bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation and propagation of neural stem cells in caprine (Capra hircus)
Authors: Agarwal Pranjali , Kumar Manish , Kumar Kuldeep , Singh Renu , Mahapatra Puspendra Saswat , Kumar Ajay , Bhure Sanjeev Kumar , Malakar Dhruba , Sarkar Mihir , Bag Sadhan
Published: March 2014

Neural stem cells (NSCs) can self‐renew and give rise to neurons, astrocytes and oligodendrocytes; they are found in the nervous system of mammalian organisms, representing a promising resource for both fundamental research and therapeutics. There have been few investigations on NSCs in the livestock species. Therefore, we have successfully isolated and characterised NSCs from the foetal brain of a small domestic animal, the goat (called GNSCs). These cells from the foetal brain showed self‐renewal, rapid proliferation with a population doubling time of 88 h, were morphologically homogeneous and maintained normal chromosome throughout the culture period. The cells expressed NSC‐specific markers (Sox2, Pax6 and Mushashi), but were negative for CD34 and CD45. They were capable of multi‐differentiation into neurons, astrocytes, oligodendrocytes, as well as adipocytes and osteocytes. The availability of such cells may hold great interest for basic and applied neuroscience.
Selection and demographic history shape the molecular evolution of the gamete compatibility protein bindin in Pisaster sea stars
Authors: Popovic Iva , Marko Peter B. , Wares John P. , Hart Michael W.
Published: March 2014

Reproductive compatibility proteins have been shown to evolve rapidly under positive selection leading to reproductive isolation, despite the potential homogenizing effects of gene flow. This process has been implicated in both primary divergence among conspecific populations and reinforcement during secondary contact; however, these two selective regimes can be difficult to discriminate from each other. Here, we describe the gene that encodes the gamete compatibility protein bindin for three sea star species in the genus Pisaster. First, we compare the full‐length bindin‐coding sequence among all three species and analyze the evolutionary relationships between the repetitive domains of the variable second bindin exon. The comparison suggests that concerted evolution of repetitive domains has an effect on bindin divergence among species and bindin variation within species. Second, we characterize population variation in the second bindin exon of two species: We show that positive selection acts on bindin variation in Pisaster ochraceus but not in Pisaster brevispinus, which is consistent with higher polyspermy risk in P. ochraceus. Third, we show that there is no significant genetic differentiation among populations and no apparent effect of sympatry with congeners that would suggest selection based on reinforcement. Fourth, we combine bindin and cytochrome c oxidase 1 data in isolation‐with‐migration models to estimate gene flow parameter values and explore the historical demographic context of our positive selection results. Our findings suggest that positive selection on bindin divergence among P. ochraceus alleles can be accounted for in part by relatively recent northward population expansions that may be coupled with the potential homogenizing effects of concerted evolution.
1,2,3‐Triazole in Heterocyclic Compounds, Endowed with Biological Activity, through 1,3‐Dipolar Cycloadditions
Authors: Lauria Antonino , Delisi Riccardo , Mingoia Francesco , Terenzi Alessio , Martorana Annamaria , Barone Giampaolo , Almerico Anna Maria
Published: March 2014

1,3‐Dipolar cycloaddition reactions can be considered a powerful synthetic tool in the building of heterocyclic rings, with applications in different fields. In this review we focus on the synthesis of biologically active compounds possessing the 1,2,3‐triazole core through 1,3‐dipolar cycloaddition reactions. The 1,2,3‐triazole skeleton can be present as a single disubstituted ring, as a linker between two molecules, or embedded in a polyheterocycle. The cycloaddition reactions are usually catalysed by copper or ruthenium. Domino reactions can be achieved through dipolarophile anion formation, generally followed by cyclisation. The variety of attainable heterocyclic structures gives an illustration of the importance of the 1,2,3‐triazole core in medicinal chemistry.
Brain networks disconnection in early multiple sclerosis cognitive deficits: An anatomofunctional study
Authors: Louapre Céline , Perlbarg Vincent , García‐Lorenzo Daniel , Urbanski Marika , Benali Habib , Assouad Rana , Galanaud Damien , Freeman Léorah , Bodini Benedetta , Papeix Caroline , Tourbah Ayman , Lubetzki Catherine , Lehéricy Stéphane , Stankoff Bruno
Published: March 2014

Severe cognitive impairment involving multiple cognitive domains can occur early during the course of multiple sclerosis (MS). We investigated resting state functional connectivity changes in large‐scale brain networks and related structural damage underlying cognitive dysfunction in patients with early MS. Patients with relapsing MS (3–5 years disease duration) were prospectively assigned to two groups based on a standardized neuropsychological evaluation: (1) cognitively impaired group (CI group, n = 15), with abnormal performances in at least 3 tests; (2) cognitively preserved group (CP group, n = 20) with normal performances in all tests. Patients and age‐matched healthy controls underwent a multimodal 3T magnetic resonance imaging (MRI) including anatomical T1 and T2 images, diffusion imaging and resting state functional MRI. Structural MRI analysis revealed that CI patients had a higher white matter lesion load compared to CP and a more severe atrophy in gray matter regions highly connected to networks involved in cognition. Functional connectivity measured by integration was increased in CP patients versus controls in attentional networks (ATT), while integration was decreased in CI patients compared to CP both in the default mode network (DMN) and ATT. An anatomofunctional study within the DMN revealed that functional connectivity was mostly altered between the medial prefrontal cortex (MPFC) and the posterior cingulate cortex (PCC) in CI patients compared to CP and controls. In a multilinear regression model, functional correlation between MPFC and PCC was best predicted by PCC atrophy. Disconnection in the DMN and ATT networks may deprive the brain of compensatory mechanisms required to face widespread structural damage. Hum Brain Mapp 35:4706–4717, 2014. © 2014 Wiley Periodicals, Inc.
The Acquisition of Academic Literacy in the Eyes of a Chinese Graduate Student
Authors: Sun Lina
Published: March 2014

This column features essays written by current middle school and high school teachers, media specialists, librarians, literacy coaches, curriculum specialists, administrators, preservice teachers, teacher educators, and adolescent and adult learners. They highlight diverse perspectives on teaching and/or learning with literacies to inspire reader reflection.
Print‐Based Texts
Authors: Blasingame James
Published: March 2014

This column provides reviews of adolescent and adult literature and provides a valuable resource for literature selection in‐ and outside the classroom.
Scaffolding High School Students’ Reading of Complex Texts Using Linked Text Sets
Authors: Elish‐Piper Laurie , Wold Linda S. , Schwingendorf Kathy
Published: March 2014

Linked text sets (LTS) offer a promising approach to bring together adolescent students and complex texts, such as those required by the Common Core State Standards, using strategic scaffolding. LTS include a variety of print and media texts that address a guiding question that is meaningful to students such as, “Why is growing up so difficult?” The LTS approach is organized around three phases: Engagement, Exploration, and Expansion. As students progress through the phases, they are able to build their interest, background knowledge, and strategies so they will be ready to read target complex texts. This manuscript illustrates LTS in action in a tenth grade ELA class using a wide variety of print and media texts including the adolescent novel, Staying Fat for Sarah Byrnes and the canonical novel, To Kill a Mockingbird as target complex texts.
Hydrothermal fabrication of hydroxyapatite/chitosan/carbon porous scaffolds for bone tissue engineering
Authors: Long Teng , Liu Yu‐Tai , Tang Sha , Sun Jin‐Liang , Guo Ya‐Ping , Zhu Zhen‐An
Published: March 2014

Porous carbon fiber felts (PCFFs) have great applications in orthopedic surgery because of the strong mechanical strength, low density, high stability, and porous structure, but they are biologically inert. To improve their biological properties, we developed, for the first time, the hydroxyapatite (HA)/chitosan/carbon porous scaffolds (HCCPs). HA/chitosan nanohybrid coatings have been fabricated on PCFFs according to the following stages: (i) deposition of chitosan/calcium phosphate precursors on PCFFs; and (ii) hydrothermal transformation of the calcium phosphate precursors in chitosan matrix into HA nanocrystals. The scanning electron microscopy images indicate that PCFFs are uniformly covered with elongated HA nanoplates and chitosan, and the macropores in PCFFs still remain. Interestingly, the calcium‐deficient HA crystals exist as plate‐like shapes with thickness of 10–18 nm, width of 30–40 nm, and length of 80–120 nm, which are similar to the biological apatite. The HA in HCCPs is similar to the mineral of natural bone in chemical composition, crystallinity, and morphology. As compared with PCFFs, HCCPs exhibit higher in vitro bioactivity and biocompatibility because of the presence of the HA/chitosan nanohybrid coatings. HCCPs not only promote the formation of bone‐like apatite in simulated body fluid, but also improve the adhesion, spreading, and proliferation of human bone marrow stromal cells. Hence, HCCPs have great potentials as scaffold materials for bone tissue engineering and implantation. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1740–1748, 2014.
Liquid diet induces memory impairment accompanied by a decreased number of hippocampal neurons in mice
Authors: Okihara Hidemasa , Ito Jin‐ichi , Kokai Satoshi , Ishida Takayoshi , Hiranuma Maya , Kato Chiho , Yabushita Tadachika , Ishida Kazuto , Ono Takashi , Michikawa Makoto
Published: March 2014

It is suggested that masticatory dysfunction affects the central nervous system; however, the underlying mechanism remains unknown. Brain‐derived neurotrophic factor (BDNF) and its receptor, TrkB, are known to play important roles in memory and learning. In this study, we examined the effects of mastication on memory, the expression levels of BDNF and TrkB, and the number of neurons in the hippocampus of mice. Male C57 BL/6J mice (3 weeks old) were randomly divided into the control group (N = 7) fed chow pellets and the experimental group (N = 7) fed a liquid diet, which reduces mastication during eating. At 14 weeks of age, we performed a passive avoidance test and found that memory and learning ability were impaired in the experimental group compared with the control group. After the behavioral experiment, brains were harvested and analyzed morphologically and biochemically. In the hippocampus of the experimental group, the expression levels of BDNF were significantly higher, whereas those of TrkB were lower than those of the control group. In the cerebral cortex, these levels remained unchanged between the two groups. The ratio of phospho‐p44/42 ERK/pan ERK, a downstream molecule of BDNF/TrkB signaling, in the experimental group was significantly lower than that of the control group in the cortex and hippocampus. The number of pyramidal neurons in the hippocampus was lower in the experimental group than in the control group. These findings suggest that reduced mastication induced by a liquid diet in early childhood may impair memory and learning ability, accompanied by neuronal loss in the hippocampus. © 2014 Wiley Periodicals, Inc.
Cholesterol oxidase production from entrapped cells ofStreptomycessp.
Authors: Niwas Ram , Singh Vineeta , Singh Rajbir , Pant Garima , Mitra Kalyan , Tripathi Chandra Kant Mani
Published: March 2014

Production of cholesterol oxidase (COD) under batch conditions through Ca‐alginate immobilized cells ofStreptomycessp. was investigated. The process was studied for optimal immobilization conditions, beads operational stability and comparisons were made with the COD production via free cells. Influence of Na‐alginate concentration (1–5 g L−1) and initial biomass loading on enzyme production were studied. Effects of initial pH of the production medium, temperature, shaker speed, as well as reuse of beads on the COD production were also investigated. It was observed that COD production with immobilized cells (5.6 U ml−1) was higher in comparison to free cells (4.5 U ml−1) under optimized conditions. The maximum COD production by free cells was observed with initial pH 7.0, rpm 200 after 96 h of incubation while immobilized cells sustain a broad pH range 6.0–9.0, rpm 300 for maximum production after 72 h. The immobilized and free cells produced maximum COD in the culture incubated at 37 and 30 °C, respectively. Other parameters bead size and Na‐alginate concentration found to be optimum with 1.5 mm and 4% w/v, respectively. Scanning electron microscope study of the immobilized cells indicated that the cells in Ca‐alginate beads remained in normal shape with no alterations in the morphology.
Enzymatic Control of Chitosan Gelation for Delivery of Periodontal Ligament Cells
Authors: Yan Xiang‐Zhen , Nijhuis Arnold W. G. , van den Beucken Jeroen J. J. P. , Both Sanne K. , Jansen John A. , Leeuwenburgh Sander C. G. , Yang Fang
Published: March 2014

The aim of this study is to optimize enzymatic control over gelation of chitosan‐based hydrogels for the delivery of periodontal ligament cells (PDLCs). The results reveal that the gelation time, strength, and degradation rate of the chitosan hydrogels can be controlled precisely by variation of the urea and urease concentrations. PDLCs remain viable inside these hydrogels for up to 30 days. Cells released from the hydrogel upon degradation and collected after 3, 15, and 30 days are able to form colonies and osteogenically differentiate. In conclusion, the enzymatic control over the gelation of chitosan hydrogels offers options for the delivery of PDLCs.
18β‐glycyrrhetinic acid attenuates anandamide‐induced adiposity and high‐fat diet induced obesity
Authors: Park Miyoung , Lee Ji‐Hae , Choi Jin Kyu , Hong Yong Deog , Bae Il‐Hong , Lim Kyung‐Min , Park Young‐Ho , Ha Hunjoo
Published: March 2014

Scope

Previous reports suggest that licorice extract has various metabolically beneficial effects and may help to alleviate adiposity and hyperlipidemia. However, underlying anti‐obesity mechanisms still remain elusive. Moreover, it is unknown which single ingredient in licorice extract would mediate such effects. We aimed to demonstrate that licorice extract and its active ingredients can inhibit adipocyte differentiation and fat accumulation.

Methods and results

18β‐glycyrrhetinic acid (18β‐GA) alleviated the effects of CB1R agonist, anandamide (AEA) on CB1R signaling in a concentration‐dependent manner. Consistently, 18β‐GA suppressed AEA‐induced adipocyte differentiation in 3T3‐L1 cells through the downregulation of AEA‐induced MAPK activation and expression of adipogenic genes including C/EBP‐α and PPAR‐γ. The protein levels of fatty acid synthase and stearoyl‐CoA desaturase 1 were also decreased and the phosphorylation of acetyl‐CoA carboxylase was increased in 18β‐GA pretreated cells. The supplementation of 18β‐GA significantly lowered body weight, fat weight, and plasma lipids levels in obese animal models.

Conclusion

These results may provide a novel insight into the molecular mechanism involved in anti‐adipogenic and anti‐obesity effects of 18β‐GA by suppressing the activation of CB1R induced by AEA. Thus, 18β‐GA may exert beneficial effects against obesity‐related metabolic disorders.
Overfeeding increases postprandial endotoxemia in men: Inflammatory outcome may depend on LPS transporters LBP and sCD14
Authors: Laugerette Fabienne , Alligier Maud , Bastard Jean‐Philippe , Drai Jocelyne , Chanséaume Emilie , Lambert‐Porcheron Stéphanie , Laville Martine , Morio Béatrice , Vidal Hubert , Michalski Marie‐Caroline
Published: March 2014

Scope

Low‐grade inflammation is a recognized hallmark of obesity. Endotoxins absorbed after high‐fat meals have recently been implicated. Plasma lipopolysaccharides binding protein (LBP) and soluble cluster of differentiation 14 (sCD14) have also been suggested as clinical markers of endotoxemia. In mice, the ratio LBP/sCD14 has been associated with high fat diet induced inflammation. We tested the hypothesis that healthy subjects develop inflammation differently during weight gain according to changes of LBP/sCD14 ratio.

Methods and results

Eighteen healthy men were overfed during 8 wk (+760 kcal/day). Endotoxemia, sCD14, LBP, and IL‐6 were measured before and after overfeeding (OF) at fasting (n = 18) and postprandially (subcohort, n = 8). OF did not modify fasting IL‐6 but increased the LBP/sCD14 ratio (P = 0.017). Subjects were categorized into tertiles for LBP/sCD14 ratio variation. Subjects in the highest tertile (+90% LBP/sCD14) increased plasma IL‐6 (+26%) versus the lowest tertile due to a decrease of sCD14 associated with high LBP. The postprandial accumulation of endotoxins increased after OF (+160%). However, only four responding subjects presented increased postprandial IL‐6 accumulation.

Conclusion

OF increases postprandial endotoxemia but the inflammatory outcome may be modulated by endotoxin handling in plasma. This study supports a new concept whereby inflammation setup during the initial phase of weight gain is linked to the relative variations of LBP and sCD14.
Polylactides—an overview
Authors: Slomkowski Stanislaw , Penczek Stanislaw , Duda Andrzej
Published: March 2014

Aliphatic polyesters derived from lactides of various configurations (LL, DD, and DL) are promising as materials not only for packaging and for production of many other commonly used polymer products but also for unique medical applications. This paper describes current situation in synthesis and major applications of polylactides. Results of basic studies of “classical” polymerization of lactides prepared with stannous carboxylates or alkoxides, allowing to obtain polymers with molar masses (Mn) up to 106 g/mol and with the low content of tin are also presented. There are discussed advantages and disadvantages of catalyzing/initiating systems that contain zinc, magnesium, calcium, and other metal carboxylates and alkoxides as well as strong organic base initiators. Syntheses of polylactides with well defined microstructure are described. Characteristic features of bulk, solution, and dispersion polymerizations are compared. An outlook for development of polylactide production and applications is presented. Copyright © 2014 John Wiley & Sons, Ltd.
All‐organic nanocomposites of functionalized polyurethane with enhanced dielectric and electroactive strain behavior
Authors: Wang Jingwen , Wu Congcong , Liu Ruonan , Li Shuqin
Published: March 2014

For a dielectric elastomer, increasing its dielectric constant substantially could lead to a high electric field induced strain under a low operation field. In this work, high dielectric constant nanocomposites were developed by chemically bonding copper phthalocyanine oligomer (CuPc), a high dielectric constant organic semiconductor, to polyurethane (PU). Transmission electron microscope‐observed morphologies revealed that the sizes of CuPc particles in a nanocomposite of PU attached with 8.78 vol.% of CuPc were in the range of 10–20 nm, much smaller than the sizes (250–600 nm) in physical blend of PU with the same volume fraction of CuPc. At 100 Hz, the nanocomposite film exhibited a dielectric constant of 391, representing a more than 60 times increase with respect to the neat PU. The enhanced dielectric response in the nanocomposite makes it possible to induce a high electromechanical response. A strain of 17.7% and an elastic energy density of 0.927 J/cm3 were achieved under an electric field of 10 V/µm. Copyright © 2014 John Wiley & Sons, Ltd.
Poly(phenylene oxide) modified cyanate resin for self‐healing
Authors: Yuan Li , Huang Sidi , Hu Yinhui , Zhang Yuzheng , Gu Aijuan , Liang Guozheng , Chen Guoqiang , Gao Yongming , Nutt Steven
Published: March 2014

Self‐healing cyanate ester resins (CE) were developed by adding low molecular weight poly(phenylene oxide) (PPO) resin, yielding a high performance CE/PPO system via a low‐temperature process. The addition of PPO improved the flexural strength and fracture toughness of the CE matrix without sacrificing thermal properties. CE/PPO formulations with 5, 10, and 15 wt.% PPO showed 43%, 65%, and 105% increase in fracture toughness due to a combination of crack deflection, crack pinning, and matrix cavitation around second‐phase particles. When PPO was introduced into the CE, dielectric properties were either unchanged or declined. During thermal treatment to heal damaged CE, liquid PPO flowed into cracks, and during subsequent cooling, solidified to bond the crack surfaces. The self‐healing efficiency for CE with 15 wt.% PPO after heating to 220°C for 1 h exhibited a recovery of 73% in toughness and 81% in microtensile strength. Copyright © 2014 John Wiley & Sons, Ltd.
Controlling quantum breathers in Heisenberg ferromagnetic spin chains via an oblique magnetic field
Authors: Tang Bing , Li De‐Jun , Tang Yi
Published: March 2014

An analytical study on controlling quantum breathers in one‐dimensional ferromagnetic XXZ spin chains through an oblique magnetic field is presented in this paper. Based on the time‐dependent Hartree approximation and the semidiscrete multiple‐scale method, we prove the existence of quantum breathers, analyze conditions for their appearance, and discuss their properties. Our results show that the appearance and features of quantum breathers can be controlled by varying the value of the oblique angle θ.
Fermi‐level pinning by carrier com‐ pensating midgap donor defect band in homoepitaxially grown p‐type ZnO by MBE
Authors: Masamoto T. , Noda K. , Maejima T. , Natsume R. , Matsuo T. , Akiyama A. , Yukue T. , Hiroe S. , Abe T. , Kasada H. , Harada Y. , Ando K.
Published: March 2014

We have performed homoepitaxial MBE growth of nitrogen (N) ‐doped ZnO and studied the postanneal effect on electrical conduction properties. A rapid postanneal after MBE growth is found to enhance the donor–acceptor (D–A) pair emission intensity, converting from n‐type (as‐grown) to p‐type conduction. The p‐type ZnO showed extremely high resistivity (>103 Ω cm) at room temperature. Carrier‐compensating donor‐like defects in N‐doped ZnO were traced by using PPC (persistent photocurrent), which is coupled with in situ Hall effect measurements. It is found that highly resistive p‐ZnO includes a high density of metastable donor‐like defects forming a deep donor band in the midgap region. This midgap donor band plays a role in Fermi‐level pinning at around the midgap position, resulting in high resistivity. Based on X‐ray photoemission spectroscopy experiments one possible origin of the deep donor band is introduced as nitrogen molecule (N2(o)) defects locating at the O atomic site. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wide‐range visible luminescence of ZnCdSe/BeZnTe type‐II superlattices grown on InP substrates
Authors: Murakami Keisuke , Nomura Ichirou , Kobayashi Toshiki , Shiraishi Tomohiro , Takamatsu Shingo , Kishino Katsumi
Published: March 2014

The photoluminescence (PL) characteristics of ZnCdSe/BeZnTe type‐II superlattices (SLs) with various thickness combinations of ZnCdSe and BeZnTe layers were investigated at room temperature. High PL peak intensities that were comparable to those of other direct‐bandgap materials, such as BeZnSeTe, were obtained. The PL peak wavelength was widely controlled from 508 to 739 nm by changing the layer thickness combination (ZnCdSe/BeZnTe) from 1 monolayer (ML)/5 ML to 6 ML/5 ML. The peak wavelengths were evaluated by comparison with theoretical values. Three‐primary‐color luminescence with PL peaks of 506, 530, and 617 nm was demonstrated for the SL sample with three types of monolithically stacked SLs with different layer thickness combinations (i.e., 1 ML/5 ML, 2 ML/5 ML, and 5 ML/5 ML). (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermomagnetic and structural analysis of as‐quenched Ni49Co1Mn37Sn13
Authors: Louidi S. , Suñol J. J. , Bachaga T. , González‐Legarreta L. , Rosa W. O. , Hernando B.
Published: March 2014

It is known that Co substitution in magnetic shape memory Ni‐Mn‐Sn alloys produces changes in their thermomagnetic behaviour. In this work, the Ni49Co1 Mn37Sn13 alloy was obtained by melt spinning in ribbon shape. The ribbon flakes were characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), vibrating sample magnetometry (VSM) and differential scanning calorimetry (DSC). SEM micrographs indicate the formation of textured ribbons with columnar grains growing up perpendicular to the ribbons plane. The crystallographic structure of the sample at room temperature is the Heusler L21. DSC cyclic scans reveal the martensitic transformation on cooling and the reverse austenitic transformation on heating below room temperature. The application of a magnetic field produces a decrease in the transformation temperatures. The small amount of Co addition increases the Curie temperature of austenite. These facts suggest that the structural and magnetic phase transformation temperatures of the ribbons could be tuned to the desired functional temperature by controlling the applied magnetic field as well as the cobalt amount. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic and magnetic properties of high‐pressure phases in the systems Mn–GaSb and Cr–GaSb
Authors: Magnitskaya Maria , Kulatov Erkin , Baturin Vladimir , Uspenskii Yurii
Published: March 2014

Ab initio study is reported on the electronic and magnetic properties of high‐pressure‐synthesized compounds M GaSb and M Ga2Sb2 (M = Mn, Cr). Based on comparison of obtained results, we discuss trends in the properties of these systems under change of 3d constituent. It is shown that CrGa2Sb2 stands out among the other compounds due to peculiarities of its electronic structure, which lead to very low and anisotropic conductivity. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Biocompatible iron oxide/porous silicon nanocomposite with tunable magnetic properties
Authors: Granitzer P. , Rumpf K. , Poelt P. , Reissner M.
Published: March 2014

Iron oxide nanoparticles of 5 and 8 nm in size have been infiltrated into the pores of porous silicon. The aim is to create a superparamagnetic (SPM) nanocomposite system with maximized magnetic field induced moment. Therefore the particle size versus the superparamagnetic behaviour has been figured out. The blocking temperature TB which indicates the transition between superparamagnetic behaviour and blocked state is not only dependent on the particle size but also on the magnetic interactions between them which can be varied by the distance between the particles. The magnetic behavior of the nanocomposite has been examined with regard to the magnetic interactions between the particles within the pores. Dependent on the size but also the distance between the particles, which has been adjusted by the various concentrations, TB has been shifted. Furthermore the modification of the porous silicon template results in a change of the transition temperature due to the variation of the particle distance of adjacent pores. To fabricate distinct composite systems suitable in biomedicine the porous silicon template as well as the loading of the pores with the particles has to be adjusted. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scaling up the production of magnetic nanoparticles for biomedical applications: cost‐effective fabrication from basalts
Authors: Martinez‐Boubeta C. , Simeonidis K. , Amarantidis St. , Angelakeris M. , Balcells L. , Monty C.
Published: March 2014

We report here the first results on magnetic nanoparticles fabricated from basalt fragments of the eruption that took place in Lanzarote (Canary Islands) between 1730 and 1736, to be used in technologies of biomedicine. This approach was inspired by the strong and extremely stable remanent magnetization of slowly cooled rocks from basaltic lavas containing finely members of the hematite–ilmenite (Fe2O3–FeTiO3) series. Besides, the presence of titanium may promote good biocompatibility and an adequate corrosion resistance, as it does in prosthesis. The green, simple, fast, and cost‐effective synthesis of magnetic nanoparticles was attempted using solar vapor‐phase condensation. This technique allows the preparation of large volumes of nanoparticles presenting a narrow particle size distribution without purification steps. Alternatively, high‐energy ball‐milling of rock powder in the presence of organic surfactants was also studied as a potential method to produce, in a one‐step approach, large quantities of nanostructured particles for biomedical applications. As a proof of concept, we explore these materials as candidates to be used in hyperthermia therapy, which promotes selective necrosis of cancer cells by raising the temperature of the tissue slightly above 43 ºC. Results are correlated to their chemical and structural properties and compared to initial igneous rock characteristics. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetism of 2d Heisenberg classical square lattices: theory vs experiments
Authors: Curély Jacques , Kliava Janis
Published: March 2014

In this article, we exclusively focus on the low‐temperature behaviors of 2d square lattices composed of (2N +1)2classical spins with isotropic couplings between first‐nearest neighbors (Heisenberg couplings), in the thermodynamic limit (N →+∞). After briefly recalling the theoretical closed‐form expressions derived for (i) the zero‐field partition function ZN (0), (ii) the spin‐spin correlation between any two lattice sites, (iii) the correlation length and (iv) the static susceptibility, we build up a diagram characterized by three low‐temperature magnetic phases. Moreover we show that the behaviors of these physical quantities as well as the diagram are in perfect agreement with the corresponding ones derived using a renormalization method. Finally we give criterions allowing to directly determine the magnetic phases characterizing 2d magnetic compounds described by our microscopic model. An experimental test is given for illustrating this theoretical study. It allows one to obtain a perfect fit of the susceptibility of [{Mn(DENA)2(N3)2}n] (DENA is the ligand diethylnicotinamide). (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Zwitterionic‐Coated “Stealth” Nanoparticles for Biomedical Applications: Recent Advances in Countering Biomolecular Corona Formation and Uptake by the Mononuclear Phagocyte System
Authors: García Karina Pombo , Zarschler Kristof , Barbaro Lisa , Barreto José A. , O'Malley William , Spiccia Leone , Stephan Holger , Graham Bim
Published: March 2014

Nanoparticles represent highly promising platforms for the development of imaging and therapeutic agents, including those that can either be detected via more than one imaging technique (multi‐modal imaging agents) or used for both diagnosis and therapy (theranostics). A major obstacle to their medical application and translation to the clinic, however, is the fact that many accumulate in the liver and spleen as a result of opsonization and scavenging by the mononuclear phagocyte system. This focused review summarizes recent efforts to develop zwitterionic‐coatings to counter this issue and render nanoparticles more biocompatible. Such coatings have been found to greatly reduce the rate and/or extent of non‐specific adsorption of proteins and lipids to the nanoparticle surface, thereby inhibiting production of the “biomolecular corona” that is proposed to be a universal feature of nanoparticles within a biological environment. Additionally, in vivo studies have demonstrated that larger‐sized nanoparticles with a zwitterionic coating have extended circulatory lifetimes, while those with hydrodynamic diameters of ≤5 nm exhibit small‐molecule‐like pharmacokinetics, remaining sufficiently small to pass through the fenestrae and slit pores during glomerular filtration within the kidneys, and enabling efficient excretion via the urine. The larger particles represent ideal candidates for use as blood pool imaging agents, whilst the small ones provide a highly promising platform for the future development of theranostics with reduced side effect profiles and superior dose delivery and image contrast capabilities.
Mechanisms of Graphene Growth on Metal Surfaces: Theoretical Perspectives
Authors: Wu Ping , Zhang Wenhua , Li Zhenyu , Yang Jinglong
Published: March 2014

Graphene is an important material with unique electronic properties. Aiming to obtain high quality samples at a large scale, graphene growth on metal surfaces has been widely studied. An important topic in these studies is the atomic scale growth mechanism, which is the precondition for a rational optimization of growth conditions. Theoretical studies have provided useful insights for understanding graphene growth mechanisms, which are reviewed in this article. On the mostly used Cu substrate, graphene growth is found to be more complicated than a simple adsorption‐dehydrogenation‐growth model. Growth on Ni surface is precipitation dominated. On surfaces with a large lattice mismatch to graphene, epitaxial geometry determin a robust nonlinear growth behavior. Further progresses in understanding graphene growth mechanisms is expected with intense theoretical studies using advanced simulation techniques, which will make a guided design of growth protocols practical.
Measurements and modelling of the power performance of a model floating wind turbine under controlled conditions
Authors: Sant Tonio , Bonnici David , Farrugia Russell , Micallef Daniel
Published: March 2014

This paper describes power performance measurements undertaken on a model floating wind turbine installed on a tension‐leg platform (TLP) in a wind/wave generator facility. Initially, the surge of the platform was measured under different rotor and wave conditions. The surge behaviour depended considerably on the rotor tip speed ratio and the wave frequency and amplitude. High‐frequency data sampling techniques were then used to derive the instantaneous power coefficient and tip speed ratio directly from the measurements, together with the surge velocity of the floating system. The power measurements were compared with those predicted by three independent numerical models, two of which are based on the blade element momentum approach and the third involving a lifting‐line free‐wake vortex model. The fluctuations of the power coefficient with time predicted by the three models were in close agreement; however, these were all significantly larger than those derived from the rotor shaft torque measurements. This was found to be due to the limitations of the torque measurement technique. Although being accurate in measuring the time‐averaged torque, the sensor was incapable of measuring the high‐frequency low‐amplitude fluctuations in the rotor shaft torque induced by the TLP surge. This was confirmed using an alternative experimental technique involving hot‐wire near‐wake measurements. The study also investigated the influence of the platform surge motion on the time‐averaged power coefficients. Both the measurements and the free‐wake vortex model revealed marginal deviations in the time‐averaged power coefficients when compared with those obtained for a fixed, non‐surging rotor. Copyright © 2014 John Wiley & Sons, Ltd.
Model‐independent periodic stability analysis of wind turbines
Authors: Bottasso C.L. , Cacciola S.
Published: March 2014

In this work, a new method is proposed for the stability analysis of wind turbines. The method uses input–output time histories obtained by conducting virtual excitation experiments with a suitable wind turbine simulation model. Next, a single‐input/single‐output periodic reduced model is identified from the recorded response and used for a stability analysis conducted according to the Floquet theory. Since only input–output sequences are used, the approach is model independent in the sense that it is applicable to wind turbine simulation models of arbitrary complexity. The use of the Floquet theory reveals a much richer picture than the one obtained by widespread classical approaches based on the use of the multi‐blade coordinate transformation of Coleman. In fact, it is shown here that, for each principal mode computed by the classical approach, there are in reality infinite super‐harmonics of varying strength fanning out from the principal one at multiples of the rotor speed. The relative strength of each harmonic in a fan provides for a way of measuring how periodically one specific fan of modes behaves. The notion of super‐harmonics allows one to justify the presence of peaks in the response spectra, peaks that cannot be explained by the classical time‐invariant analysis. The Campbell diagram, i.e., the plot of system frequencies vs. rotor speed, is in this work enriched by the presence of the super‐harmonics, revealing a much more complex pattern of possible resonant conditions with the per‐rev excitations than normally assumed. Copyright © 2014 John Wiley & Sons, Ltd.
Combined D2‐/L2‐hydroxyglutaric aciduria (SLC25A1 deficiency): clinical course and effects of citrate treatment
Authors: Mühlhausen Chris , Salomons Gajja S. , Lukacs Zoltan , Struys Eduard A. , van der Knaap Marjo S. , Ullrich Kurt , Santer René
Published: March 2014

Combined D,L‐2‐hydroxyglutaric aciduria (DL‐2HGA; OMIM #615182) is a rare neurometabolic disorder clinically characterized by muscular hypotonia, severe neurodevelopmental dysfunction, and intractable seizures associated with respiratory distress. Biochemically, DL‐2HGA patients excrete increased amounts of D‐ and L‐2‐hydroxyglutarate (D2HG and L2HG, respectively), with predominance of D2HG, and α‐ketoglutarate, and show a decrease in urinary citrate. Impaired function of the mitochondrial citrate carrier (CIC) due to pathogenic mutations within the SLC25A1 gene has been identified as the underlying molecular cause of the disease. CIC mediates efflux of the mitochondrial tricarboxylic acid (TCA) cycle intermediates citrate and isocitrate in exchange for cytosolic malate. Thus, depletion of cytosolic citrate as well as accumulation of citrate inside mitochondria have been considered to play a role in the pathophysiology of DL‐2HGA. Here, we report for the first time on a patient with a genetically confirmed diagnosis of DL‐2HGA and treatment with either malate or citrate. During malate treatment, urinary malate concentration increased, but beyond that, neither biochemical nor clinical alterations were observed. In contrast, treatment with citrate led to an increased urinary excretion of TCA cycle intermediates malate and succinate, and by trend to an increased concentration of urinary citrate. Furthermore, excretion of D2HG and L2HG was reduced during citrate treatment. Clinically, the patient showed stabilization with regard to frequency and severity of seizures. Treating DL‐2HGA with citrate should be considered in other DL‐2HGA patients, and its effects should be studied systematically.
The HSP90 inhibitor ganetespib has chemosensitizer and radiosensitizer activity in colorectal cancer
Authors: He Suqin , Smith Donald L. , Sequeira Manuel , Sang Jim , Bates Richard C. , Proia David A.
Published: March 2014

The integration of targeted agents to standard cytotoxic regimens has improved outcomes for patients with colorectal cancer (CRC) over recent years; however this malignancy remains the second leading cause of cancer mortality in industrialized countries. Small molecule inhibitors of heat shock protein 90 (HSP90) are one of the most actively pursued classes of compounds for the development of new cancer therapies. Here we evaluated the activity of ganetespib, a second-generation HSP90 inhibitor, in models of CRC. Ganetespib reduced cell viability in a panel of CRC cell lines in vitro with low nanomolar potency. Mechanistically, drug treatment exerted concomitant effects on multiple oncogenic signaling pathways, cell cycle regulation, and DNA damage repair capacity to promote apoptosis. Combinations of ganetespib and low-dose ionizing radiation enhanced the radiosensitivity of HCT 116 cells and resulted in superior cytotoxic activity over either treatment alone. In vivo, the single-agent activity of ganetespib was relatively modest, suppressing HCT 116 xenograft tumor growth by approximately half. However, ganetespib significantly potentiated the antitumor efficacy of the 5-Fluorouracil (5-FU) prodrug capecitabine in HCT 116 xenografts, causing tumor regressions in a model that is intrinsically resistant to fluoropyrimidine therapy. This demonstration of combinatorial benefit afforded by an HSP90 inhibitor to a standard CRC adjuvant regimen provides an attractive new framework for the potential application of ganetespib as an investigational agent in this disease.
Setting Expectations following Endoscopic Cubital Tunnel Release
Authors: Cobb Tyson K. , Walden Anna L. , Merrell Peter T. , Lemke Jon H.
Published: March 2014

Background

The objective was to evaluate recovery characteristics of patients undergoing endoscopic cubital tunnel release (ECuTR) by determining the following: (1) return to work (RTW) times following ECuTR compared with RTW times of patients that underwent anterior transposition of the ulnar nerve (ATUN), (2) satisfaction rates and factors affecting satisfaction, (3) resolution rates of common preoperative complaints and findings, and (4) effect of preoperative ulnar nerve subluxation on postoperative outcomes.

Methods

A total of 172 cases in 148 patients undergoing ECuTR were prospectively enrolled including 56 women and 92 men. Kaplan-Meier analyses were performed to determine RTW time for ECuTR patients and for a cohort of 15 patients that underwent ATUN. Patients were evaluated for subjective and objective complaints preoperatively and ***post-operatively. Cases were grouped by Dellon's classification preoperatively and modified by Bishop's postoperatively.

Results

Half of ECuTR patients returned to normal work within 8 days postoperatively versus 71 days following ATUN. Variables significantly negatively affecting RTW were male sex, manual labor, and worker's compensation status. Dellon's was the best predictor of postoperative satisfaction. Complete resolution of symptoms occurred in 86 % of patients for weakness, 81 % for pain, 79 % for numbness and tingling (N/T), 78 % for atrophy, 76 % for abnormal two-point discrimination, and 65 % for Wartenberg's. Preoperative ulnar nerve subluxation had no effect on outcome.

Conclusions

Improved RTW time following ECuTR versus ATUN indicates potential and substantial cost-saving implications with respect to reduced worker productivity loss. Patients with more severe preoperative Dellon's classification can expect less optimal results regarding postoperative satisfaction and resolution rates of N/T and pain.
Biodiesel Feedstock from Emulsions Produced by Aqueous Processing of Yellow Mustard
Authors: Tabtabaei Solmaz , Boocock David G. B. , Diosady Levente L.
Published: March 2014

The multi‐stage treatment of stable oil‐in‐water emulsions produced during non‐enzymatic aqueous processing of dehulled yellow mustard flour with cyclic ethers [tetrahydrofuran (THF) and 1,4‐dioxane] was investigated to produce a single‐phase oil‐solvent‐water miscella suitable for biodiesel production. While the single‐stage treatment of yellow mustard emulsion recovered 97 % and 95 % of the oil by using 4:1 THF:oil and 9:1 dioxane:oil weight ratios, respectively, miscella phases containing more than 7 % water formed, which made them unsuitable as biodiesel feedstock. Multi‐stage treatments of the emulsion using lower THF:oil and dioxane:oil weight ratios were further developed to produce oil‐solvent‐water miscella phases with low water content. While three‐stage extraction of emulsions using 0.5:1, 1:1, 1.5:1, and 2:1 dioxane:oil weight ratios did not destabilize the emulsion, three‐stage extraction using 0.5:1 and 0.75:1 THF:oil weight ratios effectively recovered over 97 % of the oil, resulting in the production of oil‐rich miscella phases containing only 1 % and 1.5 % water, respectively. These miscella phases were analyzed for free fatty acid and phosphorus contents and proved to be excellent feedstocks for the preparation of high‐purity methyl esters through single‐phase base‐catalyzed transmethylation.
Evening adolescents: The role of family relationships and pubertal development
Authors: Díaz‐Morales Juan Francisco , Escribano Cristina , Jankowski Konrad S. , Vollmer Christian , Randler Christoph
Published: March 2014

Accumulating evidence suggests that evening‐type adolescents are exposed to a number of determinants that might have a negative impact on their health condition. Despite the fact that biological and psychosocial factors are interrelated, their impacts on the shift toward eveningness during puberty have been considered only separately. In this study, the effects of frequency of conflicts and functional autonomy on the relationship between pubertal development and Morningness–Eveningness (M–E) were tested together. A sample of 2081 adolescents aged 12–16 completed pubertal development, M–E, family frequency of conflicts and functional autonomy scales. Results indicated that greater functional autonomy and more conflicts in the family were unique predictors of greater eveningness, and they both together were better predictors of M–E than an advanced age and pubertal development. Apart from biological development, family relationship seems an important factor explaining progressive tendency toward eveningness during puberty and adolescence. Some implications to adolescent development were indicated.
Scintigraphic Evaluation of Decontamination Lotion for Removal of Radioactive Contamination From Skin
Authors: Rana Sudha , Dutta Mita , Sharma Navneet , Goel Rajeev , Khan Abdul Wadood , Kotta Sabna , Ali Javed , Ansari Shahid Husain , Sultana Sarwat , Sharma Rakesh Kumar
Published: March 2014

Objective

Skin contamination is one of the most likely risks after accidental or occupational radiological accidents. Using scintigraphy, we assessed a topical lotion for its decontamination efficacy (DE) after exposure with short-lived medical radioisotopes technetium Tc 99m (99mTc) and thallium 201Tl (201Tl).

Methods

Using 99mTc (300 ± 5 μCi/100 μl) and 201Tl (100 ± 5 μCi/100 μl), the thoracoabdominal region (shaved skin) of Sprague Dawley rats and human tissue equivalent were contaminated and then decontaminated using cotton swabs soaked in formulated lotion at different time intervals. Static counts were recorded and calculated for DE. Histologic examination was performed on the animal model.

Results

The DE of the formulation for 99mTc and 201Tl was 85% ± 5 and 88% ± 2, respectively. The prepared formulation effectively removed the radionuclides from the tissue surface.

Conclusions

The formulated lotion assisted in the effective removal of radiocontaminants by decontaminating the radionuclides. Moreover, minimal and easily manageable radioactive waste was generated by this process. Further investigation regarding the infusion of formulated lotion into ready-to-use skin wipes for self-decontamination may be useful for mass casualty scenarios. (Disaster Med Public Health Preparedness. 2014;0:-)