Fabrication of silver nanoparticle/polyvinyl alcohol/polycaprolactone hybrid nanofibers nonwovens by two-nozzle electrospinning for wound dressing

In this study, two biodegradable polymers, polycaprolactone (PCL) and polyvinyl alcohol (PVA) were used to fabricate nanofiber nonwovens (NFNs). Also, the silver nanoparticles (AgNPs) successfully reduced by using tea polyphenols (TP) and incorporated in the NFNs via electrospinning. The morphologies of the NFNs and AgNPs were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), respectively. The PCL nanofibers and PVA nanofibers interweaved each other, and AgNPs with average diameter 1.53±0.15 nm were embedded in the PVA nanofibers. The properties of electrospun NFNs were characterized by pore property, swelling/weight loss, water contact angle, mechanical property, and antibacterial activity. The nanofibers cross-linked to each other forming the 3Dnetwork porous structure with diameter about 1-1.5 μm. Although the hydrophobic PCL was added in the hybrid NFNs, the NFNs still showed hydrophilic propriety, high swelling degree (i.e. swelling degree is 330 % for 48 h), and low weight loss (i.e. weight loss is 22.4 % for 48 h). Also, the hybrid PCL/PVA/AgNPs NFNs exhibited a suitable mechanical property for wound dressings (i.e. tensile strength is 4.27 MPa, and breaking elongation is 88 %). Moreover, the hybrid NFNs effectively inhibited growth of Escherichia coli and Staphylococcus aureus. In summary, this PCL/PVA/AgNPs NFNs may provide a promising candidate for accelerating wound healing.     

Preparation and characterization of electrospun polyvinyl alcoholstyrylpyridinium/<Emphasis Type="Italic">β</Emphasis>-cyclodextrin composite nanofibers: Release behavior and potential use for wound dressing

Biocompatible polyvinyl alcohol (PVA)-styrylpyridinium (SbQ)/β-cyclodextrin (β-CD) composite nanofibers were obtained by electrospinning in this study. PVA-SbQ was used as the foundation polymer as well as crosslinking agent, β-CD was incorporated to achieve expected properties such as improved mechanical properties and thermal stability. The Fourier transform infrared spectroscopy (FTIR) spectra confirmed the existence of β-CD, and the morphologies and average fiber diameters of the electrospun composite nanofibers were also analyzed by SEM. X-ray diffraction patterns (XRD) of PVA-SbQ/β-CD composite nanofibers revealed that the inclusion of β-CD in the nanofibers affected the ordered phase of PVA. Besides, the thermal analyses revealed the improvement in the thermal properties for PVA-SbQ/β-CD composite nanofibers. It was found that the crosslinked composite nanofibers showed a clear higher tensile strength (TS) as well as a greater elongation at break (EB). Eventually, antifungal drug griseofulvin (GSV) has been loaded into the composite nanofibers by formation of its inclusion complex with β-CD in aqueous solution, ultraviolet light (UV-Vis) spectral analysis showed that the drug-loading nanofibers had certain sustained release effect.     

Antimicrobial and cellular activity of poly(L-lactide)/chitosan/Imipenem antibiotic composite nanofibers

Synthesis of biocompatible polymer nanofibers is valuable, due to their use as a cover for burns and as a replacement for bandage because of their antimicrobial properties. In this study, electrospinning of chitosan(Ch) and nanofibers synthesis with antibacterial properties was investigated. Nanofibers with antibacterial properties were synthesized by electrospun of Ch/poly(L-lactide)(PLA)/Imipenem(Imi) polymer solution. The results showed that the optimized ratio of Ch/PLA polymer solution was ratio of 50:50 and Ch 2 wt% and PLA 10 wt% polymer solution was the best weight percentage for nanofiber preparation. Also, the average diameter of Ch/PLA/Imi nanofibers was 143 nm and measured with ImageJ software. Afterwards, the antibacterial properties of Imi as additives (with different percentages) was studied in the polymer solution. The scanning electron microscopy (SEM) images and antibacterial tests were showed that the electrospun of Ch/PLA/Imi polymeric nanofibers were effective against Gram negative bacteria Escherichia coli (E. coli) and inhibited growth of E. coli. The growth and viability percentage of fibroblast cells with nanofibers in αMEM culture are at desirable levels after 6 days.     

Coating of PET Textiles with Anionic Cyclodextrin Polymer for Paraquat Removal from Aqueous Solution

Polyethylene terephthalate (PET) textile was coated with anionic cyclodextrin polymer issued by crosslinking between β-CD (β-Cyclodextrin) and BTCA (1,2,3,4-butanetetracarboxylic acid) for paraquat (PQ) removal from aqueous solution. The polymer covering operated by the thermofixation method (170 ºC and 30 minutes) comprised 23.52 % of weight gain, which was related to 0.76 mmol/g of ionic exchange capacity. The functionalized textile was also characterized by FTIR, SEM and TGA. Adsorption experiment was performed employing different parameters such as the pH of the solution, adsorption time, the initial concentration of paraquat and the adsorption temperature. The suitable pH was equal to 8 and the equilibrium time was 420 minutes. At 30 ºC, the adsorption capacity of PQ was increased (5.0, 20.4, and 25.9 mg/g) when the initial concentration of paraquat was enhanced (10, 50, and 250 mg/l). Adsorption kinetics was appropriated to the pseudo-second-order model and adsorption isotherm was fitted to the Langmuir model. Thermodynamic parameters were studied at different temperatures (30, 40, and 50 ºC), in which the negative ΔH displayed an exothermic adsorption process, the negative ΔG showed a spontaneous adsorption process and the positive ΔS revealed an enhanced disorder. Eventually, the recyclability of the modified textile in methanol reached 85 % after four reusability cycles.     

Functional electrospun cellulosic nanofiber mats for antibacterial bandages

Functionalization of cellulosic nanofibers was established to develop antibacterial bandages. The functionalization was conducted through preparation of carboxymethyl cellulose (CMC) containing different metal nanoparticles (MNPs) such as copper nanoparticles (CuNPs), iron nanoparticles (FeNPs) and zinc nanoparticles (ZnNPs). Fourier Transform Infrared spectroscopy was used to characterize CMC containing MNPs and scanning electron microscopy coupled with high energy dispersive X-ray (SEM-EDX) to study the surface morphology of CMC with and without MNPs. Furthermore, back scattering electron detector was used to show the position of metal nanoparticles on the microcrystalline CMC. In addition, UV-visible spectroscopy was used to confirm MNPs formation. Nanofiber mats of CMC containing MNPs were synthesized using electrospinning technique. Surface morphology of electrospun CMC containing MNPs was characterized using SEM. The obtained data revealed that elctrospun CMC nanofibers containing MNPs were smooth and uniformly distributed without bead formation. The average fiber diameters were in the range of 150 to 200 nm and the presence of MNPs in the nanofiber did not affect the size of the electrospun nanofiber diameter. Transmission electron microscopy (TEM) images displayed that MNPs were existed inside and over the surface of the electrospun nanofibers without any agglomeration. The average particle diameters of MNPs were 29-39 nm for ZnNPs, 23-27 nm for CuNPs and 22-26 nm for FeNPs. Moreover, Water uptake of electrospun nanofiber mats and the release of MNPs from nanofibers were evaluated. Nevertheless, electrospun CMC nanofibers containing MNPs had an excellent antibacterial activity against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus.     

Facile fabrication of carbon nanotubes/polystyrene composite nanofibers for high-performance electromagnetic interference shielding

Polystyrene (PS) composites with nanofibrous structure consisting of multi-walled carbon nanotubes (MWCNTs) with 0-10 wt.% of nanofiller have been fabricated via electrospinning technique. The surface morphology and thermal properties of the composites were evaluated by scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The SEM analysis of the composite nanofibers samples revealed that the average diameter of the nanofibers increases with increasing MWCNTs content. The resultant MWCNTs/PS composite nanofibers diameters were in the range of 391±63 to 586±132 nm. The thermal stability of composites was increased after addition of MWCNTs to PS matrix. The electrical conductivity of the composites with different weight percentage of MWCNTs was investigated at room temperature. Electrical conductivity of MWCNTs/PS composite nanofiber followed percolation theory having a percolation threshold V _c= 0.45 vol% (~0.75 wt. %) and critical exponent q=1.21. The electrical conductivity and thermal properties confirmed the presence of good dispersion and alignment MWCNTs encapsulated within the electrospun nanofibers. The electromagnetic interference (EMI) shielding effectiveness of the MWCNTs/PS composites was examined in the measurement frequency range of 8.2-12.4 GHz (X-band). The total EMI shielding efficiency of MWCNTs/PS composite nanofibers increased up to 32 dB. The EMI shielding results for MWCNTs/PS composite nanofibers showed that absorption loss was the major shielding mechanism and reflection was the secondary mechanism. The present study has shown the possibility of utilizing MWCNTs/PS composite nanofibers as EMI shielding/absorption materials.     

Effective Management of the <Emphasis Type="Italic">Phthorimaea operculella</Emphasis> (Zeller) Using PVA Nanofibers Loaded with <Emphasis Type="Italic">Cinnamomum zeylanicum</Emphasis> Essential Oil

Phthorimaea operculella (Zeller) is one of the most common insect pests of cultivated potato in tropical and subtropical regions. In this research, a potential strategy to improve the insecticidal activity of plant essential oils for the effective management of P. operculella was studied. The insecticidal and residual effects of nanofiber oil (NFO) and pure essential oil (PEO) of Cinnamomum zeylanicum were assessed on PTM under laboratory conditions. The nanofibers were made by the electrospinning method using polyvinyl alcohol (PVA) polymer. The morphological characteristics of the nanofibers were evaluated by scanning electron microscopy and Fourier transform infrared spectroscopy. The chemical constituents of cinnamon essential oil (EO) were detected by GC/MS. Fumigant toxicity of NFO and PEO were evaluated on different growth stages (egg, male and female adults) of P. operculella. SEM and FTIR analyses confirmed the presence of EO on the nanofiber structure. The yield of the EO from C. zelanicum on the nanofibers was 1.86%. GC/MS analysis showed that cinnamaldehyde was the primary constituent (69.88%) of cinnamon EO. LC₅₀ values of C. zelanicum EO and NFO were 4.92 and 1.76 μl/l air for eggs, 0.444 and 0.212 μl/l air for female adults, and 0.424 and 0.192 μl/l air for male adults, respectively. Fumigant bioassays revealed that NFO was more toxic than C. zeylanicum oil against at all stages of P. operculella. The residual effect of PEO and NFO was evaluated against the egg stage of the P. operculella. NFO lost insecticidal effectiveness 47 days after application, while the efficacy of PEO decreased 15 days after application. Our results suggest that NFO of C. zeylanicum can be used as an effective new tool for the management of P. operculella.     

Investigation on the Biodegradability and Antibacterial Properties of Nanohybrid Suture Based on Silver Incorporated PGA-PLGA Nanofibers

Polyglycolic acid-poly lactic glycolic acid (PGA-PLGA) electrospun nanofibers containing silver nanoparticles have been produced and twisted into the nanofibrous yarn. The morphology of nanofibers and produced yarns, as well as the mechanical properties of the yarns, were investigated. Furthermore, in vitro antibacterial properties and in vitro degradation behavior of yarns containing various silver nanoparticles were studied. SEM images confirmed that the addition of the silver nanoparticles into the polymer solution increases the fiber diameters. The result of the mechanical test of the yarns alone and used in two different forms of the knots was measured and results showed that the strength of the yarns without the knot was significantly more than that of others. The biodegradability test showed that the mechanical properties and the weight of the yarns were quickly reduced after subjecting to in vitro condition. The result of the antibacterial test indicated that the nanofiber yarns containing %3 silver nanoparticles were the most appropriate sample with a considerably antibacterial activity against both gram-positive bacterium Staphylococcus aureus and gram-negative bacterium Escherichia Coli with inhibition zones of 8.1 and 9.5 mm, respectively; which demonstrated that silver nanoparticles retained their effectiveness after the electrospinning process. Therefore the nanofibrous yarns containing silver nanoparticles could be successfully produced by the electrospinning process with the proper antibacterial property as a candidate for the surgical sutures.     

Characterization of the surface properties of cellulosic fibers in fibrous and ground forms by IGC and contact angle measurements

Surface properties of fibrous and ground cotton and linen were investigated by inverse gas chromatography (IGC) and the contact angle with different liquids was also measured on fabrics composed of both fibers. Results proved that dispersion component of surface tension (γ _s ^d ) determined by IGC depends not only on the surface energy, but also on several factors influencing the adsorbability of probe molecules on the cellulosic substrates. For cotton samples, the trapping of n-alkanes among waxy molecules in the outer layer of fibers can be presumed. This effect results in larger γ _s ^d for cotton fibers than for linen in spite of the higher wettability of the linen fabrics. Besides the surface energy and trapping effects, the grinding also influences the γ _s ^d values. Specific enthalpy of adsorption (ΔH _A ^ab ) of polar probes could be determined on all linen samples, but only on the ground cotton sample. Lewis acid-base character calculated for linen and ground cotton samples depends on the same effects as the γ _s ^d does. The similar ΔH _A ^ab values of chloroform (acidic) and THF (basic) measured on each of the samples support the conclusion that the surface character is amphoteric, which is also proved by the high ΔH _A ^ab values of the amphoteric ethyl acetate and acetone probes.     

Role and effects of winter buds and rhizome morphology on the survival and growth of common reed (Phragmites australis)

To confirm the role of winter buds and rhizome morphology on the winter survival and subsequent growth of common reed (Phragmites australis), rhizome fragments of varying sizes with and without winter buds from three different P. australis populations were transplanted to small pots in a greenhouse and wintered by exposing them to a dry atmospheric condition. Survival ratios of the rhizome fragments with winter buds were much greater than those without winter buds regardless of population type, supporting that winter buds play a role as the insulator of rhizome fragments from dry atmosphere during winter season. Most growth characteristics of surviving P. australis from the rhizome fragments were similar to those in natural wetlands, indicating preserved growth characteristics through the rhizomes, which is an asexual organ. The average number of rhizome fragment nodes showed negative relationships with the number of blades per culm (P < .05) and basal culm diameter (P < .05) of surviving P. australis. In contrast, the diameter of planted rhizome fragments had significant positive relationships with the final shoot height (P < .05), above-ground dry weight (P < .05), root DW (P < .01), and total DW (P < .05). Rhizome volume also showed a similar correlation with the rhizome diameter. Thicker and larger rhizome fragments particularly with winter buds, indicating the young age of rhizome, seemed likely to guarantee greater survival and higher subsequent shoot growth and biomass production as well.     

<Emphasis Type="Italic">Limoniastrum monopetalum</Emphasis> stems as a new source of natural colorant for dyeing wool fabrics

In the present study, an attempt has been made to dye the wool fabric with Limoniastrum monopetalum stems, as a source of natural dye, which has not been exploited so far. Optimization of extraction parameters was done. Optimum results of extraction process were obtained with a dye concentration of 60 g/l, a temperature of 90 °C during 100 min. The study of different factors effecting dyeability of wool fabrics by aqueous L. monopetalum stems extract showed that the pH of dye bath and dyeing temperature and time affected considerably the color yield. The best results were obtained at the following conditions; pH 2, 100 °C, and 60 min. Metal mordants, when used in conjunction with L. monopetalum dye, allowed to obtain various shades. The determination of phenolic contents of aqueous L. monopetalum stems extract showed a high amount of phenolic components. Based on RP-HPLC, the coloring extract of L. monopetalum stems contains tannins and polyphenols. The major identified phenolic compounds were procatechuic, Trans-cinnamic and gallic acids. Hence, aqueous L. monopetalum stems extract could be successfully exploited for dyeing wool fabrics with high color yield (K/S).     

Encapsulation of Phytoncide in Nanofibers by Emulsion Electrospinning and their Antimicrobial Assessment

Phytoncides are volatile organic compounds released from trees and plants and are well known for their natural antibacterial activity. In this study, emulsion electrospinning was used to encapsulate phytoncide in the core of nanofibers, with the aim of developing environmentally friendly, functional nanofibers with a sustained release of the encapsulated component. Core/sheath structured phytoncide/poly(vinyl alcohol) nanofibers were successfully prepared by emulsion electrospinning using an ordinary single-nozzle electrospinning setup. An oil-in-water emulsion of an aqueous solution of poly(vinyl alcohol) (as the aqueous phase) and phytoncide (as the oil phase) was used to prepare the core/sheath structured nanofibers. Nanocomposite fibers were electrospun under various spinning conditions and emulsion formulations to find the suitable processing conditions for fabricating nanofibers with core/sheath structures. The resulting nanofibers exhibited a well-aligned core/sheath structure with fiber diameters of 250-350 nm. The release profile of phytoncide from the core of nanofibers over a 21 day period showed that phytoncide was released in a sustained manner over 14 days. The core/sheath structured phytoncide/poly(vinyl alcohol) nanofibers exhibited 99.9 % bacterial reduction against both Staphylococcus aureus and Escherichia coli, indicating that the encapsulated phytoncide in the fiber provided strong antimicrobial effects.     

Physico-chemical characteristics of a seed fiber arised from <Emphasis Type="Italic">Pergularia Tomentosa</Emphasis> L.

In the present paper, we analyze a seed fiber arising from Pergularia tomentosa L. (PTL). It was, primarily, characterized using different techniques. The morphology of the fibers was observed via Scanning Electron Microscopy (SEM). They are also checked in term of decomposition behavior through TGA/DTG instrument. The cristallinity index was determined using XRD and it was about 52 %. The chemical composition in terms of moisture percent, ash, waxes and fats, lignin, hemicellulose and cellulose were, respectively 8.5 %, 2.74 %, 1.88 %, 8.6 %, 16 % and 43.8 %. The contact angle value was measured and the evolution of drop profile was captured with video-camera using GBX Tensiometer Surfaces Sciences Studies. Further, fibers were dyed with Methylene Blue, Direct Red 79, Sumifix supra yellow 3RF and Reactive Blue 198. Color coordinates (ΔL*, Δa*, Δb*, ΔC* and ΔH*) of the samples were so measured. All obtained data were compared to cotton fibers and some other cellulosic fibers. The Results revealed that, based on such properties, PTLF could be a competitive fiber in many applications field (textile weaving, composites, etc).     

Electrospun grape seed polyphenols/gelatin composite fibers contained silver nanoparticles as biomaterials

GSP/gelatin composite nanofiber membranes containing silver nanoparticles were successfully fabricated as a novel biomaterial by electrospinning. The silver nanoparticles (AgNPs) were synthesized with the grape seed polyphenols (GSP) as reducing agent in aqueous solution of gelatin, and then the GSP/gelatin/AgNPs mixed solution was electrospun into nanofibers at 55 °C. The scanning electron microscopy (SEM) confirmed that the composite fibers were uniform and the average fiber diameter ranged between 150 nm and 230 nm with an increase in applied potentials from 14 kV to 22 kV. And the transmission electron microscopy (TEM) showed that silver nanoparticles distributed individually in the fibers with the average particle size of about 11 nm. Furthermore, the ultraviolet visible spectrophotometer (UV-vis spectroscopy) test demonstrated that all of Ag⁺ converted to Ag⁰ when the concentration of gelatin was 24 wt% and the mass ratio of GSP to AgNO₃ was about 5:2. The antibacterial activities of the fiber membranes against E.coli and S.aureus were measured via a shake flank test and demonstrated good performance after the importation of silver nanopaticles. Cytotoxicity testing also revealed that fiber membranes contained silver nanoparticles had no cyto-toxic. All the results indicated that the GSP was effective for the formation and stabilization of silver nanoparticles in composite nanofibers mats which had the potential for applications in antimicrobial tissue engineering and wound dressing.     

Study on oil adsorption/desorption kinetics and polymer network parameters of poly(lauryl methacrylate-<Emphasis Type="Italic">co</Emphasis>-hydroxyethyl methacrylate)

In the present work, oil adsorption, desorption, and resorption of poly(lauryl methacrylate-co-hydroxyethyl methacrylate) P(LMA-co-HEMA) were evaluated with different oils by a gravimetric method. Adsorption kinetics were modeled using pseudo-first-order and pseudo-second-order equations. Polymer network parameters of P(LMA-co-HEMA) regarding average molecular weight (Mc) between two crosslink piontss can be calculated by oil absorbency at equilibrium (Q _e ), the solubility parameter (δ) and polymer-solvent interaction parameter (χ) with Flory-Huggins relation. The results showed pseudo-second-order model has a better fit to the oil adsorption kinetic data The desorption can be analyzed by fitting a prediction of exponential-like decay to the deswelling curves. A typical oil desorption exhibited two stages: a burst release driven by concentration gradient, and a slow release controlled by diffusion and the elastic recovery of polymer networks. For reusability, the resorption behavior of P(LMA-co-HEMA) was also investigated. It was worth noting that oil resorption was faster than the first adsorption due to potential passages. Moreover, the adsorption capacity was not significantly changed after regeneration.     

Rooting Characteristics of <Emphasis Type="Italic">Solanum chacoense</Emphasis> and <Emphasis Type="Italic">Solanum tuberosum in Vitro</Emphasis>

The precise level of environmental control in vitro may aid in identifying genetically superior plant germplasm for rooting characteristics (RC) linked to increased foraging for plant nitrogen (N). The objectives of this research were to determine the phenotypic variation in root morphological responses of 49 Solanum chacoense (chc), 30 Solanum tuberosum Group Phureja – Solanum tuberosum Group Stenotomum (phu-stn), and three Solanum tuberosum (tbr) genotypes to 1.0 and 0.5 N rate in vitro for 28 d, and identify genotypes with superior RC. The 0.5 N significantly increased density of root length, surface area, and tips. All RC were significantly greater in chc than in either phu-stn or tbr. Based upon clustering on root length, surface area, and volume, the cluster with the greatest rooting values consisted of eight chc genotypes that may be utilized to initiate a breeding program to improve RC in potato.     

Fabrication of Polyether Sulfone Blend Imprinted Membranes for Selective Adsorption of <Emphasis Type="Italic">p</Emphasis>-hydroxybenzonic from Salicylic Acid

Highly selective polyether sulfone (PES) blend imprinted membranes for template p-hydroxybenzonic (p-HB) were synthesized by phase inversion imprinting technique using polybenzimidazoles (PBI) as a functional polymer and nanosized Al₂O₃ as the additives. The SEM analysis showed that cross-sectional morphology of membranes were strongly influenced by the content of nano-sized Al₂O₃. Compared with PES₁-MIM, PES₂-MIM and PES₄-MIM, the PES₃-MIM containing 2.0 wt.% nano-sized Al₂O₃ exhibited higher membrane flux, kinetic equilibrium adsorption value, binding capacity and better selectivity for p-HB. The experimental data of adsorption kinetic were well fitted to the pseudo-secondorder kinetic model using multiple regression analysis. Static adsorption isotherm experiments exhibited that the PES₃-MIM had the maximum adsorption capacity for p-HB. Moreover, selective experiment showed that the selectivity coefficients of PES₃-MIM for p-HB relative to salicylic acid (SA) was 3.670, showing that PES₃-MIM had excellent binding affinity and selectivity for separating p-HB form p-HB-contained aqueous solution.     

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.     

Movement patterns of three freshwater fish species after upstream transportation by fishway in the Jangheung Dam

We investigated the post-passage movement patterns of three freshwater fish species, Carassius auratus, Hemibarbus longirostris, and Silurus asotus, frequently captured in a fishway trap as they were released into the lentic dam reservoir. Acoustic telemetry was used to monitor fish movement. Acoustic tags were attached to 10 individuals (C. auratus, [n = 6], Ca1–6; H. longirostris, [n = 2], Hl1 and Hl2; and S. asotus, [n = 2], Sa1 and Sa2). The individual (Sa1) was particularly monitored to changes of vertical distribution between day and night a depth transmitter. The lentic species, C. auratus and S. asotus, were grouped into those that moved into upper streams (Ca1, Ca2, Ca3, and Sa1) and those that stayed in the reservoir (Ca4, Ca5, Ca6, and Sa2); all individuals utilized almost the entire area of the reservoir. However, H. longirostris, which favor lotic environments, showed different responses; one (Hl1) immediately moved into one of upper the streams, whereas the other (Hl2) utilized the entire dam reservoir area. No significant correlations were observed between size of the C. auratus individuals (total length and total weight) and monitored parameters (total movement distance, movement distance per day, and number of receivers encountered). Moreover, S. asotus used the water at a mean depth of 2.89 ± 1.52 m, and its vertical distribution changed more actively during the night than that during the day. Therefore, the efficacy of the Jangheung Dam fishway could be improved through release of the confluence of the inflow streams at the dam reservoir, which would provide both lentic and lotic environments without extended migration for fish.     

Agronomic fortification of rice grains with secondary and micronutrients under differing crop management and soil moisture regimes in the north Indian Plains

Although the System of Rice Intensification (SRI) has been reported to produce higher paddy (Oryza sativa L.) yields with better-quality grains, little research has addressed the latter claim. This study investigated the interactive effects of rice cultivation methods with different irrigation schedules and plant density on the uptake and concentration of sulfur (S), zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) in the grain and straw of two rice cultivars during two rainy seasons in the northern plains of India. As the two seasons differed in amounts of rainfall, there were impacts of soil moisture differences on nutrient uptake. Plots with SRI cultivation methods enhanced the grain uptake and concentrations of S, Zn, Fe, Mn and Cu by 36, 32, 28, 32 and 63%, respectively, compared to conventional transplanting (CT). Under SRI management, the highest concentrations of S, Zn and Cu in the grain and straw occurred with irrigation intervals scheduled at 3 days after disappearance of ponded water (DADPW; 3_D), whereas Fe and Mn concentrations in the grain and straw were higher with irrigation at 1 DADPW (1 _D ) compared with plots under 3 _D or 5 DADPW (5 _D ). The higher nutrient uptakes were also manifested in higher grain yield in 1 _D and 3 _D plots (by 9 and 6%, respectively) compared with 5 _D . Wider spacing (25 × 25 cm) compared with closer spacing (20 × 20 cm) significantly increased yield and the uptake and concentrations of all the said nutrients in the grains. When comparing the performance of two cultivars, the total uptakes of Zn, Fe, Mn and Cu in both grain and straw were significantly more in Hybrid 6444 than the improved variety Pant Dhan 4. Overall, SRI crop management compared to CT practices led to more biological fortification of rice grains with respect to S and the four micronutrients studied, giving a concomitant yield advantage of about 17% on average in this region.