bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of model for treatment of pulp and paper industry bleaching effluent using response surface methodology
Authors: Sridhar R. , Sivakumar V. , Immanuel V. Prince , Maran J. Prakash
Published: July 2011

The treatment of bleaching‐effluent from pulp and paper industry was investigated in a batch electrocoagulation (EC) reactor using aluminium as sacrificial electrodes. The response surface methodology (RSM) was employed to evaluate the individual and interactive effects of four independent parameters viz., current density (j: 5–25 mA/cm2), initial pH (pHo: 5–9), electrolyte (NaCl) concentration (c: 0–2 g/L) and electrolysis time (t: 10–30 min) on Colour, COD and BOD removal efficiency. The results were analyzed using Pareto analysis of variance (ANOVA). Based on RSM analysis, a second‐order polynomial regression model was developed and found to be good fit with experimental results. © 2011 American Institute of Chemical Engineers Environ Prog, 2011
Longterm forecasting of solid waste generation by the artificial neural networks
Authors: Ali Abdoli Mohammad , Falah Nezhad Maliheh , Salehi Sede Reza , Behboudian Sadegh
Published: July 2011

This study presents a new approach—preprocessing for reaching the stationary chain in time series—to unravel the interpolating problem of artificial neural networks (ANN) for long‐term prediction of solid waste generation (SWG). To evaluate the accuracy of the prediction by ANN, comparison between the results of the multivariate regression model and ANN is performed. Monthly time series datasets, by the yrs 2000–2010, for the city of Mashhad, are used to simulate the generated solid waste. Different socioeconomic and environmental factors are assessed, and the most effective ones are used as input variables. The projections of these explanatory variables are used in the estimated model to predict the generated solid waste values through the yr 2032. Ultimately, various structures of ANN models are examined to select the best result based on the performance indices criteria. Research findings clearly indicate that such a new approach can be a practical method for long‐term prediction by ANNs. Furthermore, it can reduce uncertainties and lead to noticeable increase in the accuracy of the long‐term forecasting. Results indicate that multilayer perception approach has more advantages in comparison with traditional methods in predicting the municipal SWG. © 2011 American Institute of Chemical Engineers Environ Prog, 2011
Expedient synthesis of (E)‐3‐methylcyclopentadec‐2‐en‐1‐one, an important precursor for (R)‐(−)muscones
Authors: Hagiwara Hisahiro , Adachi Teppei , Doya Masaharu , Hoshi Takashi , Suzuki Toshio
Published: July 2011

An expedient synthesis of (E)‐3‐methylcyclopentadec‐2‐en‐1‐one, an important precursor for (R)‐(−)‐muscone, was developed. The key steps were vapour‐phase intramolecular aldol condensation catalysed by zinc oxide at 360 °C followed by double bond isomerization by the addition–elimination of hydrogen chloride. Copyright © 2011 John Wiley & Sons, Ltd.
Clinical utility of hepatitis B surface antigen quantitation in patients with chronic hepatitis B: A review
Authors: Liaw Yun-Fan
Published: July 2011

This clinically relevant review focuses on recent findings concerning hepatitis B surface antigen (HBsAg) quantitation in untreated patients and treated patients with chronic hepatitis B. Recent studies and emerging data have shown that both HBsAg and hepatitis B virus (HBV) DNA levels decline during the natural course of a chronic HBV infection; they are lowest in the inactive phase, which is also characterized by the highest HBsAg/HBV DNA ratio. It has been demonstrated that the combined use of HBsAg and HBV DNA levels might help in the identification of true inactive carriers with high accuracy. Retrospective analyses of HBsAg levels in patients undergoing therapy have suggested a role for HBsAg quantitation in monitoring the response to therapy. In comparison with nucleos(t)ide analogues (NAs), interferon-based therapy results in greater overall declines in serum HBsAg levels. A rapid on-treatment decline in HBsAg levels appears to be predictive of a sustained response. With the aid of HBsAg quantitation, it appears that we can anticipate an individualized approach to tailoring the treatment duration. The proposal of early stopping rules for patients not responding to pegylated interferon (according to a lack of any HBsAg decline) represents a step toward a response-guided approach. The development of stopping rules for patients treated with NAs is desirable for reducing the need for lifelong therapy. However, before stopping rules for antiviral therapy can be applied, we need to learn more about the kinetics of HBsAg declines during the natural history of the infection and as a response to therapy so that we can better define the best timing, the relevant HBsAg cutoff levels, and the best ways to apply these rules in clinical practice. (Hepatology 2011;)
Up-regulation of Hedgehog pathway is associated with cellular permissiveness for hepatitis C virus replication
Authors: Choi Steve S. , Bradrick Shelton , Qiang Guan , Mostafavi Anahita , Chaturvedi Gaurav , Weinman Steven A. , Diehl Anna Mae , Jhaveri Ravi
Published: July 2011

Studies of the hepatitis C virus (HCV) life-cycle rely heavily on Huh7.5 cells, but the reasons why these cells are exceptionally permissive for HCV replication are not clear. Based on recent clinical observations, we hypothesized that the Hedgehog (Hh) pathway, which has not been previously associated with HCV replication, may be involved in the Huh7.5 phenotype of increased permissiveness. We tested this hypothesis by comparing levels of a variety of Hh-related cellular markers in Huh7.5 cells with the parental Huh7 cells, which are far less permissive. Here we demonstrate that Huh7.5 cells, when compared with Huh7 cells, have substantially decreased expression of epithelial markers, increased levels of mesenchymal markers, and markedly up-regulated Hh pathway activity: Shh, >100-fold, Gli1, >30-fold, Ptc, 2-fold. In Huh7.5 cells, we found that cyclopamine, an Hh pathway antagonist, reduced HCV RNA levels by 50% compared with vehicle and inactive isomer controls. Moreover, in Huh7 cells treatment with recombinant Shh ligand and SAG, both Hh pathway agonists, stimulated HCV replication by 2-fold and 4-fold, respectively. These effects were observed with both viral infections and a subgenomic replicon. Finally, we demonstrated that GDC-0449 decreased HCV RNA levels in a dose-response manner. Conclusion: We have identified a relationship between HCV and Hh signaling where up-regulated pathway activity during infection promotes an environment conducive to replication. Given that Hh activity is very low in most hepatocytes, these findings may serve to further shift the model of HCV liver infection from modest widespread replication in hepatocytes to one where a subset of cells support high-level replication. These findings also introduce Hh pathway inhibitors as potential anti-HCV therapeutics. (Hepatology 2011;)
The tumor microenvironment expression of p‐STAT3 influences the efficacy of cyclophosphamide with WP1066 in murine melanoma models
Authors: Hatiboglu Mustafa Aziz , Kong Ling‐Yuan , Wei Jun , Wang Yongtao , McEnery Kayla Anne , Fuller Gregory N. , Qiao Wei , Davies Michael A. , Priebe Waldemar , Heimberger Amy B.
Published: July 2011

Melanoma is a common and deadly tumor that upon metastasis to the central nervous system (CNS) has median survival duration of less than 5 months. Activation of the signal transducer and activator of transcription 3 (STAT3) has been identified as a key mediator that drives the fundamental components of melanoma. We hypothesized that WP1066, a novel inhibitor of STAT3 signaling, would enhance the antitumor activity of cyclophosphamide (CTX) against melanoma, including disease within the CNS. The mechanisms of efficacy were investigated by tumor‐ and immune‐mediated cytotoxic assays, in vivo evaluation of the reduction of regulatory T cells (Tregs) and by determining intratumoral p‐STAT3 expression by immunohistochemistry. Combinational therapy of WP1066, with both metronomic and cytotoxic dosing of CTX, was investigated in a model system of systemic and intracerebral melanoma in syngeneic mice. Inhibition of p‐STAT3 by WP1066 was enhanced with CTX in a dose‐dependent manner. However, in mice with intracerebral melanoma, the greatest therapeutic benefit was seen in animals treated with cytotoxic CTX dosing and WP1066, whose median survival time was 120 days, an increase of 375%, with 57% long‐term survivors. This treatment efficacy correlated with p‐STAT3 expression levels within the tumor microenvironment. The efficacy of the combination of cytotoxic dosing of CTX with WP1066 is attributed to the direct tumor cytotoxic effects of the agents and has the greatest therapeutic potential for the treatment of CNS melanoma.
The cancer stem cell niche—there goes the neighborhood?
Authors: Cabarcas Stephanie M. , Mathews Lesley A. , Farrar William L.
Published: July 2011

The niche is the environment in which stem cells reside and is responsible for the maintenance of unique stem cell properties such as self‐renewal and an undifferentiated state. The heterogeneous populations which constitute a niche include both stem cells and surrounding differentiated cells. This network of heterogeneity is responsible for the control of the necessary pathways that function in determining stem cell fate. The concept that cancer stem cells, a subpopulation of cells responsible for tumor initiation and formation, reside in their own unique niche is quickly evolving and it is of importance to understand and identify the processes occurring within this environment. The necessary intrinsic pathways that are utilized by this cancer stem cell population to maintain both self‐renewal and the ability to differentiate are believed to be a result of the environment where cancer stem cells reside. The ability of a specific cancer stem cell niche to provide the environment in which this population can flourish is a critical aspect of cancer biology that mandates intense investigation. This review focuses on current evidence demonstrating that homeostatic processes such as inflammation, epithelial to mesenchymal transition, hypoxia and angiogenesis contribute to the maintenance and control of cancer stem cell fate by providing the appropriate signals within the microenvironment. It is necessary to understand the key processes occurring within this highly specialized cancer stem cell niche to identify potential therapeutic targets that can serve as the basis for development of more effective anticancer treatments.
Triblock copolymers of ε‐caprolactone, L‐lactide, and trimethylene carbonate: Biodegradability and elastomeric behavior
Authors: Widjaja Leonardus Kresna , Kong Jen Fong , Chattopadhyay Sujay , Lipik Vitali T. , Liow Sing Shy , Abadie Marc J.M. , Venkatraman Subbu S.
Published: July 2011

For the triblock copolymer of ε‐caprolactone, trimethylene carbonate, and L‐lactide, where L‐lactide blocks form the two ends, there is a range of compositions over which elastomeric behavior is obtained. Within this composition range, these polymers show good creep and recovery at ambient temperature, and exhibit high elongations to break. Additionally, we demonstrate that the recovery is independent of stress and strain for the elastomer compositions. The range of compositions that yield elastomeric character is rationalized based on the structure; specifically, there must be a minimum crystallinity of the end blocks and no crystallinity in the midblock, in addition to molar mass requirements. These polymers degrade by simple hydrolysis, and the rate of degradation is potentially programmable by manipulation of the molar ratio of hard segment to soft segment. Compared to biodegradable polyurethane, these polymers are expected to yield less harmful degradation products, and offer more variables for manipulation of properties. These polymers are also processable from the melt at temperatures exceeding about 130°C. We expect to use these polymers in a variety of applications, including stent coatings, fully‐degradable stents, and atrial septal defect occluders. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 99A: 38–46, 2011.
Permineralization process promotes preservation of Holocene macrofossil charcoal in soils
Authors: De Lafontaine Guillaume , Couillard Pierre‐Luc , Payette Serge
Published: July 2011

The use of macrofossil soil charcoal as a palaeoecological tool to reconstruct past vegetation, climate or fire history has gained much interest in recent years. Yet little is known about taphonomy of charcoal in soils. Here we assessed the putative loss of palaeoecological information due to charcoal fragmentation after burial. We found no significant loss of charcoal mass with time. Instead, we found a significant positive relationship between the mass of charcoal particles and their age. Permineralization of charcoal particles older than ca. 5200 a explained the increased charcoal mass with time in mineral soils. The permineralization process increased the density of charcoal particles (resulting in a twofold particles mass increase) and thus offers a protection against subsequent degradation. Our results suggest high stability of palaeoecological information from charcoal macrofossils buried in mineral soils at least over the Holocene timescale. Copyright © 2011 John Wiley & Sons, Ltd.
River otter population size estimation using noninvasive latrine surveys
Authors: Mowry Rebecca A. , Gompper Matthew E. , Beringer Jeff , Eggert Lori S.
Published: July 2011

Across much of North America, river otter (Lontra canadensis) populations were extirpated or greatly reduced by the early 20th century. More recently, reintroductions have resulted in restored populations and the recommencement of managed trapping. Perhaps the best example of these river otter reintroductions occurred in Missouri, regarded as one of the most successful carnivore recovery programs in history. However, abundance estimates for river otter populations are difficult to obtain and often contentious when used to underpin management activities. We assessed the value of latrine site monitoring as a mechanism for quantifying river otter abundance. Analyses of fecal DNA to identify individual animals may result in an improved population estimate and have been used for a variety of mammal species. We optimized laboratory protocols, redesigned existing microsatellite primers, and calculated genotyping error rates to enhance genotyping success for a large quantity of river otter scat samples. We also developed a method for molecular sexing. We then extracted DNA from 1,421 scat samples and anal sac secretions (anal jelly) collected during latrine site counts along 22–34‐km stretches representing 8–77% of 8 rivers in southern Missouri in 2009. Error rates were low for the redesigned microsatellites. We obtained genotypes at 7–10 microsatellite loci for 24% of samples, observing highest success for anal jelly samples (71%) and lowest for fresh samples (collected within 1 day of defecation). We identified 63 otters (41 M, 22 F) in the 8 rivers, ranging from 2 to 14 otters per river. Analyses using program CAPWIRE resulted in population estimates similar to the minimum genotyping estimate. Density estimates averaged 0.24 otters/km. We used linear regression to develop and contrast models predicting population size based on latrine site and scat count indices, which are easily collected in the field. Population size was best predicted by a combination of scats per latrine and latrines per kilometer. Our results provide methodological approaches to guide wildlife managers seeking to initiate similar river otter fecal genotyping studies, as well as to estimate and monitor river otter population sizes. © 2011 The Wildlife Society.
Importance of scale in nest‐site selection by Arizona gray squirrels
Authors: Cudworth Nichole L. , Koprowski John L.
Published: July 2011

Nests provide a place for individuals to rest, raise young, avoid predators, and escape inclement weather; consequently, knowledge of habitat characteristics important to nest placement is critical for managing species of conservation concern. Arizona gray squirrels (Sciurus arizonensis) are endemic to mountains of southwestern United States and northwestern Mexico. We investigated factors influencing nest‐site selection at 4 spatial scales (forest‐type, nest‐site, nest‐tree, and within‐canopy placement) to provide ecological information and management recommendations for this sensitive species. Nest densities were 2.6 times higher in riparian than pine‐oak woodlands. Nest sites had more large trees, snags, logs, and canopy cover and had lower slope. Arizona gray squirrels selected tall trees with more interlocking trees and tended to place nests adjacent to the main trunk. Regardless of scale, Arizona gray squirrels seemed to select nesting areas for their ability to provide protection from predators and the elements as well as access to food. Consequently, maintaining large trees with closed canopies and downed logs should be considered when determining land management plans. © 2011 The Wildlife Society.
The results of temporal bone surgery for advanced or recurrent tumors of the parotid gland
Authors: Gidley Paul W. , Thompson Christopher R. , Roberts Dianna B. , Weber Randal S.
Published: July 2011

Objectives/Hypothesis:

To describe the results of temporal bone surgery in managing advanced or recurrent tumors of the parotid gland.

Study Design:

Retrospective review.

Methods:

Patients with advanced or recurrent tumors involving the parotid gland who underwent either mastoidectomy or temporal bone resection were reviewed for treatment outcomes.

Results:

Forty‐nine patients were identified who required either mastoidectomy (n = 33) or temporal bone resection (n = 16) for malignancies involving the parotid gland. Facial nerve sacrifice was required in 35 patients (71.4%). Perineural invasion was found in 51.1% of patients; and negative margins were achieved in 78.2% patients. Six of 10 patients presenting with normal facial function (House‐Brackmann I) and recurrent tumors maintained normal facial function following salvage surgery. Trismus, tumors larger than 4 cm, and the need for mandibulectomy were significantly correlated with higher recurrence rates (P = .025, P = .004, and P = .002, respectively). Patients with preoperative House‐Brackmann I or II had a lower risk for recurrence (P = .035) and more favorable survival at 3 years (P = .024). Patients who required parapharyngeal space dissection and those with metastatic neck disease had the poorest survival rates. The overall survival at 3 years was 72.4%.

Conclusions:

Mastoidectomy and temporal bone resection permit preservation of the facial nerve when oncologically safe; they may help to achieve negative margins, and they allow facial nerve grafting when nerve sacrifice is required. Despite the poor prognostic indicators of facial paralysis, recurrent tumors, and perineural invasion, a significant number of patients can be salvaged successfully when a temporal bone procedure is combined with parotidectomy.
The Effect of the Degree of Branching in Hyperbranched Polyesters Used as Reactive Modifiers in Epoxy Thermosets
Authors: Foix David , Khalyavina Anna , Morell Mireia , Voit Brigitte , Lederer Albena , Ramis Xavier , Serra Angels
Published: July 2011

The effect of the degree of branching (DB) of a hyperbranched polyester (GBPEX) added as a modifier of new thermosets obtained from diglycidylether of bisphenol A has been studied. The use of ytterbium triflate as cationic initiator allows the hydroxyl chain‐ends in the GBPEX to become covalently linked to the matrix through the monomer activated propagation mechanism. The curing process has been studied by DSC and rheology. The DB of the modifier does not affect appreciably the thermal stability and the chemical reworkability but shrinkage exhibits a significant reduction on increasing the DB. Thermomechanical characteristics are also improved with increasing the DB of the modifier.

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Self‐Assembly Pluronic and β‐Cyclodextrin to Hollow Nanospheres for Enhanced Gene Delivery
Authors: Fan Min‐Min , Zhang Xi , Qin Jie , Li Bang‐Jing , Sun Xun , Zhang Sheng
Published: July 2011

This paper studies a kind of hollow nanospheres prepared by self‐assembly β‐cyclodextrins (β‐CDs) and poly(ethylene oxide)‐poly(propylene oxide)‐poly(ethylene oxide) (pluronic F127) for gene delivery. It was found that this kind of hollow nanospheres enable load PEI10K/DNA and the resulting F127NH2βCD/(PEI10K/DNA) with 0.08 µg/well DNA display equal or higher gene delivery capability compared to PEI10K/DNA with 1 µg/well DNA in the absence or presence of serum. The cytotoxicity of the nanospheres was over 100 times lower than that of PEI10K.

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In vivo1H MRS for musculoskeletal lesion characterization: which factors affect diagnostic accuracy?
Authors: Wang Chien‐Kuo , Li Chun‐Wei , Hsieh Tsyh‐Jyi , Lin Chii‐Jeng , Chien Song‐Hsiung , Tsai Kun‐Bow , Chang Kung‐Chao , Tsai Hong‐Ming
Published: July 2011

In vivo 1H MRS is a noninvasive imaging technique for the identification of malignancy. Musculoskeletal lesions vary in their composition, causing field inhomogeneity and magnetic susceptibility effects which may be technical and diagnostic challenges for MRS. This study investigated the factors that affect diagnostic accuracy in the use of MRS for the characterization of musculoskeletal neoplasms. During a 7‐year period, 210 consecutive patients with musculoskeletal lesions larger than 1.5 cm in diameter were examined. MRS of a single‐voxel point‐resolved spectroscopy sequence with TE = 135 ms was undertaken using a 1.5‐T scanner. Lesions with a choline signal‐to‐noise ratio larger than 3.0 were considered to be malignant tumors. The diagnostic accuracy was calculated for all lesions and for subgroups on the basis of lesion type (bone and soft tissue), lesion composition (mixed and solid nonsclerotic), lesion size (≤4, >4–10 and >10 cm), MR scanner (MR scanner 1 and 2) and selected voxel size (≤3, >3–8 and >8 cm3). Multivariate logistic regressions were performed to estimate the associations between each factor and diagnostic accuracy. The diagnostic accuracy was 73.3% for all lesions. The accuracy was 54.4% for mixed lesions and 80.4% for solid nonsclerotic lesions (p < 0.001). The diagnostic accuracy was lower for larger lesions [86.8% for lesions of ≤4 cm, 71.6% for lesions of >4–10 cm (p = 0.04) and 63.6% for lesions of >10 cm (p = 0.007)]. There was no difference in diagnostic accuracy for bone versus soft‐tissue lesions or as a function of MR scanner or voxel size. By the use of multivariate logistic regression, a solid nonsclerotic lesion was 3.15 times (95% confidence interval, 1.59–6.27) more likely than a mixed lesion to have a diagnosis (p = 0.001). MRS can be used to characterize musculoskeletal lesions, particularly solid nonsclerotic lesions. Copyright © 2011 John Wiley & Sons, Ltd.
Adenoid cystic carcinomas constitute a genomically distinct subgroup of triple‐negative and basal‐like breast cancers
Authors: Wetterskog Daniel , Lopez‐Garcia Maria Angeles , Lambros Maryou B , A'Hern Roger , Geyer Felipe C , Milanezi Fernanda , Cabral Maria C , Natrajan Rachael , Gauthier Arnaud , Shiu Kai‐Keen , Orr Nicholas , Shousha Sami , Gatalica Zoran , Mackay Alan , Palacios Jose , Reis‐Filho Jorge S , Weigelt Britta
Published: July 2011

Adenoid cystic carcinoma (AdCC) is a rare form of triple‐negative and basal‐like breast cancer that has an indolent clinical behaviour. Four breast AdCCs were recently shown to harbour the recurrent chromosomal translocation t(6;9)(q22–23;p23–24), which leads to the formation of the MYB–NFIB fusion gene. Our aims were (i) to determine the prevalence of the MYB–NFIB fusion gene in AdCCs of the breast; (ii) to characterize the gene copy number aberrations found in AdCCs; and (iii) to determine whether AdCCs are genomically distinct from histological grade‐matched or triple‐negative and basal‐like invasive ductal carcinomas of no special type (IDC‐NSTs). The presence of the MYB–NFIB fusion gene was investigated in 13 AdCCs of the breast by fluorescence in situ hybridization (FISH) and reverse transcriptase‐PCR (RT‐PCR), and MYB and BRCA1 RNA expression was determined by quantitative RT‐PCR. Fourteen AdCCs, 14 histological grade‐matched IDC‐NSTs, and 14 IDC‐NSTs of triple‐negative and basal‐like phenotype were microdissected and subjected to high‐resolution microarray‐based comparative genomic hybridization (aCGH). The MYB–NFIB fusion gene was detected in all but one AdCC. aCGH analysis demonstrated a relatively low number of copy number aberrations and a lack of recurrent amplifications in breast AdCCs. Contrary to grade‐matched IDC‐NSTs, AdCCs lacked 1q gains and 16q losses, and in contrast with basal‐like IDC‐NSTs, AdCCs displayed fewer gene copy number aberrations and expressed MYB and BRCA1 at significantly higher levels. Breast AdCCs constitute an entity distinct from grade‐matched and triple‐negative and basal‐like IDC‐NSTs, emphasizing the importance of histological subtyping of triple‐negative and basal‐like breast carcinomas. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The lack of knowledge about the voluntary reporting system of adverse drug reactions as a major cause of underreporting: direct survey among health professionals
Authors: Pérez García Mariley , Figueras Albert
Published: July 2011

Background

Underreporting suspected adverse drug reactions (ADRs) is one of the main problems that face the pharmacovigilance (PhV) systems based on yellow card schemes.

Objectives

To measure the knowledge level on the suspected ADR voluntary reporting system among physicians and pharmacists in Venezuela and to study its relationship with different variables.

Methods

A population‐based, anonymous, and self‐administered questionnaire was addressed to health professionals along the national territory of Venezuela. An algorithm was developed to classify the knowledge level on the voluntary reporting system.

Results

Taken as a whole, the level of knowledge on the voluntary reporting system was “poor.” Among the 515 participant physicians, 62.3% (95%CI = 58.0–66.5%) had a “poor” level of knowledge; PhV was associated with “control” of medicines use, and only 24.7% had ever reported a suspected ADR. “Medical specialty” was the only variable that showed a relationship with the knowledge level (p = 0.0041). Among the 78 participant pharmacists, 66.7% had a “poor” knowledge level (95%CI = 55.1–76.9%).

Conclusions

The knowledge level on the voluntary reporting system among physicians and pharmacists in Venezuela is poor. These results strengthen the hypothesis that being unaware of the adverse effects of medicines and not knowing the existence of a PhV system is a major cause of underreporting. A careful study of the actual knowledge of PhV could be the basis to set up interventions specifically designed to overcome misleading concepts and to improve the reporting rate at a national level. Copyright © 2011 John Wiley & Sons, Ltd.
The roles of shallow and deep levels in the recombination behavior of polycrystalline silicon on glass solar cells
Authors: Wong Johnson , Huang Jialiang , Varlamov Sergey , Green Martin A. , Keevers Mark
Published: July 2011

The recombination current in polycrystalline silicon on glass solar cells can be modeled by the superposition of two processes, one which involves only shallow electronic levels and another which occurs via deep levels at charged extended defects. The former process is most likely linked to clean dislocations, whereas the latter may originate either from charged dislocations or grain boundaries. The consideration of both kinds of processes is necessary for an accurate description of the device behaviors of poly‐Si on glass solar cells over a wide range of dopant densities. The effects of varying the impurity and dislocation densities are also briefly discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Hydrogenated amorphous silicon p–i–n solar cells deposited under well controlled ion bombardment using pulse‐shaped substrate biasing
Authors: Wank Michael A. , van Swaaij Rene , van de Sanden Richard , Zeman Miro
Published: July 2011

We applied pulse‐shaped biasing (PSB) to the expanding thermal plasma deposition of intrinsic hydrogenated amorphous silicon layers at substrate temperatures of 200 °C and growth rates of about 1 nm/s. Fourier transform infrared spectroscopy of intrinsic films showed a densification with increasing deposited energy and a reduction in void content, whereas dual‐beam photoconductivity measurements showed an increase in Urbach energy above 4.8 eV/Si atom. From dark conductivity and photoconductivity measurements, we determined a maximum photoresponse of 2 × 106 at 3 eV/Si atom, which decreased at higher deposited energies because of a higher dark conductivity as a result of a lower band gap. p–i–n solar cells with PSB applied during the intrinsic layer deposition showed initial energy conversion efficiencies of 7.4% at around 1 eV/Si atom. Decreasing open‐circuit voltage at >1 eV/Si atom can be related to a lower band gap, whereas the short‐circuit current drops at >4.8 eV/Si atom, predominantly because of hole collection losses as determined from quantum efficiency measurements. The reduced fill factor for >1 eV/Si atom was presumably related to a decrease in mobility‐lifetime product because of an increase in defect density. Copyright © 2011 John Wiley & Sons, Ltd.
Reactions of a putative metabolite of the model antitumor drug 2‐(4‐aminophenyl)benzothiazole with purines and pyrimidines
Authors: Novak Michael , Chakraborty Mrinal
Published: July 2011

Derivatives of 2‐(4‐aminophenyl)benzothiazole, 1, are being investigated as antitumor drugs, and for other medicinal applications. Although drug development has proceeded rapidly, little is known about the basis for the activity of these drugs. We have previously shown that the putative N‐acetoxy metabolite of 1, 8, decomposes in water to generate a long‐lived nitrenium ion, 11 (530 ns at room temperature). The kinetics of reaction of 8 with monomeric purines and the pyrimidine cytosine in aqueous solution are consistent with trapping of 11 after rate limiting ionization of 8. This is equivalent to the behavior of similar metabolites of carcinogenic polycyclic arylamines that have also been shown to react with deoxyribonucleic acid bases via a nitrenium ion mechanism. Selectivities of 11 and the nitrenium ion 13, derived from the carcinogen 4‐aminobiphenyl, for individual purines and pyrimidines are comparable, with both ions showing a marked preference for reaction with 2′‐deoxyguanosine and xanthosine, and much lower selectivity for inosine, adenosine, and the pyrimidine cytosine (C). Products of the reactions of the two nitrenium ions with the individual purines are similar, although there are some notable differences. The product of the reaction of 11 with C is similar to the product of the reaction of N‐acetoxy‐3,5‐dimethylaniline with 2′‐deoxycytidine (d‐C). These results indicate that 11 is not unique among arylnitrenium ions in its reactions with deoxyribonucleic acid bases. The basis for selective antitumor activity of 1 and its derivatives is not due to an unusual property of the nitrenium ion. Copyright © 2011 John Wiley & Sons, Ltd.
Estimating value at risk and conditional value at risk for count variables
Authors: Göb Rainer
Published: July 2011

Risk management and risk measures like value at risk and conditional value at risk originated in the financial and insurance industries. In recent years, the interest in risk management and risk measurement has spread over all industrial sectors. Finance and insurance applications focused on continuous data like financial return, profit or loss. In other contexts, e.g. in operational risk management, discrete count data are of like importance. The present study analyses theoretical and empirical aspects of the risk measures value at risk, tail conditional expectation, conditional value at risk under the binomial, negative binomial, and Poisson distribution. Particular emphasis is on interval estimation of the risk measures. Copyright © 2011 John Wiley & Sons, Ltd.
Job Stress and Coping: Self‐Employed versus Organizationally Employed Professionals
Authors: Oren Lior
Published: July 2011

In order to examine job stress and coping among self‐employed and organizationally employed professionals, job‐related stressors and coping strategies were assessed among self‐employed (n = 149) and organizationally employed (n = 159) professionals working as accountants, lawyers, pharmacists and psychologists. Results indicate that although self‐employed workers complained about lack of security and organizationally employed workers complained about lack of autonomy, no differences were found in overall stress levels or overload. Examination of workers' coping strategies provided a partial explanation for these findings. Stress levels negatively correlated with active coping and positively correlated with passive/avoidance coping; self‐employed workers were found to cope by confronting problems, whereas organizationally employed workers were found to cope by avoiding them. These findings qualify previous research findings on self‐employed and organizationally employed workers. Copyright © 2011 John Wiley & Sons, Ltd.
A New Insight to Interfacial Phenomena Occurring at Slag‐Metal Interfaces
Authors: Muhmood Luckman
Published: July 2011

Interfacial dilatational modulus was evaluated for slag‐metal systems using oxygen and sulfur as tracers at 1823 K. The high values of the dilatational modulus (5–10 times that obtained for surfactant adsorption) was directly related to the higher change in apparent interfacial tension prevailing at the slag‐metal interface. The variation in the dilatational modulus was attributed to the non‐uniform distribution of surface active elements at the interface and also due to the varying surface pressure. Further, experiments were designed to estimate the surface shear viscosity. A relationship was established to find the surface/interfacial shear viscosity from the Newton's law of viscosity. The order of magnitude of the interfacial shear viscosity at the slag‐metal interface was estimated from the values obtained earlier for the interfacial velocity. The order of magnitude obtained for slag‐metal systems was roughly 10–100 times that usually occurring in colloidal systems. The same could be attributed to the high bulk viscosities of the individual phases in slag‐metal systems. The order of magnitude of the interfacial velocity was verified from the equation generated earlier by dimension analysis to be similar to those obtained from experiments.
Aberrant right subclavian artery: incidence and correlation with other markers of Down syndrome in second‐trimester fetuses
Authors: Paladini D. , Sglavo G. , Pastore G. , Masucci A. , D'Armiento M. R. , Nappi C.
Published: July 2011

Objective

To assess the incidence of aberrant right subclavian artery (ARSA) and other strong markers of Down syndrome and their correlation in a large population of second‐trimester Down syndrome fetuses assessed in a tertiary referral center.

Methods

Presence or absence of ARSA and other major ultrasound markers of Down syndrome was assessed in a population of 106 second‐trimester Down syndrome fetuses referred to our unit for expert assessment and/or termination of pregnancy after karyotyping performed for positive first‐ or second‐trimester screening or advanced maternal age or on maternal request. All cases in which the diagnosis of Down syndrome followed the ultrasound detection of major anomalies or soft markers were excluded from the study, as were all cases with a gestational age less than 14 + 0 weeks. We searched for the ARSA on the three vessels and trachea view using color or power Doppler. All fetuses underwent a thorough anatomic assessment and fetal echocardiography. The other Down syndrome markers assessed were: absent or hypoplastic nasal bone (NB−), defined as length < 5th centile; nuchal fold ≥ 5 mm; and mild pyelectasis (> 5 mm). In addition, the presence of major cardiac and extracardiac defects was recorded. A correlation analysis was then performed in order to investigate possible associations between markers and/or major anomalies. Postmortem or postnatal diagnostic confirmation was available in all cases.

Results

The mean (SD) gestational age at ultrasound assessment was 20.4 (4.1) weeks. The incidence of the various variables in the population of Down syndrome fetuses was: ARSA, 25%; NB−, 43%; nuchal fold ≥ 5 mm, 16%; pyelectasis, 17%; major heart defects, 41%; atrioventricular septal defect, 25%; and extracardiac anomaly, 24%. The presence of ARSA did not correlate with any of the other variables. The only positive correlations (P < 0.05) were between NB− and pyelectasis, and between cardiac and extracardiac defects.

Conclusions

This represents the largest Down syndrome population assessed for ARSA. In this series, the incidence of ARSA was 25%, lower than previously reported in much smaller series. Its presence did not correlate with the presence of any other marker or major anomaly, including heart defects. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Effect of Synthetic Ligands of PPAR α, β/δ, γ, RAR, RXR and LXR on the Fatty Acid Composition of Phospholipids in Mice
Authors: Weiss Kathrin , Mihály Johanna , Liebisch Gerhard , Marosvölgyi Tamás , Schmitz Gerd , Decsi Tamás , Rühl Ralph
Published: July 2011

Nuclear hormone receptors are transcription factors that can be activated by nutrition‐derived ligands and alter the expression of various specific target genes. Stearoyl‐Coenzyme A desaturase (SCD1) converts palmitic acid (16:0) to palmitoleic acid (16:1n‐7) as well as stearic acid (18:0) to oleic acid (18:1n‐9). At the same time, elongase 6 (ELOVL6) elongates 16:1n‐7 and 18:1n‐9 to vaccenic acid (18:1n‐7) and eicosenoic acid (20:1n‐9). We examined how synthetic selective ligands of nuclear hormone receptors alter the gene expression of hepatic enzymes in mice. In addition, we examined how the regulation of these two enzymes influences fatty acid composition of phospholipids in liver and plasma. Mice were gavaged daily for 1 week with synthetic ligands of peroxisome proliferator‐activated receptor (PPAR) α, β/δ, γ, liver X receptor (LXR), retinoic acid receptor (RAR) and retinoid‐X receptor (RXR) for 1 week. Phospholipids from liver and plasma were analysed using ESI‐MS/MS and GC after saponification. Hepatic gene expression of SCD1 and ELOVL6 was measured using QRT‐PCR. SCD1 and ELOVL6 expression increased after the gavage of LXR and RXR ligands. The analysis of fatty acid composition of total phospholipids in plasma and liver showed increased percentage contributions of the SCD1 and ELOVL6 products 18:1n‐9, 18:1n‐7 and 20:1n‐9 after LXR and RXR ligand application. Analysis of total phospholipids from plasma and liver revealed a significant increase in monounsaturated fatty acids bound in phosphatidylcholine (PtdCho) and lysophosphatidylcholine (PtdEtn) after LXR and RXR ligand administration. Increased hepatic gene expression of SCD1 and ELOVL6 after gavage of selective RXR or LXR ligands to mice resulted in increased concentrations of their metabolic products in phospholipids of liver and plasma.
Effect of Temperature and Time on the Stability of Salmon Skin Oil During Storage
Authors: Aryee Alberta N. A. , Simpson Benjamin K. , Phillip Leroy E. , Cue Roger I.
Published: July 2011

The effect of 45 days of storage at 25, 4, −18 and −80 °C on the quality indices; free fatty acid (FFA) content, peroxide value (PV), thiobarbituric acid reactive substances (TBARS), and changes in the fatty acid (FA) profile of crude oil recovered from salmon fish skins were evaluated at 5 day intervals using spectrophotometric and titrimetric methods. Higher temperatures and longer storage time resulted in higher quantities of oxidative products in the salmon skin oil (SSO). By day 45, SSO stored at 25 and 4 °C had 8.50 and 8.29% FFA, 32.43 and 26.33 μg malondialdehyde (MDA) eq g−1 oil, and 88.19 and 64.53 mequiv peroxide kg−1 oil, respectively. No significant (p > 0.05) changes in fatty acid profile were observed at all the storage temperature and time studied.
Physiochemical Properties of Jatropha curcas Seed Oil from Different Origins and Candidate Plus Plants (CPPs)
Authors: Aminul Islam A. K. M. , Yaakob Z. , Anuar N. , Primandari S. R. P. , Osman M.
Published: July 2011

The physicochemical properties of Jatropha seed oil from 9 geographical origins and 24 candidate plus plants (CPPs) were evaluated. The yield of seed oil obtained by Soxhlet extraction using n‐hexane as solvent varied from 40.0% (Malaysia) to 48.4% (Vietnam) among seeds from different origins and 32.1% (CPP‐17) to 48.8% (CPP‐01) (w/w) among CPPs. Density, specific gravity, and refractive index of oil showed very little differences among all the seed sources. Oil from Borneo had the highest free fatty acid (FFA) content (2.3%) and a South African sample had the lowest FFA (0.4%), as oleic acids. Seed oil of CPP‐13 had the highest FFA content (1.2%) and seed oil of CPP‐17 the lowest (0.3%). Most of the CPPs in this study had an FFA content of less than 1%. Jatropha seed oil of Philippine origin had the highest iodine value (187.3 mg/g oil) and seed oil from Borneo the lowest (83.5 mg/g oil). The lowest saponification values were obtained from seed oil of Philippine origin (189.5 mg KOH/g) and CPP‐22 (183.3 mg KOH/g oil) from Malaysia. The maximum higher heating value (40.3 MJ/kg) was obtained from seed oil from Borneo. The cetane numbers range from 25.4 (Indonesia) to 56.0 (Borneo) among the oils of base material and 46.4 (CPP‐15) to 53.7 (CPP‐06) among CPPs. This study gives basic information of relevance for biodiesel production using Jatropha seeds from various origins.
AMPA workshop on challenges faced by investigators conducting Alzheimer's disease clinical trials
Authors: Vellas Bruno , Pesce Alain , Robert Philippe H. , Aisen Paul S. , Ancoli‐Israel Sonia , Andrieu Sandrine , Cedarbaum Jesse , Dubois Bruno , Siemers Eric , Spire Jean‐Paul , Weiner Michael W. , May Thomas S.
Published: July 2011

The recruitment and retention of patients are among the greatest challenges currently being faced by researchers who conduct Alzheimer's disease (AD) clinical trials. To discuss these challenges and other major issues associated with clinical research in AD, an international workshop was organized by the Association MonÉgasque pour la recherche sur la Maladie d'Alzheimer at Monte Carlo, Monaco, in February 2010, with the participation of leading research experts in the field of Alzheimer's. Key topics discussed were as follows: (1) the selection, recruitment, and retention of clinical trial subjects; (2) international co‐operation among researchers; and (3) patient rights and informed consent for participants in clinical trials. This article highlights some of the challenges faced by investigators when conducting clinical trials in AD, and it also offers some recommendations aimed at overcoming these challenges.
Building an integrated neurodegenerative disease database at an academic health center
Authors: Xie Sharon X. , Baek Young , Grossman Murray , Arnold Steven E. , Karlawish Jason , Siderowf Andrew , Hurtig Howard , Elman Lauren , McCluskey Leo , Van Deerlin Vivianna , Lee Virginia M.‐Y. , Trojanowski John Q.
Published: July 2011

Background

It is becoming increasingly important to study common and distinct etiologies, clinical and pathological features, and mechanisms related to neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and frontotemporal lobar degeneration. These comparative studies rely on powerful database tools to quickly generate data sets that match diverse and complementary criteria set by them.

Methods

In this article, we present a novel integrated neurodegenerative disease (INDD) database, which was developed at the University of Pennsylvania (Penn) with the help of a consortium of Penn investigators. Because the work of these investigators are based on Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and frontotemporal lobar degeneration, it allowed us to achieve the goal of developing an INDD database for these major neurodegenerative disorders. We used the Microsoft SQL server as a platform, with built‐in “backwards” functionality to provide Access as a frontend client to interface with the database. We used PHP Hypertext Preprocessor to create the “frontend” web interface and then used a master lookup table to integrate individual neurodegenerative disease databases. We also present methods of data entry, database security, database backups, and database audit trails for this INDD database.

Results

Using the INDD database, we compared the results of a biomarker study with those using an alternative approach by querying individual databases separately.

Conclusions

We have demonstrated that the Penn INDD database has the ability to query multiple database tables from a single console with high accuracy and reliability. The INDD database provides a powerful tool for generating data sets in comparative studies on several neurodegenerative diseases.
In silico modeling systems: Learning about the prevalence and dynamics of dementia through virtual experimentation
Authors: Vickland Victor , McDonnell Geoff , Werner Joel , Draper Brian , Low Lee‐Fay , Brodaty Henry
Published: July 2011

Background

Virtual experimentation using computer modeling creates opportunities for researchers who want to better understand disease processes, foresee effects of future demographics, and evaluate combinations of interventions when applied to larger target groups.

Methods

We created a computer model of dementia prevalence consisting of six population groups representing diagnosed and undiagnosed dementia at mild, moderate, and severe levels. Dynamic transitions between these groups corresponded to the gradual progression of disease. The seventh group represented the general population without dementia aged >60 years from which new dementia cases emerged. Through a series of virtual experiments we estimated future changes in the severity‐specific prevalence of dementia in Australia.

Results

The projected total prevalence of dementia in Australia for year 2040 changed from 742,000 to 986,000 (+33%) and to 433,000 (−42%) when the incidence rate was altered by ±50%. Increasing the transition time between mild and moderate dementia from 5 to 7 years and between moderate to severe from 7 to 9 years increased the prevalence of mild dementia by 23% and decreased the prevalence of severe dementia by 24%.

Conclusions

As computer modeling becomes more accepted, in silico experiments are being routinely performed to update demographic projections. Despite its simplicity, the framework of this model integrates a large pool of knowledge and consists of components which are dynamically interconnected. The computational logic underpins series of assumptions and binds them together with demographic data.