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Blood was drawn from 18 inpatients fullfilling the DSMIII criteria for schizophrenia and their 15 age- and sex-matched clinically infection-free controls before and after neuroleptic treatment. Blood films were stained with MGG solution, mixed, and subsequently read in random order by one observer. The lymphocytes were examined by light microscopy and classified into six types: normal lymphocytes, Downey type I atypical lymphocytes, Downey type III atypical lymphocytes, stress lymphocytes, plasmocytoid lymphocytes, and large granular lymphocytes. Downey type I and III atypical lymphocytes were classified into small, medium, and large lymphocytes. Schizophrenic patients had significantly more Downey type III medium size cells before treatment (p = 0.019 before treatment and p = 0.056 after treatment) and less Downey type I small size cells (p = 0.113 before treatment and p = 0.026 after treatment). Our study supports the idea of a possible subgroup of schizophrenia exhibiting immunological aberrations. In the present study, we found morphologically more specified cells which could be involved in this alteration.
We describe microbiological, clinical and epidemiological aspects of a diphtheria outbreak that occurred in Maranhão, Brazil. The majority of the 27 confirmed cases occurred in partially (n = 16) or completely (n = 10) immunized children (n = 26). Clinical signs and characteristic symptoms of diphtheria such as cervical lymphadenopathy and pseudomembrane formation were absent in 48% and 7% of the cases, respectively. Complications such as paralysis of lower limbs were observed. Three cases resulted in death, two of them in completely immunized children. Microbiological analysis identified the isolates as Corynebacterium diphtheriae biovar intermedius with a predominant PFGE type. Most of them were toxigenic and some showed a decrease in penicillin G susceptibility. In conclusion, diphtheria remains endemic in Brazil. Health professionals need to be aware of the possibility of atypical cases of C. diphtheriae infection, including pharyngitis without pseudomembrane formation.
Invasive infections caused by Corynebacterium diphtheriae in vaccinated and non-vaccinated individuals have been reported increasingly. In this study we used multilocus sequence typing (MLST) to study genetic relationships between six invasive strains of this bacterium isolated solely in the urban area of Rio de Janeiro, Brazil, during a 10-year period. Of note, all the strains rendered negative results in PCR reactions for the tox gene, and four strains presented an atypical sucrose-fermenting ability. Five strains represented new sequence types. MLST results did not support the hypothesis that invasive (sucrose-positive) strains of C. diphtheriae are part of a single clonal complex. Instead, one of the main findings of the study was that such strains can be normally found in clonal complexes with strains related to non-invasive disease. Comparative analyses with C. diphtheriae isolated in different countries provided further information on the geographical circulation of some sequence types.
Cortical and cancellous bones were demineralized and deproteinized using 1 N
HCl and 6% NaOCl, respectively. Experiments were performed at 37°C. The rate
constants were calculated and the structural features of untreated and
completely demineralized and deproteinized samples were studied by scanning
electron microscopy, showing that intact, contiguous structures were
obtained. For both cases, the rate constant was higher for cancellous bone
than the cortical bone.
Partially demineralized (DM) bone is of interest due to its promising
osteointegrative properties for advanced bone grafts. Structural features of
partially DM (35 vol.%, 45 vol.% and 55 vol.% reduction), and untreated
cortical bone samples were studied by scanning electron microscopy.
Mechanical properties were investigated by compression testing in three
anatomical directions at different stages of DM. The radial direction
appears to be the stiffest and strongest bone direction for the all DM
We report evidence for graphene layer rearrangements in heavy ion interactions with carbon onions at 140 MeV and 70 MeV per nucleon kinetic energies. Graphene layer rearrangements have been recently predicted in spherical and cylindrical multi-layer graphene systems. The implications of graphene layer rearrangement on the tribological performance of multi-layer nano-carbons in extreme environments are discussed.
Studies of hard biological materials such as marine shells, animal teeth, horns and bones have produced fascinating ideas for mimicking their micro/nanostructure in the lab. The nacre in the abalone shell has a well-defined organic/inorganic structure that has a fracture resistance that is much higher than the individual constituents. By using biocompatible materials we have fabricated zirconium nitride/ polymethylmethacrylate alternating layers that are based on the structure of nacre. A combination of DC-magnetron sputtering and pulsed laser deposition on (100) silicon substrates was used to fabricate multilayers in a single chamber without breaking the vacuum. The ZrN films showed nanocrystalline columnar growth on the silicon substrates or on the PMMA nanolayer. High resolution SEM analysis at the inorganic/organic interface revealed well formed, uniform thickness inorganic films which are separated by the polymeric layer (30-90 nm). The ratio of the ceramic/polymer is the same as in nacre. Nanoindentation hardness values of ˜ 20GPa were measured on both the ZrN single film, similar to published values, and the ZrN/PMMA composite layers and the elastic modulus remained constant, independent of the number of layers.
Solid lubricant properties of carbon onions prepared from diamond nanoparticles through a heat treatment at 1700°C have been examined at high temperatures up to 300°C in air and vacuum. Sliding friction between a silicon disk on which carbon onions were dispersed and a stainless steel ball was measured by means of ball-on-disk type friction testing. Friction coefficients in vacuum decreased with temperatures and became stable above 100°C for longer service lives. On the contrary to this, friction coefficients in air increased with temperatures despite Raman spectroscopic analysis showed that the structure of carbon onions were stable in dry air up to 300°C.
The lack of information on the immunity of adults in Brazil against diphtheria prompted us to analyse sera from 234 blood donors aged 18–61 years (30·3% females and 69·7% males). IgG diphtheria antitoxin levels determined by means of an ELISA, validated by toxin neutralization test in Vero cells, showed that 30·7% (95% CI 25·0–37·1) of the population was fully protected ([ges ]1 IU/ml). The highest percentage of subjects fully protected was in the 31–40 years age group. Most of the subjects with uncertain or no protection (<1 IU/ml) were found in the 18–30 years age group (43·8%, OR 2·18, P=0·01). Antitoxin levels were not influenced by the increase in age. Males were more protected than females (80·5%, OR 0·44, P=0·01). The prevalence of 30% of individuals fully protected against diphtheria in blood donors in Rio de Janeiro supports the fact that immunity to diphtheria among healthy Brazilian adults is inadequate. To avoid diphtheria epidemics in the future the immunity among adults should be raised in the coming years.
A new low-temperature method to produce (InxGa1−x)2O3 (x = 0.1, 0.2, and 0.3) powders with high purity, high chemical homogeneity and improved crystallinity in the as-synthesized state has been developed. This procedure produced finely divided powders through an exothermic reaction between the precursors. The process starts with aqueous solutions of In(NO3)3 and Ga(NO3)3 as the precursors and hydrazine as the (noncarbonaceous) fuel. The combustion reaction occurred when heating the precursors between 150 and 200 °C in a closed vessel filled with an inert gas (Ar), which yields (InxGa1−x)2O3 directly. These materials were compared with powders prepared by a more typical combustion synthesis reaction between nitrates and a carbonaceous fuel at a higher ignition temperature of 500 °C.
This study compared the efficacy and tolerability of 150 mg/day imipramine and 50 mg/day sertraline for the treatment of a major depressive episode (DSM-IV) in older adults (N = 55) in an 8-week, randomized, double-blind, controlled clinical trial. Intention-to-treat analysis (last observation carried forwards) showed a reduction of 50% or more on the baseline scores of the Montgomery-Åsberg Rating Scale (MADRS) in 60.7% and 55.6% of patients receiving imipramine and sertraline, respectively (p = .698). Full remission of symptoms (MADRS < 9) was observed in 50.0% and 51.8% of patients, respectively (p = .891). Side effects were more frequent among patients treated with imipramine (86.7%) than among patients treated with sertraline (42.1%) (p = .008). Dropout rates were high in both groups (46.4% and 29.6% respectively, p = .200). These results indicate that imipramine and sertraline are equally effective for the treatment of major depression in later life, although adverse reactions are more frequent among subjects treated with imipramine than with sertraline.
Carbon nanocage structures with Ge and SiC nanoparticles were synthesized by direct current and radio frequency (dc-rf) hybrid arc discharge of C, Ge, and Si elements. High-resolution images showed the formation of Ge and SiC nanoparticles and nanowires encapsulated in carbon nanocapsules and nanotubes. The growth direction of the Ge nanowires was found to be 〈111〉 of Ge, and a structure model for Ge/C interface was proposed. The present work indicates that the various carbon nanostructures with semiconductor nanoparticles and nanowires can be synthesized by the dc-rf hybrid arc-discharge method.
The spectral change of Pleione in the present Be phase (1988-1999) is briefly described. The Hα emission reached its maximum in 1995-1999. The V/R values of Hγ and metallic lines changed from V/R < 1 in 1995 to V/R > 1 in 1998-1999. The broad component of Mg II λ4481 line further weakened in Be phase.
The long-term variation in 1968-1999 is shown for several observational quantities. These quantities which reflect various levels from the photosphere up to the outer envelope did not change in a parallel way. The basic unsolved problems are pointed out.
The Be shell star EW Lac was observed in September 1993 during a multi-site campaign. Results from visual spectroscopy and polarimetry are summarized here. He I 6678 profiles have been compared to previous observations held in 1989 and show an additional complex and highly variable circumstellar component which can due to material expelled from the star just prior to these observations. Two groups of frequencies are found again in 1993 observations compared with 1989 ones. In the frame of nrp, they could be associated to low degree g-modes.
Photoluminescence (PL) enhancement due to the screening of piezoelectric field induced by Si-doping is systematically studied in GaN/AlGaN quantum wells (QWs) fabricated by metal organic vapor-phase-epitaxy (MOVPE). The PL enhancement ratio of QWs for Si-doped directly into the wells was much larger than that for doped only into the barrier layers. This result shows that the crystal quality of the quantum well is not so damaged by heavy Si-doping, which is different from the cases of GaAs or InP material systems. The PL intensity enhancement ratio was especially large for thick wells. The typical value of the enhancement ratio was 30 times for a 5 nm-thick single QW. The optimum Si-doping concentration was approximately 4×1018 cm-3. From the well width dependence of the PL enhancement ratio and PL peak shift under high excitation conditions, we determined that the dominant effect inducing the PL enhancement is screening of piezoelectric field in the QWs. These results indicate that Si-doping is very effective for the application of GaN/AlGaN QWs to optical devices.
This investigation studied the effects of Ho3+ and Er3+ on the luminescence of the blue emitting phosphor yttrium silicate, (Y1−mCem)2SiO5. Yttrium silicate has a large emission tail that extends into the red portion of the visual spectrum. To improve the chromaticity of this phosphor to give it a more saturated blue color, the emission intensity of the tail needs to be decreased. Photoluminscence and low-voltage cathodoluminescence measurements were performed on yttrium silicate phosphors with varying concentrations of Gd3+, Ho3+ and Er3+. It was found that when co-doping with Ho3+ and Er3+, the relative intensity of the emission tail was decreased, but so to was the overall luminescence intensity of this phosphor.
We demonstrate 230-250 nm efficient ultraviolet (UV) photoluminescence (PL) from AlN(AlGaN)/AlGaN multi-quantum-wells (MQWs) fabricated by metalorganic vapor-phase-epitaxy (MOVPE). Firstly, we show the PL properties of high Al content AlGaN bulk (Al content: 85-95%) emitting from near band-edge. We systematically investigated the PL properties of AlGaN-MQWs consisting of wide bandgap AlGaN (Al content: 53-100%) barrier. We obtained efficient PL emission of 234 and 245 nm from AlN/Al0.18Ga0.82N and Al0.8Ga0.2N/Al0.18Ga0.82N MQWs, respectively, at 77 K. The optimum value of well thickness was approximately 1.5 nm. The emission from the AlGaN MQWs were several tens of times stronger than that of bulk AlGaN. We found that the most efficient PL is obtained at around 240 nm from AlGaN MQWs with Al0.8Ga0.2N barriers. Also, we found that the PL from AlGaN MQW is as efficient as that of InGaN QWs at 77 K.
Thin films of (Y0.92Eu0.08)2O3 were synthesized through chemical vapor deposition of β-diketonate precursors onto glass and sapphire substrates. The films were weakly luminescent in the as-deposited condition and were composed of spherical particles 3 μm in diameter. A KrF laser was pulsed for 25 ns from 1–3 times on the surface of the films. One pulse was sufficient to melt the film and repeated pulses caused ablation of the material. Melting of the film smoothed the surface, increased the density, and increased the photoluminescent emission intensity.
Titanium has been successfully used for decades in dental and orthopedic implants, but the mechanism for this metal's biocompatible properties have not been determined. Our hypothesis is that this biocompatibility involves interaction between the surface layer of titanium dioxide on the metal implant and reactive oxygen mediators of the inflammatory response. The affect of different titanium surface oxide layers on the reactive oxygen mediators produced during the inflammatory response has never been examined. Peroxynitrite is a highly reactive and unstable compound produced in vivo by the reaction of nitric oxide with superoxide. We investigated if titanium oxides affect the stability of peroxynitrite by promoting its breakdown. Peroxynitrite levels can be measured by its absorbance at 302 nm. At pH= 13.2, we found a 100% increase in the rate of degradation of peroxynitrite in the presence of titanium particles. Peroxynitrite is capable of nitrating 4-hydroxyphenolacetic acid (4-HPA). The nitrated form of 4-HPA can be measured by its absorbance at 432nm. 3-morpholinosydnonimine (SIN-1), a nitric oxide donor, has been shown to produce superoxide during its breakdown resulting in the formation of peroxynitrite. At physiological pH (7.4), a solution of 0.5mM 4-HPA was exposed to 5mM SIN- 1 on passivated titanium surfaces. There was a decrease of 58% nitrated 4-HPA in the solution exposed to passivated titanium compared to controls. Unpassivated titanium surfaces resulted in only a 10% decrease of nitrated 4-HPA while titanium treated with hydrogen peroxide resulted in a 70% decrease in nitrated 4-HPA concentrations compared to controls. Zirconium and palladium were also tested. These experiments suggest that titanium is capable of enhancing the breakdown of the inflammatory compound peroxynitrite which may account for the metal's biocompatible properties.