bluuebunny/crossref_metadata_2025 huggingface dataset:
The Small-school Friendship Dynamics of Adolescent Depressive Symptoms
Authors: Cheadle Jacob E. , Goosby Bridget J.
Published: June 2012

Adolescence is a time when depressive symptoms and friendships both intensify. The authors ask whether friendships change in response to depressive symptoms, whether individual distress is influenced by friends’ distress, and whether these processes vary by gender. To answer these questions, the authors use longitudinal Simulation Investigation for Empirical Network Analysis models to study how changes in friendships and depressive symptoms intertwine with each other among all adolescents as well as boy-only and girl-only networks in seven smaller K-12 Add Health schools. The findings indicate that distressed youth are more likely to be socially excluded, though depressive symptoms are also a basis for friendship formation. Moreover, friends influence one another’s mood levels. These processes differ for boys and girls, however, such that distressed girls are more likely to face exclusion and distressed boys are more likely to befriend and subsequently influence one another.
Revealing the role of phospholipase Cβ3 in the regulation of VEGF-induced vascular permeability
Authors: Hoeppner Luke H. , Phoenix Kathryn N. , Clark Karl J. , Bhattacharya Resham , Gong Xun , Sciuto Tracey E. , Vohra Pawan , Suresh Sandip , Bhattacharya Santanu , Dvorak Ann M. , Ekker Stephen C. , Dvorak Harold F. , Claffey Kevin P. , Mukhopadhyay Debabrata
Published: June 2012

VEGF induces vascular permeability (VP) in ischemic diseases and cancer, leading to many pathophysiological consequences. The molecular mechanisms by which VEGF acts to induce hyperpermeability are poorly understood and in vivo models that easily facilitate real-time, genetic studies of VP do not exist. In the present study, we report a heat-inducible VEGF transgenic zebrafish (Danio rerio) model through which VP can be monitored in real time. Using this approach with morpholino-mediated gene knock-down and knockout mice, we describe a novel role of phospholipase Cβ3 as a negative regulator of VEGF-mediated VP by regulating intracellular Ca2+ release. Our results suggest an important effect of PLCβ3 on VP and provide a new model with which to identify genetic regulators of VP crucial to several disease processes.
Second malignancies in total therapy 2 and 3 for newly diagnosed multiple myeloma: influence of thalidomide and lenalidomide during maintenance
Authors: Usmani Saad Z. , Sexton Rachel , Hoering Antje , Heuck Christoph J. , Nair Bijay , Waheed Sarah , Al Sayed Yazan , Chauhan Nabeel , Ahmad Nisar , Atrash Shebli , Petty Nathan , van Rhee Frits , Crowley John , Barlogie Bart
Published: June 2012

Thalidomide and lenalidomide constitute an important part of effective myeloma therapy. Recent data from the Intergroup Francophone du Myélome, Cancer and Leukemia Group B, and Gruppo Italiano Malattie Ematologiche dell Adulto MM-015 trials suggest that lenalidomide maintenance therapy is associated with a higher incidence of second primary malignancies (SPMs), including both hematologic and solid malignancies. In the present study, we analyzed data from the Total Therapy 2 (TT2) trial, along with the 2 Total Therapy 3 (TT3) trials. TT2 patients were assigned randomly to either a control group (no thalidomide) or to the experimental group (thalidomide during induction, between transplantations, and during consolidation and maintenance). The 2 TT3 trials used thalidomide and bortezomib during induction, before and in consolidation after tandem melphalan-based transplantation; TT3A applied VTD (bortezomib, thalidomide, dexamethasone) in the first year of maintenance and TD for 2 more years, whereas TT3B used VRD (bortezomib, lenalidomide, dexamethasone) maintenance for 3 years. The cumulative incidence of SPMs did not differ significantly among the TT trial components when measured from enrollment (P = .78) or from initiation of maintenance (P = .82). However, a pairwise comparison of the TT2 arms suggested a lower incidence of hematologic SPMs in the thalidomide maintenance arm (hazard ratio = 0.38; P = .09). These trials are registered at www.clinicaltrials.gov as NCT00573391 (TT2), NCT00081939 (TT3A), and NCT00572169 (TT3B).
Rescue of recombinant peste des petits ruminants virus: creation of a GFP-expressing virus and application in rapid virus neutralization test
Authors: Hu Qianqian , Chen Weiye , Huang Kehe , Baron Michael D , Bu Zhigao
Published: June 2012

Peste des petits ruminants virus (PPRV) causes high mortality in goats and sheep and the disease has shown a greatly increased geographic distribution over the last 15 years. It is responsible for serious socioeconomic problems in some of the poorest developing countries. The ability to create recombinant PPRV would provide a useful tool for investigating the biology of the virus and the pathology of disease, as well as for developing new vaccines and diagnostic methods. Here we report the first successful rescue of recombinant PPRV from a full-length cDNA clone of the virus genome. Successful recovery of PPRV was achieved by using a RNA polymerase II promoter to drive transcription of the full-length virus antigenome. We have used this technique to construct a virus expressing a tracer protein (green fluorescent protein, GFP). The recombinant virus replicated as well as the parental virus and could stably express GFP during at least 10 passages. The newly established reverse genetics system for PPRV provides a novel method for constructing a vaccine using PPRV as a vector, and will also prove valuable for fundamental research on the biology of the virus. We found that our recombinant virus allowed more rapid and higher throughput assessment of PPRV neutralization antibody titer via the virus neutralization test (VNT) compared with the traditional method.
Total and individual antioxidant intake and risk of epithelial ovarian cancer
Authors: Gifkins Dina , Olson Sara H , Paddock Lisa , King Melony , Demissie Kitaw , Lu Shou-En , Kong Ah-Ng Tony , Rodriguez-Rodriguez Lorna , Bandera Elisa V
Published: June 2012

Background

Limiting oxidative stress to the ovarian epithelium has been proposed as a first-line defense against ovarian cancer. Although evidence for an association between individual dietary antioxidant intake and ovarian cancer risk is conflicting, the combined evidence suggests a modest inverse association. Our study aimed to evaluate the association between total antioxidant capacity (TAC) and individual antioxidant intakes (vitamin C, vitamin E, beta-carotene, selenium, lutein, and lycopene) and ovarian cancer risk.

Methods

We conducted a population-based case–control study in New Jersey. Cases were women ages 21 years and older with newly diagnosed epithelial ovarian cancer who resided in six counties of New Jersey. Controls were women in the same age range who resided in the same geographic area. A total of 205 ovarian cancer cases and 390 controls were included. Dietary intake was ascertained using the Block food frequency questionnaire (FFQ), and TAC indices were constructed by linking FFQ-derived estimates to two standardized antioxidant capacity databases, the USDA Oxygen Radical Absorbance Capacity (ORAC) Database, and the University of Olso’s Antioxidant Food Database. Multivariate logistic regression models were used to calculate odds ratios and 95 % confidence intervals while controlling for major ovarian cancer risk factors.

Results

We found a strong inverse association with selenium from food sources (OR: 0.41; 95 % CI: 0.20-0.85, for the highest vs. lowest tertile of dietary selenium intake). However, there was little evidence of an association with dietary TAC or the others individual antioxidants. In contrast, compared to non-users, supplement users had significant increased risk for all micronutrients, but no statistically significant increased risk was observed for combined intake from foods and supplements of any of these antioxidants.

Conclusions

This study found an inverse association between selenium consumption from food sources and ovarian cancer risk, while there was little evidence of an association with TAC or any of the other individual antioxidants. Additional research is needed to confirm these findings.
Fatty acid profile and proliferation of bovine blood mononuclear cells after conjugated linoleic acid supplementation
Authors: Renner Lydia , Pappritz Julia , Kramer Ronny , Kersten Susanne , Jahreis Gerhard , Dänicke Sven
Published: June 2012

Background

Conjugated linoleic acids (CLA) are in focus of dairy cattle research because of its milk fat reducing effects. Little is known about the impact of CLA on immune function in dairy cows. Therefore, in the present study we investigated the effects of a long term supplementation of dairy cows with CLA on the fatty acid profile of peripheral blood mononuclear cells (PBMC) and their proliferation ex vivo.

Results

The supplementation of dairy cows with either 100 g/d of a control fat preparation (CON, n = 15), 50 g/d of the control fat preparation and 50 g/d CLA supplement – containing 12.0% cis-9, trans-11 and 11.9% trans-10, cis-12 CLA of total fatty acid methyl esters – (CLA-50, n = 15) or 100 g/d of the CLA supplement (CLA-100, n = 16) did not influence the major fatty acids (C18:0, C16:0, cis-9 C18:1, cis-9, cis-12 C18:2, cis-5, cis-8, cis-11, cis-14 C20:4) in the lipid fraction of PBMC. The proportion of trans-10, cis-12 CLA of total fatty acids was increased in both CLA supplemented groups, but there was no effect on the cis-9, trans-11 isomer. Furthermore, the proportion of trans-9 C18:1 and cis-12 C24:1 was reduced in the CLA-100 group. The mitogen stimulated cell proliferation was not influenced by CLA feeding.

Conclusion

CLA supplementation influenced the FA profile of some minor FA in PBMC, but these changes did not lead to differences in the mitogen induced activation of the cells.
Thickness dependency of field emission in amorphous and nanostructured carbon thin films
Authors: Shakerzadeh Maziar , Teo Edwin Hang Tong , Tay Beng Kang
Published: June 2012

Thickness dependency of the field emission of amorphous and nanostructured carbon thin films has been studied. It is found that in amorphous and carbon films with nanometer-sized sp
2 clusters, the emission does not depend on the film thickness. This further proves that the emission happens from the surface sp
2 sites due to large enhancement of electric field on these sites. However, in the case of carbon films with nanocrystals of preferred orientation, the emission strongly depends on the film thickness. sp
2-bonded nanocrystals have higher aspect ratio in thicker films which in turn results in higher field enhancement and hence easier electron emission.
Gold and silver nanoparticles for biomolecule immobilization and enzymatic catalysis
Authors: Petkova Galina A , Záruba Кamil , Žvátora Pavel , Král Vladimír
Published: June 2012

In this work, a simple method for alcohol synthesis with high enantiomeric purity was proposed. For this, colloidal gold and silver surface modifications with 3-mercaptopropanoic acid and cysteamine were used to generate carboxyl and amine functionalized gold and silver nanoparticles of 15 and 45 nm, respectively. Alcohol dehydrogenase from Thermoanaerobium brockii (TbADH) and its cofactor (NADPH) were physical and covalent (through direct adsorption and using cross-linker) immobilized on nanoparticles' surface. In contrast to the physical and covalent immobilizations that led to a loss of 90% of the initial enzyme activity and 98% immobilization, the use of a cross-linker in immobilization process promoted a loss to 30% of the initial enzyme activity and >92% immobilization. The yield of NADPH immobilization was about 80%. The best results in terms of activity were obtained with Ag-citr nanoparticle functionalized with carboxyl groups (Ag-COOH), Au-COOH(CTAB), and Au-citr functionalized with amine groups and stabilized with CTAB (Au-NH2(CTAB)) nanoparticles treated with 0.7% and 1.0% glutaraldehyde. Enzyme conformation upon immobilization was studied using fluorescence and circular dichroism spectroscopies. Shift in ellipticity at 222 nm with about 4 to 7 nm and significant decreasing in fluorescence emission for all bioconjugates were observed by binding of TbADH to silver/gold nanoparticles. Emission redshifting of 5 nm only for Ag-COOH-TbADH bioconjugate demonstrated change in the microenvironment of TbADH. Enzyme immobilization on glutaraldehyde-treated Au-NH2(CTAB) nanoparticles promotes an additional stabilization preserving about 50% of enzyme activity after 15 days storage. Nanoparticles attached-TbADH-NADPH systems were used for enantioselective (ee > 99%) synthesis of (S)-7-hydroxy-2-tetralol.
EGF-Like Factors Induce Expansion of the Cumulus Cell-Oocyte Complexes by Activating Calpain-Mediated Cell Movement
Authors: Kawashima Ikko , Liu Zhilin , Mullany Lisa K. , Mihara Toshihiro , Richards Joanne S. , Shimada Masayuki
Published: June 2012

Cumulus cell-oocyte complex (COC) expansion is obligatory for LH-induced ovulation and is initiated by LH induction of the epidermal growth factor (EGF)-like factors that mediate the synthesis of the hyaluronan-rich matrix and hyaluronan-stabilizing factors. COC expansion also involves the movement of cumulus cells within the matrix by mechanisms that have not been characterized. We document herein that two proteases, calpain 2 and to a lesser extent calpain 1, are expressed in cumulus cells and that the proteolytic activity of these enzymes is rapidly and significantly increased in COC isolated from human chorionic gonadotropin-induced ovulatory follicles in vivo. Stimulation of calpain activity was associated with proteolytic degradation of paxillin and talin (two components of focal adhesion complexes), cell detachment, and the formation of cell surface bleb-like protrusions. Injection of a calpain inhibitor in vivo reduced 1) human chorionic gonadotropin-stimulated calpain enzyme activity, 2) cell detachment, 3) membrane protrusion formation, and 4) COC expansion by mechanisms that did not alter Has2 expression. During EGF-like factor induction of COC expansion in culture, calpain activity was increased by ERK1/2 and intracellular Ca2+ signaling pathways. Inhibition of calpain activity in cultured COC blocked cumulus cell detachment, protrusion formation, and the vigorous movement of cumulus cells. As a consequence, COC expansion was impaired. Collectively, these results show that two highly coordinated processes control COC expansion. One process involves the synthesis of the hyaluronan matrix, and the other mediates cumulus cell detachment and movement. The latter are controlled by calpain activation downstream of the EGF receptor activation of the Ca2+ pathway and ERK1/2 pathways.
A Notch-dependent molecular circuitry initiates pancreatic endocrine and ductal cell differentiation
Authors: Shih Hung Ping , Kopp Janel L. , Sandhu Manbir , Dubois Claire L. , Seymour Philip A. , Grapin-Botton Anne , Sander Maike
Published: June 2012

In the pancreas, Notch signaling is thought to prevent cell differentiation, thereby maintaining progenitors in an undifferentiated state. Here, we show that Notch renders progenitors competent to differentiate into ductal and endocrine cells by inducing activators of cell differentiation. Notch signaling promotes the expression of Sox9, which cell-autonomously activates the pro-endocrine gene Ngn3. However, at high Notch activity endocrine differentiation is blocked, as Notch also induces expression of the Ngn3 repressor Hes1. At the transition from high to intermediate Notch activity, only Sox9, but not Hes1, is maintained, thus de-repressing Ngn3 and initiating endocrine differentiation. In the absence of Sox9 activity, endocrine and ductal cells fail to differentiate, resulting in polycystic ducts devoid of primary cilia. Although Sox9 is required for Ngn3 induction, endocrine differentiation necessitates subsequent Sox9 downregulation and evasion from Notch activity via cell-autonomous repression of Sox9 by Ngn3. If high Notch levels are maintained, endocrine progenitors retain Sox9 and undergo ductal fate conversion. Taken together, our findings establish a novel role for Notch in initiating both ductal and endocrine development and reveal that Notch does not function in an on-off mode, but that a gradient of Notch activity produces distinct cellular states during pancreas development.
Transient downregulation of Bmp signalling induces extra limbs in vertebrates
Authors: Christen Bea , Rodrigues Alexandre Miguel Cavaco , Monasterio Monserrat Barragán , Roig Carme Fabregat , Belmonte Juan Carlos Izpisua
Published: June 2012

Bone morphogenetic protein (Bmp) signalling has been implicated in setting up dorsoventral patterning of the vertebrate limb and in its outgrowth. Here, we present evidence that Bmp signalling or, more precisely, its inhibition also plays a role in limb and fin bud initiation. Temporary inhibition of Bmp signalling either by overexpression of noggin or using a synthetic Bmp inhibitor is sufficient to induce extra limbs in the Xenopus tadpole or exogenous fins in the Danio rerio embryo, respectively. We further show that Bmp signalling acts in parallel with retinoic acid signalling, possibly by inhibiting the known limb-inducing gene wnt2ba.
Foxp1/4 control epithelial cell fate during lung development and regeneration through regulation of anterior gradient 2
Authors: Li Shanru , Wang Yi , Zhang Yuzhen , Lu Min Min , DeMayo Francesco J. , Dekker Joseph D. , Tucker Philip W. , Morrisey Edward E.
Published: June 2012

The molecular pathways regulating cell lineage determination and regeneration in epithelial tissues are poorly understood. The secretory epithelium of the lung is required for production of mucus to help protect the lung against environmental insults, including pathogens and pollution, that can lead to debilitating diseases such as asthma and chronic obstructive pulmonary disease. We show that the transcription factors Foxp1 and Foxp4 act cooperatively to regulate lung secretory epithelial cell fate and regeneration by directly restricting the goblet cell lineage program. Loss of Foxp1/4 in the developing lung and in postnatal secretory epithelium leads to ectopic activation of the goblet cell fate program, in part, through de-repression of the protein disulfide isomerase anterior gradient 2 (Agr2). Forced expression of Agr2 is sufficient to promote the goblet cell fate in the developing airway epithelium. Finally, in a model of lung secretory cell injury and regeneration, we show that loss of Foxp1/4 leads to catastrophic loss of airway epithelial regeneration due to default differentiation of secretory cells into the goblet cell lineage. These data demonstrate the importance of Foxp1/4 in restricting cell fate choices during development and regeneration, thereby providing the proper balance of functional epithelial lineages in the lung.
In-Stream Measurement of Canola (Brassica Napus L.) Seed Oil Concentration Using in-line near Infrared Reflectance Spectroscopy
Authors: Long Daniel S. , McCallum John D. , Young Francis L. , Lenssen Andrew W.
Published: June 2012

Natural variation in the seed oil concentration of oilseed crops sent to a crushing plant can impair the recovery of the oil from the seed. Consequently, there is interest in applying in-line near infrared (NIR) spectroscopy to measure the oil concentration of the seed to be processed and, in using the information obtained, to maximise expeller efficiency. The objective of this study was to determine how well in-line NIR spectroscopy could determine the seed oil concentration of canola ( Brassica napus L.) when there was direct contact of the sensor head with the grain stream. Reflectance spectra from 850 nm to 1650 nm were obtained by sliding grain samples of canola directly across the sensor head of the Polytec 1721 NIR reflectance analyser. Reference analytical results were estimated using the NIR optical spectra as regression estimators. The resulting prediction equation with eight latent variables resulted in a coefficient of determination of 0.95, standard error of cross-validation of 0.727% and relative performance determination of 4.77. Validation results, based on site or year omission, confirmed the ability of the instrument to accurately predict seed oil concentration in a grain stream. This creates opportunities for monitoring the oil content of seed entering the expeller and using this information to adjust the expeller for maximum efficiency.
Non-Invasive Detection of Protein Content in Corn Distillers Dried Grains with Solubles: Method for Selecting Spectral Variables to Construct High-Performance Calibration Model Using near Infrared Reflectance Spectroscopy
Authors: Zhou Xingfan , Yang Zengling , Huang Guangqun , Han Lujia
Published: June 2012

Corn distillers dried grains with solubles (DDGS), a byproduct of the bioethanol industry, is commonly used as animal feed. This paper evaluates the use of backward variable selection partial least square (BVSPLS) and genetic algorithm (GA) methods to select the spectral variables of near infrared (NIR) reflectance spectroscopy and construct high-performance calibration models of protein content in corn DDGS. The BVSPLS analysis utilised 16% of the spectral variables. Compared to the full spectrum model, the model constructed from the variables selected by the BVSPLS analysis significantly improved the accuracy of the model fit and achieved a 19% decrease in the standard error of validation ( SEP) and a 23% increase in the residual validation deviation ( RPD). The GA analysis selected 8% of the total NIR spectral variables and the model constructed from these selected variables had a fitted accuracy comparable to that of the full spectrum model. The spectral variables selected by both the BVSPLS analysis and GA analysis significantly simplified the NIR calibration model and provided better correlation between the selected spectral variables and protein content of corn DDGS. These results also have important implications for the development of a rapid, non-invasive, online analysis system to detect protein content of corn DDGS in-situ.
Cyclin D1 expression in podocytes: regulated by mitogens in collaboration with integrin–extracellular matrix interaction through extracellular signal-regulated kinase
Authors: Chen Chien-An , Cheng Yu-Chi , Hwang Jyh-Chang , Chang Jer-Ming , Guh Jinn-Yuh , Chen Hung-Chun
Published: June 2012

Cyclin D1 plays significant roles in cell cycle entry and migration. We have documented that both integrin α3 β1 expressions and the number of podocytes were reduced in focal segmental glomerulosclerosis. We wondered whether integrin–extracellular matrix (ECM) interaction was involved in the regulation of cyclin D1 expression, and the possible signaling pathways in mitogen-stimulating podocytes. Cultured podocytes were divided into serum (mitogens/growth factors)-starved and serum-stimulated groups. Reverse transcription polymerase chain reaction was used to detect cyclin D1 mRNA, and Western blot analysis was used to measure protein concentrations of cyclin D1 and extracellular signal-regulated kinase (ERK) activation (p-ERK/ERK). The integrin–ECM interaction was blocked by anti- β1-integrin monoclonal antibody or RGDS (Arg-Gly-Asp-Ser). The MEK inhibitor, U0126, was used to inhibit ERK activation. The results showed that there was little cyclin D1 protein in serum-starved groups, but it was abundant in serum-stimulated groups. Both cyclin D1 mRNA and protein levels were reduced in serum-stimulated podocytes after blocking integrin–ECM interaction. ERK activation in serum-stimulated podocytes was significantly decreased after blocking integrin–ECM interaction. Cyclin D1 mRNA and protein concentrations in serum-stimulated podocytes were reduced after blocking ERK activation by U0126. We demonstrate that integrin–ECM interaction collaborates with mitogens to activate ERK/mitogen-activated protein kinase pathways which are essential for cyclin D1 expression in podocytes.
The effect of waiting times from general practitioner referral to MRI or orthopaedic consultation for the knee on patient-based outcomes
Authors: Brealey S , Andronis L , Dale V , Gibbon A J , Gilbert F J , Hendry M , Hood K , King D , Wilkinson C ,   on behalf of the DAMASK Trial Team
Published: June 2012

Objectives

The purpose of this study was to test for the effect of waiting time from general practitioner (GP) referral to MRI or to orthopaedic consultation on outcomes of patients with knee problems, and to test whether any characteristics of trial participants predicted waiting time to MRI or orthopaedics.

Methods

We undertook secondary analyses of data on 553 participants from a randomised trial who were recruited from 163 general practices during November 2002 to October 2004.

Results

Of the patients allocated to MRI, 263 (94%) had an MRI, and of those referred to orthopaedics, 236 (86%) had an orthopaedic consultation. The median (interquartile range) waiting time in days from randomisation to MRI was 41.0 (21.0–71.0) and to orthopaedic appointment was 78.5 (54.5–167.5). Waiting time was found to have no significant effect on patient outcome for both the Short Form 36-item (SF-36) physical functioning score (p=0.570) and the Knee Quality of Life 26-item (KQoL-26) physical functioning score (p=0.268). There was weak evidence that males waited less time for their MRI (p=0.049) and older patients waited longer for their orthopaedic referral (p=0.049). For patients who resided in the catchment areas of some centres there were significantly longer waiting times for both MRI and orthopaedic appointment.

Conclusion

Where patients reside is a strong predictor of waiting time for access to services such as MRI or orthopaedics. There is no evidence to suggest, however, that this has a significant effect on physical well-being in the short term for patients with knee problems.
Breast tomosynthesis and digital mammography: a comparison of diagnostic accuracy
Authors: Svahn T M , Chakraborty D P , Ikeda D , Zackrisson S , Do Y , Mattsson S , Andersson I
Published: June 2012

Objective

Our aim was to compare the ability of radiologists to detect breast cancers using one-view breast tomosynthesis (BT) and two-view digital mammography (DM) in an enriched population of diseased patients and benign and/or healthy patients.

Methods

All participants gave informed consent. The BT and DM examinations were performed with about the same average glandular dose to the breast. The study population comprised patients with subtle signs of malignancy seen on DM and/or ultrasonography. Ground truth was established by pathology, needle biopsy and/or by 1-year follow-up by mammography, which retrospectively resulted in 89 diseased breasts (1 breast per patient) with 95 malignant lesions and 96 healthy or benign breasts. Two experienced radiologists, who were not participants in the study, determined the locations of the malignant lesions. Five radiologists, experienced in mammography, interpreted the cases independently in a free-response study. The data were analysed by the receiver operating characteristic (ROC) and jackknife alternative free-response ROC (JAFROC) methods, regarding both readers and cases as random effects.

Results

The diagnostic accuracy of BT was significantly better than that of DM (JAFROC: p=0.0031, ROC: p=0.0415). The average sensitivity of BT was higher than that of DM (∼90% vs ∼79%; 95% confidence interval of difference: 0.036, 0.108) while the average false-positive fraction was not significantly different (95% confidence interval of difference: −0.117, 0.010).

Conclusion

The diagnostic accuracy of BT was superior to DM in an enriched population.
Ultrasound of the male anterior urethra
Authors: Shaida N , Berman L H
Published: June 2012

Imaging of the anterior male urethra has traditionally been performed by fluoroscopic contrast urethrography. While providing easily interpretable images, this technique has a number of disadvantages associated with it. An alternative approach is to use ultrasound to assess the lumen of the urethra and the periurethral tissues. Here we describe the development of urethral ultrasound and the ascending and descending urethral ultrasound techniques employed in our institution with reference to commonly and uncommonly encountered pathologies. We also identify common pitfalls and how to avoid them.
Radiofrequency ablation combined with transcatheter arterial embolisation in rabbit liver: investigation of the ablation zone according to the time interval between the two therapies
Authors: Lee I J , Kim Y I , Kim K W , Kim D H , Ryoo I , Lee M W , Chung J W
Published: June 2012

Objectives

This study was designed to evaluate the extent of the radiofrequency ablation zone in relation to the time interval between transcatheter arterial embolisation (TAE) and radiofrequency ablation (RFA) and, ultimately, to determine the optimal strategy of combining these two therapies for hepatocellular carcinoma.

Methods

15 rabbits were evenly divided into three groups: Group A was treated with RFA alone; Group B was treated with TAE immediately followed by RFA; and Group C was treated with TAE followed by RFA 5 days later. All animals underwent perfusion CT (PCT) scans immediately after RFA. Serum liver transaminases were measured to evaluate acute liver damage. Animals were euthanised for pathological analysis of ablated tissues 10 days after RFA. Non-parametric analyses were conducted to compare PCT indices, the RFA zone and liver transaminase levels among the three experimental groups.

Results

Group B showed a significantly larger ablation zone than the other two groups. Arterial liver perfusion and hepatic perfusion index represented well the perfusion decrease after TAE on PCT. Although Group B showed the most elevated liver transaminase levels at 1 day post RFA, the enzymes decreased to levels that were not different from the other groups at 10 days post-RFA.

Conclusions

When combined TAE and RFA therapy is considered, TAE should be followed by RFA as quickly as possible, as it can be performed safely without serious hepatic deterioration, despite the short interval between the two procedures.
A Time Predefined Variable Depth Search for Nurse Rostering
Authors: Burke Edmund K. , Curtois Timothy , Qu Rong , Vanden Berghe Greet
Published: June 2012

This paper presents a variable depth search for the nurse rostering problem. The algorithm works by chaining together single neighbourhood swaps into more effective compound moves. It achieves this by using heuristics to decide whether to continue extending a chain and which candidates to examine as the next potential link in the chain. Because end users vary in how long they are willing to wait for solutions, a particular goal of this research was to create an algorithm that accepts a user specified computational time limit and uses it effectively. When compared against previously published approaches the results show that the algorithm is very competitive.
Separation and Extension of Cover Inequalities for Conic Quadratic Knapsack Constraints with Generalized Upper Bounds
Authors: Atamtürk Alper , Muller Laurent Flindt , Pisinger David
Published: June 2012

Motivated by addressing probabilistic 0–1 programs we study the conic quadratic knapsack polytope with generalized upper bound (GUB) constraints. In particular, we investigate separating and extending GUB cover inequalities. We show that, unlike in the linear case, determining whether a cover can be extended with a single variable is 𝒩𝒫-hard. We describe and compare a number of exact and heuristic separation and extension algorithms which make use of the structure of the constraints. Computational experiments are performed for comparing the proposed separation and extension algorithms. These experiments show that a judicious application of the extended GUB cover cuts can reduce the solution time of conic quadratic 0–1 programs with GUB constraints substantially.
South Korean FTA Negotiations
Authors: Robertson Jeffrey
Published: June 2012

Scholars and practitioners have argued convincingly that there exists a distinct South Korean national style in negotiation. However, recent Free Trade Agreement negotiations between the U.S. and ROK confirm that under certain conditions, national style can be less relevant and quite possibly irrelevant.
Public Nomination and Direct Election in China
Authors: Tsai Wen-Hsuan , Kao Peng-Hsiang
Published: June 2012

This research takes the case of Public Nomination and Direct Election, currently being rolled out in the People's Republic of China, to explain the function of elections in China. We believe that the goal of implementing this election system is to increase the governing ability of the Chinese Communist Party, thus sustaining the survival of the party-state system.
Hong Kong's Democratic Movement and the Making of China's Offshore Civil Society
Authors: Hung Ho-fung , Ip Iam-chong
Published: June 2012

Hong Kong's civil society has remained vibrant since the sovereignty handover in 1997, thanks to an active defense by the democratic movement against Beijing's attempts to control civil liberties. Hong Kong is becoming mainland China's offshore civil society, serving as a free platform for information circulation and organizing among mainland activists and intellectuals.
Protein arginine methyltransferase 6-dependent gene expression and splicing: association with breast cancer outcomes
Authors: Dowhan Dennis H , Harrison Matthew J , Eriksson Natalie A , Bailey Peter , Pearen Michael A , Fuller Peter J , Funder John W , Simpson Evan R , Leedman Peter J , Tilley Wayne D , Brown Melissa A , Clarke Christine L , Muscat George E O
Published: June 2012

Protein arginine methyltransferase-6 (PRMT6) regulates steroid-dependent transcription and alternative splicing and is implicated in endocrine system development and function, cell death, cell cycle, gene expression and cancer. Despite its role in these processes, little is known about its function and cellular targets in breast cancer. To identify novel gene targets regulated by PRMT6 in breast cancer cells, we used a combination of small interfering RNA and exon-specific microarray profilingin vitrocoupled toin vivovalidation in normal breast and primary human breast tumours. This approach, which allows the examination of genome-wide changes in individual exon usage and total transcript levels, demonstrated thatPRMT6knockdown significantly affected i) the transcription of 159 genes and ii) alternate splicing of 449 genes. ThePRMT6-dependent transcriptional and alternative splicing targets identifiedin vitrowere validated in human breast tumours. Using the list of genes differentially expressed between normal andPRMT6knockdown cells, we generated aPRMT6-dependent gene expression signature that provides an indication of PRMT6 dysfunction in breast cancer cells. Interrogation of several well-studied breast cancer microarray expression datasets with thePRMT6gene expression signature demonstrated that PRMT6 dysfunction is associated with better overall relapse-free and distant metastasis-free survival in the oestrogen receptor (ER (ESR1)) breast cancer subgroup. These results suggest that dysregulation ofPRMT6-dependent transcription and alternative splicing may be involved in breast cancer pathophysiology and the molecular consequences identifying a unique and informative biomarker profile.
Sequence-Based Detection and Breakpoint Assembly of Polymorphic Inversions
Authors: Corbett-Detig Russell B , Cardeno Charis , Langley Charles H
Published: June 2012

Inversion polymorphisms have occupied a privileged place in Drosophila genetic research since their discovery in the 1920s. Indeed, inversions seem to be nearly ubiquitous, and the majority of species that have been thoroughly surveyed have been found to be polymorphic for one or more chromosomal inversions. Despite enduring interest, however, inversions remain difficult to study because their effects are often cryptic, and few efficient assays have been developed. Even in Drosophila melanogaster, in which inversions can be reliably detected and have received considerable attention, the breakpoints of only three inversions have been characterized molecularly. Hence, inversion detection and assay design remain important unsolved problems. Here, we present a method for identification and local de novo assembly of inversion breakpoints using next-generation paired-end reads derived from D. melanogaster isofemale lines. PCR and cytological confirmations demonstrate that our method can reliably assemble inversion breakpoints, providing tools for future research on D. melanogaster inversions as well as a framework for detection and assay design of inversions and other chromosome aberrations in diverse taxa.
GaN quantum dots as charge storage elements for memory devices
Authors: Dimitrakis P. , Normand P. , Bonafos C. , Papadomanolaki E. , Iliopoulos E.
Published: June 2012

We investigated the fabrication and the memory characteristics of metal-oxide-semiconductor (MOS) capacitors with GaN quantum-dots (QDs) embedded in the gate insulator. The GaN-QDs, which act as discrete charge storage nodes, were deposited by radio-frequency molecular-beam-deposition (RF-MBD). The influence of the deposition dose on the QDs size and density was investigated by TEM studies. Subsequent electrical characterization measurements on memory capacitors revealed enhanced electron charge trapping leading to significant memory windows. Charge retention measurements at room temperature showed that the sample with the lowest concentration of QDs exhibits a significant programming window after ten-years.
Properties of Hydrogenated Amorphous Silicon-Germanium Alloys Deposited by Dual Target Reactive Magnetron Sputtering
Authors: Levang Samuel J. , Doyle James R.
Published: June 2012

Hydrogenated amorphous silicon-germanium alloy thin films (a-Si1-xGex:H) were deposited using reactive magnetron sputtering. Dual targets of silicon and germanium were sputtered in an argon + hydrogen atmosphere using rf excitation. Films with x = 0.4 were deposited as a function of substrate temperature and hydrogen partial pressure, and were evaluated by dark and photoconductivity, infrared absorption, and optical transmission. Photosensitivity reached a maximum value of about 5000 between 150 and 200 °C. Using the stretching modes in the region of 2000 cm-1, the hydrogen bonding was characterized in terms of the preferential attachment ratio (PA), which represents the ratio of H bonded to silicon to that bonded to germanium. The PA shows a systematic increase with increasing temperature, independent of hydrogen partial pressure. The interplay between thermodynamic and kinetics effects in determining PA and film quality will be discussed.
EFFECTS OF INTERELECTRODE SPACING ON THE PROPERTIES OF MICROCRYSTALLINE SILICON ABSORBER AND SOLAR CELLS
Authors: Nemeth Bill , Zhang Xiaodan , Yan Yanfa , Wang Qi
Published: June 2012

We study the effect of the spacing between electrodes in very high frequency plasma enhanced chemical vapor deposition on the properties of microcrystalline silicon films and their related n-i-psolar cells. We vary the spacing from 0.2 to 1.0 cm to deposit microcrystalline silicon at 67.8 MHz while maintaining other growth parameters. The spacing between the electrodes significantly changes the plasma conditions, which govern film precursor chemistry as well as introduce etching and ion bombardment to the film; thereby, influencing nucleation and growth of the microcrystalline Si films. The resulting films were characterized by UV-Vis spectrometry, atomic force microscopy, X-ray diffraction, and transmission electron microscopy. We found that deposition rate decreases, while surface roughness and short circuit current density increase with smaller spacing.
Color separation enhancement of pixn diodes by optimizing absorption regions of a-SiGe:H/a-SiC:H alloys and using a low reflective Al-doped ZnO cathode
Authors: Bablich Andreas , Watty Krystian , Merfort Christian , Boehm Markus
Published: June 2012

Security imaging systems working with crystalline silicon CCD or CMOS detectors are not able to distinguish colorimetrically between a large number of dangerous chemical substances, for example whitish powders [1]. In order to offer an alternative to expensive and destructive chemical methods of analysis, we developed optimized hydrogenated amorphous silicon (a-Si:H) multicolor photodiodes with different spectral response characteristics for a reliable, fast, cheap and non-destructive identification of potentially dangerous substances. Experimental optical, C-V and I-V studies were performed to explore the effect of combining linear graded a‑SiC:H-/a‑SiGe:H layers with low-reflective ZnO:Al back-contacts. Typically, a-Si:H with profiled energy gaps can be found in tandem solar cells to optimize the collection of incoming photons [2,3]. We determined the absorption coefficients of a group of a-SiC:H and a-SiGe:H graded and non-graded layers to calculate the penetration depth of photons at different energies into the device structure. Knowing the indices of absorption, refraction and extinction, it is possible to engineer diodes in such a way that accumulations of charge carriers are generated precisely at varying device depths. Common chromium back reflectors avoid a sharp falling edge of the sensitivity towards longer wavelengths and lead to interference fringes in the spectral response [4]. By combining linear graded absorption zones and ZnO:Al back contacts, we designed an optimized device with a highly precise adjustment of the spectral sensitivity reaching from 420 nm to 560 nm and reduced interference fringes at a very low reverse bias voltage of maximum -2.5 V. Similar three terminal devices allow a shift from 440 nm to 630 nm, however, at a much higher reverse bias of -11 V at 560 nm [4]. Present research efforts concentrate on the development of fast and high dynamic front illumination device structures which ensure a continuous narrow-band shift of the spectral photosensitivity and an optimum adaption to a predetermined light source-/sample measurement configuration.
Photonic and plasmonic crystal based enhancement of solar cells- overcoming the Lambertian classical 4n2 limit
Authors: Biswas Rana , Xu Chun , Pattnaik Sambit , Bhattacharya Joydeep , Chakravarty Nayan , Dalal Vikram
Published: June 2012

Long wavelength photons in the red and near infrared region of the spectrum are poorly absorbed in thin film silicon cells, due to their long absorption lengths. Advanced light trapping methods are necessary to harvest these photons. The basic physical mechanisms underlying the enhanced light trapping in thin film solar cells using periodic back reflectors include strong diffraction coupled with light concentration. These will be contrasted with the scattering mechanisms involved in randomly textured back reflectors, which are commonly used for light trapping. A special class of conformal solar cells with plasmonic nano-pillar back reflectors will be described, that generates absorption beyond the classical 4n2 limit (the Lambertian limit) averaged over the entire wavelength range for nc-Si:H. The absorption beyond the classical limit exists for common 1 micron thick nc-Si:H cells, and is further enhanced for non-normal light. Predicted currents exceed 31 mA/cm2 for nc-Si:H. The nano-pillars are tapered into conical protrusions that enhance plasmonic effects. Such conformal nc-Si:H solar cells with the same device architecture were grown on periodic nano-hole, periodic nano-pillar substrates and compared with randomly textured substrates, formed by annealing Ag/ZnO or etched Ag/ZnO. The periodic back reflector solar cells with nano-pillars demonstrated higher quantum efficiency and higher photo-currents that were 1 mA/cm2higher than those for the randomly textured back reflectors. Losses within the experimental solar architectures are discussed.
High Total-Dose Proton Radiation Tolerance in TiN/HfO2/TiN ReRAM Devices
Authors: He Xiaoli , Geer Robert E.
Published: June 2012

The resistive switching properties of CMOS compatible TiN/HfO2/TiN resistive-random-access-memory (ReRAM) devices have been investigated after exposure to 1 MeV proton radiation. The HfO2-based ReRAM devices were found to have high total-ionizing-dose (TID) radiation tolerance up to 5 Grad(Si). TiN/HfO2/TiN ReRAM performance parameters include high-resistance state (HRS) resistance, low-resistance state (LRS) resistance, set and reset voltages. HfO2-based ReRAM devices exhibited no degradation in these performance parameters following proton irradiation exposure with TID from 105 to 109 rad(Si). Furthermore, the HfO2-based ReRAM devices exhibited more uniform resistive switching behavior with increased TID. Based on this radiation response it is proposed that the resistive switching mechanism in TiN/HfO2/TiN – trap-assisted tunneling associated with Hf-rich conducting filament formation – may be reinforced through proton exposure which acts to stabilize the formation/rupture of Hf-rich filaments. The high radiation tolerance of HfO2-based ReRAM devices suggests such devices may be potentially attractive for aerospace and nuclear applications.
Improvement of RRAM Device Performance Through On-Chip Resistors
Authors: Gaba Siddharth , Choi Shinhyun , Sheridan Patrick , Chang Ting , Yang Yuchao , Lu Wei
Published: June 2012

Research in non-volatile memories (NVM) has intensified in the past few years due to the ever increasing demand for information storage and the near ubiquity of handheld electronics. Resistive memory is a leading contender in this NVM market due to its high endurance, random accessibility, scalability and low programming voltage.

The addition of an external series resistor or imposing current compliance is often used to limit the current through RRAM devices and to prevent “over-programming” and stuck-at-one (SA1) errors. Here, we demonstrate that utilizing an external series resistor is not efficient in preventing over-programming and an on-chip resistor is more desirable.

Poly-silicon bottom electrode based devices (with the poly-silicon electrode acting like an on-chip resistor) and metal bottom electrode devices were fabricated and tested. The presence of the on-chip resistor is shown to enhance the endurance of the RRAM device. This technique of including an on-chip resistor prevents stored current discharge through the device as the device transitions from a high resistance to a low resistance state. A SPICE simulation is also employed to illustrate the benefit of this approach.
Reverse Bias Degradation in Shadowed Devices in TiO2 Dye-Sensitized Solar Cell Modules
Authors: Mastroianni Simone , Brown Thomas M. , Lanuti Alessandro , Cinà Lucio , Lembo Angelo , Liberatore Massimiliano , Reale Andrea , Di Carlo Aldo
Published: June 2012

Mismatched or shadowed individual cells in a module can operate in the Reverse Bias (RB) regime. Subjecting a dye solar cell (DSC) to an accelerated RB stress by forcing a constant current equal to 2-fold its ISC, produced significant alterations on the current-voltage (I-V) characteristics in RB with time and a severe loss of cell efficiency in 32h. We investigated and identified a key mechanism for RB charge transfer and degradation in DSCs. I-V characteristics in RB were found to be sensitive to the type of dye utilized and to TiCl4 substrate treatment.
The Relationship between Seeker and Spiritual Guide as portrayed in contemporary Western Sufi Autobiographies
Authors: Zebiri Kate
Published: June 2012

This article aims to explore the Shaykh-mur?d (disciple) or teacher-pupil relationship as portrayed in Western Sufi life writing in recent decades, observing elements of continuity and discontinuity with classical Sufism. Additionally, it traces the influence on the texts of certain developments in religiosity in contemporary Western societies, especially New Age understandings of religious authority. Studying these works will provide an insight into the diversity of expressions of contemporary Sufism, while shedding light on a phenomenon which seems to fly in the face of contemporary social and religious trends which deemphasize external authority and promote the authority of the self or individual autonomy.