bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological Glucose Metabolism Regulated Peptide Self‐Assembly as a Simple Visual Biosensor for Glucose Detection
Authors: Xu Xiao‐Ding , Lin Bing‐Bing , Feng Jun , Wang Ya , Cheng Si‐Xue , Zhang Xian‐Zheng , Zhuo Ren‐Xi 
Published: February 2012

AbstractA glucose oxidase (GOx)‐mediated glucose metabolism was in vitro mimicked and employed to regulate the self‐assembly of peptide‐based building blocks. In this new stimuli‐responsive self‐assembly system, two peptide‐based building blocks, respectively, having aspartic acid (gelator 1) and lysine (gelator 2) residues were designed and prepared. When adding glucose and GOx to the aqueous solution of gelator 1 or the self‐assembled fibrillar hydrogel of gelator 2 to construct glucose metabolism system, the metabolic product (gluconic acid) can trigger the protonation of the peptide molecules and induce the phase transitions of gelators 1 (sol‐gel) and 2 (gel‐sol). Because this glucose metabolism regulated peptide self‐assembly is built on the oxidation of glucose, it can be used as a simple visual biosensor for glucose detection.
Synthesis of β‐Cyclodextrin Containing Copolymer via “Click” Chemistry and Its Self‐Assembly in the Presence of Guest Compounds
Authors: Zhang Jianxiang , Ellsworth Kristin , Ma Peter X. 
Published: February 2012

AbstractWe report the synthesis of a hydrophilic copolymer with one polyethylene glycol (PEG) block and one β‐cyclodextrin (β‐CD) containing block by a “click” reaction between azido‐substituted β‐CD and propargyl flanking copolymer. 1H NMR study suggested a highly efficient conjugation of β‐CD units by this approach. The obtained copolymer was used as a host macromolecule to construct assemblies in the presence of hydrophobic guests. For assemblies containing a hydrophobic polymer, their size can be simply adjusted by simply changing the content of hydrophobic component. By serving as a guest molecule, hydrophobic drugs can also be loaded accompanying the formation of nanoparticles, and the drug payload is releasable. Therefore, the copolymer synthesized herein can be employed as a carrier for drug delivery.
Ion‐Specific Self‐Assembly of Low‐Dimension Aggregate Structures of Conjugated Polymer at Two‐Phase Interface
Authors: Zhou Chunjie , Chen Nan , Yang Jien , Liu Huibiao , Li Yuliang 
Published: February 2012

AbstractA novel and facile approach to manipulate the morphology of Cu2+‐ion‐specific assembly of conjugated polymer by coordinative interaction at an oil–water two‐phase interface is present. The application of increasing importance is the use of π‐conjugated polymers as receptors, exploiting their ability to selectively form complexes, which can obviously change the optical properties in solution and induce the formation of varied solid nano/microstructures. By this method, microtubes are formed through self‐rolling of a strained ionic bilayer film at the oil/water interface.
Numerical analysis of a locking‐free mixed finite element method for a bending moment formulation of Reissner‐Mindlin plate model
Authors: da Veiga Lourenço Beirão , Mora David , Rodríguez Rodolfo 
Published: February 2012

AbstractThis article deals with the approximation of the bending of a clamped plate, modeled by Reissner‐Mindlin equations. It is known that standard finite element methods applied to this model lead to wrong results when the thickness t is small. Here, we propose a mixed formulation based on the Hellinger‐Reissner principle which is written in terms of the bending moments, the shear stress, the rotations and the transverse displacement. To prove that the resulting variational formulation is well posed, we use the Babuška‐Brezzi theory with appropriate t ‐dependent norms. The problem is discretized by standard mixed finite elements without the need of any reduction operator. Error estimates are proved. These estimates have an optimal dependence on the mesh size h and a mild dependence on the plate thickness t. This allows us to conclude that the method is locking‐free. The proposed method yields direct approximation of the bending moments and the shear stress. A local postprocessing leading to H1 ‐type approximations of transverse displacement and rotations is introduced. Moreover, we propose a hybridization procedure, which leads to solving a significantly smaller positive definite system. Finally, we report numerical experiments which allow us to assess the performance of the method. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
ESR1 amplification in breast cancer: controversy resolved?
Authors: Albertson Donna G 
Published: February 2012

AbstractThe determination of oestrogen receptor α (ERα) expression in breast cancers has been for many years the standard of care for guiding patient management. In 2007, Holst and colleagues published the previously unappreciated observation that the ERα gene, ESR1, was amplified in 21% of breast cancers, and that ESR1 gene amplification identified those individuals with high ERα expression in their tumours and who were likely to respond to hormonal manipulation. This has been a controversial area. Others have tried to reproduce these findings but the results have been mixed with respect to amplification frequency, and even contradictory with respect to prognostic and predictive value. The controversy may have now been resolved. Ooi et al, in this issue of the journal, show that the large clustered FISH signals that have been interpreted as ESR1 amplification are sensitive to RNase treatment, indicating that FISH is detecting accumulation of ESR1 transcripts in the nucleus of breast cancer cells expressing high levels of ERα, rather than gene amplification events. This story has important lessons for translational cancer research, and in particular FISH studies of gene copy number. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
MiR‐182 overexpression in tumourigenesis of high‐grade serous ovarian carcinoma
Authors: Liu Zhaojian , Liu Jinsong , Segura Miguel F , Shao Changshun , Lee Peng , Gong Yaoqin , Hernando Eva , Wei Jian‐Jun 
Published: February 2012

AbstractMolecular pathogenesis of high‐grade serous ovarian carcinoma (HG‐SOC) is poorly understood. Recent recognition of HG‐SOC precursor lesions, defined as serous tubal intraepithelial carcinoma (STIC) in fimbria, provides a new venue for the study of early genetic changes in HG‐SOC. Using microRNA profiling analysis, we found that miR‐182 expression was significantly higher in STIC than in matched normal Fallopian tube. Further study revealed that miR‐182 was significantly overexpressed in most HG‐SOC cases. To test whether miR‐182 plays a major role in early tumourigenesis of HG‐SOC, we overexpressed miR‐182 in immortalized ovarian surface, Fallopian tube secretory cells and malignant ovarian cell lines, and found that miR‐182 overexpression resulted in increased tumour transformation in vitro, and enhanced tumour invasiveness in vitro and metastasis in vivo. Mechanistically, we demonstrated that the oncogenic properties of miR‐182 in ovarian cancer were mediated in part by its impaired repair of DNA double‐strand breaks and negative regulation of breast cancer 1 (BRCA1) and metastasis suppressor 1 (MTSS1) expression as well as its positive regulation of the oncogene high‐mobility group AT‐hook 2 (HMGA2). Our findings suggest that miR‐182 dysregulation confers powerful oncogenic potential in the tumourigenesis of HG‐SOC. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
A fatty acid‐binding protein 7/RXRβ pathway enhances survival and proliferation in triple‐negative breast cancer
Authors: Liu Rong‐Zong , Graham Kathryn , Glubrecht Darryl D , Lai Raymond , Mackey John R , Godbout Roseline 
Published: February 2012

AbstractFABP7 has been implicated in tumour cell proliferation, cell migration, and poor prognosis in patients with high‐grade astrocytoma and melanoma. In this study, we examine FABP7 expression in a cohort of 176 primary breast cancers by gene profiling and tissue microarray immunostaining. We show that FABP7 is significantly up‐regulated in triple‐negative breast cancer. Elevated FABP7 levels are associated with poor prognosis, absence of oestrogen and progesterone hormone receptors (ER, PR) and HER2, increased cell proliferation, and high tumour grade. Depletion of FABP7 in the ER/PR‐negative cell line, MDA‐MB‐435S, significantly reduced cell growth rate and sensitized the cells to growth inhibition by omega‐3 docosahexaenoic acid (DHA). A target of DHA‐bound FABP7 in the nucleus is RXRβ, a retinoid‐activated nuclear receptor that functions as a transcription factor by either homodimerizing or heterodimerizing with other nuclear receptors such as PPARs. Based on our microarray data, RXRβ, like FABP7, is an adverse prognostic factor for breast cancer. We propose that the DHA‐FABP7‐RXRβ pathway promotes cell survival/proliferation in triple‐negative breast cancer. Targeting this pathway may thus provide an alternate route for the treatment of triple‐negative breast cancer. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Chemical Composition of South American Burseraceae Non‐volatile Oleoresins and Preliminary Solubility Assessment of their Commercial Blend
Authors: Siani A. C. , Nakamura M. J. , Tappin M. R. R. , Monteiro S. S. , Guimarães A. C. , Ramos M. F. S. 
Published: February 2012

ABSTRACTIntroductionNon‐volatile oleoresins from neotropical Burseraceae are traditionally used for craft, technological and medicinal purposes. The crude resin is usually sold in popular markets of the forest communities. Adding value to this rainforest raw material requires establishing its composition.ObjectiveTo analyse the resin composition from different Burseraceae species and establish a minimally reproducible profile by gas chromatography, in order to parameterise its quality control.MethodologyCrude oleoresin samples of 10 Protium and Trattinnickia species and a commercial blend were subjected to hydrodistillation to remove volatile compounds. The chloroform‐soluble residues were methylated, analysed by GC‐FID (flame ionisation detection), and individual components were identified by analysing their mass fragmentation pattern in GC‐MS and comparison with data from the literature. The blend solubility was assayed in 30 non‐chlorinated solvents at three different proportions.ResultsThe resins consisted exclusively of triterpenes, showing a common predominance of four major compounds in all the samples, corresponding to α‐amyrin, β‐amyrin, α‐amyrenone and β‐amyrenone. This profile was complemented with minor amounts of the tetracyclic β‐elemolic and α‐elemolic acids, maniladiol, brein and other oxidised trace compounds. The better solvents for the resin were those chemically bearing more than four carbon atoms, as n‐butyl acetate, 2‐ethoxyethanol and isopropanol. The crude resin blend sold contained around 10% of insoluble material that was constituted by up to 70% inorganic residues mixed with humic acid derivatives, as attested by ash analysis and IR spectroscopy, respectively.ConclusionThe experimental results, complemented by a general inspection of the literature, demonstrated a systematically reproducible triterpene profile in Protium and Trattinnickia species. Copyright © 2012 John Wiley & Sons, Ltd.
Ultrasonic Microwave‐assisted Extraction Coupled with High‐speed Counter‐Current Chromatography for the Preparation of Nigakinones from Picrasma quassioides (D.Don) Benn
Authors: Xiao Xiaohua , Si Xiaoxi , Tong Xing , Li Gongke 
Published: February 2012

ABSTRACTIntroductionNigakinones are the main effective compounds of Picrasma quassioides (D. Don) Benn and are widely used in traditional Chinese medicine, therefore a rapid and efficient separation and purification method is necessary.ObjectiveTo develop a new method based on ultrasonic microwave‐assisted extraction (UMAE) and high‐speed counter‐current chromatography (HSCCC) for the rapid separation and purification of nigakinone and methylnigakinone from P. quassioides (D.Don) Benn.MethodologyResponse surface methodology (RSM) was used to optimise the extraction conditions of UMAE: 10.0 g of original sample was extracted with 210 mL of 90% (v/v) aqueous methanol at 60°C for 13 min, ultrasonic power was 100 W and microwave power was dynamically adjusted to the given temperature. After extraction, the extract was introduced into the HSCCC and separated with a hexane:ethyl acetate:methanol:2% acetic acid (9:11:9:11, v/v/v/v) solvent system.ResultsAbout 2.1 mg nigakinone with purity of 96.8% was obtained in one step within 200 min, methylnigakinone was also obtained with a purity of 75.6%. Their chemical structures were identified with ESI‐MS and 1H‐NMR.ConclusionUMAE coupled with HSCCC was found to be a promising and feasible alternative method to separate and purify alkaloids from natural herbs such as P. quassiodes. Copyright © 2012 John Wiley & Sons, Ltd.
Method of analyzing and quantifying the performance of mixing sections
Authors: Kubik Pavel , Vlcek Jiri , Tzoganakis Costas , Miller Luke 
Published: February 2012

AbstractIn this article, the performance of three different mixing elements on color dispersion in high‐density polyethylene and linear low‐density polyethylene polymer stream during extrusion is studied. Two similarly designed Maddock mixers and a Stratablend II mixer are used as the last part of a general purpose single screw. Moreover, an inline melt camera is used for the quantification of mixing quality by visualization of grayscale of the color dispersion and thus mixing. The Stratablend II mixer produces the lowest and most uniform standard deviation. Both the Maddock mixers showed the same trend but higher values of standard deviation. All results are then compared with a full 3D finite element method simulation. Simulations clearly indicate that the Stratablend II mixer has the best mixing abilities and that these are mainly given by its unique design with high average value of shear stress. The role of elongational stress does not appear to have a high influence on mixing for these mixers. The results also suggest that the key factor for achieving better mixing is the frequency by which a large fraction of the material passes through the high shear stress regions of the mixer. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Crystallization of low‐density polyethylene embedded inside zinc oxide nanoparticle percolating network
Authors: Liang Guo‐Dong , Liu Ting‐Ting , Qin Wang‐Ping , Zhu Fang‐Ming , Wu Qing 
Published: February 2012

AbstractThe crystallization behavior of low‐density polyethylene (LDPE) embedded inside zinc oxide (ZnO) percolating network (LDPE/60 vol% ZnO) was investigated via differential scanning calorimetry (DSC), and compared with those of LDPE bulks (neat LDPE and LDPE/1.15 vol% ZnO). Results revealed that embedded LDPE possessed by far shorter half‐crystallization time at elevated crystallization temperatures than LDPE bulks, whereas at lower crystallization temperatures longer half‐crystallization time was observed. Isothermal crystallization kinetics study revealed that the Avrami exponent of embedded LDPE varied in range of 1.8–2.0, indicating quasi‐two‐dimensional crystallization with heterogeneous nucleation, contrasting with about 3 for LDPE bulks. Moreover, crystallization activation energy of embedded LDPE was much larger than that of neat LDPE due to geometric confinement effect of ZnO network. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Electron correlation and many‐body effects at interfaces on semiconducting substrates
Authors: Tejeda Antonio , Fagot‐Révurat Y. , Cortés R. , Malterre D. , Michel E. G. , Mascaraque A. 
Published: February 2012

AbstractLow dimensional systems are characterized by at least one spatial dimension of only some atoms. Such size reduction has often important consequences for physical properties. Electronic correlation and electron–phonon coupling can originate Mott insulators or charge density waves (CDWs), both phenomena enhanced by dimensionality reduction. Interfaces offer a natural way of reducing the dimensionality. Among all the surfaces, semiconducting surfaces are particularly well adapted for electronic correlation studies. In them, correlation is enhanced because of the low dimension, the electronic localization in dangling bonds and the large inter‐orbital distances in reconstructions. Despite these factors favoring correlation, eventually stronger than in bulk systems, the field is by far much less developed. We review here the discovery of correlated surfaces, while studying the Schottky barrier of alkalis on Si or GaAs, and coetaneous studies on SiC. We summarize then the studies on K/Si(111):B, whose ${\left( {\sqrt {3} \times \sqrt {3} } \right)}R30^\circ $ was considered a surface Mott insulator with an important electron‐phonon coupling. The recent discovery of a ${\left( {2\sqrt {3} \times 2\sqrt {3} } \right)}R30^\circ $ symmetry has been first interpreted as evidence of a bipolaronic insulator, but new findings have finally proven it to be a band insulator. We will then focus on the model system Sn/Ge(111). The last unclear issue about the (3 × 3) reconstruction at 150 K was related to the Sn 4d core level. High‐resolution photoemission has clarified the core level deconvolution while refining the structural model. This metallic reconstruction is sensitive to electronic correlations which trigger a phase transition to a Mott phase below 30 K.
Risk to cyberinfrastructure systems served by cloud computing technology as systems of systems
Authors: Haimes Yacov Y. , Chittister Clyde C. 
Published: February 2012

AbstractBuilding on systems‐based philosophy, theory, methodology, and practice, the challenges associated with modeling, assessing, managing, and communicating the multidimensional risk tocyberinfrastructuresystems (CIS) serviced by cloud computing technology (CCT) as systems of systems (SoS) are explored. The article raises concerns about the euphoria in the literature about CCT and stresses the importance of understanding the complex process of modeling, assessing, managing, and communicating the risks associated with CIS‐CCT. Several themes are highlighted: the theory of scenario structuring; the epistemology of the states of the CIS‐CCT systems; the role of systems integration in CIS‐CCT; the risk to CIS‐CCT from malicious insiders' intrusion; the complex definition and quantification of the risk function associated with CIS‐CCT systems; and modeling the multiple perspectives of CIS‐CCT, focusing on hierarchical holographic modeling (HHM) and phantom system models (PSM). The paper concludes with an epilogue and list of references. © 2011 Wiley Periodicals, Inc. Syst Eng
Migration Processes, Familial Characteristics, and Schooling Dropout Among Black Youths
Authors: Thomas Kevin J. A. 
Published: February 2012

AbstractThis study uses data from the 2000 U.S. census to examine whether the schooling advantage of black immigrants’ children found in previous studies is robust. According to the results, the advantage associated with having migrant parents is not restricted to the children of immigrants. Black migrant parents, regardless of foreign-born status, have children with favorable schooling outcomes. Such parental-level influences, however, seem stronger among some immigrant groups than among native internal migrants. The study also suggests that the collective advantage of the children of immigrants is driven by positive migrant selectivity. Accordingly, comparisons between the children of native migrants and children in various immigrant groups reveal that the immigrant advantage is not robust. In fact, the results suggest that when immigrant ethnicity is considered, some children of immigrants may be disadvantaged relative to the children of native migrants. Among recent migrants, the children of native internal migrants also have more favorable outcomes than the children of immigrants, although these differences disappear after background factors are controlled. Further, internal-migrant and immigrant households are less likely to have characteristics that adversely affect schooling than nonmigrant households. Unsurprisingly, the children of nonmigrants have the worst outcomes among black youths.
THE PRACTICE OF CONSANGUINEOUS MARRIAGE IN OMAN: PREVALENCE, TRENDS AND DETERMINANTS
Authors: ISLAM M. MAZHARUL 
Published: February 2012

SummaryThe practice of consanguineous marriage has been the culturally preferred form of marriage in most Arab and the Middle Eastern countries, including Oman, but due to a paucity of population-based data in the past there is a dearth of information about its form and dynamics in Oman. Recent national-level surveys allow this gap to be filled. This paper examines the prevalence, trends and determinants of consanguineous marriages in Oman using data from the 2000 Oman National Health Survey. The results indicate a very high prevalence of consanguineous marriage in Oman, as more than half (52%) of marriages are consanguineous. First cousin unions are the most common type of consanguineous unions, constituting 39% of all marriages and 75% of all consanguineous marriages. The study observed various patterns of consanguinity, some of them common with other Arab nations, and some unique in nature. Women's age at marriage, employment, place of childhood residence and geographical region appear to be significant determinants of consanguineous marriages. Consanguineous marriage shows a strong association with marital stability, early age at marriage and early-age childbearing. There has been no appreciable change in the prevalence of consanguineous unions in Oman over the last four decades despite massive socioeconomic development and modernization. However, recent marriage cohorts show slight declining trends. The results suggest that consanguinity is likely to remain stable in the future or decline at a slow rate. Specific health education and genetic counselling should be followed in line with WHO recommendations to minimize the negative health consequences of consanguinity for child health.
Formation and evolution of buried snowpack deposits in Pearse Valley, Antarctica, and implications for Mars
Authors: Heldmann J.L. , Marinova M. , Williams K.E. , Lacelle D. , Mckay C.P. , Davila A. , Pollard W. , Andersen D.T. 
Published: February 2012

AbstractBuried snowpack deposits are found within the McMurdo Dry Valleys of Antarctica, which offers the opportunity to study these layered structures of sand and ice within a polar desert environment. Four discrete buried snowpacks are studied within Pearse Valley, Antarctica, through in situ observations, sample analyses, O-H isotope measurements and numerical modelling of snowpack stability and evolution. The buried snowpack deposits evolve throughout the year and undergo deposition, melt, refreeze, and sublimation. We demonstrate how the deposition and subsequent burial of snow can preserve the snowpacks in the Dry Valleys. The modelled lifetimes of the buried snowpacks are dependent upon subsurface stratigraphy but are typically less than one year if the lag thickness is less than c. 7 cm and snow thickness is less than c. 10 cm, indicating that some of the Antarctic buried snowpacks form annually. Buried snowpacks in the Antarctic polar desert may serve as analogues for similar deposits on Mars and may be applicable to observations of the north polar erg, buried ice at the Mars Phoenix landing site, and observations of buried ice throughout the martian Arctic. Numerical modelling suggests that seasonal snows and subsequent burial are not required to preserve the snow and ice on Mars.