463 research outputs found
Nano-friction in cavity quantum electrodynamics
The dynamics of cold trapped ions in a high-finesse resonator results from
the interplay between the long-range Coulomb repulsion and the cavity-induced
interactions. The latter are due to multiple scatterings of laser photons
inside the cavity and become relevant when the laser pump is sufficiently
strong to overcome photon decay. We study the stationary states of ions coupled
with a mode of a standing-wave cavity as a function of the cavity and laser
parameters, when the typical length scales of the two self-organizing
processes, Coulomb crystallization and photon-mediated interactions, are
incommensurate. The dynamics are frustrated and in specific limiting cases can
be cast in terms of the Frenkel-Kontorova model, which reproduces features of
friction in one dimension. We numerically recover the sliding and pinned
phases. For strong cavity nonlinearities, they are in general separated by
bistable regions where superlubric and stick-slip dynamics coexist. The cavity,
moreover, acts as a thermal reservoir and can cool the chain vibrations to
temperatures controlled by the cavity parameters and by the ions phase. These
features are imprinted in the radiation emitted by the cavity, which is readily
measurable in state-of-art setups of cavity quantum electrodynamics.Comment: 9 pages, 7 figure
Rat duodenal motility in vitro: Prokinetic effects of DL-homocysteine thiolactone and modulation of nitric oxide mediated inhibition
Homocysteine is a significant but modifiable risk factor for vascular
diseases. As gastrointestinal smooth musculature is similar to blood vessel
muscles, we investigated how elevated homocysteine levels affect nitric
oxide-mediated neurotransmission in the gut. There is accumulated evidence
that a dysfunction of NO neurons in the myenteric plexus may cause various
diseases in the gastrointestinal tract such as achalasia, diabetic
gastroparesis and infantile hypertrophic pyloric stenosis. In the present
study, we aimed to assess the effects of homocysteine on NO-mediated
responses in vitro, and to examine the effects of DL-homocysteine thiolactone
on the spontaneous motility of rat duodenum and nitrergic neurotransmission.
DL-homocysteine thiolactone concentration of 10 μmol/L leads to the immediate
increase in tone, amplitude and frequency of spontaneous movements in
isolated rat duodenum. L-NAME (30 μmol/L) leads to an increase in basal tone,
amplitude and frequency of spontaneous contractions. The relaxations induced
by EFS were significantly reduced in duodenal segments incubated in
DL-homocysteine thiolactone compared with the control group. EFS-induced
relaxations were inhibited by L-NAME in both experimental and control groups.
These results suggest that a high level of homocysteine causes an important
impairment of non-adrenergic non-cholinergic innervation of the rat duodenum.
[Projekat Ministarstva nauke Republike Srbije, br. 175043
Mechanochemical synthesis of bismuth ferrite
A powder mixture of Bi2O3 and Fe2O3 was mechanically treated in a planetary ball mill in an air from 30 to 720 minutes. It was shown that the mechanochemical formation of BiFeO3 (BFO) phase was initiated after 60 min and its amount increased gradually with increasing milling time. A detailed XRPD structural analysis is realized by Rietveld’s structure refinement method. The resulting lattice parameters, relative phase abundances, crystallite sizes and crystal lattice microstrains were determined as a function of milling time. Microstructural analysis showed a little difference in morphology of obtained powders. The primary particles, irregular in shape and smaller than 400 nm are observed clearly, although they have assembled together to form agglomerates with varying size and morphology. Dense BFO ceramics were prepared by conventional solid-state reaction at the temperature of 810ºC for 1h followed immediately by quenching process. [Projekat Ministarstva nauke Republike Srbije, br. III45007: Zero- to Three-Dimensional Nanostructures for Application in Electronics and Renewable Energy Sources: Synthesis, Characterization and Processin
Morphological and molecular characterization of human adipose tissue and lipomas of different anatomical localization and examination of isolated mesenchymal cells in vitro
Lipomi su benigni tumori masnog tkiva sa još uvek nedovoljno razjašnjenom
etiologijom i patogenezom. Lipomi su uglavnom lokalizovani potkožno ali se mogu naći i
intramuskularno, u telesnim šupljinama i organima, mogu biti solitarni ili multipli, mogu
varirati u veličini i histološkoj građi, ali podaci o njihovom molekularnom profilu i
mehanizmima nastanka su vrlo oskudni. Mezenhimske matične ćelije iz lipoma (eng. lipomaderived
stem cells - LDSCs) su predložene za primenu u tkivnom inženjerstvu i regenerativnoj
medicini od strane autora nekoliko studija zato što je pokazano da imaju karakteristike
slične mezenhimskim matičnim ćelijama iz masnog tkiva (eng. adipose-derived stem cells -
ADSCs). Osim podataka o potencijalu izolovanih LDSCs da proliferišu i da se diferentuju
u adipocite, osteoblaste i hondrocite, nema podataka o ostalim karakteristikama ovih ćelija
a ni detaljnog poređenja sa ADSCs na ćelijskom i molekularnom nivou.
Cilj jednog dela ovog istraživanja je bio ispitivanje molekularnog profila izolovanih
LDSCs i poređenje sa ADSCs u kulturi in vitro, ispitivanje kapaciteta LDSCs da se
diferentuju u adipocite i osteoblaste, na ćelijskom, proteinskom i genskom nivou,
ispitivanje uticaja kondicioniranih medijuma LDSCs na odgovor makrofaga, kao i
ispitivanje imunomodulacijske aktivnosti i efekta na zarastanje rana u sistemu indirektne
ko-kulture in vitro, u poređenju sa ADSCs. Cilj drugog dela ovog istraživanja je bio
morfološka i molekularna karakterizacija tkiva lipoma i potkožnog belog masnog tkiva
(eng. subcutaneous white adipose tissue – scWAT) različitih anatomskih lokalizacija.
Rezultati su pokazali da LDSCs i ADSCs poseduju karakteristike mezenhimskih
matičnih ćelija i da imaju sličan fenotip ali različitu molekularnu osnovu za diferencijaciju.
Obrazac ekspresije gena markera adipogeneze i prisustvo manjeg broja zrelih adipocita u
kulturi LDSCs u odnosu na ADSCs nakon 21 dan adipogene diferencijacije ukazuju na
slabiji kapacitet LDSCs za diferencijaciju u adipocite u poređenju sa ADSCs. Analiza
osteogenih markera nakon 16 dana osteogene diferencijacije je pokazala da i LDSCs i
ADSCs imaju fenotip karakterističan za osteoblaste, ali su bile u različitim fazama
osteogeneze. Kondicionirani medijumi LDSCs (LDSC-CM) i ADSCs (ADSC-CM) dovode
do funkcijske aktivacije nestimulisanih makrofaga i ispoljavaju anti-inflamacijsku aktivnost,
sa izraženijim efektom LDSC-CM. LDSC-CM i ADSC-CM deluju povoljno na zarastanje
rana u sistemu indirektne ko-kulture in vitro, bez značajnih razlika, i u nivou su pozitivne
kontrole...Lipomas are benign adipose tissue tumors with still insufficiently clarified etiology
and pathogenesis. Lipomas are mainly localized subcutaneously but can also be found
intramuscularly, in the body cavities and organs, may be solitary or multiple, may vary in
size and histological structure, but data on their molecular profile and mechanisms of
formation are still scarce. Lipoma-derived stem cells (LDSCs) have been proposed for use
in tissue engineering and regenerative medicine by the authors of several studies since it has
been shown that these cells have characteristics similar to adipose-derived stem cells
(ADSCs). In addition to data on the potential of isolated LDSCs to proliferate and
differentiate into adipocytes, osteoblasts and chondrocytes, there is no data on other
characteristics of these cells, nor a detailed comparison with ADSCs at the cellular and
molecular levels.
The aim of one part of this study was to examine the molecular profile of isolated
LDSCs and comparison with ADSCs in culture in vitro, to examine the capacity of LDSCs
to differentiate into adipocytes and osteoblasts on cellular, protein and gene level, to
examine the influence of conditioned media of LDSCs on macrophages’ response, as well
as to examine immunomodulatory activity and effect of wound healing in indirect coculture
system in vitro, in comparison with ADSCs. The aim of the second part of this study
was the morphological and molecular characterization of lipoma tissue and subcutaneous
white adipose tissue (scWAT) of various anatomical localizations.
The results showed that LDSCs and ADSCs possess the characteristics of
mesenchymal stem cells and have similar phenotype but different molecular basis for
differentiation. The pattern of expression of genes that are markers of adipogenesis and the
presence of less number of mature adipocytes in LDSCs compared to ADSCs culture after
21 day of adipogenic differentiation, indicate lower capacity of LDSCs for differentiation
into adipocytes compared to ADSCs. Analysis of osteogenic markers after 16 days of
osteogenic differentiation showed that both LDSCs and ADSCs have a characteristic
osteoblast-like phenotype, but they were at different stages of osteogenesis..
Efekti vertikalnog i horizontalnog modela pliometrijskog treninga na razvoj eksplozivne snage
The purpose of this experimental study was to determine the effects of
vertical and horizontal models of plyometric training explosive strength
development in cadet volleyball cadets. Forty -four participants were
randomly assigned to one of two experimental groups: vertical
plyometric (Е1; n=20; BH=185.5 ± 7.02 cm; BM=71.1 ± 7.44 kg),
horizontal plyometric (Е2; n=24; BH=183.8 ± 7.79 cm; BM=68.7 ±
8.69 kg). The training programs lasted 6 weeks and it consisted of two
training sessions per week. All subjects were tested for each of the
following jumps: squat jump (SJ), countermovement jump (CMJ), drop
jump (DJ) and continous jumps (CJ). After a 6-week plyometric
training some of the tested parameters of SJ increased in the vertical
plyometrics group (Hmax 13.7%; Fmax 3.4%; Vmax 6.2%; IMPcon 4.1%;
Pmax_con 10.2%), as well as in the horizontal plyometrics group
(Hmax12.2%; Fmax 5.1%; Fmax/TT 6.0%; Vmax 5.9%; IMPcon 3.7%;
Pmax_con 9.5%). Some of the tested parameters of CMJ increased in the
vertical plyometrics group (Hmax 9.8%; Vmax 1.5%; IMPcon 7.2%;
IMPuk 2.0%; Pmax_con 2,8%), as well as in the horizontal plyometric
group (Hmax 10.1%; Vmax 3.4%; IMPcon 8.5%; IMPuk 5.0%; Pmax_con
3.9%), while lower values compared to the initial measurement were
recorded in Fmax/TМ (5.2%) in the vertical plyometric group. In DJ
some of the tested parameters increased in the vertical plyometric
group (Hmax 15.7%; Tcon 14.9%; Vmax 9.9%; IMPcon 14.4%; Pmax_con
10.4%), as well as in the horizontal plyometrics group (Hmax 23.4%;
Vmax 10.6%; Pmax_con 11.9%), while lower values compared to the initial
measurement were recorded in parameter Pmax_exc (13.3%) in horizontal
plyometric group. The CJ parameters showed in the vertical
plyometrics group increased (Hmax 8.2%; IMPuk 6.8%; Pmax_uk 4.8%), as
well as in the horizontal plyometrics group (Hmax 14.5%; Texc 6.0%;
IMPexc 12.2%; IMPuk 7.5%; Pmax_exc 13.8; Pmax_uk 6.2%). The results of
this thesis showed that there were no significant differences in the
effects of different models of plyometric program in tested parameters,
except for CMJ, in favor of horizontal plyometric group. The results
suggest that both training programs were effective in the development
of various parameters of jumping ability. In practice exercises from
these plyometric training program should be combined due to a greater
effect on certain parameters of jumps
Dr Uroš Novaković: PRESELJENJE DETETA I RODITELJA KOJI VRŠI RODITELJSKO PRAVO - RELOCATION SLUČAJEVI
Chemical composition and antioxidant activity of methanol and acetone pulp and peel extracts of selected fruit from southeast Serbia
By applying more instrumental methods (UV-Vis spectrophotometry, HPLC
chromatography, ICP emission spectrophotometry), the antioxidant activity,
phenolic and mineral composition of the pulp and peel extracts of selected
types of fruit (Cydonia oblonga, Prunus persica, Malus domestica) were
determined and the effect of methanol and acetone solvent of
determined composition was investigated. The obtained results are
discussed, compared with the literature and analyzed statistically
Characteristics of Phomopsis sp. isolates of plum trees origin
Twelve isolates of Phomopsis sp. were obtained from the branches and the trunk of plums (Prunus domestica L) with decay symptoms in Valjevo, Ljig Koceljeva and Ub vicinity during 2004-2006. Morphological, pathogenic and growing characteristics were studied. Pathogen caused tissue necrosis of branches around the inoculate seats, and wrinkling and watering of plum fruits. All media were suitable for pathogen development, except prune agar. The best growth of isolates was at medium pH 5,5. The optimal temperature for growth and germination of pycnidiospores was 25°C
Lawton, Michael T: Seven aneurysms: Tenets and techniques for clipping: Thieme 2011, ISBN 978-1-60406-054-6
In this paper, the removal of methylene blue (MB) from aqueous solution by biosorption onto apricot shellshas been investigated through batch experiments. Apricot shells were chosen as a locally available and abundant waste from fruit juice industry. Methylene blue is common pollutant of waste waters from textile industry. The influence of initial MB concentration on biosorption process has been studied. The experimental data have been analysed using Langmuir and Freundlichisotherm models. The Langmuir model better fits to experimental data, which explain monolayer adsorption. Maximum biosorption capacity is 24,31 mg/g. A comparison of the biosorption capacity of waste apricot shells with biosorption capacities of similar adsorbents previously investigated indicates that apricot shells could be a promising biosorbent for removal of MB from aqueous solution
Izučavanje morfologije jajnika i citologije jajne ćelije kao osnova za uspostavljanje metoda IVM, IVF i embriotransfera
In three types of domestic animals: cattle, pigs and sheep, morphology of ovary was studied. Results such as differences in shape, size within and between species, number of follicles in maturation, changes in sex cycle, connection of follicles in maturation are presented in figures. By method of aspiration, oocytes were isolated from ovaries and their cytology analyzed as the first step in methods of in vitro maturation (IVM), followed by in vitro fertilization (IVF) and embryo transfer. These methods are wide spread in modern livestock production (cattle, horses) since they have many advantages of which the most important is to obtain more offspring from high quality female heads. Method has disadvantage: potential diminishing of biodiversity, therefore special attention is necessary in order not to endanger biodiversity and still get more offspring with high production abilities and traits. IVM, IVF and embryo transfer represent new approach to selection, fast and with similar effect like in conventional artificial insemination, therefore they should be applied in practice also in our country.Kod tri vrste domaćih životinja: goveda, svinja i ovaca, izučavana je morfologija jajnika. Rezultati: razlika u obliku, veličini inter i intraspecies, broj folikula u zrenju, promene tokom polnog ciklusa, povezanost folikula u zrenju; prikazani su na slikama. Iz jajnika su metodom aspiracije iz jajnika izolovane jajne ćelije i analizirana njihova citologija kao prvi korak u metodi in vitro sazrevanja (IVM), nakon koje slede in vitro oplodnja (IVF) i embriotransfer. Ove metode su široko rasprostranjene u modernom stočarstvu (goveda, konji) jer imaju niz prednosti od kojih je najvažnije dobijanje većeg broja potomaka od kvalitetnih ženskih grla. Metoda ima i nedostatak: moguće smanjenje biodiverziteta, i stoga treba voditi računa da se biodiverzitet ne ugrozi, a da se dobije veći broj potomstva sa visokim proizvodnim osobinama. IVM, IVF i embriotransfer su nov pristup selekciji, brzi, a sa sličnim efektom kao kod klasične veštačke selekcije, i zbog toga bi bilo dobro da nađu primenu i na našim prostorima
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