Phys. Rev. B 99, 014434 (2019) We report on the magnetocrystalline anisotropy energy (MAE) and spin
reorientation in antiferromagnetic state of spin $S=1/2$ tetramer system
SeCuO$_3$ observed in ...torque magnetometry measurements in magnetic fields
$H<5$~T and simulated using density functional calculations. We employ simple
phenomenological model of spin reorientation in finite magnetic field to
describe our experimental torque data. Our results strongly support collinear
model for magnetic structure in zero field with possibility of only very weak
canting. Torque measurements also indicate that, contrary to what is expected
for uniaxial antiferromagnet, in SeCuO$_3$ only part of the spins exhibit spin
flop instead all of them, allowing us to conclude that AFM state of SeCuO$_3$
is unconventional and comprised of two decoupled subsystems. Taking into
account previously proposed site-selective correlations and dimer singlet state
formation in this system, our results offer further proof that AFM state in
SeCuO$_3$ is composed of a subsystem of AFM dimers forming singlets immersed in
antiferromagnetically long-range ordered spins, where both states coexist on
atomic scale. Furthermore, we show, using an ab-initio approach, that both
subsystems contribute differently to the MAE, corroborating the existence of
decoupled subnetworks in SeCuO$_3$. Combination of torque magnetometry,
phenomenological approach and DFT simulations to magnetic anisotropy presented
here represents a unique and original way to study site-specific reorientation
phenomena in quantum magnets.
Single crystalline lead-substituted barium hexaferrite compounds are studied in a broad spectral range, 10 2 Hz to 2*10 14 Hz. We observe excitations of different nature including dielectric and ...magnetic relaxations coexisting within the same frequency and temperature ranges and electronic transitions between the fine-structure components of the split Fe 2 + ground state level.
We report on the magnetocrystalline anisotropy energy (MAE) and spin reorientation in antiferromagnetic state of spin \(S=1/2\) tetramer system SeCuO\(_3\) observed in torque magnetometry ...measurements in magnetic fields \(H<5\)~T and simulated using density functional calculations. We employ simple phenomenological model of spin reorientation in finite magnetic field to describe our experimental torque data. Our results strongly support collinear model for magnetic structure in zero field with possibility of only very weak canting. Torque measurements also indicate that, contrary to what is expected for uniaxial antiferromagnet, in SeCuO\(_3\) only part of the spins exhibit spin flop instead all of them, allowing us to conclude that AFM state of SeCuO\(_3\) is unconventional and comprised of two decoupled subsystems. Taking into account previously proposed site-selective correlations and dimer singlet state formation in this system, our results offer further proof that AFM state in SeCuO\(_3\) is composed of a subsystem of AFM dimers forming singlets immersed in antiferromagnetically long-range ordered spins, where both states coexist on atomic scale. Furthermore, we show, using an ab-initio approach, that both subsystems contribute differently to the MAE, corroborating the existence of decoupled subnetworks in SeCuO\(_3\). Combination of torque magnetometry, phenomenological approach and DFT simulations to magnetic anisotropy presented here represents a unique and original way to study site-specific reorientation phenomena in quantum magnets.
Magnetic properties of single crystals of the heterometallic complex Cu(bpy)\(_3\)\(_2\)Cr(C\(_2\)O\(_4\))\(_3\)NO\(_3\cdot \)9H\(_2\)O (bpy = 2,2'-bipyridine) have been investigated. From the ...recorded EPR spectra, the spin-Hamiltonian parameters have been determined. The magnetization measurements have shown magnetic anisotropy at low temperatures, which has been analysed as a result of the zero-field splitting of the Cr\(^{\mathrm{III}}\) ion. By fitting the exactly derived magnetization expression to the measured magnetization data, the axial zero-field splitting parameter, D, has been calculated. Comparing to the EPR measurements, it has been confirmed that \(D\) can be determined from the measurements of the macroscopic magnetization on the single crystals.
Nanoparticles of iron boride (Fe2B, Fe2B coated in SiO2, FexCo2−xB coated in SiO2) were synthesized
using the reduction of metal ions by sodium borohydride. X-ray diffraction confirms the amorphicity
...of the coated compounds and scanning electron microscope imaging revealed the nanoparticulated structure
of all compounds. The splitting between zero-field-cooled and field-cooled temperature dependent
magnetization curves point to the blocking of superparamagnetic particles magnetization. Magnetic hysteresis
loops are however consistent with the combined effects of blocked superparamagnetic and ferromagnetic
(multidomain) particles. The observed quite complex magnetic behaviour is in accordance with
structural studies, where additional phases and broad distribution of particle sizes were identified.
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IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UL, UM, UPUK
We performed literature search in the Pubmed database in July 2013. The key word used for search was cardiorenal syndrome type 2, limited to English language and humans. Over the last decade, a ...significant advance in the understanding of the cardiorenal syndrome has been achieved. However, precise pathogenesis remains to be clarified. Current treatment in postponing progression of cardiorenal syndrome type 2 is not efficient, although novel drugs like levosimendan and tezosentan seem promising. Future research is necessary to determine their role in the treatment of cardiorenal syndrome type 2.
U srpnju 2013. godine proveli smo pretraživanje literature u bazi podataka Pubmed. Ključna riječ je bila kardiorenalni sindrom tip 2, a pretraživanje ograničeno na radove koji su napisani na ...engleskom jeziku i koje se odnose na ljude. U ovaj pregled literature nismo uključili reference u postupku objave i sažetke. Iako je u posljednjem desetljeću postignut velik napredak u shvaćanju kardiorenalnog sindroma (KRS) točan patogenetski slijed njegova postanka i razvoja još nije do kraja razjašnjen. Samim time niti do sada poznata terapija ne može u potpunosti anulirati konektore u KRS. Uz standardnu terapiju koja je za sada nedovoljnog učinka u sprječavanju progresije KRS, obećavajući učinak imaju novi lijekovi poput levosimendana, antagonista adenozin A1 receptora i tezosentana.
Krpelji su artropodi i pripadaju rodu Artropoda, razredu paučnjaka (Arachnida), podrazredu Acaria, redu Parasitiformes, te se dijele u dvije dobro opisane obitelji: čvrsti krpelji (Ixodidae) i meki ...krpelji (Argasidae). Opisana je i treća obitelj, Nuttalliellidae, međutim s obzirom da pripadnici te vrste već duže nisu uzrokovani, nije poznata njena točna filogenetska povezanost s ostale dvije obitelji. Obitelj mekih krpelja (Argasidae) sastoji se od 193 vrste. Obitelj čvrstih krpelja (Ixodidae) sastoji se od 702 vrste svrstane u 14 rodova. Mnoge vrste krpelja igraju važnu ulogu u humanoj i veterinarskoj medicini kao vektori zaraznih bolesti poput: krpeljnog meningoencefalitisa (KME), Lyme borelioze, tularemije, erlihioze, mediteranske pjegave groznice, krimsko-kongoanske hemoragijske vrućice, itd.
Europski centar za prevenciju i nadzor bolesti (ECDC) prati kretanje i distribuciju krpelja i njihovih vrsta. U Europi se putem VectorNet mreže prate kretanja sljedećih vrsta krpelja: Dermacentor reticulatus, Hyalomma marginatum, Ixodes persulcatus, Ixodes ricinus, Ornithodorus spp i Rhipicephalus sanguineus.
Ixodes ricinus vrlo je rasprostranjen, a njegova distribucija seže od Portugala do Rusije, sjeverne Afrike do Skandinavije. Može preživjeti u različitim okolišnim uvjetima. Njegova distribucija se promijenila u mnogim zemljama posljednjih godina, tako da se može pronaći i na višim nadmorskim visinama i geografskim širinama. Krpelj vrste Ixodes ricinus uključen je u prijenos bolesti KME i Lyme borelioze.
U Republici Hrvatskoj je prema podacima Hrvatskog zavoda za javno zdravstvo u razdoblju od 2004. do 2017. godine, registrirano ukupno 5.834 slučajeva Lyme borelioze (godišnji prosjek 417 slučajeva), dok je u istom razdoblju na području grada Zagreba registrirano 1.774 slučajeva (godišnji prosjek 127 slučajeva). U promatranom razdoblju u Republici Hrvatskoj registrirano je ukupno 376 slučajeva KME (godišnji prosjek 27 slučajeva), dok je u istom razdoblju na području grada Zagreba registrirano 27 slučajeva KME (godišnji prosjek 2 slučaja). Podaci o oboljelim osobama dobiveni su iz službenih prijava zaraznih bolesti kao sastavnog dijela sustava obveznog prijavljivanja zaraznih bolesti u Republici Hrvatskoj.
Cijepljenje protiv KME i mjere osobne zaštite (odjeća, repelenti) imaju veliku važnost u individualnoj zaštiti osoba protiv bolesti koje prenose krpelji.
