Stabilization of immobilized D-amino-acid oxidase was achieved as follows. Yeast Trigonopsis variabilis producing D-amino-acid oxidase was used to deaminate cephalosporin C to glutaryl-7-aminocephalosporanic acid. Permeabilized cells were co-immobilized with manganese dioxide by entrapment in (poly)acrylamide gel so that hydrogen peroxide, liberated in the reaction, could be partially deactivated and both the enzyme and the substrate could be stabilized. Activity of entrapped cells was determined by HPLC and enzyme flow microcalorimetry. The process was evaluated in terms of activity, immobilization yield, storage stability and oxo-product formation by immobilized preparations. The storage stability of immobilized biocatalysts with MnO2 was nearly doubled and production of 2-oxoadipyl-7-aminocephalosporanic acid was 2-3-fold higher than by entrapped cells without MnO2. Glutaryl-7-aminocephalosporanic acid can be easily obtained from the resulting oxo-product by a non-enzymic reaction via externally added hydrogen peroxide.

• MeSH
• Ascomycota enzymologie   MeSH
• cefalosporiny metabolismus   MeSH
• enzymy imobilizované MeSH
• kalorimetrie MeSH
• oxidasa D-aminokyselin metabolismus   MeSH
• oxidy farmakologie   MeSH
• sloučeniny manganu farmakologie   MeSH
• stabilita enzymů účinky léků   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cefalosporiny MeSH
• cephalosporin C MeSH Prohlížeč
• enzymy imobilizované MeSH
• manganese oxide MeSH Prohlížeč
• oxidasa D-aminokyselin MeSH
• oxidy MeSH
• sloučeniny manganu MeSH

This study aimed to demonstrate the behavior of different complexes using IR spectroelectrochemistry (SEC), a technique that combines IR spectroscopy with electrochemistry. Four different Mn and Re catalysts for electrochemical CO2 reduction were studied in dry acetonitrile. In the case of Mn(apbpy)(CO)3Br (apbpy = 4(4-aminophenyl)-2,2'-bipyridine), SEC suggested that a very slow catalytic reduction of CO2 also occurs in acetonitrile in the absence of proton donors, but at rather negative potentials. In contrast, the corresponding Re(apbpy)(CO)3Br clearly demonstrated slow catalytic conversion at the first reduction potential. Switching to saturated CO2 solutions in a mixture of acetonitrile and 5% water as a proton donor, the SEC of Mn(apbpy)(CO)3Br displayed a faster catalytic behavior.

• Klíčová slova
• CO2, carbon dioxide reduction, manganese, rhenium, spectroelectrochemistry,
• Publikační typ
• časopisecké články MeSH

Manganese is naturally present in water, but its increased concentration in potable water is undesirable for multiple reasons. This study investigates an alternative method of demanganization by a newly synthesized TiO2-based adsorbent prepared through the transformation of titanyl sulphate monohydrate to amorphous sodium titanate. Its adsorption capacity for Mn2+ was determined, while a range of influential factors, such as the effect of contact time, adsorbent dosage, pH value, and added ions was evaluated. The adsorbent appeared highly effective for Mn2+ removal owing to its unique characteristics. Besides adsorption via electrostatic interactions, ion-exchange was also involved in the Mn2+ removal. Although the Mn2+ removal occurred within the whole investigated pH range of 4-8, the maximum was achieved at pH 7, with qe = 73.83 mg g-1. Equilibrium data revealed a good correlation with Langmuir isotherm in the absence of any ions or in the presence of monovalent co-existing ions, while the results in the presence of divalent co-existing ions showed a better fit to Freundlich isotherm. Additionally, the presence of monovalent cations (Na+, K+) only slightly decreased the Mn2+ removal efficiency as compared to divalent cations (Ca2+, Mg2+) that caused a greater decrease; however, the effect of anions (Cl-, SO42-) was insignificant. To provide insight into the adsorbent safety, the toxicity assessment was performed and showed no harmful effect on cell activity. Furthermore, the residual concentration of titanium after adsorption was always below the detection limit. The results imply that the synthesized TiO2-based adsorbent is a safe promising alternative method for demanganization.Highlights The synthesis of amorphous TiO2-based adsorbent was presented.The TiO2-based adsorbent was found to be efficient for Mn2+ removal.The Mn2+ removal mechanisms were adsorption and ion-exchange.Increasing pH enhanced the efficiency of Mn2+ removal.Divalent cations decreased the Mn2+ removal efficiency more than monovalent cations.

• Klíčová slova
• Adsorption, drinking water treatment, ion-exchange, manganese, titanium dioxide,
• MeSH
• adsorpce MeSH
• chemické látky znečišťující vodu * analýza   MeSH
• čištění vody * metody   MeSH
• ionty MeSH
• kationty dvojmocné MeSH
• kationty jednomocné MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• mangan MeSH
• pitná voda * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• ionty MeSH
• kationty dvojmocné MeSH
• kationty jednomocné MeSH
• mangan MeSH
• pitná voda * MeSH
• titanium dioxide MeSH Prohlížeč

Nanoparticles of manganese perovskite of the composition La(0.75)Sr(0.25)MnO(3) uniformly coated with silica were prepared by encapsulation of the magnetic cores (mean crystallite size 24 nm) using tetraethoxysilane followed by fractionation. The resulting hybrid particles form a stable suspension in an aqueous environment at physiological pH and possess a narrow hydrodynamic size distribution. Both calorimetric heating experiments and direct measurements of hysteresis loops in the alternating field revealed high specific power losses, further enhanced by the encapsulation procedure in the case of the coated particles. The corresponding results are discussed on the basis of complex characterization of the particles and especially detailed magnetic measurements. Moreover, the Curie temperature (335 K) of the selected magnetic cores resolves the risk of local overheating during hyperthermia treatment.

• MeSH
• elektromagnetická pole MeSH
• indukovaná hypertermie metody   MeSH
• kalorimetrie MeSH
• koncentrace vodíkových iontů MeSH
• mangan chemie   MeSH
• nanočástice chemie   ultrastruktura   MeSH
• oxid křemičitý chemie   MeSH
• oxidy chemie   MeSH
• sloučeniny vápníku chemie   MeSH
• spektrofotometrie infračervená MeSH
• testování materiálů metody   MeSH
• titan chemie   MeSH
• transmisní elektronová mikroskopie MeSH
• velikost částic MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• mangan MeSH
• oxid křemičitý MeSH
• oxidy MeSH
• perovskite MeSH Prohlížeč
• sloučeniny vápníku MeSH
• titan MeSH

• MeSH
• chemie farmaceutická MeSH
• chromatografie na tenké vrstvě MeSH
• hydroxidy * MeSH
• indikátory a reagencie MeSH
• mangan MeSH
• oxidace-redukce MeSH
• peroxidy analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hydroxidy * MeSH
• indikátory a reagencie MeSH
• mangan MeSH
• peroxidy MeSH

Manganese retention was observed in brains and in several other tissues of female Wistar rats after the intratracheal instillation of an inorganic manganese compound: manganese dioxide. Two categories of rats, younger (180 to 200g) and older (330 to 350g), were divided into a control group, in which animals received vehicle only (0.5 mL physiological saline), and an experimental group, in which rats received a dose of 0.48 mg of Mn/kg body weight (in 0.5 mL saline), twice a week for 3 months, for a total dosage of 11.80 mg of Mn/kg body weight. At the end of the exposure period, manganese retention in selected rat organs, brain, liver, kidney, and lung, was analyzed using atomic absorption spectrophotometry. At the end of the 6-wk or 12-wk manganese dioxide exposure period, analysis of variance of the manganese retention results revealed significant differences between Mn-exposed and unexposed rats in brain, kidney, and lung tissues (p<0.01) for both experimental age categories. Moreover, at the end of the 12-wk exposure period, significant results (p<0.05) between younger and older rats were obtained for both brain and kidneys. In both types of tissue, the manganese retention in the younger group was higher than that in older animals.

• MeSH
• intratracheální intubace MeSH
• krysa rodu Rattus MeSH
• mangan metabolismus   MeSH
• mozek metabolismus   MeSH
• orgánová specificita MeSH
• oxidy aplikace a dávkování   MeSH
• potkani Wistar MeSH
• sloučeniny manganu aplikace a dávkování   MeSH
• stárnutí metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• mangan MeSH
• manganese dioxide MeSH Prohlížeč
• oxidy MeSH
• sloučeniny manganu MeSH

• MeSH
• hydroxidy * MeSH
• indikátory a reagencie MeSH
• mangan * MeSH
• oxidace-redukce MeSH
• oxidy * MeSH
• peroxid vodíku analýza   MeSH
• potenciometrie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hydroxidy * MeSH
• indikátory a reagencie MeSH
• mangan * MeSH
• oxidy * MeSH
• peroxid vodíku MeSH

Nanostructured titanium(IV) oxide was used for the destructive adsorption and photocatalytic degradation of mitoxantrone (MTX), a cytostatic drug from the group of anthracycline antibiotics. During adsorption on a titania dioxide surface, four degradation products of MTX, mitoxantrone dicarboxylic acid, 1,4-dihydroxy-5-((2-((2-hydroxyethyl)amino)ethyl)amino)-8-((2-(methylamino)ethyl)amino)anthracene-9,10-dione, 1,4-dihydroxy-5,8-diiminoanthracene-9,10(5H,8H)-dione and 1,4-dihydroxy-5-imino-8-(methyleneamino)anthracene-9,10(5H,8H)-dione, were identified. In the case of photocatalytic degradation, only one degradation product after 15 min at m/z 472 was identified. This degradation product corresponded to mitoxantrone dicarboxylic acid, and complete mineralization was attained in one hour. Destructive adsorbent manganese(IV) oxide, MnO2, was used only for the destructive adsorption of MTX. Destructive adsorption occurred only for one degradation product, mitoxantrone dicarboxylic acid, against anatase TiO2.

• MeSH
• adsorpce MeSH
• antracykliny chemie   MeSH
• katalýza MeSH
• mitoxantron chemie   MeSH
• nanočástice chemie   MeSH
• oxidy chemie   MeSH
• sloučeniny manganu chemie   MeSH
• titan chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antracykliny MeSH
• manganese dioxide MeSH Prohlížeč
• mitoxantron MeSH
• oxidy MeSH
• sloučeniny manganu MeSH
• titan MeSH
• titanium dioxide MeSH Prohlížeč

The effects of selenium and manganese on growth of hybridomas in serum-free medium were studied. The optimum growth-supporting concentration of Na2SeO3 was about 50 nM. Omission of selenite resulted in decreased growth (60-70% of the number of cells growing with selenite when cultivated for 3 days). The optimum growth-supporting concentration of MnCl2 was 0.5 nM. The number of hybridoma cells growing 3 days without MnCl2 represented about 80% of the cell number obtained by cultivation with MnCl2. Compounds of other trace elements did not display growth-stimulating activity, when tested in short-term culture, perhaps with the exception of lithium at relatively very high concentrations (about 0.2-0.6 mM).

• MeSH
• buněčné dělení účinky léků   MeSH
• chloridy * MeSH
• hybridomy cytologie   účinky léků   MeSH
• kultivační média MeSH
• lithium farmakologie   MeSH
• mangan farmakologie   MeSH
• oxidy selenu MeSH
• selen farmakologie   MeSH
• sloučeniny manganu * MeSH
• sloučeniny selenu * MeSH
• stopové prvky farmakologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chloridy * MeSH
• kultivační média MeSH
• lithium MeSH
• mangan MeSH
• manganese chloride MeSH Prohlížeč
• oxidy selenu MeSH
• selen MeSH
• sloučeniny manganu * MeSH
• sloučeniny selenu * MeSH
• stopové prvky MeSH

• MeSH
• fenoly analýza   MeSH
• hydrochinony analýza   MeSH
• indikátory a reagencie MeSH
• mangan analýza   MeSH
• oxaláty analýza   MeSH
• oxid uhličitý MeSH
• oxidace-redukce * MeSH
• potenciometrie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fenoly MeSH
• hydrochinony MeSH
• indikátory a reagencie MeSH
• mangan MeSH
• oxaláty MeSH
• oxid uhličitý MeSH