bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical investigation of monodisperse granular flow through an inclined rotating chute
Authors: Shirsath Sushil S. , Padding Johan T. , Kuipers J. A. M. (Hans) , Peeters Tim W. J. , Clercx Herman J. H.
Published: June 2014

A discrete element model of spherical glass particles flowing down a rotating chute is validated against high quality experimental data. The simulations are performed in a corotating frame of reference, taking into account Coriolis and centrifugal forces. In view of future extensions aimed at segregation studies of polydisperse granular flows, several validation steps are required. In particular, the influence of the interstitial gas, a sensitivity study of the collision parameters, and the effect of system rotation on particle flow is investigated. Shirsath et al. have provided the benchmark laboratory measurements of bed height and surface velocities of monodisperse granular flow down an inclined rotating chute. With a proper choice of the friction coefficients, the simulations show very good agreement with our experimental results. The effect of interstitial gas on the flow behavior is found to be relatively small for 3‐mm granular particles. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3424–3441, 2014
Hodgkin lymphoma: 2014 update on diagnosis, risk‐stratification, and management
Authors: Ansell Stephen M.
Published: June 2014

Disease overview: Hodgkin lymphoma (HL) is an uncommon B‐cell lymphoid malignancy affecting 9,200 new patients annually and representing approximately 11.5% of all lymphomas in the United States.

Diagnosis: HL is composed of two distinct disease entities; the more commonly diagnosed classical HL and the rare nodular lymphocyte‐predominant HL. Nodular sclerosis, mixed cellularity, lymphocyte depletion, and lymphocyte‐rich HL are subgroups under the designation of classical HL.

Risk stratification: An accurate assessment of the stage of disease in patients with HL is critical for the selection of the appropriate therapy. Prognostic models that identify patients at low or high risk for recurrence, as well as the response to therapy as determined by positron emission tomography scan, are used to optimize therapy.

Risk‐adapted therapy: Initial therapy for HL patients is based on the histology of the disease, the anatomical stage, and the presence of poor prognostic features. Patients with early stage disease are treated with combined modality strategies using abbreviated courses of combination chemotherapy followed by involved‐field radiation therapy, while those with advanced stage disease receive a longer course of chemotherapy often without radiation therapy.

Management of relapsed/refractory disease: High‐dose chemotherapy (HDCT) followed by an autologous stem cell transplant (ASCT) is the standard of care for most patients who relapse following initial therapy. For patients who fail HDCT with ASCT, brentuximab vedotin, palliative chemotherapy, nonmyeloablative allogeneic transplant, or participation in a clinical trial should be considered. Am. J. Hematol. 89:772–779, 2014. © 2014 Wiley Periodicals, Inc.
Biocatalyic synthesis of unusually photoluminescent oligomers and electrically conducting polymers of 4‐(3‐pyrrolyl)butyric acid
Authors: Bouldin Ryan M. , Kokil Akshay , Ponrathnam Timothy , Urban Nicholas , Kumar Jayant , Samuelson Lynne A. , Nagarajan Ramaswamy
Published: June 2014

Unusually photoluminescent undoped oligomers and doped electrically conducting polymers of 4‐(3‐Pyrrolyl)butyric acid have been enzymatically synthesized using the oxidoreductase soybean peroxidase as a catalyst. This biocatalytic approach provides a direct route to a fluorescent‐undoped oligomer of pyrrole that requires no protection/deprotection chemistry. The synthesis is carried out in aqueous media that requires only monomer, enzyme, and hydrogen peroxide. The undoped oligomer exhibits stable emission properties and is highly sensitive to the presence of environmentally important metal ions, such as Co(II), Hg(II), and Cu(II) in solution. Electrically conducting polymers can also be obtained by adding a dopant to a buffered reaction solution prior to initiating the polymerization. Polymers doped with camphor‐10‐sulfonic acid exhibit conductivity values as high as 10−2 S/cm. Additionally, polymers synthesized in the presence of a biobased cationic template, N,N,N‐trimethylchitosan chloride, exhibit conductivity values that are an order of magnitude greater than polymers synthesized with the anionic polymeric template, poly(styrene sulfonic acid)‐sodium salt. The biobased synthetic strategy described here is the first report of directly obtaining an undoped, fluorescent conjugated oligomer of a pyrrole in aqueous solution. Unlike conventional chemical catalysts, the enzyme does not dope the oligomer and therefore provides the opportunity to directly obtain fluorescent conjugated species. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41035.
Submerged friction stir weld of polyethylene sheets
Authors: Gao Jicheng , Shen Yifu , Zhang Jingqing , Xu Haisheng
Published: June 2014

The objective of this research work is to join polyethylene sheets using submerged friction stir welding by varying rotation speeds and traverse speeds. The effects of process parameters on macrostructure, microstructure, and mechanical property are investigated. The result indicates that the tensile strength increases at first and then decreases with the increase of rotation speed and traverse speed. The maximum tensile strength value of underwater welded joint is 12.3 MPa which is higher than normal weld joint. The microstructure of joint is investigated by using metallurgic microscope and laser scanning confocal microscope. The major microdefect of the interface is crack and air bubble. The result of differential scanning calorimetry which is used to measure the crystalline content of materials indirectly shows the crystalline content of parent material, heat affected zone, thermomechanically affected zone, and weld nugget approximate are 54.5%, 54.0% 51.1%, and 48.2%, respectively. The chief reasons of decrease in the tensile strength are formation of crack and air bubble and the decrease of crystalline content. The analysis of small angle X‐ray scattering indicates that the long period of weld regions decreases comparing parent material. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41059.
Performances of larch (larix gmelini) tannin modified urea–formaldehyde (TUF) resin and plywood bonded by TUF resin
Authors: Zhang Jizhi , Kang Haijiao , Gao Qiang , Li Jianzhang , Pizzi Antonio , Delmotte Luc
Published: June 2014

Tannin from larch (Larix gmelini) bark extracts, as a natural renewable resource, was used to prepare tannin–urea–formaldehyde (TUF) resin. The chemical structures of larch tannin and TUF resin were characterized by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry and 13C nuclear magnetic resonance. The thermal behaviors of TUF resin were evaluated by differential scanning calorimetry (DSC) and thermomechanical analysis (TMA). The performances of TUF resin were investigated by measuring the bond strength and formaldehyde emission of its bonded plywood. It was clearly shown that larch tannin is mainly composed of prodelphinidin repeating units. Phenolic groups were introduced into TUF resin mainly linked by methylene bond. Larch tannin has an adverse effect on the resin curing. However, it promoted the rigidity and flexibility of the glued system and upgraded the properties of plywood. Therefore, larch tannin could be applied in the modification of urea–formaldehyde resin. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41064.
Effect of solvents on morphology and polymorphism of polyvinylidene fluoride membrane via supercritical CO2 induced phase separation
Authors: Xiang Yanhui , Xue Lixin , Shen Jianhui , Lin Haibo , Liu Fu
Published: June 2014

Poly vinylidene fluoride (PVDF) membranes were prepared via supercritical CO2 induced phase separation. The effects of solvent power on PVDF membrane morphology and polymorphism were investigated using N‐N‐dimethylformamide (DMF), triethyl phosphate (TEP), and their mixture respectively. The morphology evolution including cross‐section and surfaces were thoroughly studied by scanning electron microscope (SEM) and atomic force microscopy (AFM). The differences of solubility parameters between the solvent and PVDF affected the phase separation and the resultant morphology. The various crystalline phases of the membranes were mainly investigated by Fourier transform infrared spectroscopy (FTIR) and X‐ray diffractometer (XRD). Solvent with larger dipole moment tended to form polar β phase. Decreasing the difference of solubility parameters favored the formation of α phase. Furthermore, the effects of salt additive on PVDF membrane morphology and crystalline form were studied as well. Results turned out that lithium chloride (LiCl) induced a porous top surface and boosted the formation of β phase. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41065.
Effects of quasi‐3D stacking architecture on interlaminar shear strength and void content of FRP
Authors: Zhang Xiaohui , Duan Yugang , Zhao Xinming , Li Dichen
Published: June 2014

To improve the interlaminar shear strength (ILSS) of composite laminate, three different quasi‐3D stacking architecture (q‐3DSA) laminates were fabricated by using automated fiber placement process and a traditional 2D stacking architecture (2DSA) laminate was fabricated as the control sample. The distribution of voids, the density, and the ILSS of four types of laminates were tested. The results indicated that the void content of the different q‐3DSA laminates was approximately 0.71%–3.07% greater than that of the 2DSA laminate, but the ILSS of q‐3DSA laminates was 5.49%–12.54% better than that of the 2DSA laminate. The microstructure images showed that the cracks spread along the interface between the adjacent layers in the 2DSA laminate, while the cracks cross two or more layers in the q‐3DSA laminates. This behavior indicated that the q‐3DSA improved the ILSS by dispersing the interlaminar load through the bended and interlaced tows in the laminate. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41076.
Synthesis and characterization of crosslinked chitosan immobilized on bentonite and its grafted products with polyaniline
Authors: El‐Dib Fawzia I. , Hussein Mohammed H. M. , Hefni Hassan H. H. , Eshaq Ghada , ElMetwally Ahmed E.
Published: June 2014

Chitosan immobilized bentonite (CIB) namely chitosan‐coated bentonite (5% chitosan content) was synthesized in 2% acetic acid solution, followed by crosslinking, using epichlorohydrien (ECH). The so‐obtained crosslinked chitosan immobilized on bentonite (CIB‐ECH) and CIB composites were grafted with polyaniline (PANI) through oxidative‐radical copolymerization using ammonium peroxydisulfate in acidic medium to produce PANI‐grafted crosslinked chitosan immobilized on bentonite (PANI‐g‐CIB‐ECH) and PANI‐grafted‐chitosan immobilized on bentonite (PANI‐g‐CIB) composites, respectively. The resultant composites were characterized by using X‐ray diffraction (XRD), thermo gravimetric analysis/differential scanning calorimetry, scanning electron microscopy, Fourier transform infrared (FTIR), and electrical conductivity. XRD and FTIR analyses indicate that chitosan was not intercalated into the silicate layer. Also the electrical conductivity elucidates that the grafted composites fall in the range required for the application as electrostatic dissipation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41078.
Regimes of microstructural evolution as observed from rheology and surface morphology of crosslinked poly(vinyl alcohol) and hyaluronic acid blends during gelation
Authors: Kodavaty Jagadeeshwar , Deshpande Abhijit P
Published: June 2014

Hyaluronic acid (HA)‐based materials are being investigated because of their role in biological fluids and tissues. Poly(vinyl alcohol) (PVA) when blended with HA at different compositions leads to superior mechanical properties compared to pure HA. The PVAHA blend hydrogels are potential candidates for pharmaceutical, biomedical, and cosmetic applications. It is essential to understand the structure, gelation time, and morphological properties of these hydrogels. In this work, a blend system of PVA crosslinked with glutaraldehyde in the presence of HA is studied. Semidilute solutions of PVA and HA are blended, followed by gelation due to crosslinking. The crosslinked gels as well as the gel cast membranes were examined. The effect of HA on the gelation process is investigated using rheological characterization. It is shown that kinetics of gelation is influenced by HA content, though storage modulus of the gels is influenced marginally. The structural features of PVAHA gels were also probed with scanning electron microscopy and dynamic light scattering. It is argued that there is a complex interplay between intra‐ and intermolecular crosslinking of PVA and PVA–HA interactions during the gel formation. Based on the insights obtained from various probing techniques for PVAHA gels with different HA content, three broad structural features were identified. It is shown that the hydrogel is semi‐interpenetrating network at lower HA content (<10% HA), cocontinuous morphology at moderate HA content and with domains at high HA content (>20% HA). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41081.
pH responsive polymers with amino acids in the side chains and their potential applications
Authors: Roy Saswati Ghosh , De Priyadarsi
Published: June 2014

Design and synthesis of pH responsive polymeric materials has become an important subject in academia as well as in industrial field in recent years due to their applications in diverse field including controlled drug delivery, biomedical applications, membrane science, sensors and actuators, oil recovery, colloid stabilization, etc. Efforts have been made to incorporate stimuli‐responsive biomolecules in synthetic polymers to develop pH responsive “smart” non‐biological hybrid macromolecules with high water solubility, enhanced biocompatibility, bio‐mimetic structure and properties. This review is focused on the recent advances in side‐chain amino acid‐based pH responsive polymers synthesis and potential application aspects of these macromolecular architectures in drug and gene delivery, and other fields. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41084.
Flame retardance and origin of bismaleimide resin composites with green and efficient aluminum phosphates
Authors: You Qiuqin , Yuan Li , Wang Hong , Liang Guozheng , Gu Aijuan
Published: June 2014

Developing green and high efficiency inorganic flame retardants is the trend of preparing flame retarding polymer composites. Aluminum phosphates (t‐hAP) with uniform, small dimension, and hexagonal structure were facilely synthesized, which have similar size (1–2 μm) but different structures from commercial spherical‐like aluminum phosphate (cAP). The flame retardance of bismaleimide (BD)/t‐hAP and BD/cAP composites were intensively investigated. t‐hAP is proved to have much better flame retarding effect than cAP, but also exhibits advantages over Mg(OH)2 and Al(OH)3. With only 5 wt % addition of t‐hAP into BD resin, the peak and total heat releases as well as total smoke production significantly reduce 42.3, 47.8, and 67.3%, respectively; besides, better data are obtained as the loading of t‐hAP increases to 10 wt %. These attractive data result from three effects induced by t‐hAP. Besides the better protection role of sheet structure, the strong hydrogen bonding between t‐hAP and BD resin endows the composite with good dispersion of t‐hAP and high crosslinking density; moreover, t‐hAP releases H2O and NH3, diluting flammable gases during combustion. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41089.
Effect of lignin removal on mechanical, thermal, and morphological properties of polylactide/starch/rice husk blend used in food packaging
Authors: Mohammadi‐Rovshandeh Jamshid , Pouresmaeel‐Selakjani Peyman , Davachi Seyed Mohammad , Kaffashi Babak , Hassani Atieh , Bahmeyi Alireza
Published: June 2014

The aim of this work was to investigate the possibility of using cost‐effective natural filler in a biodegradable polymer and find new set of materials for green biocomposites to be used in food packaging. In this regard, rice husk (RH) and bleached rice husk (BRH) have been used in the form of powder and the effect of lignin removal on mechanical and thermal properties of prepared composites with poly(l‐lactide) and starch were studied. Using FTIR technique, the lignin removal from RH has been approved. The tensile, charpy impact, and hardness tests were implemented to investigate the mechanical properties. It was concluded that filler caused increase both in the toughness and the Young modulus of samples. It was also found that the lack of lignin in BRH samples improves the mechanical properties. It was clearly observed that the BRH samples show larger modulus, charpy impact strength, and hardness compared to those filled with RH. Despite larger values for the elongations at break of RH samples, the mechanical properties showed a significant improvement (between 25 and 50% improvements) on lignin removal. The differential scanning calorimetry thermograms revealed an improvement in crystallization behavior and reduction of Tg from 47 to 31°C in the case of BRH‐filled samples. Finally, due to the removal of toxic lignin in the samples and modification of mechanical properties by this method, the BRH could have the ability of wide use in the bioplastics and food packaging industries. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41095.
Selective Tumor Necrosis Factor Receptor I Blockade Is Antiinflammatory and Reveals Immunoregulatory Role of Tumor Necrosis Factor Receptor II in Collagen‐Induced Arthritis
Authors: McCann Fiona E. , Perocheau Dany P. , Ruspi Gerhard , Blazek Katrina , Davies Marie L. , Feldmann Marc , Dean Jonathan L. E. , Stoop A. Allart , Williams Richard O.
Published: June 2014

Objective

Tumor necrosis factor (TNF) signals via 2 receptors, TNFR type I (TNFRI) and TNFRII, with distinct cellular distribution and signaling functions. In rheumatoid arthritis (RA), the net effect of TNFR signaling favors inflammatory responses while inhibiting the activity of regulatory T cells. TNFRII signaling has been shown to promote Treg cell function. To assess the relative contributions of TNFRI and TNFRII signaling to inflammatory and regulatory responses in vivo, we compared the effect of TNF blockade, hence TNFRI/II, versus TNFRI alone in collagen‐induced arthritis (CIA) as a model of RA.

Methods

Mice with established arthritis were treated for 10 days with anti‐mouse TNFRI domain antibody (dAb; DMS5540), an isotype control dAb (DMS5538), or murine TNFRII genetically fused with mouse IgG1 Fc domain (mTNFRII‐Fc) beginning on the day of arthritis onset, and disease progression was monitored. Systemic cytokine concentrations and numbers of T cell subsets in lymph nodes and spleens were measured, and intrinsic Treg cell function was determined by ex vivo suppression assays.

Results

Progression of CIA was suppressed similarly by TNFRI (DMS5540) and TNFRI/II (mTNFRII‐Fc) blockade. However, blockade of TNFRI/II led to increased effector T cell activity, which was not observed after selective TNFRI blockade, suggesting an immunoregulatory role of TNFRII. In support of this, TNFRI blockade, but not TNFRI/II blockade, expanded and activated Treg cells. Furthermore, a dramatic increase in expression of the Treg cell signature genes FoxP3 and TNFRII was observed in joints undergoing remission, which supports the notion that these molecules have a physiologic role in the resolution of inflammation.

Conclusion

We propose that a therapeutic strategy that targets TNFRI while sparing TNFRII has the potential to both inhibit inflammation and promote Treg cell activity, which might be superior to TNF blockade.
Magnetic Coupling Constants of Self‐Assembled CuII [3×3] Grids: Alternative Spin Model from Theoretical Calculations
Authors: Calzado Carmen J. , Ben Amor Nadia , Maynau Daniel
Published: June 2014

This paper reports a theoretical analysis of the electronic structure and magnetic properties of a ferromagnetic CuII [3×3] grid. A two‐step strategy, combining calculations on the whole grid and on binuclear fragments, has been employed to evaluate all the magnetic interactions in the grid. The calculations confirm an S=7/2 ground state, which is in accordance with the magnetisation versus field curve and the thermal dependence of the magnetic moment data. Only the first‐neighbour coupling terms present non‐negligible amplitudes, all of them in agreement with the structure and arrangement of the Cu 3d magnetic orbitals. The results indicate that the dominant interaction in the system is the antiferromagnetic coupling between the ring and the central Cu sites (J3=J4≈−31 cm−1). In the ring two different interactions can be distinguished, J1=4.6 cm−1 and J2=−0.1 cm−1, in contrast to the single J model employed in the magnetic data fit. The calculated J values have been used to determine the energy level distribution of the Heisenberg magnetic states. The effective magnetic moment versus temperature plot resulting from this ab initio energy profile is in good agreement with the experimental curve and the fitting obtained with the simplified spin model, despite the differences between these two spin models. This study underlines the role that the theoretical evaluations of the coupling constants can play on the rationalisation of the magnetic properties of these complex polynuclear systems.
Antiaromaticity to Aromaticity: From Boroles to 1,2‐Azaborinines by Ring Expansion with Azides
Authors: Braunschweig Holger , Hörl Christian , Mailänder Lisa , Radacki Krzysztof , Wahler Johannes
Published: June 2014

We have exploited the reactivity of antiaromatic boroles, gaining access to aryl‐substituted monocyclic 1,2‐azaborinines. The observed ring‐expansion reaction of inherently electron‐deficient boroles with organometallic and organic azides is demonstrated for representative examples. This substance class is expected to provide a new avenue into 1,2‐azaborinine chemistry, especially in the area of functional organoboron materials. Our results are based on NMR and UV/Vis spectroscopy as well as single‐crystal X‐ray crystallography and provide a virtually quantitative approach that also offers numerous points of variation.
Nickel‐Catalyzed Site‐Selective Amidation of Unactivated C(sp3)H Bonds
Authors: Wu Xuesong , Zhao Yan , Ge Haibo
Published: June 2014

Intramolecular dehydrogenative cyclization of aliphatic amides was achieved on unactivated sp3 carbon atoms by a nickel‐catalyzed CH bond functionalization process with the assistance of a bidentate directing group. The reaction favors the CH bonds of β‐methyl groups over the γ‐methyl or β‐methylene groups. Additionally, a predominant preference for the β‐methyl CH bonds over the aromatic sp2 CH bonds was observed. Moreover, this process also allows for the effective functionalization of benzylic secondary sp3 CH bonds.
Review of Mixed‐Integer Nonlinear and Generalized Disjunctive Programming Methods
Authors: Trespalacios Francisco , Grossmann Ignacio E.
Published: June 2014

This work presents a review of the main deterministic mixed‐integer nonlinear programming (MINLP) solution methods for problems with convex and nonconvex functions. An overview for deriving MINLP formulations through generalized disjunctive programming (GDP), which is an alternative higher‐level representation of MINLP problems, is also presented. A review of solution methods for GDP problems is provided. Some relevant applications of MINLP and GDP in process systems engineering are described in this work.
Deposition of heavy oil droplets onto a circular disk at elevated temperatures
Authors: Song Jianfei , Watkinson Paul , Taghipour Fariborz , Posarac Dusko , Petkovic Bojan
Published: June 2014

Fouling of equipment surfaces affects the efficient processing of heavy hydrocarbons. An experimental study is reported on the deposition of bitumen‐containing droplets from a gas‐vapour mixture at temperatures up to incipient coking conditions. A heavy oil‐diluent feed mixture was atomized with nitrogen in a vertical spray chamber, and flowed upwards normal to a circular disk. The disk was attached to a load cell to measure total deposited mass with time, and at the end of each experiment the amount deposited was determined gravimetrically. The effects on deposition rate of heavy oil concentration in the feed mixture, temperature, and flow‐rates of feed mixture and nitrogen were determined. Different surfaces and coatings were tested. The deposition rate was found to depend most strongly on the droplet concentration, which was predicted with HYSYS, using an isothermal flash calculation. As temperature was increased, deposit H/C atomic ratio decreased and ash content increased.
Study on the Spatial Variation of the Geoelectric Field Signals Recorded at the Stations in the Eastern Huabei Area in China When a Heavy Current is Injected
Authors: Qin‐Zhong MA , Wi LI , Ji‐Hong ZHANG , Yu‐Gui GUO , Guo‐Qing FANG
Published: June 2014

In the study of seismo‐electromagnetics, the relation between the flowing characteristics of electric current and the geological structure is a very important problem. The distribution of many geoelectric field stations and heavy current inflow into the underground offer us a golden opportunity to study the scientific problem. In this paper, by studying the signals originated from grounding electrode 2100∼3004 A current of Qingdao converter station and recorded at twenty one geoelectric field stations in the east Huabei area in China, we could have a better understanding of the variation of the geoelectric field. The study shows that (1) the telluric current signals present extremely big variation along the directions of the Tan‐Lu fault and the southwest beyond the fault zone as well as the northwest of it, where current signal could be recorded, and there are obvious directionality feature and the phenomenon of sensitive site; (2) the larger the current intensity of the source is, the higher the signal strength recorded at observatory stations is. When the current intensity of the source changed from 2100 A to 3004 A the increase rate of the signals recorded on the long electrode is different from that on short electrode at many stations; (3) the uniformity degree of the geoelectric field in the area does not follow the regular patterns of homogeneous medium, which illustrates that the characteristics of inhomogeneous medium and anisotropy are obvious at many stations in the area; (4) there are few stations that could be used to determine the direction of the source, but the azimuth obtained at Anqiu, Dashan and Xinyi stations could be used to locate the source site when a large current was injected. Considering the influence of the three factors, i.e., the device system consisting of a point source and the electrode distribution of a station, the heterogeneity of medium in a large area, as well as the fine structure of the medium underground at a station, this paper has made a deep analysis and explanation of the characteristics mentioned above by numerical simulation.
Distribution and innervation of putative arterial chemoreceptors in the bullfrog (Rana catesbeiana)
Authors: Reyes Catalina , Fong Angelina Y. , Brink Dee L. , Milsom William K.
Published: June 2014

Peripheral arterial chemoreceptors have been located previously in the carotid labyrinth, the aortic arch, and the pulmocutaneous artery of frogs. In the present study we used cholera toxin B neuronal tract tracing and immunohistochemical markers for cholinergic cells (vesicular acetylcholine transporter [VAChT]), tyrosine hydroxylase (TH), and serotonin (5HT) to identify putative O2‐sensing cells in Rana catesbeiana. We found potential O2‐sensing cells in all three vascular areas innervated by branches of the vagus nerve, whereas only cells in the carotid labyrinth were innervated by the glossopharyngeal nerve. Cells containing either 5HT or TH were found in all three sites, whereas cells containing both neurotransmitters were found only in the carotid labyrinth. Cell bodies containing VAChT were not found at any site. The morphology and innervation of putative O2‐sensing cells were similar to those of glomus cells found in other vertebrates. The presence of 5HT‐ and TH‐immunoreactive cells in the aorta, pulmocutaneous artery, and carotid labyrinth appears to reflect a phylogenetic transition between the major neurotransmitter seen in the putative O2‐sensing cells of fish (5HT) and those found in the glomus cells of mammals (acetylcholine, adenosine, and catecholamines). J. Comp. Neurol. 522:3754–3774, 2014. © 2014 Wiley Periodicals, Inc.
Cytomorphologic findings of intraosseous notochordal rest on touch preparation: A case report
Authors: Bovbel Alexandra , Zaheer Atif , Maleki Zahra
Published: June 2014

Intraosseous notochordal rest is a rare intravertebral lesion of notochord origin which is presumably benign. It is usually an incidental finding in microscopic examination of vertebrectomy due to unrelated lesions or autopsy cases. Chordoma is a malignant neoplasm originating from notochord with a different clinicoradiographic presentation, prognosis, and treatment. However, the histology of intraosseous notochordal rest and chordoma is almost identical. Herein, we report cytomorphologic findings of a case of intraossous notochordal rest on touch preparation. Diagn. Cytopathol. 2015;43:243–246. © 2014 Wiley Periodicals, Inc.
Fine‐needle aspiration cytology of type A thymoma with adenoid cystic pattern: A case report with emphasis on peculiar hyaline globules in cytologic smear
Authors: Hang Jen‐Fan , Hsu Chih‐Yi , Lai Chung‐Ru
Published: June 2014

Here we report a case of type A thymoma with adenoid cystic pattern, which extended to the lower anterior neck and clinically mimicked a nontoxic thyroid goiter. The cytologic smears of fine‐needle aspiration showed cohesive fragments of short spindle cells with finely granular chromatin and inconspicuous nucleoli. Scant interspersed lymphocytes were present. On air‐dried Liu stained preparation, there were many magenta‐colored hyaline globules wrapped by spindle tumor cells. The cytomorphologic findings correlated with the adenoid cystic pattern in histology. The cytologic differential diagnosis and the prognostic aspects of type A thymoma were briefly discussed. Diagn. Cytopathol. 2015;43:247–250. © 2014 Wiley Periodicals, Inc.
Long‐term decrease in satellite vegetation indices in response to environmental variables in an iconic desert riparian ecosystem: the Upper San Pedro, Arizona, United States
Authors: Nguyen Uyen , Glenn Edward P. , Nagler Pamela L. , Scott Russell L.
Published: June 2014

The Upper San Pedro River is one of the few remaining undammed rivers that maintain a vibrant riparian ecosystem in the southwest United States. However, its riparian forest is threatened by diminishing groundwater and surface water inputs, due to either changes in watershed characteristics such as changes in riparian and upland vegetation, or human activities such as regional groundwater pumping. We used satellite vegetation indices to quantify the green leaf density of the groundwater‐dependent riparian forest from 1984 to 2012. The river was divided into a southern, upstream (mainly perennial flow) reach and a northern, downstream (mainly intermittent and ephemeral flow) reach. Pre‐monsoon (June) Landsat normalized difference vegetation index (NDVI) values showed a 20% drop for the northern reach (P < 0·001) and no net change for the southern reach (P > 0·05). NDVI and enhanced vegetation index values were positively correlated (P < 0·05) with river flows, which decreased over the study period in the northern reach, and negatively correlated (P < 0·05) with air temperatures in both reaches, which have increased by 1·4 °C from 1932 to 2012. NDVI in the uplands around the river did not increase from 1984 to 2012, suggesting that increased evapotranspiration in the uplands was not a factor in reducing river flows. Climate change, regional groundwater pumping, changes in the intensity of monsoon rain events and lack of overbank flooding are feasible explanations for deterioration of the riparian forest in the northern reach. Copyright © 2014 John Wiley & Sons, Ltd.
A nodal Godunov method for Lagrangian shock hydrodynamics on unstructured tetrahedral grids
Authors: Waltz J. , Morgan N. R. , Canfield T. R. , Charest M. R. J. , Wohlbier J. G.
Published: June 2014

We present a nodal Godunov method for Lagrangian shock hydrodynamics. The method is designed to operate on three‐dimensional unstructured grids composed of tetrahedral cells. A node‐centered finite element formulation avoids mesh stiffness, and an approximate Riemann solver in the fluid reference frame ensures a stable, upwind formulation. This choice leads to a non‐zero mass flux between control volumes, even though the mesh moves at the fluid velocity, but eliminates volume errors that arise due to the difference between the fluid velocity and the contact wave speed. A monotone piecewise linear reconstruction of primitive variables is used to compute interface unknowns and recover second‐order accuracy. The scheme has been tested on a variety of standard test problems and exhibits first‐order accuracy on shock problems and second‐order accuracy on smooth flows using meshes of up to O(106) tetrahedra. Copyright © 2014 John Wiley & Sons, Ltd.
Growth and differentiation factor 10 (Gdf10) is involved in Bergmann glial cell development under Shh regulation
Authors: Mecklenburg Nora , Martinez‐Lopez Jesus E. , Moreno‐Bravo Juan Antonio , Perez‐Balaguer Ariadna , Puelles Eduardo , Martinez Salvador
Published: June 2014

Growth differentiation factor 10 (Gdf10), also known as Bmp3b, is a member of the transforming growth factor (TGF)‐ß superfamily. Gdf10 is expressed in Bergmann glial cells, which was investigated by single‐cell transcriptional profiling (Koirala and Corfas, (2010) PLoS ONE 5: e9198). Here we provide a detailed characterization of Gdf10 expression from E14, the stage at which Gdf10 is expressed for the first time in the cerebellum, until P28. We detected Gdf10 expression in both germinal zones: in the ventricular zone (VZ) of the 4th ventricle as well as in the rhombic lip (RL). The VZ has been postulated to give rise to GABAergic neurons and glial cells, whereas the RL gives rise to glutamatergic neurons. Thus, it was very surprising to discover a gene that is expressed exclusively in glial cells and is not restricted to an expression in the VZ, but is also present in the RL. At postnatal stages Gdf10 was distributed equally in Bergmann glial cells of the cerebellum. Furthermore, we found Gdf10 to be regulated by Sonic hedgehog (Shh), which is secreted by Purkinje cells of the cerebellum. In the conditional Shh mutants, glial cells showed a reduced expression of Gdf10, whereas the expression of Nestin and Vimentin was unchanged. Thus, we show for the first time, that Gdf10, expressed in Bergmann glial cells, is affected by the loss of Shh as early as E18.5, suggesting a regulation of glial development by Shh. GLIA 2014;62:1713–1723
Apathy as a feature of prodromal Alzheimer's disease: an FDG‐PET ADNI study
Authors: Delrieu Julien , Desmidt Thomas , Camus Vincent , Sourdet Sandrine , Boutoleau‐Bretonnière Claire , Mullin Emmanuel , Vellas Bruno , Payoux Pierre , Lebouvier Thibaud ,   Alzheimer's Disease Neuroimaging Initiative
Published: June 2014

Objective

The goal of this study is to evaluate brain metabolism in mild cognitive impairment (MCI) patients with and without apathy (as determined by the Neuropsychiatric Inventory Questionnaire).

Methods

Baseline data from 65 MCI participants (11 with apathy and 54 without) from the Alzheimer's Disease (AD) Neuroimaging Initiative study were analyzed. All participants underwent a comprehensive cognitive and neuropsychiatric assessment, volumetric MRI and measures of cerebral glucose metabolism applying 18F‐fluorodeoxyglucose positron emission tomography at baseline. The presence of apathy at baseline was determined by the Neuropsychiatric Inventory Questionnaire.

Results

There was no difference between apathy and apathy‐free MCI patients regarding cognitive assessment and neuropsychiatric measures when apathy‐specific items were removed. Cerebrovascular disease load and cerebral atrophy were equivalent in both groups. Compared with the apathy‐free MCI patients, MCI patients with apathy had significantly decreased metabolism in the posterior cingulate cortex.

Conclusion

The presence of apathy in MCI patients is associated with AD‐specific pattern of brain metabolic defect. These results could suggest that apathy belongs to the spectrum of prodromal AD symptoms. Copyright © 2014 John Wiley & Sons, Ltd.
Peroxisome proliferator activated receptor gamma loaded dental implant improves osteogenesis of rat mandible
Authors: Bhattarai Govinda , Lee Young‐Hee , Yi Ho‐Keun
Published: June 2014

Peroxisome proliferator activated receptor gamma (PPARγ) has been known for their anti‐inflammatory effects. But the application of this molecule in implant‐induced inflammation has not been clearly studied yet. Here, we determined in vivo anti‐inflammatory and osteogenic effects of PPARγ coated dental implant in the rat mandible. We used chitosan gold nanoparticles (Ch‐GNPs) as a non viral vector to carry PPARγ plasmid DNA. Ch‐GNPs were conjugated with PPARγ plasmid DNA through a coacervation process. Conjugation was cast over titanium (Ti) implants (4.5 × 0.8 mm) by dipping, and implants were installed in rat mandibles. One, 2, 3, and 6 weeks post‐implantation, mandibles were examined by microcomputed tomography (µCT), immunohistochemistry, hematoxylin & eosin, and tartrate resistance acid phosphatase (TRAP) staining. In vivo Ch‐GNPs/PPARγcoated implants were associated with inhibition of implant induced inflammatory molecules interleukin‐1β and receptor activator of nuclear factor kappa‐B ligand and enhanced expression of osteogenic molecules like bone morphogenetic protein 2 and 7 (BMP‐2/‐7) by up‐regulating anti‐oxidant molecules heme oxygenase‐1. µCT demonstrated that PPARγ overexpression increased the density and volume of newly formed bone surrounding the implants compared to control (n = 4; p < 0.05). Also, PPARγ reduced the number of TRAP positive cells. These results support the view that PPARγ overexpression diminishes inflammation and enhances osteogenesis around the dental implants. Thus, implant coated with anti‐inflammatory molecules could have a significant utilization for the preparation of new biomaterials and may serve as prosthetic materials in patients suffering from inflammatory bone disease. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 587–595, 2015.
Influence of oxidative nanopatterning and anodization on the fatigue resistance of commercially pure titanium and Ti–6Al–4V
Authors: Ketabchi Amirhossein , Weck Arnaud , Variola Fabio
Published: June 2014

With an increasingly aging population, a significant challenge in implantology is the creation of biomaterials that actively promote tissue integration and offer excellent mechanical properties. Engineered surfaces with micro‐ and nanoscale topographies have shown great potential to control and direct biomaterial–host tissue interactions. Two simple yet efficient chemical treatments, oxidative nanopatterning and anodization, have demonstrated the ability to confer exciting new bioactive capacities to commercially pure titanium and Ti–6Al–4V alloy. However, the resulting nanoporous and nanotubular surfaces require careful assessment in regard to potential adverse effects on the fatigue resistance, a factor which may ultimately cause premature failure of biomedical implants. In this work, we have investigated the impact of oxidative nanopatterning and anodization on the fatigue resistance of commercially pure titanium and Ti–6Al–4V. Quantitative (e.g., S‐N curves) and qualitative analyses were carried out to precisely characterize the fatigue response of treated metals and compare it to that of polished controls. Scanning electron microscopy (SEM) imaging revealed the effects of cyclic loading on the fracture surface and on the structural integrity of chemically grown nanostructured oxides. Results from this study reinforce the importance of mechanical considerations in the development and optimization of micro‐ and nanoscale surface treatments for metallic biomedical implants. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B:563–571, 2015.
Physicochemical properties and in vitro mineralization of porous polymethylmethacrylate cement loaded with calcium phosphate particles
Authors: Sa Yue , Yang Fang , Leeuwenburgh Sander C. G. , Wolke Joop G. C. , Ye Guang , de Wijn Joost R. , Jansen John A. , Wang Yining
Published: June 2014

The main goal of this study was to evaluate the effects of incorporation of calcium phosphate (CaP) particles on the physicochemical properties and mineralization capacity of cements in vitro. Herein, two different types of CaP particles were loaded into polymethylmethacrylate (PMMA) cements exhibiting an interconnected porosity created by mixing with carboxymethylcellulose. The incorporation of CaP particles did not influence the maximum polymerization temperature of the porous PMMA, but reduced the porosity and the average pore size. Small CaP particles formed agglomerations within the PMMA pores, whereas big CaP particles were partially embedded in the PMMA matrix and partially exposed to the pores. Both types of CaP particles enhanced the mineralization capacity of PMMA cement without compromising their mechanical properties. The data presented herein suggest that porous PMMA/CaP cements hold strong promise for surgical application in bone reconstruction. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 548–555, 2015.
Degradation behavior of biodegradable Fe35Mn alloy stents
Authors: Sing N. B. , Mostavan A. , Hamzah E. , Mantovani D. , Hermawan H.
Published: June 2014

This article reports a degradation study that was done on stent prototypes made of biodegradable Fe35Mn alloy in a simulated human coronary arterial condition. The stent degradation was observed for a short‐term period from 0.5 to 168 h, which simulates the early period of stenting procedure. Potentiodynamic polarization and electrochemical impedance spectroscopy were used to quantify degradation rate and surface property of the stents. Results showed that signs of degradation were visible on both crimped and expanded stents after 1 h of test, mostly located on the stent's curvatures. The degradation rate of stent was higher compared to that of the original alloy, indicating the surface altering effect of stent fabrication processing to degradation. A single oxide layer was formed and detected as a porous structure with capacitive behavior. Expanded stents exhibited lower polarization resistance compared to the nonexpanded ones, indicating the cold work effect of expansion procedure to degradation. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 572–577, 2015.
Prospects on clinical applications of electrical stimulation for nerve regeneration
Authors: Sisken Betty F. , Walker Janet , Orgel Michael
Published: June 2014

Regenerative capability is limited in higher vertebrates but present in organ systems such as skin, liver, bone, and to some extent, the nervous system. Peripheral nerves in particular have a relatively high potential for regeneration following injury. However, delay in regrowth or growth, blockage, or misdirection at the injury site, and growth to inappropriate end organs may compromise successful regeneration, leading to poor clinical results. Recent studies indicate that low‐intensity electrical stimulation is equivalent to various growth factors, offering avenues to improve these outcomes. We present a review of studies using electric and electromagnetic fields that provide evidence for the enhancement of regeneration following nerve injury.

Electric and electromagnetic fields (EMFs) have been used to heal fracture non‐unions. This technology emerged as a consequence of basic studies [Yasuda, 1953; Fukada and Yasuda, 1957] demonstrating the piezoelectric properties of (dry) bone. The principle for using electrical stimulation for bone healing originated from the work of Bassett and Becker [1962], who described asymmetric voltage waveforms from mechanically deformed live bone. These changes were presumed to occur in bone during normal physical activity as a result of mechanical forces, and it was postulated that these forces were linked to modifications in bone structure. Endogenous currents present in normal tissue and those that occur after injury were proposed to modify bone structure [Bassett, 1989]. These investigators proposed that tissue integrity and function could be restored by applying electrical and/or mechanical energy to the area of injury. They successfully applied electrical currents to nonhealing fractures (using surgically implanted electrodes or pulsed currents using surface electrodes) to aid endogenous currents in the healing process.

A considerable technological improvement was made with the noninvasive application of EMFs [Bassett et al., 1974] to accelerate fracture repair. This newer technique allowed the treatment of hard tissues without the complications of invasive electrode insertion. In addition, soft tissue injuries were now accessible for treatment by electromagnetic fields.

In this article, we will first define the basic problems encountered in nerve injury and regeneration, and then review both in vitro and in vivo studies on the use of electric and electromagnetic fields to stimulate the healing process.
Electroporation: A general phenomenon for manipulating cells and tissues
Authors: Weaver James C.
Published: June 2014

Electroporation is a fascinating cell membrane phenomenon with several existing biological applications and others likely. Although DNA introduction is the most common use, electroporation of isolated cells has also been used for (1) introduction of enzymes, antibodies, and other biochemical reagents for intracellular assays; (2) selective biochemical loading of one size cell in the presence of many smaller cells; (3) introduction of virus and other particles; (4) cell killing under nontoxic conditions; and (5) insertion of membrane macromolecules into the cell membrane. More recently, tissue electroporation has begun to be explored, with potential applications including (1) enhanced cancer tumor chemotherapy, (2) gene therapy, (3) transdermal drug delivery, and (4) noninvasive sampling for biochemical measurement. As presently understood, electroporation is an essentially universal membrane phenomenon that occurs in cell and artificial planar bilayer membranes. For short pulses (μs to ms), electroporation occurs if the transmembrane voltage, U(t), reaches 0.5–1.5 V. In the case of isolated cells, the pulse magnitude is 103–104 V/cm. These pulses cause reversible electrical breakdown (REB), accompanied by a tremendous increase molecular transport across the membrane. REB results in a rapid membrane discharge, with the elevated U(t) returning to low values within a few microseconds of the pulse. However, membrane recovery can be orders of magnitude slower. An associated cell stress commonly occurs, probably because of chemical influxes and effluxes leading to chemical imbalances, which also contribute to eventual survival or death. Basic phenomena, present understanding of mechanism, and the existing and potential applications are briefly reviewed.