bluuebunny/crossref_metadata_2025 huggingface dataset:
Paracrine activation of hepatic stellate cells in platelet‐derived growth factor C transgenic mice: Evidence for stromal induction of hepatocellular carcinoma
Authors: Wright Jocelyn H. , Johnson Melissa M. , Shimizu‐Albergine Masami , Bauer Renay L. , Hayes Brian J. , Surapisitchat James , Hudkins Kelly L. , Riehle Kimberly J. , Johnson Simon C. , Yeh Matthew M. , Bammler Theodor K. , Beyer Richard P. , Gilbertson Debra G. , Alpers Charles E. , Fausto Nelson , Campbell Jean S.
Published: August 2013

Cirrhosis is the primary risk factor for the development of hepatocellular carcinoma (HCC), yet the mechanisms by which cirrhosis predisposes to carcinogenesis are poorly understood. Using a mouse model that recapitulates many aspects of the pathophysiology of human liver disease, we explored the mechanisms by which changes in the liver microenvironment induce dysplasia and HCC. Hepatic expression of platelet‐derived growth factor C (PDGF‐C) induces progressive fibrosis, chronic inflammation, neoangiogenesis and sinusoidal congestion, as well as global changes in gene expression. Using reporter mice, immunofluorescence, immunohistochemistry and liver cell isolation, we demonstrate that receptors for PDGF‐CC are localized on hepatic stellate cells (HSCs), which proliferate, and transform into myofibroblast‐like cells that deposit extracellular matrix and lead to production of growth factors and cytokines. We demonstrate induction of cytokine genes at 2 months, and stromal cell‐derived hepatocyte growth factors that coincide with the onset of dysplasia at 4 months. Our results support a paracrine signaling model wherein hepatocyte‐derived PDGF‐C stimulates widespread HSC activation throughout the liver leading to chronic inflammation, liver injury and architectural changes. These complex changes to the liver microenvironment precede the development of HCC. Further, increased PDGF‐CC levels were observed in livers of patients with nonalcoholic fatty steatohepatitis and correlate with the stage of disease, suggesting a role for this growth factor in chronic liver disease in humans. PDGF‐C transgenic mice provide a unique model for the in vivo study of tumor–stromal interactions in the liver.
Subclonal evolution of a classical Hodgkin lymphoma from a germinal center B‐cell‐derived mantle cell lymphoma
Authors: Schneider Stefanie , Crescenzi Barbara , Schneider Markus , Ascani Stefano , Hartmann Sylvia , Hansmann Martin‐Leo , Falini Brunangelo , Mecucci Cristina , Tiacci Enrico , Küppers Ralf
Published: August 2013

Composite lymphomas (CL) represent the occurrence of two distinct lymphomas in the same patient. Often, CL share a common cellular origin, thus representing a unique model to investigate the multistep genetic path leading to lymphomagenesis in general and to the specific development of each distinct lymphoma component in particular. Here, we present the molecular analysis of a case consisting of an unusual Hodgkin lymphoma (HL) and a mantle cell lymphoma (MCL), intimately admixed within one another in lymph nodes and bone marrow yet phenotypically distinct, in a patient who first presented with splenic/leukemic MCL two years earlier. MCL and Hodgkin and Reed/Sternberg (HRS) cells harbored identical immunoglobulin (Ig) VH gene rearrangements with shared somatic mutations, proving their common clonal origin from a (post‐)germinal center (GC) B cell. This also demonstrates the (post‐)GC origin of MCL with mutated IgV genes. Both lymphomas carried the same CCND1/IGH translocation and, unexpectedly for HL, expressed cyclin D1 and OCT2. Thus, HRS cells are able to preserve IGH locus activity (otherwise usually silenced in HL) to promote expression of an oncogene translocated into this locus. Both lymphoma populations further showed an identical TP53 function‐impairing mutation, and later acquired a TP53 heterozygous deletion independently from one another (convergent evolution). The surprisingly close genetic relationship of the lymphomas, together with their histological intermingling and the clinical history of the patient, suggests subclonal evolution of HL from MCL as a plausible pathway in alternative to that so far described in CL, i.e. separate development from a common precursor.
Nonclassical hedgehog‐gli signaling and its clinical implications
Authors: Shevde Lalita A. , Samant Rajeev S.
Published: August 2013

Hedgehog (Hh) signaling regulates embryonic patterning and organ morphogenesis. It is also involved in regeneration and repair of tissues. Aberrant Hh pathway activation is a feature of many human malignancies. Classical Hh signaling is activated by Hh ligands that can signal in an autocrine or paracrine manner generating a tumor‐stromal crosstalk. In contrast to canonical Hh signaling that culminates in the activation of GLI transcription factors, “noncanonical” Hh signaling does not involve GLI transcriptional activity. Several Hh pathway inhibitors have progressed to clinical trials, where the outcomes have not been very encouraging in many solid tumors. Here we discuss the likely role of “nonclassical” Hh‐GLI signaling that is activated by growth factors and cytokines from the tumor and/or its microenvironment; these uncouple Hh signaling from the vital regulatory protein Smoothened, and result in the activation of GLI. While efforts are being made to target tumor‐intrinsic Hh targets, it is imperative to acknowledge the role of the complex molecular networks and crosstalk between different components of the tumor microenvironment that can result in the emergence of resistance to conventional Hh therapy. These considerations have an important bearing on appreciating the need to mitigate the effects of tumor microenvironment to combat resistance to Hh inhibitors.
Stable oxygen isotope differences between the areas to the north and south of Qinling Mountains in China reveal different moisture sources
Authors: Yu Wusheng , Yao Tandong , Lewis Stephen , Tian Lide , Ma Yaoming , Xu Baiqing , Qu Dongmei
Published: August 2013

δ18O variability in daily precipitation at two stations (Lanzhou and Zhangye) north of the Qinling Mountains at the eastern margin of the Tibetan Plateau, China, and monthly precipitation δ18O at four stations to the south of the Qinling Mountains were examined. The data show that the δ18O composition of precipitation south of the Qinling Mountains is influenced strongly by the prevailing westerlies during winter and by the summer Asian monsoon during its most active periods. To the north, the westerlies prevail in winter, and δ18O trends coincide strongly with temperature. In summer, the Qinling Mountains block or weaken the Asian monsoon, which crosses them only during the most active periods. In these periods, the stations to the north experience relatively depleted δ18O values (<−7‰). During weak monsoon periods, however, most of the δ18O values in summer precipitation at Lanzhou and Zhangye are relatively enriched (>−5‰, and even as high as +9.2‰). A positive northward weighted average δ18O gradient of summer precipitation with increasing distance from the coast suggests the influence of the prevailing westerlies and of continental recycling of moisture. Both the frequency of these heavily depleted δ18O values and their duration decrease from south to north, reaching minimums at Zhangye, which may have been in the monsoonal tail region during the sampling period. The data reveal that the Qinling Mountains act as an important climatic divide along the eastern margin of the Tibetan Plateau. The effects of the Asian summer monsoon and of different moisture sources should be considered for paleoclimatic studies.
Variations in the provenance of sediment from ice sheets surrounding Baffin Bay during MIS 2 and 3 and export to the Labrador Shelf Sea: site HU2008029‐0008 Davis Strait
Authors: ANDREWS JOHN T. , GIBB OLIVIA T. , JENNINGS ANNE E. , SIMON QUENTIN
Published: August 2013

Based on quantitative X‐ray diffraction mineralogical analysis of cores HU2008029‐0006/0008 (857‐m water depth) located south of the Davis Strait sill, we seek answers to two questions: (i) the temporal correlation of NW Labrador Shelf Sea Heinrich (H‐) and Baffin Bay detrital carbonate (BBDC) events, and (ii) the provenance of the sediments? A sediment‐unmixing model (SedUnMix) is used to determine provenance variations. Although 12 radiocarbon dates were obtained there were many age reversals and we favour a depth/age model for HU2008029‐0008PC based on correlations to well‐dated neighbouring cores north and south of Davis Strait. We find no correlation between H‐ and BBDC events except for H‐0, which appears to be a broadly synchronous event along the NE Canadian margin and is correlative with an episode of major moraine building along this flank of the Laurentide Ice Sheet. Unmixing of the sediment composition based on six potential glacial source regions indicates that the bulk of the sediment in 0008PC is derived from glacial erosion of West Greenland, but is punctuated by intervals when dolomite‐rich sediments, derived from outcrops north of Baffin Bay, dominate the composition. Estimated dates on these BBDC events are ∼13, 25 and 30–38 cal ka BP.
Classification of iron‐based inks by means of micro‐Raman spectroscopy and multivariate data analysis
Authors: Piantanida Giovanna , Menart Eva , Bicchieri Marina , Strlič Matija
Published: August 2013

In this work, multivariate data analysis methods were applied to the analysis and interpretation of micro‐Raman spectra, collected from a broad set of historical iron‐based ink samples, previously characterised for the content of organic acids (gallic acid, ellagic acid and protocatechuic acid). The proposed method relies on principal component analysis of the noisy spectra typically obtained on original, degraded, organic samples, where fluorescence could affect the Raman signal. The signal components could be distinguished from the noise components and then used to build a linear discriminant analysis (LDA) model, achieving separation of the spectra into three classes. Selection of pure signal factors also improved effectiveness and performances of partial least square regression (PLS) algorithms, allowing quantification of condensed tannic acid residuals. Application of multivariate methods to discriminate signal from noise removes the need for spectral data manipulation (filtering, smoothing and differentiating). The obtained classification method for discrimination of historic inks and the regression method for determination of condensed tannic acid residuals supports the use of Raman analysis of fluorescing organic materials, and may provide information to scholars on ink composition and potentially on its provenance. Copyright © 2013 John Wiley & Sons, Ltd.
Comparison of microwave‐assisted and conventional extraction of mangiferin from mango (Mangifera indicaL.) leaves
Authors: Zou Tangbin , Wu Hongfu , Li Huawen , Jia Qing , Song Gang
Published: August 2013

Mangiferin is the main bioactive component in mango leaves, which possesses anti‐inflammatory, antioxidative, antidiabetic, immunomodulatory, and antitumor activities. In the present study, a microwave‐assisted extraction method was developed for the extraction of mangiferin from mango leaves. Some parameters such as ethanol concentration, liquid‐to‐solid ratio, microwave power, and extraction time were optimized by single‐factor experiments and response surface methodology. The optimal extraction conditions were 45% ethanol, liquid‐to‐solid ratio of 30:1 (mL/g), and extraction time of 123 s under microwave irradiation of 474 W. Under optimal conditions, the yield of mangiferin was 36.10 ± 0.72 mg/g, significantly higher than that of conventional extraction. The results obtained are beneficial for the full utilization of mango leaves and also indicate that microwave‐assisted extraction is a very useful method for extracting mangiferin from plant materials.
Concurrent extraction, clean‐up, and analysis of polybrominated diphenyl ethers, hexabromocyclododecane isomers, and tetrabromobisphenol A in human milk and serum
Authors: Shi Zhixiong , Wang Yifei , Niu Piye , Wang Jiandi , Sun Zhiwei , Zhang Shuhua , Wu Yongning
Published: August 2013

A method has been developed and validated for the concurrent extraction, clean‐up, and analysis of polybrominated diphenyl ethers (PBDEs), α‐, β‐, and γ‐hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA) in human milk and serum. Milk and serum samples were extracted using accelerated solvent extraction with acetone/hexane 1:1, v/v and liquid–liquid extraction with methyl‐tert‐butyl ether/hexane 1:1, v/v, respectively. The removal of co‐extracted biogenic materials was achieved by gel permeation chromatography followed by sulfuric acid treatment. The fractionation of the PBDEs and HBCD/TBBPA was performed using a Supelco LC‐Si SPE cartridge. The detection of the PBDEs was then performed by GC–MS and that of the HBCDs and the TBBPA was performed using UPLC–MS/MS. The pretreatment procedure was optimized, and the characteristic ions and fragmentation of the analytes were studied by MS or MS/MS. A recovery test was performed using a matrix spiking test at concentrations of 0.05–10 ng/g. The recoveries ranged from 78.6–108.8% with RSDs equal to or lower than 14.04%. The LODs were 1.8–60 pg/g. The usefulness of the developed method was tested by the analysis of real human samples, and several brominated flame retardants in different samples were detected and analyzed.
Supramolecular Hydrogel Capsules Based on PEG: A Step Toward Degradable Biomaterials with Rational Design
Authors: Rossow Torsten , Bayer Sebastian , Albrecht Ralf , Tzschucke C. Christoph , Seiffert Sebastian
Published: August 2013

Supramolecular microgel capsules based on polyethylene glycol (PEG) are a promising class of soft particulate scaffolds with tailored properties. An approach to fabricate such particles with exquisite control by droplet‐based microfluidics is presented. Linear PEG precursor polymers that carry bipyridine moieties on both chain termini are gelled by complexation to iron(II) ions. To investigate the biocompatibility of the microgels, living mammalian cells are encapsulated within them. The microgel elasticity is controlled by using PEG precursors of different molecular weights at different concentrations and the influence of these parameters on the cell viabilities, which can be optimized to exceed 90% is studied. Reversion of the supramolecular polymer cross‐linking allows the microcapsules to be degraded at mild conditions with no effect on the viability of the encapsulated and released cells.

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Botryoid‐Shaped Reactive Nanoparticles through Spontaneous Structural Reorganization of Terpolymer Micelles
Authors: Deng Junjie , Cai Yuanli
Published: August 2013

Botryoid‐shaped reactive terpolymer nanoparticles, whose aldehyde‐functional living domains are miniaturized into small‐sized discrete “grapes” and attached onto the outwardly‐branched scaffolds of fluorinated segments, are reported. These nanostructures can be fabricated by spontaneous structural reorganization of core–shell terpolymer micelles simply by manipulating drying conditions. The miniaturized discrete living domains are stabilized by outwardly‐branched scaffolds and exhibit excellent accessibility to solution media, thus can effectively respond to solution media, which is desired in sensor‐related applications.

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Dextran‐Based Self‐Healing Hydrogels Formed by Reversible Diels–Alder Reaction under Physiological Conditions
Authors: Wei Zhao , Yang Jian Hai , Du Xiao Jing , Xu Feng , Zrinyi Miklos , Osada Yoshihito , Li Fei , Chen Yong Mei
Published: August 2013

A dextran‐based self‐healing hydrogel is prepared by reversible Diels–Alder reaction under physiological conditions. Cytocompatible fulvene‐modified dextran as main polymer chains and dichloromaleic‐acid‐modified poly(ethylene glycol) as cross‐linkers are used. Both macro‐ and microscopic observation as well as the rheological recovery test confirm the self‐healing property of the dextran‐l‐poly(ethylene glycol) hydrogels (“l” means “linked‐by”). In addition, scanning electrochemical microscopy is used to qualitatively and quantitatively in situ track the self‐healing process of the hydrogel for the first time. It is found that the longitudinal depth of scratch on hydrogel surface almost completely healed at 37 °C after 7 h. This work represents a facile approach for fabrication of polysaccharide self‐healing hydrogel, which can be potentially used in several biomedical fields.

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Assessment of forest fire danger in a boreal forest environment: description and evaluation of the operational system applied in Finland
Authors: Vajda Andrea , Venäläinen Ari , Suomi Irene , Junila Päivi , Mäkelä Hanna M.
Published: August 2013

Forest fires constitute the second largest form of disturbance to the Finnish boreal forest environment, playing a significant role in vegetation succession and landscape transformation. Warning systems aiming to minimize the risk of fires are based on fire danger estimation methods using weather information. In this study, the operational fire danger rating method used in Finland, the Finnish Forest Fire Index, is introduced and its performance evaluated by analysing the relationship between the predicted daily fire danger and observed fire activity. The Finnish Forest Fire Index is a physically‐based soil surface moisture estimation method employing as input traditional surface observations, numerical weather forecast model fields and weather radar measurements. The fire danger index is found to predict high fire danger conditions well, with some decline in performance northward where the observations network is sparser than in the southern part of the country. The model indicated higher hit rates in the prediction of multiple fire (54%) and large fire days (54.3%), which are less dependent on a human‐dominated fire environment than are single fire days. Highlighted future development priorities include the direct application of numerical analyses of meteorological data in the operational computation procedure. In addition, inclusion of the impact of land cover, such as vegetation type, on the fire danger index is under development.
Soil moisture simulation by JULES in New Zealand: verification and sensitivity tests
Authors: Yang Yang , Uddstrom Michael , Revell Mike , Moore Stuart
Published: August 2013

Hourly observations of soil moisture volumetric content (at depths of 0–0.4 m) have been conducted for a few years at 55 climate stations with diverse soil types and annual rainfall in New Zealand. Thirty two of these stations also have surface meteorological observations. In this study, these observations were used for the first time to validate a land surface model (LSM) for soil moisture simulation, the Joint UK Land Environment Simulator (JULES). At the 32 stations, the yearly mean absolute differences (MADs) of the simulated soil moisture volumetric ratio were about 5% or smaller, except at four South Island stations, where larger MADs of 8–12% were found. Further analysis of rainfall and soil moisture observations at these four stations showed that the observed soil moisture includes a contribution from lateral soil water flow, which is not considered in the one‐dimensional version of JULES used in this study. For the remaining 28 stations, the relatively small yearly MADs (∼5%) were mainly due to biases. To understand the major factors contributing to the errors/biases, three sensitivity tests were conducted. These tests showed that errors in the soil texture data were the most likely contributor to the errors in simulated soil moisture. This study demonstrates that for a better simulation of soil moisture in New Zealand, especially in the lower South Island, a LSM needs to include lateral soil moisture/water flow, and to use more accurate prescriptions of the hydraulic and thermal properties of the soil.
Kinetics of sulforaphane in mice after consumption of sulforaphane‐enriched broccoli sprout preparation
Authors: Li Yanyan , Zhang Tao , Li Xiaoqin , Zou Peng , Schwartz Steven J. , Sun Duxin
Published: August 2013

Scope

Sulforaphane (SF) is a natural isothiocyanate in broccoli sprouts with cancer chemopreventive activity. This study is aimed to use different methods to develop broccoli sprout preparations to compare their ability to deliver SF to the mice and to evaluate the kinetics and biodistribution of SF.

Methods and results

The SF‐enriched sprout preparation generated by two‐step procedure (quick‐steaming followed by myrosinase treatment) contained the highest level of SF, which was 11 and 5 times higher than the freeze‐dried fresh broccoli sprouts and the quick‐steamed, freeze‐dried broccoli sprouts, respectively. After oral administration of 2.5 mg/g body weight of the broccoli sprout preparations, SF was quickly absorbed and distributed throughout the tissues. The SF‐rich preparation resulted in the highest exposure, with peak plasma SF concentration of 337 ng/mL, which is 6.0 times and 2.6 times higher compared to the other two preparations. A whole body physiologically based pharmacokinetic model (developed with ADAPT 5 software) suggests that distribution of SF is perfusion‐limited in all organs.

Conclusion

This study provides a broccoli sprout preparation that can serve as a good source of SF, and the model can be utilized to guide the dose designed for the use of broccoli sprout preparation in chemoprevention.
Graft Copolymers of Poly(Methylmethacrylate) and Poly(Lactic Acid) or Poly(3‐Hydroxybutyrate): Synthesis by Reactive Extrusion and Characterization
Authors: Frédéric Becquart , Samira Touhtouh , Mohamed Taha
Published: August 2013

Poly(lactic acid) (PLA) and poly(3‐hydroxybutyrate) PHB are grafted onto poly(methyl methacrylate) (PMMA) by reactive extrusion. Two catalysts are used, 1.5.7‐triazabicyclodec‐5‐ene (TBD) and tin (II) bis(2‐ethylhexanoate) (SnOct2). 1H NMR spectroscopy is used to characterize the structures of the products of the reactive blends. A higher amount of graft copolymer is obtained by increasing the temperature. Grafting is also influenced by the type of catalyst. TBD is more efficient than (SnOct2) for PHB grafting onto PMMA (substitution rate (SR) 19% at 230 °C). Likewise, when grafting PLA, significantly lower grafting is obtained and SnOct2 is more efficient than TBD. Thermal analyses showed that amorphous and miscible products are obtained. In the case of PMMA‐g‐PHB synthesis, increasing the temperature improves the SR from 5 to 11% with SnOct2 and from 14 to 24% with TBD. The same effect is observed in the case of PMMA‐g‐PLA synthesis. The results obtained by size exclusion chromatography corroborate both the results obtained by 1H NMR analysis and the possibility to synthesize the copolymer by reactive extrusion with a short residence time. The results obtained by thermal analysis show that two Tg are obtained in physical blends but that using a catalyst at low temperature yields in a miscible product.
Selective co‐stimulation of pudendal afferents enhances bladder activation and improves voiding efficiency
Authors: McGee Meredith J. , Grill Warren M.
Published: August 2013

Aims

Clinical application of pudendal nerve (PN) afferent stimulation to restore bladder emptying in persons with neurological disorders requires increased stimulation‐evoked voiding efficiencies (VEs). We tested the hypothesis that selective co‐stimulation of multiple PN branches, either bilateral dorsal nerve of the penis (DNP) stimulation or selective stimulation of both the cranial sensory nerve (CSN) and DNP, will evoke larger reflex bladder contractions and result in higher VEs than stimulation of any single afferent pathway alone.

Methods

We measured the strength of bladder contractions, threshold volumes, and VEs produced by unilateral and bilateral stimulation of the DNP as well as singular and selective unilateral co‐stimulation of the DNP and CSN in cats anesthetized with α‐chloralose.

Results

Co‐stimulation of afferent pathways generated significantly larger isovolumetric bladder contractions and evoked contractions at lower threshold volumes than individual stimulation. Co‐stimulation of pudendal afferents also suppressed dyssynergic activity in the external anal sphincter produced by low frequency individual stimulation. VE was significantly improved with co‐stimulation (172 ± 6% of distention evoked volumes) over individual stimulation (141 ± 6%).

Conclusions

Both types of co‐stimulation evoked larger bladder contractions and increased VE over individual branch PN afferent stimulation and distention‐evoked voiding. The decreased threshold volumes required for reflex bladder activation and increased VEs with co‐stimulation support the use of stimulation of multiple individual stimulation‐evoked reflexes to improve voiding efficiency. Neurourol. Urodynam. 33:1272–1278, 2014. © 2013 Wiley Periodicals, Inc.
Effects of fibers and nanoparticles reinforcements on the mechanical and biological properties of hybrid composite polyetheretherketone/short carbon fiber/Nano‐SiO2
Authors: Tourani Hamid , Molazemhosseini Alireza , Khavandi Alireza , Mirdamadi Shamseddin , Shokrgozar Mohamad Ali , Mehrjoo Morteza
Published: August 2013

Polyetheretherketone (PEEK) composites reinforced with short carbon fibers (SCFs) (20 vol%) and nano‐SiO2 (1, 1.5, and 2 wt%) particles were prepared by incorporating nanoparticles into PEEK/SCF composites using the internal mixer. In the development of biomaterial, both mechanical and biological characteristics must be considered. Thus, the effects of nanoparticles on the mechanical and biological properties of the PEEK/SCF composites were studied. To evaluate the mechanical properties of this biomaterial, nanoindentation method and tensile test were used. Results showed that by increasing the weight percentage of nano‐SiO2, the elastic modulus, hardness, and tensile energies were increased. In vitro biological evaluations of the samples were done by performing cytotoxicity (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐iphenyltetrazolium bromide assay) and cell adhesion assays. Cell–material interaction with the surface of the composite was examined by scanning electron microscopy (SEM). In all of the tests, osteoblast cells were used. Results of biological tests showed that the samples are biocompatible and they have no toxicity. Also, Adhered cells presented a normal morphology by SEM and many of the cells were observed to be undergoing cell division. POLYM. COMPOS., 34:1960–1968, 2013. © 2013 Society of Plastics Engineers
Explosivity of lithium perchlorate in gel polymer electrolytes
Authors: Sedlaříková Marie , Vondrák Jiri , Musil Michal , Mathieisová Hana , Libich Jiri
Published: August 2013

In this article, we report the synthesis and characterization of novel methacrylate‐based polymer electrolyte membranes for lithium batteries. The safety requirement is a top priority for rechargeable Li‐ion batteries, and especially these are used in hybrid electric vehicles and power tools. After several serious fire accidents, the safety must be submitted to the intensive investigation and this danger must be minimalized. This article describes the differences between lithium perchlorate and tetrafluoroborate as conductive component in methacrylate‐based gel electrolytes. The gel polymer electrolytes were prepared by UV irradiation process, which is well known for being easy, low cost, and fast. POLYM. COMPOS., 34:1969–1973, 2013. © 2013 Society of Plastics Engineers
Flame retardant property of novel intumescent flame retardant rigid polyurethane foams
Authors: Wu Denghui , Zhao Peihua , Liu Yaqing
Published: August 2013

The novel intumescent flame retardant rigid polyurethane foams ((PEPS‐RPUF) were prepared based on a P‐N containing intumescent flame retardant, poly ethanediamine spirocyclic pentaerythritol bisphosphonate (PEPS). The flammability, thermal, and mechanical properties of PEPS‐RPUF were discussed. Scanning electron microscopy (SEM) and compression strength tests showed PEPS exhibited favorable compatibility with polyurethane matrix and smaller negative influence on the mechanical properties of PEPS‐RPUF. Cone calorimeter, vertical burning test (UL‐94) and limiting oxygen index (LOI) showed when the content of PEPS was 25 pph, the peak heat release rate (PHRR) and total heat release (THR) decrease, respectively, from 75.2 to 52.2 kW m−2 and from 5.7 to 4.1 MJ m−2. The LOI of PEPS‐RPUF could reach 27%, and a UL‐94 V‐0 rating was achieved. The PEPS‐RPUF exhibited an outstanding water resistance that it could still obtain a V‐0 rating after water soaking. Thermogravimetric analysis (TGA) showed the charring ability of PEPS‐RPUF was improved greatly compared to RPUF. SEM and Fourier transform‐infrared spectroscopy (FT‐IR) were utilized to characterize the surface morphology and chemical structure of the intumescent chars formed from PEPS‐RPUF. The results indicated the chars were compact and smooth, which was a critical factor for protecting the substrate material from burning. POLYM. ENG. SCI., 53:2478–2485, 2013. © 2013 Society of Plastics Engineers
Tough polyamide 6/core–shell blends prepared via in situ anionic polymerization of ε‐caprolactam by reactive extrusion
Authors: Yan Dongguang , Li Guang , Huang Mingyue , Wang Chao
Published: August 2013

In this study, the molten ε‐caprolactam (CL) solution of maleated styrene‐ethylene/butylene‐styrene block copolymer (SEBS‐g‐MA) and polystyrene (PS) containing catalyst and activator were introduced into a twin screw extruder, and polyamide 6 (PA6)/SEBS/PS blends were successfully prepared via anionic polymerization of CL by reactive extrusion. The mechanical properties measurements indicated that both the elongation at break and notched Izod impact strength of PA6/SEBS/PS (85/10/5) blends were improved distinctly with slight loss of tensile and flexural strength as compared to that of pure PA6. The images of transmission electron microscopy showed that a core–shell structure with PS core and poly (ethene‐co‐1‐butene) (PEB) shell was formed within the PA6 matrix. Fourier transform infrared was used to investigate the formation mechanisms of the core–shell structure. POLYM. ENG. SCI., 53:2705–2710, 2013. © 2013 Society of Plastics Engineers
Actuation design for high‐performance shape memory polyurethanes
Authors: Kim Min Ji , Kim Byung Kyu
Published: August 2013

A series of shape memory polyurethanes were synthesized from poly(tetramethylene glycol), 4,4‐methylene diphenyl diisocyanate, and 1,3‐butanediol. The prepolymers with different molecular weights (Mc) were capped with 2‐hydroxyl ethylacrylate or 3‐aminopropyltriethoxysilane (APTES) and crosslinked by UV curing or a sol–gel reaction. Variations of the crosslinker functionality (f), subchain density (N), and hard segment content (HSC) produced systematic variations of the glass transition temperature (6–45 °C), accompanied by changes in the mechanical, dynamic mechanical and shape memory properties. More than 95% of shape fixity and 98% of shape recovery up to the fourth cycles were obtained with APTES crosslinked 3000Mc with 30% of HSC. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1473–1479
PSA enzymatic activity: A new biomarker for assessing prostate cancer aggressiveness
Authors: Ahrens Michael J. , Bertin Paul A. , Vonesh Edward F. , Meade Thomas J. , Catalona William J. , Georganopoulou Dimitra
Published: August 2013

BACKGROUND

With the advent of widespread prostate‐specific antigen (PSA) testing in recent decades, prostate cancer (PCa) has emerged as the most frequently diagnosed non‐skin cancer among men in the U.S. and Europe [1]. Greater screening rates coupled with improved detection methods have caused a controversial upsurge in the number of men undergoing prostate biopsy and subsequent treatment. However, current diagnostic techniques generally suffer from limited ability to identify which seemingly indolent cancers are biologically aggressive [2].

METHODS

We collected prostatic fluid from 778 post‐radical prostatectomy specimens and randomly selected samples from both the clinically confirmed aggressive (n = 50) and non‐aggressive (n = 50) prostate cancer populations. We measured the level of proteolytic enzyme activity of PSA (aPSA) in each sample and used receiver operating characteristic (ROC) analysis to correlate aPSA levels with prostate cancer aggressiveness.

RESULTS

We found aPSA in prostatic fluid to be inversely proportional to disease stage, such that patients with the most aggressive PCa have on average significantly reduced aPSA compared to those with less aggressive disease. Significantly, our results suggest that many (22% in our study population) of the diagnosed patients with non‐aggressive PCa could have averted or delayed radical prostatectomy.

CONCLUSIONS

Given the high level of debate surrounding PSA screening effectiveness [3–5] and the recent U.S. Preventative Services Task Force recommendation to discontinue PSA screening [6], our results provide renewed hope that a clinical monitoring tool may emerge that truly refines PCa treatment decision‐making. Prostate 73:1731–1737, 2013. © 2013 Wiley Periodicals, Inc.
Firework Plot as a Graphical Exploratory Data Analysis Tool for Evaluating the Impact of Outliers in Data Exploration and Regression
Authors: Jang Dae‐Heung , Anderson‐Cook Christine M.
Published: August 2013

Outliers can distort many measures for data analysis. We propose a new set of graphical summaries, called firework plots, as simple tools for evaluating the impact of outliers in data exploration and regression assessment. One variation of the plot focuses on the impact of extreme observations on the mean and standard deviation by using curves that trace the relative contribution to the overall summary as weights for individual observations are changed from 1 to 0 in a univariate data set. Similarly, other variations for bivariate data allow examination of the impact of changing weights on combinations of the correlation coefficient and mean with two‐ or three‐dimensional firework plots. One variation of the plot focuses on the impact on the estimated intercept, the estimated slope, and the estimated standard deviation by using curves based on the relative contribution to the overall summary as weights for individual observations are changed from 1 to 0 in a simple linear regression analysis. Similarly, other variations for a multiple regression allow the practitioner to examine the impact of changing weights on combinations of the estimated regression coefficients and the standard error with the pairwise firework plot matrix. Copyright © 2013 John Wiley & Sons, Ltd.
Regulation of high‐voltage‐activated Ca2+ channel function, trafficking, and membrane stability by auxiliary subunits
Authors: Felix Ricardo , Calderón‐Rivera Aida , Andrade Arturo
Published: August 2013

Voltage‐gated Ca2+ (CaV) channels mediate Ca2+ ions influx into cells in response to depolarization of the plasma membrane. They are responsible for initiation of excitation‐contraction and excitation‐secretion coupling, and the Ca2+ that enters cells through this pathway is also important in the regulation of protein phosphorylation, gene transcription, and many other intracellular events. Initial electrophysiological studies divided CaV channels into low‐voltage‐activated (LVA) and high‐voltage‐activated (HVA) channels. The HVA CaV channels were further subdivided into L, N, P/Q, and R‐types which are oligomeric protein complexes composed of an ion‐conducting CaVα1 subunit and auxiliary CaVα2δ, CaVβ, and CaVγ subunits. The functional consequences of the auxiliary subunits include altered functional and pharmacological properties of the channels as well as increased current densities. The latter observation suggests an important role of the auxiliary subunits in membrane trafficking of the CaVα1 subunit. This includes the mechanisms by which CaV channels are targeted to the plasma membrane and to appropriate regions within a given cell. Likewise, the auxiliary subunits seem to participate in the mechanisms that remove CaV channels from the plasma membrane for recycling and/or degradation. Diverse studies have provided important clues to the molecular mechanisms involved in the regulation of CaV channels by the auxiliary subunits, and the roles that these proteins could possibly play in channel targeting and membrane stabilization. WIREs Membr Transp Signal 2013, 2:207–220. doi: 10.1002/wmts.93

Conflict of interest: The authors have declared no conflicts of interest for this article.

For further resources related to this article, please visit the WIREs website.
Habitat use by spruce grouse in northern Wisconsin
Authors: Anich Nicholas M. , Worland Mike , Martin Karl J.
Published: August 2013

Spruce grouse (Falcipennis canadensis) habitat use varies widely across their range and is not well‐understood near the southern extent of their range. Threats to conifers from climate change make understanding habitat use at the southern edge of the range increasingly important. We obtained habitat information on 55 radiocollared spruce grouse in northern Wisconsin, USA from 16 May 2007 to 10 July 2012. Black spruce (Picea mariana) and tamarack (Larix laricina) were the most common habitat components. Some of our findings differed from previous reports, including little use of eastern hemlock (Tsuga canadensis) or northern white cedar (Thuja occidentalis), use of tamarack in summer more than any other tree species, and winter roosting and feeding in red pine (Pinus resinosa), especially where jack pine (P. banksiana) was not available. Male display points contained fewer small broadleaf saplings ( = 652 trees/ha), greater percent conifer (87%), more jack pine ( = 148 trees/ha), and denser canopy ( = 65% closure) compared with random points (3,288 small broadleaf saplings/ha, 70% conifer, 7 jack pine/ha, and 51% closure). Dense ground cover was the best predictor of brood points, although brood points were similar to random points. Winter flock points were typified by dense canopy cover ( = 76% closure) and more jack pine ( = 407/ha). Management should be focused on areas with extensive conifer, especially near black spruce–tamarack swamps. Retaining or establishing closed‐canopy coniferous uplands, especially jack pine stands 15–30 years old, adjacent to lowland conifer swamps should benefit spruce grouse populations. © 2013 The Wildlife Society.
A Novel Production Method for Nitridosilicate‐type Phosphors
Authors: Cakmak Hasan , Jansen Martin
Published: August 2013

M2–xEuxSi5N8 (M = Ca, Sr, and Eu), well performing orange‐to‐red phosphors for white‐LED applications, were prepared with a novel production route based on employing molecular and polymeric precursors. The procedure presented allows a one‐pot, solution‐based synthesis of the desired phosphors by reacting SiCl4 with liquid NH3, in which Ca, Sr, and Eu metals are dissolved, or Eu[N(Si(CH3)3)2]3 is suspended. The significant advantages of this new approach over the conventional solid state syntheses are easily achievable high purities of the starting compounds, and thus of the final phosphors, as well as processing at mild conditions, avoiding laborious handling and complex equipments.
The role of carbon flux and biometric observations in constraining a terrestrial ecosystem model: a case study in disturbed forests in East Asia
Authors: Kondo Masayuki , Ichii Kazuhito , Ueyama Masahito , Mizoguchi Yasuko , Hirata Ryuichi , Saigusa Nobuko
Published: August 2013

The process of confining unnecessary freedom is a step toward advanced ecosystem modeling. This study demonstrates the importance of carbon flux and biometric observation in constraining a terrestrial ecosystem model with a simple optimization scheme. At the selected sites from AsiaFlux network, a simultaneous optimization scheme for both carbon flux and biomass was compared with carbon flux‐oriented and biomass‐oriented optimization schemes using the Biome‐BGC model. The optimization scheme oriented to either carbon flux or biomass provided simulation results that were consistent with observations, but with reduced performance in unconstrained variables. The simultaneous optimization scheme yielded results that were consistent with observations for both carbon flux and biomass. By comparing long‐term projections simulated by three schemes, it was found that the optimization oriented only to carbon flux has limited performance because misrepresented biomass significantly affected a projection of carbon exchange through heterotrophic respiration. From these experiments, we found that (1) a process model like Biome‐BGC is capable of reproducing both carbon flux and biomass within acceptable proximity, (2) constraining biomass is importance not just because it is one of carbon cycle components, but also it significantly affects simulations of carbon flux. Thus, it is important to invest more effort to improve simulation of biomass as well as carbon flux.
Psychosocial approaches to participation in BRCA1/2 genetic risk assessment among African American women: a systematic review
Authors: Sherman Kerry A. , Miller Suzanne M. , Shaw Laura-Kate , Cavanagh Karen , Sheinfeld Gorin Sherri
Published: August 2013

Breast cancer is a significant health concern for African American women. Nonetheless, uptake of genetic risk assessment (including both genetic counseling and testing) for breast cancer gene mutations among these populations remains low. This paper systematically reviews cognitive (i.e., beliefs) and affective (i.e., emotions) factors influencingBRCA1/2genetic risk assessment among African American women as well as psychosocial interventions to facilitate informed decision making in this population. A systematic search of CINAHL, PubMed, and PsycINFO was undertaken, yielding 112 published studies. Of these, 18 met the eligibility criteria. African American woman are likely to participate in genetic risk assessment if they are knowledgeable about cancer genetics, perceive a high risk of developing breast cancer, have low expectancies of stigmatization from medical professionals, view themselves as independent from family, and have fatalistic beliefs and a future temporal orientation. Anticipated negative affective responses, such as an inability to “handle” the results of testing, are barriers to uptake. Specific perceptions, beliefs, and emotional factors are associated with genetic risk assessment among African American women. Understanding these factors is key in the development of interventions to facilitate informed decision making in this population.
Preferential apelin‐13 production by the proprotein convertase PCSK3 is implicated in obesity
Authors: Shin Kyungsoo , Pandey Aditya , Liu Xiang-Qin , Anini Younes , Rainey Jan K.
Published: August 2013

The peptide hormone apelin is translated as a 77‐residue preproprotein, truncated to the 55‐residue proapelin and, subsequently, to 13–36‐residue bioactive isoforms named apelin‐13 to ‐36. Proapelin is hypothesized to be cleaved to apelin‐36 and then to the shorter isoforms. However, neither the mechanism of proapelin processing nor the endoproteases involved have been determined. We show direct cleavage of proapelin to apelin‐13 by proprotein convertase subtilisin/kexin 3 (PCSK3, or furin) in vitro, with no production of longer isoforms. Conversely, neither PCSK1 nor PCSK7 has appreciable proapelin cleavage activity. Furthermore, we show that both proapelin and PCSK3 transcript expression levels are increased in adipose tissue with obesity and during adipogenesis, suggesting that PCSK3 is responsible for proapelin processing in adipose tissue.
Pflegebedürftigkeit und Multimorbidität
Authors: Kojer Marina
Published: August 2013

Einleitung

Menschen, die derzeit in Pflegeheimen betreut werden, sind in der Regel hochbetagt und fortgeschritten multimorbid. Die Mehrzahl von ihnen ist an Demenz erkrankt. Daher haben sich die Hauptaufgaben der Pflegeheime in den vergangenen 25 Jahren grundlegend verändert. Gute Lebensqualität für die Betroffenen kann nur durch fachgerechte Pflegeleistungen, professionelle geriatrische und palliativmedizinische Behandlung, sowie Kompetenz aller Mitarbeiter in Kommunikation mit Menschen mit Demenz gewährleistet werden.
Palliativversorgung – Konzepte und Strukturen
Authors: Schneider Nils
Published: August 2013

Einleitung

Die meisten Menschen können in der letzten Lebensphase im Rahmen der Primärversorgung vor allem durch Hausärzte und ambulante Pflegedienste betreut werden. Ein Teil der Betroffenen (ca. 10-15%) hat jedoch einen komplexeren Versorgungsbedarf, so dass eine spezialisierte ambulante Palliativversorgung erforderlich ist. Die Differenzierung zwischen allgemeiner und spezialisierter Palliativversorgung findet sich auch im Krankenhaus (Normalstation, Palliativstation, palliativer Konsiliardienst).
Gesundheitsberufe für die letzte Lebensphase in Deutschland: aktuelle Qualifikationen und zukünftige Erfordernisse
Authors: Seibel Katharina , Becker Gerhild
Published: August 2013

Einleitung

Vertreter von Gesundheitsberufen begegnen heute häufig Palliativpatienten. Diese Kontakte werden sich auf Grund des demografischen Wandels und der epidemiologischen Entwicklungen zukünftig mehren. Angesichts dieses steigenden palliativmedizinischen Betreuungsbedarfs sowie der komplexen Kompetenzerfordernisse für palliativmedizinische Aufgaben sollte es zu einem verstärkten strukturellen Ausbau der Aus- und Weiterbildung in Palliative Care kommen.
Die gesellschaftliche Sicht auf das Sterben
Authors: Stößel Ulrich
Published: August 2013

Einleitung

Mit der zunehmend - auch den öffentlichen Diskurs - beschäftigenden Frage nach der in einer Gesellschaft für angemessen gehaltenen Gestaltung des Lebensendes, tritt nunmehr auch die Public Health Perspektive eines ‚guten Sterbens‘ in den Vordergrund. Diese wird anhand aktueller Publikationen vorgestellt.
Response of General Practitioners to Infectious Disease Public Health Crises: An Integrative Systematic Review of the Literature
Authors: Kunin Marina , Engelhard Dan , Piterman Leon , Thomas Shane
Published: August 2013

Objective

Previous research has identified gaps in pandemic response planning for primary care. Identifying the challenges that general practitioners (GPs) face during public health crises of infectious diseases will help to improve prepandemic planning. In this integrative systematic review, we identified research-based evidence to (1) challenges that GPs have when participating in pandemics or epidemics and (2) whether GPs from different countries encountered different challenges.

Methods

A systematic search was conducted in MEDLINE, PubMed, Scopus, EMBASE, PsycINFO, Cochrane Library, and ProQuest Dissertations and Theses databases during October to November 2012 to identify studies relevant to experience by GPs during epidemics or pandemics.

Results

Six quantitative, 2 mixed method, and 2 qualitative studies met the inclusion criteria. The challenges identified were not exclusive to specific countries and encompassed different responses to outbreaks. These challenges included difficulties with information access; supply and use of personal protective equipment; performing public health responsibilities; obtaining support from the authorities; appropriate training; and the emotional effects of participating in the response to an infectious disease with unknown characteristics and lethality.

Conclusion

GPs’ response to public health crises in different countries presents potential for improving pandemic preparedness. (Disaster Med Public Health Preparedness. 2013;0:1-12)