Effect of chitosan and hydroxypropyl methylcellulose on size and antibacterial activity of copper nanoparticles

Background: Nanomaterials exhibit better antibacterial activity because of their distinct structural/ morphological characteristics. The particle size and shape of the nanomaterials are the two significant parameters which affect the resultant antibacterial property. Different biopolymers have been explored to prepare capped metal nanoparticles with controlled/desired particle size and morphology. Methods: The present research work explains the effect of chitosan (CH) and hydroxypropyl methylcellulose (HPMC) on the shape and size of the copper nanoparticles (Cu NPs) and their antibacterial activity. The CH-Cu and HPMC-Cu NPs were achieved by facile precipitation technique using ascorbic acid as a nucleating agent. Results: Instrumental analysis by fourier transform infrared spectroscopy, x-ray diffraction, field emission scanning electron microscopy-energy dispersive x-ray analysis and transmission electron microscope confirmed the successful synthesis of Cu NPs. Scanning and transmission electron microscopic studies revealed that the formed NPs have a spherical structure with different diameters of ~8 ± 2 nm for CH-Cu and ~38 ±2 nm for HPMC-Cu NPs. Crystalline size calculated using Debye–Scherrer equation from XRD results were also in good agreement with the above results. The developed materials CH-Cu NPs and HPMC-Cu demonstrated excellent antibacterial activity against both gram-positive and gram-negative bacteria. It was observed that the CH-Cu NPs showed a higher inhibition zone when compared to that of the HPMC-Cu NPs. Conclusions: The biopolymer capped Cu NPs of smaller particle size exhibit much better antibacterial activity and the particle size of the Cu NPs (nm) can be finetuned with the aid of selecting the most appropriate biopolymer

In vivo and In vitro studies of Bacillus megaterium var. phosphaticum on nutrient mobilization, antagonism and plant growth promoting traits

Nutrient solubilisation efficiency, plant growth promoting traits and antagonistic effects of Bacillus megaterium var. phosphaticum were studied in the laboratory and screen house during 2010-11 at Hyderabad, India. Plate agar assay indicated varied solubilisation level when the media was blended with zinc carbonate (35.6%), zinc oxide (31.1%), k-bentonite (23%), rock phosphate (19.8%), tricalcium phosphate (3.1%) and zinc sulphide (0.0%). The release of available zinc is high (17.4 ppm) on day-12 when the test organism was grown in liquid media blended with zinc carbonate. The media pH was inversely proportional to the amount of nutrients solubilised on day-12. B. megaterium var. phosphaticum is found to produce plant growth promoting substances like biofilm and chitinase enzymes (strong), giberrellic acids and siderophores (moderate) and indole acetic acid (weak). Confrontation assay confirmed it’s strong antagonistic activity against Rhizoctonia solani (41%), Macrophomina phaseolina (42%), Sclerotium rolfsii (27%) and Fusarium oxysporum (40%). The production of siderophores and chitinase enzymes justifies the strong antagonistic activity against these fungal pathogens. Potted plant assay using sunflower, Helianthus annuus as the test crop indicated superior plant growth and photosynthetic activities in treatment with B. megaterium var. phosphaticum + 75% of recommended chemical fertilizer dose as compared to treatment with 100% chemical fertilizers. It also improved significantly the uptake of nitrogen (7.97mg/100g dry mass), phosphate (3.41mg/100g dry mass), potash (38.12mg/100g dry mass), zinc (184mg/100g dry mass), iron (743mg/100g dry mass) and manganese (138mg/100g dry mass) as compared to treatments with 100% B. megaterium var. phosphaticum, 100% chemical fertilizers and untreated control. The findings of current study suggest reduction of 25% recommended dose of chemical fertilizers in combination with B. megaterium var. phosphaticum as seed dresser and soil application

Assessment of combining ability for yield and quality components in hot pepper (Capsicum annuum L.)

Six parental genotypes and their thirty F1 hybrids in a full diallel cross system with reciprocals, were used in the present study to estimate combining ability for five quantitative and five qualitative traits in hot pepper. The mean sum of squares due to general combining ability (GCA), specific combining ability (SCA) and reciprocal combining ability (RCA) were significant for all the characters which suggest that these parents could have performed differently in different combinations indicating interallelic interactions. All the traits studied exhibited greater SCA variance than GCA, suggesting that these traits are controlled by non-additive gene action. Analysis of the GCA effects of parents for various traits revealed that LCA625, K1 and PKM1 were the best general combiners for almost all the traits. Estimates of SCA effects showed that the hybrids LCA625 × K1, K1 × Arka LohitandPusa Jwala × PKM1were found to be the best combiners for yield and its attributes. The hybrid K1 × Arka Lohitwas the best reciprocal combiner for quality parameters based on its better mean performance and combining ability. These results suggest that commercial production of hot pepper hybrids and isolation of pure lines from these hybrids is a possible way to enhance the yield and fruit quality

Hidrogeles - Nanocompositos con actividad antimicrobiana

67 p.En este trabajo se sintetizaron nanopartículas de plata (AgNP) con actividad antimicrobiana por medio de síntesis verde, utilizando extracto de jengibre (Zingiber officinale) como agente reductor de las nanopartículas de plata provenientes de una solución de AgNO3 en presencia de polímeros hidrosolubles y biocompatibles. Los hidrogeles desarrollados estaban compuestos por polímeros naturales (Alginato de sodio) y sintéticos (acrilamida y acrilato de sodio) formando una red semi-interpenetrante de acrilamida y acrilato de sodio, este se sintetizó mediante copolimerización en plantilla en presencia de alginato de sodio como una matriz y N,N, metilen-bisacrilamida (MBA) como agente de reticulación. Finalmente, para llevar a cabo una reticulación química, se necesitó de un iniciador (persulfato de potasio) para formar enlaces covalentes en la estructura tridimensional del hidrogel. Las AgNP obtenidas se analizaron mediante espectroscopía UV-Vis y FTIR para determinar su formación. El estudio FTIR demostró que existían grupos funcionales hidroxilo en el extracto que reducían Ag+ a Ag0. La actividad antibacteriana de AgNP se investigó contra Bacillus cereus, Acinetobacter baumannii, Staphylococcus aureus y Salmonella typhimurium mediante el recuento bacteriano en placas de agar soya- tripticasa con el método de punto final. Las AgNP mostraron un efecto antimicrobiano con una inhibición sobre el 99% de todas las bacterias estudiadas. Los resultaron mostraron que el hidrogel con menor cantidad de alginato de sodio con respecto a acrilamida-acrilato de sodio tenía una mejor capacidad para suprimir el crecimiento bacteriano en comparación con su contraparte. Estos resultados sugieren que las AgNP podrían usarse como un material antibacteriano efectivo y como alternativa frente a la creciente resistencia antimicrobiana

Treatment guided by fractional exhaled nitric oxide in addition to standard care in 6- to 15-year-olds with asthma : the RAACENO RCT

Funding This project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a MRC and National Institute for Health and Care Research (NIHR) partnership. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 9, No. 4. See the NIHR Journals Library website for further project information.Peer reviewedPublisher PD

Are you a true worshipper? (Video)

https://place.asburyseminary.edu/ecommonsatschapelservices/8150/thumbnail.jp

Are you a true worshipper?

https://place.asburyseminary.edu/ecommonsatschapelservices/8151/thumbnail.jp

Corrosion inhibition by sodium potassium tartrate-Zn²⁺system for carbon steel in rainwater collected from roof top

382-388A synergistic effect exists between sodium potassium tartrate (SPT) and Zn²⁺ in controlling corrosion of carbon steel immersed in rain water collected from roof top and stored in concrete tank. The formulation consisting of 50 ppm of SPT and 25 ppm of Zn²⁺ has 91% corrosion inhibition efficiency (IE). As the immersion period increases IE decreases. Polarization study reveals that SPT-Zn²⁺ system functions as a mixed inhibitor. AC impedance spectra reveal that a protective film is formed on the metal surface. FTIR spectra indicate that the protective film consists of Fe²⁺-SPT complex and Zn(OH)₂. A formulation consisting of 50 ppm of SPT, 25 ppm of Zn²⁺ and 50 ppm of a biocide, N-cetyl-N,N,N-trimethyl ammonium bromide, has 98% corrosion inhibition efficiency and 100% biocidal efficiency

Biopolymer-Based Composite Hydrogels Embedding Small Silver Nanoparticles for Advanced Antimicrobial Applications: Experimental and Theoretical Insights

In this work, we report a two-step methodology for the synthesis of small silver nanoparticles embedded into hydrogels based on chitosan (CS) and hydroxypropyl methylcellulose (HPMC) biopolymers. This method uses d-glucose as an external green reducing agent and purified water as a solvent, leading to an eco-friendly, cost-effective, and biocompatible process for the synthesis of silver nanocomposite hydrogels. Their characterization comprises ultraviolet-visible spectroscopy, Fourier-transform infrared spectra, differential scanning calorimetry, scanning electron microscopy with energy-dispersive spectroscopy, and transmission electron microscopy assays. Moreover, the structural stability of the hydrogels was investigated through sequential swelling–deswelling cycles. The nanomaterials showed good mechanical properties in terms of their structural stability and revealed prominent antibacterial properties due to the reduced-size particles that promote their use as new advanced antimicrobial agents, an advantage compared to conventional particles in aqueous suspension that lose stability and effectiveness. Finally, theoretical analyses provided insights into the possible interactions, charge transfer, and stabilization process of nanoclusters mediated by the high-electron-density groups belonging to CS and HPMC, revealing their unique structural properties in the preparation of nano-scaled materials