Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Coarse (whole) and finely ground Ambersorb 1500 and coarse and fine coconut charcoal were compared as to their efficiencies in scavenging organic contaminants desorbed from sediment. Aqueous slurries of a test sediment spiked (1 ppm) with p,p(')-DDE (DDE), 2,2('),5,5(')-tetrachlorobiphenyl (TCB), naphthalene (NAP), or phenanthrene (PHEN), and containing 1% levels of the test carbons were treated by shaking at 35 degrees C while exposed to clusters of low-density polyethylene membrane (detox spiders). Controls consisted of spiked sediments and detox spiders but no added carbon of any kind and thus represented unimpeded bioavailabilities (to the spiders). After the treatments--agitation periods from 2.5 to 60 h, depending on contaminant hydrophobicity--the exposed detox spiders were analyzed. The fine carbon of either type was more effective than its coarser variant in obstructing contaminant bioavailabilities. The finer variants of both carbons obstructed the bioavailabilities of NAP and PHEN equally well as did the coarser variants of both. Whole Ambersorb 1500 and coarse coconut charcoal were similarly ineffective in intercepting TCB and DDE. Ground Ambersorb 1500 obstructed virtually all bioavailability of all four contaminants and was far more effective than fine coconut charcoal in intercepting DDE and TCB. An additional experiment compared the effectiveness of ground Ambersorb 1500 and fine coconut charcoal in obstructing the bioavailabilities from sediment of a broad array of spiked organochlorine pesticides. The performance of ground Ambersorb 1500 was again found to be superior; the bioavailable levels of each of the 27 pesticides were markedly lower in the presence of ground Ambersorb 1500 than in the presence of fine coconut charcoal.
 ...
PMID:Comparisons of coarse and fine versions of two carbons for reducing the bioavailabilities of sediment-bound hydrophobic organic contaminants. 1258 62

Spent mushroom compost (SMC) is a bulky waste byproduct of mushroom industry and produced abundantly. The SMC of Pleurotus pulmonarius immobilized laccase (0.88 mmoles min(-1) g(-1)) and manganese peroxidase (0.58 mmoles min(-1) g(-1)) of which the optimal temperatures were 45 and 75 degrees C, respectively. In laboratory test, complete degradative removal of individual naphthalene, phenanthrene, benzo[a]pyrene and benzo[g,h,i]perylene (200 mg PAH kg(-1) sandy-loam soil) by 5% SMC was obtained in two days under continuous shaking at 80 degrees C. The SMC-treated PAH samples had significantly reduced or removed their toxicities as revealed by the Microtox bioassay. These results were confirmed by gas chromatography-mass spectrometry analysis on the breakdown products. A phthalic derivative which is reported as a degradative product of PAHs by ozonation or ligninolysis was also detected in the SMC-treated samples. The results demonstrate the potential in employing SMC in ex situ bioremediation.
 ...
PMID:Use of spent mushroom compost to bioremediate PAH-contaminated samples. 1286 86

During spills of hydrocarbons in soil, it has been observed that aliphatic and the slightly aromatic hydrocarbons are first to be removed, however, branched aliphatic and aromatic compounds, polycyclic aromatic hydrocarbons (PAHs) and their similar heteroatoms with sulfur (PAS) remain strongly absorbed to soil particles. It is important to point out that studies of biodegradation of alkyl-substituted PAHs and PAS are scarce and most of them have been carried out using only available standard compounds. The aim of this investigation was to identify and to quantify the aliphatic, alkyl polycyclic aromatic, and sulfured recalcitrant fractions present in a contaminated soil with drilling wastes. A modified method of shaking-centrifugation extraction was implemented for the extraction of compounds from contaminated soil. The organic extract obtained was purified and fractionated using aluminum oxide. Gas Chromatograph with flame ionization detector (GC-FID) and Gas Chromatograph with mass spectrometer detector (GC-MS) identified the aliphatic, PAHs and PAS fractions. Hydrocarbon composition in the soil contaminated with 140,000 mg TPHs/Kg soil, consisted in 80% of branched aliphatic compounds of C10 to C22, 15% of alkyl PAHs, and 5% of PAS compounds. Lineal, lineal branched, and cyclic branched aliphatic hydrocarbons, as well as their alkyl naphthalene, anthracene and phenantrene, methyldibenzothiophene, dimethyldibenzothiophene, and dimethylnaphto[2,3-b]thiophene compounds were identified by CG-MS. The identification of compounds in soil P31, allowed us to speculate on the origin of the contamination and the natural attenuation that had occurred at this site.
 ...
PMID:Identification of recalcitrant hydrocarbons present in a drilling waste-polluted soil. 1524 35

Studies have been performed assessing the feasibility and characterizing the automation of solid-phase microextraction (SPME) on a multi-well plate format. Four polycyclic aromatic hydrocarbons (PAHs), naphthalene, fluorene, anthracene and fluoranthene, were chosen as test analytes to demonstrate the technique due to their favorable partition coefficients, K(fw), between polydimethylsiloxane (PDMS) extraction phases and water. Four different PDMS configurations were investigated regarding their suitability. These included (i) a PDMS membrane; (ii) a multi-fiber device containing lengths of PDMS-coated flexible wire; (iii) a stainless steel pin covered with silicone hollow fiber membrane and (iv) commercial PDMS-coated flexible metal fiber assemblies. Of these configurations, the stainless steel pin covered with silicone tubing was chosen as a robust alternative. An array of 96 SPME devices that can be placed simultaneously into a 96-well plate was constructed to demonstrate the high-throughput potential when performing multiple microextractions in parallel. Different agitation methods were assessed including magnetic stirring, sonication, and orbital shaking at different speeds. Orbital shaking whilst holding the SPME device in a stationary position provided the optimum agitation conditions for liquid SPME. Once the analytes had been extracted, desorption of the analytes into an appropriate solvent was investigated. Liquid-phase SPME and solvent desorption on the multi-well plate format is shown to be a viable alternative for automated high-throughput SPME analysis compatible with both gas- and liquid-chromatography platforms.
 ...
PMID:Automation of solid-phase microextraction on a 96-well plate format. 1741 54

The biodegradation characteristics of a typical polycyclic aromatic hydrocarbon, naphthalene by the strain (Pseudomonas sp. N7) were investigated by using HPLC and UV analytical techniques. The results showed that the addition of nutritious salt and microelements accelerated the degradation of naphthalene by 23.65%. Degradation efficiency increased with increasing dissolved oxygen and reached 95.66%, then remained stabilized when dissolved oxygen was over 4.3 mg/L, yet decreased with increasing naphthalene concentration. Neutral and weak alkaline condition favored the biodegradation with degradation capacity all over 82.88%. Pseudomonas sp. N7 had a maximum degradation capability of 95.66% when dealing with 100 mg/L naphthalene at 30 degrees C and pH 7.5 with 165 r/min rotary shaking for 72 h. By measuring the absorbance, pH and degradation of substrates during treatment of different substrate with strain N7, it was demonstrated that Pseudomonas sp. N7 could also degrade other aromatic hydrocarbons, such as toluene, dimethylbenzene, phenol, 2,4-nitrophenols, benzyl acid, 1-naphthol and salicylic acid, utilizing each of them as sole carbon and energy source for growth and breeding, thus showing its good biodegradation diversity. The pathway of naphthalene degradation was explored through analyzing metabolic intermediates at different degradation stages by using UV-Vis and GC-MS. The result revealed that there were two possible degradation pathways for naphthalene: one was phthalic acid pathway, and the other was that naphthalene was first oxidized to 1,2-dihydroxynaphthalene, and then the cleavage of rings caused the formation of salicylic acid, catechol, and 2-hydroxymuconic semial-dehyde. Finally these metabolites entered the tricarboxylic acid cycle (TCA).
 ...
PMID:[Characteristics and pathway of naphthalene degradation by Pseudomonas sp. N7]. 1864 40

A new method is proposed for collecting traces of nickel from aqueous solution by precipitation as the alpha-furildioxime complex and adsorption of this onto microcrystalline naphthalene. The precipitate is collected, dried, and dissolved in chloroform, and the nickel is determined spectrophotometrically at 438 nm. The linear calibration range is 2-35 mug/10 ml. The molar absorptivity is 1.6 x 10(4) l. mole(-1). cm(-1). The main advantage is that the nickel is collected quantitatively after only a few seconds'shaking. The effect of varying pH, amount of reagent, naphthalene or buffer, shaking and standing time, and interferences have been investigated.
 ...
PMID:Spectrophotometric determination of nickel after separation by adsorption of its alpha-furildioxime complex on naphthalene. 1896 60

A spectrophotometric method was developed for the determination of ferbam (iron(III) dimethyldithiocarbamate) by converting it into an iron-phenanthroline complex, which was then absorbed on microcystalline naphthalene in the presence of tetraphenylborate, and the absorbance was measured at 515 nm against a reagent blank. The molar absorptivity of the complex was 1.2 x 10(4)l mol(-1)cm(-1). Ten replicate analyses of a sample solution containing 150 mug of ferbam gave a relative standard deviation of 0.84%. Beer's law was obeyed over the concentration range 22.4-372.9 mug of ferbam. The effects of various factors such as reagent concentration and naphthalene, shaking time and diverse ions were studied in detail. The method is sensitive and selective and can be applied to the direct determination of ferbam in commercial samples and in mixtures containing various other dithiocarbamates (e.g. ziram, zineb and maneb) in foodstuffs.
 ...
PMID:Spectrophotometric determination of iron(III) dimethyldithiocarbamate (ferbam). 1896 32

Iridium is preconcentrated from the large volume of its aqueous solution using 1-(2-pyridylazo-2-naphthol) (PAN) on microcrystalline naphthalene in the pH range of 4.5-6.0. The solid mass after filtration is dissolved with 5 ml of dimethylformamide (DMF) and the metal determined by first derivative spectrophotometry. The detection limit is 20 ppb (signal to noise ratio = 2) and the calibration curve is linear over the concentration range 0.25-75.0 mug in 5 ml of the final DMF solution with a correlation coefficient of 0.9996 and relative standard deviation of +/- 1.1%. Various parameters such as the effect of pH, volume of aqueous phase, choice of solvent, reagent and naphthalene concentration, shaking time and interference of a number of metal ions on the determination of trace amount of iridium have been studied in detail to optimize the conditions for its determination in synthetic samples corresponding to various standard alloys and environmental samples.
 ...
PMID:Derivative spectrophotometric determination of iridium after preconcentration of its 1-(2-pyridylazo)-2-naphthol complex on microcrystalline naphthalene. 1896 20

The risk assessment of hydrophobic organic compounds (HOCs) in aquatic toxicity or bioconcentration tests is a challenge due to their low aqueous solubilities, sorption and losses leading to poorly defined exposure and reduced test sensitivity. Passive dosing overcomes these problems via the continual partitioning of HOCs from a dominating reservoir loaded in a biocompatible polymer such as silicone, providing defined and constant freely dissolved concentrations and eliminating spiking with co-solvents. This study characterised the performance of a passive dosing format for aquatic tests with small organism such as invertebrates and algae, consisting of PDMS silicone cast into the base of the glass test vessel. The PDMS silicone was loaded by partitioning from a methanol solution containing PAHs (logK(OW) 3.56-6.63) as model compounds, followed by removal of the methanol with water. This resulted in highly reproducible PDMS silicone HOC concentrations. When shaking, release of PAHs into aqueous solution was rapid and reproducible, and equilibrium partitioning was reached within 5h for all compounds. The buffering capacity was sufficient to maintain stable concentrations over more than 10 weeks. This format was applied in a 48h Daphnia magna immobilisation assay to test the toxicity of a range of PAHs at their aqueous solubility. D. magna immobilisation did not show a trend with aqueous solubility or hydophobicity (K(OW)) of the PAHs. However, the immobilisation data for all compounds could be fitted with one maximum chemical activity response curve. Those PAHs with the lowest maximum chemical activities resulted in no immobilisation. Naphthalene and phenanthrene showed full toxicity at aqueous solubility, and passive dosing was also used for the concentration-response testing of these compounds. The freely dissolved aqueous concentrations causing 50% immobilisation (EC-50) were 1.96 mg L(-1) for naphthalene and 0.48 mg L(-1) for phenanthrene. Therefore, passive dosing is a practical and economical means of improving the exposure of HOCs in aquatic toxicity or bioconcentration tests.
 ...
PMID:Controlling and maintaining exposure of hydrophobic organic compounds in aquatic toxicity tests by passive dosing. 2017 Sep 70

The macropolyhedral [B(19)H(22)](-) monoanion 1 and the dianion [B(19)H(21)](2-) 2 are synthesized in consistent 86-92% yields by the reaction of [PSH](+)[syn-B(18)H(21)](-) with BH(3)(SMe(2)) in 1,2-Cl(2)C(2)H(4) at 72 degrees C. ['PS' is an abbreviation for 'Proton Sponge', 1,8-bis-(dimethylamino)naphthalene. 'PSH' is its protonated derivative.] The molecular structures of 1 and 2 were elucidated as their [PS{BH(2)}](+) and [PS{BH(2)}](2)(+) salts 1a and 2a by single-crystal X-ray diffraction studies, in which all atoms were located, and supported by mass spectrometric analyses together with calculations of the cluster molecular geometries (ab ignitio and/or DFT) and of (11)B chemical shifts based on GIAO-DFT shielding tensors. Acidification of dianion 2 with CF(3)COOH in acetonitrile, H(2)SO(4) in dichloromethane, or aqueous HCl results in the clean formation of the monoanion [B(19)H(22)](-) 1. Conversely, shaking a concentrated acetonitrile solution of 1 in 0.5 M aqueous NaOH cleanly yields the [B(19)H(21)](2-) dianion 2. Reaction of a dichloromethane solution of 1 with a 36% aqueous solution of HCHO in the presence of H(2)SO(4) quantitatively converts 1 at room temperature to a 1:1 mixture of the syn- and anti-isomers of B(18)H(22). This cluster dismantling process is the first example of a syn- to anti-B(18)H(22) isomer conversion.
 ...
PMID:An experimental solution to the "missing hydrogens" question surrounding the macropolyhedral 19-vertex boron hydride monoanion [B19H22]-, a simplification of its synthesis, and its use as an intermediate in the first example of syn-B18H22 to anti-B18H22 isomer conversion. 2034 36


1 2 Next >>