bluuebunny/crossref_metadata_2025 huggingface dataset:
UXT is a novel regulatory factor of regulatory T cells associated with Foxp3
Authors: Li Weina , Wang Lili , Jiang Changli , Li Hong , Zhang Kuo , Xu Yujin , Hao Qiang , Li Meng , Xue Xiaochang , Qin Xin , Zhang Cun , Wang Huixuan , Zhang Wei , Zhang Yingqi
Published: October 2013

Regulatory T (Treg) cells are a constitutively immunosuppressive subtype of T cells that contribute to the maintenance of immunological self‐tolerance and immune homeostasis. However, the molecular mechanisms involved in the regulation of Treg cells remain unclear. In the present study, we identified ubiquitously expressed transcript (UXT) to be a novel regulator of human Treg‐cell function. In cultured human Treg cells, UXT associates with Foxp3 in the nucleus by interacting with the proline‐rich domain in the N‐terminus of Foxp3. Knockdown of UXT expression in Treg cells results in a less‐suppressive phenotype, demonstrating that UXT is an important regulator of the suppressive actions of Treg cells. Depletion of UXT affects the localization stability of Foxp3 protein in the nucleus and downregulates the expression of Foxp3‐related genes. Overall, our results show that UXT is a cofactor of Foxp3 and an important player in Treg‐cell function.
Fabrication of Flowerlike Vaterite Calcium Carbonate Crystal Aggregates by Self‐Assembly in Water/Ethanol Mixtures
Authors: Mao Bao‐Guang , Chu De‐Qing , Wang Ao‐Xuan , Wang Li‐Min , Sun Hong‐Ming , Zhang Zhi‐Yu , Yang Xiao‐Zhong
Published: October 2013

Vaterite calcium carbonate hierarchical structures with a flowerlike appearance have been successfully synthesized by means of a nanoparticle‐mediated self‐organization process in an ethanol/water mixed solution system under mild conditions without using any organic additives. A mechanism for the formation of vaterite crystal aggregates with flowerlike structures made of decussate “cigars” is presented. There are two points that play important roles in the regular organization of the terminal products: one is the concentration of carbonate, and the other is the volume ratio of ethanol/double‐distilled water. In view of the results, a nanoparticle‐mediated self‐organization process is helpful in controlling the aggregation‐driven formation of complex higher‐order‐structured materials and will provide new insights into biomineralization mechanisms. This study could provide an additional tool for designing advanced materials and could be used for the synthesis of more complex crystalline three‐dimensional structures.
The 3‐Acetyloxaphosphirane/1,3,2‐Dioxaphosphol‐4‐ene Rearrangement
Authors: Abdrakhmanova Liliya , Schnakenburg Gregor , Espinosa Arturo , Streubel Rainer
Published: October 2013

An Li/Cl phosphinidenoid complex, obtained by chlorine/lithium exchange from a [dichloro(organo)phosphane]tungsten(0) complex, reacted with aliphatic dicarbonyl derivatives to provide oxaphosphirane complexes, a 1,3,2‐dioxaphosphol‐4‐ene complex, and a P‐alkoxyphosphane complex; the latter is formally derived from the enol form of the β‐diketone. DFT calculations on the ring‐expansion rearrangement support a preferred mechanism involving a pericyclic [1,3] shift of the phosphorus fragment in an oxaphosphirane complex rather than a stepwise diradical or ionic mechanism. The latter is slightly unfavored (ΔΔE‡ = 2.2 kcal/mol) and involves heterolytic P–C bond cleavage to give a methylene oxonium phosphanide intermediate and cyclization through a low‐lying transition state featuring an unusual linear C–O–P geometry.
Estimation of the caloric value of low‐calorie cocoa butter and evaluation of its effects on biochemical and physiological parameters of rats fed high‐fat diet in vivo
Authors: Wu Wei‐Liang , Pan Lu‐Yun , Tan Zhi‐Qiang , Yuan Lu , Zhu Wen‐Liang , Li Xiao‐Ming , Liang De‐Pei , Zhou Yong , Li Jiang , Zheng Jian‐Xian
Published: October 2013

The first aim of the present work was to assess the caloric value of low‐calorie cocoa butter (LCCB) prepared by enzymatic transesterification. A growth method on restricted diet was utilized for the assessment with cocoa butter (CB) as a caloric control. Thirty weanling Wistar male rats were divided into six groups and fed for 3 weeks. The estimated caloric value of LCCB was 4.70 kcal/g, exhibited a decrement of 31%. Furthermore, a growth experiment using pair‐feeding protocol was performed to evaluate whether high LCCB diet could have any effect on the biochemical and physiological parameters, such as TAG, total cholesterol, high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, enzymatic activities of superoxide dismutase and catalase, Lee's index, liver index, the atherosclerosis index, and the risk of coronary heart disease. The results revealed that high LCCB dietary intake did not significantly alter the biochemical parameters except for the LDL‐c. The fatty acid compositions of plasmas and feces demonstrated that caprylic acid was completely consumed through hepatic portal vein for energy supply, while most behenic acid was excreted. These results suggest that the calorie of CB has been lowered by transesterification and the high LCCB diet do not readily induce obesity or oxidative stress.

Practical applications: A method to evaluate the caloric value of fats and oils is presented. A low‐calorie cocoa butter may be useful for the chocolate industry.
Seven nonsynonymous SNPs in the gene encoding human deoxyribonuclease II may serve as a functional SNP potentially implicated in autoimmune dysfunction
Authors: Kimura‐Kataoka Kaori , Ueki Misuzu , Takeshita Haruo , Fujihara Junko , Iida Reiko , Kato Hideaki , Yasuda Toshihiro
Published: October 2013

Many nonsynonymous SNPs in the human DNase II gene (DNASE2), potentially relevant to autoimmunity in conditions such as rheumatoid arthritis, have been identified, but only limited population data are available and no studies have evaluated whether such SNPs are functional. Genotyping of all the 15 nonsynonymous human DNase II SNPs was performed in three ethnic groups including 16 different populations using the PCR‐restriction fragment length polymorphism technique. A series of constructs corresponding to each SNP was examined. Fifteen nonsynonymous SNPs in the gene, except for p.Val206Ile in a Korean population, exhibited a mono‐allelic distribution in all of the populations. On the basis of alterations in the activity levels resulting from the corresponding amino acid substitutions, four activity‐abolishing and five activity‐reducing SNPs were confirmed to be functional. The amino acid residues in activity‐abolishing SNPs were conserved in animal DNase II. All the nonsynonymous SNPs that affected the catalytic activity of human DNase II showed extremely low genetic heterogeneity. However, a minor allele of seven SNPs producing a loss‐of‐function or extremely low activity‐harboring variant could serve as a genetic risk factor for autoimmune dysfunction. These functional SNPs in DNASE2 may have clinical implications in relation to the prevalence of autoimmune diseases.
Clinical applications of capillary electrophoresis based immunoassays
Authors: Moser Annette C. , Willicott Corey W. , Hage David S.
Published: October 2013

Immunoassays have long been an important set of tools in clinical laboratories for the detection, diagnosis, and treatment of disease. Over the last two decades, there has been growing interest in utilizing CE as a means for conducting immunoassays with clinical samples. The resulting method is known as a CE immunoassay. This approach makes use of the selective and strong binding of antibodies for their targets, as is employed in a traditional immunoassay, and combines this with the speed, efficiency, and small sample requirements of CE. This review discusses the variety of ways in which CE immunoassays have been employed with clinical samples. An overview of the formats and detection modes that have been employed in these applications is first presented. A more detailed discussion is then given on the type of clinical targets and samples that have been measured or studied by using CE immunoassays. Particular attention is given to the use of this method in the fields of endocrinology, pharmaceutical measurements, protein and peptide analysis, immunology, infectious disease detection, and oncology. Representative applications in each of these areas are described, with these examples involving work with both traditional and microanalytical CE systems.
Enzymatic hydrolysis of p‐nitrophenyl butyrate in CO2‐based micelle systems
Authors: Shang Wenting , Zhang Xiaogang , Yang Xiaoxi , Zhang Shuang
Published: October 2013

BACKGROUND

In this work, CO2‐based micelles with TMN series surfactants were used as reactive medium. Hydrolysis of p‐nitrophenyl butyrate catalyzed by porcine pancreas was used as a model reaction. The reactive behavior was used to optimize the reaction temperature, pH, pressure, enzyme concentration and the added water.

RESULTS AND DISCUSSION

Generally, the reaction parameters depended on the types of substrates and enzymes. For the hydrolysis of p‐nitrophenyl butyrate in CO2‐based micelles, the reactive yield reached a high level at temperature 303 K, system pressure 15 MPa, pH 6.8, water to surfactant ratio W0 15, and enzyme concentration 1 g mL‐1. In addition, the system reactivity was highest when TMN‐6 surfactant was used.

CONCLUSIONS

The activity of lipase‐catalyzed hydrolysis in CO2‐based micelle was increased significantly compared with that obtained in cyclohexane oil micelle. The combination of enzyme with supercritical CO2 represented a promising ‘green’ reaction system for bioconversions. © 2013 Society of Chemical Industry
Differentiated Overt Learning Activities for Effective Instruction in Engineering Classrooms
Authors: Menekse Muhsin , Stump Glenda S. , Krause Stephen , Chi Michelene T. H.
Published: October 2013

Background

Similar to other domains, engineering education lacks a framework to classify active learning methods used in classrooms, which makes it difficult to evaluate when and why they are effective for learning.

Purpose/Hypothesis

This study evaluated the effectiveness and applicability of the Differentiated Overt Learning Activities (DOLA) framework, which classifies learning activities as interactive, constructive, or active, for engineering classes. We tested the ICAP hypothesis that student learning is more effective in interactive than constructive activities, which are more effective than active activities, which are more effective than passive activities.

Design/Method

We conducted two studies to determine how and to what degree differentiated activities affected student learning outcomes; we measured student knowledge and understanding of materials science and engineering concepts.

Results

Study 1 showed that students scored higher on all postclass quiz questions after participating in interactive and constructive activities than after the active activities. Student scores on more difficult, inference questions suggested that interactive activities provided significantly deeper learning than constructive or active activities. Study 2 showed that student learning, in terms of gain scores, increased systematically from passive to active to constructive to interactive, as predicted by the ICAP hypothesis. All the increases, from condition to condition, were significant.

Conclusions

Our analyses of classroom activities in the engineering domain showed that they fit within the taxonomy of the DOLA framework. The results of the two studies provided evidence to support the predictions of the ICAP hypothesis.
Conceptual Understanding of Electrical Circuits in Secondary Vocational Engineering Education: Combining Traditional Instruction with Inquiry Learning in a Virtual Lab
Authors: Kollöffel Bas , de Jong Ton
Published: October 2013

Background

Traditionally, engineering curricula about electrical circuits use textbook instruction and hands‐on lessons, which are effective approaches for teaching terms and definitions, the procedural use of formulas, and how to build circuits. Nonetheless, students often lack conceptual understanding.

Purpose (Hypothesis)

The aim of this study was to discover how to facilitate the acquisition of conceptual understanding. We hypothesized that adding an instructional approach in the form of inquiry learning in a virtual lab would be more effective than relying on traditional instruction alone.

Design/Method

Students in secondary vocational engineering education were randomly assigned to one of two conditions in a quasi‐experimental study. In the traditional condition, the curriculum was supplemented with computer‐based practice. In the virtual lab condition, the traditional curriculum was supplemented with inquiry learning in a virtual lab.

Results

Results showed that students in the virtual lab condition scored significantly higher on conceptual understanding (Cohen's d = 0.65) and on procedural skills (d = 0.76). In particular, students in this condition scored higher (d = 1.19) on solving complex problems. This result occurred for both complex conceptual and procedural problems.

Conclusion

Since students in the virtual lab condition acquired better conceptual understanding and also developed better procedural skills than students in the traditional condition, it appears that conceptual understanding and procedural skills develop in an iterative fashion.
Diversity of rotavirus strains circulating in Northern Brazil after introduction of a rotavirus vaccine: High prevalence of G3P[6] genotype
Authors: da Silva Soares Luana , de Fátima dos Santos Guerra Sylvia , do Socorro Lima de Oliveira Alessilva , da Silva dos Santos Fabiola , de Fátima Costa de Menezes Euzeni Maria , Mascarenhas Joana d'Arc Pereira , Linhares Alexandre C.
Published: October 2013

Rotavirus A (RVA) is the most common cause of severe acute gastroenteritis in infants and young children worldwide, causing 453,000 deaths annually. In Brazil, the most frequent genotype identified was G1 during almost three decades in the pre‐vaccination period; however, after anti‐rotavirus vaccine introduction, there was a predominance of G2 genotype. The aim of this study was to determine the G and P genotypes of rotaviruses isolated from children under 5 years of age with acute gastroenteritis in the Northern region of Brazil, and discuss the emergence of G3P[6] genotype. A total of 783 stool specimens were obtained between January 2011 and March 2012. RVA antigen was detected in 33% (272/783) of samples using a commercial enzyme‐linked immunosorbent assay and type‐specificity was determined by reverse‐transcription polymerase chain reaction. The most common binary combination was G2P[4], representing 41% of cases, followed by G3P[6] (15%), G1P[8] (8%), G3P[8] (4%), G9P[8] (3%), and G12P[6] (2%). G3P[6] strains were analyzed further and phylogenetic analysis of VP7 gene showed that G3 strains clustered into lineage I and showed a high degree of amino acid identity with vaccine strain RV3 (95.1–95.6%). For VP4 sequences, G3P[6] clustered into lineage Ia. It was demonstrated by the first time the emergence of unusual genotype G3P[6] in the Amazon region of Brazil. This genotype shares neither VP7 nor VP4 specificity with the used vaccine and may represent a challenge to vaccination strategies. A continuous monitoring of circulating strains is therefore needed during the post‐vaccine era in Brazil. J. Med. Virol. 86:1065–1072, 2014. © 2013 Wiley Periodicals, Inc.
Emergence of two novel norovirus genotype II.4 variants associated with viral gastroenteritis in China
Authors: Fu Jian‐guang , Ai Jing , Qi Xian , Zhang Jun , Tang Fen‐yang , Zhu Ye‐fei
Published: October 2013

Noroviruses (NoVs) are the principal cause of epidemic viral gastroenteritis worldwide, including industrialized and developing countries. Eight hundred and fifty sporadic specimens from hospitalized children with acute gastroenteritis and 131 specimens from seven gastroenteritis outbreaks were collected during 2011–2012 in Jiangsu, China. All specimens were tested for the presence of norovirus (NoV) by real time RT‐PCR, and in these, 225/850 of sporadic specimens and 76/131 of outbreak specimens were positive. By sequencing, two novel variants termed JS2011/CHN variant and JS2012/CHN variant were found. By complete genome sequencing and phylogenetic analysis confirmed that both JS2011/CHN variant and JS2012/CHN variant shared more than 98% identity with GII.4 New Orleans/2009/USA strain and GII.4 Sydney/2012/AUS. Both of them had mutations in some key sites in nucleotide sequence and amino acid sequence of ORF1‐ORF3. Whether two novel variants will cause epidemic of NoV outbreaks in China deserves further attention. A national surveillance network may be needed to identify trends in molecular evolution of NoVs for prevention of future epidemics. J. Med. Virol. 86:1226–1234, 2014. © 2013 Wiley Periodicals, Inc.
Use of micro‐Raman spectrometry coupled with scanning electron microscopy to determine the chemical form of uranium compounds in micrometer‐size particles
Authors: Pointurier F. , Marie O.
Published: October 2013

In the frame of nuclear safeguards, knowledge of the chemical form (stoichiometry) of the uranium compounds present in the micrometric particulate material sampled by wiping surfaces in an inspected nuclear facility may point out the industrial process implemented in the installation. Micro‐Raman spectroscopy (MRS) coupled with scanning electron microscopy (SEM) has been used for the first time to analyze micrometer‐size particles of various uranium oxides [UO2, U3O8, UO3, and UO4 · 4(H2O)] deposited on carbon disks. Uranium particles are detected by means of SEM, and Raman analysis is then directly carried out inside the SEM measurement chamber without moving the carbon disk from SEM to MRS. When particles are deposited on appropriate carbon disks (sticky carbon tapes), despite a loss of signal‐to‐noise ratio of about an order of magnitude with regard to the stand‐alone MRS, all uranium oxides are successfully identified in particles by in‐SEM Raman analysis, obtaining similar characteristic bands as the ones obtained with the stand‐alone MRS. Moreover, with the SEM–MRS coupling, particles as small as 1 µm can be analyzed, whereas, without the SEM–MRS coupling, only particles larger than ~5 µm are efficiently analyzed, after localization inside the SEM, transfer of the sample holder into the MRS, and relocation of the particles inside the MRS. Copyright © 2013 John Wiley & Sons, Ltd.
Transcranial application of near‐infrared low‐level laser can modulate cortical excitability
Authors: Konstantinović Ljubica M. , Jelić Milan B. , Jeremić Aleksandra , Stevanović Vuk B. , Milanović Sladjan D. , Filipović Saša R.
Published: October 2013

Background and Objective

Near‐infrared low‐level laser (NIR‐LLL) irradiation penetrates scalp and skull and can reach superficial layers of the cerebral cortex. It was shown to improve the outcome of acute stroke in both animal and human studies. In this study we evaluated whether transcranial laser stimulation (TLS) with NIR‐LLL can modulate the excitability of the motor cortex (M1) as measured by transcranial magnetic stimulation (TMS).

Methods

TLS was applied for 5 minutes over the representation of the right first dorsal interosseal muscle (FDI) in left primary motor cortex (M1), in 14 healthy subjects. Motor evoked potentials (MEPs) from the FDI, elicited by single‐pulse TMS, were measured at baseline and up to 30 minutes after the TLS.

Results

The average MEP size was significantly reduced during the first 20 minutes following the TLS. The pattern was present in 10 (71.5%) of the participants. The MEP size reduction correlated negatively with the motor threshold at rest.

Conclusions

TLS with NIR‐LLL induced transitory reduction of the excitability of the stimulated cortex. These findings give further insights into the mechanisms of TLS effects in the human cerebral cortex, paving the way for potential applications of TLS in treatment of stroke and in other clinical settings. Lasers Surg. Med. 45:648–653, 2013. © 2013 Wiley Periodicals, Inc.
Aerobic capacity during cardiopulmonary exercise testing and survival with and without liver transplantation for patients with chronic liver disease
Authors: Bernal William , Martin-Mateos Rosa , Lipcsey Miklós , Tallis Caroline , Woodsford Kyne , Mcphail Mark J. , Willars Christopher , Auzinger Georg , Sizer Elizabeth , Heneghan Michael , Cottam Simon , Heaton Nigel , Wendon Julia
Published: October 2013

Chronic liver disease (CLD) is associated with muscle wasting, reduced exercise tolerance and aerobic capacity (AC). Measures of AC determined with cardiopulmonary exercise testing (CPET) may predict survival after liver transplantation (LT), but the relationship with nontransplant outcomes is uncertain. In patients assessed for LT, we examined the relationship of CPET AC parameters with the severity of liver disease, nutritional state, and survival with and without LT. Patients assessed for elective first LT who underwent CPET and an anthropometric assessment at a single center were studied. CPET-derived measures of AC that were evaluated included the peak oxygen consumption (VO2 peak) and the anaerobic threshold (AT). Three hundred ninety-nine patients underwent CPET, and 223 underwent LT; 45% of the patients had a VO2 peak < 50% of the predicted value, and 31% had an AT < 9 mL/kg/minute. The VO2 peak and AT values correlated with the Model for End-Stage Liver Disease score, but they more closely correlated with serum sodium and albumin levels. The handgrip strength correlated strongly with the VO2 peak. Patients with impaired AC had prolonged hospitalization after LT, and nonsurvivors had lower AT values than survivors 1 year after transplantation (P < 0.05); this was significant in a multivariate analysis. One hundred seventy-six patients did not undergo LT; the 1-year mortality rate was 34.6%. The AT (P < 0.05) and VO2 peak values (P < 0.001) were lower for nonsurvivors. In a multivariate analysis, AT was independently associated with nonsurvival. In conclusion, AC was markedly impaired in many patients with CLD. In patients who did not undergo transplantation, impaired AT was predictive of mortality, and in patients undergoing LT, it was related to postoperative hospitalization and survival. AC should be evaluated as a modifiable factor for improving patient survival whether or not LT is anticipated. Liver Transpl 20:54–62, 2014. © 2013 AASLD.
Meeting report of the 19th Annual International Congress of the International Liver Transplantation Society (Sydney Convention and Exhibition Centre, Sydney, Australia, June 12-15, 2013)
Authors: Oniscu Gabriel C. , Diaz Geraldine , Levitsky Josh
Published: October 2013

The International Liver Transplantation Society held its annual meeting from June 12 to 15 in Sydney, Australia. More than 800 registrants attended the congress, which opened with a conference celebrating 50 years of liver transplantation (LT). The program included series of featured symposia, focused topic sessions, and oral and poster presentations. This report is by no means all-inclusive and focuses on specific abstracts on key topics in LT. Similarly to previous reports, this one presents data in the context of the published literature and highlights the current direction of LT. Liver Transpl 20:7–14, 2014. © 2013 AASLD.
Regional perfusion by extracorporeal membrane oxygenation of abdominal organs from donors after circulatory death: A systematic review
Authors: Shapey Iestyn M. , Muiesan Paolo
Published: October 2013

Organs from donors after circulatory death (DCDs) are particularly susceptible to the effects of warm ischemia injury. Regional perfusion (RP) by extracorporeal membrane oxygenation (ECMO) is increasingly being advocated as a useful remedy to the effects of ischemia/reperfusion injury, and it has been reported to enable the transplantation of organs from donors previously deemed unsuitable. The MEDLINE, Embase, and Cochrane databases were searched, and articles published between 1997 and 2013 were obtained. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two hundred ten articles were identified, and 11 were eligible for inclusion. Four hundred eighty-two kidneys and 79 livers were transplanted from regional perfusion–supported donor after circulatory death (RP-DCD) sources. One-year graft survival was lower with uncontrolled RP-DCD liver transplantation, whereas 1-year patient survival was similar. Primary nonfunction and ischemic cholangiopathy were significantly more frequent with RP-DCDs versus donors after brain death (DBDs), but there was no difference in postoperative mortality between the 2 groups. The 1-year patient and graft survival rates for RP-DCD kidney transplantation were better than the rates with standard DCDs and were comparable to, if not better than, the rates with DBDs. At experienced centers, delayed graft function (DGF) for kidney transplantation from RP-DCDs was much less frequent in comparison with all other donor types. In conclusion, RP aids the recovery of DCD organs from ischemic injury and enables transplantation with acceptable survival. RP may help to increase the donor pool, but its benefits must still be balanced with the recognition of significantly higher rates of complications in liver transplantation. In kidney transplantation, significant reductions in DGF can be obtained with RP, and there are potentially important implications for long-term outcomes. Significant ethicolegal issues exist, and they are preventing a worldwide consensus on optimum RP protocols and an accurate appreciation of outcomes. Liver Transpl 19:1292-1303, 2013. © 2013 AASLD.
Near‐Infrared Photovoltaic Performance of Conjugated Polymers Containing Thienoisoindigo Acceptor Units
Authors: Karakawa Makoto , Aso Yoshio
Published: October 2013

Donor–acceptor‐type conjugated copolymers containing a thienoisoindigo unit are synthesized and characterized. In combination with benzodithiophene donor units, this strong acceptor moiety can be used to extend the light absorption of their conjugated copolymers to longer wavelengths. The absorption spectra of the copolymers show features that extended up to 1200 nm in the near infrared (NIR). The resulting optical energy gaps are very narrow, ranging from 1.20 to 1.29 eV. The copolymers are used as the donor material with PC61BM acceptor in the active layer of bulk‐heterojunction organic photovoltaic cells, and the devices exhibit photocurrent at NIR wavelengths with a power‐conversion efficiency of 0.52% under air mass (AM) 1.5 illumination.

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Tailoring the LCST of PNIPAAM‐b‐PLA‐b‐PNIPAAM Triblock Copolymers via Stereocomplexation
Authors: Zhang Xing , Tan Beng H. , He Chaobin
Published: October 2013

Poly(N‐isopropylacrylamide)‐block‐poly(l‐lactic acid)‐block‐poly(N‐isopropylacrylamide) (PNIPAAM‐b‐PLLA‐b‐PNIPAAM) and PNIPAAM‐b‐PDLA‐b‐PNIPAAM triblock copolymers with varying polylactic acid (PLA) lengths are synthesized using a combination of ring‐opening polymerization and atom‐transfer radical polymerization. Results of 1H NMR and gel permeation chromatography analyses show that the copolymers have a well‐defined triblock structure and the PLA segment lengths can be readily controlled with monomer feed ratio. Stereocomplexation between the enantiomeric PLA segments is confirmed with differential scanning calorimetry and wide‐angle X‐ray scattering. Dynamic light scattering experiments show that (1) the LCST of PNIPAAM in water could be tailored from 32 °C up to 38.5 °C by increasing the length of PLA segments and mixing copolymers of similar molecular weight with enantiomeric PLA segments to induce stereocomplexation, and (2) the LCST of each mixed copolymer system could be tailored within a 2–3 °C range of body temperature by manipulating the ratio of the enantiomeric copolymers in solution.

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Gestational exposure to the AhR agonist 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin induces BRCA‐1 promoter hypermethylation and reduces BRCA‐1 expression in mammary tissue of rat offspring: Preventive effects of resveratrol
Authors: Papoutsis Andreas J. , Selmin Ornella I. , Borg Jamie L. , Romagnolo Donato F.
Published: October 2013

Studies with murine models suggest that maternal exposure to aromatic hydrocarbon receptor (AhR) agonists may impair mammary gland differentiation and increase the susceptibility to mammary carcinogenesis in offspring. However, the molecular mechanisms responsible for these perturbations remain largely unknown. Previously, we reported that the AhR agonists 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) induced CpG methylation of the breast cancer‐1 (BRCA‐1) gene and reduced BRCA‐1 expression in breast cancer cell lines. Based on the information both the human and rat BRCA‐1 genes harbor xenobiotic responsive elements (XRE = 5′‐GCGTG‐3′), which are binding targets for the AhR, we extended our studies to the analysis of offspring of pregnant Sprague–Dawley rats treated during gestation with TCDD alone or in combination with the dietary AhR antagonist resveratrol (Res). We report that the in utero exposure to TCDD increased the number of terminal end buds (TEB) and reduced BRCA‐1 expression in mammary tissue of offspring. The treatment with TCDD induced occupancy of the BRCA‐1 promoter by DNA methyltransferase‐1 (DNMT‐1), CpG methylation of the BRCA‐1 promoter, and expression of cyclin D1 and cyclin‐dependent kinase‐4 (CDK4). These changes were partially overridden by pre‐exposure to Res, which stimulated the expression of the AhR repressor (AhRR) and its recruitment to the BRCA‐1 gene. These findings point to maternal exposure to AhR agonists as a risk factor for breast cancer in offspring through epigenetic inhibition of BRCA‐1 expression, whereas dietary antagonists of the AhR may exert protective effects. © 2013 Wiley Periodicals, Inc.
Granite rock fragmentation at percussive drilling – experimental and numerical investigation
Authors: Saadati M. , Forquin P. , Weddfelt K. , Larsson P.L. , Hild F.
Published: October 2013

The aim of this study is to numerically model the fracture system at percussive drilling. Because of the complex behavior of rock materials, a continuum approach is employed relying upon a plasticity model with yield surface locus as a quadratic function of the mean pressure in the principal stress space coupled with an anisotropic damage model. In particular, Bohus granite rock is investigated, and the material parameters are defined based on previous experiments. This includes different tests such as direct tension and compression, three‐point bending, and quasi‐oedometric tests to investigate the material behavior at both tension and confined compression stress states. The equation of motion is discretized using a finite element approach, and the explicit time integration method is employed. Edge‐on impact tests are performed, and the results are used to validate the numerical model. The percussive drilling problem is then modeled in 3D, and the bit‐rock interaction is considered using contact mechanics. The fracture mechanism in the rock and the bit penetration‐ resisting force response are realistically captured by the numerical model. Copyright © 2013 John Wiley & Sons, Ltd.
Resin flow monitoring inside composite laminate during resin film infusion process
Authors: Zhou Z.J. , Li M. , Gu Y.Z. , Ma X.Q. , Li Y.X. , Jia L.J. , Zhang Z.G.
Published: October 2013

In this article, a novel method of measuring resin flow front under vacuum condition is presented. The in situ monitoring system with metal hollow probe based on gas flow balance can be used in resin film infusion (RFI) process, where resin film is used and transverse flow is dominated along thickness direction of fiber preform. The diameter of the probe was chosen to increase the measuring accuracy, and the reliability of the method was evaluated by comparison of visualization experiment. Experimental results demonstrate that the method is suitable for monitoring resin flow in RFI process with and without autoclave, and can obtain the information about resin filling time, nonuniform flow front, and the permeability of fiber preform. Furthermore, by means of the established monitoring system, the influences of pressure and lay‐up sequence of carbon fiber fabric on epoxy resin flow during RFI process were investigated. In addition, resin flow pattern with changing viscosity of epoxy resin was studied. POLYM. COMPOS., 35:681–690, 2014. © 2013 Society of Plastics Engineers
Effect of fly ash washing conditions on the properties of coupling agent modified polypropylene/fly ash composites
Authors: Potgieter Herman , Liauw Christopher Mark , Velado David
Published: October 2013

Two fly ash samples (one from UK, UKFA, and another from South Africa, SAFA) were washed with water and 1 M hydrochloric acid (followed by water) prior to incorporation (at 65% wt) into polypropylene homopolymer, containing an unsaturated carboxylic acid coupling agent (Lubrizol Solplus® C800) with dicumyl peroxide free radical initiator. Melt blending was achieved using a Haake Rheomix 600 mixing chamber, and composite test plaques were compression moulded. Flexural and impact testing was then carried out. Unwashed and water washed fly ash–based composites responded well to C800 modification, and flow microcalorimetry (FMC) and diffuse reflectance Fourier transform infrared spectroscopy studies confirmed strong interaction between C800 and fly ash. However, washing the fly ash with HCl led to a reduction in composite flexural and impact properties. Scanning electron microscopy imaging of the latter composite fracture surfaces revealed poor filler‐matrix adhesion, which was thought to be due to reduced interaction between C800 and HCl washed fly ash. The latter was confirmed using FMC. Reduction of C800/fly ash interaction led to a reduction in the nucleation of polypropylene (PP) crystallization and a decrease in melt flow rate. The latter may be due to a shift in locus of PP–C800 addition reactions from the interfacial region to the bulk matrix. POLYM. COMPOS., 35:698–707, 2014. © 2013 Society of Plastics Engineers
Efficacy of Glucarpidase (Carboxypeptidase G2) in Patients with Acute Kidney Injury After High‐Dose Methotrexate Therapy
Authors: Widemann Brigitte C. , Schwartz Stefan , Jayaprakash Nalini , Christensen Robbin , Pui Ching‐Hon , Chauhan Nikhil , Daugherty Claire , King Thomas R. , Rush Janet E. , Howard Scott C.
Published: October 2013

Study Objective

Because the incidence rate of renal impairment is 2–10% for patients treated with high‐dose methotrexate and renal impairment develops in 0–12.4% of patients treated for osteosarcoma, we sought to evaluate the efficacy of glucarpidase, a recently approved drug that rapidly hydrolyzes methotrexate to inactive metabolites, which allows for nonrenal clearance in patients with delayed renal methotrexate elimination.

Design

Pooled analysis of efficacy data from four multicenter single‐arm compassionate‐use clinical trials using protocols from 1993 to 2007.

Patients

Of 476 patients with renal toxicity and delayed methotrexate elimination who were treated with intravenous glucarpidase for rescue after high‐dose methotrexate, 169 patients had at least one preglucarpidase (baseline) plasma methotrexate concentration greater than 1 μmol/L and one postglucarpidase methotrexate concentration measurement by high‐performance liquid chromatography and were included in the efficacy analysis; renal recovery was assessed in 436 patients who had at least one recorded preglucarpidase and postglucarpidase serum creatinine concentration measurement.

Measurements and Main Results

Efficacy was defined as rapid and sustained clinically important reduction (RSCIR) in plasma methotrexate concentration, with a concentration of 1 μmol/L or lower at all postglucarpidase determinations. Median age of efficacy‐evaluable patients was 20 years (range 5 weeks–84 years). Osteosarcoma (36%), non‐Hodgkin lymphoma (27%), and acute lymphoblastic leukemia (20%) were the most frequent underlying diagnoses. Median preglucarpidase serum methotrexate was 11.7 μmol/L. At the first (median 15 minutes) through the last (median 40 hours) postglucarpidase measurement, plasma methotrexate concentrations demonstrated consistent 99% median reduction. RSCIR was achieved by 83 (59%) of 140 patients. A total of 64% of patients with renal impairment greater than or equal to Common Terminology Criteria for Adverse Events grade 2 recovered to grade 0 or 1 at a median of 12.5 days after glucarpidase administration.

Conclusion

Glucarpidase caused a clinically important 99% or greater sustained reduction of serum methotrexate levels and provided noninvasive rescue from methotrexate toxicity in renally impaired patients.
Various ways to strengthen the fiber‐matrix interface for enhanced composite performance
Authors: Tiwari S. , Bijwe J.
Published: October 2013

Surface treatment (ST) of carbon fibers (CF) leads to an enhancement in fiber‐matrix adhesion. However, it deteriorates the strength of a fiber which makes its reinforcing action less effective in a composite. These effects in opposite directions control the net strength of a composite, and hence, the treatment has to be judiciously applied, which would enhance the first factor and minimize the second one. Authors have recently reported on four effective techniques (using various doses) such as treatments with nanoparticles of Ytterbium fluoride (YbF3), cold remote nitrogen–oxygen plasma (CRNOP), γ‐ray irradiation and nitric acid oxidation. Amongst these methods, nitric acid oxidation is studied in depth in the literature, and γ‐ray irradiation is sparingly studied. However, nano‐YbF3 and CRNOP were first time reported in the literature by the authors. However, comparative aspects of all these methods were not addressed. In this paper, these aspects in details are discussed to lay down the right criteria for selection of a ST technique of CF to design the desired performance of a composite. The composites with polyetherimide and treated CF (including untreated) were developed and evaluated for various properties including tribological one. Treated CF based composites exhibited excellent mechanical and tribological properties (under harsh operative conditions with wear rates ≈ 1 × 10−15 m3/Nm and μ ≈ 0.09). It was concluded that for strength and tribo‐performance, different treatments and doses are to be employed. Overall nanosized‐YbF3 treatment of CF proved to be the most promising ST method. Copyright © 2013 John Wiley & Sons, Ltd.
Copper nanoparticles seeded functionalized‐PVC plastic surface for electroless nickel deposition
Authors: Wang Ming‐Qiu , Yan Jun , Du Shi‐Guo , Meng Sheng‐Hao
Published: October 2013

A novel and facile activation process for electroless nickel deposition was developed. The semi‐interpenetrating polymer network hydrogel biofilm was used to functionalize the inert poly(vinyl chloride) (PVC) surface, and then Cu nanoparticles, which can initial the subsequent electroless nickel deposition successfully seeded on the functionalized‐PVC surface. The samples were characterized by scanning electron microscopy, X‐ray photoelectron spectroscopy, X‐ray diffraction, and transmission electron microscopy. The results show that the hydrogel film provided the PVC surface with amino groups and Cu nanoparticles of 20–50 nm in size could be functioned as the catalytic nuclei for the subsequent electroless metal deposition on PVC plastic. It can be concluded that the novel Cu activation was effective for the nickel deposition on PVC surface, because of more chemisorption sites for Cu nanoparticles generated on PVC surface. Copyright © 2013 John Wiley & Sons, Ltd.
Inverse probability weighting in nested case‐control studies with additional matching—a simulation study
Authors: Støer Nathalie C. , Samuelsen Sven Ove
Published: October 2013

Nested case‐control designs are inevitably less efficient than full cohort designs, and it is important to use available information as efficiently as possible. Reuse of controls by inverse probability weighting may be one way to obtain efficiency improvements, and it can be particularly advantageous when two or more endpoints are analyzed in the same cohort. The controls in a nested case‐control design are often matched on additional factors than at risk status, and this should be taken into account when reusing controls. Although some studies have suggested methods for handling additional matching, a thorough investigation of how this affects parameter estimates and weights is lacking. Our aim is to provide such a discussion to help developing guidelines for practitioners. We demonstrate that it is important to adjust for the matching variables in regression analyses when the matching is broken. We present three types of estimators for the inverse sampling probabilities accounting for additional matching. One of these estimators was somewhat biased when the cases and controls were matched very closely. We investigated how additional matching affected estimates of interest, with varying degree of association between the matching variables and exposure/outcome. Strong associations introduced only a small bias when the matching variables were properly adjusted for. Sometimes, exposure variables, for example, blood samples, are analyzed in batches. Rather, strong batch effects had to be present before this introduced much bias when the matching was broken. All simulations are based on a study of prostate cancer and vitamin D. Copyright © 2013 John Wiley & Sons, Ltd.
Dampening variations in wind power generation—the effect of optimizing geographic location of generating sites
Authors: Reichenberg Lina , Johnsson Filip , Odenberger Mikael
Published: October 2013

This paper presents a method to dampen the variations in the output of aggregated wind power through geographic allocation of wind power generation sites. The method, which is based on the sequential optimization of site localization, is applied to the Nordic countries and Germany, using meteorologic wind speed data as the input. The results show that the variability in aggregated wind power output mitigates by applying sequential optimization. For the data used in this work, the coefficient of variation (standard deviation/mean) was 0.54 for the optimized aggregation of sites, as compared with 0.91 for the present day installation. An optimal allocation of wind power generation site reduces the need for dispatch and other measures to deal with the intermittent nature of wind power. Copyright © 2013 John Wiley & Sons, Ltd.
Cost‐effective shaft torque observer for condition monitoring of wind turbines
Authors: Perišić Nevena , Kirkegaard Poul Henning , Pedersen Bo Juul
Published: October 2013

Improvement of condition monitoring (CM) systems for wind turbines (WTs) and reduction of the cost of wind energy are possible if knowledge about the condition of different WT components is available. CM based on the WT drive train shaft torque signal can give a better understanding of the gearbox failure mechanisms as well as provide a method for detecting mass imbalance and aerodynamic asymmetry. The major obstacle preventing the industrial application of CM based on the shaft torque signal is the costly measurement equipment which is impractical for long‐term use on operating WTs. This paper suggests a novel approach for low‐cost, indirect monitoring of the shaft torque from standard WT measurements. The shaft torque is estimated recursively from measurements of generator torque, high speed shaft and low speed shaft angular speeds using the well‐known Kalman filter theory. The performance of the augmented Kalman filter with fading memory (AKFF) is compared with the augmented Kalman filter (AKF) using simulated data of the WT for different load conditions, measurement noise levels and WT fault scenarios. A multiple‐model algorithm, based on a set of different Kalman filters, is designed for practical implementation of the shaft torque estimator. Its performance is validated for a scenario where there are frequent changes of operating points. The proposed cost‐effective shaft torque estimator overcomes all major problems, which prevent the industrial application of CM systems based on shaft torque measurements. Future work will be focused on validating the method using experimental data and developing suitable signal processing algorithms for fault detection. Copyright © 2013 John Wiley & Sons, Ltd.
Evolutionary computation for feature selection in classification problems
Authors: de la Iglesia Beatriz
Published: October 2013

Feature subset selection (FSS) has received a great deal of attention in statistics, machine learning, and data mining. Real world data analyzed by data mining algorithms can involve a large number of redundant or irrelevant features or simply too many features for a learning algorithm to handle them efficiently. Feature selection is becoming essential as databases grow in size and complexity. The selection process is expected to bring benefits in terms of better performing models, computational efficiency, and simpler more understandable models. Evolutionary computation (EC) encompasses a number of naturally inspired techniques such as genetic algorithms, genetic programming, ant colony optimization, or particle swarm optimization algorithms. Such techniques are well suited to feature selection because the representation of a feature subset is straightforward and the evaluation can also be easily accomplished through the use of wrapper or filter algorithms. Furthermore, the capability of such heuristic algorithms to efficiently search large search spaces is of great advantage to the feature selection problem. Here, we review the use of different EC paradigms for feature selection in classification problems. We discuss details of each implementation including representation, evaluation, and validation. The review enables us to uncover the best EC algorithms for FSS and to point at future research directions. WIREs Data Mining Knowl Discov 2013, 3:381–407. doi: 10.1002/widm.1106

This article is categorized under:

Technologies > Classification

Technologies > Computational Intelligence

Technologies > Data Preprocessing
Missing in the youth development literature: The organization as host, cage, and promise
Authors: Roholt Ross VeLure , Baizerman Michael , Rana Sheetal , Korum Kathy
Published: October 2013

Good, high‐quality youth development programs require effective youth organizations. While youth organizations are commonly understood as valuable and supportive of healthy youth development, attention and focus on youth organizations in both scholarship and practice are missing within the youth development field. The authors advocate for a more distinct and clearer focus on youth organizations to foster positive youth development.