Magnetic phase diagram and transport properties of FeGe_2

We have used resistivity measurements to study the magnetic phase diagram of the itinerant antiferromagnet FeGe_2 in the temperature range from 0.3->300 K in magnetic fields up to 16 T. In contrast to theoretical predictions, the incommensurate spin density wave phase is found to be stable at least up to 16 T, with an estimated critical field \mu _0H_c of ~ 30 T. We have also studied the low temperature magnetoresistance in the [100], [110], and [001] directions. The transverse magnetoresistance is well described by a power law for magnetic fields above 1 T with no saturation observed at high fields. We discuss our results in terms of the magnetic structure and the calculated electronic bandstructure of FeGe_2. We have also observed, for the first time in this compound, Shubnikov-de Haas oscillations in the transverse magnetoresistance with a frequency of 190 +- 10 T for a magnetic field along [001].Comment: 13 pages, RevTeX, 7 postscript figures, to appear in Journal of Physics: Condensed Matte

Dissipative Van der Waals interaction between a small particle and a metal surface

We use a general theory of the fluctuating electromagnetic field to calculate the friction force acting on a small neutral particle, e.g., a physisorbed molecule, or a nanoscale object with arbitrary dispersive and absorptive dielectric properties, moving near a metal surface. We consider the dependence of the electromagnetic friction on the temperature $T$, the separation $d$, and discuss the role of screening, non-local and retardation effects. We find that for high resistivity materials, the dissipative van der Waals interaction can be an important mechanism of vibrational energy relaxation of physisorbed molecules, and friction for microscopic solids. Several controversial topics related to electromagnetic dissipative shear stress is considered. The problem of local heating of the surface by an STM tip is also briefly commented on.Comment: 11 pages, No figure

Electromagnetic field correlations near a surface with a nonlocal optical response

The coherence length of the thermal electromagnetic field near a planar surface has a minimum value related to the nonlocal dielectric response of the material. We perform two model calculations of the electric energy density and the field's degree of spatial coherence. Above a polar crystal, the lattice constant gives the minimum coherence length. It also gives the upper limit to the near field energy density, cutting off its $1/z^3$ divergence. Near an electron plasma described by the semiclassical Lindhard dielectric function, the corresponding length scale is fixed by plasma screening to the Thomas-Fermi length. The electron mean free path, however, sets a larger scale where significant deviations from the local description are visible.Comment: 15 pages, 7 figure files (.eps), \documentclass[global]{svjour}, accepted in special issue "Optics on the Nanoscale" (Applied Physics B, eds. V. Shalaev and F. Tr\"ager

Once versus three times daily dosing of oral budesonide for active Crohn's disease : A double-blind, double-dummy, randomised trial

Note: J.Pokrotnieks is in the list of the main authors of the article, as well as in the list of International Budenofalk Study Group collaboration list. His surname is made visible as the main author in this bibliographic record. Funding Information: The study was funded by Dr Falk Pharma GmbH, Freiburg, Germany . The study sponsor contributed to the design of the study in collaboration with the authors, funded the analysis of the data by an independent biostatistics company, worked in conjunction with the authors to interpret the data, and reviewed the draft manuscript. The sponsor was not involved in data collection. The final decision to publish was made by the first author (AD).Background: Oral budesonide 9. mg/day represents first-line treatment of mild-to-moderately active ileocolonic Crohn's disease. However, there is no precise recommendation for budesonide dosing due to lack of comparative data. A once-daily (OD) 9. mg dose may improve adherence and thereby efficacy. Methods: An eight-week, double-blind, double-dummy randomised trial compared budesonide 9. mg OD versus 3. mg three-times daily (TID) in patients with mild-to-moderately active ileocolonic Crohn's disease. Primary endpoint was clinical remission defined as CDAI < 150 at week 8 (last observation carried forward). Results: The final intent-to-treat population comprised 471 patients (238 [9 mg OD], 233 [3 mg TID]). The confirmatory population for the primary endpoint analysis was the interim per protocol population (n = 377; 188 [9 mg OD], 189 [3 mg TID]), in which the primary endpoint was statistically non-inferior with budesonide 9. mg OD versus 3. mg TID. Clinical remission was achieved in 71.3% versus 75.1%, a difference of - 3.9% (95% CI [- 14.6%; 6.4%]; p = 0.020 for non-inferiority). The mean (SD) time to remission was 21.9 (13.8) days versus 21.4 (14.6) days with budesonide 9 mg OD versus 3. mg TID, respectively. In a subpopulation of 122 patients with baseline SES-CD ulcer score ≥ 1, complete mucosal healing occurred in 32.8% (21/64) on 9 mg OD and 41.4% (24/58) on 3 mg TID; deep remission (mucosal healing and clinical remission) was observed in 26.6% (17/64) and 32.8% (19/58) of patients, respectively. Treatment-emergent suspected adverse drug reactions were reported in 4.6% of 9 mg OD and 4.7% of 3 mg TID patients. Conclusions: Budesonide at the recommended dose of 9 mg/day can be administered OD without impaired efficacy and safety compared to 3 mg TID dosing in mild-to-moderately active Crohn's disease.publishersversionPeer reviewe

ОСОБЕННОСТИ ОСТРЫХ НАРУШЕНИЙ МОЗГОВОГО КРОВООБРАЩЕНИЯ В РОССИЙСКОЙ ФЕДЕРАЦИИ И КИТАЙСКОЙ НАРОДНОЙ РЕСПУБЛИКЕ (по данным нескольких крупных сосудистых центров)

The study focuses on comparison and analysis of the work of big stroke units in the Russian Federation and the People’s Republic of China specialized in the medical care for patients with acute stroke. 522 patients were surveyed in Russia’s and China’s regional stroke units. In the Russian Federation, patients being treated in the «City Hospital No.26» (SaintPetersburg) took part in the study. In China patients of the First Affiliated Hospital of the Chongqing Medical University, Central Hospital Jiang jin, Regional People’s Hospital Yubei district, Regional People’s Hospital Bishan (Chongqing Province). The analysis of differences was performed by the following parameters: personality traits, age, gender, level of education, income, health insurance category, profession, employment, professional activities over the last year, place of residence of the patient, features of the stroke, time during the first symptoms of stroke to hospitalization, kinds of medical services, the main risk factors and value of prevention before stroke.Исследование посвящено сравнительному анализу работы крупных сосудистых центров в Российской Федерации и Китайской Народной Республике по оказанию помощи пациентам с острым нарушением мозгового кровообращения (ОНМК). Был проведен опрос 522 пациентов в региональных сосудистых центрах РФ и КНР. В РФ в исследовании приняли участие пациенты, находящиеся на лечении в СПбГБУЗ «Городская больница № 26»; в КНР – пациенты Первой клинической больницы медицинского университета Чунцина, Центральной больницы Цзян Цзинь, Региональной народной больницы Юйбэй, Региональной народной больницы Бишань (провинция Чунцин). Был проведен анализ различий по следующим показателям: личностные факторы пациента, возраст, пол, уровень образования, уровень дохода, вид медицинского страхования, профессия, занятость, профессиональная деятельность в течение последнего года, место жительства пациента, особенности заболевания, время с момента появления первых симптомов до госпитализации, спектр оказываемых медицинских услуг, основные факторы риска и объем профилактики инсульта до заболевания

Van der Waals-Casimir-Polder interaction of an atom with a composite surface

We study the dispersion interaction of the van der Waals and Casimir-Polder (vdW-CP) type between a neutral atom and the surface of a metal by allowing for nonlocal electrodynamics, i.e. electron diffusion. We consider two models: (i) bulk diffusion, and (ii) diffusion in a surface charge layer. In both cases the transition to a semiconductor is continuous as a function of the conductivity, unlike the case of a local model. The relevant parameter is the electric screening length and depends on the carrier diffusion constant. We find that for distances comparable to the screening length, vdW-CP data can distinguish between bulk and surface diffusion, hence it can be a sensitive probe for surface states.Comment: v2: expanded references, statements on current status in the field. 10 pages, 6 figure

mental data, the frequencies of transverse phonons (700 cm Quantum control of atoms and photons by optical nanoébers

À1 ) and longitudinal oscillations (890 cm À1 ), as well as their oscillator strengths, were obtained for 1-and 2-nm-thick AlN films [8] and for 25-and 400-nm-thick AlN films on sapphire [9]. It would seem that follow-up studies of the optical characteristics of AlN during monolayer-by-monolayer growth would provide answers to very important questions, namely, how the AlN layers are formed, how their characteristics change due to great stresses in them caused by a large mismatch between lattice constants, and how the surface layers of sapphire are transformed. Unfortunately, direct surface-nonperturbing methods for measuring the fluctuating fields of surface electromagnetic excitations are absent at present, and the near-field spectroscopy (in the ATR regime) appears to be the most`delicate&apos; technique for studying the surface of crystals and thin films deposited on them. Conclusion Correct measurements of ATR spectra for many angles of incidence of light inside a prism make ATR spectroscopy, in fact, a quantitative technique for measuring the permittivity of ultrathin films, including monolayer films, in which the concept of the macroscopic permittivity appears inapplicable. Nevertheless, as is seen from the results presented above, 10-nm-thick MgO film and 1-and 2-nm-thick AlN films are well described by the standard model of the permittivity of bulk MgO and AlN, respectively. In this paper, we have studied the resonance interaction of the substrate SPs with optical phonons in films and measured the splitting of SP dispersion curves. This splitting was proved to be proportional to the square root of the film thickness. It is shown that the ATR spectroscopy can be utilized for determining the permittivity of thin and ultrathin films. Acknowledgments The authors thank G Rossetto, A Sartori, and M Bolzan (Instituto di Chimica Inorganica e delle Superfici, Padova, Italy) for preparing samples with MgO films on sapphire, and K S Zhuravlev, V G Mansurov, and T V Malin (Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences)

Mucosal Barrier in Ulcerative Colitis and Crohn’s Disease

Background. The mucus layer in the gastrointestinal tract plays important role in host innate defense, regulation of secretion, and absorption processes, maintaining colonization resistance, which composes the integrity of protective mucus barrier in the large intestine. Investigations of mucin expression in the colon mucosa can improve the understanding of protective function of mucosal barrier in ulcerative colitis (UC) and Crohn’s disease (CD). Materials and Methods. 77 patients with UC and CD were examined. Histological analysis of colon mucosa was done by standard method (haematoxylin-eosin, alcian blue at pH 1.0 and 2.5 to determine sulfated and nonsulfated glycosaminoglycans and glycoproteins, and goblet cells). To characterize the mucus production the PAS-reaction was performed. Immunohistochemistry was performed using monoclonal mouse antibodies raised against MUC2, MUC3, MUC4, and TFF3 (USBiological, USA). Results. The moderate expression of MUC2 and MUC3 (50.0% and 32.1%, ) and high expression of MUC4 and TFF3 in the colon mucosa were observed in all patients with CD. The intensive labeling of MUC4 and TFF3 occurred more often (42.9% and 57.1%, ) in patients with CD. The level of expression of secretory MUC2 and transmembrane MUC3 and MUC4 in all patients with UC was low, up to its complete absence (59.2% and 53.1% cases, ). TFF3 expression had high and medium staining intensity in patients with UC. Conclusions. Different types of mucins synthesis, secretion, and expression were found in patients with UC and CD. The expression of mucin MUC2, MUC3, MUC4, and TFF3 correlated with the activity of disease and the extent of the inflammatory process in the large intestine. The most pronounced alteration of mucins expression was observed in patients with severe UC and CD