bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal Oxide/Polymer Hybrid Nanoparticles with Versatile Functionality Prepared by Controlled Surface Crystallization
Authors: Fischer Viktor , Lieberwirth Ingo , Jakob Gerhard , Landfester Katharina , Muñoz‐Espí Rafael 
Published: September 2012

AbstractMetal oxide/polymer hybrids are prepared from polystyrene nanoparticles functionalized at the surface with phosphonate and phosphate groups. The polymer particles are synthesized with specifically designed surface‐active monomers (surfmers) and used as nucleation surfaces for the controlled in situ crystallization of cerium, iron, and zinc oxide nanocrystals. The formation of the metal oxide is driven by the addition of a base to suspensions of the polymer particles containing the corresponding precursor. The crystal formation at the particle surface is studied for the different hybrid systems by X‐ray diffraction and transmission electron microscopy (TEM). The potential catalytic activity of CeO2/polymer hybrid particles is proven with the example of the photodegradation of rhodamine B. For the case of magnetic iron oxide‐functionalized latex, a superparamagnetic behavior is found above a blocking temperature of 225 K. ZnO/polymer hybrids present a strong yellow visible photoluminescence. The approach is shown to be versatile not only in terms of the variety in the metal oxides deposited on the surface, but also because the crystallization can take place in both aqueous and alcoholic media.
In Situ Study of Size and Temperature Dependent Brittle‐to‐Ductile Transition in Single Crystal Silicon
Authors: Kang Wonmo , Saif M. Taher A. 
Published: September 2012

AbstractSilicon based micro‐ and nanometer scale devices operating at various temperatures are ubiquitous today. However, thermo‐mechanical properties of silicon at the small scale and their underlying mechanisms remain elusive. The brittle‐to‐ductile transition (BDT) is one such property relevant to these devises. Materials can be brittle or ductile depending on temperature. The BDT occurs over a small temperature range. For bulk silicon, the BDT is about 545 °C. It is speculated that the BDT temperature of silicon may decrease with size at the nanoscale. However, recent experimental and computational studies have provided inconclusive evidence, and are often contradictory. Potential reasons for the controversy might originate from the lack of an in situ methodology that allows variation of both temperature and sample size. This controversy is resolved in the present study by carrying out in situ thermo‐mechanical bending tests on single crystal silicon samples with concurrent control of these two key parameters. It is unambiguously shown that the BDT temperature reduces with sample size. For example, the BDT temperature decreases to 293 °C for a sample size 720 nm. A mechanism‐based model is proposed to interpret the experimental observations.
Fluorescence Nanoscopy of Platelets Resolves Platelet‐State Specific Storage, Release and Uptake of Proteins, Opening up Future Diagnostic Applications
Authors: Rönnlund Daniel , Yang Yang , Blom Hans , Auer Gert , Widengren Jerker 
Published: September 2012

AbstractDysregulation of how platelets store, sequester and release specific proteins seems to be implicated in many disease states, including cancer. Dual‐color immunofluorescence stimulated emission depletion (STED) microscopy with 40 nm resolution is used to map pro‐angiogenic VEGF, anti‐angiogenic PF‐4 and fibrinogen in >300 individual platelets. This reveals that these proteins are stored in a segmented, zonal manner within regional clusters, significantly smaller than the size of an α‐granule. No colocalization between the different proteins is observed. Upon platelet activation by thrombin or ADP, the proteins undergo significant spatial rearrangements, including alterations in the size and number of the protein clusters, and specific for a certain protein and the type of activation induced. Following these observations, a simple assignment procedure is used to show that the three distinct states of platelets (non‐, ADP‐ and thrombin‐activated) can be identified based on the average size, number and peripheral localization profiles of the regional protein clusters within the platelets. Thus, high‐resolution spatial mapping of specific proteins is a useful procedure to detect and characterize deviations in the selective storage, release and uptake of these proteins in the platelets. Since these deviations seem to be specific for, and may even underlie, certain patophysiological states, these findings may have interesting diagnostic and therapeutic implications.
Inclusion of Tetrachloroquinone and Metal Ions in a Macrotricyclic Molecule with a Tetrathiafulvalene Moiety Prompts Intermolecular Electron Transfer
Authors: Li Jing , Guo Jiabin , Yang Ge , Zhang Guanxin , Chen Chuanfeng , Zhang Deqing 
Published: September 2012

AbstractA triptycene‐based cylindrical macrotricyclic molecule 1, which contains one tetrathiafulvalene (TTF) unit and four glycol chains, is reported. Both absorption and ESR spectroscopic studies clearly indicate that intermolecular electron transfer occurs from TTF in 1 to tetrachloroquinone in the presence of certain metal ions (e.g. Sc3+, Pb2+, and Zn2+). Based on comparative studies with 3 and 5, the close intermolecular alignment between 1 and tetrachloroquinone is proposed to occur by the synergic coordination of metal ions with oxygen atoms of the glycol chains and tetrachloroquinone (as well as the sulfur atoms of TTF). The intermolecular electron transfer is facilitated by the positive shift of the reduction potentials of tetrachloroquinone through coordination with metal ions, and the close alignment of 1 and tetrachloroquinone, which is beneficial for stabilizing the electron‐transfer state.
Neuroanatomy of Titanosaurid Dinosaurs From the Upper Cretaceous of Patagonia, With Comments on Endocranial Variability Within Sauropoda
Authors: Carabajal Ariana Paulina 
Published: September 2012

AbstractThe purpose of this study is to provide a detailed description of the neuroanatomy of Bonatitan, Antarctosaurus, and an unnamed titanosaur from Río Negro, Argentina including the first observations on the inner ear of the two first taxa using CT scans. The materials were compared with previously described sauropod endocasts and other less complete titanosaur braincases from Argentina. The cranial endocasts show the general morphology of other sauropods being bulbous, anteroposteriorly short and transversely wide, and with enlarged and posteroventrally projected pituitary body. Particular titanosaur traits are the extremely short and horizontal olfactory tract, the absence of a floccular process and a single root for cranial nerve XII. In addition, in the basicranium the abducens nerve (CN VI) does not penetrates the pituitary fossa and the internal carotid artery enters the medial aspect of the basipterygoid process, resulting in an external opening for this vessel that is not visible in lateral view of the braincase. The titanosaurid inner ear also exhibits particular traits, such as robust semicircular canals, and anterior and posterior semicircular canals that are subequal in size. The variation observed in the sauropod endocranium indicates an evolutionary tendency in titanosaurs toward the anteroposterior shortening of the midbrain, and the reduction in size of the semicircular canals of the inner ear, in particular the anterior semicircular canal. This, together with the lack of floccular process suggests a narrower range of movements of the head for this clade. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Synthesis and Selective Inhibitory Activity Against Human COX‐1 of Novel 1‐(4‐Substituted‐thiazol‐2‐yl)‐3,5‐di(hetero)aryl‐pyrazoline Derivatives
Authors: Carradori Simone , Secci Daniela , Bolasco Adriana , De Monte Celeste , Yáñez Matilde 
Published: September 2012

AbstractNovel 1‐(4‐ethyl carboxylate‐thiazol‐2‐yl)‐3,5‐di(hetero)aryl‐2‐pyrazoline derivatives were obtained by reacting 3,5‐di(hetero)aryl‐1‐thiocarbamoyl‐2‐pyrazolines with the ethyl ester of α‐bromo‐pyruvic acid. The synthesized compounds were confirmed by spectroscopic data and assayed to evaluate their in vitro ability to inhibit both isoforms of human cyclooxygenase (hCOX). Some derivatives (compounds 5, 6, 13, 16, and 17) displayed promising selectivity against hCOX‐1 in the micromolar range and were shown to have a selectivity index similar or better than the reference drugs (indometacin, diclofenac). The introduction of a phenyl or a 4‐F‐phenyl ring on the C5 associated with a 4‐substituted phenyl or a heteroaryl group on the C3 of (4‐substituted‐thiazol‐2‐yl)pyrazoline derivatives improved the activity against hCOX‐1. Thanks to these preliminary results it could be possible to extend our knowledge of the pharmacophoric requirements for the discovery of new pyrazoline‐based hCOX‐1 inhibitors.
Antiinflammatory and chondroprotective effects of intraarticular injection of adipose‐derived stem cells in experimental osteoarthritis
Authors: ter Huurne Menno , Schelbergen Rik , Blattes Roxane , Blom Arjen , de Munter Wouter , Grevers Lilyanne C. , Jeanson Jannik , Noël Danièle , Casteilla Louis , Jorgensen Christian , van den Berg Wim , van Lent Peter L. E. M. 
Published: September 2012

AbstractObjectiveIn experimental collagenase‐induced osteoarthritis (OA) in the mouse, synovial lining macrophages are crucial in mediating joint destruction. It was recently shown that adipose‐derived stem cells (ASCs) express immunosuppressive characteristics. This study was undertaken to explore the effect of intraarticular injection of ASCs on synovial lining thickness and its relation to joint pathology in experimental mouse OA.MethodsASCs were isolated from fat surrounding the inguinal lymph nodes and cultured for 2 weeks. Experimental OA was induced by injection of collagenase into the knee joints of C57BL/6 mice. OA phenotypes were measured within 8 weeks after induction. Histologic analysis was performed, and synovial thickening, enthesophyte formation, and cartilage destruction were measured in the knee joint.ResultsASCs were injected into the knee joints of mice 7 days after the induction of collagenase‐induced OA. On day 1, green fluorescent protein–labeled ASCs were attached to the lining layer in close contact with macrophages. Thickening of the synovial lining, formation of enthesophytes associated with medial collateral ligaments, and formation of enthesophytes associated with cruciate ligaments were significantly inhibited on day 42 after ASC treatment, by 31%, 89%, and 44%, respectively. Destruction of cartilage was inhibited on day 14 (65%) and day 42 (35%). In contrast to early treatment, injection of ASCs on day 14 after OA induction showed no significant effect on synovial activation or joint pathology on day 42.ConclusionThese findings indicate that a single injection of ASCs into the knee joints of mice with early‐stage collagenase‐induced OA inhibits synovial thickening, formation of enthesophytes associated with ligaments, and cartilage destruction.
Student outcomes associated with use of asynchronous online discussion forums in gross anatomy teaching
Authors: Green Rodney A. , Hughes Diane L. 
Published: September 2012

AbstractAsynchronous online discussion forums are increasingly common in blended learning environments but the relationship to student learning outcomes has not been reported for anatomy teaching. Forums were monitored in two multicampus anatomy courses; an introductory first year course and a second year physiotherapy‐specific course. The forums are structured with a separate site for each course module and moderated weekly by staff. Students are encouraged to post to new threads (initial post) and answer queries in threads started by others (reply post). Analysis of forums was conducted separately for each course and included overall activity (posts and views) for a full semester and a detailed analysis for one week in the middle of semester. Students were classified as zero, moderate, or high contributors to the forums based on the number of posts. Final mark for the course was related to level of forum contribution using nonparametric tests. Forum threads were characterized as task‐focused, administrative, or other. A higher proportion of second year (36%) than first‐year (17%) students posted on the forums and the postings were more likely to be task‐focused and student initiated. Second‐year students that posted frequently to the forum gained a higher final mark for the course than those that did not post or only posted a moderate number of times (P < 0.01). This relationship was not evident for first‐year students who had a much higher proportion of administrative threads. Forums in anatomy courses can be powerful learning tools encouraging deeper learning and improved learning outcomes. Anat Sci Educ 6: 101–106. © 2012 American Association of Anatomists.
Connecting with different audiences: The anatomy of communication is essential
Authors: Evans Darrell J.R. 
Published: September 2012

AbstractIn the twenty‐first century, communication has become truly global. Advances in technology have opened up a host of ways in which we are able to communicate to retrieve or pass on information and knowledge. In many cases we have moved from a place‐based communication approach to one of increasing mobility. With this shift in approach, it is apparent that effective communication skills are perhaps even more important so that we can connect appropriately with diverse audiences. Despite this, relatively little attention has been paid to training our students in different modes of communication and therefore we may not be fully preparing our students to play their part in the global community. Given anatomy's place within many health‐care curricula, an ideal avenue is available for anatomists to take the lead in providing communications skills training for students. There are a variety of approaches, some of which are outlined in this article, which can be used to create appropriate opportunities for developing different communication skills and these can be woven into existing practices to ensure courses do not become overburdened. A sustained approach to communication skills training will help equip our students to communicate easily with the many aspects of modern society. Anat Sci Educ 6: 134–137. © 2012 American Association of Anatomists.
Curriculum integration = course disintegration: What does this mean for anatomy?
Authors: Bolender David L. , Ettarh Rajunor , Jerrett David P. , Laherty Richard F. 
Published: September 2012

AbstractMany basic scientists including anatomists are currently involved in decisions related to revisions of the undergraduate medical curriculum. Integration is a common theme in many of these decisions. As described by Harden, integration can occur along a multistep continuum from independent, discipline‐based courses to a completely interdisciplinary curriculum. For anatomy, each derivative of curricular integration can be shown to involve progressive disruptions of the temporal and topographical relationship between organ systems in a body region, of the temporal relationship with other courses in a harmonized curriculum, and of the relationships between components of organ systems when integration is implemented in thematic curricula. Drawing from our experience teaching in various types of integrated medical curricula, we encourage readers to proceed cautiously with their curricular decisions because each one can have gains and losses that may impact learning in the new format. Anat Sci Educ. © 2013 American Association of Anatomists.
Template‐Free Hydrothermal Synthesis of Mesoporous MgO Nanostructures and Their Applications in Water Treatment
Authors: Lian Jiabiao , Zhang Caihong , Wang Ping , Ng Dickon H. L. 
Published: September 2012

AbstractThe controlled synthesis of Mg(OH)2 nanowires and microflowers composed of nanoplates was successfully achieved by a template‐free hydrothermal synthetic method. It was found that the reaction medium played a crucial role in the morphological control of the precursor nanostructures. The high polarity of water molecules favored the polar growth of the precursor, resulting in the formation of nanowires with a diameter of 80 nm, whereas a mixed water/ethanol medium with a lower degree of polarity led to the formation of microflowers. Moreover, mesoporous MgO nanostructures could be obtained by further annealing these as‐prepared precursors in air at 500 °C for 2 h. During thermal treatment, the wire‐ and flower‐like morphologies were retained. Porosity formation was due to thermal decomposition of Mg(OH)2 and release of H2O. Both the mesoporous MgO nanowires and microflowers showed superior ability of adsorbing the organic dye methyl orange, and thus they are promising candidates for polluted water treatment.
Cloning, overexpression, purification, and characterization of a new iron superoxide dismutase from Jatropha curcas
Authors: Ou‐yang Chao , Cai Feng , Gao Shun , Niu Bei , Wang Shenghua , Chen Fang 
Published: September 2012

AbstractA novel iron superoxide dismutase (Fe‐SOD) gene from Jatropha curcas was cloned and expressed in Escherichia coli BL21 (DE3). This recombinant enzyme was isolated by a combined procedure involving immobilized metal‐ion affinity chromatography and ion‐exchange chromatography. The apparent molecular mass of this purified enzyme (designated as JcFe‐SOD) was 35 kDa on SDS‐PAGE. The full‐length complementary DNA sequence of JcFe‐SOD contained a 918‐bp open reading frame encoding a 305‐amino‐acid precursor of 34.589 kDa. The result of matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry showed that the purified enzyme may own two forms: a dimer and a monomer. The enzyme was relatively stable and showed 54% activity when incubated in 70°C for 60 Min. JcFe‐SOD was found to have good pH stability in the pH range of 5.5–9.5 at 25°C over 1 H incubation. The activity of this enzyme was gradually inhibited by increasing concentration of H2O2, 2‐mercaptoethanol, and ethylenediaminetetraacetic acid. An assay of the atomic absorption spectrum showed the presence of 0.41 atom of Fe in each SOD subunit.
Design and characterization of a protein superagonist of IL‐15 fused with IL‐15Rα and a high‐affinity T cell receptor
Authors: Stone Jennifer D. , Chervin Adam S. , Schreiber Hans , Kranz David M. 
Published: September 2012

AbstractTo avoid high systemic doses, strategies involving antigen‐specific delivery of cytokine via linked antibodies or antibody fragments have been used. Targeting cancer‐associated peptides presented by major histocompatibility complex (MHC) molecules (pepMHC) increases the number of potential target antigens and takes advantage of cross‐presentation on tumor stroma and in draining lymph nodes. Here, we use a soluble, high‐affinity single‐chain T cell receptor Vα‐Vβ (scTv), to deliver cytokines to intracellular tumor‐associated antigens presented as pepMHC. As typical wild‐type T cell receptors (TCRs) exhibit low affinity (Kd = 1–100 μM or more), we used an engineered TCR, m33, that binds its antigenic peptide SIYRYYGL (SIY) bound to the murine class I major histocompatability complex protein H2‐Kb (SIY/Kb) with nanomolar affinity (Kd = 30 nM). We generated constructs consisting of m33 scTv fused to murine interleukin 2 (IL‐2), interleukin 15 (IL‐15), or IL‐15/IL‐15Rα (IL‐15 linked to IL‐15Rα sushi domain, called “superfusion”). The fusions were purified with good yields and bound specifically to SIY/Kb with high affinity. Proper cytokine folding and binding were confirmed, and the fusions were capable of stimulating proliferation of cytokine‐dependent cells, both when added directly and when presented in trans, bound to cells with the target pepMHC. The m33 superfusion was particularly potent and stable and represents a promising design for targeted antitumor immunomodulation. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Characterization of the N370S Mutant of Glucocerebrosidase by Hydrogen/Deuterium Exchange Mass Spectrometry
Authors: Tang Liangjie , Coales Stephen J. , Morrow Jeffrey A. , Edmunds Tim , Hamuro Yoshitomo 
Published: September 2012

AbstractAn asparagine‐to‐serine substitution at residue 370 (N370S) in glucocerebrosidase (GCase) is the most prevalent mutation leading to Gaucher's disease, the most common lysosomal storage disorder. Two types of hydrogen/deuterium exchange experiment coupled with proteolysis and liquid chromatography–mass spectrometry (HDX–MS) were used to investigate the dynamic properties and unfolding stability of wt, R495H, and N370S GCases in the presence and absence of ligands. R495H GCase is used for enzyme replacement therapy and is considered to be a wt surrogate, whereas N370S is the most prevalent mutation leading to Gaucher's disease. Time‐course HDX experiments of the GCases were performed under near‐physiological conditions to detect the protein's local unfolding motions at a submolecular level. In guanidine‐titration experiments, HDX reactions were performed with various concentrations of a chemical denaturant to provide the global stability of the proteins. The two types of experiment showed that all three purified GCases, wt, R495H, and N370S, have virtually identical local unfolding motions and global stabilities in solution. Combined with previous X‐ray crystallographic studies, which showed indistinguishable backbone conformations for N370S and R495H GCase mutants and very similar melting temperatures for the wt, R495H, and N370S mutants, all three GCases are likely to have virtually identical structural and dynamic properties in solution. The guanidine‐titration experiments revealed that the pharmacological chaperone, isofagomine (IFG), interacts more weakly with the N370S mutant than with the R495H GCase; this is consistent with the higher IC50 value of IFG against N370S than against R495H. The time‐course experiments showed that IFG restricts the local unfolding motions of N370S in the same way as those of R495H when the ligand saturates the proteins.
Fluorescent DNA Labeling by N‐Mustard Analogues of S‐Adenosyl‐L‐Methionine
Authors: Du Yuhao , Hendrick Charles E. , Frye Krysta S. , Comstock Lindsay R. 
Published: September 2012

AbstractAzide and alkyne‐functionalized N‐mustard analogues of S‐adenosyl‐L‐methionine have been synthesized and were demonstrated to undergo efficient methyltransferase‐dependent DNA alkylation by M.TaqI and M.HhaI. Subsequent labeling of the DNA with a fluorophore was carried out using copper‐catalyzed azide–alkyne cycloaddition chemistry and was visualized by fluorescence scanning. This work demonstrates the utility of functionalized N‐mustard analogues as biochemical tools to study biological methylation and offers a facile way to site‐selectively label substrates of DNA methyltransferases.