3,168 research outputs found
Probing the role of Nd3+ ions in the weak multiferroic character of NdMn2O5 by optical spectroscopies
Raman and infrared spectroscopies are used as local probes to study the
dynamics of the Nd-O bonds in the weakly multiferroic NdMn2O5 system. The
temperature dependence of selected Raman excitations reveals the splitting of
the Nd-O bonds in NdMn2O5. The Nd3+ ion crystal field (CF) excitations in
NdMn2O5 single crystals are studied by infrared transmission as a function of
temperature, in the 1800-8000 cm-1 range, and under an applied magnetic field
up to 11 T. The frequencies of all 4Ij crystal-field levels of Nd3+ are
determined. We find that the degeneracy of the ground-state Kramers doublet is
lifted ({\Delta}0 ~7.5 cm-1) due to the Nd3+-Mn3+ interaction in the
ferroelectric phase, below TC ~ 28 K. The Nd3+ magnetic moment mNd(T) and its
contribution to the magnetic susceptibility and the specific heat are evaluated
from {\Delta}0(T) indicating that the Nd3+ ions are involved in the magnetic
and the ferroelectric ordering observed below ~ 28 K. The Zeeman splitting of
the excited crystal field levels of the Nd3+ ions at low temperature is also
analyzed.Comment: This paper is accepted for publication as a Regular Article in
Physical Review
ECSA Special Issue
Over 500 delegates took part in the third international ECSA conference in September 2020. Across 30 sessions, as well as keynote talks, e-poster presentations and more informal settings, they discussed and debated a diverse range of subjects related to citizen science. This special edition of âJCOMâ brings together some of the central themes that were under the spotlight at ECSA 2020. Since ECSA 2020 has been one of the first examples of a conference that moved completely online, and it has been considered a big success, we also include the Conference Report, as supplementary material with this editorial
Quantum Hall Effect on the Grassmannians
Quantum Hall Effects (QHEs) on the complex Grassmann manifolds
are formulated. We set up the Landau problem in
and solve it using group theoretical techniques
and provide the energy spectrum and the eigenstates in terms of the
Wigner -functions for charged particles on
under the influence of abelian and non-abelian
background magnetic monopoles or a combination of these thereof. In particular,
for the simplest case of we explicitly write down
the background gauge field as well as the single and many-particle
eigenstates by introducing the Pl\"{u}cker coordinates and show by calculating
the two-point correlation function that the Lowest Landau Level (LLL) at
filling factor forms an incompressible fluid. Our results are in
agreement with the previous results in the literature for QHE on and generalize them to all in a suitable
manner. Finally, we heuristically identify a relation between the Hall
effect on and the Hall effect on the odd sphere
, which is yet to be investigated in detail, by appealing to the already
known analogous relations between the Hall effects on and
and those on the spheres and , respectively.Comment: 34 pages, revtex 4-1, Minor Correction
Characterization of a novel zebrafish (Danio rerio) gene, wdr81, associated with cerebellar ataxia, mental retardation and dysequilibrium syndrome (CAMRQ)
Background: WDR81 (WD repeat-containing protein 81) is associated with cerebellar ataxia, mental retardation and disequilibrium syndrome (CAMRQ2, [MIM 610185]). Human and mouse studies suggest that it might be a gene of importance during neurodevelopment. This study aimed at fully characterizing the structure of the wdr81 transcript, detecting the possible transcript variants and revealing its expression profile in zebrafish, a powerful model organism for studying development and disease. Results: As expected in human and mouse orthologous proteins, zebrafish wdr81 is predicted to possess a BEACH (Beige and Chediak-Higashi) domain, a major facilitator superfamily domain and WD40-repeats, which indicates a conserved function in these species. We observed that zebrafish wdr81 encodes one open reading frame while the transcript has one 5' untranslated region (UTR) and the prediction of the 3' UTR was mainly confirmed along with a detected insertion site in the embryo and adult brain. This insertion site was also found in testis, heart, liver, eye, tail and muscle, however, there was no amplicon in kidney, intestine and gills, which might be the result of possible alternative polyadenylation processes among tissues. The 5 and 18 hpf were critical timepoints of development regarding wdr81 expression. Furthermore, the signal of the RNA probe was stronger in the eye and brain at 18 and 48 hpf, then decreased at 72 hpf. Finally, expression of wdr81 was detected in the adult brain and eye tissues, including but not restricted to photoreceptors of the retina, presumptive Purkinje cells and some neurogenic brains regions. Conclusions: Taken together these data emphasize the importance of this gene during neurodevelopment and a possible role for neuronal proliferation. Our data provide a basis for further studies to fully understand the function of wdr81. © 2015 Doldur-Balli et al
Characterization of arils juice and peel decoction of fifteen varieties of punica granatum l.: a focus on anthocyanins, ellagitannins and polysaccharides
Pomegranate is receiving renewed commercial and scientific interest, therefore a deeper knowledge of the chemical composition of the fruits of less studied varieties is required. In this work, juices from arils and decoctions from mesocarp plus exocarp were prepared from fifteen varieties. Samples were submitted to High Performance Liquid ChromatographyâDiode Array DetectorâMass Spectrometry, spectrophotometric and colorimetric CIEL* a* b* analyses. Antioxidant, antiradical and metal chelating properties, inhibitory activity against tyrosinase and α-amylase enzymes were also evaluated. All varieties presented the same main phenols; anthocyanins and ellagitannins were widely variable among varieties, with the richest anthocyanin content in the juices from the Wonderful and Soft Seed Maule varieties (approx. 660 mg/L) and the highest ellagitannin content in the peel of the Black variety (approx. 133 mg/g dry matter). A good correlation was shown between the colour hue and the delphinidin/cyanidin ratio in juices (R 2= 0.885). Total polysaccharide yield ranged from 3% to 12% of the peelsâ dry weight, with the highest content in the Black variety. Decoctions (24.44â118.50 mg KAE/g) showed better in vitro antioxidant properties and higher inhibitory capacity against tyrosinase than juices (not active-16.56 mg KAE/g); the inhibitory capacity against α-amylase was similar and quite potent for juices and decoctions. Knowledge about the chemical composition of different pomegranate varieties will allow for a more aware use of the different parts of the fruit
Coronary arterial anomalies in a large group of patients undergoing coronary angiography in southeast Turkey
Background: The prevalence of coronary artery anomalies (CAA) are reportedbetween 0.6â1.3% in the literature. CAA are usually asymptomatic incidental findings, but they may deteriorate coronary circulation, cause symptoms andlead to sudden cardiac death; especially in young athletes. Since interventionalprocedures are increasing rapidly for treatment of coronary artery disease (CAD) inthe modern era, comprehensive understanding of CAA is becoming progressively critical element in dealing with CAD.Materials and methods: We reviewed the database of the Cardiac Catheterisation Laboratory of Sani Konukoglu University Hospital in Gaziantep, Turkey. All patientswho were subjected to coronary angiography from 1998 to 2006 were included.Results: Among 53,655 coronary angiographies performed, CAA were foundin 653 patients (incidence of 1.21%); 590 (90.3%) patients had anomalies oforigin and distribution and 63 (11.7%) had coronary fistulae. Separate origins ofleft anterior descending (LAD) and left circumflex (LCX) coronary artery from theleft sinus of Valsalva was the most common anomaly (64.1%). Coronary arteriesbranching from anomalous aortic origin was the second most common anomaly(16.5%). Right coronary artery (RCA) originating from left sinus of Valsalva or leftmain coronary artery (LMCA) was observed in 55 (8.4%) patients, LCX arising fromRCA or right sinus of Valsalva (RSV) was seen in 52 (7.9%) patients and LMCA orLAD originating from RSV was seen in 14 (0.2%) patients. There were 16 (2.45%) patients with single coronary artery and 1 (0.15%) patient with LMCA originating from pulmonary artery.Conclusions: The incidence and the pattern of CAA in our patient population were similar with previous studies. Angiographic recognition of these vessels is importantbecause of their clinical significance and importance in patients undergoing coronary angioplasty or cardiac surgery
Activator Protein-1 Transcriptional Activity Drives Soluble Micrograft-Mediated Cell Migration and Promotes the Matrix Remodeling Machinery
Impaired wound healing and tissue regeneration have severe consequences on the patient's quality of life. Micrograft therapies are emerging as promising and affordable alternatives to improve skin regeneration by enhancing the endogenous wound repair processes. However, the molecular mechanisms underpinning the beneficial effects of the micrograft treatments remain largely unknown. In this study, we identified the active protein-1 (AP-1) member Fos-related antigen-1 (Fra-1) to play a central role in the extracellular signal-regulated kinase- (ERK-) mediated enhanced cell migratory capacity of soluble micrograft-treated mouse adult fibroblasts and in the human keratinocyte cell model. Accordingly, we show that increased micrograft-dependent in vitro cell migration and matrix metalloprotease activity is abolished upon inhibition of AP-1. Furthermore, soluble micrograft treatment leads to increased expression and posttranslational phosphorylation of Fra-1 and c-Jun, resulting in the upregulation of wound healing-associated genes mainly involved in the regulation of cell migration. Collectively, our work provides insights into the molecular mechanisms behind the cell-free micrograft treatment, which might contribute to future advances in wound repair therapies
The Value of Handheld Computers in Constructionâ,
ABSTRACT: Construction is an information intensive industry in which the accuracy and timeliness of information is paramount. Construction projects can experience extensive delays or rework due to information that is unavailable, inaccurate or simply outdated. Handheld computers (HHC) have the potential to solve some of these problems by providing field workers with accurate, reliable and timely information at the location where it is needed. Thus, HHC's can increase the amount of direct work on a project indirectly by directly decreasing the time spent on support work (such as accessing drawings and sending RFI's) and by reducing idle time. Applying a HHC evaluation method to 6 hypothetical construction field activities (punchlisting, materials tracking, MSDS access, drawing access, RFI's, and quantity surveying) showed that HHC's could potentially save time and improve accuracy at the task and activity levels of a construction project. However, barriers related to the HHC's technological limitations and to the nature of the construction industry must be overcome in order to reap the full benefits of HHC's
Engineering the magnetic and magnetocaloric properties of PrVO3 epitaxial oxide thin films by strain effects
Combining multiple degrees of freedom in strongly-correlated materials such
as transition-metal oxides would lead to fascinating magnetic and
magnetocaloric features. Herein, the strain effects are used to markedly tailor
the magnetic and magnetocaloric properties of PrVO3 thin films. The selection
of appropriate thickness and substrate enables us to dramatically decrease the
coercive magnetic field from 2.4 T previously observed in sintered PVO3 bulk to
0.05 T for compressive thin films making from the PrVO3 compound a nearly soft
magnet. This is associated with a marked enhancement of the magnetic moment and
the magnetocaloric effect that reach unusual maximum values of roughly 4.86 uB
and 56.8 J/kg K in the magnetic field change of 6 T applied in the sample plane
at the cryogenic temperature range (3 K), respectively. This work strongly
suggests that taking advantage of different degrees of freedom and the
exploitation of multiple instabilities in a nanoscale regime is a promising
strategy for unveiling unexpected phases accompanied by a large magnetocaloric
effect in oxides.Comment: This paper is accepted for publication in Applied Physics Letter
Magnetocaloric properties of Fe_{2-x}T_xP (T = Ru and Rh) from electronic structure calculations and magnetisation measurements
An analysis of the magnetocaloric properties of the pure and substituted Fe2P
compounds is made based on KKR-CPA electronic structure calculations and
magnetisation M(H,T) measurements. The computed electronic densities of states
and magnetic moments are used to calculate both the values of the electronic
and magnetic entropies, which fairly agree with the experimental findings. To
enlighten the magnetic properties above Curie temperature, the paramagnetic
state behaviours are simulated using the disordered local moments (DLM)
concept. The KKR-CPA computations show, that in Fe2P, the Fe magnetic moment of
the (3f) site disappears in the DLM state, while the moment of the (3g) site is
only little lowered, comparison made with the low temperature ferromagnetic
state.Comment: 17 pages, 8 figures, Submitted to J. Phys.
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