Prior exposure to an attenuated <Emphasis Type="Italic">Listeria</Emphasis> vaccine does not reduce immunogenicity: pre-clinical assessment of the efficacy of a <Emphasis Type="Italic">Listeria</Emphasis>vaccine in the induction of immune responses against HIV

Background  

We have evaluated an attenuated Listeria monocytogenes (Lm) candidate vaccine vector in nonhuman primates using a delivery regimen relying solely on oral vaccination. We sought to determine the impact of prior Lm vector exposure on the development of new immune responses against HIV antigens.     

Topochemical Transformations of CaX2 (X=C,Si, Ge) to Form Free‐Standing Two‐Dimensional Materials

Topochemical transformations of layered materials CaX₂ (X=Si, Ge) are the method of choice for the high‐yield synthesis of pristine, defect‐free two‐dimensional systems silicane and germanane, which have advanced electronic properties. Based on solid‐state dispersion‐corrected calculations, mechanisms for such transformations are elucidated that provide an in‐depth understanding of phase transition in these layered materials. While formation of such layered materials is highly favorable for silicane and germanane, a barrier of 1.2 eV in the case of graphane precludes its synthesis from CaC₂ topochemically. The energy penalty required for distorting linear acetylene into a trans‐bent geometry accounts for this barrier. In contrast it is highly favorable in the heavier analogues, resulting in barrierless topochemical generation of silicane and germanane. Photochemical generation of the trans‐bent structure of acetylene in its first excited state (S₁) can directly generate graphane through a barrierless condensation. Unlike the buckled structure of silicene, the phase‐h of CaSi₂ with perfectly planar silicene layers exhibits the Dirac cones at the high symmetry points K and H. Interestingly, topochemical acidification of the cubic phase of calcium carbide is predicted to generate the previously elusive platonic hydrocarbon, tetrahedrane.     

On the Diffusion in a Lattice Gas Model: Group-Theoretic Approach

Motivated by some recent results concerning the model of a noninteracting one-dimensional lattice gas with an order preservation of particles where multiple occupancy of the sites is not excluded, we give new symmetries and new reductions of the corresponding continuum nonlinear partial differential equation. Closed-form analytic solutions are found.     

High energy collision-induced dissociation of alkali-metal ion adducts of crown ethers and acyclic analogs.

High energy collision-induced dissociation (CID) techniques were applied for structural elucidation of alkali-metal ion adducts of crown ethers. The CID of alkali-metal adducts of tetraglyme and hexaethylene glycol were also evaluated to contrast the fragmentation pathways of the cyclic ethers with those of acyclic analogs. A common fragmentation channel for alkali-metal ion adducts of all the ethers, which results in distonic radical cations, is the homolytic cleavage of carbon-carbon bonds. Additionally, dissociation by carbon-oxygen bond cleavages occurs, and these processes are analogous to the fragmentation pathways observed for simple protonated ethers. The proposed fragmentation pathways for alkali-metal ion adducts of crown ethers result mostly in odd-electron, acyclic product ions. Dissociation of the alkali-metal ion adducts of the acyclic ethers is dominated by losses of various neutral species after an initial hydride or proton transfer. The CID processes for all ethers are independent of the alkali-metal ion sizes; however, the extent of dissociation of the complexes to bare alkali-metal ions increases with the size of the metal.     

Nandrolone decanoate increases the volume but not the length of the proximal and distal convoluted tubules of the mouse kidney

Anabolic androgenic steroids are widely used by athletes for increasing their muscle mass. These drugs are also used by some patients with chronic renal disease. But the effect of these drugs on the renal structure has received less attention. To investigate which parts of the kidney are affected by these drugs, mice kidneys were studied stereologically after injection of nandrolone decanoate (ND), an anabolic androgenic steroid. The treated group received nandrolone decanoate intraperitoneally (solved in olive oil) in doses of 3mg/kg of body weight and administered in one, two and three doses, respectively, in the first, second and third week of treatment. The mice in the control group received an olive oil solution. One week after the last injection, the mice were anaesthetized and their kidney removed. The analysis of data revealed that the weight of kidney was increased approximately 30% (p < or = 0.006) and its volume increased approximately 25% (p < or = 0.02) in ND treated mice in comparison with the control group. The volume of the cortex increased in ND treated animals approximately 44% (p < or = 0.006). Proximal convoluted tubules (PCT) and distal convoluted tubules (DCT) volume increased approximately 25% (p < or = 0.02) and approximately 68% (p < or = 0.02) in ND treated mice. The volume of glomeruli, other ducts, connective tissues, vessels and the length of PCT, DCT, collecting and Henle's ducts and vessels did not show significant differences. CONCLUSION: ND can increase the volume of the renal cortex and its two main parts, i.e. PCT and DCT in mice.     

An improved electrochemical method for the synthesis of some benzofuran derivatives

Electrochemical oxidation of catechol and some 3-substituted catechols (1a--c) has been studied in the presence of 2-chloro-5,5-dimethyl-1,3-cyclohexanedione (3) in aqueous solution using cyclic voltammetry and controlled-potential coulometry. The results indicate that the quinones derived from catechols (1a--c) participate in a Michael addition reaction with 2-chloro-5,5-dimethyl-1,3-cyclohexanedione (3) with consumption of only two electrons per molecule of (1a--c) to from the corresponding benzoforans (10a--c). The electrochemical synthesis of benzofurans has been successfully performed at a carbon rod electrode and in an undivided cell with high yields and purity.     

Synthesis and Structure Elucidation of Novel Spirooxindole Linked to Ferrocene and Triazole Systems via [3 + 2] Cycloaddition Reaction

In the present work, a novel heterocyclic hybrid of a spirooxindole system was synthesized via the attachment of ferrocene and triazole motifs into an azomethine ylide by [3 + 2] cycloaddition reaction protocol. The X-ray structure of the heterocyclic hybrid (1″R,2″S,3R)-2″-(1-(3-chloro-4-fluorophenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl)-5-methyl-1″-(ferrocin-2-yl)-1″,2″,5″,6″,7″,7a″-hexahydrospiro[indoline-3,3″-pyrrolizin]-2-one revealed very well the expected structure, by using different analytical tools (FTIR and NMR spectroscopy). It crystallized in the triclinic-crystal system and the P-1-space group. The unit cell parameters are a = 9.1442(2) Å, b = 12.0872(3) Å, c = 14.1223(4) Å, α = 102.1700(10)°, β = 97.4190(10)°, γ = 99.1600(10)°, and V = 1484.81(7) ų. There are two molecules per unit cell and one formula unit per asymmetric unit. Hirshfeld analysis was used to study the molecular packing of the heterocyclic hybrid. H···H (50.8%), H···C (14.2%), Cl···H (8.9%), O···H (7.3%), and N···H (5.1%) are the most dominant intermolecular contacts in the crystal structure. O···H, N···H, H···C, F···H, F···C, and O···O are the only contacts that have the characteristic features of short and significant interactions. AIM study indicated predominant covalent characters for the Fe–C interactions. Also, the electron density (ρ(r)) at the bond critical point correlated inversely with the Fe–C distances.     

Cu(II)‐promoted cyclization of hydrazonophthalazine to triazolophthalazine; Synthesis and structure diversity of six novel Cu(II)‐triazolophthalazine complexes

A novel route for the synthesis of Cu(II)‐triazolophthalazine complexes using the Cu(II)‐promoted cyclization dehydrogenation reactions of hydrazonophthalazines under reflux was presented. Two hydrazonophthalazines were cyclized to the corresponding triazolophthalazine ligands, 3‐pyridin‐2‐yl‐3,10b‐dihydro‐[1,2,4]triazolo[3,4‐a]phthalazine ( TPP ) and 3‐(3,10b‐dihydro‐[1,2,4]triazolo[3,4‐a]phthalazin‐3‐yl)‐benzoic acid ( TP3COOH ), followed by in situ complexation with Cu(II) yielding six novel Cu(II)‐triazolophthalazine complexes depending on the reaction conditions. The molecular and supramolecular structures of the Cu(II)‐triazolophthalazine complexes were discussed. The metal sites have rectangular pyramidal geometry in the [Cu(TPP)Cl₂]₂; 1 and [Cu(TP3COOEt)Cl₂(H₂O)]₂; 4 dinuclear complexes, distorted square planar in [Cu(TP3COOMe)₂Cl₂]; 3 , [Cu(TP3COOH)₂Cl₂]; 5 and [Cu(TP3COOH)₂Cl₂]·H₂O; 6 and a distorted octahedral in [Cu(TPP)(H₂O)₂(NO₃)₂]; 2 . Hirshfeld analysis showed that the O…H, C…H, Cl…H (except TP3COOH and 2 ), N…H and π‐π stacking interactions are the most important intermolecular contacts. The π‐π stacking interactions are the maximum for TP3COOH and complex 6 with net C…C/C…N contacts of 19.4% and 15.4%, respectively. The orbital–orbital interaction energies of the Cu‐N/Cu‐Cl bonds correlated inversely with the corresponding Cu‐N/Cu‐Cl distances, respectively. The charge transfer processes between Cu(II) and ligand groups were also discussed. The charge densities of the Cu(II) centers are reduced to 0.663–0.995 e due to the interactions with the ligand groups coordinating it.     

Mono- and penta-nuclear self-assembled silver(I) complexes of pyrazolyl s-triazine ligand; synthesis,structure and antimicrobial studies

The self-assembled [Ag (PTDM)NO₃] ( 1 ), [Ag (PTDM)₂(H₂O)]ClO₄^.H₂O ( 2 ) and [Ag₅(PTDM)₄(H₂O)₆(ClO₄)₄]ClO₄^.2H₂O ( 3 ) complexes were synthesized by the direct mixing of AgX (X = NO₃¯ or ClO₄¯) and 4,4′-[6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4-diyl]dimorpholine ( PTDM ) ligand in water–methanol mixture. The coordination numbers of silver range from three to five. Complex 3 is a rare case in which one nitrogen atom from the same s-triazine core of the PTDM ligand has a μ(1,1) bridging mode between Ag1 and Ag2 in the penta-nuclear array with Ag1–N1 and Ag2–N1 distances of 2.666(4) and 2.418(3) Å, respectively. Its 3D topology has a kind of primitive dense packing derived from the α-Po type structure. Hirshfeld analysis showed that the percentages of the O^…H hydrogen bonds were 32.4, 25.4, and 42.0% in complexes 1 – 3 , respectively. While the ligand showed no antimicrobial activity at the applicable concentration, the penta-nuclear complex 3 had higher antibacterial (MIC = 3.7 μmol/L) and antifungal (14.6 μmol/L) potencies toward the tested microbes compared with complexes 1 and 2 . Also, the killing doses of 3 were in the range of 7.3–58.5 μmol/L compared with 18.2–291.1 and 20.1–160.6 μmol/L for 1 and 2 , respectively. It is clear that the higher Ag-content in 3 could be the main reason for its higher antimicrobial activity.     

A strongly polynomial algorithm for a concave production-transportation problem with a fixed number of nonlinear variables

We show that the production-transportation problem involving an arbitrary fixed number of factories with concave production cost is solvable in strongly polynomial time. The algorithm is based on a parametric approach which takes full advantage of the specific structure of the problem: monotonicity of the objective function along certain directions, small proportion of nonlinear variables and combinatorial properties implied by transportation constraints.