Particle Size

We describe the construction of a bio-aerosol monitor designed to capture and record intrinsic fluorescence spectra from individual aerosol particles carried in a sample airflow and to simultaneously capture data relating to the spatial distribution of elastically scattered light from each particle. The spectral fluorescence data recorded by this PFAS (Particle Fluorescence and Shape) monitor contains information relating to the particle material content and specifically to possible biological fluorophores. The spatial scattering data from PFAS yields information relating to particle size and shape. The combination of these data can provide a means of aiding the discrimination of bio-aerosols from background or interferent aerosol particles which may have similar fluorescence properties but exhibit shapes and/or sizes not normally associated with biological particles. The radiation used both to excite particle fluorescence and generate the necessary spatially scattered light flux is provided by a novel compact UV fiber laser operating at 266nm wavelength. Particles drawn from the ambient environment traverse the laser beam in single file. Intrinsic particle fluorescence in the range 300-570nm is collected via an ellipsoidal concentrator into a concave grating spectrometer, the spectral data being recorded using a 16-anode linear array photomultiplier detector. Simultaneously, the spatial radiation pattern scattered by the particle over 5°-30° scattering angle and 360° of azimuth is recorded using a custom designed 31-pixel radial hybrid photodiode array. Data from up to ~5,000 particles per second may be acquired for analysis, usually performed by artificial neural network classification.

O presente trabalho teve por objetivos avaliar a composição de rizomas do lírio-do-bejo (Hedychium coronarium) e isolar e caracterizar seu amido, por meio de análises físicas e físico-químicas. A composição química dos grânulos de amido isolados dos rizomas também foi determinada, bem como o formato, tamanho, distribuição de tamanho de partícula por difração a laser, viscosidade de pasta em analisador rápido de viscosidade, poder de inchamento, índice de solubilidade em água, propriedade térmica por calorimetria diferencial de varredura e cristalinidade por difração de raios X. Observou-se que os rizomas apresentaram elevado teor de água e baixos teores de matéria graxa, carboidratos, cinzas, proteínas e fibras. Os rizomas de lírio-do-brejo apresentam-se inadequados para produção de amido, devido ao baixo teor de matéria seca (17,3%), com 21,97% de amido, bem como fibras longas e látex, que dificultam a extração do amido. O amido extraído apresentou pureza de 99,2%, com 37,2% de ami...

A nonlinear-dynamics transient computational analysis of the explosion phenomena associated with detonation of 100g of C4 high-energy explosive buried at different depths in sand is carried out using the AUTODYN computer program. The results obtained are compared with the corresponding experimental results obtained in Ref. . To validate the computational procedure and the materials constitutive models used in the present work, a number of detonation-related phenomena such as the temporal evolutions of the shape and size of the over-burden sand bubbles and of the detonation-products gas clouds, the temporal evolutions of the side-on pressures in the sand and in air, etc. are determined and compared with their experimental counterparts. The results obtained suggest that the agreement between the computational and the experimental results is reasonable at short postdetonation times. At longer post-detonation times, on the other hand, the agreement is less satisfactory primarily with respect to the size and shape of the sand crater, i.e. with respect to the volume of the sand ejected during explosion. It is argued that the observed discrepancy is, at least partly, the result of an inadequacy of the generic materials constitutive model for the sand which does not explicitly include the important effects of the sand particle size and the particle size distribution, as well as the effects of moisture-level controlled inter-particle friction and cohesion. It is further shown that by a relatively small adjustment of the present materials model for sand to include the potential effect of moisture on inter-particle friction can yield a significantly improved agreement between the computed and the experimentally determined sand crater shapes and sizes .

Coupling of localized surface plasmon resonances results in singular effects at the void space between noble metal nanoparticles. However, implementation of practical applications based on plasmon coupling calls for the high yield production of metal nanoparticle clusters (dimers, trimers, tetramers,.) with small gaps. Therefore, controlled assembly using colloid chemistry methods is an emerging and promising field. We present a brief overview over the controlled assembly of plasmonic nanoparticle clusters by colloid chemistry methods, together with a description of their plasmonic properties and some applications, with an emphasis in sensing through surface-enhanced Raman scattering spectroscopy for bio-detection purposes. We point out the important role of separation methods to obtain colloidal clusters in high yield. A special encouragement to explore assembly of anisotropic building blocks is pursued.

1] Aerosol hygroscopicity has a significant effect on radiative properties of aerosols. Here a lidar method, applicable to cloud-capped, well-mixed atmospheric boundary layers, is employed to determine the hygroscopic growth factor f(RH) under unperturbed, ambient atmospheric conditions. The data used for the analysis were collected under a wide range of atmospheric aerosol levels during both routine measurement periods and during the intensive operations period (IOP) in May 2003 at the Southern Great Plains (SGP) Climate Research Facility in Oklahoma, USA, as part of the Atmospheric Radiation Measurement (ARM) program. There is a good correlation ($0.7) between a lidar-derived growth factor (measured over the range 85% RH to 96% RH) with a nephelometerderived growth factor measured over the RH range 40% to 85%. For these RH ranges, the slope of the lidar-derived growth curve is much steeper than that of the nephelometerderived growth curve, reflecting the rapid increase in particle size with increasing RH. The results are corroborated by aerosol model calculations of lidar backscatter and nephelometer equivalent f(RH) based on in situ aerosol size and composition measurements during the IOP. It is suggested that the lidar method can provide useful measurements of the dependence of aerosol optical properties on relative humidity and under conditions closer to saturation than can currently be achieved with humidified nephelometers.

Natural hydraulic lime specifications changed with the new version of standard EN 459-1: 2010 and a new Portuguese NHL3.5 appeared in the market. The characteristics of mortars depend on many different parameters such as the type of binder, the type of aggregates, the use of fillers and of superplasticizers; also on mixing and curing conditions. In this paper NHL3.5 mortars with binder:aggregate volumetric proportions1:3 were prepared, varying the aggregates type and proportions between them. Two coarse sands, a medium sand, a river sand, a finer sand, a calcareous filler and a ceramic powder were used. The two last mentioned aggregates were byproducts from industry. Prismatic mortar samples and samples of mortar applied over brick were prepared and conditioned in two different situationsfollowing standard EN 1015-11 and at 65% relative humidity with initial daily water spray. Mortars were characterized in the fresh state and at the age of 28 days. Results showed the influence namely of the curing, particularly in terms of water capillary, of the superplasticizer and of the fillers. They also showed that NHL3.5 mortars seem to be adequate for old masonries conservation and repair and, in some situations, they can be an alternative to air lime based mortars.

It has been previously described that when a sample's particle size is determined using different sizing techniques, the results can differ considerably. The purpose of this study was to review several in-process techniques for particle size determination (Spatial Filtering Velocimetry, Focused Beam Reflectance Measurements, Photometric Stereo Imaging, and the Eyecon Ò technology) and compare them to well-known and widespread off-line reference methods (laser diffraction and sieve analysis). To start with, a theoretical explanation of the working mechanism behind each sizing technique is presented, and a comparison between them is established. Secondly, six batches of granules and pellets (i.e., spherical particles) having different sizes were measured using these techniques. The obtained size distributions and related D 10 , D 50 , and D 90 values were compared using the laser diffraction wet dispersion method as reference technique. As expected, each technique provided different size distributions with different D values. These dissimilarities were examined and explained considering the measurement principles behind each sizing technique. The particle property measured by each particle size analyzer (particle size or chord length) and how it is measured as well as the way in which size information is derived and calculated from this measured property and how results are presented (e.g., volume or mass distributions) are essential for the interpretation of the particle size data.

Deterministic photochemical air quality models are commonly used for regulatory management and planning of urban airsheds. These models are complex, computer intensive, and hence are prohibitively expensive for routine air quality predictions. Stochastic methods are becoming increasingly popular as an alternative, which relegate decision making to artificial intelligence based on Neural Networks that are made of artificial neurons or 'nodes' capable of 'learning through training' via historic data. A Neural Network was used to predict particulate matter concentration at a regulatory monitoring site in Phoenix, Arizona; its development, efficacy as a predictive tool and performance vis-à-vis a commonly used regulatory photochemical model are described in this paper. It is concluded that Neural Networks are much easier, quicker and economical to implement without compromising the accuracy of predictions. Neural Networks can be used to develop rapid air quality warning systems based on a network of automated monitoring stations.

Zinc oxide nanoparticles (nZnO) are one of the most highly produced nanomaterials and are used in numerous applications including cosmetics and sunscreens despite reports demonstrating their cytotoxicity. Dissolution is viewed as one of the main sources of nanoparticle (NP) toxicity, however dissolution studies can be time-intensive to perform and complicated by issues such as particle separation from solution. Our work attempts to overcome some of these challenges by utilizing new methods using UV/vis and fluorescence spectroscopy to quantitatively assess nZnO dissolution in various biologically relevant solutions. All biological buffers tested induce rapid dissolution of nZnO. These buffers, including HEPES, MOPS, and PIPES, are commonly used in cell culture media, cellular imaging solutions and to maintain physiological pH. Additional studies using X-ray diffraction, FT-IR, X-ray photoelectron spectroscopy, ICP-MS and TEM were performed to understand how the inclusion of these non-essential media components impacts the behavior of nZnO in RPMI media. From these assessments, we demonstrate that HEPES causes increased dissolution kinetics, boosts the conversion of nZnO into zinc phosphate/carbonate and, interestingly, alters the structural morphology of the complex precipitates formed with nZnO in cell culture conditions. Cell viability experiments demonstrated that the inclusion of these buffers significantly decreases the viability of Jurkat leukemic cells when challenged with nZnO. This work demonstrates that biologically relevant buffering systems dramatically impact the dynamics of nZnO including dissolution kinetics, morphology, complex precipitate formation, and toxicity profiles.

The presence of foreign matter in cotton seriously affects the cotton grade and thus the price per bale paid by the spinner to the grower, the efficiency of the spinning and ginning operations, and the quality of the final woven product. Rapid identification of the nature of the extraneous matter in cotton at each stage of cleaning and processing is necessary to permit actions to eliminate or reduce its presence and improve efficiency and quality. Although several instruments are being successfully employed for the measurement of contamination in cotton fibers based on particle size/weight, no commercial instrument is capable of accurate qualitative identification of contaminants. To this end, ATR/FT-IR spectra of retrieved foreign matter were collected and subsequently rapidly matched to an authentic spectrum in a spectral database. The database includes contaminants typically classified as "trash", cotton plant parts (hull, shale, seed-coat fragments, bract, cacyx, leaf, bark, sticks, and stems) and grass plant parts (leaf and stem); "foreign objects and materials", synthetic materials (plastic bags, film, rubber, bale wrapping and strapping); organic materials (other fibers, yarns, paper, feathers, and leather); plus entomological and physiological sugars and inorganic materials (sand and rust). The spectral matching resulted in consistently high-score identification of the foreign matter based on chemical composition, irrespective of its particle size. The method is envisioned to be employed with stand-alone rugged infrared instrumentation to provide specific identification of extraneous materials in cotton as opposed to only general classification of the type by particle size or shape.

Rice bran is a rich source of nutrients and nutraceuticals, which has bio-functional properties. Deoiled rice bran, a major byproduct of rice bran oil industry, is not yet efficiently utilized for human consumption due to its poor edible quality. Various physical processing methods like sieving, pin milling and air classification were applied to upgrade the quality of bran and also to investigate its effect on particle size distribution, content of ash, protein, total dietary fiber, insoluble fiber, soluble fiber and oryzanol as well as total antioxidant activity in bran fractions. Sieve separation resulted in an increase in the content of protein and bio-functional components like soluble fiber and oryzanol as well as total antioxidant activity. Pin milling and sieving resulted in smaller particle size fraction without loss in the content of protein and other bio-functional components and antioxidant activity. Air classification of this material resulted in significant decrease in ash content with moderate increase in protein content and significant increase in the contents of oryzanol and soluble fiber and the total antioxidant activity. This resulted in quality improvement of commercial de-oiled bran viz., reduction in coarse bran fraction (>250μ m size particles) from 65% to 0%, content of ash from 14.3 to 13.1 g/ 100 g, and insoluble fiber from 49.3 to 46.1 g/100 g, and increase in the content of protein from 13.7 to 17 g/100 g, soluble fiber from 2.75 to 4.35 g/100 g, oryzanol from 13.6 to 18.1 mg/100 g, and total antioxidant activity from 61 to 96 mM α-tocopherol equivalent/g. About 30% edible and nutrient rich rice bran, which can be used as an ingredient in the bakery products and health food formulations, was obtained from unutilized commercial de-oiled bran by this process.

The effects of various physical properties (particle size, shape, surface area, crystal structure, and phase composition) on the photocatalytic performance of nanosized TiO 2 were studied through the photodegradation of Congo Red. Kinetic results showed that anatase TiO 2 was a superior photocatalyst to rutile TiO 2 due to the inherent difference in the two crystal structures. Anatase TiO 2 nanorods with predominantly (1 0 1) surface exhibited low activity because the non-dissociative adsorption of H 2 O to this surface retarded the generation of OH • radicals required for facile photocatalytic oxidation. It was found for the first time that the shape of TiO 2 nanocrystals significantly affected their photocatalytic activities. The previously reported anatase-rutile synergetic effect in commercialized mixed-phase TiO 2 (Degussa P25) was not observed in this study, perhaps, due to poor contact between the two phases and the extremely small sizes, as well as the not-optimized phase compositions in the current work.

RESUMO-O experimento foi conduzido em delineamento completamente casualizado com o objetivo de avaliar o efeito da densidade de compactação, 500 kg (médio) e 600 kg (alto) de matéria verde por metro cúbico de massa ensilada, na qualidade final da silagem em relação ao material original. A ensilagem de milho safrinha foi realizada no dia 18/05/2004 em minissilos, com quatro repetições por grau de compactação, quando os grãos de milho se encontravam no estádio ½ leitoso ½ farináceo. As densidades de compactação afetaram significativamente os teores de açúcares solúveis (1,60 × 2,15% da MS), matéria orgânica do resíduo insolúvel em etanol a 80% (76,02 × 71,53% da MS), carboidratos não-estruturais (39,21 × 41,70% dos carboidratos totais), fibra em detergente neutro corrigida para cinzas e proteína (52,57 × 50,37% da MS), lignina em detergente ácido (2,74 × 2,57% da MS) e nitrogênio amoniacal (4,35 × 3,84% do nitrogênio total). A maior densidade de compactação resultou em melhor conservação dos glicídios solúveis, em menor alteração dos carboidratos estruturais e em menor proteólise na silagem de milho. Palavras-chave: amido, carboidrato, estádio de maturação, FDN, proteína, NDT Chemical composition of maize silages with different packing densities ABSTRACT-The experiment in a complete randomized design aimed to test the effect of two packing densities, 500 kg (medium) and 600 kg (high) of silage mass per cubic meter, on silage quality as compared to the original fresh material. Silages were prepared on May 18 th , 2004 from a late season harvest of a maize crop at the half milky half dough kernel stage. Chopped materials with 1.2 cm theoretical particle size were packed manually in 30 liters mini-silos, in four replicates for each packing density, immediately after harvest. The different packing densities affected significantly the concentration of soluble sugars (1.60 vs. 2.15% of DM), 80% ethanol insoluble organic matter (76.02 vs. 71.53% of DM), non-structural carbohydrates (39.21 vs. 41.70% of total carbohydrates), neutral detergent fiber corrected for ash and protein (52.57 vs. 50.37% of DM), acid detergent lignin (2.74 vs. 2.57% of DM), and ammonia-nitrogen (4.35 vs. 3.84% of total nitrogen), respectively, for the "medium" and "high" packing densities. A higher ensiling packing density improved the conservation of soluble sugars, altered less the structural carbohydrates and reduced proteolysis in maize silage.

Lignocellulosic materials pretreated using liquid hot water (LHW) (220~ 5 MPa, 120 s) were fermented to ethanol by batch simultaneous saccharification and fermentation (SSF) using Saccharomyces cerevisiae in the presence of Trichoderma reesei cellulase. SSF of sugarcane bagasse (as received), aspen chips (smallest dimension 3 mm), and mixed hardwood flour (-60 +70 mesh) resulted in 90% conversion to ethanol in 2-5 d at enzyme loadings of 15-30 FPU/g. In most cases, 90% of the final conversion was achieved within 75 h of inoculation. Comminution of the pretreated substrates did not affect the conversion to ethanol. The hydrolysate produced from the LHW pretreatment showed slight inhibition of batch growth of S. cerevisiae. Solids pretreated at a concentration of 100 g/L were as reactive as those pretreated at a lower concentration, provided that the temperature was maintained at 220~

Successful use of liposomes as immunological adjuvants in vaccines requires simple, easy to scale up technology capable of high-yield antigen entrapment. Recent work from this laboratory has led to the development of techniques that can generate liposomes of various sizes containing soluble antigens such as proteins or particulate antigens such as whole, live, or attenuated bacteria or viruses. Entrapment of proteins is carried out by the dehydration-rehydration procedure, which entails freeze-drying of a mixture of "empty" small unilamellar vesicles and free antigens. Upon rehydration, the large multilamellar vesicles that are formed incorporate up to 80% of the antigen used. When such liposomes are microfluidized in the presence of nonentrapped material, their size is reduced to about 100 nm in diameter, with much of the originally entrapped antigen still associated with the vesicles. A similar technique applied to the entrapment of particulate antigens (e.g., Bacillus s...

Epidemiologic studies have shown associations between ambient particulate matter (PM) and adverse health outcomes including increased mortality, emergency room visits, and time lost from school and work. The mechanisms of PM-related health effects are still incompletely understood, but a hypothesis under investigation is that many of the adverse health effects may derive from oxidative stress, initiated by the formation of reactive oxygen species (ROS) within affected cells. While the adverse effects from PM have historically been associated with the airborne concentration of PM and more recently fine-particle PM, we considered it relevant to develop an assay to quantitatively measure the ability of PM to catalyze ROS generation as the initial step in the induction of oxidative stress. This ability of PM could then be related to different sources, chemical composition, and physical and spatial/temporal characteristics in the ambient environment. The measurement of ROS-forming ability in relation to sources and other factors will have potential relevance to control of redox-active PM. If oxidative stress represents a relevant mechanism of toxicity from PM, the measurement of redox activity represents a first step in the elucidation of the subsequent downstream processes. We have developed an assay for PM redox activity, utilizing the reduction of oxygen by dithiothreitol which serves as an electron source. We have found that PM will catalyze the reduction of oxygen and have examined the distribution and chemical characteristics of the redox activity of PM fractions collected in different sites in the Los Angeles Basin. Samples of concentrated coarse, fine, and ultrafine PM, obtained with aerosol concentrators, were studied with regard to their chemical properties and redox activity. Redox activity was highest in the ultrafine fraction, in agreement with results indicating ultrafines were the most potent toward inducing that heme oxygenase expression and depleting intracellular glutathione, which has relevance to induction of oxidative stress. Comparison of the redox activity with chemical composition showed a reasonable correlation of redox activity with elemental carbon (r 2 ¼ 0:79), organic carbon (r 2 ¼ 0:53), and with benzo[ghi]perylene (r 2 ¼ 0:82), consistent with species typically found in mobile emission sources. r

Dimensional reduction of ZnO semiconductors is expected to create wide-ranging application possibilities from roomtemperature ultraviolet (UV) lasers, sensors, photocatalysts, solar cells, [4] to field-emission (FE) devices. In general, ZnO nanowires as one-dimensional (1D) materials with diameters of less than 10 nm are expected to display novel and unique physical and chemical properties due to quantum confinement. Furthermore, it is very important to fabricate a dense array of ZnO nanowires on an appropriate substrate so that the nanowires can be directly addressed, surface area can be optimized, and/or collective properties may be induced. A host of techniques have been developed for the synthesis of aligned 1D ZnO nanostructures with sizes in the range of 10-100 nm on a variety of substrates for nanodevice applications. [6] For example, well-aligned ZnO nanowires that are 10-15 nm across have been grown from patterned, thin gold dots on sapphire substrates by a vapor-liquid-solid (VLS) process. To our knowledge, however, little has been reported on the synthesis of well-aligned ZnO nanowires with diameters of less than 10 nm. Although 6nm ZnO nanobelts have been obtained by solid-vapor deposition, [9] they are randomly oriented. Therefore, one of the synthetic challenges of nanowire materials is to reduce the nanowire diameter and, at the same time, align the nanowires in a controlled fashion. Here, we demonstrate the first synthesis of aligned ZnO nanofibers, which are no thicker than 10 nm and % 500 nm in length, by hydrothermal treatment of a Zn foil in an ammonia/alcohol aqueous solution. It should be emphasized that the reaction was carried out at a relatively low temperature without any catalyst. We have established that the use of ammonia/alcohol is crucial to the growth of the aligned ultrathin ZnO nanofibers. Photoluminescence (PL) measurement at room temperature shows a prominent peak at 373 nm (3.32 eV), which is about 100 meV blue-shifted from the bulk ZnO emission (3.24 eV, 383 nm) due to the ultrafine dimension along the radial direction of the ZnO nanofibers.

Context Evidence on the health risks associated with short-term exposure to fine particles (particulate matter Յ2.5 µm in aerodynamic diameter [PM 2.5 ]) is limited. Results from the new national monitoring network for PM 2.5 make possible systematic research on health risks at national and regional scales.

We investigated the effect of optical thick metal films on the surface-enhanced Raman scattering (SERS) activity of individual Au nanoparticle (NP) monomers and dimers. The film presence is revealed to be positive for the SERS activity of individual NP monomers, while it is not always positive for the electromagnetic enhancement at hot spots for SERS of the dimer, which is explained well by our numerical simulations. The polarized SERS signals from the NP dimer are elucidated well in terms of the plasmon hybridization of the dimer. SERS contributions both from individual NP surfaces and the junction between the NP and its supporting substrate were discussed as well.

Cytocompatible, co-doped cerium oxide nanoparticles exhibited strong upconversion properties that were found to kill lung cancer cells by inducing apoptosis thereby demonstrating the potential to be used as clinical contrast agents for imaging and as therapeutic agents for treatment of cancer.

The aim of the present study was to prepare, optimize and characterize ketoprofen proniosomes. The niosomes were prepared using a slurry method followed by in vitro evaluation after embedding the proniosomes-derived niosomes into a carbopol matrix. A central, composite Box-Wilson design was used for the optimization with the total lipid concentration (X 1 ), surfactant loading (X 2 ) and amount of drug (X 3 ) as the independent variables. Prepared proniosomes were characterized for percentage drug entrapment (PDE) and mean volume diameter (MVD). Multiple regression analysis and contour plots were used to relate the dependent and independent variables. Checkpoint batches were also prepared to prove the validity of the evolved mathematical model and contour plots. The optimization model predicted the levels of X 1 , X 2 and X 3 (-1, -0.3 and 0.92, respectively), for a maximized response of PDE with constraints of ≤ 5 μm on MVD. Optimized batch was used to prepare a niosomal gel, which showed significantly higher cumulative amount of drug permeated and steady state transdermal flux compared to plain gel. This work has demonstrated the use of the central composite Box-Wilson design, regression analysis, and contour plots in optimizing ketoprofen proniosomes. Developed niosomal gel formulation has also demonstrated permeation enhancement of ketoprofen compared to plain gel.

Determinations of IgG subclasses were made by electroimmunoassay and crossed immunoelectrophoresis, and Gm markers were typed in sera from seventeen patients with well-defined immunodeficiency diseases. Certain IgG subclass and Gm patterns were recognized in various diseases: IgG2 deficiency and homozygosity of Gm(4,5) in the cartilage-hair-hypoplasia syndrome, in the ataxia telangiectasia syndrome and in selective IgG subclass deficiency; and IgG3 deficiency and homozygosity of Gm(1,-5) in the Wiskott-Aldrich syndrome. The findings suggest a common structural or regulator gene defect in some immunodeficiency diseases. In IgA deficiencies, the levels of IgG1 were raised. In patients with IgG subclass deficiencies there was sometimes a compensatory increase of the remaining IgG subclasses, with a preponderance of IgG1 and IgG3. The increased IgGI showed restricted heterogeneity with only an increase ofthe electrophoretically cathodal part. This part contained both kappa and lambda chains. IgG subclass deficiency indicates treatment with gammaglobulin even if the serum levels of IgG are normal or increased.

Spray drying techniques have been applied to improve the solubility and dissolution rate of poorly water-soluble salicylic acid. Spray drying of the acid dispersed in acacia solutions resulted in as much as a 50% improvement in the solubility of the product. Solubility improvement was closely related not only to the concentration of acacia but also the amount of amorphous material in the spray-dried products. The heat of solution was inversely related to these parameters. The dissolution rate of spray-dried product was almost instantaneous being about 60 times faster than that of the original powder. A great improvement in the wettability of the spray-dried material seemed to be mainly responsible for the increase of dissolution rate.

The derivative from sucrose was prepared by substituting hydroxyl groups with chlorine. Identification of the modified sucrose was performed using the following analysis: Thin Layer chromatography (TLC), high performance liquid chromatography (HPLC), H-NMR, mass spectroscopy (MS), Inferred 1 spectroscopy (IR), melting point, OH groups. Moreover, some physical properties including: melting point, viscosity, surface tension and solubility.

Synthesis of metallic and semiconductor nanoparticles through physical and chemical routes has been extensively reported. However, green synthesized metal nanoparticles are currently in the limelight due to the simplicity, cost-effectiveness and eco-friendliness of their synthesis. This study explored the use of aqueous leaf extract of Costus afer in the synthesis of silver nanoparticles (CA-AgNPs). The optical and structural properties of the resulting silver nanoparticles were studied using UV-visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infra-red spectrophotometer (FTIR). TEM images of the silver nanoparticles confirmed the existence of monodispersed spherical nanoparticles with a mean size of 20 nm. The FTIR spectra affirmed the presence of phytochemicals from the Costus afer leaf extract on the surface of the silver nanoparticles. The electrochemical characterization of a CA-AgNPs/multiwalled carbon nanot...

Fine particles of aluminum oxide (amorphous, a, 3' and 0) have been synthesized by spray pyrolysis as a function of both in situ and annealing temperatures and nature of precursors used in the preparation method. A scanning electron micrograph study shows as-received materials constituted by filled spherical particles, the ulterior annealing leading to the formation of small crystallites on the precursor spheres.

Effect of 4 independent variables-temperature (50-90°C), particle size (0.42-0.85 mm), mixing time (10-50 min) and solvent (ethanol) to meal ratio (10-50) on curcumin yield from turmeric (Curcuma longa L) was studied using central composite rotatable design. The experimental value of curcumin yield ranged between 4.49 and 12.89%. The second order model obtained for curcumin yield revealed a coeffi cient of determination (R 2) of 0.78 and standard error of 0.72. The linear, square and interaction terms were signifi cant at p <0.05 while lack of fi t was non-signifi cant at p >0.05. Surface graphs were plotted to optimize the curcumin extraction. The maximum curcumin yield was obtained when temperature, particle size, mixing time and solvent to meal ratio were 60°C, 0.42 mm, 30 min and 50, respectively.

Low-frequency ionic current noise in solid-state nanopores imposes a limitation on the time resolution achieved in translocation experiments. Recently, this 1/ f noise was described as obeying Hooge's phenomenological relation, where the noise scales inversely with the number of charge carriers present. Here, we consider an alternative model in which the low-frequency noise originates from surface charge fluctuations. We compare the models and show that Hooge's relation gives the best description for the low-frequency noise in solid-state nanopores over the entire salt regime from 10 −3 to 1.6 M KCl.

Supporting information AFM Studies. Alkanethiol materials. 1-adamantanethiol (AD) of 95% purity was purchased from Sigma-Aldrich (Missouri, USA) and was used as received. Ethanol solvent of 99.99% purity was purchased from Gold Shield Chemical Co. (California, USA) and served as the solvent for AD. Preparation of 1-adamantanethiol Self-Assembled Monolayers (SAM). The SAM preparation used in this study follows established procedures. 1, 2 Gold with 99,999% purity was purchased from Alfa Aesar (Massachusetts, USA) was deposited in a high-vacuum evaporator (Model DV502-A, Denton Vacuum, New Jersey, USA) at a base pressure below 2 x 10-7 Torr onto freshly cleaved mica substrates

Background: The effectiveness of aerosol therapy is significantly reduced by the mucus layer covering the airways of the tracheobronchial tree. According to the present concept, drug particles are delivered to the lung together with the functional carrier particle that facilitates both the drug transport into the lungs and the penetration of deposited particles through the mucus. The approach of manufacturing multicomponent powders with mucoactive compounds and anti-asthmatic medicines (DSCG) bound together in a single particle is additionally considered. Methods: Powders were produced with the spray-drying technique from aqueous precursor solutions containing pure low molecular weight dextran, pure mannitol and dextran/mannitol-N-acetyl cysteine (NAC) mixtures (4:1 and 1:1). NAC has been selected for this purpose as a compound, which is known to be mucolytic. Dextran and mannitol are potentially applicable in the field of inhalation drug delivery. They have been used as stabilizers of functional carrier particles. Powders were characterized for their yield and physicochemical properties including: morphology (SEM), moisture content and thermal properties (DSC). Aerosol performance was determined with NGI impactor after standardized aerosolization of the produced powders in a commercial DPI. Results: Particle size distributions of dextran-NAC powders were characterized by high fine particle fraction (45-62%), which assures good particle deposition in the lower airways. The thermodynamic properties of the powders based on the temperature of the glass transition T g (50-63 • C) suggest the required stability during storage at moderate humidity. Conclusions: Preliminary examination of the required properties of these particles confirms their potential as functional carriers for pulmonary drug delivery.

It was investigated the effect of particle size, use of infrared radiation, and type of freeze-drying (vacuum or atmospheric) on some nutritional properties of blueberries. Particle size and type of freeze-drying had negative effects on ascorbic acid and total polyphenols content, while the use of infrared radiation had positive effects on them. Particle size negatively affected antioxidant activity. Ascorbic acid was significantly decreased in freeze-dried blueberries compared to fresh fruit, in all the conditions studied. The total polyphenols content was significantly lower in atmospheric freezedried blueberries compared to the fresh ones, unlike in vacuum freeze-drying, where this nutritional property was increased. Antioxidant activity of freeze-dried blueberries did not differ significantly from that found in fresh fruits. In order to minimize the impairment of the nutritional properties of freeze-dried blueberries, it is suggested to use infrared radiation, a relatively small particle size and vacuum freeze-drying.

The possibility of producing titanium alloy Ti ? 6Al ? 4V with minimal residual porosity from mixtures of elemental powders by the method of pressing and sintering without hot deformation during or after sintering was investigated. Various powder mixtures based on titanium and titanium hydride with alloying additions of either elemental powders having different particle sizes, or master alloys, were studied. It was shown that the synthesis of Ti ? 6Al ? 4V from mixtures of titanium hydride and master alloys is optimal with respect to the attainment of high relative density. In this case the sintered material has density up to 99%, homogeneous microstructure with relatively small (100-120 µm) ß-phase grains, and a low concentration of impurities, in particular oxygen, which provide a high level of mechanical properties s(ten = 970 MPa, d = 6%).

Cyclosporine (CsA), commercially available as iv or oral Sandimrnune, is a potent immunosuppressant which can induce doserelated nephrotoxocity. In addition, the iv product contains a solubilizing agent, Cremophore EL, which in itself is reported to be nephrotoxic and can induce, in sensitized patients, anaphylactic reactions. Solubilization of CsA with liposomes or lipid emulsions could provide a suitable alternative dosage form for iv administration. With this in mind, male New Zealand white rabbits were given iv CsA (10 mglkg) in three different dosage forms: (7) CsA:liposornes; (2) CsA:lntralipid (soybean oil and phospholipids); and (3) the commercially available Sandimmune (cyclosporine). The CsA concentration in whole blood samples was analyzed by HPLC. The terminal disposition half-life of CsA (t,,, p) ranged from 400 to 475 min and was not statistically different among the three groups. However, the distribution characteristics of CsA changed dramatically depending on the dosage form. The volume of distribution of CsA at steady state (Vd,,) in Sandimmune was 2.7 ? 0.2 Ukg and was significantly lower than that of either lntralipid (10.6-+ 2.7 Ukg) or liposomes (7.4-+ 2.3 Ukg). A significantly lower total body clearance (TBC) of CsA also was seen for Sandimmune (1 2.7 f 0.3 rnuminlkg) as compared with that of either lntralipid (24.4 f 8.2 mUminlkg) or liposomes (18.9 5 3.9 mUmin1kg). Since CsA is extensively bound to lipoproteins, it is surprising that both test vehicles showed a different distribution pattern. It is speculated that in addition to the benefit of removing Cremophore EL from the product, the different distribution of CsA:liposomes or CsA:lntralipid may prove useful in altering the nephrotoxocity and immunosuppression of CsA during iv therapy.

Embolism is responsible for half of cerebral infarctions, yet few animal models were developed due to the unpredictability of the embolus-induced infarcts. We manufactured artificial embolic particles by blending chitin and poly(D,L-Lactide-co-glycolide) (chitin/PLGA) for their good biocompatibility and rapid hydration expansion property. We subdivided the chitin/PLGA microparticles into 10 size groups (from 38e45 mm to 255e350 mm) and injected them through the external carotid artery toward the bifurcation of the common carotid artery in the rat. Reduced blood flow of the ipsilateral hemisphere was evident immediately after the injection of particles. The spherical appearance of the particle was critical in occluding the cerebral vessels. Particle 212e250mm produced the greatest diffuse infarction in the ipsilateral hemisphere, including the cortex, hippocampus, basal ganglion, thalamus, midbrain and cerebellum. Particle 75-90mm induced single or sparse isolated infarcts mainly located in the subcortical region, resembling lacunar stroke observed in humans. Particle 38e45mm frequently crossed to the contralateral hemisphere and induced diffuse infarctions in both hemispheres. The cortex infarct volumes were positively correlated to neurologic score and seizure incidence. In conclusion, we have established embolic stroke animal models, including a novel model that mainly expresses lacunar infarction, by intravenous injection of chitin/PLGA microparticles.

This study was designed to test the hypothesis that furosemide (Fur) can be entrapped into surfactant free pegylated nanocarriers (NCs) for controlled drug release. To test this hypothesis, Fur-loaded NCs were prepared by emulsion solvent diffusion method. A 2 3 factorial design was used to optimize the effect of three formulation variables [amounts of Fur (X 1 ), poly(lactic-co-glycolic acid) (X 2 ) and poly-caprolactone-polyethylene glycol (X 3 )] on particle mean diameter (Y 1 ), polydispersity index (PDI, Y 2 ), and percent drug encapsulation efficiency (EE%, Y 3 ). The NCs were characterized for morphology, thermal behavior, optical properties, crystallinity, and drug release kinetics using electron microscopy (EM), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), and high performance liquid chromatography, respectively. The optimum formula produced with 6 mg of Fur, 7 mg of PLGA, and 1 mg of PCL-PEG corresponded to 183.26 nm, 0.26, and 88.29% as Y 1 , Y 2 and Y 3 values, respectively. DSC thermograms, FTIR spectra and PXRD diffractograms indicated that Fur was encapsulated in its polymorphic crystalline form I within the NCs polymeric matrix. This was further confirmed by a comparative study between native Fur, Fur nanocrystal and Fur loaded NCs using scanning EM, PXRD and drug release kinetics. The release kinetics of the optimized formula fit the Higuchi model indicating that the drug was released by diffusion in 12 h. These results indicate that pegylated Fur-loaded NCs could be successfully prepared with high EE% and sustained release profile intended for the inner ear drug delivery.

A series of ceria nanoparticles were synthesized by using a microemulsion method. The effect of relative concentration of surfactant/water on the size and the surface roughness of ceria nanoparticles was examined using transmission electron microscopy (TEM) and atomic force microscopy (AFM) respectively. The investigation confirmed a relationship between the size and the roughness properties of the nanoceria as a function of the water to surfactant ratio. With increasing dilution of the surfactant, the size distribution became narrow such that average particle size decreased linearly as the ratio increased without affecting lower size threshold of particles (∼10 nm). The surface roughness, on the other hand was found to increase with increasing water to surfactant ratio implying diluted surfactant would provide rougher surface of ceria nanoparticles. The information can be used to tailor the adhesion properties of nanoceria by optimizing the size distribution as well as surface roughness as a function of water to surfactant ratio.

The effect of six different preservatives on the production process and stability of resveratrol nanosuspensions was investigated. Nanosuspensions of the anti-oxidant resveratrol were prepared by high pressure homogenization (1,500 bar, 20 homogenization cycles). The preservatives used were: caprylyl glycol (0.75%), Euxyl PE 9010 (1.0%), Hydrolite-5 (2.0), Phenonip (0.75%), Rokonsal PB-5 (0.5%) and MultiEx Naturotics (2.0%). Preservation is essential for oral and dermal nanosuspensions, but can impair the stability. The effect of the preservatives on stability as a function of cycle numbers was determined by size measurements (photon correlation spectroscopy (PCS), laser diffraction (LD) and light microscopy). Zeta potential measurements were performed for determination of the Stern potential (measurements in water) and as stability criterion (measurements in original dispersion medium), to elucidate the mechanism of destabilization. The preservatives could be placed into three grou...

Electrochemical insertion of sodium ions into carbon using solid polymer electrolytes or organic liquid electrolytes is described. Cells with the configuration Na/P(EO)sNaCF3SOJCP(EO) = polyethylene oxide) or Na/liquid electrolyte/C were galvanostatically discharged, charged, and cycled. The extent of insertion into C (Le., x in Na § was found to be a strong function of the type and particle size of the carbon used, and the reversibility of the process was highly dependent upon the type of electrolyte used. The possibility of designing a sodium ion rocking chair cell is discussed, and a first-generation example, using a petroleum coke anode, polymer electrolyte, and sodium cobalt bronze cathode is described.

Dry powder formulations are often composed of fine drug particles and coarser carrier particles, typically alpha-lactose monohydrate. However, the performance of a powder formulation may be highly dependent on the lactose quality and source. This study investigated the characteristics of lactose that influence the drug-to-carrier interaction and the performance of lactose-based dry powder inhaler formulations. The selected lactoses differed in the preparation processes and the content of fine lactose particles. Efficiency testing was done using fluticasone propionate and terbutaline sulphate as model drugs. Inverse gas chromatography was used to determine the surface heterogeneity distribution of different energy sites of the lactose and to understand the mechanism by which the fine carrier particles can improve the performance of dry powder inhalers. To assess the adhesion of respirable-sized drug to carrier particles, a simple method was developed based on aspiration and consideri...

In Part I the chemical and microstructural nature of Cu-K-V catalysts for diesel soot combustion was assessed. In this second communication the reaction mechanism of these catalysts is studied by testing their activity through either differential scanning calorimetry (DSC) or temperature-programmed oxidation (TPO), performed on catalyst-carbon mixtures. The following parameters were varied: the particle size of both the catalyst and the carbon powders, the catalyst-to-carbon weight ratio, the catalyst composition (besides the standard Cu-K-V catalyst defined in Part I, binary catalysts based on a single copper or potassium vanadate + KC1 were also considered).

An attempt to alleviate the problem caused by the presence of reactive dyes in textile effluents was undertaken. Since alunite is a very abundant and inexpensive, we decided to experiment with it as a potential adsorbent for a certain type of the supracited pollutants used in cellulose fibers dyeing. The adsorption of Reactive Blue 114 (RB114), Reactive Yellow 64 (RY64) and Reactive Red 124 (RR124) by calcined alunite was studied by varying parameters such as the calcination temperature and time, particle size, pH, agitation time and dye concentration. Acidic pH was favorable for the adsorption of RB114 and alkaline pH was favorable to both RY64 and RR124. The equilibrium data fit the Langmuir isotherm. The adsorption capacities were found to be 170.7, 236 and 153 mg dye per gram of calcined alunite for RB114, RY64 and RR124, respectively. The pseudo first-and second-order kinetic models were used to describe the kinetic data, and the rate constants were evaluated. The experimental data were fitted by the second-order kinetic model, which indicates that chemicalsorption is the rate limiting step, inside of mass transfer.

The purpose of the study was to develop a simple, sensitive and rapid RP-HPLC method for the determination of desloratadine in marketed products. Chromatographic determination was performed in a reverse phase C 18 column (250 mm × 3.3 mm I.D. , 5µm particle size) using a mixture of acetonitrile ‫׃‬ n-pentane sulphonic acid sodium salt monohydrate, adjusted to pH 3.0± 0.05 with phosphoric acid ‫׃06(‬ 40 v/v) as mobile phase and delivered at a flow rate of 1 ml/min. The UV detection was set at 254 nm. The calibration range was from 2.0 to 40 µg/ml. The method was validated in term of linearity (r 2 >0.98, RSD= 1.958%), precision (RSD=3.757 %) and accuracy (deviation<2.653%, RSD< 2.203%). The limit of quantification was 2 µg/ml and the limit of detection was 0.1 µg/ml. The linear ranges of desloratadine were 20.23 ± 0.368 µg/ml and 6.545 ± 0.0495 µg/ml in tablet (potency = 99.175 ± 0.718 %) and syrup (potency = 101.15 ± 1.838 %) respectively. The potency of desloratadine in marketed products was determined by this method with acceptable precision and reproducibility.

Selective partial oxidation of methane to syngas over LaNiO 3 , La 0.8 Ca(or Sr) 0.2 NiO 3 and LaNi 1−x Co x O 3 (where x = 0.2-1) perovskites at extremely short contact time ( ≈0.8 ms) has been investigated. Also, simultaneous oxidative conversion and steam and CO 2 reforming of methane to syngas over LaNiO 3 at short contact time ( ≈9 ms) has been studied at different temperatures and CH 4 /O 2 feed ratios. The catalysts, before and after reaction, were characterized by XRD and SEM. LaNiO 3 perovskite shows high activity and selectivity in the oxidative conversion of methane to syngas. However, the partial substitution of its La by Ca or Sr and also the partial or complete substitution of its Ni by Co causes a large decrease in both its activity and its selectivity. LaNiO 3 is transformed to its catalytically active form, Ni 0 /La 2 O 3 , during the initial period of the process. This catalyst shows very good performance in the simultaneous oxidative conversion (which is exothermic) and steam and CO 2 reforming reactions (which are endothermic) of methane to syngas, at short contact time, operating in a most energy efficient manner and also requiring only a little or no external energy.