Green synthesis of strontium nanoparticles self‐assembled in the presence of carboxymethyl cellulose: an in vivo imaging study

Carboxymethyl cellulose (CMC) is one of the main derivatives of cellulose and is used as a drug carrier for hydrophobic and hydrophilic drugs, imaging in vivo, and biological applications. Encapsulation is a technology in which target compounds are coated with wall compounds to form microcapsules. This study reports a new chemical processing wet method for precipitation and encapsulation of strontium nanoparticles (Sr NPs) within CMC structures using a sonochemical method. Preparation parameters such as microwave power and irradiation time as well as morphology and particle size of Sr NPs were also investigated. Products were characterized by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and atomic force microscopy. In this study, CMC was used as a biological stabilizer in a retentive phase to encapsulate Sr NPs. For the first time, Sr NPs were synthesized using CMC in a cost‐effective, simple, fast, micellation‐assisted, ultrasound method. Sr NPs were encapsulated in green capping agent structures of either 1%, 2% or 3% weight to provide an efficient optical nanostructure with a high yield at wavelengths 200–700 nm for use in in vivo imaging studies.     

Magnetic Field Effect on Fresnel Coefficients of the Thin Slab of Graphite Nanocomposite

In this theoretical study, optical properties of a thin slab including graphite nanoparticles doped in a host medium such as silica and silicon have been investigated. A constant magnetic field is used for controlling Fresnel coefficients of the slab. Depending on the direction of the normal vector of the basal plane of the graphite structure with respect to the electric field of the incident electromagnetic wave (perpendicular or parallel), optical behavior of graphite is different. Electric permittivity of an individual magnetized graphite nanoparticle is calculated by a semi-empirical Drude-like model for both kinds of the normal vector of the basal plane orientation. By means of well-known Maxwell-Garnett theory, effective permittivity of the magnetized nanocomposite slab is obtained. It is shown that at the mid-IR frequency range, exerting a magnetic field of few hundred Tesla can lead to the substantial variations of Fresnel coefficients. Effect of the magnetic field on the optical properties of the slab is more evident when the population of the graphite nanoparticles with the parallel orientation of the basal plane is increased.

     

Margollus bokanicus n. sp. from Iran,the Fourth Species of a Rare Nematode Genus (Dorylaimida,Tylencholaimellidae)

Margollus bokanicus n. sp., collected from natural habitats in Khorasaneh district, Bokan, West Azarbaijan province, Iran, is described. Morphological and morphometric data are provided as well as drawings and light microscopy illustrations. The new species is characterized by a medium size body length (0.60 to 0.73 mm), labial and postlabial sclerotizations, lip region 7-μm wide, offset by constriction and long neck (167 to 207 μm), long pharyngeal basal bulb (27 to 36 μm) or 16% to 17% of total neck length, female genital system monodelphic–opisthodelphic, anterior branch reduced to a uterine sac (26–29 μm) or 1.1 to 1.3 times the body diameter, long posterior uterus (25–28 μm) or 1.1 to 1.3 times the body diameter, V = 40 to 47, cylindroid female tail (17 to 24 μm, c = 31 to 38, c’ = 1.1 to 1.4), and males unknown. This taxon is easily distinguishable from other Margollus species by its smaller general size and more posterior vulva. A compendium of Margollus species is also presented.     

A survey of aflatoxins in sesame seeds imported into Khorasan Province, Iran

Sesame seed is one of the main nutrient substances which is used in the food industries of Khorasan Razavi, Iran. Because it is likely that stored sesame seeds are contaminated with mycotoxins, the levels of aflatoxins (AF) in five lots of imported sesame seeds before their distribution to the market were studied during one year. A total of 269 sub-samples were obtained from a total of 9,321 tons of sesame seeds from five importing companies. Aflatoxins at >1 μg/kg were found in 50 % of all samples, but at low levels in most cases, which is illustrated by mean AFB₁ and total AF levels of 1.25?±?3.70 and 1.43?±?4.38 μg/kg, respectively. A few (1.9 %) samples exceeded the National Iranian Standard maximum accepted level for AFB₁ (5 μg/kg) or total AF (15 μg/kg); the maximum total AF level found in one sample was 48 μg/kg. The results indicate that the risk of a violative AF contamination in imported sesame seeds is not negligible but is currently relatively low.     

TRIM28 and β-Actin Identified via Nanobody-Based Reverse Proteomics Approach as Possible Human Glioblastoma Biomarkers

Malignant gliomas are among the rarest brain tumours, and they have the worst prognosis. Grade IV astrocytoma, known as glioblastoma multiforme (GBM), is a highly lethal disease where the standard therapies of surgery, followed by radiation and chemotherapy, cannot significantly prolong the life expectancy of the patients. Tumour recurrence shows more aggressive form compared to the primary tumour, and results in patient survival from 12 to 15 months only. Although still controversial, the cancer stem cell hypothesis postulates that cancer stem cells are responsible for early relapse of the disease after surgical intervention due to their high resistance to therapy. Alternative strategies for GBM therapy are thus urgently needed. Nanobodies are single-domain antigen-binding fragments of heavy-chain antibodies, and together with classical antibodies, they are part of the camelid immune system. Nanobodies are small and stable, and they share a high degree of sequence identity to the human heavy chain variable domain, and these characteristics offer them advantages over classical antibodies or antibody fragments. We first immunised an alpaca with a human GBM stem-like cell line prepared from primary GBM cultures. Next, a nanobody library was constructed in a phage-display vector. Using nanobody phage-display technology, we selected specific GBM stem-like cell binders through a number of affinity selections, using whole cell protein extracts and membrane protein-enriched extracts from eight different GBM patients, and membrane protein-enriched extracts from two established GBM stem-like cell lines (NCH644 and NCH421K cells). After the enrichment, periplasmic extract ELISA was used to screen for specific clones. These nanobody clones were recloned into the pHEN6 vector, expressed in Escherichia coli WK6, and purified using immobilised metal affinity chromatography and size-exclusion chromatography. Specific nanobody:antigen pairs were obtained and mass spectrometry analysis revealed two proteins, TRIM28 and β-actin, that were up-regulated in the GBM stem-like cells compared to the controls.     

Investigating the Parameters Affecting the Stability of Superparamagnetic Iron Oxide-Loaded Nanoemulsion Using Artificial Neural Networks

Nanoemulsions are increasingly being investigated for their fascinating capability of loading both hydrophobic and hydrophilic molecules while their stability is still an issue, being affected by various factors. In this study, to evaluate the dominant factors affecting the stability of nanoemulsions, artificial neural networks (ANNs) were implemented. Nanoemulsions of almond oil in water containing oleic acid-coated superparamagnetic iron oxide nanoparticles were prepared using a mixture of Tween 80 and Span 80 as surfactant system and ethanol as a co-surfactant. The ratio of transparency of the samples at 30 min and 7 days after preparation was taken as an indication of the stability of samples. Four independent variables, namely, concentration of nanoparticle, surfactant, oil, and alcohol were investigated to find their relations with the dependent variable (i.e., transparency ratio). Using ANNs modeling, it was concluded that the stability is affected by all variables, with all variables showing reverse effect on the stability beyond an optimum amount.Key words: artificial neural networks, nanoemulsion, optimization, stability, superparamagnetic iron oxide     

Contrasting soil microbial responses to fertilization and tillage systems in canola rhizosphere

Information regarding the simultaneous evaluation of tillage and fertilization on the soil biological traits in canola production is not available. Therefore, field experiments were conducted in 2007–2010 in a split plot based on randomized complete block design with three replications. Main plots consisted of conventional tillage (CT); minimum tillage (MT) and no tillage (NT). Six strategies of fertilization including (N₁): farmyard manure (cattle manure); (N₂): compost; (N₃): chemical fertilizers; (N₄): farmyard manure + compost; (N₅): farmyard manure + compost + chemical fertilizers and (N₆): control, were arranged in sub plots. Results showed that the addition of organic manure increased the soil microbial biomass. No tillage system increased microbial biomass compared to other tillage systems. The activities of all enzymes were generally higher in the N₄ treatment. The activity of phosphatase and urease tended to be higher in the no tillage treatment compared to the CT and MT treatments.     

The dengue virus M protein localises to the endoplasmic reticulum and forms oligomers

The dengue virus membrane (M) protein is a key component of the mature virion. Here, we characterised the cellular behaviour of M using a recombinant protein construct to understand its inherent properties. Using confocal microscopy, we showed that M and its intracellular precursor, prM, localised to the endoplasmic reticulum. M protein was also detected on the cell surface and secreted, suggesting that M can enter the secretory pathway. In addition, cross-linking studies showed that M can form dimers and tetramers. These findings suggest that M behaves as a secretory protein analogous to the major envelope protein E.