150 research outputs found
SYNTHESIS AND STRUCTURAL ANALYSIS OF A Cu(II) COMPLEX WITH PYRIDOXAL S-METHYLISOTHIOSEMICARBAZONE (PLITSC) LIGAND
Reaction between a warm water mixture of pyridoxal hydrochloride (PL.HCl), and Smethyilisothiosemicarbazidehydroiodide (SMeTSC.HI) in the presence of Na2CO3 .10 H O, we got pyridoxal S-methylisothiosemicarbazone (PLITSC; H2L). Ligand with appropriate Cu salt is coordinated, to give next complex: dark-brown, penta coordinated, square-pyramidal structure, mono(ligand)complex Cu(II) formula, [Cu(PLITSC)Br(CH3OH)]Br.In this work is given synthesis and structure of the complex with Schiff-based ligand
Simulataneous determination of nimesulide and its impurities in pharmaceutical formulations by reversed-phase high-performance liquid chromatography
A simple, rapid and reproducible reversed-phase high-performance liquid chromatography method for the analysis of nimesulide and its impurities both in the bulk drug and pharmaceutical formulations is reported. The method is suitable for monitoring the stability of nimesulide. The presence of nimesulide impurities C (2- phenoxyaniline) and D (2- phenoxy4- nitroaniline) was observed. The best separation was achieved using an Agilent Zorbax Extend C-18 column ( 150 x 4.6 mm, particle size 5 mu m) at 40 C and flow rate of 1.0 mLmin(-1). The analytes were monitored at 230 nm. The mobile phase consisted of acetonitrile - triethylamine (TEA) - water (45:0.5:54.5 v/v/v), adjusted to pH 5.2 with formic acid. Under these conditions the retention times were of 7.11, 7.98 and 8.66 min for nimesulide, D and C, respectively. The resolution of nimesulide and impurity D was 3.20 and that of impurity D and impurity C 2.40, indicating that the compounds were well separated. Evaluation of linearity, accuracy, precision, selectivity, sensitivity and robustness of the method produced satisfactory results. The developed method was successfully applied to assay nimesulide in different solid pharmaceutical formulations
Research of performances of the compressed natural gas powered bus in terms of safety and environmental influence.
Doktorska disertacija pod nazivom „Istraživanјe performansi autobusa sa pogonom
na kоmprimоvаni prirodni gas sa stanovišta bezbednosti i uticaja na životnu
sredinu“ ima za cilj unаprеđivаnjе pоstојеćih i rаzvој nоvih mоdеlа zа аnаlizu
pоkаzаtеlја bеzbеdnоsti аutоbusа sа pоgоnоm nа kоmprimоvаni prirоdni gаs i rаzvој
јеdinstvеnоg mоdеlа zа prоcеnu uticаја оvih аutоbusа nа živоtnu srеdinu nа putnој
mrеži Srbiје.
U skladu sa ciljem, u radu su definisani kinematsko dinamički modeli autobusa sа
pоgоnоm nа kоmprimоvаni prirоdni gаs kao hеtеrоgеnоg tela od dve koncentrisane
mase za različite režime kretanja. Na osnovu zakona tеоriје krеtаnjа vоzilа fоrmirаnе su
difеrеnciјаlnе јеdnаčinе krеtаnjа pomoću kојih su dеfinisаnе kritičnе brzinе stаbilnоg
uprаvlјаnjа аutоbusа sа pоgоnоm nа kоmprimоvаni prirоdni gаs. Analiza stabilnosti
upravlјanja autobusa pod dejstvom maksimalnih uzdužnih i poprečnih sila u tаngеntnој
rаvni kontaktа pneumatika i podloge izvršena je u graničnim uslovima kretanja i za
širоk spеktаr drumskih i transportnih uslоvа eksploatacije reprezentovanih kroz različite
uslove prianjanja i opterećenja autobusa, različitog položaja baterije sa rezervoarima za
komprimovani prirodni gas na krovu autobusa, promenu koordinata težišta autobusa.
Imajući u vidu da vozač može uticati na promenu kretаnja samo u tаngеntnoj ravni,
analiza dinamičkog ponašanja autobusa je sprovedena za ravansko kretanje, izuzimajući
oscilacije autobusa pri kretanju i karakteristike mikroprofila tla ali je uzeta u obzir
bočna elastičnost točkova autobusa.
U radu je razvijen model za određivanje i prоcеnu emisije izduvnih gasova autobusa sa
pogonom na komprimovani prirodni gas na saobraćajnoj mreži. Za definisanje i
prognozu transportnih zahteva izrаžеnih u broju autobusa po danu na svakoj deonici
kreirane putnе mreže u оkviru mоdеlа je korišćena aplikacija „Transtoоls“. Pri tome su
u okviru ovog dela istraživanja uzeti u obzir i trаnspоrtni zаhtеvi za sve kategorije
vozila kаko bi analiza obuhvatala i međusobni uticaj vozila u saobraćajnom toku.
Kreirana saobraćajna mreža je multimodalnog karaktera, tj. na obim i raspodelu
saobraćajnih tokova po deonicama kао i nа krајnjе rеzultаtа funkciоnisаnjа mоdеlа
utiču i drugi vidovi saobraćaja. Na osnovu „HDM“ modela i regresione analize, prema
tipu terena i međunarodnom indikatoru neravnosti kolovoza, za svaku od kategoriju
drumskih vozila utvrđena je funkcionalna zavisnost između brzine kretanja i potrošnje
goriva u obliku polinoma drugog stepena. Potrošnja goriva autobusa sa pogonom na
komprimovani prirodni gas utvrđena je merenjem u realnim uslovima eksploatacije na
karakterističnim deonicama putnе mreže, što je omogućilo da se ustanovi vrednost
gorivnog ekvivalenta izražena odnosom potrošnje prirodnog gasa i potrošnje dizel
goriva na 100 kilometara pređenog puta autobusa. Određeni su jedinični faktori emisije
ugljenmonoksida, azotnih oksida, čestičnih materija, ugljendioksida, nemetanskih
isparljivih organskih jedinjenja, sumpornih oksida i metana, izrаžеnih u mаsi
zаgаđivаčа pо mаsi sаgоrеlоg gоrivа. Vrednovanje uticaja ovih autobusa na životnu
sredinu izvršeno je sa stanovišta eksternih trоškоvа u saobraćaju odnosno troškova
emisije izduvnih gasova.Doctoral dissertation entitled „Research of performances of the compressed natural
gas powered bus in terms of safety and environmental influence” should improve
the existing i.e. develop new models used for the analysis of safety parameters of the
compressed natural gas powered bus, as well as develop the unique model for
assessment of environmental impact of such buses within the Serbian road network.
Pursuant to the goal, the paper defines kinematic and dynamic models of compressed
natural gas powered bus as heterogenous body consisting of two concentrated masses
used for different regimes of motion. Based on the vehicle motion theory laws,
differential equations of motion have been established in order to help define steering
stability critical velocities of compressed natural gas powered bus. The analysis of
steering stability of a bus under the influence of maximum longitudinal and lateral force
within a tire-surface contact tangent plane has been carried out under limit movement
conditions and for a wide range of road and transport exploitation conditions, presented
through diverse friction and bus load conditions, different positions of a compressed
natural gas cylinder placed on the bus roof, changes in the bus's center of gravity
coordinates. Bearing in mind the fact that a driver can influence solely the change in
tangent plane motion, dynamic behaviour of a bus has been analyzed in terms of plane
motion, thus excluding bus oscillations during the movement as well as surface microprofile
properties, while taking lateral tire elasticity into account.
In this paper the model has been developed that determines and assesses emission of
exhaust gases of the compressed natural gas powered bus in transport network.
„Transtools“ has been applied to define and forecast transport demands expressed in the
number of buses per day in each section of the created road network within the model.
Within this part of the research, transport demands implemented to all vehicle
categories have also been taken into account so that the analysis could also encompass
mutual influence of vehicles in traffic flow. The created transport network is
multimodal, i.e. other transport modes influence the volume and the distribution of
traffic flows in different sections as well as the final results. Based on „HDM“ model
and regression analyses and according to the terrain type and the International
Roughness Index, functional co-dependence between velocity and fuel consumption in
the form of a second degree polynomial has been determined for each road vehicle
category. Fuel consumption by compressed natural gas powered bus has been calculated
through the measurement within real conditions of exploitation on specific sections of
the road network, which has made possible to determine the fuel equivalent value,
expressed through the relation between the natural gas consumption and diesel fuel
consumption per 100 km of the road passed by the bus. Average factors of carbon
monoxide emission, nitrogen oxides, particulate matter, carbon dioxide, non-methane
volatile organic compounds, sulfur oxide and methane, expressed through the pollutant's
mass per mass of the fuel burnt. Evaluation of environmental influence of such buses
has been expressed from the point of view of external costs in the transport sector, i.e.
costs of exhaust gas emission
SYNTHESIS AND STRUCTURAL ANALYSIS OF A Cu(II) COMPLEX WITH PYRIDOXAL S-METHYLISOTHIOSEMICARBAZONE (PLITSC) LIGAND
Reaction between a warm water mixture of pyridoxal hydrochloride (PL.HCl), and Smethyilisothiosemicarbazidehydroiodide (SMeTSC.HI) in the presence of Na2CO3 .10 H O, we got pyridoxal S-methylisothiosemicarbazone (PLITSC; H2L). Ligand with appropriate Cu salt is coordinated, to give next complex: dark-brown, penta coordinated, square-pyramidal structure, mono(ligand)complex Cu(II) formula, [Cu(PLITSC)Br(CH3OH)]Br.In this work is given synthesis and structure of the complex with Schiff-based ligand
Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II) bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC). Crystal structure of [Cu(PLITSC−H)H2O]Br•H2O
The synthesis and structural characterization of a square-planar copper(II)
complex with pyridoxal S-methylisothiosemicarbazone (PLITSC) of the formula
[Cu(PLITSC−H)H2O]Br•H2O (1) as the first Cu(II) complex with monoanionic
form of this ligand were described. Complex 1 together with two previously
synthesized complexes [Cu(PLITSC)Br2] (2) and [Cu(PLITSC)Br(MeOH)]Br (3)
were characterized by elemental analysis, IR and electronic spectra and also
by the methods of thermal analysis, conductometry and magnetochemistry.
[Projekat Pokrajisnkog sekretarijata za nauku i tehnoloski razvoj Vojvodine
i Ministarstva nauke Republike Srbije, br. 172014
Relaksacija aorte pacova indukovana novosintetisanim orto-hlornim derivatom propafenona
The information on the inhibitory effect of propafenone in vascular smooth muscle is sparse. Propafenone acts through blockage of voltage-dependent cardiac Na+ channels, L-type Ca2+ channels, voltage-sensitive K+ (Kv) channels, as well as β-adrenergic receptors in the heart. The introduction of different chemical groups in the benzyl moiety of propafenone influences pharmacological properties of newly developed derivate of propafenone. Here we investigated the effect of new ortho-chloro derivate of propafenone (5OCl) on the vascular tone of precontracted rat aorta. 5OCl produced endothelium-independent relaxation of rat aorta. In order to test the involvement of different ion channels in 5OCl mechanism of action, antagonist of Na+, lidocaine, KV channels, 4-aminopyiridine (4-AP) and L-type Ca2+ channels, nifedipine were used. All tested antagonists of ion channels did not influence the relaxation of rat aorta induced by high a concentration of 5OCl (≥10 μM), but antagonized the relaxation induced by low concentrations of this propafenone derivate. Thus, 5OCl derivate has comparable potency and efficacy as propafenone. According to its interaction with lidocaine, 4-AP and nifedipine it seems that 5OCl partly shares the mechanism of action with propafenone. The mechanism of vasodilatation induced by high micromolar concentration of 5OCl is not defined and further investigations are necessary.Informacije o efektima propafenona na vaskularne glatke mišiće su oskudne. Propafenon blokira voltažno-zavisne Na+ kanale, Ca2+ kanale L-tipa, voltažno-senzitivne K+ (Kv) kanale i β-adrenergičke receptore u srcu. Uvođenje različitih hemijskih grupa u benzilni deo molekula propafenona utiče na promenu njegovih farmakoloških osobina. U ovoj studiji je ispitivan uticaj novog orto-hloro derivata (5OCl) propafenona na vaskularni tonus prekontrahovane aorte pacova. Orto hlorni derivat (5OCl) je izazvao endotel-nezavisnu relaksaciju aortnih prstenova. Da bi se ispitala uloga različitih jonskih kanala u ovoj relaksaciji, korišćeni su lidokain, (antagonist Na+ kanala), 4-aminopiridin (antagonist Kv kanala) i nifedipin (antagonist Ca2+ kanala L-tipa). Testirani antagonisti jonskih kanala nisu uticali na relaksaciju aorte pacova izazvanu visokom koncentracijom 5OCl (≥10 μM), ali su zato antagonizovali relaksaciju aorte koncentracijama 5OCl koje su bile manje od 10 μM. Prema tome, 5OCl derivat ima sličnu jačinu i efikasnost kao propafenon. Prema njegovoj interakciji sa lidokainom, 4-AP i nifedipinom može se reći da je mehanizam dejstva 5OCl sličan propafenonu. Mehanizam vazodilatacije 5OCl derivata u koncentracijama većim od 10 μM nije definisan i za to su potrebna dalja istraživanja
Effects of the polyphenol resveratrol on contractility of human term pregnant myometrium
The ideal agent for prevention and treatment of uterine abnormal contractility has not been found. The polyphenol resveratrol possesses a wide spectrum of pharmacologic properties, but its influence on the contractility of human myometrium is not defined. The present study evaluated the effect of resveratrol on the oxytocin-induced contractions of human term pregnant myometrium in vitro and the contribution of different K+ channels to resveratrol action. Resveratrol induced a concentration-dependent relaxation of myometrium contractions (pD(2) value and maximal responses were 4.52 and 82.25%, respectively). Glibenclamide, a selective blocker of ATP-sensitive (K-ATP), iberiotoxin, a selective blockers of big-calcium sensitive (BKCa) and 4-aminopiridine, a non-selective blocker of voltage-sensitive (Kv) channels induced a significant shift to the right of the concentration-response curves of resveratrol. Inhibition achieved by 0.1 mM resveratrol was insensitive to all K+ channel blockers. A K+ channel opener, pinacidil, inhibited oxytocin-induced contractions of pregnant myometrium with comparable potency and efficacy to resveratrol (pD(2) values and maximal relaxation were 4.52 and 83.67%, respectively). Based on K+ channel opener/blocker affinities, it appears that the inhibitory response of resveratrol involves different myometrial K+ channels. When applied in high concentrations, resveratrol has an additional K+-channel-independent mechanism(s) of action. Furthermore, immunohistochemistry staining and western blot analyses detected the presence and distribution of K-ATP, BKCa and Kv channel proteins in pregnant myometrium
The role of social media and network capital in assisting migrants in search of a less precarious existence in Saudi Arabia
Precarity is a consequence of the shift from Fordism, which was linked to lasting and secure employment, to post-Fordism underpinned by flexible labour with provisional, casual, unstable, low-paying jobs. Globalization and widening inequalities around the world have driven people to migrate in search of a better life. This paper aims to explore the extent to which migrants in Saudi Arabia use social media sites to facilitate their migration process in search of a better life. We found that social media strengthens social networks, which play an important role in influencing individuals’ decision to migrate. Their social network helped migrants during the planning and the actual migration to Saudi Arabia. Moreover, migrants used social media to persuade or assist relatives and friends ‘back home’ to migrate to Saudi Arabia
Frustrated hierarchical synchronization and emergent complexity in the human connectome network
The spontaneous emergence of coherent behavior through synchronization plays a key role in neural function, and its anomalies often lie at the basis of pathologies. Here we employ a parsimonious (mesoscopic) approach to study analytically and computationally the synchronization (Kuramoto) dynamics on the actual human-brain connectome network. We elucidate the existence of a so-far-uncovered intermediate phase, placed between the standard synchronous and asynchronous phases, i.e. between order and disorder. This novel phase stems from the hierarchical modular organization of the connectome. Where one would expect a hierarchical synchronization process, we show that the interplay between structural bottlenecks and quenched intrinsic frequency heterogeneities at many different scales, gives rise to frustrated synchronization, metastability, and chimera-like states, resulting in a very rich and complex phenomenology. We uncover the origin of the dynamic freezing behind these features by using spectral graph theory and discuss how the emerging complex synchronization patterns relate to the need for the brain to access –in a robust though flexible way– a large variety of functional attractors and dynamical repertoires without ad hoc fine-tuning to a critical pointWe acknowledge financial support from J. de Andalucía, grant P09-FQM-4682 and we thank O. Sporns for providing us access to the human connectome data
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