Origin of the Electroluminescence from Annealed-ZnO/GaN Heterojunction Light-Emitting Diodes

This paper addressed the effect of post-annealed treatment on the electroluminescence (EL) of an n-ZnO/p-GaN heterojunction light-emitting diode (LED). The bluish light emitted from the 450 °C-annealed LED became reddish as the LED annealed at a temperature of 800 °C under vacuum atmosphere. The origins of the light emission for these LEDs annealed at various temperatures were studied using measurements of electrical property, photoluminescence, and Auger electron spectroscopy (AES) depth profiles. A blue-violet emission located at 430 nm was associated with intrinsic transitions between the bandgap of n-ZnO and p-GaN, the green-yellow emission at 550 nm mainly originating from the deep-level transitions of native defects in the n-ZnO and p-GaN surfaces, and the red emission at 610 nm emerging from the Ga-O interlayer due to interdiffusion at the n-ZnO/p-GaN interface. The above-mentioned emissions also supported the EL spectra of LEDs annealed at 700 °C under air, nitrogen, and oxygen atmospheres, respectively.     

Thermographic monitoring of wound healing and oral health-related quality of life in patients treated with laser (aPDT) after impacted mandibular third molar removal

The objective of this study was to assess the impact of low-level laser therapy on wound swelling, wound temperature changes, and oral health-related quality of life (OHRQoL) after surgical removal of impacted lower third molars. Forty patients with impacted lower third molars requiring surgical removal participated in this study; all were Pell–Gregory class IIB or IIC. The patients were divided randomly into two groups for post-extraction therapy. One group received antimicrobial photodynamic therapy (aPDT) and the other received no additional therapy (placebo group). Temperature measurements were done using an infrared thermographic camera on days 3 and 7 postoperative. OHRQoL was assessed in both groups on day 7 using the Oral Health Impact Profile questionnaire translated into Croatian (OHIP-14-CRO). Prior to surgical treatment, there was no difference in patient characteristics between the two groups. A significantly lower temperature and less wound swelling were recorded on day 3 postoperative in the aPDT group compared to the control group (P < 0.001). Participants in the aPDT group also had significantly lower OHIP-14-CRO summary scores (P < 0.01). The present study showed beneficial effects of the aPDT modality of low-level laser therapy: postoperative wound swelling was reduced and wound temperature decreased, and OHRQoL was better through the 7-day postoperative period in comparison to the placebo group.     

Plant Growth Absorption Spectrum Mimicking Light Sources

Plant factories have attracted increasing attention because they can produce fresh fruits and vegetables free from pesticides in all weather. However, the emission spectra from current light sources significantly mismatch the spectra absorbed by plants. We demonstrate a concept of using multiple broad-band as well as narrow-band solid-state lighting technologies to design plant-growth light sources. Take an organic light-emitting diode (OLED), for example; the resulting light source shows an 84% resemblance with the photosynthetic action spectrum as a twin-peak blue dye and a diffused mono-peak red dye are employed. This OLED can also show a greater than 90% resemblance as an additional deeper red emitter is added. For a typical LED, the resemblance can be improved to 91% if two additional blue and red LEDs are incorporated. The approach may facilitate either an ideal use of the energy applied for plant growth and/or the design of better light sources for growing different plants.     

半导体激光与等离子电切术治疗浅表性膀胱肿瘤的疗效比较

目的 探讨1 470 nm半导体激光治疗浅表性膀胱肿瘤的临床疗效.方法 将2012年1月至2014年1月收治的浅表性膀胱肿瘤患者216例,分为激光组和电切组,分别行1 470 nm半导体激光和等离子电切术治疗,比较两组患者的疗效.结果 激光组的手术时间、术中出血量、留置尿管时间及术后住院时间均明显小于电切组,且激光组术中和术后6h的血肾上腺素、去甲肾上腺素及血管紧张素Ⅱ水平均明显低于电切组(P＜0.05).激光组未发生闭孔神经反射和膀胱穿孔,总并发症发生率为5.1％,术后24个月膀胱肿瘤复发率为7.1％;电切组闭孔神经反射发生率为7.6％,膀胱穿孔发生率为1.7％,总并发症发生率为15.3％,术后24个月膀胱肿瘤复发率为17.8％;激光组的上述指标均明显低于电切组(P＜0.05).结论 1 470 nm半导体激光手术治疗非浸润性膀胱肿瘤临床疗效确切,操作简单,术后并发症发生率低,安全性高,中远期复发率低,且对患者应激水平影响小.