Thermoelectric Characteristics of Flexible Reduced Graphene Oxide/Silver Selenide Nanowire Composites Prepared by a Facile Vacuum Filtration Process

The reduced graphene oxide/silver selenide nanowire (rGO/Ag2Se NW) composite powders were fabricated via a wet chemical approach, and then flexible rGO/Ag2Se NW composite film was prepared by a facile vacuum filtration method combined with cold-pressing treatment. A highest power factor of 228.88 μWm-1K-2 was achieved at 340 K for the cold-pressed rGO/Ag2Se NW composite film with 0.01 wt% rGO. The rGO/Ag2Se NW composite film revealed superior flexibility as the power factor retained 94.62% after bending for 500 times at a bending radius of 4 mm, which might be due to the interwoven network structures of Ag2Se NWs and pliability of rGO as well as nylon membrane. These results demonstrated the GO/Ag2Se NW composite film has a potential for preparation of flexible thermoelectric devices.

Using Passive Samplers to Track per and Polyfluoroalkyl Substances (PFAS) Emissions From the Paper Industry: Laboratory Calibration and Field Verification

Per and polyfluoroalkyl substances (PFAS) are becoming more stringently regulated and as such, a more diverse suite of environmental monitoring methods is needed. In this work a polar organic chemical integrative sampler (POCIS) with a nylon membrane and a combination of Oasis WAX and Fluoroflash® sorbents was calibrated in the laboratory and deployed in the field. A static renewal system was used to determine sampling rates for 12 PFAS which ranged between 0.69 ± 0.27 to 5.68 ± 1.80 L/day. POCIS devices were deployed for 10 days in lake Tyrifjorden, Norway which is known to be contaminated by a closed down factory producing paper products, in order to track the evolution of the PFAS contamination in a river system draining into the lake. Th sampling campaign enabled the stretch of the river which was responsible for the emissions of PFAS to lake Tyrifjorden to be identified. Freely dissolved concentrations determined with the POCIS were lowest at the site considered to reflect a diffuse PFAS contamination and highest at the site located downstream the factory. Perfluorooctanesulfonic acid (PFOS), perfluorohexanoic acid (PFHxA) and perfluorooctane sulfonamidoacetic acid (EtFOSAA) dominated the concentration profile at this site. Emissions of PFAS to lake Tyrifjorden were estimated to be 3.96 g/day for the sum of the 12 investigated PFAS.

CuI/Nylon Membrane Hybrid Film with Large Seebeck Effect

Room-temperature thermoelectric materials are important for converting heat into electrical energy. As a wide-bandgap semiconductor material, CuI has the characteristics of non-toxicity, low cost, and environmental friendliness. In this work, CuI powder was synthesized by a wet chemical method, then CuI film was formed by vacuum assisted filtration of the CuI powder on a porous nylon membrane, followed by hot pressing. The film exhibits a large Seebeck coefficient of 600 μV · K−1 at room temperature. In addition, the film also shows good flexibility (∼95% retention of the electrical conductivity after being bent along a rod with a radius of 4 mm for 1000 times). A finger touch test on a single-leg TE module indicates that a voltage of 0.9 mV was immediately generated within 0.5 s from a temperature difference of 4 K between a finger and the environment, suggesting the potential application in wearable thermal sensors.

DEVELOPMENT OF A TECHNOLOGY FOR PRODUCING A STABLE INJECTABLE DOSAGE FORM OF A HYDROPHOBIC INDOLOCARBAZOLE DERIVATIVE

Objective: Development of a technology for the production of a stable injectable dosage form (IDF) of indolocarbazole derivative LHS-1269. Methods: LHS-1269 is an active pharmaceutical ingredient that was synthesized in the N. N. Blokhin National Medical Research Center of Oncology of the Ministry of Health of the Russian Federation. The IDF includes dimethyl sulfoxide (DMSO), 95% ethanol, Kollidon® 17PF and water for injection. Magnetic stirrer and overhead stirrer with a propeller stirring element were used to prepare the model solution of the IDF of LHS-1269. Sterilizing filtration of the solution was performed with 0.2−0.22 um polycarbonate, cellulose, polyvinylidene fluoride, polyethersulfone and nylon membrane filters. The aqueous solution of LHS-1269 was lyophilized in Edwards Minifast DO.2 freeze dryer. Assay of LHS-1269 was performed by spectrophotometry at 320±3 nm. Potentiometry was used to measure pH, a viscosimetry method was used to measure the viscosity of the solutions. The average weight was estimated by weighing a sample of 10 vials with the concentrate. Results: 0.5% aqueous solution of LHS-1269 was produced by mixing the solution of the active substance in DMSO and ethanol with an aqueous solution of polyvinylpyrrolidone gradually at the ratio of LHS-1269/DMSO/ethanol/Kollidon® of 1/11/32/40 by weight. The aqueous solution of the study substance cannot be lyophilized, so a sequence of technological operations was presented to produce an anhydrous concentrate “LHS-1269, concentrate for solution for injection and infusion 25 mg”. Conclusion: A technology was developed to produce a stable IDF of a hydrophobic indolocarbazole derivative LHS-1269, a high-potential antitumor drug.

14 Telomere length in cloned camels produced by somatic cell nuclear transfer is not different from that in their naturally produced counterparts

There are controversial reports on the restoration of eroded telomere length in offspring produced by somatic cell nuclear transfer (SCNT) in different animal species. To the best of our knowledge, no earlier studies report telomere length in naturally produced or cloned animals in any of the camelid species. Therefore, the present study was conducted to estimate the telomere length in dromedary camels produced by SCNT, and their age-matched naturally produced counterparts by terminal restriction fragment (TRF) analysis. Genomic DNA was extracted from venous blood collected from 6 cloned animals (aged 3, 12, and 24 months), and their age-matched counterparts by a conventional phenol/chloroform protocol. Denatured and neutralized DNA was blotted onto a positively charged nylon membrane and fixed by baking at 80°C for 3h. After washing in a prewarmed digoxigenin (DIG) easy hybridization solution at 42°C for 1h, DNA hybridization was carried out using a telomere (TTAGGG)n-specific, DIG-labelled hybridization probe (Roche Diagnostics, Germany) at 42°C for 4h. Stringent washes were carried out at the same temperature, followed by chemiluminescence reaction. The signals were captured using the Azure Biosystems C600 gel documentation system. Molecular weights of the unknown TRF bands on the gel were calculated using known molecular weight marker provided by Telo TAGGG Telomere Length Assay Kit (Roche Diagnostics). A TeloTool program from MATLAB software with a built-in probe intensity correction algorithm was used for TRF analysis. The experiment was replicated 3 times, and the data, presented as mean±s.e.m., were analysed using a 2-sample t-test (Minitab statistical software). No difference (P>0.05) was found in the mean telomere length of cloned camels compared with their naturally produced age-matched counterparts (21.7±0.3 vs. 22.1±0.3; 21.9±0.3 vs. 22.1±0.3; 22.2±0.5 vs. 22.0±0.1; 20.5±0.5 vs. 22.5±0.7; 20.1±0.1 vs. 22.5±0.7; 21.7±1.1 vs. 22.6±0.2), respectively. In conclusion, this is the first study where telomere length has been reported in naturally produced and cloned dromedary camels produced by SCNT. We found that telomere lengths in cloned camels were similar to those of their age-matched naturally produced counterparts, suggesting that the camel cytoplast reprograms the somatic cell nucleus and restores the telomere length to its totipotency stage.