Presence Of CS2 Research Articles

Short-interval intracortical inhibition blocks long-term potentiation induced by paired associative stimulation

Paired associative stimulation (PAS) of the motor cortex leads to increased motor evoked potential (MEP) amplitudes in the stimulated hand muscles. We hypothesized that evoking GABA(A) receptor-mediated short-interval intracortical inhibition (SICI) simultaneously with excitatory PAS would depress long-term potentiation plasticity in motor cortex. Four different PAS paradigms were tested, standard PAS (PAS25) and three conditioned PAS protocols (CS2-PAS25, CS2-PAS25adj, and CS10-PAS25adj). A subthreshold conditioning stimulus 2 ms (CS2) or 10 ms (CS10) before the test stimuli was added to the conditioned PAS protocols. Since CS2 has inhibitory and CS10 has facilitatory effect on cortical excitability, in the CS2-PAS25adj and CS10-PAS25adj protocols, TS intensity was adjusted to produce a 1-mV MEP in the presence of CS2 or CS10 to control for the degree of corticospinal excitation. As expected, MEP amplitudes after PAS25 were higher compared with that at baseline, but importantly, MEP amplitudes did not change after PAS was induced in the presence of SICI in either the CS2-PAS25 or CS2-PAS25adj condition. Furthermore, the CS10-PAS25adj protocol showed significantly increased MEP amplitude at 60 min after PAS compared with baseline. These results show that SICI blocked the induction of long-term potentiation-like plasticity in the motor cortex, indicating that GABAergic circuits play an important role in the regulation of cortical plasticity. The study demonstrates a noninvasive and nonpharmacological way to achieve focal modulation of plasticity.

Direct benzylation of 1,3-dicarbonyl compounds catalyzed by Cs2.5H0.5PW12O40 in solvent-free conditions

Various 1,3-dicarbonyl compounds reacted readily with benzylic alcohols in the presence of Cs2.5H0.5PW12O40 salt to produce 2-benzylic-1,3-dicarbonyl compounds in high yields. It was found that this catalyst could be completely recovered and reused without loss of its catalytic activities and is thus environmentally conscious especially in solvent-free conditions. The use of this method provides improved modification of the direct benzylation of 1,3-carbonyl compounds in terms of low reaction times, solvent-free conditions, usage of a small amount of the catalyst, and a clean reaction profile. Furthermore, the use of this catalyst is feasible because of its easy preparation, its easy handling, its stability, its easy recovery, its reusability, being environmentally green, its excellent activity, and its selectivity.

Carbon Disulfide Inhibits Neurite Outgrowth and Neuronal Migration of Dorsal Root Ganglion In Vitro

ABSTRACTCarbon disulfide (CS2) is a neurotoxic industrial solvent and widely used in the vulcanization of rubber, rayon, cellophane, and adhesives. Although the neurotoxicity of CS2 has been recognized for over a century, the precise mechanism of neurotoxic action of CS2 remains unknown. In the present study, a embryonic rat dorsal root ganglia (DRG) explants culture model was established. Using the organotypic DRG cultures, the direct neurotoxic effects of CS2 on outgrowth of neurites and migration of neurons from DRG explants were investigated. The organotypic DRG cultures were exposed to different concentrations of CS2 (0.01 mmol/L, 0.1 mmol/L, 1 mmol/L). The number of nerve fiber bundles extended from DRG explants decreased significantly in the presence of CS2 (0.01 mmol/L, 15.00 ± 2.61, p < .05; 0.1 mmol/L, 11.17 ± 1.47, p < .001; 1 mmol/L, 8.00 ± 1.41, p < .001) as compared with that in the absence of CS2 (17.83 ± 2.48). The number of neurons migrated from DRG explants decreased significantly in the presence of CS2 (0.01 mmol/L, 79.50 ± 9.40, p < .01; 0.1 mmol/L, 62.50 ± 14.15, p < .001; 1 mmol/L, 34.67 ± 7.58, p < .001) as compared with that in the absence of CS2 (99.33 ± 15.16). And also, the decreases in the number of nerve fiber bundles and migrated DRG neurons were in a dose-dependent manner of CS2. These data implicated that CS2 could inhibit neurite outgrowth and neuronal migration from DRG explants in vitro.

A Novel, One‐Pot Four‐Component Route to 2′‐Thioxo‐2′,3′‐dihydrospiro[indole‐3,6′‐[1,3]thiazin]‐2‐one Derivatives

AbstractAn efficient route to 2′,3′‐dihydro‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives is described. It involves the reaction of isatine, 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ5‐phosphanylidene)ethan‐1‐one, and different amines in the presence of CS2 in dry MeOH at reflux (Scheme 1). The alkyl carbamodithioate, which results from the addition of the amine to CS2, is added to the α,β‐unsaturated ketone, resulting from the reaction between 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ5‐phosphanylidene)ethan‐1‐one and isatine, to produce the 3′‐alkyl‐2′,3′‐dihydro‐4′‐phenyl‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives in excellent yields (Scheme 2). Their structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses.

Metam sodium intoxication: the specific role of degradation products – methyl isothiocyanate and carbon disulphide – as a function of exposure

Introduction. The objective was to evaluate the toxicity of poisoning by metam sodium, a dithiocarbamate fumigant, the breakdown products of which are methyl isothiocyanate (MITC), carbon disulphide (CS2), and dihydrogen sulphide (H2S). Methods. This is a retrospective, observational case series of metam sodium exposure cases reported to the Angers Poison and Toxicovigilance Centre from 1992 through 2009. Results. A total of 106 cases of metam sodium exposure were recorded and 102 cases were included in this study. All cases of exposure were unintentional. Occupational poisoning occurred in eight cases. The most common route of exposure was inhalation (n = 96). In 79 cases, the patients were people living near fields where metam sodium had recently been applied. Most of the reported symptoms involved irritation of the eyes (n = 76), throat and nose (n = 65), attributable to MITC. Cough and dyspnoea occurred in four cases but no persistent, irritant-induced asthma or persistent exacerbation of asthma was observed. Sixteen patients at two different sites of pollution were exposed to emanations from the drainage system in their homes following the illicit discharge of metam sodium into the sewers. Most presented with nausea and headaches, but only four experienced eye or throat irritation. A breakdown product other than MITC was involved: air analysis at one site revealed the presence of CS2 (337 mg/m3) and no H2S. Two of these patients, who had consumed some alcohol, experienced dysgeusia but no disulfiram-like reaction. The only lethal case recorded was a truck driver who was found dead of acute lung injury after falling into a tank that had previously contained metam sodium. Two patients who ingested a dilute solution, presented with mild epigastric pain. Four skin exposures caused erythema (n = 2), moderate burns (n = 1), and urticaria (n = 1). According to the poisoning severity score, their symptoms were minor in 99% of cases. Conclusion. Acute metam sodium exposure usually causes minor symptoms. They vary as a function of the circumstances of exposure, which determine the degradation product that forms. On contact with moist soil, metam sodium decomposes into MITC and causes irritant symptoms. Under specific conditions, such as a spillage in the drainage system, metam sodium can degrade into CS2 and cause neurological signs.

CS&lt;SUB&gt;2&lt;/SUB&gt;を用いたメカノケミカル法によるネオジム酸化物の低温硫化

For the recovery of nuclear materials from the spent nuclear fuel by the sulfide process, fission products such as rare-earths are selectively sulfurized by CS2 at temperatures below 500 °C. However, sulfurization at lower temperatures would be favorable from the safety handling of CS2. In this paper, low temperature sulfurization of neodymiumu oxide Nd2O3 by mechanochemical method in the presence of CS2 was studied. When Nd2O3 powder was milled with CS2 by planetary mill in argon atmosphere followed by heatreatment in Ar, the broaden peaks for Nd2O2S phase were found by XRD analysis. These peaks for Nd2O2S became sharpened by the heat treatment at temperatures 500 — 600 °C in argon atmosphere. The relative intensity ratio of Nd2O2S peaks to Nd2O3 peaks increased with increasing milling time as well as the increasing CS2 amount . Finally, the experimental results were in good agreement with those of thermodynamic consideration.

Determination of the dispersion of supported Pt particles by gas-phase and liquid-phase measurements

Abstract The dispersion of a Pt/γ-Al2O3 catalyst was investigated by various experimental techniques. The values obtained by gas-phase hydrogen and carbon monoxide adsorption and transmission electron microscopy (TEM) were consistent for the metal:adsorbate stoichiometry of 1:1. However, these methods overestimated the number of active sites available for a liquid-phase reaction. For the hydrogenation of styrene in the presence of CS2 as a catalyst poison, only the defect sites were found to be active in the catalytic reaction. The defect sites were related to the initial coverage dependent region of the adsorption heats measured by gas-phase microcalorimetry.

Sulfurization of rare-earth oxides with CS2

In the scheme of spent fuel reprocessing by using sulfides, selective sulfurization of rare-earths in the fuel is considered followed by either magnetic separation or selective leaching of rare-earth sulfides from uranium oxides such as UO2. In this paper, sulfurization behavior of rare-earth oxides was investigated by XRD and TG methods in the presence of CS2. From the results of thermogravimetric study the sulfurization of europium proceeds as follows; sulfurization from Eu2O3 to Eu3S4 occurs at ca. 400 °C, then the Eu3S4 decomposes to EuS via non-stoichiometric sulfides at temperatures between 450 and 700 °C. From the results of thermogravimetry for Nd2O3, it was found that the weight curve showed monotonic increase from ca. 600 to 1000 °C. At 1000 °C, the value of weight increase was close to that for the formation of Nd2S3 from Nd2O3. The XRD result of the 1000 °C product showed a formation of a single phase of Nd2S3 which is compared with the thermogravimetric result as well as our previous results. The selective sulfurization of rare-earths in the mixture of rare-earth and uranium oxides was discussed by both experimental results and thermodynamical consideration.

Smithsonite flotation using potassium amyl xanthate and hexylmercaptan

The influence of potassium amyl xanthate (KAX) and hexylmercaptan (HM) adsorption on smithsonite surface at various concentrations were investigated through using zeta potential, contact angle, microflotation and diffuse reflectance FTIR studies at different pH. The zeta potential measurements of KAX showed that the adsorption of ionic charge (more negative charge after KAX treatment) takes place on the surface of pure crystalline smithsonite. The charges vary between −38 and −45 mV at pH 10·5. Flotation results using potassium amyl xanthate reveal that the maximum recovery of 81·3% and the maximum contact angle of 98·7° occurs at pH 10·5 at KAX concentration of 2·96 × 10−3M in sodium sulphide (2·6 × 10−2M) and copper sulphate (9·4 × 10−3M) solutions. The highest recovery and contact angle for flotation by means of HM occurs at pH 9 at values of 78·6% and 92·3° respectively with HM concentration 1·1 × 10−2M. The FTIR spectra studies of smithsonite conditioned by KAX confirmed the adsorption of KAX and the presence of CS2 on smithsonite surface. The FTIR spectra in HM studies showed the adsorption of RS− on the oxidised zinc surface and the S–H bond in the mercaptan is destroyed on adsorption. The comparison between the results using anionic collectors showed that the presence of different amounts of reagents on smithsonite surface in two cases confer different degree of hydrophobicity on the smithsonite surface.

Phase-Transfer Catalyzed Alkylation and Cycloalkylation of 3-Substituted-1H-pyrazol-2-in-5-ones in the Absence or Presence of Carbon Disulphide

PTC-alkylation of 3-substituted-1H-pyrazol-2-in-5-ones by different organohalogen reagents at 25ˆC in the presence of tetrabutylammonium bromide as-catalyst was investigated either in the absence or presence of CS2. This work aims to study the comparative reactivity of N-versus O-versus C-alkylation and cycloalkylation.

Preparation and Catalytic Effect of Gold Nanoparticles in Water Dissolving Carbon Disulfide

Stable gold nanoparticles of 2-nm diameter are prepared in water by chemical reduction of AuCl4- by NaBH4 in the presence of CS2 without adding any other stabilizers. The nanoparticles are proved to be Au and not Au sulfides by electron diffraction. In their UV−visible absorption spectra the surface plasmon (SP) band at around 520 nm is strongly damped, due to small particle size and possibly chemisorption of a CS2 derivative. The time course of UV−vis reveals a rapid decrease of the 290-nm CT band of AuCl4- upon addition of CS2, suggesting their interaction before reduction of Au3+. After the reduction of Au3+ has been completed, an intense band is built up at 330 nm which can be assigned to a reaction product of CS2 and NaBH4. Furthermore, it is found that this reaction is promoted by Au nanoparticles, although no change was observed for the SP band intensity. This catalytic effect is also found for citrate-capped Au hydrosols.

Crystal structure of the coordination polymer [Co(bipy)1.5(NO3)2]·CS2 (bipy=4,4′-bipyridine), a new motif for a network sustained by ‘T-shape’ building blocks

The crystal structure of the coordination polymer [Co(bipy)1.5(NO3)2]·1 (bipy=4,4′-bipyridine), reveals that, if crystallized in the presence of CS2, it exists as a novel two-dimensional bilayer motif. This is in contrast to what might have been expected since a one-dimensional molecular-ladder motif is exhibited by 1 when crystallized in the presence of MeCN or CHCl3. A molecule of CS2 is clathrated inside the bilayer via what appear to be C–H···S hydrogen bonds from 4,4′-bipyridine ligands. Adjacent bilayers pack efficiently in a gear-like fashion. The existence of this new structural supramolecular isomer is rationalized on the basis of a template effect from the CS2 guest molecule.

Determination of the number of active centers in Ziegler‐Natta polymerization of propene using sulfur‐containing terminating agents, 1. Application of carbon disulfide

AbstractPolymerization of propene catalyzed with TiCl3 · 1/3(AlCl3)/AlEt2Cl or TiCl3 · 1/3(AlCl3)/AlEt3 systems in heptane at 323,2 K in the presence of CS2 was studied. It was demonstrated that the sharp decrease of rate, observed upon addition of CS2, is not due to a decrease of the organometal concentration, although some consumption of the organometal was evidenced by means of IR measurement. Tagging of the growing chains was monitored by determination of the sulfur content in the polymer. Side reactions of CS2, leading to a blank content of sulfur in polypropylene, were observed in the presence of catalytical components even after their deactivation. Thus, a thorough washing of the polymer was necessary. A substantial increase of heptane solubles observed upon addition of larger amounts of CS2 was found to be due to a much lower molecular weight of the polymer, while stereospecificity of the catalytical system was virtually preserved. It was concluded that CS2 behaves as a suitable terminating and tagging agent.

Insertion of phenylethyne-thiolate or -selenolate into metal–carbene bonds: synthons for co-ordinated thioacyl or selenoacyl anions and for anionic thiocarbene or selenocarbene complexest

Reaction of lithium ethynethiolate or ethyneselenolate, LiX1CCPh (X1= S or Se), with carbene complexes [M(CO)5{C(OR1)Ph}](M = Cr or W; R1= Me or Et) afforded, by the formation of carbon-carbon bonds, a series of adducts, Li[M(CO)5{C(OR1)PhC(Ph)CX1}]. The adducts reacted regioselectively with electrophiles: acidification with HCl gave α,β-unsaturated thio- and seleno-aldehyde complexes, [M(CO)5{X1CHC(Ph)C(OR1)Ph}], alkylating agents [Et3O][BF4] or Mel gave α,β-unsaturated thio-or seleno-carbene complexes, [M(CO)5{C(X1R3)-C(Ph)C(OR1)Ph](X1R3SEt, SMe, or SeEt), which cleanly and spontaneously converted into sulphur- or selenium-co-ordinated indene derivatives, [M(CO)5{(X1R3)CH(C6H4-o)-C(OR1)CPh}](X1R3SEt or SeEt), and, finally, disulphides R4SSR4(R4Me, Et, or Ph) or the diselenide PhSeSePh yielded thio- or seleno-ester complexes[M(CO)5{X1C(X2R4)C(Ph)C(OR1)Ph](X2R4SMe, SEt, SPh, or SePh). Four X-ray crystal-structure determinations established the stereochemical configurations of selected members of the various classes of acyclic products. The isomeric compound to one of the thioaldehyde complexes, [W(CO)5{SC(Ph)CHC(OEt)Ph}], obtained from the adducts with X = S or Se and R1= Et on acidification in the presence of CS2 or CSe2, was also characterized structurally by single-crystal X-ray diffraction.

Ein einfacher Weg zu Dithiocarbimidato‐Platin(II)‐Komplexen

A Simple Route to Dithiocarbimidato Platinum(II) Complexes Dithiocarbimidato complexes 3 are formed by reaction of cis-(Ph3P)2PtCl2 with primary amines in the presence of CS2. BF3 can be added to the lone pair of the N-atom in 3a. The IR and NMR data are reported.

ChemInform Abstract: THE TRANSYLIDATION REACTION OF A SELENONIUM YLIDE WITH SULFIDES

AbstractIn einer Austauschreaktion erhält man aus der Selenverbindung (I) und den Thioethern (II) in Schwefelkohlenstoff /Trichlormethan bei Raumtemperatur die Dialkylsulfoniumylide (IV).

THE TRANSYLIDATION REACTION OF A SELENONIUM YLIDE WITH SULFIDES

Abstract Several dialkylsulfonium ylides were obtained almost quantitatively by the transylidation reaction of dibenzylselenonium cyano(methoxycarbonyl)methylide with alkyl sulfides in the presence of CS2.

Pharmacokinetics of inhaled carbon disulphide in rats in relation to its inhibitory effect on the side-chain oxidation of hexobarbital.

In acute inhalational exposure even low doses of carbon disulphide (CS2) inhibit the oxidative drug metabolism: This inhibition, studied by the example from the side-chain oxidation of hexobarbital, increases steadily in adult female rats during exposure to 100 ppm over 8 hrs, as shown by the prolonged hypnotic-narcotic effect; it is completely reversible within 24 hrs so that repeated identical doses of CS2 do not give rise to a cumulative effect. The cause of this phenomenon is an inhibition of the microsomal oxydative enzyme system in the liver, as could be demonstrated in purified enzyme preparations from liver homogenates of rats exposed to 50 ppm CS2 over 2–8 hrs. This inhibitory effect is intimately linked with the presence of CS2 in the organism, as seen from its pharmacokinetic behaviour. In the course of an 8-hr inhalation (400 ppm CS2) the rate of saturation in the blood and liver is most rapid during the first few hours. After the termination of the exposure CS2 is distributed in the blood and liver at a ratio of 3:2. Approximately one third of the CS2 that has passed into the liver is found in the isolated microsomas where it is detectable for several hours. Elimination of the inhaled CS2 from the blood and liver occurs at a halflife of 35 min and 65 min, respectively. The preferred route of elimination is by exhalation, approximately 10% of the14CS2 activity being recovered within 4 hrs following subcutaneous injection of14CS2. Significant oxidation of CS2 to urinary sulphate has not been found to occur after inhalation. Since the inhibition of the microsomal mixed-function oxygenases due to inhaled CS2 occurs primarily during its retention in the organism, it is concluded that initially CS2 itself acts as the inhibitor, but it appears probable that CS2 metabolites (for example, thiurams) are also implicated.

Essais de Chloration Dirigée. XX: Etude des Réactivités Relatives Dans la Photochloration de Chloroalcanes

AbstractThe propyl, isopropyl, butyl, isobutyl, amyl, isoamyl and hexyl‐chlorides were submitted to photochlorination in the liquid phase at ordinary temperature in pure phase as wel in solvents. The relative reactivities (r. r.) observed in the presence of CS2 clearly shown that the influence of this solvent increases when the inductive effects on the reaction centers decrease. Furthermore, these r. r. permit to estimate how far in the aliphatic chain the influence of the chlorine substituent is extended. Finally, these r. r. are quantitatively analysed by means of the relationship: .This latter takes into account the inductive, hyper conjugative and mesomeric effects.The results obtained at higher temperatures on the propyl, butyl, butylidène, amyl, isoamyl and hexylchlorides confirm that the bêtachloroalkyl radicals decompose by “vicinal effect” and that differences of activation energies between different positions are not important. Finally, the structure‐reactivity correlation obtained at 40° C is compared with the results observed at room temperature.

Essais de Chloration Dirigée: XIV. Effets de Solvant sur la Photochloration D'Hydrocarbures Arylaliphatiques(1)

AbstractIn the photochlorination of arylaliphatic hydrocarbons (C6H5R; R = C2H5; n. C3H7; i. C3H7; n. C4H9; sec. C4H9; n. C5H11) substitution only takes place in the side chain, and preferentially in the α position, as was showed in the previous paper. Now, in order to make clear which effect is operative‐ either the polar effect of the substituent or a complexation effect of the aromatic nucleus of the reagent, photochlorination of the title compounds was examinated in various solvents (CCl4, aromatics and CS2). Firstly, diluting by CCl4, it was observed that relative reactivity, r. r. (a/b), of an hydrogen a versus another b, varies with the concentration and can be expressed as a linear function: Including complexation constant K1, specific rate ka1 and relative reactivity kao/kbo at infinite dilution (whose numerical values can be calculated by means of the former formula), if R is C2H5; n. C3H7; i. C3H7; sec. C4H9, and with a more sophisticated one: for the other terms, R = n. C4H9, n. C5H11. With benzene, selectivity is enhanced but with chlorobenzene it is depressed. Finally, the best results concerning the selectivity are obtained by photochlorination in the presence of CS2. We mention here the most interesting result of cumene (R = i. C3H7), giving up to 98% of α‐chloroisomer in the presence instead of 86% of the same in the absence of CS2.