Sulfamoylbenzoic Acid Ester Derivatives As Potential Local Anesthetics. I

Journal of Medicinal Chemistry. Jul, 1969  |  Pubmed ID: 5793167

Synthesis of New Urethans. P-Ethylsulfonyl- and P-dimethylsulfamoylcarbanilic Acid Esters

Journal of Medicinal Chemistry. Nov, 1970  |  Pubmed ID: 5479885

Cyclic AMP and Cyclic GMP Levels in Glandular Stomach of Restrained Rats

Research Communications in Chemical Pathology and Pharmacology. Oct, 1977  |  Pubmed ID: 199924

Cyclic AMP and cyclic GMP were measured in glandular stomach of rats subjected to saline administration, cold (4 degrees C), restraint and restraint+cold after 15, 30, 60, 90 and 120 minutes. All animals subjected to restraint+cold had gastric ulceration after 2 hours. A significant but transient decrease in cAMP was observed 15 minutes after restraint+cold. A marked, sustained and significant decrease of cGMP was observed in the same group of animals. It is concluded that it seems unlikely to be a correlation between cAMP and cGMP changes of the stomach and the restraint-induced gastric ulceration.

Spectrophotometric Determination of Acidity Constants of Some Anthraquinones and Anthrones in Methanol-water Mixtures

Talanta. May, 1993  |  Pubmed ID: 18965689

The acidity constants of some synthetic derivatives of 9,10-anthraquinone and 9-anthrone in methanol-water mixtures at 25 degrees have been determined spectrophotometrically. A linear reverse relationship is observed between pK(a1) of all acids and the mole fraction of methanol. The influence of substituents in the molecular structure on the ionization constants is discussed.

Characteristics of Human Tumour Cell Lines After Induction of Multidrug Resistance

International Journal of Oncology. Jun, 1996  |  Pubmed ID: 21544481

A colorimetric technique was used to investigate some aspects of multidrug resistant (MDR)-induced cell lines. Continuous contact of the inducing agent with cells was necessary for MDR induction and this was followed by a series of phases i.e., a selection phase (ESP) lasted up to 6 days, a conditioning phase (CP) lasted up to 14 days and an expansion phase (EP) lasted up to 7 days. Gene transfection to correct missing MHC class I antigens on the Fen cell line did not affect cell behaviour. Of particular interest was the finding that the withdrawal of the MDR inducing agent did not reverse MDR phenotype immediately.

Solubilities of Some Recently Synthesized 1,8-dihydroxy-9,10-anthraquinone Derivatives in Supercritical Carbon Dioxide

Talanta. Apr, 1999  |  Pubmed ID: 18967538

The solubility of four recently synthesized 1,8-dihydroxy-9,10-anthraquinone derivatives, as potential complexing agents in some extraction and membrane transport experiments, have been measured in supercritical carbon dioxide. The measurements were carried out in the pressure range 120-400 atm at temperatures 35, 45, 55, 65, and 75 degrees C. The measured solubilities were correlated using the model proposed by Chrastil. The calculated results show good agreement with the experimental data.

Spectrophotometric Study of the Reaction of Iodine and Bromine with Two New Macrocycle Diamides and Di-ortho Methoxybenzoyl Thiourea in Chloroform Solution

Talanta. Jul, 1999  |  Pubmed ID: 18967628

The complex formation reactions of iodine and bromine with two new macrocycle diamides (1 and 2) and di-ortho methoxybenzoyl thiourea (DOMBT) (3) have been studied spectrophotometrically at various temperatures in chloroform solution. In all cases the resulting 1:2 (macrocycle to halogen) or (DOMBT to halogen) molecular complexes were formulated as (macrocycle...X(+))X(3)(-) or (DOMBT.... X(+))X(3)(-). The formation constants of the resulting molecular complexes were evaluated from computer fitting of the absorbance-mole ratio data. For iodine complexes we found that the values of K(f) vary in the order of 1 approximately 2>3. In the case of bromine complexes the values of K(f) are larger (>10(8)) and vary in the order of 1>2>3. The enthalpy and entropy of complexation reactions of iodine with 1, 2 and 3 were determined from the temperature dependence of the formation constants. In all cases it was found that the complexation reactions are enthalpy stabilized, but entropy destabilized.

Strontium-selective Membrane Electrodes Based on Some Recently Synthesized Benzo-substituted Macrocyclic Diamides

Analytical Chemistry. Nov, 1999  |  Pubmed ID: 21662839

Eight different recently synthesized macrocyclic diamides were studied to characterize their abilities as strontium ion carriers in PVC membrane electrodes. The electrode based on 1,13-diaza-2,3;11,12-dibenzo-4,7,10-trioxacyclopentadecane-14,15-dione exhibits a Nernstian response for Sr(2+) ions over a wide concentration range (1.0 × 10(-)(1)-3.2 × 10(-)(5) M) with a limit of detection of 8.0 × 10(-)(6) M (0.7 ppm). The response time of the sensor is ∼10 s, and the membrane can be used for more than three months without observing any deviation. The electrode revealed comparatively good selectivities with respect to many alkali, alkaline earth, and transition metal ions. It was used as an indicator electrode in potentiometric titration of carbonate ions with a strontium ion solution.

Solid Phase Extraction and Determination of Lead in Soil and Water Samples Using Octadecyl Silica Membrane Disks Modified by Bis[1-hydroxy-9,10-anthraquinone-2-methyl]sulfide and Flame Atomic Absorption Spectrometry

Talanta. Jul, 2000  |  Pubmed ID: 18968021

A simple, reliable and relatively fast method has been developed to selectively separate and concentrate trace amounts of lead from aqueous samples for the measurement by flame atomic absorption spectrometry. By the passage of aqueous samples through an octadecyl-bonded silica membrane disk modified by a recently synthesized bis(anthraquinone)sulfide, Pb(2+) ions adsorb quantitatively and almost all matrix elements will pass through the disk to drain. The retained lead ions are then stripped from the disk by minimal amount of acetic acid as eluent. The proposed method permitted large enrichment factors of about 300 and higher. The limit of detection of the proposed method is 50 ng Pb(2+) per 1000 ml. The effects of various cationic interferences on the recovery of lead in binary mixtures were studied. The method was successfully applied to the determination of lead in soil and water samples.

Claisen Rearrangement of Allyloxyanthraquinones with Silver/potassium Iodide in Acetic Acid As a New and Efficient Reagent

The Journal of Organic Chemistry. May, 2000  |  Pubmed ID: 10808462

Environmental Exposure to Toxocara As a Possible Risk Factor for Asthma: a Clinic-based Case-control Study

Clinical Infectious Diseases : an Official Publication of the Infectious Diseases Society of America. Apr, 2001  |  Pubmed ID: 11264048

The zoonotic ascarid Toxocara has been suggested as a possible etiologic agent of asthma. We conducted a clinic-based case-control study to examine whether the zoonotic infection acquired by ingesting Toxocara eggs is associated with asthma in children. Blood samples were collected from children aged 2-15 years, 95 of whom had asthma and 229 of whom did not have asthma. Risk factors for asthma and Toxocara infection were assessed by a questionnaire given to each child's parent or legal guardian. Blood samples were tested for the presence of Toxocara antibodies, using an enzyme-linked immunosorbent assay. No significant association was found between Toxocara infection and asthma. Significant associations were found between asthma and risk factors and between Toxocara infection and risk factors. High prevalence of Toxocara infection was noted among Hispanic children of Puerto Rican descent.

A Schiff Base Complex of Zn(II) As a Neutral Carrier for Highly Selective PVC Membrane Sensors for the Sulfate Ion

Analytical Chemistry. Jul, 2001  |  Pubmed ID: 11467529

Novel polymeric membrane (PME) and coated graphite (CGE) sulfate-selective electrodes based on a recently synthesized Schiff base complex of Zn(II) were prepared. The electrodes reveal a Nernstian behavior over wide SO4(2-) ion concentration ranges (5.0 x 10(-5)-1.0 x 10(-1) M for PME and 1.0 x 10(-7)-1.0 x 10(-1) M for CGE) and very low detection limits (2.8 x 10(-5) M for PME and 8.5 x 10(-8) M for CGE). The potentiometric response is independent of the pH of the solution in the pH range 3.0-7.0. The electrodes manifest advantages of low resistance, very fast response, and, most importantly, good selectivities relative to a wide variety of other anions. In fact, the selectivity behavior of the proposed SO4(2) ion-selective electrodes shows a great improvement compared to the previously reported electrodes for sulfate ion. The electrodes can be used for at least 3 months without any appreciable divergence in potentials. The electrodes were used as an indicator electrode in the potentiometric titration of sulfate and barium ions and in the determination of iron in ferrous sulfate tablets.

HIV-1 LTR Subtype and Perinatal Transmission

Virology. Sep, 2001  |  Pubmed ID: 11531404

Multiple subtypes of HIV-1 have been identified; however, there is little data on the relative transmissibility of viruses belonging to different subtypes. A matched case-control study addressed whether viruses with different long terminal repeat (LTR) subtypes were transmitted equally from mother to infant. The LTR subtype was determined for 45 matched cases and controls who participated in a clinical trial in Tanzania. HIV-1 subtypes A, C, and D and intersubtype recombinant sequences were identified. Exact matched logistic regression analysis showed that viruses containing subtype A or intersubtype recombinant LTRs were 3.2 and 4.8 times more likely to be transmitted from mother to infant than viruses with subtype D LTRs. Viruses containing subtype C LTRs were 6.1 times more likely to be transmitted than those with subtype D LTRs. These differences in transmission were independent of maternal CD4 at enrollment. Thus, it appears that HIV-1 subtype may be associated with differing rates of perinatal transmission in Tanzania.

Phenol-containing Macrocyclic Diamides As New Catalysts in the Highly Regioselective Conversion of Epoxides to Beta-hydroxy Thiocyanates

The Journal of Organic Chemistry. Nov, 2001  |  Pubmed ID: 11681940

The regioselective ring-opening reactions of some epoxides with ammonium thiocyanate in the presence of a series of new phenol-containing macrocyclic diamides and also dibenzo-18-crown-6-, 18-crown-6-, benzo-15-crown-5-, and pyridine-containing macrocyclic diamide have been studied. The epoxides were subject to cleavage by NH(4)SCN in the presence of these catalysts under mild reaction conditions in various aprotic solvents. In this study, reagents and conditions have been discovered with which the individual beta-hydroxy thiocyanates can be synthesized in high yield and with more than 90% regioselectivity. The results can be discussed in terms of a four-step mechanism: (1) formation of complex between catalyst and NH(4)SCN, (2) release of SCN(-) nucleophile from the complex, (3) reaction of the active nucleophile at the less sterically hindered site in the epoxide, and (4) regeneration of catalyst. The major advantages of this method are as follows: (1) high regioselectivity, (2) simple regeneration of catalyst, (3) its reuse through several cycles without a decrease in activity, and (4) ease of workup of the reaction.

Cobalt(II)-selective Membrane Electrode Based on a Recently Synthesized Benzo-substituted Macrocyclic Diamide

Analytical Sciences : the International Journal of the Japan Society for Analytical Chemistry. Sep, 2001  |  Pubmed ID: 11708057

A PVC-membrane electrode based on a recently synthesized 18-membered macrocyclic diamide is presented. The electrode reveals a Nernstian potentiometric response for Co2+ over a wide concentration range (2.0 x 10(-6)-1.0 x 10(-2) M). The electrode has a response time of about 10 s and can be used for at least 2 months without any divergence. The proposed sensor revealed very good selectivities for Co2+ over a wide variety of other metal ions, and could be used over a wide pH range (3.0-8.0). The detection limit of the sensor is 6.0 x 10(-7) M. It was successfully applied to the direct determination and potentiometric titration of cobalt ion.

Cesium-selective Membrane Electrode Based on a Recently Synthesized 16-membered Macrocyclic Diamide

Fresenius' Journal of Analytical Chemistry. Dec, 2001  |  Pubmed ID: 11798106

A PVC membrane sensor for the Cs+ ion based on 1,5-diaza-2,3,4-naphthyl-8,11,14-trioxacyclohexadecane-6,16-dione (L) has been prepared. The sensor has a linear dynamic range of 5.0 x 10(-1) - 6.9 x 10(-6) mol L(-1), a Nernstian slope of 59.5 +/- 0.8 mV decade(-1), and a detection limit of 4.7 x 10(-6) mol L(-1). It has a fast response time of <15 s and can be used for at least 8 weeks without any considerable divergence in potentials. The selectivity of the proposed electrode relative to alkali, alkaline earth, and transition metal ions was comparatively good. The electrode could be used in the pH range 4.5-11.0.

Solid Phase Extraction and Determination of Ultra Trace Amounts of Copper(II) Using Octadecyl Silica Membrane Disks Modified by 11-hydroxynaphthacene-5,12-quinone and Flame Atomic Absorption Spectrometry

Talanta. Jun, 2001  |  Pubmed ID: 18968309

A simple and selective method for rapid extraction and determination of trace amounts of copper(II) ions using octadecyl-bonded silica membrane disks modified with 11-hydroxynaphthacene-5,12-quinone and flame atomic absorption spectrometry is presented. Extraction efficiency and the influence of pH, flow rates, amount of ligand and type and least amount of stripping acid were evaluated. Maximum capacity of the membrane disks modified by 5 mg of the ligand was found to be 360 mug of Cu(2+) ion. The break through volume is larger than 2000 ml. The limit of detection of the proposed method is 0.2 ng ml(-1). The effects of various cationic interferences on the percent recovery of copper in binary mixtures were studied. The method was applied to the recovery of Cu(2+) ions from four different water samples and a synthetic sample.

Quantitative Structure-property Relationship Study of Acidity Constants of Some 9,10-anthraquinone Derivatives Using Multiple Linear Regression and Partial Least-squares Procedures

Talanta. Jul, 2001  |  Pubmed ID: 18968333

A quantitative structure-property relationship study is suggested for the prediction of acidity constants of some recently synthesized 9,10-anthraquinone derivatives in binary methanol-water mixtures. Modeling of the acidity constant of the anthraquinones as a function of physicochemical parameters and mole fraction of methanol was established by means of the partial least-squares algorithm based on singular value decomposition (PLS-SVD) and multiple linear regression. The PLS-SVD procedure resulted in a better prediction ability and was found to be insensitive to noneffective descriptors. The classification of anthraquinones by the calculated descriptors was established.

Differential Pulse Anodic Stripping Voltammetric Determination of Lead(II) with a 1,4-bis(prop-2'-enyloxy)-9,10-anthraquinone Modified Carbon Paste Electrode

Talanta. Aug, 2001  |  Pubmed ID: 18968374

A sensitive and selective method for the determination of lead(II) with a 1,4-bis(prop-2'-enyloxy)-9,10-anthraquinone (AQ) modified carbon paste electrode has been developed. The method is based on non-electrolytic preconcentration via complex formation with modifier, followed by an accumulation period with a negative potential (-1.5 V), and then by a proper anodic stripping. The analytical performance was evaluated with respect to the quantity of modifier in the paste, concentration of electrolyte solution, preconcentration time, lead(II) concentration, and other variables. A linear calibration graph was obtained in the concentration range 2.00x10(-9)-1.06x10(-5) M Pb(II) (n=21, r=0.9999) with 30 s preconcentration time. The detection limit was found to be 1x10(-9) M. For eight preconcentration/determination cycles, the differential pulse voltammetric response was reproduced with 5.0 and 3.7% relative standard deviations at 2.00x10(-8) and 2.00x10(-6) M Pb(II), respectively. Rapid and convenient renewal of electrode surface allows the use of a single modified electrode surface in multiple analytical determinations over several weeks. Many coexisting metal ions had little or no effect on the determination of lead(II). The developed method was applied to lead determination in waste waters.

Uranyl-selective PVC Membrane Electrodes Based on Some Recently Synthesized Benzo-substituted Macrocyclic Diamides

Talanta. Aug, 2002  |  Pubmed ID: 18968747

Four different recently synthesized macrocyclic diamides were studied to characterize their abilities as uranyl ion carriers in PVC membrane electrodes. The electrodes based on macrocycle 1,18-diaza-3,4;15,16-dibenzo-5,8,11,14,21,24-hexaoxacyclohexaeicosane-2,17-dione resulted in a Nernstian response for UO(2)(2+) ion over wide concentration ranges. The linear concentration range for the polymeric membrane electrode (PME) is 3.0x10(-6)-8.2x10(-3) M with a detection limit of 2.2x10(-6) and that for the coated graphite electrode (CGE) is 5.0x10(-7)-1.5x10(-3) M with a detection limit of 3.5x10(-7) M. The electrodes manifest advantages of low resistance, very fast response and, most importantly, good selectivities relative to a wide variety of other cations.

A 9,10-anthraquinone Derivative Having Two Propenyl Arms As a Neutral Ionophore for Highly Selective and Sensitive Membrane Sensors for Copper(II) Ion

Analytical Sciences : the International Journal of the Japan Society for Analytical Chemistry. Aug, 2002  |  Pubmed ID: 12200832

New polymeric membrane (PME) and coated graphite (CGE) copper(II)-selective electrodes based on 1-hydroxy-2-(prop-2'-enyl)-4-(prop-2'-enyloxy)-9,10-anthraquinone were prepared. The electrodes reveal linear emf-pCu2+ responses over wide concentration ranges (1.0 x 10(-5)-1.0 x 10(-1) M with a slope of 27.3 mV decade-1 for PME and 8.0 x 10(-8)-5.0 x 10(-2) M with a slope of 29.1 mV decade-1 for CGE) and very low limits of detection (8.0 x 10(-6) M for PME and 5.0 x 10(-8) M for CGE). The potentiometric response is independent of the pH of the test solution in the pH range 3.0-6.0. The proposed electrodes possess very good selectivities over a wide variety of other cations, including alkali, alkaline earth, transition and heavy metal ions, the selectivity coefficients for the CGE being much improved over those for the PME. The electrodes were used as indicator electrodes in the potentiometric titration of Cu2+ and in the recovery of copper ions from wastewater.

Highly Selective Methodology for the Direct Conversion of Aromatic Aldehydes to Glycol Monoesters

The Journal of Organic Chemistry. May, 2003  |  Pubmed ID: 12737600

Al(2)O(3)/MeSO(3)H (AMA) was found to be an extremely efficient reagent for the conversion of aromatic aldehydes and diols to glycol monoesters. The remarkable selectivity achieved with this reagent is an attractive feature of the present method.

Novel Membrane Potentiometric Sulfate Ion Sensor Based on Zinc-phthalocyanine for the Quick Determination of Trace Amounts of Sulfate

Analytical Sciences : the International Journal of the Japan Society for Analytical Chemistry. Jul, 2003  |  Pubmed ID: 12880081

Poly(vinyl chloride) (PVC) based membranes of zinc-phthalocyanine (ZPC) with hexadecyltrimethylammonium bromide (HTAB) as a cation excluder, and dibutyl phthalate (DBP) and benzyl acetate (BA) as plasticizing solvent mediators were prepared and investigated as a SO4(2-) selective electrode. The best performance was observed with a membrane having a composition of ZPC-PVC-HTAB-BA in a ratio of 5%:32%:3%:60%, which works well over a wide concentration range (1.0 x 10(-2) - 1.0 x 10(-6) M) with a Nemstian slope of -29.2 mV per decade of activity, between the pH values of 2.0 to 7.0. This sensor shows a very fast response time of 10 s, and can be used over a period of 2 months with good reproducibility. The proposed sensor displays excellent selectivity for SO4(2-) over a large number of common inorganic anions. The sensor has been successfully applied for the direct and indirect determination of sulfate and zinc in zinc sulfate tablets, respectively. It was also used as an indicator electrode in the potentiometric titration of sulfate ions with barium ions.

Selective Determination of Trace Copper(II) by Cathodic Adsorptive Stripping Voltammetry with a Naphthol-derivative Schiff's Base

Annali Di Chimica. May-Jun, 2003  |  Pubmed ID: 12911148

A selective and sensitive stripping voltammetric method for the determination of trace amounts of copper(II) with a recently synthesized naphthol-derivative Schiff's base (2,2'-[1,2-ethanediylbis(nitriloethylidyne)]bis(1-naphthalene)) is presented. The method is based on adsorptive accumulation of the resulting copper-Schiff's base complex on a hanging mercury drop electrode, followed by the stripping voltammetric measurement at the reduction current of adsorbed complex at -0.15 V (vs. Ag/AgCl). The optimal conditions for the stripping analysis of copper include pH 5.5 to 6.5, 8 microM Schiff's base and an accumulation potential of -0.05 V (vs. Ag/AgCI). The peak current is linearly proportional to the copper concentration over a range 2.3-50.8 ng ml(-1) with a limit of detection of 1.9 ng ml(-1). The accumulation time and RSD are 90 s and (3.2-3.5)%, respectively. The method was applied to the determination of copper in some analytical grade salts, tap water, human serum and sheep's liver.

Hydroxy-thioxanthones As Suitable Neutral Ionophores for the Preparation of PVC-membrane Potentiometric Sensors for Al(III) Ion

Analytical Sciences : the International Journal of the Japan Society for Analytical Chemistry. Feb, 2004  |  Pubmed ID: 15055955

The complexation of five recently synthesized hydroxy-thioxanthone derivatives with Al3+ ion was studied in a methanol solution spectrophotometrically, and the stepwise formation constants of the resulting 1:1 and 2:1 (ligand-to-metal) complexes were evaluated. The suitability of the thioxanthone derivatives as neutral ionophores for the preparation of a new Al3+ ion-selective PVC-membrane electrode was investigated, and 1-hydroxy-3-methyl-thiocanthone was selected as the best compound for this purpose. The prepared electrode exhibits a Nernstian response for Al3+ ions over a wide concentration range (2.0 x 10(-2) to 2.0 x 10(-6) M), with a limit of detection of 1.0 x 10(-6) M. It has a very fast response time of about 5 s and can be used for at least 3 months without any considerable divergence in the potentials. The proposed membrane sensor revealed very good selectivities for Al3+ over a wide variety of other metal ions, and could be used at a working pH range of 3.4 - 5.0. It was used as an indicator electrode in potentiometric titration of aluminum ions with EDTA, and in the determination of Al3+ in different real samples.

QSAR Analysis for ADA Upon Interaction with a Series of Adenine Derivatives As Inhibitors

Nucleosides, Nucleotides & Nucleic Acids. 2004  |  Pubmed ID: 15113027

The kinetic parameters of adenosine deaminase such as Km and Ki were determined in the absence and presence of adenine derivatives (R1-R24) in sodium phosphate buffer (50 mM; pH 7.5) solution at 27 degrees C. These kinetic parameters were used for QSAR analysis. As such, we found some theoretical descriptors to which the binding affinity of adenosine deaminase (ADA) towards several adenine nucleosides as inhibitors is correlated. QSAR analysis has revealed that binding affinity of the adenine nucleosides upon interaction with ADA depends on the molecular volume, dipole moment of the molecule, electric charge around the N1 atom, and the highest of positive charge for the related molecules.

[Tetrakis(4-N,N-dimethylaminobenzene)porphyrinato]manganese(III) Acetate As a Novel Carrier for a Selective Iodide PVC Membrane Electrode

Analytical Sciences : the International Journal of the Japan Society for Analytical Chemistry. May, 2004  |  Pubmed ID: 15171284

[5,10,15,20-Tetrakis(4-N,N-dimethylaminobenzene)porphyrinato]Mn(III) acetate (MnTDPAc) was applied as an ionophore for an iodide-selective PVC membrane electrode. The influences of the membrane composition, pH of the test solution and foreign ions on the electrode performance were investigated. The sensor exhibited not only excellent selectivity to iodide ion compared to Cl- and lipophilic anions such as ClO4- and salicylate, but also a Nernstian response with a slope of -59.4 +/- 1.2 mV per decade for iodide ions over a wide concentration range from 1.0 x 10(-2) to 7.5 x 10(-6) M at 25 degrees C. The potentiometric response was independent of the pH of the solution in the pH range of 2 - 8. The electrode could be used for at least 2 months without any considerable divergence in the potential. Good selectivity for iodide ion, a very short response time, simple preparation and relatively long-term stability were the silent characteristics of this electrode. It was successfully used as an indicator electrode in the potentiometric titration of iodide ions, and also in the determination of iodide from seawater samples and drug formulations.

Reactions on a Solid Surface. A Simple, Economical and Efficient Friedel-Crafts Acylation Reaction over Zinc Oxide (ZnO) As a New Catalyst

The Journal of Organic Chemistry. Oct, 2004  |  Pubmed ID: 15387635

Zinc oxide (ZnO) brings about a rapid Friedel-Crafts acylation of a range of activated and unactivated aromatic compounds such as anisole and chlorobenzene with acid chlorides in solvent-free conditions at room temperature. The ZnO powder can be reused up to three times after simple washing with dichloromethane.

Application of Artificial Neural Network to Simultaneous Potentiometric Determination of Silver(I), Mercury(II) and Copper(II) Ions by an Unmodified Carbon Paste Electrode

Talanta. Oct, 2004  |  Pubmed ID: 18969646

The response characteristics and selectivity coefficients of an unmodified carbon paste electrode (CPEs) towards Ag(+), Cu(2+) and Hg(2+) were evaluated. The electrode was used as an indicator electrode for the simultaneous determination of the three metal ions in their mixtures via potentiometric titration with a standard thiocyanate solution. A three-layered feed-forward artificial neural network (ANN) trained by back-propagation learning algorithm was used to model the complex non-linear relationship between the concentration of silver, copper and mercury in their different mixtures and the potential of solution at different volumes of the added titrant. The network architecture and parameters were optimized to give low prediction errors. The optimized networks were able to precisely predict the concentrations of the three cations in synthetic mixtures.

Solid Phase Extraction and Determination of Sub-ppb Levels of Hazardous Hg2+ Ions

Journal of Hazardous Materials. Jan, 2005  |  Pubmed ID: 15629571

A simple, rapid and reliable method has been developed to selectively separate and concentrate ultra trace amounts of mercury(II) ions from aqueous samples for its highly sensitive measurement by cold vapor atomic absorption spectrometry (CV-AAS). The Hg(2+) ions were adsorbed selectively and quantitatively during the passage of aqueous samples through octadecyl silica membrane disks modified by isopropyl 2-[(isopropoxycarbothiolyl)disulfanyl]ethane thioate (IIDE). The retained Hg(2+) ions were then stripped from the disk with minimal amounts of 0.5 M hydrobromic acid (two 8 ml portions) as eluent, and determined by CV-AAS. The break-through volume of the method is greater than 3000 ml, which results in enrichment factors >150. Maximum capacity of the membrane disks modified with 10mg of the ligand was found to be 350+/-30 microg of mercury(II), and the limit of detection is 0.005 ng ml(-1). The effect of various cationic interferences on the recovery of mercury in binary mixtures was studied. The method was applied to the recovery of Hg(2+) ions from different synthetic and tap water samples, as well as the determination of mercury in human hair samples.

Simultaneous Determination of Phenol and Mononitrophenol Isomers Using PLS Regression and Conventional and Derivative Spectrophotometry

Annali Di Chimica. Jan-Feb, 2005  |  Pubmed ID: 15801178

The partial least squares regression method (PLS) was tested as a calibration procedure for the simultaneous determination of phenol, o-nitrophenol, m-nitrophenol and p-nitrophenol by both conventional and first derivative UV/Vis spectrophotometry. The experiments were conducted in the acidic, neutral and basic media. The results obtained by the application of the PLS procedure on the conventional and first derivative spectra in two solvent media were compared. It was found that the results obtained in the basic medium have better performance characteristics than those obtained in the acidic or neutral media. Comparable results were obtained in the case of both conventional and first derivative absorbance data. The proposed method was applied to the determination of the four phenol derivatives in natural spiked water samples at concentration levels between 1.0 and 10.0 microg ml(-1) with average recoveries in the range 96% - 99%.

Determination of Silver(I) by Electrothermal-AAS in a Microdroplet Formed from a Homogeneous Liquid-liquid Extraction System Using Tetraspirocyclohexylcalix[4]pyrroles

Analytical Sciences : the International Journal of the Japan Society for Analytical Chemistry. Apr, 2005  |  Pubmed ID: 15844331

A simple and efficient method for the selective separation and preconcentration of Ag+ using homogeneous liquid-liquid extraction was developed. Tetraspirocyclohexylcalix[4]pyrrole (TSCC4P) was synthesized and investigated as a suitable selective complexing ligand for Ag+. Zonyl FSA (FSA) was applied as a phase-separator agent under mild pH conditions. Under the optimal conditions ([TSCC4P] = 3.4 x 10(-4) M, [THF] = 25.0% v/v, [FSA] = 1.25% w/v, and pH = 4.5), 5 microg of Ag+ in 6.0 ml aqueous phase could be extracted quantitatively into 20 microl of the sedimented phase. The maximum concentration factor was 300-fold. The limit of detection of the proposed method was 0.005 ng/ml. The reproducibility of the proposed method was at most 3.5%. The influence of the pH, type and volume of the water-miscible organic solvent, concentration of FSA, concentration of the complexing ligand and the effect of different diverse ions on the extraction and determination of Ag+ were investigated. The proposed method was applied to the extraction and determination of Ag+ in different water samples.

Development of a PVC-membrane Ion-selective Bulk Optode, for UO2(2+) Ion, Based on Tri-n-octylphosphine Oxide and Dibenzoylmethane

Analytical and Bioanalytical Chemistry. Jun, 2005  |  Pubmed ID: 15942759

A novel uranyl ion-selective bulk optode membrane, incorporating tri-n-octylphosphine oxide for cation recognition and a lipophilic chromoionophore dibenzoylmethane, has been prepared. The PVC membrane composition was optimized to result in the widest working concentration range. The response range of the proposed optode is 4.1 x 10(-6) to 2.0 x 10(-4) mol L(-1) UO2(2+). The probe works at pH 4.0. Ion interference is low and selectivity, reproducibility, and stability are good.

Spectrofluorometric Study of Complexation of Some Amino Derivatives of 9,10-anthraquinone with Beta-cyclodextrin

Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy. Nov, 2005  |  Pubmed ID: 16257738

Complexation reactions between 1-amino-9,10-anthraquinone (AA1), 1-amino-2-methyl-9,10-anthraquinone (AA2), 1-amino-2,4-dimethyl-9,10-anthraquinone (AA3) and 1-amino-2-ethyl-9,10-anthraquinone (AA4) and beta-cyclodextrin were studied spectrofluorometrically, under optimized experimental conditions. The formation constants of the resulting 1:1 beta-cyclodextrin complexes were evaluated and found to decrease in the order AA4>AA1>AA3>AA2. Possible reasons for the observed stability sequence are discussed based on the structures proposed for the resulting inclusion complexes.

The Development and Utility of a Clinical Algorithm to Predict Early HIV-1 Infection

Journal of Acquired Immune Deficiency Syndromes (1999). Dec, 2005  |  Pubmed ID: 16280704

The association between self-reported clinical factors and recent HIV-1 seroconversion was evaluated in a prospective cohort of 4652 high-risk participants in the HIV Network for Prevention Trials (HIVNET) Vaccine Preparedness Study. Eighty-six individuals seroconverted, with an overall annual seroconversion rate of 1.3 per 100 person-years. Four self-reported clinical factors were significantly associated with HIV-1 seroconversion in multivariate analyses: recent history of chlamydia infection or gonorrhea, recent fever or night sweats, belief of recent HIV exposure, and recent illness lasting > or =3 days. Two scoring systems, based on the presence of either 4 or 11 clinical factors, were developed. Sensitivity ranged from 2.3% (with a positive predictive value of 12.5%) to 72.1% (with a positive predictive value of 1%). Seroconversion rates were directly associated with the number of these clinical factors. The use of scoring systems comprised of clinical factors may aid in detecting early and acute HIV-1 infection in vaccine and microbicide trials. Organizers can educate high-risk trial participants to return for testing during interim visits if they develop these clinical factors. Studying individuals during early and acute HIV-1 infection would allow scientists to investigate the impact of the intervention being studied on early transmission or pathogenesis of HIV-1 infection.

Copper(II)-selective Fluorimetric Bulk Optode Membrane Based on a 1-hydroxy-9,10-anthraquinone Derivative Having Two Propenyl Arms As a Neutral Fluorogenic Ionophore

Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy. Jan, 2006  |  Pubmed ID: 16307904

A new optical chemical sensor has been developed for the selective determination of copper(II) ions in aqueous solutions. The reversible sensing system was prepared by incorporating 1-hydrpxy-2-(prop-2'-enyl)-4-(prop-2'-enyloxy)-9,10-anthraquinone (AQ) as a neutral Cu2+-selective fluoroionophore in the plasticized PVC membrane with potassium tetrakis(p-chlorophenyl borate) as an anionic additive. The response of the sensor is based on the fluorescence quenching of AQ by Cu2+ ions. At a pH 5.5, the proposed sensor displays a calibration response for Cu2+ over a wide concentration rang of 1.0 x 10(-2) to 1.0 x 10(-6) M, with a relatively fast response of less than 40 s. In addition to high stability and reproducibility, the sensor shows a unique selectivity towards Cu2+ ion with respect to common co-existing cations. The proposed fluorescence optode was applied successfully to the determination of copper(II) in black tea samples.

Copper(II)-selective Fluorimetric Bulk Optode Membrane Based on a 1-hydroxy-9,10-anthraquinone Derivative Having Two Propenyl Arms As a Neutral Fluorogenic Ionophore

Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy. Jan, 2006  |  Pubmed ID: 16344241

A new optical chemical sensor has been developed for the selective determination of copper(II) ions in aqueous solutions. The reversible sensing system was prepared by incorporating 1-hydroxy-2-(prop-2'-enyl)-4-(prop-2'-enyloxy)-9,10-anthraquinone (AQ) as a neutral Cu2+-selective fluoroionophore in the plasticized PVC membrane with potassium tetrakis(p-chlorophenyl borate) as an anionic additive. The response of the sensor is based on the fluorescence quenching of AQ by Cu2+ ions. At a pH 5.5, the proposed sensor displays a calibration response for Cu2+ over a wide concentration range of 1.0 x 10(-2) to 1.0 x 10(-6) M, with a relatively fast response of less than 40 s. In addition to high stability and reproducibility, the sensor shows a unique selectivity towards Cu2+ ion with respect to common co-existing cations. The proposed fluorescence optode was applied successfully to the determination of copper(II) in black tea samples.

ZnO As a New Catalyst for N-formylation of Amines Under Solvent-free Conditions

The Journal of Organic Chemistry. Aug, 2006  |  Pubmed ID: 16901164

The treatment of amines with formic acid in the presence of ZnO under solvent-free conditions brings about highly and efficient N-formylation to give the corresponding formamides in excellent yields. The N-formylation reaction not only involves mild conditions, simple operation, and high yields but also high chemoselectivity.

Depression in Mothers of Children with Thalassemia or Blood Malignancies: a Study from Iran

Clinical Practice and Epidemiology in Mental Health : CP & EMH. 2006  |  Pubmed ID: 17020622

Several studies have found that parents of children with chronic diseases or disabilities have higher depression scores than control parents. Mothers usually take on the considerable part of the extra care and support that these children need and thus are at markedly increased risks of suffering from psychological distress and depression. The main aim of the present study was to investigate if mothers of children with thalassemia or blood malignancies have higher scores of depression compared with a group of control mothers.

Interaction of an Fe Derivative of TMAP (Fe(TMAP)OAc) with DNA in Comparison with Free-base TMAP

International Journal of Biological Macromolecules. Jul, 2007  |  Pubmed ID: 17343908

We investigated the interaction of meso-tetrakis (N-para-methylanilium) porphyrin (TMAP) in its free base and Fe(II) form (Fe(TMAP)OAc) as a new derivative, with high molecular weight DNA at different ionic strengths, using various spectroscopic methods and microcalorimetry. The data obtained by spectrophotometery, circular dichroism (CD), fluorescence quenching and resonance light scattering (RLS) have demonstrated that TMAP association with DNA is via outside binding with self-stacking manner, which is accompanied with the "end-on" type complex formation in low ionic strength. However, in the case of Fe(TMAP)OAc, predominant mode of interaction is groove binding and after increasing in DNA concentration, unstable stacking-type aggregates are formed. In addition, isothermal titration calorimetric measurements have indicated the exothermic process of porphyrins binding to DNA, but the exothermisity in metal derivative of porphyrin is less than the free base. It confirmed the formation of a more organized aggregate of TMAP on DNA surface. Interactions of both porphyrins with DNA show high sensitivity to ionic strength. By addition of salt, the downfield CD signal of TMAP aggregates is shifted to a higher wavelength, which indicates some changes in the aggregates position. In the case of Fe(TMAP)OAc, addition of salt leads to changes in the mode of binding from groove binding to outside binding with self-stacking, which is accompanied with major changes in CD spectra, possibly indicating the formation of "face-on" type complex.

Comparison of MRI Findings with Traditional Criteria in Diagnosis of Pendred Syndrome

International Journal of Audiology. Feb, 2007  |  Pubmed ID: 17365057

Pendred syndrome, defined as the constellation of goiter, sensori-neural hearing loss, and positive perchlorate discharge test, is the most frequent cause of congenital deafness. Newly introduced diagnostic approaches to the disease are rather expensive and complicated, therefore we evaluated the value of MRI as the sole, or adjunctive diagnostic approach, and compared it with the traditional ones. Presuming the classic triad as the gold standard, we compared MRI findings in six such defined patients with six cases having goiter, hearing loss, and normal perchlorate discharge test. Our results indicated that MRI was 83.6% sensitive and 66.7% specific in patients fulfilling all three criteria (complete), while in the 'partial' group the sensitivity and specificity were 66.7% and 100% respectively. In conclusion, MRI, although impressive as an adjunctive diagnostic tool, may not replace the holistic approach, and the latter may be more convenient, cheaper, and still more accurate. However in 'partial' cases with equivocal findings, and in relatives of the patients, MRI may be a valuable diagnostic adjunct.

Structure-retention and Mobile Phase-retention Relationships for Reversed-phase High-performance Liquid Chromatography of Several Hydroxythioxanthone Derivatives in Binary Acetonitrile-water Mixtures

Analytica Chimica Acta. Dec, 2007  |  Pubmed ID: 18022405

The reversed-phase high-performance liquid chromatographic (RP-HPLC) behavior of some newly synthesized hydroxythioxanthone derivatives using binary acetonitrile-water mixtures as mobile phase has been examined. First, the variation in the retention time of each molecule as a function of mobile phase properties was studied by Kamlet-Taft solvatochromic equations. Then, the influences of molecular structure of the hydroxythioxanthone derivatives on their retention time in various mobile phase mixtures were investigated by quantitative structure-property relationship (QSPR) analysis. Finally, a unified model containing both the molecular structure parameters and mobile phase properties was developed to describe the chromatographic behavior of the systems studied. Among the solvent properties, polarity/polarizability parameter (pi*) and hydrogen-bond basicity (beta), and among the solute properties, the most positive local charge (MPC), the sum of positive charges on hydrogen atoms contributing in hydrogen bonding (SPCH) and lipophilicity index (logP) were identified as controlling factors in the RP-HPLC behavior of hydroxythioxanthone derivatives in actonitrile-water binary solvents.

Linear and Nonlinear Quantitative Structure-property Relationship Models for Solubility of Some Anthraquinone, Anthrone and Xanthone Derivatives in Supercritical Carbon Dioxide

Analytica Chimica Acta. Mar, 2008  |  Pubmed ID: 18267136

A quantitative structure-property relation (QSPR) study was conducted on the solubility in supercritical fluid carbon dioxide (SCF-CO2) of some recently synthesized anthraquinone, anthrone and xanthone derivatives. The data set consisted of 29 molecules in various temperatures and pressures, which form 1190 solubility data. The combined data splitting-feature selection (CDFS) strategy, which previously developed in our research group, was used as descriptor selection and model development method. Modeling of the relationship between selected molecular descriptors and solubility data was achieved by linear (multiple linear regression; MLR) and nonlinear (artificial neural network; ANN) methods. The QSPR models were validated by cross-validation as well as application of the models to predict the solubility of three external set compounds, which did not have contribution in model development steps. Both linear and nonlinear methods resulted in accurate prediction whereas more accurate results were obtained by ANN model. The respective root mean square error of prediction obtained by MLR and ANN models were 0.284 and 0.095 in the term of logarithm of g solute m(-3) of SCF-CO2. A comparison was made between the models selected by CDFS method and the conventional stepwise feature selection method. It was found that the latter produced models with higher number of descriptors and lowered prediction ability, thus it can be considered as an over-fitted model.

Reversed-phase High Performance Liquid Chromatography (RP-HPLC) Characteristics of Some 9,10-anthraquinone Derivatives Using Binary Acetonitrile-water Mixtures As Mobile Phase

Talanta. Oct, 2008  |  Pubmed ID: 18804645

The retention behavior of 28 synthesized 9,10-anthraquinone derivatives in a reversed-phase (RP) high performance liquid chromatography (HPLC) system has been studied on a C18-RP column using acetonitrile-water mixtures as mobile phase. The influences of the composition of mobile phase and the solute structure on the retention times of 9,10-anthraquinone derivatives were investigated by linear solvation free energy relationship (LSFER) and quantitative structure-retention relationship (QSRR) analyses. Among different solvatochromic parameters of solvent systems, their polarity/polarizability parameter (pi*) was identified as the controlling factor affecting retention behavior of these compounds. A four-parametric QSRR model was obtained between solute structures and retention indices. Finally, a unified model containing both the molecular structure parameters and mobile phase properties was developed to describe the chromatographic behavior of the systems studied. The resulted QSRR models could explain and predict higher than 90% of variances in the retention indices. Among the solvent properties, polarity/polarizability parameter (pi*), and among the solute properties, HATS5v (leverage-weighted autocorrelation of lag 5/weighted by atomic van der Waals volumes, GETAWAY descriptors), Mor14p (3D-MoRSE-signal 14/weighted by atomic polarizabilities, 3D-MoRSE descriptors), GATS5p (Geary autocorrelation-lag 5/weighted by atomic polarizabilities, 2D autocorrelations) and R6u+(R maximal autocorrelation of lag 6/unweighted, GETAWAY descriptors) were identified as controlling factors in the RP-HPLC behavior of 9,10-anthraquinone derivatives in actonitrile-water binary solvents.

Highly Correlating Distance/connectivity-based Topological Indices 5. Accurate Prediction of Liquid Density of Organic Molecules Using PCR and PC-ANN

Journal of Molecular Graphics & Modelling. Nov, 2008  |  Pubmed ID: 18948045

The primary goal of a quantitative structure-property relationship (QSPR) is to identify a set of structurally based numerical descriptors that can be mathematically linked to a property of interest. Recently, we proposed some new topological indices (Sh indices) based on the distance sum and connectivity of a molecular graph that derived directly from two-dimensional molecular topology for use in QSAR/QSPR studies. In this study, the ability of these indices to predict the liquid densities (rho) of a large and diverse set of organic liquid compounds (521 compounds) has been examined. Ten different Sh indices were calculated for each molecule. Both linear and non-linear modeling methods were implemented using principal component regression (PCR) and principal component-artificial neural network (PC-ANN) with back-propagation learning algorithm, respectively. Correlation ranking procedure was used to rank the principal components and entered them into the models. PCR analysis of the data showed that the proposed Sh indices could explain about 91.82% of variations in the density data, while the variations explained by the ANN modeling were more than 97.93%. The predictive ability of the models was evaluated using external test set molecules and root mean square errors of prediction of 0.0308 g ml(-1) and 0.0248 g ml(-1) were obtained for liquid densities of external compounds by linear and non-linear models, respectively.

An Efficient and Selective Flourescent Optode Membrane Based on 7-[(5-chloro-8-hydroxy-7-quinolinyl)methyl]-5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatriazacyclopentadecine-3,11(4H,12H)-dione As a Novel Fluoroionophore for Determination of Cobalt(II) Ions

Analytica Chimica Acta. Dec, 2008  |  Pubmed ID: 19068326

A novel fluorescence chemical sensor for the highly sensitive and selective determination of Co(2+) ions in aqueous solutions is prepared. The cobalt sensing system was prepared by incorporating 7-[(5-chloro-8-hydroxy-7-quinolinyl)methyl]-5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatriazacyclopentadecine-3,11(4H,12H)-dione (L) as a neutral cobalt-selective fluoroionophore in the plasticized PVC membrane containing sodium tetraphenylborate as a liphophilic anionic additive. The response of the sensor is based on the strong selective fluorescence quenching of L by Co(2+) ions. At a pH 5.0, the proposed sensor displays a calibration curve over a wide concentration range of 5.0 x 10(-7) to 2.0 x 10(-2)M with a relatively fast response time of less than 5 min. In addition to high stability and reproducibility, the sensor shows a unique selectivity towards Co(2+) ion with respect to common coexisting cations. The proposed fluorescence optode was successfully applied to the determination of cobalt content of vitamin B12 ampoule, cobalt cake, cobalt alloy and tap water samples.

Novel PVC-membrane Potentiometric Sensors Based on a Recently Synthesized Sulfur-containing Macrocyclic Diamide for Cd2+ Ion. Application to Flow-injection Potentiometry

Journal of Hazardous Materials. Dec, 2009  |  Pubmed ID: 19640638

A new sulfur-containing macrocyclic diamide, 1,15-diaza-3,4,12,13-dibenzo-5,11-dithia-8-oxa-1,15-(2,6-pyrido)cyclooctadecan-2,14-dione, L, was synthesized, characterized and used as an active component for fabrication of PVC-based polymeric membrane (PME), coated graphite (CGE) and coated silver wire electrodes (CWE) for sensing Cd(2+) ion. The electrodes exhibited linear Nernstian responses to Cd(2+) ion in the concentration range of 3.3 x 10(-6) to 3.3 x 10(-1)M (for PME, LOD=1.2 x 10(-6)M), 2.0 x 10(-7) to 3.3 x 10(-1)M (for CWE, LOD=1.3 x 10(-7)M) and 1.6 x 10(-8) to 1.3 x 10(-1)M (for CGE, LOD=1.0 x 10(-8)M). The CGE was used as a proper detection system in flow-injection potentiometry (FIP) with a linear Nernstian range of 3.2 x 10(-8) to 1.4 x 10(-1)M (LOD=1.3 x 10(-8)M). The optimum pH range was 3.5-7.6. The electrodes revealed fairly good discriminating ability towards Cd(2+) in comparison with a large number of alkali, alkaline earth, transition and heavy metal ions. The electrodes found to be chemically inert, showing a fast response time of <5s, and could be used practically over a period of about 2-3 months. The practical utility of the proposed system has also been reported.

Lead-selective Poly(vinyl Chloride) Electrodes Based on Some Synthesized Benzo-substituted Macrocyclic Diamides

Journal of Hazardous Materials. Dec, 2009  |  Pubmed ID: 19643538

A series of recently synthesized benzo- and pyridine-substituted macrocyclic diamides were studied to characterize their abilities as lead ion carriers in PVC membrane electrodes. The electrode based on 3,15,21-triaza-4,5;13,14-dibenzo-6,9,12-trioxabicycloheneicosa-1,17,19-triene-2,16-dione exhibits a Nernstian response for Pb2+ ions over a wide concentration range (1.3 x 10(-2) to 3.6 x 10(-6) mol L(-1)) with a limit of detection of 2.0 x 10(-6) mol L(-1) (0.4 ppm). The response time of the sensor is approximately 16 s, and the membrane can be used for more than two months without observing any deviation. The electrode revealed comparatively good selectivities with respect to many cations including alkali earth, transition and heavy metal ions. The proposed sensor could be used in pH range of 3.7-6.5. It was used as an indicator electrode in potentiometric titration of chromate ions with a lead ion solution.

Bis(2-hydroxy-benzaldehyde Oxime) O,O'-butane-1,4-diyldicarbonyl Ether

Acta Crystallographica. Section E, Structure Reports Online. 2009  |  Pubmed ID: 21583166

The mol-ecule of the title compound, C(20)H(20)N(2)O(6), lies across a crystallographic inversion centre, the asymmetric unit comprising one half-mol-ecule. An intra-molecular O-H⋯N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. Pairs of inter-molecular C-H⋯O hydrogen bonds link neighbouring mol-ecules into a layer with R(2) (2)(38) ring motif. The crystal structure is further stabilized by the inter-molecular C-H⋯π inter-actions.

Rhinosinusitis Predispose Asthmatic Patients to Severe Bronchial Asthma

Iranian Journal of Allergy, Asthma, and Immunology. Dec, 2009  |  Pubmed ID: 20404390

In this study, we evaluated the relationship between rhinosinusitis to the severity of asthma in asthmatic patients.This cross-sectional study was conducted on 90 patients with asthma referring to Imam Khomeini Hospital in Ardabil city. Asthma control stepping method was used for staging of asthma severity. Patients' clinical signs and paraclinical findings were individually evaluated and compared with particular attention to the presence or absence of rhinosinusitis. Chi square and t-test were used to analyze the data in SPSS15 software.Rhinosinusitis was found in 66 (73%) of the 90 patients. The Forced Expiratory Volume in 1 second (FEV1) was significantly lower in the patients who also had rhinosinusitis (P=0.002).Comparing severity of asthma, most of the patients with rhinosinusitis were in stage3 (42.4%) but most of the patients without rhinosinusitis were in stage1 (41.6%) (p=0.002).The results of this study confirm the correlation between asthma severity and rhinosinusitis in asthmatic patients. Therefore, in diagnosing asthma in patients, the possibility of the rhinosinusitis should be determined and treated.

Synthesis and Characterization of Novel Ion-imprinted Polymeric Nanoparticles for Very Fast and Highly Selective Recognition of Copper(II) Ions

Talanta. Dec, 2010  |  Pubmed ID: 21111191

This work reports the preparation of new Cu(2+) ion-imprinted polymeric nanoparticles using 1-hydroxy-4-(prop-2'-enyloxy)-9,10-anthraquinone (AQ) as a vinylated chelating agent. The Cu(2+) ion found to form a stable 1:1 complex with AQ in methanol solution. The resulting Cu(2+)-AQ complex was copolymerized with ethyleneglycol dimethacrylate, as a cross-linking monomer, via precipitation polymerization method. The imprint copper ion was removed from the polymeric matrix using a 0.1 mol L(-1) HNO(3) solution. The Cu(2+)-imprinted polymeric nanoparticles were characterized by IR spectroscopy, scanning electron microscopy (SEM) and N(2) adsorption-desorption isotherms. The SEM micrographs showed colloidal nanoparticles of 60-100 nm in diameter and slightly irregular in shape. Optimum pH for maximum sorption was 7.0. Sorption and desorption of Cu(2+) ion on the IIP nanoparticles were quite fast and achieved completely over entire investigated time periods of 2-30 min. Maximum sorbent capacity and enrichment factor of the prepared IIP for Cu(2+) were 73.8 μmol g(-1) and 56.5, respectively. The relative standard deviation and limit of detection (C(LOD)=3S(b)/m) of the method were evaluated as 2.6% and 0.1 ng mL(-1), using inductively coupled plasma-atomic emission spectrometry, respectively. It was found that the imprinting technology results in increased affinity of the prepared material toward Cu(2+) ion over other metal ions with the same charge and close ionic radius. The relative standard deviations for six and twenty replicates with the same nanoparticles were found to be 1.7% and 2.1%, respectively.

2-[(E)-(4-Methyl-phen-yl)imino-meth-yl]-6-(morpholin-4-ylmeth-yl)phenol

Acta Crystallographica. Section E, Structure Reports Online. 2010  |  Pubmed ID: 21522655

In the title compound, C(19)H(22)N(2)O(2), the morpholine ring adopts an almost perfect normal chair conformation with puckering parameters Q(T), θ and ϕ of 0.5642 (18) Å, 177.32 (17) and ϕ = 10 (4)°, respectively. The two benzene rings make a dihedral angle of 42.67 (8)° with each other. An intra-molecular O-H⋯N hydrogen bond helps to stabilize the mol-ecular conformation. Aromatic C-H⋯π inter-actions and π-π stacking inter-actions [centroid-centroid distance = 3.6155 (15) Å] between the benzene rings contribute to the stabilization of the crystal structure.

Multi-wavelength Spectrophotometric Determination of Acidity Constant of Some Newly Synthesized Schiff Bases and Their QSPR Study

Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy. Jan, 2010  |  Pubmed ID: 20004138

The acidity constants of some newly synthesized Schiff base derivatives were determined by hard-model based multivariate data analysis of the spectrophotometric data in the course of pH-metric titration in 50% (v/v) methanol-water binary solvent. The employed data analysis method was also able to extract the pure spectra and pH-dependent concentration profiles of the acid-base species. The molecules that possess different substituents (both electron donating and withdrawing) on the ortho-, meta- and para-positions of one of the phenyl ring showed variable acidity constants ranging from 8.77 to 11.07 whereas the parent molecule had an acidity constant of 10.25. To investigate the quantitative effects of changing of substitution pattern on the acidity constant, a quantitative structure-property relation analysis was conducted using substituent constants and molecular descriptor. Some models with high statistical quality (measured by cross-validation Q(2)) were obtained. It was found that the acidity constant of the studied molecules in the methanol-water mixed solvent not only is affected by electronic features of the solutes but also by the lipophilic interaction between methanol part of solvent and the deprotonated solutes.

Effects of Oral Creatine and Resistance Training on Serum Myostatin and GASP-1

Molecular and Cellular Endocrinology. Apr, 2010  |  Pubmed ID: 20026378

Myostatin is a catabolic regulator of skeletal muscle mass. The purpose of this study was to determine the effect of resistance training for 8 weeks in conjunction with creatine supplementation on muscle strength, lean body mass, and serum levels of myostatin and growth and differentiation factor-associated serum protein-1 (GASP-1). In a double-blinded design 27 healthy male subjects (23.42+/-2.2 years) were assigned to control (CON), resistance training+placebo (RT+PL) and resistance training+creatine supplementation (RT+CR) groups. The protocol consisted of 3 days per week of training for 8 weeks, each session including three sets of 8-10 repetitions at 60-70% of 1 RM for whole-body exercise. Blood sampling, muscular strength testing and body composition analysis (full body DEXA) were performed at 0, 4th and 8th weeks. Myostatin and GASP-1 was measured. Resistance training caused significant decrease in serum levels of myostatin and increase in that of GASP-1. Creatine supplementation in conjunction with resistance training lead to greater decreases in serum myostatin (p<0.05), but had not additional effect on GASP-1 (p>0.05). The effects of resistance training on serum levels of myostatin and GASP-1, may explain the increased muscle mass that is amplified by creatine supplementation.

(3R*,4R*)-1-(4-Chloro-phen-yl)-4-[2-hy-droxy-3-(morpholinomethyl)-phen-yl]-3-phen-oxy-azetidin-2-one

Acta Crystallographica. Section E, Structure Reports Online. 2011  |  Pubmed ID: 21523011

The β-lactam ring of the title compound, C(26)H(25)ClN(2)O(4), is nearly planar (r.m.s. deviation = 0.025 Å) and the morpholine ring adopts a chair conformation. The mean plane of the β-lactam ring makes dihedral angles of 21.6 (4), 84.4 (4) and 33.7 (4)° with the two benzene rings and the phenyl ring, respectively. The conformation of the title compound is stabilized by intra-molecular C-H⋯O and O-H⋯N inter-actions. The crystal structure features C-H⋯π and aromatic π-π stacking inter-actions [centroid-centroid distances = 3.684 (4) and 3.883 (4) Å].

The GUDMAP Database--an Online Resource for Genitourinary Research

Development (Cambridge, England). Jul, 2011  |  Pubmed ID: 21652655

The GenitoUrinary Development Molecular Anatomy Project (GUDMAP) is an international consortium working to generate gene expression data and transgenic mice. GUDMAP includes data from large-scale in situ hybridisation screens (wholemount and section) and microarray gene expression data of microdissected, laser-captured and FACS-sorted components of the developing mouse genitourinary (GU) system. These expression data are annotated using a high-resolution anatomy ontology specific to the developing murine GU system. GUDMAP data are freely accessible at www.gudmap.org via easy-to-use interfaces. This curated, high-resolution dataset serves as a powerful resource for biologists, clinicians and bioinformaticians interested in the developing urogenital system. This paper gives examples of how the data have been used to address problems in developmental biology and provides a primer for those wishing to use the database in their own research.

Carbon Nanotube Composite Coated Platinum Electrode for Detection of Ga(III)

Journal of Hazardous Materials. Jan, 2011  |  Pubmed ID: 20980100

This study demonstrates the application of composite multi-walled carbon nanotube (MWCNT) polyvinylchloride (MWNT-PVC) based on 7-(2-hydroxy-5-methoxybenzyl)-5,6,7,8,9,10-hexahydro-2H benzo [b][1,4,7,10,13] dioxa triaza cyclopentadecine-3,11(4H,12H)-dione ionophore for gallium sensor. The sensor shows a good Nernstian slope of 19.68 ± 0.40 mV/decade in a wide linear range concentration of 7.9 × 10(-7) to 3.2 × 10(-2)M of Ga(NO(3))(3). The detection limit of this electrode is 5.2 × 10(-7)M of Ga(NO(3))(3). This proposed sensor is applicable in a pH range of 2.7-5.0. It has a short response time of about 10s and has a good selectivity over nineteen various metal ions. The practical analytical utility of this electrode is demonstrated by measurement of Ga(III) in river water.

Establishing a CGMP Pancreatic Islet Processing Facility: the First Experience in Iran

Cell and Tissue Banking. Aug, 2011  |  Pubmed ID: 21818570

It has been predicted that one of the greatest increase in prevalence of diabetes will happen in the Middle East bear in the next decades. The aim of standard therapeutic strategies for diabetes is better control of complications. In contrast, some new strategies like cell and gene therapy have aimed to cure the disease. In recent years, significant progress has occurred in beta-cell replacement therapies with a progressive improvement of short-term and long term outcomes. In year 2005, considering the impact of the disease in Iran and the promising results of the Edmonton protocol, the funding for establishing a current Good Manufacturing Practice (cGMP) islet processing facility by Endocrinology and Metabolism Research Center was approved by Tehran University of Medical Sciences. Several islet isolations were performed following establishment of cGMP facility and recruitment of all required equipments for process validation and experimental purpose. Finally the first successful clinical islet isolation and transplantation was performed in September 2010. In spite of a high cost of the procedure it is considered beneficial and may prevent long term complications and the costs associated with secondary cares. In this article we will briefly describe our experience in setting up a cGMP islet processing facility which can provide valuable information for regional countries interested to establish similar facilities.

MP2, DFT and Ab Initio Calculations on Thioxanthone

Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy. Nov, 2011  |  Pubmed ID: 21820349

Density functional theory (DFT), HF and MP2 calculations have been carried out to investigate thioxanthone molecule using the standard 6-31+G(d,p) basis set. The results of MP2 calculations show a butterfly structure for thioxanthone. The calculated results show that the predicted geometry can well reproduce the structural parameters. The predicted vibrational frequencies were assigned and compared with experimental IR spectra. A good harmony between theory and experiment is found. The theoretical electronic absorption spectra have been calculated using CIS method. (13)C and (1)H NMR of the title compound have been calculated by means of B3LYP density functional method with 6-31+G(d,p) basis set. The comparison of the experimental and the theoretical results indicate that density functional B3LYP method is able to provide satisfactory results for predicting NMR properties.

Evaluating Risk Factors for Protein-energy Malnutrition in Children Under the Age of Six Years: a Case-control Study from Iran

International Journal of General Medicine. 2011  |  Pubmed ID: 21887115

Protein-energy malnutrition is one of the most important public health problems in Iran. It not only accounts for more than half of child mortality but can also produce somatic and mental impairment in survivors. The main aim of this study was to identify risk factors for protein-energy malnutrition in children under 6 years of age in Namin city.