Influence of Sulfonation of Inert Macroporous and Macronet Resins on the SO<Subscript>2</Subscript> Adsorption Capacity

The influence of sulfonation of both macroporous and hyper-cross-linked polystyrenic polymers on their adsorption capacity for SO₂ removal from residual gases was studied through equilibrium experiments and microstructural analysis. The results showed that the insertion of functional sulfonic active groups leads to a decrease of adsorption capacity of macroporous and macronet resins mainly due to decreasing of specific surface area of the resins. The results were compared with those obtained for powdered activated carbon, which has an adsorption capacity higher compared with that of macroporous resins and lower than those of macronet resins. The high adsorption capacity of macronet resins has been attributed to the advanced cross-linking of the polystyrene chains that leads to the formation of a three-dimensional network with a high specific surface area. The fitting of the experimental data on the typical adsorption isotherms (Langmuir and Freundlich) highlighted the surface heterogeneity of macroporous and macronet resins.     

Toxoplasma gondii in Romanian household cats: evaluation of serological tests, epidemiology and risk factors

Felines are the key species in the epidemiology of Toxoplasma gondii infection, as they are the definitive host of the parasite and are the only species that can shed resistant oocysts in the environment. Different assays are in use for the detection of antibodies against T. gondii in cats. However, assay validation studies are limited. For that reason it was our aim to first evaluate 6 serological tests (one commercial and 2 in-house ELISAs, ImmunoComb, IFAT and MAT) for antibodies (IgG) against T. gondii in cats by Bayesian modeling. Factors associated with seropositivity were evaluated by bivariable and multivariable methods. The test evaluation indicated the commercial ELISA had the highest Youden Index. The estimated sensitivity ranged between 95.7% and 97.1% and the specificity between 97.3% and 97.6%. Using this commercial ELISA 111 out of 236 cats (47%) were positive for T. gondii antibodies. Two peaks in the percentage of strong positive samples (S/P≥200) were observed, around 10-months-old and 8-years-old. In bivariable analysis the seroprevalence was significantly higher in adult cats, cats with mixed diet, with outdoor access, in cats from a rural area and in cats from centre and north-western Romania. Adult age (adults: OR 6.98; 95% CI: 2.02-24.14 and geriatrics (cats older than 10-years): OR 12.01; 95% CI: 1.60-90.15) and outdoor access (OR 6.38; 95% CI: 2.32-17.53) remained significant risk factors in the multivariable logistic regression analysis. Our results suggest that T. gondii infection is common in household cats in Romania, and especially in those with outdoor access.     

Mercerization mediated modification of cellulosic fibers with NIPAAm and some compounds with antioxidant activity

A two step process was used for the modification of a cellulose/chitin mixed fibers: the first step was an alkali treatment with a NaOH solution (20 %), which was followed by the reaction with one of the reagents such as Nisopropylacrylamide, p-hydroxybenzoic acid, gallic acid, or eugenol. Both the samples activated with the alkali treatment and modified with chemicals were characterized by attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and thermal analysis. Results revealed the morphological and structural changes of the fiber surface after the surface grafting, which significantly altered the cellulose/chitin mixed fiber properties. Thermal analysis results showed an increase in the thermal stability of the treated samples. Antioxidant activity of cellulose/chitin mixed fibers modified with phenolic compounds showed that the efficiency depends on the chemical nature of phenolic compound.     

Development of Biocomposite Alginate-Cuttlebone-Gelatin 3D Printing Inks Designed for Scaffolds with Bone Regeneration Potential

Fabrication of three-dimensional (3D) scaffolds using natural biomaterials introduces valuable opportunities in bone tissue reconstruction and regeneration. The current study aimed at the development of paste-like 3D printing inks with an extracellular matrix-inspired formulation based on marine materials: sodium alginate (SA), cuttlebone (CB), and fish gelatin (FG). Macroporous scaffolds with microporous biocomposite filaments were obtained by 3D printing combined with post-printing crosslinking. CB fragments were used for their potential to stimulate biomineralization. Alginate enhanced CB embedding within the polymer matrix as confirmed by scanning electron microscopy (ESEM) and micro-computer tomography (micro-CT) and improved the deformation under controlled compression as revealed by micro-CT. SA addition resulted in a modulation of the bulk and surface mechanical behavior, and lead to more elongated cell morphology as imaged by confocal microscopy and ESEM after the adhesion of MC3T3-E1 preosteoblasts at 48 h. Formation of a new mineral phase was detected on the scaffold’s surface after cell cultures. All the results were correlated with the scaffolds’ compositions. Overall, the study reveals the potential of the marine materials-containing inks to deliver 3D scaffolds with potential for bone regeneration applications.     

Prevalence and risk factors of Giardia duodenalis in dogs from Romania

The protozoan Giardia duodenalis is a mammalian-infecting parasite that produces diarrhoea and malabsorption in its hosts. A survey to investigate canine infections with G. duodenalis in Romania was undertaken between June 2008 and December 2009. The objectives of the study were to (i) estimate the prevalence of infection in different dog populations (kennels, shelters, shepherd, household) using microscopy and a commercially available enzyme-linked immunosorbent assay (ELISA) test kit; (ii) to establish the level of agreement and characteristics of the tests; and (iii) to identify risk factors for infection by multivariate logistic regression models. Faecal samples were collected from 614 dogs aged from 1 month to 16 years (mean ± SD=2.88 ± 2.86 years). Each sample was tested for the presence of cysts using a flotation method with saturated sodium chloride solution and 416 out of 614 stool samples were further examined for the presence of G. duodenalis specific antigens using Giardia Microwell ELISA (SafePath? Laboratories). Giardia cysts were identified in 8.5% of total dogs (52/614) and statistical significantly more frequently in dogs living in communities. The cysts prevalence according with dog populations was as follows: 7.2%(9/125) in kennel dogs; 16.5%(27/164 in shelter dogs; 4.3%(2/46) in shepherd dogs; 4.8%(4/84) in household dogs from urban areas; and 5.1%(10/195) in household dogs from rural areas. The overall prevalence of Giardia infection by ELISA was 34.6% (144/416). The prevalence was significantly higher in kennel dogs (50%; 13/26), shelter dogs (47.7%; 74/155) and shepherd dogs (40.5%; 17/42) than in household dogs from urban areas (34.1%; 15/44) and household dogs from rural areas (16.8%; 25/149). It was noticed poor agreement between microscopy and ELISA (k=0.19). The microscopy performed best, with an Youden Index of 0.74, a Se of 73.68% and a Sp of 100%. ELISA had 100% Sp, but only 19.44% Se. Young dogs (up to 12 months age) and living in communities were identified as risk factors for infection by multivariate logistic regression analysis. 71.2% (37/52) Giardia cysts positive dogs presented co-infections with other intestinal parasites: Toxocara canis (14/52; 26.9%), Isospora ohioensis (12/52; 23.1%), Ancylostoma caninum (9/52; 17.3%), Uncinaria stenocephala (7/52; 13.5%), Trichocephalus vulpis (6/52; 11.5%), Hammondia heydorni/Neospora caninum (5/52; 9.6%), Sarcocystis spp. (5/52; 9.6%), Isospora canis (4/52; 7.7%), Capillaria aerophila (3/52; 5.8%), Strongyloides stercoralis (2/52; 93.8%), Dipylidium caninum (1/52; 1.9%) and Toxascaris leonina (1/52; 1.9%).     

Translocation and accumulation of heavy metals in Ocimum basilicum L. plants grown in a mining-contaminated soil

Purpose

The evaluation of the ecotoxicity effects of some heavy metals on the plant growth and metal accumulation in Ocimum basilicum L. cultivated on unpolluted and polluted soils represented the objective of the present study.

Materials and methods

The basil aromatic herb was evaluated in a laboratory experiment using soil contaminated with Cd, Co, Cr, Cu, Ni, Pb, and Zn, similar to the one from a mining area. The soils and different organs of the basil plants were analyzed, the total contents of the added elements being determined using inductively coupled plasma optical emission spectrometry. The ability of basil plants to accumulate metals from soil and to translocate them in their organs was evaluated by transfer coefficient, translocation factor, enrichment factor, and geo-accumulation index determinations.

Results and discussion

The basil plants grown in the metal-polluted soil showed stimulation effects comparing with the plants from the control soil. At the end of the exposure period, the plants had a visible increase of biomass and presented inflorescences and the leaves’ green pigment was intensified. The metals gathered differently in plant organs: Cd, Co, Cr, and Pb were accumulated in roots, while Cu, Ni, and Zn in flowers. Cr and Pb exceeded the toxic levels in roots. Also, the heavy metal intake depends on the plant development stages; thus, Cd, Cr, and Pb were accumulated more in mature plant leaves. The Cd and Pb contents were higher than the World Health Organization and European Commission permissible limits.

Conclusions

The experimental results revealed that the basil plants exposed to a mixture of heavy metals have the potential to reduce the metal mobility from soil to plants. Translocation process from roots to flowers and to leaves was observed for Cu, Ni, and Zn, emphasizing a competition between metals. The calculated bioaccumulation factors were insignificant, but Cd and Pb concentrations exceeded the legal limits in the mature plants, being restricted for human or animal consumption.

     

Retrospective evaluation of notched and fragmented QRS complex in dogs with naturally occurring myxomatous mitral valve disease

Myxomatous mitral valve disease (MMVD) is the most common cardiac disease in dogs. The association of QRS notching (nQRS) or fragmentation (fQRS) with disease severity is currently unknown. The study objective was to assess the prevalence of nQRS and fQRS in dogs with MMVD and its severity according to ACVIM classification and to compare the results with a group of healthy dogs. This retrospective cross-sectional study included 34 healthy control dogs and 155 dogs with spontaneous MMVD (42% of dogs in class B1, 23% in class B2 and 35% in class C). fQRS was defined as nQRS complexes in two contiguous leads in the frontal plane (leads I and aVL) and (II, III or aVF). A one-way ANOVA with Bonferroni post-hoc test was used to assess the differences in continuous data between control and MMVD groups. Of the MMVD group, 58% showed nQRS in at least one lead and 27% presented fQRS. There was no difference between the number of leads with a nQRS and disease severity (p = 0.75) nor did the number of leads with a nQRS correlate with left atrial size (r = 0.48; p = 0.5). The number of dogs with fQRS did not differ among classes of MMVD (p = 0.21). nQRS and fQRS were more prevalent in dogs with MMVD compared to control dogs (p < 0.01). This study did not identify any relationship between the number of leads with a nQRS and disease severity. However, dogs with MMVD had a higher prevalence of nQRS and fQRS compared to control group.