDC, 550 VDC, 650 VDC in electrolytes containing 500 g Ca(NO3)2∙4H2O in 1000 mL H3PO4, are presented in the paper. In the same electrolyte three Titanium samples, one after other, were treated, with the PEO processing time equaling 3 minutes after each immersion. Based on SEM and EDS results, it was possible to state that all obtained coatings are porous and their calcium-to-phosphorus (Ca/P) ratio decreases with decreasing PEO voltage. In addition, it was found out that electrolyte aging results in decreasing Ca/P ratio, too.
Źródło:
World Scientific News; 2017, 83; 29-44
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Order-disorder structural transitions in synthetic filaments of fast and slow skeletal muscle myosins under relaxing and activating conditions.
Autorzy:
Podlubnaya, Zoya
Malyshev, Sergey
Nieznański, Krzysztof
Stępkowski, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/1044221.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
method of slow skeletal muscle myosin preparation.
Ca2+-induced structural transitions
myosin filaments
fast and slow skeletal muscle myosin
Opis:
In the previous study (Podlubnaya et al., 1999, J. Struc. Biol. 127, 1-15) Ca2+-induced reversible structural transitions in synthetic filaments of pure fast skeletal and cardiac muscle myosins were observed under rigor conditions (-Ca2+/+ Ca2+). In the present work these studies have been extended to new more order-producing conditions (presence of ATP in the absence of Ca2+) aimed at arresting the relaxed structure in synthetic filaments of both fast and slow skeletal muscle myosin. Filaments were formed from column-purified myosins (rabbit fast skeletal muscle and rabbit slow skeletal semimebranosus proprius muscle). In the presence of 0.1 mM free Ca2+, 3 mM Mg2+ and 2 mM ATP (activating conditions) these filaments had a spread structure with a random arrangement of myosin heads and subfragments 2 protruding from the filament backbone. Such a structure is indistinguishable from the filament structures observed previously for fast skeletal, cardiac (see reference cited above) and smooth (Podlubnaya et al., 1999, J. Muscle Res. Cell Motil. 20, 547-554) muscle myosins in the presence of 0.1 mM free Ca2+. In the absence of Ca2+ and in the presence of ATP (relaxing conditions) the filaments of both studied myosins revealed a compact ordered structure. The fast skeletal muscle myosin filaments exhibited an axial periodicity of about 14.5 nm and which was much more pronounced than under rigor conditions in the absence of Ca2+ (see the first reference cited). The slow skeletal muscle myosin filaments differ slightly in their appearance from those of fast muscle as they exhibit mainly an axial repeat of about 43 nm while the 14.5 nm repeat is visible only in some regions. This may be a result of a slightly different structural properties of slow skeletal muscle myosin. We conclude that, like other filaments of vertebrate myosins, slow skeletal muscle myosin filaments also undergo the Ca2+-induced structural order-disorder transitions. It is very likely that all vertebrate muscle myosins possess such a property.
Źródło:
Acta Biochimica Polonica; 2000, 47, 4; 1007-1017
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhanced bioactivity of calcium phosphate coatings obtained by a direct electrodeposition from Hanks solution on Ti surface
Zwiększona bioaktywnosc powłok fosforanowo-wapniowych otrzymanych metodą bezpośredniego elektroosadzania na powierzchni Ti z roztworu Hanka
Autorzy:
Pisarek, M.
Roguska, A.
Marcon, L.
Andrzejczuk, M.
Janik-Czachor, M.
Powiązania:
https://bibliotekanauki.pl/articles/351188.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biokompatybilność
powłoki Ca-P
osteoblasty (U2OS)
biocompatibility
Ca-P coatings
electrodeposition
BSA protein
Opis:
The main requirements for titanium biomaterials are: (a) biocompatibility, (b) resistance to biological corrosion and (c) antisepticity. These requirements may be met by a new generation of titanium biomaterials with a specific surface layer of strictly defined microstructure, chemical and phase composition. Recently, various surface modifications have been applied to form a bioactive layer on Ti surface, which is known to accelerate osseointegration. The purpose of this study was to investigate bioactivity of porous calcium phosphate coatings prepared by a direct electrodeposition on Ti surface from a modified Hanks’ solution. The thick 200 nm coatings, were prepared via cathodic polarization at constant voltage -1.5 V vs. OCP in a Hanks’ solution. In order to evaluate the potential use of the coatings for biomedical applications, the adsorption of bovine serum albumin (BSA), the most abundant protein in blood, and living cells attachment (osteoblasts, U2OS) were studied. The observed differences in living cells attachment suggest a more promising initial cellular response of Ca-P coatings with a pre-adsorbed albumin. The topography and a cross-section view of the Ca-P coatings were characterized using SEM and STEM techniques. The surface analytical techniques (AES, XPS, and FTIR) were used to characterize their chemical composition before and after protein BSA adsorption.
Wymagania stawiane biomateriałom tytanowym to przede wszystkim: (a) biozgodność, (b) odporność na korozję oraz (c) antyseptyczność. Wymagania te mogą zostać spełnione poprzez wytworzenie nowej generacji biomateriałów tytanowych o określonej powierzchni właściwej, z ściśle określoną mikrostrukturą, składem fazowym i chemicznym. Współczesnie znane są różne metody modyfikacji powierzchni Ti prowadzące do formowania bioaktywnych warstw, które przyspieszają proces osteointegracji. Celem naszych badań było zbadanie bioaktywności porowatych powłok fosforanowo-wapniowych (Ca-P) przygotowanych poprzez bezpośrednie elektroosadzanie na powierzchni Ti z roztworu Hanka. Grubość wytworzonych powłok wynosiła około 200 nm, przy parametrach procesu elektroosadzania: napięcie - 1.5 V vs. OCP, czas 8000 s, roztwór Hanka. W celu dokonania oceny możliwości zastosowania badanych powłok dla potrzeb biomedycznych zastosowano adsorpcje albuminy surowicy bydlecej (BSA), która jest najczęstszą występującą proteina we krwi oraz testy komórkowe przyłączania się osteoblastów (linia komórkowa U2OS). Obserwowane zmiany podczas testów z żywymi komórkami sugerują bardziej obiecujacą początkową odpowiedz dla powłok fosforanowo-wapniowych z wstępnie zaadsorbowana albumina. Do obserwacji topografii powierzchni otrzymanych powłok oraz struktury na przekroju zastosowano mikroskopie wysokorozdzielczą SEM oraz TEM. Zastosowano również techniki powierzchniowo czułe: AES, XPS, FTIR w celu okreslenia składu chemicznego warstw przed oraz po adsorpcji protein na ich powierzchni.
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 1; 261-267
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Catalytic pyrolysis of metal free PCBs with ZSM-5 and Ca(OH)2
Autorzy:
Pandere, Vaibhav
Gautam, Alok
Gautam, Shina
Powiązania:
https://bibliotekanauki.pl/articles/2173423.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
catalytic pyrolysis
PCBs
ZSM-5
Ca(OH)2
fuels
PCB
paliwo
Opis:
Presence of heavier molecules and toxic brominated compounds in pyrolysis products of printed circuit boards (PCB) make their use difficult. In the present work to overcome this problem PCBs were pyrolyzed in presence of catalysts such as ZSM-5 and Ca(OH)2 to study their effect on pyrolysis products. The comparison of non-catalytic pyrolysis of PCB was done with oil and gas compositions produced by both techniques. Pyrolysis experiments were done at a lab scale set-up. However, the increased concentrations of ZSM-5 were found to increase char and gases were found to be rich in CH4 and O2. The composition of oils was mainly composed of phenols, phenol derivatives and aromatic compounds, which increased with pyrolysis with ZSM-5 and Ca(OH)2. Ca(OH)2 was found effective in removing brominated compounds from oil and no halogens were observed in oil. Char produced during pyrolysis was mesoporous in nature and composed of some fractions of metals and glass fibers.
Źródło:
Chemical and Process Engineering; 2022, 43, 2; 171--182
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 27

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