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KOH
Kinds of KOH Terms modified by KOH Selected AbstractsOnychomycosis: diagnosis and topical therapyDERMATOLOGIC THERAPY, Issue 2 2002Philip Fleckman Onychomycosis (true fungal infection of the nail plate) is a common malady that may present in several clinical patterns. Because many noninfectious disorders of the nail may masquerade as onychomycosis, the clinical diagnosis must be confirmed by wet mount (potassium hydroxide [KOH] examination), culture, or histology before treatment is begun. Although systemic therapy of onychomycosis with the newer drugs is more effective, the prospect of effective topical therapy is a welcome alternative in many situations. Choices for topical therapy are limited in the United States at this time. As new, improved choices are added to the therapeutic armamentarium, topical therapy my supersede systemic. In addition, the potential for synergism with systemic therapy and for prophylaxis of cleared infections is only now being explored. [source] The Determination of Methanol Using an Electrolytically Fabricated Nickel Microparticle Modified Boron Doped Diamond ElectrodeELECTROANALYSIS, Issue 5 2010Kathryn Abstract A nickel modified boron doped diamond (Ni-BDD) electrode and nickel foil electrode were used in the determination of methanol in alkaline solutions. The Ni-BDD electrode was electrodeposited from a 1,mM Ni(NO3)2 solution (pH,5), followed by repeat cycling in KOH. Subsequent analysis utilised the Ni(OH)2/NiOOH redox couple to electrocatalyse the oxidation of methanol. Methanol was determined to limits of 0.3,mM with a sensitivity of 110,nA/mM at the Ni-BDD electrode. The foil electrode was less sensitive achieving a limit of 1.6,mM and sensitivity of 27,nA/mM. SEM analysis of the electrodes found the Ni-BDD to be modified by a quasi-random microparticle array. [source] Effect of alkali metal hydroxides on the enantioseparation of amines using di- O -isopropylidene-keto- L -gulonic acid as the selector in NACEELECTROPHORESIS, Issue 22 2006Ylva Hedeland Dr. Abstract The present work demonstrates the importance of the ionic composition in the BGE for enantioseparation. (,)-2,3:4,6-di- O -Isopropylidene-2-keto- L -gulonic acid ((,)-DIKGA) has been used as the chiral selector in methanolic and ethanolic BGEs. The influence of added alkali metal hydroxides on the EOF and the chiral separation of amines (atenolol, isoprenaline, pindolol and propranolol) have been studied. The ion-pair formation constants in ethanol were determined by precision conductometry for the enantiomers of pindolol with (,)-DIKGA, for Li+, Na+ and Cs+ with (,)-DIKGA, and also for the corresponding alkali metal hydroxides. The effective mobilities and the enantiomeric mobility differences were affected by the type of alkali metal hydroxide (LiOH, NaOH, KOH, RbOH or CsOH) added to the BGE. The effective mobility and mobility difference were increased with decrease in solvated radius of the alkali metal cation. These differences could partly be correlated to the ion-pair formation constants of the alkali metal cations with the chiral selector, affecting the equilibrium concentration of the free selector. The electroosmosis was also affected by the alkali metal hydroxide added to the BGE. The cathodic electroosmosis decreased with decreasing solvated radius of the alkali metal cation added to the BGE. Interestingly, the cathodic EOF was even reversed, i.e. became anodic in the ethanolic BGEs containing KOH, RbOH or CsOH and the methanolic ones with RbOH and CsOH. [source] Characterization of hydroxyaromatic compounds in vegetable oils by capillary electrophoresis with direct injection in an oil-miscible KOH/propanol/methanol mediumELECTROPHORESIS, Issue 17 2005Carla R. B. Mendonça Abstract The separation of hydroxyaromatic compounds in vegetable oils, including synthetic antioxidants (3- tert -butyl-4-hydroxyanisol and 2,6-di- tert -butyl-4-hydroxytoluene), E-vitamers and other natural oil components, by nonaqueous capillary electrophoresis in an oil-miscible background electrolyte (BGE) was investigated. The BGE contained 40,mM KOH in a methanol/1-propanol (PrOH) mixture (15:85 v/v). The oil samples were 1:1 diluted with PrOH and directly injected in the capillary. Under negative polarity (cathode at the injection end), the anionic solutes moved faster than the electroosmotic flow, being well-resolved among them and from the triacylglycerols. Using virgin palm, extra virgin olive, wheat germ, virgin soybean and other oils, the capability of the procedure to quickly yield a characteristic profile of the biophenols present in the sample was demonstrated. The , -, (,,+,,)- (as unresolved pair) and , -tocopherols of a soybean oil sample were quantified. [source] Lanthanum(III) Oxide as a Recyclable Catalyst for the Synthesis of Diaryl Sulfides and Diaryl SelenidesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 34 2009Sabbavarapu Narayana Murthy Abstract La2O3 as a new and efficient recyclable catalyst in coupling various aryl halides with aromatic/alkyl thiols and diphenyl diselenide in combination with KOH as a base and DMEDA as a ligand in DMSO at 110 °C is reported. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Heteroarylation of 1-Azulenyl Methyl Sulfide: Two-Step Synthetic Strategy for 1-Methylthio-3-(heteroaryl)azulenes Using the Triflate of N -Containing HeterocyclesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 34 2008Junya Higashi Abstract 1-Azulenyl methyl sulfide reacts with highly electrophilic trifluoromethanesulfonates of N -heterocycles, that is, pyridine, isoquinoline, 1,10-phenanthroline, benzothiazole, quinoline, and acridine, to give 1-methylthio-3-(dihydroheteroaryl)azulenes in good yields. In the case of the reaction with the trifluoromethanesulfonate of pyridine, 1-methylthio-3-pyridylazulene was obtained directly under certain reaction conditions. Treatment of the 1-methylthio-3-(dihydroheteroaryl)azulenes with KOH or tBuOK afforded the corresponding 1-methylthio-3-(heteroaryl)azulenes in good yields. The redox behavior of these 1-methylthio-3-(heteroaryl)azulenes was examined by cyclic voltammetry and differential pulse voltammetry.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Ring Expansion of 2-(,-Hydroxyalkyl)azetidines: A Synthetic Route to Functionalized PyrrolidinesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 19 2008François Durrat Abstract A series of 2-(,-hydroxyalkyl)azetidines synthesized from enantiomerically pure ,-amino alcohols and presenting various patterns both on the four-membered ring and on the adjacent hydroxy group were treated with either thionyl chloride or methanesulfonyl chloride in the presence of triethylamine. The thus-prepared 2-(,-chloro- or ,-methanesulfonyloxyalkyl)azetidines were shown to rearrange stereospecifically into 3-(chloro- or methanesulfonyloxy)pyrrolidines. When this rearrangement is conducted in the presence of an added nucleophile (NaN3, KCN, KOH, or NaOAc), the produced pyrrolidine incorporates the added nucleophile at C-3 stereospecifically. The relative configuration of the substituents in the formed pyrrolidines is consistent with a mechanism involving the formation of an intermediate bicyclic aziridinium ion, which is opened regioselectively at the bridgehead carbon atom. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Recoverable Phase-Transfer Catalysts with Fluorinated Anions: Generation and Reactions of Dichlorocarbene and CCl3 Anion in the Heterogeneous System KOH(s)/CHCl3/nBu4NPF6EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 10 2008Galina V. Kryshtal Abstract Tetraalkylammonium salts bearing PF6, and BF4, anions have been recognized as recoverable phase-transfer catalysts for the synthesis of 1,1-dichlorocyclopropane and ,-(trichloromethyl)carbinol derivatives from alkenes or aldehydes in the heterogeneous system KOH(s)/CHCl3. The catalysts retained their catalytic activity over several reactioncycles.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Synthesis and Reactivity of 23 - tert -Butyl- and 23 -Phenyltetraarylazuliporphyrins: an Analysis of the Effect of Bulky Substituents on Oxidative Ring Contractions to Benzocarbaporphyrins,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 24 2007Jessica A. El-Beck Abstract 6- tert -Butyl- and 6-phenylazulene reacted with pyrrole and benzaldehyde in a molar ratio of 1:3:4 in the presence of BF3·Et2O in chloroform, followed by oxidation with DDQ, to give 23 -substituted tetraphenylazuliporphyrins in 15,20,% yield. Slightly higher yields of the related meso -tetrakis(4-chlorophenyl)azuliporphyrins were obtained using 4-chlorobenzaldehyde. The presence of an electron-donating tert -butyl substituent increased the diatropic character of the azuliporphyrin system as determined by the proton NMR chemical shifts for the internal CH resonance, while intermediary results were noted for 23 -phenylazuliporphyrins. Addition of TFA afforded dications with increased aromatic ring currents, but electron-donating substituents (tBu,>,Ph) again produced a larger upfield shift for the internal CH signal due to stabilization of the tropylium character that is required so that the system can attain carbaporphyrin-type aromaticity. The substituted azuliporphyrins reacted with nickel(II) acetate or palladium(II) acetate to give the corresponding organometallic derivatives. In addition, oxidations with tBuOOH and KOH afforded benzocarbaporphyrin products in approximately 50,% yield. The presence of tert -butyl or phenyl substituents did not block these oxidative ring contraction processes, and the rate of reaction was slightly increased compared to 23 -unsubstituted azuliporphyrins. The major products were 22 - tert -butyl or phenyl-substituted benzocarbaporphyrins and minor products with an additional formyl substituent were also isolated. These products are consistent with an initial nucleophilic addition occurring at the position adjacent to the R group on the azulene ring. Detailed mechanisms are proposed to explain these observations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Ammonium fluoride extraction for determining inorganic sulphur in acid forest soilsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2000J. Prietzel Summary Current methods for determining inorganic sulphur (S) in aerated mineral soil horizons often result in underestimates. To overcome this defect we developed a new method combining a batch extraction with 0.5 m NH4F solution at a soil:solution ratio of 1:5 with a subsequent analysis of the mobilized SO42, by ion chromatography. The ammonium fluoride extraction enables us to characterize inorganic sulphate in non-calcareous forest soils. It is more efficient than conventional procedures in which inorganic S is extracted with phosphate or bicarbonate solution. In contrast to the extraction with strongly alkaline reagents (NaOH, KOH, LiOH), the NH4+,NH3 buffer system in NH4F prevents the pH of the suspension from exceeding 9.0 and thus the undesired conversion of organic S into SO42, by auto-oxidation and hydrolysis of ester sulphate. In a comparison we demonstrated that the inorganic S in six German forest soils is underestimated by up to 50% or 200 kg S ha,1 in the uppermost 60 cm, if it is assessed by extraction with 0.016 m KH2PO4 or 0.5 m NaHCO3 instead of 0.5 m NH4F. Conversely, the pool of ester sulphate is overestimated almost threefold. [source] Development of a Direct Alcohol Alkaline Fuel Cell StackFUEL CELLS, Issue 4 2010D. Gaurava Abstract Direct alcohol alkaline fuel cells (DAAFC) are one of the potential fuel cell types in the category of low temperature fuel cells, which could become an energy source for portable electronic equipment in future. In the present study, a simple DAAFC stack has been developed and studied to evaluate the maximum performance for a given fuel (methanol or ethanol) and electrolyte (KOH) at various concentrations and temperatures. The open circuit voltage of the stack of four cells was nearly 4.0,V. A particular combination, 2,M fuel (methanol or ethanol) and 3,M KOH, results in maximum power density of the stack. The maximum power density obtained from the DAAFC stack (25,°C) was 50,mW,cm,2 at 20,mA,cm,2 for methanol and 17,mA,cm,2 for ethanol. The stack power density corroborated with that obtained from a single cell, indicating there was no further loss in the stack. [source] Nitrogen-Enriched Nonporous Carbon Electrodes with Extraordinary SupercapacitanceADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Denisa Hulicova-Jurcakova Abstract Nitrogen-enriched nonporous carbon materials derived from melamine,mica composites are subjected to ammonia treatment to further increase the nitrogen content. For samples preoxidized prior to the ammonia treatment, the nitrogen content is doubled and is mainly incorporated in pyrrol-like groups. The materials are tested as electrodes for supercapacitors, and in acidic or basic electrolytes, the gravimetric capacitance of treated samples is three times higher than that of untreated samples. This represents a tenfold increase of the capacitance per surface area (3300,µF,cm,2) in basic electrolyte. Due to the small volume of the carbon materials, high volumetric capacitances are achieved in various electrolytic systems: 280,F,cm,3 in KOH, 152,F,cm,3 in H2SO4, and 92,F,cm,3 in tetraethylammonium tetrafluoroborate/propylene carbonate. [source] Direct Amination of meso -Tetraarylporphyrin Derivatives , Easy Route to A3B-, A2BC-, and A2B2 -Type Porphyrins Bearing Two Nitrogen-Containing Substituents at the meso -Positioned Phenyl GroupsHELVETICA CHIMICA ACTA, Issue 10 2007Stanis, aw Ostrowski Abstract meso -Tetraarylporphyrinato complexes 1a,g (ZnII, CuII, and NiII) bearing one or two nitro-substituted aryl moieties react with 1,1,1-trimethylhydrazinium iodide in the presence of tBuOK in THF at 0,5° or in the presence of KOH in DMSO at 60,70° according to a nucleophilic substitution of an H-atom, thus affording porphyrins 2a,g and 3f,g with amino-functionalized meso -positioned aryl substituents in yields up to 73% (Scheme,1 and Table). The products obtained are attractive intermediates for further derivatization of porphyrins and may be of potential use as sensitizers in photodynamic cancer therapy. [source] One-pot PTC synthesis of polyfused pyrazolesHETEROATOM CHEMISTRY, Issue 3 2003Gamal A. El-Saraf Thienopyrazole 2, 3, 5, or 6 and thienopyrazolothiazepine 7, 9, and 11 derivatives were prepared via the reaction of the 3-aminopyrazoline-5-one 1 with CS2 and different molar ratio of a variety of halo compounds having an active methylene under PTC conditions. Also, treatment of 1 with CS2 and alcoholic KOH in 2:1:1 molar ratio afforded dipyrazolopyridine derivatives 12 and 14. On other hand, the pyrazolothiadiazineone derivative 13 was obtained by treating compound 1 with CS2 and alcoholic KOH in 1:2:2 molar ratio. Under PTC conditions, compound 1, CS2, and ethyl cyanoacetate or malononitrile to gave the pyrazolopyridine derivatives 16 and 17. Coupling of compound 1 with diazonium acetates afforded the hydrazone derivatives 18a,b, which were oxidized with bromine to give pyrazolotriazoles 19a,b or cyclized with aldehydes to give pyrazolotriazine derivatives 20a,e. Bromination of compound 1 afforded monobromopyrazole derivative 21, which could be condensed to a dipyrazolopyrazindione 23. Finally, the dibromopyrazole derivative 22 was cyclized with 2-mercaptoethanol or o-phenylenediamine to give the spiropyrazoles 24a,b. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:211,217, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10129 [source] The Origin of the Magnetism of Etched SiliconADVANCED MATERIALS, Issue 1 2009Patrick J. Grace A recent report of ferromagnetism appearing in silicon after etching in hot KOH (Kopnov et al., Adv. Mater.2007, 19, 925) is shown to be due to iron from the pyrex glassware, which precipitates on the silicon surface in the form of well-separated ferromagnetic nanoparticles. The reaction is explained in terms of the Pourbaix diagram. [source] Kinetics of the simultaneous oxidation of nickel(II) and sulfur(IV) by oxygen in alkaline medium in Ni(II),sulfur(IV),O2 systemINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 8 2010Anil Kumar Sharma In the Ni(II),S(IV),O2 system in the region of pH > 8.4, both Ni(II) and S(IV) are simultaneously autoxidized, and when sulfur is consumed fully NiOOH precipitates. At pH > 8.4, ethanol has no effect on the rate, whereas ammonia strongly inhibits the reaction when pH > 7.0. The kinetics of the reaction, in both the presence and the absence of ethanol, is defined by the rate law where k is the rate constant, KO is the equilibrium constant for the adsorption of O2 on Ni(OH)2 particle surface. In ammonia buffer, the factor F is defined by where K, KOH, K1, K2, K3, and K4 are the stability constants of NiSO3, NiOH+, Ni(NH3)2+, Ni(NH3), Ni(NH3), and Ni(NH3), respectively. In unbuffered medium, the factor F reduces to The values of k and Ksp were found to be (1.3 ± 0.08) × 10,1 s,1 and (4.2 ± 3.5) × 10,16, respectively, at 30°C. A nonradical mechanism that assumes the adsorption of both SO32, and O2 on the Ni(OH)2 particle surface has been proposed. At pH , 8.2, Ni(II) displays no catalytic activity for sulfur(IV)-autoxidation and it is also not oxidized to NiOOH. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 464,478, 2010 [source] Kerion and dermatophytic granuloma.INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 3 2006Mycological, histopathological findings in 19 children with inflammatory tinea capitis of the scalp Background, Inflammatory tinea capitis or kerion is the result of a hypersensitivity reaction to a dermatophytic infection. Majocchi's granuloma, in contrast, usually begins as a suppurative folliculitis and culminates in a granulomatous reaction. Objectives, To present clinical, mycological and histopathological findings for 19 cases of kerion of the scalp in children. Methods, Nineteen children were investigated (14 boys and five girls) with a mean age of 6.5 years. A potassium hydroxide (KOH) exam and culture in Sabouraud dextrose agar were performed, followed by a biopsy with hematoxylin and eosin, periodic acid-schiff (PAS) and Gomori-Grocott stains. The same investigations were carried out in four control cases of noninflammatory tinea capitis. Results, Clinical history varied from 2 to 16 weeks (mean 6.6 weeks). Diagnosis was confirmed by a positive KOH exam: all cases except one had a positive culture. The following dermatophytes were isolated: Microsporum canis (32%), Trichophyton mentagrophytes (27%), Trichophyton tonsurans (21%), Trichophyton rubrum (10%) and Microsporum gypseum (5%). The histopathological findings were: suppurative folliculitis (SF) 11%, SF plus suppurative dermatitis 37%, suppurative and granulomatous dermatitis (SGD) 26% and SGD plus fibrosing dermatitis 26%. Fungi were observed in 63% of the histopathological sections. Perifollicular infiltrates (PF) around the parasitized hair follicles were identified in the four noninflammatory control cases due to M. canis. Conclusions, Kerion Celsi is an inflammatory or suppurative type of tinea capitis caused by zoophylic dermatophytes (M. canis and T. mentagrophytes), but also by antrophophylic (T. tonsurans and T. rubrum) and geophylic (M. gypseum) dermatophytes. Histopathological findings showed a spectrum from mild suppurative folliculitis to dense granulomatous infiltrates without a clear relationship with the clinical features. [source] Evolution of histoid leprosy (de novo) in lepromatous (multibacillary) leprosyINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 7 2005Virendra N. Sehgal MD A 26-year-old man presented with persistent redness of the face over the past 2 years and thickening of the ears for a year. The current state was preceded by three to four episodes of epistaxis, 2,3 months previously. The patient had not received any treatment. Cutaneous examination revealed indurated (infiltrated) plaques on the face and ears over an apparently normal-looking skin, and numerous, small, ill-defined, slightly hypopigmented, shiny macules all over the body. They were bilateral and symmetric (Fig. 1a,b). There was no variation in the cutaneous sensations of temperature, touch, and pain. The patient showed loss of the lateral eyebrows and conjunctival congestion. Examination of the nerves revealed enlargement of the ulnar, radial, posterior tibial, and right common peroneal nerves; however, there was no tenderness of the nerves. Systemic examination was within normal limits. Examination of a slit-skin smear (under oil immersion), prepared from a representative lesion (plaque), demonstrated an abundance of solid and uniform-staining acid-fast bacilli, occurring either singly or in parallel clumps/globii, in an average field (6+). Furthermore, a scraping mount (10% KOH) prepared from the lesion on the back was negative. Figure 1. (a, b) Histoid leprosy Hematoxylin and eosin-stained sections prepared from a biopsy taken from a plaque revealed a conspicuous granuloma composed of peculiar spindle-shaped histiocytes. Several of the granulomas were present in the mid and lower dermis. They were characterized by whorled, criss-cross, or parallel patterns. Solid and uniform-staining, slender, rod-like (length three times that of the breadth) acid-fast bacilli were found scattered throughout the section. A few histiocytes closely packed with acid-fast bacilli, together with lymphocytic infiltrates, were also seen. There was a prominent eosinophilic stained clear zone just below the epidermis. It was free from acid-fast bacilli as well as the inflammatory infiltrate (Fig. 2a,b). A definitive diagnosis of untreated lepromatous leprosy (LL) changing to histoid leprosy (de novo) was made. Figure 2. (a, b) Histoid leprosy depicting granuloma formed by histiocytes displaying whorl-wind, criss-cross or interlacing pattern, and a clear zone beneath the epidermis (H&E ×40) Solid and uniform staining acid fast bacilli, , slender, rod-like, length 3 times that of breadth found scattered throughout the granuloma (H&E ×100) [source] Enlarging pigmented patches on the handINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 10 2003Matthew Muellenhoff DO This case illustrates the clinical and pathological features of Tinea mgra. Awareness of the characteristic features of this cutaneous infection, especially in areas where the organism is endemic, can ultimately lead clinicians to the appropriate diagnosis. If Tinea nigra should be considered in the differential diagnosis of palmoplantar pigmentation, potassium hydroxide (KOH) preparation may facilitate the diagnosis. [source] Nargile (Hubble-Bubble) smoking-induced hand eczemaINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 11 2002Meltem Onder MD A 65-year-old retired man with hand eczema presented to the Dermatology clinic in October of 2001. He complained of scaly, fissured plaque-type lesions over the radial margin of his right index finger and thumb (Fig. 1). He first noticed these changes 2 years ago. There was no history of irritation from his occupation. None of the other family members were affected. There was no history of atopy or psoriasis. Figure 1. Hyperkeratotic scaly plaques along the outer margin of the right index finger and thumb related with habit of nargile smoking The physical examination was remarkable for scaly, fissured, hyperkeratotic patches on the palms and palmar surfaces of the finger tips of the right hand. No nail changes were noted. The other fingers were free from lesions. There were no changes on the feet or soles. A diagnosis of eczema was suspected. Hobbies and repeated trauma to the hands were investigated. He had a habit of "nargile" smoking,starting at 35 years of age and he was using this apparatus more than 2 h a day. We performed patch tests with European standart test serial and they were negative. Yeast examination using KOH was negative. The diagnosis of Nargile (Hubble-bubble) eczema was made. It was advised that he stop smoking. Mild topical corticosteroids and emollient with urea were started. Clinical evaluation demonstrated resolution of the lesions after 2 weeks of therapy. [source] Hard palate perforation: an unusual finding in paracoccidioidomycosisINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 4 2001Luiz G. M. Castro MD A 36-year-old black man presented to his dermatologist in May 1996 complaining of mucosal lesions in the mouth, as well as perforation of the hard palate. The lesions had started approximately 7 months before and had worsened gradually. Other complaints included odynophagia, dysphagia, mild dyspnea, and dry cough. The patient was in good general health, but reported a 3 kg weight loss over the previous semester. The hard and soft palate presented erythematous ulcers with a finely granulated base and irregular, but clearly defined margins. A perforation (diameter, 0.5 cm) of the hard palate was seen in the center of the ulcerated region (Fig. 1). Direct examination of 10% KOH cleared specimens showed typical double-walled, multiple budding yeast structures. Paracoccidioidomycosis (PCM) serologic reactions tested positive for double immunodiffusion (DI), complement fixation (CF) 1 : 256 and counterimmunoelectrophoresis (CIE) 1 : 128. Hematoxylin and eosin-stained sections of oral lesions showed an ulcer covered by a fibrous leukocytic crust, with a lymphoplasmacytic infiltrate, as well as multinuclear giant cells containing round bodies with a double membrane. Gomori,Grocott staining showed budding and blastoconidia suggestive of PCM. Lung computed tomography (CT) exhibited findings consistent with pulmonary PCM. Diagnosis of the chronic multifocal form of PCM with oral and pulmonary manifestations was established. Drug therapy was initiated with ketoconazole (KCZ) 200 mg twice daily, which led to clinical cure in approximately 2 months. Serum antibody values rose 30 days after institution of therapy (CIE 1 : 256; CF 1 : 512), peaking at day 60 (CIE 1 : 1024; CF 1 : 1024). Three months later the daily dose was reduced to 200 mg and titers declined slowly. The diameter of the perforation remained unchanged (Fig. 2). The hard palate perforation was corrected with a palatoplasty 27 months after initiation of drug therapy (Fig. 3). KCZ was discontinued when serologic cure was achieved after 34 months of treatment (DI weakly positive; CIE 1 : 8; CF not measurable). The patient was discharged 46 months after the first visit. Figure 1. Ulcers with a finely granulated base on the hard palate with irregular but clearly defined margins. A perforation (diameter, 0.5 cm) of the hard palate is seen in the center of the ulcerated region Figure 2. Clinical aspect after 2 months of oral ketoconazole 200 mg twice daily. Resolution of ulceration was evident, but the diameter of the perforation remained unchanged Figure 3. Final result of palatoplasty to cover hard palate perforation [source] Effect of particle size and drying temperature on drying rate and oil extracted yields of Buccholzia coriacea (MVAN) and Butyrospermum parkii ENGLINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2007César Kapseu Summary The effect of particle size and drying temperature on drying rate and oil extracted yields of Buccholzia coriacea (MVAN) and Butyrospermum parkii (ENGL) was investigated. Air drying studies carried out on B. coriacea and B. parkii, tropical food sources subject to high post-harvest losses, have resulted in the establishment of a significant difference between oil yields extracted from samples of various particle size pretreatments (paste, 4 mm, 8 mm and whole kernels) dried at 45 and 60 °C with the highest oil yield given by the 4 mm thick slices dried at 45 °C. The influence of temperature and particle thickness on the drying rate has been evaluated. The drying constants were found to depend on both temperature and particle thickness. Analysis of the oil extracted from the 4 mm thick slices dried at 45 °C showed that apart from the acid value (52.4%), the saponification (181.2 mg g,1 KOH), peroxide (8.6 meq kg,1) and the unsaponifiable (7.43%) matter values of the extracted shea butter remain within the limits cited in the literature while a close analysis of the cake suggests that it could be a good mineral source. [source] Small-scale production and storage quality of dry-milled degermed maize products for tropical countriesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2003Christian Mestres Summary A small-scale, single operation, dry degerminator, originating from Brazil was tested on six maize samples (from France and Mali) at two moisture contents (10 and 15% wb). The yield of brewery maize grits (<1% lipids) was higher for extensively dry (10% mc) and hard grains. It ranged from 50 to 70% for four cultivars, which was equivalent or higher than for industrial plants. The rancidity of the products was controlled by the fat acidity level, which was 40,60 mg KOH 100 g,1db, after 4 months storage of degermed flour. This indicates that degermed products can be stored at 35 °C for up to 6 months without developing significant rancid off-flavour. Thus the Brazilian dry degerminator appears suitable for the treatment of maize in the tropical zone of Africa. [source] Sulfonated N -Heterocyclic Carbenes for Pd-Catalyzed Sonogashira and Suzuki,Miyaura Coupling in Aqueous SolventsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010Sutapa Roy Abstract The reactions of the N,N, -diarylimidazolium and N,N, -diarylimidazolinium salts with chlorosulfonic acid result in the formation of the respective disulfonated N -heterocyclic carbene (NHC) precursors in reasonable yields (46,77%). Water-soluble palladium catalyst complexes, in situ obtained from the respective sulfonated imidazolinium salt, sodium tetrachloropalladate (Na2PdCl4) and potassium hydroxide (KOH) in water, were successfully applied in the copper-free Sonogashira coupling reaction in isopropyl alcohol/water mixtures using 0.2,mol% catalyst loading. The preformed (disulfonatedNHC)PdCl(cinnamyl) complex was used in aqueous Suzuki,Miyaura reactions at 0.1,mol% catalyst loading. The coupling protocol reported here is very useful for Sonogashira reactions of N - and S -heterocyclic aryl bromides and chlorides with aryl- and alkylacetylenes. [source] Poly(ethylene terephthalate) recycling and recovery of pure terephthalic acid by alkaline hydrolysisADVANCES IN POLYMER TECHNOLOGY, Issue 4 2002G. P. Karayannidis Abstract Poly(ethylene terephthalate) (PET) taken from postconsumer soft-drink bottles was subjected to alkaline hydrolysis after cutting it into small pieces (flakes). The reaction took place in an autoclave at 120,200°C with aqueous NaOH solutions and at 110,120°C with a nonaqueous solution of KOH in methyl Cellosolve. The disodium or dipotassium terephthalate received was treated with sulfuric acid and terephthalic acid (TPA) of high purity was separated. The 1H NMR spectrum of the TPA revealed an about 2% admixture of isophthalic acid together with the pure 98% TPA. The purity of the TPA obtained was tested by determining its acidity and by polymerizing it with ethylene glycol by using tetrabutyl titanate as catalyst. A simple theoretical model was developed to describe the hydrolysis rate. The activation energy calculated was 99 kJ/mol. This method is very useful in recycling of PET bottles and other containers because nowadays TPA is replacing dimethyl terephthalate (the traditional monomer) as the main monomer in the industrial production of PET. © 2002 Wiley Periodicals, Inc. Adv Polym Techn 21: 250,259, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.10029 [source] Novel gel-entrapped base catalysts for the Claisen,Schmidt reactionJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 7 2004Sachin S Chaphekar Abstract Novel gel-entrapped base catalysts (GEBCs) were prepared by entrapping aqueous solutions of bases in a gel matrix of agar agar. The bases used were NaOH, KOH, morpholine and piperidine. Ternary phase diagrams were constructed for the water,base,agar agar system to identify the various phases and especially the solid phase, useful as a solid base catalyst. The 10% NaOH solid gel was used to effect the Claisen,Schmidt reaction between benzaldehydes and acetophenones in ethanol under heterogeneous conditions to obtain 70,100% yield of the products. The solid GEBCs obtained using other bases were also used for the same reaction; however, the yields were lower. The catalyst needed no activation prior to use and could be recycled. Copyright © 2004 Society of Chemical Industry [source] POTASSIUM HYDROXIDE REPLACEMENT FOR LYE (SODIUM HYDROXIDE) IN TOMATO PEELINGJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2006D.J. DAS ABSTRACT Lye (sodium hydroxide [NaOH]) peeling is the most common method for peeling tomatoes in the Midwest U.S. With the rise in the cost of NaOH and the associated disposal problems, alternative methods for peeling need to be examined. Solutions of NaOH, potassium hydoxide (KOH) and calcium hydroxide (Ca[OH]2) at different concentrations were compared to determine their efficacy as peeling agents. Ca(OH)2 was ineffective as a peeling agent because of its low solubility. KOH produced peeling equivalent to NaOH, but at half the normality. A lower normality is needed because of the increased reactivity of KOH compared to NaOH. This is further demonstrated by the addition of salts to the solution. The use of KOH instead of NaOH may result in cost savings and decreased waste disposal problems. [source] Reduction of Limonene Chlorohydrins in Commercial Citrus OilsJOURNAL OF FOOD SCIENCE, Issue 1 2005Robert J. Braddock ABSTRACT: Commercial cold-pressed citrus oils containing terpene chlorohydrins may have quality and safety implications for end-users of these oils. Concentrations of (1S, 2S, 4R)-2-chloro-8- p -menthen-1-ol (1), (1R, 2R, 4R)-2-chloro-8- p -menthen-1-ol (2), and (1R, 2R, 4R)-2,9-dichloro-8- p -menthen-1-ol (3) in some citrus essential oils ranged from less than 1 ppm to 30 ppm measured by gas chromatography with a halogen detector. Reduction reactions of these compounds were accomplished by continuous mixing (reaction) of the oil with dilute solutions of KOH. Greater than 95% reduction of 1 and 3 were accomplished after reaction for 15 h with 0.5 N KOH or after 24 h with 0.25 N KOH in oils with either 25 or 30 ppm (1). Similar treatment of an oil containing 5 ppm (1) resulted in reduction to below the threshold limit of quantification (0.4 ppm). Sensory analyses of tasting solutions did not detect any flavor difference between untreated or KOH-treated oils. [source] Microwave-assisted synthesis of quinolone derivatives and related compoundsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010Suhas Pednekar The Gould-Jacob type of reaction for the synthesis of ethyl 5-ethyl-8-oxo-5,8-dihydro-[1,3]-dioxolo[4,5-g]quinoline-7-carboxylate 4 has been carried out conventionally by the condensation between N -ethyl-3,4-methylenedioxyaniline 1 and diethyl ethoxymethylenemalonate 2 gave the unsaturated ester 3 and thermal cyclization in refluxing diphenyl oxide gave quinolone ethyl ester 4 and the results obtained were compared with single step microwave irradiation under solvent free conditions for the synthesis of 4. The esters on basic hydrolysis formed free acid 5, which, upon treatment with thionyl chloride gave the acid chloride 6. Treatment of acid chloride with o -phenylenediamine, hydrazine hydrate, ammonia, urea, and thiourea gave the amides (7,11). CS2 treatment in presence of KOH on 8 gave 12. We prepared 7,12 derivatives by conventional as well as microwave irradiation. These compounds have been characterized on the basis of IR, 1H NMR, MS, and elemental analysis. All the compounds prepared herein were screened for their antibacterial activity. Compounds 4, 5 possess promising antibacterial activity and compound 8 showed significant antibacterial activity. J. Heterocyclic Chem., (2010). [source] Synthesis of some novel methylene-bis-pyrimidinyl-spiro-4-thiazolidinones as biologically potent agentsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2008A. Srinivas A series of novel methylene-bis-pyrimidinyl-spiro-4-thiazolidinones 6a-h have been synthesized by cyclocondensation of thioglycolic acid with methylene-bis-(N -cyclohexylidene- N -pyrimidine) 5a-h, which in turn have been prepared by the reaction of cyclohexanone with methylene-bis-2-aminopyrimidines 4a-h, which are prepared by the reaction of guanidine hydrochloride with methylene-bis-chalcones 3a-h. The compounds 3a-h have been synthesized by the reaction of 5-(3-formyl-4-hydroxybenzyl)-2-hydroxybenzaldehyde 2 with various acetophenones in presence of KOH. The compound 2 is prepared by the reported method. The structures of the compounds synthesized have been confirmed by their elemental analysis and spectral data. Their antibacterial and antifungal activities have also been evaluated. [source] | |||||||||||||||||||||||||||||||||||||||||||