Masses of constituent quarks confined in open bottom hadrons

We apply color-spin and flavor-spin quark-quark interactions to the meson and baryon constituent quarks, and calculate constituent quark masses, as well as the coupling constants of these interactions. The main goal of this paper was to determine constituent quark masses from light and open bottom hadron masses, using the fitting method we have developed and clustering of hadron groups. We use color-spin Fermi-Breit (FB) and flavor-spin Glozman-Riska (GR) hyperfine interaction (HFI) to determine constituent quark masses (especially $b$ quark mass). Another aim was to discern between the FB and GR HFI because our previous findings had indicated that both interactions were satisfactory. Our improved fitting procedure of constituent quark masses showed that on average color-spin (Fermi-Breit) hyperfine interaction yields better fits. The method also shows the way how the constituent quark masses and the strength of the interaction constants appear in different hadron environments.Comment: 15 pages, 6 tables, 1 figure. Accepted for publication in Mod. Phys. Lett.

Investigation of different extraction procedures for the determination of major and trace elements in coal by ICP-AES and ion chromatography

This paper presents the extraction of major and trace elements from a coal sample, in deionized water, by using three different extraction techniques. Rotary mixing and ultrasonic extraction were examined for different extraction times, while the microwave-assisted extraction was performed at different temperatures. Metal concentrations (Na, K, Ca, Mg, Al, Fe, Mn, Be, Cd, Co, Cr, Hg, As, Ni, Se, Sb and Pb) in solution were determined employing inductively coupled plasma atomic emission spectrometry; whereas the results obtained for Na, K, Ca and Mg were compared employing ion chromatography. Comparing the rotary-and ultrasonic-assisted extractions, it was shown that the former technique was more efficient for the determination of Fe, Na and Pb, whereas the latter one proved more efficient for the determination of Co and Cr ions. Microwave-assisted extraction was shown to be the most efficient method for all the tested elements in coal. In addition, sequential extraction of the elements was realized using microwave digestion. The results of the sequential extraction experiments indicated associations of investigated elements with a mineral phase and organic matrix. Sequential extraction provided information on possible leaching of As, Cd, Co, Cr, Ni, Pb, Fe and Mn under environmental conditions

Electrical conductivity of plasmas of DB white dwarf atmospheres

The static electrical conductivity of non-ideal, dense, partially ionized helium plasma was calculated over a wide range of plasma parameters: temperatures $1\cdot 10^{4}\textrm{K} \lesssim T \lesssim 1\cdot 10^{5}\textrm{K}$ and mass density $1 \times 10^{-6} \textrm{g}/\textrm{cm}^{3} \lesssim \rho \lesssim 2 \textrm{g}/\textrm{cm}^{3}$. Calculations of electrical conductivity of plasma for the considered range of plasma parameters are of interest for DB white dwarf atmospheres with effective temperatures $1\cdot 10^{4}\textrm{K} \lesssim T_{eff} \lesssim 3\cdot 10^{4}\textrm{K}$. Electrical conductivity of plasma was calculated by using the modified random phase approximation and semiclassical method, adapted for the case of dense, partially ionized plasma. The results were compared with the unique existing experimental data, including the results related to the region of dense plasmas. In spite of low accuracy of the experimental data, the existing agreement with them indicates that results obtained in this paper are correct

Interaction of different third intracellular loop fragments of human dopamine d2l receptor with a-subunit of gi1 protein - prospective therapeutic application

In order to find the essential structural motif of the D2L dopamine receptor necessary for the interaction with a-subunit of Gi1 protein, four fragments of the third cytoplasmic loop (CPL3) of this receptor were cloned, expressed in E. coli and purified. After that, fusion proteins with glutathione-S-transferase (GST) were prepared and the interactions quantified by a colorimetric assay for GST activity determination. The presence of D2L-CPL3 fragment-Gia1 complexes was detected by SDS-polyacrylamide gel electrophoresis (PAGE). Kd values for the interaction of the three fragments with Gia1 were similar and in nmol/L range of concentrations, while the peptide representing the insert in the long form of the dopamine D2 receptor expressed about 10-fold lower binding affinity. These results could serve to design new therapeutic agents that might act at the level of receptor/G protein interaction rather than at the level of ligand-receptor binding.U cilju pronalaženja bitnih strukturnih motiva potrebnih za interakciju sa a podjedinicom Gi1 proteina klonirana su, eksprimirana i prečišćena 4 fragmenta treće citoplazmatične petlje (CPL3) dopaminskog D2L receptora koji su dalje pripremljeni kao fuzioni proteini sa glutation-S-transferazom (GST). Interakcije su kvantifikovane bojenom reakcijom za određivanje aktivnosti GST. Postojanje kompleksa D2L-CPL3 fragment- Gia1 je dokazano elektroforetskom analizom na SDS-poliakrilamidnom gelu (PAGE). Kd vrednosti za tri fragmenta su bile vrlo slične i u nmol/L opsegu koncentracija, dok je peptid koji predstavlja insert u dugom obliku dopaminskog D2 receptora posedovao oko 10 puta manji afinitet vezivanja za Gia1. Ovi rezultati mogu biti osnova za sintezu novih terapeutskih agenasa koji bi delovali na nivou interakcije receptora i G proteina umesto na nivou vezivanja liganda za receptor

Cell-selective toxicity of hydroxyapatite-chitosan oligosaccharide lactate particles loaded with a steroid cancer inhibitor

The applicative potential of synthetic calcium phosphates, especially hydroxyapatite (HAp), has become intensely broadened in the past 10 years, from bone tissue engineering to multiple other fields of biomedicine. Hybrid systems based on nano hydroxyapatites (HAp) are the subject of numerous studies in preventive and regenerative medicine. HAp nanoparticles coated with bioresorbable polymers have been successfully used as fillers, carriers of antibiotics, vitamins and stem cells in bone tissue engineering, etc. In this study we utilize an emulsification process and freeze drying to load the hybrid system made of nano HAp particles coated with chitosan oligosaccharide lactate (ChOSL) with two different but similar steroid derivatives: 3β-hydroxy- 16-hydroxymino-androst-5-ene-17-one (A), C19H27NO3 and 3β, 17β-dihydroxy-16-hydroxyminoandrost- 5-ene (B), C19H29NO3. The cell-selective toxicity of HAp particles coated with of A- or B-loaded ChOSL was examined simultaneously on the following cell lines: human breast carcinoma (MCF-7, MDA-MB-231), human lung carcinoma (A549) and human lung fibroblasts (MRC-5), using dye exclusion (DET) and MTT assays. 1H NMR, 13C NMR and high-resolution time-of-flight mass spectrometry (MS) techniques confirmed the intact structure of the derivatives A or B. FT-IR, XRD, DTA, TGA and DSC techniques confirmed the drug loading process of steroide (A or B) in core–shell particles based on nano hydroxyapatite. Atomic force microscopy and particle size analyses were used to confirm that the particles were spherical with sizes between 80 and 240 nm. The measured values of electrokinetic parameters (zeta potential, electrophoretic mobility and conductivity) were significantly different for the steroid free carrier (HAp/ChOLS) and A- or B-loaded ChOSL. The value of the topological molecular polar surface area (TPSA, the sum of the surfaces of polar atoms and groups in the molecule), were also different for drug free carrier and A- or BHAp/ ChOLS. Highly selective anticancer activity was noted towards breast cancer cells (MDAMB- 231) by B-loaded HAp/ChOLS. DET testing after 48 hours (after incubation and recovery) of the treatment with A-HAp/ChOSL and B-HAp/ChOSL particles showed a high viability of healthy cells (over 80%). The lowest viability was found in MDA-MB-231 cancer cells treated with B-HAp/ChOSL (28%). The obtained results of the DET and MTT tests showed that the particles of A-HAp/ChOLS exhibited nearly four-fold greater cytotoxicity towards breast cancer cells (MDA-MB-231) than towards healthy cells (MRC-5). B-HAp/ChOSL particles exhibited nearly six times greater cytotoxicity to all breast cancer cells than to healthy ones

Influence of process parameters of simultaneous anodization/anaphoretic electrodeposition synthesis of hydroxyapatite/titanium oxide composite coatings on adhesion

In-situ synthesis of hydroxyapatite/titanium oxide (HAp/TiO2) coating on titanium was performed via anaphoretic deposition of hydroxyapatite (HAp) and simultaneous anodization of Ti to produce highly adherent and strengthened composite coating. The influence of electric potential, time, electrolyte concentration and pH value of the anodization process on titanium surface roughness and anodization of titanium was examined, as well as influence of same process parameters on adhesion strength and compactness of composite HAp/TiO2 coatings was investigated. Prior to novel in situ method of synthesis of hydroxyapatite/titanium oxide composite coatings by simultaneous anodization/anaphoretic electrodeposition described in this manuscript, optimization of anodization process of titanium was performed. Anodization was executed under different electric potentials and different distances of counter electrodes from working electrodes, but all anodization processes had constant quantity of electric charge. Characterization of titanium samples, prepared from grade 6 Ti, and having rectangular contact surfaces of 10×10×0.89 mm included SEM/EDS analyses, X-ray diffraction analyses, AFM surface topography, morphology and roughness analyses and linear measurements of roughness. A chemical precipitation method was used to prepare hydroxyapatite powder by the reaction of calcium oxide (obtained by calcination of CaCO3 for 5 h at 1000 °C in air) and phosphoric acid. A stoichiometric amount of the calcium oxide was stirred in distilled water and phosphoric acid was added drop wise to the suspension in order to obtain hydroxyapatite powder, Ca10(PO4)6(OH)2. Two types of HAp coatings were prepared, in order to compare the adhesion, morphology and consistency of the HAp and composite HAp/TiO2 on Ti, namely cathaphoretic and anaphoretic coatings, respectively [1,2]. The prepared coatings were characterized by field emission scanning electron microscopy, X-ray diffraction and electron dispersive spectroscopy. Adhesion was investigated by ASTM D 3359 – 97 Test method B. Uniform and adherent HAp/TiO2 composite coating on Ti was obtained. Since smaller size of HAp crystals within highly porous coating structures is of improved binding ability to various biomolecules, our coating is expected to be of excellent coverage and compactness. The obtained coating can be good candidate for bone implants due to improved adhesion

Supplementary information for the article: Pantović Pavlović, Marijana R., Boris P. Stanojević, Miroslav M. Pavlović, Marija D. Mihailović, Jasmina S. Stevanović, Vladimir V. Panić, and Nenad L. Ignjatović. 2021. “Anodizing/Anaphoretic Electrodeposition of Nano-Calcium Phosphate/Chitosan Lactate Multifunctional Coatings on Titanium with Advanced Corrosion Resistance, Bioactivity, and Antibacterial Properties.” ACS Biomaterials Science & Engineering 7 (7): 3088–3102. https://doi.org/10.1021/acsbiomaterials.1c00035

The aim of this work was to investigate corrosion resistivity, bioactivity, and antibacterial activity of novel nano-amorphous calcium phosphate (ACP) potentially multifunctional composite coatings with and without chitosan oligosaccharide lactate (ChOL), ACP + ChOL/TiO2 and ACP/TiO2 ACP + ChOL/TiO2, respectively, on the titanium substrate. Supplementary information: The ANOVA results of antimicrobial activity on S. aureus are shown in Table S1 and the ANOVA results of antimicrobial activity on P. aeruginosa are shown in Table S2. The analysis showed significant difference at the 5% level of confidence.Supplementary information for the article: [https://hdl.handle.net/21.15107/rcub_dais_11739]Supplementary information for the article: [https://doi.org/10.1021/acsbiomaterials.1c00035]Related to the accepted manuscript: [https://hdl.handle.net/21.15107/rcub_dais_11784

Biocompatible Germanium-Doped Hydroxyapatite Nanoparticles for Promoting Osteogenic Differentiation and Antimicrobial Activity

Hydroxyapatite (HAp) has been the main protagonist in the quest for an ideal biomaterial for regenerative medicine over the last half a century. To control its properties, this material has commonly been doped with chemical elements other than its natural stoichiometric constituents: Ca, O, P, and H. Here, we report on the first analysis of the biological response to germanium-doped hydroxyapatite (Ge-HAp). Cytotoxicity, osteogenic differentiation induction, and colony formation potential were measured on dental pulp stem cells, while the antimicrobial effect was assessed against Gram-negative Escherichia coli, Gram-positive methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans. All analyses were run in comparison to Ge-free HAp. Cell viability was inversely dependent on the nanoparticle concentration and incubation time. Adding Ge to HAp reduced cell viability relative to HAp after 24–72 h incubation periods, but the effect was reversed after longer incubations, when the viability of cells treated with low doses of Ge-HAp exceeded that of HAp-treated cells and became comparable with control culture. Both HAp and Ge-HAp induced mineral formation in the cell culture, but the effect was more pronounced for Ge-HAp. Likewise, relative to both control cells and cells exposed to HAp, Ge-HAp upregulated the expression of all three osteogenic markers analyzed, namely, alkaline phosphatase, RUNX2, and osteocalcin, exerting the key influence on osteogenesis in its early, differentiation stage. The colony formation capacity of stem cells, however, was impaired by HAp and even more so by Ge-HAp. The antimicrobial effect was dependent on the microorganisms tested. Thus, whereas the antimicrobial activity was absent against E. coli, it was evident against MRSA and C. albicans. While the antibacterial activity against MRSA was weakened by the addition of Ge to HAp, the antimycotic activity against C. albicans was intensified with the addition of Ge. These findings demonstrate a significant potential of Ge-doped HAp nanoparticles in regenerative medicine due to their pronounced biocompatibility, osteoinductivity, and antimicrobial activity

Highly selective anticancer activity of core shell particles based on hydroxyapatite, chitosan lactate and different androstane derivatives

Hybrid systems based on nano hydroxyapatites (HAp) are the subject of numerous studies in preventive and regenerative medicine. Special interests are directed towards the creation of a system based on HAp for use in a nano-oncology. The main objective of this research is directed towards the creation of a system with cytotoxic properties towards the cancer cells with the same time, minimum side effects. Carriers base on core shell of HAp/chitosan-poly(D,L)-lactide-coglycolide (PLGA) loaded with androstane-based cancer inhibitor could be seen as promising drug delivery platforms for selective cancer therapies. In this study we utilize an emulsification process and freeze drying to load the composite particles based on HAp nanocarrier, chitosane (Ch), PLGA and chitosan oligosaccharide lactate (ChOL) with 17β-hydroxy-17α-picolyl-androst-5-en-3β-acetate (A) and 3β,17β-dihydroxy-16-hydroxymino-androst-5-en (B), a chemotherapeutic derivatives of androstane. The picolyl androstane derivatives showed high potency in the cell inhibitors of hormone-dependent cancers (lung, prostate and colon cancer; adeno and cervix carcinoma; etc.). 1H NMR, 13C NMR and high-resolution time-of-flight mass spectrometry (MS) techniques confirmed the intact structure of the derivatives A and B. The thermogravimetric and differential thermal analysis (TGA, DTA) coupled with mass spectrometry was used to qualitatively confirm the drug loading process. FT-IR, XRD, AFM and DSC techniques have confirmed the success of androstane (A and B) loading process in core shell particles base on nano hydroxyapatite. All the synthesized particles were found to be spherical in shape with a uniform size distribution from d50=167 to d50=231 nm. Highly selective anticancer activity was noted towards the human lung carcinoma (A549) by A loaded HAp/Ch-PLGA and towards the human breast adenocarcinoma (MDA-MB-231) by B loaded HAp/ChOL. The obtained results of the DET and MTT tests were in agreement

Tumor-selective hybrid system based on hydroxyapatite nanocarrier, chitosan, poly(lactic-co-glycolic acid) and androstan derivate

The applicative potential of synthetic calcium phosphates, especially hydroxyapatite (HAp), has become intensely broadened in the past 10 years, from bone tissue engineering to multiple other fields of biomedicine. Previously we have shown that hydroxyapatite nanoparticles coated with chitosan-poly(D,L)-lactide-co-glycolide (HAp/Ch-PLGA) target lungs following their intravenous administration into mice. For this purpose radioactive 125-Iodine (125I), a low energy gamma emitter, was used to develop a novel in situ method for radiolabeling of particles and investigation of their biodistribution. In this study we utilize an emulsification process and freeze drying to load the composite particles based on hydroxyapatite nanocarrier, chitosane and poly(lactic-co-glycolic acid) with 17β- hydroxy-17α-picolyl-androst-5-en-3β-acetate (A), a chemotherapeutic derivative of androstane. The picolyl androstane derivatives showed high potency in the cell inhibitors of hormonedependent cancers (adenocarcinoma, prostate cancer, cervix carcinoma, colon cancer, etc.). 1H NMR, 13C NMR and high-resolution time-of-flight mass spectrometry (MS) techniques confirmed the intact structure of the derivative A following its entrapment within HAp/Ch-PLGA particles. The synthesized particles of A-loaded HAp/Ch-PLGA were found to be spherical in shape with a uniform size distribution of d50=168 nm. The release of A from HAp/Ch-PLGA was sustained, with no burst release or plateauing after three weeks. The obtained results of the DET and MTT tests show that the particles of A-loaded HAp/Ch-PLGA exhibit almost three times higher cytotoxicity towards lung adenocarcinoma cells (A549) than towards healthy cells (MRC5), while at the same time allowing twice as fast recovery of healthy cells. We have also analyzed the period of recovery of healthy, as well as cancer cells, following the treatment with A-loaded HAp/Ch-PLGA. After treatment with A-loaded HAp/Ch-PLGA, healthy cells recover twice as fast as the malignant ones. Immunofluorescent staining of primary fibroblasts interacting with HAp/Ch-PLGA and A-HAp/Ch-PLGA particles demonstrates no negative morphological or proliferative effects on cells