bluuebunny/crossref_metadata_2025 huggingface dataset:
What are the cut‐off levels for IL‐6 and CRP in neonatal sepsis?
Authors: Celik İstemi Han , Demirel Fatma Gamze , Uras Nurdan , Oguz Serife Suna , Erdeve Omer , Biyikli Zeynep , Dilmen Ugur
Published: November 2010

Neonatal sepsis, characterized by systemic signs of infection in the first month of life, remains an important clinical syndrome. Despite advances in neonatology, it has high rates of mortality and morbidity. The combine or alone usage of interleukin‐6 (IL‐6) and C‐reactive protein (CRP) has recently been proven to be useful in the early diagnosis of sepsis in newborns. The study included 282 patients; there were 232 in Group I (170 proven and 62 clinical sepsis) and 50 in Group II (control group). The optimum cut‐off value in the diagnosis of neonatal sepsis was found to be 24.65 pg/ml for IL‐6 and 4.82 mg/l for CRP. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of this IL‐6 cut‐off for neonatal sepsis were 72, 84, 95, and 42%, respectively. Sensitivity, specificity, PPV, and NPV of the CRP cut‐off for neonatal sepsis were 67, 97, 99, and 39%, respectively. The combination of IL‐6 (>24.65 pg/ml) and CRP (>4.82 mg/l) in the diagnosis of neonatal sepsis gave sensitivity, specificity, PPV, and NPV of 53, 100, 100, and 33%, respectively. To our knowledge, this is the largest reported study seeking to determine cut‐off levels for IL‐6 and CRP in the diagnosis of neonatal sepsis. In conclusion, we think that it is useful to evaluate IL‐6 and CRP, in combination, for the early diagnosis of neonatal sepsis. J. Clin. Lab. Anal. 24:407–412, 2010. © 2010 Wiley‐Liss, Inc.
Effect of spironolactone, potassium canrenoate, and their common metabolite canrenone on dimension Vista Digoxin Assay
Authors: Dasgupta Amitava , Johnson Myrtle J.
Published: November 2010

Spironolactone, a potassium sparing diuretic metabolized to canrenone, is often used with digoxin to treat various conditions including congestive heart failure. Potassium canrenoate is a similar drug that is also metabolized to canrenone. Due to reported interference of spironolactone, potassium canrenoate, and their common metabolite canrenone with digoxin immunoassays, we investigated potential interference of these compounds with Dimension Vista Digoxin immunoassay using Flex reagent cartridge. Aliquots of a drug‐free serum pool were supplemented with various amounts of spironolactone, potassium canrenoate, or canrenone and apparent digoxin values were measured using Dimension Vista digoxin assay, we observed none‐detected value except when aliquots were supplemented with higher amounts of spironolactone or canrenone. Similarly, when aliquots of a serum digoxin pool (prepared by pooling specimens from patients receiving digoxin) where further supplemented with various amounts of spironolactone, potassium canrenoate, or canrenone, we observed moderately falsely elevated digoxin values only in specimens containing higher amounts of spironolactone or canrenone. We conclude that spironolactone and canrenone but not potassium canrenoate may cause modest interference with Dimension Vista digoxin assay but such interferences may not be clinically significant except with very high amounts of canrenone. J. Clin. Lab. Anal. 24:413–417, 2010. © 2010 Wiley‐Liss, Inc.
Is specific gravity a good estimate of urine osmolality?
Authors: Imran Sethi , Eva Goldwater , Christopher Shutty , Flynn Ethan , Henner David
Published: November 2010

Context: Urine specific gravity (USG) is often used by clinicians to estimate urine osmolality. USG is measured either by refractometry or by reagent strip. Objective: We studied the correlation of USG obtained by either method with a concurrently obtained osmolality. Design: Using our laboratory's records, we retrospectively gathered data on 504 urine specimens on patients on whom a simultaneously drawn USG and an osmolality were available. Out of these, 253 USG's were measured by automated refractometry and 251 USG's were measured by reagent strip. Urinalysis data on these subjects were used to determine the correlation between USG and osmolality, adjusting for other variables that may impact the relationship. The other variables considered were pH, protein, glucose, ketones, nitrates, bilirubin, urobilinogen, hemoglobin, and leukocyte esterase. The relationships were analyzed by linear regression. Results: This study demonstrated that USG obtained by both reagent strip and refractometry had a correlation of approximately 0.75 with urine osmolality. The variables affecting the correlation included pH, ketones, bilirubin, urobilinogen, glucose, and protein for the reagent strip and ketones, bilirubin, and hemoglobin for the refractometry method. At a pH of 7 and with an USG of 1.010 predicted osmolality is approximately 300 mosm/kg/H2O for either method. For an increase in SG of 0.010, predicted osmolality increases by 182 mosm/kg/H2O for the reagent strip and 203 mosm/kg/H2O for refractometry. Pathological urines had significantly poorer correlation between USG and osmolality than “clean” urines. Conclusion: In pathological urines, direct measurement of urine osmolality should be used. J. Clin. Lab. Anal. 24:426–430, 2010. © 2010 Wiley‐Liss, Inc.
Correction for effect of cold storage on immature platelet fraction
Authors: Osei‐Bimpong Andrew , Saleh Mohammad , Sola‐Visner Martha , Widness John , Veng‐Pedersen Peter
Published: November 2010

It is common practice to store samples and measure the immature platelet fraction (IPF) only when the initial standard complete blood count and the blood smear indicate thrombocytopenia. However, the cold storage introduces an inherent error in the %IPF. A falsely elevated %IPF carries the risk of potentially misleading the clinicians' interpretation of the thrombopoietic activity, thus hindering the clinical utility of this parameter. To address this issue, we determined the IPF% in individual blood samples from 29 adults at 0, 4, 8, 10, 12, 21, and 24 hr after the blood draw. This study demonstrated that the effect of 4°C storage is linear over a 24 hr period and independent of the initial IPF%. These observations have enabled the development of a proposed algorithm for a corrected IPF%, which is equal to the uncorrected IPF% minus 1.34 times the length of time in hours of storage at 4°C. The proposed correction algorithm extends the utility of this clinically important laboratory parameter. However, care should be taken not to extrapolate the algorithm significantly beyond 24 hr storage, because the experimental data only covered this range. J. Clin. Lab. Anal. 24:431–433, 2010. © 2010 Wiley‐Liss, Inc.
Efficient and one‐pot catalytic synthesis of 2‐imidazolines and bis‐imidazolines with p‐toluenesulfonic acid under solvent free conditions
Authors: Nasr‐Esfahani Masoud , Montazerozohori Morteza , Mehrizi Safie
Published: November 2010

A practical, efficient, and inexpensive method for the synthesis of 2‐imidazoline from the reaction of nitriles with ethylenediamine or 1,2‐propanediamine using p‐toluenesulfonic acid or pyridinium p‐toluenesulfonate under reflux conditions is reported. This catalyst can be successfully applied for the chemoselective conversion of dicyanobenzenes to corresponding mono‐ and bis‐imidazolines. The applications of these catalysts are feasible because of easy preparation, easy handling, stability, inexpensive, good activity, and eco‐friendly. J. Heterocyclic Chem., (2011).
Synthesis of 2,3‐diaryl‐3,4‐dihydro‐2H‐1,3‐benzoxazines and their fungicidal activities
Authors: Tang Zilong , Chen Weiwen , Zhu Zhonghua , Liu Hanwen
Published: November 2010

A series of novel 2,3‐diaryl‐3,4‐dihydro‐2H‐1,3‐benzoxazines have been prepared in high yields from o‐arylaminomethylphenols and aromatic aldehydes in the presence of SnCl4 for the first time, and their fungicidal activities were investigated too. Some of the products showed good fungicidal activities against Rhizoctonia solani justified by 100% activity of compound 1b. J. Heterocyclic Chem., (2010)
Synthesis of novel 2‐(2‐methylsulfonyl‐1‐methyl‐1H‐imidazol‐5‐yl)‐5‐(alkylsulfonyl)‐1,3,4‐thiadiazoles
Authors: Javidnia Azita , Akbarzadeh Tahmineh , Firoozpour Loghman , Khoobi Mehdi , Shafiee Abbas , Foroumadi Alireza
Published: November 2010

Starting from 5‐hydroxymethyl‐2‐mercapto‐1‐methyl‐1H‐imidazole (1), a series of 2‐(1‐methyl‐2‐methylsulfonyl‐1H‐imidazol‐5‐yl)‐5‐alkylthio and 5‐alkylsulfonyl‐1,3,4‐thiadiazole derivatives (9a, 9b, 9c, 9d and 10a, 10b, 10c, 10d) were prepared as potential antimicrobial agents. The structure of the obtained compounds was confirmed by NMR, IR, Mass spectroscopy, and elemental analysis. J. Heterocyclic Chem., (2010)
Determination of uric acid in human urine by capillary zone electrophoresis with indirect laser‐induced fluorescence detection
Authors: Yang Jiajia , Hu Menglin , Cai Yuanli , Tang Jing , Li Hui
Published: November 2010

A CZE with indirect LIF detection method was used for the determination of uric acid (UA) in human urine. UA and its coexisting analytes (i.e. hypoxanthine, xanthine and ascorbic acid) could be well separated within 4.5 min at a voltage of 25 kV with 25°C cartridge temperature in a running buffer composed of 5 mM sodium borate, 10% methanol (v/v) and 0.3 μM fluorescein sodium (apparent pH of the final mixed hydro‐organic solution of sodium borate, methanol and fluorescein is 9.5). Under the optimum condition, the method has good linearity relationships (correlation coefficients: 0.9973–0.9987) with ranges of 25–500, 25–350, 25–250 and 25–300 μg/mL for hypoxanthine, ascorbic acid, xanthine and UA, respectively. The detection limits for the analytes were in the range of 0.29–0.90 μg/mL. The intra‐day RSD values for migration times and peak areas were less than 0.43 and 3.27%, respectively. This method was applied to the quantitation of UA in human urine with recoveries in the range of 93.1–107.3%.
Selectivity in separation using π electron‐rich stationary phases for the comprehensive two‐dimensional analysis of café espresso
Authors: Stevenson Paul G. , Mnatsakanyan Mariam , Dennis Gary R. , Shalliker R. Andrew
Published: November 2010

The multidimensional high‐performance liquid chromatography separations of the complex sample matrix found in café espresso coffee were completed on the propyl phenyl and butyl phenyl columns that contain 3 and 4 carbon atoms in the spacer chain, respectively. Phenyl type stationary phases are able to undergo unique π–π interactions with aromatic compounds. Previous works have found that there are differences in retention characteristics between these chain lengths and this was explored further here. It was found that when analysing the separations by quadrants, using a geometric approach to factor analysis and by measuring the normalised mean radius, subtle differences in the separations were observed and the butyl phenyl phase was more selective for the high to medium polarity species. However, there was very little difference in separation behaviour for the hydrophobic components within the coffee sample. Overall, the analysis of the entire separation showed very little difference.
Diaminotrehalose‐capped β‐cyclodextrin, a new member of hemispherodextrins: Synthesis, thermodynamic and spectroscopic characterization and its exploitation in chiral electrokinetic chromatography
Authors: Cucinotta Vincenzo , Giuffrida Alessandro , Grasso Giulia , Maccarrone Giuseppe , Mazzaglia Antonino , Messina Marianna , Vecchio Graziella
Published: November 2010

The diaminotrehalose‐capped derivative of β‐CD, a new member of hemispherodextrins, was synthesized and characterized by NMR spectroscopy. Its protonation constants were determined by potentiometry, and the inclusion of both the enantiomers of dansyl‐phenylalanine was investigated by NMR spectroscopy. Its stereoselective properties were exploited in electrokinetic chromatography by separating four enantiomeric pairs of dansyl derivatives of amino acids.
New approaches of LC‐MS compatible method development on α1‐acid glycoprotein‐based stationary phase for resolution of enantiomers by HPLC
Authors: Michishita Takashi , Franco Pilar , Zhang Tong
Published: November 2010

Protein‐based chiral stationary phases, in particular α1‐acid glycoprotein, are chromatographic materials with a very broad application range. The chiral recognition ability of this selector allows the resolution of more than 90% of the molecules tested. A step‐by‐step description of the screening approach that we have developed is described in this article with two objectives in mind: obtaining a high success rate with a straightforward methodology that can be generally applied and allowing LC‐MS compatibility. Second, the screening strategy is required to take into account the main functional nature of the racemic compound to be resolved (neutral, acidic or basic) for method optimisation step, but should be independent of other structural features, in order to allow the routine application of screening sequences and the application to the largest number of samples.
Resource loss, resource gain, and mental health among survivors of Hurricane Katrina
Authors: Zwiebach Liza , Rhodes Jean , Roemer Lizabeth
Published: November 2010

Prior research has shown that losses of personal, social, and material resources resulting from traumatic events significantly contribute to psychopathology. Gains of such resources have been shown to have protective effects on posttrauma mental health. Few previous studies of resource change, however, have controlled for pretrauma mental health. The current study, which included 402 survivors of Hurricane Katrina, made use of data collected prehurricane to examine patterns of loss and gain and subsequent mental health. The loss of social support, physical health, and personal property were shown to significantly affect posthurricane psychological distress over and above the effect of prehurricane psychological functioning and disaster exposure. Gains in resources showed no effect. Implications for practice and policy were discussed.
Consensus QSAR Related to Global or MOA Models: Application to Acute Toxicity for Fish
Authors: Lozano Sylvain , Halm‐Lemeille Marie‐Pierre , Lepailleur Alban , Rault Sylvain , Bureau Ronan
Published: November 2010

Under REACH legislation, alternative methods (in silico or in vitro) like QSAR (Quantitative Structure‐Activity Relationships) models are expected to play a significant role. QSARs are based on the assumption that substances with similar chemical structures may have the same biological activities. However, identification of chemical classes could be problematic because chemicals often exhibit different chemical moieties, thereby confounding efforts to achieve a meaningful classification. This publication is focus on the notion of global model with the integration of a recent genetic algorithm for the generation of QSAR models. Starting from three datasets (EPAFHM, ECBHPV, AQUIRE), prediction of acute toxicity for fish (Pimephales promelas) with a global consensus model was carried out leading to very interesting statistics. The integration of the notion of Mode of Action was the second point of this study. A Bayesian classification associated to the genetic algorithm for consensus models was created leading to a good estimation of toxicity associated to derivatives with nonspecific MOA.
9‐oxo‐10(E),12(E)‐octadecadienoic acid derived from tomato is a potent PPAR α agonist to decrease triglyceride accumulation in mouse primary hepatocytes
Authors: Kim Young‐Il , Hirai Shizuka , Takahashi Haruya , Goto Tsuyoshi , Ohyane Chie , Tsugane Taneaki , Konishi Chiaki , Fujii Takashi , Inai Shuji , Iijima Yoko , Aoki Koh , Shibata Daisuke , Takahashi Nobuyuki , Kawada Teruo
Published: November 2010

Scope: Tomato is one of the most common crops worldwide and contains many beneficial compounds that improve abnormalities of lipid metabolism. However, the molecular mechanism underlying the effect of tomato on lipid metabolism is unclear. It has been commonly accepted that peroxisome proliferator‐activated receptor α (PPARα) is one of the most important targets for ameliorating abnormalities of lipid metabolism. Therefore, we focused on the activation of PPARα and attempted to detect active compounds activating PPARα in tomato.

Methods and results: To identify such active compounds, we screened fractions of tomato extracts using PPARα luciferase reporter assay. One fraction, rechromatographed‐fraction eluted in 57 min (RF57), significantly increased PPARα reporter activity, in which a single compound is detected by LC/MS analysis. On the basis of LC/MS and NMR analyses, we determined the chemical structure of the active compound in RF57 as 9‐oxo‐10(E),12(E)‐octadecadienoic acid (9‐oxo‐ODA). The RF57 fraction significantly increased the mRNA expression levels of PPARα target genes involved in fatty acid oxidation and O2 consumption in mouse primary hepatocytes. Furthermore, RF57 inhibited cellular triglyceride accumulation in the hepatocytes.

Conclusion: These findings suggest that tomatoes containing 9‐oxo‐ODA that acts on PPARα are valuable for ameliorating abnormalities of lipid metabolism.
Acteoside inhibits PMA‐induced matrix metalloproteinase‐9 expression via CaMK/ERK‐ and JNK/NF‐κB‐dependent signaling
Authors: Hwang Yong Pil , Kim Hyung Gyun , Choi Jae Ho , Park Bong Hwan , Jeong Myung Ho , Jeong Tae Cheon , Jeong Hye Gwang
Published: November 2010

Scope: Acteoside, an active phenylethanoid glycoside found in bitter tea and many medicinal plants, displays chemopreventive properties. The aim of our study was to determine the effect of acteoside on tumor invasion and migration; the possible mechanisms involved in this inhibition were investigated in human fibrosarcoma HT‐1080 cells.

Methods and results: We employed invasion, migration and gelatin zymography assays to characterize the effect of acteoside on HT‐1080 cells. Transient transfection assays were performed to investigate gene promoter activities, and immunoblot analysis to study its molecular mechanisms of action. We found that acteoside suppresses phorbol‐12‐myristate‐13‐acetate (PMA)‐enhanced matrix metalloproteinase‐9 (MMP‐9) expression at the protein, mRNA, and transcriptional levels through the suppression of NF‐κB activation. In addition, acteoside repressed the PMA‐induced phosphorylation of ERK1/2 (ERK, extracellular regulated kinase) and JNK1/2. Further, we found that acteoside decreased the PMA‐induced influx of Ca2+ and repressed PMA‐induced calmodulin‐dependent protein kinase (CaMK) phosphorylation. Furthermore, treatment with BAPTA/AM, W7, or capsazepine markedly decreased PMA‐induced MMP‐9 secretion and cell migration, as well as ERK and JNK/NF‐κB activation.

Conclusion: Acteoside inhibited PMA‐induced invasion and migration of human fibrosarcoma cells via Ca2+‐dependent CaMK/ERK and JNK/NF‐κB‐signaling pathways. Acteoside therefore has the potential to be a potent anticancer agent in therapeutic strategies for fibrosarcoma metastasis.
Potential health‐promoting effects of astaxanthin: A high‐value carotenoid mostly from microalgae
Authors: Yuan Jian‐Ping , Peng Juan , Yin Kai , Wang Jiang‐Hai
Published: November 2010

The ketocarotenoid astaxanthin can be found in the microalgae Haematococcus pluvialis, Chlorella zofingiensis, and Chlorococcum sp., and the red yeast Phaffia rhodozyma. The microalga H. pluvialis has the highest capacity to accumulate astaxanthin up to 4–5% of cell dry weight. Astaxanthin has been attributed with extraordinary potential for protecting the organism against a wide range of diseases, and has considerable potential and promising applications in human health. Numerous studies have shown that astaxanthin has potential health‐promoting effects in the prevention and treatment of various diseases, such as cancers, chronic inflammatory diseases, metabolic syndrome, diabetes, diabetic nephropathy, cardiovascular diseases, gastrointestinal diseases, liver diseases, neurodegenerative diseases, eye diseases, skin diseases, exercise‐induced fatigue, male infertility, and HgCl2‐induced acute renal failure. In this article, the currently available scientific literature regarding the most significant activities of astaxanthin is reviewed.
Regulation of genes involved in lipid metabolism by dietary oxidized fat
Authors: Ringseis Robert , Eder Klaus
Published: November 2010

Although oxidized fats are widely considered to have detrimental effects on human health, a large number of feeding studies with experimental animals have consistently demonstrated that oxidized fats, compared with fresh fats, cause a reduction in the concentrations of triacylglycerols and cholesterol in liver and plasma. The reason for these effects became clear when recently it was shown that thermo‐oxidized fats contain characteristic substances such as hydroxylated fatty acids and cyclic fatty acid monomers which are potent ligands and activators of peroxisome proliferator‐activated receptor α – a transcription factor controlling genes involved in fatty acid and lipoprotein metabolism. In addition, oxidized fats have also been reported to inhibit expression of genes involved in fatty acid synthesis and cholesterol homeostasis. These effects are mediated by inhibiting the maturation of sterol regulatory‐element binding proteins, which are transcription factors regulating genes involved in fatty acid synthesis and cholesterol homeostasis. This review summarizes the phenotypical alterations of lipid metabolism observed in feeding studies dealing with oxidized fats and addresses the molecular mechanisms underlying these lipid metabolism alterations, in particular the lipid lowering effects of dietary oxidized fats.
The influence of soft segment length on structure and properties of poly(trimethylene terephthalate)‐block‐poly(tetramethylene oxide) segmented random copolymers
Authors: Szymczyk A. , Nastalczyk J. , Sablong R.J. , Roslaniec Z.
Published: November 2010

Two series of multiblock poly(ether‐ester)s based on poly(trimethylene terephthalate) (PTT) as the rigid segments and poly(tetramethylene oxide) (PTMO) as the flexible/soft segments were synthesized with the aim of developing of the new family polyester thermoplastic elastomers (TPEs) based on PTT as rigid segment. The content of PTMO segments in the polymer chains was varied from 20 to 80 wt%. The investigations were mainly focused on the influence of flexible segments length with starting PTMG molecular weight at 1000 and 2000 g/mol, respectively, on the phase structure, thermal and mechanical properties of resulting copolymers. The copolymers were characterized by Size Exclusion Chromatography (SEC), Differential Scanning Calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), Wide‐angle X‐ray scattering (WAXS), Small‐angle X‐ray scattering (SAXS), and other standard physical methods. Cyclic tensile properties of them were studied with the aim to evaluate the elastic properties. SEC results clearly demonstrated the formation of molecular weight segmented copolymers with microphase separated structure as denoted by DSC and DMTA. The enhanced phase separation was observed for copolymers containing longer flexible segments.

According to the characterizations, copolymers containing 50–80 wt% of flexible segments showed elastic behavior. Comparison of the values of permanent set for copolymers with shorter and longer flexible segments has shown that copolymers containing 30 and 40 wt% of long PTMO flexible segments have the best elastic properties (low permanent set). Copyright © 2010 John Wiley & Sons, Ltd.
Band gap‐voltage offset and energy production in next‐generation multijunction solar cells
Authors: King R. R. , Bhusari D. , Boca A. , Larrabee D. , Liu X.‐Q. , Hong W. , Fetzer C. M. , Law D. C. , Karam N. H.
Published: November 2010

The potential for new 4‐, 5‐, and 6‐junction solar cell architectures to reach 50% efficiency is highly leveraging for the economics of concentrator photovoltaic (CPV) systems.The theoretical performance of such next‐generation cells, and experimental results for 3‐ and 4‐junction CPV cells, are examined here to evaluate their impact for real‐world solar electricity generation. Semiconductor device physics equations are formulated in terms of the band gap‐voltage offsetWoc  (Eg/q) − Voc, to give a clearer physical understanding and more general analysis of the multiple subcell band gaps in multijunction cells. Band gap‐voltage offset is shown experimentally to be largely independent of band gap Egfor a wide range of metamorphic and lattice‐matched semiconductors from 0.67 to 2.1 eV. Its theoretical Egdependence is calculated from that of the radiative recombination coefficient, and at a more fundamental level using the Shockley‐Queisser detailed balance model, bearing out experimental observations. Energy production of 4‐, 5‐, and 6‐junction CPV cells, calculated for changing air mass and spectrum over the course of the day, is found to be significantly greater than for conventional 3‐junction cells. The spectral sensitivity of these next‐generation cell designs is fairly low, and is outweighed by their higher efficiency. Lattice‐matched GaInP/GaInAs/Ge cells have reached an independently confirmed efficiency of 41.6%, the highest efficiency yet demonstrated for any type of solar cell. Light I‐V measurements of this record 41.6% cell, of next‐generation upright metamorphic 3‐junction cells with 40% target production efficiency, and of experimental 4‐junction CPV cells are presented. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of initial power stabilization over crystalline‐Si photovoltaic modules maximum power
Authors: Munoz M.A. , Chenlo F. , Alonso‐García M.C.
Published: November 2010

Measurements that suppliers offer in specification sheets are not always close to the actual power measured in independent laboratories such as CIEMAT. Independent measurements tend to be lower than those printed on the label sometimes even lower than the allowed tolerance indicated by the manufacturer on the same label. Furthermore, a potentially significant power reduction has been reported when Standard EN50380 (which requires photovoltaic (PV) modules to be exposed to more than 20 kWh/m2of sunlight prior to taking the measurements that appear on the label) is followed. This is the initial power stabilization and this work studies the power stabilization that tends to appear in crystalline PV modules. Crystalline PV modules usually decrease in power around 1%, but decreases >4% have also been reported. These power losses are only detected after the mentioned power stabilization. Copyright © 2010 John Wiley & Sons, Ltd.
Impurity‐to‐efficiency simulator: predictive simulation of silicon solar cell performance based on iron content and distribution
Authors: Hofstetter J. , Fenning D. P. , Bertoni M. I. , Lelièvre J. F. , Cañizo1 C. del , Buonassisi T.
Published: November 2010

We present a simulation tool that predicts solar cell efficiency based on iron content in as‐grown wafer and solar cell processing conditions. This “impurity‐to‐efficiency” (I2E) simulation tool consists of three serial components, which are independently and jointly validated using published experimental results: (1) a kinetic model that calculates changes in the distribution of iron and phosphorus atoms during annealing; (2) an electronic model that predicts depth‐dependent minority carrier lifetime based on iron distribution; and (3) a device simulator that predicts solar cell performance based on the minority carrier lifetime distribution throughout the wafer and the device architecture. The I2E model is demonstrated to be an effective predictor of cell performance for both single‐crystalline and multi‐crystalline silicon solar cells. We demonstrate the process optimization potential for the I2E simulator by analyzing efficiency improvements obtained using low‐temperature annealing, a processing concept that has been successfully applied to achieve higher solar cell efficiencies on Fe‐contaminated materials. Copyright © 2010 John Wiley & Sons, Ltd.
Highly thermostable and low birefringent norbornene‐styrene copolymers with advanced optical properties: A potential plastic substrate for flexible displays
Authors: Ban Hoang The , Hagihara Hideaki , Tsunogae Yasuo , Cai Zhengguo , Shiono Takeshi
Published: November 2010

This article reports the synthesis and characterization of an extremely high thermostable cyclic olefin copolymer with advanced optical properties resulting from the vinyl addition copolymerization of norbornene with styrene catalyzed by a substituted fluorenylamidodimethyltitanium catalyst [Me2Si(3,6‐tBu2Flu)(tBuN)]TiMe2 activated with a [Ph3C] [B(C6F5)4]/Al(iBu)3 cocatalyst using o‐dichlorobenzene as solvent. The prepared copolymer possesses a glass transition temperature as high as polyimide (Tg > 300 °C) and a high transmittance which is comparable with that of the conventional optical resins ([T] > 90%). The incorporation of polystyrene, which exhibits a negative birefringence into the vinyl‐added polynorbornene that possesses an intrinsic positive birefringence, effectively reduced the birefringent magnitude of the norbornene‐styrene copolymer due to a mutual compensation between these opposite‐sign birefringences. The absence of any functional and aromatic heterocyclic groups and the presence of highly hydrophobic saturated bicyclic rings in the copolymer main chains effectively prevented the diffusion of water/oxygen and thus enhanced the dimensional and optical stabilities of the material. Preliminary results on the characterization of the thermal stability, mechanical, and optical properties of the vinyl‐added norbornene‐styrene copolymers indicate that they satisfy all the rigorous requirements for a polymer to be applied as a flexible substrate for the manufacturing of the flexible displays. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Synthesis and characterization of functional fluorinated telomers
Authors: Durand Nelly , Ameduri Bruno , Boutevin Bernard
Published: November 2010

The synthesis and characterizations of fluorinated telomers based on vinylidene fluoride (VDF) by iodine transfer polymerization (ITP) are presented. These telomers were prepared in the presence of ω‐iodoperfluorinated functional chain transfer agents, C6F13I or C4F9I. ITPs were initiated by thermal decomposition of bis(4‐tert‐butylcyclohexyl) peroxydicarbonate (BBCHPDC), in solution (in the presence of acetonitrile). The obtained telomers were characterized by different analyses such as elemental analyses, nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy, size exclusion chromatography, X‐ray diffraction (XRD), and finally by thermal analyses such as differential scanning calorimetry (DSC) and thermogravimetric analyses. These technical analyses enabled one to assess their chemical structures, various thermal properties, and their crystalline forms. The assignments of the characteristic signals obtained by 19F NMR spectroscopy enabled one to calculate the average degrees of polymerization (DPn) and percentages of CH2CF2I end group functionalities that depend on the initiator and the fractionation process after reaction. A good control of polymerization was shown by the absence of reversed CH2CF2CF2CH2 (VDF–VDF dyads) and narrow polydispersity indices (<1.2). The XRD and DSC evidenced the influence of the chain length of the telomers on the crystallinity rate (>70%) and indicated two crystalline forms, α and β, that depended on DPn values. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Modification of polysulfones by click chemistry: Amphiphilic graft copolymers and their protein adsorption and cell adhesion properties
Authors: Yilmaz Gorkem , Toiserkani Hojjat , Demirkol Dilek Odaci , Sakarya Serhan , Timur Suna , Yagci Yusuf , Torun Lokman
Published: November 2010

Well‐defined amphiphilic graft copolymer with hydrophobic polysulfone (PSU) backbone and hydrophilic poly(acrylic acid) (PAA) side chains were synthesized and characterized. For this purpose, commercially available PSU was converted to azido‐functionalized polymer (PSU‐N3) by successive chloromethylation and azidation processes. Independently, poly(tert‐butyl acrylate) (PtBA) with an alkyne‐end‐group is obtained by using suitable initiator in atom transfer radical polymerization (ATRP). Then, this polymer was successfully grafted onto PSU‐N3 by click chemistry to yield polysulfone‐graft‐poly(tert‐butyl acrylate), (PSU‐g‐PtBA). Finally, amphiphilic polysulfone‐graft‐poly(acrylic acid), (PSU‐g‐PAA), membranes were obtained by hydrolyzing precursor the PSU‐g‐PtBA membranes in trifluoroacetic acid. The final polymer and intermediates at various stages were characterized by 1H NMR, FTIR, GPC, and SEM analyses. Protein adsorption and eukaryotic and prokaryotic cell adhesion on PSU‐g‐PAA were studied and compared to those of PSU‐g‐PtBA and unmodified PSU. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Thermally crosslinkable hole‐transporting poly(fluorene‐co‐triphenylamine) for multilayer polymer light‐emitting diodes
Authors: Su Wen‐Fen , Chen Ruei‐Tang , Chen Yun
Published: November 2010

This article reports the synthesis and characterization of a novel thermally crosslinkable hole‐transporting poly (fluorene‐co‐triphenylamine) (PFO‐TPA) by Suzuki coupling reaction, followed with its application in the fabrication of multilayer light‐emitting diodes by wet processes. The thermal, photophysical, and electrochemical properties of PFO‐TPA were investigated by differential scanning calorimeter, thermogravimetric analysis, optical spectroscopy, and cyclic voltammetry, respectively. Thermally crosslinked PFO‐TPA, through pendant styryl groups, demonstrates excellent thermal stability (Td > 400 °C, Tg = 152 °C), solvent resistance, and film homogeneity. Its highest occupied molecular orbital level (−5.30 eV) lies between those of PEDOT:PSS (−5.0 ∼ −5.2 eV) and poly(9,9‐dioctylfluorene) (PFO: −5.70 eV), forming a stepwise energy ladder to facilitate hole injection. Multilayer device with crosslinked PFO‐TPA as hole‐injection layer (HIL) (ITO/PEDOT:PSS/HIL/PFO/LiF/Ca/Al) was readily fabricated by successive spin‐coating processes, its maximum luminance efficiency (3.16 cd/A) were about six times higher than those without PFO‐TPA layer (0.50 cd/A). The result of hole‐only device also confirmed hole‐injection and hole‐transport abilities of crosslinked PFO‐TPA layer. Consequently, the device performance enhancement is attributed to more balanced charges injection in the presence of crosslinked PFO‐TPA layer. The thermally crosslinkable PFO‐TPA is a promising material for the fabrication of efficient multilayer polymer light‐emitting diodes because it is not only a hole‐transporting polymer but also thermally crosslinkable. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Cobalt‐mediated radical polymerization routes to poly(vinyl ester) block copolymers
Authors: Bunck David N. , Sorenson Gregory P. , Mahanthappa Mahesh K.
Published: November 2010

Cobalt‐mediated radical polymerizations (CMRPs) utilizing redox initiation are demonstrated to produce poly(vinyl ester) homopolymers derived from vinyl pivalate (VPv) and vinyl benzoate (VBz), and their block copolymers with vinyl acetate (VAc). Combining anhydrous Co(acac)2, lauroyl peroxide, citric acid trisodium salt, and VPv at 30 °C results in controlled polymerizations that yield homopolymers with Mn = 2.5–27 kg/mol with Mw/Mn = 1.20–1.30. Homopolymerizations of scrupulously purified VBz proceed with lower levels of control as evidenced by broader polydispersities over a range of molecular weights (Mn = 4–16 kg/mol; Mw/Mn = 1.34–1.65), which may be interpreted in terms of the decreased nucleophilicity of these less electron donating propagating polymer chain ends. Based on these results, we demonstrate that sequential CMRP reactions present a viable route to microphase separated poly(vinyl ester) block copolymers as shown by small‐angle X‐ray scattering analyses. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Ring‐opening polymerization of cyclic esters promoted by phosphido‐diphosphine pincer group 3 complexes
Authors: D'auria Ilaria , Mazzeo Mina , Pappalardo Daniela , Lamberti Marina , Pellecchia Claudio
Published: November 2010

Phosphido‐diphosphine Group 3 metal complexes 1–4 [(o‐C6H4PR2)2P‐M(CH2SiMe3)2; R = Ph, 1: M = Y, 2: M = Sc; R = iPr, 3: M = Y, 4: M = Sc] are very efficient catalysts for the ring‐opening polymerization (ROP) of cyclic esters such as ε‐caprolactone (ε‐CL), L‐lactide, and δ‐valerolactone under mild polymerization conditions. In the ROP of ε‐CL, complexes 1–4 promote quantitative conversion of high amount of monomer (up to 3000 equiv) with very high turnover frequencies (TOF) (∼4 × 104 molCL/molI h) showing a catalytic activity among the highest reported in the literature. The immortal and living ROP of ε‐CL and L‐lactide is feasible by combining complexes 1–4 with 5 equiv of 2‐propanol. Polymers with controlled molecular parameters (Mn, end groups) and low polydispersities (Mw/Mn = 1.05–1.09) are formed as a result of fast alkoxide/alcohol exchange. In the ROP of δ‐valerolactone, complexes 1–4 showed the same activity observed for lactide (L‐ and D,L‐lactide) producing high molecular weight polymers with narrow distribution of molar masses. Complexes 1–4 also promote the ROP of rac‐β butyrolactone affording atactic low molecular weight poly(hydroxybutyrate) bearing unsaturated end groups probably generated by elimination reactions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Efficient accelerating effect of carbonyldiimidazole on epoxy‐dicyandiamide curing system
Authors: Liu Xiang Dong , Sudo Atsushi , Endo Takeshi
Published: November 2010

Carbonyldiimidazole (CDI) was inventively used as an accelerator for the curing reaction of diglycidyl ether of bisphenol A (DGEBA) with dicyandiamide (DICY) and a high acceleration more effective than imidazole in double usage was observed. This result implies the accelerating role of CDI in the curing process is complex and involved not only the release of imidazole. To detail the accelerating mechanism of CDI, a series of curing reactions was studied by differential scanning calorimetry (DSC), NMR, IR, and viscosity monitoring. The results suggested that the accelerating mechanism of CDI involves (1) acylation of DICY with CDI to give the corresponding adduct with enhanced solubility, (2) the consequent release of imidazole that can react with epoxide, and (3) abstraction of proton of DICY by the alkoxide moiety to give the corresponding DICY anion endowed with enhanced nucleophilicity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Synthesis and characterization of four alkyl 2‐cyanoacrylate monomers and their precursors for use in latent fingerprint detection
Authors: Tahtouh Mark , Kalman John R. , Reedy Brian J.
Published: November 2010

Four novel cyanoacrylates, 2‐cyanoethyl 2‐cyanoacrylate, 1‐cyanoethyl 2‐cyanoacrylate, trideuteromethyl 2‐cyanoacrylate and pentadeuteroethyl 2‐cyanoacrylate have been synthesized using a Diels‐Alder protection/deprotection route involving anthracene. The common route for the synthesis of alkyl 2‐cyanoacrylates was found to be unsatisfactory for the production of small quantities of the targeted cyanoacrylates, which have potential as reagents for the mid‐infrared spectral imaging of fingerprints on difficult surfaces. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Infiltrating P3HT polymer into ordered TiO2 nanotube arrays
Authors: Lim Siew Leng , Liu Yiliang , Liu Gang , Xu Sheng Yong , Pan Hua Yong , Kang En‐Tang , Ong Chong Kim
Published: November 2010

Infiltration of regioregular poly(3‐hexyl thiophene) (RR P3HT) polymer into ordered TiO2 nanotube arrays is confirmed by UV–Vis absorption spectrometer measurement, time‐of‐flight secondary ion mass spectrometer (TOF‐SIMs) depth profiling and transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Ordered TiO2 nanotube arrays of thickness 19 µm were formed by 2‐step anodization of titanium foil in an ethylene‐glycol‐based solution and a dip‐coating method was used to infiltrate the polymer into the TiO2 nanotubes. UV–Vis absorption spectrometer measurement of P3HT/TiO2 nanotubes shows a peak absorption at 500 nm due to embedded polymer within the nanotube arrays. TOF‐SIMs depth profiling up to 500 nm shows P3HT polymer is infiltrated into the TiO2 nanotube arrays. Furthermore, energy‐dispersive X‐ray spectroscopy (EDX) of the TEM indicates the presence of sulfur and carbon atoms due to the P3HT polymer. Polymer nanotubes can be observed with SEM after TiO2 nanotubes infiltrated with polymer are etched by dilute HF solution.
Torque magnetometry analysis of magnetic anisotropy distribution in Ni nanowire arrays
Authors: Vega Victor , Prida Victor M. , García Jose Angel , Vazquez Manuel
Published: November 2010

Highly ordered arrays of Ni nanowires have been prepared by pulsed electrochemical deposition into nanopores of anodic alumina membranes (NAAMs) used as templates. They have been experimentally characterized by magnetic torque measurements and vibrating sample magnetometer (VSM) techniques in order to determine the magnetic anisotropy of the hexagonal array of nanowires. A detailed analysis of the experimental data has been performed based on a phenomenological model taking into account the influence of the nanowire shape anisotropy added to the dipolar magnetostatic interactions among them. An overall agreement is obtained between the simulations derived from the model and the experimental magnetic torque anisotropy curves.
Mechanical relaxation in supercooled liquids of bulk metallic glasses
Authors: Wen Ping , Zhao Zuo Feng , Pan Ming Xiang , Wang Wei Hua
Published: November 2010

We report the mechanical relaxation behaviors in typical supercooled liquids of bulk metallic glasses (BMGs). The metallic supercooled liquids are ideal systems for studying intrinsic motions of glass‐former supercooled liquids because their structure is close to the simple “dense random packing of spheres” model. We show that the primary relaxation in the frequency domain is dissipative and can be described by the empirical Kohlrausch–Williams–Watts function, and the temperature dependence of the primary relaxation time has the Vogel–Fulcher–Tamman form. Beyond the primary relaxation, an excess wing is found on the high‐frequency tail of the primary relaxation. A corresponding shoulder is exhibited at a given frequency in the temperature region below the glass‐transition temperature. The experimental results confirm that the decoupling between the slowβrelaxation and the primary (α) relaxation exists in metallic supercooled liquids. Based on the current models of the glass transition, we demonstrate that the dynamically heterogeneity originates in the heterogeneous microstructure of metallic supercooled liquids, and a picture of the heterogeneous microstructure is provided.
Controlled growth of rutile TiO2by atomic layer deposition on oxidized ruthenium
Authors: Popovici Mihaela , Swerts Johan , Tomida Kazuyuki , Radisic Dunja , Kim Min‐Soo , Kaczer Ben , Richard Olivier , Bender Hugo , Delabie Annelies , Moussa Alain , Vrancken Christa , Opsomer Karl , Franquet Alexis , Pawlak Malgorzata A. , Schaekers Marc , Altimime Laith , Van Elshocht Sven , Kittl Jorge A.
Published: November 2010

Crystalline rutile TiO2films were grown by atomic layer deposition on oxidized Ru electrodes using a titanium methoxide as the metal precursor and O3as the oxidant. A protective layer of ∼0.3 nm TiO2grown with H2O as the oxidant was first deposited in order to avoid etching of the Ru bottom electrode by the O3used for the growth of the TiO2(bulk) layer. Electrical evaluation of the capacitor stacks with TiO2as dielectric, RuO2/Ru and Pt as the bottom and top electrodes respectively, resulted in superior characteristics of the rutile phase as compared to the anatase. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Effect of Four Coffee types on Normotensive rats and Normal/Hypertensive Human Volunteers
Authors: Awaad Amani S. , Soliman G. A. , Al‐Outhman Mounerah R. , Al‐Shdoukhi Ibtehaj F. , Al‐Nafisah Rawan S. , Al‐Shamery Jawaher , Al‐Samkhan Ramlah , Baqer Mariam , Al‐Jaber Nabila A.
Published: November 2010

Coffee is a commonly consumed beverage. The purpose of this study was to determine the effect of the four coffee types on blood pressure (BP). The caffeine percentage was tested on one cup (250 mL) of each type of coffee (Arabian, Turkish, American and an instant coffee preparation) using two methods. 65 adult male rats and 400 healthy human volunteers were used in this study. Normotensive rats were treated orally with a single dose of normal saline with varying types of coffee. Normotensive and mildly hypertensive human volunteers were administered a cup (250 mL) of any type of coffee separately. Tail cuff and a strain‐gauge plethysmograph were used to measure the systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) of the rats, and volunteers, respectively before and 0.5, 1.0, 1.5, and 2 h post administration. The mean arterial pressure (MAP) was calculated mathematically using SBP and DBP. The alkaloidal percentage of different types of coffee showed the presence variable contents and amount of active materials. The study showed that Arabian, Turkish, American and instant coffee all have the potential to cause a BP lowering effect. Variable antimicrobial activities were recorded for the different types of coffee when tested bacteria. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of Capsaicin on Lipid Catabolism in 3T3‐L1 Adipocytes
Authors: Lee Mak‐Soon , Kim Chong‐Tai , Kim In‐Hwan , Kim Yangha
Published: November 2010

Capsaicin (8‐methyl‐N‐vanillyl‐6‐nonenamide) is a pungent ingredient of red peppers, and has been reported to reduce body weight gain and adiposity in rodents. The present study investigated the effects of capsaicin on lipid catabolism in differentiated 3T3‐L1 adipocytes. Capsaicin decreased the intracellular lipid content in a concentration‐dependent manner. The release of glycerol into the medium was increased by the addition of capsaicin. The mRNA levels of genes involved in lipid catabolism such as hormone sensitive lipase (HSL), carnitine palmitoyl transferase‐Iα (CPTI‐α) and uncoupling protein 2 (UCP2) were up‐regulated significantly. These results suggest that capsaicin exerts its lipolytic action by increasing the hydrolysis of triacylglycerol in adipocytes, and that these effects are mediated at least partially by regulation of the expression of multiple genes that are involved in the lipid catabolic pathway, such as HSL and CPT‐Iα, and those involved in thermogenesis such as UCP2. Copyright © 2010 John Wiley & Sons, Ltd.
Effect of berberine and Berberis aetnensis C. Presl. alkaloid extract on glutamate‐evoked tissue transglutaminase up‐regulation in astroglial cell cultures
Authors: Campisi Agata , Acquaviva Rosaria , Mastrojeni Silvana , Raciti Giuseppina , Vanella Angelo , De Pasquale Rita , Puglisi Salvatore , Iauk Liliana
Published: November 2010

Berberis aetnensis C. Presl. is a bushy‐spiny shrub common on Mount Etna (Sicily, Italy), containing various alkaloids with several pharmacological properties. This study assessed the effect of berberine and of the alkaloid extract of B. aetnensis roots on the glutamate‐evoked tissue transglutaminase (TG2) up‐regulation in rat astrocyte primary cultures, used as an in vitro model of excitotoxicity. The findings show that the alkaloid extract of B. aetnensis roots consists mainly of berberine. Furthermore, berberine and the alkaloid extract of B. aetnensis roots were able to restore the oxidative status modified by glutamate and the levels of TG2 to control values. It was found that berberine or the alkaloid extract of B. aetnensis roots are able to ameliorate the excessive production of glutamate, protein misfolding and aggregation, mitochondrial fragmentation, and neurodegeneration. Thus, it is suggested that berberine and the alkaloid extract of B. aetnensis roots, may represent a natural therapeutic strategy in the neuropathological conditions associated with excitotoxicity. Copyright © 2010 John Wiley & Sons, Ltd.