The Implementation of Public E-services for Immovable Property Contracts in Lithuania: Legal Aspects

This article analyzes the implementation model of Public E-Services in The Immovable Property Contracts (PESIPC)between Lithuanian State Enterprise (SE) “Centre of Registries†(Centre of Registries) and notary, and its legalaspects. the PESIPC informational system in Lithuania was instituted to simplify the contract conclusion andregistration procedures by eliminating appearance in person of the interested parties directly in the Centre ofRegistries, because all contract procedures would be completed at the notary office. All the official informationconcerning registry and cadastre of immovable property required for concluding and confirming the contract, must bedelivered through the Internet directly to notaries and interested parties. Both the preparation of contract documentsand the registration of varied legal facts and contracts themselves in the register of immovable property shall becomeautomatic. This is one of the first the PESIPC systems introduced in Europe, thus it is especially important to analyzethe legal aspects of practice of the above-mentioned informational system

Interaction of Water-Soluble CdTe Quantum Dots with Bovine Serum Albumin

Semiconductor nanoparticles (quantum dots) are promising fluorescent markers, but it is very little known about interaction of quantum dots with biological molecules. In this study, interaction of CdTe quantum dots coated with thioglycolic acid (TGA) with bovine serum albumin was investigated. Steady state spectroscopy, atomic force microscopy, electron microscopy and dynamic light scattering methods were used. It was explored how bovine serum albumin affects stability and spectral properties of quantum dots in aqueous media. CdTe–TGA quantum dots in aqueous solution appeared to be not stable and precipitated. Interaction with bovine serum albumin significantly enhanced stability and photoluminescence quantum yield of quantum dots and prevented quantum dots from aggregating

Rsc Adv

A Forster resonance energy transfer (FRET) system of semiconductor quantum dots and porphyrins represents a new promising photosensitizing tool for the photodynamic therapy of cancer. In this work, we demonstrate the ability of a non-covalent complex formed between commercial lipid-coated CdSe/ ZnS quantum dots (QD) bearing different terminal groups (carboxyl, amine or non-functionalized) and a second-generation photosensitizer, chlorin e(6) (Ce-6) to enter living HeLa cells with maintained integrity and perform FRET from two-photon excited QD to bound Ce-6 molecules. Spectroscopic changes, the highly efficient FRET, observed upon Ce-6 binding to QD, and remarkable stability of the QD-Ce-6 complex in different media suggest that Ce-6 penetrates inside the lipid coating close to the inorganic core of QD. Two-photon fluorescence lifetime imaging microscopy (FLIM) on living HeLa cells revealed that QD-Ce-6 complexes localize within the plasma membrane and intracellular compartments and preserve high FRET efficiency (similar to 50%). The latter was confirmed by recovery of QD emission lifetime after photobleaching of Ce-6. The intracellular distribution pattern and FRET efficiency of QD-Ce-6 complexes did not depend on the charge of QD terminal groups. Given the non-covalent nature of the complex, its exceptional stability in cellulo can be explained by a combination of hydrophobic interactions and coordination of carboxyl groups of Ce6 with the ZnS shell of QD. These findings suggest a simple route to the preparation of QD-photosensitizer complexes featuring efficient FRET and high stability in cellulo without using time-consuming conjugation protocols

Fabrication and Properties of Porphyrin Nano- and Micro-particles with Novel Morphology

New types of porphyrin nano- and micro-particles composed of J- and H-heteroaggregates were prepared by electrostatic self-assembly of two oppositely charged porphyrins, tetrakis(4-trimethylammoniophenyl)porphyrin (H2TAPP4+) and tetrakis(4-sulfonatophenyl)porphyrin cobalt(II) (CoTPPS4−), in aqueous solutions. Transmission electron microscopy (TEM) images showed novel morphology and size distribution of porphyrin particles fabricated under different experimental conditions. The assembly process of the nano- and micro-particles was monitored by UV–Vis spectra. Fluorescence spectra and UV–Vis spectra provided optical information on the formation of the nano- and micro-particles. Cyclic voltammograms of the porphyrin particles indicated that the electron gain and loss of the H2TAPP4+ion were restrained, and the electron transfer of the CoTPPS4−ion was promoted in the J- and H-type porphyrin heteroaggregates within the particles. The stability and constitution of the nano- and micro-particles were confirmed by UV-light irradiation, heat-treatment, and pH and ionic strength changes. Photoelectrochemical measurements showed that the photoelectron transfer of TiO2modified with the particles was more efficient than that of TiO2sensitized by either monomers. The photoelectronic and photocatalytic properties of the products indicated that the pyramidal or spherical configuration of the nano- and micro-particles was favorable for the absorption and transfer of the energy. It can be found that TiO2sensitized by the porphyrin nano- and micro-particles exhibits significant improvement in energy conversion and photocatalytic activity with reference to pure TiO2

Photodynamic Antimicrobial Chemotherapy in Aquaculture: Photoinactivation Studies of Vibrio fischeri

BACKGROUND: Photodynamic antimicrobial chemotherapy (PACT) combines light, a light-absorbing molecule that initiates a photochemical or photophysical reaction, and oxygen. The combined action of these three components originates reactive oxygen species that lead to microorganisms' destruction. The aim was to evaluate the efficiency of PACT on Vibrio fischeri: 1) with buffer solution, varying temperature, pH, salinity and oxygen concentration values; 2) with aquaculture water, to reproduce photoinactivation (PI) conditions in situ. METHODOLOGY/PRINCIPAL FINDINGS: To monitor the PI kinetics, the bioluminescence of V. fischeri was measured during the experiments. A tricationic meso-substituted porphyrin (Tri-Py(+)-Me-PF) was used as photosensitizer (5 µM in the studies with buffer solution and 10-50 µM in the studies with aquaculture water); artificial white light (4 mW cm(-2)) and solar irradiation (40 mW cm(-2)) were used as light sources; and the bacterial concentration used for all experiments was ≈10(7) CFU mL(-1) (corresponding to a bioluminescence level of 10(5) relative light units--RLU). The variations in pH (6.5-8.5), temperature (10-25°C), salinity (20-40 g L(-1)) and oxygen concentration did not significantly affect the PI of V. fischeri, once in all tested conditions the bioluminescent signal decreased to the detection limit of the method (≈7 log reduction). The assays using aquaculture water showed that the efficiency of the process is affected by the suspended matter. Total PI of V. fischeri in aquaculture water was achieved under solar light in the presence of 20 µM of Tri-Py(+)-Me-PF. CONCLUSIONS/SIGNIFICANCE: If PACT is to be used in environmental applications, the matrix containing target microbial communities should be previously characterized in order to establish an efficient protocol having into account the photosensitizer concentration, the light source and the total light dose delivered. The possibility of using solar light in PACT to treat aquaculture water makes this technology cost-effective and attractive

Novel, Meso-Substituted Cationic Porphyrin Molecule for Photo-Mediated Larval Control of the Dengue Vector Aedes aegypti

Dengue is a life-threatening viral disease of growing importance, transmitted by Aedes mosquito vectors. The control of mosquito larvae is crucial to contain or prevent disease outbreaks, and the discovery of new larvicides able to increase the efficacy and the flexibility of the vector control approach is highly desirable. Porphyrins are a class of molecules which generate reactive oxygen species if excited by visible light, thus inducing oxidative cell damage and cell death. In this study we aimed at assessing the potential of this photo-mediated cytotoxic mechanism to kill Aedes (Stegomyia) aegypti mosquito larvae. The selected porphyrin molecule, meso-tri(N-methylpyridyl),meso-mono(N-tetradecylpyridyl)porphine (C14 for simplicity), killed the larvae at doses lower than 1 µM, and at light intensities 50–100 times lower than those typical of natural sunlight, by damaging their intestinal tissues. The physicochemical properties of C14 make it easily adsorbed into organic material, and we exploited this feature to prepare an ‘insecticidal food’ which efficiently killed the larvae and remained active for at least 14 days after its dispersion in water. This study demonstrated that photo-sensitizing agents are promising tools for the development of new larvicides against mosquito vectors of dengue and other human and animal diseases

Exciton relaxation in nanotubular TPPS4 aggregates in water solution and in polymeric matrix

Exciton properties in meso-Tetra (4-sulphonatophenyl)porphin e (TPPS4) aggregates in water solution and in PVA matrix were investigated at different temperatures by means of transient absorption and fluorescence spectroscopy. Analysis of the steady state and transient absorption spectra shows that excitons delocalized over about 10 TPPS molecules are formed under the aggregate excitation to the higher energy absorption band, however they localize on one or two molecules after relaxation to the lowest energy excited state. The transient absorption and time resolved fluorescence show different relaxation kinetics, which is interpreted in terms of competition between the exciton relaxation to the nonradiative state and quenching by the quenching centers reached during thermally activated exciton diffusion. Exciton-exciton annihilation starts at high excitation intensity when more than I exciton per 20 molecules is created indicating that excitations visit about 20 molecules during their lifetime. The exciton relaxation becomes faster in optically annealed samples, when optically destroyed molecules create additional quenching centers. (c) 2006 Elsevier B.V. All rights reserved

Quantum dots affect expression of CD133 surface antigen in melanoma cells

Simona Steponkiene1-3, Simona Kavaliauskiene1, Rasa Purviniene4, Ricardas Rotomskis3,5, Petras Juzenas11Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Radiumhospital, Oslo, Norway; 2Faculty of Natural Sciences, Vilnius University, Vilnius, Lithuania; 3Biomedical Physics Laboratory of Oncology Institute, Vilnius University, Vilnius, Lithuania; 4Immunology Laboratory of Oncology Institute, Vilnius University, Vilnius, Lithuania; 5Biophotonics Laboratory, Laser Research Center, Vilnius University, Vilnius, LithuaniaBackground: In novel treatment approaches, therapeutics should be designed to target cancer stem cells (CSCs). Quantum dots (QDs) are a promising new tool in fighting against cancer. However, little is known about accumulation and cytotoxicity of QDs in CSCs.Methods: Accumulation and cytotoxicity of CdTe-MPA (mercaptopropionic acid) QDs in CSCs were assessed using flow cytometry and fluorescence-activated cell sorting techniques as well as a colorimetric cell viability assay.Results: We investigated the expression of two cell surface-associated glycoproteins, CD44 and CD133, in four different cancer cell lines (glioblastoma, melanoma, pancreatic, and prostate adenocarcinoma). Only the melanoma cells were positive to both markers of CD44 and CD133, whereas the other cells were only CD44-positive. The QDs accumulated to a similar extent in all subpopulations of the melanoma cells. The phenotypical response after QD treatment was compared with the response after ionizing radiation treatment. The percentage of the CD44high-CD133high subpopulation decreased from 72% to 55%–58% for both treatments. The stem-like subpopulation CD44highCD133low/- increased from 26%–28% in the untreated melanoma cells to 36%–40% for both treatments.Conclusion: Treatment of melanoma cells with QDs results in an increase of stem-like cell subpopulations. The changes in phenotype distribution of the melanoma cells after the treatment with QDs are comparable with the changes after ionizing radiation.Keywords: prominin-1, CD44, glycoproteins, flow cytometry, FACS, nanoparticle