Inhibition of progesterone receptor activity in recombinant yeast by soot from fossil fuel combustion emissions and air particulate materials

Numerous environmental pollutants have been detected for estrogenic activity by interacting with the estrogen receptor, but little information is available about their interactions with the progesterone receptor. In this study, emission samples generated by fossil fuel combustion (FFC) and air particulate material (APM) collected from an urban location near a traffic line in a big city of China were evaluated to interact with the human progesterone receptor (hPR) signaling pathway by examining their ability to interact with the activity of hPR expressed in yeast. The results showed that the soot of a petroleum-fired vehicle possessed the most potent anti-progesteronic activity, that of coal-fired stove and diesel fired agrimotor emissions took the second place, and soot samples of coal-fired heating work and electric power station had lesser progesterone inhibition activity. The anti-progesteronic activity of APM was between that of soot from petroleum-fired vehicle and soot from coal-fired establishments and diesel fired agrimotor. Since there was no other large pollution source near the APM sampling sites, the endocrine disrupters were most likely from vehicle emissions, tire attrition and house heating sources. The correlation analysis showed that a strong relationship existed between estrogenic activity and anti-progesteronic activity in emissions of fossil fuel combustion. The discoveries that some environmental pollutants with estrogenic activity can also inhibit OR activity indicate that further studies are required to investigate potential mechanisms for the reported estrogenic activities of these pollutants. (c) 2005 Elsevier B.V. All rights reserved.

Nanoporous metal organic framework materials for hydrogen storage

Hydrogen is expected to play an important role in future transportation as a promising alternative clean energy source to carbon-based fuels. One of the key challenges to commercialize hydrogen energy is to develop appropriate onboard hydrogen storage systems, capable of charging and discharging large quantities of hydrogen with fast enough kinetics to meet commercial requirements. Metal organic framework (MOF) is a new type of inorganic and organic hybrid nanoporous particulate materials. Its diverse networks can enhance hydrogen storage through tuning the structure and property of MOFs. The MOF materials so far developed adsorb hydrogen through weak dispersion interactions, which allow significant quantity of hydrogen to be stored at cryogenic temperatures with fast kinetics. Novel MOFs are being developed to strengthen the interactions between hydrogen and MOFs in order to store hydrogen under ambient conditions. This review surveys the development of such candidate materials, their performance and future research needs. (C) 2009 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

A bond model for DEM simulation of cementitious materials and deformable structures

There is an increasing use of the discrete element method (DEM) to study cemented (e.g. concrete and rocks) and sintered particulate materials. The chief advantage of the DEM over continuum based techniques is that it does not make assumptions about how cracking and fragmentation initiate and propagate, since the DEM system is naturally discontinuous. The ability for the DEM to produce a realistic representation of a cemented granular material depends largely on the implementation of an inter-particle bonded contact model. This paper presents a new bonded contact model based on the Timoshenko beam theory which considers axial, shear and bending behaviour of the bond. The bond model was first verified by simulating both the bending and dynamic response of a simply supported beam. The loading response of a concrete cylinder was then investigated and compared with the Eurocode equation prediction. The results show significant potential for the new model to produce satisfactory predictions for cementitious materials. A unique feature of this model is that it can also be used to accurately represent many deformable structures such as frames and shells, so that both particles and structures or deformable boundaries can be described in the same DEM framework. 

Substrate-induced coagulation (SIC) of nano-disperse carbon black in non-aqueous media : a method of manufacturing highly conductive cathode materials for Li-ion batteries by self-assembly

Substrate-induced coagulation (SIC) is a coating process based on self-assembly for coating different surfaces with fine particulate materials. The particles are dispersed in a suitable solvent and the stability of the dispersion is adjusted by additives. When a surface, pre-treated with a flocculant e.g. a polyelectrolyte, is dipped into the dispersion, it induces coagulation resulting in the deposition of the particles on the surface. A non-aqueous SIC process for carbon coating is presented, which can be performed in polar, aprotic solvents such as N-Methyl-2- pyrrolidinone (NMP). Polyvinylalcohol (PVA) is used to condition the surface of substrates such as mica, copperfoil, silicon-wafers and lithiumcobalt oxide powder, a cathode material used for Li-ion batteries. The subsequent SIC carbon coating produces uniform layers on the substrates and causes the conductivity of lithiumcobalt oxide to increase drastically, while retaining a high percentage of active battery material.

Auger spectroscopy of stratospheric particles : the influence of aerosols on interplanetary dust

Particle collections from the stratosphere via either the JSC Curatorial Program or the U2 Program (NASA Ames) occur between 16km and 19km altitude and are usually part of ongoing experiments to measure parameters related to the aerosol layer. Fine-grained aerosols (<0.1µm) occur in the stratosphere up to 35km altitude and are concentrated between 15km and 25km altitude[1]. All interplanetary dust particles (IDP's) from these stratospheric collections must pass through this aerosol layer before reaching the collection altitude. The major compounds in this aerosol layer are sulfur rich particulates (<0.1µm) and gases and include H2S04, OCS, S02 and CS2 [2].In order to assess possible surface reactions of interplanetary dust particles (IDP's) with ambient aerosols in the stratosphere, we have initiated a Surface Auger Microprobe (SAM) and electron microscope study of selected particles from the JSC Cosmic Dust Collection.

Accurate stratospheric particle size distributions from two separate flat-plate collection surfaces

Over the past two decades, flat-plate particle collections have revealed the presence of a remarkable variety of both terrestrial and extraterrestrial material in the stratosphere [1-6]. The ratio of terrestrial to extraterrestrial material and the nature of material collected may vary over observable time scales. Variations in particle number density can be important since the earth’s atmospheric radiation balance, and therefore the earth’s climate, can be influenced by articulate absorption and scattering of radiation from the sun and earth [7-9]. In order to assess the number density of solid particles in the stratosphere, we have examined a representative fraction of the so1id particles from two flat-plate collection surfaces, whose collection dates are separated in time by 5 years.

Mineralogy of chondritic interplanetary dust particles

From a mineralogical survey of approximately 30 chondritic micrometeorites collected from the lower stratosphere and studied in detail using current electron microscopy techniques, it is concluded that these particles represent a unique group of extraterrestrial materials. These micrometeorites differ significantly in form and texture from components of carbonaceous chondrites and contain some mineral assemblages which do not occur in any meteorite class. Electron microscope investigations of chondritic micrometeorites have established that these materials (1) are extraterrestrial in origin, (2) existed in space as small objects, (3) endured minimal alteration by planetary processes since formation, and (4) can suffer minimal pulse heating (<600°C) on entering earth's atmosphere. The probable sources for chondritic interplanetary dust particles (IDPs) are cometary and asteroidal debris and, perhaps to a lesser extent, interstellar regions. These sources have not been conclusively linked to any specific mineralogical subset of IDP, although the chondritic porous (CP) aggregate is considered of likely cometary origin. Chondritic IDPs occur in two predominant mineral assemblages: (1) carbonaceous phases and phyllosilicates and (2) carbonaceous phases and nesosilicates or inosilicates, although particles with both types of silicate assemblages are observed. Olivines, pyroxenes, layer silicates, and carbon-rich phases are the most commonly occurring minerals in many chondritic IDPs. Other phases often observed in variable proportions include sulphides, spinels, metals, metal carbides, carbonates, and minor amounts of sulphates and phosphates. Individual mineral grain sizes range from micrometers (primarily pyroxenes and olivines) to nanometers, with the predominant size for all phases less than 100 nm. Specific mineral characteristics for particular chondritic IDPs provide an indication of processes which may have occurred prior to collection in the earth's stratosphere. For example, pyroxene mineralogy in some chondritic aggregates is consistent with condensation from a vapor phase and, we consider, with condensation in a turbulent solar nebula at relatively low temperatures (<1000°C). Carbonaceous phases present in other CP aggregates have been used to imply low-temperature formation processes such as Fischer-Tropsch synthesis (∼530°C) or carbonization and graphitization (∼315°C). Alteration processes have been implicated in the formation of some layer silicates in CP aggregates and may have involved hydrocryogenic alteration at <0°C. In general, interpretations of transformation processes on submicrometer-size minerals in chondritic IDPs are consistent with formation at a radius equivalent to the asteroid belt or greater during the later stages of solar nebula evolution using currently available models.

Mineralogy of chondritic porous aggregates : current status

Chondritic porous aggregates (CPA's) belong to an important subset of small particles (usually between 5 and 50 micrometers) collected from the stratosphere by high flying aircraft. These aggregates are approximately chondritic in elemental abundance and are composed of many thousands of small­er, submicrometer particles. CPA particles have been the subject of intensive study during the past few years [1-3] and there is strong evidence that they are a new class of extraterrestrial material not represented in the meteorite collection [3,4]. However, CPA's may be related to carbonaceous chondrites and in fact, both may be part of a continuum of primitive extraterrestrial materials [5]. The importance of CPA's stems from suggestions that they are very primitive solar system material possibly derived from early formed proto­ planets, chondritic parent bodies, or comets [3, 6]. To better understand the origin and evolution of these particles, we have attempted to summarize all of the mineralogical data on identified CPA's published since about 1976.

Water ingression and the role of interface on the compressive properties of epoxy filled with treated fly ash

Polymer composites are generally filled with either fibrous or particulate materials to improve the mechanical properties. In choosing the fillers one looks for materials that are inexpensive and available in abundance, in order to realize a cost reduction also. Also, often these fibres/fillers are treated to improve the matrix adhesion and thereby mechanical properties. The present study is focussed on the influence of water ingression in such filler-modified composites and the attendant changes in the compressive properties. The changes in property effected following exposure to aqueous media and the influence interface modification has on the scenario is emphasized in the work. It is seen that for plain epoxy and fly ash filled systems the strengths are increased following exposure to aqueous media. The composites with surface-treated ash particles, on the other hand, record a drop in the values. Modulus values show are increased to varying degree in unfilled and filled systems. The study also includes a fractographic analysis of the tested samples with and without exposure to water.

Study of environmental burden of lead in children using teeth as bioindicator

The south region of Sao Paulo city hosts the Guarapiranga dam, responsible for water supply to 25% of the city population. Their surroundings have been subject to intense and irregular occupation by people from very low socioeconomics classes. Measurements undertaken on sediment and particulate materials in the dam revealed concentrations of lead. copper, zinc and cadmium above internationally accepted limits. Epidemiological and toxicological studies undertaken by the World Health Organization in individuals exhibiting lead concentrations in blood, near or below the maximum recommended (10 mu g dl(-1)), surprisingly revealed that toxic effects are more intense in individuals belonging to low socioeconomics classes. Motivated by these facts, we aimed at the investigation of chronic incorporation of lead. as well as the use of our BIOKINETICS code, which is based on an accepted ICRP biokinetics model for lead, in order to extrapolate the results from teeth to other organs. The focus of our data taking was children from poor families, living in a small, restrict and allegedly contaminated area in Sao Paulo city. Thus, a total of 74 human teeth were collected. The average concentration of lead in teeth of children 5 to 10 years old was determined by means of a high-resolution inductively coupled plasma mass spectrometer (ICP-MS). For standardization of the measurements, an animal bone certified material (H-Animal Bone), from the International Atomic Energy Agency, was analyzed. The amount of lead in children living in the surroundings of the dam, was approximately 40% higher than those from the control region, and the average lead concentration was equal to 1.3 mu g g(-1) approximately. Grouping the results in terms of gender, tooth type and condition, it was concluded that a carious molar of boys is a much more efficient contamination pathway for lead, resulting in concentrations 70% higher than in the control region. We also inferred the average concentrations of lead in other organs of these children, by making use of our BIOKINETIC code. (C) 2008 Elsevier Ltd. All rights reserved.

Nano related research in fibres and textiles

With the increasing hype surrounding what nanotechnology can actually deliver, research emphasis in this area needs to be placed on how nanotechnology can bring tangible benefits to existing industries and ordinary consumers. This paper gives selected examples of real world applications of nano-structured materials, including nano fibrous and particulate materials. It reviews recent research into nano-structured surface coating of textile substrates for enhanced functionalities, and the development of fine and uniform nanofibres for advanced applications. Emphasis has been placed on relevant research activities in the Centre for Material and Fibre Innovation at Deakin University, Australia. In the nano-structured surface coating area, several examples of enhancing fabric performance and functionality are provided, including silica coating for photochromic textiles, superhydrophobic surface coating and transparent ZnO coating to reduce colour fading of textiles exposed to UV radiation. In the nanofibre area, these activities include: elimination of beaded fibres without increasing the average diameter of the electrospun nanofibres, electrospinning of side-by-side bi-component nanofibres, new insight into the evolution of fibre morphology in electrospinning and the electrospinning technology itself.

A new approach to the granulation of beta-cyclodextrin inclusion complexes

Cyclodextrins (CDs) are annular oligosaccharides containing 6-12 glucose unities joined together by alpha-1,4 bonds. They have a conical-truncated shape with a lipophilic cavity in which different molecules can be included resulting in a stable inclusion complex. The cyclodextrins have been widely applied in pharmaceutical technology with the objective of increasing the solubility, stability and bioavailability of drugs in different pharmaceutical dosage forms, such as tablets. In order to obtain beta-CD tablets, liquid dispersions of drug/beta-CD are usually submitted to different drying processes, like spray-drying, freeze-drying or slow evaporation, being this dry material added to a number of excipients. However, such drying processes can generate particulate materials showing problems of flow and compressibility, needing their conversion into granulates by means of wetting with granulation liquid followed by additional drying. In this work, the main objective was to evaluate the preparation of tablets without the need of this additional drying step. For this purpose an aqueous dispersion containing acetaminophen/beta-CD complex and cornstarch was dried using a spouted bed and the obtained granules were compressed in tablets. Acetaminophen was used as model drug due to its low water solubility and the inexpensive and widely available cornstarch was chosen as excipient. Acetaminophen powder was added into a beta-cyclodextrin solution prepared in distilled water at 70 degrees C. Stirring was kept until this dispersion cooled to room temperature. Then cornstarch was added and the resulting dispersion was dried in spouted bed equipment. This material was compressed into tablets using an Erweka Korsh EKO tablet machine. This innovative approach allowed the tablets preparation process to be carried out with fewer steps and represents a technological reliable strategy to produce beta-cyclodextrin inclusion complexes tablets. (C) 2010 Elsevier By. All rights reserved.

Use of levoglucosan, potassium, and water-soluble organic carbon to characterize the origins of biomass-burning aerosols

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of environmental burden of lead in children using teeth as bioindicator

The south region of São Paulo city hosts the Guarapiranga dam, responsible for water supply to 25% of the city population. Their surroundings have been subject to intense and irregular occupation by people from very low socioeconomics classes. Measurements undertaken on sediment and particulate materials in the dam revealed concentrations of lead. copper, zinc and cadmium above internationally accepted limits. Epidemiological and toxicological studies undertaken by the World Health Organization in individuals exhibiting lead concentrations in blood, near or below the maximum recommended (10 mu g dl(-1)), surprisingly revealed that toxic effects are more intense in individuals belonging to low socioeconomics classes. Motivated by these facts, we aimed at the investigation of chronic incorporation of lead. as well as the use of our BIOKINETICS code, which is based on an accepted ICRP biokinetics model for lead, in order to extrapolate the results from teeth to other organs. The focus of our data taking was children from poor families, living in a small, restrict and allegedly contaminated area in São Paulo city. Thus, a total of 74 human teeth were collected. The average concentration of lead in teeth of children 5 to 10 years old was determined by means of a high-resolution inductively coupled plasma mass spectrometer (ICP-MS). For standardization of the measurements, an animal bone certified material (H-Animal Bone), from the International Atomic Energy Agency, was analyzed. The amount of lead in children living in the surroundings of the dam, was approximately 40% higher than those from the control region, and the average lead concentration was equal to 1.3 mu g g(-1) approximately. Grouping the results in terms of gender, tooth type and condition, it was concluded that a carious molar of boys is a much more efficient contamination pathway for lead, resulting in concentrations 70% higher than in the control region. We also inferred the average concentrations of lead in other organs of these children, by making use of our BIOKINETIC code. (C) 2008 Elsevier Ltd. All rights reserved.

Pre-harvest sugarcane burning: Determination of emission factors through laboratory measurements

Sugarcane is an important crop for the Brazilian economy and roughly 50% of its production is used to produce ethanol. However, the common practice of pre-harvest burning of sugarcane straw emits particulate material, greenhouse gases, and tropospheric ozone precursors to the atmosphere. Even with policies to eliminate the practice of pre-harvest sugarcane burning in the near future, there is still significant environmental damage. Thus, the generation of reliable inventories of emissions due to this activity is crucial in order to assess their environmental impact. Nevertheless, the official Brazilian emissions inventory does not presently include the contribution from pre-harvest sugarcane burning. In this context, this work aims to determine sugarcane straw burning emission factors for some trace gases and particulate material smaller than 2.5μm in the laboratory. Excess mixing ratios for CO2, CO, NOX, UHC (unburned hydrocarbons), and PM2.5 were measured, allowing the estimation of their respective emission factors. Average estimated values for emission factors (g kg-1 of burned dry biomass) were 1,303 ± 218 for CO2, 65 ± 14 for CO, 1.5 ± 0.4 for NOX, 16 ± 6 for UHC, and 2.6 ± 1.6 for PM2.5. These emission factors can be used to generate more realistic emission inventories and therefore improve the results of air quality models. © 2012 by the authors; licensee MDPI, Basel, Switzerland.