Dielectronic recombination rate for the Be-sequence

The dielectronic recombination (DR) rate coefficient α^DR is explicitly calculated for the Mo, Fe, Ar, and Ox target ions of the Be-sequence with four electrons, in the isolated resonance approximation. This work extends the previous study of the Mo³⁸⁺ ions at 1.4, 2.8, and 5.6 keV electron temperatures. Both Δn≠0 and Δn = 0 transitions are considered in detail. The Δn≠0 contribution still dominates, but the Δn = 0 effect becomes quite large for heavy ions. An explicit LS coupling scheme is employed throughout for the dominant transitions calculated here, and contributions from many other intermediate states and cascade transitions are included by comparing the dominant contribution with the more complete Mo³⁸⁺ case and proportionately scaling their effect. Nonrelativistic Hartree-Fock wave functions are used in the evaluation of the Auger and radiative amplitudes, and the continuum wave functions are calculated using the Hartree-Fock direct potential and explicit nonlocal exchange potential. The scaling property of α^DR and its breakdown are examined, and an improved form of the phenomenological formula is proposed.     

Amphiphilic Peptide–Polymer Conjugates with Side‐Conjugation

Polymers conjugated to the exterior of a protein mediate its interactions with surroundings, enhance its processability and can be used to direct its macroscopic assemblies. Most studies to date have focused on peptide–polymer conjugates based on hydrophilic polymers. Engineering amphiphilicity into protein motifs by covalently linking hydrophobic polymers has the potential to interface peptides and proteins with synthetic polymers, organic solvents, and lipids to fabricate functional hybrid materials. Here, we synthesized amphiphilic peptide–polymer conjugates in which a hydrophobic polymer is conjugated to the exterior of a heme‐binding four‐helix bundle and systematically investigated the effects of the hydrophobicity of the conjugated polymer on the peptide structure and the integrity of the heme‐binding pocket. In aqueous solution with surfactants present, the side‐conjugated hydrophobic polymers unfold peptides and may induce an α‐helix to β‐sheet conformational transition. These effects decrease as the polymer becomes less hydrophobic and directly correlate with the polymer hydrophobicity. Upon adding organic solvent to solubilize the hydrophobic polymers, however, the deleterious effects of hydrophobic polymers on the peptide structures can be eliminated. Present studies demonstrate that protein structure is sensitive to the local environment. It is feasible to dissolve amphiphilic peptide–polymer conjugates in organic solvents to enhance their solution processability while maintaining the protein structures.

     

On the ideal of functions with compact support in pointfree function rings

As usual, let RL\mathcal{R}L denote the ring of real-valued continuous functions on a completely regular frame L. We consider the ideals R_s(L)\mathcal{R}_{s}(L) and R_K(L)\mathcal{R}_{K}(L) consisting, respectively, of functions with small cozero elements and functions with compact support. We show that, as in the classical case of C(X), the first ideal is the intersection of all free maximal ideals, and the second is the intersection of pure parts of all free maximal ideals. A corollary of this latter result is that, in fact, R_K(L)\mathcal{R}_{K}(L) is the intersection of all free ideals. Each of these ideals is pure, free, essential or zero iff the other has the same feature. We observe that these ideals are free iff L is a continuous frame, and essential iff L is almost continuous (meaning that below every nonzero element there is a nonzero element the pseudocomplement of which induces a compact closed quotient). We also show that these ideals are zero iff L is nowhere compact (meaning that non-dense elements induce non-compact closed quotients).     

Photodynamic efficacy of chlorin p6: a pH dependent study in aqueous and lipid environment

Photodynamic efficacy of chlorin p6, a potential candidate of photodynamic therapy (PDT), has been studied at pH 5.0, 6.0 and 7.6 in aqueous and lipid environment. Increased chlorin p6 mediated photodynamic bleaching of N,N-dimethyl-4-nitrosoaniline (RNO), a measure of singlet oxygen yield, was obtained at higher pH. Rate of photodynamic bleaching of RNO was also higher at higher pH and the rate decreased with lowering in pH of irradiated solution. Photodynamic oxidation of tryptophan was also found to be higher at higher pH. Diminished oxidation of RNO was obtained with decrease in pH of irradiated solution. Both, RNO bleaching and tryptophan oxidation was significantly reduced by sodium azide, a known quencher of singlet oxygen. At lower pH, chlorin p6 mediated photodynamic malondialdehyde (MDA) and lipid hydroperoxide formation in egg lecithin liposome was higher. At higher pH chlorin p6 was found to be photodynamically more effective in aqueous environment whereas at lower pH chlorin p6 was photodynamically more effective in hydrophobic environment.     

Pointfree functional compactness

By introducing a conservative notion of functional compactness to frames and using frame-theoretic techniques, we identify two classes of topological spaces that can be densely embedded in functionally compact ones. Since θ-open elements of frames (corresponding in spaces to complements of Veličko’s [15] θ-closed subspaces) play an important role in functional compactness, we also study the concept of co-rigidity in frames and show that it is enjoyed by all θ-open elements of functionally compact frames. Dedicated to the memory of Sergio Salbany     

In Vitro Antileishmanial and Antischistosomal Activities of Anemonin Isolated from the Fresh Leaves of Ranunculus multifidus Forsk

Leishmaniasis and schistosomiasis are neglected tropical diseases (NTDs) infecting the world’s poorest populations. Effectiveness of the current antileishmanial and antischistosomal therapies are significantly declining, which calls for an urgent need of new effective and safe drugs. In Ethiopia fresh leaves of Ranunculus multifidus Forsk. are traditionally used for the treatment of various ailments including leishmaniasis and eradication of intestinal worms. In the current study, anemonin isolated from the fresh leaves of R. multifidus was assessed for its in vitro antileishmanial and antischistosomal activities. Anemonin was isolated from the hydro-distilled extract of the leaves of R. multifidus. Antileishmanial activity was assessed on clinical isolates of the promastigote and amastigote forms of Leishmania aethiopica and L. donovani clinical isolates. Resazurin reduction assay was used to determine antipromastigote activity, while macrophages were employed for antiamastigote and cytotoxicity assays. Antischistosomal assays were performed against adult Schistosoma mansoni and newly transformed schistosomules (NTS). Anemonin displayed significant antileishmanial activity with IC₅₀ values of 1.33 nM and 1.58 nM against promastigotes and 1.24 nM and 1.91 nM against amastigotes of L. aethiopica and L. donovani, respectively. It also showed moderate activity against adult S. mansoni and NTS (49% activity against adult S. mansoni at 10 µM and 41% activity against NTS at 1 µM). The results obtained in this investigation indicate that anemonin has the potential to be used as a template for designing novel antileishmanial and antischistosomal pharmacophores.     

Concerning P-frames, essential P-frames, and strongly zero-dimensional frames

We give characterizations of P-frames, essential P-frames and strongly zero-dimensional frames in terms of ring-theoretic properties of the ring of continuous real-valued functions on a frame. We define the m-topology on the ring RL{\mathcal{R}L} and show that if L belongs to a certain class of frames properly containing the spatial ones, then L is a P-frame iff every idealof RL{\mathcal{R}L} is m-closed. We define essential P-frames (analogously to their spatial antecedents) and show that L is a proper essential P frame iff all the nonmaximal prime ideals of RL{\mathcal{R}L} are contained in one maximal ideal. Further, we show that L is strongly zero-dimensional iff RL{\mathcal{R}L} is a clean ring, iff certain types of ideals of RL{\mathcal{R}L} are generated by idempotents.     

Photoinduced carbene generation from diazirine modified task specific phosphonium salts to prepare robust hydrophobic coatings

3-Aryl-3-(trifluormethyl)diazirine functionalized highly fluorinated phosphonium salts (HFPS) were synthesized, characterized, and utilized as photoinduced carbene precursors for covalent attachment of the HFPS onto cotton/paper to impart hydrophobicity to these surfaces. Irradiation of cotton and paper, as proof of concept substrates, treated with the diazirine-HFPS leads to robust hydrophobic cotton and paper surfaces with antiwetting properties, whereas the corresponding control samples absorb water readily. The contact angles of water were determined to be 139° and 137° for cotton and paper, respectively. In contrast, water placed on the untreated or the control samples (those treated with the diazirine-HFPS but not irradiated) is simply absorbed into the surface. Additionaly, the chemically grafted hydrophobic coating showed high durability toward wash cycles and sonication in organic solvents. Because of the mode of activation to covalently tether the hydrophobic coating, it is amenable to photopatterning, which was demonstrated macroscopically.