bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of superantigens in group A streptococcal isolates from Salvador, Brazil
Authors: Berman Hillary F , Tartof Sara Yee , Reis Joice N , Reis Mitermayer G , Riley Lee W 
Published: May 2014

Abstract

Background
Group A streptococcus (GAS) causes invasive disease, superficial disease, and can asymptomatically colonize humans. Superantigens are one virulence factor found in GAS. Previous studies found associations between the genes that encode superantigens and emm type of GAS. It is unknown if these associations are due to underlying biological factors that limit the distribution of superantigens or, alternatively, if these associations are due to the expansion of local GAS linages where these studies took place. To further address this question we screened GAS isolates collected from Salvador, Brazil for 11 known superantigen genes.

Methods
Seventy-seven GAS isolates were screened by PCR for superantigen genes. These superantigen genes were speA, speC, speG, speH, speI, speJ, speK, speL, speM, ssa, and smeZ. We used Fisher’s two-sided exact test to identify associations between superantigens and GAS emm type. We then compared our results to previous reports of superantigen prevalence and superantigen association with emm type.

Results
In our collection we found several emm type and superantigen genotype combinations that have previously been reported in isolates from Europe and Australia. We also found that speA was significantly associated with emm type 1, and that speC was significantly associated with emm type 12.

Conclusions
Our study reports superantigen genotypes of GAS from a region of the world that is lacking this information. We found evidence of common GAS superantigen genotypes that are spread worldwide as well as novel superantigen genotypes that, so far, are unique to Brazil.
Reimbursement of hormonal contraceptives and the frequency of induced abortion among teenagers in Sweden
Authors: Sydsjö Adam , Sydsjö Gunilla , Bladh Marie , Josefsson Ann 
Published: May 2014

Abstract

Background
Reduction in costs of hormonal contraceptives is often proposed to reduce rates of induced abortion among young women. This study investigates the relationship between rates of induced abortion and reimbursement of dispensed hormonal contraceptives among young women in Sweden. Comparisons are made with the Nordic countries Finland, Norway and Denmark.

Methods
Official statistics on induced abortion and numbers of prescribed and dispensed hormonal contraceptives presented as “Defined Daily Dose/thousand women” (DDD/T) aged 15-19 years were compiled and related to levels of reimbursement in all Swedish counties by using public official data. The Swedish numbers of induced abortion were compared to those of Finland, Norway and Denmark. The main outcome measure was rates of induced abortion and DDD/T.

Results
No correlation was observed between rates of abortion and reimbursement among Swedish counties. Nor was any correlation found between sales of hormonal contraceptives and the rates of abortion. In a Nordic perspective, Finland and Denmark, which have no reimbursement at all, and Norway all have lower rates of induced abortion than Sweden.

Conclusions
Reimbursement does not seem to be enough in order to reduce rates of induced abortion. Evidently, other factors such as attitudes, education, religion, tradition or cultural differences in each of Swedish counties as well as in the Nordic countries may be of importance. A more innovative approach is needed in order to facilitate safe sex and to protect young women from unwanted pregnancies.
Abnormal coexistence of unipolar, bipolar, and threshold resistive switching in an Al/NiO/ITO structure
Authors: Yuan Xin-Cai , Tang Jin-Long , Zeng Hui-Zhong , Wei Xian-Hua 
Published: May 2014

Abstract
This paper reports an abnormal coexistence of different resistive switching behaviors including unipolar (URS), bipolar (BRS), and threshold switching (TRS) in an Al/NiO/indium tin oxide (ITO) structure fabricated by chemical solution deposition. The switching behaviors have been strongly dependent on compliance current (CC) and switching processes. It shows reproducible URS and BRS after electroforming with low and high CC of 1 and 3 mA, respectively, which is contrary to previous reports. Furthermore, in the case of high-forming CC, TRS is observed after several switching cycles with a low-switching CC. Analysis of current-voltage relationship demonstrates that Poole-Frenkel conduction controlled by localized traps should be responsible for the resistance switching. The unique behaviors can be dominated by Joule heating filament mechanism in the dual-oxygen reservoir structure composed of Al/NiO interfacial layer and ITO. The tunable switching properties can render it flexible for device applications.
Hydrothermal growth of TiO2 nanowire membranes sensitized with CdS quantum dots for the enhancement of photocatalytic performance
Authors: Li Yang , Zhang Lili , Wu Wenjian , Dai Peng , Yu Xinxin , Wu Mingzai , Li Guang 
Published: May 2014

Abstract
In this paper, TiO2 nanowires (NWs) on Ti foils were prepared using a simple hydrothermal approach and annealing treatment. CdS quantum dots (QDs) were assembled onto the crystallized TiO2 NWs by sequential chemical bath deposition. Ultraviolet-visible absorption spectra showed that CdS adds bands in the visible to the TiO2 absorption and exhibited a broad absorption band in the visible region, which extended the scope of absorption spectrum and helped improve the photocatalytic degradation efficiency. The results of photocatalytic experiment revealed that CdS-TiO2 NWs possessed higher photocatalytic activities toward methyl orange than pure TiO2 nanowires. The degradation efficiency of 96.32% after ten cycles indicated that the as-prepared CdS-TiO2 composite exhibited excellent long-time recyclable ability and can be reused for the degradation of contaminants.
Self-organized vanadium and nitrogen co-doped titania nanotube arrays with enhanced photocatalytic reduction of CO2 into CH4
Authors: Lu Dandan , Zhang Min , Zhang Zhihua , Li Qiuye , Wang Xiaodong , Yang Jianjun 
Published: May 2014

Abstract
Self-organized V-N co-doped TiO2 nanotube arrays (TNAs) with various doping amount were synthesized by anodizing in association with hydrothermal treatment. Impacts of V-N co-doping on the morphologies, phase structures, and photoelectrochemical properties of the TNAs films were thoroughly investigated. The co-doped TiO2 photocatalysts show remarkably enhanced photocatalytic activity for the CO2 photoreduction to methane under ultraviolet illumination. The mechanism of the enhanced photocatalytic activity is discussed in detail.
Synthesis and crystal structures of 2-methyl-4-aryl-5-oxo-5H-indeno [1,2-b] pyridine carboxylate derivatives
Authors: Pandian Ramesh , Naushad Edayadulla , Vijayakumar Vinodhkumar , Peters Günther H , Mondikalipudur Nanjappagounder Ponnuswamy 
Published: May 2014

Abstract

Background
Hantzsch 1,4-dihydropyridines (Hantzsch1,4-DHP) have been extensively utilized as the analogs of nicotinamide adenine dinucleotide (NADH) coenzyme to study the mechanism and various redox processes. During the redox processes 1,4-DHP systems undergo transformation into the corresponding pyridine derivatives through oxidation. Consequently, the interest in this aromatization reaction, investigation of a wide range of 1, 4-DHPs continues to attract the attention of researchers. Herein, we report the preparation of pyridine derivatives and the crystal structures determined by X-ray crystallographic methods.

Results
The crystal structures and conformational studies of two organic compounds, namely ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (I) and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (II) are reported. The terminal ethyl group of the compound I is disordered over two positions with the refined occupancies of 0.645 & 0.355 and C8 one dimensional zig-zag chain running along 101 direction through C-H…O type of intermolecular interactions. In the compound II, C-H…O interactions connect the molecules to form an R2
2 (16) dimer running along 011 direction.

Conclusion
The crystal structures ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate have been investigated in detail. The terminal ethyl group of compound I is disordered. In compound II, the substitution of Cl atom in the phenyl ring alters the configuration of carboxylate group with respect to the pyridine indane ring.
PERK: a novel therapeutic target for neurodegenerative diseases?
Authors: Ma Tao , Klann Eric 
Published: May 2014

AbstractIdentification of therapeutic targets based on novel mechanistic studies is urgently needed for neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and prion disease. Multiple lines of evidence have emerged to suggest that inhibition of the stress-induced endoplasmic reticulum kinase PERK (protein kinase RNA-like endoplasmic reticulum kinase) is a potential therapeutic strategy for these diseases. A recently published study demonstrated that oral treatment with a newly characterized PERK inhibitor was able to rescue disease phenotypes displayed in prion disease model mice. Here, we discuss the background and rationale for targeting PERK as a viable therapeutic approach as well as implications of these findings for other neurodegenerative diseases. The promise and caveats of applying this strategy for disease therapy also are discussed.
B cell subsets and dysfunction of regulatory B cells in IgG4-related diseases and primary Sjögren’s syndrome: the similarities and differences
Authors: Lin Wei , Jin Lixia , Chen Hua , Wu Qingjun , Fei Yunyun , Zheng Wenjie , Wang Qian , Li Ping , Li Yongzhe , Zhang Wen , Zhao Yan , Zeng Xiaofeng , Zhang Fengchun 
Published: May 2014

Abstract
Introduction
IgG4-related disease (IgG4-RD) is a multisystem-involved autoimmune disease. Abnormally activated and differentiated B cells may play important roles. Regulatory B cells (Breg) are newly defined B cell subgroups with immunosuppressive functions. In this study, we investigated the differences of B cell subsets, the expressions of co-stimulatory molecules on B cells, and the function of Breg cells in patients with IgG4-RD, primary Sjögren’s syndrome (pSS) as well as in healthy controls (HC).

Methods
Newly diagnosed IgG4-RD patients (n = 48) were enrolled, 38 untreated pSS patients and 30 healthy volunteers were recruited as disease and healthy controls. To analyze B cell subsets and B cell activity, PBMCs were surface stained and detected by flow cytometry. The function of Breg cells was tested by coculturing isolated CD19 + CD24hiCD38hi Breg cells with purified CD4 + CD25- T cells. Serum cytokines were measured by ELISA and cytometric bead array. Relationship between clinical data and laboratory findings were analyzed as well.

Results
Compared with pSS patients and HC, IgG4-RD patients had a lower frequency of peripheral Breg cells. Interestingly, CD19 + CD24-CD38hi B cell subsets were significantly higher in peripheral B cells from IgG4-RD patients than in pSS patients and HC, which correlated with serum IgG4 levels. The expression of BAFF-R and CD40 on B cells was significantly lower in IgG4-RD patients compared with those in pSS patients and HC. Unlike HC, Breg cells from pSS patients lacked suppressive functions.

Conclusions
B cells in patients with IgG4-RD and pSS display a variety of abnormalities, including disturbed B cell subpopulations, abnormal expression of key signaling molecules, co-stimulatory molecules, and inflammatory cytokines. In addition, a significantly increased B cell subset, CD19 + CD24-CD38hi B cells, may play an important role in the pathogenesis of IgG4-RD.
Genetic factors underlying discordance in chromatin accessibility between monozygotic twins
Authors: Kim Kwoneel , Ban Hyo-Jeong , Seo Jungmin , Lee Kibaick , Yavartanoo Maryam , Kim Sang Cheol , Park Kiejung , Cho Seong Beom , Choi Jung Kyoon 
Published: May 2014

Abstract
Background
Open chromatin is implicated in regulatory processes; thus, variations in chromatin structure may contribute to variations in gene expression and other phenotypes. In this work, we perform targeted deep sequencing for open chromatin, and array-based genotyping across the genomes of 72 monozygotic twins to identify genetic factors regulating co-twin discordance in chromatin accessibility.

Results
We show that somatic mutations cause chromatin discordance mainly via the disruption of transcription factor binding sites. Structural changes in DNA due to C:G to A:T transversions are under purifying selection due to a strong impact on chromatin accessibility. We show that CpGs whose methylation is specifically regulated during cellular differentiation appear to be protected from high mutation rates of 5′-methylcytosines, suggesting that the spectrum of CpG variations may be shaped fully at the developmental level but not through natural selection. Based on the association mapping of within-pair chromatin differences, we search for cases in which twin siblings with a particular genotype had chromatin discordance at the relevant locus. We identify 1,325 chromatin sites that are differentially accessible, depending on the genotype of a nearby locus, suggesting that epigenetic differences can control regulatory variations via interactions with genetic factors. Poised promoters present high levels of chromatin discordance in association with either somatic mutations or genetic-epigenetic interactions.

Conclusion
Our observations illustrate how somatic mutations and genetic polymorphisms may contribute to regulatory, and ultimately phenotypic, discordance.
Genome-wide mutational landscape of mucinous carcinomatosis peritonei of appendiceal origin
Authors: Alakus Hakan , Babicky Michele L , Ghosh Pradipta , Yost Shawn , Jepsen Kristen , Dai Yang , Arias Angelo , Samuels Michael L , Mose Evangeline S , Schwab Richard B , Peterson Michael R , Lowy Andrew M , Frazer Kelly A , Harismendy Olivier 
Published: May 2014

Abstract
Background
Mucinous neoplasms of the appendix (MNA) are rare tumors which may progress from benign to malignant disease with an aggressive biological behavior. MNA is often diagnosed after metastasis to the peritoneal surfaces resulting in mucinous carcinomatosis peritonei (MCP). Genetic alterations in MNA are poorly characterized due to its low incidence, the hypo-cellularity of MCPs, and a lack of relevant pre-clinical models. As such, application of targeted therapies to this disease is limited to those developed for colorectal cancer and not based on molecular rationale.

Methods
We sequenced the whole exomes of 10 MCPs of appendiceal origin to identify genome-wide somatic mutations and copy number aberrations and validated significant findings in 19 additional cases.

Results
Our study demonstrates that MNA has a different molecular makeup than colorectal cancer. Most tumors have co-existing oncogenic mutations in KRAS (26/29) and GNAS (20/29) and are characterized by downstream PKA activation. High-grade tumors are GNAS wild-type (5/6), suggesting they do not progress from low-grade tumors. MNAs do share some genetic alterations with colorectal cancer including gain of 1q (5/10), Wnt, and TGFβ pathway alterations. In contrast, mutations in TP53 (1/10) and APC (0/10), common in colorectal cancer, are rare in MNA. Concurrent activation of the KRAS and GNAS mediated signaling pathways appears to be shared with pancreatic intraductal papillary mucinous neoplasm.

Conclusions
MNA genome-wide mutational analysis reveals genetic alterations distinct from colorectal cancer, in support of its unique pathophysiology and suggests new targeted therapeutic opportunities.
A new esthetic fiber-reinforced polymer composite resin archwire: a comparative atomic force microscope (AFM) and field-emission scanning electron microscope (FESEM) study
Authors: Chng Chai Kiat , Foong Kelvin , Gandedkar Narayan H , Chan Yiong Huak , Chew Chong-Lin 
Published: May 2014

Abstract

Background
Fiber-reinforced polymer composite (FRPC) archwires could provide an esthetic solution to conventional orthodontic archwires. This study was carried out with the following aims: (1) to compare the sliding friction of FRPC archwire with nickel titanium archwire using various archwire-bracket combinations and (2) to determine the correlation between surface roughness and friction of the FRPC and NiTi archwires.

Methods
Four different brackets (Gemini® (Gemini-3M Unitek, St. Paul, MN, USA), ICE® (ICE-Ormco- Orange, CA, USA), Clarity® (Clarity-3M Unitek, St. Paul, MN, USA), and SmartClip® (SmartClip-3M Unitek, St. Paul, MN, USA)) in combination with FRPC wires and NiTi wires (0.018 in) were studied for archwire friction with simulated wear and surface roughness using scanning electron microscope (SEM) and atomic force microscope (AFM), respectively. Statistical analysis of frictional wear generated and surface roughness between the various archwire and bracket groups was evaluated by one-way ANOVA at 5% level. Least significant difference (LSD) multiple comparisons were used to determine the archwire-bracket group difference.

Results
Gemini®-FRPC group generated the highest frictional wear (mean, 313.10; SD, 802.59) and ICE®-FRPC group produced the highest roughness values among all the groups tested (Ra = 496.13 nm, RMS = 635.49 nm). No correlation was found between frictional wear and surface roughness of the archwires of the various groups.

Conclusions
FRPC archwire shows promise in its application as an esthetic aligning archwire. However, further research and refinement in its manufacture would be necessary to fully realize its potential as an esthetic archwire.
Archaeology after the End of history
Authors: Plantzos Dimitris 
Published: May 2014

This paper offers a survey of the rapid changes observed in the field of archaeological theory in the last 20 years or so; in the midst of cataclysmic changes in the way scholars, and the public at large, attempt to comprehend the past, archaeologists have learnt to trust significantly less their valuable raw data and "facts", in favour of more nuanced accounts allowing for the complexity of the phenomena they study. More to the point, they slowly realise that, as historians, they are internal to the problems under their scrutiny. <br />
The idea of culture and the history of emotions
Authors: Petri Rolf 
Published: May 2014

<p>Recently, emotions have achieved a prominent place in historical research. The article tries to outline a reasonable itemisation of the three main streams in this field of study: the history of individual emotions, the study of the role that emotions have in historical processes, and the reflection about the influence of emotions on history writing. The second part addresses the methodological and theoretical status of the study of past emotions. The author criticises their definition as merely cultural phenomena, maintaining that the historian should contextualise historically the very paradigms of “culture” and “emotion”, “passion”, “sentiment”, “mood”, and the like. S/he should also better explore what emotions are, both by cross-disciplinary debate and theoretical reflection. Otherwise the history of emotions will restrict its critical potential and remain imprisoned within modernity’s canonical self-descriptions.</p><p> </p>
Design and execution of clinical trials in orthopaedic surgery
Authors: Mundi R. , Chaudhry H. , Mundi S. , Godin K. , Bhandari M. 
Published: May 2014

High-quality randomised controlled trials (RCTs) evaluating surgical therapies are fundamental to the delivery of evidence-based orthopaedics. Orthopaedic clinical trials have unique challenges; however, when these challenges are overcome, evidence from trials can be definitive in its impact on surgical practice. In this review, we highlight several issues that pose potential challenges to orthopaedic investigators aiming to perform surgical randomised controlled trials. We begin with a discussion on trial design issues, including the ethics of sham surgery, the importance of sample size, the need for patient-important outcomes, and overcoming expertise bias. We then explore features surrounding the execution of surgical randomised trials, including ethics review boards, the importance of organisational frameworks, and obtaining adequate funding. Cite this article: Bone Joint Res 2014;3:161–8.
Young African Norwegian women and diaspora: Negotiating identity and community through digital social networks
Authors: Mainsah Henry 
Published: May 2014

Abstract
This article explores the ways in which Norwegians of African descent explore their relationship with the African diaspora through the multimodal practices of digital online media. Through the stories of two young Norwegian women the article examines how community, ties and ways of belonging are envisioned at both the local and the transnational levels, and at the intersection between online and offline spaces. These stories are drawn from a larger digital ethnography of the African diaspora in Norway. The article underlines the need to locate understandings of ‘diaspora’ and the ‘digital’ within relations and positionalities in specific national contexts and spaces. The article aims to add to the existing literature on how diasporas in general and African diasporas in particular are technologically mediated.
Modes of self-representation: Visualized identities of former Yugoslav migrant women in the Netherlands
Authors: Van Gorp Jasmijn 
Published: May 2014

Abstract
This study investigates visualized identities of ‘former Yugoslav’ migrant women in the Netherlands. Ten women with roots in Serbia, Bosnia-Herzegovina or Croatia were asked to depict their identities in a series of photographs over the course of one week. Subsequently they were prompted to contextualize their photographs during an individual ‘photo-elicitation’ interview. The author identifies four modes of photographic self-representation by means of a step-wise analysis of the 1175 photographs: archival photos, self-portraits, still lifes and snapshots. The study shows how the four modes are used to visualize different intersecting identities. It appears that conviviality, togetherness, is one of the main features in their visualized identities. Moreover, the photographs not only mediate the people, events and objects of the migrants’ lived cultures but also elements of the research project in itself.
Traces of dispersion: Online media and diasporic identities
Authors: Diminescu Dana , Loveluck Benjamin 
Published: May 2014

Abstract
Drawing mainly on the e-Diasporas Atlas project (www.e-diasporas.fr), this article seeks to understand how the web has affected diasporic self-representations. More specifically, by engaging with both media theory and migration studies, it addresses the new modes of boundary formations that arise in the context of migration flows, and how these are mediated by the web. It sheds light on two main levels of online diasporic identity-building. The first can be situated firmly within a paradigm of ‘graphic reason’, and relates to the socio-semiotic traces documented on diasporic websites. The second examines traces of another kind, which are formed by the hyperlinked networks of e-Diasporas on the web, and which can be situated within a paradigm of ‘digital reason’. Some of the consequences for diasporic identity-formation are drawn out, particularly issues relating to strategies of visibility on the web.