bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of cropping systems on heavy metal distribution and mercury fractionation in the Wanshan mining district, China: Implications for environmental management
Authors: Wang Jianxu , Feng Xinbin , Anderson Christopher W.N. , Qiu Guangle , Bao Zhengduo , Shang Lihai
Published: June 2014

The authors studied the concentration of heavy metals and mercury fractionation in contaminated soil in 2 agricultural land use systems (paddy rice and dry land) at the Wanshan mercury mine in China. The average concentrations of chromium, lead, copper, nickel, and zinc were generally lower in paddy rice soil relative to corn field soil. Soil under corn field production was slightly contaminated with lead (22–100 mg/kg), copper (31–64 mg/kg), and nickel (22–76 mg/kg) and moderately contaminated with zinc (112–635 mg/kg). In both soils, correlation of these metals with the titanium concentration in the soil indicates a geogenic origin for each metal (lead, r = 0.48; copper, r = 0.63; nickel, r = 0.47; zinc, r = 0.48). The mercury and antimony concentration in soil was high under both cropping systems, and future remediation efforts should consider the potential environmental risk presented by these metals. The concentration of bioavailable mercury in soil ranged from 0.3 ng/g to 11 ng/g across the 2 cropping systems. The majority of mercury (>80%) was associated with organic matter and the residual fraction. However, soil under paddy rice production exhibited a significantly lower concentration of Fe/Mn oxide–bound mercury than that under corn field production. This may be a function of the reduction of Fe/Mn oxides in the paddy rice soil, with the subsequent release of adsorbed metals to the soil solution. Sequential change from corn field to paddy rice production, as practiced in Wanshan, should therefore be avoided. Mercury adsorbed to Fe/Mn oxides in corn field soil potentially could be released into the soil solution and be made available for biomethylation under the flooded water management conditions of a rice paddy. Environ Toxicol Chem 2014; 33:2147–2155. © 2014 SETAC
The beta-adrenoceptor agonist isoproterenol rescues acetaminophen-injured livers through increasing progenitor numbers by Wnt in mice
Authors: Soeda Junpei , Mouralidarane Angelina , Ray Shuvra , Novelli Marco , Thomas Steven , Roskams Tania , Diehl Anna Mae , Oben Jude A.
Published: June 2014

Acetaminophen (APAP)-induced acute liver injury (AILI) is a major health problem. Accumulating evidence suggests that the sympathetic nervous system (SNS) regulates neuronal and hematopoietic progenitors. SNS signaling affects hepatic progenitor/oval cells (HPCs) and β-adrenoceptor agonism will expand HPCs to reduce AILI. Dopamine β-hydroxylase-deficient mice (Dbh−/−), lacking catecholamine SNS neurotransmitters, isolated HPCs, and immature ductular 603B cells were initially used to investigate SNS involvement in HPC physiology. Subsequently, control mice were treated with APAP (350 mg/kg) followed by the β-adrenoceptor agonist, isoproterenol (ISO), or the β-adrenoceptor antagonist, propranolol. Mechanistic studies examined effects of non-SNS HPC expansion on AILI, involvement of the canonical Wnt/β-catenin pathway (CWP) in the action of ISO on HPC expansion and comparison of ISO with the current standard of care, N-acetylcysteine (NAC). Dbh−/− mice lacking catecholamines had low HPC numbers, reconstituted by ISO. In vitro, ISO-induced proliferation of 603B cells was CWP dependent. In control mice, AILI raised HPC numbers, further increased by ISO, with attenuation of liver injury. Delayed administration of NAC did not, but delayed ISO did, reverse AILI. Propranolol worsened AILI. AILI activated the CWP, and ISO enhanced Wnt-ligand production. HPCs were the major source of Wnt ligands. Recombinant Wnt3a and ISO-603B-conditioned media, but not ISO alone, protected isolated hepatocytes from death, reversed by DKK1—a Wnt antagonist. Additionally, tumor-associated weak inducer of apoptosis expanded HPCs and protected against AILI. Furthermore, allotransplantation of HPCs from APAP+ISO-treated mice to other APAP-injured mice improved AILI, an effect antagonized by DKK1. Conclusion: SNS catecholamines expand HPCs, which are both targets and sources of Wnt ligands. Hepatoprotection by ISO is mediated by para- and autocrine effects of Wnt signaling. ISO represents novel pharmacotherapy for AILI. (Hepatology 2014;60:1023–1034)
Processing of gelatin‐based cryogels with improved thermomechanical resistance, pore size gradient, and high potential for sustainable protein drug release
Authors: Gorgieva Selestina , Kokol Vanja
Published: June 2014

Porous gelatin (GEL) cryogels were processed by spatiotemporal and temperature‐controlled gelation and freezing‐lyophilizaton process, followed by zero‐length crosslinking, using different molarities of reagents (EDC and NHS) and reaction media (100% PBS or 20/80% PBS/EtOH mixture) for variable time extensions (1–24 h). In this way, tuneable cryogels with gradient microporosity (from 100 µm to 1000 µm) were formed, being mainly influenced by crosslinkers' concentration and EtOH addition. Later affect the pore morphology (from round to ellipsoid), consequently modulating the steady‐state physiological swelling profile toward twice lower values (∼ 600%) comparing to stepwise swelling of in 100% PBS media crosslinked cryogels. While the presence of EtOH decelerate the crosslinking kinetic by retaining cryogels' microstructure formed during freezing, the 100% PBS and higher EDC molarity resulted in approximately 40% crosslinking degree, being expressed as a thermal resistance of cryogels up to approximately 73°C. Finally, the tuneable enzymatic resistance allow time‐dependent poly‐l‐Lysine (pL) release profile in up to month period. The processed GEL cryogels have potential in broad range biomedical applications, especially as sustainable, protein‐based drug delivery systems. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1119–1130, 2015.
Dental implant surface treatments may modulate cytokine secretion in Porphyromonas gingivalis‐stimulated human gingival fibroblasts: A comparative study
Authors: Stavroullakis Alexander , Brito Carlos , Chen Hong Yang , Bajenova Elena , Prakki Anuradha , Nogueira‐Filho Getulio
Published: June 2014

Peri‐implantitis is an inflammation that affects dental implants and can lead to implant loss. The aim of this study was to analyze the in vitro effect of different implant surface treatments on cytokine production by human gingival fibroblasts (HGFs) stimulated or not with Porphyromonas gingivalis lipopolysaccharide (PgLPS). Six different titanium implants were tested: turned, sandblasted, anodized, acid‐etched, TiO2‐blasted/acid‐etched, and grit‐blasted/acid‐etched. HGFs were seeded with each implant in a 6‐well plate and assayed before LPS treatment (−LPS) or after 36 h of LPS (+LPS) treatment. Protein concentrations were measured using a Pierce bicinchoninic acid (BCA) assay and cytokine secretions were analyzed using a multiplex cytokine array. Scanning electron microscopy was performed for sterile implants and after cell attachment. Protein levels were consistent across all implants indicating that cell growth was uniform (p > 0.05). Sandblasted and turned surfaces significantly increased the secretion of interleukin (IL)−6, −8, −10, MCP‐1 and VEGF (p < 0.05) when compared with the other surfaces. PgLPS stimulus increased cytokine secretion in all tested surfaces. In conclusion, different implant surfaces had various effects on HGFs' cytokine secretion. The findings may provide insights into the progression of peri‐implantitis. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1131–1140, 2015.
Development of a sutureless dural substitute from Bombyx mori silk fibroin
Authors: Flanagan Kelly E. , Tien Lee W. , Elia Roberto , Wu Julian , Kaplan David
Published: June 2014

Silk solvent casting, electrospinning, and electrogelation techniques were used to create a biodegradable, biocompatible silk fibroin dural substitute. The all‐silk system was designed and produced to improve on currently available materials, grafts and tissue sealants used for dural closure in neurosurgery. The silk biomaterial was successfully fabricated as a dual layer adhesive system designed to seal durotomies while also functioning as a dural regeneration scaffold. The mechanical characteristics, biocompatibility, biodegradability, and hydrodynamic sealing capability of the material were evaluated. Results showed that the biomaterial was biocompatible with neural cells and fibroblasts, had mechanical properties mimicking the natural dura, was biodegradable with controllable degradation, and was able to seal against a hydrodynamic pressure of 205 mmHg, which greatly exceeds the maximum cerebrospinal fluid pressure seen in both cranial and spinal dural closures of 50 mmHg. Based on its design and experimental results, the adhesive silk dual layer composite biomaterial shows potential as a sutureless dural repair system that would improve on current dural closure techniques. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 485–494, 2015.
Surface modification of coronary stents with SiCOH plasma nanocoatings for improving endothelialization and anticoagulation
Authors: Zhang Qin , Shen Yang , Tang Chaojun , Wu Xue , Yu Qingsong , Wang Guixue
Published: June 2014

The surface properties of intravascular stent play a crucial role in preventing in‐stent restenosis (ISR). In this study, SiCOH plasma nanocoatings were used to modify the surfaces of intravascular stents to improve their endothelialization and anticoagulation properties. SiCOH plasma nanocoatings with thickness of 30–40 nm were deposited by low‐temperature plasmas from a gas mixture of trimethysilane (TMS) and oxygen at different TMS:O2 ratios. Water contact angle measurements showed that the SiCOH plasma nanocoating surfaces prepared from TMS:O2 = 1:4 are hydrophilic with contact angle of 29.5 ± 1.9°. The SiCOH plasma nanocoated 316L stainless steel (316L SS) wafers were first characterized by in vitro adhesion tests for blood platelets and human umbilical vein endothelial cells. The in vitro test results showed that the SiCOH plasma nanocoatings prepared from TMS:O2 = 1:4 had excellent hemo‐ and cytocompatibility. With uncoated 316L SS stents as the control, the SiCOH plasma nanocoated 316L SS stents were implanted into rabbit abdominal artery model for in vivo evaluation of re‐endothelialization and ISR inhibition. After implantation for 12 weeks, the animals testing results showed that the SiCOH plasma nanocoatings accelerated re‐endothelialization and inhibited ISR with lumen reduction of 26.3 ± 10.1%, which were considerably less than the 41.9 ± 11.6% lumen reduction from the uncoated control group. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 464–472, 2015.
Gro2mat: A package to efficiently read gromacs output in MATLAB
Authors: Dien Hung , Deane Charlotte M. , Knapp Bernhard
Published: June 2014

Molecular dynamics (MD) simulations are a state‐of‐the‐art computational method used to investigate molecular interactions at atomic scale. Interaction processes out of experimental reach can be monitored using MD software, such as Gromacs. Here, we present the gro2mat package that allows fast and easy access to Gromacs output files from Matlab. Gro2mat enables direct parsing of the most common Gromacs output formats including the binary xtc‐format. No openly available Matlab parser currently exists for this format. The xtc reader is orders of magnitudes faster than other available pdb/ascii workarounds. Gro2mat is especially useful for scientists with an interest in quick prototyping of new mathematical and statistical approaches for Gromacs trajectory analyses. © 2014 Wiley Periodicals, Inc.
Brønsted Acid‐Catalyzed Three‐Component 1,3‐Dipolar Cycloadditions of 1,2‐Disubstituted Alkynes with Aldehyde‐Generated Azomethine Ylides
Authors: Tan Wei , Du Bai‐Xiang , Guo Lu , Li Mei , Xing Gui‐Juan , Shi Feng
Published: June 2014

The first 1,3‐dipolar cycloadditions (1,3‐DCs) of 1,2‐disubstituted alkynes with aldehyde‐generated azomethine ylides have been established, leading to the efficient synthesis of poly‐substituted 2,5‐dihydropyrroles.The Brønsted acid‐catalyzed three‐component 1,3‐DCs of but‐2‐ynedioates, aldehydes, and diethyl 2‐aminomalonate tolerate a wide range of substrates, offering structurally diverse poly‐substituted 2,5‐dihydropyrroles in high yields. This protocol not only provides an easy and efficient approach to poly‐substituted 2,5‐dihydropyrroles but also greatly enriches the chemistry of 1,3‐DCs, especially alkyne‐involved 1,3‐DCs.
Regiochemistry‐Aligned Copolymerization of Propylene with p‐Methylstyrene and 1,4‐Diviny­lbenzene Using an ansa‐Metallocene Catalyst
Authors: Dong Cheng , Wang Ning , Qin Yawei , Niu Hui , Dong Jin‐Young
Published: June 2014

Copolymerization of propylene with styrenic α‐olefin monomers is rare with C2‐symmetric ansa‐metallocene‐type catalysts, which are the dominant single‐site catalysts for isospecific propylene polymerization. This makes it difficult to obtain compositionally narrow‐distributed reactive polypropylene with isotactic stereoregularity (iPP) bearing benzyl and styryl moieties, which are important precursors for iPP functionalization. In this paper, rac‐CH2(3‐t‐Bu‐1‐Ind)2ZrCl2 is paired with methylaluminoxane (MAO) and used in copolymerization of propylene with p‐methyl­styrene (p‐MS) and 1,4‐divinylbenzene (DVB). Due to the unified primary regiochemistry of the catalyst toward both propylene and the styrenic monomers, both copolymerizations are viable, with the incorporation of the styrenic monomers not disastrously decreasing the catalyst activity. The fingerprint primary–primary consecutive sequences of propylene and p‐MS/DVB are clearly identified by 13C NMR. As high as 1.37 mol% of p‐MS and 0.93 mol% of DVB are incorporated into iPP at fairly high catalyst activities. It is noteworthy that DVB is incorporated with a selective mono‐enchainment mode, leaving iPP with pendant styryl groups on the linear backbone. Both the iPP/p‐MS and iPP/DVB copolymers show narrow molecular weight distributions (<3), indicating a single‐site characteristic of the copolymerizations. Overall, copolymerization of propylene with p‐MS and DVB with a C2‐symmetric ansa‐metallocene catalyst is made possible by unification of the insertion regiochemistry of the comonomers.

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Shaking on Standing: A Critical Review
Authors: Erro Roberto , Bhatia Kailash P. , Cordivari Carla
Published: June 2014

Orthostatic tremor is a rare condition, though its exact prevalence is unknown, which is clinically characterized by a feeling of unsteadiness or being about to fall on standing and which disappears on walking, sitting, or lying down. It is generally accepted that classic orthostatic tremor manifests with a high‐frequency tremor (>13 Hz) of the legs when standing. However, a number of patients initially reported as orthostatic tremor did not actually have such electrophysiological features. It is our experience that there is a clinical spectrum of different conditions presenting as shaking on standing, and this highlights the importance of the electrophysiology to aid the differential diagnosis of these disorders. Here, we provide a critical review of the clinical spectrum of shaking on standing, along with demonstrative electrophysiological recordings of some of these conditions.
High‐order partial differential equation de‐noising method for vibration signal
Authors: Zhao Lei , Yin Aijun
Published: June 2014

A novel approach for 1D vibration signal de‐noising filter using partial differential equation (PDE) is presented. In particular, the numerical solution of higher‐order PDE is generated, and we show that it enables the amplitude‐frequency characteristic in filter to be estimated more accurately, which results in better de‐noising performance in comparison with the low‐order PDE. The de‐noising tests on different degree of artificial noise are conducted. Experimental tests have been rigorously compared with different de‐noising methods to verify the efficacy of the proposed high‐order PDE filter method. Copyright © 2014 John Wiley & Sons, Ltd.
An offline–online homogenization strategy to solve quasilinear two‐scale problems at the cost of one‐scale problems
Authors: Abdulle A. , Bai Y. , Vilmart G.
Published: June 2014

A simple and concise finite element algorithm for the reliable and efficient resolution of nonlinear elliptic or parabolic multiscale problems of nonmonotone type is presented. Our method, based on a macroscopic and a microscopic discretization, combines reduced‐order modeling techniques with numerical homogenization. By precomputing a low dimensional reduced basis for the solution of the cell problems, one drastically reduces the cost of the iteration scheme at the macroscopic level, which become similar to the cost of solving a single scale nonlinear problem. A crucial step of our algorithm is in the selection of the reduced basis performed in an offline stage. This selection procedure relies on a new a posteriori nonlinear estimator. Both the offline and online costs are independent of the smallest scale in the physical problem. The performance and accuracy of the algorithm are illustrated on 2D and 3D stationary and evolutionary nonlinear multiscale problems.Copyright © 2014 John Wiley & Sons, Ltd.
A coupled FEM/DEM approach for hierarchical multiscale modelling of granular media
Authors: Guo Ning , Zhao Jidong
Published: June 2014

A hierarchical multiscale framework is proposed to model the mechanical behaviour of granular media. The framework employs a rigorous hierarchical coupling between the FEM and the discrete element method (DEM). To solve a BVP, the FEM is used to discretise the macroscopic geometric domain into an FEM mesh. A DEM assembly with memory of its loading history is embedded at each Gauss integration point of the mesh to serve as the representative volume element (RVE). The DEM assembly receives the global deformation at its Gauss point from the FEM as input boundary conditions and is solved to derive the required constitutive relation at the specific material point to advance the FEM computation. The DEM computation employs simple physically based contact laws in conjunction with Coulomb's friction for interparticle contacts to capture the loading‐history dependence and highly nonlinear dissipative response of a granular material. The hierarchical scheme helps to avoid the phenomenological assumptions on constitutive relation in conventional continuum modelling and retains the computational efficiency of FEM in solving large‐scale BVPs. The hierarchical structure also makes it ideal for distributed parallel computing to fully unleash its predictive power. Importantly, the framework offers rich information on the particle level with direct link to the macroscopic material response, which helps to shed lights on cross‐scale understanding of granular media. The developed framework is first benchmarked by a simulation of single‐element drained test and is then applied to the predictions of strain localisation for sand subject to monotonic biaxial compression, as well as the liquefaction and cyclic mobility of sand in cyclic simple shear tests. It is demonstrated that the proposed method may reproduce interesting experimental observations that are otherwise difficult to be captured by conventional FEM or pure DEM simulations, such as the inception of shear band under smooth symmetric boundary conditions, non‐coaxial granular response, large dilation and rotation at the edges of shear band and critical state reached within the shear band. Copyright © 2014 John Wiley & Sons, Ltd.
Downregulation of lipogenesis and fatty acid oxidation in the subcutaneous adipose tissue of morbidly obese women
Authors: Auguet Teresa , Guiu‐Jurado Esther , Berlanga Alba , Terra Ximena , Martinez Salomé , Porras José Antonio , Ceausu Andra , Sabench Fátima , Hernandez Mercé , Aguilar Carmen , Sirvent Joan Josep , Castillo Daniel Del , Richart Cristóbal
Published: June 2014

Objective

The aim of this study was to analyse the expression of crucial genes in fatty acid metabolism in visceral (VAT) and subcutaneous (SAT) adipose tissue samples from morbidly obese women.

Methods

The VAT and SAT expression of key genes in 145 morbidly obese women (MO, BMI > 40 Kg/m2) and 18 normal weight control women by RT‐PCR and Western Blot was analyzed.

Results

In SAT, the expression levels of the genes related to lipogenesis and fatty acid oxidation were significantly lower in MO than in controls. In VAT, most of the lipogenic genes studied had similar expression levels in MO and control cohort. Regarding inflammation, IL6 was significantly higher in MO in both tissues whereas TNFα mRNA expression was significantly higher only in VAT.

Conclusions

Our results indicate that in morbidly obese patients, lipogenesis and fatty acid oxidation are downregulated in SAT, whereas in VAT these pathways are almost unchanged. By contrast, inflammation is induced in both adipose tissues. It is hypothesized that, in this type of extreme obesity, SAT works to limit any further development of fat mass, decreasing the expression of lipogenic and FA oxidative genes whereas VAT depot might have lost this capability.
Pregnancy‐associated plasma protein A regulates mitosis and is epigenetically silenced in breast cancer
Authors: Loddo Marco , Andryszkiewicz Joanna , Rodriguez‐Acebes Sara , Stoeber Kai , Jones Allison , Dafou Dimitra , Apostolidou Sophia , Wollenschlaeger Alex , Widschwendter Martin , Sainsbury Richard , Tudzarova Slavica , Williams Gareth Haydn
Published: June 2014

Aberrant mitosis is a common feature of cancer, yet little is known about the altered genes causing mitotic defects. We screened human tumours for cells with morphological signatures of highly specific mitotic defects previously assigned to candidate genes in a genome‐wide RNA interference screen carried out in HeLa cells (www.mitocheck.org). We discovered a striking enrichment of early mitotic configurations indicative of prophase/prometaphase delay in breast cancer. Promoter methylation analysis of MitoCheck candidate genes assigned to the corresponding 'mitotic delay' class linked this defect to epigenetic silencing of the gene encoding pregnancy‐associated plasma protein‐A (PAPPA), a secreted protease. PAPPA silencing was highly prevalent in precursor lesions and invasive breast cancer. Experimental manipulation of PAPPA protein levels in human mammary epithelial cells and in breast cancer cell lines demonstrates that progression through early mitosis is dependent on PAPPA function, and that breast cancer cells become more invasive after down‐regulation of this protease. PAPPA regulates mitotic progression through modulating the IGF‐1 signalling pathway resulting in activation of the forkhead transcription factor FoxM1, which drives a transcriptional cluster of essential mitotic genes. Our results show that PAPPA has a critical function in normal cell division and is targeted early in breast cancer development. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of dicumyl peroxide and phenolic resin as a mixed curing system on the mechanical properties and morphology of TPVs based on HDPE/ground tire rubber
Authors: He Maoyong , Li Yingchun , Qiao Bing , Ma Xinghui , Song Jingjing , Wang Meng
Published: June 2014

Thermoplastic vulcanizates (TPVs) are a special group of thermoplastic elastomer with the characteristic that consists of rubber elasticity and the processability of thermoplastic polymers. TPVs based on high density polyethylene (HDPE)/ground tire rubber (GTR) with phenolic resin (HY‐2045) and dicumyl peroxide (DCP) as vulcanizing agents are prepared through dynamic vulcanization in this article. The blends consisting of 40/60 HDPE/GTR are melt‐mixed in an internal mixer and then pressed with a compression molding machine. The aim of this experiment is to study the influence of a compound curing agent system on the mechanical properties of the HDPE/GTR composites. The results indicate that the mechanical properties of the HDPE/GTR blends are improved significantly by adding 4 phr HY‐2045 and 0.3 phr DCP than those of TPVs without any vulcanizing agents after dynamic vulcanization. The X‐ray photoelectron spectroscopy study and the FTIR‐ATR analysis confirmed that the crosslinking phenomenon occurred in the preparation of TPVs; and the gel fraction analysis indicates that the GTR components and the HDPE components of the HDPE/GTR blends are all moderately crosslinked. In addition, the morphology of the HDPE/GTR blends has been investigated by scanning electron microscopy. POLYM. COMPOS., 36:1907–1916, 2015. © 2014 Society of Plastics Engineers
Gel time and polymerization kinetics of unsaturated polyester resin/clay montmorillonite nanocomposites
Authors: Ramirez Daniel , Gómez Germán , Jaramillo Franklin
Published: June 2014

This article presents the variation of viscosity, gel point, and curing kinetic process of nanocomposites based on unsaturated polyester resin (UPR) and natural nano‐clay CloisiteNa+® and organomodified Cloisite15A® montmorillonites (MMT). Different amounts (1–10 wt%) of nanoclays were added homogeneously before the cross‐linking reaction of the thermoset polymer. The complex viscosity before curing was especially dependent on the CloisiteNa+® content more than Cloisite15A®. The G' and G'' slope also as the complex viscosity criterion were used to determine the nanocomposites gel time variation. Isothermal differential scanning calorimetry measurements were performed to calculate the reaction order and the rate constant using different empirical equations. These results demonstrated a catalytic effect of the clays on the UPR cure, with diffusion controlled phenomena predominating at high conversions. The X‐ray diffraction patterns were useful for identifying the nanocomposites formation, and gave information about the clays dispersion, which served to support the rheological and polymerization kinetic results. Finally, natural MMT CloisiteNa+®decreased gel time and was more compatible with UPR than the organomodified Cloisite15A®. POLYM. COMPOS., 36:1931–1940, 2015. © 2014 Society of Plastics Engineers
Etching and Post‐Treatment Surface Stability of Track‐Etched Polycarbonate Membranes by Plasma Processing Using Various Related Oxidizing Plasma Systems
Authors: Tompkins Brendan D. , Dennison Jordan M. , Fisher Ellen R.
Published: June 2014

Oxidizing plasmas (O2, CO2, H2O (g), and formic acid (g)) were used to modify track‐etched polycarbonate (PC) membranes and explore the mechanisms and species responsible for etching. Etch rates were measured using scanning electron microscopy; modified surfaces were characterized with X‐ray photoelectron spectroscopy and water contact angle. These results were combined with optical emission spectroscopy to provide insight into etch mechanisms. Although oxide functionalities implanted were similar, H2O (g) and formic acid vapor plasmas yielded the lowest contact angles. The CO2, H2O (g), and formic acid (g) plasma‐modified surfaces were found to be similarly stable 1 month after treatment. Etch rate correlated directly to the relative gas‐phase density of atomic oxygen and hydroxyl radicals.
Quantitative proteomics in cardiovascular research: Global and targeted strategies
Authors: Shen Xiaomeng , Young Rebeccah , Canty John M. , Qu Jun
Published: June 2014

Extensive technical advances in the past decade have substantially expanded quantitative proteomics in cardiovascular research. This has great promise for elucidating the mechanisms of cardiovascular diseases and the discovery of cardiac biomarkers used for diagnosis and treatment evaluation. Global and targeted proteomics are the two major avenues of quantitative proteomics. While global approaches enable unbiased discovery of altered proteins via relative quantification at the proteome level, targeted techniques provide higher sensitivity and accuracy, and are capable of multiplexed absolute quantification in numerous clinical/biological samples. While promising, technical challenges need to be overcome to enable full utilization of these techniques in cardiovascular medicine. Here, we discuss recent advances in quantitative proteomics and summarize applications in cardiovascular research with an emphasis on biomarker discovery and elucidating molecular mechanisms of disease. We propose the integration of global and targeted strategies as a high‐throughput pipeline for cardiovascular proteomics. Targeted approaches enable rapid, extensive validation of biomarker candidates discovered by global proteomics. These approaches provide a promising alternative to immunoassays and other low‐throughput means currently used for limited validation.
N‐glycoprotein surfaceomes of four developmentally distinct mouse cell types
Authors: Kropp Erin M. , Bhattacharya Subarna , Waas Matthew , Chuppa Sandra L. , Hadjantonakis Anna‐Katerina , Boheler Kenneth R. , Gundry Rebekah L.
Published: June 2014

Purpose

Detailed knowledge of cell surface proteins present during early embryonic development remains limited for most cell lineages. Due to the relevance of cell surface proteins in their functional roles controlling cell signaling and their utility as accessible, nongenetic markers for cell identification and sorting, the goal of this study was to provide new information regarding the cell surface proteins present during early mouse embryonic development.

Experimental Design

Using the cell surface capture technology, the cell surface N‐glycoproteomes of three cell lines and one in vitro differentiated cell type representing distinct cell fates and stages in mouse embryogenesis were assessed.

Results

Altogether, more than 600 cell surface N‐glycoproteins were identified represented by >5500 N‐glycopeptides.

Conclusions and Clinical Relevance

The development of new, informative cell surface markers for the reliable identification and isolation of functionally defined subsets of cells from early developmental stages will advance the use of stem cell technologies for mechanistic developmental studies, including disease modeling and drug discovery.
Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors in Osun, South‐Western Nigeria
Authors: Obembe Adebimpe O. , Olaogun Matthew M. , Olalemi Alaba E.
Published: June 2014

Background and purpose

Functional limitations in stroke survivors are sometimes associated with fatigue. This study assessed the functional limitations due to fatigue in community‐dwelling stroke survivors undergoing physiotherapy. The differences in functional limitations due to fatigue were determined between sexes, stroke types, sides of affectation, age categories and levels of disability. Relationships between functional limitation due to fatigue and these variables were also determined.

Methods

This was a cross‐sectional study involving 63 stroke survivors (35 male survivors and 28 female survivors) with ages ranging from 45 to 79 years (mean = 53.68 ± 10.95 years). Functional limitation due to fatigue was assessed with the modified fatigue impact scale (MFIS). Modified Rankin scale was used to categorize the disability of the participants. Data were analysed using descriptive (mean, standard deviation, percentage and frequency) and inferential (Mann–Whitney U‐test and Spearman correlation analysis) statistics. Significance was set at 0.05 α level.

Results/findings

The mean MFIS score was 31.74 ± 12.39. Many participants (58.7%) had moderate functional limitations due to fatigue. The result of Mann–Whitney U‐test showed significant difference in functional limitation due to fatigue between participants with slight disability and those with moderate disability (p = 0.000), with participants with moderate disability having higher MFIS scores (more functional limitations). There was also a significant correlation between functional limitation due to fatigue and level of disability (ρ = 0.625, p = 0.000).

Discussion

Functional limitation due to fatigue occurs frequently in stroke survivors and is related to level of disability. Functional limitations due to fatigue should be assessed frequently in all stroke survivors with varying degrees of disability and the outcome should be considered during rehabilitation and retraining of physical function. Copyright © 2014 John Wiley & Sons, Ltd.
The role of the SHH gene in prostate cancer cell resistance to paclitaxel
Authors: Statkiewicz Malgorzata , Maryan Natalia , Lipiec Agnieszka , Grecka Emilia , Grygorowicz Monika A. , Omiotek Marcin , Gorska Agnieszka , Mikula Michal , Malecki Maciej
Published: June 2014

BACKGROUND

The increased activity of the Sonic Hedgehog (SHH) pathway has been demonstrated in many types of cancer including prostate cancer (PCa). It has been shown that SHH pathway is involved in tumor angiogenesis and in regulation of metabolism of cancer stem cells. The increased activity of the SHH pathway is responsible for generation and maintenance of the multidrug resistance in cancer cells. A key role in the development of this insensitivity to cytotoxic drugs play ATP‐binding cassette (ABC) transporters.

METHODS

SHH encoding plasmid was stably transfected into PCa cell lines DU145 and LNCaP. The expression of SHH was silenced by shRNA and the level of SHH was tested by quantitative (q)PCR and western blot methods. The effect of SHH overexpression in cells after treatment with paclitaxel was measured by MTT assay, crystal violet assay and flow cytometry. The level of 44 ABC transporters was estimated by qPCR.

RESULTS

Expression of exogenous SHH protein in DU145 and LNCaP cell lines enhanced their resistance to paclitaxel along with increased expression of ABC transporters transcripts. Paclitaxel treatment further enhanced the expression of increased ABC transporters transcripts in cells overexpressing SHH.

CONCLUSIONS

Overexpression of SHH enhances PCa cell lines resistance to paclitaxel. Higher level of SHH leads to increase in ABC transporters expression in a manner dependent on paclitaxel. Prostate 74:1142–1152, 2014. © 2014 Wiley Periodicals, Inc.
PDE10A inhibitors stimulate or suppress motor behavior dependent on the relative activation state of the direct and indirect striatal output pathways
Authors: Megens Anton A. H. P. , Hendrickx Herman M. R. , Mahieu Michel M. A. , Wellens Annemie L. Y. , de Boer Peter , Vanhoof Greet
Published: June 2014

The enzyme phosphodiesterase 10A (PDE10A) regulates the activity of striatal, medium spiny neurons (MSNs), which are divided into a behaviorally stimulating, Gs‐coupled D1 receptor‐expressing “direct” pathway and a behaviorally suppressant, Gi‐coupled D2 receptor‐expressing “indirect” pathway. Activating both pathways, PDE10A inhibitors (PDE10AIs) combine functional characteristics of D2 antagonists and D1 agonists. While the effects of PDE10AIs on spontaneous and stimulated behavior have been extensively reported, the present study investigates their effects on suppressed behavior under various conditions of reduced dopaminergic neurotransmission: blockade of D1 receptors with SCH‐23390, blockade of D2 receptors with haloperidol, or depletion of dopamine with RO‐4‐1284 or reserpine. In rats, PDE10AIs displayed relatively low cataleptic activity per se. After blocking D1 receptors, however, they induced pronounced catalepsy at low doses close to those required for inhibition of apomorphine‐induced behavior; slightly higher doses resulted in behavioral stimulant effects, counteracting the catalepsy. PDE10AIs also counteracted catalepsy and related behaviors induced by D2 receptor blockade or dopamine depletion; catalepsy was replaced by behavioral stimulant effects under the latter but not the former condition. Similar interactions were observed at the level of locomotion in mice. At doses close to those inhibiting d‐amphetamine‐induced hyperlocomotion, PDE10AIs reversed hypolocomotion induced by D1 receptor blockade or dopamine depletion but not hypolocomotion induced by D2 receptor blockade. It is concluded that PDE10AIs stimulate or inhibit motor behavior dependent on the relative activation state of the direct and indirect striatal output pathways.
A Review of the Pharmacological Effects of Piceatannol on Cardiovascular Diseases
Authors: Tang Yee‐Ling , Chan Shun‐Wan
Published: June 2014

The incidence of cardiovascular diseases (CVDs) is high in both developed and developing countries. It has a high global rate of mortality and causes heavy social burden. Drugs are available for managing or treating CVDs and its complications. Consumption of dietary supplements or functional foods for reducing the risk of CVDs has also gained wide recognition by the general public. Piceatannol, an analog and metabolite of resveratrol, is a natural stilbene commonly found in the skin of grapes and wine. Piceatannol is believed to be a potent compound with certain cardiovascular therapeutic effects, such as the prevention of hypercholesterolemia, arrhythmia, atherosclerosis, and angiogenesis. It also has vasorelaxation and antioxidant activities. A comprehensive review of piceatannol concludes that piceatannol has the potential to be developed into health products for the cardiovascular system to help modern society reduce the high CVD incidence. However, further investigations are warranted in order to increase the bioavailability and understand the biological mechanisms and safety of using piceatannol. Copyright © 2014 John Wiley & Sons, Ltd.
Review of Plants and Their Constituents in the Therapy of Cerebral Ischemia
Authors: Behravan Effat , Razavi Bibi Marjan , Hosseinzadeh Hossein
Published: June 2014

Cerebral ischemia is a condition in which there is insufficient blood flow to the brain to meet metabolic demand. This leads to cerebral hypoxia and thus to the death of neuronal cells or stroke. The limited number of medicines currently available for patients following ischemic stroke and insufficient data on efficiency of these chemicals in the treatment of stroke led us to the search for novel therapeutic approaches. Recent studies have focused on the possible capacity of natural compounds extracted from vegetables and fruits, to prevent human disabilities caused by cerebral ischemia. In this review, we will discuss some plants and their constituents that may protect brain ischemia or delay the neurological disorders following a stroke. We have reviewed different studies in scientific databases that investigate herbal compounds and their effects on cerebral ischemia. Copyright © 2014 John Wiley & Sons, Ltd.
Linking Stream Sediment Deposition and Aquatic Habitat Quality in Pearl Mussel Streams: Implications for Conservation
Authors: Denic M. , Geist J.
Published: June 2014

The introduction of fine sediments into streams is considered to have a major effect on habitat quality affecting the reproduction of sensitive species such as unionid mussels and salmonid fishes. To date, there is a lack of information on the magnitude and spatio‐temporal resolution of sediment introduction.

This study aimed to quantify the spatio‐temporal deposition of fine sediments in headwater streams in relation to the status of Margaritifera margaritifera and Salmo trutta. Fine sediment deposition was linked to physicochemical conditions of the adjacent streambed.

The mean observed deposition of fine sediments over the study period was 3.4 kg m−2 month−1 with a high spatio‐temporal variation ranging from <0.01 to 20.3 kg m−2 month−1. Discharge had the strongest influence on deposition rates.

Mean differences in redox potential between free‐flowing water and the interstitial zone were 90 mV. The spatio‐temporal variability of physicochemical parameters increased with degree of degradation. High‐quality reaches had more constant conditions.

Our results indicate that monitoring of sediment quality and deposition in streams has to comprise several time points and study reaches, or should at least be conducted during periods with the most adverse habitat conditions, to allow valid assessments of habitat quality. In streams with increased fine sediment deposition, in‐stream restoration measures are insufficient for the enhancement of pearl mussel habitats as a result of rapid clogging of interstitial pores. Only integrative catchment management based on detailed habitat analysis can ensure sufficient habitat quality for species sensitive to siltation. Copyright © 2014 John Wiley & Sons, Ltd.
Defense mechanisms against Sybil attack in vehicular ad hoc network
Authors: Ali Mohammadi Mahdiyeh , Pouyan Ali A.
Published: June 2014

Many researchers have focused on vehicular ad hoc networks in recent years. Because of the nature of wireless networks, security of these networks may be compromised against attackers. This leads to losses such as loss of people's lives and loss of productivity in trades and payment services. One of the harmful attacks against sensor and ad hoc networks is Sybil attack, which attacker tries to forge some identities. These identities can be real ones belonging to other vehicles in the network or bogus identities made by the attackers. The purposes of creating dummy entities are for network disruption, traffic safety violation and, briefly, for the attacker's goals. In this paper, we describe a general classification of various methods for Sybil attack detection in vehicular ad hoc network. We then analyze advantages and disadvantages of the selected researches in each class to evaluate their performance with regard to safety and privacy issues. Copyright © 2014 John Wiley & Sons, Ltd.
ToF‐SIMS imaging of lipids and lipid related compounds in Drosophila brain
Authors: Phan Nhu T. N. , Fletcher John S. , Sjövall Peter , Ewing Andrew G.
Published: June 2014

Drosophila melanogaster (fruit fly) has a relatively simple nervous system but possesses high order brain functions similar to humans. Therefore, it has been used as a common model system in biological studies, particularly drug addiction. Here, the spatial distribution of biomolecules in the brain of the fly was studied using time‐of‐flight SIMS. Fly brains were analyzed frozen to prevent molecular redistribution prior to analysis. Different molecules were found to distribute differently in the tissue, particularly the eye pigments, diacylglycerides, and phospholipids, and this is expected to be driven by their biological functions in the brain. Correlations in the localization of these molecules were also observed using principal components analysis of image data, and this was used to identify peaks for further analysis. Furthermore, consecutive analyses following 10 keV Ar2500+ sputtering showed that different biomolecules respond differently to Ar2500+ sputtering. Significant changes in signal intensities between consecutive analyses were observed for high mass molecules including lipids. Copyright © 2014 John Wiley & Sons, Ltd.
A Quantifiable Risky Decision Model: Incorporating Individual Memory into Informational Cascade
Authors: Wang Fei , Wei Jiuchang , Zhao Dingtao
Published: June 2014

People memory system plays a key role in the decision‐making process (DMP). In order to examine its influence on decision‐making, an individual's memory‐based decision‐making system is developed, and then, we integrate the multi‐agent decision systems and construct a sequential risky decision model on the basis of an informational cascade. This study aims at exploring the public's decisions on whether or not to take protective actions under risk. The findings indicate that people with different strength of ties to friends and relatives make huge differences on decision‐making. In the group with weak ties, the agent's total size of decision information and the level of risk perception are reducing in the sequential decision process. We further prove that people with weak ties are more prone to take no protective action, and the probability is also decreasing with the decision turn. The sequence of people with strong ties makes decisions dynamically with the intensity of released information. Finally, the influences of forgetting rate and memory capacity on people's decision‐making are examined. The model provides a new line of thought about building a multi‐agent system of DMP, which is also very helpful for the design of an information management system during emergencies. Copyright © 2014 John Wiley & Sons, Ltd.
Applying statistical thinking to ‘Big Data’ problems
Authors: Hoerl Roger W. , Snee Ronald D. , De Veaux Richard D.
Published: June 2014

Much has been written recently about ‘Big Data’ and the new possibilities that mining this vast amount of data brings. It promises to help us understand or predict everything from the Higgs boson to what a customer might purchase next from Amazon. As with most new phenomena, it is hard to sift through the hype and promotion to understand what is actually true and what is actually useful. One implicit or even explicitly stated assumption in much of the Big Data literature is that statistical thinking fundamentals are no longer relevant in the petabyte age. However, we believe just the opposite. Fundamentals of good modeling and statistical thinking are crucial for the success of Big Data projects. Sound statistical practices, such as ensuring high‐quality data, incorporating sound domain (subject matter) knowledge, and developing an overall strategy or plan of attack for large modeling problems, are even more important for Big Data problems than small data problems. WIREs Comput Stat 2014, 6:222–232. doi: 10.1002/wics.1306

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Bootstrap and Resampling

Data: Types and Structure > Massive Data

Data: Types and Structure > Traditional Statistical Data

Applications of Computational Statistics > Education in Computational Statistics
Particle‐induced pulmonary acute phase response may be the causal link between particle inhalation and cardiovascular disease
Authors: Saber Anne T. , Jacobsen Nicklas R. , Jackson Petra , Poulsen Sarah Søs , Kyjovska Zdenka O. , Halappanavar Sabina , Yauk Carole L. , Wallin Håkan , Vogel Ulla
Published: June 2014

Inhalation of ambient and workplace particulate air pollution is associated with increased risk of cardiovascular disease. One proposed mechanism for this association is that pulmonary inflammation induces a hepatic acute phase response, which increases risk of cardiovascular disease. Induction of the acute phase response is intimately linked to risk of cardiovascular disease as shown in both epidemiological and animal studies. Indeed, blood levels of acute phase proteins, such as C‐reactive protein and serum amyloid A, are independent predictors of risk of cardiovascular disease in prospective epidemiological studies. In this review, we present and review emerging evidence that inhalation of particles (e.g., air diesel exhaust particles and nanoparticles) induces a pulmonary acute phase response, and propose that this induction constitutes the causal link between particle inhalation and risk of cardiovascular disease. Increased levels of acute phase mRNA and proteins in lung tissues, bronchoalveolar lavage fluid and plasma clearly indicate pulmonary acute phase response following pulmonary deposition of different kinds of particles including diesel exhaust particles, nanoparticles, and carbon nanotubes. The pulmonary acute phase response is dose‐dependent and long lasting. Conversely, the hepatic acute phase response is reduced relative to lung or entirely absent. We also provide evidence that pulmonary inflammation, as measured by neutrophil influx, is a predictor of the acute phase response and that the total surface area of deposited particles correlates with the pulmonary acute phase response. We discuss the implications of these findings in relation to occupational exposure to nanoparticles. WIREs Nanomed Nanobiotechnol 2014, 6:517–531. doi: 10.1002/wnan.1279

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease

Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials