bluuebunny/crossref_metadata_2025 huggingface dataset:
Addition of ferulic acid, ethyl ferulate, and feruloylated monoacyl‐ and diacylglycerols to salad oils and frying oils
Authors: Warner K. , Laszlo J. A.
Published: November 2006

To determine antioxidative effects of ferulic acid and esterified ferulic acids, these compounds were added to soybean oils (SBO), which were evaluated for oxidative stability and frying stability. Additives included feruloylated MAG and DAG (FMG/FDG), ferulic acid, ethyl ferulate, and TBHQ. After frying tests with potato chips, oils were analyzed for retention of additives and polar compounds. Chips were evaluated for hexanal and rancid odor. After 15 h frying, 71% of FMG/FDG was retained, whereas 55% of ethyl ferulate was retained. TBHQ and ferulic acid levels were 6% and <1%, respectively. Frying oils with ethyl ferulate or TBHQ produced significantly less polar compounds than SBO with no additives. Chips fried in SBO with TBHQ or ferulic acid had significantly lower amounts of hexanal and significantly less rancid odor after 8 d at 60°C than other samples. Oils were also aged at 60°C, and stability was analyzed by PV, hexanal, and rancid odor. Oils with TBHQ or FMG/FDG had significantly less peroxides and hexanal, and a lower rancid odor intensity than the control. FMG/FDG inhibited deterioration at 60°C, whereas ethyl ferulate inhibited the formation of polar compounds in frying oil. Ferulic acid acted as an antioxidant in aged fried food. TBHQ inhibited oil degradation at both temperatures.
Phospholipases: Occurrence and production in microorganisms, assay for high‐throughput screening, and gene discovery from natural and man‐made diversity
Authors: Song Jae Kwang , Han Jeong Jun , Rhee Joon Shick
Published: November 2006

Various kinds of phospholipids have wide industrial applications such as in food and nutraceuticals, cosmetics, agricultural products, and pharmaceuticals. The demand for reliable biocatalysts for the production of phospholipid products, such as phospholipases A1, A2, C, and D, has steadily increased over the past several decades. A large number of microbial phospholipases have been isolated and characterized, and the increasing availability of these enzymes could eventually lead to the sustained development of phospholipid‐related biotechnology. Although a number of reactions have been performed using phospholipases, a reliable and efficient supply of superior phospholipases in quantity is still a challenge for their practical application. High‐throughput functional assay methods for phospholipases should be devised to develop superior new species from the huge diversity of phospholipases. Recent biotechnological advances in the discovery of new phospholipase genes from natural sources, such as extremophiles of phospholipases by protein engineering, such as directed evolution, can provide valuable means of rapidly developing practical uses of phospholipases for various applications.
Optimization of Brassica carinata oil methanolysis for biodiesel production
Authors: Vicente Gemma , Martínez Mercedes , Aracil José
Published: November 2006

Synthesis of FAME from Brassica carinata oil to produce biodiesel was accomplished using potassium hydroxide as the catalyst. A factorial design of experiments and a central composite design were used. The variables chosen were: type of Brassica carinata oil, initial catalyst concentration, and temperature; and the responses were FAME purity and yield. The type of B. carinata oil included high‐erucic B. carinata (HEBC) and lowerucic B. carinata (LEBC) varieties. The results show that the type of B. carinata oil does not affect the purity and yield of FAME. However, HEBC oil is more suitable for biodiesel production because its iodine value is lower and within the European Union specifications. The initial catalyst concentration is the most important factor, having a positive influence on FAME purity but a negative effect on FAME yield. The temperature has a significant positive effect on FAME purity and a significant negative influence on FAME yield. Second‐order models were obtained to predict FAME purity and yield as a function of catalyst concentration and temperature for HEBC oil methanolysis. The best conditions for this process are 25°C, and 1.2–1.5 wt% for the catalyst concentration.
A differential scanning calorimetry study of the crystallization kinetics of tristearin‐tripalmitin mixtures
Authors: MacNaughtan W. , Farhat I. A. , Himawan C. , Starov V. M. , Stapley A. G. F.
Published: November 2006

A comprehensive study of the isothermal crystallization kinetics of tripalmitin‐tristearin mixtures was carried out using DSC, with data fitted to the Avrami equation. Polymorphs were identified by subsequent melting of samples in the differential scanning calorimeter, with additional confirmatory information obtained from wide‐angle X‐ray diffraction. It was found that α‐, β′‐, and β‐forms require small (<1.0°C), moderate (3.5–8.5°C), and large (9.0–13.0°C) amounts of subcooling below their respective polymorph melting temperatures for nucleation to occur. Concurrent crystallization of β and β′ polymorphs was not observed. The β polymorphs exhibited sharper heat flow exotherms than β′, due to the higher crystallization driving forces experienced. Analysis of apparent induction times shows that the activation free energy of nucleation for the β‐form is significantly higher than for the β′‐form. Samples rich in either species crystallized faster (both shorter apparent induction times and sharper peaks) than samples with equivalent compositions. Driving‐force arguments do not fully explain this behavior, strongly suggesting that mass transfer resistances (greatest for equivalent compositions) have a significant effect on kinetics. Multiple crystallization events were observed for 50–80% tristearin samples between 56 and 60°C and were attributed to a demixing of tripalmitin‐rich and tristearin‐rich β phases, in line with established phase diagrams.
Production of heat‐sensitive monoacylglycerols by enzymatic glycerolysis in tert‐pentanol: Process optimization by response surface methodology
Authors: Damstrup M. L. , Jensen T. , Sparsø F. V. , Kiil S. Z. , Jensen A. D. , Xu X.
Published: November 2006

The aim of this study was to optimize production of MAG by lipase‐catalyzed glycerolysis in a tert‐pentanol system. Twenty‐nine batch reactions consisting of glycerol, sunflower oil, tert‐pentanol, and commercially available lipase (Novozym®435) were carried out, with four process parameters being varied: Enzyme load, reaction time, substrate ratio of glycerol to oil, and solvent amount. Response surface methodology was applied to optimize the reaction system based on the experimental data achieved. MAG, DAG, and TAG contents, measured after a selected reaction time, were used as model responses. Well‐fitting quadratic models were obtained for MAG, DAG, and TAG contents as a function of the process parameters with determination coefficients (R2) of 0.89, 0.88, and 0.92, respectively. Of the main effects examined, only enzyme load and reaction time significantly influenced MAG, DAG, and TAG contents. Both enzyme amount and reaction time showed a surprisingly nonlinear relationship between factors (process parameters) and responses, indicating a local maximum. The substrate ratio of glycerol to oil did not significantly affect the MAG and TAG contents; however, it had a significant influence on DAG content. Contour plots were used to evaluate the optimal conditions for the complex interactions between the reaction parameters and responses. The optimal conditions established for MAG yield were: enzyme load, 18% (w/w of oil); glycerol/oil ratio, 7∶1 (mol/mol); solvent amount, 500% (vol/wt of oil); and reaction time, 115 min. Under these conditions, a MAG content of 76% (w/w of lipid phase) was predicted. Verification experiments under optimized reaction conditions were conducted, and the results agreed well with the range of predictions.
A study of the oxidation and wear properties of vegetable oils: Soybean oil without additives
Authors: Castro Waleska , Perez Joseph M. , Erhan Sevim Z. , Caputo Filomena
Published: November 2006

The use of biodegradable lubricants in diverse applications continues to increase. Vegetable oils (e.g., soybean oil) are the main biodegradable lubricant base stocks used world‐wide. However, there are concerns about their oxidative stability and low‐temperature performance. Improvements in oxidative stability can be made through chemical or genetic modifications. This work compared the effects of oils with different chemical compositions. Soybean oil, high‐oleic soybean oil, and epoxidized soybean oil were compared in laboratory bench tests. The tests conducted include the Penn State sequential four‐ball wear test and the Penn State micro‐oxidation test. Oxidation products from the micro‐oxidation test were analyzed by FTIR and gel permeation chromatography. In this paper, all oils were evaluated neat, without additives.
Retention of isoflavones and saponins during the processing of soy protein isolates
Authors: Lin Jun , Krishnan Padmanaban G. , Wang Chunyang
Published: November 2006

The mass balance of saponins during processing of soy protein isolates (SPI) was established, and the effects of precipitating and washing (P/W) temperatures (0, 10, 25, 40, and 50°C) on the retention of isoflavones and saponins were investigated in this study. About 41% of total saponins in soy flour (SF) were found to remain in SPI during processing, whereas 42% remained unextracted in the solid waste. None was detected in the whey or wash water. The study also revealed that only about 27% of total isoflavones from SF remained in the final SPI when P/W was performed at 50°C. As much as 40% of the total isoflavones could be retained in SPI when P/W was conducted at 25, 10, or 0°C. When the P/W temperature was 50°C, the percentages of total isoflavones lost during extraction, precipitation, and washing were 28, 22, and 6%, respectively. When the temperature was changed to 0°C, the percentages of isoflavones lost during extraction, precipitation, and washing were 28, 11, and 5%, respectively. The P/W temperatures did not affect the distribution of saponins in different streams during the processing of SPI. Lowering the P/W temperature did not significantly lower the protein content in SPI unless the temperature was reduced to 0°C.
Esterification of lauric acid using lipase immobilized in the micropores of a hollow‐fiber membrane
Authors: Goto Muneharu , Kawakita Hidetaka , Uezu Kazuya , Tsuneda Satoshi , Saito Kyoichi , Goto Masahiro , Tamada Masao , Sugo Takanobu
Published: November 2006

A porous anion‐exchange hollow‐fiber membrane was prepared by radiation‐induced graft polymerization and chemical modification to immobilize lipase for enzymatic reaction in an organic solvent. The amount of anion‐exchange group introduced to the porous hollow‐fiber membrane was 2.5 mol/kgfiber. A lipase solution was allowed to permeate through the porous anion‐exchange hollow‐fiber membrane, and lipase molecules that adsorbed onto the grafted polymer brush were cross‐linked with glutaraldehyde. The lipase was immobilized at a density of 0.14 kglipase/kgfiber, which was equivalent to a degree of multilayer binding of 20. Esterification was carried out by passing a solution of lauric acid and benzyl alcohol in anhydrous issoctane through the lipase‐immobilized membrane, and lipase activity was determined. A reaction percentage of 50% was achieved at space velocity 68 h−1. The maximum immobilized lipase and native lipase activities were 8.9 and 0.38 mol/(h·kglipase), respectively. Thus, the activity of the immobilized lipase was 23.4 times higher than that of the native lipase.
A novel method for solvent fractionation of two CLA isomers
Authors: Uehara Hidetaka , Suganuma Tomomi , Negishi Satoshi , Ueno Satoru , Sato Kiotaka
Published: November 2006

Conjugated linoleic acid (CLA) is commercially available as a mixture consisting of almost equal amounts of the cis‐9,trans‐11‐CLA (c9, t11) and trans‐10, cis‐12‐CLA (t10, c12) isomers. Separation of the two isomers is highly significant since each exhibits different biochemical properties. Highly efficient separation could be accomplished by crystallization in acetone (solvent) of the two CLA isomers (solutes) in the presence of medium‐chain fatty‐acid (MCFA) additives. The relative concentration ratios of the two CLA isomers in the solvent‐crystallized materials varied depending on which MCFA were added. Addition of lauric and decanoic acids resulted in the crystals predominantly containing t10,c12, whereas octanoic acid yielded those predominantly containing c9,t11. We have confirmed that onetime solvent crystallization using decanoic acid and octanoic acid additives increased the t10,c12 and c9,t11 concentrations, and that repeated solvent crystallization resulted in the ratio of c9,t11 to t10,c12 of at least 4∶96 or 98∶2.
Carotenoids from red palm methyl esters by nanofiltration
Authors: Darnoko D. , Cheryan Munir
Published: November 2006

Palm oil contains high concentrations of carotenoids and tocopherols that can be recovered by first converting them to methyl esters and then applying membrane technology to separate the carotenoids from the methyl esters. Several solvent‐stable nanofiltration membranes were investigated for this application. Flux with a model red palm methyl ester solution ranged from 0.5 to 10 Lm−2h−1, and rejection of β‐carotene was 60–80% at a transmembrane pressure of 2.76 MPa and 40°C. A multistage membrane process was designed for continuous production of palm carotene concentrate and decolorized methyl esters. With a feed rate of 10 tons per hour of red palm methyl esters containing 0.5 gL−1 β‐carotene, the process could produce 3611 L·h−1 of carotene concentrate containing 1.19 gL−1 carotene and 7500 Lh−1 of decolorized methyl esters containing less than 0.1 gL−1 β‐carotene. The economics of this process is promising.
Approaches to quantification of microstructure for model lipid systems
Authors: Liang Baomin , Sebright Jason L. , Shi Yuping , Hartel Richard W. , Perepezko John H.
Published: November 2006

Semisolid fat samples with different solid fat contents and microstructures were prepared by crystallization of mixtures of model lipid systems containing high‐melting and lowmelting lipids and analyzed for microstructural properties. Microstructure images were acquired by confocal scanning light microscopy and showed fat crystals or fat crystal flocs combined with their surrounding continuous phase to constitute microstructural units and a microstructural network that was formed through their interaction. Fat crystal flocs and their centroids, microstructure units, and their interface boundaries were identified by image analysis. Several methods to quantify microstructure were compared. A new concept was introduced: the microstructure density, defined as the number of microstructural units per unit volume of the system. Also, the Richardson plot and particle counting methods (PCM) were used to find the fractal dimension of the crystal network. The Euler characteristic and nearest neighbor features of the microstructure were obtained as well by use of custom‐developed programs. The different metrics of semisolid lipid microstructure were compared in terms of their physical meaning, means of acquisition, and consistency. The results showed that the quantitative microstructure parameters obtained from different approaches, except the fractal dimesion determined by the PCM, can identify both differences and similarities of microstructural characteristics in the model lipid systems studied in this work.
Determining the acid number of biodiesel
Authors: Mahajan Sonam , Konar Samir K. , Boocock David G. b.
Published: November 2006

Commerical biodiesel is composed of FAME. It may also contain small amounts of FA, which are quantified by an acid number, expressed as milligrams of potassium hydroxide required to neutralize 1 g of sample. In 2006, the ASTM D 6751 biodiesel acid‐number limit was harmonized with the European biodiesel value of 0.50. ASTM D 664 is the standard reference method for measuring the acid number of both ASTM biodiesel and petroleum‐derived diesel. This potentiometric method cites acceptable repeatability and mediocre reproducibility, but no information on accuracy. ASTM D 974 is a non‐aqueous colorimetric titration that uses potassium hydroxide in isopropanol as the titrant and p‐naphtholbenzein as indicator. It was designed for petroleum products and is suitable for colored samples. It has been tested on nine palmitic acid/soybean oil standards in the acid‐number range of 0.198 to 1.17. All accuracies were within 3.3%. The repeatability was approximately 6% at an acid number of 0.5. The reproducibility appears to be only slightly greater than the repeatability at an acid number of 0.5. It is concluded that ASTM D 974 is a good method for evaluating the acid‐number compliance of biodiesel samples.
Determination of solid fat content (SFC) of binary fat blends and use of these data to predict SFC of selected ternary fat blends containing low‐erucic rapeseed oil
Authors: Braipson‐Danthine Sabine , Deroanne Claude
Published: November 2006

Several oils and fats often used for the industrial preparation of European shortenings were blended in binary systems. The equilibrium (after 48 h at 15°C) solid fat contents (SFC; determined by pulsed NMR spectroscopy) were measured and plotted against blend composition. SFC of the blends resulted from the SFC of each fat for the considered temperature as well as the type of interaction existing between those fats (namely, ideal behavior, monotectic interaction, eutectic interaction, and so on). The type of relationship fitted was dependent on the kind of interaction: Linear relationships were found for total compatibility between fats, and polynomial‐type (order 2) relationships were found for fats exhibiting incompatibility. Some corresponding ternary oils and fats blends were also prepared and analyzed. Selected relationships (regression equations of the fitted curves) obtained for binary blends were combined in order to calculate the SFC of the corresponding ternary blends. Experimental values were generally close to predicted ones. The representation of SFC as a function of composition is interesting as it allows one to determine rapidly and easily the type of molecular interaction between two fats and also to determine equations that can be combined to calculate easily the SFC of corresponding ternary blends crystallized in the same way with a good accuracy. The texture (hardness) of several binary and ternary blends was also measured. The combination of the results obtained for SFC with the results obtained for the hardness of binary blends allows the prediction of the hardness of a corresponding ternary blend under the same conditions.
The effect of shear on the crystallization of cocoa butter
Authors: Sonwai S. , Mackley M. R.
Published: November 2006

This paper examines the effect of shear on the crystallization of cocoa butter using a combination of three different experimental techniques and a single crystallization temperature of 20°C. Rheological measurements were carried out to study the effect of a shear step on the crystallization kinetics of the fat. Without a shear step, little rheological change was observed at 20°C; however, with the application of a shear step the onset of significant rheological change occurred and was strongly influenced by the magnitude of the shear step. Detailed crystallographic measurements could be made with in situ X‐ray experiments during flow‐induced crystallization. The imposition of continuous shear changed both crystal polymorphic structure and crystallization kinetics in a systematic way. Finally, optical measurements were used to follow changes in crystal morphology as a consequence of continuous shear. These results revealed the form and kinetics of crystal growth. In general the results complemented each other, and an overall picture of the way shear influenced cocoa butter growth could be formed. The observations could be the basis for a future mathematical model of growth kinetics and provide insight into the way shear influences crystallization kinetics, morphology, and polymorphic structure.
FA composition of the oil extracted from farmed atlantic salmon (Salmo salar L.) viscera
Authors: Sun Ting , Xu Zhimin , Prinyawiwatkul Witoon
Published: November 2006

The FA composition of visceral oil extracted from farmed Atlantic salmon (Salmo salar L.) viscera was studied. Seventeen FA were identified in the extracted visceral oil, and the major FA were 18∶1n9, 16∶0, 16∶1n7, 20∶5n3 (EPA), 14∶0, and 22∶6n3 (DHA). The percentages of saturated, monounsaturated, and polyunsaturated FA in the total FA were 31.7, 36.0, and 32.2%, respectively. Compared with other fish oils, oil from farmed Atlantic salmon had much higher EPA (1.64 g/100 g) and DHA (1.47 g/100 g) contents. The FA profile of the salmon visceral oil was similar to that of the salmon fillet. Thus, the salmon visceral oil could be a replacement for the oil obtained from edible salmon fillet and used in functional foods or feeds requiring a high level of omega‐3 FA. Furthermore, producing visceral oil is also beneficial to salmon fish industry by adding value back to the processing waste.
Standard biodiesel from soybean oil by a single chemical reaction
Authors: Mahajan Sonam , Konar Samir K. , Boocock David G. B.
Published: November 2006

Laboratory methods are described for producing standard biodiesel from low‐acid‐number vegetable oils in single‐step reactions without distillation of the products. Either sodium hydroxide or methoxide is used as the catalyst. Biodiesel fuel is currently made from vegetable oils using basic catalysts. With this methodology, the oils must be reacted two or three times with methanol, in the presence of sodium methoxide, to make a product that meets the standard for the total chemically bound and unbound glycerol content. Previously it was thought that sodium hydroxide could never be used as the catalyst because it forms soap with the ester, which lowers the yield and makes product isolation difficult. Two of the described methods use sodium hydroxide as the catalyst and the other uses sodium methoxide. These methods rely on the use of oxolane as co‐solvent to manipulate phase behavior during the reaction. Reactant molar ratios and base concentrations are also optimized to drive the reactions to the necessary degree of completion.
Optimization of enzymatic degumming process for rapeseed oil
Authors: Yang Bo , Wang Yong‐Hua , Yang Ji‐Guo
Published: November 2006

An enzymatic process optimization and a largescale plant trial for rapeseed oil degumming were carried out by a novel microbial lipase. Response surface methodology was used to obtain the desired data in the process optimization. Enzyme dosage, temperature, and pH were important determining factors affecting oil degumming. The optimal set of variables was an enzyme dosage of 39.6 mg/kg, a temperature of 48.3°C, and a pH of 4.9. The phosphorus content could be reduced to 3.1 mg/kg at the optimal levels of the tested factors. An enzymatic degumming plant trial was performed on a 400 tons/d oil production line. pH was found to play an important role in degumming performance. When the pH was 4.6–5.1, the corresponding phosphorus content of degummed rapeseed oil could be reduced to less than 10 mg/kg, which met the demands of the physical refining process.
Clinical characteristics and pain management among patients with painful peripheral neuropathic disorders in general practice settings
Authors: Gore Mugdha , Dukes Ellen , Rowbotham David J. , Tai Kei‐Sing , Leslie Douglas
Published: November 2006

Alleviating chronic pain is a global healthcare priority. Understanding the medical profile and current treatment patterns in patients with painful neuropathic disorders (PNDs) is crucial to the development of effective pain management strategies. Thus, our objective was to describe the demographic and clinical characteristics of persons with PNDs and their use of pain medications. Using the general practice research database, we categorized PNDs in two ways: Pure PNDs (which include diabetic neuropathy, postherpetic neuralgia, etc.; N = 16,690) and Mixed PNDs (which include back/neck pain with neuropathic involvement; N = 14,309). On average, PND patients were 55 years old (Pure, 55.4 [SD = 16.9] years; Mixed, 54.3 [SD = 16.4] years). Over a third had other chronic pain‐related (Pure, 37.5%; Mixed, 37.1%) and nearly a quarter had non‐pain related (Pure, 28.1%; Mixed, 24.1%) comorbidities. Use of medications with clinically demonstrated efficacy in PNDs was higher among patients with Pure PNDs (tricyclic antidepressants [Pure, 16.6%; Mixed, 10.1%]; 2nd generation antidepressants [Pure, 11.0%; Mixed, 9.7%]; and antiepileptics [Pure, 12.2%; Mixed, 2.6%]), whereas use of NSAIDs (Pure, 43.1%; Mixed, 65.2%) and opioids (Pure, 8.5%; Mixed, 14.3%) was higher among patients with Mixed PNDs. Average daily doses of select neuropathic pain‐related medications among PND patients (Pure and Mixed) were lower than those recommended for neuropathic pain. Among both Pure and Mixed PND patients, use and doses of evidenced‐based neuropathic pain‐related medications was low, and lower than the use of NSAIDs (a medication class with no proven efficacy for PNDs) in each group, suggesting possible sub‐optimal neuropathic pain management among these patients.
New measures of insecticidal efficacy and safety obtained with the 39K promoter of a recombinant baculovirus
Authors: Regev Avital , Rivkin Hadassah , Gurevitz Michael , Chejanovsky Nor
Published: November 2006

Baculoviruses are orally infectious to insects and considered to be natural insecticides. To enhance their speed‐of‐kill these viruses were engineered to express arthropod neurotoxins under the control of various strong promoters. Although this strategy proved to be efficient, it raised recently concerns about safety. We analyzed the speed‐of‐kill and safety of Autographa californica multiple nucleopolyhedrovirus expressing the insecticidal scorpion neurotoxin AaIT and found that the mortality of Helicoverpa armigera larvae was enhanced significantly when the expression was controlled by the baculovirus delayed‐early promoter 39K rather than the very late promoter p10. This improvement was also reflected in better protection of cotton leaves on which these insects were fed. Using lacZ as a sensitive reporter we also found that expression driven by the 39K promoter was detected in insect but not in mammalian cells. These results imply that by selection of an appropriate viral promoter, engineered baculoviruses may comply with the high standard biosafety requirements from a genetically modified organism (GMO). Our results provide further support for the potential use of engineered baculoviruses in insect pest control in a safely manner.
Human PEP‐1‐ribosomal protein S3 protects against UV‐induced skin cell death
Authors: Choi Soo Hyun , Kim So Young , An Jae Jin , Lee Sun Hwa , Kim Dae Won , Ryu Hea Jin , Lee Nam Il , Yeo Seung Il , Jang Sang Ho , Won Moo Ho , Kang Tae-Cheon , Kwon Hyung Joo , Cho Sung-Woo , Kim Joon , Lee Kil Soo , Park Jinseu , Eum Won Sik , Choi Soo Young
Published: November 2006

The consequences of ultraviolet (UV) exposure are implicated in skin aging and cell death. The ribosomal protein S3 (rpS3) is one of the major proteins by which cells counteract the deleterious effects of UV and it plays a role in the repair of damaged DNA. In the present study, we investigated the protective effects of PEP‐1‐rpS3 fusion protein after UV‐induced cell injury. A human rpS3 gene was fused with PEP‐1 peptide in a bacterial expression vector to produce a genetic in‐frame PEP‐1‐rpS3 fusion protein. The expressed and purified fusion proteins were efficiently transduced into skin cells in a time‐ and dose‐dependent manner. Once inside the cells, transduced PEP‐1‐rpS3 fusion protein was stable for 48 h. We showed that transduced PEP‐1‐rpS3 fusion protein increased cell viability and dramatically reduced DNA lesions in the UV exposed skin cells. Immunohistochemical analysis revealed that PEP‐1‐rpS3 fusion protein efficiently penetrated the epidermis as well as the dermis of the subcutaneous layer when sprayed on animal skin. These results suggest that PEP‐1‐rpS3 fusion protein can be used in protein therapy for various disorders related to UV, including skin aging and cancer.
A major role of PKC θ and NFκB in the regulation of hTERT in human T lymphocytes
Authors: Sheng Wei-Yun , Chen Yi-Ru , Wang Tzu-Chien V.
Published: November 2006

Expression of the telomerase catalytic subunit (TERT) is the rate‐limiting determinant of telomerase activity in most human cells. In this work, we examined the participation of protein kinase C (PKC) in the regulation of hTERT expression in human T lymphocytes. Transient expression assays using luciferase reporter plasmids containing hTERT promoter showed that overexpression of PKC θ, but not the other PKC isoforms, could activate the promoter activity of hTERT in resting T lymphocytes. Among the PKC θ‐activated signalings, we presented evidence that the expression of hTERT is mediated through NFκB but not through MEK or c‐Jun N‐terminal kinase pathways. Analysis of the hTERT promoter occupancy in vivo using chromatin immunoprecipitation assays, however, did not detect an increased binding of NFκB to the hTERT promoter in the activated T cells, although an increased binding of cMyc and Sp1 was detected. Together with the observation that inhibition of NFκB eliminated the induction of cMyc in activated T cells, these results suggest that PKC θ‐activated NFκB signaling regulates the expression of hTERT via cMyc in human T lymphocytes.
Prediction of the deleterious nsSNPs in ABCB transporters
Authors: Li Yanhong , Wang Yonghua , Li Yan , Yang Ling
Published: November 2006

The non‐synonymous SNPs (nsSNPs) in coding regions, neutral or deleterious, could lead to the alteration of the function or structure of proteins. We have developed the computational models to analyze the deleterious nsSNPs in the transporters and predict ones in ABCB (ATP‐binding cassette B) transporters of interest. The RPLS (ridge partial least square) and LDA (linear discriminant analysis) methods were applied to the problem, by training on a selection of datasets from a specified source, i.e., human transporters. The best combination of datasets and prediction attributes was ascertained. The prediction accuracy of the theoretical RPLS model for the training and testing sets is 84.8% and 80.4%, respectively (LDA: 84.3% and 80.4%), which indicates the models are reasonable and may be helpful for pharmacogenetics studies.
Daily precipitation‐downscaling techniques in three Chinese regions
Authors: Wetterhall Fredrik , Bárdossy András , Chen Deliang , Halldin Sven , Xu Chong‐Yu
Published: November 2006

Four methods of statistical downscaling of daily precipitation were evaluated on three catchments located in southern, eastern, and central China. The evaluation focused on seasonal variation of statistical properties of precipitation and indices describing the precipitation regime, e.g., maximum length of dry spell and maximum 5‐day precipitation, as well as interannual and intra‐annual variations of precipitation. The predictors used in this study were mean sea level pressure, geopotential heights at 1000, 850, 700, and 500 hPa, and specific humidity as well as horizontal winds at 850, 700, and 500 hPa levels from the NCEP/NCAR reanalysis with 2.5° × 2.5° resolution for 1961–2000. The predictand was daily precipitation from 13 stations. Two analogue methods, one using principal components analysis (PCA) and the other Teweles‐Wobus scores (TWS), a multiregression technique with a weather generator producing precipitation (SDSM) and a fuzzy‐rule‐based weather‐pattern‐classification method (MOFRBC), were used. Temporal and spatial properties of the predictors were carefully evaluated to derive the optimum setting for each method, and MOFRBC and SDSM were implemented in two modes, with and without humidity as predictor. The results showed that (1) precipitation was most successfully downscaled in the southern and eastern catchments located close to the coast, (2) winter properties were generally better downscaled, (3) MOFRBC and SDSM performed overall better than the analogue methods, (4) the modeled interannual variation in precipitation was improved when humidity was added to the predictor set, and (5), the annual precipitation cycle was well captured with all methods.
Hydrothermal exploration of the Fonualei Rift and Spreading Center and the Northeast Lau Spreading Center
Authors: German C. R. , Baker E. T. , Connelly D. P. , Lupton J. E. , Resing J. , Prien R. D. , Walker S. L. , Edmonds H. N. , Langmuir C. H.
Published: November 2006

We report evidence for active hydrothermal venting along two back‐arc spreading centers of the NE Lau Basin: the Fonualei Rift and Spreading Center (FRSC) and the Northeast Lau Spreading Center (NELSC). The ridge segments investigated here are of particular interest as the potential source of a mid‐water hydrothermal plume (1500–2000 m depth) which extends more than 2000 km across the SW Pacific Ocean dispersing away from an apparent origin close to the most northeastern limits of the Lau Basin. Our results indicate the presence of at least four new hydrothermal plume sources, three along the FRSC and one on the NELSC, the latter situated within 150 km of the maximum for the previously identified SW Pacific regional‐scale plume. However, TDFe and TDMn concentrations in the southernmost FRSC plume that we have identified only reach values of 19 and 13 nmol/L and dissolved 3He anomalies in the same plume are also small, both in relation to the SW Pacific plume and to local background, which shows evidence for extensive 3He enrichment throughout the entire Lau Basin water column. Our results reveal no evidence for a single major point hydrothermal source anywhere in the NE Lau Basin. Instead, we conclude that the regional‐scale SW Pacific hydrothermal plume most probably results from the cumulative hydrothermal output of the entire topographically restricted Lau Basin, discharging via its NE‐most corner.
An assessment of satellite surface radiation products for highlands with Tibet instrumental data
Authors: Yang Kun , Koike Toshio , Stackhouse Paul , Mikovitz Colleen , Cox Stephen J.
Published: November 2006

This study presents results of comparisons between instrumental radiation data in Tibet and two satellite products: the Global Energy and Water cycle Experiment ‐ Surface Radiation Budget (GEWEX‐SRB) and International Satellite Cloud Climatology Project ‐ Flux Data (ISCCP‐FD). Severe and systematic errors were found in monthly‐mean SRB shortwave radiation (SW) and FD longwave radiation (LW). Errors in diurnal variations are even larger than the monthly mean errors. Though the LW errors can be reduced nearly 10 W m−2 after an altitudinal correction, the remaining errors are still higher than that for other regions. The large errors in SRB SW were caused by neglecting elevation effects, but the errors in FD LW were mainly due to significant errors in input data. We suggest reanalyzing all ancillary data and reprocessing these satellite surface radiation data, at least for highland areas like Tibet.
Satellite‐observed U.S. power plant NOx emission reductions and their impact on air quality
Authors: Kim S.‐W. , Heckel A. , McKeen S. A. , Frost G. J. , Hsie E.‐Y. , Trainer M. K. , Richter A. , Burrows J. P. , Peckham S. E. , Grell G. A.
Published: November 2006

Nitrogen oxide (NOx) emissions resulting from fossil fuel combustion lead to unhealthy levels of near‐surface ozone (O3). One of the largest U.S. sources, electric power generation, represented about 25% of the U.S. anthropogenic NOx emissions in 1999. Here we show that space‐based instruments observed declining regional NOx levels between 1999 and 2005 in response to the recent implementation of pollution controls by utility companies in the eastern U.S. Satellite‐retrieved summertime nitrogen dioxide (NO2) columns and bottom‐up emission estimates show larger decreases in the Ohio River Valley, where power plants dominate NOx emissions, than in the northeast U.S. urban corridor. Model simulations predict lower O3 across much of the eastern U.S. in response to these emission reductions.
Cluster PEACE observations of electron pressure tensor divergence in the magnetotail
Authors: Henderson P. D. , Owen C. J. , Lahiff A. D. , Alexeev I. V. , Fazakerley A. N. , Lucek E. , Rème H.
Published: November 2006

Cluster crossed the magnetotail neutral sheet on four occasions between 16:38 and 16:43 UT on 08/17/2003. The four‐spacecraft capabilities of Cluster are used to determine spatial gradients from the magnetic field vectors and, for the first time, full electron pressure tensors. We find that the contribution to the electric field from the Hall term (max of ∼6 mV/m) pointed towards the neutral sheet, whereas that from the electron pressure divergence (max of ∼1 mV/m) pointed away from the neutral sheet. The electric field contributions in this direction were closely anti‐correlated. During this period Clusters 1 and 4 were sometimes above and below the neutral sheet respectively. This allowed the simultaneous observation of magnetic fields that are interpreted as two quadrants of the Hall magnetic field system. An associated field‐aligned current system was detected using the curlometer and moments of the particle distributions.
Evaluation of the potential of NASA multi‐satellite precipitation analysis in global landslide hazard assessment
Authors: Hong Yang , Adler Robert , Huffman George
Published: November 2006

Intense storms with high‐intensity, long‐duration rainfall have great potential to trigger rapidly moving landslides, resulting in casualties and property damage across the world. In recent years, through the availability of remotely sensed datasets, it has become possible to conduct global‐scale landslide hazard assessment. This paper evaluates the potential of the real‐time NASA TRMM‐based Multi‐satellite Precipitation Analysis (TMPA) system to advance our understanding of, and predictive ability for, rainfall‐triggered landslides. Early results show that the landslide occurrences are closely associated with the spatial patterns and temporal distribution of rainfall characteristics. Particularly, the number of landslide occurrences and the relative importance of rainfall in triggering landslides rely on the influence of rainfall attributes (e.g. rainfall climatology, antecedent rainfall accumulation, and intensity‐duration of rainstorms). TMPA precipitation data are available in both real‐time and post‐real‐time versions, which are useful to assess the location and timing of rainfall‐triggered landslide hazards by monitoring landslide‐prone areas while receiving heavy rainfall. For the purpose of identifying rainfall‐triggered landslides, an empirical global rainfall intensity‐duration threshold is developed by examining a number of landslide occurrences and their corresponding TMPA precipitation characteristics across the world. These early results, in combination with TRMM real‐time precipitation estimation system, may form a starting point for developing an operational early warning system for rainfall‐triggered landslides around the globe.
Characterizing the superparamagnetic grain distribution f(V, Hk) by thermal fluctuation tomography
Authors: Jackson Mike , Carter‐Stiglitz Brian , Egli Ramon , Solheid Peter
Published: November 2006

In 1965, D. J. Dunlop showed that the joint distribution of particle volumes and microcoercivities f(V, Hk0) can be determined for magnetically monomineralic, thermally stable single‐domain (SSD) ensembles by taking advantage of the joint temperature and field dependence of relaxation time. We have developed a procedure that follows Dunlop's strategy to obtain f(V, Hk0) for ensembles containing both superparamagnetic and SSD grains, based on backfield remanence curves measured over a range of temperatures. Each point on the derivative curves represents the integrated contribution from grains that lie along a corresponding blocking contour on the Néel plot. A suitable set of such line integral samples can be used to reconstruct the f(V, Hk0) distribution using the methods of tomographic imaging. Samples of the basal Tiva Canyon Tuff have narrow size distributions of elongate Ti‐poor titanomagnetite. Tomographic inversion of the low‐temperature backfield spectra yield sharply peaked f(V, Hk0) distributions, from which we calculate modal grain dimensions in good agreement with those observed by transmission electron microscopy. Analysis of synthetic samples containing bimodal populations clearly distinguishes the two modes. Because our simplified forward calculations incompletely account for the effects of orientation distribution, the width of the coercivity distribution at each temperature is underestimated, and consequently, the inverse calculations yield grain distributions that are overly broad. Frequency‐ and temperature‐dependent susceptibilities calculated for the inverted f(V, Hk0) distributions accord fairly well with measured susceptibilities for the weakly interacting Tiva Canyon samples, less well for a moderately interacting paleosol specimen, and poorly for a strongly interacting ferrofluid.
Rottlerin inhibits P2X7 receptor‐stimulated phospholipase D activity in chronic lymphocytic leukaemia B‐lymphocytes
Authors: Shemon Anne N , Sluyter Ronald , Wiley James S
Published: November 2006

Phospholipase D (PLD) is a ubiquitous enzyme that can be activated by extracellular adenosine 5′‐triphosphate (ATP) or phorbol 12‐myristate 13‐acetate (PMA) in B‐lymphocytes from subjects with chronic lymphocytic leukaemia (CLL). In this study, ATP‐ but not PMA‐induced PLD stimulation in CLL B‐lymphocytes was abolished in the presence of an anti‐P2X7 receptor monoclonal antibody, as well as in B‐lymphocytes from CLL subjects homozygous for the Glu496 to Ala loss‐of‐function P2X7 polymorphism. Rottlerin, an inhibitor of novel protein kinase C (PKC) isoforms, but not GF 109203X, an inhibitor of conventional PKC isoforms, impaired the ATP‐stimulated PLD activity in CLL B‐lymphocytes. In contrast, both inhibitors impaired PLD activity stimulated by PMA, a known mediator of PKC activation. The inhibition of P2X7‐stimulated PLD activity by rottlerin was attributed to a target downstream of P2X7 activation, as the ATP‐mediated 86Rb+ efflux from CLL B‐lymphocytes was not altered in the presence of rottlerin. Our results indicate a possible role for novel PKC isoforms in the regulation of P2X7‐mediated PLD activity.
Of cascades and perfect storms: the immunopathogenesis of dengue haemorrhagic fever‐dengue shock syndrome (DHF/DSS)
Authors: Pang Tikki , Cardosa Mary Jane , Guzman Maria G
Published: November 2006

The past four decades has witnessed a consolidation of the original observations made in the 1970s that dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) have an immunological basis. Following reinfection with a dengue virus of different serotype, severe disease is linked to high levels of antibody‐enhanced viral replication early in illness which is followed by a cascade of memory T‐cell activation and a ‘storm’ of inflammatory cytokines and other chemical mediators. These compounds are released mainly from T cells, monocytes/macrophages and endothelial cells, and ultimately cause an increase in vascular permeability. The consolidation of the evidence has been largely due to several important prospective sero‐epidemiological studies in areas endemic for DHF/DSS, which have shown that risk of severe disease is significantly higher in secondary dengue infections. These advances have underscored the fact that DHF/DSS pathogenesis is a complex, multifactorial process involving cocirculation of various dengue virus serotypes and the interplay of host and viral factors that influence disease severity. The continued search to define risk factors in susceptible populations must be combined with the new techniques of molecular virology and innovative approaches in vaccine design to achieve the ultimate objective of developing a safe and effective vaccine.
Invariant Thr244 is essential for the efficient acylation step of the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase from Streptococcus mutans
Authors: Pailot Arnaud , D'Ambrosio Katia , Corbier Catherine , Talfournier François , Branlant Guy
Published: November 2006

One of the most striking features of several X-ray structures of CoA-independent ALDHs (aldehyde dehydrogenases) in complex with NAD(P) is the conformational flexibility of the NMN moiety. However, the fact that the rate of the acylation step is high in GAPN (non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase) from Streptococcus mutans implies an optimal positioning of the nicotinamide ring relative to the hemithioacetal intermediate within the ternary GAPN complex to allow an efficient and stereospecific hydride transfer. Substitutions of serine for invariant Thr244 and alanine for Lys178 result in a drastic decrease of the efficiency of hydride transfer which becomes rate-limiting. The crystal structure of the binary complex T244S GAPN–NADP shows that the absence of the β-methyl group leads to a well-defined conformation of the NMN part, including the nicotinamide ring, clearly different from that depicted to be suitable for an efficient hydride transfer in the wild-type. The ∼0.6-unit increase in pKapp of the catalytic Cys302 observed in the ternary complex for both mutated GAPNs is likely to be due to a slight difference in positioning of the nicotinamide ring relative to Cys302 with respect to the wild-type ternary complex. Taken together, the data support a critical role of the Thr244 β-methyl group, held in position through a hydrogen-bond interaction between the Thr244 β-hydroxy group and the ϵ-amino group of Lys178, in permitting the nicotinamide ring to adopt a conformation suitable for an efficient hydride transfer during the acylation step for all the members of the CoA-independent ALDH family.
Functional characterization of the dimerization domain of the ferric uptake regulator (Fur) of Pseudomonas aeruginosa
Authors: Bai Erdeni , Rosell Federico I. , Lige Bao , Mauk Marcia R. , Lelj-Garolla Barbara , Moore Geoffrey R. , Mauk A. Grant
Published: November 2006

The functional properties of the recombinant C-terminal dimerization domain of the Pseudomonas aeruginosa Fur (ferric uptake regulator) protein expressed in and purified from Escherichia coli have been evaluated. Sedimentation velocity measurements demonstrate that this domain is dimeric, and the UV CD spectrum is consistent with a secondary structure similar to that observed for the corresponding region of the crystallographically characterized wild-type protein. The thermal stability of the domain as determined by CD spectroscopy decreases significantly as pH is increased and increases significantly as metal ions are added. Potentiometric titrations (pH 6.5) establish that the domain possesses a high-affinity and a low-affinity binding site for metal ions. The high-affinity (sensory) binding site demonstrates association constants (KA) of 10(±7)×106, 5.7(±3)×106, 2.0(±2)×106 and 2.0(±3)×104 M−1 for Ni2+, Zn2+, Co2+ and Mn2+ respectively, while the low-affinity (structural) site exhibits association constants of 1.3(±2)×106, 3.2(±2)×104, 1.76(±1)×105 and 1.5(±2)×103 M−1 respectively for the same metal ions (pH 6.5, 300 mM NaCl, 25 °C). The stability of metal ion binding to the sensory site follows the Irving–Williams order, while metal ion binding to the partial sensory site present in the domain does not. Fluorescence experiments indicate that the quenching resulting from binding of Co2+ is reversed by subsequent titration with Zn2+. We conclude that the domain is a reasonable model for many properties of the full-length protein and is amenable to some analyses that the limited solubility of the full-length protein prevents.