The role of hydrogen in room-temperature ferromagnetism at graphite surfaces

We present a x-ray dichroism study of graphite surfaces that addresses the origin and magnitude of ferromagnetism in metal-free carbon. We find that, in addition to carbon $\pi$ states, also hydrogen-mediated electronic states exhibit a net spin polarization with significant magnetic remanence at room temperature. The observed magnetism is restricted to the top $\approx$10 nm of the irradiated sample where the actual magnetization reaches $\simeq 15$ emu/g at room temperature. We prove that the ferromagnetism found in metal-free untreated graphite is intrinsic and has a similar origin as the one found in proton bombarded graphite.Comment: 10 pages, 5 figures, 1 table, submitted to New Journal of Physic

Susceptibility of Leishmania major to Veronica persica Poir. extracts - In vitro and in vivo assays

Leishmania major is an intracellular parasite generally responsible for cutaneous leishmaniasis (CL), one of the most encountered skin diseases especially in Pakistan, Iran, Iraq, and Saudi Arabia. Current treatment options are not ideal, due to unwanted side effects and increasing resistance and availability is often limited in developing countries. Medicinal plants continue to attract attention because of their beneficial effects in the prevention or/and accelerating the healing process of various diseases. In this study, in vitro and in vivo susceptibility of L. major to Veronica persica Poir. extract, a medicinal plant with many applications, has been evaluated. Antileishmanial activity of plant extract was investigated both on cultured L. major promastigotes and in mice challenged with L. major. Animals were divided into three groups including control (without any treatment), test (treated with plant extract) and glucantime (the reference drug) treated groups. After treatments, skin lesion sizes and body weights of animals were checked during 4 weeks. The potential of the plant extract in decreasing the number of parasites in spleen cells of animals as well as inducing the nitric oxide (NO) production by macrophage cells was also investigated. In vitro tests showed that the plant extract was able to reduce the survival time of promastigotes in a concentration-dependent manner. In vivo experiments also revealed a significant influence of V. persica extracts on accelerating the healing process as well as reducing the overall disease burden in animal model by inducing NO production in macrophage cells. Our findings indicated the promising potential of V. persica extract as an ideal candidate in the treatment of CL caused by L. major

Proton-induced magnetic order in carbon: SQUID measurements

In this work we have studied systematically the changes in the magnetic behavior of highly oriented pyrolytic graphite (HOPG) samples after proton irradiation in the MeV energy range. Superconducting quantum interferometer device (SQUID) results obtained from samples with thousands of localized spots of micrometer size as well on samples irradiated with a broad beam confirm previously reported results. Both, the para- and ferromagnetic contributions depend strongly on the irradiation details. The results indicate that the magnetic moment at saturation of spots of micrometer size is of the order of $10^{-10}$ emu.Comment: Invited contribution at ICACS2006 to be published in Nucl. Instr. and Meth. B. 8 pages and 6 figure

A comparison of the magnetic properties of Proton- and Iron-implanted graphite

In this work we have investigated the changes of the magnetic properties of highly oriented pyrolytic graphite samples after irradiation either with $\sim 3 \times 10^{14}$ protons or $3.5 \times 10^{13} ... 3.5 \times 10^{14}$ iron ions with energies in the MeV range. Our results show that iron and proton irradiations can produce similar paramagnetic contributions depending on the implantation temperature. However, only protons induce a ferromagnetic effect.Comment: 4 pages with three figures. To be published in EPJ

Integrated optical addressing of a trapped ytterbium ion

We report on the characterization of heating rates and photo-induced electric charging on a microfabricated surface ion trap with integrated waveguides. Microfabricated surface ion traps have received considerable attention as a quantum information platform due to their scalability and manufacturability. Here we characterize the delivery of 435 nm light through waveguides and diffractive couplers to a single ytterbium ion in a compact trap. We measure an axial heating rate at room temperature of $0.78\pm0.05$ q/ms and see no increase due to the presence of the waveguide. Furthermore, the electric field due to charging of the exposed dielectric outcoupler settles under normal operation after an initial shift. The frequency instability after settling is measured to be 0.9 kHz.Comment: 7 pages, 8 figure

Gene Expression and Immunohistochemistry in Adipose Tissue of HIV Type 1-Infected Patients with Nucleoside Analogue Reverse-Transcriptase Inhibitor-Associated Lipoatrophy

BackgroundLong-term use of both zidovudine (AZT) and stavudine (d4T) is associated with lipoatrophy, but it occurs possibly through different mechanisms MethodsSurgical biopsy specimens of subcutaneous adipose tissue were obtained from 18 human immunodeficiency virus type 1 (HIV-1)-infected lipoatrophic patients (the LA+ group) who were treated with either zidovudine (the AZT+LA+ group; n=10) or stavudine (the d4T+LA+ group; n=8) and from 10 nonlipoatrophic HIV-1-infected patients (the LA− group) who received antiretroviral therapy. Mitochondrial DNA (mtDNA) copy numbers, gene expression, and immunohistochemistry data were analyzed ResultsmtDNA copy numbers were significantly reduced in the LA+ group, compared with the LA− group, and in the d4T+LA+ group, compared with the AZT+LA+ group. The ratio of mtDNA-encoded cytochrome COX3 to nuclear DNA-encoded COX4 expression was significantly lower in the LA+ group than in the LA− group. Compared with the LA− group, the LA+ group had significantly lower expression of genes involved in adipogenesis (SREBP1cand CEBPB) lipid (fatty acid synthase), and glucose (GLUT4) metabolism. Expression of genes involved in mitochondrial biogenesis (PGC1B) apoptosis (FAS) inflammation (IL1B) oxidative stress (PCNA and SOD1) and lamin B was significantly higher in the LA+ group than in the LA− group. The d4T+LA+ group had significantly lower expression of genes involved in mitochondrial biogenesis (POLG1) energy metabolism (the COX3/COX4 ratio), adipogenesis (SREBP1c and CEBPA) perilipin, and hexokinase than did the AZT+LA+ group. There were 7-fold more macrophages in adipose tissue specimens obtained from patients in the LA+ group, compared with the LA− group ConclusionsLipoatrophy is characterized by mtDNA depletion, inflammation, and signs of apoptosis. Changes were more profound in the d4T+LA+ group than in the AZT+LA+ grou

A combined first and second order variational approach for image reconstruction

In this paper we study a variational problem in the space of functions of bounded Hessian. Our model constitutes a straightforward higher-order extension of the well known ROF functional (total variation minimisation) to which we add a non-smooth second order regulariser. It combines convex functions of the total variation and the total variation of the first derivatives. In what follows, we prove existence and uniqueness of minimisers of the combined model and present the numerical solution of the corresponding discretised problem by employing the split Bregman method. The paper is furnished with applications of our model to image denoising, deblurring as well as image inpainting. The obtained numerical results are compared with results obtained from total generalised variation (TGV), infimal convolution and Euler's elastica, three other state of the art higher-order models. The numerical discussion confirms that the proposed higher-order model competes with models of its kind in avoiding the creation of undesirable artifacts and blocky-like structures in the reconstructed images -- a known disadvantage of the ROF model -- while being simple and efficiently numerically solvable.Comment: 34 pages, 89 figure

Pulicaria vulgaris Gaertn. Essential oil : an alternative or complementary treatment for Leishmaniasis

Leishmaniasis is a neglected parasitic protozoal disease that affects approximately 12 million people and represents a public health problem in Iran. The objectives of this study were to obtain the essential oil (EO) from Pulicaria vulgaris Gaertn. growing in Iran and to carry out in-vitro antileishmanial screening of the EO against promastigotes of Leishmania major and Leishmania infantum. The EO from the aerial parts of P. vulgaris was extracted by hydrodistillation. Serial dilutions of the EO were screened for in-vitro antileishmanial activity using 96-well microtiter plates. The P. vulgaris EO was active against the promastigote forms of L. major and L. infantum, with IC 50 values of 244.70 and 233.65 \u3bcg/mL, respectively. Pulicaria vulgaris EO may serve as an alternative or complementary treatment for leishmaniasis

Hydro-climatic and ecological behaviour of the drought of Amazonia in 2005

In 2005, southwestern Amazonia experienced the effects of an intense drought that affected life and biodiversity. Several major tributaries as well as parts of the main river itself contained only a fraction of their normal volumes of water, and lakes were drying up. The consequences for local people, animals and the forest itself are impossible to estimate now, but they are likely to be serious. The analyses indicate that the drought was manifested as weak peak river season during autumn to winter as a consequence of a weak summertime season in southwestern Amazonia; the winter season was also accompanied by rainfall that sometimes reached 25% of the climatic value, being anomalously warm and dry and helping in the propagation of fires. Analyses of climatic and hydrological records in Amazonia suggest a broad consensus that the 2005 drought was linked not to El Niño as with most previous droughts in the Amazon, but to warming sea surface temperatures in the tropical North Atlantic Ocean