the complexation reaction between hydroxyl ammonium (honh3+ ) cation with 18-crown-6 (18c6) ligand was studied in dimethylsulfoxide – water (dmso-h2o), methanol – water (meoh-h2o) and dimethylformamid – methanol (dmf-meoh), binary solutions at different temperatures using conductometric method. the obtained results show that the stoichiometry of the complex formed between honh3+ cation with (18...

in the present study, the cooperative and diminutive interplay between halogen, hydride, and cation-σ interactions are studied in hmgh···li+(na+)···nccl, li+(na+)···hmgh···clcn and hmgh···clcn···li+(na+) complexes by means of ab initio calculations. to better understand the cooperative or diminutive effects in the ternary systems, the corresponding binary complexes are also considered. the esti...

heterogeneous proton exchange membranes (pem) are synthesized using the dry phase inversion technique. the casting solutions are prepared by dispersing a finely ground cation exchange resin particle in n,n-dimethylacetamide (dmac) solution of polyvinyl-chloride (pvc). results show that ion exchange capacity is increased with the addition of 1 %-wt nanosilica (from 0.14 to 0.27 meq/g) while it i...

objective: the aim of present study was cloning and expression of phic31 integrase cdna in a bacterial expression vector. thus, an intra molecular assay vector was applied to show in vitro activity of recombinant protein. materials and methods: in this experimental study, phic31 cdna was subcloned into a prokaryotic expression vector and transformed into e.coli bl21 (de3). recombinant phic31 in...

background: dental techniques are frequently used in human identifi cation; some of those include comparative analyses of dental features that, being rare or unique to an individual, can establish a positive identifi cation. the usefulness of each feature depends on its population, frequency, and uniqueness. the aim of this study was to determine the prevalence of talon cusps in a portuguese po...

Ca2+-ATPase activity has been characterized in Streptomyces griseus. The enzyme has a pH optimum of 8.5 at 37 degrees C. Its Ca2+ requirement can be substituted by Cd2+, Zn2+ and Mn2+. Mg2+ inhibits the enzyme non-competitively.

An efficient sensor for Zn(2+) and Cu(2+) was designed based on different binding modes. The sensor displays ratiometric signals for Zn(2+), due to the Zn(2+)-triggered amide tautomerization; while dual-mode selective behaviors for Cu(2+) result from the deprotonation of the amide tautomer.

background: enhancing nursing students’ critical thinking is a challenge faced by nurse educators. this study aimed at determiningthe effect of clinical concept mapping on discipline-based critical thinking of nursing students. materials and methods: in this quasi-experimental post-test only design, a convenient sample of 4th year nursing students (n = 32)participated. they were randomly divide...

in the present study, the interactions of three different lithium species li+, li3+ and ch3li with several different sites of the most stable tautomers of dna nucleo-bases are presented. this investigation is based on the results of thermochemical properties, quantum theory of atoms in molecules (qtaim) and natural bond orbital (nbo) analysis, obtained at b3lyp/6-311++g(d,p) level of theory. th...