The influence of the chain length and the functional group steric accessibility of thiols on the phase transfer efficiency of gold nanoparticles from water to toluene

The papers were published with the financial support from the budget of the West Pomeranian Voivodeship.This paper describes the influence of the chain length and the functional group steric accessibility of thiols modifiers on the phase transfer process efficiency of water synthesized gold nanoparticles (AuNPs) to toluene. The following thiols were tested: 1-decanethiol, 1,1-dimethyldecanethiol, 1-dodecanethiol, 1-tetradecanethiol and 1-oktadecanethiol. Nanoparticles (NPs) synthesized in water were precisely characterized before the phase transfer process using Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM). The optical properties of AuNPs before and after the phase transfer were studied by the UV-Vis spectroscopy. Additionally, the particle size and size distribution before and after the phase transfer of nanoparticles were investigated using Dynamic Light Scattering (DLS). It turned out that the modification of NPs surface was not effective in the case of 1,1-dimethyldecanethiol, probably because of the difficult steric accessibility of the thiol functional group to NPs surface. Consequently, the effective phase transfer of AuNPs from water to toluene did not occur. In toluene the most stable were nanoparticles modified with 1-decanethiol, 1-dodecanethiol and 1-tetradecanethiol.This work was supported by FP7-NMP-2010-SMALL-4 program (HYMEC), project number 263073. Scientific work supported by the Polish Ministry of Science and Higher Education, funds for science in 2011–2014 allocated for the cofounded international project

The influence of caffeine on the biomechanical properties of bone tissue during pregnancy in a population of rats

The influence of pregnancy on bone tissue metabolism is not completely understood. Caffeine also has a potentially negative influence on bones. The aim of this study was the evaluation of changes in the bones of pregnant rats under the influence of caffeine. The experiment was carried out on Wistar rats. The evaluation of rats’ bone tissue quality was performed based on bone density measurements and resistance examinations. It analyzed the impact of caffeine on the degree of bone tissue mineralization and the composition of the bones. The mean value of pelvises ‘wet’ and ‘dry’ densities in a group of pregnant rats with caffeine intake was lower compared to the control group. The deformation in maximal load point of the femur shaft in the experimental group was significantly higher than in the control group. In the experimental group, the percentage of water in the bones was significantly higher, while the content of inorganic phase was significantly lower compared to the control group. The changes of biomechanical parameters in the group of pregnant rats with caffeine intake indicate its negative influence on the bone. Our results show higher plasticization of the bone shafts of the animals under the influence of caffeine. Higher deformation of bone shafts may have an effect on the statics of the skeleton. The administration of caffeine significantly affected the quantitative composition of the bone. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 3, pp. 504–511

The influence of caffeine on the biomechanical properties of bone tissue during pregnancy in a population of rats

The influence of pregnancy on bone tissue metabolism is not completely understood. Caffeine also has a potentially negative influence on bones. The aim of this study was the evaluation of changes in the bones of pregnant rats under the influence of caffeine. The experiment was carried out on Wistar rats. The evaluation of rats’ bone tissue quality was performed based on bone density measurements and resistance examinations. It analyzed the impact of caffeine on the degree of bone tissue mineralization and the composition of the bones. The mean value of pelvises ‘wet’ and ‘dry’ densities in a group of pregnant rats with caffeine intake was lower compared to the control group. The deformation in maximal load point of the femur shaft in the experimental group was significantly higher than in the control group. In the experimental group, the percentage of water in the bones was significantly higher, while the content of inorganic phase was significantly lower compared to the control group. The changes of biomechanical parameters in the group of pregnant rats with caffeine intake indicate its negative influence on the bone. Our results show higher plasticization of the bone shafts of the animals under the influence of caffeine. Higher deformation of bone shafts may have an effect on the statics of the skeleton. The administration of caffeine significantly affected the quantitative composition of the bone. (<i>Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 3, pp. 504–511</i>

Detection Limits of DLS and UV-Vis Spectroscopy in Characterization of Polydisperse Nanoparticles Colloids

Dynamic light scattering is a method that depends on the interaction of light with particles. This method can be used for measurements of narrow particle size distributions especially in the range of 2–500 nm. Sample polydispersity can distort the results, and we could not see the real populations of particles because big particles presented in the sample can screen smaller ones. Although the theory and mathematical basics of DLS technique are already well known, little has been done to determine its limits experimentally. The size and size distribution of artificially prepared polydisperse silver nanoparticles (NPs) colloids were studied using dynamic light scattering (DLS) and ultraviolet-visible (UV-Vis) spectroscopy. Polydisperse colloids were prepared based on the mixture of chemically synthesized monodisperse colloids well characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), DLS, and UV-Vis spectroscopy. Analysis of the DLS results obtained for polydisperse colloids reveals that several percent of the volume content of bigger NPs could screen completely the presence of smaller ones. The presented results could be extremely important from nanoparticles metrology point of view and should help to understand experimental data especially for the one who works with DLS and/or UV-Vis only

The role of tannic acid and sodium citrate in the synthesis of silver nanoparticles

We describe herein the significance of a sodium citrate and tannic acid mixture in the synthesis of spherical silver nanoparticles (AgNPs). Monodisperse AgNPs were synthesized via reduction of silver nitrate using a mixture of two chemical agents: sodium citrate and tannic acid. The shape, size and size distribution of silver particles were determined by UV–Vis spectroscopy, dynamic light scattering (DLS) and scanning transmission electron microscopy (STEM). Special attention is given to understanding and experimentally confirming the exact role of the reagents (sodium citrate and tannic acid present in the reaction mixture) in AgNP synthesis. The oxidation and reduction potentials of silver, tannic acid and sodium citrate in their mixtures were determined using cyclic voltammetry. Possible structures of tannic acid and its adducts with citric acid were investigated in aqueous solution by performing computer simulations in conjunction with the semi-empirical PM7 method. The lowest energy structures found from the preliminary conformational search are shown, and the strength of the interaction between the two molecules was calculated. The compounds present on the surface of the AgNPs were identified using FT-IR spectroscopy, and the results are compared with the IR spectrum of tannic acid theoretically calculated using PM6 and PM7 methods. The obtained results clearly indicate that the combined use of sodium citrate and tannic acid produces monodisperse spherical AgNPs, as it allows control of the nucleation, growth and stabilization of the synthesis process.This work was supported by the Polish Ministry of Science and Higher Education within Research Grant No. NN507 350435 and by the National Science Centre Poland Grant No. 2014/13/B/NZ5/01356

Role of Donor Activating KIR–HLA Ligand–Mediated NK Cell Education Status in Control of Malignancy in Hematopoietic Cell Transplant Recipients

AbstractSome cancers treated with allogeneic hematopoietic stem cell transplantation (HSCT) are sensitive to natural killer cell (NK) reactivity. NK function depends on activating and inhibitory receptors and is modified by NK education/licensing effect and mediated by coexpression of inhibitory killer-cell immunoglobulin-like receptor (KIR) and its corresponding HLA I ligand. We assessed activating KIR (aKIR)-based HLA I–dependent education capacity in donor NKs in 285 patients with hematological malignancies after HSCT from unrelated donors. We found significantly adverse progression-free survival (PFS) and time to progression (TTP) in patients who received transplant from donors with NKs educated by C1:KIR2DS2/3, C2:KIR2DS1, or Bw4:KIR3DS1 pairs (for PFS: hazard ratio [HR], 1.70; P = .0020, Pcorr = .0039; HR, 1.54; P = .020, Pcorr = .039; HR, 1.51; P = .020, Pcorr = .040; and for TTP: HR, 1.82; P = .049, Pcorr = .096; HR, 1.72; P = .096, Pcorr = .18; and HR, 1.65; P = .11, Pcorr = .20, respectively). Reduced PFS and TTP were significantly dependent on the number of aKIR-based education systems in donors (HR, 1.36; P = .00031, Pcorr = .00062; and HR, 1.43; P = .019, Pcorr = .038). Furthermore, the PFS and TTP were strongly adverse in patients with missing HLA ligand cognate with educating aKIR-HLA pair in donor (HR, 3.25; P = .00022, Pcorr = .00045; and HR, 3.82; P = .027, Pcorr = .054). Together, these data suggest important qualitative and quantitative role of donor NK education via aKIR-cognate HLA ligand pairs in the outcome of HSCT. Avoiding the selection of transplant donors with high numbers of aKIR-HLA-based education systems, especially for recipients with missing cognate ligand, is advisable

Impact of clinical phenotypes on management and outcomes in European atrial fibrillation patients: a report from the ESC-EHRA EURObservational Research Programme in AF (EORP-AF) General Long-Term Registry

Background: Epidemiological studies in atrial fibrillation (AF) illustrate that clinical complexity increase the risk of major adverse outcomes. We aimed to describe European AF patients\u2019 clinical phenotypes and analyse the differential clinical course. Methods: We performed a hierarchical cluster analysis based on Ward\u2019s Method and Squared Euclidean Distance using 22 clinical binary variables, identifying the optimal number of clusters. We investigated differences in clinical management, use of healthcare resources and outcomes in a cohort of European AF patients from a Europe-wide observational registry. Results: A total of 9363 were available for this analysis. We identified three clusters: Cluster 1 (n = 3634; 38.8%) characterized by older patients and prevalent non-cardiac comorbidities; Cluster 2 (n = 2774; 29.6%) characterized by younger patients with low prevalence of comorbidities; Cluster 3 (n = 2955;31.6%) characterized by patients\u2019 prevalent cardiovascular risk factors/comorbidities. Over a mean follow-up of 22.5 months, Cluster 3 had the highest rate of cardiovascular events, all-cause death, and the composite outcome (combining the previous two) compared to Cluster 1 and Cluster 2 (all P <.001). An adjusted Cox regression showed that compared to Cluster 2, Cluster 3 (hazard ratio (HR) 2.87, 95% confidence interval (CI) 2.27\u20133.62; HR 3.42, 95%CI 2.72\u20134.31; HR 2.79, 95%CI 2.32\u20133.35), and Cluster 1 (HR 1.88, 95%CI 1.48\u20132.38; HR 2.50, 95%CI 1.98\u20133.15; HR 2.09, 95%CI 1.74\u20132.51) reported a higher risk for the three outcomes respectively. Conclusions: In European AF patients, three main clusters were identified, differentiated by differential presence of comorbidities. Both non-cardiac and cardiac comorbidities clusters were found to be associated with an increased risk of major adverse outcomes

Tannic Acid Modified Silver Nanoparticles Show Antiviral Activity in Herpes Simplex Virus Type 2 Infection

The interaction between silver nanoparticles and herpesviruses is attracting great interest due to their antiviral activity and possibility to use as microbicides for oral and anogenital herpes. In this work, we demonstrate that tannic acid modified silver nanoparticles sized 13 nm, 33 nm and 46 nm are capable of reducing HSV-2 infectivity both in vitro and in vivo. The antiviral activity of tannic acid modified silver nanoparticles was size-related, required direct interaction and blocked virus attachment, penetration and further spread. All tested tannic acid modified silver nanoparticles reduced both infection and inflammatory reaction in the mouse model of HSV-2 infection when used at infection or for a post-infection treatment. Smaller-sized nanoparticles induced production of cytokines and chemokines important for anti-viral response. The corresponding control buffers with tannic acid showed inferior antiviral effects in vitro and were ineffective in blocking in vivo infection. Our results show that tannic acid modified silver nanoparticles are good candidates for microbicides used in treatment of herpesvirus infections.This work was supported by the Polish National Science Centre grant No. 2011/03/B/NZ6/04878 (for MK) and Centre for Preclinical Research and Technology (CePT) Project No. POIG.02.02.00-14-024/08-0 (for MG and MD). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

El tema de la soledad en Góngora, Gustavo Garcia Saravi y Juan Goytisolo

The aim of this article is to compare two representatives of modern Spanish literature with the Baroque poet, Góngora. Góngora’s distinct influence on the poetry of an Argentinian poet, Gustavo Garcia Saravf and the Spanish prose writer, Juan Goytisolo on the level of content and form may be observed. The author also considers the problem of human fate, marked with suffering and loneliness, which is described by all the three authors from the perspective of a pilgrim