bluuebunny/crossref_metadata_2025 huggingface dataset:
Sudan Black B Reduces Autofluorescence in Murine Renal Tissue
Authors: Sun Yan , Yu Hong , Zheng Dong , Cao Qi , Wang Ya , Harris David , Wang Yiping
Published: October 2011

Context.—Renal tissue emits intense autofluorescence, making it difficult to differentiate specific immunofluorescence signals and thus limiting its application to clinical biopsy material.

Objective.—To identify and minimize autofluorescence of renal tissue and demonstrate a simple, efficient method to reduce autofluorescence using Sudan black B.

Design.—In this study, the sources and features of autofluorescence emitted from kidney tissue were examined. Broad autofluorescence was visualized in both frozen and paraffin kidney sections of normal mice and mice with Adriamycin-induced nephropathy using confocal laser scanning microscopy. Autofluorescence appeared in commonly used 4′,6-diamidino-2-phenylindole, fluorescein isothiocyanate, and Texas Red channels but not in far-red channel, and emitted extensively from red cells, injured tubulointersitial cells, and protein casts in diseased kidney. To eliminate autofluorescence, Sudan black B was used on formaldehyde-fixed paraffin sections and frozen sections of mouse kidney. The effects of Sudan black B in various concentrations were tested on kidney tissue.

Results.—The 0.1% Sudan black B effectively blocked autofluorescence from both paraffin and frozen sections without adversely affecting specific fluorescence signals. Interestingly, the solvent for Sudan black B, 70% ethanol, was also shown to reduce autofluorescence on frozen sections, but not on paraffin sections.

Conclusions.—This study demonstrates a simple, efficient, and cost-effective method to reduce autofluorescence using Sudan black B, and also provides a comprehensive approach to identify and minimize autofluorescence of renal tissue.
Benign Gastrointestinal Mesenchymal BUMPS: A Brief Review of Some Spindle Cell Polyps With Published Names
Authors: Rittershaus Ahren C , Appelman Henry D
Published: October 2011

Context.—There are several benign, predominantly spindle cell, mesenchymal proliferations involving the mucosa and/or submucosa in the gut, which present as polyps and pathologists see as polypectomy specimens. These include perineuriomas, Schwann cell nodules, ganglioneuromas, leiomyomas of the muscularis mucosae, inflammatory fibroid polyps, and granular cell tumors.

Objectives.—To evaluate these mesenchymal polyps for their morphologic, immunohistochemical, ultrastructural, and molecular characteristics and to determine some of their associations.

Data Sources.—Personal observations based on years of analyzing endoscopic biopsies and a review of the world's literature.

Conclusions.—These polyps do surface every so often. There is significant literature covering inflammatory fibroid polyps and granular cell tumors, but there is little literature about the other entities.
Lymphoproliferative Disorders of the Gastrointestinal Tract: A Review and Pragmatic Guide to Diagnosis
Authors: Burke Jerome S.
Published: October 2011

Context.—The gastrointestinal tract is the most common site of extranodal lymphomas. Although all histologic categories of malignant lymphoma develop in the gastrointestinal tract, large B-cell lymphomas predominate, followed by extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT) type; the latter is especially prevalent in stomach. The acceptance of extranodal marginal zone lymphoma of MALT type as a clinicopathologic entity has reduced the number of cases that formerly were interpreted as florid lymphoid hyperplasia (“pseudolymphoma”). Nonetheless, the distinction of lymphoid hyperplasia from a lymphoma of MALT type in small biopsy specimens remains problematic.

Objective.—To assess the relevant morphologic, immunologic, molecular, and genetic properties of gastrointestinal lymphomas and to present a feasible tactic for diagnosis, expressly for small biopsy specimens.

Data Sources.—Case-derived material and literature review using PubMed (National Library of Medicine).

Conclusions.—Most gastrointestinal lymphomas are readily amenable to an unqualified diagnosis, primarily those cases consisting of monomorphic large cells whether of B- or T-cell lineage, including cases associated with enteropathy. Diagnosis for infiltrates dominated by small lymphocytes remains taxing, as the differential diagnosis embraces not only MALT lymphoma and lymphoid hyperplasia but also mantle cell lymphoma, follicular lymphoma, and chronic lymphocytic leukemia/small lymphocytic lymphoma. Adherence to strict morphologic criteria is the standard for diagnosis, but these criteria should be augmented by immunologic studies together with judicious use of molecular techniques to determine clonality. In establishing a diagnosis of gastric marginal zone lymphoma of MALT type, determination of t(11;18)(q21;q21) status may be required since this translocation has clinical ramifications.
Searching NCBI Databases Using Entrez
Authors: Gibney Gretchen , Baxevanis Andreas D.
Published: October 2011

One of the most widely used interfaces for the retrieval of information from biological databases is the NCBI Entrez system. Entrez capitalizes on the fact that there are pre‐existing, logical relationships between the individual entries found in numerous public databases. The existence of such natural connections, mostly biological in nature, argued for the development of a method through which all the information about a particular biological entity could be found without having to sequentially visit and query disparate databases. Two basic protocols describe simple, text‐based searches, illustrating the types of information that can be retrieved through the Entrez system. An alternate protocol builds upon the first basic protocol, using additional, built‐in features of the Entrez system, and providing alternative ways to issue the initial query. The support protocol reviews how to save frequently issued queries. Finally, Cn3D, a structure visualization tool, is also discussed. Curr. Protoc. Hum. Genet. 71:6.10.1‐6.10.24 © 2011 by John Wiley & Sons, Inc.
Next Generation Sequencing to Characterize Mitochondrial Genomic DNA Heteroplasmy
Authors: Huang Taosheng
Published: October 2011

This protocol describes the methodology to characterize mitochondrial DNA (mtDNA) heteroplasmy by parallel sequencing. Mitochondria play an important role in essential cellular functions. Each eukaryotic cell contains hundreds of mitochondria with hundreds of mitochondria genomes. Mutant and wild‐type mtDNA may co‐exist as heteroplasmy, and cause human disease. The purpose of this protocol is to simultaneously determine mtDNA sequence and quantify the heteroplasmic level. This protocol includes a two‐fragment mitochondrial genome DNA PCR amplification. The PCR product is then mixed at an equimolar ratio. The samples are then barcoded and sequenced with high‐throughput, next‐generation sequencing technology. This technology is highly sensitive, specific, and accurate in determining mtDNA mutations and the level of heteroplasmy. Curr. Protoc. Hum. Genet. 71:19.8.1‐19.8.12 © 2011 by John Wiley & Sons, Inc.
Strategies for the Fabrication of Porous Platinum Electrodes
Authors: Kloke Arne , von Stetten Felix , Zengerle Roland , Kerzenmacher Sven
Published: October 2011

Porous platinum is of high technological importance due to its various applications in fuel cells, sensors, stimulation electrodes, mechanical actuators and catalysis in general. Based on a discussion of the general principles behind the reduction of platinum salts and corresponding deposition processes this article discusses techniques available for platinum electrode fabrication. The numerous, different strategies available to fabricate platinum electrodes are reviewed and discussed in the context of their tuning parameters, strengths and weaknesses. These strategies comprise bottom‐up approaches as well as top‐down approaches. In bottom‐up approaches nanoparticles are synthesized in a first step by chemical, photochemical or sonochemical means followed by an electrode formation step by e.g. thin film technology or network formation to create a contiguous and conducting solid electrode structure. In top‐down approaches fabrication starts with an already conductive electrode substrate. Corresponding strategies enable the fabrication of substrate‐based electrodes by e.g. electrodeposition or the fabrication of self‐supporting electrodes by dealloying. As a further top‐down strategy, this review describes methods to decorate porous metals other than platinum with a surface layer of platinum. This way, fabrication methods not performable with platinum can be applied to the fabrication of platinum electrodes with the special benefit of low platinum consumption.
Correlation between molecular structure parameters and network properties of silane‐grafted and moisture cross‐linked polyethylenes
Authors: Azizi H. , Morshedian J. , Barikani M. , Wagner M. H.
Published: October 2011

The degree of silane grafting and cross‐linking of several high‐density polyethylenes (HDPE) was studied. The results are compared with those of a low‐density polyethylene (LDPE) and a linear low‐density polyethylene (LLDPE). Molecular characterization was done by gel permeation chromatography. The differences in grafting and cross‐linking performance are correlated to the different structural parameters of the polymers such as molecular weight, molecular weight distribution, polydispersity index (PDI), and branching. The results show that molecular weight plays the main role in silane‐grafting and cross‐linking performance. For samples with approximately similar PDI, the grafting level increased with both increasing number average molecular weight and weight average molecular weight, whereas the gel content increased with increasing weight average molecular weight. However, a zigzag relation was observed for the variation of grafting and cross‐linking performances with PDI. The presence of long‐chain branching affects the size of molecules and reduces the grafting efficiency due to coil contraction and more intramolecular entanglements. The order of the degree of grafting for the different polyethylenes investigated was LLDPE > HDPE > LDPE, whereas the order for the gel content was LDPE > LLDPE > HDPE. The presence of unsaturated groups led to increase in the grafting level. However, there is no overall rule based on the density of polyethylene. Different grades of polyethylene show different behaviors depending on the silane and peroxide concentration. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 286–300, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20224
On the characterization and spinning of an organic‐purified lignin toward the manufacture of low‐cost carbon fiber
Authors: Baker Darren A. , Gallego Nidia C. , Baker Frederick S.
Published: October 2011

A Kraft hardwood lignin (HWL) and an organic‐purified hardwood lignin (HWL‐OP) were evaluated as potential precursors for the production of low‐cost carbon fibers. It was found that the unpurified HWL exhibited poor spinnability while the HWL‐OP exhibited excellent spinnability characteristics. Fibers of various diameters were obtained from the HWL‐OP. Thermostabilization studies showed that oxidative stabilization can only be used to convert HWL‐OP‐based fibers into carbon fibers if extremely low heating rates are applied. Carbonized lignin‐based fibers had tensile strength of 0.51 GPa and tensile modulus of 28.6 GPa. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of hydrophilic chain length on the aqueous solution behavior of block amphiphilic copolymers PMMA‐b‐PDMAEMA
Authors: Xiao Guilin , Hu Zhibiao , Zeng Guangpeng , Wang Yongqiang , Huang Yaqun , Hong Xinlin , Xia Bilai , Zhang Gaoyong
Published: October 2011

A series of amphiphilic block copolymers, polymethyl methacrylate (PMMA)‐b‐poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA), were synthesized by atom transfer radical polymerization (ATRP) method. Surface tension, dynamic light scattering (DLS), transmission electron microscope (TEM), and atomic force microscopy (AFM) studies were performed to investigate the aqueous micellar behavior of these block amphiphiles. At a fixed degree of polymerization (DP) of PMMA block (DP = 55), the PDMAEMA block length was found to have a significant influence on the critical micelle concentration (cmc) values and hydrodynamic size of aggregates. An increase in the DP of PDMAEMA from 11 to 337, resulted in a decrease in the cmc from 1.44 × 10−5 to 5.81 × 10−7 M (a factor of almost 24.8), and a decrease in the Z (2Rh) from 85.5 to 15.5 nm (pH = 4), respectively. TEM and AFM results indicated that by changing the soluble block lengths, spherical, short rod, crew‐cut, vesicles or large aggregates can be observed in the solution. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Characterization of linear low‐density polyethylene/poly(vinyl alcohol) blends and their biodegradability by Vibrio sp. isolated from marine benthic environment
Authors: Francis Vidya , Subin S. Raghul , Bhat Sarita G. , Thachil Eby Thomas
Published: October 2011

Increasing amounts of plastic waste in the environment have become a problem of gigantic proportions. The case of linear low‐density polyethylene (LLDPE) is especially significant as it is widely used for packaging and other applications. This synthetic polymer is normally not biodegradable until it is degraded into low molecular mass fragments that can be assimilated by microorganisms. Blends of nonbiodegradable polymers and biodegradable commercial polymers such as poly (vinyl alcohol) (PVA) can facilitate a reduction in the volume of plastic waste when they undergo partial degradation. Further, the remaining fragments stand a greater chance of undergoing biodegradation in a much shorter span of time. In this investigation, LLDPE was blended with different proportions of PVA (5–30%) in a torque rheometer. Mechanical, thermal, and biodegradation studies were carried out on the blends. The biodegradability of LLDPE/PVA blends has been studied in two environments: (1) in a culture medium containing Vibrio sp. and (2) soil environment, both over a period of 15 weeks. Blends exposed to culture medium degraded more than that exposed to soil environment. Changes in various properties of LLDPE/PVA blends before and after degradation were monitored using Fourier transform infrared spectroscopy, a differential scanning calorimeter (DSC) for crystallinity, and scanning electron microscope (SEM) for surface morphology among other things. Percentage crystallinity decreased as the PVA content increased and biodegradation resulted in an increase of crystallinity in LLDPE/PVA blends. The results prove that partial biodegradation of the blends has occurred holding promise for an eventual biodegradable product. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Use of polyester/glass‐fiber residues as fillers for composites
Authors: Silva L. V. , Angrizani C. C. , Souza J. R. , Amico S. C. , Medeiros J. T. N.
Published: October 2011

In this work, the performance of polyester (P)/glass fiber mats (G) and P/G/calcium carbonate (CaCO3) composites was compared with that of P/G/fiberglass waste composites. The residues used were conventional P/G postconsumer light resin‐transfer‐molding parts, obtained via knife or ball milling. Composites with up to 50 wt % reinforcement were prepared by hot compression molding and characterized via physical (density and water sorption), thermal (thermogravimetry and burnout), and mechanical (impact, Barcol hardness, and tensile) testing. The results show that the simple grinding and reincorporation of the composite residues yielded new composites with generally worse characteristics than the ones with calcium carbonate. Then, the waste was sorted by removing most of the pure resin particles from it. This yielded a resin‐rich fraction, which could be better used for energy recovery and resin‐covered fibers. The use of the latter as a filler yielded composites with better overall properties than those with calcium carbonate for a controlled amount of W; thus showing potential use as a replacement for the commonly used inorganic filler, maintaining the mechanical properties, decreasing the raw material cost, and reducing the amount of composite waste discarded in the environment. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Application of cellulose sulfoacetate obtained from sugarcane bagasse as an additive in mortars
Authors: Nascimento Bárbara , Filho Guimes Rodrigues , Frigoni Elaine Selaro , Soares Heline Mendes , da Silva Meireles Carla , Cerqueira Daniel Alves , Valente Artur José Monteiro , de Albuquerque Carvalho Rui , de Assunção Rosana Maria Nascimento , de Castro Motta Leila Aparecida
Published: October 2011

In this study, cellulose sulfoacetate (CSA) was produced with cellulose extracted from sugarcane bagasse with sulfuric acid as a catalyst under homogenous conditions so that the derivative could be applied as an additive for mortar of Portland (Cimento Portland de alta resistência inicial, CPV‐ARI) cement. The IR spectra showed that only precipitate C presented the characteristic band of sulfate groups (807 cm−1) and was, therefore, the sulfoacetylated derivative. CSA presented a degree of acetylation of 2.70 and a degree of sulfonation of 0.063, and the presence of sulfate groups in the derivative displaced the position of C(6) to a lower field in the 13C‐NMR spectrum and influenced reduced viscosity as a function of concentration. The evaluation of CSA as an additive showed that for a polymer/cement ratio of 0.6%, an increase of 13.80% was achieved consistently, and an increase of 21.05% in the potential tensile of adhesion strength was also achieved. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The role of synthetic and natural fillers on three‐body abrasive wear behaviour of glass fabric–epoxy hybrid composites
Authors: Mohan N. , Natarajan S. , KumareshBabu S. P.
Published: October 2011

Polymer matrix composites are a promising candidate in tribological applications due to possibility of tailoring their properties with special fillers. The comparative performance of Glass–Epoxy (G‐E) composites with influence of synthetic fillers such as graphite (Gr) and silicon carbide (SiC) and biobased natural filler jatropha oil cake (JOC) was experimentally investigated. All the composites were fabricated using vacuum‐assisted resin infusion (VARI) technique. The mechanical properties were studied in accordance with ASTM standards. The three‐body abrasive wear studies were carried out with rubber wheel abrasion tester as per ASTM‐G65 standard. Two different loads namely 22 N and 32 N with different abrading distances viz, 135, 270, 405, and 540 m are test parameters. The results reveal that addition of JOC in G‐E composites has significant influence on wear under varied abrading distance/load. Further, it was found that SiC filled G‐E composites exhibited better wear resistance compared to Gr/JOC filled G‐E composites. The operating wear mechanisms have been studied by using scanning electron microscopy. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Characterization of macroporous 1‐vinyl‐2‐pyrrolidone copolymers obtained by suspension polymerization
Authors: Maciejewska Małgorzata
Published: October 2011

Radical suspension copolymerization of 1‐vinyl‐2‐pyrrolidone (VP) with three different cross‐linkers: divinylbenzene (DVB), trimethylolpropane trimethacrylate (TRIM), and di(methacryloxymethyl) naphthalene (DMN) was used to prepare macroporous microspheres. During the copolymerization, the mixture of toluene and n‐dodecane as a pore‐forming diluent was used. All samples were characterized in terms of particle size and distribution, nitrogen content, specific surface area total pore volume, and pore size distribution. It was found that specific surface area of the obtained beads is strongly dependent on the diluent system and the type of cross‐linker and achieves value from 27 to 845 m2/g. To determine the influence of chemical structure of cross‐linkers on the selectivity and polarity of the copolymers, inverse gas chromatography was applied. In addition, VP–DVB and VP–DMN copolymers were modified by sulfonation into cation‐exchangers with cation exchange capacity equal 1.98 and 2.31 mmol/g, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
PTCR characteristics of poly(styrene‐co‐acrylonitrile) copolymer/stainless steel powder composites
Authors: Kar Prativa , Shrivastava Nilesh K. , Mallick Sumana , Khatua B. B.
Published: October 2011

Positive temperature coefficient of resistivity (PTCR) characteristics of poly(styrene‐co‐acrylonitrile) copolymer (SAN)/stainless steel (SS) powder (80 wt %) composites prepared by melt‐mixing method has been investigated with reference to SAN/carbon black (CB) composites. The SAN/CB (10 wt %) composites showed a sudden rise in resistivity (PTC trip) at 125°C, above the glass transition temperature (Tg) of SAN (Tg ≈ 107°C). However, the PTC trip temperature of SAN/SS (80 wt %) composites appeared at 94°C, well below the Tg of SAN. Addition of 1 phr of nanoclay increased the PTC trip temperature of SAN/CB (10 wt %) composites to 130°C, while SAN/SS (80 wt %)/clay (1 phr) nanocomposites showed the PTC trip at 101°C. We proposed that the mismatch in coefficient of thermal expansion (CTE) between SAN and SS played a key role that led to a disruption in continuous network structure of SS even at a temperature below the Tg of SAN. The dielectric properties study of SAN/SS (80 wt %) composites indicated possible use of the PTC composites as dielectric material. DMA results showed higher storage modulus of SAN/SS composites than the SAN/CB composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Thermal, structural, and optical properties of γ‐irradiated poly(vinyl alcohol)/poly(ethylene glycol) thin film
Authors: Nouh S. A. , Nagla A. G. , Othman M. H. , Eman S. A. , Lotfi Z. I.
Published: October 2011

Poly(vinyl alcohol)/poly(ethylene glycol) (PVA/PEG) copolymer was prepared using casting technique. The obtained PVA/PEG thin films have been irradiated with gamma rays with doses ranging from 1.5 to 20 Gy. The resultant effect of gamma irradiation on the thermal properties of PVA/PEG has been investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The onset temperature of decomposition To and activation energy of thermal decomposition Ea were calculated, results indicating that the PVA/PEG thin film decomposes in one main weight loss stage. Also, the gamma irradiation in dose range 4–12 Gy led to a more compact structure of PVA/PEG copolymer, which resulted in an improvement in its thermal stability with an increase in the activation energy of thermal decomposition. The variation of transition temperatures with gamma dose has been determined using DTA. The PVA/PEG thermograms were characterized by the appearance of an endothermic peak due to melting of crystalline phase. In addition, structural property studies using X‐ray diffraction and infrared spectroscopy were performed on both nonirradiated and irradiated samples. Furthermore, the transmission of the PVA/PEG samples and any color changes were studied. The color intensity (E was greatly increased with increasing the gamma dose and was accompanied by a significant increase in the blue and green color components. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Thermal and insulating properties of epoxy/aluminum nitride composites used for thermal interface material
Authors: Yu Hui , Li Liangliang , Kido Teruo , Xi Guannan , Xu Guangchen , Guo Fu
Published: October 2011

We synthesized an epoxy matrix composite adhesive containing aluminum nitride (AlN) powder, which was used for thermal interface materials (TIM) in high power devices. The experimental results revealed that adding AlN fillers into epoxy resin was an effective way to boost thermal conductivity and maintain electrical insulation. We also discovered a proper coupling agent that reduced the viscosity of the epoxy‐AlN composite by AlN surface treatment and increased the solid loading to 60 vol %. For the TIM sample made with the composite adhesive, we obtained a thermal conductivity of 2.70 W/(m K), which was approximately 13 times larger than that of pure epoxy. The dielectric strength of the TIM was 10 to 11 kV/mm, which was large enough for applications in high power devices. Additionally, the thermal and insulating properties of the TIM did not degrade after thermal shock testing, indicating its reliability for use in power devices. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Prompt modification of styrene‐butadiene rubber surface with trichloroisocyanuric acid by increasing chlorination temperature
Authors: Yin Long , Zhou Hongbing , Quan Yiwu , Fang Jianglin , Chen Qingmin
Published: October 2011

In this article, the surface of styrene‐butadiene rubber (SBR) was brushed with trichloroisocyanuric acid (TCI) (1 or 2 wt % in ethyl acetate) and then thermally treated under different conditions. The chemical modification was characterized by contact angle measurement and surface energy, ATR‐FTIR spectroscopy, scanning electron microscopy (SEM), and single‐lap shear test. The results revealed that the increase of the chlorination temperature was very effective for SBR surface modification by TCI, leading to enhanced surface wettability and shear strength within several minutes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Application of tin(IV) porphyrin complexes as novel catalysts for the synthesis of new copolyurethanes with cyclopeptide moiety
Authors: Rafiemanzelat Fatemeh , Abdollahi Elahe , Moghadam Majid , Mirkhani Valiollah , Tangestaninejad Shahram , Mohammadpoor‐Baltork Iraj
Published: October 2011

New electron deficient tin(IV) porphyrins were used as efficient catalysts for the reaction of 4,4′‐methylene‐bis‐(4‐phenylisocyanate) (MDI), with L‐leucine anhydride cyclodipeptide (LAC) and polyethyleneglycol‐400 (PEG‐400) and the results were compared with those obtained in the presence of a commercial catalyst, dibutyltin dilaurate (DBTDL). Molar ratio of catalysts to MDI, polymerization reaction time, viscosity, and yield of the resulting poly(ether‐urethane‐urea)s (PEUU) were compared in the presence of different catalysts. The rate of NCO conversion in the presence of each catalysts under the same reaction conditions was also compared and followed by FT‐IR NCO absorption band. FT‐IR, GPC, and viscosity studies have shown that tin(IV) porphyrins afford higher viscosity and reaction progress. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Fibrin as a scaffold for cardiac tissue engineering
Authors: Barsotti Maria Chiara , Felice Francesca , Balbarini Alberto , Di Stefano Rossella
Published: October 2011

Fibrin is a natural biopolymer with many interesting properties, such as biocompatibility, bioresorbability, ease of processing, ability to be tailored to modify the conditions of polymerization, and potential for incorporation of both cells and cell mediators. Moreover, the fibrin network has a nanometric fibrous structure, mimicking extracellular matrix, and it can also be used in autologous applications. Therefore, fibrin has found many applications in tissue engineering, combined with cells, growth factors, or drugs. Because a major limitation of cardiac cell therapy is low cell engraftment, the use of biodegradable scaffolds for specific homing and in situ cell retention is desirable. Thus, fibrin‐based injectable cardiac tissue engineering may enhance cell therapy efficacy. Fibrin‐based biomaterials can also be used for engineering heart valves or cardiac patches. The aim of this review is to show cardiac bioengineering uses of fibrin, both as a cell delivery vehicle and as an implantable biomaterial.
Ein Beitrag zu vereinfachten Berechnungsverfahren für die Heißbemessung von Stahlbetondruckgliedern
Authors: Held Markus , Gelien Marion
Published: October 2011

Kragstützen, ist ein aktuelles Thema, welches sowohl in der Praxis als auch in der Forschung tätige Ingenieure nach wie vor beschäftigt. Der Ansatz der Zonenmethode als einziges gemäß deutschem Nationalem Anwendungsdokument (NAD) zugelassenes, vereinfachtes Berechnungsverfahren wird fortlaufend erweitert und angepasst, um auch nichtlinearen Berechnungen zu genügen.

Der vorliegende Beitrag beschäftigt sich zum einen mit der Frage, wie gut diese Anpassungen gelingen und zum anderen mit der Frage nach der Notwendigkeit einer weiteren Verifizierung dieser Methode.

Contribution to the simplified calculation of fire resistance design of concrete columns

Fire resistance design of concrete columns, especially cantilever columns, is a contemporary issue, which affects engineers in research and practice. The approach called zone method is continually upgraded and matched to answer nonlinear calculation methods. In the presented paper it is investigated wether the upgrading is successful. The necessity of further verification of the zone method is discussed.
Lynx: A user‐friendly computer application for simulating fatigue growth of planar cracks using FEM
Authors: Branco R. , Antunes F. V. , Costa J. D.
Published: October 2011

People engaged in fracture mechanics education recognise the need to combine theory and effective practice in order to enhance students' skills in this field. Nevertheless, real experiments are not always possible for education purposes because they require too much time, involve specialised equipment and specimen preparation. In these circumstances, numerical simulation is a valid alternative to guarantee the link between theory and practice. In this article, a computer application capable of simulating the fatigue crack growth (FCG) of planar cracks under mode‐I cyclic loading is presented. This tool incorporates an extensive range of real significance problems found in the context of FCG. Besides, an intuitive and user‐friendly interface was provided in order to improve its functionality and to allow the user to define quickly and easily fundamental input data. Default values are proposed for less experienced users, seeking the minimum effort in numerical model definition. The use of this software in educational context is expected to provide a major insight into FCG phenomenon. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:529–540, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.10.1002/cae.20578
4,5‐Bis(dialkylamino)‐Substituted Imidazolium Systems: Facile Access to N‐Heterocyclic Carbenes with Self‐Umpolung Option
Authors: Huber Stefan M. , Heinemann Frank W. , Audebert Pierre , Weiss Robert
Published: October 2011

The first synthesis of 4,5‐bis‐ (dimethylamino)‐substituted imidazolium compounds was developed, which is based on the reaction of a 1,2‐diamino‐1,2‐bis(phosphonio)ethene with lithiated formamidines. This represents the first application of this class of ethene derivatives for the preparation of heterocycles. These N‐heterocyclic carbene (NHC) precursors show a remarkably reduced basicity and nucleophilicity of their NMe2 groups, which is due to the strong anomeric interactions of the latter with the imidazolium core. According to DFT calculations, these NHCs are capable of self‐umpolung if sufficiently strong acceptor substituents are introduced at the carbene center. To test the self‐umpolung capabilities of the NHCs, various substituents were attached to the carbene center and the obtained compounds were characterized by single‐crystal X‐ray analysis as well as quantum chemical computations. Strong acceptor substituents are required to induce self‐umpolung, such as in the phosphonio‐substituted derivative, for which partial self‐umpolung was found. The N,N′‐bis(4‐dimethylaminophenyl)‐substituted imidazolium compound represents a special case, as it incorporates as much as three two‐step redox systems within the NHC framework. This will probably result in a high electronic flexibility of the corresponding nucleophilic carbenes, especially when they serve as ligands in transition metal complexes.
RNA‐Gerüst bringt Ordnung in die Zelle
Authors: Groß Michael
Published: October 2011

Die noch in den Kinderschuhen steckende synthetische Biologie will die lebende Zelle neu erschaffen und dabei irgendwie anders gestalten. Wie das synthetische Leben jedoch aussehen soll, weiß man noch nicht genau. Zu den wenigen Beispielen gehören ein künstlicher Stoffwechselweg und Craig Venters synthetisches Bakterien‐Genom. Jetzt kommt ein Gerüst hinzu, das in einer Bakterienzelle für Ordnung sorgt.
Soil Budget, Net Export, and Potential Sinks of Nitrogen in the Lower Oglio River Watershed (Northern Italy)
Authors: Soana Elisa , Racchetti Erica , Laini Alex , Bartoli Marco , Viaroli Pierluigi
Published: October 2011

A nitrogen mass balance, realized for the lower Oglio River basin (Po River Plain, northern Italy), suggested an elevated impact of agricultural activities in this watershed. Livestock manure, synthetic fertilizers, biological fixation, atmospheric deposition, and wastewater sludge contributed 51, 34, 12, 2, and 1% of total N (TN) input, respectively (basin average 450 kg N ha−1 arable land (AL) year−1, overall input 100 115 t N year−1). Crop uptake, ammonia volatilization and denitrification in soils contributed 65, 21, and 14%, respectively, of TN output (basin average 270 kg N ha−1 AL year−1, overall output 60 060 t N year−1). N inputs exceeded outputs by 40 056 t N year−1, resulting in a basin average surplus of about 180 kg N ha−1 AL year−1. About 34% of the N surplus was exported annually from the basin while the remaining amount (about 26 800 t N year−1) underwent other unaccounted for processes within the watershed.

The relevance of nitrogen removal via denitrification in aquatic compartments within the watershed was evaluated. Denitrification in the secondary drainage network can represent a relevant nitrogen sink due to great linear extension (over 12 500 km), with estimated nitrogen loss up to 8500 t N year−1. Denitrification in the riverbed and in perifluvial wetlands have the potential to remove only a small fraction of the nitrogen surplus (<3%). Evidence suggests the relevance of groundwater as a site of nitrogen accumulation.
Development of Polymeric and Polymer‐Based Hybrid Adsorbents for Chromium Removal from Aqueous Solution
Authors: Kaya Ismet Gul Buyruklardan , Duranoglu Dilek , Beker Ulker , Senkal Bahire Filiz
Published: October 2011

Ferric oxide‐loaded hybrid sorbents are environmentally benign and exhibit sorption behaviors for chromium removal from waters. In the current study, glycidyl methacrylate‐based polymer (GMD) and nanosized ferric oxide loaded glycidyl methacrylate‐based polymer (GMDFe) were prepared and assayed to examine the effect of ferric oxide loading on chromium sorption from aqueous solution for the first time from the equilibrium and kinetic points of view. The experimental equilibrium data, suitably fitted by the Langmuir and Freundlich isotherms, have shown that ferric oxide loaded hybrid sorbent exhibits higher adsorption capacity than glycidyl methacrylate‐based polymer (GMD). The Langmuir isotherm model was found to be the most suitable one for the Cr(VI) adsorption. The maximum adsorption capacities of GMD and GMDFe sorbents were determined at pH 4 as 109.54 and 157.52 mg/g, respectively. A series of column experiments was carried out to determine the breakthrough curves. The column was regenerated by eluting Cr(VI) using NaOH (10% w/v) solution after adsorption studies.
Prevalence of BRCA mutations in an unselected population of triple‐negative breast cancer
Authors: Hartman Anne‐Renee , Kaldate Rajesh R. , Sailer Lisa M. , Painter Lisa , Grier Charles E. , Endsley Robbin R. , Griffin Marlena , Hamilton Stephanie A. , Frye Cynthia A. , Silberman Mark A. , Wenstrup Richard J. , Sandbach John F.
Published: October 2011

BACKGROUND:

This study assessed BRCA1 and BRCA2 mutation prevalence in an unselected cohort of patients with triple‐negative breast cancer (BC).

METHODS:

One hundred ninety‐nine patients were enrolled. Triple negativity was defined as <1% estrogen and progesterone staining by immunohistochemistry and HER‐2/neu not overexpressed by fluorescence in situ hybridization. Having given consent, patients had BRCA1 and BRCA2 full sequencing and large rearrangement analysis. Mutation prevalence was assessed among the triple‐negative BC patients and the subset of patients without a family history of breast/ovarian cancer. Independent pathological review was completed on 50 patients.

RESULTS:

Twenty‐one deleterious BRCA mutations were identified—13 in BRCA1 and 8 in BRCA2 (prevalence, 10.6%). In 153 patients (76.9%) without significant family history (first‐degree or second‐degree relatives with BC aged <50 years or ovarian cancer at any age), 8 (5.2%) mutations were found. By using prior National Comprehensive Cancer Network (NCCN) guidelines recommending testing for triple‐negative BC patients aged <45 years, 4 of 21 mutations (19%) would have been missed. Two of 21 mutations (10%) would have been missed using updated NCCN guidelines recommending testing for triple‐negative BC patients aged <60 years.

CONCLUSIONS:

The observed mutation rate was significantly higher (P = .0005) than expected based on previously established prevalence tables among patients unselected for pathology. BRCA1 mutation prevalence was lower, and BRCA2 mutation prevalence was higher, than previously described. Additional mutation carriers would have met new NCCN testing guidelines, underscoring the value of the updated criteria. Study data suggest that by increasing the age limit to 65 years, all carriers would have been identified. Cancer 2011;. © 2011 American Cancer Society.
Comparison of the use and results of sentinel lymph node biopsy in children and young adults with melanoma
Authors: Mu Euphemia , Lange Julie R. , Strouse John J.
Published: October 2011

BACKGROUND:

Data on sentinel lymph node (SLN) biopsy in children with melanoma are limited. In this study, the authors compared the factors associated with SLN biopsy use and metastases in pediatric and young adult patients with melanoma.

METHODS:

The 2008 Surveillance, Epidemiology, and End Results (SEER) databases were used to examine melanoma cases from 2003 to 2008. Data extracted include age, sex, race, stage, tumor thickness, ulceration, lymph node status, surgical treatment, and survival. Logistic regression models were used for adjusted analyses.

RESULTS:

In total, 717 children (age <20 years) and 1368 young adults (age 20‐24 years) were identified who were diagnosed with melanoma. Factors that were associated with SLN biopsy use included tumor ulceration (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.4‐4.3) and greater thickness (OR, 17; 95% CI, 12‐24 for >1 mm vs ≤1 mm), but not younger age (OR, 1.3; 95% CI, 0.94‐1.8) in adjusted analyses. SLN metastasis was correlated with ulceration (OR, 3.0; 95% CI, 1.6‐5.8), increased thickness (OR, 6.8; 95% CI, 3.1‐15 for 2.01‐4.0 mm vs ≤1 mm), and for the interaction between age <20 years and thickness 1.01 to 2.00 mm (OR, 6.5; 95% CI, 1.7‐25) in adjusted analyses. Children with nonulcerated melanomas that measured 1.01 to 2.00 mm in thickness were significantly more likely to have SLN metastases than young adults (24% vs 4%; P < .001).

CONCLUSIONS:

Thickness and ulceration were strong predictors of both the use of SLN biopsy and positive SLN biopsy results in children and young adults with melanoma. Compared with young adults, children were more likely to have SLN metastases despite having similar rates of SLN biopsy use. Cancer 2011;. © 2011 American Cancer Society.
The use of bevacizumab among women with metastatic breast cancer: A survey on clinical practice and the ongoing controversy
Authors: Dawood Shaheenah , Shaikh Asim Jamal , Buchholz Thomas A. , Cortes Javier , Cristofanilli Massimo , Gupta Sudeep , Gonzalez‐Angulo Ana M.
Published: October 2011

BACKGROUND:

The US Food and Drug Administration's (FDA's) recent decision to remove the indication of bevacizumab for metastatic breast cancer (MBC) has fueled a debate in the breast cancer community. We conducted a survey to assess the perception of health care workers involved in the management of women with MBC on the FDA's decision to ascertain how it will affect practice and to determine how bevacizumab is commonly used in the community for MBC.

METHODS:

E‐mails were sent out between September and November 2010 using a database of 3000 addresses maintained by the United Arab Emirates Cancer Congress. Individuals working for Roche or Genentech were excluded. The survey consisted of 22 questions that were divided into 3 parts addressing each participant's demographic profile, their opinion of the FDA's decision, and the typical use of bevacizumab in the community in the setting of MBC.

RESULTS:

A total of 564 participants were included in the final analysis, contributing to an 18.8% response rate. Of these participants, 14.6% were from the United States, 7.8% were from Canada, 31.1% were from Europe, 2.0% were from the United Arab Emirates, 11.1% were from Asia, and 33.3% were from other countries. The majority of participants believed progression‐free survival to be a surrogate for overall survival, that cost played a role in the FDA's decision, and that the decision would adversely affect the future of newer drugs currently being investigated for MBC. The majority of participants indicated that they would use bevacizumab for triple receptor–negative MBC (46.5%), would use it in a first‐line setting (44.7%), and would use it in combination with paclitaxel (51.9%).

CONCLUSION:

Our survey results highlight the discord between the opinion of community oncologists and the FDA's recent decision to withdraw the indication of bevacizumab for MBC. Cancer 2011;. © 2011 American Cancer Society.
Dried blood spots (DBS) for doping control analysis
Authors: Thomas Andreas , Geyer Hans , Guddat Sven , Schänzer Wilhelm , Thevis Mario
Published: October 2011

Whole blood sample collection on cellulose paper has a more than 30‐year‐long tradition, especially in neonatal screening. The sampling is minimally invasive, fast, discreet, and robust against manipulation.

The present approach highlights the potential to determine doping agents in dried blood spots (DBS) after extraction and subsequent analysis by liquid chromatography‐mass spectrometry (LC‐MS). The assay is focused on selected model compounds of which the circulating target concentration is of particular interest. Here, pre‐ or post‐competition testing with DBS allows probing for the conditions (i.e. presence or absence of relevant drugs) in the athlete's circulation during competition, which complements earlier approaches towards the identification of urinary indicators for the temporal application of substances prohibited in‐competition only.

Precise (< 20%), linear, and robust conditions with limits of detection in low ng/ml range were accomplished by means of LC coupled to high resolution/high accuracy mass spectrometry for the selected model compounds benzoylecgonine, cocaine, pseudoephedrine, amphetamine, salbutamol, and JWH‐018. Deuterium‐labelled internal standards were used to yield reliable quantitative results. In addition, the non‐targeted screening approach (positive/negative switching combined with tandem mass spectrometry (MS/MS) experiments) enables the retrospective qualitative data evaluation for a comprehensive selection of known and unknown substances as exemplarily shown by the extraction of 20 target compounds (corticosteroids, aromatase inhibitors, anabolic steroids, beta‐blockers, etc.) at 20 ng/ml.

The simple and fast nature of the assay allows for an easy implementation into existing procedures and will potentially enhance the effectiveness of testing by reducing costs and effort of pre‐analysis workload. Copyright © 2011 John Wiley & Sons, Ltd.
The Muenke syndrome mutation (FgfR3P244R) causes cranial base shortening associated with growth plate dysfunction and premature perichondrial ossification in murine basicranial synchondroses
Authors: Laurita Jason , Koyama Eiki , Chin Bianca , Taylor Jesse A. , Lakin Gregory E. , Hankenson Kurt D. , Bartlett Scott P. , Nah Hyun‐Duck
Published: October 2011

Muenke syndrome caused by the FGFR3P250R mutation is an autosomal dominant disorder mostly identified with coronal suture synostosis, but it also presents with other craniofacial phenotypes that include mild to moderate midface hypoplasia. The Muenke syndrome mutation is thought to dysregulate intramembranous ossification at the cranial suture without disturbing endochondral bone formation in the skull. We show in this study that knock‐in mice harboring the mutation responsible for the Muenke syndrome (FgfR3P244R) display postnatal shortening of the cranial base along with synchondrosis growth plate dysfunction characterized by loss of resting, proliferating and hypertrophic chondrocyte zones and decreased Ihh expression. Furthermore, premature conversion of resting chondrocytes along the perichondrium into prehypertrophic chondrocytes leads to perichondrial bony bridge formation, effectively terminating the postnatal growth of the cranial base. Thus, we conclude that the Muenke syndrome mutation disturbs endochondral and perichondrial ossification in the cranial base, explaining the midface hypoplasia in patients. Developmental Dynamics 240:2584–2596, 2011. © 2011 Wiley Periodicals, Inc.
Intratumor OX40 stimulation inhibits IRF1 expression and IL‐10 production by Treg cells while enhancing CD40L expression by effector memory T cells
Authors: Burocchi Alessia , Pittoni Paola , Gorzanelli Andrea , Colombo Mario P. , Piconese Silvia
Published: October 2011

Treg cells maintain the tumor microenvironment in an immunosuppressive state preventing an effective anti‐tumor immune response. A possible strategy to overcome Treg‐cell suppression focuses on OX40, a costimulatory molecule expressed constitutively by Treg cells while being induced in activated effector T cells. OX40 stimulation, by the agonist mAb OX86, inhibits Treg‐cell suppression and boosts effector T‐cell activation. Here we uncover the mechanisms underlying the therapeutic activity of OX86 treatment dissecting its distinct effects on Treg and on effector memory T (Tem) cells, the most abundant CD4+ populations strongly expressing OX40 at the tumor site. In response to OX86, tumor‐infiltrating Treg cells produced significantly less interleukin 10 (IL‐10), possibly in relation to a decrease in the transcription factor interferon regulatory factor 1 (IRF1). Tem cells responded to OX86 by upregulating surface CD40L expression, providing a licensing signal to DCs. The CD40L/CD40 axis was required for Tem‐cell‐mediated in vitro DC maturation and in vivo DC migration. Accordingly, OX86 treatment was no longer therapeutic in CD40 KO mice. In conclusion, following OX40 stimulation, blockade of Treg‐cell suppression and enhancement of the Tem‐cell adjuvant effect both concurred to free DCs from immunosuppression and activate the immune response against the tumor.