bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Evidence for a Peroxide Intermediate and a Reactive Enzyme–Substrate–Dioxygen Configuration in a Cofactor‐free Oxidase
Authors: Bui Soi , von Stetten David , Jambrina Pablo G. , Prangé Thierry , Colloc'h Nathalie , de Sanctis Daniele , Royant Antoine , Rosta Edina , Steiner Roberto A. 
Published: October 2014

AbstractCofactor‐free oxidases and oxygenases promote and control the reactivity of O2 with limited chemical tools at their disposal. Their mechanism of action is not completely understood and structural information is not available for any of the reaction intermediates. Near‐atomic resolution crystallography supported by in crystallo Raman spectroscopy and QM/MM calculations showed unambiguously that the archetypical cofactor‐free uricase catalyzes uric acid degradation via a C5(S)‐(hydro)peroxide intermediate. Low X‐ray doses break specifically the intermediate C5OO(H) bond at 100 K, thus releasing O2 in situ, which is trapped above the substrate radical. The dose‐dependent rate of bond rupture followed by combined crystallographic and Raman analysis indicates that ionizing radiation kick‐starts both peroxide decomposition and its regeneration. Peroxidation can be explained by a mechanism in which the substrate radical recombines with superoxide transiently produced in the active site.
Xenon(II) Polyfluoridotitanates(IV): Synthesis and Structural Characterization of [Xe2F3]+ and [XeF]+ Salts
Authors: Radan Kristian , Goreshnik Evgeny , Žemva Boris 
Published: October 2014

AbstractThermal reaction between XeF2 and excess TiF4 resulted in the unexpected formation of a highly ionized XeII species. The products [Xe2F3][Ti8F33] and [XeF]2[Ti9F38] represent the first examples of [Xe2F3]+ and [XeF]+ compounds, which differ from known XeII salts containing discrete fluoride anions with pentavalent metalloid/metal centers. A new structural type of 2D polyanion [Ti8F33]− and the formation and structure of the novel 1D [Ti9F38]2− are discussed. Both products were characterized by single‐crystal X‐ray analysis and Raman spectroscopy.
Molecular‐Level Understanding of the Photocatalytic Activity Difference between Anatase and Rutile Nanoparticles
Authors: Kim Wooyul , Tachikawa Takashi , Moon Gun‐hee , Majima Tetsuro , Choi Wonyong 
Published: October 2014

AbstractThe generation of oxidants on illuminated photocatalysts and their participation in subsequent reactions are the main basis of the widely investigated photocatalytic processes for environmental remediation and selective oxidation. Here, the generation and the subsequent diffusion of .OH from the illuminated TiO2 surface to the solution bulk were directly observed using a single‐molecule detection method and this molecular phenomenon could explain the different macroscopic behavior of anatase and rutile in photocatalysis. The mobile .OH is generated on anatase but not on rutile. Therefore, the photocatalytic oxidation on rutile is limited to adsorbed substrates whereas that on anatase is more facile and versatile owing to the presence of mobile .OH. The ability of anatase to generate mobile .OH is proposed as a previously unrecognized key factor that explains the common observations that anatase has higher activity than rutile for many photooxidative reactions.
Coumarin‐Based Fluorogenic Probes for No‐Wash Protein Labeling
Authors: Chen Yingche , Clouthier Christopher M. , Tsao Kelvin , Strmiskova Miroslava , Lachance Hugo , Keillor Jeffrey W. 
Published: October 2014

AbstractA fluorescent protein‐labeling strategy was developed in which a protein of interest (POI) is genetically tagged with a short peptide sequence presenting two Cys residues that can selectively react with synthetic fluorogenic reagents. These fluorogens comprise a fluorophore and two maleimide groups that quench fluorescence until they both undergo thiol addition during the labeling reaction. Novel fluorogens were prepared and kinetically characterized to demonstrate the importance of a methoxy substituent on the maleimide in suppressing reactivity with glutathione, an intracellular thiol, while maintaining reactivity with the dithiol tag. This system allows the rapid and specific labeling of intracellular POIs.
Nasal Anatomy of the Non‐mammaliaform Cynodont Brasilitherium riograndensis (Eucynodontia, Therapsida) Reveals New Insight into Mammalian Evolution
Authors: Ruf Irina , Maier Wolfgang , Rodrigues Pablo G. , Schultz Cesar L. 
Published: October 2014

ABSTRACTThe mammalian nasal cavity is characterized by a unique anatomy with complex internal features. The evolution of turbinals was correlated with endothermic and macrosmatic adaptations in therapsids and in early mammals, which is still apparent in their twofold function (warming and moistening of air, olfaction). Fossil evidence for the transformation from the nonmammalian to the mammalian nasal cavity pattern has been poor and inadequate. Ossification of the cartilaginous nasal capsule and turbinals seems to be a feature that occurred only very late in synapsid evolution but delicate ethmoidal bones are rarely preserved. Here we provide the first µCT investigation of the nasal cavity of the advanced non‐mammaliaform cynodont Brasilitherium riograndensis from the Late Triassic of Southern Brazil, a member of the sister‐group of mammaliaforms, in order to elucidate a critical anatomical transition in early mammalian evolution. Brasilitherium riograndensis already had at least partially ossified turbinals as remnants of the nasoturbinal and the first ethmoturbinal are preserved. The posterior nasal septum is partly ossified and contributes to a mesethmoid. The nasal cavity is posteriorly expanded and forms a distinctive pars posterior (ethmoidal recess) that is ventrally separated from the nasopharyngeal duct by a distinct lamina terminalis. Thus, our observations clearly demonstrate that principal features of the mammalian nasal cavity were already present in the sister‐group of mammaliaforms. Anat Rec, 297:2018–2030, 2014. © 2014 Wiley Periodicals, Inc.
Morphology of the Nasal Capsule of Primates—With Special Reference to Daubentonia and Homo
Authors: Maier Wolfgang , Ruf Irina 
Published: October 2014

ABSTRACTPrimitive mammals are considered macrosmatic. They have very large and complicated nasal capsules, nasal cavities with extensive olfactory epithelia, and relatively large olfactory bulbs. The complicated structures of the nasal capsule follow a relatively conservative “bauplan,” which is normally easy to see in earlier fetal stages; especially in altricial taxa it differentiates well into postnatal life. As anteriormost part of the chondrocranium, the nasal capsule is at first cartilaginous. Most of it ossifies endochondrally, but “appositional bone” (“Zuwachsknochen”) is also common. Many fetal structures become resorbed. Together, all surviving bone structures form the ethmoid bone, but cartilages of the external nose and of the vomeronasal complex can persist throughout life. We describe in detail the anatomy of Daubentonia madagascariensis based on a fetal stage (41 mm HL) and an adult skull was analyzed by µCT. We found that the nasal capsule of this species is by far the most complicated one of all extant Primates. We also describe older fetuses of Homo sapiens (35 and 63 mm HL) as representative of a derived primate. The most significant feature of man—and probably of all anthropoids—is the complete loss of the recessus frontoturbinalis and its associated structures. It can be demonstrated that the evolutionary reductions within the primate nasal capsule mainly affect those structures associated with olfaction, whereas cartilages that are important for the biomechanics of the facial skull of the fetus persist. Anat Rec, 297:1985–2006, 2014. © 2014 Wiley Periodicals, Inc.
Mapping the Nasal Airways: Using Histology to Enhance CT‐Based Three‐Dimensional Reconstruction in Nycticebus
Authors: Deleon Valerie Burke , Smith Timothy D. 
Published: October 2014

ABSTRACTThree‐dimensional reconstructions of imaging data are an increasingly common approach for studying anatomical structure. However, certain aspects of anatomy, including microscopic structure and differentiating tissue types, continue to benefit from traditional histological analyses. We present here a detailed methodology for combining data from microCT and histological imaging to create 3D virtual reconstructions for visualization and further analyses. We used this approach to study the distribution of olfactory mucosa on ethmoturbinal I of an adult pygmy slow loris, Nycticebus pygmaeus. MicroCT imaging of the specimen was followed by processing, embedding, and sectioning for histological analysis. We identified corresponding features in the CT and histological data, and used these to reconstruct the plane of section in the CT volume. The CT volume was then digitally re‐sliced, such that orthogonal sections of the CT image corresponded to histological sections. Histological images were annotated for the features of interest (in this case, the contour of soft tissue on ethmoturbinal I and the extent of olfactory mucosa), and annotations were transferred to binary masks in the CT volume. These masks were combined with density‐based surface reconstructions of the skull to create an enhanced 3D virtual reconstruction, in which the bony surfaces are coded for mucosal function. We identified a series of issues that may be raised in this approach, for example, deformation related to histological processing, and we make recommendations for addressing these issues. This method provides an evidence‐based approach to 3D visualization and analysis of microscopic features in an anatomic context. Anat Rec, 297:2113–2120, 2014. © 2014 Wiley Periodicals, Inc.
Computational Fluid Dynamics as Surgical Planning Tool: A Pilot Study on Middle Turbinate Resection
Authors: Zhao Kai , Malhotra Prashant , Rosen David , Dalton Pamela , Pribitkin Edmund A 
Published: October 2014

ABSTRACTControversies exist regarding the resection or preservation of the middle turbinate (MT) during functional endoscopic sinus surgery. Any MT resection will perturb nasal airflow and may affect the mucociliary dynamics of the osteomeatal complex. Neither rhinometry nor computed tomography (CT) can adequately quantify nasal airflow pattern changes following surgery. This study explores the feasibility of assessing changes in nasal airflow dynamics following partial MT resection using computational fluid dynamics (CFD) techniques. We retrospectively converted the pre‐ and postoperative CT scans of a patient who underwent isolated partial MT concha bullosa resection into anatomically accurate three‐dimensional numerical nasal models. Pre‐ and postsurgery nasal airflow simulations showed that the partial MT resection resulted in a shift of regional airflow towards the area of MT removal with a resultant decreased airflow velocity, decreased wall shear stress and increased local air pressure. However, the resection did not strongly affect the overall nasal airflow patterns, flow distributions in other areas of the nose, nor the odorant uptake rate to the olfactory cleft mucosa. Moreover, CFD predicted the patient's failure to perceive an improvement in his unilateral nasal obstruction following surgery. Accordingly, CFD techniques can be used to predict changes in nasal airflow dynamics following partial MT resection. However, the functional implications of this analysis await further clinical studies. Nevertheless, such techniques may potentially provide a quantitative evaluation of surgical effectiveness and may prove useful in preoperatively modeling the effects of surgical interventions. Anat Rec, 297:2187–2195, 2014. © 2014 Wiley Periodicals, Inc.
Breathing Life Into Dinosaurs: Tackling Challenges of Soft‐Tissue Restoration and Nasal Airflow in Extinct Species
Authors: Bourke Jason M. , Ruger Porter WM. , Ridgely Ryan C. , Lyson Tyler R. , Schachner Emma R. , Bell Phil R. , Witmer Lawrence M. 
Published: October 2014

ABSTRACTThe nasal region plays a key role in sensory, thermal, and respiratory physiology, but exploring its evolution is hampered by a lack of preservation of soft‐tissue structures in extinct vertebrates. As a test case, we investigated members of the “bony‐headed” ornithischian dinosaur clade Pachycephalosauridae (particularlyStegoceras validum) because of their small body size (which mitigated allometric concerns) and their tendency to preserve nasal soft tissues within their hypermineralized skulls. Hypermineralization directly preserved portions of the olfactory turbinates along with an internal nasal ridge that we regard as potentially an osteological correlate for respiratory conchae. Fossil specimens were CT‐scanned, and nasal cavities were segmented and restored. Soft‐tissue reconstruction of the nasal capsule was functionally tested in a virtual environment using computational fluid dynamics by running air through multiple models differing in nasal soft‐tissue conformation: a bony‐bounded model (i.e., skull without soft tissue) and then models with soft tissues added, such as a paranasal septum, a scrolled concha, a branched concha, and a model combining the paranasal septum with a concha. Deviations in fluid flow in comparison to a phylogenetically constrained sample of extant diapsids were used as indicators of missing soft tissue. Models that restored aspects of airflow found in extant diapsids, such as appreciable airflow in the olfactory chamber, were judged as more likely. The model with a branched concha produced airflow patterns closest to those of extant diapsids. These results from both paleontological observation and airflow modeling indicate thatS. validumand other pachycephalosaurids could have had both olfactory and respiratory conchae. Although respiratory conchae have been linked to endothermy, such conclusions require caution in that our re‐evaluation of the reptilian nasal apparatus indicates that respiratory conchae may be more widespread than originally thought, and other functions, such as selective brain temperature regulation, could be important. Anat Rec, 297:2148–2186, 2014. © 2014 Wiley Periodicals, Inc.
Evolutionary and bioinformatic analysis of the spike glycoprotein gene of H120 vaccine strain protectotype of infectious bronchitis virus from India
Authors: Kamble Nitin Machindra , Pillai Aravind S. , Gaikwad Satish S. , Shukla Sanjeev Kumar , Khulape Sagar Aashok , Dey Sohini , Mohan C. Madhan 
Published: October 2014

AbstractThe infectious bronchitis virus is a causative agent of avian infectious bronchitis (AIB), and is is an important disease that produces severe economic losses to the poultry industry worldwide. Recent AIB outbreaks in India have been associated with poor growth in broilers, drop in egg production, and thin egg shells in layers. The complete spike gene of Indian AIB vaccine strain was amplified and sequenced using a conventional reverse transcription polymerase chain reaction and is submitted to the GenBank (accession no KF188436). Phylogenetic analysis revealed that the vaccine strain currently used belongs to H120 genotype, an attenuated strain of Massachusetts (Mass) serotype. Nucleotide and amino acid sequence comparisons have shown that the reported spike gene from Indian isolates have 71.8%–99% and 71.4%–96.9% genetic similarity with the sequenced H120 strain. The study identifies live attenuated IBV vaccine strain, which is routinely used for vaccination, for the first time. Based on nucleotide and amino acid relatedness studies of the vaccine strain with reported IBV sequences from India, it is shown that the current vaccine strain is efficient in controlling the IBV infection. Continuous monitoring of IBV outbreaks by sequencing for genotyping and in vivo cross protection studies for serotyping is not only important for epidemiological investigation but also for evaluation of efficacy of the current vaccine.
Molecular chaperones (TrxA, SUMO, Intein, and GST) mediating expression, purification, and antimicrobial activity assays of plectasin in Escherichia coli
Authors: Chen Xin , Shi Jiawei , Chen Rui , Wen Yaoan , Shi Yu , Zhu Zhe , Guo Songwen , Li Ling 
Published: October 2014

AbstractPlectasin (PS) is the first defensin to be isolated from a fungus, the saprophytic ascomycete Pseudoplectania nigrella, and active against Streptococcus pneumoniae and S. aureus, including antibiotic‐resistant pathogens. To establish a bacterium‐based production system, we compared the efficiency of four molecular chaperones and corresponding cleavage to the expression and purification of plectasin. The results showed that the yield of plectasin combined with thioredoxin A (TrxA) and small ubiquitin‐related modifier (SUMO) was at a higher level (0.0356 and 0.0358 g L−1, respectively) than that with intein (0.0238 g L−1) and glutathione‐S‐transferase (GST) (0.0243 g L−1). TrxA–plectasin, SUMO–plectasin, and 2–plectasin were cleaved at the correct site and purified, but their considerable amount was not cleaved and remained as a fusion peptide. The antimicrobial activity of plectasin cleaved from SUMO—plectasin against methicillin‐resistant Staphylococcus aureus (MRSA), penicillin‐resistant S. pneumoniae (PRSP), and vancomycin‐resistant enterococci (VRE)—was stronger than ampicillin (Amp) for the same amount of substance (P ≤ 0.05). This is the first study to complete and compare the effect of different molecular chaperones and corresponding cleavage with the expression and purification of plectasin in the Escherichia coli expression system, which laid the foundation for future research and may develop the application and production of plectasin.
Iron(III)‐porphyrin Complex FeTSPP: A Versatile Water‐soluble Catalyst for Oxidations in Organic Syntheses, Biorenewables Degradation and Environmental Applications
Authors: Böhm Philipp , Gröger Harald 
Published: October 2014

AbstractThe metal complex FeTSPP (5,10,15,20‐tetrakis‐(4‐sulfonato‐phenyl)‐porphyrin‐iron(III) chloride; also denoted as FeTPPS), which consists of an iron(III) center ion (an environmentally advantageous metal) and a highly water‐soluble heme ligand, represents an exciting and already broadly applied catalyst in the area of “green” oxidation reactions in aqueous media. This commercially available iron catalyst shows a high oxidation potential for many substrates. Further advantages are its high stability and ability not to aggregate in aqueous solution. This Minireview gives an overview of the structural properties of FeTSPP in aqueous solution and selected applications as an oxidation catalyst for organic syntheses, biorenewable degradations, and environmental applications.
Zirconium Materials from Mixed Dicarboxylate Linkers: Enhancing the Stability for Catalytic Applications
Authors: Rasero‐Almansa Antonia M. , Corma Avelino , Iglesias Marta , Sánchez Félix 
Published: October 2014

AbstractWe report the synthesis of two series of zirconium‐based metal–organic frameworks from solutions composed of a mixed‐ligand system (naphthalene dicarboxylic acid/4‐amino‐2,6‐naphthalenedicarboxylic acid or [1,1′‐biphenyl]‐4,4′‐dicarboxylic acid (BPDC)/2‐amino‐[1,1′‐biphenyl]‐4,4′‐dicarboxylic acid). Materials synthesized with low loadings of functionalized linkers exhibit higher long‐term chemical stability and similarly high thermal stability relative to those with 100 % amino linkers. These materials and their corresponding rhodium derivatives prove excellent catalysts in one‐pot reactions. Moreover, the recycling experiments demonstrate an interesting prospect for the long‐term reusability of these catalysts.
Preparation of Chemically Modified RNA Origami Nanostructures
Authors: Endo Masayuki , Takeuchi Yosuke , Emura Tomoko , Hidaka Kumi , Sugiyama Hiroshi 
Published: October 2014

AbstractIn nucleic acid nanotechnology, designed RNA molecules are widely explored because of their usability originating from RNA’s structural and functional diversity. Herein, a method to design and prepare RNA nanostructures by employing DNA origami strategy was developed. A single‐stranded RNA scaffold and staple RNA strands were used for the formation of RNA nanostructures. After the annealing of the mixtures, 7‐helix bundled RNA tile and 6‐helix bundled RNA tube structures were observed as predesigned shapes. These nanostructures were easily functionalized by introducing chemical modification to the RNA scaffolds. The DNA origami method is extended and utilized to construct RNA nanostructures.
Fractional Reactive Extraction for Symmetrical Separation of 4‐Nitro‐D,L‐Phenylalanine in Centrifugal Contactor Separators: Experiments and Modeling
Authors: Tang Kewen , Wen Ping , Zhang Panliang , Huang Yan 
Published: October 2014

AbstractThe enantioselective liquid–liquid extraction of 4‐nitro‐D,L‐phenylalanine (D,L‐Nphy) using PdCl2{(s)‐BINAP} as extractant in dichloroethane was studied experimentally in a countercurrent cascade of 10 centrifugal contactor separators (CCSs) at 5°C, involving flow ratio, extractant concentration, and Cl− concentration. The steady‐state enantiomeric excess (ee) in both stream exits was 90.86% at a 93.29% yield. The predicted value was modeled using an equilibrium stage approach. The correlation between model and experiment was satisfactory. The model was applied to optimize the production of both enantiomers in >97% ee and >99% ee. 14 stages and 16 stages are required for 97% ee and 99% ee for both enantiomers, respectively. Chirality 27:75–81, 2015. © 2014 Wiley Periodicals, Inc.
Study of Al2O3 addition to synthetic Ca‐based sorbents for CO2 sorption capacity and stability in cyclic operations
Authors: Karami Davood , Mahinpey Nader 
Published: October 2014

AbstractSynthetic CaO sorbents were prepared using alumina as a sintering inhibitor via a simple precipitation method. The effects of three mixing procedures on the physical properties and CO2 capture performance of the sorbents were examined. The cyclic CO2 capture performance of the sorbent derived from the precipitation of calcium salts over colloidal alumina (highly dispersed alumina gel) showed the best performance of the three mixing methods. It was found that variation of alumina‐to‐CaO ratios did not significantly change the sintering influence on the sorbent capacity in cyclic operations. CaO particles homogeneously mingled with alumina at higher ratios. Sintering prevention, however, was not observed. This important observation indicates that alumina appeared to merely act as a binder for the fabrication of mechanically enhanced strength particles that are suitable for large‐scale operations. It was determined that CO2 uptake was not dependent on either the mixing technique or the type of synthetic materials incorporated into a sorbent in cyclic operation. The sorbent derived from the precipitation of calcium salts over colloidal alumina with an alumina‐to‐CaO ratio of 20:80 achieved the highest CO2 uptake of 13.1 moles/kg sorbent for half an hour of carbonation in the first cycle and retained a sorption capacity of 6.5 moles/kg sorbent after 17 successive cycles (50 % activity loss), which is in agreement with the reported results. It was demonstrated that the quantity of CO2 uptake increased moderately with decreasing sorbent particle sizes. The effect of pressure on sorbent CO2 uptake was insignificant.