Local Bézout Theorem

AbstractWe give an elementary proof of what we call the Local Bézout Theorem. Given a system of n polynomials in n indeterminates with coefficients in a Henselian local domain, (V,m,k), which residually defines an isolated point in kn of multiplicity r, we prove (under some additional hypothesis on V) that there are finitely many zeroes of the system above the residual zero (i.e., with coordinates in m), and the sum of their multiplicities is r. Our proof is based on techniques of computational algebra

An Artificial Miniaturized Peroxidase for Signal Amplification in Lateral Flow Immunoassays

Signal amplification strategies are widely used for improving the sensitivity of lateral flow immunoassays (LFiAs). Herein, the artificial miniaturized peroxidase Fe(III)-MimochromeVI*a (FeMC6*a), immobilized on gold nanoparticles (AuNPs), is used as a strategy to obtain catalytic signal amplification in sandwich immunoassays on lateral flow strips. The assay scheme uses AuNPs decorated with the mini-peroxidase FeMC6*a and anti-human-IgG as a detection antibody (dAb), for the detection of human-IgG, as a model analyte. Recognition of the analyte by the capture and detection antibodies is first evidenced by the appearance of a red color in the test line (TL), due to the accumulation of AuNPs. Subsequent addition of 3,3',5,5'-tetramethylbenzidine (TMB) induces an increase of the test line color, due to the TMB being converted into an insoluble colored product, catalyzed by FeMC6*a. This work shows that FeMC6*a acts as an efficient catalyst in paper, increasing the sensitivity of an LFiA up to four times with respect to a conventional LFiA. Furthermore, FeMC6*a achieves lower limits of detection that are found in control experiments where it is replaced with horseradish peroxidase (HRP), its natural counterpart. This study represents a significant proof-of-concept for the development of more sensitive LFiAs, for different analytes, based on properly designed artificial metalloenzymes

A Comparative Analysis of Orexins in the Physio-Pathological Processes of the Male Genital Tract: New Challenges? A Review

Orexins A (OXA) and B (OXB) and their specific receptors, receptor 1 (OX1R) and 2 (OX2R) for orexins, are hypothalamic peptides involved in orchestrating several functions in the central nervous system and peripheral organs, including sleep, excitement, nutrition, reward, circadian rhythm, anxiety, cognition, and reproduction. The aim of this narrative review is, in particular, to speculate the role of orexins in the male genital tract of animal species and human beings. The experimental evidence collected in recent years assumed that in the testes of the animal species here described, orexins are directly involved in steroidogenesis and spermatogenesis regulation. In the epididymis, these peptides are locally synthesized, thus suggesting their role governing the fertilizing capability of the immature male gamete. In addition to playing a physiological role, orexins are involved in numerous inflammatory and/or neoplastic pathologies too. The expression of the orexinergic system in prostate cancer suggests that they might play a potential therapeutic function. Overall, the future directions of this literature review allow us to hypothesize a role of the orexinergic complex not only as a marker for the diagnosis of certain tumors affecting the male genital tract but also for the treatment of hypo/infertility condition

Engaging diverse student audiences in contemporary blended learning environments in Australian higher business education: implications for design and practice

This research reports on a student audience engaging in an Australian university’s undergraduate commerce program core unit that is offered across three separate geographic campus locations and online. The research extends upon work undertaken on student engagement in online settings and lies in the domain of blended learning design and practice in the Australian higher education business context. Findings, inter alia, are presented across six major student engagement dimensions as applied to the interplay between online and located/campus learning (i.e. Online Active Learning, Online Social Interaction, Online Collaboration, Online Teaching, Online Assessment, and Online Contact with Staff). Implications for blended learning design, eLearning and practice in such complex environments are examined

Synthesis of temporin L hydroxamate-based peptides and evaluation of their coordination properties with iron (III)

Ferric iron is an essential nutrient for bacterial growth. Pathogenic bacteria synthesize iron-chelating entities known as siderophores to sequestrate ferric iron from host organisms in order to colonize and replicate. The development of antimicrobial peptides (AMPs) conjugated to iron chelators represents a promising strategy for reducing iron availability, inducing bacterial death, and enhancing simultaneously the efficacy of AMPs. Here we designed, synthesized, and characterized three hydroxamate-based peptides Pep-cyc1, Pep-cyc2, and Pep-cyc3, derived from a cyclic temporin L peptide (Pep-cyc) developed previously by some of us. The Fe3+ complex formation of each ligand was characterized by UVvisible spectroscopy, mass spectrometry, IR, and NMR spectroscopies. In addition, the effect of Fe3+ on the stabilization of -helix conformation of hydroxamate-based peptides and the cotton effect were examined by CD spectroscopy. Moreover, the antimicrobial results obtained in vitro on some Gram-negative strains (K. Pneumoniae and E. coli) showed the ability of each peptide to chelate efficaciously Fe3+ obtaining a reduction of MIC values in comparison to their parent peptide Pepcyc. Our results demonstrated that siderophore conjugation could increase the efficacy and selectivity of AMPs used for the treatment of infectious diseases caused by Gram-negative pathogens

Bioactive cembrane derivatives from the Indian Ocean soft coral, Sinularia kavarattiensis

Marine organisms and their metabolites represent a unique source of potential pharmaceutical substances. In this study, we examined marine-derived substances for their bioactive properties in a cell-based Chikungunya virus (CHIKV) replicon model and for in vitro anti-inflammatory activity. In the screening of a marine sample library, crude extracts from the Indian soft coral, Sinularia kavarattiensis, showed promising activity against the CHIKV replicon. Bioassay-guided chemical fractionation of S. kavarattiensis resulted in the isolation of six known norcembranoids (1–6) and one new compound, named kavaranolide (7). The structures were elucidated on the basis of NMR and MS spectroscopic data. Compounds 1–3 and 5–7 were evaluated for their replicon-inhibiting potential in the CHIKV model by using a luminescence-based detection technique and live cell imaging. Compounds 1 and 2 showed moderate inhibition of the CHIKV replicon, but imaging studies also revealed cytotoxic properties. Moreover, the effects of the isolated compounds on primary microglial cells, an experimental model for neuroinflammation, were evaluated. Compound 2 was shown to modulate the immune response in microglial cells and to possess potential anti-inflammatory properties by dose-dependently reducing the release of pro- and anti-inflammatory cytokines.Peer reviewe