Er+ implantation in SnO2:SiO2 layers: Structure changes and light emission

Structure changes and light emission behavior in Er⁺ implanted SnO₂:SiO₂ layers are studied, using transmission electron microscopy (TEM), Rutherford backscattering (RBS) and cathodoluminescence (CL). SnO₂:SiO₂ layers of different composition deposited with RF magnetron sputtering on Si wafers were implanted with 200 keV Er⁺ to a fluence of 3 × 10¹⁵ cm^?2 at room temperature. The implanted structures were then annealed at 600–1000 °C for 30 min, resulting in the formation of crystalline SnO₂ nanoclusters. Cross-section TEM revealed a strong reduction of the SnO₂ crystallite size down to several nanometers in the implanted area of the SnO₂:SiO₂ layer as compared to the undoped layer. In addition, a very narrow layer of SnO₂ nanocrystals appears at the SiO₂/Si interface. Several narrow CL emission peaks and wide bands were found which could be related to the decay of SnO₂ free excitons, to oxygen deficiency centers in SiO₂ and to transitions between the energy levels in the Er ions, apparently located at nanoclusters. The mechanisms of nanostructuring as well as the emission process are discussed.     

Sildenafil-Induced Revascularization of Rat Hindlimb Involves Arteriogenesis through PI3K/AKT and eNOS Activation

Hypoxia and inflammation play a major role in revascularization following ischemia. Sildenafil inhibits phosphodiesterase-5, increases intracellular cGMP and induces revascularization through a pathway which remains incompletely understood. Thus, we investigated the effect of sildenafil on post-ischemic revascularization. The left femoral artery was ligated in control and sildenafil-treated (25 mg/kg per day) rats. Vascular density was evaluated and expressed as the left/right leg (L/R) ratio. In control rats, L/R ratio was 33 ± 2% and 54 ± 9%, at 7- and 21-days post-ligation, respectively, and was significantly increased in sildenafil-treated rats to 47 ± 4% and 128 ± 11%, respectively. A neutralizing anti-VEGF antibody significantly decreased vascular density (by 0.48-fold) in control without effect in sildenafil-treated animals. Blood flow and arteriolar density followed the same pattern. In the ischemic leg, HIF-1α and VEGF expression levels increased in control, but not in sildenafil–treated rats, suggesting that sildenafil did not induce angiogenesis. PI3-kinase, Akt and eNOS increased after 7 days, with down-regulation after 21 days. Sildenafil induced outward remodeling or arteriogenesis in mesenteric resistance arteries in association with eNOS protein activation. We conclude that sildenafil treatment increased tissue blood flow and arteriogenesis independently of VEGF, but in association with PI3-kinase, Akt and eNOS activation.     

Case of Mycobacterium mucogenicum in a home hemodialysis patient

We present a case of a patient on home hemodialysis who developed Mycobacterium mucogenicum bacteremia. While infections with this particular organism are rare, disseminated infections have been reported and have been associated with significant morbidity and mortality. Diagnosis required appropriate cultures, understanding of natural habitat of organism and complete environmental analysis including blood, dialysis sample port, reverse osmosis and incoming water supply cultures. The patient was treated successfully with systemic antibiotics, removal of central venous catheter, patient education and complete exchange of the hemodialysis circuit.     

Differential pathogenic effect of two Helicobacter-like organisms in dog gastric mucosa

Postorchidectomy treatment options in patients with stage I seminoma include surveillance (reserving treatment for patients who relapse), adjuvant radiation therapy (RT), and adjuvant chemotherapy. Adjuvant retroperitoneal RT remains the treatment of choice in most centers; however, the success of surveillance in stage I nonseminomatous germ cell testis tumors, the establishment of curative chemotherapy for advanced disease, and the improvements in CT have led to re-examination of the standard treatment approach. The available data from the surveillance and adjuvant RT series suggest that almost 100% of patients with stage I testicular seminoma are cured, whichever approach is chosen. This article presents an overview of the available information on all treatment options, the pros and cons of each approach, and indications for where surveillance fits into the armamentarium of clinicians dealing with this disease.     

Photoluminescence and optical properties of Mg x Zn1−x Te alloys

The photoluminescence and optical properties of Mg _x Zn_1–x Te alloys have been studied in the composition range 0<x<0.48. The results are discussed taking into account the formation of band tails due to the alloying effect or random distribution of impurities. The role of residual defects in magnesium-rich alloys is emphasized. On the other hand, a preliminary investigation showed that it is possible to incorporate lithium by high-temperature diffusion in Mg _x Zn_1–x Te alloys without altering the magnitude or the homogeneity of the magnesium concentration. Evidence is obtained for an increased quantum efficiency after lithium doping.     

Are self-report measures of dyadic relationships influenced by impression management biases?

This study systematically examined the effects of impression management biases on the reporting of dyadic relationship information. In an anonymous mail survey, 196 participants (101 women, 95 men) in marital or cohabiting relationships completed a measure of impression management and several relationship measures. Analyses indicated that impression management biases did not affect women's self-reports. Among men, impression management biases were significantly associated with many of their reports about their relationships. However, statistically controlling for these biases did not reduce the magnitude of correlations between measures of marital quality and the other relationship measures. Furthermore, partners' agreement about observable aspects of their relationship did not change when the influences of these biases were statistically removed. The authors conclude that researchers can generally trust in the veridicality of anonymous self-report data about commonplace aspects of marriage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Utilisation de la deflection photothermique pour l'etude de l'effet du chlore sur l'absorption par les etats de la bande interdite dans a-SiHCl

Chlorinated and hydrogenated amorphous silicon (a-SiHCl) have been prepared by glow-discharge of a gas mixture (SiCl₄+H₂). Optical absorption and photothermal deflection spectroscopy have been made on samples with different chlorine contents. Due to its higher sensitivity, the photothermal deflection spectroscopy shows a decrease of the gap states absorption at low energies when the chlorine content is increased.     

Two methods of reducing the dynamic range of a holographic filter

Two methods of reducing the dynamic range of the transmittance of computer-generated interconnection holograms are presented and compared. The holograms are used in an optical implementation of an associative memory to connect the input and the output planes but are representative of more generalN(4) interconnection holograms. Because the holograms play a double correlation-reconstruction role, the standard spectrum-smoothing techniques (e.g., random phase) cannot be applied. We show, in computer simulations and optical experiments, that by using deterministic phase functions that can be realized in the optical system (defocusing the hologram or controlling the phases of the diffraction spots of a Dammann grating used in the system input) the hologram dynamic range can be lowered, reducing the errors during the hologram binarization and increasing the hologram's diffraction efficiency.