Proton-hole states in 57Co studied with the 58Ni(d, 3He) 57Co reaction at 78 MeV

The ⁵⁸Ni(d, ³He)⁵⁷Co reaction was measured at a bombarding energy of 78 MeV. Energy levels up to 7.0 MeV excitation energy in ⁵⁷Co were studied. Angular distributions of the ³He particles, corresponding to transitions to the ground state and to 42 excited states in ⁵⁷Co, were analyzed in the range of θ_lab = 2.7° to 25°. Exact finite-range DWBA calculations were employed to extract l-values and spectroscopic factors. Shell-model calculations were carried out in an fp-shell model space. In addition, calculations of the energy levels in ⁵⁷Co were performed in the SU(6) particle-vibration model (PTQM). Satisfactory agreement is observed between the experimental results and both theoretical predictions.     

Cryopreservation of spores of Dicksonia sellowiana: an endangered tree fern indigenous to South and Central America

Spores of Dicksonia sellowiana (Presl.) Hook., an endangered tree fern, were stored in liquid nitrogen. Surface sterilized spores were placed in 1 ml sterile polypropylene cryotubes and were plunged into liquid nitrogen cryo-cans for 15 minutes, 15 days, 1 month and 3 months. In all, of the treatments the percentage of germination was higher than the control (fresh spores). Germination in Dyer and MS media supplement with 10 (-7) M and 5 x 10(-7) M BA was also promoted as comparing to control. There was no difference between the germination of spores thawed rapidly in a water bath at 45 degree C during 5 minutes or slowly at room temperature. Cryopreservation seems to promote germination of some dormant spores of D. sellowiana. The pre-treatment in cryoprotective solution of dimethyl sulphoxide 15%(v/v) in 1 M glycerol inhibited the germination of cryopreserved spores     

Past,present, and future developments in enantioselective analysis using capillary electromigration techniques

Enantioseparation of chiral products has become increasingly important in a large diversity of academic and industrial applications. The separation of chiral compounds is inherently challenging and thus requires a suitable analytical technique that can achieve high resolution and sensitivity. In this context, CE has shown remarkable results so far. Chiral CE offers an orthogonal enantioselectivity and is typically considered less costly than chromatographic techniques, since only minute amounts of chiral selectors are needed. Several CE approaches have been developed for chiral analysis, including chiral EKC and chiral CEC. Enantioseparations by EKC benefit from the wide variety of possible pseudostationary phases that can be employed. Chiral CEC, on the other hand, combines chromatographic separation principles with the bulk fluid movement of CE, benefitting from reduced band broadening as compared to pressure-driven systems. Although UV detection is conventionally used for these approaches, MS can also be considered. CE-MS represents a promising alternative due to the increased sensitivity and selectivity, enabling the chiral analysis of complex samples. The potential contamination of the MS ion source in EKC-MS can be overcome using partial-filling and counter-migration techniques. However, chiral analysis using monolithic and open-tubular CEC-MS awaits additional method validation and a dedicated commercial interface. Further efforts in chiral CE are expected toward the improvement of existing techniques, the development of novel pseudostationary phases, and establishing the use of chiral ionic liquids, molecular imprinted polymers, and metal-organic frameworks. These developments will certainly foster the adoption of CE(-MS) as a well-established technique in routine chiral analysis.     

Übergangsmetallsubstituierte Gallane: Synthese,Struktur und Bindungsverhältnisse von [(CO)4CoGaEt2(NC7H13)], [(PMe3)(CO)3CoGaCl2(NMe3)], [(CO)4CoGaCl3]K und [(CO)5MnGaEt2(NC7H13)]

Transition Metal substituted Gallanes: Synthesis and X-Ray Structures of [(CO)₄CoGaEt₂(NC₇H₁₃)], [(PMe₃)(CO)₃CoGaCl₂(NMe₃)], [(CO)₄CoGaCl₃]K, and [(CO)₅MnGaEt₂(NC₇H₁₃)] The transition metal substituted gallanes [(CO)₅MnGaEt₂(NC₇H₁₃)] ( 1 ), [(PMe₃)(CO)₃CoGaCl₂ · (NMe₃)] ( 2 ), [(CO)₄CoGaEt₂(NC₇H₁₃)] ( 3 ), and [(CO)₄CoGaCl₃]K ( 4 ) were obtained by the reaction of the potassium/sodium salts of the manganese- and cobaltcarbonylmetallates with the chlorogallium species ClGaEt₂(NC₇H₁₃), Cl₃Ga(NMe₃), and GaCl₃. The structures were established by single crystal X-ray analysis 1 : space group P2₁/c (I.T.-No.: 14); Z = 4; a = 1425.4(2) pm, b = 1007.4(1) pm, c = 1429.9(3) pm; β = 113.92(1)°; 2 : space group P2₁/m (I.T.-No.: 11); Z = 2; a = 746.1(1) pm, b = 1131.2(1) pm, c = 1061.5(1) pm; β = 101.87(1)°; 3 : space group P2₁/c (I.T.-No.: 14); Z = 8; a = 1405.9(2) pm, b = 1786.2(2) pm, c = 1430.9(2) pm; β = 91.47(1)°; 4 : space group P2₁/c; Z = 4; a = 1185.7(1) pm, b = 895.4(1) pm, c = 1144.7(3) pm; β = 106.47(2)°. The model compounds [{L′(CO)₃Co}GaX₂L] (L′ = CO, PH₃; L = NH₃, X = H, Cl) with polar σ(Co–Ga) bonds and the effect of the substituent on the bond length are characterized with DFT-calculations.     

Ruthenium(II)-Catalyzed Double Annulation of Quinones: Step-Economical Access to Valuable Bioactive Compounds

Double ruthenium(II)-catalyzed alkyne annulations of quinones were accomplished. Thus, a strategy is reported that provides step-economical access to valuable quinones with a wide range of applications. C−H/N−H activations for alkyne annulations of naphthoquinones provided challenging polycyclic quinoidal compounds by forming four new bonds in one step. The singular power of the thus-obtained compounds was reflected by their antileukemic activity.     

An environment-adjusted evaluation of citizen satisfaction with local police effectiveness: Evidence from a conditional Data Envelopment Analysis approach

Hard data alone are not sufficient to evaluate local police effectiveness in the new age of community policing. Citizens can provide useful feedback regarding strengths and weaknesses of police operations. However, citizen satisfaction indicators typically fail to accurately convey the multidimensional nature of local policing and account for characteristics that are non-controllable for the local police departments. In this paper, we construct a measure of perceived effectiveness of community oriented police forces that accounts for both multidimensional aspects of local policing and exogenous influences. In specific, this paper suggests the use of a multivariate conditional, robust order-m version of a non-parametric Data Envelopment Analysis approach with no inputs. We show the potentiality of the method by constructing and analyzing perceived effectiveness indicators of local police forces in Belgium. The findings suggest that perceived police effectiveness is significantly conditioned by the demographic and socioeconomic environment.     

Dual Redox and Thermoresponsive Double Hydrophilic Block Copolymers with Tunable Thermoresponsive Properties and Self‐Assembly Behavior

The synthesis, tunable thermoresponsive properties, and self‐assembly of dual redox and thermoresponsive double hydrophilic block copolymers having pendant disulfide linkages (DHBCss) are reported. Well‐defined DHBCss composed of a hydrophilic poly(ethylene oxide) block and a dual thermo‐ and reduction‐responsive random copolymer block containing pendant disulfide linkages are synthesized by atom transfer radical polymerization. Their lower critical solution temperature (LCST) transitions are adjusted through modulating pendant hydrophobic–hydrophilic balance with disulfide–thiol–sulfide chemistry. Further, these DHBCss derivatives are converted to disulfide‐crosslinked nanogels at temperatures above LCST through temperature‐driven self‐assembly and in situ disulfide crosslinking. They exhibit enhanced colloidal stability and further reduction‐responsive degradability, thus demonstrating versatility of dual thermo‐ and reduction‐responsive smart materials.