Redox Chemistries for Vacancy Modulation in Plasmonic Copper Phosphide Nanocrystals.

Copper phosphide (CuP) nanocrystals are promising materials for nanoplasmonics due to their substoichiometric composition, enabling the generation and stabilization of excess delocalized holes and leading to localized surface plasmon resonance (LSPR) absorption in the near-IR. We present three Cu-coupled redox chemistries that allow postsynthetic modulation of the delocalized hole concentrations and corresponding LSPR absorption in colloidal CuP nanocrystals. Changes in the structural, optical, and compositional properties are evaluated by powder X-ray diffraction, electronic absorption spectroscopy, P magic-angle spinning solid-state nuclear magnetic resonance spectroscopy, and elemental analysis.

Selective Amplification of SPR Biosensor Signal for Recognition of rpoB Gene Fragments by Use of Gold Nanoparticles Modified by Thiolated DNA.

An experimental approach for improving the sensitivity of the surface plasmon resonance (SPR) DNA hybridization sensor using gold nanoparticles (GNPs), modified by specific oligonucleotides, was elaborated. An influence of the ionic strength on the aggregation stability of unmodified GNPs and GNPs modified by the thiolated oligonucleotides was investigated by monitoring a value of light extinction at 520 nm that can be considered as a measure of a quantity of the non-aggregated GNPs. While the unmodified GNPs started to aggregate in 0.

Surface Plasmon Resonance Investigations of Bioselective Element Based on the Recombinant Protein A for Immunoglobulin Detection.

The developed surface plasmon resonance (SPR) biosensor based on the recombinant Staphylococcal protein A with an additional cysteine residue (SPA-Cys) used as a biorecognition component showed a good selectivity and sensitivity for the immunoglobulin detection. The developed biosensor with SPA-Cys-based bioselective element can also be used as a first step of immunosensor creation. The successful immobilization of SPA-Cys on the nanolayer gold sensor surface of the SPR spectrometer was performed.

SPR Detection and Discrimination of the Oligonucleotides Related to the Normal and the Hybrid bcr-abl Genes by Two Stringency Control Strategies.

In this study, we applied two stringency control strategies for surface plasmon resonance (SPR) detection of DNA hybridization and discrimination of completely and partially complementary 24-mer sequences. These sequences are specific to the human normal bcr and the hybrid bcr-abl genes, protein products of which are responsible for some leukemia. SPR sensors based on resonance phenomena in nanoscale gold films are well suited for label-free, real-time investigations of the macromolecule interactions.

Discrimination of single base mismatched oligonucleotides related to the rpoB gene of Mycobacterium tuberculosis using a surface plasmon resonance biosensor.

Single base mismatched oligonucleotides related to the rpoB gene of Mycobacterium tuberculosis, the mutations of which cause drug resistance of the infectious agent, were detected and discriminated using a surface plasmon resonance biosensor system. Thiol-modified oligonucleotides of the selected sequence (the probe) and 1-mercapto-6-hexanol were immobilized on a gold sensor surface. Hybridization between immobilized probe P2 and perfectly matched target T2 as well as a single base mismatched target TN was investigated in buffer solutions of various stringencies.

Surface plasmon resonance detection of oligonucleotide sequences of the rpoB genes of Mycobacterium tuberculosis.

Oligonucleotide sequences related to the normal and mutated rpoB genes of Mycobacterium tuberculosis are detected using a surface plasmon resonance (SPR) biosensor system. A bioselective element was prepared by immobilizing the thiol-modified oligonucleotides of the selected sequence (the capture probe P2) that contains the mutated TCG→TTG codon 531 (evoking drug resistance) of the rpoB gene of M. tuberculosis on a gold sensor surface.

Imprinted polymer layer for recognizing double-stranded DNA.

A method of preparing a thin polymer layer able to recognize double-stranded DNA (dsDNA) was developed by using 2-vinyl-4,6-diamino-1,3,5-triazine (VDAT) as a functional monomer for creating a DNA-imprinted polymer. The formation of hydrogen bonds between VDAT and A-T base pairs in dsDNA was confirmed by measuring the effects of VDAT on the melting point and the NMR and CD spectra of dsDNA. An imprinted polymer that can recognize dsDNA of the verotoxin gene was prepared by polymerizing VDAT, acrylamide, a crosslinking agent, and the template verotoxin dsDNA on a silanized glass surface.

Study of the factors influencing peak asymmetry on chromatography using a molecularly imprinted polymer prepared by the epitope approach.

Investigations of the effect of sample load on peak asymmetry during chromatography on molecularly imprinted polymer prepared by the epitope approach showed that the shape of the peaks for the template Tyr-Pro-Leu-Gly-NH2 and for acetyl-L-tyrosine ethyl ester changed considerably until a split was observed. In contrast, the asymmetry of the peaks corresponding to oxytocin, which possesses the same C-terminus tripeptide as the template and interacts with the imprinted polymer, remained essentially unaltered. The circular dichroism (CD) spectra of these peptides showed significant dependence on peptide concentration, and the dependence was nearly the same for all the tested peptides.

Towards molecularly imprinted polymers selective to peptides and proteins. The epitope approach.

In this paper, we describe the epitope approach to molecular imprinting. The applicability of molecular imprinting, a method that allows the preparation of biomimetic compounds (artificial receptors and antibodies), is extended by this approach. Our approach makes it possible to obtain imprinted polymers selective to peptides and proteins whereas, to date, molecular imprinting has been used primarily for the preparation of polymers that selectively bind to relatively low molecular weight substances.

Recognition of oxytocin and oxytocin-related peptides in aqueous media using a molecularly imprinted polymer synthesized by the epitope approach.

An artificial polymeric receptor prepared by the epitope approach of molecular imprinting was shown to recognize the peptide hormone, oxytocin, in aqueous media. The proposed approach is based on using (as a template) a compound, whose structure represents a small exposed fragment of a larger molecule (as an epitope represents an antigen). A HPLC study has demonstrated the important role of ionic interactions and the N-terminal amino group of oxytocin and oxytocin-related peptides in the process of their recognition by the molecularly imprinted polymer in the aqueous-rich media.

An approach to conductometric immunosensor based on phthalocyanine thin film.

A new approach to conductometric biosensors utilizing iodine-sensitive phthalocyanine thin films has been proposed. The excellent sensitivity of the tetra-tert-butyl copper phthalocyanine (ttb-CuPc) to free iodine was used for the first time to detect a peroxidase-initiated reaction in an aqueous medium. To minimize the interfering effect of aqueous electrolytes on the impedance responses of the ttb-CuPc film itself, Au/Cr interdigitated planar electrodes bearing ttb-CuPc thin films were protected with hydrophobic gas-permeable membranes, namely thermally evaporated calixarene or plasma polymerized hexamethyldisiloxane films.

[The dynamics of erythrocyte metabolism in severe forms of meningococcal infection and suppurative meningitis in children].

In 63 children with severe meningococcal infection (MI) and meningitides of another origin red cell metabolism was studied: levels of ATP, ADP, AMP, ATP/ADP, ATP/AMP, energetic charge, 2,3-DPG, FAD, piruvate, lactate, activity of lactate dehydrogenase, piruvate kinase, glucose-6-phosphate dehydrogenase, glutatione reductase, Mg2+, Na+, K(+)-dependent ATPase. All the disease periods were characterized by combined pathobiochemical shifts of different degree typical for varying metabolic systems and correlating with the infection severity. The discussion covers pathogenetic and clinical significance of red cell metabolism shifts in patients with MI and purulent meningitides.

Adaptogenic and cardioprotective action of Galleria mellonella extract in rats and frogs.

Pharmacological and metabolic effects of Galleria mellonella larvae extract used in Russian folk medicine to treat cardiovascular and senile diseases were studied. It was shown that the extract possesses adaptogenic, cardiotropic, cardioprotective, and hypocoagulant properties. The extract possesses low toxicity and does not cause significant changes in biochemical parameters in the blood serum of laboratory animals.

[The effect of heparin in vasorenal hypertension on blood electrolyte balance, on the abdominal aortic walls and on the erythrocyte rheological properties in rats].

The paper provides the results of experimental studies of the effects of heparin given to albino rats with vasorenal hypertension in a dose of 150 U/kg on electrolyte levels in plasma, erythrocytes, cardiac and abdominal aortic tissues, the viscosity coefficient and charge of erythrocytic suspension, transmural difference of abdominal aortic potentials. Heparin has been shown to correct hypertension-induced changes in the transmural difference of abdominal aortic potentials, the charge and viscosity coefficient of erythrocytic suspension, the gradient of sodium, potassium, and calcium in the system of erythrocyte-plasma-abdominal aortic wall.

[Determination of the optimal condition of hemoprotein immobilization on the polystyrene surface].

The effect of pH, buffer composition, salts concentration and protein content on the immobilization efficiency of peroxidase, hemoglobin and their conjugates with bovine serum albumin (BSA) have been studied. All the substances were immobilized on the surface of polystyrene matrix. When using the 0.

[Effect of vasorenal hypertension and neodicoumarin on the rheological properties of erythrocytes and the balance of blood electrolytes, heart and abdominal aorta wall in rats].

It has been shown that with vasorenal hypertension, erythrocyte suspension viscosity coefficient increases, the abdominal aorta transmural potential difference decreases with lower levels of Na+, K+, Ca2+, and Mg2+ in plasma, cardiac and abdominal aorta tissue and higher red blood cell Na+ levels. Neodicumarinum, 3 mg/kg, modified Na+ and K+ imbalance in the red blood cell-plasma-abdominal aorta wall system, which had been caused by vasorenal hypertension. At the same time the changes in Ca2+ and Mg2+ levels in the abdominal aorta and heart tissue, as well as the value of red blood cell suspension viscosity coefficient were demonstrated to be effectively abolished with neodicumarinum in a dose of 30 mg/kg.

[Effect of acute hemorrhage on hemostasis in dogs not adapted to high-altitude conditions].

Acute blood loss was easier after 3-day stay high in the mountains than after a stay in a low place. This is explained by increased blood fibrinolytic activity and high blood antithrombin level recorded by the third day of the animals' stay in the mountains.

[State of the hemostasis system in patients with malignant III-stage neoplasms of the maxilla and larynx].

Hemostasis of patients with III stage malignant neoplasms of the maxilla and larynx was investigated. We examined 40 patients, 8 of which had maxillary tumor and 32 had laryngeal tumor. The age of the patients varied from 44 to 68 years.

[Synthesis of ovalbumin and globin during simultaneous translation of their mRNA in the presence of tRNA of different origin in the cell-free protein-synthesizing system from wheat germ].

Competition among ovalbumin and globin mRNA under their simultaneous translation in the tRNA-dependent cell-free system from wheat germ was studied. One of the mRNAs was added to samples in a constant amount, that provided 50% protein synthesis level of the maximum, other--in increasing amount (from 0 to the maximum). The ration of ovalbumin and globin synthesis rates has been shown to depend essentially (1.

[Modulation of the selective translation of mRNA in cell-free system exposed to tRNA].

The homo- and heterologous tRNA were studied for their influence on the synthesis rate of globin and ovalbumin under simultaneous translation of their mRNAs in the tRNA-dependent cell-free system from wheat germ. In the presence of the fixed concentrations of one of the mRNAs the different amounts of the other mRNA (from 6 up to saturation of the system) were added to the samples. The ratio of the synthesis rate of the translation products after their electrophoretic characterization is determined on the basis of the autoradiogram scanning.

[Effect of succinic acid on blood coagulability and the catecholamine balance].

A single administration of succinic acid was shown to cause a dose-dependent decrease of the blood coagulability in rats. Seven-day administration of succinic acid (50 mg/kg) resulted in a distinct increase of the blood coagulability, an accumulation of adrenaline in the heart and adrenal gland tissues. Hypercoagulation was noted on the 5th day after withdrawal of succinic acid (50 and 200 mg/kg).

[Metabolic effects of succinic and nicotinic acids in emotional pain stress].

In experiments on rats it was shown that administration of succinic and nicotinic acids in doses of 30 and 4 mg/kg for 5 days elevated pyruvic acid level and changed catecholamine balance in tissues of the aorta and heart. The administration of the drugs to rats with current-induced stress partially eliminated unfavourable shifts in carbohydrate metabolism and catecholamine balance in the aortic and cardiac tissues. Succinic acid had more pronounced metabolic activity.

[Metabolic effects of papaverine and pentamine combinations with nicotinic and succinic acids in experimental vascular pathology in rabbits].

It has been shown in rabbit experiments that a 7-day administration of papaverine and pentamine in doses of 1 mg/kg without administering nicotinic (4 mg/kg) and succinic (50 mg/kg) acids and in conjunction with their administration given in courses led to a distinct change in carbohydrate-phosphorus metabolism in blood vessels of rabbits with pituitrin hypertension. The drug combination removed unfavourable metabolic shifts seen in the vessels in the experimental pathology more effectively than separate drug administration.