Imobilizacija Na,K-ATPpaze izolovane iz sinaptičkih plazma-membrana mozga pacova

Rat brain Na,K-ATPase partially purified by SDS from synaptic plasma membranes (SPM) was immobilized by adsorption on nitrocellulose (NC), polyvinylidene fluoride (PVDF) and glass fiber (GF) membranes, Partial SDS solubilization increased the enzyme activity by 40%. With regard to the presentation of the enzyme activity. nitrocellulose Was shown to be the optimal support for die immobilization, The enzyme showed the highest percentage activity (14%) after 30 min of SPM adsorption. at 20 degreesC under the vaccum. with 25 mug of proteins per NC disc filter. In addition, adsorption on NC stabilizes the Na,K-ATPase, since the activity was substantial 72 h after adsorption at 20 degreesC, After adsorption. the sensitivity of the enzyme to HgCl2 and CdCl2 inhibition was higher, The results show that immobilized Na,K-NTPase SPM can be used as a practical model for the detection of metal ions in different samples.Delimično prečišćena Na,K-ATPaza sinaptičkih plazma–membrana (SPM) mozga pacova imobilizovana je adsorpcijom na nitrocelulozne (NC) poliviniliden-fluorid (PVDF) membrane i membrane od staklenih vlakana (SV). Aktivnost enzima delimično prečišćenog solubilizacijom SDS-om povećana je oko 40%. Najveći procenat aktivnosti (14%) enzim zadržava posle 30 minuta adsorpcije SPM na 20ºC, pod vakuumom, sa 25 μg proteina po nitroceluloznom disku. Na,K-ATPaza imobilizovana na nitroceluloznoj membrani stabilna je 72 sata na 20ºC. Adsorpcijom, osetljivost enzima na inhibiciju Hg2+ i Cd2+ se povećava. Rezultati pokazuju da se imobilizovana Na,K-ATPaza SPM može koristiti za detekciju toksičnih metalnih jona u različitim uzorcima

Debye relaxation in high magnetic fields

Dielectric relaxation is universal in characterizing polar liquids and solids, insulators, and semiconductors, and the theoretical models are well developed. However, in high magnetic fields, previously unknown aspects of dielectric relaxation can be revealed and exploited. Here, we report low temperature dielectric relaxation measurements in lightly doped silicon in high dc magnetic fields B both parallel and perpendicular to the applied ac electric field E. For B//E, we observe a temperature and magnetic field dependent dielectric dispersion e(w)characteristic of conventional Debye relaxation where the free carrier concentration is dependent on thermal dopant ionization, magnetic freeze-out, and/or magnetic localization effects. However, for BperpE, anomalous dispersion emerges in e(w) with increasing magnetic field. It is shown that the Debye formalism can be simply extended by adding the Lorentz force to describe the general response of a dielectric in crossed magnetic and electric fields. Moreover, we predict and observe a new transverse dielectric response EH perp B perp E not previously described in magneto-dielectric measurements. The new formalism allows the determination of the mobility and the ability to discriminate between magnetic localization/freeze out and Lorentz force effects in the magneto-dielectric response.Comment: 19 pages, 6 figure

Transfer of Aflatoxin M1 From the Contaminated Milk Into Cheese and Whey

Aflatoxin M1 is a major metabolite of aflatoxin B1 which is formed when animals ingest contaminated feed. Aflatoxin B1, when ingested by an animal, is rapidly absorbed in the gastrointestinal tract and transformed into a metabolite aflatoxin M1, appearing in the blood after 15 minutes and then secreted in the milk from the mammary gland. Aflatoxin B1 shows hepatotoxic and carcinogenic effects and aflatoxin M1 has a distinct genotoxicity, carcinogenicity and cytotoxicity. The resistance to heat treatment and mild acidic conditions used in the production of cheese or other dairy products (such as, for example, yogurt, cream, butter, and ice cream) has been accounted for the contamination of such products. It is known that aflatoxin M1 is bound to milk proteins, mainly casein, and therefore the toxin is more concentrated in the cheese than in the milk used in cheese production. In practice, aflatoxin M1 can be found in dairy products at levels that are 2-5 times higher than in milk. As a result of the binding of aflatoxin M1 to milk proteins the toxin is distributed more in curd than in whey. Control of samples of milk from the Vojvodina market was conducted during March and April of 2014, in the Dairy Laboratory and Laboratory for the Analysis of Animal Feed and Animal Products, the Department of Animal Science, Faculty of Agriculture, Novi Sad. The method used was HPLC with fluorescence detection with pre-treatment of milk on immunoaffinity columns. The analysis of milk was performed on milk of 12 dairies whose products can be found on the Vojvodina market. The manufacturer with the highest levels of aflatoxin M1 in milk was chosen and a semi-hard cheese was made of such milk. The results showed the expected increase of concentration of aflatoxin M1 in cheese and whey. Since Serbia has no regulation that determines the minimum allowable level of aflatoxin M1 in cheese and other dairy products, the results were compared with acceptable values for cheese in some European countries

The Use of the Yeast Kluyveromyces Fragilis B0399 in the Production of Probiotic Yogurt

Rising interest for probiotics in the recent years was caused by the possibility of their use in prevention and cure of different types of human and animal intestinal disorders. During 20th century many research studies were concentrated on finding new types of probiotic cultures. In this work, for the production of probiotic yogurt, we used commercially available, new generation probiotic lactic yeast “Turval B0399”, produced by Italian company Turval Laboratories. Turval B0399 is the culture of yeast species Kluyveromyces marxianus fragilis B0399. This yeast is characterized by the unique ability of fermenting with the enzyme β-galactosidase and by production of lactic acid, a fundamental substance in cell metabolic reactions. This probiotic yeast, naturally resistant to antibiotics, mitigate negative effects of antibiotics - by competitive colonisation of intestine it regulates intestinal dismicrobism by preventing the growth of pathogens, such as Candida albicans, while increasing the number of residential bifidobacterias. It keeps intestinal homeostasis, improves immunity (in in vitro studies it was shown to decrease the production of proinflammatory cytokines, while in studies on patients with atopic dermatitis it decreased the IgE level). It improves the general metabolism and is very successful in prevention and treatment of different intestinal disorders (Crohn's disease and Irritable Bowel syndrome). In this work we studied the growth of the yeast Kluyveromyces fragilis B0399 and its influence on the growth of the probiotic bacteria Lactobacillus acidofilus LA5 and Bifidobacterium lactis BB12 with the final aim of achieving the maximal number of live cells during the production of probiotic yogurt (>106 cfu/g). The experimental production of the probiotic yogurt with Turval B0399 was done in the Dairy Laboratory of the Department of Animal Science, Faculty of Agriculture, University of Novi Sad, while all microbiological analyses were done in JPS Dairy Institute, Novi Beograd. During the production of probiotic yogurt we followed the activity of the yeast Kluyveromyces fragilis B0399 in different concentrations – 0.5%; 1%; and 3% and under different fermentation temperatures - 39◦C; 23,5◦C and 4◦C (in the cooled probiotic yogurt). Among all studied conditions we managed to obtain the sufficient number of live yeast cells in the final product when adding 1% of Turval product during the fermentation phase on 23,5◦C, when the number of live cells is 3.5x107cfu/g probiotic bacteria and 3.6x105 cfu/g Kluyveromyces fragilis B0399. Clinical studies have shown that in order to exhibit its probiotic functions the daily uptake of the yeast Kluyveromyces fragilis has to be ≥10 millions of live cells (certified by the Italian Ministry of Health). Sensor properties of this probiotic yogurt, odour, taste and colour, are preserved up to expiry date of 30 days. Final product is safe for use and has beneficial properties for good intestinal performance and general health of its consumers

Effect of Consecutive Cut and Vegetation Stage on Cncps Protein Fractions in Alfalfa (Medicago Sativa L.)

Crude protein (CP) of forages can be separated into fractions of differentiated abilities to provide available amino acids in the lower gut of ruminants. This knowledge is critical to develop feeding systems and to predict animal responses. The objective of this research was to asses whether CP concentrations and the relative proportion of CP fractions by CNCPS in alfalfa (Medicago sativa L.) cv K-28 were affected by different cuts and vegetation stages. Fraction B2, which represents true protein of intermediate ruminal degradation rate, was the largest single fraction in all cuts except in the third cut. Soluble fraction A was less than 400 g kg-1 CP in all cuts except in the third cut, while the unavailable fraction C ranged from 56 g kg-1 CP in the first cut to 134.8 g kg-1 CP in the fourth cut. The remaining fraction B3 (true protein of very low degradation rate) only represented less than 60 g kg-1 of total CP. Results showed that undegraded dietary protein represented a small proportion of total CP in alfalfa from the first to the fourth cut

Kaemika app, Integrating protocols and chemical simulation

Kaemika is an app available on the four major app stores. It provides deterministic and stochastic simulation, supporting natural chemical notation enhanced with recursive and conditional generation of chemical reaction networks. It has a liquid-handling protocol sublanguage compiled to a virtual digital microfluidic device. Chemical and microfluidic simulations can be interleaved for full experimental-cycle modeling. A novel and unambiguous representation of directed multigraphs is used to lay out chemical reaction networks in graphical form

Seismic response assessment and protection of statues and busts

Recent post-earthquake surveys carried out in Europe have shown that earthquake actions pose an immense threat to museums and their contents. For example, during the earthquake on 21 July 2017 in the island of Kos (Greece), severe and widespread damage on the city’s archaeological museum was reported (Figure 1). The earthquake extensively damaged the sculpture exhibition, where many pieces were dislocated, leaned against the walls, or overturned. Fortunately, the earthquake occurred when human visitors were not in the museum, since the damage to the exhibits varied from very light (minor fracturing) to severe (complete overturning and fracture of artefacts). In the case of heavy and slender sculptures, the overturning mechanism, apart from damaging the sculptures themselves, is a serious threat to other standing exhibits in the gallery and the visitors. It is, therefore, of paramount importance to have at our disposal methods and tools for characterising the seismic risk of museum artefacts and, where necessary, proposing cost-efficient protective measures. The study of the seismic vulnerability of museum artefacts, especially of slender, human-formed statues, is related to the research on the dynamic response of rocking rigid blocks. The dynamic characteristics of the hosting structures are also important. This is evident from the fact that, on many occasions, damage to the structure was reported leaving the exhibits intact and vice-versa. Although the problem is coupled, it can be studied looking separately at the structure and its contents, provided that the contents are not attached to the building. The seismic response of building contents is a topic of growing interest, since it is directly related to seismic loss assessment and earthquake community resilience. Building contents can be either attached to the structure, or may consist of objects that are simply standing. Museum exhibits belong to the latter category, while free-standing components are often studied as rocking objects and hence their response is sensitive to acceleration and velocity-based quantities and also to their geometry. Today, there is lack of standards, while the existing approaches are general in concept and do not sufficiently address the variety of rocking objects. The problem becomes more complicated when it comes to priceless objects such as museum artefacts where more refined and targeted studies are required for understanding their seismic response and also for proposing rapid tools for assessing their seismic risk. The paper presents an extensive experimental campaign on the seismic response of artefacts, with emphasis on statues and busts. The tests took place in the framework of SEREME project (Seismic Resilience of Museum Contents) at the AZALEE seismic simulator of CEA in Saclay, Paris under the auspices of the SERA project. The aim is to understand the seismic response of statues and busts and then develop novel and cost-effective risk mitigation schemes for improving the seismic resilience of museum valuable contents. The study is focused on the investigation of the seismic response of two real-scale marble roman statues and three busts of three roman emperors standing on pedestals of different types and size. Both isolated and non-isolated artefacts are considered, while two new and highly efficient base isolation systems, tailored to art objects, will be tested. The first isolator is a pendulum-based system, while the second utilizes Shape Memory Alloy wires. Furthermore, the paper examines the importance of the hosting building, i.e. building type and story. Specifically tailored, numerical models of varying complexity, for single and two-block rocking systems, were developed for the needs of this study and are also assessed against the experimental results

GLACE: the global land–atmosphere coupling experiment. Part I: overview

Permission to place copies of these works on this server has been provided by the American Meteorological Society (AMS). The AMS does not guarantee that the copies provided here are accurate copies of the published work. © Copyright 2006 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/AMS) or from the AMS at 617-227-2425 or [email protected] Global Land–Atmosphere Coupling Experiment (GLACE) is a model intercomparison study focusing on a typically neglected yet critical element of numerical weather and climate modeling: land–atmosphere coupling strength, or the degree to which anomalies in land surface state (e.g., soil moisture) can affect rainfall generation and other atmospheric processes. The 12 AGCM groups participating in GLACE performed a series of simple numerical experiments that allow the objective quantification of this element for boreal summer. The derived coupling strengths vary widely. Some similarity, however, is found in the spatial patterns generated by the models, with enough similarity to pinpoint multimodel “hot spots” of land–atmosphere coupling. For boreal summer, such hot spots for precipitation and temperature are found over large regions of Africa, central North America, and India; a hot spot for temperature is also found over eastern China. The design of the GLACE simulations are described in full detail so that any interested modeling group can repeat them easily and thereby place their model’s coupling strength within the broad range of those documented here

Stabilization of mid-sized silicon nanoparticles by functionalization with acrylic acid

We present an enhanced method to form stable dispersions of medium-sized silicon nanoparticles for solar cell applications by thermally induced grafting of acrylic acid to the nanoparticle surface. In order to confirm their covalent attachment on the silicon nanoparticles and to assess the quality of the functionalization, X-ray photoelectron spectroscopy and diffuse reflectance infrared Fourier spectroscopy measurements were carried out. The stability of the dispersion was elucidated by dynamic light scattering and Zeta-potential measurements, showing no sign of degradation for months