Sample records for chemical substances by ph

  1. Structure of Bacterial Extracellular Polymeric Substances at Different pH Values as Determined by SAXS

    Dogsa, Iztok; Kriechbaum, Manfred; Stopar, David; Laggner, Peter


    Extracellular polymeric substances (EPS) play an important role in cell aggregation, cell adhesion, and biofilm formation, and protect cells from a hostile environment. The EPS was isolated by trichloroacetic acid/ethanol extraction from broth culture of a marine bacterium isolate. The EPS was composed of glucose and galactose as determined by HPLC and TLC; the protein content was on average 15 ± 5% of EPS dry mass. The solution structure of EPS at different values of pH was revealed by small...

  2. Risks and Chemical Substances.

    Blumberg, Avrom A.


    Examines exposure to chemicals within the home and three important ways in which hazardous substances can be identified and evaluated. Suggests a rational picture of human health risks and contains an introductory discussion of reasons for exposure, epidemiology, cancer causes and patterns, animal testing, toxins, and risk. (LZ)

  3. The Focus and Substance of Formative Comment Provided by PhD Examiners

    Holbrook, Allyson; Bourke, Sid; Fairbairn, Hedy; Lovat, Terence


    In practice and process PhD examination is distinctive, reflecting the high expectations of students whose learning has been directed to their becoming researchers. This article builds on previous research on the examination of Australian theses that revealed that examiners in Science (n?=?542) and Education (n?=?241) provide a substantial…

  4. Indoor air pollution by chemical substances; Kagaku busshitsu ni yoru shitsunai kuki osen

    Matsumura, T. [National Institute of Hygienic Sciences, Tokyo (Japan)


    The economy in our country entered the high growth period in the 1960,s, and specially the chemical industry based on fossil fuel brought about raped development. This was accompanied by widespread amicability of construction materials and household articles made from chemical substances in offices and households. As a results of the first oil crisis in 1973, energy conservation has since been intended, particularly the amount of ventilation in the office was reduced to about 1/3-1/4 of that in Europe and America. Accordingly, many working people in office have complained of various symptoms such as headache and dizziness. It subsequently became clear that the causes were hazardous pollutants in the room. From the above point of view, we focused on air pollution in terms of chemical substances in the room(office and living environment) in this paper. We introduce the present state of air pollution in the room with reference to the results of our studies and literature inside and outside the country. 35 refs., 10 tabs.

  5. Excitation by irritant chemical substances of sensory afferent units in the cat's cornea.

    Belmonte, C; Gallar, J; Pozo, M A; Rebollo, I


    1. Single-unit electrical activity was recorded from thin myelinated sensory nerve fibres innervating the cornea of deeply anaesthetized cats. 2. Based on their responses to mechanical (calibrated von Frey hairs), chemical (10 mM-acetic acid and/or 616 mM-NaCl) and thermal (ice-cold or heat up to 51 degrees C) stimuli, corneal A delta fibres were classified as polymodal nociceptors (63%), high-threshold mechanoceptors (22%) and mechano-heat nociceptors (15%). Thin myelinated fibres responding only to cold were found in the limbus of the eye. 3. Application of 10 mM-acetic acid on the corneal surface for 30 s evoked in polymodal fibres a brisk discharge of impulses often followed by a low-frequency impulse activity. NaCl (616 mM) produced a more gradual and sustained firing response. 4. The responses of polymodal fibres to acid were proportional to extracellular pH values (pH range: 4.5-6.0). After sensitization to repeated heating, most mechano-heat units developed a sensitivity to acidic stimulation. 5. Topical 0.33 mM-capsaicin excited polymodal nociceptors of the cornea; 5 min after capsaicin about 15% of these fibres were inactivated to all subsequent stimuli. In the rest of the fibres, chemical and thermal sensitivity disappeared after 0.33-3.3 mM-capsaicin, but mechanosensitivity was preserved. 6. Corneal mechanoceptors and limbal cold receptors were not affected by capsaicin (up to 33 mM). 7. These experiments demonstrate that the cornea of the cat is innervated by polymodal as well as mechanoceptive A delta nociceptors. In polymodal nociceptive fibres, mechanical and chemical sensitivities appear to be subserved by separate transduction mechanisms. PMID:1890657

  6. Brain temperature and pH measured by 1H chemical shift imaging of a thulium agent

    Coman, Daniel; Trubel, Hubert K.; Rycyna, Robert E.; Hyder, Fahmeed


    Temperature and pH are two of the most important physiological parameters and are believed to be tightly regulated because they are intricately related to energy metabolism in living organisms. Temperature and/or pH data in mammalian brain are scarce, however, mainly due to lack of precise and non-invasive methods. At 11.7T, we demonstrate that a thulium-based macrocyclic complex infused through the blood stream can be used to obtain temperature and pH maps of rat brain in vivo by 1H chemical...

  7. Short-column anion-exchange chromatography for soil and peat humic substances profiling by step-wise gradient of high pH aqueous sodium ethylenediaminetetraacetate.

    Hutta, Milan; Ráczová, Janka; Góra, Róbert; Pessl, Juraj


    Novel anion-exchange liquid chromatographic method with step gradient of aqueous EDTA(4-) based mobile phase elution has been developed to profile available Slovak soil humic substances and alkaline extracts of various soils. The method utilize short glass column (30mm×3mm) filled in with hydrolytically stable particles (60μm diameter) Separon HEMA-BIO 1000 having (diethylamino)ethyl functional groups. Step gradient was programmed by mixing mobile phase composed of aqueous solution of sodium EDTA (pH 12.0; 5mmolL(-1)) and mobile phase constituted of aqueous solution of sodium EDTA (pH 12.0, 500mmolL(-1)). The FLD of HSs was set to excitation wavelength 480nm and emission wavelength 530nm (λem). Separation mechanism was studied by use of selected aromatic acids related to humic acids with the aid of UV spectrophotometric detection at 280nm. The proposed method benefits from high ionic strength (I=5molL(-1)) of the end mobile phase buffer and provides high recovery of humic acids (98%). Accurate and reproducible profiling of studied humic substances, alkaline extracts of various types of soils enables straightforward characterization and differentiation of HSs in arable and forest soils. Selected model aromatic acids were used for separation mechanism elucidation. PMID:26143606

  8. Aqueous media treatment and decontamination of hazardous chemical and biological substances by contact plasma

    Usage of non-equilibrium contact plasma for processes of decontamination and neutralization in conditions of manifestation of chemical, biological and radiation terrorism takes on special significance due to portability of equipment and its mobility in places where toxic liquid media hazardous for people's health are located. Processes of decontamination of aqueous media, seminated with pathogenic microorganisms and viruses, treatment of water containing toxic heavy metals, cyanides, surface-active substances, and heavy radioactive elements, are investigated. Examples of activation processes in infected water and toxic aqueous solutions present convincing evidence of the way, how new quality technological approach for achievement of high enough degree of the said media treatment is used in each specific case. Among new properties of water activated as a result of action of non-equilibrium contact plasma, it is necessary to mention presence of cluster structure, confirmed by well-known spectral and physical-chemical methods, presence of peroxide compounds, active particles and radicals. Anti-microbial activity which is displayed under action of plasma in aqueous media (chemically pure water, drinking water, aqueous solutions of sodium chloride, potassium iodide, as well as other inorganic compounds) towards wide range of pathogenic and conventionally pathogenic microorganisms allows use them as reliable, accessible and low-cost preparations for increasing the degree of safety of food products. Combination of such processes with known methods of filtration and ultra-filtration gives an efficient and available complex capable of withstanding any threats, which may arise for population and living organisms. Present-day level of machine-building, electrical engineering, and electronics allows predict creation of industrial plasma installations, adapted to conditions of various terrorist threats, with minimized power consumption and optimized technological parameters

  9. pH effect on the synthesis of magnetite nanoparticles by the chemical reduction-precipitation method

    Ângela L. Andrade; Diana M. Souza; Márcio C. Pereira; José D. Fabris; Rosana Z. Domingues


    This work aimed at putting in evidence the influence of the pH on the chemical nature and properties of the synthesized magnetic nanocomposites. Saturation magnetization measurements evidenced a marked difference of the magnetic behavior of samples, depending on the final pH of the solution after reaction. Magnetite and maghemite in different proportions were the main magnetic iron oxides actually identified. Synthesis with final pH between 9.7-10.6 produced nearly pure magnetite with little ...

  10. Physical-chemical characterization and stability study of alpha-trypsin at ph 3.0 by differential scanning calorimetry

    Santos, A.M.C.; Santana, M.A.; Gomide, F.T.F.; Oliveira, J.S.; Vilas Boas, F.A.S.; Santoro, M.M.; Teixera, K.N. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas (ICB). Dept. de Bioquimica e Imunologia; Miranda, A.A.C.; Biondi, I. [Universidade Estadual de Feira de Santana (UEFS), BA (Brazil). Dept. de Ciencias Biologicas; Vasconcelos, A.B.; Bemquerer, M.P. [EMBRAPA Recursos Geneticos e Biotecnologia, Brasilia, DF (Brazil). Parque Estacao Biologica (PqEB)


    Full text: {alpha}-Trypsin is a serine-protease with a polypeptide chain of 223 amino acid residues and six disulfide bridges. It is a globular protein with predominance of antiparallel {beta}-sheet secondary structure and it has two domains with similar structures. In the present work, a stability study of {alpha}-trypsin in the acid pH range was performed and physical-chemical denaturation parameters were measured by using differential scanning calorimetry (DSC). The {alpha}-trypsin has a shelf-life (t{sub 95%}) of about ten months at pH 3.0 and 4 deg C and its hydrolysis into the {psi}-trypsin isoform is negligible during six months as monitored by mass spectrometry (Micromass Q-ToF). The observed {delta}H{sub cal}/{delta}H{sub vH} ratio is close to unity for {alpha}-trypsin denaturation, which suggests the occurrence of a two-state transition, devoid of molten-globule intermediates. At pH 3.0, {alpha}-trypsin unfolded with T{sub m} 325.9 K and {delta}H= 99.10 kcal mol{sup -1}, and the change in heat capacity between the native and unfolded forms of the protein was estimated to be 1.96 {+-} 0.18 kcal mol{sup -1} K{sup -1}. The stability of {alpha}-trypsin calculated at 298 K and at pH 3.0 was {delta}G{sub U} = 6.10 kcal mol{sup -1}. These values are in the range expected for a small globular protein. These results show that the thermodynamic parameters for unfolding of {beta}-trypsin do not change substantially after its conversion to {alpha}-trypsin.

  11. Physical-chemical characterization and stability study of alpha-trypsin at ph 3.0 by differential scanning calorimetry

    Full text: α-Trypsin is a serine-protease with a polypeptide chain of 223 amino acid residues and six disulfide bridges. It is a globular protein with predominance of antiparallel β-sheet secondary structure and it has two domains with similar structures. In the present work, a stability study of α-trypsin in the acid pH range was performed and physical-chemical denaturation parameters were measured by using differential scanning calorimetry (DSC). The α-trypsin has a shelf-life (t95%) of about ten months at pH 3.0 and 4 deg C and its hydrolysis into the Ψ-trypsin isoform is negligible during six months as monitored by mass spectrometry (Micromass Q-ToF). The observed ΔHcal/ΔHvH ratio is close to unity for α-trypsin denaturation, which suggests the occurrence of a two-state transition, devoid of molten-globule intermediates. At pH 3.0, α-trypsin unfolded with Tm 325.9 K and ΔH= 99.10 kcal mol-1, and the change in heat capacity between the native and unfolded forms of the protein was estimated to be 1.96 ± 0.18 kcal mol-1 K-1. The stability of α-trypsin calculated at 298 K and at pH 3.0 was ΔGU = 6.10 kcal mol-1. These values are in the range expected for a small globular protein. These results show that the thermodynamic parameters for unfolding of β-trypsin do not change substantially after its conversion to α-trypsin

  12. Effect of pH, ionic strength, foreign ions and humic substances on Th(IV) sorption to GMZ bentonite studied by batch experiments

    Bentonite has been studied extensively because of its strong sorption and complexation ability. Herein, GMZ bentonite from Gaomiaozi county (Inner Mongolia, China) was investigated as the candidate of backfill material for the removal of Th(IV) ions from aqueous solutions. The results indicate that the sorption of Th(IV) is strongly dependent on pH and ionic strength at pH 5. Outer-sphere surface complexation or ion-exchange are the main mechanism of Th(IV) sorption on GMZ bentonite at low pH values, whereas the sorption of Th(IV) at pH > 5 is mainly dominated by inner-sphere surface complexation or surface precipitation. Soil fulvic acid (FA) and humic acid (HA) have a positive influence on the sorption of Th(IV) on bentonite at pH < 5. The different addition sequences of HA and Th(IV) to GMZ bentonite suspensions have no obvious effect on Th(IV) sorption to HA-bentonite hybrids. The high sorption capacity of Th(IV) on GMZ bentonite suggests that the GMZ bentonite can remove Th(IV) ions from large volumes of aqueous solutions in real work. (author)

  13. Chemical Experiments Measuring ph and Gases on "Planetary" Soil by the HUSAR-5 NXT-based Rover Model

    Lang, Agota; Bérczi, Szaniszló; Erdélyi, Soma; Nickl, Istvan; Kiss, Daniel; Erdősi, Ferenc; Panyi, Tamas; Szalay, Kristof


    Introduction: We report two chemical experiments studying the soil on the surface of a planet. Both experiments are built on the HUSAR-5 rover model (Hungarian University Surface Analyser Rover) in a Hungarian high school. In the first experiment our rover uses optical lens as classical heating experiment and gas-sensor to measure the chemical components liberated by the heating. In the second experiment we measure chemical characteristics of the soil by using the indicator method. We report the constructions and experiments carried out by our rover. The task of the first mission: The main goal of the experiment is to move and fix the lens so that the plane of the lens should be perpendicular to the axis of the incident solar light. It is important that the focus of the lens should reach the soil exactly, and it should be operated at any incidence position. We solved this problem using three motors. Two move the lens around horizontal axes, and the third one around a vertical one. The technological structure of HUSAR-5 instruments has been built from LEGO elements, driven by LEGO Mindstorms motors and controlled by NXT "brain". We used a photoresistor, whose signal was lead into the NXT. The steps of the measuring process are the followings I. For focusing: 1. Basic position: The lens is in resting position exactly a focus distance above the soil. The holding arm is horizontal, and the plane of the lens is also horizontal, parallel to the soil. 2. After selecting the location of the measurement, the NXT first moves the lens and finds the position (with the help of the lightsensor) where the intensity of the light is the largest. 3. The other motor moves the arm up and down and positions the lens plane perpendicular to the solar lights. The program takes into the memory both measured angles. 4. The forth step is lifting up the arm into the necessary position. From the initial position the lifting motor states the arm to this position which is calculated by the

  14. Cytotoxic substances produced by a fungal strain from a sponge: physico-chemical properties and structures.

    Amagata, T; Usami, Y; Minoura, K; Ito, T; Numata, A


    Five novel metabolites, trichodenones A-C (1-3), harzialactone A (4) and B (5), have been isolated together with known R-mevalonolactone (6) from the culture broth of a strain of Trichoderma harzianum OUPS-N115 originally separated from the sponge Halichondria okadai. Their structures have been elucidated by spectral evidence. Among them, 1-3 exhibited significant cytotoxicity against cultured P388 cells. PMID:9531985

  15. Atividade alelopática de substâncias químicas isoladas da Acacia mangium e suas variações em função do PH Allelopathic activity of chemical substances isolated from Acacia mangium and its variations in function of PH

    S.M. Luz


    Full Text Available Os objetivos deste trabalho foram isolar, identificar e caracterizar a atividade alelopática de substâncias químicas produzidas por Acacia mangium, além de determinar as variações na atividade das substâncias em função da variação do pH da solução. A atividade alelopática foi avaliada em bioensaios de germinação (25 ºC de temperatura e fotoperíodo de 12 horas e crescimento de radícula e hipocótilo (25 ºC de temperatura e fotoperíodo de 24 horas das plantas daninhas malícia (Mimosa pudica e mata-pasto (Senna obtusifolia. Avaliou-se a interferência do pH (3,0 e 9,0 da solução na atividade alelopática das substâncias sobre a germinação das sementes da espécie malícia. Os triterpenoides lupenona (3-oxolup-20(29-eno e lupeol (3β-hidroxilup-20(29-eno, obtidos das folhas caídas da planta doadora, isolados e em par, evidenciaram baixo efeito alelopático inibitório da germinação de sementes e do crescimento do hipocótilo, especialmente do primeiro, cujos efeitos não ultrapassaram o valor de 2,0%. Os efeitos promovidos sobre o crescimento da radícula foram de maior magnitude, atingindo valores superiores a 40%, com destaque para as inibições promovidas pela substância lupenona. Isoladamente, as substâncias promoveram efeitos superiores aos efetivados pelas substâncias analisadas em pares, indicando a existência de antagonismo. O pH da solução influenciou a atividade alelopática das substâncias; para lupenona os efeitos foram mais intensos em pH ácido, enquanto para lupeol os melhores resultados foram verificados em condições alcalinas, mostrando que este fator é ponto importante a ser considerado em trabalhos de campo.The aim of this study was to isolate, identify and characterize the allelopathic activity of the substances produced by Acacia mangium and to determine the variations of this activity according to the pH variation of the solution. The allelopathic activity was evaluated in germination

  16. Effect of pH and dissociation on the fate and exposure of ionizable chemicals

    Franco, Antonio; Trapp, Stefan


    Ionizable organic chemicals comprise an important fraction of pharmaceuticals, pesticides as well as industrial chemicals. It has been estimated that 33% of the preregistered REACH substances is mostly ionized at pH 7. To extend the appliccability of existing exposure models, a Multimedia Activity...... Model for Ionics (MAMI) was recently developed and tested. In the present study, the impact of the parameters describing ionization was assessed by performing the sensitivity and the uncertainty analysis on MAMI for the acids 2,4-D, pentachlorophenol, bisphenol-A, perfluorooctanoic acid and the bases...... parameters. The sensitivity analysis showed that the parameters describing ionization, pH and the dissociation constant (pKa), are among the most sensitive model parameters. The uncertainty analysis, however, indicated that these parameters are not the major source of uncertainty, which statistically...

  17. 76 FR 75794 - Significant New Use Rules on Certain Chemical Substances; Withdrawal of Two Chemical Substances


    ... notices (PMNs), i.e., rutile, tin zinc, calcium-doped (PMN P-06-36; CAS No. 389623-01-2) and rutile, tin zinc, sodium-doped (PMN P-06-37; CAS No. 389623-07-8). These chemical substances are subject to TSCA... withdrawing the rules issued for rutile, tin zinc, calcium-doped (PMN P-06-36; CAS No. 389623-01-2) and...

  18. Chemical substances as risk factors of nephropathy in diabetes mellitus

    Zofia Marchewka


    Full Text Available Although diabetes mellitus, a metabolic disease, does not fall into the group of diseases induced by toxic substances or environmental pollution, there is much evidence that some chemicals have considerable importance in its development. Exposure to substances with potential renal toxicity is especially dangerous for diabetics because it accelerates and intensifies diabetic nephropathy. This paper discusses the relationship between the xenobiotics and the development of diabetes mellitus and diabetic nephropathy with particular emphasis on those substances that causes the greatest damage to the kidneys. These are cadmium, iron, lead, arsenic, polychlorinated organic compounds, nitrogen compounds, and contrast agents. In addition, the mechanisms of diabetes mellitus induction or kidney damage by these xenobiotics are described.

  19. Effects of pH value and coagulant dosage on contact filtration of humic substances

    蒋绍阶; 刘宗源; 梁建军


    Humic substances (especially fulvic acid (FA)) are the major components of natural organic matter (NOM) that widely exist in drinking water source. Due to their potential effects on public health,the removal of FA was one of the main concerns during the water treatment. Therefore,the contact filtration of FA by using aluminum sulfate as coagulant on the basis of jar tests was carried out. The effects of pH and coagulant dosage on the FA removal and the development of head loss were investigated. The results show that the range of pH value during the FA contact filtration can be effectively influenced by the dosage of aluminum sulfate,and the high aluminum sulfate dosage is an important factor that can result in early filter breakthrough. The FA filtration by deep-bed filtration or by membrane filtration is sometimes disparate under the same coagulation conditions. The choice of aluminum sulfate dosage by the method of membrane filtration,i.e. the "true color measurement",may result in inappropriate filter run,whereas it can be determined with simple jar tests by observing the formation of micro flocs. Considering the effects of pH on aluminum sulfate dosage and FA removal,the optimal pH range of 5.5?6.0 is suggested.

  20. Study of the crystallographic phase change on copper (I) selenide thin films prepared through chemical bath deposition by varying the pH of the solution

    Sandoval-Paz, M. G.; Rodríguez, C. A.; Porcile-Saavedra, P. F.; Trejo-Cruz, C.


    Copper (I) selenide thin films with orthorhombic and cubic structure were deposited on glass substrates by using the chemical bath deposition technique. The effects of the solution pH on the films growth and subsequently the structural, optical and electrical properties of the films were studied. Films with orthorhombic structure were obtained from baths wherein both metal complex and hydroxide coexist; while films with cubic structure were obtained from baths where the metal hydroxide there is no present. The structural modifications are accompanied by changes in bandgap energy, morphology and electrical resistivity of the films.

  1. Removal of low level of 239+240Pu in aqueous solution between pH 2-6 by calcium alginate and its variation with aquatic humic substance

    During this work laboratory simulated experiments were carried out for the removal of low level of 239+240Pu from the aqueous solution. Water samples after filtering through 0.22 mm filter paper were spiked with 250 Bq/1 of 239+240Pu as Pu(NO3)4. The pH of the solutions were controlled between 2-6 by using 0.01M NaOH/HNO3. Spiked samples were kept in the argon atmosphere for a week. The spiked water is passed separately through 20 cm column having about 4 gm of calcium alginate beads. Calcium-alginate beads were prepared by immobilising 2% sodium alginate in 0.2 M calcium chloride solution. At different pH about 95-98% Pu was retained in the beads and significant variation was not observed at pH range studied. To understand the impact of dissolved organic substance on the absorption characteristics of Pu(IV) on calcium-alginate beads, about 0.01% (weight/volume) humic acid solution was mixed in the ratio of 1-4/100 (V/V) experimental solutions. It was observed that the presence of organic matter decreased the absorption by 40% which clearly indicate the complexation of Pu(IV) with humic acid, which was not further forming complex within the alginate beads. The various physicochemical characteristics were measured before and after passing the solution. About 40% of Pu is recovered from sodium alginate beads by using 0.1 M HNO3. (author)

  2. Occupational exposure to airborne chemical substances in paintings conservators

    Anna Jeżewska


    Full Text Available Background: This paper presents the results of the quantitative study of the airborne chemical substances detected in the conservator's work environment. Material and Methods: The quantitative tests were carried out in 6 museum easel paintings conservation studios. The air test samples were taken at various stages of restoration works, such as cleaning, doubling, impregnation, varnishing, retouching, just to name a few. The chemical substances in the sampled air were measured by the GC-FID (gas chromatography with flame ionization detector test method. Results: The study results demonstrated that concentrations of airborne substances, e.g., toluene, 1,4-dioxane, turpentine and white spirit in the work environment of paintings conservators exceeded the values allowed by hygiene standards. It was found that exposure levels to the same chemical agents, released during similar activities, varied for different paintings conservation studios. It is likely that this discrepancy resulted from the indoor air exchange system for a given studio (e.g. type of ventilation and its efficiency, the size of the object under maintenance, and also from the methodology and protection used by individual employees. Conclusions: The levels of organic solvent vapors, present in the workplace air in the course of painting conservation, were found to be well above the occupational exposure limits, thus posing a threat to the worker's health. Med Pr 2014;65(1:33–41

  3. The chemical substances and the neurotoxic effect on workers

    Rosa Morales


    Full Text Available (Received: 2013/10/02 - Accepted: 2013/12/13Tens of thousands of workers are exposed to pollution by the neurotoxicity found in their different workplaces, small businesses, handcrafting industries and even at home. The problem gets worst due to the lack of information on the risks posed by these substances and the safety controls to be taken during its use, on the other hand, the overconfidence that exists about the abstraction of this danger when it comes to the exposure to small doses of toxicity by ignoring the cumulative effects of these substances every time they enter the body. In Ecuador, nowadays there are few studies that distinguish this exposure to these substances, and none on the incidence of the neurotoxic syndrome, considering it an important field to research. Workers who are exposed to chemical toxic substances are now associated to adverse human health effects, due to its aggression and because of the worker´s safety before breaking health directly. They enter the body by the respiratory, dermal or digestive system, and show a great affinity with the body grease so that it accumulates and affects the different organs, tissues, the central nervous system, the bone marrow and liver. Immediate acute and chronic long-term effects were detected due to the intensity and duration of the exposure. Some symptoms include drowsiness, loss of appetite, headache, dizziness, depression, anxiety, nervousness, fatigue, irritability, memory problems, mental sluggishness, apathy, seizures, motor skills incoordination, genetic alterations, among others.

  4. Effect of Ph on the Physical Properties of ZnIn2Se4 Thin Films Grown by Chemical Bath Deposition

    P. Babu


    Full Text Available ZnIn2Se4 (ZIS due to its potential applications in various fields, particularly as a buffer layer in the fabrication of heterojuction solar cells. In the present work, thin films of ZIS have been synthesized by a simple and economic method, chemical bath deposition at different pH values that vary from 9 to 11. The deposition was carried out for a fixed bath temperature (Tb of 90 °C and constant reaction time of 60 min. Ammonia and hydrazine hydrate were used as complexing agents. The chemical and physical properties of the deposited ZIS films were analyzed using appropriate techniques. The X-ray diffraction analysis revealed that the deposited films were polycrystalline and showed (112 peak as the preferred orientation. Scanning electron micrographs revealed that the samples had large number of granule like particles in different sizes. The optical transmittance of these samples was found to be > 75 % in the visible region and the evaluated energy band gap varied from 2.15 eV to 2.64 eV with the change of pH value in the range, 9 - 11. The detailed study of these results were presented and discussed.

  5. Developments of segregation process and chemical analysis for virus receptor recognizing environmental signal substance by affinity binding assaying

    Virus receptors recognizing environmental signal were segregated and analyzed chemically by affinity binding assaying using radio-isotope marked compound. Pathogenic protein in rice stem virus was indicated possibility of a protein which participates in transfer process between the virus cells. An enzyme, Chitobiose was separated from a bacteria, actinomycete. It was cleared by 3H chitobiose affinity binding assaying that two kinds of chitobiose binding protein existed in cell membrane of the actinomycete. A different kind of protein was founded in the cell membrane which was raised in existence of chitobiose. Observation showed that the protein was different from a protein in the cell membrane which was raised in non-existence of chitobiose. These two kinds of protein might be formed a complex compound on the surface of cell membrane. (M. Suetake)

  6. Removal of humic substances by biosorption

    VUKOVI(C) Marija; DOMANOVAC Tomislav; BRI(S)KI Felicita


    Fungal pellets of Aspergillus niger 405, Aspergillus ustus 326, and Stachybotrys sp. 1103 were used for the removal of humic substances from aqueous solutions. Batchwise biosorption, carried out at pH 6 and 25℃, was monitored spectrophotometrically and the process described with Freundlich's model. Calculated sorption coefficients K/and n showed that A. niger exhibited the highest efficiency. A good match between the model and experimental data and a high correlation coefficient (R2) pointed out to judicious choice of the mechanism for removal of humic substances from the reaction medium. The sorption rate constants (k) for A. ustus and Stachybotrys sp. were almost equal, however higher than that for A. niger. Comparison of test results with the simulated ones demonstrated the applicability of the designed kinetic model for removal of humic substances from natural water by biosorption with fungal pellets. Different morphological structure of the examined fungal pellets showed that faster sorption does not imply the most efficient removal of humic substances. Desorption of humic substances from fungal pellets was complete, rapid, and yielded uniform results.

  7. Flows of Chemical Substances in Latvian Pine Forests Ecosystems

    Tērauda, Evija


    FLOWS OF CHEMICAL SUBSTANCES IN LATVIAN PINE FORESTS ECOSYSTEMS Annotation As a basis of the study, data from integrated monitoring stations of Latvia have been used. The objective of the study is to study turnover of substances in ecosystems of pine forests in the boreo-nemoral zone. The results of the study showed that the mean concentration of studied elements (except Pb) increased in the order: bulk precipitation

  8. 77 FR 75390 - Significant New Use Rules on Certain Chemical Substances


    ..., automotive coating, wastewater treatment, solid waste. CAS number: 1392095-50-9. Chemical substance definition: The waste solids produced from the treatment of wastewaters from automotive pretreatment... amount of the substances reasonably likely to be removed from the waste stream by such treatment may...

  9. Chemical leasing business models: a contribution to the effective risk management of chemical substances.

    Ohl, Cornelia; Moser, Frank


    Chemicals indisputably contribute greatly to the well-being of modern societies. Apart from such benefits, however, chemicals often pose serious threats to human health and the environment when improperly handled. Therefore, the European Commission has proposed a regulatory framework for the Registration, Evaluation and Authorization of Chemicals (REACH) that requires companies using chemicals to gather pertinent information on the properties of these substances. In this article, we argue that the crucial aspect of this information management may be the honesty and accuracy of the transfer of relevant knowledge from the producer of a chemical to its user. This may be particularly true if the application of potentially hazardous chemicals is not part of the user's core competency. Against this background, we maintain that the traditional sales concept provides no incentives for transferring this knowledge. The reason is that increased user knowledge of a chemical's properties may raise the efficiency of its application. That is, excessive and unnecessary usage will be eliminated. This, in turn, would lower the amount of chemicals sold and in competitive markets directly decrease profits of the producer. Through the introduction of chemical leasing business models, we attempt to present a strategy to overcome the incentive structure of classical sales models, which is counterproductive for the transfer of knowledge. By introducing two models (a Model A that differs least and a Model B that differs most from traditional sales concepts), we demonstrate that chemical leasing business models are capable of accomplishing the goal of Registration, Evaluation and Authorization of Chemicals: to effectively manage the risk of chemicals by reducing the total quantity of chemicals used, either by a transfer of applicable knowledge from the lessor to the lessee (Model A) or by efficient application of the chemical by the lessor him/herself (Model B). PMID:17958507

  10. Arsenic redox transformation by humic substances and Fe minerals

    Kappler, Andreas, E-mail: [Geomicrobiology, Center for Applied Geosciences, University of Tuebingen, Sigwartstrasse 10, D-72076 Tuebingen (Germany); Amstaetter, Katja [Geomicrobiology, Center for Applied Geosciences, University of Tuebingen, Sigwartstrasse 10, D-72076 Tuebingen (Germany); Borch, Thomas [Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523-1170 (United States)] [Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1170 (United States); Larese-Casanova, Philip; Jiang Jie; Bauer, Iris [Geomicrobiology, Center for Applied Geosciences, University of Tuebingen, Sigwartstrasse 10, D-72076 Tuebingen (Germany); Paul, Andrea [IGB, Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany)


    Highlights: > As(III) oxidation by reduced humic substance model quinone (AQDS) containing semiquinone radicals. > As(III) oxidation by reactive Fe(II)-goethite systems. > Potential explanation for the presence of As(V) in reduced groundwater aquifers. - Abstract: The toxicity and mobility of the redox-active metalloid As strongly depends on its oxidation state, with As(III) (arsenite) being more toxic and mobile than As(V) (arsenate). It is, therefore, necessary to know the biogeochemical processes potentially influencing As redox state to understand and predict its environmental behavior. The first part of this presentation will discuss the quantification of As redox changes by pH-neutral mineral suspensions of goethite [{alpha}-Fe{sup III}OOH] amended with Fe(II) using wet-chemical and synchrotron X-ray absorption (XANES) analysis (). First, it was found that goethite itself did not oxidize As(III). Second, in contrast to thermodynamic predictions, Fe(II)-goethite systems did not reduce As(V). However, surprisingly, rapid oxidation of As(III) to As(V) was observed in Fe(II)-goethite systems. Iron speciation and mineral analysis by Moessbauer spectroscopy showed rapid formation of {sup 57}Fe-goethite after {sup 57}Fe(II) addition and the formation of a so far unidentified additional Fe(II) phase. No other Fe(III) phase could be detected by Moessbauer spectroscopy, EXAFS, scanning electron microscopy, X-ray diffraction or high-resolution transmission electron microscopy. This suggests that reactive Fe(III) species form as an intermediate Fe(III) phase upon Fe(II) addition and electron transfer into bulk goethite but before crystallization of the newly formed Fe(III) as goethite. The second part of the presentation will show that semiquinone radicals produced during microbial or chemical reduction of a humic substance model quinone (AQDS, 9,10-anthraquinone-2,6-disulfonic acid) can react with As and change its redox state (). The results of these experiments showed

  11. Data showing chemical compositions of the essential oils of the leaves of Cymbopogon citratus obtained by varying pH of the extraction medium.

    Ajayi, E O; Sadimenko, A P; Afolayan, A J


    This article describes the various chemical components as obtained from the oils in the leaves of Cymbopogon citratus using hydrodistillation and solvent-free microwave extraction methods. Furthermore, extractions of the oils were also carried out with a slight in pH variation and compared, "GC-MS evaluation of C. citratus (DC) Stapf oil obtained using modified hydrodistillation and microwave extraction methods" (Ajayi et al., 2016 [1]). The current article contains one table exhibiting a list of compounds in the four different methods of extraction. Comparative studies amongst the various methods of extraction are highlighted in the table. PMID:27419197

  12. Shape control of cadmium hydroxides (Cd(OH)2) sensitive to pH quenching depth and massive production of CdSe nanocrystals by their chemical transformation

    This study demonstrates that the structure of cadmium hydroxides (Cd(OH)2) precipitated from a basic cadmium nitrate solution can be finely controlled by adjusting the pH of the precursor solution. The synthesis process involves only pouring the saturated solution into pure water to quench the pH and the total process is finished within 30 s. At a shallow pH quenching, the unstable nanoparticles turned into microparticles via a ripening process. Cd(OH)2 was precipitated in the form of one-dimensional nanowires and then two-dimensional plates as the pH quenching was increased. At a large pH quenching, porous aggregates of Cd(OH)2 were obtained due to the too fast precipitation. The ultrafine Cd(OH)2 nanowires were readily transformed into CdSe chain-like nanocrystals. The transformation was quick and gave 100% yield, facilitating massive production of CdSe nanocrystals in an aqueous condition. The Cd(OH)2 nanowires were directly grown on Si nanowires and transformed into CdSe chain-like nanocrystals, decorating the surface of each Si nanowire.

  13. Analysis of determination modalities concerning the exposure and emission limits values of chemical and radioactive substances

    This document presents the generic approach adopted by various organizations for the determination of the public exposure limits values to chemical and radioactive substances and for the determination of limits values of chemical products emissions by some installations. (A.L.B.)

  14. The Matthew effect in environmental science publication: A bibliometric analysis of chemical substances in journal articles

    Grandjean, Philippe; Eriksen, Mette Lindholm; Ellegaard, Ole;


    publication rates. The persistence in the scientific literature of the top-20 chemicals was only weakly related to their publication in journals with a high impact factor, but some substances achieved high citation rates. Conclusions The persistence of some environmental chemicals in the scientific literature......Background While environmental research addresses scientific questions of possible societal relevance, it is unclear to what degree research focuses on environmental chemicals in need of documentation for risk assessment purposes. Methods In a bibliometric analysis, we used SciFinder to extract...... Chemical Abstract Service (CAS) numbers for chemicals addressed by publications in the 78 major environmental science journals during 2000-2009. The Web of Science was used to conduct title searches to determine longterm trends for prominent substances and substances considered in need of research...

  15. Probing the chemical steps of nitroalkane oxidation catalyzed by 2-nitropropane dioxygenase with solvent viscosity, pH, and substrate kinetic isotope effects.

    Francis, Kevin; Gadda, Giovanni


    Among the enzymes that catalyze the oxidative denitrification of nitroalkanes to carbonyl compounds, 2-nitropropane dioxygenase is the only one known to effectively utilize both the neutral and anionic (nitronate) forms of the substrate. A recent study has established that the catalytic pathway is common to both types of substrates, except for the initial removal of a proton from the carbon of the neutral substrates [Francis, K., Russell, B., and Gadda, G. (2005) J. Biol. Chem. 280, 5195-5204]. In the present study, the mechanistic properties of the enzyme have been investigated with solvent viscosity, pH, and kinetic isotope effects. With nitroethane or ethylnitronate, the kcat/Km and kcat values were independent of solvent viscosity, consistent with the substrate and product binding to the enzyme in rapid equilibrium. The abstraction of the proton from the alpha carbon of neutral substrates was investigated by measuring the pH dependence of the D(kcat/KNE) value with 1,1-[2H2]-nitroethane. The formation of the enzyme-bound flavosemiquinone formed during catalysis was examined by determining the pH dependence of the kcat/Km values with ethylnitronate and nitroethane and the inhibition by m-nitrobenzoate. Finally, alpha-secondary kinetic isotope effects with 1-[2H]-ethylnitronate were used to propose a non-oxidative tautomerization pathway, in which the enzyme catalyzes the interconversion of nitroalkanes between their anionic and neutral forms. The data presented suggest that enzymatic turnover of 2-nitropropane dioxygenase with neutral substrates is limited by the cleavage of the substrate CH bond at low pH, whereas that with anionic substrates is limited by the non-oxidative tautomerization of ethylnitroante to nitroethane at high pH. PMID:17105207

  16. A wearable fingernail chemical sensing platform: pH sensing at your fingertips.

    Kim, Jayoung; Cho, Thomas N; Valdés-Ramírez, Gabriela; Wang, Joseph


    This article demonstrates an example of a wearable chemical sensor based on a fingernail platform. Fingernails represent an attractive wearable platform, merging beauty products with chemical sensing, to enable monitoring of our surrounding environment. The new colorimetric pH fingernail sensor relies on coating artificial nails with a recognition layer consisted of pH indicators entrapped in a polyvinyl chloride (PVC) matrix. Such color changing fingernails offer fast and reversible response to pH changes, repeated use, and intense color change detected easily with naked eye. The PVC matrix prevents leaching out of the indicator molecules from the fingernail sensor toward such repeated use. The limited narrow working pH range of a single pH indicator has been addressed by multiplexing three different pH indicators: bromothymol blue (pH 6.0-7.6), bromocresol green (pH 3.8-5.4), and cresol red (pH 7.2-8.8), as demonstrated for analyses of real-life samples of acidic, neutral, and basic character. The new concept of an optical wearable chemical sensor on fingernail platforms can be expanded towards diverse analytes for various applications in connection to the judicious design of the recognition layer. PMID:26838451

  17. Stability and mobility of cerium oxide nanoparticles in soils: effects of humic substances, pH and ionic strength

    Chen, Yirui; Mu, Linlin; Li, Chunyan; Bai, Lingyun; Jacobson, Astrid; Darnault, Christophe


    Among the large number of types of nanomaterials used in the field of nanotechnology, cerium oxide nanoparticles (CeO2 NPs) are among the top five most commonly utilized by industry, agriculture and nanomedicine for their unique physico-chemical properties. They are used, for example, in the production of catalysts, as fuel additives, and as polishing agents. Therefore, the release and encounter of CeO2 NPs in the environment following their application, waste disposal, life-cycle and accidents is inevitable. It is critical to examine the behavior of CeO2 NPs released in the environment to assess the risk they pose to the environmental and public health. In particular, little is known about the fate and transport of CeO2 NPs in soils and groundwater. To assess the behavior of CeO2 NPs, it is important to investigate the factors that affect their stability and mobility. Humic substances are a major component of soils and have been shown to have the potential to impact the transport and retention of nanoparticles in soils. Consequently, our study characterizes the impacts of humic and fulvic acids on the stability and mobility of cerium oxides in model porous media under various pH and ionic strength conditions. Batch experiments conducted at various concentrations of humic and fulvic acids coupled with a wide range of pHs and ionic strengths were investigated. Selected parameters from these batch studies were then used as experimental conditions representative of environmental systems to perform column transport experiments to assess of the mobility of CeO2 NPs in saturated porous media, which is the first step in simulating their behavior in soil and groundwater systems.

  18. Influence of pH on Chemical Forms of Phosphate Adfsorbed on Gothite Surfaces



    Chemical forms of the phosphate adsorbed on goethite surfaces and characteristics of the coordinate groups which exchange with P on goethite surfaces in solutions with different pll values were investigated.Results showed that the chemical forms of P on goethite surfaces changed from the dominance of monodentate corrdination to that of bidentate one with increasing pH of the solution.By influencing types of phosphate ions in solutions,pH affected the chemical forms of P on goethite surfaces,The amount of OH- displaced by phosphae on goethite surfaces was the most at pH 7.0,the second at pH 9.0,and the least at pH 4.5.

  19. Risk communication about chemical substance. Case studies in communication under guidelines established by local autonomies and trend of information sources; Kagaku busshitsu ni kansuru risuku komyunikeshon. Jichitai seitei no shishin ni motozuku komyunikeshon jirei to johogen no doko

    Yoshimi, H. [Kanagawa Environmental Research Center, Kanagawa (Japan)


    Actions and measures is left to local autonomies, to chemical substances that are in commercial markets and are out of national regulations for their emission and disposal, even though they have public concerns for environmental effects. Thus, a trend to establish guidelines to prevent pollution by those chemicals has been spreading among autonomies facing actions and measures to them. Present status and problems are explained, of the guideline establishment and communication between autonomies and citizens or business owners to promote their self-management according to guidelines. Further, recent trends are introduced, of information sources on chemical substances that serve as a base of the communication. Guidelines of some prefectures ask business owners to collect information on substances that they deal with and needs environmental attention, by a format mimicking to MSDS (Material Safety Data Sheet). On the other hands, other guidelines stipulate that prefectures should provide business owners with information in forms of data-book, off-line or on-line data-base to aid them to collect information. Some guidelines stipulate to settle agreements or to organize councils on environmental safety. 6 refs., 2 figs., 1 tab.

  20. Risk Assessment of New Chemical Substances: System Realisation and Validation II

    Toet C; de Nijs ACM; Vermeire TG; Poel P van der; Tuinstra J


    In the project "Evaluation System new substances", methods are developed to systematically predict and assess the hazards for man and environment related to the production and use of new chemical substances. Part of the project is the realisation of a Risk Assessment System for New Chemical Substances, which is described in this report. This system is a computer program, available for advisory tasks concerning the assessment of hazard and risk of new chemical substances (level 0). A...

  1. Aquatic toxicity of forty industrial chemicals: Testing in support of hazardous substance spill prevention regulation

    Curtis, M. W.; Ward, C. H.


    The U.S. Environmental Protection Agency is presently developing hazardous substance spill regulations to help prevent water pollution. Aquatic animal toxicity data are used as criteria for the designation and categorization of substances as hazardous, even though this type of data is not available for many industrial chemicals. Static 96-hr. toxicity tests were conducted with 40 such chemicals to provide basic toxicity data for regulatory decision making. Thirty-two of the 40 chemicals tested were hazardous to aquatic life as determined by 96-hr. LC 50's less than or equal to 500 mg/l. All 40 chemicals were tested with the fresh-water fathead minnow, Pimephales promelas, and ten chemicals were also tested with the salt-water grass shrimp, Palaemonetes pugio.

  2. Guidelines of Italian CCTN for classification of some effects of chemical substances

    Mucci, N. [ISPESL, Monteporzio Catone, Rome (Italy). Dip. di Medicina del Lavoro; Camoni, I. [Ist. Superiore di Sanita`, Rome (Italy). Lab. di Tossicologia Applicata


    Definitions of the categories and the criteria for the classification of chemical substances on the basis of their potential carcinogenic, mutagenic and toxic-reproductive effects, elaborated by the Italian National Advisory Toxicological Committee (CCTN) in 1994. Besides all the allocations effected by the CCTN in the period 1977-1995 are reported, updated according to these criteria.

  3. Low corrosive chemical decontamination method using pH control. 2. Decomposition of reducing agent by using catalyst with hydrogen peroxide

    In the development of a new chemical decontamination method which provides a high decontamination effect, less corrosion of base metal, and less radioactive waste generation, we developed a decomposition method for oxalic acid coexisting with hydrazine to decrease the amount of radioactive waste. Using a catalyst of 0.5wt% Ru supported by activated carbon grains, we decomposed oxalic acid and hydrazine, simultaneously and efficiently, with a stoichiometric concentration of H2O2. The decomposition ratios were decreased by the deposition of oxides. But even if the simulated reducing agent solution with high concentrations of coexisting Fe and K ions, which negatively effect decomposition ratio, was decomposed, the decomposition ratios of oxalic acid and hydrazine were kept high during decomposition of the amount of reducing agent used in actual chemical decontamination. Additionally, we examined the deposition ratios of metal ions on the catalyst as metal oxides. These results indicated about 2% of the radioactive species which were removed by the chemical decontamination were deposited on the catalyst column. 59Fe and 51Cr were estimated to be about 90% of the total deposited amount of radioactive species and about 60% of the dose equivalent in the model calculation. But this problem should be easily dealt with by using shielding. (author)

  4. Assessment of chemical emissions in life cycle impact assessment - focus on low substance data availability and

    Larsen, Henrik Fred


    substance data on known emissions. To be able to characterize the potential toxic impacts on humans and the environment of chemical emissions, substance data on fate and effect are needed. The second goal of this thesis is to investigate how to deal with low substance data availability on especially effect...... ranking by negative logKow values is observed when logKow is a direct factor in the expression, and there is a significant influence of the way in which the BCF is estimated and included. The second part of the second goal of this thesis, which deals with low availability of substance effect data, is......, crustacean and fish, which in practice represent the trophic levels primary producers, primary consumers and secondary consumers, the use of a minimum of three acute EC50 values from each of these three throphic levels is recommended when estimating HC50EC50. Due to the comparative nature of LCA, the...

  5. 76 FR 38169 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data


    ... FR 22402) (FRL-7312-2), and later amended by a final rule titled ``Revocation of TSCA Section 4... 12, 2006 (71 FR 18650) (FRL-7751-7). Section 4(d) of TSCA (15 U.S.C. 2603(d)) requires EPA to publish... AGENCY Toxic Substances Control Act Chemical Testing; Receipt of Test Data AGENCY:...

  6. Development of a technical scheme for the management of chemical dangerous substances in hospitable environments

    The chemical substances that are used in the hospitals, and their remainders, represent risks for the environment, the health and security of those who work in these establishments, and of the civil population. The deficiency of a norm that establishes the directives for the handling responsible for such products in the hospitals that our country has motivated the elaboration of a technical scheme that serves as it guides for the correct manipulation, storage and safe disposition of chemical substances in the twenty-nine hospitals of the Caja Costarricense del Seguro Social, establishing Procedures of Standard Operation for its management. To development of the guideline proposal it took a sample of hospitals that includes three levels of comple complexity: national, regional and peripheral. Applying a methodology of evaluation of risks two factors of risk of hospitable were determined, the zones and the population but affected by the existence of chemical substances, which allowed to identify some operative deficiencies in the product handling diverse. The qualitative analysis of the results lead to the elaboration of a technical scheme that includes an instrument for the identification of risks, guideline for the management responsible for hospitable chemical substances, a friendly tool computations like complementary source of intelligence and the proposal of a governing group in charge of the monitoring of the fulfillment of these lineament. (Author)

  7. Endocrine disrupting chemicals: harmful substances and how to test them

    Olea-Serrano Nicolás


    Full Text Available This paper presents an analysis of the opinions of different groups from: scientists, international regulatory bodies, non-governmental organizations and industry; with an interest in the problem of identifying chemical substances with endocrine disrupting activity. There is also discussion of the consequences that exposure to endocrine disruptors may have for human health, considering concrete issues related to: the estimation of risk; the tests that must be used to detect endocrine disruption; the difficulties to establish an association between dose, time of exposure, individual susceptibility, and effect; and the attempts to create a census of endocrine disruptors. Finally, it is proposed that not all hormonal mimics should be included under the single generic denomination of endocrine disruptors.

  8. Self-assembly of humic acid: influence of pH and chemical composition

    Chilom, G.; Nagy, Z.; Delp, S.; Huff, G.; Rice, J. A.


    Interest in enhancing the residence time of soil organic matter (SOM) through natural or engineered mechanisms as a possible means of sequestering organic carbon to mitigate the impacts of carbon-dioxide induced global warming effects has steadily increased over the last decade. Humic substances are major organic constituents of SOM and were recently shown that can self-organize or self-assemble into a composite material with different characteristics than those of the starting materials, and the organized state controls its mineralization by microorganisms. This study examines the role of pH and the relative concentration of humic-like amphiphilic (HA2) and lipid-like (L1) components in the self-assembly of the lipid-humic composite (L0). The L0, L1 and HA2 fractions were isolated using a combination of organic solvent and aqueous alkaline extractions from two humic acid samples at various pH values. HA2 and L1 isolated at low pH were mixed in various mass ratios in organic solvent in order to “reassemble” L0. The data show that the amount of L0 decreased with increasing the pH and reached a constant value from pH 6 to pH 11, and the proportion of L1 increased with the pH. Comparative measurements of the specific heat capacity as a function of temperature of the recombined L0 reveal differences when compared to the physical mixture of the HA2 and L1 depending on the ratio of the components. These differences are an indication that the recombined L0’s solid-state structure is more than just a mixture of components and is determined by specific interactions between its components.

  9. Sorption of 63Ni(II) to montmorillonite as a function of pH, ionic strength, foreign ions and humic substances

    Different kinds of clay minerals have been studied extensively in the removal of radionuclides from large volumes of aqueous solutions because of their high sorption capacity. Herein, the Na-montmorillonite was characterized by using XRD and FTIR in detail. The sorption of 63Ni(II) from aqueous solution to montmorillonite as a function of pH, ionic strength, foreign ions, humic substances and temperature was studied by batch technique. The sorption of 63Ni(II) on montmorillonite achieved equilibration quickly. The sorption of 63Ni(II) to montmorillonite was strongly dependent on pH, and dependent on ionic strength at low pH and independent of ionic strength at high pH values. The sorption of 63Ni(II) on montmorillonite was enhanced at low pH in the presence of humic acid (HA), while a negative effect of HA on 63Ni(II) sorption was found at high pH values. At low pH values, the sorption of 63Ni(II) was attributed to outer-sphere surface complexation or ion exchange, whereas the sorption was dominated by inner-sphere surface complexation at high pH values. The montmorillonite sample is a suitable material in the preconcentration of radionuclides from large volumes and the material can be used as backfill material in nuclear waste repository. (author)

  10. Discovery of Small Molecule Inhibitors of the PH Domain Leucine-Rich Repeat Protein Phosphatase (PHLPP) by Chemical and Virtual Screening

    Sierecki, Emma; Sinko, William; McCammon, J. Andrew; Newton, Alexandra C.


    PH domain Leucine-rich repeat protein phosphatase (PHLPP) directly dephosphorylates and inactivates Akt and protein kinase C, poising it as a prime target for pharmacological intervention of two major survival pathways. Here we report on the discovery of small molecule inhibitors of the phosphatase activity of PHLPP, a member of the PP2C family of phosphatases for which there are no general pharmacological inhibitors. First, the Diversity Set of the NCI was screened for inhibition of the puri...

  11. Nonlocal Effects of Chemical Substances on the Brain Produced through Quantum Entanglement

    Hu H.


    Full Text Available Photons are intrinsically quantum objects and natural long-distance carriers of information. Since brain functions involve information and many experiments have shown that quantum entanglement is physically real, we have contemplated from the perspective of our recent hypothesis on the possibility of entangling the quantum entities inside the brain with those in an external chemical substance and carried out experiments toward that end. Here we report that applying magnetic pulses to the brain when an anesthetic or pain medication was placed in between caused the brain to feel the effect of the said substance for several hours after the treatment as if the test subject had actually inhaled the same. The said effect is consistently reproducible. We further found that drinking water exposed to magnetic pulses, laser light or microwave when a chemical substance was placed in between also causes consistently reproducible brain effects in various degrees. Further, through additional experiments we have verified that the said brain effect is the consequence of quantum entanglement between quantum entities inside the brain and those of the chemical substance under study, induced by the photons of the magnetic pulses or applied lights. We suggest that the said quantum entities inside the brain are nuclear and/or electron spins and discuss the profound implications of these results.

  12. Risk Assessment of New Chemical Substances: System Realisation and Validation II

    Toet C; de Nijs ACM; Vermeire TG; van der Poel P; Tuinstra J


    In the project "Evaluation System new substances", methods are developed to systematically predict and assess the hazards for man and environment related to the production and use of new chemical substances. Part of the project is the realisation of a Risk Assessment System for New Chemic

  13. 76 FR 81441 - Proposed Significant New Use Rules on Certain Chemical Substances


    ... chemical substances rutile, tin zinc, calcium-doped (CAS No. 389623-01- 2) and rutile, tin zinc, sodium... orders. The two chemical substances are identified as rutile, tin zinc, calcium-doped (PMN P-06-36; CAS..., tin zinc, calcium-doped and (P- 06-37) Rutile, tin zinc, sodium-doped. CAS numbers: (P-06-36)...

  14. 77 FR 18752 - Benzidine-Based Chemical Substances; Di-n


    ...'-[2-(2-hydroxy-1- naphthalenyl)diazenyl][1,1 '-biphenyl]-4-yl]diazenyl]- , lithium salt (1:3) 68214-82...)(2) SNUR for the benzidine-based chemical substances listed at Sec. 721.1660 (61 FR 52287, October 7...; Significant New Uses of Certain Chemical Substances; Final Rule (61 FR 52287, October 7, 1996). F. What...

  15. Transport of dangerous substances by road

    This book is a collection of the Finnish acts and regulations concerning transport of dangerous substances by road as of 31st March 1985. Included are: Act and Decree on the Transport of Dangerous Substances by Road (Nos 510/74 and 861/74), both as amended; Decree setting up a related Commission (No. 862/74), as amended; Act on the Contract for Carriage of Goods by Road (No. 345/79); Decree bringing into force the ADR (No. 289/79); and Decision of the Ministry of Communications on the Transport of Dangerous Substances by Road (No. 610/78) as amended by Decisions No. 344/79, 995/79, 218/82 and 935/83. (NEA)

  16. Mechanisms of humic substances degradation by fungi

    Chen, Y.; Hadar, Y.; Grinhut, T.


    Humic substances (HS) are formed by secondary synthesis reactions (humification) during the decay process and transformation of biomolecules originating from plants and other dead organisms. In nature, HS are extremely resistant to biological degradation. Thus, these substances are major components in the C cycle and in the biosphere and therefore, the understanding of the process leading to their formation and transformation and degradation is vital. Fungi active in the decomposition process of HS include mainly ascomycetes and basidiomycetes that are common in the upper layer of forest and grassland soils. Many basidiomycetes belong to the white-rot fungi (WRF) and litter-decomposing fungi (LDF). These fungi are considered to be the most efficient lignin degraders due to their nonspecific oxidizing enzymes: manganese peroxidase (MnP), lignin peroxidase (LiP) and laccase. Although bacteria dominate compost and participate in the turnover of HS, their ability to degrade stable macromolecules such as lignin and HS is limited. The overall objectives of this research were to corroborate biodegradation processes of HS by WRF. The specific objectives were: (i) To isolate, identify and characterize HS degrading WRF from biosolids (BS) compost; (ii) To study the biodegradation process of three types of HS, which differ in their structure, by WRF isolated from BS compost; and (iii) To investigate the mechanisms of HA degradation by WRF using two main approaches: (a) Study the physical and chemical analyses of the organic compounds obtained from direct fungal degradation of HA as well as elucidation of the relevant enzymatic reactions; and (b) Study the enzymatic and biochemical mechanisms involved during HA degradation. In order to study the capability of fungi to degrade HS, seventy fungal strains were isolated from biosolids (BS) compost. Two of the most active fungal species were identified based on rDNA sequences and designated Trametes sp. M23 and Phanerochaetesp., Y6

  17. Families Affected by Parental Substance Use.

    Smith, Vincent C; Wilson, Celeste R


    Children whose parents or caregivers use drugs or alcohol are at increased risk of short- and long-term sequelae ranging from medical problems to psychosocial and behavioral challenges. In the course of providing health care services to children, pediatricians are likely to encounter families affected by parental substance use and are in a unique position to intervene. Therefore, pediatricians need to know how to assess a child's risk in the context of a parent's substance use. The purposes of this clinical report are to review some of the short-term effects of maternal substance use during pregnancy and long-term implications of fetal exposure; describe typical medical, psychiatric, and behavioral symptoms of children and adolescents in families affected by substance use; and suggest proficiencies for pediatricians involved in the care of children and adolescents of families affected by substance use, including screening families, mandated reporting requirements, and directing families to community, regional, and state resources that can address needs and problems. PMID:27432847

  18. Four-Component Relativistic DFT Calculations of (13)C Chemical Shifts of Halogenated Natural Substances.

    Casella, Girolamo; Bagno, Alessandro; Komorovsky, Stanislav; Repisky, Michal; Saielli, Giacomo


    We have calculated the (13)C NMR chemical shifts of a large ensemble of halogenated organic molecules (81 molecules for a total of 250 experimental (13)C NMR data at four different levels of theory), ranging from small rigid organic compounds, used to benchmark the performance of various levels of theory, to natural substances of marine origin with conformational degrees of freedom. Carbon atoms bonded to heavy halogen atoms, particularly bromine and iodine, are known to be rather challenging when it comes to the prediction of their chemical shifts by quantum methods, due to relativistic effects. In this paper, we have applied the state-of-the-art four-component relativistic density functional theory for the prediction of such NMR properties and compared the performance with two-component and nonrelativistic methods. Our results highlight the necessity to include relativistic corrections within a four-component description for the most accurate prediction of the NMR properties of halogenated organic substances. PMID:26541625

  19. Dynamic regulation of gastric surface pH by luminal pH

    Chu, Shaoyou; Tanaka, Shin; Kaunitz, Jonathan D.; Montrose, Marshall H.


    In vivo confocal imaging of the mucosal surface of rat stomach was used to measure pH noninvasively under the mucus gel layer while simultaneously imaging mucus gel thickness and tissue architecture. When tissue was superfused at pH 3, the 25 μm adjacent to the epithelial surface was relatively alkaline (pH 4.1 ± 0.1), and surface alkalinity was enhanced by topical dimethyl prostaglandin E2 (pH 4.8 ± 0.2). Luminal pH was changed from pH 3 to pH 5 to mimic the fasted-to-fed transition in intra...

  20. Hemolytic anemia caused by chemicals and toxins

    Anemia - hemolytic - caused by chemicals or toxins ... Possible substances that can cause hemolytic anemia include: Anti-malaria drugs (quinine compounds) Arsenic Dapsone Intravenous water infusion (not half-normal saline or normal saline) Metals (chromium/chromates, ...

  1. Quantitative Exposure Assessment of Various Chemical Substances in a Wafer Fabrication Industry Facility

    Park, Hyunhee; Jang, Jae-Kil; Shin, Jung-Ah


    Objectives This study was designed to evaluate exposure levels of various chemicals used in wafer fabrication product lines in the semiconductor industry where work-related leukemia has occurred. Methods The research focused on 9 representative wafer fabrication bays among a total of 25 bays in a semiconductor product line. We monitored the chemical substances categorized as human carcinogens with respect to leukemia as well as harmful chemicals used in the bays and substances with hematologi...

  2. Use of reserve substances by irradiated tubers

    The response of tubers of potato (Solanum tuberosun L.) and sweet potato (Ipomoea batatas L.) to gamma radiation from 60 Co were investigated. The use of reserve substances by the tubers increased when the irradiation dose raise up to the level of GR10-20 and then decreased down to the values lower than the control non-irradiated tubers

  3. Study the Migration Process of Chemical Substances through the Packaging/Food Interface during Microwave Treatment

    Fang Duan


    Full Text Available The diffusion of chemical substances from packaging into food endangers people’s health. The migration amount of the chemical substances increases with the time and temperature, but the diffusion process for different kinds of packaging materials differs much. Most recently, the research community showed a renewed interest on the diffusion process of chemical substances through packaging/food interface during microwave treatment. In this study, the diffusion coefficient model is suggested and then the migration process is studied based on Fick’s diffusion law. The results are finally compared with the experimental data, showing good agreement.

  4. Changes in Some Chemical Characteristics of Compost Treated with Energetic Substances and Microbial Inoculants

    The main point of this study is the production of organic compost as an alternative source of nutrient and in the same time to reduce the environmental hazards caused by excessive application of chemical fertilizers. In this respect, the farm wastes (plant residues plus animal manure) were collected and treated with different energetic substances and microbial inoculants, in different ratios and combinations, to produce different compost forms. The composting process was carried out in cement tanks constructed in the field and designed with bottom outlet for collecting the compost tea (filtrate) to be used as a source of organic nutrients. Different characteristics of composted materials were determined to evaluate the quality and maturity of produced combinations. Samples of composted materials were collected for laboratory analyses with intervals begin from 24 hrs (0 time) up to 60 days. The given data revealed that ph values of composted materials tended to increase with time up to 60 days of incubation. This holds true with different composting treatments. In the same time, ph values were fluctuated according to composting treatments. Electrical conductivity (EC) values tended to increase up to 30 days and the highest values was recorded with T6 and the lowest one was recorded with T4. Both the treatments and incubation period have significant effects on nitrogen content of the composted materials. Also, T6 was the best treatment, which enriched the composted materials. The C/N ratio was decreased during the composting process. The initial ratio of C/N, which ranged between 22 and 72, substantially decreased in all windrows depending on its chemical composition. The originated organic matter was more able to degrade with time progress up to 60 days of incubation. In the same time, the addition of T6 had encouraged this process of degradation (mineralization of organic N). It seems that phosphorus percent in compost was frequently affected by additives. The

  5. Dangerous chemical substances – Tools supporting occupational risk assessment

    Elżbieta Dobrzyńska


    Full Text Available The assessment of risk associated with exposure to chemicals in the work environment is a task that still poses a lot of difficulties for the employers. At the same time the probability of adverse health effects faced by an employee as a result of such risks, and the related employer’s material losses should motivate employers to seek effective solutions aimed at assessing the risks and controling them to an acceptable level by the application of appropriate preventive measures. The paper presents examples of tools to assist the employer in the risk assessment associated with the presence of chemical agents in the workplace. Examples of guides, manuals, checklists and various interactive tools, developed in Poland and other European Union (EU countries, as well as in countries outside the EU and international organizations are described. These tools have been developed to meet the current requirements of the law and allow a rough estimation of chemical risk and based on these estimates take further steps to improve working conditions and safety. Med Pr 2014;65(5:683–692

  6. Radium-226 determination in different substances without preliminary chemical isolation

    A method of radium-226 determination, based on the measurement of radon-222 quantity, extracted from the substance analyzed, is developed. Determination limit of radium, equal to 6.6x10-15 mass.%, is achieved at the expense of application of low-background proportional counter and special vacuum installation to fill the detector with working gas mixture

  7. Extraction of groundwater humic substances and characterization by synthetic resin

    Groundwater was sampled in depth of about 50m for extraction of humic substances in the groundwater. The extraction and concentration of the humic substances were performed with synthetic adsorption resins. The extracted humic substances and reference humic substances were made a comparison in chemical property. Aquatic humic substances from Nordic Lake and non-aquatic Aldrich Co. humic acids were selected for the reference material. The unprocessed groundwater and the humic substances extracted from the groundwater were compared in UV-vis spectra, fluorescence spectra and the concentration ratio of humic acid and fulvic acid which were important in order to know characteristics of humic substances. Humic substances extracted from the groundwater were compared with Nordic humic substances in molecular weight distribution, IR spectra and NMR spectra from a viewpoint of complexation with radionuclides. This resulted that the extracted humic substances showed similar characteristics to humic substances in the groundwater, and that the extracted humic substances had similar characteristics to Nordic humic substances in containing acidic functional group which contributed to complexation and in americium complexation where americium complexed uniformly, independent of the molecular weight distribution as important characteristics for evaluation of effects on migration of radionuclides. These obtained results imply that employed method was applicable to extract dissolved humic substances from groundwater in a non-destructive manner and the dissolved humic substances occurring in groundwater in Japan are similar to aquatic Nordic humic substances, which are available to purchase at IHSS (International Humic Substances Society), in complexation behavior with some kind of metal ions. (author)

  8. Effect of pH, Temperature, and Chemicals on the Endoglucanases and β-Glucosidases from the Thermophilic Fungus Myceliophthora heterothallica F.2.1.4. Obtained by Solid-State and Submerged Cultivation.

    Teixeira da Silva, Vanessa de Cássia; de Souza Coto, Amanda Lais; de Carvalho Souza, Rafael; Bertoldi Sanchez Neves, Marcello; Gomes, Eleni; Bonilla-Rodriguez, Gustavo Orlando


    This work reports endoglucanase and beta-glucosidase production by the thermophilic fungus Myceliophthora heterothallica in solid-state (SSC) and submerged (SmC) cultivation. Wheat bran and sugarcane bagasse were used for SSC and cardboard for SmC. Highest endoglucanase production in SSC occurred after 192 hours: 1,170.6 ± 0.8 U/g, and in SmC after 168 hours: 2,642 ± 561 U/g. The endoglucanases and beta-glucosidases produced by both cultivation systems showed slight differences concerning their optimal pH and temperature. The number of endoglucanases was also different: six isoforms in SSC and ten in SmC. Endoglucanase activity remained above 50% after incubation between pH 3.0 and 9.0 for 24 h for both cultivation systems. The effect of several chemicals displayed variation between SSC and SmC isoenzymes. Manganese activated the enzymes from SmC but inhibited those from SSC. For β-glucosidases, maximum production on SmC was 244 ± 48 U/g after 168 hours using cardboard as carbon source. In SSC maximum production reached 10.9 ± 0.3 U/g after 240 h with 1 : 1 wheat bran and sugarcane bagasse. Manganese exerted a significant activation on SSC β-glucosidases, and glucose inhibited the enzymes from both cultivation systems. FeCl3 exerted the strongest inhibition for endoglucanases and β-glucosidases. PMID:27242927

  9. Effect of pH, Temperature, and Chemicals on the Endoglucanases and β-Glucosidases from the Thermophilic Fungus Myceliophthora heterothallica F.2.1.4. Obtained by Solid-State and Submerged Cultivation

    Vanessa de Cássia Teixeira da Silva


    Full Text Available This work reports endoglucanase and beta-glucosidase production by the thermophilic fungus Myceliophthora heterothallica in solid-state (SSC and submerged (SmC cultivation. Wheat bran and sugarcane bagasse were used for SSC and cardboard for SmC. Highest endoglucanase production in SSC occurred after 192 hours: 1,170.6 ± 0.8 U/g, and in SmC after 168 hours: 2,642 ± 561 U/g. The endoglucanases and beta-glucosidases produced by both cultivation systems showed slight differences concerning their optimal pH and temperature. The number of endoglucanases was also different: six isoforms in SSC and ten in SmC. Endoglucanase activity remained above 50% after incubation between pH 3.0 and 9.0 for 24 h for both cultivation systems. The effect of several chemicals displayed variation between SSC and SmC isoenzymes. Manganese activated the enzymes from SmC but inhibited those from SSC. For β-glucosidases, maximum production on SmC was 244 ± 48 U/g after 168 hours using cardboard as carbon source. In SSC maximum production reached 10.9 ± 0.3 U/g after 240 h with 1 : 1 wheat bran and sugarcane bagasse. Manganese exerted a significant activation on SSC β-glucosidases, and glucose inhibited the enzymes from both cultivation systems. FeCl3 exerted the strongest inhibition for endoglucanases and β-glucosidases.

  10. Monitoring of ampicillin and its related substances by NMR.

    Shamsipur, Mojtaba; Talebpour, Zahra; Bijanzadeh, Hamid Reza; Tabatabaei, Shamsoddin


    A 1H NMR procedure for the monitoring of ampicillin (Amp) and its main related substance in different media, has been developed. The characteristics peak of Amp, 6-aminopenicillanic acid (6-APA), phenylglycine (PhG), and penicilloic acid in the range of 0.5-0.9 and 3.0-4.5 ppm were used for their identification in drugs and serum samples. The quantitative works were performed based on the intensity of protons of the methyl group link to the beta-lactam cyclic of Amp and 6-APA and the aromatic protons of PhG relative to the protons of methylene group of maleic acid, as internal standard, at constant temperature. The resulting data are compared with those obtained with an HPLC method proposed by British Pharmacopoeia. Statistical studies show that, at a confidence limit of %95, there is no significant difference between the two methods. In comparison with the HPLC method, the proposed NMR method does not require any sample pretreatment, standard solution preparation, long analysis time and use of any carcinogenic solvent. The method was applied to the determination of Amp and its related substances in synthetic mixtures, drug powders and serum samples. PMID:12408898

  11. Possibilities of the misuse of chemical poisonous substance against civil population



    There are numberless possibilities of how to misuse combat poisonous substances against a civilian population. In my bachelor work I dealt with a standard of a civilian population{\\crq}s protection after a terrorist attack with a use of one of the chosen nerve paralytic substances (NPS), and an ability of an integrated rescue system (IRS) how to solve this incurred situation. Nerve paralytic substance (NPS) belong to combat poisonous substances and they are characterized by its high toxicity....

  12. [Chemical constituents in higher polar substances from Desmodium caudatum].

    Zhu, Dan; Wang, Di; Wang, Guang-Hui; Guo, Zhi-Jian; Zou, Xiu-Hong; Lin, Ting; Chen, Hai-Feng


    In this study the chemical constituents of the higher polar sustances from Desmodium caudatum were investigated.The compounds were isolated by using column chromatographies over silicagel, polyamide, ODS, Sephadex LH-20, and preparative HPLC. The structures of these compounds were identified on the basis of NMR and MS spectra. Thirteen compounds were obtained and their structures were identified as vanillin(1), loliolide(2), indole-3-carboxaldehyde(3), salicylic acid(4), swertisin(5), saccharumoside C(6), isosinensin (7), kaempferol 3-O-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside (8), isovitexin (9), vitexin (10), nothofagin(11), resveratroloside (12), and 2"-α-rhamnopyranosyl-7-O-methylvitexin (13). Except for compound 5, the remaining compounds were isolated from D. caudatum for the first time. Compounds 2, 3, 6-8, 11-13 were separated from the genus Desmodium for the first time. PMID:25509297

  13. Investigation of the genotoxicity of substances migrating from polycarbonate replacement baby bottles to identify chemicals of high concern.

    Mertens, Birgit; Simon, Coraline; Van Bossuyt, Melissa; Onghena, Matthias; Vandermarken, Tara; Van Langenhove, Kersten; Demaegdt, Heidi; Van Hoeck, Els; Van Loco, Joris; Vandermeiren, Karin; Covaci, Adrian; Scippo, Marie-Louise; Elskens, Marc; Verschaeve, Luc


    Due to the worldwide concern that bisphenol A might act as an endocrine disruptor, alternative materials for polycarbonate (PC) have been introduced on the European market. However, PC-replacement products might also release substances of which the toxicological profile - including their genotoxic effects - has not yet been characterized. Because a thorough characterization of the genotoxic profile of all these substances is impossible in the short term, a strategy was developed in order to prioritize those substances for which additional data are urgently needed. The strategy consisted of a decision tree using hazard information related to genotoxicity. The relevant information was obtained from the database of the European Chemicals Agency (ECHA), in silico prediction tools (ToxTree and Derek Nexus(TM)) and the in vitro Vitotox(®) test for detecting DNA damage. By applying the decision tree, substances could be classified into different groups, each characterized by a different probability to induce genotoxic effects. Although none of the investigated substances could be unequivocally identified as genotoxic, the presence of genotoxic effects could neither be excluded for any of them. Consequently, all substances require more data to investigate the genotoxic potential. However, the type and the urge for these data differs among the substances. PMID:26802677

  14. Data banks of chemical substances and their toxicity

    Rapid proliferation in the development of new chemical compounds, coupled with the discovery and/or identification of those already in existence, has led to a significant need to investigate their physicochemical and biological properties, to document the knowledge gained, and to communicate that knowledge in as convenient a manner as possible. This paper presents and briefly discusses several prominent chemical databases

  15. Data banks of chemical substances and their toxicity

    Craig, D.K.


    Rapid proliferation in the development of new chemical compounds, coupled with the discovery and/or identification of those already in existence, has led to a significant need to investigate their physicochemical and biological properties, to document the knowledge gained, and to communicate that knowledge in as convenient a manner as possible. This paper presents and briefly discusses several prominent chemical databases.

  16. Data banks of chemical substances and their toxicity

    Craig, D.K.


    Rapid proliferation in the development of new chemical compounds, coupled with the discovery and/or identification of those already in existence, has led to a significant need to investigate their physicochemical and biological properties, to document the knowledge gained, and to communicate that knowledge in as convenient a manner as possible. This paper presents and briefly discusses several prominent chemical databases.

  17. Evidence of the chemical reaction of (18)O-labelled nitrite with CO2 in aqueous buffer of neutral pH and the formation of (18)OCO by isotope ratio mass spectrometry.

    Tsikas, Dimitrios; Böhmer, Anke; Gros, Gerolf; Endeward, Volker


    Inorganic nitrite (NO2(-), ON-O(-) ←→ (-)O-NO) is the autoxidation product of nitric oxide (NO). Nitrite can also be formed from inorganic nitrate (ONO2(-)), the major oxidation product of NO in erythrocytes, by the catalytic action of bacterial nitrate reductase in gut and oral microflora. Nitrite can be reduced to NO by certain cellular proteins and enzymes, as well as in the gastric juice under acidic conditions. Hemoglobin, xanthine oxidoreductase and carbonic anhydrase (CA) have been reported to convert nitrite to NO. Renal CA isoforms are involved in the reabsorption of nitrite and may, therefore, play an important role in NO homeostasis. Yet, the mechanisms underlying the action of CA on nitrite are incompletely understood. The nitrate/nitrite system is regarded as a reservoir of NO. We have recently shown that nitrite reacts chemically with carbon dioxide (CO2), the regular substrate of CA. The present communication reports a stable isotope ratio mass spectrometry (IRMS) study on the reaction of NO2(-) and CO2 performed in 50 mM HEPES buffer of pH 7.4 at 37 °C. By using (18)O-labelled nitrite ((18)ON-O(-)/(-18)O-NO) and CO2 we observed formation of (18)O-labelled CO2. This finding is an unequivocal evidence of the chemical reaction of (18)ON-O(-)/(-18)O-NO with CO2. The reaction is rapid and involves nucleophilic attack of the negatively charged nitrite via one of its oxygen atoms on the partially positively charged CO2 molecule to form the putative intermediate (18)ON-O-CO2(-)/(-)O2C-(18)O-NO. The by far largest fraction of this intermediate decomposes back to (18)ON-O(-)/(-18)O-NO and CO2. A very small fraction of the intermediate, however, rearranges and finally decomposes to form (18)OCO and nitrite. This reaction is slower in the presence of an isolated erythrocytic CA isoform II. In summary, NO2(-), CO2 and CA are ubiquitous. The chemical reaction of NO2(-) with CO2 and its modulation by CA isoforms may play important roles in the transport of

  18. 75 FR 63827 - Integrated Risk Information System (IRIS); Request for Chemical Substance Nominations for 2011...


    ... AGENCY Integrated Risk Information System (IRIS); Request for Chemical Substance Nominations for 2011... quantitative and qualitative risk information on effects that may result from exposure to specific chemical... delivery/courier. Please follow the detailed instructions provided in the SUPPLEMENTARY INFORMATION...

  19. 78 FR 62443 - Perfluoroalkyl Sulfonates and Long-Chain Perfluoroalkyl Carboxylate Chemical Substances; Final...


    ... Executive Order 12866 (58 FR 51735, October 4, 1993), the Office of Management and Budget (OMB) has... people and the environment will generally not be exposed to chemical substances in articles (see 49 FR... acknowledges that importers of articles may have varying levels of knowledge about the chemical content of...

  20. Characterization of a novel mutation in NS1 protein of influenza A virus induced by a chemical substance for the attenuation of pathogenicity.

    Kohei Sasaki

    Full Text Available It is generally accepted that live attenuated influenza vaccine (LAIV has the potential for use as a vaccination against flu. In this study, we demonstrated the nature of an influenza A virus (IAV mutant induced by treating the IAV with a stable furan derivative, (1R,2R-1-(5'-methylfur-3'-ylpropane-1,2,3-triol (MFPT, which had been isolated from Streptomyces sp. strain FV60 with the objective of it being an LAIV candidate. The resulting MFPT-resistant (MFPTr IAVs possessed attenuated pathogenicity in vitro and in vivo when compared with that of the parent virus (H1N1 subtype, NWS strain. Sequencing analysis revealed that a novel mutation, C490U in ns gene (P164S in NS1, was detected in all MFPTr virus clones tested. Therefore, NS1 might be a main target of MFPT, and it was suggested that the P164S mutation contributed to the attenuated pathogenicity of the mutants. Although the phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway is one of the targets of NS1, the MFPTr virus suppressed the phosphorylation of Akt when compared with the wild-type (WT virus. It was suggested that this might lead to the subsequent inhibition of the cleavage of PARP-1 and caspase-3, which is important for the progression of apoptosis. At the same time, nucleoprotein (NP was found to be retained in the nuclei in MFPTr virus-infected cells while nuclear export of NP was detected in WT virus-infected cells. In addition, the expression levels of interferon-β transcripts were significantly decreased in MFPTr virus-infected cells. From these results it can be shown that the mutation, NS1P164S, might be one of the key residues to control NS1 function concerning the induction of apoptosis. In conclusion, MFPT induced favorable mutation in the ns gene for the attenuation of IAV, and therefore might provide the novel methodology for preparing LAIVs.

  1. Monitoring natural organic matter in surface water by UV spectroscopy : effects of calcium, magnesium and pH value

    Rodrigues, A. L.; Nogueira, R; Janknecht, P.; Brito, A. G.


    The aim of this study was to evaluate the effects of dissolved magnesium and calcium ions on the determination of humic substances in water by spectrophotometry at 254 nm. Quantifications were carried out for different pH values, both with and without filtration of the samples. The smallest effects were observed for unfiltered samples and neutral pH values.

  2. The uptake of polluting chemicals into the plant and its relationship to physical-chemical substance properties

    The accumulation behaviour of 14C-labelled organic pollutants under laboratory and field conditions was investigated in spring barley and garden cress and evaluated in the light of a number of previously selected substance properties. The studies in the laboratory were restricted to one week, while those in the field were carried out over the entire growing season. They had the purpose of determining the accumulation of certain pollutants in the test plants with reference to the residues detected for those substances in the soil. The laboratory studies were focused on benzene and five chlorated derivatives as well as a further few chemicals from other groups of substances. The substances investigated in the field were benzene and an additional three chlorated benzenes. The accumulation of organic pollutants in the above-ground parts and roots of barley can rather easily be forecasted on the basis of the compounds' structural properties like molecular weight, molecule volume and connectivity indices. This applies to the majority of cases, providing the mineralisation of the substances in the soil is only minor and no unduly large amounts of metabolites are formed, the physical-chemical properties of which deviate greatly from those of the mother substances. Any such forecasts for cress should preferably be made on the basis of distribution parameters of the individual compounds. It was found that the results from laboratory and field studies were in reasonable agreement, thus permitting the same conclusions to be drawn as to the biotransfer of the test substances from the soil and the probable links between these observations and physical-chemical substance properties. (orig./MG)

  3. PH Sensitive Polymers for Improving Reservoir Sweep and Conformance Control in Chemical Flooring

    Mukul Sharma; Steven Bryant; Chun Huh


    There is an increasing opportunity to recover bypassed oil from depleted, mature oilfields in the US. The recovery factor in many reservoirs is low due to inefficient displacement of the oil by injected fluids (typically water). The use of chemical flooding methods to increase recovery efficiencies is severely constrained by the inability of the injected chemicals to contact the bypassed oil. Low sweep efficiencies are the primary cause of low oil recoveries observed in the field in chemical flooding operations even when lab studies indicate high oil recovery efficiency. Any technology that increases the ability of chemical flooding agents to better contact the remaining oil and reduce the amount of water produced in conjunction with the produced oil will have a significant impact on the cost of producing oil domestically in the US. This translates directly into additional economically recoverable reserves, which extends the economic lives of marginal and mature wells. The objective of this research project was to develop a low-cost, pH-triggered polymer for use in IOR processes to improve reservoir sweep efficiency and reservoir conformance in chemical flooding. Rheological measurements made on the polymer solution, clearly show that it has a low viscosity at low pH and exhibits a sudden increase in viscosity (by 2 orders of magnitude or more) at a pH of 3.5 to 4. This implies that the polymer would preferentially flow into zones containing water since the effective permeability to water is highest in these zones. As the pH of the zone increases due to the buffering capacity of the reservoir rock, the polymer solution undergoes a liquid to gel transition causing a sharp increase in the viscosity of the polymer solution in these zones. This allows operationally robust, in-depth conformance treatment of such water bearing zones and better mobility control. The rheological properties of HPAM solutions were measured. These include: steady-shear viscosity and

  4. The effect of pH, temperature and heating time on inulin chemical stability

    Paweł Glibowski


    Full Text Available Background. Inulin is a storage carbohydrate found in many plants especially in chicory root, Jerusalem artichoke and dahlia tuber. It is a prebiotic with many functional properties. In earlier research concerning chemical stability of inulin, the effect of pH on rheological properties of inulin gels was mainly analysed. In these studies, the effect of time, temperature and pH on inulin chemical stability was not analysed profoundly especially considering the inulin concentrations unable to form gel structure. Thus, the aim of this work was to study the effect of the above mentioned factors on inulin chemical stability in water solution. Material and methods. 5% (w/w inulin solutions at pH 1-12 were heated at 20, 40, 60, 80 and 100°C for 5-60 min. After the neutralisation the content of reducing sugar was analysed according to Miller’s method (1959 with 3,5-dinitrosalicylic acid. Results. The conducted studies showed that inulin chemical stability at pH £ 4 decreased with an increase of heating time and temperature. In a neutral and basic environment inulin was chemically stable regardless of heating time and temperature. Conclusions. Inulin application in food systems may be limited in acidic products especially when heated above 60°C during the production process. However, in products at pH ≥ 5, the degradation of this fructan does not occur even at thermal processing.

  5. meeting) structurally related to a subgroup of substances within the group of ‘ Furfuryl and furan derivatives with and without additional side - chain substituents and heteroatoms from chemical group 14’ evaluated by JECFA in FGE.13Rev2 (2011)

    Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further...... evaluation is necessary, as laid down in Commission Regulation (EC) No 1565/2000. The substances are evaluated through a stepwise approach that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and...... toxicity. FGE.65 concerns a group of 33 sulfur-substituted furan derivatives evaluated by the JECFA at their 59th meeting. The Panel concluded in FGE.65 that the evaluation could not be finalised for four of the 33 substances [FL-no: 13.056, 13.160, 13.193 and 13.194] due to lack of toxicity data. In the...

  6. Substance Abuse by Youth and Young Adults in Rural America

    Lambert, David; Gale, John A.; Hartley, David


    Purpose: Addressing substance abuse in rural America requires extending our understanding beyond urban-rural comparisons to how substance abuse varies across rural communities of different sizes. We address this gap by examining substance abuse prevalence across 4 geographic levels, focusing on youth (age 12-17 years) and young adults (age 18-25…

  7. Fixation and transport of uranium by humic substances (1962)

    One enter upon the study of the part taken by organic substances in ores that contain uranium in a disseminated form, without mineralization, being considered the reaction between uranium and humus. 'Humic acids' are extracted from the peat by ammonia. By the fact of their ability to cationic exchange, these are forming humates with metal cations; monovalent humates, normally soluble in water, can become insoluble after treatment of humic acids with methanal. The polyvalent humates are insoluble in water, especially humates of U (IV) and uranyl U (VI). Action of Li, Na, K, Mg, Ca uranyl carbonates solutions on the humic acids results in the formation of humates containing uranyl and the other cation. 100 g of humic acids give a fixation of no more than 38 g of uranium as uranyl. In contact with uraniferous weakly concentrated solutions, they fix 4 to 8 g according to pH, with a yield in the extraction greater than 95 per cent. The action of a sodium humate solution on a humate of uranyl give a solution containing a soluble sodium and uranyl humate. The solution is precipitated at various degrees by the polyvalent cations and insoluble humic substances. In all cases, the fixation of uranium with such prepared humic acids corresponds to a chemisorption of uranyl cations. (author)

  8. Extraction of scandium by organic substance melts

    Regularities of scandium extraction by the melts of octadecanicoic acid, n-carbonic acids of C17-C20 commerical fraction and mixtures of tributylphosphate (TBP) with paraffin at (70+-1) deg C have been studied. The optimum conditions for scandium extraction in the melt of organic substances are determined. A scheme of the extraction by the melts of higher carbonic acids at ninitial metal concentrations of 10-5 to 10-3 mol/l has been suggested. The scandium compound has been isolated in solid form, its composition having been determined. The main advantages of extraction by melts are as follows: a possibility to attain high distribution coefficients, distinct separation of phases after extraction, the absence of emulsions, elimination of employing inflammable and toxic solvents, a possibility of rapid X-ray fluorescence determinatinon of scandium directly in solid extract

  9. Analysis of determination modalities concerning the exposure and emission limits values of chemical and radioactive substances; Analyse des modalites de fixation des valeurs limites d'exposition et d'emission pour les substances chimiques et radioactives

    Schieber, C.; Schneider, T


    This document presents the generic approach adopted by various organizations for the determination of the public exposure limits values to chemical and radioactive substances and for the determination of limits values of chemical products emissions by some installations. (A.L.B.)

  10. Regulation of antigen presentation by acidic pH


    The effect of pH on functional association of peptide antigens with APC membranes was investigated by using aldehyde-fixed B cells and class II- restricted T cell hybridomas to assess antigen/MHC complex formation. The results indicated that the rate and extent of functional peptide binding was markedly increased at pH 5.0 as compared with pH 7.3. The pH dependence of binding was preserved after pretreatment of fixed APC with pH 5.0 buffer, suggesting that pH had a direct effect on the intera...

  11. Effects of radiation and chemical substances on cells and organism

    The book treats the radiation chemistry part of biophysics and applied biophysics in the sphere of ionizing radiation. Discussed are the concepts of radiation units and radioactivity units and the relative biological efficiency. The effects of ionizing and UV radiations are analyzed at the level of macromolecular changes. Chapters dealing with genetic radiation effects discuss the effects at the cellular level with respect to cell proliferation. All these problems are used to illustrate the effect on the organism as a whole. The chapters on applied biophysics deal with the indications of radiation and chemical damage, sensitivity of cells and the organism, and the study and influencing of growth at the cellular level. The concluding chapter is devoted to the environmental impact of radiation. (J.P.)

  12. 78 FR 69414 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data


    ... October 21, 2011 (76 FR 65385) (FRL-8885-5) (docket ID number EPA-HQ-OPPT-2009-0112). The table in this... AGENCY Toxic Substances Control Act Chemical Testing; Receipt of Test Data AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: This notice announces EPA's receipt of test data on...

  13. 76 FR 38170 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data


    ... issue of March 16, 2006 (71 FR 13708) (FRL-7335-2). Section 4(d) of TSCA (15 U.S.C. 2603(d)) requires... AGENCY Toxic Substances Control Act Chemical Testing; Receipt of Test Data AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: This notice announces EPA's receipt of test data on...

  14. 78 FR 27048 - Significant New Use Rules on Certain Chemical Substances


    ... average), tube ends (open, capped, circular, other), tube width/diameter (measure inner and outer diameters or range), tube length (range) including a description of any deformities found in the tubes... significant new use rules (SNURs) under the Toxic Substances Control Act (TSCA) for 15 chemical...

  15. Influence of soil pH on the sorption of ionizable chemicals

    Franco, Antonio; Fu, Wenjing; Trapp, Stefan


    The soil-water distribution coefficient of ionizable chemicals (K-d) depends on the soil acidity, mainly because the pH governs speciation. Using pH-specific K-d values normalized to organic carbon (K-OC) from the literature, a method was developed to estimate the K-OC of monovalent organic acids...... and bases. The regression considers pH-dependent speciation and species-specific partition coefficients, calculated from the dissociation constant (pK(a)) and the octanol-water partition coefficient of the neutral molecule (log P-n). Probably because of the lower pH near the organic colloid-water...... impact of pH on the total sorption is contrasting. In fact, the shortcomings of the model assumptions affect the predictive power for acids and for bases differently. We evaluated accuracy and limitations of the regressions for their use in the environmental fate assessment of ionizable chemicals....

  16. The testing of materials within the purview of the laws concerning the control of chemical substances

    The main approach adopted for this book is the question of whether and to what extent the commercially available chemical products (ranging from foodstuffs and drugs to pesticides and similar pollutants) have been assessed for environmental and health safety prior to release. The relevant existing laws concerning the testing and characterisation of substances are analysed and compared with a view to the major environmental principle, to prevent chemicals-induced hazards to health and the environment. The book reviews the following laws (and their implementing provisions): law on chemical substances, pesticides, fertilisers, drugs, detergents, leaded petrol, food and feedstuffs, explosives, and transport of hazardous materials. Environmentally significant laws reviewed include the waste management act, the atomic energy act (non-recycable wastes, plutonium, tritium), the water management act, and the act for protection against harmful effects on the environment. (orig./HP)

  17. Hemispheric pollution behavior studies of chemical and radiation substances

    Researchers at an air monitoring station in Quillayute, WA, measuring aerosol levels in the upper atmosphere, have determined from data collected from 1975 to 1977 that ozone concentrations peak in the spring and fall. The high ozone level in the spring probably results from ocean-trajectory air being brought in by strong off-shore flows; high levels in September and October may result from upper air being pushed down by upper-level high pressure areas and from polluted, stagnant air from the Puget Sound industrial area pushed westward by shifting flows

  18. Study of humic substances by fluorescence spectroscopy

    Sona Konecna


    Full Text Available The purpose of this study is to determine main fluorophores of soil humic substances using 2D and 3D synchronous fluorescencespectroscopy (SFS. The measured synchronous spectra werecompared with standards IHSS. Differences between humic andfulvic acids as well as our and IHSS samples are discussed.

  19. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat [Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia); Amin, Mohd. Cairul Iqbal Mohd [Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)


    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

  20. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat; Amin, Mohd. Cairul Iqbal Mohd


    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

  1. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier

  2. The physico-chemical properties and biostimulative activities of humic substances regenerated from lignite.

    David, Jan; Smejkalová, Daniela; Hudecová, Sárka; Zmeškal, Oldřich; von Wandruszka, Ray; Gregor, Tomáš; Kučerík, Jiří


    The positive effect of humic acids on the growth of plant roots is well known, however, the mechanisms and role of their physical structure in these processes have not been fully explained yet. In this work, South-Moravian lignite was oxidized by means of nitric acid and hydrogen peroxide to produce a set of regenerated humic acids. The elemental composition, solid state stability and solution characteristics were determined and correlated in vitro with their biological activity. A modified hydroponic method was applied to determine the effects of their potassium salts on Zea mays seedlings roots with respect to the plant weight, root length, root division, and starch and protein content. The relations between the determined parameters were evaluated through Principal Component Analysis and Pearson's correlation coefficients. The results indicated that the most important factor determining the biological activity of South-Moravian lignite potassium humates is related to the nature of self-assemblies, while the chemical composition had no direct connection with the root growth of Zea mays seedlings. It was demonstrated a controlled processing that provided humic substances with different chemical and physicochemical properties and variable biological activity. PMID:24790812

  3. Indoor Air in Beauty Salons and Occupational Health Exposure of Cosmetologists to Chemical Substances

    Nikos Evlogias


    Full Text Available The indoor environment in four beauty salons located in Athens (Greece was examined in order to investigate the occupational health exposure of cosmetologists to various chemical products typically used in their work. Chemical substances chosen for investigation were volatile organic compounds (VOCs, formaldehyde, ozone and carbon dioxide. Total VOCs levels measured showed significant variation (100–1,450 μg m-3 depending on the products used and the number of treatments carried out, as well as ventilation. The main VOCs found in the salons were aromatics (toluene, xylene, esters and ketones (ethyl acetate, acetone, etc. which are used as solvents in various beauty products; terpenes (pinene, limonene, camphor, menthenol which have a particular odor and others like camphor which have specific properties. Ozone concentrations measured in all salons were quite low (0.1 and 13.3 μg m-3 and formaldehyde concentrations detected were lower than the detection limit of the method in all salons (<0.05 ppm. Carbon dioxide levels ranged between 402 and 1,268 ppm, depending on the number of people present in the salons during measurements and ventilation. Cosmetologists may be exposed to high concentrations of a mixture of volatile organic compounds although these levels could be decreased significantly by following certain practices such as good ventilation of the areas, closing the packages of the beauty products when not in use and finally selecting safer beauty products without strong odor.

  4. Identification of Substances by THz Spectroscopy and Multivariate Analysis

    Pohl, Andreas / AP; Deßmann, Nils / ND; Dutzi, Katja / KD; Hübers, Heinz-Wilhelm / HWH


    The identification of different substances based on terahertz transmittance spectra and multivariate analysis (MVA) is demonstrated. Transmittance spectra are obtained by the use of a Fourier transform infrared spectrometer (FTIR). By means of principal component analysis (PCA) and partial least squares regression (PLS) the spectral data were analyzed in order to discriminate and to identify the substances from each other.

  5. Influence of soil pH on the sorption of ionizable chemicals

    Franco, Antonio; Fu, Wenjing; Trapp, Stefan


    The soil-water distribution coefficient of ionizable chemicals (K-d) depends on the soil acidity, mainly because the pH governs speciation. Using pH-specific K-d values normalized to organic carbon (K-OC) from the literature, a method was developed to estimate the K-OC of monovalent organic acids...... and bases. The regression considers pH-dependent speciation and species-specific partition coefficients, calculated from the dissociation constant (pK(a)) and the octanol-water partition coefficient of the neutral molecule (log P-n). Probably because of the lower pH near the organic colloid......-water interface, the optimal pH to model dissociation was lower than the bulk soil pH. The knowledge of the soil pH allows calculation of the fractions of neutral and ionic molecules in the system, thus improving the existing regression for acids. The same approach was not successful with bases, for which the...

  6. Study of structure and chemical composition of soil humic substances isolated from humic podzol

    Enev, V.; Klučáková, M.; Novák, František

    Brno : Masarykova univerzita, 2014, s. 23-27. ISBN 978-80-210-6842-1. [Pracovní setkání fyzikálních chemiků a elektrochemiků /14./. Brno (CZ), 03.06.2014-04.06.2014] Grant ostatní: GA MŠk(CZ) LO1211 Institutional support: RVO:60077344 Keywords : structure * chemical composition * soil humic substances * humic podzol Subject RIV: DF - Soil Science

  7. Influence of airborne chemical substances on the behaviour of radionuclides in boreal forest ecosystems

    Atmospheric deposition of chemical substances may influence the behaviour of radionuclides in soil and their uptake in plants. This is a fact that has so far received limited attention in radioecological studies. This paper presents briefly two cases where differences in atmospheric deposition of heavy metals from a strong pollution source and marine aerosols, respectively, influence the turnover of radionuclides in natural boreal ecosystems. (au)

  8. Classification of chemical substances, reactions, and interactions: The effect of expertise

    Stains, Marilyne Nicole Olivia


    This project explored the strategies that undergraduate and graduate chemistry students engaged in when solving classification tasks involving microscopic (particulate) representations of chemical substances and microscopic and symbolic representations of different chemical reactions. We were specifically interested in characterizing the basic features to which students pay attention while classifying, identifying the patterns of reasoning that they follow, and comparing the performance of students with different levels of preparation in the discipline. In general, our results suggest that advanced levels of expertise in chemical classification do not necessarily evolve in a linear and continuous way with academic training. Novice students had a tendency to reduce the cognitive demand of the task and rely on common-sense reasoning; they had difficulties differentiating concepts (conceptual undifferentiation) and based their classification decisions on only one variable (reduction). These ways of thinking lead them to consider extraneous features, pay more attention to explicit or surface features than implicit features and to overlook important and relevant features. However, unfamiliar levels of representations (microscopic level) seemed to trigger deeper and more meaningful thinking processes. On the other hand, expert students classified entities using a specific set of rules that they applied throughout the classification tasks. They considered a larger variety of implicit features and the unfamiliarity with the microscopic level of representation did not affect their reasoning processes. Consequently, novices created numerous small groups, few of them being chemically meaningful, while experts created few but large chemically meaningful groups. Novices also had difficulties correctly classifying entities in chemically meaningful groups. Finally, expert chemists in our study used classification schemes that are not necessarily traditionally taught in classroom

  9. Sorption and desorption of uranium(VI) on GMZ bentonite. Effect of pH, ionic strength, foreign ions and humic substances

    The sorption and desorption of uranium(VI) on GMZ bentonite was investigated as functions of contact time, pH, ionic strength, foreign ions, HSs and initial U(VI) using batch experiments. It is revealed that the sorption strongly depended on pH, cations (Li+, Na+ and K+) and anions (CO32-, SO42- and PO43-). HA benefits the sorption at pH <7.0, while inhibited the sorption at higher pH. Moreover, the hysteresis occurred in the sorption-desorption process in the presence/absence of humic substances. The results could provide data base for the safety assessment of the deep geological disposal repository of high radioactive waste. (author)

  10. Extraction of substances assisted by ultrasound (UAE)

    Different compounds present in vegetables with functional or technological properties, have gained great importance in food, pharmaceutical and cosmetic markets. Efficient methods, economical and environment friendly are sought for the extraction of these substances. A literature review has been performanced of recent publications on different extraction methods and their comparison to the ultrasound assisted extraction (UAE) to assess their effectiveness and industrial viability. The ultrasound assisted extraction (UAE) has been found to be more efficient than traditional mining methods, and cheaper and easier than non-traditional extraction methods such as microwave-assisted extraction, so it checks its industrial viability. (author)

  11. Inorganic fractions in extracellular polymeric substance extracted from activated sludge and biofilm samples by different methods.

    Zhang, Leiyan; Geng, Jinju; Ding, Lili; Ren, Hongqiang


    This study highlighted the inorganic fractions in the extracellular polymeric substance (EPS) extract from two activated sludges and one biofilm. Nine EPS extraction methods (centrifugation, sonication, cation exchange resin (CER) + sonication, CER, heating, formaldehyde + heating, formaldehyde + NaOH, ethanol and EDTA) were used in the study. The EPS extracts had large inorganic fractions, which ranged from 28% to 94% of the EPS dry weight. The EPS inorganic fraction was dependent on the source of the sludge and wastewater, the kinds of bacteria and the extraction method. The EPS extracts obtained by heating and sonication had smaller inorganic fractions than those obtained by centrifugation. The compositions of the inorganic fraction of EPS extracts obtained with CER and sonication + CER showed similar trends. The chemical extraction methods could contaminate the inorganic composition of EPS extracts by impurities, carrying over of the extractant itself or by changing the pH of the solution. Ethanol was the most effective extractant for obtaining inorganic ions. PMID:22828296

  12. Soil pH Dynamics and Nitrogen Transformations Under Long-Term Chemical Fertilization in Four Typical Chinese Croplands

    MENG Hong-qi; XU Ming-gang; L Jia-long; HE Xin-hua; LI Jian-wei; SHI Xiao-jun; PENG Chang; WANG Bo-ren; ZHANG Hui-min


    Long-term fertilization experiment provides the platform for understanding the proton budgets in nitrogen transformations of agricultural ecosystems. We analyzed the historical (1990-2005) observations on four agricultural long-term experiments in China (Changping, Chongqing, Gongzhuling and Qiyang) under four different fertilizations, i.e., no-fertilizer (control), sole chemical nitrogen fertilizer (FN), sole chemical phosphorous and potassium fertilizers (FPK) and chemical nitrogen, phosphorous and potassium fertilizers (FNPK). The significant decline in topsoil pH was caused not only by chemical N fertilization (0.29 and 0.89∆pH at Gongzhuling and Qiyang, respectively) but also by chemical PK fertilization (0.59∆pH at Gongzhuling). The enhancement of available nutrients in the topsoil due to long-term direct nutrients supply with chemical fertilizers was in the descending order of available P (168-599%)>available K (16-189%)>available N (9-33%). The relative rate of soil pH decline was lower under long-term judicious chemical fertilization (-0.036-0.034 ∆pH yr-1) than that under long-term sole N or PK fertilization (0.016-0.086 ∆pH yr-1). Long-term judicious chemical fertilization with N, P and K elements decreases the nutritional limitation to normal crop growth, under which more N output was distributed in biomass removal rather than the loss via nitrate leaching. We concluded that the N distribution percentage of nitrate leaching to biomass removal might be a suitable indicator to the sensitivity of agricultural ecosystems to acid inputs.

  13. Impact of temperature, pH, and salinity changes on the physico-chemical properties of model naphthenic acids.

    Celsie, Alena; Parnis, J Mark; Mackay, Donald


    The effects of temperature, pH, and salinity change on naphthenic acids (NAs) present in oil-sands process wastewater were modeled for 55 representative NAs. COSMO-RS was used to estimate octanol-water (KOW) and octanol-air (KOA) partition ratios and Henry's law constants (H). Validation with experimental carboxylic acid data yielded log KOW and log H RMS errors of 0.45 and 0.55 respectively. Calculations of log KOW, (or log D, for pH-dependence), log KOA and log H (or log HD, for pH-dependence) were made for model NAs between -20 °C and 40 °C, pH between 0 and 14, and salinity between 0 and 3 g NaCl L(-1). Temperature increase by 60 °C resulted in 3-5 log unit increase in H and a similar magnitude decrease in KOA. pH increase above the NA pKa resulted in a dramatic decrease in both log D and log HD. Salinity increase over the 0-3 g NaCl L(-1) range resulted in a 0.3 log unit increase on average for KOW and H values. Log KOW values of the sodium salt and anion of the conjugate base were also estimated to examine their potential for contribution to the overall partitioning of NAs. Sodium salts and anions of naphthenic acids are predicted to have on average 4 log units and 6 log units lower log KOW values, respectively, with respect to the corresponding neutral NA. Partitioning properties are profoundly influenced by the by the relative prevailing pH and the substance's pKa at the relevant temperature. PMID:26706930

  14. Chemical speciation of polycyclic aromatic hydrocarbons in sediments: Partitioning and extraction of humic substances

    The primary objective of this study was to examine the chemical speciation of polycyclic aromatic hydrocarbons (PAHs) found in sediments endowed with different characteristics. To achieve this purpose and because the nature of the sediments influences the distribution of PAHs, we have analyzed four different types of sediments. To study the role of organic matter in the sequestration of PAHs, we fractionated humic substances into humic acids and humin-mineral fractions. After their separation and purification, the humic components were examined for their sorptive reactivity by extracting them with organic solvents; these extracts were subsequently subjected to GC/MS analysis. Our results show that PAHs are distributed between labile and sequestered fractions in sediments. A slower uptake of PAHs occurs when the sequestered fraction is formed, and this process can be prolonged and may be influenced by the characteristics if the sediment. Our study suggests that organic contaminants are available in muddy sediments for a longer period of time than in sandy sediments.

  15. Cadmium sorption in solution by a chitin: effect of pH; Sorption du cadmium en solution par une chitine: effet du pH

    Benguella, B.; Benaissa, H. [Universtie de Tlemcen, Lab. de Materiaux Sorbants et Traitement des Eaux, Dept. de Chimie, Faculte des Sciences, Tlemcen (Algeria)


    The pH is an essential factor to take into consideration in the sorption mechanisms of metals: it acts both on the metal speciation in solution and on the chemical behaviour of the surface of the sorbing material, and thus indirectly on the sorption mechanism. The effect of the initial pH of the solution on the cadmium sorption by raw state chitin has been studied in static conditions. The approach used is the determination of the sorption kinetics and equilibria for different values of initial pH (pH < 7-7.5). An increase of the initial pH value of the solution leads to an increase of the cadmium sorption capacity by chitin at the equilibrium. The Langmuir model has revealed to be convenient for a mathematical description of the sorption isotherms obtained. (J.S.)

  16. Comparison of Rumen Fluid pH by Continuous Telemetry System and Bench pH Meter in Sheep with Different Ranges of Ruminal pH


    We aimed to compare the measurements of sheep ruminal pH using a continuous telemetry system or a bench pH meter using sheep with different degrees of ruminal pH. Ruminal lactic acidosis was induced in nine adult crossbred Santa Ines sheep by the administration of 15 g of sucrose per kg/BW. Samples of rumen fluid were collected at the baseline, before the induction of acidosis (T 0) and at six, 12, 18, 24, 48, and 72 hours after the induction for pH measurement using a bench pH meter. During ...

  17. Analysis of atorvastatin and related substances by MEKC

    Nigović, Biljana; Damić, Miranda; Kočevar Glavač, Nina; Injac, Rade; Štrukelj, Borut


    A new micellar electrokinetic capillary chromatographic (MEKC) method has beendeveloped for simultaneous quantitation of atorvastatin and its related substances. The separation was carried out in an extended light path capillaryat applied voltage of 30 kV using a background electrolyte consistingof 10 mM sodium tetraborate buffer pH 9.5, 50 mM sodium dodecyl sulphate and 20% (v/v) methanol. The addition of methanol to the running buffer resulted in a very effective choice to achieve resolutio...

  18. Modulation by Substance P in the Lamprey Spinal Cord

    Thörn Pérez, Carolina


    Neuromodulation is a key element for animal adaptation to environmental circumstances. Neuromodulators can alter the output of a physiological system by acting on the motor circuit by transforming intrinsic firing properties and altering synaptic strength. Substance P belongs to the family of tachykinin, which are peptidergic neuromodulators. The main focus of this thesis has been to characterize the effects of substance P in neurons and networks in the lamprey spinal cord. ...

  19. Microscale pH regulation by splitting water

    Cheng, Li-Jing; Chang, Hsueh-Chia


    We present a simple, flexible approach for pH regulation in micro-chambers by injecting controllable amounts of protons and hydroxide ions via field-enhanced dissociation of water molecules. Under a DC voltage bias, the polymeric bipolar membranes integrated in microfluidics devices generate and separate H+ and OH− ions without gas production or contaminant generation resulting from electron-transfer reactions. Robust local on-chip pH and pH gradients are sustained with no need of additional ...

  20. A microfluidic platform with pH imaging for chemical and hydrodynamic stimulation of intact oral biofilms.

    Gashti, M Parvinzadeh; Asselin, J; Barbeau, J; Boudreau, D; Greener, J


    A microfluidic platform with a fluorescent nanoparticle-based sensor is demonstrated for real-time, ratiometric pH imaging of biofilms. Sensing is accomplished by a thin patterned layer of covalently bonded Ag@SiO2+FiTC nanoparticles on an embedded planar glass substrate. The system is designed to be sensitive, responsive and give sufficient spatial resolution to enable new micro-scale studies of the dynamic response of oral biofilms to well-controlled chemical and hydrodynamic stimulation. Performance under challenging operational conditions is demonstrated, which include long-duration exposure to sheer stresses, photoexcitation and pH sensor biofouling. After comprehensive validation, the device was used to monitor pH changes at the attachment surface of a biofilm of the oral bacteria, Streptococcus salivarius. By controlling flow and chemical concentration conditions in the microchannel, biochemical and mass transport contributions to the Stephan curve could be probed individually. This opens the way for the analysis of separate contributions to dental caries due to localized acidification directly at the biofilm tooth interface. PMID:26956837

  1. Psychoactive substance use by truck drivers: a systematic review

    Girotto, Edmarlon; Mesas, Arthur Eumann; de Andrade, Selma Maffei; Birolim, Marcela Maria


    The aim of this study was to summarise the scientific evidence on the prevalence of psychoactive substance use and on the factors associated with their intake among truck drivers. A systematic review was performed in the databases PubMed, Scientific Electronic Library Online, Latin American and Caribbean Health Sciences, and Cochrane and 36 cross-sectional studies were identified with quantitative results about the use of psychoactive substances by truck drivers. Out of these, 28 were carried...

  2. Preferences for Treatment Setting by Substance Users in India

    Anju Dhawan; Anita Chopra; Rajat Ray


    Background: Drug and alcohol use is a growing public health concern for India. Treatment services delivery for substance use disorders is available through three sectors viz. Government (GO) centres under Ministry of Health and FW, Non-Government (NGO) under Ministry of Social Justice and Empowerment and the private sector. Information on ttreatment utilisation and preferences of treatment settings by substance users are not available for India. Methods: A performa was filled up prospectively...

  3. Physico-chemical characterization of secondary organic aerosol derived from catechol and guaiacol as a model substance for atmospheric humic-like substances

    J. Ofner


    Full Text Available Secondary organic aerosol was produced from the aromatic precursors catechol and guaiacol by reaction with ozone in the presence and absence of simulated sunlight and humidity and investigated for its properties as a proxy for humic-like substances (HULIS. Beside a small particle size, a relatively low molecular weight and typical optical features in the UV/VIS spectral range, HULIS contain a typical aromatic and/or olefinic chemical structure and highly oxidized functional groups within a high chemical diversity. Various methods were used to characterize the secondary organic aerosols obtained: Fourier transform infrared spectroscopy (FTIR demonstrated the formation of different carbonyl containing functional groups as well as structural and functional differences between aerosols formed at different environmental conditions. UV/VIS spectroscopy of filter samples showed that the particulate matter absorbs far into the visible range up to more than 500 nm. Ultrahigh resolved mass spectroscopy (ICR-FT/MS determined O/C-ratios between 0.3 and 1 and main molecular weights between 200 and 500 Da. Temperature-programmed-pyrolysis mass spectroscopy identified carboxylic acids and lactones as major functional groups. Particle sizing using CNC-DMPS demonstrated the formation of small particles during a secondary organic aerosol formation process. Particle imaging using field-emission-gun scanning electron microscopy (FEG-SEM showed spherical particles, forming clusters and chains. Hence, secondary organic aerosols from catechol and guaiacol are appropriate model substances for studies of the processing of aromatic secondary organic aerosols and atmospheric HULIS on the laboratory scale.

  4. Synthesis of iron-based chemical looping sorbents integrated with pH swing carbon mineral sequestration.

    Kim, Hyung Ray; Lee, Dong Hyun; Fan, Liang-Shih; Park, Ah-Hyung Alissa


    The previously developed pH swing carbon mineral sequestration immobilizes the gaseous CO2 into a thermodynamically stable solid, MgCO3, using Mg-bearing minerals such as serpentine. This mineral carbonation technology is particularly promising since it generates value-added solid products: high surface area silica, iron oxide, and magnesium carbonate, while providing a safe and permanent storage option for CO2. By carefully controlling the pH of the system, these solids products can be produced with high purity. This study focuses on the synthesis of iron oxide particles as a chemical looping sorbent in order to achieve the integration between carbon capture and storage technologies. Since the solubility of Fe in aqueous phase is relatively low at neutral pH, the effect of the weak acid and chelating agents on the extraction of Fe from serpentine was investigated. The synthesized iron-based chemical looping sorbent was found to be as effective as commercially available iron oxide nanoparticles at converting syngas into high purity H2, while producing a sequestration-ready CO2 stream. PMID:19908801

  5. Chemical modification and pH dependence of kinetic parameters to identify functional groups in a glucosyltransferase from Strep. Mutans

    A glucosyltransferase, forming a predominantly al-6 linked glucan, was partially purified from the culture filtrate of S. mutans GS-5. The kinetic properties of the enzyme, assessed using the transfer of 14C glucose from sucrose into total glucan, were studied at pH values from pH 3.5 to 6.5. From the dependence of km on pH, a group with pKa = 5.5 must be protonated to maximize substrate binding. From plots of V/sub max/ vs pH two groups, with pKa's of 4.5 and 5.5 were indicated. The results suggest the involvement of either two carboxyl groups (one protonated, one unprotonated in the native enzyme) or a carboxyl group (unprotonated) and some other protonated group such as histidine, cysteine. Chemical modification studies showed that Diethylyrocarbonate (histidine specific) had no effect on enzyme activity while modification with p-phydroxy-mercuribenzoate or iodoacetic acid (sulfhydryl reactive) and carbodimide reagents (carboxyl specific) resulted in almost complete inactivation. Activity loss was dependent upon time of incubation and reagent concentration. The disaccharide lylose, (shown to be an inhibitor of the enzyme with similar affinity to sucrose) offers no protection against modification by the sulfhydryl reactive reagents

  6. Anti-biofilm potential of phenolic acids: the influence of environmental pH and intrinsic physico-chemical properties.

    Silva, Sara; Costa, Eduardo M; Horta, Bruno; Calhau, Conceição; Morais, Rui M; Pintado, M Manuela


    Phenolic acids are a particular group of small phenolic compounds which have exhibited some anti-biofilm activity, although the link between their activity and their intrinsic pH is not clear. Therefore, the present work examined the anti-biofilm activity (inhibition of biomass and metabolic activity) of phenolic acids in relation to the environmental pH, as well as other physico-chemical properties. The results indicate that, while Escherichia coli was not inhibited by the phenolic acids, both methicillin resistant Staphylococcus aureus and methicillin resistant Staphylococcus epidermidis were susceptible to the action of all phenolic acids, with the pH playing a relevant role in the activity: a neutral pH favored MRSE inhibition, while acidic conditions favored MRSA inhibition. Some links between molecular polarity and size were associated only with their potential as metabolic inhibitors, with the overall interactions hinting at a membrane-based mechanism for MRSA and a cytoplasmic effect for MRSE. PMID:27434592

  7. Chemical Leukoderma Improved by Low-dose Steroid Pulse Therapy

    Jung, Jae Yoon; Yeom, Kkot Bora; Eun, Hee Chul


    Chemical leukoderma occurs due to the toxic effect of a specific chemical preceding allergic contact dermatitis. The mechanism is either destruction or inhibition of melanocytes by the offending substance. Clinicohistopathologically, no absolute criteria can differentiate chemical leukoderma from vitiligo. However, chemical leukoderma can be diagnosed clinically by a history of repeated exposure to a known or suspected depigmenting agent at the primary site. There is no agreed treatment guide...

  8. Gallic Acid as a Complexing Agent for Copper Chemical Mechanical Polishing Slurries at Neutral pH

    Kim, Yung Jun; Kang, Min Cheol; Kwon, Oh Joong; Kim, Jae Jeong


    Gallic acid was investigated as a new complexing agent for copper (Cu) chemical mechanical polishing slurries at neutral pH. Addition of 0.03 M gallic acid and 1.12 M H2O2 at pH 7 resulted in a Cu removal rate of 560.73±17.49 nm/min, and the ratio of the Cu removal rate to the Cu dissolution rate was 14.8. Addition of gallic acid improved the slurry performance compared to glycine addition. X-ray photoelectron spectroscopy analysis and contact angle measurements showed that addition of gallic acid enhanced the Cu polishing behavior by suppressing the formation of surface Cu oxide.

  9. pH sensing by intracellular Salmonella induces effector translocation.

    Yu, Xiu-Jun; McGourty, Kieran; Liu, Mei; Unsworth, Kate E; Holden, David W


    Salmonella enterica is an important intracellular bacterial pathogen of humans and animals. It replicates within host-cell vacuoles by delivering virulence (effector) proteins through a vacuolar membrane pore made by the Salmonella pathogenicity island 2 (SPI-2) type III secretion system (T3SS). T3SS assembly follows vacuole acidification, but when bacteria are grown at low pH, effector secretion is negligible. We found that effector secretion was activated at low pH from mutant strains lacking a complex of SPI-2-encoded proteins SsaM, SpiC, and SsaL. Exposure of wild-type bacteria to pH 7.2 after growth at pH 5.0 caused dissociation and degradation of SsaM/SpiC/SsaL complexes and effector secretion. In infected cells, loss of the pH 7.2 signal through acidification of host-cell cytosol prevented complex degradation and effector translocation. Thus, intravacuolar Salmonella senses host cytosolic pH, resulting in the degradation of regulatory complex proteins and effector translocation. PMID:20395475

  10. The high pH chemical and radiation compatibility of various liner materials

    A flexible membrane liner has been proposed to line a concrete vault in which liquid low-level radioactive waste will be solidified. High-density polyethylene (HDPE) and polypropylene liners were tested at the Pacific Northwest Laboratory in an EPA method 9090 format to determine their chemical compatibility with the waste. Radiation effects were also investigated. The liners were immersed in a highly caustic (pH>14), primarily inorganic solution at 90 degrees C. The liners were subjected to radiation doses up to 38.9 Mrad, which was the expected dose the liner would receive over a 30-year life inside the vault. Recent changes have placed the liner outside the vault. The acceptance criteria for judging the compatibility of the liner with radiation should be different than those used for judging chemical compatibility. The radiation damage over the life of the liner can be simulated in a short-term test. Both HDPE and polypropylene liners were judged to be acceptable from a chemical and radiation standpoint when placed outside of the vault, while several other liners were not compatible. Radiation did not have a significant effect on chemical degradation rates

  11. 75 FR 35977 - Significant New Use Rules on Certain Chemical Substances


    ... Harmonized Test Guideline 850.1400) with rainbow trout; and a daphnid chronic toxicity test (OCSPP Harmonized... tests would help characterize the environmental effects of the PMN substances: A fish acute toxicity...-hour renewal intervals; a fish acute toxicity test mitigated by humic acid (OCSPP Harmonized...

  12. Substance Flow Analysis and Source Mapping of Chemical UV-filters

    Chemical ultraviolet (UV)-filters are used in sunscreens to protect the skin from harmful UV radiation which may otherwise cause sunburns and skin cancer. Commonly used chemical UV-filters are known to cause endocrine disrupting effects in both aquatic and terrestrial animals as well as in human skin cells. Here, source mapping and substance flow analysis were applied to find the sources of six UV-filters (oxybenzone, avobenzone, 4-methylbenzylidene camphor, octyl methoxycinnamate, octyl dimethyl PABA and homosalate) and to identify the most dominant flows of these substances in Denmark. Urban water, composed of wastewater and surface waters, was found to be the primary recipient of UV-filters, whereby wastewater received an estimated 8.5-65 tonnes and surface waters received 7.1-51 tonnes in 2005. In wastewater treatment plants, their sorption onto sludge is perceived to be an important process and presence in effluents can be expected due to a lack of biodegradability. In addition, the use of UV-filters is expected to continue to increase significantly. Not all filters (e.g., octyl dimethyl PABA and homosalate) are used in Denmark. For example, 4-MBC is mainly associated with self-tanning liquids and private import of sunscreens

  13. Substance Flow Analysis and Source Mapping of Chemical UV-filters

    Eriksson, E., E-mail:; Andersen, H. R.; Ledin, A. [Technical University of Denmark, Department of Environmental Engineering (Denmark)


    Chemical ultraviolet (UV)-filters are used in sunscreens to protect the skin from harmful UV radiation which may otherwise cause sunburns and skin cancer. Commonly used chemical UV-filters are known to cause endocrine disrupting effects in both aquatic and terrestrial animals as well as in human skin cells. Here, source mapping and substance flow analysis were applied to find the sources of six UV-filters (oxybenzone, avobenzone, 4-methylbenzylidene camphor, octyl methoxycinnamate, octyl dimethyl PABA and homosalate) and to identify the most dominant flows of these substances in Denmark. Urban water, composed of wastewater and surface waters, was found to be the primary recipient of UV-filters, whereby wastewater received an estimated 8.5-65 tonnes and surface waters received 7.1-51 tonnes in 2005. In wastewater treatment plants, their sorption onto sludge is perceived to be an important process and presence in effluents can be expected due to a lack of biodegradability. In addition, the use of UV-filters is expected to continue to increase significantly. Not all filters (e.g., octyl dimethyl PABA and homosalate) are used in Denmark. For example, 4-MBC is mainly associated with self-tanning liquids and private import of sunscreens.

  14. Chemical modification of triplex-forming oligonucleotide to promote pyrimidine motif triplex formation at physiological pH.

    Torigoe, Hidetaka; Nakagawa, Osamu; Imanishi, Takeshi; Obika, Satoshi; Sasaki, Kiyomi


    Extreme instability of pyrimidine motif triplex DNA at physiological pH severely limits its use in wide variety of potential applications, such as artificial regulation of gene expression, mapping of genomic DNA, and gene-targeted mutagenesis in vivo. Stabilization of pyrimidine motif triplex at physiological pH is, therefore, crucial for improving its potential in various triplex-formation-based strategies in vivo. To this end, we investigated the effect of 3'-amino-2'-O,4'-C-methylene bridged nucleic acid modification of triplex-forming oligonucleotide (TFO), in which 2'-O and 4'-C of the sugar moiety were bridged with the methylene chain and 3'-O was replaced by 3'-NH, on pyrimidine motif triplex formation at physiological pH. The modification not only significantly increased the thermal stability of the triplex but also increased the binding constant of triplex formation about 15-fold. The increased magnitude of the binding constant was not significantly changed when the number and position of the modification in TFO changed. The consideration of the observed thermodynamic parameters suggested that the increased rigidity of the modified TFO in the free state resulting from the bridging of different positions of the sugar moiety with an alkyl chain and the increased hydration of the modified TFO in the free state caused by the introduction of polar nitrogen atoms may significantly increase the binding constant at physiological pH. The study on the TFO viability in human serum showed that the modification significantly increased the resistance of TFO against nuclease degradation. This study presents an effective approach for designing novel chemically modified TFOs with higher binding affinity of triplex formation at physiological pH and higher nuclease resistance under physiological condition, which may eventually lead to progress in various triplex-formation-based strategies in vivo. PMID:22245184

  15. 78 FR 41768 - Chemical Substances and Mixtures Used in Oil and Gas Exploration or Production; TSCA Section 21...


    ... AGENCY 40 CFR Chapter I Chemical Substances and Mixtures Used in Oil and Gas Exploration or Production...(a) to require manufacturers and processors of oil and gas exploration and production (E&P) chemical... Oil and Gas Exploration or Production.'' August 4, 2011. 3. EPA, ORD. EPA's Study of...

  16. Inhibition of crystallization caused by Proteus mirabilis during the development of infectious urolithiasis by various phenolic substances.

    Torzewska, Agnieszka; Rozalski, Antoni


    Infectious urolithiasis is a consequence of persistent urinary tract infections caused by urease producing bacteria e.g. Proteus mirabilis. These stones are composed of struvite and carbonate apatite. Their rapid growth and high recurrence indicate that so far appropriate methods of treatment have not been found. In the present study, the inhibitory effect of phenolic compounds was investigated in vitro against formation of struvite/apatite crystals. The impact of these substances with different chemical structures on crystallization caused by clinical isolates of P. mirabilis was tested spectrophotometrically using a microdilution method. Among the 11 tested compounds resveratrol, epigallocatechin gallate, peralgonidin, vanillic and coffee acids at the concentrations 250-1000 μg/ml inhibited P. mirabilis urease activity and crystallization. However, only vanillic acid had such an effect on all tested strains of P. mirabilis. Therefore, using an in vitro model, bacterial growth, crystallization, urease activity and pH were examined for 24h in synthetic urine with vanillic acid. Effect of vanillic acid was compared with that of other known struvite/apatite crystallization inhibitors (acetohydroxamic acid, pyrophosphate) and it was shown that vanillic acid strongly inhibited bacterial growth and the formation of crystals. It can be assumed that this compound, after further studies, can be used in the treatment or prophylaxis of infectious urolithiasis. PMID:24239192

  17. Towards Process-Ontology: A Critical Study of Substance-Ontological Premises:Ph.D. Thesis at the Department of Philosophy, University of Pittsburgh, USA

    Seibt, Johanna


    The thesis proposes therapeutic revision of fundamental assumptions in contemporary ontological thought. I show that non of the prevalent theories of objects, by virtue of certain implicit substance-ontological assumptions provides a viable account of the numerical, qualitative, and trans-temporal identity of objects. I argue that in order to explain the identity of objects we must abandon these substance-ontological premises together with the idea that objects enjoy ontological primacy. Whil...

  18. Creation of the ecology standards for the releases of the radionuclides and some chemical substances into environment

    An approach to creation of standards for radionuclide and other hazardous substance releases and effluents taking into account complex effects of hazardous substances on ecosystems is discussed. The approach is based on approximated standardization method according to indeterminate quality criterion. Determination of the ecosystem normal state when creating the standards for releases and effluents, as well as standardization of radiation and chemical effects upon ecosystems are reduced to the unified complex. The classification of aquatic objects in respect to radiation state is suggested. The standardization of radioactive substance releases and effluents based on the three-level system of standards is considered. 19 refs

  19. Research on elucidation of mechanism revealing capability of decomposing and removing harmful chemical substances in microorganisms and its utilization

    Recently, artificial harmful chemical substances are released in environment, and cause contamination as those are not decomposed by microorganisms. This research aims at clarifying the environmental factors which affect the revelation of the functions of decomposing and removing harmful chemical substances of microorganisms, separating and refining the enzymes and proteins which take part in the decomposition and removal and elucidating their properties, and further analyzing the genes taking part in the decomposition and removal functions and making the mechanism of revelation clear, elucidating the techniques giving the decomposition and removal functions to native bacteria living in nature and the conditions of improving the decomposing function, and utilizing these technologies for cleaning environment. As for the separation of the bacteria which decompose aliphatic halogen compounds and their decomposing characteristics, the experimental method and the effects that ethane concentration and carbon source exerted to the decomposition and others are reported. The elucidation of the mechanism of accumulating cesium in bacteria was carried out, and it is described. (K.I.)

  20. Substance P and substance K receptor binding sites in the human gastrointestinal tract: localization by autoradiography

    Gates, T.S.; Zimmerman, R.P.; Mantyh, C.R.; Vigna, S.R.; Maggio, J.E.; Welton, M.L.; Passaro, E.P. Jr.; Mantyh, P.W.


    Quantitative receptor autoradiography was used to localize and quantify the distribution of binding sites for /sup 125/I-radiolabeled substance P (SP), substance K (SK) and neuromedin K (NK) in the human GI tract using histologically normal tissue obtained from uninvolved margins of resections for carcinoma. The distribution of SP and SK binding sites is different for each gastrointestinal (GI) segment examined. Specific SP binding sites are expressed by arterioles and venules, myenteric plexus, external circular muscle, external longitudinal muscle, muscularis mucosa, epithelial cells of the mucosa, and the germinal centers of lymph nodules. SK binding sites are distributed in a pattern distinct from SP binding sites and are localized to the external circular muscle, external longitudinal muscle, and the muscularis mucosa. Binding sites for NK were not detected in any part of the human GI tract. These results demonstrate that: (1) surgical specimens from the human GI tract can be effectively processed for quantitative receptor autoradiography; (2) of the three mammalian tachykinins tested, SP and SK, but not NK binding sites are expressed in detectable levels in the human GI tract; (3) whereas SK receptor binding sites are expressed almost exclusively by smooth muscle, SP binding sites are expressed by smooth muscle cells, arterioles, venules, epithelial cells of the mucosa and cells associated with lymph nodules; and (4) both SP and SK binding sites expressed by smooth muscle are more stable than SP binding sites expressed by blood vessels, lymph nodules, and mucosal cells.

  1. A Chemical Risk Ranking and Scoring Method for the Selection of Harmful Substances to be Specially Controlled in Occupational Environments

    Saemi Shin


    Full Text Available This study aimed to devise a method for prioritizing hazardous chemicals for further regulatory action. To accomplish this objective, we chose appropriate indicators and algorithms. Nine indicators from the Globally Harmonized System of Classification and Labeling of Chemicals were used to identify categories to which the authors assigned numerical scores. Exposure indicators included handling volume, distribution, and exposure level. To test the method devised by this study, sixty-two harmful substances controlled by the Occupational Safety and Health Act in Korea, including acrylamide, acrylonitrile, and styrene were ranked using this proposed method. The correlation coefficients between total score and each indicator ranged from 0.160 to 0.641, and those between total score and hazard indicators ranged from 0.603 to 0.641. The latter were higher than the correlation coefficients between total score and exposure indicators, which ranged from 0.160 to 0.421. Correlations between individual indicators were low (−0.240 to 0.376, except for those between handling volume and distribution (0.613, suggesting that each indicator was not strongly correlated. The low correlations between each indicator mean that the indicators and independent and were well chosen for prioritizing harmful chemicals. This method proposed by this study can improve the cost efficiency of chemical management as utilized in occupational regulatory systems.

  2. PhD by Publication: A Student's Perspective

    Peter Kanowski


    Full Text Available This article presents the first author's experiences as an Australian doctoral student undertaking a PhD by publication in the arena of the social sciences. She published nine articles in refereed journals and a peer-reviewed book chapter during the course of her PhD. We situate this experience in the context of current discussion about doctoral publication practices, in order to inform both postgraduate students and academics in general. The article discusses recent thinking about PhD by publication and identifies the factors that students should consider prior to adopting this approach, in terms of university requirements, supervisors' attitudes, the research subject matter, intellectual property, capacity and working style, and issues of co-authorship. It then outlines our perceptions of the advantages and disadvantages of undertaking a PhD by publication. We suggest that, in general, the advantages outweigh the disadvantages. We conclude by reflecting on how the first author's experiences relate to current discussions about fostering publications by doctoral students.

  3. Antimycobacterial activity of chemically defined natural substances from the Caribbean flora in Guadeloupe.

    Rastogi, N; Abaul, J; Goh, K S; Devallois, A; Philogène, E; Bourgeois, P


    Eight chemically defined, naturally occurring compounds were extracted from the tropical flora of the Caribbean island of Guadeloupe: pilocarpine, an alkaloid from Pilocarpus racemosus; heraclenol and isomeranzin, coumarins from Triphasia trifolia; lochnerin, an indole alkaloid from Rauwolfia biauriculata; ibogaine and voacangine, indole alkaloids from Tabernaemontana citrifolia; texalin, an oxazole from Amyris elemifera; and canellal, a sesquiterpene dialdehyde from Canella winterana. An essential oil fraction from Canella winterana was also tested. The antimycobacterial activity of these substances was tested against Mycobacterium tuberculosis, M. avium and M. kansasii using the Middlebrook 7H11 agar medium, the Bactec 460-TB radiometric methodology, and determination of bacterial viable counts. Three compounds, namely ibogaine, voacangine and texalin, showed antimycobacterial activity. Investigations on the structure-modification and structure-activity relationships of these compounds may help determine new targets for future drug development. PMID:9626931

  4. Intellectual substance of lyrics by Joseph Brodsky

    Plekhanova I. I.


    Full Text Available The features of J. Brodsky’s lyricism, which are caused by intellectual dominant of his consciousness, are explored in the article. Intellect here is understood as “directed thinking” (C. G. Jung; in artistic version it is described as project-reflexive thinking. The article gives basic characteristics of the poet’s consciousness, which caused maximum closeness between biographic and poetic “Me”, striving for alienation from the world and self-discipline in spiritual development. The connection between attitude towards the world and its’ artistic realization is observed. Brodsky’s way of thinking is noted for its abstractness of goal, for its insight of integrity of existence and non-existence. But this way of thinking is realized as decoding of material signs of manifestation of holism.

  5. Stabilization of extracellular polymeric substances (Bacillus subtilis) by adsorption to and coprecipitation with Al forms

    Mikutta, R.; Zang, U.; Chorover, J.; Haumaier, L.; Kalbitz, K.


    Extracellular polymeric substances (EPS) are continuously produced by bacteria during their growth and metabolism. In soils, EPS are bound to cell surfaces, associated with biofilms, or released into solution where they can react with other solutes and soil particle surfaces. If such reaction results in a decrease in EPS bioaccessibility, it may contribute to stabilization of microbial-derived organic carbon (OC) in soil. Here we examined: (i) the chemical fractionation of EPS produced by a c...

  6. Development of a new QSPR based tool to predict explosibility properties of chemical substances within the framework of REACH and GHS

    Fayet, Guillaume; ROTUREAU, Patricia; Joubert, Laurent; Adamo, Carlo


    The new European régulation of Chemicals named REACH (for "Registration, Evaluation and Authorization of Chemicals") turned out in the practical registration phase in December 2008. It requires the new assessment of hazard properties for up to 140000 substances. In this context, the development of alternative prédictive methods for assessing hazardous properties of chemical substances is promoted in REACH and in the related new European classification System of substances CLP (Classification,...

  7. Fiber-Optic pH Sensor

    Ganesh, A. Balaji; Radhakrishnan, T. K.

    The new enhancement in the determination of pH using optical fiber system is described here. This work uses the membrane made of cellulose acetate membrane for reagent immobilization and congo red (pKa 3.7) and neutral red (pKa 7.2) as pH indicators. An effective covalent chemical binding procedure is used to immobilize the indicatorsE The response time, reversibility, linear range, reproducibility, and long-term stability of fiber optic sensor with congo red as well as neutral red have been determined. The linear range measured for the sensor based on the congo red and neutral red is 4.2-6.3 and 4.1-9.0, respectively. The response time of sensor membrane is measured by varying the substance pH values between 11.0 and 2.0.

  8. A methodology for determining environmental threshold quantities for substances covered by CEPA's Environmental Emergency Regulation

    Sections 199 and 200 of the Canadian Environmental Protection Act (CEPA) 1999 oblige persons who own or manage specified toxic and hazardous substances to develop and implement environmental emergency plans. This paper discussed the methodology for determining how a chemical is assessed for recommending an environmental emergency plan. For Section 199, once substances are declared toxic, each chemical is assessed to determine whether it requires a plan or not. For Section 200, any chemical can be added under the E2 regulations, as long as it can be ascertained that the substance is toxic according to the following criteria: it has an immediate or long-term harmful effect on the environment or its biological diversity; it constitutes a danger to the environment on which human life depends; and/or it constitutes a danger in Canada to human life or health. An overview of the risk evaluation framework was provided, including details of the pre-assessment filter. Summaries of trigger criteria were presented, as well as environmental hazard ratings and details of persistence of organic chemicals in the environment and bioaccumulation. Aquatic toxicity and ingestion toxicity details were also provided. Human hazard ratings included carcinogenicity, inhalation toxicity, dermal toxicity, rabbit and rat toxicity and corrosion and skin irritation ratings. Issues concerning vapour cloud explosions were examined. A reactivity table was presented with hazard descriptions. European Union Threshold quantities were examined, as well as a list of comparisons of selected substances of CEPA with the European Union. It was concluded that the Environmental Emergency Branch (EEB) has created environmental thresholds by first examining how other countries have protected the environment. Substance thresholds for the United States have focused on protecting humans, while Europe has established threshold quantities that work for their countries. The EEB has selected classification tables

  9. The Matthew Effect in Environmental Science Publication: A Bibliometric Analysis of Chemical Substances in Journal Articles

    Grandjean Philippe; Eriksen Mette L; Ellegaard Ole; Wallin Johan A


    Abstract Background While environmental research addresses scientific questions of possible societal relevance, it is unclear to what degree research focuses on environmental chemicals in need of documentation for risk assessment purposes. Methods In a bibliometric analysis, we used SciFinder to extract Chemical Abstract Service (CAS) numbers for chemicals addressed by publications in the 78 major environmental science journals during 2000-2009. The Web of Science was used to conduct title se...

  10. Morphosynthesis of alanine mesocrystals by pH control.

    Ma, Yurong; Cölfen, Helmut; Antonietti, Markus


    Crystallization of DL-alanine is studied as a single polymorph model case to analyze the different modes of crystallization of polar organic molecules in absence of any structure directing additives. Depending on supersaturation, which is controlled either by temperature or by pH, and in the absence of additives, crystallization by mesoscale assembly of nanoparticles is found over a wide range of conditions, leading to so-called mesocrystals. This supplements the classical molecule-based crystallization mechanism, which is identified at lower supersaturations and at pH values away from the isoelectric point (IEP). The resulting alanine crystals are characterized by SEM, XRD, and single-crystal analysis. Time-resolved conductivity measurements and dynamic light scattering of the reaction solutions reveal information about precursor structures and reaction kinetics. A formation mechanism is proposed for the alanine mesocrystals. PMID:16771332

  11. Physico-chemical model of toxic substances in the Great Lakes

    A physico-chemical model of the fate of toxic substances in the Great Lakes is constructed from mass balance principles and incorporates principal mechanisms of particulate sorption-desorption, sediment-water and atmosphere-water interactions, and chemical and biochemical decay. Calibration of the toxic model is through comparison to plutonium-239 data collected in the 1970s using a 23 year time variable calculation and indicates that in general, the sediments are interactive with the water column in the Great Lakes through resuspension and or horizontal transport. Fifty percent response times of 239Pu following a cessation of load extend beyond 10 years with sediment resuspension. The calibration model was applied to polychlorinated biphenyl (PCB) using a high and low estimate of contemporary external load and with and without volatilization. Calibration of the model to data on benzo(a)pyrene confirms that on a lake-wide scale the principal external source in the atmosphere and for the larger lakes such as Michigan the response time of the lake to external loads is about 6-10 years while for Lake Erie response time is about 2 years. Application of the model to cadmium in the lakes, using a solids dependent partition coefficient indicates that the lakes do not reach equilibrium over a 100 year period. Calculated high concentrations of cadmium in interstitial water (e.g., 10 microgram/l) indicate the importance of measuring interstitial cadmium concentrations

  12. Effect of pH on biologic degradation of Microcystis aeruginosa by alga-lysing bacteria in sequencing batch biofilm reactors

    Hongjing LI; Mengli HAO; Jingxian LIU; Chen CHEN1; Zhengqiu FAN; Xiangrong WANG


    In this paper, the effect of pH on biological degradation of Microcystis aeruginosa by alga-lysing bacteria in laboratory-scale sequencing batch biofilm reactors (SBBRs) was investigated. After 10 d filming with waste activated sludge, the biological film could be formed, and the bioreactors in which laid polyolefin resin filler were used to treat algal culture. By comparing the removal efficiency of chlorophyll a at different aerobic time, the optimum time was determined as 5 h. Under pH 6.5, 7.5, and 8.5 conditions, the removal rates of Microcystis aeruginosa were respectively 75.9%, 83.6%, and 78.3% (in term of chlorophyll a), and that of Chemical Oxygen Demand (CODMn) were 30.6%, 35.8%, and 33.5%. While the removal efficiencies of ammonia nitrogen (NH+ -N) were all 100%. It was observed that the sequence of the removal efficiencies of algae, NH+ -N and organic matter were pH 7.5 〉 pH 8.5 〉 pH 6.5. The results showed that the dominant alga-lysing bacteria in the SBBRs was strain HM-01, which was identified as Bacillus sp. by Polymerase Chain Reaction (PCR) amplification of the 16S rRNA gene, Basic Local Alignment Search Tool (BLAST) analysis, and compar- ison with sequences in the GenBank nucleotide database. The algicidal activated substance which HM-01 strain excreted could withstand high temperature and pressure, also had better hydrophily and stronger polarity.

  13. Effect of test concentration in the ready biodegradability test for chemical substances: Improvement of OECD test guideline 301C.

    Nabeoka, Ryosuke; Taruki, Masanori; Kayashima, Takakazu; Yoshida, Tomohiko; Kameya, Takashi


    In Japan, understanding the environmental persistence of chemicals is very important for risk assessment, and ready biodegradability tests are mainly conducted according to the Organisation for Economic Co-operation and Development test guideline 301C. However, the highest test concentration specified in test guideline 301C, 100 mg/L, may cause microbial toxicity and incomplete biodegradation. The authors performed test guideline 301C tests at test concentrations of 30 mg/L for 13 substances that were readily biodegradable in ready biodegradability tests but not in test guideline 301C tests. Of the 5 substances with potential to cause microbial toxicity at 100 mg/L, the percentage of biodegradation of sodium dimethyldithiocarbamate, 4-chloro-3-cresol (CC), thymol (THY), and p-tert-butyl-α-methylbenzenepropionaldehyde measured by biochemical oxygen demand (BOD) increased in the test guideline 301C test at 30 mg/L, suggesting a reduction in toxicity effects. Furthermore, CC and THY met the criteria for ready biodegradability, which are more than 60% of biodegradation by BOD and a 10-d window. Of the 8 substances with a low potential for causing microbial toxicity at 100 mg/L, the percentage of biodegradation of only 2-(diethylamino)ethanol increased in the test guideline 301C test at 30 mg/L. Employing a lower test concentration in the standard test guideline 301C test will contribute to improvement of consistency between results of a test guideline 301C test and other ready biodegradability tests. PMID:26211908

  14. Concentration of 'forgotten' substances using the XAD concentration method. Suitability of the method for hydrophilic chemicals

    Collombon MT; LER


    Concentration of forgotten substances using the XAD concentration method In the nineties, RIVM developed a method to concentrate toxic substances on XAD (a synthetic resin). Using bioassays, the toxicity can be determined in the concentrate. 'Modern' toxic substances tend to be more polar then 'clas

  15. Adapting SimpleTreat for simulating behaviour of chemical substances during industrial sewage treatment.

    Struijs, J; van de Meent, D; Schowanek, D; Buchholz, H; Patoux, R; Wolf, T; Austin, T; Tolls, J; van Leeuwen, K; Galay-Burgos, M


    The multimedia model SimpleTreat, evaluates the distribution and elimination of chemicals by municipal sewage treatment plants (STP). It is applied in the framework of REACH (Registration, Evaluation, Authorization and Restriction of Chemicals). This article describes an adaptation of this model for application to industrial sewage treatment plants (I-STP). The intended use of this re-parametrized model is focused on risk assessment during manufacture and subsequent uses of chemicals, also in the framework of REACH. The results of an inquiry on the operational characteristics of industrial sewage treatment installations were used to re-parameterize the model. It appeared that one property of industrial sewage, i.e. Biological Oxygen Demand (BOD) in combination with one parameter of the activated sludge process, the hydraulic retention time (HRT) is satisfactory to define treatment of industrial wastewater by means of the activated sludge process. The adapted model was compared to the original municipal version, SimpleTreat 4.0, by means of a sensitivity analysis. The consistency of the model output was assessed by computing the emission to water from an I-STP of a set of fictitious chemicals. This set of chemicals exhibit a range of physico-chemical and biodegradability properties occurring in industrial wastewater. Predicted removal rates of a chemical from raw sewage are higher in industrial than in municipal STPs. The latter have typically shorter hydraulic retention times with diminished opportunity for elimination of the chemical due to volatilization and biodegradation. PMID:27344605

  16. Adapting SimpleTreat for simulating behaviour of chemical substances during industrial sewage treatment

    Struijs, J.; van de Meent, D.; Schowanek, D.; Buchholz, H.; Patoux, R.; Wolf, T.; Austin, T.; Tolls, J.; van Leeuwen, K.; Galay-Burgos, M.


    The multimedia model SimpleTreat, evaluates the distribution and elimination of chemicals by municipal sewage treatment plants (STP). It is applied in the framework of REACH (Registration, Evaluation, Authorization and Restriction of Chemicals). This article describes an adaptation of this model for

  17. [A survey of utilization of and problems with the MSDS in chemical substances management at workplaces in Kanagawa Prefecture].

    Koshi, Kimiko; Mouri, Tetuo; Sugimori, Hiroki; Numano, Takashi; Ashida, Toshifumi; Hiro, Hisanori; Miyake, Hitoshi; Fukushima, Michiko; Ishiwata, Kouichi


    Kanagawa Occupational Health Promotion Center conducted a survey on how the MSDS is utilized at workplaces with more than 50 employees handling chemical substances, and what measures are taken to help employees to thoroughly understand information in the Material Safety Data Sheet (MSDS). Questionnaires were sent out to 265 enterprises in Kanagawa prefecture, putting questions to industrial physicians and industrial hygiene supervisors. The objective of the survey was to find out how MSDS is adopted in the system to manage occupational health, what improvements the survey respondents want in MSDS and what expectations the respondents have of our center. 193 enterprises (72.8%) returned answers to the questionnaire. The major findings are as follows. (1) In many companies, information on hazardous/toxic materials is "controlled by a division using such materials", and roughly half of the companies have compiled a common list shared throughout the company. (2) For the most part suppliers submit to the MSDS. Larger companies have a higher rate of posting up or filing the MSDS at their workplaces. Only 25.8% of the companies "rewrite the MSDS so that workers can understand it." (3) Companies that carry out a hazard/toxicity assessment before introducing a new chemical substance account for 72.1%, which is higher than we expected. It indicates that even though the companies don't manage the MSDS adequately, they are highly concerned about hazard control of chemical substances. (4) The rate of answering that "the current MSDS is not easy to understand" is higher among large-sized enterprises and lower among enterprises with fewer than 300 employees. (5) Asked what improvement needs to be made on the MSDS, the industrial physicians and industrial hygiene supervisors gave same answers such as "Workers find the terminology difficult to understand." and "Levels of toxicity can't be clearly identified." (6) The respondents expect our center to provide information for the MSDS

  18. Nitrification at Low pH by Aggregated Chemolithotrophic Bacteria

    De Boer, W.; Klein Gunnewiek, P.J.A.; Veenhuis, M; Bock, E; Laanbroek, H. J.


    A study was performed to gain insight into the mechanism of acid-tolerant, chemolithotrophic nitrification. Microorganisms that nitrified at pH 4 were enriched from two Dutch acid soils. Nitrate production in the enrichment cultures was indicated to be of a chemolithoautotrophic nature as it was (i) completely inhibited by acetylene at a concentration as low as 1-mu-mol/liter and (ii) strongly retarded under conditions of carbon dioxide limitation. Electron microscopy of the enrichment cultur...

  19. Risk of severe driver injury by driving with psychoactive substances

    Hels, Tove; Lyckegaard, Allan; Bernhoft, Inger Marie;


    approximated by odds ratios and calculated by logistic regression. The estimates were adjusted for age, gender and country. The highest risk of the driver being severely injured was associated with driving positive for high concentrations of alcohol (≥0.8 g/L), alone or in combination with other psychoactive......Driving with alcohol and other psychoactive substances imposes an increased risk of severe injury accidents. In a population-based case-control design, the relative risks of severe driver injury (MAIS ≥ 2) by driving with ten substance groups were approximated by odds ratios (alcohol, amphetamines...... (N = 2490) were collected from severely injured drivers of passenger cars or vans in selected hospitals in various regions of the countries. Control samples (N = 15,832) were sampled in a uniform sampling scheme stratified according to country, time, road type and season. Relative risks were...

  20. Freshwater microalgae harvested via flocculation induced by pH decrease

    Liu, Jiexia; Zhu, Yi; Tao, Yujun; Zhang, Yuanming; Li, Aifen; Li, Tao; Sang, Ming; Zhang, Chengwu


    Background Recent studies have demonstrated that microalga has been widely regarded as one of the most promising raw materials of biofuels. However, lack of an economical, efficient and convenient method to harvest microalgae is a bottleneck to boost their full-scale application. Many methods of harvesting microalgae, including mechanical, electrical, biological and chemical based, have been studied to overcome this hurdle. Results A new flocculation method induced by decreasing pH value of g...

  1. A step-by-step procedure for pH model construction in aquatic systems

    A. F. Hofmann


    Full Text Available We present, by means of a simple example, a comprehensive step-by-step procedure to consistently derive a pH model of aquatic systems. As pH modelling is inherently complex, we make every step of the model generation process explicit, thus ensuring conceptual, mathematical, and chemical correctness. Summed quantities, such as total inorganic carbon and total alkalinity, and the influences of modeled processes on them are consistently derived. The different time scales of processes involved in the pH problem (biological and physical reactions: days; aquatic chemical reactions: fractions of seconds give rise to a stiff equation system. Subsequent reformulations of the system reduce its stiffness, accepting higher non-linear algebraic complexity. The model is reformulated until numerically and computationally simple dynamical solutions, like a variation of the operator splitting approach (OSA and the direct substitution approach (DSA, are obtained. As several solution methods are pointed out, connections between previous pH modelling approaches are established. The final reformulation of the system according to the DSA allows for quantification of the influences of kinetic processes on the rate of change of proton concentration in models containing multiple biogeochemical processes. These influences are calculated including the effect of re-equilibration of the system due to a set of acid-base reactions in local equilibrium. This possibility of quantifying influences of modeled processes on the pH makes the end-product of the described model generation procedure a powerful tool for understanding the internal pH dynamics of aquatic systems.

  2. Segregation of metals-containing wastewater by pH

    A pH-based sampling system has shown that there is a high correlation between low pH and metals contamination for the wastewater from the 4500 area (manhole 190) and the 2000 area (pump station). Wastewater from the Radiochemical Engineering Development Center (REDC) and the High Flux Isotope Reactor (HFIR) has not shown any metals concentrations above the National Pollutant Discharge Elimination System (NPDES) permit limits for the Nonradiological Wastewater Treatment Plant (NRWTP). It is recommended that pH be used as the diversion criteria for wastewater from manhole 190 and the pump station to be sent to the metals tank of the NRWTP. Any wastewater with a pH less than 6.0 or greater than 10.0 should be sent to the metals tank. Based on the results of 29 weeks of sampling, it is expected that on the order of 36m3/wk (9500 gal/wk) of wastewater will be diverted to the metals tank of the NRWTP. Wastewater from REDC and HFIR can be sent to the nonmetals tank, but it should be sampled periodically and analyzed by Inductively Coupled Plasma (ICP) spectrophotometer to confirm that the metals concentration is not increasing. 1 ref., 2 figs., 9 tabs

  3. External and internal contamination by radioactive substances (tutorial)

    Kučerová, Lenka


    The text concerns the creation of a complete education programme focussing on internal and external contamination by radioactive substances. The education programme is composed of several chapters explaining the given problem to the student. The first part of the text explains certain basic facts concerning ionizing radiation, radioactivity, and the quantities characterizing these phenomena. Further, the text explains the effects of ionizing radiation on the human body. The third section desc...

  4. Anoxic Biodegradation of Isosaccharinic Acids at Alkaline pH by Natural Microbial Communities.

    Simon P Rout

    Full Text Available One design concept for the long-term management of the UK's intermediate level radioactive wastes (ILW is disposal to a cementitious geological disposal facility (GDF. Under the alkaline (10.013.0 anoxic conditions expected within a GDF, cellulosic wastes will undergo chemical hydrolysis. The resulting cellulose degradation products (CDP are dominated by α- and β-isosaccharinic acids (ISA, which present an organic carbon source that may enable subsequent microbial colonisation of a GDF. Microcosms established from neutral, near-surface sediments demonstrated complete ISA degradation under methanogenic conditions up to pH 10.0. Degradation decreased as pH increased, with β-ISA fermentation more heavily influenced than α-ISA. This reduction in degradation rate was accompanied by a shift in microbial population away from organisms related to Clostridium sporosphaeroides to a more diverse Clostridial community. The increase in pH to 10.0 saw an increase in detection of Alcaligenes aquatilis and a dominance of hydrogenotrophic methanogens within the Archaeal population. Methane was generated up to pH 10.0 with acetate accumulation at higher pH values reflecting a reduced detection of acetoclastic methanogens. An increase in pH to 11.0 resulted in the accumulation of ISA, the absence of methanogenesis and the loss of biomass from the system. This study is the first to demonstrate methanogenesis from ISA by near surface microbial communities not previously exposed to these compounds up to and including pH 10.0.

  5. Study on the complexation of humic substances with calcium ion by ion selective electrode method

    Introduction: Humic substances (HS), which are one of main organic components in soil and aquatic environment, can influence the migration and fate of nuclides through formation of complexes. To quantitatively describe such complex formation, it is essential to consider the formation of major dissolved constituents ions, such as alkali or alkali earth ions, with HSUI. This paper reports the result on the study of the complex formation of calcium ion with soil HS and polyacrylic acid, where polyacrylic acid is selected to observed the effect of heterogeneous composition of HS. Experimental: As an initial solution for the titration experiment, the fixed amounts of calcium ion, NaNO3 solution and HS or PAA were mixed in a 150 mL plastic bottle, which was covered with Laboatory Film (Parafilm 'M'). Then, a fixed amount of NaOH solution was added step by step and the concentration of calcium ion and pH in solution were measured (IM-40S ion meter, DKK.TOA CORP. Japan) simultaneously after each addition. All the experiments were conducted in the 0.01 mol/L NaNO3 solution at 298.2 K in temperature under Ar atmosphere. The humic substances, Elliott soil humic acid (HA) (Cat.No.1sl02H) and Elliott soil Fulvic acid (FA) (Cat.No. lsl02H ), were obtained from International Humic Substances Society(IHSS). Polyacrylic acids (PAA) were obtained from polyscience Inc.(M.W. ca. 450.000). The other chemicals are of analytical grade. De-ionized water (Milli-Q Pureline, Yamato, Japan) was used to prepare the solution. Results and discussion: Fig. 1. shows tile typical titration curves of 500 mg/L HA containing 0.00, 6.24, 20.4, 41.6 mg/L total calcium ion in 0.010 mol/L NaN3 at 298.2 K under Ar atmosphere. The differences between the titration curves of the solution with and without calcium ion indicate the formation of complex with HA. Fig. 1 also shows the plots of the concentration of free calcium ion versus the amounts of added NaOH obtained from the titration of the solution with

  6. Input of trace substances to coniferous forests by fog interception at high elevations of Black Forest

    The deposition of trace substances to a coniferous forest has been estimated by means of a one-dimensional cloud droplet deposition model. For a period of 21 months the liquid water content has been measured and 89 samples of cloud water from the weather station Feldberg have been analysed for chemical composition. These data and meteorological routine observations have been used as input parameters for the deposition model. Deposition calculations to a 40 years old coniferous forest for the period 1982-1991 showed that the cloud water deposition amounts to 33% of the precipitation amount on the average and varies between 23 and 43% in single years. The highest cloud water deposition rates occur during fall and winter. The trace substance concentration in cloud water has been found to be higher than in precipitation, by a factor between 6 and 12, depending on the type of ions. Typically seasonal variations of normalized ion concentrations could be shown to exist as well as dependencies on wind direction. Air mass transport from the industries of the Stuttgart area resulted in higher trace substance concentrations in cloud water. The deposition of trace substances via fog interception during the summer months is as high and in the winter months higher than that by wet deposition. The forests at high elevations of Black Forest are charged appreciably by fog interception. (orig.). 31 figs., 5 tabs., 39 refs

  7. A step-by-step procedure for pH model construction in aquatic systems

    A. F. Hofmann


    Full Text Available We present, by means of a simple example, a comprehensive step-by-step procedure to consistently derive a pH model of aquatic systems. As pH modeling is inherently complex, we make every step of the model generation process explicit, thus ensuring conceptual, mathematical, and chemical correctness. Summed quantities, such as total inorganic carbon and total alkalinity, and the influences of modeled processes on them are consistently derived. The model is subsequently reformulated until numerically and computationally simple dynamical solutions, like a variation of the operator splitting approach (OSA and the direct substitution approach (DSA, are obtained. As several solution methods are pointed out, connections between previous pH modelling approaches are established. The final reformulation of the system according to the DSA allows for quantification of the influences of kinetic processes on the rate of change of proton concentration in models containing multiple biogeochemical processes. These influences are calculated including the effect of re-equilibration of the system due to a set of acid-base reactions in local equilibrium. This possibility of quantifying influences of modeled processes on the pH makes the end-product of the described model generation procedure a powerful tool for understanding the internal pH dynamics of aquatic systems.

  8. Sex differences in the cumulative incidence of substance use by birth cohort

    Colell Ortega, Esther, 1961-; S??nchez Niub??, Albert; Domingo i Salvany, Ant??nia


    BACKGROUND: Men present higher overall rates of substance use and abuse than women; yet, evidence suggests that an increase of substance use by the younger cohorts of women in recent decades is narrowing this gap in western societies. Moreover, younger cohorts may also be reporting earlier initiation of substance use, representing an increased risk for developing substance-related problems. With this study we intend to identify changes in the patterns of substance use of men and women in Spai...

  9. In vitro antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis in root canals

    Marcia Carneiro Valera


    Full Text Available Objective: The aim of this study was to evaluate the antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis inoculated in root canals. Material and Methods: Seventy-two human tooth roots were contaminated with C. albicans and E. faecalis for 21 days. The groups were divided according to the auxiliary chemical substance into: G1 2.5% sodium hypochlorite (NaOCl, G2 2% chlorhexidine gel (CHX, G3 castor oil, G4 glycolic Aloe vera extract, G5 glycolic ginger extract, and G6 sterile saline (control. The samples of the root canal were collected at different intervals: confirmation collection, at 21 days after contamination; 1st collection, after instrumentation; and 2nd collection, seven days after instrumentation. Microbiological samples were grown in culture medium and incubated at 37°C for 48 hours. Results: The results were submitted to the Kruskal-Wallis and Dunn (5% statistical tests. NaOCl and CHX completely eliminated the microorganisms of the root canals. Castor oil and ginger significantly reduced the number of CFU of the tested bacteria. Reduction of CFU/mL at the 1st and 2nd collections for groups G1, G2, G3 and G4 was greater in comparison to groups G5 and G6. Conclusion: It was concluded that 2.5% sodium hypochlorite and 2% chlorhexidine gel were more effective in eliminating C. albicans and E. faecalis, followed by the castor oil and glycolic ginger extract. The Aloe vera extract showed no antimicrobial activity.

  10. Preferences for treatment setting by substance users in India

    Anju Dhawan


    Full Text Available Background: Drug and alcohol use is a growing public health concern for India. Treatment services delivery for substance use disorders is available through three sectors viz. Government (GO centres under Ministry of Health and FW, Non-Government (NGO under Ministry of Social Justice and Empowerment and the private sector. Information on ttreatment utilisation and preferences of treatment settings by substance users are not available for India. Methods: A performa was filled up prospectively for each consecutive new patient seeking treatment for drug/alcohol use (excluding tobacco at De-addiction centres funded by MOH&FW; NGOs under MoSJE and private psychiatrists between 15 th July to 15 th October, 2011. All data available for 182 drug using persons from private, 1228 persons from 35 NGOs and 1700 persons from GO organizations were entered into SPSS-21.0, data quality checks performed and analysed. Results: There was a variance in the population profile in the three sectors providing treatment delivery for substance users in India. Treatment seeking for illicit drugs (heroin, opiates and cannabis was higher in GO sector; injection drug use was higher in NGO sector while alcohol was higher in private sector. Conclusions: Strengthening linkages between GO and NGO sector is important for an improved coverage and quality of treatment services in the country. The Andersen′s Behavioural Model as theoretical background to clarify some issues in analyzing with larger datasets is warranted.

  11. Endocrine disrupting chemicals and other substances of concern in food contact materials: an updated review of exposure, effect and risk assessment.

    Muncke, Jane


    Food contact materials (FCM) are an underestimated source of chemical food contaminants and a potentially relevant route of human exposure to endocrine disrupting chemicals (EDCs). Quantifying the exposure of the general population to substances from FCM relies on estimates of food consumption and leaching into food. Recent studies using polycarbonate plastics show that food simulants do not always predict worst-case leaching of bisphenol A, a common FCM substance. Also, exposure of children to FCM substances is not always realistically predicted using the common conventions and thus possibly misjudged. Further, the exposure of the whole population to substances leaching into dry foods is underestimated. Consumers are exposed to low levels of substances from FCM across their entire lives. Effects of these compounds currently are assessed with a focus on mutagenicity and genotoxicity. This approach however neglects integrating recent new toxicological findings, like endocrine disruption, mixture toxicity, and developmental toxicity. According to these new toxicology paradigms women of childbearing age and during pregnancy are a new sensitive population group requiring more attention. Furthermore, in overweight and obese persons a change in the metabolism of xenobiotics is observed, possibly implying that this group of consumers is insufficiently protected by current risk assessment practice. Innovations in FCM risk assessment should therefore include routine testing for EDCs and an assessment of the whole migrate toxicity of a food packaging, taking into account all sensitive population groups. In this article I focus on recent issues of interest concerning either exposure to or effects of FCM-related substances. Further, I review the use of benzophenones and organotins, two groups of known or suspected EDCs, in FCM authorized in the US and EU. PMID:21073950

  12. Assessing the potential hazard of chemical substances for the terrestrial environment. Development of hazard classification criteria and quantitative environmental indicators.

    Tarazona, J V; Fresno, A; Aycard, S; Ramos, C; Vega, M M; Carbonell, G


    Hazard assessment constitutes an essential tool in order to evaluate the potential effects of chemical substances on organisms and ecosystems. It includes as a first step, hazard identification, which must detect the potential dangers of the substance (i.e. the kind of effects that the substance may produce), and a second step to quantify each danger and to set the expected dose/response relationships. Hazard assessment plays a key role in the regulation of chemical substances, including pollution control and sustainable development. However, the aquatic environment has largely received more attention than terrestrial ecosystems. This paper presents the extrapolation of several basic concepts from the aquatic to the terrestrial compartment, and suggests possibilities for their regulatory use. Two specific proposals are discussed. The first focuses on the scientific basis of the hazard identification-classification criteria included in the EU regulations and their extrapolation to the terrestrial environment. The second focuses on the OECD programme for environmental indicators and the development of a soil pollution pressure indicator to quantify the potential hazards for the soil compartment and its associated terrestrial ecosystem related to the toxic chemicals applied deliberately (i.e. pesticides) or not (i.e. heavy metals in sludge-based fertilisers; industrial spills) to the soil. PMID:10803544

  13. pH modeling for maximum dissolved organic matter removal by enhanced coagulation

    Jiankun Xie; Dongsheng Wang; John van Leeuwen; Yanmei Zhao; Linan Xing; Christopher W. K. Chow


    Correlations between raw water characteristics and pH after enhanced coagulation to maximize dissolved organic matter (DOM)removal using four typical coagulants (FeCl3,Al2(SO4)3,polyaluminum chloride (PAC1) and high performance polyaluminum chloride (HPAC)) without pH control were investigated.These correlations were analyzed on the basis of the raw water quality and the chemical and physical fractionations of DOM of thirteen Chinese source waters over three seasons.It was found that the final pH after enhanced coagulation for each of the four coagulants was influenced by the content of removable DOM (i.e.hydrophobic,and higher apparent molecular weight (AMW) DOM),the alkalinity and the initial pH of raw water.A set of feed-forward semi-empirical models relating the final pH after enhanced coagulation for each of the four coagulants with the raw water characteristics were developed and optimized based on correlation analysis.The established models were preliminarily validated for prediction purposes,and it was found that the deviation between the predicted data and actual data was low.This result demonstrated the potential for the application of these models in practical operation of drinking water treatment plants.

  14. Suppressive effects of coffee on the SOS responses induced by UV and chemical mutagens

    SOS-inducing activity of UV or chemical mutagens was strongly suppressed by instant coffee in Salmonella typhimurium TA1535/pSK1002. As decaffeinated instant coffee showed a similarly strong suppressive effect, it would seem that caffeine, a known inhibitor of SOS responses, is not responsible for the effect observed. The suppression was also shown by freshly brewed coffee extracts. However, the suppression was absent in green coffee-bean extracts. These results suggest that coffee contains some substance(s) which, apart from caffeine, suppresses SOS-inducing activity of UV or chemical mutagens and that the suppressive substance(s) are produced by roasting coffee beans. (Auth.)

  15. Peptide hydrogelation triggered by enzymatic induced pH switch

    Cheng, Wei; Li, Ying


    It remains challenging to develop methods that can precisely control the self-assembling kinetics and thermodynamics of peptide hydrogelators to achieve hydrogels with optimal properties. Here we report the hydrogelation of peptide hydrogelators by an enzymatically induced pH switch, which involves the combination of glucose oxidase and catalase with D-glucose as the substrate, in which both the gelation kinetics and thermodynamics can be controlled by the concentrations of D-glucose. This novel hydrogelation method could result in hydrogels with higher mechanical stability and lower hydrogelation concentrations. We further illustrate the application of this hydrogelation method to differentiate different D-glucose levels.

  16. A General Method for the Rapid Determination of Carbon-14- and Hydrogen-3-Labelled Substances by Gas Chromatography

    A method is described for the determination of 14C- and 3H- labelled substances by gas chromatography using different size flow counters. The method of cracking substances in a current of hydrogen gas is especially suitable for 3H-labelled compounds because it is free from the disadvantages encountered when the substances are first oxidized and the water formed subsequently converted. The general applicability of this method is shown for different classes of compounds. The analysis is independent of the chemical composition of the compound. By using a part oi the apparatus very rapid analyses of vaporizable 14C- and apparently all 3H-labelled substances can be made by direct injection into the reaction chamber. The apparatus can also be used for the oxidation procedure. (author)

  17. SOLUPLOT, Eh-pH Diagram, aO2-pH Diagram Plots for Aqueous Chemical Systems

    1 - Description of problem or function: SOLUPLOT is a program designed to calculate and plot complex potential - pH diagrams and log oxygen activity - pH diagrams for aqueous chemical systems, considering speciation of ligands, from free energy and thermodynamic activity data. These diagrams, commonly referred to as Eh-pH and aO2-pH diagrams, respectively, define areas of predominance in Eh-pH diagrams or aO2-pH space for chemical species of a chemical system at equilibrium. Over an area of predominance, one predominant species is at greater activity than the other species of the system considered. The diagram axes, pH (a measure of hydrogen ion activity) and either Eh or log aO2 (measures of the tendency toward either oxidation or reduction), are parameters commonly applied in describing the chemistry of aqueous systems. 2 - Method of solution: SOLUPLOT calculates a diagram involving the speciation of ligands in three general steps. First the speciation of a pH-dependent ligand system, if specified in the input data, is calculated. Since this system is solely pH-dependent, areas of predominance are defined by constant pH lines which divide the diagram vertically into a number of rectangular subsections. Secondly the program calculates the speciation of an Eh-pH- dependent ligand system, if so specified in the input data. This speciation may be represented by vertical, horizontal, and sloping bounds. The initial diagram is now effectively divided into a number of sub-diagrams, each representing the intersection of the area of predominance of one Eh-pH-dependent ligand species. Finally the program takes each sub-diagram separately and calculates the speciation of the main system. Within each sub-diagram the program actually calculates two speciations, one among all the species in the main system (the solid-aqueous diagram), and one among only the aqueous species (the aqueous species diagram). The main system within a sub-diagram includes main system species, all non

  18. Formation of slow-reacting substance by guinea pig immunoglobulins.

    Jancar, S.; Akimura, O. K.; Dias da Silva, W.


    The capacity of guinea pig antibodies to mediate the antigen-induced release of slow-reacting substance (SRS) in the rat peritoneal cavity is restricted to IgG2 and, to a lesser extent, to IgG1 populations of immunoglobulin. IgM and homocytotropic antibody of the reaginic type lacked this activity. The process was partially blocked by previous decomplementation of the rats, was not affected by previous reduction of the circulating leukocytes, and was partially suppressed by previous depletion of circulating platelets with an antiserum to rat platelets. PMID:11696

  19. Fiscal 1997 report on the results of the international standardization R and D. Measurement of ultra-micro chemical substances and measuring methods of hormone effects; 1997 nendo seika hokokusho kokusai hyojun soseigata kenkyu kaihatsu. Chobiryo kagaku busshitsu no keisoku horumon eikyo sayo sokuteiho



    Concerning the measurement system of ultra-micro hazardous chemical substances in the global environment, the paper examined the present situation of chemical substances such as dioxins, made an experimental study on the method to analyze dioxins in exhaust gas from an aspect of international consistency, and worked out a JIS draft. As to the standard measuring method of hormone effects of chemical substances, the paper developed the competitive bonding experiment system to measure bonding ability of chemical substances to homo sapiens estrogen receptor (ER). By measuring ER bonding ability of 78 kinds of chemical substances, the measuring method was developed. In the development of the assay system for detection of hormone-like compounds, the assay system with transfer activity via estrogen receptor as an index was established using cultured cells and yeast. Further, the development was made of a measuring method of receptor bonding activity of hormone-like substances. 33 refs., 151 figs., 66 tabs.

  20. Compensation of damage caused by diverted nuclear substances

    This paper provides a comprehensive analysis of the insurance system for nuclear liability. As a rule, if nuclear fuel, radioactive products or waste are governed by nuclear energy law providing for strict and channelled liability, their legal holder will pay for damage arising from them anywhere within 20 years after theft or diversion and 10 years after the nuclear incident. In most countries, atomic liability insurers will implicitly grant their cover through policies underwritten by legal holders. If diverted substances have a low specific radioactivity, their legal holder remains liable according to common law and insurance policies cover this conventional liability. (NEA)

  1. Erythema multiforme possibly triggered by food substances in a dog.

    Itoh, Teruo; Nibe, Kazumi; Kojimoto, Atsuko; Mikawa, Mayumi; Mikawa, Kazuhiro; Uchida, Kazuyuki; Shii, Hiroki


    A 5-year-old female border collie presented with erythematous skin lesions at the axillae, groin, mucocutaneous junctions, and pinnae. Biopsy revealed lymphocytic interface dermatitis with hydropic degeneration of basal cells and keratinocyte apoptosis. Based on gross and histological features, diagnosis of erythema multiforme was made. The disease was resolved by treatment with azathioprine, prednisolone, and a hypoallergenic diet. Finally, the skin lesion was controlled without drug therapy but recurred easily every time commercial foods except the hypoallergenic diet were used, suggesting that food substances triggered this outbreak. PMID:16953090

  2. Tracking chemicals in products around the world: introduction of a dynamic substance flow analysis model and application to PCBs.

    Li, Li; Wania, Frank


    Dynamically tracking flows and stocks of problematic chemicals in products (CiPs) in the global anthroposphere is essential to understanding their environmental fates and risks. The complex behavior of CiPs during production, use and waste disposal makes this a challenging task. Here we introduce and describe a dynamic substance flow model, named Chemicals in Products - Comprehensive Anthropospheric Fate Estimation (CiP-CAFE), which facilitates the quantification of time-variant flows and stocks of CiPs within and between seven interconnected world regions and the generation of global scale emission estimates. We applied CiP-CAFE to polychlorinated biphenyls (PCBs), first to evaluate its ability to reproduce previously reported global-scale atmospheric emission inventories and second to illustrate its potential applications and merits. CiP-CAFE quantifies the pathways of PCBs during production, use and waste disposal stages, thereby deducing the temporal evolution of in-use and waste stocks and identifying their long-term final sinks. Time-variant estimates of PCB emissions into air, water and soil can be attributed to different processes and be fed directly into a global fate and transport model. By capturing the international movement of PCBs as technical chemicals, and in products and waste, CiP-CAFE reveals that the extent of global dispersal caused by humans is larger than that occurring in the natural environment. Sensitivity analysis indicates that the model output is most sensitive to the PCB production volume and the lifetime of PCB-containing products, suggesting that a shortening of that lifetime is key to reducing future PCB emissions. PMID:27431909

  3. Detection of Baking Soda in Flat Bread by Direct pH Metery and Alkalinity Measurement

    Jahed Khaniki, G. H. R.; Vaezi, F.; Yunesian, M.; Nabizadeh, R.; Paseban, G. H. A.

    The objective of this study is evaluation of direct pH metery and alkalinity measurement methods for determination of baking soda in lavash bread (a kind of flat bread) in order to introduce and recommend a good practice of control. For running the experiments, various samples of lavash bread having different concentrations of baking soda were prepared. Ten grams of each sample were mixed with distilled water and then the prepared solutions were filtrated. The filtrates were then analyzed for pH and total alkalinity according to the distractions described in Standard Methods. Results show a significant correlation between the pH values of bread samples and the amount of baking soda. Also, a positive correlation has been observed between the alkalinity of bread samples and used baking soda. By comparing the R2-values specified for these two methods it could be concluded that the direct pH metery method is more reasonable. Furthermore, by this simple method it is possible to accelerate the detection of minute amounts of this chemical in bread.

  4. Extraction of extracellular polymeric substances (EPS) from anaerobic granular sludges: comparison of chemical and physical extraction protocols

    Abzac, D', P.; Bordas, F; Van Hullebusch, E.; Lens, P. N. L.; Guibaud, G.


    The characteristics of the extracellular polymeric substances (EPS) extracted with nine different extraction protocols from four different types of anaerobic granular sludge were studied. The efficiency of four physical (sonication, heating, cationic exchange resin (CER), and CER associated with sonication) and four chemical (ethylenediaminetetraacetic acid, ethanol, formaldehyde combined with heating, or NaOH) EPS extraction methods was compared to a control extraction protocols (i.e., centr...

  5. Effect of freeze-thaw cycling on the chemical composition of aqueous solutions of organic substances

    By means of spectrophotometry and chemical analysis, it was found that multiply repeated freezing-thawing cycles for aqueous solutions of carbohydrates, choline chloride, and diphenylpicrylhydrazyl (DPPH) alter the chemical composition of the final solutions. In most cases, one or two freeze-thaw cycles are shown to result in the same changes as those observed upon γ irradiation with absorbed doses of 200-300 Gy. The DPPH decay detected during the repetition of this treatment suggests that the degradation of organic molecules involves the stage of formation of free radicals. It was assumed that the cause of the observed processes is cavitation

  6. Fiber optic chemical sensor systems for monitoring pH changes in concrete

    Basheer, Muhammed P.; Grattan, Kenneth T. V.; Sun, Tong; Long, Adrian E.; McPolin, Daniel; Xie, Weiguo


    Carbonation-induced corrosion of steel is one of the principal causes of deterioration of reinforced concrete structures. When concrete carbonates, its pH decreases from a value in excess of 12.6 to less than 9 and, hence, a measure of the pH is an indicator of the degree of carbonation. This paper describes the development, testing and evaluation of two types of fibre optic sensors for the pH monitoring. One of these used a sol-gel based probe tip, into which an indicator dye has been introduced and the second used a disc containing an indicator operating over a narrower range of pH with shorter lifetime. Both were connected to a portable spectrometer system, which is used to monitor the spectral changes in optical absorption of the probe tip. A white light source to interrogate the active elements is used as the systems operate in the visible part of the spectrum. The two types of sensors have been found to be sensitive to the changes in pH due to carbonation, but the response time depended on the thickness of the coating material in the case of the sol-gel sensor. The durability of the sensors is still under investigation. The disc type sensor has a life span of approximately 1 month and, hence, it is not suitable for embedding in concrete for long-term monitoring of pH changes. However, it can be used for assessing the pH in vivo. The harder sol-gel is more durable and, hence, has a slower, but acceptable response time.

  7. Influência pH na reposta de sementes de plantas daninhas a substâncias promotoras de germinação Influence of pH on the action of chemicals on weed seeds

    Ricardo Carmona


    Full Text Available Determinou-se o efeito do pH na ação de algumas subst âncias promotoras de germinação em sementes de Chenopodium album L., Avena fatua L. e Rumex crispus L. A azida de sódio (A, nitrato de potássio + etileno (NE, NE + A, NE + A + tiuréia + peróxido de hidrogênio foram testados em solo (em bandej as e em papel (in vitro com soluções tampão em ambiente controlado. O efeito do NE no estímulo à germinação de sementes não foi afetado pelo pH na faixa de 3 a 9. A azida de sódio foi a substância que mais afetou as sementes, sendo este efeito pH dependente. Este composto foi extremamente deletério em sementes de C. album e A. fatua em solo ácido (pH 4,0, enquanto em solo básico ele estimulou a germinação em sementes de A. fatua, através da superação da dormência A combinação de NE + A em pH 6,2 inibiu a germinação de C. album e A. fatua, mostrando um antagonismo entre estes compostos. A mistura dos cinco compostos reduziu a influência do pH na ação deletéria da azida de sódio. O efeito deletério da azida foi menos afetado pela temperatura do que sua ação como superador de dormência. A solução extraída do solo não afetou a resposta de tratamentos químicos in vitro em diferentes temperaturas comparado a soluções tampão em pH semelhante. Discute-se a influência das características do solo na eficácia de substâncias químicas como superadores de dormência ou tratamentos deletérios às sementes.The effects of pH on the action of some dormancy-relieving chemicals were investi gated on seeds of Chenopodium album, Avena fatua and Rumex crispus. Sodium azide (A, potassium nitrate + ethephon (NE, NE + A, NE + A + thiourea + hydrogen peroxide were tested in soil trays or in paper (in vitro with buffer solutions in controlled environment. The response to NE was not affected by pH from 3 to 9. Sodium azide had the gre ate st effect on seed decline, but its effect was pH-dependent. This compound was extremely

  8. 77 FR 66149 - Significant New Use Rules on Certain Chemical Substances


    ... Register issue of April 24, 1990 (55 FR 17376) (April 24, 1990 SNUR). Consult that preamble for further... a raw material for production of copper chemicals and as a raw material for the production of animal... (PCDFs) by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) study...

  9. Chemical and spectroscopic characterization of humic substances isolated from South- Bohemian peat

    Enev, V.; Novák, František; Klučáková, M.

    Ioannina : University of Ioannina, 2014. s. 226-227. [Meeting of the International Humic Substances Society. Natural Organic Matter: Structure-Dynamics-Innovative Applications /17./. 01.09.2014-05.09.2014, Ioannina] Grant ostatní: GA MŠk(CZ) LO1211 Institutional support: RVO:60077344 Keywords : humic substances * UV/ Vis * FTIR spectroscopy * fluorescence spectroscopy * absorption and fluorescence coefficients Subject RIV: DF - Soil Science

  10. Self-mutilation induced by psychotropic substances: a systematic review.

    Gahr, Maximilian; Plener, Paul Lukas; Kölle, Markus Alexander; Freudenmann, Roland Wolfgang; Schönfeldt-Lecuona, Carlos


    Self-mutilation (SM) not only occurs among patients with schizophrenia, personality disorders or transsexuality but also as a phenomenon induced by psychotropic substances (PS). We intended to find characteristics of patients at risk to perform SM induced by PS (SMIPS), frequent PS within this phenomenon and typical presentations of SMIPS. A systematic review of the literature (including Medline, the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials and Scopus) was conducted. On October 2011 we identified 26 cases (23 publications) of SM related to PS. Majority of patients (85%) was male, mean age was 30 years (median 41 years). Seventy-three percent of patients developed SM subsequent to the use of one PS, 27% presented SM after the use of more than one PS. Alcohol (25%), hallucinogens (25%) and amphetamines (22%) were found most frequently among the reported substances. Major impairment was present in 80%. Our findings suggest male sex, young age, a previous history of abuse of PS and the current use of alcohol, hallucinogens or amphetamines to favour SMIPS. PMID:22841344

  11. Reducing groundwater pollution by toxic substances: Procedures and policies

    Waterstone, Marvin


    One major source of water-related health problems is the improper disposal of toxic substances in the environment. Toxic materials leaching from unregulated and unlined pits, ponds, lagoons, and landfills have created a widespread environmental nightmare in the United States and many other parts of the world. At present, there are two major and interrelated components of this problem in the United States. The first is the issue of cleaning up abandoned disposal sites that pose actual or potential threats to water supplies. The second aspect of the problem concerns the necessity of siting proper management, treatment, or disposal facilities in the future. Priorities must be set to allow efficient, effective, and equitable allocation of the scarce resources that are available for accomplishing these tasks. This article examines a number of the issues involved in setting these priorities, and presents the results obtained from a study of risk estimation and evaluation in the context of groundwater contamination by toxic substances. The article introduces a new concept of risk estimation, which is shown to produce more accurate and credible risk analyses. Finally, the relationships between risk credibility and public perceptions of procedural fairness and equity are examined as these factors bear on the institutional aspects of implementing policies for site cleanup and/or facility siting.

  12. Production of bacteriocin-like substances by lactic acid bacteria isolated from regional ovine cheese

    Cássia Regina Nespolo


    Full Text Available Lactic acid bacteria (LAB were isolated from ovine milk and cheeses manufactured in the South Region of Brazil. Among 112 bacterial isolates investigated, 59 were chosen through a screening for LAB. Among these 59 strains of LAB, 21% showed antimicrobial, proteolytic and lipolytic activities. Based on this screening, Lactobacillus plantarum LCN 17 and Lactobacillus rhamnosus LCN 43 were selected and tested for the production of bacteriocin-like substances (BLS. The BLS produced by both isolates showed antimicrobial activity against Listeria monocytogenes, whereas that produced by L. plantarum LCN 17 presented higher stability to different temperature, pH and enzyme treatments. These strains present potential for production of BLS, and for use as starter cultures.

  13. Characterization of laser-tissue interaction processes by low-boiling emitted substances

    Weigmann, Hans-Juergen; Lademann, Juergen; Serfling, Ulrike; Lehnert, W.; Sterry, Wolfram; Meffert, H.


    Main point in this study was the investigation of the gaseous and low-boiling substances produced in the laser plume during cw CO2 laser and XeCl laser irradiation of tissue by gas chromatography (GC)/mass spectrometry. The characteristic emitted amounts of chemicals were determined quantitatively using porcine muscular tissue. The produced components were used to determine the character of the chemical reaction conditions inside the interaction zone. It was found that the temperature, and the water content of the tissue are the main parameter determining kind and amount of the emitted substances. The relative intensity of the GC peak of benzene corresponds to a high temperature inside the interaction area while a relative strong methylbutanal peak is connected with a lower temperature which favors Maillard type reaction products. The water content of the tissue determines the extent of oxidation processes during laser tissue interaction. For that reason the moisture in the tissue is the most important parameter to reduce the emission of harmful chemicals in the laser plume. The same methods of investigation are applicable to characterize the interaction of a controlled and an uncontrolled rf electrosurgery device with tissue. The results obtained with model tissue are in agreement with the situation characteristic in laser surgery.

  14. Substances in human urine that strongly inhibit bacterial mutagenicity of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and related heterocyclic amines.

    Malaveille, C; Hautefeuille, A; Brun, G; Vineis, P; Bartsch, H


    Extracts of human urine were shown to contain substances that strongly inhibited the liver S9-mediated mutagenicity of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in Salmonella typhimurium TA98 strain in a liquid incubation assay. The inhibitory effect was unrelated to cytotoxicity and was similar with urine extracts from smokers and non-smokers. Under similar assay conditions, the mutagenicity of the related amino-imidazoazaarenes, 2-amino-3-methyl-imidazo[4,5-f]quinoline, 2-amino-3,8-dimethylimidazo[4,5-f]-quinoline and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline was also found to be strongly inhibited by urine extracts. Decreased or enhanced mutagenicity was seen with 2-acetyl-aminofluorene and 2-aminoanthracene depending on the type of assay, and the time of incubation in liquid medium. A weak inhibition of the mutagenicity of 2-nitrofluorene, a direct-acting mutagen, was observed only after a short incubation time. Mutagenicity of 4-nitroquinoline N-oxide was not altered by the presence of urine extracts at concentrations shown to be inhibitory for the mutagenicity of heterocyclic aromatic amines. Our data suggest that the inhibitory substances in urine act through their capacity to non covalently bind the parent heterocyclic and aromatic amines, thus affecting their availability in aqueous medium for diffusion into liver microsomes where metabolic activation takes place. PMID:1473240

  15. Influence of pH value on Cu (II biosorption by lignocellulose peach shell waste material

    Lopičić Zorica R.


    Full Text Available In the last decade, the pollution made by anthropogenic sources has reached large amounts with special attention on heavy metals because of their high toxicity, persistence and bioaccumulation tendency. Since the conventional methods for their removing are either too expensive or create large quantities of toxic sludge, the great attention has been paid to the new technologies such as biosorption, technology that use cheap, abundant, organic waste for sequestering pollutants from contaminated mediums. Among the other factors that affect biosorption process, pH value is one the most important because it directs both the metal solution chemistry as well as the activity of the biomass functional groups. In this paper the influence of pH value on biosorption of Cu (II by unmodified low-cost lignocellulose biosorbent - peach shell (PS particles, have been studied. The chemical composition of PS, point of zero charge (pHPZC as well as its surface morphology is also presented. Results have showed that this biosorbent contains mainly cellulose and lignin, the components that carry the functional groups responsible for metal binding. Its multilayer surface contains many pores and channels that help diffusion in deeper layers and force biosorption process. Point of zero charge determination was performed with three different KNO3 ionic strengths: 0,1M, 0,01M and 0,001M. The obtained value for pHPZC was 4,75±0,1 and showed that this biosorbent is non-sensitive to ionic strength of electrolyte applied. Biosorption experiments were done with peach shell particles whose diameter was -0,5+0,1mm at 25oC . The initial copper (II concentration was 50 mg/dm3 while the biosorbent concentration was 10g/dm3. Experiments were done with and without keeping pH constant. The influence of pH on biosorption process was examined in 2-6 pH range. The percentage of Cu (II removed by PS, reaches its maximum at pH 6, with the 90,43% removing but this percentage can also be

  16. Chemically driven switches for online detection of pH changes in microfluidic devices

    Mela, P.; Onclin, S.; Goedbloed, M.H.; Levi, S.A.; Hulst, van N.F.; Berg, van den A.


    The internal walls of microfabricated fluidic channels were functionalized with a selfassembled monolayer of Rhodamine B lactam. This molecule has the capability to interconvert between its open fluorescent amide form and the closed non-fluorescent lactam form upon changes of the pH conditions. The

  17. Optimal choice of pH for toxicity and bioaccumulation studies of ionizing organic chemicals

    Rendal, Cecilie; Kusk, Kresten Ole; Trapp, Stefan


    processes were identified to explain the behavior of ionizing compounds with changing pH: the change in lipophilicity when a neutral compound becomes ionized, electrical attraction, and the ion trap. The literature was screened for bioaccumulation and toxicity tests of ionizing organic compounds performed...

  18. 32P assessed phosphate uptake by tomato plants Hebros in relation to soil nutrient substance supplies

    The uptake of phosphates by tomato plants, cv.Hebros, was assessed by 32P in a vegetation pot experiment. Leached meadow-cinnamon soil was used, taken from a stationary field experiment to which, for a period of eight years, various rates of NPK were applied. As a result of that significant changes occurred in the soil nutrient substance supplies (concerning total and mobile forms of nitrogen, phosphorus, potassium, pH and salts concentration). It was established that the coefficient of phasphate utilization by tomato plants was the highest (19.15%) on soil receiving a N210P210K210 fertilizer application. Long-term fertilization with higher rates at a 1:1:1 NPK ratio increased the content of nutrient substances in the soil, but the coefficient of utilization of available phosphate diminished and was lowest (11.40%) in the case when a N960P960K720 mineral fertilizer rate was applied. Following prolonged mineral fertilization with growing N rates (from 240 up to 720 kg/ha) at a background of P720K210, the coefficient of phosphate utilization by tomato plants also diminished from 16.16 to 12.26%. (author)

  19. Inhibition of propionibacterium acnes by bacteriocin-like inhibitory substances (BLIS) produced by Streptococcus salivarius.

    Bowe, Whitney P; Filip, Jennifer C; DiRienzo, Joseph M; Volgina, Alla; Margolis, David J


    We report the in vitro inhibition of Propionibacterium acnes (P. acnes) by a bacteriocin-like inhibitory substance (BLIS-like substance) produced by Streptococcus salivarius (S. salivarius). Bacteriocins are proteinaceous substances produced by bacteria that are capable of inhibiting the growth of similar bacterial strains. Unlike classical antibiotics, they have a relatively narrow spectrum of killing activity, resulting in a reduction in the intensity of selection for resistance. These findings suggest that BLIS may potentially be used for its anti-P. acnes activity in the treatment of acne. PMID:17039652

  20. Nitrite fixation by humic substances: Nitrogen-15 nuclear magnetic resonance evidence for potential intermediates in chemodenitrification

    Thorn, K.A.; Mikita, M.A.


    Studies have suggested that NO2/-, produced during nitrification and denitrification, can become incorporated into soil organic matter and, in one of the processes associated with chemodenitrification, react with organic matter to form trace N gases, including N2O. To gain an understanding of the nitrosation chemistry on a molecular level, soil and aquatic humic substances were reacted with 15N-labeled NaNO2, and analyzed by liquid phase 15N and 13C nuclear magnetic resonance (NMR). The International Humic Substances Society (IHSS) Pahokee peat and peat humic acid were also reacted with Na15NO2 and analyzed by solid-state 15N NMR. In Suwannee River, Armadale, and Laurentian fulvic acids, phenolic rings and activated methylene groups underwent nitrosation to form nitrosophenols (quinone monoximes) and ketoximes, respectively. The oximes underwent Beckmann rearrangements to 2??amides, and Beckmann fragmentations to nitriles. The nitriles in turn underwent hydrolysis to 1??amides. Peaks tentatively identified as imine, indophenol, or azoxybenzene nitrogens were clearly present in spectra of samples nitrosated at pH 6 but diminished at pH 3. The 15N NMR spectrum of the peat humic acid exhibited peaks corresponding with N-nitroso groups in addition to nitrosophenols, ketoximes, and secondary Beckmann reaction products. Formation of N-nitroso groups was more significant in the whole peat compared with the peat humic acid. Carbon-13 NMR analyses also indicated the occurrence of nitrosative demethoxylation in peat and soil humic acids. Reaction of 15N-NH3 fixated fulvic acid with unlabeled NO2/- resulted in nitrosative deamination of aminohydroquinone N, suggesting a previously unrecognized pathway for production of N2 gas in soils fertilized with NH3.Studies have suggested that NO2-, produced during nitrification and denitrification, can become incorporated into soil organic matter and, in one of the processes associated with chemodenitrification, react with organic

  1. Oxidative stability of egg and soy lecithin as affected by transition metal ions and pH in emulsion.

    Wang, Guang; Wang, Tong


    Oxidative stability of egg and soy lecithin in emulsion was evaluated with two transition metal ions, cupric and ferric ion, at two concentration levels (50 and 500 microM). The effect of pH on lipid oxidation was also examined under these two concentrations for each ion. Egg lecithin (EL) had similar peroxide value (PV) development pattern as soy lecithin (SL) when treated with cupric ion under both acidic and neutral pH. Acidic pH of 3 accelerated oxidation of both EL and SL, especially under high concentration of copper. When treated with ferric ion, EL oxidized much faster than SL did. EL had higher value of thiobarbituric acid-reactive substances (TBARS) than SL, possibly because of its higher content of long-chain polyunsaturated fatty acids (PUFA). Acidic pH accelerated TBARS development for both EL and SL, but EL had more significantly increased values. Cupric ion was more powerful than ferric in catalyzing oxidation of both EL and SL under both acidic and neutral pH conditions as measured by PV and TBARS. Linoleic acid may contribute to higher PV production, however, arachidonic acid and docosahexaenoic acid may have contributed more to TBARS production. Overall, SL showed better oxidative stability than EL under the experimental conditions. This study also suggests that using multiple methods is necessary in properly evaluating lipid oxidative stability. PMID:18991454

  2. Vacuolation induced by unfavorable pH in cyanobacteria

    赵以军; 吴红艳; 郭厚良; 许敏; 程凯; 祝海燕


    Six species or strains of cyanobacteria, Anabaena sp. 595, Plectonema boryanum 246, Scytonema hofmanni 248, Nostoc sp. 96, Oscillatoria animlis 284 and Spirulina maxima 438, were cultured in unfavorable pH conditions for vacuole induction. At pH 5.0, 6.5, or 7.0, vacuoles were observed to form in both Anabaena sp. 595 and Plectonema boryanum 246, especially in the former. The vacuolation took place with some morphological changes, such as the cells being inflated, spherical and vacuolated, and with unequalized division. The induced vacuoles in An- abaena sp. 595 and Plectonema boryanum 246 were in spherical shape and in rather transparent appearance under a phase microscope. For Scytonema hofmanni 248, it was less sensitive to pH, its vacuole formation was found only at pH 6.5. No vacuolization occurred in the cells of Nostoc sp. 96, Oscillatoria animlis 284 and Spirulina maxima 438 at all pH conditions we used. Vacuolization under unfavorable pH provides a new proof for the existence of vacuole in cells of cyanobacteria and reflects the prokaryote's function in ecological environment.

  3. Critical Factors Associated with Substance Abuse and Chemical Dependency in Nurse Anesthesia.

    Norris, Jack; And Others


    Conducted survey to identify characteristics associated with chemical dependency among chemically dependent nurse anesthetists. Subjects were 21 nurse anesthetists who had been chemically dependent, had completed some form of drug treatment, and had been chemically free for at least one year. Investigated areas of employment setting, educational…

  4. All-Russia conference on chemical analysis of substances and materials. Abstracts of reports

    Collection contains abstracts of reports on chemical analysis of foods, drugs, environmental materials. Methods of chemical analysis used in such regions as chemical control in agriculture, criminology, art and archaeology, biotechnology, geology, chemistry and petrochemistry, metallurgy, metrology are presented. Theoretical, methodological and applied aspects of chemical analysis are considered

  5. Synthesis and characterization Bi2O2S thin film via chemical bath deposition at low pH.

    Kariper, I Afşin


    Bismuth oxysulfide thin film was prepared using Bi(NO3)3 and Na2S as reactive. Since bismuth in the form of bismuth oxide is dissolved into water, bismuth and sulfide concentration of the chemical bath is very important. Bismuth oxysulfide (Bi2O2S) thin films were produced below pH2. Tested bismuth and sulfide concentrations are as follows: 2×10(-1)M, 2×10(-2)M, 2×10(-3)M, 2×10(-4)M bismuth and 1×10(-1)M, 1×10(-2)M, 1×10(-3)M, 1×10(-4)M sulfide. The structure of the films was examined via X-ray diffraction (XRD). Optical properties, such as transmission and absorbance were measured with Ultra violet-visible spectrum, and then refractive index and reflectivity were calculated. The pH of chemical bath was stabilized below pH of 2 using 13.85mL concentrated nitric acid. Deposition time and temperature of the baths were 4h and 30°C. It has been found that bismuth and sulfide concentrations affected the structure and thickness of the film. Also, optical band gap of the films varied with concentration, parallel to the change of the structure and film thickness. PMID:27043873

  6. ATSDR evaluation of health effects of chemicals. VI. Di(2-ethylhexyl)phthalate. Agency for Toxic Substances and Disease Registry.

    Fay, M; Donohue, J M; De Rosa, C


    Di(2-ethylhexyl)phthalate (also known as DEHP, bis(2-ethylhexyl)phthalate, or BEHP; CAS Registry Number 117-81-7) is a widely-used plasticizer. It is found in numerous plastic articles, such as paints, inks, floor tiles, upholstery, shower curtains, footwear, plastic bags, food-packaging materials, toys, and medical tubing. Not surprisingly, DEHP appears at many waste sites. As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals that are of greatest public health concern at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priority List (NPL) sites. These profiles comprehensively summarize toxicological and environmental information. This article constitutes the release of the bulk of ATSDR's profile for DEHP (ATSDR, 1993) into the mainstream scientific literature. An extensive listing of human and animal health effects, organized by route, duration, and endpoint, is presented. Toxicological information on toxicokinetics, biomarkers, interactions, sensitive subpopulations, reducing toxicity after exposure, and relevance to public health is also included. Environmental information encompasses physical properties, production and use, environmental fate, levels seen in the environment, analytical methods, and a listing of regulations. ATSDR, at the behest of Congress and therefore the citizenry, prepares these profiles to inform the public about site contaminants. PMID:10786378

  7. Control of Chemical Risks by Substitution of Harmful Substances

    Jacobsen, Thomas


    Substitution of volatile, organic solvents with non-volatile, low-toxic esters of fatty acids for cleaning purposes in offset printing has successfully been implemented in several European countries. Similar substitutions in other industrial cleaning processes seem possible, especially regarding ...

  8. Effect of pH and chemical mechanical planarization process conditions on the copper–benzotriazole complex formation

    Cho, Byoung-Jun; Kim, Jin-Yong; Hamada, Satomi; Shima, Shohei; Park, Jin-Goo


    Benzotriazole (BTA) has been used to protect copper (Cu) from corrosion during Cu chemical mechanical planarization (CMP) processes. However, an undesirable Cu–BTA complex is deposited after Cu CMP processes and it should be completely removed at post-Cu CMP cleaning for next fabrication process. Therefore, it is very important to understand of Cu–BTA complex formation behavior for its applications such as Cu CMP and post-Cu CMP cleaning. The present study investigated the effect of pH and polisher conditions on the formation of Cu–BTA complex layers using electrochemical techniques (potentiodynamic polarization and electrochemical impedance spectroscopy) and the surface contact angle. The wettability was not a significant factor for the polishing interface, as no difference in the contact angles was observed for these processes. Both electrochemical techniques revealed that BTA had a unique advantage of long-term protection for Cu corrosion in an acidic condition (pH 3).

  9. 40 CFR 710.46 - Chemical substances for which information is not required.


    ..., cellulose, gum), rubber, or lignin. (iii) This exclusion does not apply to a polymeric substance that has... 8052-42-4 Asphalt 61789-60-4 Pitch 63231-60-7 Paraffin waxes and hydrocarbon waxes, microcryst. 64741... Asphalt, oxidized 64742-94-5 Solvent naphtha (petroleum), heavy arom. 64742-95-6 Solvent...

  10. 77 FR 58665 - Significant New Use Rules on Certain Chemical Substances


    ... Register issue of April 24, 1990 (55 FR 17376) (April 24, 1990 SNUR). Consult that preamble for further... methods, periodic monitoring, respiratory protection, and recordkeeping. However, no comparable NCEL... states that the generic (non-confidential) use of the substances will be as pigment dispersants. Based...

  11. Combined effects of ionising gamma radiation and some chemical substances on the Allium sativum growth

    Co 60 - gamma ionising radiations act in different doses and flows on Allium sativum. They accelerate the germination of bulblets with a couple of days by comparison with the sample. The 10 Gy dose stimulates the plants growth. The 30 Gy dose or 'shock dose' related to the radiation flow and with chemicals used in the treatment, produces strong decays or raises of biological parameter values. The growth region which is implied in growing regulators synthesis is perturbed. The calculation of nuclear and cytoplasmic volumes of nucleus-cytoplasm ratio confirms the perturbation at this level. (Author)

  12. Restoration of radiation injury by ginseng, 2. Some properties of the radioprotective substances

    Yonezawa, M.; Katoh, N.; Takeda, A. (Radiation Center of Osaka Prefecture, Sakai (Japan))


    Some properties of the radioprotective substances in a ginseng extract that increased the 30-day survival ratio in irradiated mice were studied. Methanol-soluble fraction of the extract did not protect the irradiated animals. Acid or alkali (0.12 N) inactivated the extract at 60/sup 0/C. But the radioprotective activity was stable after heating the ginseng extract in physiological saline at pH 7 in a boiling-water bath for 15 min. The ginseng extract was separated into two fractions by CM-cellulose column chromatography. One of them (CM-A) was significantly efficacious at 5% level, and the other (CM-B) at 0.1% level with the doses proportional to their yields. CM-B, not containing saponin, was subjected to further purification, UV spectrum and a biuret test suggested the presence of protein in this fraction. The supernatant obtained after heating CM-B solution at pH 7 was separated into three fractions, namely G-I, G-II and G-III, by gel-chromatography with a Sephadex G-75 column. Both G-I (0.44 mg per animal) and G-III (0.84 mg, calculated dose) were significantly efficacious, but G-II (0.47 mg) was not.

  13. Transcription of denitrification genes and kinetics of NO, N2O and N2 by soil bacteria as affected by pH

    Liu, B.; Bakken, L. R.; Frostegard, A.


    Nitrous oxide (N2O), which is to a large part derived from denitrification in soil, is a major greenhouse gas and was also recently shown to be the single most important ozone-depleting substance. Previous studies demonstrate that the N2O/N2 product ratio of denitrification is strongly dependent on pH, increasing with decreasing soil pH. The mechanisms involved are, however, poorly understood. We here present an investigation of soils from a long-term liming experiment. Since it is difficult to control which pH is actually experienced by bacterial cells in intact soils, we extracted cells on a Nycodenz gradient and exposed them to different pH levels. Bacteria extracted from soils of 3 different pHs (4.0, 6.1 and 8.0) were incubated in minimal medium supplemented with nitrate (2mM) and glutamic acid (5 mM), buffered at three pH levels (5.7, 6.1 and 7.6). Both the pH of the medium and original soil pH showed profound effect on the denitrification activity in terms of gas emission kinetics. N2O reductase (N2OR) activity was only present when cells from the high pH soils (pH 6.1 and 8.0) were exposed to high pH medium (pH 7.6). Functional genes (nirS, nirK and nosZ) and their transcripts were quantified in the extracts from pH6.1-soil. A 10-25 fold higher expression of nosZ vs nirS was found when incubated at pH 7.6 compared to pH 6.1 and 5.7. The low but significant transcription of nosZ at pH 6.1 and 5.7 did not result in detectable N2O reduction however. Cells that had been allowed to assemble their proteome while growing in pH7 medium showed N2OR activity which was practically unaffected by pH within the range 5-7. On the contrary, no N2OR activity was detected if the proteome had been formed at pH 6. The cells extracted from acid soils (pH 5.8 and 6.1) showed very low nosZ transcritption and no N2OR activity if exposed to pH 7 during the transition from oxic to anoxic conditions, suggesting an adaptation to low pH in the sense that they do not transcribe the gene

  14. Bioremediation of toxic substances by mercury resistant marine bacteria

    De, J.; Sarkar, A.; Ramaiah, N.

    Bioremediation of toxic substances includes microbe-mediated enzymatic transformation of toxicants to non-toxic, often assimilable, forms. Mercury-resistant marine bacteria are found to be very promising in dealing with mercury, and a host of other...

  15. A simultaneous determination of related substances by high performance liquid chromatography in a drug product using quality by design approach.

    Tol, Trupti; Kadam, Nilesh; Raotole, Nilesh; Desai, Anita; Samanta, Gautam


    The combination of Abacavir, Lamivudine and Dolutegravir is an anti-retroviral formulation that displays high efficacy and superiority in comparison to other anti-retroviral combinations. Analysis of related substances in this combination drug product was very challenging due to the presence of nearly thirty peaks including the three active pharmaceutical ingredients (APIs), eleven known impurities and other pharmaceutical excipients. Objective of this study was to develop a single, selective, and robust high performance liquid chromatography method for the efficient separation of all peaks. Initially, one-factor-at-a-time (OFAT) approach was adopted to develop the method. But, it could not resolve all the critical peaks in such complex matrix. This led to the advent of two different HPLC methods for the determination of related substances, one for Abacavir and Lamivudine and the other for Dolutegravir. But, since analysis of a single sample using two methods instead of one is time and resource consuming and thus expensive, an attempt was made to develop a single and robust method by adopting quality by design (QbD) principles. Design of Experiments (DoE) was applied as a tool to achieve the optimum conditions through Response surface methodology with three method variables, pH, temperature, and mobile phase composition. As the study progressed, it was discovered that establishment of the design space was not viable due to the completely distant pH requirements of the two responses, i.e. (i) retention time for Lamivudine carboxylic acid and (ii) resolution between Abacavir impurity B and unknown impurity. Eventually, neglecting one of these two responses each time, two distinguished design spaces have been established and verified. Edge of failures at both design spaces indicate high probability of failure. It therefore, becomes very important to identify the most robust zone or normal operating range (NOR) within the design space with low risk of failure and high

  16. Prenatal Substance Exposure: What Predicts Behavioral Resilience by Early Adolescence?

    Liebschutz, Jane; Crooks, Denise; Rose-Jacobs, Ruth; Cabral, Howard J.; Heeren, Timothy C.; Gerteis, Jessie; Appugliese, Danielle P.; Heymann, Orlaith D.; Lange, Allison V.; Frank, Deborah A.


    Understanding behavioral resilience among at-risk adolescents may guide public policy decisions and future programs. We examined factors predicting behavioral resilience following intrauterine substance exposure (IUSE) in a prospective longitudinal birth-cohort study of 136 early adolescents (age 12.4–15.9) at-risk for poor behavioral outcomes. We defined behavioral resilience as a composite measure of lack of early substance use initiation (before age 14), lack of risky sexual behavior, or l...

  17. Speeding chemical reactions by focusing

    Lacasta, A. M.; Ramírez-Piscina, L.; Sancho, J. M.; Lindenberg, K.


    We present numerical results for a chemical reaction of colloidal particles which are transported by a laminar fluid and are focused by periodic obstacles in such a way that the two components are well mixed and consequently the chemical reaction is speeded up. The roles of the various system parameters (diffusion coefficients, reaction rate, and obstacles sizes) are studied. We show that focusing speeds up the reaction from the diffusion limited rate ˜t-1/2 to very close to the perfect mixing rate, ˜t-1.

  18. Speeding chemical reactions by focusing

    Lacasta, A M; Sancho, J M; Lindenberg, K


    We present numerical results for a chemical reaction of colloidal particles which are transported by a laminar fluid and are focused by periodic obstacles in such a way that the two components are well mixed and consequently the chemical reaction is speeded up. The roles of the various system parameters (diffusion coefficients, reaction rate, obstacles sizes) are studied. We show that focusing speeds up the reaction from the diffusion limited rate (t to the power -1/2) to very close to the perfect mixing rate, (t to the power -1).

  19. Use of computer-assisted prediction of toxic effects of chemical substances

    The current revision of the European policy for the evaluation of chemicals (REACH) has lead to a controversy with regard to the need of additional animal safety testing. To avoid increases in animal testing but also to save time and resources, alternative in silico or in vitro tests for the assessment of toxic effects of chemicals are advocated. The draft of the original document issued in 29th October 2003 by the European Commission foresees the use of alternative methods but does not give further specification on which methods should be used. Computer-assisted prediction models, so-called predictive tools, besides in vitro models, will likely play an essential role in the proposed repertoire of 'alternative methods'. The current discussion has urged the Advisory Committee of the German Toxicology Society to present its position on the use of predictive tools in toxicology. Acceptable prediction models already exist for those toxicological endpoints which are based on well-understood mechanism, such as mutagenicity and skin sensitization, whereas mechanistically more complex endpoints such as acute, chronic or organ toxicities currently cannot be satisfactorily predicted. A potential strategy to assess such complex toxicities will lie in their dissection into models for the different steps or pathways leading to the final endpoint. Integration of these models should result in a higher predictivity. Despite these limitations, computer-assisted prediction tools already today play a complementary role for the assessment of chemicals for which no data is available or for which toxicological testing is impractical due to the lack of availability of sufficient compounds for testing. Furthermore, predictive tools offer support in the screening and the subsequent prioritization of compound for further toxicological testing, as expected within the scope of the European REACH program. This program will also lead to the collection of high-quality data which will broaden the

  20. Determination of radium-226 in different substances without prior chemical separation

    A method is developed for the determination of radium-226, based on the measurement of the amount of radium-222, extracted from the substance being analyzed. The limit of detection of radium, equal to 6.6 X 10-15 mass%, is achieved because of the use of a low-background proportional counter and a special vacuum facility for filling the detector with the working gas mixture

  1. 77 FR 42990 - Significant New Use Rules on Certain Chemical Substances


    ..., tin zinc, calcium-doped (CAS No. 389623-01-2) and rutile, tin zinc, sodium-doped (CAS No. 389623-07-8... substances are identified as rutile, tin zinc, calcium-doped (PMN P-06-36; CAS No. 389623-01-2) and rutile... proposed rules for rutile, tin zinc, calcium-doped (PMN P-06-36; CAS No. 389623- 01-2) and rutile, tin...

  2. Regulation of the Glutamate-Glutamine Transport System by Intracellular pH in Streptococcus lactis



    Various methods of manipulation of the intracellular pH in Streptococcus lactis result in a unique relationship between the rate of glutamate and glutamine transport and the cytoplasmic pH. The initial rate of glutamate uptake by S. lactis cells increases more than 30-fold when the intracellular pH

  3. Calculation of Propulsive Nozzle Flowfields in Multidiffusing Chemically Reacting Environments. Ph.D. Thesis - Purdue Univ.

    Kacynski, Kenneth John


    An advanced engineering model has been developed to aid in the analysis and design of hydrogen/oxygen chemical rocket engines. The complete multispecies, chemically reacting and multidiffusing Navier-Stokes equations are modelled, including the Soret thermal diffusion and the Dufour energy transfer terms. In addition to the spectrum of multispecies aspects developed, the model developed in this study is also conservative in axisymmetric flow for both inviscid and viscous flow environments and the boundary conditions employ a viscous, chemically reacting, reference plane characteristics method. Demonstration cases are presented for a 1030:1 area ratio nozzle, a 25 lbf film cooled nozzle, and a transpiration cooled plug and spool rocket engine. The results indicate that the thrust coefficient predictions of the 1030:1 and the 25 lbf film cooled nozzle are within 0.2 to 0.5 percent, respectively, of experimental measurements when all of the chemical reaction and diffusion terms are considered. Further, the model's predictions agree very well with the heat transfer measurements made in all of the nozzle test cases. The Soret thermal diffusion term is demonstrated to have a significant effect on the predicted mass fraction of hydrogen along the wall of the nozzle in both the laminar flow 1030:1 nozzle and the turbulent flow plug and spool nozzle analysis cases performed. Further, the Soret term was shown to represent an important fraction of the diffusion fluxes occurring in a transpiration cooled rocket engine.

  4. A novel process of dye wastewater treatment by linking advanced chemical oxidation with biological oxidation

    Zou Haiming


    Full Text Available Dye wastewater is one of typically non-biodegradable industrial effluents. A new process linking Fenton’s oxidation with biological oxidation proposed in this study was investigated to degrade the organic substances from real dye wastewater. During the combination process, the Fenton’s oxidation process can reduce the organic load and enhance biodegradability of dye wastewater, which is followed by biological aerated filter (BAF system to further remove organic substances in terms of discharge requirement. The results showed that 97.6% of chemical oxygen demand (COD removal by the combination process was achieved at the optimum process parameters: pH of 3.5, H2O2 of 2.0 mL/L, Fe(II of 500 mg/L, 2.0 h treatment time in the Fenton’s oxidation process and hydraulic retention time (HRT of 5 h in the BAF system. Under these conditions, COD concentration of effluent was 72.6 mg/L whereas 3020 mg/L in the influent, thus meeting the requirement of treated dye wastewater discharge performed by Chinese government (less than 100 mg/L. These results obtained here suggest that the new process combining Fenton’s oxidation with biological oxidation may provide an economical and effective alternative for treatment of non-biodegradable industrial wastewater.

  5. Stimulation of granulocytic cell iodination by pine cone antitumor substances

    Antitumor substances (Fractions VI and VII) prepared from the NaOH extract of pine cone significantly stimulated the iodination (incorporation of radioactive iodine into an acid-insoluble fraction) of human peripheral blood adherent mononuclear cells, polymorphonuclear cells (PMN), and human promyelocytic leukemic HL-60 cells. In contrast, these fractions did not significantly increase the iodination of nonadherent mononuclear cells, red blood cells, other human leukemic cell lines (U-937, THP-1, K-562), human diploid fibroblast (UT20Lu), or mouse cell lines (L-929, J774.1). Iodination of HL-60 cells, which were induced to differentiate by treatment with either retinoic acid or tumor necrosis factor, were stimulated less than untreated cells. The stimulation of iodination of both PMN and HL-60 cells required the continuous presence of these fractions and was almost completely abolished by the presence of myeloperoxidase inhibitors. The stimulation activity of these fractions was generally higher than that of various other immunopotentiators. Possible mechanisms of extract stimulation of myeloperoxidase-containing cell iodination are discussed

  6. Method for the determination of an antigen or a hapten in a fluid sample by the use of a labelled substance

    The invention deals with a method for the determination of substances in a fluid sample that have a mutal specific binding affinity, such as antigens and antibodies. A column contains an insoluble, porous matrix with which specific binding partners to the substance to be determined are immobilized by chemical coupling to the matrix material. A predetermined quantity of a fluid sample containing the substance to be determined, and a reference sample containing a labelled form of the substance, together with an eluting liquid, is allowed to flow through the column. Followed by a determination of the relative amount of the labelled component retained in or eluted from the column, comparison to standard values affords a reading of the concentration or absolute amount of the substance to be determined in the fluid sample

  7. Comparison of the rationale used in setting occupational exposure standards for ionizing radiation and hazardous chemical substances

    Ten chemicals which create significant occupational hazard are reviewed. They are toluene diisocyanate, hydrogen fluoride, n-hexane, carbon disulphide, cadmium, inorganic mercury, cobalt, nitroglycerol, silica and vinyl chloride. Each is discussed under the headings of physiological intake and elimination in humans, characteristics of acute and chronic toxicity, sites of occupational exposure and rationale for limits of such exposure. Since radioactive substances yield ionizing radiation as the common hazard the treatment of the current permissible levels of exposure is somewhat simpler. Having set out industrial standards for exposure to hazardous substances and radionuclides, a detailed comparison is made. Exposure limits to ioninzing radiation are sufficiently low to remove the appearance of directly related injury. It is expected however that low level exposure may have a stochastic effect, that is, there is the possibility of a slightly increased incidence of neoplasms in a large exposed population, but numbers will be too small to be able to attribute any particular case to the exposure. TLVs on the other hand, depending on the particular chemical, may be high enough in the workplace to permit some directly related signs or symptoms in the exposed individual. 244 refs

  8. A rapid chemical method of labelling human plasma proteins with sup(99m)Tc-pertechnetate at pH 7.4

    A successful method for labelling human plasma proteins with sup(99m)Tc-pertechnetate by chemical means is described. The labelling methodology involves the production of Sup(99m)Tc-(Sn)citrate complex species with high protein binding capacity at pH 7.4 condition following initial chemical reduction of sodium sup(99m)Tc-pertechnetate by stannous chloride. A combined labelling efficiency range of 95-99% for sup(99m)Tc-labelled fibrinogen, immune gamma globulin and serum albumin is achieved. The actual amount of labelled protein content in the product is found to be 85-95% when assayed by ITLC and 74-85% by TCAA protein precipitation. In vitro experimental data indicate that sup(99m)Tc-fibrinogen contains an average of 85% clottable protein with an average clottability of 95%. This strongly suggests that the radioactive proteins retain much of their biological and physiological activities after the labelling process. (author)

  9. 78 FR 4446 - Exempt Chemical Preparations Under the Controlled Substances Act


    ... and dependence and are controlled to protect the public health and safety. Section 201 of the CSA (21...... Flurazepam ....... Vial: 1 mL 12/22/2011 American Radiolabeled Chemicals, Inc... Heroin (1 mg/mL) Vial: 1 mL 12/22/2011 American Radiolabeled Chemicals, Inc... Heroin Vial: 1 mL 12/22/2011 American...

  10. 78 FR 66700 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data


    ... FR 13708) (FRL-7335-2) (docket identification (ID) number EPA-HQ-OPPT-2005-0033). EPA received data... (76 FR 1067) (FRL-8846-9) (docket ID number EPA-HQ-OPPT-2007-0531). EPA received data on 5 chemicals...; Third Group of Chemicals,'' published in the Federal Register issue of October 21, 2011 (76 FR...

  11. Influence of alkaline (PH 8.3-12.0) and saline solutions on chemical, mineralogical and physical properties of two different bentonites - batch experiments at 25 deg. C

    Document available in extended abstract form only. Construction of a spent fuel repository deep in the bedrock will need supporting structures using cement materials. A part of them can be removed before closure but still it is estimated that about 1000 tonnes will remain in the host rock. Degradation of cementitious materials produces leachates of high pH. If such an alkaline plume reaches the bentonite buffer, it may induce mineralogical and chemical changes in bentonite over long term, and further affect the safety functions of the buffer. Laboratory experiments were done with the objective to gain data of possible alterations in mineralogical, chemical and physical properties of bentonites contacted with high-pH saline solutions. Two untreated, high grade, Na- and Ca-bentonites, were used in batch experiments, which were carried out in an anaerobic glove-box at 25±1 deg. C for 554 days. Each bentonite sample (20 g) was leached with approximately 3.8 L of leaching solution, which equals 190 mL/g of bentonite. The bentonites were leached with three types of simulated cement waters (pH 9.7, 11.3 and 12.0) and one saline groundwater simulate (pH 8.3) as a reference. The leaching solutions were 0.3 M, and contained NaCl and CaCl2, and trace amounts of SiO2, K, Br, Mg and SO4. Dissolved oxygen and carbon dioxide were removed from leaching solutions before mixing of bentonite in PC bottles. The samples were placed on a platform shaker in order to allow better contact between bentonite and the leaching solution. The evolution of pH in the samples was followed by measuring the pH-value of each sample in the solution phase approximately twice a week and the solution was renewed when values of two to three consecutive measurements did not change. On average, the leaching solution was renewed once a month. For each renewal of the leaching solution the phases were separated, the reacted solution withdrawn, and the chemical composition analysed. Before analysis the

  12. CRIM-TRACK: Sensor System for Detection of Criminal Chemical Substances

    Munk, Jens Kristian; Buus, Ole Thomsen; Larsen, Jan;


    drug-detecting scenario. Such decisions will be programmed to match user preference. Sensor output can be as detailed as the sensor allows. The user can be informed of the statistics behind the detection, identities of all detected substances, and quantities thereof. The response can also be simplified...... to “yes” vs. “no”. The technology under development in CRIM-TRACK will provide custom officers, police and other authorities with an effective tool to control trafficking of illegal drugs and drug precursors....

  13. CRIM-TRACK: Sensor System for Detection of Criminal Chemical Substances

    Munk, Jens Kristian; Buus, Ole Thomsen; Larsen, Jan;


    -detecting scenario. Such decisions will be programmed to match user preference. Sensor output can be as detailed as the sensor allows. The user can be informed of the statistics behind the detection, identities of all detected substances, and quantities thereof. The response can also be simplified to “yes” vs. “no......”. The technology under development in CRIM-TRACK will provide custom officers, police and other authorities with an effective tool to control trafficking of illegal drugs and drug precursors....

  14. Impact of soil pH and organic matter on the chemical bioavailability of vanadium species: The underlying basis for risk assessment.

    Reijonen, Inka; Metzler, Martina; Hartikainen, Helinä


    The main objective of this study was to unravel the chemical reactions and processes dictating the potential bioavailability of vanadium (V). In environmental solutions V exists in two stable oxidation states, +IV and +V, of which + V is considered to be more toxic. In this study, the effect of speciation and soil pH on the chemical accessibility of V was investigated with two soils: 1) field soil rather rich in soil organic matter (SOM) and 2) coarse mineral soil low in SOM. Fresh soil samples treated with V(+V) (added as NaVO3) or V(+IV) (added as VOSO4) (pH adjusted to the range 4.0-6.9) were incubated for 3 months at 22 °C. The adsorption tendency of V species was explored by water extraction (Milli-Q water, 1:50 dw/V) and by sequential extraction (0.25 M KCl; 0.1 M KH2/K2HPO4; 0.1 M NaOH; 0.25 M H2SO4, 1:10 dw/V). The potential bioavailability of V was found to be dictated by soil properties. SOM reduced V(+V) to V(+IV) and acted as a sorbent for both species, which lowered the bioaccessibility of V. A high pH, in turn, favored the predominance of the V(+V) species and thus increased the chemical accessibility of V. PMID:26807983

  15. Separation and identification of moxifloxacin impurities in drug substance by high-performance liquid chromatography coupled with ultraviolet detection and Fourier transform ion cyclotron resonance mass spectrometry

    Cai Sheng Wu; Zhi Xin Jia; Bao Ming Ning; Jin Lan Zhang; Song Wu


    In this paper,a high-performance liquid chromatography coupled with ultraviolet detection and Fourier transform-ion cyclotron resonance mass spectrometry (HPLC-UV/FTICRMS) method was described for the investigation of impurity profile in moxifloxacin (MOX) drug substance and chemical reference substance.Ten impurities were detected by HPLC-UV,while eight impurities were identified by using the high accurate molecular mass combined with multiple-stage mass spectrometric data and fragmentation rules.In addition,to our knowledge,five impurities were founded for the first time in MOX drug substance.

  16. Simultaneous determination by HPLC of 6 components in zedoary turmeric oil and its related injections with replacement method of chemical reference substance%HPLC替代对照品法同时测定莪术油及其注射液中6种成分的含量

    何欢; 马双成; 张启明; 田颂九


    Objective:To establish and validate an HPLC method with single marker to simultaneously determine six components in zedoary turmeric oil and its related injections.Methods:The relative correction factors(RCF)of the five components(curdione,curcumol,curzerene,furanodiene,β-elemene)were measured by HPLC under different conditions with germacrone as standard reference.Assay of zedoary turmeric oil and its related injections was determined by replacement method of chemical reference substance and the conventional HPLC method with the above SIX components as the index components.The analysis was performed on a Waters Symmetry C_(18)(4.6 mm×250 mm,5 m)column;The mobile phase was composed of methanol-water with a linear gradient elution:The flow rate Was 1.0 mL·min~(-1) and the temperature of colulun was 30 ℃;The UV detection wavelength was set at 215 nm.Results:The quantitative results of the new method were almost consistent with the results of conventional HPLC method.Conclusion:For the first time,the replacement method of chemical reference substance is adopted in HPLC simultaneous determination of zedoary turmeric oil and its related injections.The new method is economical and practical which is highly effective and accurate for quality control of zedoary turmeric oil and its related injections.%目的:建立HPLC替代对照品法同时测定莪术油及其注射液中6种成分含量.方法:本文采用HPLC方法,在不同条件下测定(牛龙)牛儿酮与其他5种成分(莪术二酮、莪术醇、莪术烯、呋喃二烯及β-榄香烯)间的相对校正因子(RCF).以上述6种成分为指标,分别利用替代对照品法和常规含量测定方法对莪术油及其注射液进行含量测定.色谱条件:采用Waters Symmetry C_(18)(4.6 mm×250 mm,5 μm)色谱柱,流动相为甲醇-水,梯度洗脱,流速1.0 mL·min~(-1),柱温30℃,检测波长215 nm.结果:以替代对照品法测得的结果与常规含量测定方法结果一致.结论:本试验在

  17. Capturing intracellular pH dynamics by coupling its molecular mechanisms within a fully tractable mathematical model.

    Yann Bouret

    Full Text Available We describe the construction of a fully tractable mathematical model for intracellular pH. This work is based on coupling the kinetic equations depicting the molecular mechanisms for pumps, transporters and chemical reactions, which determine this parameter in eukaryotic cells. Thus, our system also calculates the membrane potential and the cytosolic ionic composition. Such a model required the development of a novel algebraic method that couples differential equations for slow relaxation processes to steady-state equations for fast chemical reactions. Compared to classical heuristic approaches based on fitted curves and ad hoc constants, this yields significant improvements. This model is mathematically self-consistent and allows for the first time to establish analytical solutions for steady-state pH and a reduced differential equation for pH regulation. Because of its modular structure, it can integrate any additional mechanism that will directly or indirectly affect pH. In addition, it provides mathematical clarifications for widely observed biological phenomena such as overshooting in regulatory loops. Finally, instead of including a limited set of experimental results to fit our model, we show examples of numerical calculations that are extremely consistent with the wide body of intracellular pH experimental measurements gathered by different groups in many different cellular systems.

  18. Accelerated tests of hardened cement pastes alteration by organic acids: analysis of the pH effect

    Effluents, such as liquid manure and silage effluents, stored in silos often made of concrete, contain organic acids that are chemically very aggressive for the cement-based matrix. The pH of liquid manure is comprised between 6 and 8, and the pH of silage effluent is about 4. There has already been much research done on manure's effect on concrete using aggressive solutions with a pH of or inferior to 4, in order to accelerate alteration kinetics. These studies aimed at simulating liquid manure and silage effluent, equally. The goal of this article is to validate the use of solutions with a pH of 4 to implement accelerated studies on alterations occurring to structures exposed to the acidic part of liquid manure. In this study, the alteration mechanisms of the cement-based matrix produced by two solutions of organic acids with pH of 4 and 6 were compared. At the end of the experiment, carried out on ordinary Portland cement and slag cement pastes, the kinetics of alteration of the cement pastes immersed in the solution with a pH of 4 was ninefold higher than in the solution with a pH of 6. The chemical and mineralogical modifications of the paste were analyzed by electron microprobe, XRD and BSE mode observations. It was shown that the alteration mechanisms of the paste are sensibly identical for both solutions: almost complete decalcification, the disappearance of the crystallized or amorphous hydrated phases and the probable formation of a silica gel containing aluminum and iron, mainly. The differences in alteration mechanisms between the two solutions are minor and mainly concern the stability of the anhydrous phases: C4AF and slag grains

  19. Bullying Victimization and Substance Use Among U.S. Adolescents: Mediation by Depression

    Luk, Jeremy W.; Jing WANG; Simons-Morton, Bruce G.


    This study examined the link between bullying victimization and substance use and tested the mediating role of depression in male and female adolescents. Cross-sectional data were collected from a national sample of 1,495 tenth graders who participated in the 2005/06 Health Behaviors in School-aged Children U.S. Survey. Victimization, depression and substance use were all measured as latent variables. Substance use was measured by drinking alcohol, being drunk, smoking cigarettes and using ma...

  20. Substance P Depolarizes Lamprey Spinal Cord Neurons by Inhibiting Background Potassium Channels

    Thörn Pérez, Carolina; Hill, Russell H.; Grillner, Sten


    Substance P is endogenously released in the adult lamprey spinal cord and accelerates the burst frequency of fictive locomotion. This is achieved by multiple effects on interneurons and motoneurons, including an attenuation of calcium currents, potentiation of NMDA currents and reduction of the reciprocal inhibition. While substance P also depolarizes spinal cord neurons, the underlying mechanism has not been resolved. Here we show that effects of substance P on background K+ channels are the...

  1. Characterisation of inhibitory substances produced by two Pseudoalteromonas species and the cyanobacterial strain Flo1

    Rau, Jan Erik


    In the present study the inhibitory substances of P. aurantia NCIMB 2052T and P. citrea NCIMB 1889T were investigated with respect to their substantial and functional nature, their inhibitory potential, their stability against various treatments as well as the growth phases and incubation conditions when the substances are produced. In addition, an inhibitory substance produced by strain Flo1 was examined regarding its structure, function, and inhibitory potential. Furthermore, its taxonomic ...

  2. Six rapid assessments of alcohol and other substance use in populations displaced by conflict

    Adelekan Moruf; Macdonald David; Schilperoord Marian; Burton Ann; Oppenheimer Edna; Ezard Nadine; Sakarati Abandokoth; van Ommeren Mark


    Abstract Background Substance use among populations displaced by conflict is a neglected area of public health. Alcohol, khat, benzodiazepine, opiate, and other substance use have been documented among a range of displaced populations, with wide-reaching health and social impacts. Changing agendas in humanitarian response-including increased prominence of mental health and chronic illness-have so far failed to be translated into meaningful interventions for substance use. Methods Studies were...

  3. Management of sites potentially polluted by radioactive substances - Methodological guidebook

    This document is the update of the 'methodological guidelines for the management of industrial areas potentially contaminated by radioactive substances', published in 2001 by IRSN. Revisions intended to bring coherence between management of areas polluted by radioactive substances and the general policy applied to polluted sites described in a document published in February 2007 by the French Ministry in charge of Environment. Requirements introduced both by the law relative to waste management of June 28, 2006 and the ministerial order of 17 November 2008 were introduced. The involvement of all stakeholders during the process was stressed. The updating, mainly lead to introduce a clear distinction between polluted areas where uses are established and those without use or at redevelopment stage. When the uses are established, an 'Interpretation of the condition of environment' is conducted. Alternatively, the remediation process follows a 'management plan'. The revision also led to the disappearance of the 'doubt removal' phase which has been incorporated as an entire part in the site characterisation. Among other significant changes, it may be noted the evolution of the 'risk assessment' tools from simplified risk assessment and detailed risk assessment to a single tool allowing the quantitative assessment of exposure (EQER). Finally, the guidelines highlight stakeholder involvement in identifying the different participants and in reminding the benefits of a consultative approach. Whatever the remediation process: interpretation of the condition of environment or management plan; site characterisation is required as soon as a pollution is suspected. It includes literature reviews and field investigations primarily to confirm or deny the presence of pollution and, where appropriate, to determine its location, nature and level. The effort accorded to site characterisation must be proportionate to identified issues. The first step consists in comparing the

  4. Apparent formation constants of actinide complexes with humic substances determined by solvent extraction

    Apparent formation constants of Pu(IV) with two kinds of humic substances (HSs) were determined in 0.1M NaClO4 at 25°C using a back-solvent extraction method. The effect of solution conditions, such as the pH, the initial metal and HS concentrations, and the ionic strength, on the formation constants was investigated. The obtained data were compared with the other actinide series. (author)

  5. Simulation of dye adsorption by beech sawdust as affected by pH.

    Batzias, F A; Sidiras, D K


    The effect of pH on the batch kinetics of methylene blue adsorption on beech sawdust was simulated, in order to evaluate sawdust potential use as low cost adsorbent for wastewater dye removal. The zero point of charge pH(pzc) of the sawdust, in order to explain the effect of pH in terms of pH(pzc), was measured by the mass titration and the automatic titration methods. The adsorption capacity, estimated according to Freundlich's model, indicate that increase of the pH enhances the adsorption behaviour of the examined material. The lower adsorption of methylene blue at acidic pH is due to the presence of excess H(+) ions that compete with the dye cation for adsorption sites. As the pH of the system increases, the number of positively charged sites decreases while the number of the negatively charged sites increases. The negatively charged sites favour the adsorption of dye cation due to electrostatic attraction. The increase in initial pH from 8.0 to 11.5 increases the amount of dye adsorbed. PMID:16934396

  6. History of the occupational exposure to chemical substances in workers with laryngeal cancer

    A case-control study was realized to 400 patients, 200 of them histologically confirmed as incident cases of larynx cancer by the National Institute for Oncology and Radiobiology of Havana, and the others 200 as controls, coming from another hospitals. A survey was applied to both groups, collecting every theirs worker histories with emphasis on occupational exposure, that were codified by an expert group taking into account the carcinogens present according to the guided code of the Epidemiological Units of Environmental Cancer and the Fields Studies and Intervention of International Agency for Research on Cancer (IARC). According to the results obtained, all the patients, cases and controls, presented 1 526 tasks in their labour histories, that represented an average greater than 3 tasks for each one of them. They main activities were in the agriculture, the defence and the sugar cane industry. The most predominant exposures were to the abrasive dusts, motor emissions, mists of mineral oils, gasoline/petroleum/diesel/kerosene and pesticides. In general, the valuation of the chemical risk was considered of low intensity, 1-5% of the real time to the exposure and all had the certain probability of the agent's aggressor presence.

  7. 78 FR 49547 - Manufacturer of Controlled Substances; Notice of Registration; American Radiolabeled Chemicals, Inc.


    ..., 2013, 78 FR 23596, American Radiolabeled Chemicals, Inc., 101 Arc Drive, St. Louis, Missouri 63146... Dimethyltryptamine (7435) I 1- piperidine I (7470). Dihydromorphine (9145) I Heroin (9200) I Normorphine (9313)...

  8. CRIM-TRACK: sensor system for detection of criminal chemical substances

    Munk, Jens K.; Buus, Ole T.; Larsen, Jan; Dossi, Eleftheria; Tatlow, Sol; Lässig, Lina; Sandström, Lars; Jakobsen, Mogens H.


    Detection of illegal compounds requires a reliable, selective and sensitive detection device. The successful device features automated target acquisition, identification and signal processing. It is portable, fast, user friendly, sensitive, specific, and cost efficient. LEAs are in need of such technology. CRIM-TRACK is developing a sensing device based on these requirements. We engage highly skilled specialists from research institutions, industry, SMEs and LEAs and rely on a team of end users to benefit maximally from our prototypes. Currently we can detect minute quantities of drugs, explosives and precursors thereof in laboratory settings. Using colorimetric technology we have developed prototypes that employ disposable sensing chips. Ease of operation and intuitive sensor response are highly prioritized features that we implement as we gather data to feed into machine learning. With machine learning our ability to detect threat compounds amidst harmless substances improves. Different end users prefer their equipment optimized for their specific field. In an explosives-detecting scenario, the end user may prefer false positives over false negatives, while the opposite may be true in a drug-detecting scenario. Such decisions will be programmed to match user preference. Sensor output can be as detailed as the sensor allows. The user can be informed of the statistics behind the detection, identities of all detected substances, and quantities thereof. The response can also be simplified to "yes" vs. "no". The technology under development in CRIM-TRACK will provide custom officers, police and other authorities with an effective tool to control trafficking of illegal drugs and drug precursors.

  9. A Survey of Substance Use for Cognitive Enhancement by University Students in the Netherlands

    Kimberly Johanna Schelle


    Full Text Available Background:Pharmacological cognitive enhancement, using chemicals to change cellular processes in the brain in order to enhance one’s cognitive capacities, is an often discussed phenomenon. The prevalence among Dutch university students is unknown.Methods:The study set out to achieve the following goals: (1 give an overview of different methods in order to assess the prevalence of use of prescription, illicit and lifestyle drugs for cognitive enhancement (2 investigate whether polydrug use and stress have a relationship with cognitive enhancement substance use (3 assessing opinions about cognitive enhancement prescription drug use. A nationwide survey was conducted among 1572 student respondents of all government supported Dutch universities. Results:The most detailed level of analysis ─ use of specific substances without a prescription and with the intention of cognitive enhancement ─ shows that prescription drugs, illicit drugs and lifestyle drugs are respectively used by 1.7%, 1.3% and 45.6% of the sample. The use of prescription drugs and illicit drugs is low compared to other countries. We have found evidence of polydrug use in relation to cognitive enhancement. A relation between stress and the use of lifestyle drugs for cognitive enhancement was observed. We report the findings of several operationalizations of cognitive enhancement drug use to enable comparison with a wider variety of previous and upcoming research.Conclusions:Results of this first study among university students in the Netherlands revealed a low prevalence of cognitive enhancement drug use compared to other countries. Multiple explanations, such as a difference in awareness of pharmacological cognitive enhancement among students, accessibility of drugs in the student population and inclusion criteria of enhancement substances are discussed. We urge enhancement researchers to take the different operationalizations and their effects on the prevalence numbers into

  10. Administrative regulations concerning the carriage of dangerous substances by civil aircraft

    The Regulations, which entered into force on the date they were adopted, apply to the transport of dangerous substances by civil aircraft in Norway and by aircraft registered in Norway for transport outside Norwegian territory. They provide that such substances, including radioactive materials, must be carried in accordance with the IATA Restricted Articles Regulations