In this article, we describe a chronic case of rhinofacial mucormycosis caused by Mucor irregularis, formerly known as Rhizomucor variabilis var. variabilis, a rare mycotic agent in humans. The infection caused progressive destruction of the nasal septum and soft and hard palate, leading to collapse of the nose bridge and an ulcerative gaping hole. The mucoralean mold cultured from a nasal biopsy specimen was determined by multilocus DNA sequence data to be conspecific with M. irregularis. CASE REPORTAn 18-year-old male patient from south India presented to
The prevalence of fungal infections in newborns and small infants is on the rise consequent to the improved care and survival of preterm babies. Most of these premature infants are immunocompromised and subjected to invasive monitoring and therapy in neonatal intensive care units making them susceptible to nosocomial infections. We report a rare case of right ventricular mass secondary to candida krusei infection which was excised surgically. This article reemphasizes the importance of stringent aseptic practices in neonatal intensive care units to prevent nosocomial infections and the early use of echocardiography in neonates presenting with atypical unexplained symptoms to hasten diagnosis and facilitate timely intervention.
This study identified the optimum conditions for cleavage of acetyl groups from wood hemicelluloses for possible conversion to salts of acetate or to acetic acid in kraft pulp mills. Acetyl groups in wood hemicelluloses can be hydrolyzed by either OH- (hydroxide) or H+ (hydronium) ions. Experimental data are presented for the extraction of industrial northeast hardwood chips using alkali streams that are available in the kraft pulp mills: caustic, green liquor, and white liquor. The effects of extraction time, chip soaking temperature, alkali concentration, and extraction temperature on cleavage of acetyl groups were investigated. Soaking at elevated temperature was found to be more effective than no soaking or soaking at room temperature. The rate of cleavage of acetyl groups from wood hemicelluloses was proportional to the initial hydroxide ion concentration in the liquor. Both white liquor and 0.5 N sodium hydroxide had higher rates of hydrolysis of acetyl groups compared to green liquor, which contained fewer hydroxide ions. The initial hydroxide ion concentration in the liquor also determined the mechanism by which acetyl groups were hydrolyzed from the hemicellulose backbone. If the extraction liquor contained excess hydroxide ions, then most acetyl groups were directly hydrolyzed from the xylan polymer to form sodium acetate, and the xylan remained in the wood, provided the temperature was low. The extraction temperature had a negligible effect on rate of cleavage of acetyl groups if the liquor contained excess hydroxide ions.
A 57-year-old lady presenting with angina was found to have multiple coronary arterio venous fistulae (CAVF) arising from both left and the right coronary arteries and draining into the pulmonary artery. She underwent successful surgical closure of these CAVF.
Kraft pulping is the predominant technology in the pulp and paper industry for removing lignin from wood carbohydrates to produce paper, board, packaging, tissue, and specialty cellulose. However, the kraft process is energy intensive and expensive, and its yield is limited by the degradation of carbohydrates. Pretreatment can increase carbohydrate yield by limiting degradation via primary peeling of reducing end groups. However, protection of galactoglucomannan (GGM), the primary hemicellulose component of softwood, is minimal when conventional pretreatments are used. Here, we investigated the effectiveness of sodium methyl mercaptide pretreatment on southern pine wood chips under a range of experimental conditions. We found that pretreatment of biomass with 4.38% sodium methyl mercaptide at pH 12 and 105 °C for 60 min provided small but significant increases in xylan and cellulose yields relative to control conditions, but preservation of GGM was minimal. To provide insight into molecular-scale details of primary peeling, pretreatment, and alkaline hydrolysis, we performed classical molecular dynamics (MD) simulations under selected process conditions and quantum mechanical (QM) calculations of selected reactions. MD simulations showed that C1 of the GGM reducing end is more readily accessible by HO– and CH3S– ions than in cellulose. The free energy barrier for peeling calculated with QM is lower for GGM than for cellulose, indicating increased susceptibility to peeling. In addition, we found that GGM may be more susceptible to internal chain cleavage than cellulose. Thus, even though reducing end groups may be protected initially through pretreatment, new unprotected reducing end groups may be generated through alkaline hydrolysis. Taken together, these findings show the promise of methyl mercaptide as a pretreatment technology for cellulose retention and also provide molecular insight for improving its effectiveness toward GGM.
Our objective was to develop a process for recovering acetyl groups from industrial northeast hardwood chips. Extraction experiments showed that the white liquor charge of 6% effective alkali at 50°C and liquor-to-wood ratio of 4:1 leads to the complete extraction of acetyl groups from industrial hardwood chips. Electrodialysis was assessed as a technique for separating and concentrating sodium acetate from synthetic hardwood extract. Preliminary separation experiments using dilute sodium acetate showed that the sodium acetate can be concentrated up to approximately 24% by weight from an initial concentration of about 2% by weight. The effects of current density, feed concentration, electro-osmosis, and osmosis on the separation of sodium acetate were evaluated. Finally, selectivity experiments were performed to study the effect of various components of the white liquor on the separation of sodium acetate. Fully oxidized synthetic white liquor was used in selectivity experiments to avoid deleterious effects of Na2S. Selectivity experiments using synthetic oxidized white liquor showed a significant decrease in the separation efficiency due to the presence of sodium hydroxide, sodium carbonate, and sodium sulfate in the synthetic extract.
The objective of this work was to determine the process conditions for converting sodium acetate, the major component of alkaline hardwood extract, into acetic acid and sodium hydroxide using bipolar membrane electrodialysis (BPMED). The effects of current density and sodium acetate concentration in the feed-salt solution were evaluated using synthetic sodium acetate solution in a feed and bleed mode. This mode of operation represents semibatch processing and was useful for determining the current efficiencies, energy consumption, and other system parameters for the production of about 160 g/L of acetic acid; maximum achievable concentration of acetic acid in electrodialysis; and 30 g/L of sodium hydroxide, which is the concentration sufficient for the extraction of sodium acetate from hardwood. The feed and bleed mode experiments performed at 60 mA/cm2 using 130 and 85 g/L sodium acetate as feed-salt solutions produced similar results, except for a small change in the amount of water transported into the acid and base compartments. The feed and bleed mode experiment performed at low current density of 40 mA/cm2 using 50 g/L sodium acetate as feed-salt solution produced almost similar quantities of acetic acid and sodium hydroxide as those in the other feed and bleed mode experiments. However, the energy consumption and current efficiencies were lower than those for the experiments performed at the current density of 60 mA/cm2.
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