Zinc and cadmium silanethiolates with methanol/water co-ligands were prepared and characterized by means of infrared spectroscopy, 1H, 13C and 113Cd NMR spectroscopy, and single-crystal X-ray ...diffraction. Facile exchange of methanol to water within zinc complex was observed similar to the process undergoing in the active site of alcohol dehydrogenase. Display omitted
Zinc and cadmium complexes containing silanethiolate anions and methanol or water were synthesized and characterized by X-ray diffraction, FT-IR and NMR spectroscopy, and DFT calculations. The Zn/Cd complexes 1 and 2 exhibit the same composition but different coordination spheres of the metal ions, Cd{SSi(OAr)3}2(CH3OH)·CH3OH (1) versus Zn{SSi(OAr)3}2(CH3OH)2 (2) where Ar=2,6-diisopropylphenyl. Contrary to zinc, the cadmium ion utilizes very weak donors to complete its coordination sphere; it forms contacts to phenyl rings of the silanethiolate ligand. Two zinc analogs of the general formula Zn{SSi(OAr)3}2(L)2 where L=CH3OH (2) or H2O (3) are compared. In 3, methanol is replaced by water even at low concentration of water in the reaction mixture. The exchange is accompanied by the reorganization of the hydrophobic environment of the water/methanol ligand in the complex. A tetranuclear zinc complex Zn4(CH3OH)4{SSi(OAr)3}4(CH3COO)4 4 featuring an unusual unsupported Zn4(CH3COO)44+ core was also obtained and characterized.
The aim of the study was the application and evaluation of real-time PCRs based on the fluorescence of SYBR Green I intercalating dye for the detection of three
genes in contaminated liver and blood ...samples. The goals for detection were
gene as a chromosomal marker,
gene located on plasmid pXO1, and
gene located on plasmid pXO2.
Five
strains were used for the experiments. Additionally, single strains of other species of the genus
,
.
,
,
, and
, and strains of six other species were used for evaluation of the specificity of the tests. Three SYBR Green I real-time PCRs were conducted allowing confirmation of
in the biological samples.
The observation of amplification curves in real-time PCRs enabled the detection of the chromosomally encoded
gene,
gene, and
gene of
. The specificity of the tests was confirmed by estimation of the melting temperature of the PCR products. The sensitivity and linearity of the reactions were determined using regression coefficients. Strains of other microbial species did not reveal real-time PCR products.
All real-time PCRs for the detection of
in biological samples demonstrated a significant sensitivity and high specificity.
The aim of the study was the application and comparison of real-time PCR methods based on the fluorescence of SYBR Green I intercalating dye and TaqMan probes for the detection of the 23S rDNA gene ...of
spp. and the
A gene of
in biological samples of the liver, brain, and blood.
Five strains of
and single strains of each species
,
,
,
and
were used for the experiments. Additionally, five strains of other species of bacteria were used for evaluation of the specificity of tests. In the first stage of the study SYBR Green I real-time PCRs, one allowing detection of the 23S rDNA gene and two based on the amplification the
A gene, were performed. In the next part, three TaqMan probe-based real-time PCRs allowing confirmation of belonging to
spp. and
were conducted.
The observation of amplification curves in real-time PCRs enabled the detection of both genes. A high regression coefficient of 0.99 was found for all reactions. Specific amplification products were obtained for the 23S rDNA and
A genes which confirm their belonging to
spp. and
, respectively. Other microbial species did not reveal real-time PCR products.
Both real-time PCR methods for the detection of
spp. and
in biological samples demonstrated a significant sensitivity and high specificity.
Although the effect of semi-rigid steel beam-to-column connections on the behaviour of steel frames and their substantial economic benefits are recognized nowadays, many structural analyses still ...consider connections as either fixed or pinned. For that reasons, there is need to be able the generate moment-rotation responses of semi-rigid connections that can be used for analysis and design proposes. Characteristic of the joints can be found using FEM models. The objective of the analysis was to find moment-rotation curves for beam-to-column joints with flange cleats and compare them to curves obtained from experimental studies. Numerical elastic-plastic 3D finite models was performed in order to establish a numerical analysis method for evaluating deformation of connections. For all joints there were obtained the FE results lightly underestimates results achieved from experiments. Some differences in the initial value of stiffness and resistances indicate the need for further work on improving FEM models. The inclusion of dimensional deviations of the IPE nad HEB sections, variability in the values of the prestressing forces of the bolts and the not centric positions of the bolts in the holes in the FEM model may contribute to increasing the degree of compliance of the results from experimental and numerical analyzes.
Four heteroleptic complexes of nickel(ii), cobalt(ii) and zinc(ii), containing a monodentate silanethiolate ligand derived from tris(2,6-diisopropylphenoxy)silanethiol (TDST), were prepared and ...characterized. Nickel(ii) and cobalt(ii) complexes of the formula M(NH3)2(TDST)2 (M = Ni(ii) complex , M = Co(ii) complex ) were obtained from the respective chlorides. Zinc complexes of the general formula Zn(acac)(TDST)(L), where L = EtOH (complex ) or H2O (complex ), were obtained from zinc acetylacetonate. A single-crystal X-ray structural analysis revealed that all crystalline products are solvent adducts. The geometries of ligands in the complexes are typical: distorted tetrahedral in zinc and cobalt(ii) complexes and square planar in nickel(ii) compounds. Magnetic studies performed for Ni(ii) and Co(ii) compounds confirmed the diamagnetic character of the first complex and high-spin paramagnetic configuration of the latter. Nickel(ii) and cobalt(ii) complexes were additionally characterized by UV-Vis and IR spectroscopy. IR bands for ligands in the complexes were assigned with the help of the DFT vibrational frequency calculations.
The innate nonspecific immunity is the first line of defense against viral infection. Toll-like receptors (TLRs) and retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) are two main receptor ...families detecting viral nucleic acid. So far, three RLR family members were characterized: RIG-I, MDA5 and LGP2. RLR constitute a family of cytoplasmic helicases, which recognized intracellular single-stranded and double-stranded RNA that is introduced to cytosol during viral infection and replication. In this work we review the current knowledge about the mechanisms of viral recognition by RIG-I-like receptors and their signaling pathways for the activation of type I interferons and pro-inflammatory cytokines synthesis.
Abstract Background Human cytomegalovirus (HCMV) is the most widespread cause of congenital infection. The effects of various viral strains and viral loads on the infection outcome have been under ...debate. Objectives To determine the distribution of gN variants in HCMV strains isolated from children with congenital or postnatal infection and to establish the relationship between the viral genotype, the viral load, and the sequelae. Study design The study population included congenitally HCMV-infected newborns and children with postnatal or unproven congenital HCMV infection. The genotyping was performed by RFLP analysis of PCR-amplified fragments, and the viral load was measured by quantitative real-time PCR. Results Our results demonstrated that the HCMV genotypes gN3b, gN4b, and gN4c were prevalent in the patients examined. There were no differences in the distributions of gN genotypes in the congenitally and postnatally infected children. Multiple HCMV strains were detected in both groups of children. A significant association between the HCMV gN4 genotype and the incidence of neurological disorders was observed ( p = 0.045). Our results suggest that the detection of the gN2 or the gN4 genotype may be indicative of serious manifestations in children. In contrast, the gN3b and the gN1 genotypes represent less pathogenic HCMV strains. The HCMV load in urine was significantly higher in children with congenital infection compared with children with postnatal infection. No correlation was found between the viral load and the genotype. Conclusion Our results suggest that the gN genotype may be a virological marker of symptomatic HCMV infection in newborns.
A series of novel conjugates of cobalt bis(1,2-dicarbollide)(-I) with 5-ethynyl-2′-deoxyuridine and its cyclic derivatives were synthesized. Conjugates with 5-ethynyl-2-deoxyuridine were prepared by ...the direct Sonogashira coupling of a series of cobalt bis(1,2-dicarbollide)(-I) terminal alkynes and 5-iodo-2′-deoxyuridine. Their furo2,3-dpyrimidin-2(3H)-one isomers were obtained either by intermolecular cyclization of the above conjugates or by Sonogashira coupling using Pd/C as a catalyst. Action of ammonia on these furo2,3-dpyrimidin-2(3H)-one conjugates resulted in pyrrolo2,3-dpyrimidin-2(3H)-one conjugates. Most of the designed compounds have shown low cytotoxicity in several cell lines. Some 5-ethynyl-2-deoxyuridine and furo2,3-dpyrimidin-2(3H)-one conjugates have also presented antiviral activity.
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New products of the reaction of silicon disulfide with phenols: phenoxysilane, cyclodisilthiane and silanethiol have been characterized by FT-IR, NMR and X-ray diffraction. The outcome of the ...reaction depends on the presence of the steric hindrance in the ortho position of the reacting phenol. The intramolecular interactions in the compounds are mainly XH---pi (X=C, S) whereas the intermolecular interactions are very weak CH---π/CH---O contacts as in aryloxysilane or electrostatic dipole-dipole attractions in cyclodisilthiane and silanethiol. The energy of intramolecular S–H---π interaction is estimated with the use of DFT/GGA BLYP-D XC potentials. Display omitted
•X-ray molecular structures of three phenoxysilyl compounds are reported.•Vibrational spectra of two polymorphs of phenoxysilanethiol are analyzed.•The energy of intramolecular SH---π interaction is estimated from DFT calculations.•DFT calculations are in good agreement with experimental results.
The reaction of silicon disulfide with alkylphenols yields tetraphenoxysilane, cyclodisilthiane and silanethiol. The outcome of the reaction depends on the presence of the steric hindrance in the ortho position on the reacting phenol. New products of the reaction of silicon disulfide with phenols are characterized by FT-IR, NMR, X-ray diffraction and DFT calculations. The intramolecular interactions in the compounds are mainly XH---π (X=C, S) whereas the intermolecular interactions are either very weak CH---π/CH---O contacts found in aryloxysilane or electrostatic dipole–dipole attraction in cyclodisilthiane and silanethiol. The S–H---π interactions in the obtained silanethiol are analyzed with the use of DFT/GGA BLYP-D XC potentials. The energy of intramolecular S–H---π interaction is estimated.
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