Packaged Droplet Microresonator for Thermal Sensing with High Sensitivity

Liquid droplet and quasi-droplet whispering gallery mode (WGM) microcavities have been widely studied recently for the enhanced spatial overlap between the liquid and WGM field, especially in sensing applications. However, the fragile cavity structure and the evaporation of liquid limit its practical applications. Here, stable, packaged, quasi-droplet and droplet microcavities are proposed and fabricated for thermal sensing with high sensitivity. The sensitivity and electromagnetic field intensity distribution are analyzed by Mie theory, and a quantified definition of the quasi-droplet is presented for the first time to the best of our knowledge. By doping dye material directly into the liquid, lasing packaged droplet and quasi-droplet microcavity sensors with a high thermal sensitivity of up to 205.3 pm/°C are experimentally demonstrated. The high sensitivity, facile fabrication, and mechanically robust properties of the optofluidic, packaged droplet microresonator make it a promising candidate for future integrated photonic devices

Investigation on the Effect of Annealing Temperature on the Side Ohmic Contact Characteristics for Double Channel GaN/AlGaN Epitaxial Layer

A side ohmic contact mode for the double channel GaN/AlGaN epitaxial layer is proposed in this paper. Rectangle transmission line model (TLM) electrodes are prepared, and the specific contact resistance is tested at the annealing temperatures from 700 °C to 850 °C. The results show that the minimum specific contact resistance is 2.58 × 10−7 Ω·cm2 at the annealing temperature of 750 °C, which is three to four times lower than the surface contact mode. Scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and atomic force microscope (AFM) were carried out for the analysis of the morphology, element composition, and the height fluctuation at the contact edge. With the increase in the annealing temperature, the specific contact resistance decreases due to the alloying of electrodes and the raised number of N vacancies. However, when the annealing temperature exceeds 800 °C, the state of the stress in the electrode films transforms from compressive stress to tensile stress. Besides, the volume expansion of metal electrode film and the increase in the roughness at the contact edge leads to the degradation of the side ohmic contact characteristics

Quality of life and its predictors in first-episode schizophrenia and individuals at clinical high-risk for psychosis

Abstract Background This is a cross-sectional study comparing the degree of subjective quality of life (QOL) impairment and its predictive factors in first-episode schizophrenia (FES) and individuals at clinical high-risk (CHR) for psychosis. Methods Seventy-seven FES, 59 CHR, and 64 healthy controls (HC) were included. The QOL of all participants was assessed using the World Health Organization Quality of Life (WHOQOL)-Brief Form (BREF). Psychiatric symptoms of individuals with FES were assessed with the Positive and Negative Syndrome Scale (PANSS), five factors were further identified through factor analysis; for individuals with CHR and HC, the Scale of Prodromal Symptoms (SOPS) was used. Results The total and four sub-domain scores of the WHOQOL-BREF in the FES and CHR groups were lower than those of the HC group. The overall and psychological health scores in the CHR group were lowest. In the FES group, after applying Bonferroni’s correction, there is a negative correlation between the total QOL scores and anxiety/depressive symptom scores (r = –0.34, P = 0.003). The stepwise multiple regression analysis showed that the QOL of both FES and CHR group were negatively affected by anxiety/depressive symptoms and unemployment (P < 0.05). Conclusions Compared with FES, CHR individuals are more dissatisfied with their QOL. Although diagnostic assessment of FES and CHR relies heavily on positive symptoms, the QOL is more affected by anxiety/depressive symptoms and social functioning

Controlling Listeria monocytogenes, Campylobactor jejuni, Salmonella enterica Typhimurium and Escherichia coli O157:H7 in Meat Products by Irradiation Combined with Modified Atmosphere Packaging

Four of the bacterial pathogens that are of major concern to the meat industry, Listeria monocytogenes, Campylobacter jejuni, Salmonella enterica Typhimurium and Escherichia coli O157:H7 were studied for their susceptibility to high carbon dioxide atmospheres during irradiation and storage by utilizing high-carbon-dioxide modified atmosphere packages (MAP) compared to vacuum packaging. Frankfurters and cooked pork chops (L. monocytogenes), chicken breasts (C. jejuni and S. enterica) and ground beef (E. coli O157:H7) were inoculated with the respective pathogens, packaged in vacuum or MAP and irradiated with doses appropriate to each pathogen. Surviving bacteria were monitored during refrigerated and temperature-abused storage. While irradiation was very effective for reducing the number of pathogens on each product, the use of high carbon dioxide atmosphere in MAP did not increase the effectiveness of irradiation as an antimicrobial treatment. The MAP treatment resulted in less recovery of L. monocytogenes than vacuum for cooked pork chops during refrigerated storage, and for E. coli O157:H7 on ground beef when exposed to room temperature, but not for the other pathogens or products. Consequently, while irradiation is a very effective means of reducing or eliminating bacterial pathogens on meat products, the addition of a high-carbon dioxide MAP system during storage of the products did not greatly improve the control of these pathogens.</p