Eight persons from five institutions in different countries carried out polymerizations of aniline following the same preparation protocol. In a "standard" procedure, aniline hydrochloride was ...oxidized with ammonium peroxydisulfate in aqueous medium at ambient temperature. The yield of polyaniline was higher than 90 % in all cases. The electrical conductivity of polyaniline hydrochloride thus prepared was 4.4 ± 1.7 S cm
(average of 59 samples), measured at room temperature. A product with defined electrical properties could be obtained in various laboratories by following the same synthetic procedure. The influence of reduced reaction temperature and increased acidity of the polymerization medium on polyaniline conductivity were also addressed. The conductivity changes occurring during the storage of polyaniline were monitored. The density of polyaniline hydrochloride was 1.329 g cm
. The average conductivity of corresponding polyaniline bases was 1.4 x108 S cm
, the density being 1.245 g cm
. Additional changes in the conductivity take place during storage. Aging is more pronounced in powders than in compressed samples. As far as aging effects are concerned, their assessment is relative. The observed reduction in the conductivity by ~10 % after more than one-year storage is large but, compared with the low conductivity of corresponding polyaniline (PANI) base, such a change is negligible. For most applications, an acceptable level of conductivity may be maintained throughout the expected lifetime.
In spite of extensive electrical characterization of polyaniline, the information on its mechanical properties is missing in the literature. Complex Young's modulus of polyaniline compressed into ...pellets was measured at room temperature and an influence of preparation conditions of the polyaniline pellets on mechanical properties was studied. Young's modulus of PANI hydrochloride pellets was 0.9
±
0.2
GPa and that of polyaniline base 1.3
±
0.2
GPa. These values are comparable with common polymers, such as bulk polystyrene, 1.8
±
0.1
GPa, or compressed polystyrene powder, 0.80
±
0.02
GPa. Modulus of polyaniline is independent of the compression pressure above 300
MPa, the time of compression had no effect.
Through stochastic simulations, accuracies of breeding values and response to selection were assessed under traditional pedigree-(BLUP) and genomic-based evaluation methods (GBLUP) in forest tree ...breeding. The latter provides a methodological foundation for genomic selection. We evaluated the impact of clonal replication in progeny testing on the response to selection realized in seed orchards under variable marker density and target effective population sizes. We found that clonal replication in progeny trials boosted selection accuracy, thus providing additional genetic gains under BLUP. While a similar trend was observed for GBLUP, however, the added gains did not surpass those under BLUP. Therefore, breeding programs deploying extensive progeny testing with clonal propagation might not benefit from the deployment of genomic information. These findings could be helpful in the context of operational breeding programs.
Polyaniline (PANI) is one of the most studied conducting polymers. Its properties can be modified by controlling the way of protonation. Polyaniline base was immersed in aqueous solutions of 42 ...inorganic or organic acids in order to find out, which is able to constitute a salt with the PANI base and what are the properties of products. The conductivity of the reprotonated PANI bases is determined especially by the pH of acid solutions. The highest conductivity, 1.22
S
cm
−1, was found after reprotonation of PANI base with 50% tetrafluoroboric acid. The reaction with most strong inorganic acids yielded samples with a conductivity of 10
−1
S
cm
−1. Sulfonic acids gave products having conductivity of the order of 10
−2–10
−1
S
cm
−1. Carboxylic acids were less efficient in protonation, and their ability to produce a conducting polymer depended on increasing the acid concentration. Acids containing an acidic hydroxyl group, like picric acid, also protonated PANI to a good level of conductivity. The lowest conductivity, 1.8
×
10
−10
S
cm
−1, was observed in the absence of any acid. The density of reprotonated PANI varied between 1.19 and 2.06
g
cm
−3, the contact angle between 29° and 102°, and volume change between −14% and +33%, depending of the acid used. The reprotonation of PANI base with various acids offers the opportunity to prepare materials with great variability and versatility in properties.
Background. This report describes data collected by the Czech Registry of Renal Biopsies (CRRB). Methods. Twenty-eight centres provided data on all biopsies of native kidneys performed in the Czech ...Republic (population 10.3 million) over the period 1994–2000. Data on serum creatinine concentration (sCr), 24 h proteinuria, haematuria, serum albumin level, arterial hypertension, diabetes mellitus, histological diagnosis and complications after renal biopsy were collected. Results. Altogether 4004 biopsies in 3874 patients were performed (males 57.9%, children ≤15 years 17.7%, elderly >60 years 14.3%). Microhaematuria was present in 65.9%, macrohaematuria in 9.2%, nephrotic proteinuria (≥3.5 g/24 h) in 39.3%, and low-grade proteinuria (<3.5 g/24 h) in 41.4%. Among adults, hypertension was present in 45.2%, mild renal insufficiency in 23% (sCr 111–200 µmol/l) and advanced renal insufficiency in 13.7% (sCr 201–400), while 11.5% of patients had sCr >400 µmol/l. The most frequent renal diseases were primary (59.8%) and secondary (25.4%) glomerulonephritis (GN). Tubulointerstitial nephritis (TIN) was observed in 4.4% and hypertensive nephroangiosclerosis in 3.4%. The samples were non-diagnostic in 4.6%. Among primary GNs, the most frequent diagnoses were: IgA nephropathy (IgAN) 34.5%, minimal change disease (MCD) 12.4%, non-IgA mesangioproliferative GN (MesGN) 11.3%, focal segmental glomerulosclerosis (FSGS) 10.8% and membranous GN (MGN) 9.3%. Among secondary GNs, systemic lupus erythematosus (SLE) represented 23.0%, necrotizing vasculitis (NV) 15.5%, Henoch–Schönlein purpura 5.7%, thin basement membrane glomerulopathy (TBN) 19.3%, Alport syndrome 6.9%, renal amyloidosis 9.9% and myeloma kidney 2.9%. Among children, the most common were IgAN (19.2%), MCD (17.6%) and TBM glomerulopathy (12.3%), while among the elderly the most common were MGN (11.0%), NV (10.7%) and amyloidosis (9.6%). The most common in patients with nephrotic proteinuria were MCD (50.5%) among children, but IgAN (24.6%) in adults aged 16–60 years and MGN (16.8%) among the elderly. IgAN (21.3%) and FSGS (8.3%) were the most common diagnoses among patients with mild renal insufficiency, but TIN (11.6%) and NV (11.3%) were the most common in more advanced renal insufficiency. Since 1999, diabetic patients represented 12.2% of adults, with mean proteinuria 8.9 g/24 h; diabetic glomerulosclerosis was found in 42.4% (with microhaematuria present in 66%) and non-diabetic renal diseases in 47.5% (IgAN in 17.5%, MGN and NAS in 11.1% and NV in 9.5%). The mean annual incidence (per million population) was: primary GN 32.4, secondary GN 13.8, IgAN 11.2, MCD 4.0, MesGN 3.7, FSGS 3.5, SLE 3.2, MGN 3.0, TBM 2.7, TIN 2.4 and NV 2.1. Ultrasound needle guidance was used in 56%, preferably in children (79%). The frequency of serious complications (gross haematuria, symptomatic haematoma, blood transfusion) remained at 3%. Conclusion. The CRRB provides important data on the epidemiology of GN based on a whole country population.
•The gelatin-stabilized polyaniline colloids with or without silver have been prepared.•Polyaniline colloids having spindle-like morphology and the particle size smaller than 200nm.•The similar ...oxidation of aniline with silver nitrate leads to hybrid composite with more complex morphology.•Synthetized colloids were deposited using spiral bar coating and flexography printing technique.•The prepared layers possess high antibacterial activity.
The oxidation of aniline with ammonium peroxydisulfate in the presence of gelatin yields spindle-like colloidal polyaniline particles having the particle size smaller than 200nm. The similar oxidation of aniline with silver nitrate leads to hybrid composite polyaniline–silver nanoparticles with more complex morphology. The composites were characterized by transmission electron microscopy, dynamic light scattering and UV–vis spectroscopy. The cytoxicity of colloids has also been investigated. To test biointerface properties, the synthetized colloids were deposited to poly(ethylene terephthalate) foil using spiral bar coating and flexography printing technique. Prepared layers were tested for eukaryotic cell adhesion and proliferation, and antibacterial activity. The prepared surfaces do not only allow for eukaryotic cell adhesion and proliferation but also they possess significant antibacterial properties against Escherichia coli and Staphylococcus aureus, even without silver nanoparticles. This newly prepared surface has therefore high practical potential in variety of application in regenerative medicine or biosensing.
The sedimentation caused by the high density of suspended particles used in magnetorheological fluids is a significant obstacle for their wider application. In the present paper, core--shell ...structured carbonyl iron--polyaniline particles in silicone oil were used as a magnetorheological suspension with enhanced dispersion stability. Bare carbonyl iron particles were suspended in silicone oil to create model magnetorheological suspensions of different loading. For a magnetorheological suspension of polyaniline-coated particles the results show a decrease in the base viscosity. Moreover, the polyaniline coating has a negligible influence on the MR properties under an external magnetic field B. The change in the viscoelastic properties of magnetorheological suspensions in the small-strain oscillatory shear flow as a function of the strain amplitude, the frequency and the magnetic flux density was also investigated.
Electrospun membranes with an active response are playing an increasing role in tissue regeneration by improving the ability of the materials to mimic the cellular microenvironment during cell ...culture. In this context, this work reports on the development of poly(vinylidene fluoride) (PVDF) electrospun fibers coated with polyaniline (PANI) and with polypyrrole (PPy). Both PANI and PPy successfully coated the fibers, with the surface electrical conductivity of the coatings reaching values of σ = 1.19 S.m−1 for PVDF-PPy and σ = 3.84 × 10−3 S.m−1 for PVDF-PANI. Furthermore, the PVDF samples became hydrophilic upon their coating with either PANI or PPy, the fiber mats adsorbing the water drop after a few seconds. The coated samples remain biocompatible, resulting in a slight improvement in the metabolic activity of L929 fibroblasts.
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•Electroactive PVDF membranes coated with conductive polymers have been developed.•Polyaniline and polypyrrole have been used as conductive coatings.•The hybrid polymers are hydrophilic and biocompatible.•The hybrid membranes are suitable for advanced tissue regeneration strategies.
Virtual reality (VR) has been on the scene for several decades already. Its first applications were in gaming. However, hardware and software were expensive and thus not for everybody. Since that ...time, the development of technology proceeded fast and enabled to open new application areas for VR. Currently many commercial systems are available for gaming, training and education, simulations, design, and also for medical purposes. In the article we focus on VR applications in healthcare. First we present existing commercial solutions, and research studies showing the potential of VR in healthcare. In recent years there have appeared many interesting projects and applications aimed at ageing population as target users. We present examples of such projects. Based on our previous experience and after analysis of available solutions, we propose a conceptual architecture od software environment for development of such applications and discuss their potential use. Finally, the implementation of the proposed architecture for interactive application of experience sets is described.
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•Transesterification of triacetin and castor oil with methanol.•Esterification of ricinoleic acid with methanol.•Carbon and silica supported organo-sulfonic acids-polyaniline ...catalysts.•A role of the type of support and organo-sulfonic acid.
Polyaniline doped with methanosulfonic (MSA) or camphorosulfonic (CSA) acid was deposited on silica and carbon support during polymerization of appropriate aniline salt carried out in the presence of immersed carriers. The activity of obtained catalysts was examined in the transesterification of triglycerides (triacetin and castor oil) and esterification of ricinoleic acid with methanol. The textural (specific surface area, porosity, pore diameter), morphological and acid (concentration and strength of acid centers) properties of catalysts were studied by number of techniques. The activity of acid sites in the silica and carbon supported MSA- and CSA-polyaniline catalysts was observed to be distinctly higher than activity of their counterparts with alkyl-free sulfuric acid-polyaniline coatings. A role of the type of support (carbon, silica), textural characteristics (porous structure), morphology of the polymer coating and the type of organo-sulfonic acid was studied. An enhancement in catalytic performance (higher activity, lower active sites blockage) due to organic group in close proximity to the SO3H sites varied depending on the type of reaction, being the highest in reactions with bulky reactants such as triglycerides from castor oil and ricinoleic acid. Among all catalysts, silica coated with methanosulfonic acid-polyaniline (SiO2-pani-MSA) exhibits the best catalytic performance in all tested reactions.
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