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Depression and obesity are highly prevalent, and major impacts on public health frequently co-occur. Recently, we reported that having depression moderates the effect of the FTO gene, suggesting its implication in the association between depression and obesity.
To confirm these findings by investigating the FTO polymorphism rs9939609 in new cohorts, and subsequently in a meta-analysis.
The sample consists of 6902 individuals with depression and 6799 controls from three replication cohorts and two original discovery cohorts. Linear regression models were performed to test for association between rs9939609 and body mass index (BMI), and for the interaction between rs9939609 and depression status for an effect on BMI. Fixed and random effects meta-analyses were performed using METASOFT.
In the replication cohorts, we observed a significant interaction between FTO, BMI and depression with fixed effects meta-analysis (β=0.12, P = 2.7 × 10−4) and with the Han/Eskin random effects method (P = 1.4 × 10−7) but not with traditional random effects (β = 0.1, P = 0.35). When combined with the discovery cohorts, random effects meta-analysis also supports the interaction (β = 0.12, P = 0.027) being highly significant based on the Han/Eskin model (P = 6.9 × 10−8). On average, carriers of the risk allele who have depression have a 2.2% higher BMI for each risk allele, over and above the main effect of FTO.
This meta-analysis provides additional support for a significant interaction between FTO, depression and BMI, indicating that depression increases the effect of FTO on BMI. The findings provide a useful starting point in understanding the biological mechanism involved in the association between obesity and depression.
New oral treatments are needed for all forms of leishmaniasis. Here, the improved oral efficacy of quercetin (Qc) and its penta-acetylated derivative (PQc) was evaluated in cutaneous leishmaniasis after encapsulation in lipid-core nanocapsules (LNCs) of poly(ε-caprolactone). Leishmania amazonensis-infected BALB/c mice were given 51 daily oral doses of free drugs (16 mg kg−1) or LNC-loaded drugs (0·4 mg kg−1). While treatment with free Qc reduced the lesion sizes and parasite loads by 38 and 71%, respectively, LNC-Qc produced 64 and 91% reduction, respectively. The antileishmanial efficacy of PQc was similar but not as potently improved by encapsulation as Qc. None of the treatments increased aspartate aminotransferase, alanine aminotransferase or creatinine serum levels. These findings indicate that when encapsulated in LNC, Qc and, to a lesser extent, PQc can safely produce an enhanced antileishmanial effect even at a 40-fold lower dose, with implications for the development of a new oral drug for cutaneous leishmaniasis.
Leishmania amazonensis promastigotes are known to express furosemide (Lasix®)-sensitive P-type membrane Na+-ATPase. In the present study, furosemide activity was studied in intracellular amastigotes and infected BALB/c mice to investigate its efficacy in cutaneous leishmaniasis (CL). Intracellular parasites, but not macrophages, were found to be sensitive to killing by furosemide (IC50 = 87 µmvs CC50 ≫ 1000 µm, respectively). Although furosemide did not induce nitric oxide production or intracellular pH changes in infected macrophages, it led to a significant reactive oxygen species (ROS) burst. Freshly isolated tissue parasites expressed a high degree of Na+-ATPase activity that decreased with culture, indicative of a higher enzyme expression in amastigotes than in promastigotes. Both intraperitoneal and oral treatment of L. amazonensis-infected mice with furosemide dosages equivalent to that prescribed as a diuretic significantly reduced the parasite's growth compared with the situation in untreated mice. Combination with oral furosemide increased the efficacy and safety of intraperitoneal treatment with sodium stibogluconate (SSG). To summarize, furosemide control of intracellular leishmanial growth by means of parasite Na+-ATPase inhibition, and macrophage ROS activation may help explain its sole and SSG-combined therapeutic effect against murine CL.
We present the preliminary results of an 8-month monitoring campaign carried out on 6 AGN during the period December 1991 – July 1992. All but one of our targets showed continuum and/or line variability. The data were obtained using the 2D-Prutti + Cassegrain spectrograph at the CTIO 1.0-m telescope, and reduced following standard procedures. The slit width was 5″ and the nuclear spectra were extracted in a 10″ aperture. The wavelength coverage is 3500–7200Å, with 8Å resolution. The data were flux calibrated using standard stars and then normalized using the [O III] λ5007Å line flux for each object. NGC 6814: our spectra reveal that this object is still in a low state of activity and within the S/N ratio of our data, no variability was observed during this campaign. The stellar population is dominant in the nuclear spectrum and a synthesis using the star cluster library of Bica (1988) indicates a mainly old (∼ 86% of the continuum flux at 5870Å due to a population with age ≥ 10 Gyr), [Z/Z⊙] ≥ 0.3 stellar content, with an intrinsic reddening of E(B–V)=0.20. NGC 3227: using an off-nuclear spectrum corresponding to the two 5″×10″ regions 20.4″ E/W of the nucleus, we obtained also a mainly old (77% at 5870Å with age ≥ 10 Gyr), [Z/Z⊙]=0.3) synthetic stellar population, which contributes ∼ 43% of the nuclear light at 5600Å. The cross correlation of the 4245Å continuum and Hβ light curves results in a 18±3 -day lag. IC 4329A: our data show evidence of variability as a slow and constant increase in both continuum and lines fluxes, but no isolated event was detected. ESO141-G55: the light curves show small variations in the continuum, but no noticeable line variability. Akn 120 and Fairall 9: the data consists of two sets of spectra, separated by ∼ 6 months. Within each set little or no variability was detected, but strong line and continuum variations occurred between them.
The cubic polytype of silicon carbide is a stimulating candidate for Micro-Electro-Mechanical-Systems (MEMS) applications due to its interesting physical and chemical properties. Recently, we demonstrated the possibility to elaborate 3C-SiC membranes on 3C-SiC pseudo-substrates, using a silicon epilayer grown by Low Pressure Chemical Vapor Deposition as a sacrificial layer. Such structures could be the starting point for the elaboration of new MEMS devices. However, the roughness still represents a major concern. Therefore, in this contribution, we investigate the influence of an excimer laser irradiation on the Si epilayer surface prior to the 3C-SiC epilayer growth. We compare these results with the 3C-SiC epilayer grown directly on the as-grown Si epilayer.
We present infrared (IR) long-slit spectroscopy of two galaxies with Seyfert 2 nuclei, NGC 2110 and the Circinus galaxy, both known from previous studies to exhibit anisotropic high-excitation gaseous emission. In the “unified models” for Seyferts, this anisotropy is due to collimation of the ionizing nuclear radiation by an optically thick molecular torus which surrounds the nucleus. We have looked for signatures of this torus and its collimating effect in the IR (J and K bands), taking advantage of the reduced relative attenuation at these wavelengths. The two galaxies are found to show extended emission in the lines [Fe II] λl.257 µm, Paβ, H2λ2.12 °m, and Brγ, both along the collimation axis as well as perpendicular to it. The [Fe II] line is found to trace the high-excitation emission, and, in the case of NGC 2110, is more extended along the collimation axis. The H2 emission, although consistent with the presence of a molecular torus, extends for hundreds of parsecs and the derived kinematics is consistent with circular rotation in the plane of the galaxies. The emission-line ratios [Fe II]/Paβ and H2/Brγ are much smaller in Circinus (respectively ~ 0.5 and 1) than in NGC 2110 (~ 7 and ≥ 4, respectively), and indicate the presence of a nuclear starburst in the former galaxy. IR rotation curves were determined for both galaxies. In the case of NGC 2110, the IR rotation curve shows different behavior than the rotation curve determined from optical lines, which shows the importance of obscuration effects in the study of the gas kinematics.
Laser and oven annealing effects on hydrogen concentration, hydrogen diffusion and material microstructure in hydrogenated amorphous silicon films deposited on crystalline silicon substrates are compared. For laser annealing, a 6 W green (532 nm) continuous wave laser with 100 µm focus diameter was applied and samples of about 1 cm2 were scanned in ambient with a line distance of 50 µm and at a speed of 1 – 100 mm/s. Hydrogen content and microstructure were measured by infrared spectroscopy, and hydrogen diffusion was investigated by secondary ion mass spectroscopy (SIMS) measurements of depth profiles of deuterium and hydrogen in layered structures of deuterated and hydrogenated material. The results show that in both annealing experiments hydrogen diffuses predominantly in form of atoms although some formation of H2 molecules cannot be excluded. By comparison of laser and oven treatment, an effective temperature describing the laser treated state can be defined. Furthermore, the temperature of the thin silicon film during laser treatment is estimated.
This work is part of an ongoing project which aims to detect terrestrial planets in our neighbouring star system α Centauri using the Doppler method. Owing to the small angular separation between the two components of the α Cen AB binary system, the observations will to some extent be contaminated with light coming from the other star. We are accurately determining the amount of contamination for every observation by measuring the relative strengths of the H-α and NaD lines. Furthermore, we have developed a modified version of a well-established Doppler code that is modelling the observations using two stellar templates simultaneously. With this method we can significantly reduce the scatter of the radial velocity (RV) measurements due to spectral cross-contamination and hence increase our chances of detecting the tiny signature caused by potential Earth-mass planets. After correcting for the contamination we achieve RV precision of ~2.5 m s−1 for a given night of observations. We have also applied this new Doppler code to four southern double-lined spectroscopic binary systems (HR159, HR913, HR7578 and HD181958) and have successfully recovered radial velocities for both components simultaneously.
An accurate cartesian method is devised to simulate incompressible viscous flows past an arbitrary moving body. The Navier-Stokes equations are spatially discretized onto a fixed Cartesian mesh. The body is taken into account via the ghost-cell method and the so-called penalty method, resulting in second-order accuracy in velocity. The accuracy and the efficiency of the solver are tested through two-dimensional reference simulations. To show the versatility of this scheme we simulate a three-dimensional self propelled jellyfish prototype.
Fish consumption is the major dietary source of EPA and DHA, which according to rodent experiments may reduce body fat mass and prevent obesity. Only a few human studies have investigated the association between fish consumption and body-weight gain. We investigated the association between fish consumption and subsequent change in body weight. Women and men (n 344 757) participating in the European Prospective Investigation into Cancer and Nutrition were followed for a median of 5·0 years. Linear and logistic regression were used to investigate the associations between fish consumption and subsequent change in body weight. Among women, the annual weight change was 5·70 (95 % CI 4·35, 7·06), 2·23 (95 % CI 0·16, 4·31) and 11·12 (95 % CI 8·17, 14·08) g/10 g higher total, lean and fatty fish consumption per d, respectively. The OR of becoming overweight in 5 years among women who were normal weight at enrolment was 1·02 (95 % CI 1·01, 1·02), 1·01 (95 % CI 1·00, 1·02) and 1·02 (95 % CI 1·01, 1·04) g/10 g higher total, lean and fatty consumption per d, respectively. Among men, fish consumption was not statistically significantly associated with weight change. Adjustment for potential over- or underestimation of fish consumption did not systematically change the observed associations, but the 95 % CI became wider. The results in subgroups from analyses stratified by age or BMI at enrolment were not systematically different. In conclusion, the present study suggests that fish consumption has no appreciable association with body-weight gain.
Studies have suggested that moderate alcohol consumption is associated with a reduced risk of CVD and premature mortality in individuals with diabetes mellitus. However, history of alcohol consumption has hardly been taken into account. We investigated the association between current alcohol consumption and mortality in men and women with diabetes mellitus accounting for past alcohol consumption. Within the European Prospective Investigation into Cancer and Nutrition (EPIC), a cohort was defined of 4797 participants with a confirmed diagnosis of diabetes mellitus. Men and women were assigned to categories of baseline and past alcohol consumption. Hazard ratios (HR) and 95 % CI for total mortality were estimated with multivariable Cox regression models, using light alcohol consumption (>0–6 g/d) as the reference category. Compared with light alcohol consumption, no relationship was observed between consumption of 6 g/d or more and total mortality. HR for >6–12 g/d was 0·89 (95 % CI 0·61, 1·30) in men and 0·86 (95 % CI 0·46, 1·60) in women. Adjustment for past alcohol consumption did not change the estimates substantially. In individuals who at baseline reported abstaining from alcohol, mortality rates were increased relative to light consumers: HR was 1·52 (95 % CI 0·99, 2·35) in men and 1·81 (95 % CI 1·04, 3·17) in women. The present study in diabetic individuals showed no association between current alcohol consumption >6 g/d and mortality risk compared with light consumption. The increased mortality risk among non-consumers appeared to be affected by their past alcohol consumption rather than their current abstinence.
The transfer of thin monocrystalline silicon films to foreign substrates is of great interest for a number of applications such as silicon on insulator devices, active matrix displays and thin film solar cells. We present a transfer approach for the fabrication of monocrystalline Si films on foreign substrates based on the formation of quasi-monocrystalline Si-films. Our transfer approach is compatible with high temperature processing such as epitaxial growth at 1100°C, thermal oxidation and phosphorous diffusion. Reuse of Si host wafers is demonstrated by the subsequent epitaxial growth of three monocrystalline Si films on a single host wafer. Monocrystalline Si films with a thickness of 15 µm and a diameter of 3” are transferred to glass and flexible plastic substrates. The typical light point defect density in films transferred from virgin wafers ranges between 10 to 100 cm−2, while stacking fault and dislocation densities are ≤ 100 cm−2. The minority carrier diffusion length in the epitaxial Si films is around 50 µm.
Electronic properties of thin epitaxial silicon films deposited at temperatures below 650°C by means of ion-assisted deposition strongly depend on substrate orientation as well as on deposition temperature: In (100)-oriented epitaxial films we find a low density of structural defects, and the minority carrier diffusion length is only limited by the presence of point defects or point defect complexes. These investigations also show an improvement of the electronic quality with increasing deposition temperature. Epitaxy on non-(100)-oriented substrates results in a significantly higher density of structural defects. The electronic properties of films deposited on stable flat surfaces, such as (111)- and (113)-oriented substrates are inferior as compared to (100)-oriented films, but are still superior to those of films deposited on faceted surfaces, as shown by light beam induced current and electron back-scattering diffraction measurements of polycrystalline thin films.
We crystallize amorphous silicon (a-Si) layers (thicknesses: ∼300nm and ∼1300nm for comparison) that are deposited on glass substrates (Corning 7059) by low pressure chemical vapor deposition using a continuous wave Ar+-laser. We scan the raw beam with a diameter of ∼60νm in single traces and traces with varying overlap (30-60%). With optimized process parameters (fluence, scan velocity, overlap) we achieve polycrystalline Si with grains as wide as 100νm. The grain boundary population is dominated by first and second order twin boundaries as analyzed by electron backscattering analysis in the scanning electron microscope and convergent beam electron diffraction in the transmission electron microscope. These twins are known not (or only marginally) to degrade the electrical properties of the material. In addition to twins, dislocations and twin lamellae occur at varying densities (depending on grain orientation and process parameters). The recombination activity of the defects is analyzed by EBIC and according to these measurements crystallization receipts are defined that yield the reduction of electrically detrimental defects.
Silicon lamellae grown laterally over silicon dioxide by liquid phase epitaxy are investigated using X-ray double crystal topography. The lamellae are grown from Indium solution. All of the lamellae show growth striations with indium concentration differences of about 1016...4x1017 cm−3 Overgrowth widths up to 320μm are obtained on sides of the seeding window by growth under conditions of low supersaturation. Facetting of the lamella edges then becomes less pronounced and, therefore,striations are detected farther away from the windows.
About 60% of the lamellae are free of crystallographic defects. In the defective lamellae single dislocations parallel to the sample surface are detected. They extend between seeding window edges and re—entrant corners at the lamella edges. Dislocations probably form during the cooling process due to strains near the edges of the seeding windows, and as a result of indium incorporation in high concentration.
We deposit phosphorus-doped, amorphous Si by low pressure chemical vapor deposition and subsequently crystallize the films by furnace annealing at a temperature of 600°C. Optical in-situ monitoring allows one to control the crystallization process. Phosphorus doping leads to faster crystallization and a grain size enhancement with a maximum grain size of 15 μm. Using transmission electron microscopy we find a log-normal grain size distribution in our films. We demonstrate that this distribution not only arises from solid phase crystallization of amorphous Si but also from other crystallization processes based on random nucleation and growth. The log-normal grain size distribution seems to be a general feature of polycrystalline semiconductors.
This contribution describes the preparation of a single crystalline Si thin-film separable from a reusable Si wafer. The method relies on: i) etching of a porous silicon layer ii) high-temperature annealing and iii) transfer of the recrystallized film to a foreign substrate. As a result of the process we obtain 1 to 30 μm thick monocrystalline Si films that contain voids with a size of several 100 nm. Due to its “swiss-cheese-like” structure the material is termed as “quasi-monocrystalline Si”. Sub micrometer thin layers are almost compact, while in several micron thick films voids cause scattering of incident light. This effect increases the effective absorption coefficient by light trapping and seems promising for the application of our quasi-monocrystalline films in thin film solar cells. Quasi-monocrystalline p-type silicon reaches a hole mobility of 78 cm2/ Vs measured by room-temperature Hall-effect. High carrier mobility and adjustable optical characteristics make these films suitable for display and photovoltaic applications. Quasi-monocrystalline films are processed using conventional high-temperature Si processing; finished devices can be transferred to a foreign substrate such as glass, while the starting wafer can be reused several times.