Mean Size Distribution Research Articles

Green synthesis of silver nanoparticles: Characterization and its potential biomedical applications

Abstract In recent times, research on the synthesis of noble metal nanoparticles (NPs) has developed rapidly and attracted considerable attention. The use of plant extracts is the preferred mode for the biological synthesis of NPs due to the presence of biologically active constituents. Aloe vera is a plant endowed with therapeutic benefits especially in skincare due to its unique curative properties. The present study focused on an environmental friendly and rapid method of phytosynthesis of silver nanoparticles (Ag-NPs) using A. vera gel extract as a reductant. The synthesized Ag-NPs were characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, Fourier transform infrared (FTIR), and dynamic light scattering (DLS). TEM micrographs showed spherical-shaped synthesized Ag-NPs with a diameter of 50–100 nm. The UV-Vis spectrum displayed a broad absorption peak of surface plasmon resonance (SPR) at 450 nm. The mean size and size distribution of the formed Ag-NPs were investigated using the DLS technique. Antibacterial studies revealed zones of inhibition by Ag-NPs of A. vera (9 and 7 mm) against Pseudomonas aeruginosa and Escherichia coli, respectively. Furthermore, the antifungal activity was screened, based on the diameter of the growth inhibition zone using the synthesized Ag-NPs for different fungal strains. Anticancer activity of the synthesized Ag-NPs against the mouse melanoma F10B16 cell line revealed 100% inhibition with Ag-NPs at a concentration of 100 µg mL−1. The phytosynthesized Ag-NPs demonstrated a marked antimicrobial activity and also exhibited a potent cytotoxic effect against mouse melanoma F10B16 cells. The key findings of this study indicate that synthesized Ag-NPs exhibit profound therapeutic activity and could be potentially ideal alternatives in medicinal applications.

Tumor Microenvironment and Clonal Monocytes of Chronic Myelomonocytic Leukemia Induce a Procoagulant Climate within the Tumor Niche

Context:Chronic myelomonocytic leukemia (CMML) is a myeloid hematological malignancy close to myelodysplastic syndromes (MDS) (Itzykson, Leukemia 2013).The role of tumor microenvironment (TME) in the pathogenesis of MDS is increasingly highlighted, particularly the interactions between mesenchymal stem cells (MSCs) and hematopoietic tumor cells within the endosteal niche (Raaijmakers, Nature 2010). Studies about CMML TME focused on the vascular niche and demonstrated an increased angiogenesis and higher medullar vascular endothelial growth factor rates (Aguayo, Blood 2000; Bellamy, Blood 2001). MSCs have been less studied in the specific subset of CMML.Moreover, cancer is associated with a procoagulant state participating in tumor development and metastasis process (d'Asti, Meth Mol Biol 2016). Monocytes are important cells regarding coagulation as they shed procoagulant, tissue factor (TF)-bearing microparticles (del Conde, Blood 2005).We hypothesized that MSCs and clonal monocytes induce a procoagulant “climate” within the tumor endosteal niche in CMML patients, via the extracellular vesicles (EVs) they release. This procoagulant state could participate to tumor development.Methods:We isolated MSCs from CMML (n=3) and control (n=3) patients' marrow aspirations, monocytes from CMML (n=3) and reactional monocytosis (n=4) patients' blood. We also cultured HL60 cell line as a reference, as HL60-derived EVs are procoagulant (Gheldof, Thromb Res 2014).HL60 and MSCs were cultured with classical conditions and incubated in a medium free of serum EVs 72 hours before EVs collect. Monocytes were cultured for 40 hours in a serum-free medium to induce vesiculation and prevent contamination from serum EVs.EVs were extracted by sequential centrifugations of culture supernatant. The pellets obtained after 10 000 g and 100 000 g ultra-centrifugations corresponded to the « medium EVs » containing mostly microparticles and « small EVs » respectively, containing exosomes along with small microparticles (Tkach, Cell 2016).Concentration, mean size and size distribution of these EVs were analyzed by Nanoparticle Tracking Analysis (NS300, Malvern, UK). We tested always the same number of EVs for hemostasis tests.The exploration of coagulation was mainly performed with thrombin generation assay (TGA). Phospholipids were systematically added so that the phospholipid concentration would not limit the coagulation reaction.A fibrinolysis assay was performed on EVs deriving from MSCs and HL60 with a new technique currently developed: fibrinography. Relying on fibrin properties of light diffusion, it is a structural analysis of the nanostructure of the fibrin clot displaying the number of protofibrils per fibrin fiber during the coagulation and lysis reactions.Results:We showed that the vesiculation rate of MSCs (i.e. the number of EVs released by one cell) is significantly higher than the vesiculation rate of HL60 cells and monocytes (p = 0.02). The mean size of medium EVs (226 nm) was significantly higher than the mean size of small EVs (188 nm, p = 0.01).TGA data are shown in the figure 1. With poor-platelet normal plasma, we showed that CMML MSCs but not control MSCs have a higher procoagulant activity than HL60 cells and 0.5pM of TF (Fig. 1A). We also demonstrated that small EVs derived from CMML monocytes and MSCs, but not from control cells, display a procoagulant activity (Fig. 1B and 1C).TGA experiments were repeated with FVII-deficient plasma and did not display any thrombin generation when EVs were added. This implies that EVs procoagulant activity is mediated by TF present in the EVs.Fibrinography coagulation data confirmed the TGA results and displayed a higher sensitivity than TGA during the early phase of coagulation. Analysis of fibrinolysis data showed a longer clot lysis time in presence of CMML small or medium EVs (p = 0.02) compared to healthy controls, corresponding to a higher clot resistance to fibrinolysis (Fig. 2).Conclusion:Overall, our findings reveal a procoagulant “climate” within the endosteal tumor niche in CMML mediated by clonal monocytes but also TME. This may induce a net of fibrin in the tumor hematopoietic niche, which could participate in leukemia progression. [Display omitted] DisclosuresPark:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Hospira/Pfizer: Research Funding; Celgene: Research Funding.

Measurements and Approximations for Submicron‐Aerosol Size Distribution Functions

AbstractResults of field measurements taken in the near‐Caspian (2002, 2003, 2007, 2009, 2010, 2011, 2013, 2014, 2016 years) and near‐Aral sea (1998) deserts under the conditions of weak winds (almost in the absence of saltation processes) and strong heating of the land surface are given. These results show that the fine mineral dust aerosol (0.1–1 m) considerably contributes to the total aerosol content of the atmospheric surface layer under such conditions. The scaling of daytime mean size distribution at a height of 2 m is approximated by dependence , where changes from 4 to 6 for different years of measurements, in contrary to the law for fraction m. Different compositions of aerosol particles at m and m, including multicomponent fractions (less than m) may result in different probabilities of their integration and disintegration. It is hypothesized that the equilibrium distribution of submicron aerosol is a result of sequential disintegration of aerosol particles with a possibility for their reintegration. The simplest distribution approximations are given based on the Kolmogorov direct differential equation which is usually used in considering the Poisson distributions in equations for queuing systems.

A Comparison of Different Approaches for Characterizing Microplastics in Selected Personal Care Products.

Any uncertainty in determining numbers of microplastics in the environment may be a barrier to assessing their impact and may stem from various aspects of methodologies used to quantify them. We undertook a comparison of approaches to quantify and characterize microplastics in 4 personal care products. The aim was not only to determine how many particles were present but to assess any differences due to the methods used. Counting of extracted microplastics was undertaken using particle size analysis, light microscopy, and imaging flow cytometry. Micro-Fourier transform infrared spectroscopy (µ-FTIR) was used to characterize the particles in each product. The mean size distribution of microplastics differed depending on the method employed, and it was apparent that imaging flow cytometry was affected by high background noise that may require staining of plastics to overcome. The application of µ-FTIR confirmed polyethylene as the microplastic in each product. Methodological challenges encountered in the study and the literature have highlighted the need for standardization of methods for determining microplastics. Environ Toxicol Chem 2022;41:880-887. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Influence of liquid media and laser energy on the production of MgO nanoparticles by laser ablation

Nano and micro-sized metal particles are interesting solutions for several applications, from electronics to biomedical fields. In recent years, MgO has been gaining attention due to its nontoxicity and antibacterial activity, making this an interesting material for implants coating for instance.This study aims the fabrication/preparation of nanoparticles by laser ablation in liquid from the Mg bulk. The influence of liquid media and laser energy on the morphology, size and properties of the obtained nanoparticles was assessed. A Nd:YAG nanosecond laser of 1064 nm of wavelength at different laser energies was employed to irradiate Mg target in three environments (distilled water+SDS, ethanol and propanol). Ultraviolet–visible (UV–vis) absorption spectrophotometry, scanning electron microscopy with a transmission electron detector (STEM) and transmission electron microscopy (TEM) were used for characterizing the obtained particles, viz. particles’ mean size and size distribution. The composition of the obtained nanoparticles was analyzed by SAED patterns. The results showed that the characteristics of the obtained nanoparticles were prominently influenced by varying laser energy and liquid medium. The smaller particles are obtained when using ethanol and propanol (having 16.7 nm and 15.3 nm respectively), as compared to distilled water+surfactant.

Tensile Strength of PMMA/n-ZrSiO<sub>4</sub> Composites Using Dynamic Mechanical Analyzer (DMA)

This study aimed to determine the tensile strength and strain properties of poly(methyl methacrylate) (PMMA)/nano-zircon (n-ZrSiO4) composites with various nano-zircon sizes. Wet milling method for 5 and 15 h without annealing treatment was used to obtain the nano-zircon powders. Results showed that milling for 15 hours can reduce zircon size up to 93 nm. Meanwhile, the composites were synthesized with zircon compositions of 1, 2.5, and 5 wt.%. Dynamic Mechanical Analyzer (DMA) measurement were carried out to characterize the tensile-strain dependence on filler compositions of the PMMA/n-ZrSiO4 composites. The PMMA/n-ZrSiO4 composite with 5 wt.% and 15h milling zircon exhibited the highest tensile strength, ca. 10.02 MPa or 2 times of the pure PMMA. The tensile strength of the composites can be explained from the mean size and size distribution of the filler.

Fiber-Reinforced-Phospholipid Vehicle-Based Delivery of l-Ascorbic Acid: Development, Characterization, ADMET Profiling, and Efficacy by a Randomized, Single-Dose, Crossover Oral Bioavailability Study.

l-ascorbic acid (AA) or vitamin C is a crucial nutrient needed for optimal health. However, being unable to be synthesized by the body, it is thus necessary to be included in health care products. Moreover, AA is one of the antioxidants that occur naturally, which is used in pharmaceutical and food products as an antioxidant additive. However, AA is vulnerable to environmental settings and undergoes oxidative degradation to dehydroascorbic acid and further to inactive products. Therefore, new research strategies and approaches are required to augment its stability. The objective of this study is to develop and characterize a fiber-reinforced-phospholipid (FRP) matrix-based vehicle, Zeal-AA, for the delivery of AA and optimize the oral bioavailability of the obtained AA powder using an efficacy study by open-label, randomized, single-dose, two-treatment, two-sequence, two-period, two-way crossover. The structural and surface morphologies were analyzed by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and differential scanning calorimetry studies. Encapsulation efficiency, mean particle size, size distribution, ζ-potential measurements, and ADMET profiling revealed the potential delivery system for AA. AUC0–t was found to be 55.23 (mg/dL) for Zeal-AA, whereas it was 9.38 (mg/dL) for AA, and Cmax was found to be 6.69 (mg/dL) for Zeal-AA, whereas it was 1.23 (mg/dL) for AA, with a fold difference of bioavailability in terms of AUC found to be 5.9 fold. The results show that a single oral dose of Zeal-AA is capable of rising the AA levels in the body relative to the control up to 24 h.

Enhanced Cryoprotective Effect of Melatonin and Resveratrol by Coencapsulation: Improved In Vitro Development of Vitrified-Warmed Mouse Germinal Vesicle Oocytes.

Oocyte vitrification, as a vital step in reproductive medicine, is strongly associated with lower development caused by cryodamaging factors, such as oxidative stress. In this study, we evaluated the antioxidative synergistic effects of Melatonin (Mel) and Resveratrol (RES) coencapsulated by solid lipid nanocarriers (SLNs) against the pure antioxidant combination (Mel+RES). In this research, the formation of Mel+RES-SLN was confirmed by Fourier-transformed infrared spectroscopy. The average mean diameter, size distribution, polydispersity index, and zeta potential of particles were measured by Zetasizer, and the morphology was evaluated by scanning electron microscopy. In addition, the encapsulation efficiency (EE%) or drug loading capacity (DL%) of the nanocapsule was determined by spectrophotometric methods. Germinal vesicle (GV)-stage oocytes harvested from 6- to 12-week-old female NMRI mice were randomly divided into seven groups for in vitro studies. In these groups, (0, 10-12 M + 0.5 μM, 10-9 M + 2 μM, or 10-6 M + 10 μM) of Mel+RES/Mel+RES-SLN were added into vitrification media. After thawing, oocytes were matured, fertilized, and cultured for 3 days. Extra/intracellular reactive oxygen species (ROS) levels were measured in in vitro maturation medium after 24 hours. Our results revealed a significant improvement in the normal morphology of warmed GV-stage oocytes, GV breakdown (GVBD) rate, Metaphase II (MII)-stage oocyte formation, fertilization rate, early embryo development, and a significant reduction in intra/extracellular ROS level when vitrification media was supplemented with the lowest Mel+RES-SLN concentration. In vitro studies also demonstrated that the highest concentration of Mel+RES-SLN was safe, without a detrimental effect on embryonic development upon treatment. In conclusion, the lowest concentration of Mel+RES-SLN supplementation in GV-stage oocyte vitrification media improved maturation, fertilization, and embryo development rate and decreased extra/intracellular ROS level through an enhanced/controlled intracellular penetration compared to the pure Mel+RES.

Evaluation of the properties of daughter bubbles generated by inertial cavitation of preformed microbubbles

Inertial cavitation (IC) of the preformed microbubbles is being investigated for ultrasound imaging and therapeutic applications. However, microbubbles rupture during IC, creating smaller daughter bubbles (DBs), which may cause undesired bioeffects in the target region. Thus, it is important to determine the properties of DBs to achieve controllable cavitation activity for applications. In this study, we theoretically calculated the dissolution dynamics of sulfur hexafluoride bubbles. Then, we applied a 1-MHz single tone burst with different peak negative pressures (PNPs) and pulse lengths (PLs), and multiple 5-MHz tone bursts with fixed acoustic conditions to elicit IC of the preformed SonoVue microbubbles and scattering of DBs, respectively. After the IC and scattering signals were received by a 7.5-MHz transducer, time- and frequency-domain analysis was performed to obtain the IC dose and scattering intensity curve. The theoretical dissolution curves and measured scattering intensity curves were combined to determine the effect of the incident pulse parameters on the lifetime, mean radius and distribution range of DBs. Increased PNP reduced the lifetime and mean size of the DBs population and narrowed the size distribution. The proportion of small DBs (less than resonance size) increased from 36.83% to 85.98% with an increase in the PNP from 0.6 to 1.6 MPa. Moreover, increased PL caused a shift of the DB population to the smaller bubbles with shorter lifetime and narrower distribution. The proportion of small bubbles increased from 25.74% to 95.08% as the PL was increased from 5 to 100 µs. Finally, increased IC dose caused a smaller mean size, shorter lifetime and narrower distribution in the DB population. These results provide new insight into the relationship between the incident acoustic parameters and the properties of DBs, and a feasible strategy for achieving controllable cavitation activity in applications.

Optimization, physicochemical characterization, and antimicrobial activity of a novel simvastatin nano-niosomal gel against E. coli and S. aureus

Niosomes, as a kind of drug delivery system, is widely used for the topical delivery of lipophilic drugs. Optimization of niosomes plays an essential role in enhancing their therapeutic efficiencies. This study aims to prepare an optimized niosomal formulation of simvastatin (nSIM), a lipophilic member of statins, through the experiment (Response Surface methodology). Optimized niosomes were characterized in size, polydispersity index (PDI), entrapment efficiency (EE), stability, releasing pattern, and antimicrobial activity. The different molar ratio of surfactant and cholesterol were applied to prepare various formulation of simvastatin loaded niosome. Mean particle size and size distribution were analyzed by dynamic light scattering. Antibacterial activity was determined by MIC and MBC tests against Staphylococcus aureus and Escherichia coli. The release rate of simvastatin from noisome nanoparticles was studied by the Franz diffusion cell method. The release pattern was studied through zero order, first order, Higuchi, Korsmeyer-Peppas, and Hixson-Crowell kinetics models. Optimized niosomes were obtained by span 80, drug to cholesterol ratio of 0.4 with 7 min sonication time. Mean particle size, PDI, zeta potential, and entrapment efficiency (EE%) of optimized nSIM were obtained about 168 nm, 0.34, -32.40, and 96 %, respectively. The niosomes significantly decreased the drug's releasing rate and enhanced antibacterial activity against S. aureus and E. Coli. It was found that the release pattern of drug followed the Higuchi kinetic model which means drug release is by diffusion. Overall, our findings indicated that the prepared simvastatin loaded niosomes showed good stability and biological properties than free drug. Our study suggests that niosomal formulation could be considered as a promising strategy for the delivery of poor water-soluble drugs that enhance antibacterial activity.

Optimization and ecofriendly synthesis of iron oxide nanoparticles as potential antioxidant

The present study involves the use of Box-Behnken design for optimization of the energy-efficient process variables, eco-friendly synthesis of nanoparticles of iron oxide using Coriandrum sativum L. (cilantro) leaf extract. The factors, which significantly influenced mean nanoparticle size, surface charge, and size distribution, were the volume of leaf extract, agitation speed, and temperature. The developed model using Box-Behnken design was validated by synthesizing the iron nanoparticles using optimized operational conditions i.e. 10 ml volume of leaf extract, 1500 rpm agitation speed and 30 °C temperature. This resulted in the formation of highly stable iron oxide nanoparticles with mean particle size 161.5 nm and polydispersity index 0.132 with a zeta potential of −19.5 mV. The free radical inhibitory activity of prepared iron oxide nanoparticles was found comparable to ascorbic acid. These results reveal that iron nanoparticles for a biomedical application can be prepared at ambient temperature in an eco-friendly manner.

Measurement and Characterisation of Metallic Iron Particles on Coal-Based Reduction and Magnetic Separation of Refractory Titanomagnetite

Coal-based reduction followed by magnetic separation is a promising technology for processing refractory iron ores. Analysis of the size distribution of metallic iron particles is an effective approach for exploring the mechanisms of coal-based reduction. As metallic iron particles exhibit very complex shapes compared with nature ores, approaches for measuring and characterising metallic iron particles still remain unclear. In this study, the size of metallic iron particles was measured and characterised using manual point-counting by optical microscopy technics and image analysis. The effects of CaF2 as an additive on behaviour of the particle size distribution (i.e. mean size and cumulative frequency distribution) were also determined. Results indicate that CaF2 had a significant effect on the growth of metallic iron particles. When the CaF2 dosage increased from 0 to 8%, the mean size according to the area method increased from 9.03 to 16.28 μm, while the promotion effect gradually weakened and generated many fine metallic iron particles when the CaF2 dosage exceeded 8%. An increase in CaF2 dosage also led to cumulative distribution curves gradually shifting to the right mainly because F− can break the crystal structure of each phase during the carbothermic reduction of titanomagnetite and reduce the stability of the lattice structure, thus reducing the melting point and accelerating the growth of metallic iron grains. Compared to different measuring methods, the area method is a more suitable approach for measuring and characterising the size of metallic iron particles.

Coupled cluster-dislocation dynamics of irradiation-induced defects

We present a new formulation for modeling concurrent radiation damage and plasticity of irradiated materials during service. We consider the case of irradiated zirconium as an example, where the dominant microstructure features are vacancy and interstitial type dislocation loops. We first develop Cluster Dynamics (CD) equations that describe the temporal evolution of both types of loops, taking into account their nucleation and growth. The size distribution is described, where interstitial loops agglomerate mainly by single-step absorption of a few mobile defect species. Vacancy loops are nucleated heterogeneously at collision cascades sites by collapse of loose vacancy clusters into Stacking Fault Tetrahedra (SFT) that transform into sessile vacancy loops on the basal planes within a dose of a few displacements per atom (dpa). A quasi steady-state for fast mobile point defects is quickly reached, while the nucleation and further growth of dislocation loops continues in a slow transient to high radiation dose. The results are consistent with experimental observations of dislocation loop density, mean size and size distribution. CD equations are then used to establish a discrete representation of the dislocation microstructure and point defect radiation-induced super-saturation conditions in finite grains of Zr as function of irradiation dose through statistical sampling of the size distribution. Discrete Dislocation Dynamics (DDD) simulations involving glide motion of dislocations are performed to determine the mechanical state of deformation and the collective behavior of dislocation loops in post-irradiated materials. Results of DDD simulations show that spatial correlation of loops, their reorientation, and their dose-dependent evolution are in qualitative agreement with experimental observations.

Foliar Application of Low Concentrations of Titanium Dioxide and Zinc Oxide Nanoparticles to the Common Sunflower under Field Conditions.

Nano-fertilisers have only recently been introduced to intensify plant production, and there still remains inadequate scientific knowledge on their plant-related effects. This paper therefore compares the effects of two nano-fertilisers on common sunflower production under field conditions. The benefits arising from the foliar application of micronutrient-based zinc oxide fertiliser were compared with those from the titanium dioxide plant-growth enhancer. Both the zinc oxide (ZnO) and titanium dioxide (TiO2) were delivered by foliar application in nano-size at a concentration of 2.6 mg·L−1. The foliar-applied nanoparticles (NPs) had good crystallinity and a mean size distribution under 30 nm. There were significant differences between these two experimental treatments in the leaf surfaces’ trichomes diversity, ratio, width, and length at the flower-bud development stage. Somewhat surprisingly, our results established that the ZnO-NPs treatment induced generally better sunflower physiological responses, while the TiO2-NPs primarily affected quantitative and nutritional parameters such as oil content and changed sunflower physiology to early maturation. There were no differences detected in titanium or zinc translocation or accumulation in the fully ripe sunflower seeds compared to the experimental controls, and our positive results therefore encourage further nano-fertiliser research.

Cholesterol free niosome production by microfluidics: Comparative with other conventional methods

The extended use of niosomes in food, cosmetic and pharmaceutical industries demands novel preparation processes which could enhance nanovesicles production with controlled size and size distribution. Microfluidics (MF) are a novel promising set of preparation methods for this purpose. Studies comparing methods for niosome preparation are still scarce.In this work, niosomes using MF were produced and the effect of membrane compounds concentration and the relation between organic and aqueous ratio (flow rate ratio, FRR) on the resulting mean size and size distribution were studied. Two different cholesterol free formulations were tested using Tween® 80 and Span® 80 in presence and absence of 1-dodecanol as membrane stabilizer. The effect of FRR showed to be the key parameter in niosomes production, being more critical than membrane compounds concentration and the vesicle membrane composition.Additionally, the same formulations were also produced by two conventional methods, thin film hydration (TFH) and ethanol injection (EI), and results were compared. The size of the niosomes obtained by MF was smaller and more homogeneous than those achieved by TFH and similar to EI. Therefore, MF is confirmed as a novel technology that can facilitate the development and optimization of new nanodelivery systems with controlled size and polydispersity, two essential parameters for successful biotechnological applications.

Droplet size distributions in liquid–liquid semi-batch Taylor vortex flow

Optical methods were used to measure droplet size distributions in a liquid–liquid Taylor vortex reactor oriented vertically along its main axis and operated in a semi-batch fashion with continuous feed of the dispersed phase and no feed or removal of the continuous liquid. The effects of two operational parameters on droplet size distributions were considered, including the inner cylinder angular velocity and the dispersed phase inlet flow rate. Both the mean droplet diameter and the droplet size distribution were found to depend upon the jet Reynolds number and were independent of cylinder rotation speed up to the largest azimuthal Reynolds number investigated (60 000). The droplet size distribution underwent a transition from a unimodal distribution at low cylinder rotation speeds to a bimodal distribution at intermediate speeds. At the largest rotation speeds considered, the bimodal distribution became right-skewed. These observations provide support for the hypothesis that the mean droplet size and size distribution are determined primarily by jet breakage dynamics at the tips of inlet nozzles. Furthermore, the mean droplet size data collected from two geometrically distinct reactors can be collapsed onto a universal curve by plotting the Weber number against the jet Reynolds number.

Conidial heat resistance of various strains of the food spoilage fungus Paecilomyces variotii correlates with mean spore size, spore shape and size distribution

Contamination by spores is often the cause of fungal food spoilage. Some distinct strains of the food spoilage fungus Paecilomyces variotii are able to produce airborne conidia that are more heat-resistant than similar species. These ellipsoid asexual spores can vary in size between strains, but also within strains. Here, we compared four measurement techniques to measure conidia size and distribution of five heat-sensitive and five heat-resistant P. variotii strains. Light microscopy (LM), Scanning Electron Microscopy (SEM) and Coulter Counter (CC) were used to measure and compare the spherical equivalent diameter, while CC and flow cytometry were used to study spore size distributions. The flow cytometry data was useful to study spore size distributions, but only relative spore sizes were obtained. There was no statistic difference between the method used of spore size measurement between LM, SEM and CC, but spore size was significantly different between strains with a 2.4-fold volume difference between the extremes. Various size distribution and shape parameters were correlated with conidial heat resistance. We found significant correlations in mean spore size, aspect ratio, roundness and skewness in relation to heat resistance, which suggests that these parameters are indicative for the conidial heat resistance of a P. variotii strain.

Curcumin Containing PEGylated Solid Lipid Nanoparticles for Systemic Administration: A Preliminary Study.

Curcumin (CUR) has a wide range of pharmacological properties, including anti-inflammatory and antioxidant activities, and it can be considered a good candidate for the potential treatment of central nervous system (CNS) pathologies, although its use in clinical practice is compromised due to its high lipophilicity. Solid lipid nanoparticles (SLNs) are well-known nanocarriers representing a consolidated approach for the delivery of lipophilic compounds, but their systemic use is limited due their short half-life. The formulation of stealth SLNs (pSLNs) could be a valid strategy to overcome this limit. Curcumin-loaded-pSLNs were prepared by the solvent evaporation method. Formulation was characterized for their mean size, zeta potential, size distribution, and morphology. Drug antioxidant activity was evaluated by Oxygen Radical Absorbance Capacity (ORAC) assay. Finally, the obtained formulations were analyzed in terms of long-term stability. Curcumin-loaded-pSLNs showed good technological parameters with a mean particle size below 200 nm, as confirmed by TEM images, and a zeta potential value around −30 mV, predicting good long-term stability. Differential Scanning Calorimetry (DSC) analysis confirmed that PEG micelles interacted with the SLN surface; this suggests the location of the PEG on the pSLN surface. Therefore, these preliminary studies suggest that the produced formulation could be regarded as a promising carrier for the systemic administration.

Determination of Relative Frequency of Calretinin Expression in Patients with Breast Cancer in Yazd, Iran

Introduction: Breast cancer is known as the most common type of cancer among women in the world. Several methods have been proposed to predict the behavior of breast carcinoma. Recently calretinin has been found to be a reliable factor in predicting tumor survival rate in breast cancer. The aim of this study was to evaluate the relative frequency of calretinin expression in patients with breast cancer in Yazd,Iran. Material and methods: In this cross-sectional retrospective study, the clinicopathologic features and the outcome of patients with breast cancer from 2017 to 2018 were reviewed at Shahid Sadoughi Hospital, Yazd, Iran. The influence of potential prognostic parameters in the overall survival was investigated by log-rank test and Cox regression analysis. Results: Among 100 cases with breast carcinoma, 14.5% were positive for calretinin. The distribution of the rate of positivity of IHC markers including ER, PR, P53, Ki67 and Her2 was 62.9%, 57.1%, 46.2%, 80.5% and 22.1%, respectively. The most common grade and stage were grade2 and stage3 respectively. There was no significant difference in the status of IHC markers (including ER, PR, Her2 and Ki67) in terms of calretinin. 66.7% of the patients with calretinin positive results were P53 positive. The results of the mean tumor size distribution in the two groups of positive and negative calretinin showed a significant difference (P-value = 0.05). A lower age at the time of diagnosis was found in patients with calretinin positive results (P-value = 0.119). The mean survival rate in calretinin positive group was 6.71 years and 6.62 years in calretinin negative patients which was not statistically significant. Conclusion: The results of this study indicated an association between calretinin expression and other IHC markers (although not statistically significant) in predicting poor prognosis in breast cancer patients. In addition, we found a statistically significant association among calretinin with smaller tumor size and lower age at the time of diagnosis in patients with breast cancer.

Consumption of Meretrix meretrix (Linnaeus 1758) by selective shell size reduces heavy metal toxicity risk and overfishing in Tawau, North Borneo

AbstractMeretrix meretrix can accumulate heavy metals from the contaminated environment in its tissues and passed on these elements through the food chain, which can cause health hazards. The mean size distribution of the M. meretrix wild population at Batu Payung, Tawau, North Borneo, was determined by the linear morphometric analysis of outer shell length, and bivalve was categorized by the outer shell length size at 5‐mm interval cluster groups. The selected heavy metals concentration in wild M. meretrix whole tissues was determined by an Induced Couple Plasma‐Optical Emission Spectrometer (ICP‐OES) to provide baseline data for policymakers and stakeholders to formulate sustainable harvest management. The largest group of outer shell size (45.00–50.00 mm) had the concentration of the least heavy metals in its tissues among other smaller shell size cluster groups, indicating M. meretrix outer shell length size of more than 45 mm cleanse excessive heavy metals out of their body more efficiently. A negative correlation between nonessential heavy metals (Cd, Pb) concentration in M. meretrix edible tissues and its outer shell length size signified that the largest group of outer shell size was safer to consume. M. meretrix is also facing overfishing like elsewhere in North Borneo.