bluuebunny/crossref_metadata_2025 huggingface dataset:
Design principles for the area density of dimple patterns
Authors: Wang Xiaolei , Wang Jingqiu , Zhang Bo , Huang Wei
Published: May 2014

Increasing interest has been paid to surface texturing in order to improve tribological properties of sliding surfaces. Currently, the patterns of micro-dimples have attracted more attention since such closed texture cells are supposed to generate additional hydrodynamic pressure easily. It has been proven that the area density of the dimple pattern is a critical parameter for hydrodynamic pressure generation. However, the optimal values of area density obtained by theoretical models are usually different to that obtained from experiments, which show material dependence. In order to understand the design principles of the area density for mixed lubrication regime, a brief review on the studies related to the area density issue of dimple patterns is carried out; the phenomena during contacting and sliding are analyzed numerically in this paper. It is found that the stress concentration and deformation will occur on the contacting and sliding area, and influence the tribological properties of the textured surface significantly depending on the area density and material properties. These negative influences should be considered carefully during surface texture design.
Atomically smooth gallium nitride surface prepared by chemical-mechanical polishing with different abrasives
Authors: Zou Chunli , Pan Guoshun , Shi Xiaolei , Gong Hua , Zhou Yan
Published: May 2014

For chemical-mechanical polishing of epitaxial gallium nitride (GaN), a two-step experiment method with two kinds of abrasives, aluminum oxide (Al2O3) and colloidal silica (SiO2), was put forward. The average material removal rates of GaN by the slurry with Al2O3 and SiO2 abrasives were 594.79 and 66.88 nm/h, respectively. An atomically flat surface with roughness (Ra) of 0.056 nm was obtained after the second chemical-mechanical polishing process with SiO2-based slurry, which presented an atomic step-terrace structure. The material removal characteristics of GaN surfaces were investigated in detail. A model was proposed to describe the different behaviors of the two kinds of abrasive during chemical-mechanical polishing process.
Effects of microsize SiC, Al2O3, and ZnO particulates on mechanical and tribological properties of synthesized ortho- and meta-cresol novolac epoxy composites
Authors: Dass Kali , Chauhan SR , Gaur Bharti
Published: May 2014

In this paper, the mechanical and tribological properties of synthesized ortho- and meta-cresol novalac epoxy resin composites have been explored. Three microsize fillers SiC, Al2O3, and ZnO particulates (10 wt%) have been used as reinforcement for the composites. The dry sliding wear tests were conducted on the pin-on-disc apparatus at sliding velocities of 0.9 m/s, 1.8 m/s, 2.7 m/s, and 3.6 m/s) and applied normal loads of 10 N, 20 N, 30 N, and 40 N. By evaluating the mechanical and tribological properties, positive synergetic effect was found. It was also found that the coefficient of friction increases and specific wear rate decreases with an increase in the sliding velocity, whereas specific wear rate increases with an increase in the applied normal and decreases with an increase in the sliding velocity. Also, the worn surfaces of novalac epoxy composites were analyzed with the help of scanning electron microscope.
Awareness and use of a new urgent care telephone service, NHS 111: cross-sectional population survey
Authors: Knowles Emma , O'Cathain Alicia , Turner Janette , Nicholl Jon
Published: May 2014

Objectives

Telephone-accessed health care plays a significant part in the delivery of urgent care internationally. NHS 111 is a telephone service set up to improve and simplify access to non-emergency National Health Service health care in England. The first aim of this research was to describe population awareness and use of this new service, overall and within different sub-groups. In doing so, the second aim was to identify any inequity in awareness or use of telephone-accessed health care.

Methods

We undertook a telephone survey to assess awareness and use of NHS 111 in four sites. Random digit dialing was undertaken to identify 2000 respondents in each site. The survey was undertaken in 2011, approximately 9–10 months after the launch of NHS 111 in each site. Eight thousand and ten members of the general population completed a questionnaire.

Results

Fifty-nine percent of respondents had heard of NHS 111 and 9% reported ever using NHS 111. Respondents were less likely to have used NHS 111 if they were older (p ≤ 0.001), male (p ≤ 0.001), and did not have a disability/limiting long-term illness (p ≤ 0.001) or own their home (p = 0.039).

Conclusions

The use of the telephone as an important means of access to urgent care may be problematic if some groups in the population are less likely to use it. Policy makers and service providers may need to consider other ways of offering access to care or deliver targeted publicity campaigns to encourage the use of telephone-accessed health care amongst specific groups within a population.
‘Myspace led girl to Mideast’: Race, the online predator myth, and the pathologization of violence
Authors: Hasinoff Amy Adele
Published: May 2014

In June 2006 a 16-year-old Michigan girl reached an airport in Jordan in her attempt to visit a boyfriend she met on Myspace, 20-year-old Ali from the West Bank town of Jericho. The national media attention to this relationship begins with fears that Ali was an online predator, moves to stories of the pair as star-crossed lovers and constructions of Ali as a dangerous Arab terrorist, and ends with the conclusion that Ali was simply a bad boyfriend. I examine the media representations of this atypical case to illustrate the need to denaturalize and challenge typical constructions of sexual danger as embodied in racialized and pathologized figures such as the online predator.
Injuries sustained by bicyclists
Authors: Melo Nicolas , Berg Regan J , Inaba Kenji
Published: May 2014

Although generally a safe activity with considerable health benefit, the wide social prevalence of cycling, its performance by both young and elderly riders, and the increasing operation of bicycles in complex urban environments results in a significant incidence of trauma. Orthopedic injuries, followed by head and facial trauma, are most frequent but all anatomic regions can be affected and the spectrum of injury ranges from minor to severe and potentially fatal. Clinicians need to be aware of the range of injuries and causative mechanisms as many patients may present with relatively minor signs and symptoms despite significant underlying pathology. Non-commuter, recreational cyclists are also at risk for injury due to: variable terrain and environmental conditions; increased competitive and risk-taking behavior; technical equipment failure; and poor compliance with protective equipment. Numerous injury preventative strategies have been advocated including: increased rider training; creation of dedicated traffic lanes for commuting cyclists; bike-awareness education for motorists and interventions to improve cyclist visibility; increased utilization of protective equipment and programs to reduce concomitant drug or alcohol use. Of all preventative strategies, bicycle helmets have received the most study, leading to legislated use in some jurisdictions. As urban environments become more congested for commuter cyclists, and interest in recreational and competitive cycling grows, bicycle injury is likely to become more prevalent.
A study of the effects of NH3 maldistribution on a urea-selective catalytic reduction system
Authors: Song Xiaobo , Naber Jeffrey D , Johnson John H
Published: May 2014

The maldistribution of urea/NH3 at the selective catalytic reduction inlet and the resulting NH3/NOx ratio variation have been reported to have negative effects on the NOx conversion efficiency and NH3 slip in heavy-duty diesel applications. Maldistribution is caused by incomplete mixing and decomposition of the injected urea water solution within the exhaust flow in the aftertreatment system. How NH3 and the NH3/NOx ratio are distributed at the selective catalytic reduction inlet in an engine aftertreatment system and how the resultant maldistribution affects the system performance and the kinetics are presented in this combined experimental and modeling study. The distribution profiles of the selective catalytic reduction inlet NH3 and NH3/NOx ratio were determined through engine experiments. The NH3 maldistribution effects on the selective catalytic reduction performance and kinetics were quantified by using a multi-channel one-dimensional model that takes into consideration the NH3 maldistribution. It was determined that the NH3 maldistribution is a major factor causing the difference in catalyst performance in the engine exhaust as compared to the laboratory reactor environment, and these results explain specific differences in the model calibrations determined from the laboratory reactor and engine data. Improving the selective catalytic reduction inlet NH3 uniformity can improve the NOx conversion efficiency by up to 7% and reduce NH3 slip by 10–20 ppm. A single-channel one-dimensional selective catalytic reduction model calibrated to the engine data that accounts for the NH3 maldistribution phenomena can be applied for the development of on-board diagnostic and control strategies.
Supporting multifaceted viewing of word clouds with focus+context display
Authors: Liu Xiaotong , Shen Han-Wei , Hu Yifan
Published: May 2014

Word clouds provide an effective way to visually summarize important keywords from a large collection of text. Despite their increasing popularity, relatively less attention has been paid on developing interactive techniques for flexible word cloud navigation and manipulation. In this article, we present a focus + context display technique to support multifaceted viewing of word clouds. In our algorithm, the sizes of words in a word cloud are first changed to reflect the current importance metric selected by the user and then scaled to balance space utilization and word readability. To remove word overlaps caused by changes of sizes while maintaining the positional dependency modeled by a directed acyclic graph, we propose a force-directed model that also maximizes the utilization of display space. We demonstrate the effectiveness and usefulness of our techniques through case studies using a real-world dataset and evaluate the performance of the constraint-based overlap removal method in achieving stable layouts during importance transformation.
Combined incubation of platelets and endothelial cells with glycated albumin: Altered thrombogenic and inflammatory responses
Authors: Rubenstein David A , Maria Zahra , Yin Wei
Published: May 2014

Diabetes mellitus is a salient risk factor for the development of cardiovascular diseases (CVDs). Part of this risk is associated with the presence of advanced glycation end products (AGEs), which have been shown to up-regulate platelet or endothelial cell inflammatory and thrombogenic responses that are associated with CVDs. However, platelets perform mechanisms that alter endothelial cell inflammatory and thrombogenic responses, and endothelial cells perform similar mechanisms on platelets. Thus, our goal was to evaluate platelet and endothelial cell inflammatory and thrombogenic reactions that AGEs elicit during concurrent exposure. Endothelial cells were incubated with AGEs for 5 days, after which platelets were added. A time course for CVD inflammatory and thrombogenic responses was quantified as a function of extent of glycation. In general, the presence of platelets reduced AGE-induced endothelial cell responses associated with CVD progression and the presence of endothelial cells reduced platelet adhesion and activation responses, as compared with individual exposures. In general, the presence of irreversibly glycated albumin promoted CVD development to a greater extent than reversibly glycated albumin. This suggests that under diabetic conditions, platelets and endothelial cells can negatively feedback on each other, likely via enhanced adhesion, to elicit a reduced response associated with CVD progression.
Electromagnetic absorbance properties of a textile material coated using filtered arc-physical vapor deposition method
Authors: Esen M , Ilhan I , Karaaslan M , Unal E , Dincer F , Sabah C
Published: May 2014

We explore the structure of a textile absorber in terms of its electromagnetic and absorption properties in the microwave region. Its absorption characteristics are similar to those reported for various metamaterial-based absorbers, exhibiting absorption as high as 98% at resonance. In addition, the angular behavior of the absorption properties of the sample reveal incident angle independency, which is the other added value of the study. Also, the suggested textile absorber has a simple configuration, which introduces flexibility to adjust its material properties and easily tune its structure to suit other frequencies. The proposed textile absorber and its variations have myriad potential applications in radar technology, long distance radio telecommunication, and so on. Although in its current state the proposed structure provides almost perfect absorption covering a wide range of microwave C-Band, the developing technology will soon allow manufacturing textiles that can manipulate lights, leading to the design of invisibility cloak and other science fiction devices besides finding important application areas in medical science.
A microphysiological system model of therapy for liver micrometastases
Authors: Clark Amanda M , Wheeler Sarah E , Taylor Donald P , Pillai Venkateswaran C , Young Carissa L , Prantil-Baun Rachelle , Nguyen Transon , Stolz Donna B , Borenstein Jeffrey T , Lauffenburger Douglas A , Venkataramanan Raman , Griffith Linda G , Wells Alan
Published: May 2014

Metastasis accounts for almost 90% of cancer-associated mortality. The effectiveness of cancer therapeutics is limited by the protective microenvironment of the metastatic niche and consequently these disseminated tumors remain incurable. Metastatic disease progression continues to be poorly understood due to the lack of appropriate model systems. To address this gap in understanding, we propose an all-human microphysiological system that facilitates the investigation of cancer behavior in the liver metastatic niche . This existing LiverChip is a 3D-system modeling the hepatic niche; it incorporates a full complement of human parenchymal and non-parenchymal cells and effectively recapitulates micrometastases. Moreover, this system allows real-time monitoring of micrometastasis and assessment of human-specific signaling. It is being utilized to further our understanding of the efficacy of chemotherapeutics by examining the activity of established and novel agents on micrometastases under conditions replicating diurnal variations in hormones, nutrients and mild inflammatory states using programmable microdispensers. These inputs affect the cues that govern tumor cell responses. Three critical signaling groups are targeted: the glucose/insulin responses, the stress hormone cortisol and the gut microbiome in relation to inflammatory cues. Currently, the system sustains functioning hepatocytes for a minimum of 15 days; confirmed by monitoring hepatic function (urea, α-1-antitrypsin, fibrinogen, and cytochrome P450) and injury (AST and ALT). Breast cancer cell lines effectively integrate into the hepatic niche without detectable disruption to tissue, and preliminary evidence suggests growth attenuation amongst a subpopulation of breast cancer cells. xMAP technology combined with systems biology modeling are also employed to evaluate cellular crosstalk and illustrate communication networks in the early microenvironment of micrometastases. This model is anticipated to identify new therapeutic strategies for metastasis by elucidating the paracrine effects between the hepatic and metastatic cells, while concurrently evaluating agent efficacy for metastasis, metabolism and tolerability.
Nonintubated Video-Assisted Thoracoscopic Surgery Under Epidural Anesthesia Compared With Conventional Anesthetic Option
Authors: Liu Jun , Cui Fei , Li Shuben , Chen Hanzhang , Shao Wenlong , Liang Lixia , Yin Weiqiang , Lin Yongping , He Jianxing
Published: May 2014

Objective. The purposes of this study were to evaluate the feasibility, safety, and advantages of nonintubated video-assisted thoracoscopic surgery (VATS) under epidural anesthesia, by comparing with the performance of conventional approaches. Patients and methods. A total of 354 patients (245 men and 109 women) were recruited in this study. The surgical procedures included bullae resection, pulmonary wedge resection, and lobectomy. The anesthetic technique (epidural vs general) was selected randomly. Patients who underwent nonintubated VATS under epidural anesthesia comprised the intervention group, and patients who received VATS under general anesthesia with double lumen tube comprised the control group. Results. In total, 167 patients were included in the intervention group, and 180 patients were included in the control group. The 2 treatment groups of bullae resection showed significant differences in postoperative fasting time, duration of postoperative antibiotic use depending on the time when the white blood cells decreased to normal levels, and duration of postoperative hospital stay ( P < .05). Nonintubated VATS is associated with a decreased level of inflammatory cytokines ( P < .05). Conclusion. VATS under anesthesia with nontracheal intubation is safe and feasible, and has demonstrated advantages, including shorter postoperative fasting time, shorter duration of antibiotic use, and shorter hospital stay, compared with VATS under general anesthesia with double lumen tube.
Mastering Instruments Before Operating on a Patient
Authors: Zheng Bin , Fu Bo , Al-Tayeb Thamer A. , Hao Yi Fan , Qayumi A. Karim
Published: May 2014

Background. We examined the impact of tool complexity on surgeons’ performance and evaluated the value of using a simulation-based program for reducing training cost. Methods. Three pairs of surgical graspers with increasing mechanical complexity, which were designed for open, laparoscopic, and endoscopic procedures, were used in performing a simple object transportation task. Task times and mental workload of 17 surgeons were compared using all 3 variations of the graspers to test the impact of tool complexity on surgical performance. Subsequently, 4 of these surgeons decided to enter a 3-week training phase and practiced with these 3 surgical instruments on a daily basis. Learning curves were plotted to examine the value of using simulation for proficiency training with these tools. Results. Task time was significantly prolonged as tool complexity increased. Practice in a simulated environment shortened the task time significantly and moderately reduced mental workloads. However, the difference in task time varied among the 3 types of tools. Between days 1 and 9, task times for each types of grasper were reduced by 55% (endoscopic), 42% (open), and 22% (laparoscopic). Conclusions. Tool complexity may degrade a surgeon’s performance. Extensive simulation training programs are important for surgeons to gain proficiency in handling a tool before they practice on patients.
Roles and skills comparison among principals in Greek schools
Authors: Geraki Akrivoula
Published: May 2014

This paper examines the relationship between leadership roles and skills in secondary schools in Greece. Drawing upon a sample of 124 secondary public school principals, a structured questionnaire was developed to measure leadership roles and skills. The Competing Values Framework (CVF) was adopted to operationalize the eight leadership roles. The threefold classification of skills by Katz (1974) was enriched by a fourth categorization in order to identify principals’ skills. The results indicate that Greek principals are inclined to perform the roles of innovator, director, monitor and facilitator more intensely, giving less attention to the broker, producer, coordinator and mentor roles. The importance of the innovator role in explaining the variance of two of four skill categories was confirmed; while the monitor role was strongly associated with human skills. The administrative skills were negatively associated with the facilitator role while the conceptual skills were not found to be correlated to any role. It is argued that understanding the nature of the associations could enable education policy makers and principals to pursue these roles and behaviors, thereby contributing to improvement of the school.
Local authorities and the school system
Authors: Hatcher Richard
Published: May 2014

Coalition government policies have put into question the role of local authorities in a ‘self-improving school system’. In a number of local authorities new authority-wide partnership bodies are being set up involving all local schools, including academies, and controlled by headteachers. This article begins with an analysis of the new partnerships, differentiating their functions and the education policy leadership roles of headteacher-led and local authority-led partnerships. It then examines as a case study the evolution of a new partnership in Birmingham from the initial model proposed by the local authority through to the emergence of a headteacher-initiated model. The article proposes an analytical framework for the new partnerships, situating them in the wider theoretical context of network governance and the role of the state in local government theory and policy. It concludes with a discussion of the questions of educational principle about agency and purpose in local education policymaking which the new partnership developments raise.
An exploration of the relationship between readiness for change and organizational trust in Turkish public schools
Authors: Zayim Merve , Kondakci Yasar
Published: May 2014

Readiness for change is one of the constructs that fosters positive behaviours, attitudes and thinking towards new adjustments on the part of employees. As one of the internal context variables, trust acts as a catalyst for supportive behaviours in times of change and uncertainty by reducing change related resistance and stress. Based on this understanding, this study explores the predictive value of organizational trust for cognitive, emotional and intentional readiness for change among a group of primary and secondary school teachers in Turkey. The data from 603 public school teachers were collected using the Omnibus T-Scale and Readiness for Change-Cognitive Emotional Intentional Scale. Taking each dimension of readiness for change as a criterion variable, three sets of predictors were defined for three separate hierarchical regression analyses. The results provided empirical evidence concerning the relationship between intentional, emotional and cognitive readiness for change and perceived faculty trust in colleagues and in the principal after statistically controlling for the school level and teacher demographics at primary and secondary level public schools. The results were interpreted within the scope of the current literature as well as structural and functional characteristics of Turkish education system.
A longitudinal VBM study monitoring treatment with erythropoietin in patients with Friedreich ataxia
Authors: Santner Wolfram , Schocke Michael , Boesch Sylvia , Nachbauer Wolfgang , Egger Karl
Published: May 2014

Background

Recombinant human erythropoietin (rhuEPO) has received considerable attention because of its neuroprotective properties. It has recently been reported that rhuEPO increases frataxin levels in combination with clinical improvement in rhuEPO treated patients with Friedreich ataxia (FRDA).

Purpose

To determine possible therapy dependent intracranial volume changes after treatment with rhuEPO using voxel-based morphometry (VBM).

Material and Methods

Nine FRDA patients were scanned on the same 1.5-Tesla MRI scanner before and after treatment with rhuEPO. FRDA patients received 5000 IU rhuEPO thrice weekly subcutaneously for a time period of 8 weeks followed by 2000 IU thrice weekly over 6 months. To test for re-test reliability a control group of 12 healthy volunteers were scanned twice on the same scanner without rhuEPO treatment. Neurological state was defined by the Friedreich Ataxia Rating Scale (FARS) and the Scale for the Assessment and Rating of Ataxia (SARA). Statistical parametric mapping software was used for image processing and statistical analysis.

Results

When comparing follow-up scans after rhuEPO treatment with baseline scans ( P <0.001 uncorrected) an increase of gray matter volume was observed bilaterally in the Pulvinar and the posterior parietal cortex. Moreover, clinical improvement detected using specific Ataxia scores correlated with VBM results in the pulvinar.

Conclusion

Given the limitation of a small sample size, our study confirms previous findings that MRI may serve as reliable biomarker in neurodegenerative diseases as well as in monitoring of microstructural changes representing disease progression and/or therapy effects.
Intended and unintended consequences of democracy promotion assistance to Georgia after the Rose Revolution
Authors: Driscoll Jesse , Hidalgo F Daniel
Published: May 2014

What are the political consequences of democratization assistance to regimes transitioning from authoritarian rule? By exploiting the downstream effects of a field experiment designed to encourage citizen monitoring of Georgia’s 2008 parliamentary elections, we evaluate the political consequences of one type of democracy promotion aid. The intervention increased citizen activism, but it also had the unanticipated effect of suppressing overall voter turnout by approximately 5%. We hypothesize that the civic education campaign was interpreted as a sign of increased political attention to a selected voting precinct, which suppressed opposition turnout. Two additional experiments provide additional evidence for the hypothesis.
Loss of Stat1 decreases megakaryopoiesis and favors erythropoiesis in a JAK2-V617F–driven mouse model of MPNs
Authors: Duek Adrian , Lundberg Pontus , Shimizu Takafumi , Grisouard Jean , Karow Axel , Kubovcakova Lucia , Hao-Shen Hui , Dirnhofer Stephan , Skoda Radek C.
Published: May 2014

Key Points

Stat1 deletion in the presence of JAK2-V617F alters phenotypic manifestations by reducing megakaryopoiesis and favoring erythropoiesis. IFNγ is elevated in serum of mice with thrombocytosis and in patients with essential thrombocythemia and may drive Stat1 activation.
A fuzzy characterization of QF rings
Authors: Li Wenxi , Chen Jianlong , Shen Liang
Published: May 2014

Let R be a ring. R is called a quasi-Frobenius (QF) ring if R is right artinian and

R
R

is an injective right R-module. In this article, we introduce (weak) fuzzy homomorphisms of modules to obtain a fuzzy characterization of QF rings. We also obtain some fuzzy characterizations of right artinian rings and right CF rings. These results throw new light on the research of QF rings and the related CF conjecture.

MSC:03E72, 16L60.
The synergistic effect of homocysteine and lipopolysaccharide on the differentiation and conversion of raw264.7 macrophages
Authors: Gao Shanshan , Wang Lijun , Liu Weimin , Wu Yue , Yuan Zuyi
Published: May 2014

Background

Macrophages play pivotal roles in the progression of atherosclerosis (AS) and their heterogeneous differentiation patterns have been studied extensively. The classical subtype of activated macrophage, M1, promotes the progression of AS. Conversely, the alternative subtype of activated macrophage, M2, is regarded as a repressor of AS. Homocysteine (Hcy) may influence macrophage subtype polarization both in vivo and in vitro. Homocysteinemia (HHcy) is an independent risk factor in coronary heart disease and the effect of Hcy on macrophage differentiation has not been studied until now.

Methods

Different concentrations of Hcy in combination with a fixed concentration of lipopolysaccharide (LPS, 200 ng/mL) were used to treat RAW264.7 macrophages. Real-time PCR was used to detect and quantify RNA transcripts indicative of M1 and M2 differentiation. The efficacy and specificity for each chemical stimulant in inducing macrophage differentiation were also investigated. The M2 macrophages (anti-inflammatory subtype) induced using classical methods (IL-4, 10 ng/mL) were also treated with different concentrations of Hcy complemented with LPS. The synergistic effect of Hcy and LPS in the converting the M2 subtype to M1 was also studied.

Results

Macrophages can be induced to differentiate towards M1 by a combination of Hcy with LPS, with the strongest effect observed at an Hcy concentration of 50 μmol/L. After inducing macrophages to the M2 subtype using IL-4, treatment with both Hcy and LPS could elicit conversion from the M2 to M1 subtype.

Conclusion

Combined treatment with Hcy and LPS can induce the polarization of cultured RAW264.7 macrophages into the pro-inflammatory subtype, as well as promote subtype conversion from anti-inflammatory to pro-inflammatory.
Effects of Al interlayer coating and thermal treatment on electron emission characteristics of carbon nanotubes deposited by electrophoretic method
Authors: Kim Bu-Jong , Kim Jong-Pil , Park Jin-Seok
Published: May 2014

The effects of aluminum (Al) interlayer coating and thermal post-treatment on the electron emission characteristics of carbon nanotubes (CNTs) were investigated. These CNTs were deposited on conical-shaped tungsten (W) substrates using an electrophoretic method. The Al interlayers were coated on the W substrates via magnetron sputtering prior to the deposition of CNTs. Compared with the as-deposited CNTs, the thermally treated CNTs revealed significantly improved electron emission characteristics, such as the decrease of turn-on electric fields and the increase of emission currents. The observations of Raman spectra confirmed that the improved emission characteristics of the thermally treated CNTs were ascribed to their enhanced crystal qualities. The coating of Al interlayers played a role in enhancing the long-term emission stabilities of the CNTs. The thermally treated CNTs with Al interlayers sustained stable emission currents without any significant degradation even after continuous operation of 20 h. The X-ray photoelectron spectroscopy (XPS) study suggested that the cohesive forces between the CNTs and the underlying substrates were strengthened by the coating of Al interlayers.
Detection and identification of Legionella species in hospital water supplies through Polymerase Chain Reaction (16S rRNA)
Authors: Rafiee Mohammad , Jahangiri-rad Mahsa , Hajjaran Homa , Mesdaghinia Alireza , Hajaghazadeh Mohammad
Published: May 2014

Legionella spp. are important waterborne pathogens that are normally transmitted through aerosols. The present work was conducted to investigate the presence of Legionella spp. and its common species in hospital water supplies. Considering the limitations of culture method, polymerase chain reaction (PCR) assays were developed to detect the gene 16S rRNA irrespective of the bacterial serotype. Four well-established DNA extraction protocols (freeze & thaw and phenol-chloroform as two manual protocols and two commercial kits) were tested and evaluated to release DNA from bacterial cells. A total of 45 samples were collected from seven distinct hospitals’ sites during a period of 10 months. The PCR assay was used to amplify a 654-bp fragment of the 16S rRNA gene. Legionella were detected in 13 samples (28.9%) by all of the methods applied for DNA extraction. Significant differences were noted in the yield of extracted nucleic acids. Legionella were not detected in any of the samples when DNA extraction by freeze & thaw was used. Excluding this method and comparing manual protocol with commercial kits, Kappa coefficient was calculated as 0.619 with p < 0.05. Although no meaningful differences were found between the kits, DNA extraction with Bioneer kit exhibited a higher sensitivity than classical Qiagen. Showerheads and cold-water taps were the most and least contaminated sources with 55.5 and 9 percent positive samples, respectively. Moreover two positive samples were identified for species by DNA sequencing and submitted to the Gene Bank database with accession Nos. FJ480932 and FJ480933. The results obtained showed that despite the advantages of molecular assays in Legionella tracing in environmental sources, the use of optimised DNA extraction methods is critical.
Anoctamin 1 Calcium-Activated Chloride Channel Downregulates Estrogen Production in Mouse Ovarian Granulosa Cells
Authors: Sun Meiyan , Sui Yujie , Li Lihua , Su Weiheng , Hao Feng , Zhu Qi , Di Weihua , Gao Hongwen , Ma Tonghui
Published: May 2014

Calcium-dependent chloride conductances have been described in chicken and human granulosa cells (GCs) and may be involved in steroidogenesis. However, the molecular identities of corresponding chloride channels remain unknown. The purpose of this study was to explore the expression and function of the Anoctamin 1 (ANO1) calcium-activated chloride channel (CaCC) in mouse ovary. ANO1 mRNA and protein expression was identified in mouse ovary GCs by RT-PCR, immunoblot, and immunostaining. Patch-clamp analysis on freshly isolated GCs identified an outwardly rectifying Ca2+-activated Cl− current that was completely blocked by a selective ANO1 inhibitor T16Ainh-A01. Knockdown of ANO1 mRNA or incubation with a selective inhibitor T16Ainh-A01 enhanced estradiol production, whereas a selective ANO1 activator Eact significantly inhibited estradiol production in primary cultured GCs. The ANO1 expression or activation increases the phosphorylation of ERK1/2 and decreases aromatase expression. The ANO1 expression level is remarkably higher at the proestrous and estrous stages in the estrous cycle. In vivo study indicated a profound induction of ANO1 expression in ovarian GCs by pregnant mare serum gonadotropin (PMSG) that can be further augmented by hCG treatment, suggesting that both FSH and LH may upregulate ANO1 expression at the proestrous and estrous stages. ANO1 expression was remarkably reduced in DHEA-induced PCOS ovary. These data identified for the first time the expression of ANO1 Ca2+ activated Cl− channel in mouse ovarian GCs and determined its negative regulation on estrogen production possibly through MEK-ERK signaling cascade. The present study provided new insights into the molecular mechanisms for the regulation of folliculogenesis and ovulation.
Initial Presentation and Late Results of Treatment of Post-Chernobyl Papillary Thyroid Carcinoma in Children and Adolescents of Belarus
Authors: Fridman Mikhail , Savva Natallia , Krasko Olga , Mankovskaya Svetlana , Branovan Daniel I. , Schmid Kurt W. , Demidchik Yuri
Published: May 2014

Background:

The aim of this population-based study was to evaluate the clinical and pathological characteristics and outcome of papillary thyroid carcinoma (PTC) that have arisen in the Belarusian childhood population exposed to the radioactive fallout from the Chernobyl accident within a long-term period.

Patients and Methods:

The long-term treatment results were investigated in 1078 children and adolescents (<19 years old) with PTC who were surgically treated during the years 1990 through 2005.

Results:

Patients had high rates of metastatic PTC at presentation, with 73.8% of cases having lymph node involvement and 11.1% having distant spread. The most influential factor for lymph node metastases at initial treatment was lymphatic vessel invasion (P < .0001) and for distant metastases, lateral lymph node involvement (P < .0001). The overall survival was 96.9% ± 0.9% with a median follow-up of 16.21 years, and 20-year event-free survival and relapse-free survival were 87.8% ± 1.6% and 92.3% ± 0.9%, respectively. Patients had significantly lower probability of both loco-regional (P < .001) and distant relapses (P = .005) after total thyroidectomy (TT) and radioactive iodine therapy (RAI). For loco-regional relapses after TT, only RAI influenced the prognosis significantly (P < .001). For distant relapses after TT, the refusal to treat with RAI (hazard ratio [HR] = 9.26), vascular invasion (HR = 8.68), and age at presentation (HR = 6.13) were significant risk factors. For loco-regional relapses after non-TT, the principal risk factors were age less than 15 years old at presentation (HR = 5.34) and multifocal growth of tumor (HR = 5.19). For distant relapses after non-TT, the lateral neck metastases were the only unfavorable factor (HR = 9.26).

Conclusion:

The outcome of PTC both in children and in adolescents exposed to the post-Chernobyl radioiodine fallout was rather favorable. TT with RAI is recommended for minimizing loco-regional or distant relapses.
IGF-1 and Growth Response to Adult Height in a Randomized GH Treatment Trial in Short Non-GH-Deficient Children
Authors: Kriström Berit , Lundberg Elena , Jonsson Björn , Albertsson-Wikland Kerstin ,   on behalf of the study group
Published: May 2014

Context:

GH treatment significantly increased adult height (AH) in a dose-dependent manner in short non-GH-deficient children in a randomized, controlled, clinical trial; the mean gain in height SD score (heightSDS) was 1.3 (range 0–3), compared with 0.2 in the untreated group.

Objective:

The objective of the study was to analyze the relationship between IGF-1SDS, IGF binding protein-3 SDS (IGFBP3SDS), and their ratioSDS with a gain in the heightSDS until AH in non-GH-deficient short children.

Design and Setting:

This was a randomized, controlled, multicenter clinical trial.

Intervention:

The intervention included GH treatment: 33 or 67 μg/kg · d plus untreated controls.

Subjects:

One hundred fifty-one non-GH-deficient short children were included in the intent-to-treat (ITT) population and 108 in the per-protocol (PP) population; 112 children in the ITT and 68 children in the PP populations had idiopathic short stature (ISS).

Main Outcome Measures:

Increments from baseline to on-treatment study mean IGF-1SDS (ΔIGF-1SDS), IGFBP3SDS, and IGF-1 to IGFBP3 ratioSDS were assessed in relationship to the gain in heightSDS.

Results:

Sixty-two percent of the variance in the gain in heightSDS in children on GH treatment could be explained by four variables: ΔIGF-1SDS (explaining 28%), bone age delay, birth length (the taller the better), and GH dose (the higher the better). The lower IGF-1SDS was at baseline, the higher was its increment during treatment. For both the AllPP- and the ISSPP-treated groups, the attained IGF-1SDS study level did not correlate with height gain.

Conclusion:

In short non-GH-deficient children, the GH dose-related increment in IGF-1SDS from baseline to mean study level was the most important explanatory variable for long-term growth response from the peripubertal period until AH, when IGF-1SDS, IGFBP3SDS, and their ratioSDS were compared concurrently.
CDC73 Intragenic Deletion in Familial Primary Hyperparathyroidism Associated With Parathyroid Carcinoma
Authors: Korpi-Hyövälti Eeva , Cranston Treena , Ryhänen Eeva , Arola Johanna , Aittomäki Kristiina , Sane Timo , Thakker Rajesh V. , Schalin-Jäntti Camilla
Published: May 2014

Context:

CDC73 mutations frequently underlie the hyperparathyroidism-jaw tumor syndrome, familial isolated hyperparathyroidism (FIHP), and parathyroid carcinoma. It has also been suggested that CDC73 deletion analysis should be performed in those patients without CDC73 mutations.

Objective:

To investigate for CDC73 deletion in a family with FIHP previously reported not to have CDC73 mutations.

Patients and Methods:

Eleven members (six affected with primary hyperparathyroidism and five unaffected) were ascertained from the family, and multiplex ligation-dependent probe amplification was performed to detect CDC73 deletion using leukocyte DNA.

Results:

A previously unreported deletion of CDC73 involving exons 1–10 was detected in five affected members and two unaffected members who were 26 and 39 years of age. Two affected members had parathyroid carcinomas at the ages of 18 and 32 years, and they had Ki-67 proliferation indices of 5 and 14.5% and did not express parafibromin, encoded by CDC73. Primary hyperparathyroidism in the other affected members was due to adenomas and atypical adenomas, and none had jaw tumors. Two affected members had thoracic aortic aneurysms, which in one member occurred with parathyroid carcinoma and renal cysts.

Conclusion:

A previously unreported intragenic deletion of exons 1 to 10 of CDC73 was detected in a three-generation family with FIHP, due to adenomas, atypical adenomas, and parathyroid carcinomas. In addition, two affected males had thoracic aortic aneurysms, which may represent another associated clinical feature of this disorder.
Androgen-Dependent Sertoli Cell Tight Junction Remodeling Is Mediated by Multiple Tight Junction Components
Authors: Chakraborty Papia , William Buaas F. , Sharma Manju , Smith Benjamin E. , Greenlee Anne R. , Eacker Stephen M. , Braun Robert E.
Published: May 2014

Sertoli cell tight junctions (SCTJs) of the seminiferous epithelium create a specialized microenvironment in the testis to aid differentiation of spermatocytes and spermatids from spermatogonial stem cells. SCTJs must be chronically broken and rebuilt with high fidelity to allow the transmigration of preleptotene spermatocytes from the basal to adluminal epithelial compartment. Impairment of androgen signaling in Sertoli cells perturbs SCTJ remodeling. Claudin (CLDN) 3, a tight junction component under androgen regulation, localizes to newly forming SCTJs and is absent in Sertoli cell androgen receptor knockout (SCARKO) mice. We show here that Cldn3-null mice do not phenocopy SCARKO mice: Cldn3−/− mice are fertile, show uninterrupted spermatogenesis, and exhibit fully functional SCTJs based on imaging and small molecule tracer analyses, suggesting that other androgen-regulated genes must contribute to the SCARKO phenotype. To further investigate the SCTJ phenotype observed in SCARKO mutants, we generated a new SCARKO model and extensively analyzed the expression of other tight junction components. In addition to Cldn3, we identified altered expression of several other SCTJ molecules, including down-regulation of Cldn13 and a noncanonical tight junction protein 2 isoform (Tjp2iso3). Chromatin immunoprecipitation was used to demonstrate direct androgen receptor binding to regions of these target genes. Furthermore, we demonstrated that CLDN13 is a constituent of SCTJs and that TJP2iso3 colocalizes with tricellulin, a constituent of tricellular junctions, underscoring the importance of androgen signaling in the regulation of both bicellular and tricellular Sertoli cell tight junctions.
Estimating the surface area of birds: using the homing pigeon (Columba livia) as a model
Authors: Perez Cristina R. , Moye John K. , Pritsos Chris A.
Published: May 2014

Estimation of the surface area of the avian body is valuable for thermoregulation and metabolism studies as well as for assessing exposure to oil and other surface-active organic pollutants from a spill. The use of frozen carcasses for surface area estimations prevents the ability to modify the posture of the bird. The surface area of six live homing pigeons in the fully extended flight position was estimated using a noninvasive method. An equation was derived to estimate the total surface area of a pigeon based on its body weight. A pigeon's surface area in the fully extended flight position is approximately 4 times larger than the surface area of a pigeon in the perching position. The surface area of a bird is dependent on its physical position, and, therefore, the fully extended flight position exhibits the maximum area of a bird and should be considered the true surface area of a bird.
Stroma provides an intestinal stem cell niche in the absence of epithelial Wnts
Authors: Kabiri Zahra , Greicius Gediminas , Madan Babita , Biechele Steffen , Zhong Zhendong , Zaribafzadeh Hamed , Edison  , Aliyev Jamal , Wu Yonghui , Bunte Ralph , Williams Bart O. , Rossant Janet , Virshup David M.
Published: May 2014

Wnt/β-catenin signaling supports intestinal homeostasis by regulating proliferation in the crypt. Multiple Wnts are expressed in Paneth cells as well as other intestinal epithelial and stromal cells. Ex vivo, Wnts secreted by Paneth cells can support intestinal stem cells when Wnt signaling is enhanced with supplemental R-Spondin 1 (RSPO1). However, in vivo, the source of Wnts in the stem cell niche is less clear. Genetic ablation of Porcn, an endoplasmic reticulum resident O-acyltransferase that is essential for the secretion and activity of all vertebrate Wnts, confirmed the role of intestinal epithelial Wnts in ex vivo culture. Unexpectedly, mice lacking epithelial Wnt activity (PorcnDel/Villin-Cre mice) had normal intestinal proliferation and differentiation, as well as successful regeneration after radiation injury, indicating that epithelial Wnts are dispensable for these processes. Consistent with a key role for stroma in the crypt niche, intestinal stromal cells endogenously expressing Wnts and Rspo3 support the growth of PorcnDel organoids ex vivo without RSPO1 supplementation. Conversely, increasing pharmacologic PORCN inhibition, affecting both stroma and epithelium, reduced Lgr5 intestinal stem cells, inhibited recovery from radiation injury, and at the highest dose fully blocked intestinal proliferation. We conclude that epithelial Wnts are dispensable and that stromal production of Wnts can fully support normal murine intestinal homeostasis.
A microdevice to locally electroporate embryos with high efficiency and reduced cell damage
Authors: Mazari Elsa , Zhao Xuan , Migeotte Isabelle , Collignon Jérôme , Gosse Charlie , Perea-Gomez Aitana
Published: May 2014

The ability to follow and modify cell behaviour with accurate spatiotemporal resolution is a prerequisite to study morphogenesis in developing organisms. Electroporation, the delivery of exogenous molecules into targeted cell populations through electric permeation of the plasma membrane, has been used with this aim in different model systems. However, current localised electroporation strategies suffer from insufficient reproducibility and mediocre survival when applied to small and delicate organisms such as early post-implantation mouse embryos. We introduce here a microdevice to achieve localised electroporation with high efficiency and reduced cell damage. In silico simulations using a simple electrical model of mouse embryos indicated that a dielectric guide-based design would improve on existing alternatives. Such a device was microfabricated and its capacities tested by targeting the distal visceral endoderm (DVE), a migrating cell population essential for anterior-posterior axis establishment. Transfection was efficiently and reproducibly restricted to fewer than four visceral endoderm cells without compromising cell behaviour and embryo survival. Combining targeted mosaic expression of fluorescent markers with live imaging in transgenic embryos revealed that, like leading DVE cells, non-leading ones send long basal projections and intercalate during their migration. Finally, we show that the use of our microsystem can be extended to a variety of embryological contexts, from preimplantation stages to organ explants. Hence, we have experimentally validated an approach delivering a tailor-made tool for the study of morphogenesis in the mouse embryo. Furthermore, we have delineated a comprehensive strategy for the development of ad hoc electroporation devices.