bluuebunny/crossref_metadata_2025 huggingface dataset:
TEMPO‐Promoted C(sp3)−H Hydroxylation of 2‐Oxindoles at Room Temperature
Authors: Zhu Wen‐Ming , Bao Wen‐Hui , Ying Wei‐Wei , Chen Wei‐Ting , Huang Yi‐Ling , Ge Guo‐Ping , Chen Gan‐Ping , Wei Wen‐Ting
Published: January 2018

3‐Hydroxy‐2‐oxindoles are valuable biologically active molecules, and efficient methods for their synthesis under mild condition are highly sought after. Here we report a base‐ and metal‐free C(sp3)−H hydroxylation of 2‐oxindoles promoted by commercially available inexpensive TEMPO and atmospheric air as a hydroxylation reagent at room temperature. This protocol provides a mild and simple strategy for the construction of C−O bonds in moderate to good yields with wide functional group tolerance.
Matriclans shape populations: Insights from the Angolan Namib Desert into the maternal genetic history of southern Africa
Authors: Oliveira Sandra , Fehn Anne‐Maria , Aço Teresa , Lages Fernanda , Gayà‐Vidal Magdalena , Pakendorf Brigitte , Stoneking Mark , Rocha Jorge
Published: January 2018

Objectives

Southern Angola is a poorly studied region, inhabited by populations that have been associated with different migratory movements into southern Africa. Apart from Kx'a‐speaking San foragers and Bantu‐speaking pastoralists, ethnographic and linguistic studies have suggested the existence of an enigmatic array of pre‐Bantu communities, like the Kwepe (formerly Khoe‐Kwadi speakers), Twa and Kwisi. Here, we evaluate previous peopling hypotheses by assessing the relationships between different southern Angolan populations, based on newly collected linguistic data and complete mtDNA genomes.

Materials and methods

We analyzed 295 complete mtDNA genomes and linguistic data from seven groups from the Namib Desert (Himba, Kuvale, Tjimba, Twa, Kwisi, Kwepe) and Kunene Province (!Xun), placing special emphasis on the evaluation of the genealogical consistency of the matriclanic system that characterizes most of these groups.

Results

We found that the maternal genetic structure of all groups from the Namib Desert was strongly shaped by the consistency of their matriclanic system. The tracking of the maternal heritage enhanced population differentiation by genetic drift and is likely to have caused the divergent mtDNA profiles of the Kwepe, Twa, and Kwisi, who probably formed a single population within the spectrum of Bantu genetic variation. Model‐based analyses further suggest that the dominant pastoral groups Kuvale and Himba may be grouped into a Bantu proto‐population which also included the ancestors of present‐day Tjimba and Herero, as well as the Khoe‐Kwadi speaking Damara foragers from Namibia.

Discussion

The view from southwestern Angola offers a new perspective on the populating history of southern Africa and the Bantu expansions by showing that social stratification and different subsistence patterns are not always indicative of remnant groups, but may reflect Bantu‐internal variation and ethnogenesis.
Pretreatment lesional volume impacts clinical outcome and thrombectomy efficacy
Authors: Xie Yu , Oppenheim Catherine , Guillemin Francis , Gautheron Vincent , Gory Benjamin , Raoult Hélène , Soize Sébastien , Felblinger Jacques , Hossu Gabriela , Bracard Serge ,   on behalf of the THRACE investigators
Published: January 2018

Objective

We aimed to characterize the association between pretreatment lesional volume measured on diffusion‐weighted images and functional outcome, and estimate the impact on thrombectomy efficacy for ischemic stroke with anterior proximal intracranial arterial occlusion.

Methods

Anterior circulation ischemic stroke patients who had pretreatment diffusion‐weighted imaging in the THRACE study were included. Lesional volume was semiautomatically segmented. Logistic regression was applied to model clinical outcome as a function of lesional volume. Outcomes included functional independence (modified Rankin Scale [mRS] 0–2), degree of disability (ordinal mRS 0–6), and mortality at 3 months.

Results

Of 298 included patients, with median lesional volume 17.2ml (interquartile range [IQR], 9.2–51.8) and median mRS 2 (IQR, 1–4), 51.0% achieved functional independence. Increased lesional volume was an independent predictor for a lower probability of functional independence (odds ratio [OR], 0.90 [95% confidence interval {CI}, 0.81–0.99] per 10ml; p < 0.001), a less favorable degree of disability (common OR, 0.86 [95% CI, 0.81–0.90] per 10ml; p < 0.001), and a higher mortality rate (OR, 1.21 [95% CI, 1.08–1.37] per 10ml; p < 0.001). For additional thrombectomy, the number of patients needed to treat to achieve functional independence in 1 patient increased with lesional volume (10 for a volume of 80ml; 15 for 135ml). No significant treatment‐by‐dichotomized volume interaction for functional independence and mortality was observed.

Interpretation

Pretreatment lesional volume is an independent predictor for functional outcome in acute ischemic stroke with proximal intracranial occlusion. The clinical benefit of adding mechanical thrombectomy to thrombolysis decreased with the increase of lesional volume. Ann Neurol 2018;83:178–185
Association of prothrombin complex concentrate administration and hematoma enlargement in non–vitamin K antagonist oral anticoagulant–related intracerebral hemorrhage
Authors: Gerner Stefan T. , Kuramatsu Joji B. , Sembill Jochen A. , Sprügel Maximilian I. , Endres Matthias , Haeusler Karl Georg , Vajkoczy Peter , Ringleb Peter A. , Purrucker Jan , Rizos Timolaos , Erbguth Frank , Schellinger Peter D. , Fink Gereon R. , Stetefeld Henning , Schneider Hauke , Neugebauer Hermann , Röther Joachim , Claßen Joseph , Michalski Dominik , Dörfler Arnd , Schwab Stefan , Huttner Hagen B. ,   for the RETRACE II (German‐Wide Multicenter Analysis of Oral Anticoagulation–Associated Intracerebral Hemorrhage II) Investigators
Published: January 2018

Objective

To investigate parameters associated with hematoma enlargement in non–vitamin K antagonist oral anticoagulant (NOAC)‐related intracerebral hemorrhage (ICH).

Methods

This retrospective cohort study includes individual patient data for 190 patients with NOAC‐associated ICH over a 5‐year period (2011–2015) at 19 departments of neurology across Germany. Primary outcome was the association of prothrombin complex concentrate (PCC) administration with hematoma enlargement. Subanalyses were calculated for blood pressure management and its association with the primary outcome. Secondary outcomes include associations with in‐hospital mortality and functional outcome at 3 months assessed using the modified Rankin Scale.

Results

The study population for analysis of primary and secondary outcomes consisted of 146 NOAC‐ICH patients with available follow‐up imaging. Hematoma enlargement occurred in 49/146 (33.6%) patients with NOAC‐related ICH. Parameters associated with hematoma enlargement were blood pressure ≥ 160mmHg within 4 hours and—in the case of factor Xa inhibitor ICH—anti‐Xa levels on admission. PCC administration prior to follow‐up imaging was not significantly associated with a reduced rate of hematoma enlargement either in overall NOAC‐related ICH or in patients with factor Xa inhibitor intake (NOAC: risk ratio [RR] = 1.150, 95% confidence interval [CI] = 0.632–2.090; factor Xa inhibitor: RR = 1.057, 95% CI = 0.565–1.977), regardless of PCC dosage given or time interval until imaging or treatment. Systolic blood pressure levels < 160mmHg within 4 hours after admission were significantly associated with a reduction in the proportion of patients with hematoma enlargement (RR = 0.598, 95% CI = 0.365–0.978). PCC administration had no effect on mortality and functional outcome either at discharge or at 3 months.

Interpretation

In contrast to blood pressure control, PCC administration was not associated with a reduced rate of hematoma enlargement in NOAC‐related ICH. Our findings support the need of further investigations exploring new hemostatic reversal strategies for patients with factor Xa inhibitor–related ICH. Ann Neurol 2018;83:186–196
Insights into the Desaturation of Cyclopeptin and its C3 Epimer Catalyzed by a non‐Heme Iron Enzyme: Structural Characterization and Mechanism Elucidation
Authors: Liao Hsuan‐Jen , Li Jikun , Huang Jhih‐Liang , Davidson Madison , Kurnikov Igor , Lin Te‐Sheng , Lee Justin L. , Kurnikova Maria , Guo Yisong , Chan Nei‐Li , Chang Wei‐chen
Published: January 2018

AsqJ, an iron(II)‐ and 2‐oxoglutarate‐dependent enzyme found in viridicatin‐type alkaloid biosynthetic pathways, catalyzes sequential desaturation and epoxidation to produce cyclopenins. Crystal structures of AsqJ bound to cyclopeptin and its C3 epimer are reported. Meanwhile, a detailed mechanistic study was carried out to decipher the desaturation mechanism. These findings suggest that a pathway involving hydrogen atom abstraction at the C10 position of the substrate by a short‐lived FeIV‐oxo species and the subsequent formation of a carbocation or a hydroxylated intermediate is preferred during AsqJ‐catalyzed desaturation.
p–π Conjugated Polymers Based on Stable Triarylborane with n‐Type Behavior in Optoelectronic Devices
Authors: Meng Bin , Ren Yi , Liu Jun , Jäkle Frieder , Wang Lixiang
Published: January 2018

p–π conjugation with embedded heteroatoms offers unique opportunities to tune the electronic structure of conjugated polymers. An approach is presented to form highly electron‐deficient p–π conjugated polymers based on triarylboranes, demonstrate their n‐type behavior, and explore device applications. By combining alternating [2,4,6‐tris(trifluoromethyl)phenyl]di(thien‐2‐yl)borane (FBDT) and electron‐deficient isoindigo (IID)/pyridine‐flanked diketopyrrolopyrrole (DPPPy) units, we achieve low‐lying lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels, high electron mobilities, and broad absorptions in the visible region. All‐polymer solar cells with these polymers as electron acceptors exhibit encouraging photovoltaic performance with power conversion efficiencies of up to 2.83 %. These results unambiguously prove the n‐type behavior and demonstrate the photovoltaic applications of p–π conjugated polymers based on triarylborane.
RuBisCO‐inspirierte CO2‐Aktivierung und Umwandlung durch einen Iridium(I)‐Komplex
Authors: Langer Jens , Hamza Andrea , Pápai Imre
Published: January 2018

Die Synthese eines neuen Iridium(I)‐Komplexes mit dem Enamidophosphan‐Anion dbuP− und seine einzigartige Reaktivität gegenüber CO2 werden vorgestellt. Der Komplex bindet zwei Äquivalente CO2 und initiiert dabei eine hoch selektive Reaktionskaskade, die reversibel zur Spaltung sowohl von CO2 als auch des Enamido‐Liganden führt. Die computergestützte Analyse des Systems lässt auf die Bildung eines relativ stabilen CO2‐Komplexes als Schlüsselintermediat der CO2‐Spaltung schließen, was experimentell bestätigt werden konnte. Die untersuchte Umwandlung weist einige Parallelen zur enzymatischen CO2‐Fixierung durch RuBisCO auf.
Palladium(II)‐Mediated C−H Tritiation of Complex Pharmaceuticals
Authors: Yang Haifeng , Dormer Peter G. , Rivera Nelo R. , Hoover Andrew J.
Published: January 2018

Tritium‐labeled molecules are critical tools for elucidating the binding and metabolic properties of bioactive compounds, particularly during pharmaceutical discovery. Direct tritiation of inert C−H bonds with T2 gas is an ideal approach for tritium labeling, but significant gaps remain for direct tritiation of structurally complex molecules with diverse functional groups. Here we report the first application of palladium(II) C−H activation chemistry for tritiation with T2 gas. This practical transformation exhibits novel substrate scope and greater functional group tolerance compared to previous state of the art tritiation methods, and has been applied to directly tritiate 9 complex pharmaceuticals and an unprotected dipeptide. The isolated tritium‐labeled products exhibit >15 Ci mmol−1 specific activity, exceeding the typical requirements for application in studies of molecular interaction and metabolism.
Synthesis of a phosphorus‐ and nitrogen‐containing flame retardant and evaluation of its application in waterborne polyurethane
Authors: Wang Shuang , Du Zongliang , Cheng Xu , Liu Yuansen , Wang Haibo
Published: January 2018

A phosphorus‐ and nitrogen‐containing intumescent flame retardant, pentaerythritol di‐N‐hydroxyethyl phosphamide (PDNP), was synthesized with phosphorus oxychloride, pentaerythritol, and ethanolamine as raw materials. Using the prepared PDNP as a chain extender, a series of flame‐retardant waterborne polyurethanes (WPU) were prepared, and their structures were characterized using NMR and Fourier transform infrared spectroscopy (FTIR). Additionally, the thermal properties and flame retardancy of WPU films were investigated by thermogravimetric analysis, limiting oxygen index (LOI) tests, cone calorimeter tests, and thermogravimetry‐FTIR. These results indicated that PDNP materials exhibit good char‐forming ability at high temperature and that PDNP‐modified waterborne polyurethane obtained an LOI value of 26.0% for a PDNP content of 9 wt %. Finally, the morphology and the element distributions of char residues of WPU were analyzed by scanning electron microscopy and energy dispersive spectrometry after combustion. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46093.
Garlic oil–loaded PLGA nanoparticles with controllable size and shape and enhanced antibacterial activities
Authors: Fahmy Sherif Ashraf , Mamdouh Wael
Published: January 2018

The present work focuses on producing polymer composite nanoparticles (NPs) composed of garlic oil (GO) and poly(lactic‐co‐glycolic) acid (PLGA) by the single emulsion/solvent evaporation (SE/SE) method and high‐speed homogenizing. Different preparation parameters were found to greatly affect the stability and size uniformity of the prepared PLGA/GO NP formulations, which were carefully controlled. Scanning electron microscopy, Fourier transform infrared spectroscopy, and UV–vis spectroscopy and dynamic light scattering and zeta potential were used to characterize the NPs. Antibacterial assessment of the prepared PLGA/GO NPs against E. coli and S. aureus was carried out. Interestingly, the NP size ranged between 201 and 319 nm, which is 10 times less than the size of the regular GO particles in bulk solution. The antibacterial activities show enhancement by 70–78% of bacterial inhibition compared with a GO bulk solution. This work sheds light on the potential use of GO NP formulations as nanobiotics and the critical NP preparation parameters that need to be considered. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46133.
Stochastic intrinsic Kriging for simulation metamodeling
Authors: Mehdad Ehsan , Kleijnen Jack P.C.
Published: January 2018

Kriging (or a Gaussian process) provides metamodels for deterministic and random simulation models. Actually, there are several types of Kriging; the classic type is the so‐called universal Kriging, which includes ordinary Kriging. These classic types require estimation of the trend in the input‐output data of the underlying simulation model; this estimation weakens the Kriging metamodel. We therefore consider the so‐called intrinsic Kriging (IK), which originated in geostatistics, and derive IK types for deterministic simulations and random simulations, respectively. Moreover, for random simulations, we derive experimental designs that specify the number of replications that varies with the input combination of the simulation model. To compare the performance of IK and classic Kriging, we use several numerical experiments with deterministic simulations and random simulations, respectively. These experiments show that IK gives better metamodels, in most experiments.
In situ downstream strategies for cost‐effective bio/surfactant recovery
Authors: Najmi Ziba , Ebrahimipour Gholamhossein , Franzetti Andrea , Banat Ibrahim M.
Published: January 2018

Since 60–80% of total costs of production are usually associated with downstream collection, separation, and purification processes, it has become advantageous to investigate how to replace traditional methods with efficient and cost‐effective alternative techniques for recovery and purification of biosurfactants. In the traditional techniques, large volumes of organic solvents are usually used for increasing production cost and the overall environmental burden. In addition, traditional production and separation methods typically carried out in batch cultures reduce biosurfactant yields due to product inhibition and lower biosurfactants activity as a result of interaction with the organic solvents used. However, some in situ recovery methods that allow continuous separation of bioproducts from culture broth leading to an improvement in yield production and fermentation efficiency. For biosurfactants commercialization, enhancement of product capacity of the separation methods and the rate of product removal is critical. Recently, interest in the integration of separation methods with a production step as rapid and efficient techniques has been increasing. This review focuses on the technology gains and potentials for the most common methods used in in situ product removal: foam fractionation and ultrafiltration, especially used to recover and purify two well‐known biosurfactants: glycolipids (rhamnolipids) and lipopeptides (surfactins).
A validated LC‐MS/MS method for the determination of senkyunolide I in dog plasma and its application to a pharmacokinetic and bioavailability studies
Authors: Li Jin‐Qi , Wang Jia‐Feng , Li Jie , Zhang Shu‐han , He Dan , Tong Rong‐Sheng , She Shu‐Ya
Published: January 2018

Senkyunolide I is one of the major bioactive components in the herbal medicine Ligusticum chuanxiong. The aim of this study was to develop and validate a fast, simple and sensitive LC‐MS/MS method for the determination of senkyunolide I in dog plasma. The plasma samples were processed with acetonitrile and separated on a Waters Acquity UPLC BEH C18 column (50 × 2.1 mm, 1.7 μm). The mobile phase consisted of 0.1% formic acid aqueous and acetonitrile was delivered at a flow rate of 0.3 mL min−1. The detection was achieved in the positive selected reaction monitoring mode with precursor‐to‐product transitions at m/z 225.1 → 161.1 for senkyunolide I and at m/z 349.1 → 305.1 for an internal standard. The assay was linear over the tested concentration range, from 0.5 ng mL−1 to 1000 ng mL−1, with a correlation coefficient >0.9992. The mean extraction recovery from dog plasma was within the range of 85.78–93.25%, while the matrix effect of the analyte was within the range of 98.23–108.89%. The intra‐ and inter‐day precisions (RSD) were <12.12% and the accuracy (RR) ranged from 98.89% to 104.24%. The validated assay was successfully applied to pharmacokinetic and bioavailability studies of senkyunolide I in dogs. The results demonstrated that (a) senkyunolide I showed short elimination half‐life (<1 h) in dog, (b) its oral bioavailability was >40% and (c) senkyunolide I showed dose‐independent pharmacokinetic profiles in dog plasma over the dose range of 1–50 mg kg−1.
Use of a novel embolic filter in carotid artery stenting: 30‐Day results from the EMBOLDEN Clinical Study
Authors: Gray William A. , Mehta Manish , Alani Firas , Kasirajan Karthikeshwar , Begg Richard J. , Bacharach J. Michael , Soukas Peter A. ,   EMBOLDEN Clinical Study Investigators
Published: January 2018

Objectives

The EMBOLDEN study was conducted to test the safety and efficacy of a novel emboli protection filter design for use in carotid artery stenting (CAS) in patients with severe carotid stenosis who were at high risk of operative complications from carotid endarterectomy (CEA).

Background

General considerations for filter design usually involve trade‐offs between trackability/profile and wall apposition/capture efficiency. The GORE® Embolic Filter (GEF) is intended to address these design goals via a hybrid construction.

Methods

Patients at high risk for CEA (N = 250) were treated with CAS using the GEF study device paired with an FDA‐approved carotid stent. The primary outcome was death, stroke, and myocardial infarction (MI) at 30 days, compared to a pre‐determined performance goal. Neurologic outcomes were judged by an independent assessor and angiographic results evaluated by an independent central core lab.

Results

The GEF study device was successfully deployed in 96.4% of procedures. The primary endpoint of 30‐day death, stroke, and MI occurred in 4.0% of subjects and was significantly lower than the pre‐defined performance goal (P < 0.001). The 30‐day rate for death and major stroke was 1.2% and for death and any stroke was 3.6%. The rate of major adverse events was 5.4% among octogenarians and 3.2% among non‐octogenarians.

Conclusion

In patients at high risk for CEA undergoing CAS, the GEF not only showed high rates of successful deployment but also met the primary endpoint of low death, stroke, and MI rates, thus demonstrating safety and effectiveness.
A Seed‐Mediated Approach for the Preparation of Modified Heterogeneous Catalysts
Authors: Harmel Justine , Berliet Adrien , Dembélé Kassiogé , Marcelot Cécile , Gay Anne‐Sophie , Ersen Ovidiu , Maury Sylvie , Fécant Antoine , Chaudret Bruno , Serp Philippe , Soulantica Katerina
Published: January 2018

Colloidal chemistry is very efficient in providing nanocrystals of well‐controlled structural characteristics. Although nanoparticles are essential components of heterogeneous catalysts, colloidal methods are rarely employed for their preparation. We have employed a seed‐mediated growth approach for modifying the structural characteristics of a conventional cobalt‐based Fischer–Tropsch catalyst. The Co particles of this catalyst can play the role of seeds for the overgrowth of shape‐ and structure‐controlled cobalt nanostructures by using a simple wet chemical method involving a molecular cobalt precursor and stabilizing agents. Thus, cobalt nanorods exhibiting the hexagonal compact structure were selectively grown on the immobilized Co particles of a reference Co/Al2O3–SiO2 catalyst. The as‐obtained catalyst shows a better stability than a reference catalyst for the Fischer–Tropsch reaction. The removal of most of the ligands from the nanorod catalyst allows the catalyst activity to be improved while maintaining its stability. This is a proof of concept concerning the implementation of wet chemistry nanoparticle synthesis for the modification of heterogeneous catalysts.
Commercial Gold(I) and Gold(III) Compounds Supported on Carbon Materials as Greener Catalysts for the Oxidation of Alkanes and Alcohols
Authors: Carabineiro Sónia A. C. , Martins Luísa M. D. R. S. , Pombeiro Armando J. L. , Figueiredo José L.
Published: January 2018

Strategies are presented for single‐pot efficient oxidative functionalization of cyclohexane and alcohols, under mild conditions, catalysed by Au(I) or Au(III) compounds supported on different carbon materials with three different surface treatments. The obtained materials were tested for the oxidation of cyclohexane under mild conditions (room temperature and atmospheric pressure), using an environmentally friendly oxidant (tert‐butyl hydroperoxide, TBHP, 70 % aqueous solution). All materials were very selective to the production of cyclohexanol and cyclohexanone with no trace of by‐products detected. The catalysts were also tested in the selective oxidation of methyl benzyl alcohol, cyclohexanol, and 2‐octanol with TBHP, under microwave irradiation, to the corresponding aldehydes or ketones. In general, better results are obtained for the heterogenised complexes and that the most efficient support is CNT‐ox‐Na. This is the first report on the oxidation of C−H bonds using the mononuclear gold complexes used; only the oxidation of unsaturated units had been reported previously. The sp3‐C−H activation is much more difficult than the oxidation of unsaturated molecules with molecular oxidants.
Detection of Indistinct Fe−N Stretching Bands in Iron(V) Nitrides by Photodissociation Spectroscopy
Authors: Andris Erik , Navrátil Rafael , Jašík Juraj , Sabenya Gerard , Costas Miquel , Srnec Martin , Roithová Jana
Published: January 2018

We report for the first time infrared spectra of three non‐heme pseudo‐octahedral iron(V) nitride complexes with assigned Fe−N stretching vibrations. The intensities of the Fe−N bands in two of the complexes are extremely weak. Their detection was enabled by the high resolution and sensitivity of the experiments performed at 3 K for isolated complexes in the gas phase. Multireference CASPT2 calculations revealed that the Fe−N bond in the ground doublet state is influenced by two low‐lying excited doublet states. In particular, configuration interaction between the ground and the second excited state leads to avoided crossing of their potential energy surfaces along the Fe−N coordinate, which thus affects the ground‐state Fe−N stretching frequency and intensity. Therefore, DFT calculated Fe−N stretching frequency strongly depends on the amount of Hartree–Fock exchange potential. As a result, by tuning the amount of Hartree–Fock exchange potential in the B3LYP functional, it was possible to obtain theoretical spectra perfectly consistent with the experimental data. The theory shows that the intensity of the Fe−N stretching vibration can almost vanish due to strong coupling with other stretching modes of the ligands.
Synthesis of Galactosylated Glycosylphosphatidylinositol Derivatives from Trypanosoma brucei
Authors: Grube Maurice , Lee Bo‐Young , Garg Monika , Michel Dana , Vilotijević Ivan , Malik Ankita , Seeberger Peter H. , Varón Silva Daniel
Published: January 2018

Trypanosoma brucei uses variant surface glycoproteins (VSGs) to evade the host immune system and ensure parasitic longevity in animals and humans. VSGs are attached to the cell membrane by complex glycosylphosphatidylinositol anchors (GPI). Distinguishing structural feature of VSG GPIs are multiple α‐ and β‐galactosides attached to the conserved GPI core structure. T. brucei GPIs have been associated with macrophage activation and alleviation of parasitemia during infection, acting as disease onset delaying antigens. Literature reports that link structural modifications in the GPIs to changes in biological activity are contradictory. We have established a synthetic route to prepare structurally overlapping GPI derivatives bearing different T. brucei characteristic structural modifications. The GPI collection will be used to assess the effect of galactosylation and phosphorylation on T. brucei GPI immunomodulatory activity, and to perform an epitope mapping of this complex glycolipid as potential diagnostic marker for Trypanosomiasis. A strategy for the synthesis of a complete α‐tetragalactoside using the 2‐naphthylmethyl protecting group and for subsequent attachment of GPI fragments to peptides is presented.
Structure‐Packing‐Property Correlation of Self‐Sorted Versus Interdigitated Assembly in TTF⋅TCNQ‐Based Charge‐Transport Materials
Authors: Niyas M. A. , Ramakrishnan Remya , Vijay Vishnu , Hariharan Mahesh
Published: January 2018

Among the various donor–acceptor (D‐A) charge‐transfer co‐crystals investigated in the past few decades, tetrathiafulvalene‐tetracyanoquinodimethane (F⋅Q, popularly known as TTF⋅TCNQ)‐based co‐crystals have fascinated materials chemists owing to their exceptional conducting and magnetic properties that arise from the packing in crystal structures. Here, crystallographic information files of eighteen F⋅Q‐based co‐crystals are extracted from the Cambridge Structural Database (CSD) and classified into Class 1 (D‐on‐D and A‐on‐A segregated stacks; F⋅Q, F1⋅Q‐F6⋅Q, and F⋅Q1), Class 2 (‐A‐D‐A‐D‐A‐D‐ mixed stacks; F6a⋅Q‐F11⋅Q and F⋅Q2), and Class 3 [‐A‐D‐A‐A‐D‐A‐; Class 3a (F12⋅Q and F13⋅Q) and ‐D‐D‐A‐A‐; Class 3b (F14⋅Q)] systems according to their packing modes. Hirshfeld surface analysis, PIXEL energy calculations, and quantum theory of atoms in molecules (QTAIM) analysis are performed on the selected multicomponent charge‐transfer crystals for the first time, in an attempt to explore the driving forces that give rise to different classes of 3 D crystal packing, which in turn mandates the expedient electronic properties exhibited by the investigated co‐crystals. PIXEL calculations reveal that the dispersion energy component makes the maximum contribution to the total lattice energy for most of the F⋅Q‐based co‐crystals under study. Although the Q‐on‐Q dimer is the energetically most favored dimer in F⋅Q, the substituents on F capable of forming hydrogen‐bonding, C⋅⋅⋅S, and other weak intermolecular interactions result in the greater stability of the F‐on‐F dimer for F1⋅Q‐F6⋅Q (except F2⋅Q). The C⋅⋅⋅S, Csp⋅⋅⋅S, S⋅⋅⋅N, and π⋅⋅⋅π interaction‐driven D‐on‐A dimer is found to be the most stable dimer of all the Class 2 co‐crystals. Band structure and density‐of‐state calculations of the representative co‐crystals in each class indicate different electronic structures according to the packing arrangement. F⋅Q and F6⋅Q with a high interaction of electronic orbitals between D‐on‐D and A‐on‐A in segregated stacks are found to be metal‐like (bandgap,Eg=0.003 eV) and metallic (overlapping bands in the Fermi level), respectively, whereas the polymorph of F6⋅Q belonging to Class 2 (F6a⋅Q) displays a semiconductor‐type band structure (Eg=0.053 eV). F12⋅Q of Class 3a exhibits a metal‐like band structure (Eg=0.001 eV). The fine tuning of chromophores with diverse functional substituents capable of triggering weak intermolecular interactions that give rise to the desired packing and charge‐transfer properties has the potential to open floodgates of opportunity for research in the chemistry of materials and fabrication of efficient electronic devices.
Chemistry of the 8‐Nitroguanine DNA Lesion: Reactivity, Labelling and Repair
Authors: Alexander Katie J. , McConville Matthew , Williams Kathryn R. , Luzyanin Konstantin V. , O'Neil Ian A. , Cosstick Richard
Published: January 2018

The 8‐nitroguanine lesion in DNA is increasingly associated with inflammation‐related carcinogenesis, whereas the same modification on guanosine 3′,5′‐cyclic monophosphate generates a second messenger in NO‐mediated signal transduction. Very little is known about the chemistry of 8‐nitroguanine nucleotides, despite the fact that their biological effects are closely linked to their chemical properties. To this end, a selection of chemical reactions have been performed on 8‐nitroguanine nucleosides and oligodeoxynucleotides. Reactions with alkylating reagents reveal how the 8‐nitro substituent affects the reactivity of the purine ring, by significantly decreasing the reactivity of the N2 position, whilst the relative reactivity at N1 appears to be enhanced. Interestingly, the displacement of the nitro group with thiols results in an efficient and specific method of labelling this lesion and is demonstrated in oligodeoxynucleotides. Additionally, the repair of this lesion is also shown to be a chemically feasible reaction through a reductive denitration with a hydride source.
Grain Size Modulation and Interfacial Engineering of CH3NH3PbBr3 Emitter Films through Incorporation of Tetraethylammonium Bromide
Authors: Jamaludin Nur Fadilah , Yantara Natalia , Ng Yan Fong , Li Mingjie , Goh Teck Wee , Thirumal Krishnamoorthy , Sum Tze Chien , Mathews Nripan , Soci Cesare , Mhaisalkar Subodh
Published: January 2018

Metal halide perovskites have demonstrated breakthrough performances as absorber and emitter materials for photovoltaic and display applications respectively. However, despite the low manufacturing cost associated with solution‐based processing, the propensity for defect formation with this technique has led to an increasing need for defect passivation. Here, we present an inexpensive and facile method to remedy surface defects through a postdeposition treatment process using branched alkylammonium cation species. The simultaneous realignment of interfacial energy levels upon incorporation of tetraethylammonium bromide onto the surface of CH3NH3PbBr3 films contributes favorably toward the enhancement in overall light‐emitting diode characteristics, achieving maximum luminance, current efficiency, and external quantum efficiency values of 11 000 cd m−2, 0.68 cd A−1, and 0.16 %, respectively.
Clinical characteristics of type 2 diabetes patients with discordance between HbA1c and fasting plasma glucose in the real world: An analysis of the ORBIT study
Authors: Shu Hua , Lu Juming , Zhang Puhong , Zhu Dongshan , Li Xian , Ji Jiachao , Zhao Fang , Ji Linong
Published: January 2018

Background

We aimed to determine the clinical characteristics of type 2 diabetes patients on basal insulin therapy with inadequate glucose control due to discordance between glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) in the real world.

Methods

This was a retrospective analysis of data from the ORBIT study in China. Clinical characteristics of patients with discordance between HbA1c and FPG at baseline and at the end of 6 months of follow‐up were analysed using multinomial logistic regression in 4 study groups divided by HbA1c and FPG.

Results

Overall, of 6721 patients initiated on basal insulin, 853 achieved HbA1c < 7% but FPG ≥ 7 mmol/L (group 2), while 997 had FPG < 7 mmol/L but HbA1c ≥ 7% (group 3) at the end of follow‐up. Patients in group 3 had a longer duration of type 2 diabetes compared with those in group 2 (7.22 ± 5.30 vs 6.00 ± 4.80 y, P < .05). Patients on glargine (32.90%) or detemir (36.88%) treatment accounted for a higher proportion of patients with both HbA1c and FPG controlled than those on neutral protamine Hagedorn therapy (23.45%; P < .05). Per the multinomial logistic analysis, higher frequency of self‐monitoring of blood glucose (SMBG) and use of glargine or detemir therapy were significantly inversely associated with risk of discordance between HbA1c and FPG, while dose of insulin was a risk factor for discordance at the end of follow‐up (all P < .05).

Conclusions

Patients treated with insulin analogues (glargine or detemir), instead of neutral protamine Hagedorn, and with more frequent SMBG are more likely to exhibit concordance between HbA1c and FPG.
Complex demographic heterogeneity from anthropogenic impacts in a coastal marine predator
Authors: Oro Daniel , Álvarez David , Velando Alberto
Published: January 2018

Environmental drivers, including anthropogenic impacts, affect vital rates of organisms. Nevertheless, the influence of these drivers may depend on the physical features of the habitat and how they affect life history strategies depending on individual covariates such as age and sex. Here, the long‐term monitoring (1994–2014) of marked European Shags in eight colonies in two regions with different ecological features, such as foraging habitat, allowed us to test several biological hypotheses about how survival changes by age and sex in each region by means of multi‐event capture–recapture modeling. Impacts included fishing practices and bycatch, invasive introduced carnivores and the severe Prestige oil spill. Adult survival was constant but, unexpectedly, it was different between sexes. This difference was opposite in each region. The impact of the oil spill on survival was important only for adults (especially for females) in one region and lasted a single year. Juvenile survival was time dependent but this variability was not synchronized between regions, suggesting a strong signal of regional environmental variability. Mortality due to bycatch was also different between sex, age and region. Interestingly the results showed that the size of the fishing fleet is not necessarily a good proxy for assessing the impact of bycatch mortality, which may be more dependent on the fishing grounds and the fishing gears employed in each season of the year. Anthropogenic impacts affected survival differently by age and sex, which was expected for a long‐lived organism with sexual size dimorphism. Strikingly, these differences varied depending on the region, indicating that habitat heterogeneity is demographically important to how environmental variability (including anthropogenic impacts) and resilience influence population dynamics.
Online Parameter Estimation for Lithium‐Ion Battery by Using Adaptive Observer for Fractional‐Order System
Authors: TAKAMATSU TAKAHIRO , OHMORI HIROMITSU
Published: January 2018

Due to the prevalence of Li‐ion battery, the importance of the battery management system (BMS) is increasing. BMS is the system for managing the operation of batteries and monitoring their state of health. By using the observer containing parameter estimator for analyzing the equivalent circuit model of batteries, the online diagnosis of the batteries becomes possible. However, the Li‐ion battery has complicated dynamics derived from the Warburg impedance, which described the diffusion phenomena of the Li‐ion. Applying fractional calculus to the expression of the system, the dynamics of Warburg impedance can be described simply. By designing the adaptive observer which can treat the system described as fractional‐order system, it is expected to become possible to identify equivalent circuit containing Warburg element online without approximation. In this paper, we designed the Kreisselmeier‐type adaptive observer for the linear fractional‐order system. Then, we applied the proposed observer to the half‐cell of the lithium‐ion battery modeled by Randles circuit under semi‐infinite linear diffusion, and confirm the effectiveness of proposed adaptive observer by numerical simulation.
Reactions of 1‐Arylbenziodoxolones with Azide Anion: Experimental and Computational Study of Substituent Effects
Authors: Yusubov Mekhman S. , Soldatova Natalia S. , Postnikov Pavel S. , Valiev Rashid R. , Svitich Dmitry Y. , Yusubova Roza Y. , Yoshimura Akira , Wirth Thomas , Zhdankin Viktor V.
Published: January 2018

New substituted 1‐arylbenziodoxolones were prepared and their reactivity with azide anion as a nucleophile was investigated. It was found that independent of the presence of substituents, all reactions of 1‐arylbenziodoxolones proceed as nucleophilic substitution of the iodonium leaving group in the electron‐deficient benziodoxolone benzene ring. The presence of bulky substituents in the ortho position of the aryl ring slows the reaction down, while the presence of a moderately electron‐withdrawing bromine substituent in para position to the iodine atom in the benziodoxolone ring moderately increases the rate of substitution. The presence of a strongly electron‐withdrawing nitro group in the para position to the iodine atom in the benziodoxolone ring dramatically increases the rate of substitution. These observations are in agreement with the electronic requirements for internal nucleophilic substitution in the benziodoxole ring. A quantum‐chemical computational study of the possible reaction paths is in agreement with the observed effects of substituents on the reactivity of arylbenziodoxolones in this reaction.
Can ground densification improve seismic performance of the soil‐foundation‐structure system on liquefiable soils?
Authors: Olarte Juan , Dashti Shideh , Liel Abbie B.
Published: January 2018

Over the past few decades, soil densification has been widely employed to reduce the liquefaction hazard or consequences on structures. The decision to mitigate and the design of densification specifications are typically based on procedures that assume free‐field conditions or experience. As a result, the influence of ground densification on the performance of structures and the key mechanisms of soil‐structure interaction remains poorly understood. This paper presents results of four centrifuge tests to evaluate the performance of 3‐ and 9‐story, potentially inelastic structures on liquefiable ground with and without densification. Densification was shown to generally reduce the net excess pore pressures and foundation permanent settlements (although not necessarily to acceptable levels), while amplifying the accelerations on the foundation. The influence of these demands on the performance of the foundation and superstructure depended on the structure's strength and dynamic properties, as well as ground motion characteristics. In addition, densification tended to amplify the moment demand at the beam and column connections, which increased permanent flexural deformations and P‐Δ effects (particularly on the heavier and weaker structure) that could have an adverse effect on foundation rotation. The experimental results presented aim to provide insight into the potential tradeoffs of ground densification, which may reduce foundation permanent settlement, but amplify shaking intensity that can result in larger foundation rotation, flexural drifts, and damage to the superstructure, if not considered in design. These considerations are important for developing performance‐based strategies to design mitigation techniques that improve performance of the soil‐foundation‐structure system in a holistic manner.
Filtering action of embedded massive foundations: New analytical expressions and evidence from 2 instrumented buildings
Authors: Conti Riccardo , Morigi Marco , Rovithis Emmanouil , Theodoulidis Nikos , Karakostas Christos
Published: January 2018

This paper deals with the effect of the foundation mass on the filtering action exerted by embedded foundations. The system under examination comprises a rigid rectangular foundation embedded in a homogeneous isotropic viscoelastic half‐space under harmonic shear waves propagating vertically. The problem is addressed both theoretically and numerically by means of a hybrid approach, where the foundation mass is explicitly included in the kinematic interaction between the foundation and the surrounding soil, thus referring to a “quasi‐kinematic” interaction problem. Based on the results of an extensive parametric study, it is shown that the filtering problem depends essentially on three dimensionless parameters, i.e.: the dimensionless frequency of the input motion, the foundation width‐to‐embedment depth ratio, and the foundation‐to‐soil mass density ratio. In complements to the translational and rotational kinematic interaction factors that are commonly adopted to quantify the filtering effect of rigid massless foundations on the free‐field motion, an additional kinematic interaction factor is introduced, referring to the horizontal motion at the top of a rigid massive foundation. New analytical expressions for the above kinematic interaction factors are proposed and compared with foundation‐to‐free‐field transfer functions computed from available earthquake recordings on two instrumented buildings in LA (California) and Thessaloniki (Greece). Results indicate that the foundation mass can have a strong beneficial effect on the filtering action with increasing foundation‐to‐soil mass density and foundation width‐to‐embedment depth ratios.
Influence of dilution water ionic composition on acute major ion toxicity to the mayfly Neocloeon triangulifer
Authors: Soucek David J. , Mount David R. , Dickinson Amy , Hockett J. Russell
Published: January 2018

Field and laboratory studies have shown that mayflies (Ephemeroptera) tend to be relatively sensitive to elevated major ion concentrations, but little is known about how ionic composition influences these responses. The present study evaluated the acute toxicity of major ion salts to the mayfly Neocloeon triangulifer over a range of background water quality conditions. The mayfly was particularly sensitive to Na2SO4, with the median lethal concentration (LC50) of 1338 mg SO4/L being lower than LC50s reported for 7 other species at that hardness. Increasing hardness of the dilution water from 30 to 150 mg/L (as CaCO3) resulted in doubling of LC50s for sodium salts, and an approximately 1.5-fold increase in LC50 for MgSO4. Potassium salt toxicity was not strongly influenced by hardness, consistent with findings for other species. When hardness was held constant but the Ca to Mg ratio was manipulated, the ameliorative effect on Na2SO4 and NaCl did not appear as strong as when hardness was varied; but for MgSO4 the amelioration relative to Ca activity was similar between the 2 experiments. The toxicity of K salts to N. triangulifer was similar to Na salts on a millimolar basis, which contrasts with several other species for which K salts have been much more toxic. In addition, the toxicity of KCl to N. triangulifer was not notably affected by Na concentration, as has been shown for Ceriodaphnia dubia. Finally, plotting LC50s in terms of ion activity (Cl, SO4, Na, Mg, or K) over the range of Ca activities in dilution water resulted in significant positive relationships, with comparable slopes to those previously observed for C. dubia over the same range of Ca activities. Environ Toxicol Chem 2018;37:1330–1339. © 2018 SETAC
Neural correlates of subjective CS/UCS association in appetitive conditioning
Authors: Tapia León Isabell , Kruse Onno , Stalder Tobias , Stark Rudolf , Klucken Tim
Published: January 2018

Explicit knowledge of conditioned stimulus (CS)/unconditioned stimulus (UCS) associations is proposed as important factor in classical conditioning. However, while previous studies have focused on its roles in fear conditioning, it has been neglected in the context of appetitive conditioning. The present functional magnetic resonance study aimed to investigate neural activation and functional connectivity linked to subjective CS/UCS association in appetitive conditioning. In total, 85 subjects participated in an appetitive acquisition procedure in which a neutral stimulus (CS+) was paired with a monetary reward, while another neutral stimulus (CS‐) was never paired with the reward. Directly afterwards, subjective CS/UCS association was assessed by measuring the extent to which the CS+ was thought to be associated with the UCS compared to the CS‐. Close relationships were established between subjective CS/UCS association and activations in the primary visual cortex (V1) during the early phase of conditioning and in the striatum during the late conditioning phase. In addition, we observed inverse relationships between subjective CS/UCS association and both V1/ventromedial prefrontal cortex (vmPFC) and striatal/vmPFC connectivity. The results suggest the involvement of decoupling vmPFC connectivity in reward learning in general and the roles of attentional processes in the formation of the subjective CS/UCS association during the early phase and reward prediction during the late phase of appetitive conditioning.
Selective Encapsulation and Enhancement of the Emission Properties of a Luminescent Cu(I) Complex in Mesoporous Silica
Authors: Donato Loïc , Atoini Youssef , Prasetyanto Eko Adi , Chen Pengkun , Rosticher Céline , Bizzarri Claudia , Rissanen Kari , De Cola Luisa
Published: January 2018

We describe a synthetic approach to prepare new luminescent silica‐based materials through the encapsulation of a neutral copper(I) complex inside the pores of mesoporous silica nanoparticles (MSN). The copper(I) complex is present, in the solid state, as two polymorphs, blue and yellow emissive, and in solution it shows a pale yellow color that is also mirrored by an emission in the yellow‐orange region of the electromagnetic spectrum. The X‐ray structures of single crystals have been obtained for both polymorphs. The complex encapsulation in MSN is achieved by its entrapment inside micelles followed by condensation of the silica source. Interestingly, the entrapment leads to the isolation of only one species. Indeed, the compound inside the MSN exhibits remarkable photophysical properties, showing an intense blue emission in solution and in the solid state. Powder X‐ray diffraction of the hybrid materials proves that the complex entrapped in MSN is indeed the blue polymorph. The confinement provides not only a method to isolate only one form of the complex, but also a certain rigidity, more stability of the system by protection of the complex from undesirable oxidation, leading to a highly emissive material possessing a photoluminescence quantum yield of 65%.