Microbial-Physical Synthesis of Fe and Fe3O4 Magnetic Nanoparticles Using Aspergillus niger YESM1 and Supercritical Condition of Ethanol

Magnetic Fe and Fe3O4 (magnetite) nanoparticles are successfully synthesized using Aspergillus niger YESM 1 and supercritical condition of liquids. Aspergillus niger is used for decomposition of FeSO4 and FeCl3 to FeS and Fe2O3, respectively. The produced particles are exposed to supercritical condition of ethanol for 1 hour at 300∘ C and pressure of 850 psi. The phase structure and the morphology measurements yield pure iron and major Fe3O4 spherical nanoparticles with average size of 18 and 50 nm, respectively. The crystal size amounts to 9 nm for Fe and 8 nm for Fe3O4. The magnetic properties are measured to exhibit superparamagneticand ferromagnetic-like behaviors for Fe and Fe3O4 nanoparticles, respectively. The saturation magnetization amounts to 112 and 68 emu/g for Fe and Fe3O4, respectively. The obtained results open new route for using the biophysical method for large-scale production of highly magnetic nanoparticles to be used for biomedical applications

Phylogenetic Diversity and Antimicrobial Activities of Culturable Endophytic Actinobacteria Isolated from Different Egyptian Marine Sponges and Soft Corals

A cultivation-based approach was employed to isolate and compare the endophytic culturable actinobacterial diversity associated with different Egyptian marine sponges and soft corals. A total of 13 culturable actinobacteria isolates were obtained, five of which isolated from different sponges, two (AE27 and AE32) and three (AE29, AE41 and AE46) were isolated from Haliclona sp. and Callyspongia sp. collected from Sharm El-Sheikh and Hurghada, Egypt, respectively. Eight were isolated from different five soft corals, out of them two (AE2 and AE19), two (AE3 and AE15), two (AE20 and AE23), one (AE35) and one (AE13) were isolated from Rhytisma sp., Xenia sp., Lobularia sp., and Dendronephthya sinaiensis (collected from Sharm El-Sheikh, Egypt) and the Dendronephthya hemprichi (collected from Hurghada, Egypt), respectively. The 16S rRNA genes of the 13 actinobacteria isolates were amplified and sequenced (GenBank Accession numbers JF292923 – JF292930 and JF319146 – JF319150). A BLAST analysis revealed that the 13 actinobacteria isolates belonged to three known families and genera. Six strains isolated from all sponges and soft corals belonged to the genus Streptomyces (AE15, AE19, AE20 and AE35, isolated from soft corals; Xenia sp., Rhytisma sp., Lobularia sp., and Dendronephthya sinaiensis as well as AE29 and AE41, isolated from sponges; Callyspongia sp., respectively). Six strains (AE2, AE3 and AE23, isolated from soft corals; Rhytisma sp., Xenia sp. and Lobularia sp. as well as AE27, AE32 and AE46, isolated from sponges; Haliclona sp. and Callyspongia sp., respectively) belonged to the genus Nocardiopsis. Only one isolate (AE13) derived from Dendronephthya hemprichi was belonged to the genus Pseudonocardia. The phylogenetic analysis revealed that four culturable actinobacteria strains (AE2, AE27, AE32 and AE46) were more distantly related to other previously published Nocardiopsis dassonvillei. Screening for antimicrobial activity revealed that out of the 13 culturable actinobacteria isolates, only five (AE15, AE19, AE20, AE29 and AE41) belonged to the genus Streptomyces have anticandida or anti-positive Gram bacteria activity

Enhanced magnetic anisotropy in cobalt-carbide nanoparticles

An outstanding problem in nano-magnetism is to stabilize the magnetic order in nanoparticles at room temperatures. For ordinary ferromagnetic materials, reduction in size leads to a decrease in the magnetic anisotropy resulting in superparamagnetic relaxations at nanoscopic sizes. In this work, we demonstrate that using wet chemical synthesis, it is possible to stabilize cobalt carbide nanoparticles which have blocking temperatures exceeding 570 K even for particles with magnetic domains of 8 nm. First principles theoretical investigations show that the observed behavior is rooted in the giant magnetocrystalline anisotropies due to controlled mixing between C p- and Co d-states

Effect of different pretreatments on egyptian sugar-cane bagasse saccharification and bioethanol production

AbstractSugar-cane processing generates large amount of bagasse. Disposal of bagasse is critical for both agricultural profitability and environmental protection. Sugar-cane bagasse is a renewable resource that can be used to produce ethanol.In this study, twelve microbial isolates, five bacteria, four yeasts and three filamentous fungi were isolated from sugar-cane bagasse. Bacterial and yeast isolates were selected for their ability to utilize different sugars and cellulose. Chipped and ground bagasse was subjected to different pretreatment methods; physically through steam treatment by autoclaving at 121°C and 1.5bar for 20min and/or different doses of gamma γ irradiation (50 and 70Mrad). Autoclaved pretreated bagasse was further biologically treated through the solid state fermentation process by different fungal isolates; F-66, F-94 and F-98 producing maximum total reducing sugars of 18.4., 26.1 and 20.4g/L, respectively.Separate biological hydrolysis and fermentation (SHF) process for bagasse was done by the two selected fungal isolates; Trichoderma viride F-94 and Aspergillus terreus F-98 and the two yeast isolates identified as Candida tropicalis Y-26 and Saccharomyces cerevisiae Y-39. SHF processes by F-94 and Y-26 produced 226kg of ethanol/ton bagasse while that of F-98 and Y-39 produced 185kg of ethanol/ton bagasse

Synthesis, antimicrobial activities and GAPDH docking of novel 1, 2, 3-triazole derivatives

Purpose: To synthesize new triazole derivatives in order to overcome the problem of side effects of antimicrobial agents and microbial resistance, while broadening the spectrum of antimicrobial activity. Methods: The starting triazole, compound 1, was prepared through click chemistry and reacted with chloroacetyl chloride to yield compound II. Triazole 1 was reacted with acids and aldehydes to produce oxadiazole (III) and azomethine (IV) which cyclized in acetic anhydride to give a new acetylated oxadiazole (V). Minimum inhibitory concentration (MIC) and resorufin assays were used for antibacterial and anti-parasitic screening, respectively. Compounds II and IVb were subjected to molecular docking studies using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) Molecular Operating Environment (MOE) program. Results: Novel oxazole-triazole derivative (III) showed high activity against Pseudomonas aeruginosa and moderate activity against Staphylococcus epidermidis, whereas compound IVc showed moderate activity against Staphylococcus epidermidis. Chloro-acetyl-triazole II and 2-hydroxyphenyl-triazole Schiff base (Ivb) showed pronounced activity against the kinetoplastid parasites, Leishmania major, Leishmania mexicana and Trypanosoma brucei. Conclusion: The new synthesized triazoles represent a new antimicrobial scaffold and identifies potential new lead compounds for follow-up and for further mechanistic studies

Enhancement of β-phase in PVDF films embedded with ferromagnetic Gd₅Si₄ nanoparticles for piezoelectric energy harvesting

Self-polarized Gd5Si4-polyvinylidene fluoride (PVDF) nanocomposite films have been synthesized via a facile phase-inversion technique. For the 5 wt% Gd5Si4-PVDF films, the enhancement of the piezoelectric β-phase and crystallinity are confirmed using Fourier transform infrared (FTIR) spectroscopy (phase fraction, Fβ, of 81% as compared to 49% for pristine PVDF) and differential scanning calorimetry (crystallinity, ΔXc, of 58% as compared to 46% for pristine PVDF), respectively. The Gd5Si4 magnetic nanoparticles, prepared using high-energy ball milling were characterized using Dynamic Light Scattering and Vibrating Sample Magnetometry (VSM) to reveal a particle size of ∼470 nm with a high magnetization of 11 emu/g. The VSM analysis of free-standing Gd5Si4-PVDF films revealed that while the pristine PVDF membrane shows weak diamagnetic behavior, the Gd5Si4-PVDF films loaded at 2.5 wt% and 5 wt% Gd5Si4 show enhanced ferromagnetic behavior with paramagnetic contribution from Gd5Si3 phase. The interfacial interactions between Gd5Si4 and PVDF results in the preferential crystallization of the β-phase as confirmed via the shift in the CH2 asymmetric and symmetric stretching vibrations in the FTIR. These results confirm the magnetic Gd5Si4 nanoparticles embedded in the PVDF membrane lead to an increased β-phase fraction, which paves the way for future efficient energy harvesting applications using a combination of magnetic and piezoelectric effects

Chemical Profiling of Significant Antioxidant and Phytotoxic Microwave-Extracted Essential Oil from Araucaria heterophylla Resin

Due to the various hazards of using synthetic chemical compounds in pharmaceutics, agriculture, and industry, scientists and researchers do their best to explore and assess new green natural compounds from natural resources with potent activity. The essential oil (EO) from the resin collected from Araucaria heterophylla Salisb. was extracted by the microwave technique and chemically characterized via GC-MS analysis. Furthermore, the extract EO was assessed for its antioxidant and phytotoxic activities. The EO has 33 compounds, mainly terpenes (98.23%), and the major compounds were α-pinene (62.57%), β-pinene (6.60%), germacrene D (5.88%), and β-caryophyllene (3.56%). The extracted EO showed substantial antioxidant activity, where it showed IC50 values of 142.42 and 118.03 mg L−1 for DPPH and ABTS, respectively. On the other hand, the EO revealed considerable phytotoxicity against the weed Chenopodium murale, where the EO showed IC50 values of 304.0, 230.1, and 147.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. Moreover, the EO showed the same pattern of allelopathic inhibition against the weed Sonchus oleraceus, where it showed IC50 values of 295.7, 224.5, and 106.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. The present study showed that the extraction technique affects the constituents of the EO, particularly the quantitative composition. The EO of A. heterophylla resin also revealed considerable antioxidant and phytotoxic activity against weeds. Therefore, it can be considered a promising natural resource that could be integrated into the weed management approach. However, further study is recommended for deep characterization of their authentic compounds and evaluation of their mode of action(s) on a wide spectrum of weeds

Frequentist Interpretation of Probability

Three series of azole piperazine derivatives that mimic dicyclotyrosine (cYY), the natural substrate of the essential Mycobacterium tuberculosis cytochrome P450 CYP121A1, were prepared and evaluated for binding affinity and inhibitory activity (MIC) against M. tuberculosis. Series A replaces one phenol group of cYY with a C3-imidazole moiety, series B includes a keto group on the hydrocarbon chain preceding the series A imidazole, whilst series C explores replacing the keto group of the piperidone ring of cYY with a CH2-imidazole or CH2-triazole moiety to enhance binding interaction with the heme of CYP121A1. The series displayed moderate to weak type II binding affinity for CYP121A1, with the exception of series B 10a, which displayed mixed type I binding. Of the three series, series C imidazole derivatives showed the best, although modest, inhibitory activity against M. tuberculosis (17d MIC = 12.5 μg/mL, 17a 50 μg/mL). Crystal structures were determined for CYP121A1 bound to series A compounds 6a and 6b that show the imidazole groups positioned directly above the haem iron with binding between the haem iron and imidazole nitrogen of both compounds at a distance of 2.2 Å. A model generated from a 1.5 Å crystal structure of CYP121A1 in complex with compound 10a showed different binding modes in agreement with the heterogeneous binding observed. Although the crystal structures of 6a and 6b would indicate binding with CYP121A1, the binding assays themselves did not allow confirmation of CYP121A1 as the target