56 research outputs found
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Fractal and textural analysis of nuclear chromatin structural complexity in postnatal development and aging
Prethodne studije su utvrdile da tokom starenja veliki broj bioloÅ”kih struktura kao Å”to su tkiva i organi gubi svoju kompleksnost i da takav gubitak vodi smanjenoj sposobnosti adaptacije na fizioloÅ”ki stres. MeÄutim, za sada nema podataka da li se sliÄne strukturne promene deÅ”avaju na individualnim Äelijama i njihovom genetskom materijalu.
Strukturna kompleksnost se može kvantifikovati na nekoliko naÄina. SkoraÅ”nje studije su utvrdile da hromatin, kao i mnoge druge bioloÅ”ke strukture u svojoj morfologiji ispoljavaju karakteristike fraktala. Koncept fraktala se u osnovi bazira na principu samosliÄnosti, odnosno na Äinjenici da manji delovi nekog fiziÄkog ili bioloÅ”kog sistema nalikuju sistemu kao celini. Kompleksnost fraktalnih struktura se može meriti odreÄivanjem fraktalne dimenzije i lakunarnosti kao dva najznaÄajnija parametra fraktalne analize. Kao dodatak fraktalnoj analizi, danas se Äesto koristi i teksturalna analiza uz pomoÄ koje se mogu odrediti parametri teksturalne heterogenosti i neureÄenosti bioloÅ”ke strukture kao Å”to je entropija. U naÅ”oj studiji, na miÅ”ijem eksperimentalnom modelu, ispitivane su starosne promene u strukturnoj kompleksnosti nukleusnog hromatina na ukupno 10 Äelijskih populacija u timusu, slezini, bubregu i jetri. TakoÄe su opisane promene u kompleksnosti nukleusne strukture na kulturi Äelija nakon indukcije DNK oÅ”teÄenja UV zraÄenjem...Previous studies have found that during aging a large number of
biological structures such as tissues and organs loses its complexity
and that such loss leads to reduced ability to adapt to physiological
stress. However, so far there is no information on whether similar structural changes occur in individual cells and their genetic material.
Structural complexity can be
quantified in several ways.
Recent studies
have determined that the
chromatin,
as well as
many other
biological structures exhibit
fractal
characteristics
in
their morphology.
The concept of
fractals
is
based
on the principle of
self
-
similarity,
or
the
fact
that the
lower
parts
of a physical
or
biological system
resemble
the system
as a
whole.
The complexity of
fractal structures
Can be
measured
by determining
the fractal dimension
and
lacunarity
as the
two
most important parameters of
fractal analysis. In addition to the
fractal
analysis,
textural analysis as a method
is
also
frequently
used.
Textural analysis can
determine the
parameters of
textural
heterogeneity
and
disorganization (i.e.entropy)of
biological
structures.
In our study,
on
the
mouse
experimental model,
we
studied
age
-
related
changes in chromate in structural complexity
in the total of
10 cell populations in the thymus, spleen, kidney and liver. Also, we described changes in the complexity of the nuclear structure
in
a
cell
culture after the induction of DNA damage by UV radiation..
POTENTIAL OF CHAMPIGNONS CULTIVATED ON DIGESTED ORGANIC WASTE IN THE PREVENTION AGAINST OXIDATIVE STRESS AND NEURAL DAMAGE
Agaricus bisporus also known as champignon or white button mushroom was
cultivated on digested organic waste. Its aqueous extract was investigated for the
antioxidant potential, which could strengthen the protection of organism against
oxidative stress damages. Likewise, acetylcholinesterase (AChE) inhibitory activity
was observed. The crucial role of AChE in neural transmission makes it a primary
target of a large number of cholinesterase-inhibiting drugs involved in the
prevention of neurodegenerative diseases e.g. Alzheimerās disease (AD). The
antioxidant activities were evaluated by in vitro models including, 1,1-diphenyl-2-
picrylhydrazyl (DPPH) free radical scavenging activity, prevention of lipid
peroxidation (LPx) in a linoleic acid model system and chelating ability on ferrous
ions. Based on the analysis, hot water extracts showed a typical carbohydrate
pattern with the presence of polyphenols and small amounts of proteins. With
regard to scavenging ability on DPPH radicals, the EC50 value for A. bisporus was
0.89 mg/ml, the EC50 value of the chelating abilities on ferrous ions was 1.38
mg/ml and for inhibition of LPx EC50 value was found to be 1.77 mg/ml. Extract of
A. bisporus had a noticeable inhibition towards AChE, IC50=1.02 mg/ml and
exerted weak toxicity against healthy human peripheral blood mononuclear cells
(PBMC). More than 60% of cell viability was observed at 2 mg/ml. The good
antioxidative properties and AChE inhibitory activity of A. bisporus aqueous
extract make it suitable for everyday use as an inexpensive dietary supplement
Biohidrogelovi poli(metakrilne kiseline): bubrenje i kontrolisano otpuŔtanje kofeina
Modern society are faced with lot of challenges in the treatment of many diseases, especiallywith serious ones such as cancer. Safer and more efficient treatment of the cancer patients are maingoals which researchers are aiming. One of the good approaches can be drug delivery systems.Still, a lot of anticancer drugs are poorly water-soluble and their encapsulation and controlled releasecan be quite challenging. Present study is focused to improve drug delivery system based onhydrophilic poly(methacrylic acid) and amphiphilic casein with encapsulated poorly water-solublecaffeine, which has been developed through our previous research. The hydrogels with 1.6mol% ofcrosslinker and 100% of neutralization degree of methacrylic acid are synthetized (PMAC-100N-4M). The swelling process of the PMAC-100N-4M hydrogels and caffeine release are analyzed intwo environments which simulate human stomach and intestines. It is also investigated how thechange in the encapsulated caffeine weight and the addition of liposomes with encapsulated caffeine,affect swelling degree of the PMAC-100N-4M hydrogels and release of caffeine. The resultsshow that controlled release of caffeine is improved, therefore overall therapy can be enhanced.Savremeno druÅ”tvo je suoÄeno sa mnogim izazovima u tretamanu raznih bolesti, naroÄito ozbiljnih oboljenja kao Å”to je rak. Glavni ciljevi nauÄnika su da se postigne bezbednija i efikasnija terapija pacijenata koji se leÄe od raka. Jedan od dobrih naÄina da se to postigne su sistemi za dostavu lekova. Ipak, mnogi antikancerogeni lekovi su slabovodorastvorni, pa bi veliki izazov mogao da bude inakpsulacija i njihovo kontorlisano otpuÅ”tanje iz sistema za dostavu lekova. Cilj ovog rada je da se unapredi sistem za dostavu lekova na bazi hidrofilne poli(metakrilne kiseline) i amfifilnog kazeina sa inkapsuliarnim slabo vodorastvornim kofeinom, koji je razvijen tokom naÅ”eg prethodnog istraživanja. U ovom radu sintetisani su hidrogelovi sa 1,6mol% umreživaÄa i 100% neutralisanom metakrilnom kiselinom (PMAC-100N-4M). Procesi bubrenja PMAC-100N-4M hidrogelova i kontrolisanog otpuÅ”tanja kofeina su ispitivani u dve sredine koje simuliraju želudac i tanko crevo Äoveka. TakoÄe je ispitano kako promena koliÄine inkapsuliranog kofeina i dodatak lipozomne suspenzije sa inkapsuliranim kofeinom utiÄe na procese bubrenja PMAC-100N-4M hidorgelova i otpuÅ”tanje kofeina. Rezultati pokazuju da je proces kontrolisanog otpuÅ”tanje kofeina unapreÄen, a samim tim je moguÄe unaprediti i celokupnu terapiju
Synthesis, optical and magnetic properties studies of multiferroic BiFeO3
Nanosized bismuth ferrite powder has a potential application in the production of lead free piezoelectric materials for actuators as well as magnetoelectric sensors. The simple, low-costing and energy-saving hydrothermal method has advantages over the conventional methods. BiFeO3 powders were made using Bi(NO3)35H2O and Fe(NO3)3 9H2O as starting material and 8 M KOH as mineralizer. The particle size and morphology were analyzed using scanning electron microscopy (SEM). The phase composition of obtained samples was determined by X-ray diffraction (XRD) analysis. It revealed that synthesized material crystallize in space group R3c with cell parameters a = b = 5.5780(10) Ć
and c = 13,863(3) Ć
. IR and Raman spectroscopy have been performed on the synthesized bismuth ferrite (BFO) powders in order to confirm the formation of pure and well-crystallized BFO nanocrystallites. 57Fe Mƶssbauer spectroscopy was performed in order to provide information on Fe cation arrangement in the BiFeO3 phase. The magnetic and optical properties of properties of BFO samples were characterized by SQUID magnetometry, and ultravioletāvisible spectroscopy. Temperature dependence of magnetization shows antiferromagnetic-paramagnetic phase transition at TN = 220 K, while below this temperature weak ferromagnetic ordering is detected
Evaluation of Watson-like Integrals for Hyper bcc Antiferromagnetic Lattice
Watson-like integrals for a d-dimensional bcc antiferromagnetic lattice
I_d(\eta) and J_d(\eta) and another two similar integrals are evaluated in an
exact way in terms of generalized hypergeometric functions. A simple formula
connecting Id and Jd+1 is given along with the differential equations for
I_d(\eta) and J_d(\eta). An application of I_d and J_d in the theory of the
Heisenberg antiferromagnet is discussed, together with possible generalizations
to non-integer values of d. Corresponding integrals for sc lattices are also
briefly reviewed.Comment: 13 pages, 2 figures, Accepted for publication in Journal of Physics
A: Mathematical & Theoretical 201
Is WO3 catalyst for hydrogen desorption?
Magnesium hydride, as hydrogen storage material, meets the requirements such as high gravimetric hydrogen capacity (7,6 wt%), low cost and weight, abundance and H2 absorption/desorption cycling possibility. Given that the oxide additives show the good impact on desorption properties, mechanical milling of MgH2 with addition of 5, 10 and 15% wt. WO3 was performed. The microstructure and morphology of composites were analysed by XRD, PSD and SEM and correlated to hydrogen desorption properties which have been investigated by DSC. The results have shown that WO3 has a positive effect on the desorption kinetics as well as on the change of the desorption mechanism
Is WO3 catalyst for hydrogen desorption?
Magnesium hydride, as hydrogen storage material, meets the requirements such as high gravimetric hydrogen capacity (7,6 wt%), low cost and weight, abundance and H2 absorption/desorption cycling possibility. Given that the oxide additives show the good impact on desorption properties, mechanical milling of MgH2 with addition of 5, 10 and 15% wt. WO3 was performed. The microstructure and morphology of composites were analysed by XRD, PSD and SEM and correlated to hydrogen desorption properties which have been investigated by DSC. The results have shown that WO3 has a positive effect on the desorption kinetics as well as on the change of the desorption mechanism
Hydrogen Storage in Metal Hydrides: Experimental Approach
The paper deals with the destabilization methods for improving the storage properties of metal hydrides. The experimental approach was used to point out the influence of various types of defects on the structure and stability of hydrides. As a case study, Mg-based hydrides have been investigated. As shown by our research, ion irradiation is the way to introduce a well-defined concentration of defects (Frankel pairs) at the surface and sub-surface layers of a material. Defects at the surface play the main role in sorption reactions since they enhance the dissociation of hydrogen. Further, our research shows that ball-milling introduces defects through the entire sample volume, refines the structure and thus decreases the path for hydrogen diffusion. Surface-modified material demonstrates better thermodynamic and kinetics properties than bulk modified hydride materials.Published in Bulletin of the Chemists and Technologistsof Bosnia and Herzegovina as Special Issue (2024)
Natural Clay Pyrophyllite Activation with Silver and Composite Characterization
In this work, a hybrid pyrophyllite/AgNPs system was designed by mechanochemical activation of pyrophyllite, Al2Si4O 10(OH) 2. Tuning this systemās properties is especially important in terms of possible biomedical applications. The reaction was triggered by adding 2, 5, and 10wt% of silver in the form of AgNO3, indicating green synthesis of AgNPs. Thereby, the grinding time was adjusted from 20 to 320 minutes. The collected samples were analyzed by FTIR, XRD, SEM with EDX, TGA, DTA and PSD. The FTIR spectra of the pyrophyllite/AgNPs system showed the disappearance of some bands characteristic of pyrophyllite itself due to breaking of some bonds during the grinding, and the appearance of some new bands. SEM-EDS analysis confirmed that pyrophyllite structure changed during the mechanochemical treatment, indicating a homogeneous distribution of silver along the analyzed surface. PSD analysis showed that the average particle size distribution is approximately the same for all samples, despite the different wt% of silver. While XRD patterns of samples with 2 and 5 wt% of AgNO 3 did not show reflections originating from silver, the peak at 38.16Ė of the pyrophyllite sample milled for 20 minutes with 10 wt% of silver could be assigned to silver in the metal form. DTA curves of pyrophyllite/AgNO 3 samples milled for 20, 80 or 320 min had similar shapes for different silver content added. TGA curves of pyrophyllite/AgNO 3 samples milled for 20 min with 2, 5, and 10 wt% of silver showed a total weight loss of about 10% while for samples milled for 320 min reduced weight loss was observed due to the agglomeration of particles.Published in Bulletin of the Chemists and Technologistsof Bosnia and Herzegovina as Special Issue (2024)
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