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1

Attachment of 2,2-bipyridine onto a silica gel for application as a sequestering agent for copper, cadmium and lead ions from an aqueous medium

100%

Souza E., Cristante V., Padilha P., Jorge S., Martines M., Silva R., Carmo D., Castro G.

Polish Journal of Chemical Technology

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2011

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vol. 13

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issue 4

28-33

EN

A method was developed to attach 2,2-bipyridine (BP) onto a silica gel surface by a two-step reaction. The first step consisted of a reaction between the matrix and a silylating agent, 3-chloropropyltrimethoxysilane. In the second step of the reaction, a ligand molecule was attached onto Si-CPTS, yielding the product Si-BP. The modified material contained 0.431±0.01 mmol of 2,2-bipyridine per gram of modified silica, as confirmed by FT-IR spectra of the proposed structure. The surface modification was characterized by the BET technique, which revealed a decrease in the surface area from 614 to 450 m2 g-1. The series of adsorption isotherms for the metal ions were adjusted to fit a modified Langmuir equation. The maximum number of moles of copper, cadmium and lead ions adsorbed was 0.64, 0.53, and 0.54 mmol g-1, respectively. The surface saturation was calculated as φ fraction and the values obtained, Cu(II) = 1.160, Cd(II) = 1.044 and Pb(II) = 0.997, suggest a type 1:1 metal-ligand complex.

2

Studies on the production of glucose isomerase byBacillus licheniformis

100%

Nwokoro O.

Polish Journal of Chemical Technology

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2015

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vol. 17

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issue 3

84-88

EN

This work reports the effects of some culture conditions on the production of glucose isomerase by Bacillus licheniformis. The bacterium was selected based on the release of 3.62 mg/mL fructose from the fermentation of glucose. Enzyme was produced using a variety of carbon substrates but the highest enzyme activity was detected in a medium containing 0.5% xylose and 1% glycerol (specific activity = 6.88 U/mg protein). Media containing only xylose or glucose gave lower enzyme productivies (specific activities= 4.60 and 2.35 U/mg protein respectively). The effects of nitrogen substrates on glucose isomerase production showed that yeast extract supported maximum enzyme activity (specific activity = 5.24 U/mg protein). Lowest enzyme activity was observed with sodium trioxonitrate (specific activity = 2.44 U/mg protein). In general, organic nitrogen substrates supported higher enzyme productivity than inorganic nitrogen substrates. Best enzyme activity was observed in the presence of Mg2+ (specific activity = 6.85 U/mg protein) while Hg2+ was inhibitory (specific activity = 1.02 U/mg protein). The optimum pH for best enzyme activity was 6.0 while optimum temperature for enzyme production was 50ºC.

3

Advanced oxidation processes for decolorization of aqueous solution containing acid red G azo dye

88%

Surpăţeanu M., Zaharia C.

Open Chemistry

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2004

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vol. 2

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issue 4

573-588

EN

Some investigations concerning the decolorization of Acid Red G azo dye by photooxidation with hydrogen peroxide were performed. The influences of pH, oxidant concentration, and the presence of Fe2+ or other metal ions (Co2+, Cu2+, Ni2+, Mn2+) as potential catalysts, were investigated. The best results were obtained in the presence of ferrous ions in acid and neutral media. The other ions are not as effective as Fe2+ for dye decolorization. Co2+ and Cu2+ ions have a catalytic action, at low concentration, within a wide range of pH. Ni2+ and Mn2+ ions have no catalytic effect in photooxidation with hydrogen peroxide at acid Ni2+ and Mn2+ ions have no catalytic effect in photooxidation with hydrogen peroxide at acid pH values, but show a weak action in alkaline media.

4

Cloning, purification and enzymatic characterization of recombinant human superoxide dismutase 1 (hSOD1) expressed in Escherichia coli

88%

Lin F., Yan D., Chen Y., E F., Shi H., Han B., Zhou Y.

Acta Biochimica Polonica

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2018

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vol. 65

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issue 2

235-240

EN

Superoxide dismutase 1 (SOD1) is a metalloenzyme that catalyzes the disproportionation of superoxide into molecular oxygen and hydrogen peroxide. In this study, the human SOD1 (hSOD1) gene was cloned, expressed and purified. The hSOD1 gene was amplified from a pool of Bxpc3 cell cDNAs by PCR and cloned into expression vector pET-28a (+). The recombinant soluble hSOD1 was expressed in E. coli BL21 (DE3) at 37°C and purified using nickel column affinity chromatography. Soluble hSOD1 was produced with a yield of 5.9 μg/mL medium. As metal ions can have a certain influence on protein structure and activity, we researched the influences of different concentrations of Cu2+ and Zn2+ on hSOD1 activity at induction and the time of activity detection. The results implied that Cu2+ and Zn2+ do not enhance SOD1 expression and solubility; they can, however, improve the catalytic activity at induction. Meanwhile, Cu2+ and Zn2+ also enhanced the enzyme activity at the time of detection. Furthermore, most other bivalent cations had the potential to replace Zn2+ and Cu2+, and also improved enzyme activity at the time of detection.

5

Application of atomic absorption spectrometry with continuous light source to analyze selected metals important for human health in different parts of oranges

88%

Szwerc W., Sowa I.

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vol. 27

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issue 3

145-147

EN

The publication describes the application of high-resolution continuum source atomic absorption spectrometry (H-R CS AAS) to determine some physiologically essential and toxic elements occurring in citrus fruits of different origins. Before analysis, the samples were mineralized using a mixture of deionized water and 69% nitric acid 3:1 (v/v) in high pressure microwave digestion at 188°C during one hour. The obtained validation parameters for AAS such as high linearity (the correlation coefficient R > 0.997) and high precision expressed as relative standard deviation (%RSD) were satisfactory for quantification. Cadmium at concentration range from 0.29 to 0.43 mg/kg was determined in all tested samples, however the obtained values did not exceed Polish standards. The higher concentration of potassium comparing to sodium and calcium was noted in each investigated samples. The highest variation was observed for calcium, its concentration strongly depended on the country of origin.

6

Signalling: basics and evolution.

75%

Williams R. J. P.

Acta Biochimica Polonica

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2004

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vol. 51

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issue 2

281-298

EN

Signalling concerns the transfer of information from one body, a source, to another, a receiver in order to stimulate activity. The problem arises with the word information. It is defined as what is transferred in a sequence of things, say between people, e.g. words or signs. The idea of signalling between people is then obvious but it is not clear in cell biology. Information transfer, signalling, is required for the organisation of all cellular activity but we must ask what is transferred and how is it transmitted and received? Sometimes it is assumed that all information, i.e. organisation in a cell, is represented in the DNA sequence. This is incorrect. We shall show that the environment is a second source of information concerning material and energy. The receiving party from both DNA and the environment is general metabolism. The metabolism then signals back and sends information to both DNA and uptake from the environment. Even then energy is needed with machinery to send out all signals. This paper examines the way signalling evolved from prokaryotes through to man. In this process the environmental information received increased to the extent that finally the brain is a phenotypic as much as a genotypic organ within a whole organism. By phenotypic we mean it is organised by and interactive with information from the environment.

7

Surface replacement arthroplasty in the surgical treatment of hip osteoarthritis

63%

Ochocki K., Pasek J., Kasperczyk S., Koczy B., Stołtny T.

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2023

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vol. 88

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issue 2

83-88

PL

Endoprotezoplastyka powierzchniowa, zwana kapoplastyką jest metodą oszczędnej endoprotezoplastyki stawu biodrowego, która stanowi alternatywę chirurgiczną zarezerwowaną zwykle dla młodszych, aktywnych pacjentów. Wprowadzanie kolejnych generacji implantów o artykulacji metal-metal spowodowało wzrost zainteresowania tą metodą leczenia. Pomimo niekwestionowanych zalet i obiecujących wyników początkowych, kapoplastyka obarczona jest jednak pewnymi ograniczeniami i wadami. Jedną z nich jest wzrost stężenia jonów metali, które choć niezbędne do prawidłowego funkcjonowania organizmu ludzkiego, w dużych ilościach mogą prowadzić do poważnych reakcji tkanek miękkich przylegających do protezy, w tym do metalozy, ALVAL (Aseptic Lyphocytic Vasculitis-Associated Lesion) czy tworzenia guzów rzekomych. Pomimo licznych badań i doniesień naukowych istnieje potrzeba dalszych prac nad związkiem między poziomami stężeń jonów metali u osób po kapoplastyce, a biologicznymi, przyczynowymi mechanizmami rozwoju niekorzystnych reakcji w organizmie.

EN

Surface arthroplasty, also referred to as resurfacing, is a method of sparing hip arthroplasty, which is a surgical alternative usually reserved for younger, active patients. The introduction of successive generations of implants with metal-on-metal articulation resulted in increased interest in this method of treatment. Despite the unquestionable advantages and promising initial results, resurfacing has some limitations and disadvantages. One of them is the increase in the concentration of metal ions. Although they are necessary for the proper functioning of the human body, in large amounts they can lead to serious reactions of the soft tissues adjacent to the prosthesis, including metallosis, ALVAL (Aseptic Lyphocytic Vasculitis-Associated Lesion), or the formation of pseudotumours. Despite numerous studies and scientific reports, there is a need for further work on the relationship between the concentration levels of metal ions in people after resurfacing and the biological, causal mechanisms of the development of adverse reactions in the body.

Refine search results

Attachment of 2,2-bipyridine onto a silica gel for application as a sequestering agent for copper, cadmium and lead ions from an aqueous medium

Studies on the production of glucose isomerase byBacillus licheniformis

Advanced oxidation processes for decolorization of aqueous solution containing acid red G azo dye

Cloning, purification and enzymatic characterization of recombinant human superoxide dismutase 1 (hSOD1) expressed in Escherichia coli

Application of atomic absorption spectrometry with continuous light source to analyze selected metals important for human health in different parts of oranges

Signalling: basics and evolution.

Surface replacement arthroplasty in the surgical treatment of hip osteoarthritis