One-step hydrothermal preparation of Ta-doped ZnO nanorods for improving decolorization efficiency under visible light

In this work, Ta-doped ZnO (Ta-ZnO) nanomaterials were synthesized by the hydrothermal method at different temperatures (110, 150, and 170 °C) for the photodegradation of methylene blue (MB) under visible light. Ta doping significantly affects the crystal defects, optical properties, and MB photocatalytic efficiency of ZnO materials. The optical absorption edge of Ta-ZnO 150 was redshifted compared to undoped ZnO, correlating to bandgap narrowing (E_gTa–ZnO = 2.92 eV; E_gZnO = 3.07 eV), implying that Ta doped ZnO is capable of absorbing visible light. Besides, Ta-doping was the reason for enhanced blue light emission in the photoluminescence spectrum, which is related to the oxygen defect V⁰_O. It is also observed in the XPS spectra, where the percentage of oxygen in the oxygen-deficient regions (O_531.5 eV) of Ta-ZnO150 is higher than that of ZnO150. It is an important factor in enhancing ZnO''s photocatalytic efficiency. The MB degradation efficiency of Ta-doped ZnO reached the highest for Ta-ZnO 150 and was 2.5 times higher than ZnO under a halogen lamp (HL). Notably, the influence of hydrothermal temperature on the structural, morphological, and photoelectrochemical properties was discussed in detail. As a result, the optimal hydrothermal temperature for synthesizing the nanorod is 150 °C. Furthermore, photocatalytic experiments were also performed under simulated sunlight and natural sunlight. The nature of the photo-oxidative degradation of MB was also investigated.

The Ta doped ZnO nanorods (Ta-ZnO) were synthesized by a hydrothermal method at different temperatures (110, 150, and 170 °C) for the photodegradation of methylene blue (MB) under visible light.     

Optical Coherence Tomography‐Guided Retinal Prosthesis Design: Model of Degenerated Retinal Curvature and Thickness for Patient‐Specific Devices

Retinitis pigmentosa affects over 1.5 million people worldwide and is a leading cause of vision loss and blindness. While retinal prostheses have shown some success in restoring basic levels of vision, only generic, “one‐size‐fits‐all” devices are currently being implanted. In this study, we used optical coherence tomography scans of the degenerated retina from 88 patients with retinitis pigmentosa to generate models of retinal thickness and curvature for the design of customized implants. We found the average retinal thickness at the fovea to be 152.9 ± 61.3 μm, increasing to a maximum retinal thickness of 250.9 ± 57.5 μm at a nasal eccentricity of 5°. These measures could be used to assist the development of custom‐made penetrating electrodes to enhance and optimize epiretinal prostheses. From the retinal thickness measurements, we determined that the optimal length of penetrating electrodes to selectively stimulate retinal ganglion cell bodies and interneuron axons in the ganglion cell layer should be 30–100 μm, and to preferentially stimulate interneurons in the inner nuclear layer, electrodes should be 100–200 μm long. Electrodes greater than 200 μm long had the potential to penetrate through the retina into the choroid, which could cause devastating complications to the eye and should be avoided. The two‐ and three‐dimensional models of retinal thickness developed in this study can be used to design patient‐specific epiretinal implants that will help with safety and to optimize the efficacy of neuronal stimulation, ensuring the best functional performance of the device for patients.     

Pterygium surgery in Victoria: A survey of ophthalmologists

Aim: To determine the surgical approaches and adjunctive therapies currently used by Victorian ophthalmologists for the treatment of primary and recurrent pterygia. Method: Ophthalmologists practising in Victoria were asked to complete a written survey relating to their experience with pterygium surgery. Results: Responses were received from 142 of 165 ophthalmologists surveyed (86%). Of these, 107 (75%) had performed at least one pterygium operation during the preceding 2 years. Excision followed by beta irradiation was the most commonly performed procedure for both primary (57%) and recurrent (35%) pterygia. The next most commonly performed procedure for primary pterygia was excision leaving bare sclera (15%) and, for recurrent pterygia, excision with autologous conjunctival transplantation (26%). Considerable variation was observed in surgical technique, choice of adjunctive therapy, postoperative care and in the surgeons' estimates of the frequency of major complications. Conclusion: Although there is little consensus regarding the surgical management of pterygium, beta irradiation remains the most commonly used adjunctive therapy in Victoria.     

Practicing doctors' perceptions on new learning objectives for Vietnamese medical schools

Background  

As part of the process to develop more community-oriented medical teaching in Vietnam, eight medical schools prepared a set of standard learning objectives with attention to the needs of a doctor working with the community. Because they were prepared based on government documents and the opinions of the teachers, it was necessary to check them with doctors who had already graduated and were working at different sites in the community.     

Monitoring rotavirus environmental contamination in a pediatric unit using polymerase chain reaction.

Rotavirus environmental contamination in a pediatric unit was investigated. Surfaces were swabbed, then viruses eluted, ultracentrifuged, and detected by polymerase chain reaction (PCR) amplification. Of 55 samples, 25 (46%) tested positive. Rotavirus RNA was more prevalent on surfaces in direct contact with children (thermometers and play mats) than on other environmental surfaces (washbasins, door handles, etc). PCR has proved useful for monitoring rotavirus environmental contamination.     

Effects of vasoactive neuropeptides on human saphenous vein.

OBJECTIVE--To assess the role of neuropeptides in the control of vascular tone in the human saphenous vein the actions of substance P, vasoactive intestinal peptide, calcitonin gene related peptide, neuropeptide Y, and somatostatin on this blood vessel were examined. METHODS--In vitro organ bath techniques were used with preparations of saphenous veins obtained from 29 patients (aged 41-66) who were undergoing coronary bypass surgery. RESULTS--Substance P, vasoactive intestinal peptide, and calcitonin gene related peptide relaxed pre-constricted vessels in a dose dependent manner with a rapid onset of action, taking one to two minutes to reach a plateau at each dose. Substance P (10(-9) to 10(-6) mol/l) induced relaxation with a maximum response (mean (SEM)) 23.0 (6.6)% of the total relaxation induced by glyceryl trinitrate 1 microgram/ml and a 50% maximal effective concentration of 6.8 x 10(-9) mol/l. Vasoactive intestinal peptide (10(-10) to 10(-7) mol/l) produced a relaxation of 27.0 (5.1)% at 10(-7) mol/l. The maximum responses induced by substance P and vasoactive intestinal peptide were significantly reduced, to 3.7 (2.8)% and 4.7 (2.0)% respectively, after removal of the endothelium. Calcitonin gene related peptide (10(-10) to 10(-7) mol/l) elicited only 14.3 (2.6)% relaxation at 10(-7) mol/l, and this was not affected by removal of the endothelium. By contrast, neuropeptide Y and somatostatin exerted concentration dependent constriction on resting vessels. Neuropeptide Y (10(-10) to 10(-7) mol/l) caused prolonged contraction (roughly 20 minutes to reach a maximum plateau at each dose). At 10(-7) mol/l, the constriction amounted to 28.0 (12.0)% of the response to 90 mM KCl, in ring segments with or without endothelium. Somatostatin (10(-10) to 10(-6) mol/l) quickly caused contraction with a maximum response of 42.7 (15.0)% and a maximum response of 42.7 (15.0)% and a 50% maximal effective concentration of 6.7 x 10(-6) mol/l. The constriction was greatly increased when endothelium was removed, with a maximum response of 78.2 (16.8)% and a 50% maximal effective concentration of 4.3 x 10(-7) mol/l. CONCLUSIONS--Vasoactive peptides have diverse effects on the vascular tone these effects are endothelium dependent. The exact physiological role and implication for performance of bypass grafts require further investigation.     

Treatment of chronic experimentalStaphylococcus aureus osteomyelitis with LY146032 and vancomycin

LY146032 and vancomycin were compared as therapeutic agents in the treatment of chronicStaphylococcus aureus osteomyelitis in the rat. Quantitative cultures disclosed that one of 16, none of 16, and two of 17 tibiae were sterile from the control, LY146032, and vancomycin groups, respectively. From positive cultures, geometric mean staphylococcal CFU per gram of bone were as follows: control, 5.13±1.58; LY146032, 5.36±0.43 (p=0.57); and vancomycin, 4.33±1.73 (p=0.078). Mean gross pathology was decreased significantly in both treatment groups. LY146032 was no more effective than vancomycin in reducing bacterial counts.