bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Axially Chiral Cyclo‐Biaryldiol Ligands with Adjustable Dihedral Angles
Authors: Zhang Pengxiang , Yu Jipan , Peng Fei , Wu Xudong , Jie Jiyang , Liu Can , Tian Hua , Yang Haijun , Fu Hua 
Published: October 2016

AbstractA new type of axially chiral cyclo‐[1,1′‐biphenyl]‐2,2′‐diol (CYCNOL) ligands with adjustable dihedral angles have been developed by varying the bridge chain length. Eight‐, nine‐ and ten‐membered cyclo‐ligands were prepared and evaluated by using two representative examples: enantioselective additions of diethylzinc to aldehydes and organometallic reagents to enones. The results revealed that the fine regulation of dihedral angles through variation of the bridge chain length was effective in the asymmetric synthesis.
Solving the Hydrogen and Lithium Substructure of Poly(triazine imide)/LiCl Using NMR Crystallography
Authors: Mesch Maria B. , Bärwinkel Kilian , Krysiak Yaşar , Martineau Charlotte , Taulelle Francis , Neder Reinhard B. , Kolb Ute , Senker Jürgen 
Published: October 2016

AbstractPoly(triazine imide) with incorporated lithium chloride has recently attracted substantial attention due to its photocatalytic activity for water splitting. However, an apparent H/Li disorder prevents the delineation of structure–property relationships, for example, with respect to band‐gap tuning. Herein, we show that through a combination of one‐ and two‐dimensional, multinuclear solid‐state NMR spectroscopy, chemical modelling, automated electron diffraction tomography, and an analysis based on X‐ray pair distribution functions, it is finally possible to resolve the H/Li substructure. In each cavity, one hydrogen atom is bound to a bridging nitrogen atom, while a second one protonates a triazine ring. The two lithium ions within each cavity are positioned between two nitrogen atoms of neighbouring triazine rings. The thereby induced local dipole moments cause slight buckling of the framework and lateral displacements of the Cl− ions at a coherence length below 2 nm. Nevertheless, the average structure conforms to space group P212121. In this way, we demonstrate that, in particular, the above‐mentioned techniques allow for smart interplay in delineating the real structure of PTI/LiCl.
Dioxoiodane Compounds as Versatile Sources for Iodine(I) Chemistry
Authors: Muñiz Kilian , García Belén , Martínez Claudio , Piccinelli Alessandro 
Published: October 2016

AbstractThe general synthesis, isolation and characterization of electrophilic iodine reagents of the general formula R4N[I(O2CAr)2] is reported. These compounds are air‐ and moisture‐stable iodine(I) reagents, which were characterized including X‐ray analysis. They represent conceptually new iodine(I) reagents with anions as stabilizers. These compounds display the expected performance as electrophilic reagents upon interaction with electron‐rich substrates. The performance of these compounds in a total of 47 different reactions of vicinal iodooxygenation of alkenes is studied and some key features on the reagents are revealed.
Copper‐Aβ Peptides and Oxidation of Catecholic Substrates: Reactivity and Endogenous Peptide Damage
Authors: Pirota Valentina , Dell'Acqua Simone , Monzani Enrico , Nicolis Stefania , Casella Luigi 
Published: October 2016

AbstractThe oxidative reactivity of copper complexes with Aβ peptides 1–16 and 1–28 (Aβ16 and Aβ28) against dopamine and related catechols under physiological conditions has been investigated in parallel with the competitive oxidative modification undergone by the peptides. It was found that both Aβ16 and Aβ28 markedly increase the oxidative reactivity of copper(II) towards the catechol compounds, up to a molar ratio of about 4:1 of peptide/copper(II). Copper redox cycling during the catalytic activity induces the competitive modification of the peptide at selected amino acid residues. The main modifications consist of oxidation of His13/14 to 2‐oxohistidine and Phe19/20 to ortho‐tyrosine, and the formation of a covalent His6‐catechol adduct. Competition by the endogenous peptide is rather efficient, as approximately one peptide molecule is oxidized every 10 molecules of 4‐methylcatechol.
D3h‐Symmetrical Shape‐Persistent Macrocycles Consisting of Pyridine–Acetylene–Phenol Conjugates as an Efficient Host Architecture for Saccharide Recognition
Authors: Abe Hajime , Yoneda Tetsuhiro , Ohishi Yuki , Inouye Masahiko 
Published: October 2016

AbstractHexagonal shape‐persistent macrocycles (SPMs) consisting of three pyridine and three phenol rings linked with acetylene bonds were developed as a preorganized host for saccharide recognition by push–pull‐type hydrogen bonding. Three tert‐butyl or 2,4,6‐triisopropylphenyl substituents were introduced on the host to suppress self‐aggregation by steric hindrance. In spite of the simple architecture, association constants Ka of the host with alkyl glycoside guests reached the order of 106 m−1 on the basis of UV/Vis titration experiments. This glycoside recognition was much stronger than that in the cases of acyclic equivalent hosts because of the entropic advantage brought by preorganization of the hydrogen‐bonding sites. Solid–liquid extraction and liquid–liquid transport through a liquid membrane were demonstrated by using native saccharides, and much preference to mannose was observed.
Total Synthesis and Functional Evaluation of Fourteen Derivatives of Lysocin E: Importance of Cationic, Hydrophobic, and Aromatic Moieties for Antibacterial Activity
Authors: Kaji Takuya , Murai Motoki , Itoh Hiroaki , Yasukawa Jyunichiro , Hamamoto Hiroshi , Sekimizu Kazuhisa , Inoue Masayuki 
Published: October 2016

AbstractLysocin E (1) is a structurally complex 37‐membered depsipeptide comprising 12 amino‐acid residues with an N‐methylated amide and an ester linkage. Compound 1 binds to menaquinone (MK) in the bacterial membrane to exert its potent bactericidal activity. To decipher the biologically important functionalities within this unique antibiotic, we performed a comprehensive structure‐activity relationship (SAR) study by systematically changing the side‐chain structures of l‐Thr‐1, d‐Arg‐2, N‐Me‐d‐Phe‐5, d‐Arg‐7, l‐Glu‐8, and d‐Trp‐10. First, we achieved total synthesis of the 14 new side‐chain analogues of 1 by employing a solid‐phase strategy. We then evaluated the MK‐dependent liposomal disruption and antimicrobial activity against Staphylococcus aureus by 1 and its analogues. Correlating data between the liposome and bacteria experiments revealed that membrane lysis was mainly responsible for the antibacterial functions. Altering the cationic guanidine moiety of d‐Arg‐2/7 to a neutral amide, and the C7‐acyl group of l‐Thr‐1 to the C2 or C11 counterpart decreased the antimicrobial activities four‐ or eight‐fold. More drastically, chemical mutation of d‐Trp‐10 to d‐Ala‐10 totally abolished the bioactivities. These important findings led us to propose the biological roles of the side‐chain functionalities.
Green, Multi‐Gram One‐Step Synthesis of Core–Shell Nanocomposites in Water and Their Catalytic Application to Chemoselective Hydrogenations
Authors: Urayama Teppei , Mitsudome Takato , Maeno Zen , Mizugaki Tomoo , Jitsukawa Koichiro , Kaneda Kiyotomi 
Published: October 2016

AbstractWe devise a new and green route for the multi‐gram synthesis of core–shell nanoparticles (NPs) in one step under organic‐free and pH‐neutral conditions. Simply mixing core and shell metal precursors in the presence of solid metal oxides in water allowed for the facile fabrication of small CeO2‐covered Au and Ag nanoparticles dispersed on metal oxides in one step. The CeO2‐covered Au nanoparticles acted as a highly efficient and reusable catalyst for a series of chemoselective hydrogenations, while retaining C=C bonds in diverse substrates. Consequently, higher environmental compatibility and more efficient energy savings were achieved across the entire process, including catalyst preparation, reaction, separation, and reuse.
Cytohistologic correlation of recurrent urothelial carcinoma detected in urinary diversion specimens
Authors: Xing Juan , Roy Somak , Monaco Sara E. , Pantanowitz Liron 
Published: October 2016

BACKGROUNDUrinary diversion specimens from patients who undergo radical cystectomy are often submitted for urine cytology to screen for recurrent urothelial carcinoma. The objective of the current study was to investigate the frequency and cytohistologic features of cancer recurrence in diversion urine specimens.METHODSA 10‐year retrospective review of archival urinary diversion specimens was conducted. For abnormal cytology cases, cytology slides were reviewed, and their cytomorphology and available corresponding histopathology were documented.RESULTSIn total, 679 diversion urine cytology specimens were identified, of which 39 specimens from 25 patients (5.7 %) had abnormal cytology diagnoses. Seven of 25 patients (28%) had postcystectomy surgical follow‐up, and 5 of them manifested with local recurrence. Among the patients who had local recurrence, 3 (60%) developed lymph node and distant metastases and subsequently died. Sites of tumor recurrence included anastomoses in 4 of 5 patients and the penile urethra in 1 of 5 patients. The diversion urine cytology slides in patients who had carcinoma revealed scant, well preserved urothelial cells either alone or in clusters with high‐grade features, including eccentrically located, enlarged, hyperchromatic nuclei; irregular nuclear borders; and high nuclear‐to‐cytoplasmic ratios.CONCLUSIONSThe current data demonstrate that abnormal cytology in urinary diversion specimens is rare but, when present, can help to detect recurrent urothelial carcinoma. Careful examination of these specimens is warranted to screen for features of high‐grade urothelial carcinoma among a degenerated cellular and sometimes inflammatory background. Cancer Cytopathol 2017;125:120–127. © 2016 American Cancer Society.
Safety, Tolerability, and Pharmacokinetics of ARC‐520 Injection, an RNA Interference‐Based Therapeutic for the Treatment of Chronic Hepatitis B Virus Infection, in Healthy Volunteers
Authors: Schluep Thomas , Lickliter Jason , Hamilton James , Lewis David L. , Lai Ching‐Lung , Lau Johnson YN , Locarnini Stephen A. , Gish Robert G. , Given Bruce D. 
Published: October 2016

AbstractARC‐520 Injection, an RNA interference drug for the treatment of hepatitis B that targets cccDNA‐derived viral mRNA transcripts with high specificity, effectively reduces the production of viral proteins and HBV DNA. In this phase 1 randomized, double‐blind, placebo‐controlled study, 54 healthy volunteers (half male, half female) received a single, intravenous dose of 0.01–4.0 mg/kg ARC‐520 Injection (n = 36) or placebo (n = 18). Assessments included safety, tolerability, pharmacokinetics, and pharmacodynamics (cytokines and complement). Pharmacokinetics of the siRNA and peptide excipient components contained in ARC‐520 Injection showed a relatively short half‐life of 3–5 and 8–10 hours, respectively. Dose exposure linearity was demonstrated within the dose range. ARC‐520 Injection was well tolerated, with adverse‐event frequency the same as placebo and no serious adverse events. ARC‐520 Injection was initially found to induce histamine release through mast cell degranulation, resulting in 2 moderate hypersensitivity reactions. However, after initiation of pretreatment with oral antihistamine, no further hypersensitivity reactions occurred. Low‐level, transient complement induction and sporadic, mild, and transient elevations of several cytokines were observed but not associated with any symptoms. ARC‐520 Injection showed a favorable tolerability profile in this single‐dose study in healthy volunteers. Oral antihistamine pretreatment is recommended in the future to offset mast cell degranulation stimulation.
Catalyst and Process Design for the Continuous Manufacture of Rare Sugar Alcohols by Epimerization–Hydrogenation of Aldoses
Authors: Lari Giacomo M. , Gröninger Olivier G. , Li Qiang , Mondelli Cecilia , López Núria , Pérez‐Ramírez Javier 
Published: October 2016

AbstractSugar alcohols are applied in the food, pharmaceutical, polymer, and fuel industries and are commonly obtained by reduction of the corresponding saccharides. In view of the rarity of some sugar substrates, epimerization of a readily available monosaccharide has been proposed as a solution, but an efficient catalytic system has not yet been identified. Herein, a molybdenum heteropolyacid‐based catalyst is developed to transform glucose, arabinose, and xylose into less‐abundant mannose, ribose, and lyxose, respectively. Adsorption of molybdic acid onto activated carbon followed by ion exchange to the cesium form limits leaching of the active phase, which greatly improves the catalyst stability over 24 h on stream. The hydrogenation of mixtures of epimers is studied over ruthenium catalysts, and it is found that the precursor to the desired polyol is advantageously converted with faster kinetics. This is explained by density functional theory on the basis of its more favorable adsorption on the metal surface and the lower energy barrier for the addition of a hydrogen atom to the primary carbon atom. Finally, different designs for a continuous process for the conversion of glucose into mannitol are studied, and it is uncovered that two reactors in series with one containing the epimerization catalyst and the other containing a mixture of the epimerization and hydrogenation catalysts increases the mannitol/sorbitol ratio to 1.5 from 1 for a single mixed‐bed reactor. This opens a prospective route to the efficient valorization of renewables to added‐value chemicals.
Performance optimization of duty‐cycled MAC in delay‐energy constrained sensor network under uniform and nonuniform traffic generation
Authors: Doudou Messaoud , Barcelo‐Ordinas Jose M. , Djenouri Djamel , Badache Nadjib , Garcia‐Vidal Jorge 
Published: October 2016

SummaryDuty‐cycle at the media access control (MAC) layer plays a key role in energy savings and network lifetime extension. It consists in putting a node's radio in the sleep state as soon as it has no communication activity. Traditional wireless sensor network MAC protocols are designed with short duty‐cycles at the cost of long delays. Careful design is required for joint energy‐delay constrained applications, where the optimal parameters should be thoroughly derived. The present paper deals with this issue and mathematically derives optimal values of key MAC parameters under low data rate applications for 3 well‐known duty‐cycled MAC protocols, WiseMAC, SCP‐MAC, and LMAC as representatives of 3 MAC protocol categories, respectively, preamble‐sampling, slotted contention‐based, and frame‐based. The analysis provides also the optimum traffic sampling rate that guarantees the minimum energy consumption. It shows the role of these parameters in achieving the targeted end‐to‐end delay constraints under network models with uniform traffic generation, for ring and grid topologies. As a second contribution, the model is extended to nonuniform traffic scenarios, where a certain percentage of deployed nodes are relays whose role is to balance traffic forwarding and save the overall network energy. The results reveal that different optimal internal MAC parameters and traffic generation rates can be found for different configurations of relay nodes deployment, which achieve minimal network energy consumption while satisfying the application required end‐to‐end delay threshold.
Thalamic neuronal specification and early circuit formation
Authors: Gezelius Henrik , López‐Bendito Guillermina 
Published: October 2016

ABSTRACTThe thalamus is a central structure of the brain, primarily recognized for the relay of incoming sensory and motor information to the cerebral cortex but also key in high order intracortical communication. It consists of glutamatergic projection neurons organized in several distinct nuclei, each having a stereotype connectivity pattern and functional roles. In the adult, these nuclei can be appreciated by architectural boundaries, although their developmental origin and specification is only recently beginning to be revealed. Here, we summarize the current knowledge on the specification of the distinct thalamic neurons and nuclei, starting from early embryonic patterning until the postnatal days when active sensory experience is initiated and the overall system connectivity is already established. We also include an overview of the guidance processes important for establishing thalamocortical connections, with emphasis on the early topographical specification. The extensively studied thalamocortical axon branching in the cortex is briefly mentioned; however, the maturation and plasticity of this connection are beyond the scope of this review. In separate chapters, additional mechanisms and/or features that influence the specification and development of thalamic neurons and their circuits are also discussed. Finally, an outlook of future directions is given. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 830–843, 2017
Nonmotorized recreation and motorized recreation in shrub‐steppe habitats affects behavior and reproduction of golden eagles (Aquila chrysaetos)
Authors: Spaul Robert J. , Heath Julie A. 
Published: October 2016

AbstractDifferent forms of outdoor recreation have different spatiotemporal activity patterns that may have interactive or cumulative effects on wildlife through human disturbance, physical habitat change, or both. In western North America, shrub‐steppe habitats near urban areas are popular sites for motorized recreation and nonmotorized recreation and can provide important habitat for protected species, including golden eagles. Our objective was to determine whether recreation use (i.e., number of recreationists) or recreation features (e.g., trails or campsites) predicted golden eagle territory occupancy, egg‐laying, or the probability a breeding attempt resulted in ≥1 offspring (nest survival). We monitored egg‐laying, hatching and fledging success, eagle behavior, and recreation activity within 23 eagle territories near Boise, Idaho, USA. Territories with more off‐road vehicle (ORV) use were less likely to be occupied than territories with less ORV use (β = −1.6, 85% CI: −2.8 to −0.8). At occupied territories, early season pedestrian use (β = −1.6, 85% CI: −3.8 to −0.2) and other nonmotorized use (β = −3.6, 85% CI: −10.7 to −0.3) reduced the probability of egg‐laying. At territories where eagles laid eggs, short, interval‐specific peaks in ORV use were associated with decreased nest survival (β = −0.5, 85% CI: −0.8 to −0.2). Pedestrians, who often arrived near eagle nests via motorized vehicles, were associated with reduced nest attendance (β = −11.9, 85% CI: −19.2 to −4.5), an important predictor of nest survival. Multiple forms of recreation may have cumulative effects on local populations by reducing occupancy at otherwise suitable territories, decreasing breeding attempts, and causing nesting failure. Seasonal no‐stopping zones for motorized vehicles may be an alternative to trail closures for managing disturbance. This study demonstrates the importance of considering human disturbance across different parts of the annual cycle, particularly where multiple forms of recreation have varying spatiotemporal use patterns that create human–wildlife interactions.
Linking climate to changing discharge at springs in Arches National Park, Utah, USA
Authors: Weissinger R. , Philippi T. E. , Thoma D. 
Published: October 2016

AbstractGroundwater‐fed springs are essential habitat for many dryland species. Climate projections forecast an increasingly arid climate for the southwestern United States. Therefore, an understanding of the relationships between climate and spring discharge is increasingly important. Monthly discharge measurements were recorded from 2001 to 2014 at three jointed bedrock springs in and near Arches National Park, Utah, United States. Discharge was compared with the potential evapotranspiration (PET) and precipitation derived from Daymet gridded climate data. Despite the similarities in location, aquifer type, and climate exposure, all three springs showed different responses to local climate. Two springs emerging from the western aquifer had decreases in discharge during differing portions of their record, while the eastern aquifer spring had stable discharge. At the monthly scale, there was a strong inverse relationship between measured discharge and PET at all three springs, likely due to vegetation accessing the water prior to its surface expression. Annual average winter discharge from both western aquifer springs responded to reductions in 10‐year cumulative winter precipitation, while discharge from the eastern aquifer spring did not correspond well to precipitation within the period of record. Uncertainty in climate projections for aquifer recharge remains high, but increasing air temperatures will likely lead to increased PET and reduced spring surface flow. Better characterization of climate and spring discharge relationships will help managers protect contributing areas that may be more susceptible to groundwater withdrawal and better understand the available habitat for groundwater‐dependent ecosystems and species.
Stimulating TRPV1 externalization and synthesis in dorsal root ganglion neurons contributes to PGE2 potentiation of TRPV1 activity and nociceptor sensitization
Authors: Ma W. , St‐Jacques B. , Rudakou U. , Kim Y.N. 
Published: October 2016

AbstractBackgroundPersistent peripheral sensitization contributes to chronic pain. Plasticity of nociceptive dorsal root ganglion (DRG) neurons (nociceptors) induced by pro‐inflammatory mediators contributes to sensitization. Prostaglandin E2 (PGE2) enriched in injured tissues is known not only directly to sensitize DRG neurons, but also to potentiate sensitizing effects of other pain mediators such as capsaicin and its receptor transient receptor potential vanilloid‐1 (TRPV1). It remains unknown whether PGE2 potentiates TRPV1 activity by stimulating its synthesis, cell surface and axonal trafficking in DRG neurons.MethodsCombined biochemical, morphological, pharmacological and behavioral approaches have been used to address this issue in both in vitro and in vivo models.ResultsPGE2 increased TRPV1 externalization in cultured rat DRG neurons in a time‐ and concentration‐dependent manner, an event blocked by an inhibitor of protein synthesis or anterograde export. EP1 and EP4, but not EP2 and EP3, mediated this event. EP1 agonist‐induced TRPV1 externalization was suppressed by inhibitors of CaMKII, PLC, PKC and PKCε, while EP4 agonist‐induced TRPV1 externalization by inhibitors of cAMP/PKA and ERK/MAPK. Pre‐exposure to PGE2 potentiated release of calcitonin gene‐related peptide from cultured DRG neurons evoked by subsequent capsaicin stimulation. This event was blocked by an inhibitor of protein synthesis or export, suggesting that PGE2‐induced TRPV1 synthesis and externalization is coupled to enhanced TRPV1 activity. Pre‐exposure to PGE2 not only prolonged tactile allodynia evoked by subsequent capsaicin challenge, but also increased TRPV1 levels in L4‐6 DRG, sciatic nerves and plantar skin.ConclusionsOur data indicate that facilitating TRPV1 synthesis, cell surface and axonal trafficking is a novel mechanism underlying PGE2 potentiation of TRPV1 activity.