Ion-Exchanged Waveguides in Glass Doped with PbS Quantum Dots

The lowest-loss (≤1 dB/cm) ion-exchanged waveguides in glass doped with PbS quantum dots are presented. Near-field mode profile and refractive index profile using the refracted near-field technique were measured for these waveguides. We demonstrate that the optical properties of this glass unchanged during the ion-exchange process

Histopathological features of gastrointestinal mucosal biopsies in children with juvenile idiopathic arthritis

BACKGROUND: The association between inflammatory bowel disease and joint involvement is well established. There is a paucity of data describing histopathological features of the gut in relation to juvenile idiopathic arthritis (JIA). METHODS: We retrospectively identified 33 (21 male) children aged 3-16 y with JIA (11 with oligoarthritis, 5 with polyarthritis, 8 with systemic onset arthritis, 8 with enthesitis-related arthritis (ERA), and 1 with psoriatic arthritis) with significant gastrointestinal (GI) symptoms who underwent upper and/or lower endoscopy. The histopathological findings were reviewed in addition to presence of autoantibodies and concomitant treatment. RESULTS: The most common GI indications for endoscopy were persistent abdominal pain (14/33 (42%)) and diarrhea (10/33 (30%)). Of the 33 children, 28 (85%) had gut mucosal inflammation, mostly affecting the colon (80%). Active inflammation of the gut was found in 5 of 28 (17%) children, and 15 of 28 (53%) children showed mild nonspecific inflammation. Eight patients (27%) had predominantly an eosinophilic infiltrate. Twenty-six patients had previously received treatment for JIA. There was a negative association with the use of immunomodulators and the presence of eosinophil inflammation. CONCLUSION: The majority of children with JIA and GI symptoms have histological evidence of mild nonspecific inflammation, but some having active colitis and prominent eosinophil infiltrate

ROS-Mediated Apoptotic Cell Death of Human Colon Cancer LoVo Cells by Milk δ-Valerobetaine

δ-Valerobetaine (δVB) is a constitutive milk metabolite with antioxidant and anti-inflammatory activities. Here, we tested the antineoplastic properties of milk δVB on human colorectal cancer cells. CCD 841 CoN (non-tumorigenic), HT-29 (p53 mutant adenocarcinoma) and LoVo (APC/RAS mutant adenocarcinoma) cells were exposed to 3 kDa milk extract, δVB (2 mM) or milk+δVB up to 72 h. Results showed a time- and dose-dependent capability of δVB to inhibit cancer cell viability, with higher potency in LoVo cells. Treatment with milk+δVB arrested cell cycle in G2/M and SubG1 phases by upregulating p21, cyclin A, cyclin B1 and p53 protein expressions. Noteworthy, δVB also increased necrosis (P < 0.01) and when used in combination with milk it improved its activity on live cell reduction (P < 0.05) and necrosis (P < 0.05). δVB-enriched milk activated caspase 3, caspase 9, Bax/Bcl-2 apoptotic pathway and reactive oxygen species (ROS) production, whereas no effects on ROS generation were observed in CCD 841 CoN cells. The altered redox homeostasis induced by milk+δVB was accompanied by upregulation of sirtuin 6 (SIRT6). SIRT6 silencing by small interfering RNA blocked autophagy and apoptosis activated by milk+δVB, unveiling the role of this sirtuin in the ROS-mediated apoptotic LoVo cell death

Stable Catechol Keto Tautomers in Cytotoxic Heterodimeric Cyclic Diarylheptanoids from the Seagrass Zostera marina

Two diarylheptanoid heterodimers, zosterabisphenones A (1) and B (2), were isolated from the seagrass Zostera marina. They feature unprecedented catechol keto tautomers, stable because of steric constraints. Their structure elucidation was based on extensive low-temperature NMR studies and ECD and MS data, with the essential aid of DFT prediction of NMR and ECD spectra. Zosterabisphenone B (2) was selectively cytotoxic against the adenocarcinoma colon cancer cell line HCT116 with IC50 3.6 ± 1.1 μM at 48 h

Antimicrobial activity of lipids extracted from Hermetia illucens reared on different substrates

Abstract: As the problem of antimicrobial resistance is constantly increasing, there is a renewed interest in antimicrobial products derived from natural sources, particularly obtained from innovative and eco-friendly materials. Insect lipids, due to their fatty acid composition, can be classified as natural antimicrobial compounds. In order to assess the antibacterial efficacy of Hermetia illucens lipids, we extracted this component from the larval stage, fed on different substrates and we characterized it. Moreover, we analyzed the fatty acid composition of the feeding substrate, to determine if and how it could affect the antimicrobial activity of the lipid component. The antimicrobial activity was evaluated against Gram-positive Micrococcus flavus and Gram-negative bacteria Escherichia coli. Analyzing the fatty acid profiles of larval lipids that showed activity against the two bacterial strains, we detected significant differences for C4:0, C10:0, C16:1, C18:3 n3 (ALA), and C20:1. The strongest antimicrobial activity was verified against Micrococcus flavus by lipids extracted from larvae reared on strawberry, tangerine, and fresh manure substrates, with growth inhibition zones ranged from 1.38 to 1.51 mm, while only the rearing on manure showed the effect against Escherichia coli. Notably, the fatty acid profile of H. illucens seems to not be really influenced by the substrate fatty acid profile, except for C18:0 and C18:2 CIS n6 (LA). This implies that other factors, such as the rearing conditions, larval development stages, and other nutrients such as carbohydrates, affect the amount of fatty acids in insects. Key points: • Feeding substrates influence larval lipids and fatty acids (FA) • Generally, there is no direct correlation between substrate FAs and the same larvae FAs • Specific FAs influence more the antimicrobial effect of BSF lipids Graphical abstract: [Figure not available: see fulltext.

Quantum light transport in phase-separated Anderson localization fiber

Anderson localization, a strong localization effect that prevents wave diffusion, is fundamentally important in manipulating wave propagation in a disordered medium. This work uses a phase separated glass Anderson localization optical fiber and demonstrates quantum light transport, which shows the potential for transmission of high dimensional quantum information, thereby enabling quantum imaging and quantum communication applications.Propagation of light by Anderson localization has been demonstrated in micro-nano-structured fibers. In this work, we introduce a phase separated glass Anderson localization optical fiber for quantum applications. By using a spontaneous parametric down-conversion source, multi-photon detection with a single-photon avalanche diode array camera, and signal post-processing techniques, we demonstrate quantum light transport, where spatial correlations between photon pairs are preserved after propagation. In order to better understand and improve light transport, we study light localization, observing a dependence on wavelength. Our results indicate that the proposed phase separated fiber may become an effective platform for quantum imaging and communication

Objective Knowledge Mediates the Relationship between the Use of Social Media and COVID-19-Related False Memories

The exposure to relevant social and/or historical events can increase the generation of false memories (FMs). The Coronavirus Disease 2019 (COVID-19) pandemic is a calamity challenging health, political, and journalistic bodies, with media generating confusion that has facilitated the spread of fake news. In this respect, our study aims at investigating the relationships between memories (true memories, TMs vs. FMs) for COVID-19-related news and different individual variables (i.e., use of traditional and social media, COVID-19 perceived and objective knowledge, fear of the disease, depression and anxiety symptoms, reasoning skills, and coping mechanisms). One hundred and seventy-one university students (131 females) were surveyed. Overall, our results suggested that depression and anxiety symptoms, reasoning skills, and coping mechanisms did not affect the formation of FMs. Conversely, the fear of loved ones contracting the infection was found to be negatively associated with FMs. This finding might be due to an empathy/prosociality-based positive bias boosting memory abilities, also explained by the young age of participants. Furthermore, objective knowledge (i) predicted an increase in TMs and decrease in FMs and (ii) significantly mediated the relationships between the use of social media and development of both TMs and FMs. In particular, higher levels of objective knowledge strengthened the formation of TMs and decreased the development of FMs following use of social media. These results may lead to reconsidering the idea of social media as the main source of fake news. This claim is further supported by either the lack of substantial differences between the use of traditional and social media among participants reporting FMs or the positive association between use of social media and levels of objective knowledge. The knowledge about the topic rather than the type of source would make a difference in the process of memory formation

Purification and characterization of a lipoxygenase enzyme from durum wheat semolina

Purification of a lipoxygenase enzyme from the cultivar Tresor of durum wheat semolina (Triticum turgidum var. durum Desf) was reinvestigated furnishing a new procedure. The 895-fold purified homogeneous enzyme showed a monomeric structure with a molecular mass of 95 +/- 5 kDa. Among the substrates tested, linoleic acid showed the highest k(cat)/K(m) value; a beta-carotene bleaching activity was also detected. The enzyme optimal activity was at pH 6. 8 on linoleic acid as substrate and at pH 5.2 for the bleaching activity on beta-carotene, both assayed at 25 degrees C. The dependence of lipoxygenase activity on temperature showed a maximum at 40 degrees C for linoleic acid and at 60 degrees C for bleaching activity on beta-carotene. The amino acid composition showed the presence of only one tryptophan residue per monomer. Far-UV circular dichroism studies carried out at 25 degrees C in acidic, neutral, and basic regions revealed that the protein possesses a secondary structure content with a high percentage of alpha- and beta-structures. Near-UV circular dichroism, at 25 degrees C and at the same pH values, pointed out a strong perturbation of the tertiary structure in the acidic and basic regions compared to the neutral pH condition. Moreover, far-UV CD spectra studying the effects of the temperature on alpha-helix content revealed that the melting point of the alpha-helix is at 60 degrees C at pH 5.0, whereas it was at 50 degrees C at pH 6.8 and 9.0. The NH(2)-terminal sequence allowed a homology comparison with other lipoxygenase sequences from mammalian and vegetable sources