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Abstract: We report on growth of MnTe layers by molecular beam epitaxy on Al2O3 substrates and of ZnTe layers on hybrid MnTe/Al2O3 substrates. The aim of our work was to prepare hexagonal phases of epitaxial thin films of these two materials. In the case of MnTe, the hexagonal NiAs-type phase was prepared by depositing the film directly on Al2O3 substrates. On the other hand, the crystal structure of ZnTe layers grown on hybrid MnTe/Al2O3 substrates was found to depend on the layer thickness: layers thinner than 0.05 μm grew in a metastable hexagonal wurtzite structure, but with further increases of the thickness, the cubic zinc blende phase of ZnTe tended to appear. The structural properties of MnTe and ZnTe layers were characterized by high energy electron and X-ray diffraction methods. Electrical properties of MnTe films were assessed by the Hall effect measurements. The topography and microstructure were analyzed by atomic force microscope. The Néel temperature and magnetic domains structure of antiferromagnetic hexagonal MnTe layers were obtained from neutron experiments. [Copyright &y& Elsevier]

Abstract: Static magnetic susceptibility and ESR spectra of layered semiconducting InSe crystals containing Mn were investigated. Solid solution In1−X Mn X Se is responsible for ferromagnetism at Curie temperature T C >270 K. Single wide line ESR spectrum was observed. It practically disappeared at 90 K. Paramagnetic constant background of magnetic susceptibility originates from atypical Van-Vleck Mn3+ (d4) ions, which are in a state of nonmagnetic singlet in crystal field, and magnetization of crystals in ferromagnetic state. Very narrow (2 Oe) line with g =1.999 appears at temperatures lower than 23 K which is apparently due to the electrons localized on the levels of space quantization. Two maxima at ∼160 K and ∼260 K are observed as the temperature dependence of magnetic susceptibility. They are obliged to inclusions of antiferromagnetic MnSe. At high magnetic fields of 6 and 50 kOe, the first peak widens and disappears. [Copyright &y& Elsevier]

Abstract: The electronic structure of Ge0.4 Mn0.5 Eu0.1 Te has been investigated by means of resonant photoemission spectroscopy. The spectra were acquired for the photon energy ranges of 130–155 and 40–60 eV corresponding to the Eu 4d   4f and Mn 3p   3d resonances, respectively. The features related to Eu 4f and Mn 3d states were revealed in the emission from the valence band. It was shown that europium ions occur as Eu2+. The Mn2+ 3d states contribute to the whole valence band with a maximum of the Mn 3d distribution at 3.9 eV. [Copyright &y& Elsevier]

Abstract: We fabricated a simple magnetoresistive microdevice formed by a narrow constriction of submicron width in the epitaxial film of a ferromagnetic (Ga,Mn)As semiconductor, and investigated magnetic properties of the film and the low-temperature charge-carrier transport through the constriction. We have revealed sharp jumps of a lowered conductance in a non-constricted sample and jumps of an enhanced conductance in the constricted one, which appeared when the sweeping magnetic field crossed the regions of the coercive field of the film. We argue that the both features result from a contribution of a magnetic domain wall to the conductance. While the spin-orbit interaction can be responsible for the negative contribution of a domain wall to the conductance, presumably the suppression of the weak localization effects by a domain wall located in the constriction results in the positive contribution to the conductance. [Copyright &y& Elsevier]

Abstract: Magnetoresistance of a semiconducting ferromagnetic nanostructure with a laterally constrained domain wall is analyzed theoretically in the limit of sharp domain walls and fully polarized electron gas is considered. The spin–orbit interaction of Rashba type is included into considerations. It is shown that the magnetoresistance in such a case can be relatively large, which is in a qualitative agreement with recent experimental observations. It is also shown that spin–orbit interaction can enhance the magnetoresistance. The role of localization corrections is also briefly discussed. [Copyright &y& Elsevier]

Abstract: We report on the fabrication of thin ZnO:N film by thermal oxidation of zinc nitride layers sputter-deposited on quartz, sapphire, GaN, and ZnO surfaces. Through optimising several crucial technological steps we have achieved p-type conductivity with the carrier concentration in mid 1017 cm−3 range and mobility of ∼10cm2/Vs. Rich photoluminescence spectra have been observed in the region corresponding to the fundamental energy gap region with peaks that can be related to acceptor bound exciton transitions. The transmittance of p-ZnO:N in the whole visible spectrum is ∼80%. [Copyright &y& Elsevier]

Thin layers of semimagnetic (diluted magnetic) Sn1−xMnxTe semiconductor with Mn content x⩽0.04 and layer thickness 0.2–2 μm were grown by molecular beam epitaxy (MBE) on BaF2 (1 1 1) substrates with SnTe buffer layer. Apart from SnTe and Mn fluxes, we employed an additional Te flux to provide the efficient way of controlling the deviation from stoichiometry in the layers. By manipulating the MBE growth conditions we obtained SnMnTe crystalline layers with the conducting hole concentration in the range from p=5×1019 cm−3 (no extra Te flux) to p=2×1021 cm−3 (additional Te flux present). In the layers grown under extra Te flux conditions we observe ferromagnetic transition with the Curie temperature TC⩽6 K (depending on both x and p). Layers with the same Mn content but grown with no extra Te flux are paramagnetic. This dramatic change of magnetic properties, referred to as a carrier concentration-induced ferromagnetic transition, can be understood in the framework of a model attributing the ferromagnetic interactions in SnMnTe to the mechanism of indirect exchange via conducting holes (Ruderman–Kittel–Kasuya–Yosida interaction). [Copyright &y& Elsevier]

Quantum effects characteristic of mesoscopic systems have been revealed in a study of vertical electron transport through GaAs-based heterostructures with a small lattice mismatch. At low temperatures and under strong magnetic field applied parallel to the axes of misfit dislocations generated at the interface, they manifest themselves as regular conductance fluctuations, appearing as a function of applied voltage and magnetic field. We interpret these fluctuations as being caused by trapping of charge carriers on quasi-stationary orbits, formed around the charged dislocations. [Copyright &y& Elsevier]

In this paper, we report on the effect of excess manganese on the magnetic properties of the (La0.7Ca0.3)1−xMn1+xO3 perovskites. All samples display a colossal magnetoresistance effect which becomes considerably enhanced with increasing manganese content. The magnetic behaviour of manganites studied was shown to depend strongly on the values of manganese doping and applied magnetic field. For the samples with x=0.1 and 0.2, in addition to an anomaly connected with paramagnet–ferromagnet transition, there are anomalies in the field-cooled (FC) and zero-field-cooled (ZFC) magnetization at low temperatures. In low magnetic fields (H<150 Oe), the MFC(T) curves have a kink near TC, and the FC and ZFC magnetization drop appears below 45 K. In applied fields of H>200 Oe, a jump upwards takes place in the MFC(T) and MZFC(T) curves at the same temperature. A low-temperature anomaly in AC susceptibility also indicates a change in magnetic ordered state. From M(T,H) and χ(T) dependencies, one can assume the existence of regions with different magnetic order at T<45 K: a main part of the sample being a ferromagnetically ordered one and a minor one being a noncollinear state. The latter is most probably to present mesoscopic inhomogeneity containing clusters with canted spin structure. The large irreversibility in the FC and ZFC magnetization arises due to the blocking of cluster magnetic moment below TC. [Copyright &y& Elsevier]

Abstract: It is expected that joint existence of ferromagnetic properties and ferroelectric structural phase transition in diluted magnetic semiconductors IV–VI leads to new possibilities of these materials. Temperature of ferroelectric transition for such crystals can be tuned by the change of Sn/Ge ratio. Magnetic susceptibility, Hall effect, resistivity and thermoelectric power of Ge1− x − y Sn x Mn y Te single crystals grown by Bridgeman method (x=0.083–0.115; y=0.025–0.124) were investigated within 4.2–300K. An existence of FM ordering at T C∼50K probably due to indirect exchange interaction between Mn ions via degenerated hole gas was revealed. A divergence of magnetic moment temperature dependences at T⩽T C in field-cooled and zero-field-cooled regimes is obliged to magnetic clusters which are responsible for superparamagnetism at T>T C≈T f (freezing temperature) and become ferromagnetic at T C arranging spin glass state at T

We present the studies of structural, magnetic, and magnetotransport properties of Cd1-x-y Mnx Zny SnAs2 crystals with the average Mn contents x changing from 0.013 to 0.170 and Zn contents y varying from 0.002 to 0.051. Homogenous distribution of Mn ions is observed for the samples with x = 0.025. The presence of Mn As clusters in the studied alloy for x > 0.025 induces room-temperature ferromagnetism with the Curie temperature TC, with values around 325K. High crystal quality leads to high carrier mobility values observed for all of our samples, as high as 7100 cm²/(Vs) for x = 0.025 and y = 0.028. The Shubnikov-de Haas oscillations are observed at T = 50 K for all of our samples. The oscillations allowed the calculation of the effective mass m*, giving values of about 0.11-0.12me. The presence of magnetic impurities has a strong influence on the magnetoresistance of the alloy. For the samples with x = 0.076, the Shubnikov-de Haas oscillations are observed on the background of a strong linear positive magnetoresistance, present up to room temperature. The maximum values of the linear positive magnetoresistance are close to 200% for the sample with x = 0.170 and y = 0.002, at T = 1.5K. This positive magnetoresistance is related to the presence of Mn As clusters in the semiconductor lattice. [ABSTRACT FROM AUTHOR]

Abstract: The electronic structure of polycrystalline Ge0.86Mn0.14Te—ferromagnetic semiconductor with T C=110K, has been studied by means of resonant photoemission spectroscopy for photon energies close to the Mn 3p→3d excitation. The contribution of Mn 3d states to the electronic structure of the system was revealed and position of the Mn ions in the crystal, characteristic of GeTe-based diluted magnetic semiconductors was proved. [Copyright &y& Elsevier]

Photocurrent-voltage characteristic (PC-V) is a method of determining the critical parameter in X-ray and gamma-ray detector plates, i.e., the carrier mobility-lifetime product, μτ. We show for the (Cd,Mn)Te samples that the measurement results depend strongly on the surface treatment and the space charge distribution. The PC-V characteristics obtained for ħω > Eg and ħω ~ Eg indicated that etching with 20% HCl caused an appearance of a significant concentration of very shallow surface traps at the (Cd,Mn)Te sample surface. These traps seriously changed the results of measurements of PC-V characteristics and PC kinetics. We also noticed a small contribution of holes to photoconductivity in the PC kinetics. The measurements of PC-V characteristics for ħω > Eg may test the detector plate surface quality.

We present the studies of structural, transport and magnetotransport properties of [Formula: see text]Cd x GeAs 2 crystals with the chemical content changing from 0 to 1. The structural studies indicate that this alloy exists as a composite two-phase material in almost the entire range of average chemical compositions. The two phase nature of our samples does have a significant influence on the carrier transport and magnetotransport of the composite alloy. The change of the conductivity type is observed at room temperature, from p-type for [Formula: see text] to n-type for x  >  0.18, respectively. The Hall carrier mobility measured at room temperature decreases as a function of x from about 35 cm 2 (V · s) -1 for the sample with x  =  0 down to 3 cm 2 (V · s) -1 for the sample with x  =  0.233. For x  >  0.233 the Hall carrier mobility shows an increase with x, up to the highest value around 875 cm 2 (V · s) -1 observed for the sample with x  =  1. Temperature dependent resistivity measurements indicate the presence of thermal activation of carriers with activation energy, E a , with values from 20 to 30 meV for all the studied samples. The temperature dependent Hall effect data show that the grain boundary limited transport is strong in all our samples. For the samples with [Formula: see text] the negative MR is observed at temperatures lower than 100 K and at low magnetic field values, [Formula: see text] T. This effect is interpreted as a weak localization phenomenon with low values of phase coherence length, [Formula: see text] nm.

We present studies of structural, magnetic, and electrical properties of Zn1-x Mn x SnSb2+MnSb nanocomposite ferromagnetic semiconductors with the average Mn-content, [Formula: see text], changing from 0.027 up to 0.138. The magnetic force microscope imaging done at room temperature shows the presence of a strong signal coming from MnSb clusters. Magnetic properties show the paramagnet-ferromagnet transition with the Curie temperature, T C, equal to about 522 K and the cluster-glass behavior with the transition temperature, T CG, equal to about 465 K, both related to MnSb clusters. The magnetotransport studies show that all investigated samples are p-type semiconductors with high hole concentration, p, changing from 10(21) to 10(22) cm(-3). A large increase in the resistivity as a function of the magnetic field is observed at T  <  10 K and small magnetic fields, [Formula: see text] mT, for all the studied samples with a maximum amplitude of the magnetoresistance about 460% at T  =  1.4 K. The large increase in the resistivity is most probably caused by the appearance of the superconducting state in the samples at T  <  4.3 K.

Aims: Evaluation of safety and efficacy of ProNOVA XR, a new generation of polymer-free sirolimus eluting stents (SES), utilizing a pharmaceutical excipient for timed release of sirolimus from the XR platform., Methods and Results: Safety and efficacy of ProNOVA XR coronary stent system was examined in EURONOVA prospective, single arm, multi-center registry of 50 patients with de novo native coronary lesions up to 28 mm in length in arteries between 2.25 and 4 mm. At 6-month, in-stent late lumen loss by QCA was 0.45 ± 0.41 mm and in-stent neointimal volume obstruction in the IVUS sub-study was 14 ± 11%. One-year clinical follow-up revealed a favorable safety profile, with 2% of in-hospital MACE and 6.4% of MACE from hospital discharge up to 12 months (including 1 cardiac death >30 days after stent implantation and 2 TLRs). According to the ARC definition, there was no definite or probable stent thrombosis and 1 possible stent thrombosis (2%) up to 12 months of clinical follow-up., Conclusions: In this preliminary evaluation, ProNOVA XR polymer-free sirolimus eluting stent system appeared safe with an early promise of adequate effectiveness in the treatment of de novo coronary lesions in up to 12 months of clinical, angiographic and IVUS follow-up., (Copyright © 2013 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.)

Wellens syndrome is characterised by negative or biphasic T waves in V2-V4 leads and critical stenosis of proximal part of the left descending coronary artery. These ECG changes without atherosclerotic changes in coronary angiography, i.e. coronary artery spasm are called pseudo-Wellens syndrome. We describe a patient with acute coronary syndrome and pseudo-Wellens syndrome as a cause of vasospastic angina. These ECG abnormalities need differentiation with acute pulmonary embolism.

Aims: The MGuard stent (bare metal stent wrapped externally with a polymer mesh sleeve) is designed to prevent distal embolisation by reducing thrombus and plaque fragments released during and post percutaneous coronary intervention (PCI). The aim of this study was to confirm the clinical feasibility, safety and performance of the MGuard stent during primary PCI for ST-segment elevation myocardial infarction (STEMI)., Methods and Results: The present study was a multicentre, prospective, single arm study in which 60 patients with STEMI <12 hours were enrolled. Predilatation was performed in 61.7% of the cases and thrombus aspiration in 18.3%. In one (1.7%) patient the stent could not cross the lesion. Final TIMI grade 3 flow was observed in 90.0% of patients, with myocardial blush grade 3 in 73.3% of patients and complete (>70%) ST-segment resolution 60 minutes after PCI in 61.4% of patients. In 5.0% of cases distal embolisation occurred. The total major adverse cardiac events rate during the 6-month follow-up was 1.7%., Conclusions: Based on this experience, the MGuard stent implantation in STEMI patients is safe and highly effective. A larger randomised trial is warranted to confirm the clinical endpoints.

Early rapid platelet inhibition with abciximab before primary percutaneous coronary intervention (PPCI) for ST-segment elevation myocardial infarction (STEMI) is suggested as beneficial. In previous studies on early abciximab administration clopidogrel was administered in cathlab in low loading dose. We investigated the role of early abciximab administration on top of early clopidogrel 600 mg loading dose in patients with STEMI treated with PPCI. A total of 73 non-shock STEMI < 6 h patients admitted to remote hospitals with anticipated delay to PPCI < 90 min were randomly assigned to three study groups--24 pts received abciximab before transfer to cathlab (early = group EA), 27 in cathlab during PPCI (late = group LA) and in 22 abciximab administration was left to operator's discretion during PPCI (selective = SA; given in 22.7% of patients). All patients received clopidogrel (600 mg), aspirin and heparin (70 U/kg) before transfer to cathlab. Angiography revealed more frequent infarct-related artery patency (TIMI 2 + 3: EA vs LA vs SA: 45.8 vs 18.5 vs 13.6%, P = 0.024), better myocardial tissue perfusion (MBG 2 + 3: EA vs LA vs SA: 45.8 vs 14.8 vs 13.6%, P = 0.02) in EA group in baseline angiography. There was no difference in these angiographic parameters and ECG ST-segment resolution after PPCI. In multivariate analysis early abciximab administration was an independent predictor of infarct-related artery patency in baseline angiography (OR 6.5; 95% CI 1.83-23.1; P = 0.004). Early abciximab administration before transfer for PPCI in patients with STEMI pretreated with 600 mg of clopidogrel results in more frequent infarct-related artery patency and better myocardial tissue perfusion before PPCI.

We present a case of a 78-year-old female who was admitted to the hospital due to clinical and electrographic features of ST-elevation acute myocardial infarction. Coronary angiography revealed normal coronary arteries and severe left ventricular contractility abnormalities, detected initially by echocardiography, which resolved within 20 days from hospital admission. Because of these findings and typical echocardiographic picture, a transient left ventricular apical ballooning syndrome (the tako-tsubo syndrome) was diagnosed.

In a nitrogen (N) saturated forest downwind from Los Angeles, California, the cumulative response to long-term background-N and N-amendment on black oak (Quercus kelloggii) was described in a below-average and average precipitation year. Monthly measurements of leaf and branch growth, gas exchange, and canopy health attributes were conducted. The effects of both pollutant exposure and drought stress were complex due to whole tree and leaf level responses, and shade versus full sun leaf responses. N-amended trees had lower late summer carbon (C) gain and greater foliar chlorosis in the drought year. Leaf water use efficiency was lower in N-amended trees in midsummer of the average precipitation year, and there was evidence of poor stomatal control in full sun. In shade, N-amendment enhanced stomatal control. Small differences in instantaneous C uptake in full sun, lower foliar respiration, and greater C gain in low light contributed to the greater aboveground growth observed.

A novelty of the present studies is the use of alpha 1-antitrypsin (A-1--AT) as an endogenous marker of enteric protein loss. Enteric clearance of alpha 1-antitrypsin was determined in 10 patients with the symptoms of PLE, and in 6 healthy individuals. Alpha 1-Antitrypsin concentration has been assayed in single, random samples of feces collected from 42 patients and 12 healthy individuals (normal values: 1.31 +/- 0.72 mg/g of feces). Markedly increased enteric clearance and A-1-AT concentrations in single, random samples of feces have been found in patients with enteric lymphangiectasis, Crohn's disease, ulcerative colitis, and constrictive pericarditis, slightly lower in coeliac, chronic diarrhoea, nonspecific hemorrhagic colitis, esophagitis, lambliasis, hypogammaglobulinemia, Wiskott-Aldrich syndrome, Rendu-Osler-Weber syndrome, hepatitis in newborn, and Gilbert's disease. Statistically significant positive clearance has been noted (r = 0.997; p less than .001). A single assay of A-1-AT in feces is simple, repeatable, and sensitive technique in the diagnosis and evaluation of these diseases in which the symptoms of enteric protein loss are seen.

LH and prolactin were measured in plasma of 5 cows before and after enucleation of the persistent corpus luteum. Two cows returned to normal oestrous cycles following enucleation and did not differ from normal, cycling cows, with respect to hormone levels. Three other ones developed follicular cysts following enucleation and had decreased levels of LH and prolaction as compared with cycling cows. On the day of enucleation the fluctuations in LH-levels were higher than either before or after enucleation.

Epizootiological studies on lamb losses on a large scale farm (4.5 thousand mothers) were carried out. The results of the studies denied the direct effect of maize silage on the genesis of enzootia of listeriosis. The earlier reports were confirmed, i.e. that the direct cause of enzootia of listeriosis is the weakening of an animal organism due to other microbiological, zoohigienical, nutritional factors (e.g. not proper content of mineral compounds). Maize silage has a destructive effect on the health of lambs as well as other fodders with unsuitable biochemical composition. The results of the studies were prepared in Basic language using Hellwig's method "Determination of the maximum capacity of data carrier", to enable the automation of statistical data. Verification of the above mentioned method was done on the basis of the results of the studies performed on a sheep farm. Essential influence of the content of magnesium and iron as well as statistically known interdependencies between the indices studied were revealed and confirmed. "Listing" of the programme; data and result printout, to be used widely, was enclosed.