Control of mosaic disease using microbial biostimulants: insights from mathematical modelling

Ricerche di Matematica - A major challenge to successful crop production comes from viral diseases of plants that cause significant crop losses, threatening global food security and the livelihoods...     

Optical Control of GABAA Receptors with a Fulgimide-Based Potentiator

Optogenetic and photopharmacological tools to manipulate neuronal inhibition have limited efficacy and reversibility. We report the design, synthesis, and biological evaluation of Fulgazepam, a fulgimide derivative of benzodiazepine that behaves as a pure potentiator of ionotropic γ-aminobutyric acid receptors (GABA_ARs) and displays full and reversible photoswitching in vitro and in vivo. The compound enables high-resolution studies of GABAergic neurotransmission, and phototherapies based on localized, acute, and reversible neuroinhibition.     

A Novel Squarylium Dye for Monitoring Oxidative Processes in Lipid Membranes

A novel squaraine probe SQ-1 has been found to be appropriate for monitoring the peroxidation processes in membrane systems. Formation of free radicals was triggered by methemoglobin (metHb) or cytochrome c (cyt c) binding to the model lipid membranes composed of zwitterionic lipid phosphatidylcholine (PC) and anionic lipid cardiolipin (CL). Protein association with the lipid vesicles was followed by drastic quenching of SQ-1 fluorescence. The observed spectral changes were suppressed in the presence of free radical scavengers, butylated hydroxytoluene (BHT) and thiourea (TM) suggesting that SQ-1 decolorization can be attributed to its reactions with lipid radicals.     

Weakly non-Hermitian square well

Inside a box of size L we contemplate the simplest -symmetric piece-wise constant potential of size ℓ < L and purely imaginary strength ig and describe all its bound states in closed form. Presented at the 3rd International Workshop “Pseudo-Hermitian Hamiltonians in Quantum Physics”, Istanbul, Turkey, June 20–22, 2005.     

Ion insertion into ionic liquid supported toluene generated by electrochemical redox reaction

Ion transfer across the toluene|water, toluene–ionic liquid mixture|water and ionic liquid|water boundary generated by electrochemical redox reaction of tert-butylferrocene (tBuFc) was studied with the glassy carbon (GC) electrode partially covered by the organic liquid deposit and immersed in the aqueous electrolyte solution. The electrooxidation of the redox probe in toluene deposit is followed by ejection of newly formed cation into the aqueous solution. The same reaction in the toluene–ionic liquid deposit promotes anion insertion. This pathway is also found at the electrode modified with ionic liquid.     

Adsorption of Poly(rA) on the Carbon Nanotube Surface and its Hybridization with Poly(rU)

Adsorption of poly(rA) on a single‐walled carbon nanotube surface in aqueous suspension and the subsequent hybridization of this polymer with free poly(rU) is studied. A comparison of the temperature dependence of the absorbance of free poly(rA) and poly(rA) adsorbed on the nanotube surface [poly(rA)^NT] at ν_max=38 500 cm^?1 shows that the thermostability of the adsorbed polymer is higher. Molecular dynamics simulations demonstrate that more than half of the adenines are not stacked on the tube surface and some of them undergo self‐stacking. After addition of a complementary poly(rU) to the poly(rA)^NT suspension, a double‐stranded polymer is formed as confirmed by the characteristic S‐like form of its melting curve. However, the melting temperature of this polymer is lower than that of the free poly(rA)?poly(rU) duplex. This result indicates that poly(rU) hybridization with poly(rA)^NT occurs with defects along the whole length of the polymer because of π–π stacking between nitrogen bases and the nanotube surface, which hinders the usual hybridization process. Computer modeling demonstrates different possible structures of hybridized polymers on the nanotube surface.     

Reversibly Switchable Phase-Dependent Emission of Quinoline and Phenothiazine Derivatives towards Applications in Optical Sensing and Information Multicoding

Three new quinoline and di-tert-butyl phenothiazine isomeric derivatives were synthesized and characterized towards applications for oxygen sensing and optical information multicoding. The compounds with phenylene linker showed outstanding phase-dependent reversibility between ON/OFF states (low and high emission intensity, drastic shifting of emission colors, short- and long-lived fluorescence) in systematic grinding/fuming cycles, as required for multichannel memory devices based on optical information multicoding. The conformational diversity of the phenothiazine unit resulted in dual emission of the doped films implemented by the different luminescence mechanisms with peaks located at 414/530, 416/540, and 440/582 nm. The presence of a phenylene linker and thus two rotational degrees of freedom resulted in quenching of the delayed fluorescence of quasi-equatorial conformers in the solid state. The compound containing no phenylene bridge was characterized by two different driving photoluminescence mechanisms of the doped films: short fluorescence of the quasi-axial conformer and thermally activated delayed fluorescence of the quasi-equatorial form. This compound showed oxygen sensitivity with a Stern–Volmer constant of 7.5×10⁻⁴ ppm⁻¹.     

Amination of brominated nanoporous activated carbon beads for the preparation of CO2 adsorbents

Abstract

Nanoporous activated carbon (NAC) beads that prepared by carbonization of microporous polymer 2,6-di-tert-butyl pyridine beads were subjected to bromination followed by amination to synthesize the NAC derivatives carrying amino groups. Grafted bromine groups, 0.41?mmol of Br per 1?g of NAC, are hydrolytic stable at 100 °С and can be successfully substituted by amino groups. SEM, TEM, and texture studies were shown a nanoporosity decrease. However, the aminated NAC beads maintained a narrow nanopore size distribution and high specific surface area, retaining a spherical shape. These beads were evaluated for capturing CO₂ and showed good reversible adsorption capacity. The preparation method can easily be scaled up, and the NAC beads can be used for other adsorption applications where shaped carbon solids with developed nanoporosity are required.     

The Recognition of and Reactions to Nucleic Acid Nanoparticles by Human Immune Cells

The relatively straightforward methods of designing and assembling various functional nucleic acids into nanoparticles offer advantages for applications in diverse diagnostic and therapeutic approaches. However, due to the novelty of this approach, nucleic acid nanoparticles (NANPs) are not yet used in the clinic. The immune recognition of NANPs is among the areas of preclinical investigation aimed at enabling the translation of these novel materials into clinical settings. NANPs’ interactions with the complement system, coagulation systems, and immune cells are essential components of their preclinical safety portfolio. It has been established that NANPs’ physicochemical properties—composition, shape, and size—determine their interactions with immune cells (primarily blood plasmacytoid dendritic cells and monocytes), enable recognition by pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) and RIG-I-like receptors (RLRs), and mediate the subsequent cytokine response. However, unlike traditional therapeutic nucleic acids (e.g., CpG oligonucleotides), NANPs do not trigger a cytokine response unless they are delivered into the cells using a carrier. Recently, it was discovered that the type of carrier provides an additional tool for regulating both the spectrum and the magnitude of the cytokine response to NANPs. Herein, we review the current knowledge of NANPs’ interactions with various components of the immune system to emphasize the unique properties of these nanomaterials and highlight opportunities for their use in vaccines and immunotherapy.