56 research outputs found
Manganese(I)-Catalyzed H-P Bond Activation via Metal-Ligand Cooperation
Here we report that chiral Mn(I) complexes are capable of H-P bond activation. This activation mode enables a general method for the hydrophosphination of internal and terminal α,β-unsaturated nitriles. Metal-ligand cooperation, a strategy previously not considered for catalytic H-P bond activation, is at the base of the mechanistic action of the Mn(I)-based catalyst. Our computational studies support a stepwise mechanism for the hydrophosphination and provide insight into the origin of the enantioselectivity
Efficiency of Sanitary Treatment in Poultry Breeding and Poultry Meat Processing Plant
The aim of this study was to observe the effectiveness of disinfection on a broiler farm and in a plant processing the poultry from this farm. The broiler farm was disinfected with a preparation based on peracetic acid while a preparation based on quarternary ammonium salt was used in the processing plant. We evaluated swabs taken from surfaces, which come into contact with broilers and broiler meat. Results of the swabs taken by standard microbiological swabbing method were evaluated with results of the swabs taken by the ATP-bioluminescence method. The microbiological examination included total counts of microorganisms, coliform count and moulds. When using the standard plate counts method on the broiler farm we found that the plate counts in 0% of swabs were 100 CFU. In the processing plant, out of 22% of swabs 100. The bioluminescence method was applied only in the processing plant where 300 RLU were measured in 80, 10 and 10% of swabs, resp. Our observations and results allowed us to conclude that the disinfectants tested appeared suitable for the respective premises and the ATP bioluminescence method could be use as a as a suitable complement for detection of cleanliness of individual surfaces
Anatomical Differences Determine Distribution of Adenovirus after Convection-Enhanced Delivery to the Rat Brain
Background: Convection-enhanced delivery (CED) of adenoviruses offers the potential of widespread virus distribution in the brain. In CED, the volume of distribution (Vd) should be related to the volume of infusion (Vi) and not to dose, but when using adenoviruses contrasting results have been reported. As the characteristics of the infused tissue can affect convective delivery, this study was performed to determine the effects of the gray and white matter on CED of adenoviruses and similar sized super paramagnetic iron oxide nanoparticles (SPIO). Methodology/Principal Findings: We convected AdGFP, an adenovirus vector expressing Green Fluorescent Protein, a virus sized SPIO or trypan blue in the gray and white matter of the striatum and external capsule of Wistar rats and towards orthotopic infiltrative brain tumors. The resulting Vds were compared to Vi and transgene expression to SPIO distribution. Results show that in the striatum Vd is not determined by the Vi but by the infused virus dose, suggesting diffusion, active transport or receptor saturation rather than convection. Distribution of virus and SPIO in the white matter is partly volume dependent, which is probably caused by preferential fluid pathways from the external capsule to the surrounding gray matter, as demonstrated by co-infusing trypan blue. Distant tumors were reached using the white matter tracts but tumor penetration was limited. Conclusions/Significance: CED of adenoviruses in the rat brain and towards infiltrative tumors is feasible when regional anatomical differences are taken into account while SPIO infusion could be considered to validate proper catheter positioning and predict adenoviral distribution
Periparturient Period in Terms of Body Condition Score and Selected Parameters of Hormonal Profiles
The majority of all diseases in dairy cows occur during the period from three weeks before parturition to three weeks after parturition, in the periparturient or transitional period. The objective of this study was to evaluate the dynamics of selected parameters of: the hormonal profiles, the body condition score (BCS) and their interrelationships. The study was carried out on 15 dairy cows of the Slovak Pied Cattle, from three weeks before to nine weeks after parturition, which were divided into six groups. The concentrations of leptin during ante partum increased from 23.08 ± 10.58 ng.ml−1 to 26.80 ± 11.47 ng.ml−1, then gradually decreased (P > 0.05), and conversely, the concentrations of ghrelin before parturition were found to be decreasing and during the postpartal period, the concentrations increased, with the highest value of 35.94 ± 16.85 pg.ml−1. In the case of insulin, we found the opposite tendency of ghrelin. We observed significantly higher values of BCS in dry cows than in cows after parturition (P < 0.001). Comparing the BCS and the parameter of the hormonal profiles, we found both positive and negative correlations: leptin and ghrelin (r = −0.235, P < 0.05), and BCS and insulin (r = 0.232, P < 0.05), and BCS and leptin (r = 0.360, P < 0.001). The interrelationships between the hormones and the body condition score, provided evidence that the variations in concentrations of leptin, ghrelin and insulin were related to variations in the BCS
The Contribution to the Study of Dentition State of the Brno Population in the 2nd Half of 18th Century and in the 19th Century
The aim of the present study is the description of dentition of skeleton remains from former Town cemetery Malá Nová (nowadays Antonínská Street), which was used as burial site in 1785-1883. A total of 1024 teeth were appraised and 3227 dental alveoli were examined. The caries intensity (I-CE) of the permanent dentition was proved to be about 38.3% and the caries frequency (F-CE) reached up to 83.8%. These two values were higher in the women. From the different types of teeth, most of dental caries were found on molars, afterwards degressively on premolars, incisors and canines. The inflammation changes of dental alveoli were found in 12.7% cases, the degenerative productive process manifestations in 8.3%, the value of the enamel hypoplasia was 4.2%, the teeth retention was observed in 33.8% individuals and the hyperodontia in 0.7% of all studied cases. Results of this study showed that the caries rate in the Brno population of 2nd half of 18th century and in the 19th century, was expressively worse than in historically older populations as well as worse than in the current population
Toxic metal complexes of macrocyclic cyclen molecule – synthesis, structure and complexing properties
Toxic metal (Cd2+, Hg2+, Pb2+, and Ag+) complexes with the tetradentate macrocyclic ligand - cyclen (1,4,7,10-tetraazacyclododecane, [12]aneN4, L) were prepared and studied in the solid state by IR, X-ray diffraction, elemental and thermal analysis. Diffraction results have yielded three molecular structures, [Cd([12]ane-κ4N1,4,7,10)(NO3)2)] (1), [Hg([12]ane-κ4N1,4,7,10)(NO3-κ2O,O`)]NO3 (2), [Pb2([12]ane-κ4N1,4,7,10)2][Pb(NO3)6] (3) and one polymeric structure {[Ag2([12]ane-κ3N1,4,7)(μ2-[12]aneN10)](NO3)2∙2H2O)}n (4) featuring a unique coordination mode not observed before with cyclen as a ligand. The monodentate (1) and chelate (with small bite angle 50.3(3)°, (2) coordination modes of nitrate ligands were confirmed. Stereochemically active 6s2 lone pair was suggested in 3 and DFT results confirmed no significant metal–metal covalent bond. The stability constants of the complexes with Cd2+ and Pb2+ ions were determined by potentiometric methods in aqueous solutions. Additionally, the structures of complexes in solution were observed by 1H NMR. Both methods confirm similar cyclen complexing properties toward Zn2+ biometal and Cd2+, Pb2+ toxic metals
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