Water-based UV curable hybrid urethane-acrylates formed by acid–base interaction between tertiary amine containing polyurethane and acrylic acid for photocoating and ink applications

Urethane acrylate hybrids are commonly used in polyurethane dispersions (PUD). PUDs are key ingredients in UV curing applications and UV curing is widely used in coatings and inks. The preparation of PUDs involves many volatiles in the form of solvents and reagents that are also carried over in the UV curing step. This article reports a process, which totally eliminates these volatile components and additionally introduces many flexibilities. The process involves acid–base interaction between tertiary amine containing polyurethane and acidic vinyl monomer like acrylic acid forming polyurethane-acrylate (PU-AA) hybrids in water. The developed process also overcomes the prepolymer and “endcapping” approaches used in the preparation of PUDs that restrict the molecular weight of polyurethanes. Simultaneously, because of the prevalence of large number of vinyl components in the polymer backbone through the acid–base interaction, it functions as a multifunctional acrylate similar to the reactive diluents used in UV curing applications. Thus, it helps to increase the cross-linking density of the UV cured substrates. In general, high crosslinking density helps to improve characteristics like hardness, scratch, solvent and stain resistance of coated substrates. The process has been demonstrated to form transparent and opaque coated substrates and cured inks. This development potentially helps to shift the process from an industrial activity to do-it-yourself domain and has implications for the development of components for 3D printing sustainably.     

Indoleamine 2,3 Dioxygenase 1—The Potential Link between the Innate Immunity and the Ischemia-Reperfusion-Induced Acute Kidney Injury?

Ischemia-reperfusion injury (IRI) is of the most common causes of acute kidney injury (AKI); nevertheless, the mechanisms responsible for both early kidney injury and the reparative phase are not fully recognised. The inflammatory response following ischemia is characterised by the crosstalk between cells belonging to the innate immune system—dendritic cells (DCs), macrophages, neutrophils, natural killer (NK) cells, and renal tubular epithelial cells (RTECs). A tough inflammatory response can damage the renal tissue; it may also have a protective effect leading to the repair after IRI. Indoleamine 2,3 dioxygenase 1 (IDO1), the principal enzyme of the kynurenine pathway (KP), has a broad spectrum of immunological activity from stimulation to immunosuppressive activity in inflamed areas. IDO1 expression occurs in cells of the innate immunity and RTECs during IRI, resulting in local tryptophan (TRP) depletion and generation of kynurenines, and both of these mechanisms contribute to the immunosuppressive effect. Nonetheless, it is unknown if the above mechanism can play a harmful or preventive role in IRI-induced AKI. Despite the scarcity of literature in this field, the current review attempts to present a possible role of IDO1 activation in the regulation of the innate immune system in IRI-induced AKI.     

The Long and the Short of Mate Attraction in a Psylloid: do Semiochemicals Mediate Mating in <Emphasis Type="Italic">Aacanthocnema dobsoni</Emphasis> Froggatt?

Mating is preceded by a series of interdependent events that can be broadly categorized into searching and courtship. Long-range signals convey species- and sex-specific information during searching, while short-range signals provide information specific to individuals during courtship. Studies have shown that cuticular hydrocarbons (CHCs) can be used for mate recognition in addition to protecting insects from desiccation. In Psylloidea, four species rely on semiochemicals for long-range mate attraction. Psyllid mating research has focused on long-range mate attraction and has largely ignored the potential use of cuticular hydrocarbons (CHCs) as mate recognition cues. This study investigated whether CHCs of Aacanthocnema dobsoni have semiochemical activity for long- and short-range communication prior to mating. Using a solid sampler for solvent-less injection of whole psyllids into coupled gas chromatography/mass spectrometry, we found quantitative, sex- and age-related differences in CHC profiles. Males had higher proportions of 2-MeC₂₈, 11,15-diMeC₂₉, and n-C₃₃ alkanes, while females had higher proportions of 5-MeC₂₇, 3-MeC₂₇, 5,15-diMeC₂₇, n-C₂₉ and n-C₃₀ alkanes. In males and females, 84 and 68 % of CHCs varied with age, respectively. Y-tube olfactometer bioassays provided no evidence that males or females responded to odors emanating from groups of conspecifics of the opposite sex. Tests of male and female psyllids for attraction to branchlets previously occupied by conspecifics showed no evidence of attraction to possible semiochemical residues. Our short-range chemoreception bioassay showed that males were as indifferent to freshly killed individuals of either sex with intact CHC profiles as to those treated with hexane (to remove CHCs). Aacanthocnema dobsoni utilizes substrate–borne vibrations (SBVs) for communication. Therefore, our results indicate that SBVs are probably more important than semiochemicals for long-range mate attraction. Furthermore, CHCs are unlikely to mediate short-range mate recognition or provide mate assessment cues.     

Palladium‐Catalyzed Oxidative Intramolecular C?C Bond Formation via Double sp2 C?H Activation between the 2‐Position of Imidazoles and a Benzene Ring

Oxidative intramolecular C C bond formation via double sp² C H activation between the 2‐position of imidazoles and a benzene ring catalyzed by palladium(II) has been developed, which provides an atom‐economical, concise and efficient methodology to synthesize imidazole‐ or benzimidazole‐fused isoquinoline polyheteroaromatic compounds.     

Metal catalysis with nanostructured metals supported on strongly acidic cross-linked polymer frameworks. Part I. The behaviour of M2+ ions (M = Ni,Pd, Pt,Cu) supported on Rohm & Haas’s resin A70 and Du Pont’s SAC-13, towards H2 in the solid state and NaBH4 in aqueous medium

The macroreticular Rohm & Haas resin A70 and the DuPont silica/nafion microcomposite SAC-13 undergo facile metalation with Ni^II, Pd^II, Pt^II, Cu^II cationic species to give materials that do react with both molecular hydrogen in the “dry” state and sodium borohydride in the aqueous phase. The distribution of the reduced species in the body of the support particles is sensitive to the reduction protocol.     

The formation of [RuCl(p-cymene)(Me2HPz)(PPh2OR)]Cl (Me2HPz=3, 5-dimethylpyrazole; R=H,Me and p-Tol) complexes from the cleavage of the P–N bond of a P-coordinated P(Me2Pz)Ph2 ligand by ROH molecules in a ruthenium(II) complex. Crystal structure of [RuCl(p-cymene)(Me2HPz)(PPh2OH)]Cl

The complex [RuCl₂(p-cymene)]₂ reacts with 1-(3,5-dimethyl)pyrazolyldiphenylphosphine (P(Me₂Pz)Ph₂) to give the complex RuCl₂(p-cymene)(P(Me₂Pz)Ph₂). This compound reacts with ROH molecules (R=H, Me and p-Tol) to give [RuCl(p-cymene)(Me₂HPz)(PPh₂OR)]Cl (R=H, Me and p-Tol) complexes, which contain both Me₂HPz and PPh₂OR coordinated molecules.