Synthesis,characterization and crystal structures of new Zinc(II) and Nickel(II) complexes containing morpholine moiety and their antibacterial studies

The ligand 1,2-dimorpholinoethane (DME) was used to prepare Zn(II) and Ni(II) complexes of the general formulation MLX₂ (L = DME, X = Cl or NO₃). Zinc(II) complex exhibits spectral properties indicative of a distorted tetrahedral geometry, with DME coordinating through two nitrogen atoms and two chlorides completing the tetrahedron. This is in contrast to the six-coordinated, distorted octahedral geometry exhibited by nickel(II) complex of DME when NO₃ was used as counter ions. The X-ray diffraction confirms the structures of two complexes and shows that the ligand coordinates through two nitrogen atoms while the two ether linkages are not involved in complexation, which would have been the case if the morpholine rings were in the boat form. The ligand and related complexes have antibacterial activity against the five Gram-positive bacteria: Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Streptococcus pyogenes and also against the three Gram-negative bacteria: Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442 and Klebsiella pneumonia ATCC 70063. The results showed that in some cases the antibacterial activity of the complexes exceeded the one of sulfisoxazole used as a standard.     

Mechanism of enhanced conversion of 1,2,3-trichloropropane by mutant haloalkane dehalogenase revealed by molecular modeling

1,2,3-Trichloropropane (TCP) is a highly toxic, recalcitrant byproduct of epichlorohydrin manufacture. Haloalkane dehalogenase (DhaA) from Rhodococcus sp. hydrolyses the carbon–halogen bond in various halogenated compounds including TCP, but with low efficiency (k _cat/K _m = 36 s^-1 M^-1). A Cys176Tyr-DhaA mutant with a threefold higher catalytic efficiency for TCP dehalogenation has been previously obtained by error-prone PCR. We have used molecular simulations and quantum mechanical calculations to elucidate the molecular mechanisms involved in the improved catalysis of the mutant, and enantioselectivity of DhaA toward TCP. The Cys176Tyr mutation modifies the protein access and export routes. Substitution of the Cys residue by the bulkier Tyr narrows the upper tunnel, making the second tunnel “slot” the preferred route. TCP can adopt two major orientations in the DhaA enzyme, in one of which the halide-stabilizing residue Asn41 forms a hydrogen bond with the terminal halogen atom of the TCP molecule, while in the other it bonds with the central halogen atom. The differences in these binding patterns explain the preferential formation of the (R)- over the (S)-enantiomer of 2,3-dichloropropane-1-ol in the reaction catalyzed by the enzyme.     

Evaluation of photodynamic therapy (PDT) procedures using microfluidic system

A hybrid PDMS/glass microfluidic system for evaluation of the efficiency of photodynamic therapy is presented. 5-aminolevulinic acid (ALA) was used as a precursor of photosensitizer. The geometry of the microdevice presented in this paper enables to test different concentrations of the photosensitizer in a single assay. The viability of the A549 cells was determined 24 h after PDT procedure (irradiation with light which induced a photosensitizer accumulated in carcinoma cells, λ = 625 nm). The presented results confirmed the possibility to perform the photodynamic therapy process in vitro in microscale and the possibility to assess its effectiveness. Moreover, because two identical microstructures on a single chip were performed, the microchip can be used for examination simultaneously various cell lines (carcinoma and normal) or various photosensitizers.     

Self-service reservation in the fieldforce

On-line service reservation is becoming increasingly popular in the service industry. As services become more complex, requiring co-ordination among individual actions, the planning for making service appointments is normally conducted manually by the operators, often resulting in slow responses to customers. To tackle this problem, we have developed a real-time service reservation portal that takes an order from a user and works out appointment options, based on the availability of enterprise resources, for the user to book on-line. The portal is capable of dealing with complex workflow appointing, supporting interactive fine-tuning in individual appointments, respecting customer preferences and work policies, monitoring progress of workflow, informing the customer of status changes in job scheduling, dispatching and execution, as well as handling exceptions automatically. We have integrated the portal, code-named FieldReserve, with other components in the BT fieldforce optimisation suite (FOS) that covers functions of resource planning, scheduling and execution for the fieldforce to demonstrate the feasibility and potential benefits of this technology. Benefits demonstrated are to provide customers with instant response of service reservation, to provide volume control on reservation, to break away from one-size-fits-all lead times for service fulfilment, to provide customers with equal access to service provision, and to bring transparency of service progress to customers. Currently, we are actively engaging with businesses and have obtained strong support to downstream the key values of this technology in commercial contexts.     

Synthesis of novel azanorbornylpurine derivatives

Azanorbornylpurine derivatives were prepared by Mitsunobu reaction of appropriate hydroxyazanorbornane derivative with 6-chloropurine or construction of purine base at azanorbornylamines. The prepared target compounds were evaluated for antiviral activity and effect on neuronal and muscle nicotinic acetylcholine receptors.     

Total Synthesis of (+)- and (−)-Ononitol

Abstract

A practical, five-step synthetic sequence for conversion of myo-inositol into enantiomerically pure (+)- and (?)-ononitols in 17% and 18% overall yield, respectively, has been developed.     

Improving etch selectivity and stability of novolak based negative resists by fluorine plasma treatment

Fluorine plasma treatment is applied to cross-link a novolak based negative tone optical resist (maN-2400) to achieve increased dry etching selectivity. Furthermore, fluorine plasma treatment is used to strengthen the same resist to keep it in place during a second lithography step on top of the first one. Using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, cross-linking and passivation of the resist during plasma treatment is demonstrated. In contrast to the application of a baking process after resist development, AFM images show that fluorine plasma treatment preserves the intrinsic structure of the resist.     

Highly oriented crystalline Er:YAG and Er:YAP layers prepared by PLD and annealing

High quality, thick, highly oriented crystalline thin films of Yttrium Aluminum Garnet (Y₃Al₅O₁₂) and Yttrium Aluminum Perovskite (YAlO₃) doped with Erbium were prepared by pulsed laser deposition. Samples were created in vacuum or oxygen environment. Depositions were arranged at room temperature, or at high substrate temperatures ranging from 800 to 1100 °C. Amorphous layers were annealed by laser, or in oven (argon flow, temperatures in range from 1200 to 1400 °C). Fused silica and sapphire (0 0 0 1) were used as substrates. Properties of films were characterized by X-ray diffraction, atomic force microscopy, and by photoluminescence measurement. Size of crystalline grains was in the range 116-773 nm. Thickness of layers was up to 17 μm.