Major Inorganic Constituents Research Articles

Optimization of Biologically Inspired Electrospun Scaffold for Effective Use in Bone Regenerative Applications.

Human bone is composed of organic and inorganic composite materials, contributing to its unique strength and flexibility. Hydroxyapatite (HAP) has been extensively studied for bone regeneration, due to its excellent bioactivity and osteoconductivity, which makes it a highly valuable biomaterial for tissue engineering applications. For better therapeutic effects, composite nanofibers containing polyvinyl alcohol (PVA) and polyvinyl Pyrrolidone (PVP) were developed using an electrospinning technique in this study. Herein, hydroxyapatite (a major inorganic constituent of native bone) concentrations varying from 5 to 25% were reinforced in the composite, which could alter the properties of nanofibers. The as-prepared composite nanofibers were characterized by SEM, TEM, XRD, and FT-IR spectroscopy, and a bioactivity assessment was performed in simulated body fluid (SBF). The ICP-OES analysis was used to determine the concentration of Ca2+ and PO42- ions before and after SBF immersion. To optimize the material selection, the nanofibrous scaffolds were subjected to cell proliferation and differentiation in MG-63 osteoblast cell lines, but no significant toxicity was observed. In conclusion, HAP-PVA-PVP scaffolds exhibit unique physical and chemical properties and ideal biocompatibility, with great promise to serve as effective candidates for bone tissue applications.

Consistent histories of anthropogenic western European air pollution preserved in different Alpine ice cores

Abstract. Individual high-Alpine ice cores have been proven to contain a well-preserved history of past anthropogenic air pollution in western Europe. The question of how representative one ice core is with respect to the reconstruction of atmospheric composition in the source region has not been addressed so far. Here, we present the first study systematically comparing longer-term ice-core records (1750–2015 CE) of various anthropogenic compounds, such as major inorganic aerosol constituents (NH4+, NO3-, SO42-), black carbon (BC), and trace species (Cd, F−, Pb). Depending on the data availability for the different air pollutants, up to five ice cores from four high-Alpine sites located in the European Alps analysed by different laboratories were considered. Whereas absolute concentration levels can partly differ depending on the prevailing seasonal distribution of accumulated precipitation, all seven investigated anthropogenic compounds are in excellent agreement between the various sites for their respective, species-dependent longer-term concentration trends. This is related to common source regions of air pollution impacting the four sites less than 100 km away including western European countries surrounding the Alps. For individual compounds, the Alpine ice-core composites developed in this study allowed us to precisely time the onset of pollution caused by industrialization in western Europe. Extensive emissions from coal combustion and agriculture lead to an exceeding of pre-industrial (1750–1850) concentration levels already at the end of the 19th century for BC, Pb, exSO42- (non-dust, non-sea salt SO42-), and NH4+, respectively. However, Cd, F−, and NO3- concentrations started surpassing pre-industrial values only in the 20th century, predominantly due to pollution from zinc and aluminium smelters and traffic. The observed maxima of BC, Cd, F−, Pb, and exSO42- concentrations in the 20th century and a significant decline afterwards clearly reveal the efficiency of air pollution control measures such as the desulfurization of coal, the introduction of filters and scrubbers in power plants and metal smelters, and the ban of leaded gasoline improving the air quality in western Europe. In contrast, NO3- and NH4+ concentration records show levels in the beginning of the 21th century which are unprecedented in the context of the past 250 years, indicating that the introduced abatement measures to reduce these pollutants were insufficient to have a major effect at high altitudes in western Europe. Only four ice-core composite records (BC, F−, Pb, exSO42-) of the seven investigated pollutants correspond well with modelled trends, suggesting inaccuracies of the emission estimates or an incomplete representation of chemical reaction mechanisms in the models for the other pollutants. Our results demonstrate that individual ice-core records from different sites in the European Alps generally provide a spatially representative signal of anthropogenic air pollution trends in western European countries.

Aluminum speciation in forest soils and forest floor density fractions using synchrotron-based XANES spectroscopy

The speciation of aluminum (Al) in soils is important for Al cycling and Al toxicity in terrestrial ecosystems. Current soil Al speciation methods are mostly wet-chemical, discriminating among operationally defined fractions rather than distinct Al species. We performed synchrotron-based X-ray absorption near edge structure (XANES) spectroscopy at the Al K-edge (1560 eV) for Al speciation in different horizons of three forest soil profiles and O layer density fractions. We deconvoluted the spectra by linear combination fitting (LCF; 1550–1690 eV), using reference spectra of 22 diluted inorganic and organic Al-bearing soil constituents. Our first time application of Al XANES spectroscopy + LCF for soil Al speciation revealed methodological challenges and difficulties. Thus, a minimum sample Al content of 5 mg g−1 was necessary to yield spectra with satisfactory signal-to-noise ratio in reasonable acquisition time, and Al contents > 15 mg g−1 resulted in spectrum distortion by self absorption, requiring adequate sample dilution prior to XANES analysis. Nevertheless, Al K-edge XANES spectroscopy allowed for estimating the relative contribution of different Al species to total Al in our soil and density fraction samples. The Al XANES spectra of different Al carboxylates were very similar. The same was true for different Al phenol species, different 2:1 clay minerals (illite, montmorillonite, chlorite), different 1:1 clay minerals (kaolinite, halloysite), and different feldspars (orthoclase, anorthite), jeopardizing a reliable differentiation and quantification of these specific compounds. We therefore combined these compounds into the groups SOM carboxyl(ate)-bound Al, SOM phenol-bound Al, 1:1 clay mineral-bound Al, 2:1 clay mineral-bound Al, and feldspar-bound Al. XANES results showed a decreasing contribution of organically bound Al to total soil Al with soil depth (O layers 20–43 %; Ah horizons 10–22 %; B horizons 0–12 %). Major inorganic Al-bearing constituents in the fine earth of all soils were 2:1 clay minerals and feldspars, followed by 1:1 clay minerals (kaolinite), and Fe oxyhydroxides with partial Al substitution. Gibbsite or allophane did contribute only marginally to fine-earth Al in our soils. Different Oa layer density fractions with different SOM content and SOM decomposition status also differed in Al content and Al speciation, indicating the existence of spatially separated forest floor constituents with different Al speciation. Aluminum in the mineral-dominated density fraction > 1.6 g cm−3 with advanced SOM decomposition, comprising about 50 % of total Oa mass, was entirely bound in clay minerals (65–70 % of total Al) and feldspars (30–35 % of total Al). In contrast, Al in the mineral-poor density fraction < 1.0 g cm−3 was entirely bound to SOM as Al-organo complex, with Al bound to SOM phenol groups (>75 % of total Al) being more relevant than Al bound to SOM carboxyl(ate) groups. However, the latter density fraction comprised only 4 % of total Oa mass in both soils. Aluminum K-edge XANES spectroscopy, particularly when combined with total element analysis and XRD, is a promising novel tool for speciation of Al in soils and in SOM-mineral associations, with a great potential to promote our understanding of Al biogeochemistry in terrestrial ecosystems.

Calcium Phosphate Nanoparticles as Carriers of Therapeutic Peptides

Calcium phosphate is a natural biomineral and the major inorganic constituent of bones and teeth. Therefore, synthetic calcium phosphates that mimic the biogenic ones possess excellent biocompatibility as well as biodegradability and are promising materials for medicine. Due to their unique physiochemical properties, calcium phosphate nanoparticles (CaP NPs) are extensively exploited in nanomedicine as carriers of biomolecules, including peptides, proteins, and nucleic acids. In this regard, peptides are of particular interest as they are exceptionally selective and efficacious for the treatment of a broad range of diseases. Among various peptides for biomedical applications, cardio-specific peptides are particularly interesting since they represent a valuable alternative to conventional treatments. Moreover, they can contribute to overcome important clinical limitations, including drug resistance and non-specific biodistribution of traditional drug products. In this work, we have investigated the loading of a therapeutic mimetic peptide, which was previously shown to improve myocardial contraction and results in the restoration of cardiac function. Peptide-loaded CaP NPs were prepared by exploiting a biomineralization approach, by using a mineralizing solution containing Ca2+, Mg2+, and PO43- ions. Several experimental conditions were tested by varying the reaction time, as well as the drug concentration. Colloidal stability, morphology, size, as well as drug loading were evaluated to identify the best candidate to be tested in vitro in the future.

Mine Water Source Discrimination Based on Hydrogeochemical Characteristics in the Northern Ordos Basin, China

Sudden inrushes of mine water from coal roofs threaten the safe production of coal in China’s northern Ordos Basin. However, due to similar hydrochemical characteristics, routine hydrochemical analysis fails to discriminate the water sources. In this study, a new method, based on the characteristics of dissolved organic matter (DOM), the major inorganic constituents, and environmental isotopes was used to discriminate mine water sources. It turns out that the total dissolved solids concentration is less than 560.0 mg/L in the shallow aquifer and surface water, but exceeds 1000 mg/L in the deep aquifers. The concentrations of deuterium (D) and oxygen isotope (18O) gradually decrease in the Quaternary, Cretaceous, and Jurassic aquifers, and with increased burial depth, the age of groundwater increases. The surface water and underground aquifers differ with respect to the concentration, type, fluorescence intensity, and fluorescence regional integral of DOM. The DOM concentration and the fluorescent parameter values both generally decrease with increased burial depth. Comprehensive analysis of DOM, inorganic constituents, and environmental isotopes in water samples can be used to distinguish water sources, which may help prevent and control mine water hazards in the study area.

Hydroxyapatite nanoparticles synthesized via reverse microemulsions and their adsorption/desorption properties with enrofloxacin

Calcium phosphates are regularly used in biomedical materials, such as bone cement, bone replacement material and drug carriers, as they are the major inorganic constituents of human hard tissue. Different pH conditions were tested to obtain calcium phosphate materials. In acidic conditions, the brushite or monetite phases with bulk structures were synthesized even while keeping a constant Ca/P ratio of 1.67; by contrast, at alkaline conditions, the hydroxyapatite phase was found to exhibit a needle-like shape. An annealing process on the hydroxyapatite phase generated nanoparticles featuring improved crystallinity and a quasi-spherical shape. The results showed that the pH bears a direct effect on the resulting calcium phosphate phase, and only in alkaline conditions it was possible to reach the hydroxyapatite phase; also, the Ca/P ratio in the starting reagents plays an important role in the morphology of the final product. An analysis of the efficiencies of adsorption and desorption of the antibiotic enrofloxacin was carried out on the quasi-spherical hydroxyapatite nanoparticles. It was demonstrated that these nanoparticles could be loaded with 92% of the enrofloxacin in solution and they can also deliver 74% of the antibiotic during the first 12 h, which could prove useful if these nanoparticles are used as coatings for dental or orthopedic implants.

Impact of Gamma Radiation and Rice Husk Nanosilica on the Physico-Mechanical Properties of Styrene Butadiene Rubber/Natural Rubber Blend

Silica is the major inorganic constituent of the rice husk. High-surface area amorphous silica, Extracted Nanosilica (ENS), was developed by washing out the rice husk, followed by combustion and finally chemically treated. ENS was characterized by FTIR, XRD and TEM techniques. Reinforcement of natural rubber (NR)/styrene butadiene rubber (SBR) blend with varying ratio of ENS, namely 5, 10 and 20 phr, and separately with 20 phr Hisil (commercial silica) was established. Vulcanization of the produced composites was applied by gamma irradiation at a total dose range from 50 to 200 kGy. The radiation-cured nanocomposites were examined via mechanical, physical and thermal investigations. The SEM micrographs affirmed the homogenous distribution of silica particles throughout the polymer matrices. The results ensured noticeable enhancement in the investigated properties of the nanocomposites.

Extraction of high purity amorphous silica from rice husk by chemical process

High purity amorphous silica (SiO2) is extracted from agriculture waste (rice husk) that supplied from Al-Najaf province, Iraq. Silica is the major inorganic constituent of the rice husk. It is prepared with using acid pretreatment of (3N HCl), then burned it at (700°C) for 4 hrs, and followed with leaching process by 1.5, 2, 2.5, and 3N NaOH. The extracted results are high-surface area of amorphous silica particles. Extracted results are silica particles were high surface area of amorphous silica particles. These particles were characterized by X-Ray diffraction (XRD), and X-Ray Fluorescence (XRF) and Atomic force microscopy (AFM) techniques. High pure amorphous silica observed from rice husk ash was confirmed by XRD diffraction. The silica purity results measured by X-Ray fluorescence was 99.714% for leaching at 3N NaOH. Results from (AFM) of silica with nanoscale sizes and microparticles with diameters ranging from (87-114) nm.

Digital Microfluidics for the Detection of Selected Inorganic Ions in Aerosols.

A prototype aerosol detection system is presented that is designed to accurately and quickly measure the concentration of selected inorganic ions in the atmosphere. The aerosol detection system combines digital microfluidics technology, aerosol impaction and chemical detection integrated on the same chip. Target compounds are the major inorganic aerosol constituents: sulfate, nitrate and ammonium. The digital microfluidic system consists of top and bottom plates that sandwich a fluid layer. Nozzles for an inertial impactor are built into the top plate according to known, scaling principles. The deposited air particles are densely concentrated in well-defined deposits on the bottom plate containing droplet actuation electrodes of the chip in fixed areas. The aerosol collection efficiency for particles larger than 100 nm in diameter was higher than 95%. After a collection phase, deposits are dissolved into a scanning droplet. Due to a sub-microliter droplet size, the obtained extract is highly concentrated. Droplets then pass through an air/oil interface on chip for colorimetric analysis by spectrophotometry using optical fibers placed between the two plates of the chip. To create a standard curve for each analyte, six different concentrations of liquid standards were chosen for each assay and dispensed from on-chip reservoirs. The droplet mixing was completed in a few seconds and the final droplet was transported to the detection position as soon as the mixing was finished. Limits of detection (LOD) in the final droplet were determined to be 11 ppm for sulfate and 0.26 ppm for ammonium. For nitrate, it was impossible to get stable measurements. The LOD of the on-chip measurements for sulfate was close to that obtained by an off-chip method using a Tecan spectrometer. LOD of the on-chip method for ammonium was about five times larger than what was obtained with the off-chip method. For the current impactor collection air flow (1 L/min) and 1 h collection time, the converted LODs in air were: 0.275 μg/m3 for sulfate, 6.5 ng/m3 for ammonium, sufficient for most ambient air monitoring applications.

A review on polyphosphate coacervates—structural properties and bioapplications

The coacervation process of Graham’s Salt Na(PO3)n enabled the preparation of polyphosphate coacervates (CPPs) by adding different metallic ions (Mn+), and/or low-molecular-weight solvents at a specific solution, which resulted in a phase separation. The more viscous phase is termed as CPP and the less viscous one is the supernatant. CPPs have been extensively studied in recent years as a glass precursor at room temperature. Preparation at room temperature allows the preservation of the physicochemical properties of a wide range of active principles that may be used in controlled drug-delivery systems. Despite the present limitations of CPPs in terms of high hygroscopicity, this vulnerability to water is considered one of the great advantages of this material regarding applications in the controlled release of drugs and tissue engineering. Thus, in the presence of water, CPPs will dissolve in calcium and phosphate ions, which are the major inorganic constituents of bone and hydroxyapatite (HAP). It is believed that, in contact with body fluids, CPPs will degrade and, as this process occurs, they will be replaced by HAP. Therefore, CPPs configure a potential biomaterial that offers excellent properties with a wide range of biomedical applications that will be discussed and reviewed in this paper, including the structural properties and the recent improvements of materials based on CPPs and related devices.

Biosynthesis of Hydroxyapatite Nanoparticles, Characterization for the Treatment of Prostate Cancer in Nursing Care

Hydroxyapatite [Ca10(PO4)6(OH)2] is the one of the major inorganic constituents of natural bone, which has been broadly used in medical and biological applications. The present research work reports on the preparation of hydroxyapatite nanoparticles (HA NPs) via a green and eco-friendly approach based on the use of pectin. The crystalline size, purity and morphology of the as-fabricated HA NPs were studied by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, energy dispersive X-ray (EDAX) spectroscopic analysis and scanning electron microscopy (SEM), correspondingly. Further, cytotoxicity investigations showed a dose dependent cytotoxicity towards prostate cancer cells (PC3 cells). Overall, the results illustrated herein suggest that the as-developed HA NPs may offer prospects for the development of drugs for prostate cancer treatment in nursing care for children.

Synthesis and Characterization of Chitosan- Polyvinyl alcohol Blend Modified by Genipin and Nanohydroxyapatite for Bone Tissue Engineering

Use nanohydroxyapatite into the polymeric matrix as bioactive material for bone tissue engineering has enormous therapeutic potential because beneficial properties biocompatibility, biodegradability, and consider a major inorganic constituent of the bone matrix. The blended films of Chitosan and Polyvinyl alcohol with Genipin as cross-link agent were studied with and without addition Nanohydroxyapatite. Samples were prepared by solvent casting. The resulting films blended composite were characterized by Fourier transfer infrared (FTIR) spectroscopy, degradation behavior, swelling degree and tensile strength. Degree of swelling, and weight loss of the films blended composite was decreased with an increase of genipin and nanohydroxyapatie concentrations while tensile strength was increased with an increase of genipin and nanohydroxyapaite concentrations. The results showed that the chitosan composite could be used as effective biomaterials for bone regeneration engineering with different degradation rates.

Adsorption/desorption studies of norfloxacin on brushite nanoparticles from reverse microemulsions

Calcium phosphates are used in biomedical materials, such as bone cement, bone replacement material and drug carriers, as they are the major inorganic constituents of hard human tissue. Different reverse microemulsions were prepared to synthesize brushite materials with diverse shapes and sizes. SEM analysis showed that from ME1 an irregular amorphous material was obtained, those from ME2 formed macroscopic sheets and nanoparticles synthesized from ME3 formed nanorods-like structures. Due to their size and shape, those nanoparticles were used as drug carriers for controlled drug release. The results suggest a direct effect of the type of reverse microemulsion used, and that the amount of water added to the reverse microemulsion may also affect the phase of the final material. An evaluation of adsorption and desorption of the antibiotic norfloxacin was carried out on the nanoparticles obtained from ME3 and demonstrated that the nanoparticles could be used not only as a tissue engineering material but also as a controlled drug delivery system.

Oxidation of Pharmaceuticals by Ferrate(VI) in Hydrolyzed Urine: Effects of Major Inorganic Constituents.

Destruction of pharmaceuticals excreted in urine can be an efficient approach to eliminate these environmental pollutants. However, urine contains high concentrations of chloride, ammonium, and bicarbonate, which may hinder treatment processes. This study evaluated the application of ferrate(VI) (FeVIO42-, Fe(VI)) to oxidize pharmaceuticals (carbamazepine (CBZ), naproxen (NAP), trimethoprim (TMP), and sulfonamide antibiotics (SAs)) in synthetic hydrolyzed human urine and uncovered new effects from urine's major inorganic constituents. Chloride slightly decreased pharmaceuticals' removal rate by Fe(VI) due to the ionic strength effect. Ammonium (0.5 M) in undiluted hydrolyzed urine posed a strong scavenging effect, but lower concentrations (≤0.25 M) of ammonium enhanced the pharmaceuticals' degradation by 300 μM Fe(VI), likely due to the reactive ammonium complex form of Fe(V)/Fe(IV). For the first time, bicarbonate was found to significantly promote the oxidation of aniline-containing SAs by Fe(VI) and alter the reaction stoichiometry of Fe(VI) and SA from 4:1 to 3:1. In depth investigation indicated that bicarbonate not only changed the Fe(VI)/SA complexation ratio from 1:2 to 1:1 but provided a stabilizing effect for Fe(V) intermediate formed in situ, enabling its degradation of SAs. Overall, the results of this study suggested that Fe(VI) is a promising oxidant for the removal of pharmaceuticals in hydrolyzed urine.

Influence of inherent alkali metal chlorides on pyrolysis mechanism of a lignin model dimer based on DFT study

In order to understand the catalytic effects of inherent inorganic elements in biomass on the pyrolysis mechanism of lignin, density functional theory with a Gaussian method of M06-2X and basic set of 6-31 + G(d,p) was employed to simulate the pyrolysis pathways of a β-O-4 type lignin dimer model compound (1-methoxy-2-(4-methoxyphenethoxy)benzene) catalyzed by NaCl and KCl which are major inorganic constituents of biomass at microscale level. The calculation results indicate that cations (Na+ and K+) in alkali metal chlorides are facile to combine with the oxygen-containing functional groups in the lignin dimer model compound. Both cations increase the Cβ−O bond length and shorten the Cα–Cβ bond length, which will further affect their bond dissociation energies. In the initial pyrolysis process of the lignin dimer model compound, NaCl and KCl can promote the Cβ–O homolytic reaction and concerted decomposition reaction, while restrain the Cα–Cβ homolytic reaction. Therefore, the lignin dimer model compound decomposes mainly through the concerted decomposition and Cβ–O homolytic mechanisms under NaCl and KCl catalytic pyrolysis conditions, producing 1-methoxy-4-vinylbenzene, 1-ethyl-4-methoxybenzene, 2-methoxyphenol, catechol and 2-hydroxybenzaldehyde, among which NaCl and KCl have inhibitory effect on 2-hydroxybenzaldehyde, but have promoting effect on the other pyrolytic products.

Adsorption of tetradecanoic acid on kaolinite minerals: Using flash pyrolysis to characterise the catalytic efficiency of clay mineral adsorbed fatty acids

The clay mineral kaolinite is one of the major inorganic constituents of sedimentary rocks. Kaolinite-carboxylic acid interactions are of considerable importance from the geochemical perspective. The two-fold aim of this study was to quantify the adsorption of tetradecanoic acid on kaolinite and then the flash pyrolysis of adsorbed fatty acids-kaolinite samples to understand the transformation of adsorbed fatty acids on kaolinite. Adsorption of tetradecanoic acid on kaolinite results in an s-isotherm which reflects the multilayer adsorption. Adsorption of tetradecanoic acid on kaolinite involves its both functionalities i.e. siloxane (tetrahedral face) and hydroxyl surface (octahedral face) as indicated from the pyrolysis results. Flash pyrolysis of tetradecanoic acid adsorbed kaolinite mainly yielded saturated/unsaturated hydrocarbons, aromatic hydrocarbons, and ketones while pure tetradecanoic acid generated saturated/unsaturated hydrocarbons and a series of unsaturated and saturated low molecular weight fatty acids. We have successively tested an empirical approach to identify organic compounds formed from fatty acid adsorbed kaolinite to the organic compounds obtained from fatty acid adsorbed alumina and silica. Kaolinite mainly reflects the transformation of carboxylic acids into hydrocarbons and ketones via hydroxyl surface (octahedral face). Ketonisation is mainly observed at multilayer adsorption of tetradecanoic acid on kaolinite. The major implication of the work is the understanding of fatty acids adsorption on kaolinite via both surfaces of the mineral which is helpful to understand the fate of fatty acids as they pass into the geosphere during diagenesis.

The preparation and characterization of HA/β-TCP biphasic ceramics from fish bones

Abstract The aim of this research is to observe the physicochemical characterization and evaluate the biocompatibility of the HA/β-TCP biphasic calcium phosphate ceramics (BCP) produced from fish bones. In addition, the mechanism of the formation of BCP after calcination of fish bones was discussed. Three kinds of fish bones (Salmo salar, Anoplopoma fimbria and Sardine) were prepared and calcined for one hour at different temperatures ranging from 600 °C to 1100 °C in a muffle furnace. The calcined bones were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (GTA), inductively coupled plasma optical atom emissions spectroscopy (ICP-OES), X-ray fluorescence (XRF) and scanning electron microscopy (SEM). The in vitro cytotoxicity assessment was used to evaluate the biocompatibility of the biphasic ceramics. BCP materials were produced from all kinds of fish bones by calcination above 700 °C, the carbonated hydroxyapatite and multiple trace element were also found in the calcined bones. With the increase of temperature, the ratio of HA/β-TCP varied and the major organic components were progressively removed. The carbonated hydroxyapatite disappeared when temperature rises above 900 °C. Rising temperature also caused crystal growth that eventually gave rise to the increase of the BCP grain size and influenced the mesoporous structure. The BCP materials were confirmed to have no obvious cytotoxicity to mesenchymal stem cells (MSC) in the in vitro cytotoxicity assessment. Calcium-deficient hydroxyapatite(CDHA) may make up the major inorganic constituent of fish bones that could decompose to HA and β-TCP when calcined above 700 °C. 800–900 °C is considered to be the optimal temperature to fabricate BCP materials which contain more β-TCP, carbonated hydroxyapatite and retain distinct mesoporous structure while has good biocompatibility. With the unique composition and structure, these three kinds of fish-bone-derived BCP materials can be further applied to fabricate bioceramic scaffolds for biomedical applications.

Physiological studies in pteridophytes of Lohgad area, Pune, India

The present study mainly focuses on the physiological importance of pteridophytic floras present in the Lohgad area of Maharashtra state, India. Adiantum, Pteris, Chelanthus farinose, Nephrolepsis cordifolia & Pleopeltis rostrata were commonly found and selected in the present research. Photosynthetic pigments like total chlorophylls, carotenes, Polyphenol, major organic and inorganic constituents like Na, K, Ca, Cu and Mn are reduced in the all pteridophytes studied. Carotenes, Polyphenol content was seen to be maximum in fern, Pleopeltis and Pteris as compared to others. Mg content has maximum in all pteridophytes. In case of Pleopeltis there is maximum concentration of all major inorganic constituents was observed.

Hand dug wells in Namibia: An underestimated water source or a threat to human health?

The rural population of parts of northern and western Namibia uses hand dug wells for their domestic water supply, partly because no other source (e.g., deep tube wells) is available, but also as a substitute for pipeline water that is often perceived as being too expensive. The water quality of these wells is usually not monitored or controlled, thus a study has been carried out in four study areas in Namibia: southern Omusati/Oshana area, Okongo/Ohangwena area, Omatjete/Omaruru area, Okanguati/Kunene area. Hand dug wells have been tested for on-site parameters: electric conductivity, pH and temperature while samples were taken for major inorganic constituents and several minor and trace constituents including fluoride and nitrate. In addition a sampling campaign in 2010 included the determination of coliform bacteria and Escherichia coli. Results were classified according to the Namibian Water Guidelines. The constituents making the water unfit for human consumption are fluoride, nitrate, sulphate and total dissolved solids. Contamination by E. coli was indicated in nearly all wells that are used for livestock watering. For the Omatjete/Omaruru study area an isotope based study on the source of nitrate has indicated manure as a source. The range of recharge values obtained for the studied villages ranges from 1mm/a to locally more than 100mm/a. Overall the water resource in the shallow perched aquifers in the study areas is in many places inappropriate for human consumption. Treatment to improve the quality or introduction of protection measures is necessary to bring this resource to an acceptable quality according to national and/or international standards.

PM2.5 Chemical Source Profiles of Emissions Resulting from Industrial and Domestic Burning Activities in India

A study has been performed to develop PM_(2.5) (particles with aerodynamic diameters≦2.5) chemically speciated source profiles of different industrial and domestic burning practices in India. A total of fifty-five PM_(2.5) samples have been collected in emissions resulting from (1) industrial furnaces, (2) household fuels, (3) municipal solid waste burning, and (4) welding workshop burning practices, and categorized for eleven subtypes of sources. The collected samples were subjected to chemical analysis for twenty-one elemental (AI, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, S, Sb, Se, V, Zn), nine ionic (Na^+, K^+, Mg^(2+), Ca^(2+), NH_4^+, CI^-, F, NO_3^(-), SO_4^(2-)), OC, and EC source indicator species using atomic absorption spectrometry , ion chromatography and carbon analysis (thermal/optical transmittance method), respectively. The carbonaceous fraction was most abundant in household fuel burning emissions (47.6±7.45% to 65.92±13.13%). The ionic/elemental ratios of major inorganic constituents (Ca^(2+)/Ca, Mg^(2+)/Mg and Na+/Na) have been identified to describe the PM_(2.5) emissions from combustion or re-suspension dusts during industrial activities. Brick Kiln processes (BKP) have been identified as the major emitter of the highest number oftoxic species (Cd, Co, Mo, Sb and V), followed by steel rerolling mills (Hg and Pb) and steel processing industries (As, Ni). The source marker calculations also confirmed that K^+, Mn, and As are good markers for biomass burning, metallurgical industrial emission, and coal burning, respectively, similar to the findings in previous studies.