High-Efficiency All-Dielectric Metalenses for Mid-Infrared Imaging

Metasurfaces-based flat optics, which can make use of existing foundry planar technology for high-throughput production, allows the arbitrary control of the wavefront and polarization of light within subwavelength thick structures. So far, however, flat optics for the mid-infrared (MIR) has received far less attention than devices operating at visible or near-infrared wavelengths. Here, polarization-insensitive, highly efficient, all-dielectric metalenses operating in the MIR around 4 µm are demonstrated. The metalens is designed using rigorous coupled-wave analysis and is based on hydrogenated amorphous silicon (α-Si:H) nanopillars supported by an MgF2 substrate. The metalenses produce close to a diffraction-limited focal spot and can resolve structures on the wavelength scale where the focusing efficiency reaches 78% at a magnification of 120×. The imaging qualities are comparable with commercial bulk-molded chalcogenide aspheric lenses. These results provide novel solutions for existing MIR technology and nurture new functionalities with the population of miniaturized and planarized optoelectrical devices.The authors acknowledge the facility support from the ANU node of the Australian National Fabrication Facility (ANFF). This work was supported by China Scholarship Council (201506310074); Australian Research Council (ARC) Future Fellowship (FT110100853); and the ARC Centre of Excellence for Ultrahigh Bandwidth Devices for Optical Systems (CE110001018)

Effects of Stocking Density on Growth, Nonspecific Immune Response, and Antioxidant Status in African Catfish (Clarias gariepinus)

Abstract African catfish were stocked at densities of 35, 65, 95, and 125 kg/m 3 for 60 days. The effects of the stocking density on growth, non-specific immune response, and antioxidant status were investigated on days 30 and 60. Serum cortisol levels were assayed on day 60. Increased stocking density led to decreased growth. Most non-specific immune indices (total number of leukocytes, differential leukocyte count in percent, respiratory burst activity, C3 and C4 complements, spleen and head kidney mass indices) were unaffected by the stocking density (p>0.05). There were significant differences between the 35 and 125 kg/m 3 treatments in lysozyme activity on day 60 (p<0.05) but no significant effects of stocking density on malondialdehyde (MDA) level on either day 30 or day 60 (p>0.05). On day 30, only glutathione peroxidase (GSH-Px) activity was stimulated by increased stocking density while, on day 60, increased stocking density resulted in increased glutathione (GSH), GSH-Px activity, and superoxide dismutase (SOD) activity. The serum cortisol level on day 60 was unaffected by stocking density (p>0.05). Findings suggest that high physiological welfare standards were maintained in African catfish reared in high stocking densities. The IJA appears exclusively as a peer-reviewed online open-access journal at http://www.siamb.org.il. To read papers free of charge, please register online at registration form. Sale of IJA papers is strictly forbidden. 2 Wang et al. Introduction Raising fish at relatively high stocking densities maximizes the use of culture area and is an effective measure for improving farm profitability. However, growth performance, health status, and disease susceptibility are related to stress conditions caused by high density. High stocking density can have positive or negative effects on fish growth and this interaction seems to be species-specific The African catfish (Clarias gariepinus) is one of the most important cultured fish in China because of its fast growth, high disease resistance, and hypoxia tolerance. Increased stocking density may make fish more susceptible to stress and disease, followed by severe losses of stock. The purpose of this study was to investigate the effects of stocking density on the growth, cortisol level, non-specific immune response, and oxidative status of African catfish during nursing

Whole-genome sequencing of the snub-nosed monkey provides insights into folivory and evolutionary history

Colobines are a unique group of Old World monkeys that principally eat leaves and seeds rather than fruits and insects. We report the sequencing at 146× coverage, de novo assembly and analyses of the genome of a male golden snub-nosed monkey (Rhinopithecus roxellana) and resequencing at 30× coverage of three related species (Rhinopithecus bieti, Rhinopithecus brelichi and Rhinopithecus strykeri). Comparative analyses showed that Asian colobines have an enhanced ability to derive energy from fatty acids and to degrade xenobiotics. We found evidence for functional evolution in the colobine RNASE1 gene, encoding a key secretory RNase that digests the high concentrations of bacterial RNA derived from symbiotic microflora. Demographic reconstructions indicated that the profile of ancient effective population sizes for R. roxellana more closely resembles that of giant panda rather than its congeners. These findings offer new insights into the dietary adaptations and evolutionary history of colobine primates

Preparation and Application of Electrodes in Capacitive Deionization (CDI): a State-of-Art Review

As a promising desalination technology, capacitive deionization (CDI) have shown practicality and cost-effectiveness in brackish water treatment. Developing more efficient electrode materials is the key to improving salt removal performance. This work reviewed current progress on electrode fabrication in application of CDI. Fundamental principal (e.g. EDL theory and adsorption isotherms) and process factors (e.g. pore distribution, potential, salt type and concentration) of CDI performance were presented first. It was then followed by in-depth discussion and comparison on properties and fabrication technique of different electrodes, including carbon aerogel, activated carbon, carbon nanotubes, graphene and ordered mesoporous carbon. Finally, polyaniline as conductive polymer and its potential application as CDI electrode-enhancing materials were also discussed

Effects of Stocking Density on Growth, Nonspecific Immune Response, and Antioxidant Status in African Catfish (Clarias gariepinus)

African catfish were stocked at densities of 35, 65, 95, and 125 kg/m3 for 60 days. The effects of the stocking density on growth, non-specific immune response, and antioxidant status were investigated on days 30 and 60. Serum cortisol levels were assayed on day 60. Increased stocking density led to decreased growth. Most non-specific immune indices (total number of leukocytes, differential leukocyte count in percent, respiratory burst activity, C3 and C4 complements, spleen and head kidney mass indices) were unaffected by the stocking density (p>0.05). There were significant differences between the 35 and 125 kg/m3 treatments in lysozyme activity on day 60 (p0.05). On day 30, only glutathione peroxidase (GSH-Px) activity was stimulated by increased stocking density while, on day 60, increased stocking density resulted in increased glutathione (GSH), GSH-Px activity, and superoxide dismutase (SOD) activity. The serum cortisol level on day 60 was unaffected by stocking density (p>0.05). Findings suggest that high physiological welfare standards were maintained in African catfish reared in high stocking densities

Blockage of High-Affinity Choline Transporter Increases Visceral Hypersensitivity in Rats with Chronic Stress

Background. Visceral hypersensitivity is a common feature of irritable bowel syndrome. Cholinergic system involves in the development of visceral hypersensitivity, and high-affinity choline transporter (CHT1) is of crucial importance in choline uptake system. However, involvement of CHT1 in visceral hypersensitivity remains unknown. The research aimed to study the CHT1 expression in dorsal root ganglions (DRGs) and the role of CHT1 in visceral hypersensitivity. Methods. Repetitive water avoidance stress (WAS) was used to induce visceral hypersensitivity in rats. Colorectal distension (CRD) was determined, and the abdominal withdrawal reflex (AWR) and threshold intensity data were recorded to measure the visceral sensitivity. After intraperitoneal injection of hemicholinium-3 (HC-3), the specific inhibitor of CHT1, CRD data were also recorded. The CHT1 expression of DRGs was investigated by Western blotting, immunohistochemistry, and quantitative RT-PCR. Acetylcholine levels in the DRGs were detected by the assay kit. Results. Repetitive WAS increased the AWR score of CRD at high distension pressure and decreased the mean threshold of rats. The CHT1 expression and acetylcholine concentration of DRG were significantly increased in WAS rats. After the administration of HC-3, the AWR score in WAS group was significantly increased at higher distension pressure while the threshold intensity was significantly reduced compared to the normal saline group. Acetylcholine concentration was significantly lower than the normal saline rats. Conclusion. Our research firstly reports that CHT1 is overexpressed in noninflammatory visceral hypersensitivity, and blockage of CHT1 can enhance the visceral hypersensitivity. CHT1 may play an inhibitory role in visceral hypersensitivity