Search results

1

A novel α-glucosidase from the moss Scopelophila cataractae

100%

Yamasaki Y., Nakashima S., Konno H.

Acta Biochimica Polonica

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2007

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vol. 54

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issue 2

401-406

EN

Scopelophila cataractae is a rare moss that grows on copper-containing soils. S. cataractae protonema was grown on basal MS medium containing copper. A starch-degrading activity was detected in homogenates of the protonema, after successive extraction with phosphate buffer and buffer containing 3 M LiCl. Buffer-soluble extract (BS) and LiCl-soluble extract (LS) readily hydrolyzed amylopectin to liberate only glucose, which shows that α-glucosidase (EC 3.2.1.20) in BS and LS hydrolyzed amylopectin. The Km value of BS for maltose was 0.427. The Km value of BS for malto-oligosaccharide decreased with an increase in the molecular mass of the substrate. The value for maltohexaose was 0.106, which is about four-fold lower than that for maltose. BS was divided into two fractions of α-glucosidase (BS-1 and BS-2) by isoelectric focusing. The isoelectric points of these two enzymes were determined to be 4.36 (BS-1) and 5.25 (BS-2) by analytical gel electrofocusing. The two enzymes readily hydrolyzed malto-oligosaccharides. The two enzymes also hydrolyzed amylose, amylopectin and soluble starch at a rate similar to that with maltose. The two enzymes readily hydrolyzed panose to liberate glucose and maltose (1 : 1), and the Km value of BS for panose was similar to that for maltotriose, whereas the enzymes hydrolyzed isomaltose only weakly. With regard to substrate specificity, the two enzymes in BS are novel α-glucosidases. The two enzymes also hydrolyzed β-limit dextrin, which has many α-1,6-glucosidic linkages near the non-reducing ends, more strongly than maltose, which shows that they do not need a debranching enzyme for starch digestion. The starch-degrading activity of BS was not inhibited by p-chloromercuribenzoic acid or α-amylase inhibitor. When amylopectin was treated with BS and LS in phosphate buffer, pH 6.0, glucose, but not glucose-1-phosphate, was detected, showing that the extracts did not contain phosphorylase but did contain an α-glucosidase. These results show that α-glucosidases should be capable of complete starch digestion by themselves in cells of S. cataractae.

2

Characterization of Cu/SiC surface composite produced by friction stir processing

100%

Iwaszko J., Kudła K., Iwaszko J., Kudła K.

Bulletin of the Polish Academy of Sciences: Technical Sciences

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2020

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issue 3

3

Thermodynamic Properties of Cu-S Solutions

100%

Kucharski M.

Archives of Metallurgy and Materials

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2018

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vol. 63

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issue 4

4

Influence of cadmium and copper on tissue element levels of pregnant rats

88%

Turgut S., Enli Y., Emmungil G., Turgut G., Demir S., Kaptanoglu B., Genç O.

Open Medicine

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2007

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vol. 2

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issue 4

447-457

EN

In the current study, we examined the effects of Cd on Cd, Cu, Zn and Fe levels in placenta and maternal and fetal plasma and tissues, the placental weight, total fetal and maternal body weights, and fetal and maternal tissue weights during pregnancy. A total of 21 adult female rats were treated during gestation with drinking water containing one of the following: 70 mg/L of CdCl2, a combination of 70 mg/L of CdCl2 and 70 mg/L of CuSO4, or no addition (control). Placenta Cu and Fe levels, fetal liver and kidney Cu levels, and fetal liver tissue weights were lower in the group administered Cd than in the control group. Also, Cd levels in the placenta, maternal and fetal liver, and maternal kidney were higher in the group treated with Cd than in controls. In the group administered both Cd and Cu, fetal body and tissue weights did not change, but Cd levels in the placenta, maternal and fetal liver, and maternal kidneys were higher than in controls. Zn and Fe levels in the maternal kidney and fetal liver were also lower in this group. Cd exposure during pregnancy resulted in Cd accumulation in maternal and fetal tissues during pregnancy and a decrease in the total weight of fetuses, and the combination of Cd and Cu caused some changes in the both maternal and fetal levels of Cu, Zn, and Fe, but it did not cause changes in the total fetal body weight or the weights of individual tissues.

5

New feats of alkene and alkyne asymmetric hydroamination catalyzed by copper and rhodium hydrides

88%

Dondoni A.

Asymmetric Catalysis

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2015

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vol. 2

|

issue 1

EN

Hydroamination of unsaturated carbon-carbon bonds is a useful C-N bond forming reaction as it leads to products (amines, imines, enamines) of high synthetic value. While the hydroamination of terminal alkenes and alkynes under metal catalysis has been widely developed, the corresponding reactions with internal substrates remain a challenge. Two recent studies by Buchwald and by Dong which focus on enantioselective hydroamination of internal alkenes and alkynes respectively are of significant importance. [43,44] The results reported broaden the scope of hydroamination as a useful C-N bond forming process and allow acess to chiral amines which are difficult to synthesize by other methods.

6

Cd2+-promoted mitochondrial permeability transition: a comparison with other heavy metals.

88%

Belyaeva E. A., Glazunov V. V., Korotkov S. M.

Acta Biochimica Polonica

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2004

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vol. 51

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issue 2

545-551

EN

We compared action of Cd2+, Hg2+, and Cu2+ on isolated rat liver mitochondria in the absence of added Ca2+ and Pi. The heavy-metal ions produced dose-dependently: (1) enhanced membrane permeabilizaton manifested in mitochondrial swelling and activation of basal respiration, (2) inhibition of uncoupler-stimulated respiration, and (3) membrane potential dissipation. Among the metals, Cu2+ exhibited maximal stimulatory effect on basal respiration and minimal inhibitory action on DNP-uncoupled respiration whilst Cd2+ promoted the strongest depression of uncoupled respiration and the largest swelling in NH4NO3 medium. Dithiothreitol induced a basal respiration release if added after high [Cd2+] and [Hg2+], and the stimulation was CsA-insensitive.

7

Influence of industry pollution on the efficacy of common lambsquarters (Chenopodium album L.) control by pyridate

75%

Dopierała U.

Journal of Plant Protection Research

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2006

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vol. 46

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issue 4

8

Comparison of the content of selected heavy metals in the liver tissue of the wild boar (Sus scrofa), red fox (Vulpes vulpes) and red deer (Cervus elaphus), living in north-eastern Poland

75%

Cebulska K., Sobiech P., Tobolski D., Wysocka D., Janiszewski P., Zalewski D., Gugołek A., Illek J., Cebulska K., Sobiech P., Tobolski D., Wysocka D., Janiszewski P., Zalewski D., Gugołek A., Illek J.

Polish Journal of Veterinary Sciences

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2021

9

THE EFFECT OF A COMPOSITE CHITOSAN/COPPER(II) ION COATING ON THE CORROSION RESISTANCE OF GRADE 4 TITANIUM IN SALINE: PRELIMINARY RESULTS

75%

Łosiewicz B., Osak P., Kubisztal J.

Progress on Chemistry and Application of Chitin and its Derivatives

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2023

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vol. 28

89-102

EN

In the present work, we successfully used electrophoretic deposition to produce a new composite chitosan-copper(II) [Cu(II]) ion coating on grade 4 titanium (Ti). We prepared the coating with an environmentally friendly in situ chemical reduction process from a 2% (v/v) aqueous acetic acid solution with 1 g dm–3 chitosan and 10 g dm–3 copper acetate at 20 V for 300 s at room temperature. We evaluated the relationship between physicochemical properties and corrosion resistance of the coatings with energy dispersive spectroscopy, Fourier-transform infrared spectroscopy, a scanning Kelvin probe, and electrochemical methods. The composite coating contained 2.1 ± 0.1 wt.% of Cu, which ensures antibacterial activity. We determined the mechanism and kinetics of the electrochemical corrosion of the composite chitosan–Cu(II) ion coating on grade 4 Ti in saline solution (0.9% sodium chloride) at 37°C. The surface modification makes grade 4 Ti a more attractive material for use in dentistry.

10

Epicatechin-copper 9II) complexes: Damage of small intestinal epithelium

75%

Stavrescu R., Kimura T., Hayakawa F., Ando T.

Open Chemistry

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2003

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vol. 1

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issue 1

35-52

EN

Four epicatechins [(−)-epicatechin (EC), (−)-epicatechin gallate (ECg), (−)-epigallocatechin (EGC), (−)-epigallocatechin gallate (EGCg)] and their corresponding copper complexes were compared with regard to their effect on the viability of Caco-2 colon cancer cells in vitro, measured by 3-(4,5-dimethylthyazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay. The viability of Caco-2 cells exposed to EC (1 mM), ECg (1 mM) or EGC (1mM) respectively, for 30 min, was comparable to that of the saline control group, while EGCg (1 mM) apparently enhanced cellular activity. in contrast, the cells treated with epicatechin-copper complexes were killed. Bivalent copper 91 mM), in similar conditions, did not affect the cells. No cell leakage or other histological differences were observed, implying a rapid cell death. The suggested mechanism of killing is by OH radical attack, produced in the presence of epicatechin-copper complexes, but not in the presence of either of the epicatechins or copper alone. The reaction sites are discussed.

11

Fabrication and Characteristics of Copper-Intermetallics Composites

75%

Kargul M., Konieczny M., Kargul M., Konieczny M.

Archives of Foundry Engineering

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2020

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vol. 20

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issue 3

12

Analysis of Slag Activity on Corrosion of Ceramic Materials in a Slurry Furnace

75%

Wędrychowicz M., Basiura B., Bydałek A. W.

Archives of Foundry Engineering

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2018

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issue 3

13

Synthesis of Copper-Based Multi-Walled Carbon Nanotube Composites

75%

Domagała K., Borlaf M., Kata D., Graule T., Domagała K., Borlaf M., Kata D., Graule T.

Archives of Metallurgy and Materials

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2020

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vol. 65

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issue 1

14

Impact of composts with the participation of municipal sewage sludge on the content of the total forms of copper, manganese and zinc in soil

75%

Krzywy-Gawrońska E.

Polish Journal of Chemical Technology

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2010

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vol. 12

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issue 4

15-18

EN

Pot experiment was conducted in the hall of vegetation at University of Agriculture in Szczecin over the years 2001 - 2003 on the soil of IVa complex of agriculture usefulness (very good rye) numbered among loamy sand as regards to the granulometric composition. The composts used in the experiment were after 8 months of decomposition. There was more nitrogen and phosphorus in the composts in comparison with potassium. In the pattern of the research the doses of composts, corresponding with 100, 200 and 300 kg N·ha-1, i.e. 0.63; 0.99 and 0.126 g N pot were used. The experiment was conducted in four repetitions. In 2001 spring rape Licomos variety was the test plant, in 2002 it was the spring triticale Wanad variety and in 2003 oats Polar variety. In the second and third year of the research of the soil there was 0.475 g N, 0.137 g P and 0.315 g K applied into every pot. It corresponded with the doses of 150 kg N·ha-1, 43.6 P·ha-1 and 100 kg K·ha-1. Mineral fertilizers were used in the form of urea, double superphosphate, 60% potassium salt.The obtained results of the research indicate that the content of the total forms of copper, manganese and zinc in the composts, with the participation of sewage sludge fulfilled the norms concerning the organic fertilizers.Over the years, since the time of an application into the soil the composts with the participation of municipal sewage sludge, the content of the total forms of copper, manganese and zinc has decreased. It was caused by the uptake of these micronutrients by plants.

15

Friction stir welds of Al alloy-Cu: an investigation on effect of plunge depth

71%

Wahid M. A., Siddiquee A. N., Khan Z. A., Asjad M., Wahid M. A., Siddiquee A. N., Khan Z. A., Asjad M.

Archive of Mechanical Engineering

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2016

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vol. 63

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issue 4

16

The content of toxic metals in different types of tea and their impact on consumers health

63%

Watrak S., Rajkowska-Myśliwiec M., Protasowicki M.

Kosmos

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2016

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vol. 65

|

issue 4

563-571

EN

Tea is one of the most popular beverages in the world, which, along with a number of beneficial health ingredients, such as trace elements, also contains undesired substances - as impurities. Among the impurities occur heavy metals, and their presence in tea leaves can pose serious problems to human health because they are not biodegradable, remain in the environment and can become part of the food chain. The total metal content of the tea leaves and infusions depends on the type of tea (green, black) and on the influence of other factors, including the properties of the soil. Despite the limited extent of metal migration from the dried tea to infusions, tea pollution with metals such as lead, cadmium or mercury is not indifferent to human health.

PL

Herbata jest jednym z najbardziej popularnych napojów na świecie, który obok wielu korzystnych dla zdrowia składników, jak mikroelementy, zawiera również te niepożądane - stanowiące zanieczyszczenie. Wśród nich znajdują się metale ciężkie, których obecność w liściach herbaty może stwarzać poważne problemy dla zdrowia ludzkiego, ponieważ nie ulegają one biodegradacji, a pozostając w środowisku mogą stać się częścią łańcucha pokarmowego. Całkowita zawartość metali w liściach herbat oraz w naparach zależy od rodzaju herbaty (zielona, czarna) oraz od wpływu wielu innych czynników, w tym właściwości gleby. Pomimo ograniczonej migracji metali z suszu do naparów zanieczyszczenie herbat metalami tj. ołów, kadm czy rtęć nie jest obojętne dla zdrowia człowieka. REFERENCES

17

Wpływ prenatalnego narażenia miedzią na ośrodkowy układ dopaminergiczny u dorosłych szczurów

63%

Szkilnik R., Kliber M., Nowak P., Jośko J., Bojanek K., Adwent M., Kórössy E., Brus H., Brus R.

Annales Academiae Medicae Silesiensis

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2009

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vol. 63

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issue 6

7-14

EN

BACKGROUND The eff ect of prenatal exposition of rats with copper on its level in the newborns’ organs and central dopaminergic system activity in adult rats was examined. MATERIAL AND METHODS Pregnant rats during entire time of pregnancy drank water with cupprum sulfuricum (CuSO4) where concentration of metal was 100 ppm. Control rats drank the water only without cuprum. After delivery water with metal was substituted with water only, and newborns stayed with their mothers till 21st day of life, then separated. In newborn copper content was estimated in the brain, liver and kidney. In adult rats the level of biogenic amines was measured in the brain and some behavioral studies were performed such as oral activity, stereotyped and yawning behavior, using central dopamine receptor agonists (SKF 38393, apomorphine, 7-OH-DPAT). RESULTS AND CONCLUSION Exposition of rats during intrauteral development (prenatal) with copper caused signifi cant increase concentration examined metal in the brain, liver and kidney of newborn rats. In adult rats signifi cant decrease of dopamine in the striatum was noticed in the rats pretreated with copper. Beside increase reactivity of the central dopamine D1 receptor reactivity was observed, and manifested by increased oral activity after SKF 38393 and stereotyped behavior after apomorphine apply. Additionally decreased reactivity of the central dopamine D3 receptor was manifested by decreased yawning behavior after 7-OH-DPAT injection. From above we concluded that copper can be one of the environmental agent which can aff ected of the central dopaminergic system in mammalians.

PL

WSTĘP Celem pracy było zbadanie wpływu ekspozycji miedzią szczurzyc w trakcie ciąży na zawartość metalu w tkankach noworodków a także na funkcję ośrodkowego układu dopaminergicznego u dorosłego potomstwa. MATERIAŁ I METODY Ciężarne samice przez cały okres ciąży piły wodę z dodatkiem siarczanu miedzi (CuSO4) w stężeniu metalu 100 ppm. Kontrolne szczurzyce piły wodę bez metalu. Z chwilą urodzenia roztwór miedzi zamieniano na wodę. Noworodki pozostawały z matkami do 21 dnia życia. U noworodków oznaczono zawartość miedzi w mózgu, wątrobie i nerkach. U dorosłych potomnych szczurów płci męskiej wykonano oznaczenia zawartości amin biogennych w mózgu oraz oceniono zachowanie jak aktywność ruchową pyska, stereotypię apomorfi nową i liczbę ziewnięć, spontaniczną jak też po podaniu agonistów ośrodkowych receptorów dopaminowych (SKF 38393, apomorfi na, 7-OH-DPAT). WYNIKI I WNIOSKI Prenatalna ekspozycja szczurów miedzią spowodowała znaczny wzrost zawartości metalu w mózgu, wątrobie i nerkach w porównaniu z kontrolą. U dorosłych szczurów narażonych w okresie rozwoju śródmacicznego na miedź wykazano obniżenie zawartości dopaminy w prążkowiu oraz wzrost reaktywności receptorów dopaminowych D1 manifestujący się nasileniem aktywności ruchowej pyska po podaniu SKF 38393 i nasileniem zachowania stereotypowego po podaniu apomorfi ny oraz obniżenie reaktywności receptorów dopaminowych D3 manifestujące się zmniejszeniem liczby ziewnięć po podaniu 7-OH-DPAT. Z powyższego wynika, że narażenia (ekspozycja) miedzią w okresie rozwoju śródmacicznego prowadzi do kumulacji metalu w tkankach noworodków a także trwałego zaburzenia funkcji ośrodkowego układu dopaminergicznego u ssaków.

18

The concentration of copper, zinc, manganese and selenium in the serum and liver of goats with caprine arthritis-encephalitis

63%

Milczarek M., Czopowicz M., Szara E., Szara T., Nalbert T., Kosieradzka I., Kaba J., Milczarek M., Czopowicz M., Szara E., Szara T., Nalbert T., Kosieradzka I., Kaba J.

Polish Journal of Veterinary Sciences

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2018

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vol. 21

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issue 4

19

Modified bentonite-derived materials as catalysts for selective catalytic reduction of nitrogen oxides

63%

Szymaszek A., Kubeł M., Samojeden B., Motak M., Szymaszek A., Kubeł M., Samojeden B., Motak M.

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vol. 41

|

issue 1

20

Mitochondrial respiratory chain inhibitors modulate the metal-induced inner mitochondrial membrane permeabilization

63%

Belyaeva E. A.

Acta Biochimica Polonica

|

2010

|

vol. 57

|

issue 4

435-441

EN

To elucidate the molecular mechanisms of the protective action of stigmatellin (an inhibitor of complex III of mitochondrial electron transport chain, mtETC) against the heavy metal-induced cytotoxicity, we tested its effectiveness against mitochondrial membrane permeabilization produced by heavy metal ions Cd2+, Hg2+, Cu2+ and Zn2+, as well as by Ca2+ (in the presence of Pi) or Se (in form of Na2SeO3) using isolated rat liver mitochondria. It was shown that stigmatellin modulated mitochondrial swelling produced by these metals/metalloids in the isotonic sucrose medium in the presence of ascorbate plus tetramethyl-p-phenylenediamine (complex IV substrates added for energization of the mitochondria). It was found that stigmatellin and other mtETC inhibitors enhanced the mitochondrial swelling induced by selenite. However, in the same medium, all the mtETC inhibitors tested as well as cyclosporin A and bongkrekic acid did not significantly affect Cu2+-induced swelling. In contrast, the high-amplitude swelling produced by Cd2+, Hg2+, Zn2+, or Ca2+ plus Pi was significantly depressed by these inhibitors. Significant differences in the action of these metals/metalloids on the redox status of pyridine nucleotides, transmembrane potential and mitochondrial respiration were also observed. In the light of these results as well as the data from the recent literature, our hypothesis on a possible involvement of the respiratory supercomplex, formed by complex I (P-site) and complex III (S-site) in the mitochondrial permeabilization mediated by the mitochondrial transition pore, is updated.

Refine search results

A novel α-glucosidase from the moss Scopelophila cataractae

Characterization of Cu/SiC surface composite produced by friction stir processing

Thermodynamic Properties of Cu-S Solutions

Influence of cadmium and copper on tissue element levels of pregnant rats

New feats of alkene and alkyne asymmetric hydroamination catalyzed by copper and rhodium hydrides

Cd2+-promoted mitochondrial permeability transition: a comparison with other heavy metals.

Influence of industry pollution on the efficacy of common lambsquarters (Chenopodium album L.) control by pyridate

Comparison of the content of selected heavy metals in the liver tissue of the wild boar (Sus scrofa), red fox (Vulpes vulpes) and red deer (Cervus elaphus), living in north-eastern Poland

THE EFFECT OF A COMPOSITE CHITOSAN/COPPER(II) ION COATING ON THE CORROSION RESISTANCE OF GRADE 4 TITANIUM IN SALINE: PRELIMINARY RESULTS

Epicatechin-copper 9II) complexes: Damage of small intestinal epithelium

Fabrication and Characteristics of Copper-Intermetallics Composites

Analysis of Slag Activity on Corrosion of Ceramic Materials in a Slurry Furnace

Synthesis of Copper-Based Multi-Walled Carbon Nanotube Composites

Impact of composts with the participation of municipal sewage sludge on the content of the total forms of copper, manganese and zinc in soil

Friction stir welds of Al alloy-Cu: an investigation on effect of plunge depth

The content of toxic metals in different types of tea and their impact on consumers health

Wpływ prenatalnego narażenia miedzią na ośrodkowy układ dopaminergiczny u dorosłych szczurów

The concentration of copper, zinc, manganese and selenium in the serum and liver of goats with caprine arthritis-encephalitis

Modified bentonite-derived materials as catalysts for selective catalytic reduction of nitrogen oxides

Mitochondrial respiratory chain inhibitors modulate the metal-induced inner mitochondrial membrane permeabilization