Solid inclusion complexes of vanillin with cyclodextrins: their formation, characterization, and high-temperature stability

This study reports the formation of solid vanillin/cyclodextrin inclusion complexes (vanillin/CD ICs) with the aim to enhance the thermal stability and sustained release of vanillin by inclusion complexation. The solid vanillin/CD ICs with three types of CDs (α-CD, β-CD, and γ-CD) were prepared using the freeze-drying method; in addition, a coprecipitation method was also used in the case of γ-CD. The presence of vanillin in CD ICs was confirmed by FTIR and (1)H NMR studies. Moreover, (1)H NMR study elucidated that the complexation stoichiometry for both vanillin/β-CD IC and vanillin/γ-CD IC was a 1:1 molar ratio, whereas it was 0.625:1 for vanillin/α-CD IC. XRD studies have shown channel-type arrangement for CD molecules, and no diffraction peak for free vanillin was observed for vanillin/β-CD IC and vanillin/γ-CD IC, indicating that complete inclusion complexation was successfully achieved for these CD ICs. In the case of vanillin/α-CD IC, the sample was mostly amorphous and some uncomplexed vanillin was present, suggesting that α-CD was not very effective for complexation with vanillin compared to β-CD and γ-CD. Furthermore, DSC studies for vanillin/β-CD IC and vanillin/γ-CD IC have shown no melting point for vanillin, elucidating the true complex formation, whereas a melting point for vanillin was recorded for vanillin/α-CD IC, confirming the presence of some uncomplexed vanillin in this sample. TGA thermograms indicated that thermal evaporation/degradation of vanillin occurred over a much higher temperature range (150-300 °C) for vanillin/CD ICs samples when compared to pure vanillin (80-200 °C) or vanillin/CD physical mixtures, signifying that the thermal stability of vanillin was increased due to the inclusion complexation with CDs. Moreover, headspace GC-MS analyses indicated that the release of vanillin was sustained at higher temperatures in the case of vanillin/CD ICs due to the inclusion complexation when compared to vanillin/CD physical mixtures. The amount of vanillin released with increasing temperature was lowest for vanillin/γ-CD IC and highest for vanillin/α-CD IC, suggesting that the strength of interaction between vanillin and the CD cavity was in the order γ-CD > β-CD > α-CD for solid vanillin/CD ICs.     

Dietary Supplementation of Brown Seaweed and/or Nucleotides Improved Shrimp Performance,Health Status and Cold-Tolerant Gene Expression of Juvenile Whiteleg Shrimp during the Winter Season

This study was aimed to evaluate the efficiency of Sargassum polycystum and nucleotides- supplemented diets to improve immune response and cold-tolerance of juvenile Litopenaeus vannamei. Four treatments were evaluated: T1, the control, shrimp received only a basal diet; T2, a basal diet with 500 ppm nucleotides; T3, a basal diet with 500 ppm S. polycystum powdered; T4, a basal diet with 500 ppm nucleotides and 500 ppm S. polycystum powdered. Shrimp were fed experimental diets for 56 days. Results revealed shrimp fed T4 diet exhibited the best significant improvement in water quality, survival, growth, and feed utilization indices followed by T2, and T3, while T1 showed the worst values. Additionally, nonspecific immune responses (phagocytosis (%), lysozyme, phenoloxidase, super oxide dismutase (SOD) activity, total nitric oxide) were improved with 1.7–3.2-fold in T4 higher than T1. Histomorphology of hepatopancreas in T4 showed the most increased activation of the hepatic glandular duct system compared with the other treatments. Moreover, nucleotides/seaweed-supplemented diets upregulated relative expression of cMnSOD, Penaeidin4, and heat shock protein70 (HSP70) genes, while translationally controlled tumor protein (TCTP) was downregulated. In conclusion, the synergistic effects of both S. polycystum and nucleotides have many advantages as a growth promoter, immunostimulant, antimicrobial, and cold-tolerant stimulant to L. vannamei.     

Functionalization of the aquatic weed water hyacinth <Emphasis Type="Italic">Eichhornia crassipes</Emphasis> by using zinc oxide nanoparticles for removal of organic dyes effluent

In this study, purified Eichhornia crassipes dead biomass, coated biomass with ZnO nanoparticles (NPs) and one coated with both ZnO NPs and polyethylenimine (PEI) were successfully fabricated as a bioadsorbent and biodegradent of organic dyes from the textile dye effluent. These ZnO NPs are capable of enhancing the dispersability and adsorption capacity of PEI and the anionic dyes. The surface analyses of Eichhornia crassipes, Eichhornia crassipes/ZnO NPs and Eichhornia crassipes/ZnO NPs/ PEI were characterized by SEM, specific surface area and micropore volume. The effect of three parameters including Eichhornia crassipes concentration, dye concentration and contact time on the color removal percent and degradation percent were evaluated. The results showed that the bleached Eichhornia crassipes was an efficient adsorbent for cationic dyes. Also, the effectiveness of Eichhornia crassipes/ZnO NPs was employed as photocatalytic agent for the degradation of C.I. Direct Red 23 in the presence and absence of UV irradiation. Moreover, Eichhornia crassipes/ZnO NPs/PEI shows a high adsorption capacity toward the anionic dyes C.I. Acid Red 40 and C.I. Reactive Orange 91. It was found that, Eichhornia crassipes/ZnO NPs was completely degraded C.I. Direct Red 23 by >90 % within 90 min of UV irradiation time, whereas in the absence of UV irradiation it required a substantially longer time (120 min) to achieve a similar degradation percent. In addition, Eichhornia crassipes/ZnO NPs/PEI was most effective and show the maximum adsorption capacity for C.I. Reactive Orange 91 and C.I. Acid Red 40 and its efficiency for the color removal percent was 100 % for C.I. Reactive Orange 91 and 95 % for C.I. Acid Red 40 in less than 60 min processing time.     

Histological and histochemical studies on the oviduct microcirculation of the laying Japanese quail (Coturnix japonica)

The health of oviduct circulation is very important for normal egg production. The present work describes the histology and histochemistry of vessels of different types on the oviduct of quail. Arteria, venae and lymphatics of the oviduct were described clearly. In addition, special vascular elements were observed presenting circular, longitudinal and oblique smooth muscle fibres on the blood vessel wall. Glomus cells were observed at typical glomus vessels, atypical glomus vessels and on the wall of some of arteria and arteriolae. Also, spirally oriented blood vessels were observed. Dark brown pigment was detected in the wall of arteria, venae, lymphatics and the special types of blood vessels.     

Polypyrrole/polyacrylonitrile composite films: Dielectric, spectrophotometric and morphologic characterization

Spectrophotometric, morphologic and dielectric properties of polyacrylonitrile (PAN) composite films in the presence of pyrrole derivatives were reported in this paper. The composite films were fabricated by oxidative polymerization of pyrrole (Py), N-methyl pyrrole (NMPy) and N-phenyl pyrrole (NPhPy) by cerium(IV) on polyacrylonitrile matrix. The effect of temperature on the dielectric properties was studied in the frequency range from 0.05 Hz up to 10 MHz and in the temperature range from 0 °C up to 250 °C. Conductivity was increased with temperature due to increase of the mobility of charge carriers in the composite films. By increasing the temperature, the dipoles become free and respond to the applied electric field in composite structure; thus, the polarization and dielectric constant increases. PNPhPy-PAN composite films exhibited the highest dielectric constant, AC conductivity and tan delta.     

Genotoxic impact of cadmium on root meristem of <Emphasis Type="Italic">Vicia faba</Emphasis> L.

Genotoxic studies with reference to pollution biomonitoring is a recent approach and can be used for maintenance of crop productivity. Effect of the cadmium chloride in the pure germ line of broad bean (Vicia faba L.) were evaluated in relation to the chromosomal abnormalities and rate of cell division. Seeds grown in the nutrient medium for 48 hrs containing different concentrations of cadmium chloride (control, 0.05 mM, 0.1 mM, 0.2 mM, 0.4 mM and 0.8 mM) showed different genotoxic effects such as polyploidy, multipolarity, chromosomal bridge with fragments, lagging chromosome and micronuclei. Relative division rate (RDR) was decreased with increasing cadmium concentration while relative abnormality rate (RAR) increased suggesting that cadmium may cause genetic changes in pure germ line and produce irrepairable damage in root meristem. Therefore, combining plant bioassays and root analysis of Cd⁺⁺ content would allow us to define phytotoxicity thresholds in plants.     

Toxicity, inheritance of fenpyroximate resistance, and detoxification-enzyme levels in a laboratory-selected fenpyroximate-resistant strain of Tetranychus urticae Koch (Acari: Tetranychidae)

A strain (BEYO 2) of Tetranychus urticae was selected with fenpyroximate for 14 selections. The resulting strain (named FPY 14) became resistant to fenpyroximate. The present study examines the inheritance of fenpyroximate resistance, the toxicity of some insecticides and acaricides, detoxification enzymes [esterase, glutathione S-transferase (GST), and monooxygenase (P450)], and the synergistic ratios of certain synergists [piperonyl butoxide (PBO), S-benzyl-O,O-diisopropyl phosphorothioate (IBP), and triphenyl phosphate (TPP)] in the FPY 14 strain of T. urticae. A spray tower-Petri dish method was used in the selection and toxicity studies. The level of fenpyroximate resistance was 64.43-fold higher in the FPY 14 strain and 1.06-fold higher in the BEYO 2 strain compared to the GSS (German susceptible strain) strain. The FPY 14 strain was 7.80-, 6.90-, 6.43-, 4.78- and 2.78-fold more resistant to abamectin, chlorpyrifos, propargite, clofentezine and amitraz, respectively. Fenpyroximate resistance is inherited as an incompletely dominant trait with no sex linkage. None of the synergists showed a significant synergistic effect. In the FPY 14 strain, the activities of esterase, GST and P450 enzymes were 1.92-, 1.06- and 3.96-fold higher, respectively, when compared to the susceptible GSS strain. The P450 and esterase enzymes might play a role in the mechanism of resistance to fenpyroximate.     

Risky Behaviors: Effects of Toxorhynchites splendens (Diptera: Culicidae) Predator on the Behavior of Three Mosquito Species

Viable biocontrol agents for mosquito control are quite rare, therefore improving the efficacy of existing biological agents is an important study. We need to have a better understanding of the predation-risk behavioral responses toward prey. This research examined prey choices by Toxorhynchites splendens by monitoring the behavioral responses of Aedes aegypti, Aedes albopictus, and Anopheles sinensis larvae when exposed to the predator. The results show that Tx. splendens prefers to consume Ae. aegypti larvae. The larvae exhibited different behavioral responses when Tx. splendens was present which suggest vulnerability in the presence of predators. “Thrashing” and “browsing” activities were greater in Ae. aegypti larvae. Such active and risky movements could cause vulnerability for the Ae. aegypti larvae due to increasing of water disturbance. In contrast, Ae. albopictus and An. sinensis larvae exhibited passive, low-risk behaviors, spending most of the time on the “wall” position near the edges of the container. We postulated that Ae. aegypti has less ability to perceive cues from predation and could not successfully alter its behavior to reduce risk of predation risk compared with Ae. albopictus and An. sinensis. Our results suggest that Tx. splendens is a suitable biocontrol agent in controlling dengue hemorrhagic vector, Ae. aegypti.     

Genetic mapping and inheritance of Russian wheat aphid resistance gene in accession IG 100695

The Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is an important pest of small‐grain cereals, particularly wheat, worldwide. The most efficient strategy against the RWA is to identify sources of resistance and to introduce them into susceptible wheat genotypes. This study was conducted to determine the mode of inheritance of the RWA resistance found in ICARDA accession IG 100695, to identify wheat microsatellite markers closely linked to the gene and to map the chromosomal location of the gene. Simple sequence repeat (SSR) marker scores were identified in a mapping population of 190 F₂ individuals and compared, while phenotypic screening for resistance was performed in F_2 : 3 families derived from a cross between ‘Basribey’ (susceptible) and IG 100695 (resistant). Phenotypic segregation of leaf chlorosis and rolling displayed the effect of a single dominant gene, temporarily denoted Dn100695, in IG 100695. Dn100695 was mapped on the short arm of chromosome 7D with four linked SSR markers, Xgwm44, Xcfd14, Xcfd46 and Xbarc126. Dn100695 and linked SSR markers may be useful for improving resistance for RWA in wheat breeding.