Resonant Thermoelectric Nanophotonics

Photodetectors are typically based either on photocurrent generation from electron–hole pairs in semiconductor structures or on bolometry for wavelengths that are below bandgap absorption. In both cases, resonant plasmonic and nanophotonic structures have been successfully used to enhance performance. Here, we show subwavelength thermoelectric nanostructures designed for resonant spectrally selective absorption, which creates large localized temperature gradients even with unfocused, spatially uniform illumination to generate a thermoelectric voltage. We show that such structures are tunable and are capable of wavelength-specific detection, with an input power responsivity of up to 38 V W^(–1), referenced to incident illumination, and bandwidth of nearly 3 kHz. This is obtained by combining resonant absorption and thermoelectric junctions within a single suspended membrane nanostructure, yielding a bandgap-independent photodetection mechanism. We report results for both bismuth telluride/antimony telluride and chromel/alumel structures as examples of a potentially broader class of resonant nanophotonic thermoelectric materials for optoelectronic applications such as non-bandgap-limited hyperspectral and broadband photodetectors

Neurodegenerative Diseases and Autophagy

Most neurodegenerative diseases are characterized by the accumulation of aggregated proteins within neurons. These aggregate-prone proteins cause toxicity, a phenomenon that is further exacerbated when there is defective protein clearance. Autophagy is an intracellular clearance pathway that can clear these protein aggregates and has been shown to be beneficial in the treatment of neurodegenerative diseases in a variety of model systems. Here, we introduce the key components of the autophagy machinery and signaling pathways that control this process and discuss the evidence that autophagic flux may be impaired and therefore a contributing factor in neurodegenerative disease pathogenesis. Finally, we review the use of autophagy upregulation as a therapeutic strategy to treat neurodegenerative disorders

A genetic cause of Alzheimer disease: mechanistic insights from Down syndrome

Down syndrome, caused by an extra copy of chromosome 21, is associated with a greatly increased risk of early onset Alzheimer disease. It is thought that this risk is conferred by the presence of three copies of the gene encoding amyloid precursor protein (APP), an Alzheimer risk factor, although the possession of extra copies of other chromosome 21 genes may also play a role. Further study of the mechanisms underlying the development of Alzheimer disease in Down syndrome could provide insights into the mechanisms that cause dementia in the general population

Extra-cellular matrix proteins induce matrix metalloproteinase-1 (MMP-1) activity and increase airway smooth muscle contraction in asthma

Airway remodelling describes the histopathological changes leading to fixed airway obstruction in patients with asthma and includes extra-cellular matrix (ECM) deposition. Matrix metalloproteinase-1 (MMP-1) is present in remodelled airways but its relationship with ECM proteins and the resulting functional consequences are unknown. We used airway smooth muscle cells (ASM) and bronchial biopsies from control donors and patients with asthma to examine the regulation of MMP-1 by ECM in ASM cells and the effect of MMP-1 on ASM contraction. Collagen-I and tenascin-C induced MMP-1 protein expression, which for tenascin-C, was greater in asthma derived ASM cells. Tenascin-C induced MMP-1 expression was dependent on ERK1/2, JNK and p38 MAPK activation and attenuated by function blocking antibodies against the β1 and β3 integrin subunits. Tenascin-C and MMP-1 were not expressed in normal airways but co-localised in the ASM bundles and reticular basement membrane of patients with asthma. Further, ECM from asthma derived ASM cells stimulated MMP-1 expression to a greater degree than ECM from normal ASM. Bradykinin induced contraction of ASM cells seeded in 3D collagen gels was reduced by the MMP inhibitor ilomastat and by siRNA knockdown of MMP-1. In summary, the induction of MMP-1 in ASM cells by tenascin-C occurs in part via integrin mediated MAPK signalling. MMP-1 and tenascin-C are co-localised in the smooth muscle bundles of patients with asthma where this interaction may contribute to enhanced airway contraction. Our findings suggest that ECM changes in airway remodelling via MMP-1 could contribute to an environment promoting greater airway narrowing in response to broncho-constrictor stimuli and worsening asthma symptoms

Uncovering LED light effects on plant growth: new angles and perspectives - LED light for improving plant growth, nutrition and energy-use efficiency

Light supplementation can increase crop yield in greenhouses by promoting photosynthesis and plant growth. However, the high energy costs associated with light supplementation are a predominant factor that limits development and profit improvement of controlled environment agriculture. Light-emitting diodes (LEDs) are a promising technology that has tremendous potential to improve irradiance efficiency and to replace traditionally used horticultural lighting. Compared with traditional light sources (e.g., high-pressure sodium lamps and metal halide lamps) used in crop production, LEDs have distinct advantages, such as their small size, long lifetime and high photoelectric conversion efficiency. Most importantly, as a monochromatic light source, the spectrum of LEDs can be adjusted based on plant growth requirements. This project aimed to investigate energy-use efficiency, vegetable nutrition and photosynthesis improvement of light supplementation in a protected horticulture system. In the initial phase, the effects of LED light on plant growth and light-use efficiency for pak choi and photosynthetic performance were investigated. The results showed that the highest fresh and dry weight and leaf area were observed under red and blue LED light, with the blue light percentage at 23%. Compared with fluorescent lamps (FL) with photosynthetic photon flux density (PPFD) at 220 μmol m-2 s-1, the light-use efficiency increased by 55, 114 and 115% for mixed red and blue LEDs with PPFD at 100, 150 and 220 μmol m-2 s-1, respectively. Monochromatic red- and blue-light LEDs resulted in significant decreases in Pn of tomato plants, but the stomatal conductance (Gs) for monochromatic blue LEDs was higher than that for FL. The effect of light spectrum composition on lettuce nutrition quality was also studied. Continuous light with combined red, green and blue LEDs exhibited a remarkable decrease in nitrate. Moreover, continuous LED light for 24 h significantly increased phenolic compound content and free-radical scavenging capacity in lettuce leaf

Mucus extravasation and retention phenomena: a 24-year study

<p>Abstract</p> <p>Background</p> <p>Mucoceles are benign lesions related to the minor salivary glands and their respective ducts frequently affecting oral structures which are generally asymptomatic. Mucoceles are generally characterized by swollen nodular lesions preferentially located on the lower lip and differ from the so-called ranulas, which are lesions located on the floor of the mouth and related to the sublingual or submandibular glands.</p> <p>Methods</p> <p>The objective of the present study was to analyze data such as age, gender, race and site of the lesion of 173 mucocele cases diagnosed at the Discipline of Stomatology, São José dos Campos Dental School, UNESP, over a period of 24 years (April 1980 to February 2003).</p> <p>Results</p> <p>Of the 173 cases analyzed, 104 (60.12%) were females and 69 (39.88%) were males. Age ranged from 4 to 70 years (mean ± SD: 17 ± 9.53) and most patients were in the second decade of life (n = 86, 49.42%); white (n = 124, 71.68%). The lower lip was the site most frequently affected by the lesions (n = 135, 78.03%), whereas the lowest prevalence was observed for the soft palate, buccal mucosa, and lingual frenum.</p> <p>Conclusion</p> <p>In this study, mucoceles predominated in white female subjects in the second decade of life, with the lower lip being the most frequently affected site.</p

New records of rare species in the Mediterranean Sea (May 2020)

This Collective Article presents information about 17 taxa belonging to four Phyla (one Cnidaria, two Arthropoda, four Mollusca, and ten Chordata) and extending from the Western Mediterranean to the Levantine Sea. The new records were reported from nine countries as follows: Algeria: first published records of the clingfishes Apletodon dentatus and Lepadogaster lepadogaster after 1955; France: first record of the tripletail Lobotes surinamensis in French Mediterranean waters; Italy: new records of the rare bonito Orcynopsis unicolor and the recently described nudibranch Elysia rubeni from Sicily; first records of the parasitic cirriped Sacculina eriphiae and the nudibranch Dondice trainitoi in the Ionian Sea; first record of the nudibranch Taringa tritorquis in the Mediterranean Sea; first record of the tripletail Lobotes surinamensis in the North Ionian Sea; first documented record of the cephalopod Macrotritopus defilippi in the Adriatic Sea; Slovenia: first record of the Mediterranean endemic cryptobenthic goby Odondebuenia balearica; Montenegro: several recent occurrences of the critically endangered bull ray Aetomylaeus bovinus in the South-eastern Adriatic Sea; Greece: records of the nudibranch Dondice trainitoi in the Eastern Mediterranean Sea; new record of the occurrence of the Mediterranean spearfish Tetrapturus belone from Greece (Rhodes Island); Turkey: recent captures of the vulnerable ocean sunfish Mola mola, caught by purse-seine, in the Aegean Sea and the Dardanelles; new record of the luvar Luvarus imperialis along the Aegean coast of Turkey; Cyprus: first record of the habitat-forming hydroid Lytocarpia myriophyllum, often in considerable densities; first confirmed record of the agujon needlefish Tylosurus imperialis; Syria: first record of the decapod Ethusa mascarone