bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymmetric Synthesis of 3‐Allyloxindoles and 3‐Allenyloxindoles by Scandium(III)‐Catalyzed Claisen Rearrangement Reactions
Authors: Lai Zeng‐Wei , Liu Chuan , Sun Hongbin , You Shu‐Li
Published: August 2017

Scandium‐catalyzed asymmetric Claisen rearrangement reactions of 2‐allyloxyindoles and 2‐propargyloxyindoles provide a novel approach to diverse 3‐allyloxindoles and 3‐allenyloxindoles in excellent yields (up to 99%) and enantioselectivity (up to 99% ee) under mild reaction conditions. The scandium catalyst was derived from Sc(OTf)3 and Pybox ligand.
Dual‐pH/Magnetic‐Field‐Controlled Drug Delivery Systems Based on Fe3O4@SiO2‐Incorporated Salecan Graft Copolymer Composite Hydrogels
Authors: Hu Xinyu , Wang Yongmei , Zhang Liangliang , Xu Man , Zhang Jianfa , Dong Wei
Published: August 2017

Salecan is a water‐soluble extracellular β‐glucan and has excellent physicochemical and biological properties for hydrogel preparation. In this study, a new pH/magnetic field dual‐responsive hydrogel was prepared by the graft copolymerization of salecan with 4‐pentenoic acid (PA) and N‐hydroxyethylacrylamide (HEAA) in the presence of Fe3O4@SiO2 nanoparticles for doxorubicin hydrochloride (DOX) release. Integration of Fe3O4@SiO2 nanoparticles in salecan‐g‐poly(PA‐co‐HEAA) copolymers afforded magnetic sensitivity to the original material. DOX‐loaded hydrogels exhibited a clear capacity for pH/magnetic field dual‐responsive controlled drug release. Lowering the pH to acidic conditions or introducing an external magnetic field caused an enhancement in DOX release. This salecan‐g‐poly(PA‐co‐HEAA)/Fe3O4@SiO2 composite hydrogel is a promising drug carrier for magnetically targeted drug delivery with enhanced DOX cytotoxicity against A549 cells.
Flow features and device‐induced blood trauma in CF‐VADs under a pulsatile blood flow condition: A CFD comparative study
Authors: Chen Zengsheng , Jena Sofen K. , Giridharan Guruprasad A. , Koenig Steven C. , Slaughter Mark S. , Griffith Bartley P. , Wu Zhongjun J.
Published: August 2017

In this study, the flow features and device‐associated blood trauma in 4 clinical ventricular assist devices (VADs; 2 implantable axial VADs, 1 implantable centrifugal VAD, and 1 extracorporeal VAD) were computationally analyzed under clinically relevant pulsatile flow conditions. The 4 VADs were operated at fixed pump speed at a mean rate of 4.5 L/min. Mean pressure difference, wall shear stress, volume distribution of scalar shear stress (SSS), and shear‐induced hemolysis index (HI) were derived from the flow field of each VAD and were compared. The computationally predicted mean pressure difference across the 3 implantable VADs was ~70 mmHg, and the extracorporeal VAD was ~345 mmHg, which matched well with their reported pressure‐flow curves. The axial VADs had higher mean wall shear stress and SSS compared with the centrifugal VADs. However, the residence time of the centrifugal VADs was much longer compared with the axial VADs because of the large volume of the centrifugal VADs. The highest SSS was observed in one axial VAD, and the longest exposure time was observed in 1 centrifugal VAD. These 2 VADs generated the highest HI. The shear‐induced HI varied as a function of flow rate within each cardiac cycle. At fixed pump speed, the HI was greatest at low flow rate due to longer exposure time to shear stress compared with at high flow rate. Subsequently, we hypothesize that to reduce the risk of blood trauma during VAD support, shear stress magnitude and exposure time need to be minimized.
Formation, Structure, and Composition of Methylaluminoxane
Authors: Linnolahti Mikko , Collins Scott
Published: August 2017

The structurally ill‐characterized methylaluminoxane (MAO) is the activator of choice in olefin polymerization catalysis. We have carried out large scale and systematic quantum chemical calculations to simulate the thermodynamics of its formation by controlled hydrolysis of trimethylaluminum (TMA), extending the studies up to 25 Al atoms, and thus, to the real size domain of MAO. In agreement with previous postulates on its structure, MAO is shown to favor cage‐like structures, which commonly contain associated TMA, regardless of size or shape. The sites containing associated TMA are reactive, and explain the function of MAO as a catalyst activator. The compositions of MAOs show overall agreement with experiments, and exhibit structural transitions from chains to rings to sheets to eventually cages as a function of size. The most stable cage structure is obtained for a composition of (MeAlO)16(Me3Al)6, which is in precise agreement with mass spectrometric studies of corresponding anions, and adapts a tubular molecular structure with a molecular weight of 1360 g mol−1. Our mass spectrometric measurements enable detection of both major and minor anion species.
Analysing phase progression in Susan's case
Authors: F. Ferreira Joana , Vasco António B. , Basseches Michael , Santos Andreia , Ferreira João M.
Published: August 2017

This study adds a phase‐by‐phase perspective to the case of Susan, with the aim of better understanding the processes of change in this therapeutic case. A team of 3 raters integrated the sequential phases of the Paradigmatic Complementarity Metamodel with a moment‐by‐moment tracking method—the Developmental Analysis of Psychotherapy Process method—to analyse this therapeutic process and clarify what happened throughout that may explain phase gains and how the therapist facilitated them. The results suggest that Susan evolved in accordance with the sequence of phases proposed by the Paradigmatic Complementarity Metamodel. We illustrate and explain this with therapeutic interactions representative of Susan's development within the evolving therapeutic process. This case study is the third of a series intended to contribute towards the optimization of clinical decisions in therapeutic processes by identifying markers of phase progression and assessing the value of the therapeutic interventions offered.
Tracking and understanding phase progression in Lisa's case
Authors: Ferreira Joana F. , Vasco António B. , Basseches Michael , Conceição Nuno , Vaz‐Velho Catarina , Goldman Rhonda
Published: August 2017

This study adds a phase‐by‐phase perspective to the well‐known, and thoroughly analysed on a moment‐by‐moment basis, case of Lisa. The aim is to see whether this phase‐by‐phase analysis adds anything valuable to the understanding of the processes of change in this case and the therapeutic processes in general.

In this good‐outcome case study, a team of raters integrated the temporal sequencing phase component of the Paradigmatic Complementarity Metamodel (PCM) with a moment‐by‐moment tracking method—the Developmental Analysis of Psychotherapy Process Method (DAPP)—to analyse what occurred along the process that could explain the phase transitions and consolidations observed and how the therapist facilitated them.

We illustrate and explain the therapeutic progression with therapeutic interactions from the dyad. The results suggest that Lisa evolved in accordance with the sequence of phases proposed by the PCM until phase 4 (out of 7). However, only phase 2 gains show evidence of structural consolidation.

The sequence of phases proposed by the PCM seems to represent a natural progression for patients throughout the therapeutic process, and the consideration of a phase‐by‐phase map in analysing and thinking of therapeutic cases may be a valuable tool regarding clinical decision making.
Prevalence of apical periodontitis and frequency of root‐filled teeth in an adult Sudanese population
Authors: Ahmed I. , Ali R.W. , Mudawi A.M.
Published: August 2017

The aim of this study was to estimate the prevalence of teeth with apical periodontitis (AP) and root‐filled (RF) teeth in an adult Sudanese population. Panoramic and periapical radiographs were obtained for 200 patients over 18 years of age seeking routine dental care and attending the dental clinics (University of Khartoum) and the dental hospital (University of Science and Technology) for the first time. The periapical status of all teeth (except third molars) was categorized on the basis of the presence or absence of radiographic signs of AP. In addition, the frequency of RF teeth was recorded. Data were analyzed using the chi‐square test and odds ratio (OR).

The periapical status of 4,967 teeth was assessed. AP in one or several teeth was identified in 95 (47%) patients and in 3.3% of the teeth. The prevalence of AP was higher in molar teeth (7.3%) than in premolar (3.5%) and anterior teeth (0.9%, p ≤ .001). There were 80 (1.6%) RF teeth in 42 (21%) patients. The probability of root‐filling in molar and premolar teeth was almost twice that of anterior teeth (OR with 95% confidence intervals: 1.06 < 1.91 < 3.44, p ≤ .05).

The prevalence of RF teeth increased with age (OR of 48 ± year = 3.06, p ≤ .001). Statistical analysis showed that the probability of radiological detection of AP in RF teeth was 17‐fold higher than in nonfilled ones (OR with 95% confidence intervals: 9.87 < 16.83 < 28.25, p ≤ .001).

Therefore, the probability of AP, RF teeth with or without AP, and missing teeth was high in molar teeth than in anterior or premolar teeth. The frequency of RF teeth was low compared to that demonstrated in most other epidemiological studies. This highlights the need to focus on improving the quality of restorations and the procedure by which root canal is shaped and disinfected.
Wide‐band dual‐resonance capacitive cross‐coupled divide‐by‐5 injection‐locked frequency divider
Authors: Jang Sheng‐Lyang , Lu Kei‐Wu , Huang Yi‐Ru
Published: August 2017

A wide locking range divide‐by‐5 injection‐locked frequency divider (ILFD) is proposed and was implemented in the TSMC 0.18‐μm 1P6M CMOS process. Conventional divide‐by‐5 ILFD has limited locking range. The proposed divide‐by‐5 ILFD is based on a capacitive cross‐coupled voltage‐controlled oscillator (VCO) with a dual‐resonance resonator, which is implemented in the divide‐by‐5 ILFD to obtain a wide overlapped locking range. At the drain‐source bias VDD of 0.9 V and at the incident power of 0 dBm, the measured locking range of the divide‐by‐5 ILFD is 3.2 GHz, from the incident frequency 9.4 to 12.6 GHz, the percentage is 29.09%. The core power consumption is 2.98 mW. The die area is 0.987 × 1.096 mm2.
The effect of trypan blue treatment on autofluorescence of fixed cells
Authors: Shilova Olga N. , Shilov Evgeny S. , Deyev Sergey M.
Published: August 2017

Controlling background fluorescence remains an important challenge in flow cytometry, as autofluorescence can interfere with the detection of chromophores. Furthermore, experimental procedures can also affect cellular fluorescence in certain regions of the emission spectrum. In this work, the effects of fixation, permeabilization, and heating on cellular autofluorescence are analyzed in various spectral regions, along with the influence of trypan blue as a quenching dye for these treatments. The impact of these procedures on the staining of SK‐BR‐3 cells with a dim green fluorophore, a miniSOG (mini Singlet Oxygen Generator) flavoprotein in the form of the recombinant protein DARPin‐miniSOG, is also evaluated. The data presented here indicate that fixation of certain types of cells leads to noticeable increase of the autofluorescence. Our results also suggest that trypan blue should be used as an autofluorescence quencher only with bright green emitters since it interferes with the fluorescent signal in a longer‐wavelength region of the spectrum and as a result causes reduction of the signal from dim green fluorescent agents. © 2017 International Society for Advancement of Cytometry
Resolution ofR‐(−)andS‐(+)‐enantiomers of clenbuterol in pharmaceutical preparations and black‐market products using liquid chromatography–tandem mass spectrometry
Authors: Velasco‐Bejarano Benjamín , Bautista Jahir , Noguez Ma. Olivia , Camacho Evangelina , Rodríguez Martha E. , Rodríguez Leonardo
Published: August 2017

Several banned substances are illegally used by athletes in racemic mixtures for performance enhancement. These include clenbuterol, methyl hexaneamine, methamphetamines, and amphetamines. Clenbuterol is present in a large number of doping samples from Olympic and non‐Olympic athletes that have adverse analytical findings (AAFs). In some cases, the presence of these substances could be the result of consumption of meat contaminated with clenbuterol. In other cases, the origin is not clear. In this study, 27 products with racemic clenbuterol were evaluated using a new analytical methodology for the resolution ofR‐(−) andS‐(+)‐enantiomers of clenbuterol by liquid chromatography–tandem mass spectrometry (LC–MS/MS) using a chiral column in 15 min with good separation. The method developed can also be used for the analysis of other biological matrices such as urine, serum, and meat. The resolution between two peaks' (Rs) value obtained using chromatographic data was 1.03. Both clenbuterol enantiomers were present in all products analyzed and the ratio was nearly 1. The origin of the product was not important for determining the presence of one or both enantiomers. All products displayed a 50:50 ratio of clenbuterol enantiomers. To the best of our knowledge, clenbuterol ratio determination of a large number of pharmaceutical preparations and black‐market products has not been reported previously. The information shown could be used by national anti‐doping organizations and the athletes with AAFs attributed to clenbuterol. Copyright © 2017 John Wiley & Sons, Ltd.
Riverine fish diversity varies according to geographical isolation and land use modification
Authors: Nicol Elizabeth , Stevens Jamie R. , Jobling Susan
Published: August 2017

Understanding the environmental factors driving species‐genetic diversity correlations (SGDCs) is critical for designing appropriate conservation and management strategies to protect biodiversity. Yet, few studies have explored the impact of changing land use patterns on SGDCs specifically in aquatic communities. This study examined patterns of genetic diversity in roach (Rutilus rutilus L.) together with fish species composition across 19 locations in a large river catchment, spanning a gradient in land use. Our findings show significant correlations between some, but not all, species and genetic diversity end points. For example, genetic and species differentiation showed a weak but significant linear relationship across the Thames catchment, but additional diversity measures such as allelic richness and fish population abundance did not. Further examination of patterns in species and genetic diversity indicated that land use intensification has a modest effect on fish diversity compared to the combined influence of geographical isolation and land use intensification. These results indicate that environmental changes in riparian habitats have the potential to amplify shifts in the composition of stream fish communities in poorly connected river stretches. Conservation and management strategies for fish populations should, therefore, focus on enhancing connectivity between river stretches and limit conversion of nearby land to arable or urban use to maintain current levels of biodiversity.
Marine protected area restricts demographic connectivity: Dissimilarity in a marine environment can function as a biological barrier
Authors: Sato Masaaki , Honda Kentaro , Uy Wilfredo H. , Baslot Darwin I. , Genovia Tom G. , Nakamura Yohei , Bernardo Lawrence Patrick C. , Kurokochi Hiroyuki , Pantallano Allyn Duvin S. , Lian Chunlan , Nadaoka Kazuo , Nakaoka Masahiro
Published: August 2017

The establishment of marine protected areas (MPAs) can often lead to environmental differences between MPAs and fishing zones. To determine the effects on marine dispersal of environmental dissimilarity between an MPA and fishing zone, we examined the abundance and recruitment patterns of two anemonefishes (Amphiprion frenatus and A. perideraion) that inhabit sea anemones in different management zones (i.e., an MPA and two fishing zones) by performing a field survey and a genetic parentage analysis. We found lower levels of abundance per anemone in the MPA compared to the fishing zones for both species (n = 1,525 anemones, p = .032). The parentage analysis also showed that lower numbers of fishes were recruited from the fishing zones and outside of the study area into each anemone in the MPA than into each anemone in the fishing zones (n = 1,525 anemones, p < .017). However, the number of self‐recruit production per female did not differ between the MPA and fishing zones (n = 384 females, p = .516). Because the ocean currents around the study site were unlikely to cause a lower settlement intensity of larvae in the MPA, the ocean circulation was not considered crucial to the observed abundance and recruitment patterns. Instead, stronger top‐down control and/or a lower density of host anemones in the MPA were potential factors for such patterns. Our results highlight the importance of dissimilarity in a marine environment as a factor that affects connectivity.
ATLANTIC‐CAMTRAPS: a dataset of medium and large terrestrial mammal communities in the Atlantic Forest of South America
Authors: Lima Fernando , Beca Gabrielle , Muylaert Renata L. , Jenkins Clinton N. , Perilli Miriam L. L. , Paschoal Ana Maria O. , Massara Rodrigo L. , Paglia Adriano P. , Chiarello Adriano G. , Graipel Maurício E. , Cherem Jorge J. , Regolin André L. , Oliveira Santos Luiz Gustavo R. , Brocardo Carlos R. , Paviolo Agustín , Di Bitetti Mario S. , Scoss Leandro M. , Rocha Fabiana L. , Fusco‐Costa Roberto , Rosa Clarissa A. , Da Silva Marina X. , Hufnagell Ludmila , Santos Paloma M. , Duarte Gabriela T. , Guimarães Luiza N. , Bailey Larissa L. , Rodrigues Flávio Henrique G. , Cunha Heitor M. , Fantacini Felipe M. , Batista Graziele O. , Bogoni Juliano A. , Tortato Marco A. , Luiz Micheli R. , Peroni Nivaldo , De Castilho Pedro V. , Maccarini Thiago B. , Filho Vilmar Picinatto , Angelo Carlos De , Cruz Paula , Quiroga Verónica , Iezzi María E. , Varela Diego , Cavalcanti Sandra M. C. , Martensen Alexandre C. , Maggiorini Erica V. , Keesen Fabíola F. , Nunes André V. , Lessa Gisele M. , Cordeiro‐Estrela Pedro , Beltrão Mayara G. , De Albuquerque Anna Carolina F. , Ingberman Bianca , Cassano Camila R. , Junior Laury Cullen , Ribeiro Milton C. , Galetti Mauro
Published: August 2017

Our understanding of mammal ecology has always been hindered by the difficulties of observing species in closed tropical forests. Camera trapping has become a major advance for monitoring terrestrial mammals in biodiversity rich ecosystems. Here we compiled one of the largest datasets of inventories of terrestrial mammal communities for the Neotropical region based on camera trapping studies. The dataset comprises 170 surveys of medium to large terrestrial mammals using camera traps conducted in 144 areas by 74 studies, covering six vegetation types of tropical and subtropical Atlantic Forest of South America (Brazil and Argentina), and present data on species composition and richness. The complete dataset comprises 53,438 independent records of 83 species of mammals, includes 10 species of marsupials, 15 rodents, 20 carnivores, eight ungulates and six armadillos. Species richness averaged 13 species (±6.07 SD) per site. Only six species occurred in more than 50% of the sites: the domestic dog Canis familiaris, crab‐eating fox Cerdocyon thous, tayra Eira barbara, south American coati Nasua nasua, crab‐eating raccoon Procyon cancrivorus and the nine‐banded armadillo Dasypus novemcinctus. The information contained in this dataset can be used to understand macroecological patterns of biodiversity, community, and population structure, but also to evaluate the ecological consequences of fragmentation, defaunation, and trophic interactions.
Lanthanide(III) Sandwich and Half‐Sandwich Complexes with Bulky Cyclooctatetraenyl Ligands: Synthesis, Structures, and Magnetic Properties
Authors: Lorenz Volker , Liebing Phil , Böhme Michael , Buchholz Axel , Plass Winfried , Geue Niklas , Hilfert Liane , Busse Sabine , Engelhardt Felix , Hrib Cristian G. , Edelmann Frank T.
Published: August 2017

Five new lanthanide(III) sandwich and half‐sandwich complexes with bulky cyclooctatetraenyl ligands have been prepared and fully characterized, including single‐crystal X‐ray structure determination. The treatment of anhydrous lanthanide(III) chlorides, LnCl3 (Ln = Pr, Tb, Yb), with 2 equivalents of Li2COT′′ [COT′′ = 1,4‐bis(trimethylsilyl)cyclooctatetraene dianion] followed by crystallization in the presence of a coordinating solvent afforded the anionic sandwich complexes [Li(THF)4][Pr(COT′′)2] (1), [Li(DME)3][Tb(COT′′)2] (2; DME = 1,2‐dimethoxyethane), and [Li(TMEDA)2][Yb(COT′′)2] (3; TMEDA = N,N,N′,N′‐tetramethylethylenediamine). Attempted oxidation of 2 with silver iodide did not afford the neutral terbium(IV) sandwich complex [Tb(COT′′)2]. Instead, the tri(µ‐iodido)‐bridged dinuclear half‐sandwich complex [Li(DME)2][Tb2(µ‐I)3(COT′′)2] (4) was isolated in 72 % yield. In this complex, the Li(DME)2 fragment is attached to one of the µ‐iodido ligands. A closely related binuclear lutetium complex, [Li(DME)3][Lu2(µ‐Cl)3(COTbig)2]·DME (5), was obtained by using the “superbulky“ COTbig ligand [COTbig = 1,4‐bis(triphenylsilyl)cyclooctatetraenyl dianion]. In addition to the spectroscopic and structural characterization, the magnetic properties of the paramagnetic terbium(III) derivative 2 have been investigated and further complemented by ab initio computational methods. These results have been used to discuss the structural requirements for potential terbium(III) single‐ion magnets.
Cyanido‐Bridged FeII–MI Dimetallic Hofmann‐Like Spin‐Crossover Coordination Polymers Based on 2,6‐Naphthyridine
Authors: Piñeiro‐López Lucía , Valverde‐Muñoz Francisco Javier , Seredyuk Maksym , Bartual‐Murgui Carlos , Muñoz M. Carmen , Real José Antonio
Published: August 2017

Two new 3D spin‐crossover (SCO) Hofmann‐type coordination polymers {Fe(2,6‐naphthy)[Ag(CN)2][Ag2(CN)3]} (1; 2,6‐naphthy = 2,6‐naphthyridine) and {Fe(2,6‐naphthy)[Au(CN)2]2}·0.5PhNO2 (2) were synthesized and characterized. Both derivatives are made up of infinite stacks of {Fe[Ag(CN)2]2[Ag2(CN)3]}n and {Fe[Au(CN)2]2}n layered grids connected by pillars of 2,6‐naphthy ligands coordinated to the axial positions of the FeII centers of alternate layers. The in situ generated [Ag2(CN)3]– linkers define wide rectangular windows that favor the interpenetration of three identical 3D networks, strong argentophilic interactions between them, and the generation of a densely packed structure without accessible void spaces. In contrast, the smaller rhombus‐shaped window in 2 affords a structure made up of doubly interpenetrated 3D networks with strong aurophilic interactions between them and accessible voids partially occupied by nitrobenzene molecules. Compound 1 displays a relatively abrupt two‐step SCO in the temperature interval 150–215 K, whereas 2 features an incomplete one‐step SCO behavior (T1/2 = 166 K) that extends over 150 K.
A Direct One‐Pot Synthesis of Asymmetric Dehydrobenzopyrido[12]annulenes and Their Physicochemical Properties
Authors: Baxter Paul N. W. , Karmazin Lydia , DeCian André , Varnek Alexandre , Gisselbrecht Jean‐Paul , Strub Jean‐Marc , Cianferani Sarah
Published: August 2017

A direct one‐pot synthesis of asymmetric dehydrobenzopyrido[12]annulenes 2 and 3 containing one or two pyridine rings is reported that employs a Stephens–Castro mediated cross‐coupling of mixtures of ethynylcuprate precursors. The spectroscopic and theoretical properties of 2 and 3 are compared to those of the threefold symmetric dehydrotribenzo[12]annulene 1, and dehydrotripyrido[12]annulenes 4 and 5 and dehydrodibenzodipyrido[16]annulene byproduct 6, and showed 1–5 to be essentially isoelectronic band gap materials whose electron accepting ability increases with increasing nitrogen incorporation. The structures of 2, 4 and 6 were also unambiguously characterized by X‐ray crystallography. The results highlight the potential dehydroaryl[12]annulenes incorporating pyridines offer for the construction of high carbon content electronic materials.
Synthesis of Uniquely Functionalized Pyrrolines from Hydroxypyrrolines
Authors: Dvorko Marina Yu. , Shabalin Dmitrii A. , Schmidt Elena Yu. , Ushakov Igor A. , Trofimov Boris A.
Published: August 2017

Rare 5‐functionalized Δ1‐pyrrolines were synthesized in good to excellent yields by substitution of the hydroxy group in 5‐hydroxy‐Δ1‐pyrrolines with amines, alcohols, and thiols.
A3‐Coupling Reaction and [Ag(IPr)2]PF6: A Successful Couple
Authors: Beillard Audrey , Métro Thomas‐Xavier , Bantreil Xavier , Martinez Jean , Lamaty Frédéric
Published: August 2017

The recently described homoleptic cationic [Ag(IPr)2]PF6 [IPr = 1,3‐bis(2,6‐diisopropylphenyl)imidazolylidene] complex proved to be a versatile and highly efficient catalyst for the production of propargylamines by using the A3‐coupling reaction. The reaction conditions were equally applicable to aliphatic and aromatic aldehydes and alkynes, including highly hindered aromatic aldehydes. Propargylamines were prepared in short reaction times with low catalyst loadings by using MeOH as a low‐toxicity solvent. In addition, the catalyst was stable enough to support continuous‐flow conditions, which showed that the reaction conditions are scalable.
Cobalt‐Catalyzed Regioselective Hydroboration of Terminal Alkenes
Authors: Zhang Guoqi , Wu Jing , Wang Man , Zeng Haisu , Cheng Jessica , Neary Michelle C. , Zheng Shengping
Published: August 2017

Cobalt(II) catalysts based on flexible PNP or NNN ligands were explored for the regioselective hydroboration of alkenes. A known CoII–PNP pincer complex was found to efficiently catalyze alkene hydroboration with excellent anti‐Markovnikov selectivity, whereas a newly synthesized dinuclear CoII–NNN complex was found to catalyze the hydroboration of a range of aromatic terminal alkenes with good Markovnikov selectivities (up to 98:2, b/l). This represents a rare example of Markovnikov selectivity in the hydroboration of alkenes using an inexpensive, flexible‐ligand‐supported dinuclear cobalt catalyst.
The effects of leader illegitimacy on leaders' and subordinates' responses to relinquishing power decisions
Authors: Ratcliff Nathaniel J. , Vescio Theresa K.
Published: August 2017

This research examined how leader illegitimacy affects leaders' and subordinates' responses to relinquishing power decisions. The processes underlying responses to leader illegitimacy and relinquishing power were also examined. Across four studies, participants were placed in leader roles (Studies 1a/1b) or subordinate roles (Studies 2a/2b) in an online competition. In Studies 1a/1b, participants assigned a leadership role learned, via a leadership skills test, that their leadership was illegitimate or legitimate. By contrast, in Studies 2a/2b, participants assigned a subordinate role were confronted with either an illegitimate leader who retained their power after performing poorly or a legitimate leader who received the leader role after a poor‐performing leader had relinquished their power. Results demonstrated that leaders who felt they did not belong in their leadership role relinquished more power when their leadership was illegitimate (vs. legitimate) and subordinates who felt less in control and greater anger supported illegitimate (vs. legitimate) leaders less.
Liquid‐liquid Extraction Coupled to Batch Injection Analysis for Electroanalysis of Levofloxacin at Low Concentration Level
Authors: Alencar Letícia Machado , de Oliveira Luiz Henrique , Backes Rafael , Rosa Tamires Macedo , de Oliveira Paulo Roberto , da Silva Rodrigo Amorim Bezerra , Trindade Magno Aparecido Gonçalves
Published: August 2017

This work presents the integration between phase‐separation by magnetic‐stirring salt‐induced high‐temperature liquid‐liquid extraction (PS‐MSSI‐HT‐LLE) and batch injection analysis with amperometric detection (BIA‐AD) as an alternative strategy for pre‐concentration of analytes before hydrodynamic electroanalysis. To demonstrate the performance of this analytical system, the emerging contaminant levofloxacin was quantified in tap, aquarium and lake water at low concentration level. In the optimized conditions, BIA‐AD enabled fast (160 h−1) and reproducible results (RSD<2 %) and the PS‐MSSI‐HT‐LLE allowed the detection of levofloxacin concentration levels not detected by direct electroanalysis (70 and 80 nmol L−1) corresponding to 100‐folds enrichment factors. The performance of proposed method was evaluated by addition‐recovery test and was obtained satisfactory recovery values (between 70 and 96 %). Moreover, PS‐MSSI‐HT‐LLE allows the pre‐concentration of many samples simultaneously, which is advantageous over pre‐concentration on working electrode surface (stripping methods).
Genotoxic effects of high dose rate X‐ray and low dose rate gamma radiation in ApcMin/+ mice
Authors: Graupner Anne , Eide Dag M. , Brede Dag A. , Ellender Michele , Lindbo Hansen Elisabeth , Oughton Deborah H. , Bouffler Simon D. , Brunborg Gunnar , Olsen Ann Karin
Published: August 2017

Risk estimates for radiation‐induced cancer in humans are based on epidemiological data largely drawn from the Japanese atomic bomb survivor studies, which received an acute high dose rate (HDR) ionising radiation. Limited knowledge exists about the effects of chronic low dose rate (LDR) exposure, particularly with respect to the application of the dose and dose rate effectiveness factor. As part of a study to investigate the development of colon cancer following chronic LDR vs. acute HDR radiation, this study presents the results of genotoxic effects in blood of exposed mice. CBAB6 F1 Apc+/+ (wild type) and ApcMin/+ mice were chronically exposed to estimated whole body absorbed doses of 1.7 or 3.2 Gy 60Co‐γ‐rays at a LDR (2.2 mGy h−1) or acutely exposed to 2.6 Gy HDR X‐rays (1.3 Gy min−1). Genotoxic endpoints assessed in blood included chromosomal damage (flow cytometry based micronuclei (MN) assay), mutation analyses (Pig‐a gene mutation assay), and levels of DNA lesions (Comet assay, single‐strand breaks (ssb), alkali labile sites (als), oxidized DNA bases). Ionising radiation (ca. 3 Gy) induced genotoxic effects dependent on the dose rate. Chromosomal aberrations (MN assay) increased 3‐ and 10‐fold after chronic LDR and acute HDR, respectively. Phenotypic mutation frequencies as well as DNA lesions (ssb/als) were modulated after acute HDR but not after chronic LDR. The ApcMin/+ genotype did not influence the outcome in any of the investigated endpoints. The results herein will add to the scant data available on genotoxic effects following chronic LDR of ionising radiation. Environ. Mol. Mutagen. 58:560–569, 2017. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society
Electrochemical Lithium Recovery with a LiMn2O4–Zinc Battery System using Zinc as a Negative Electrode
Authors: Kim Seongsoo , Lee Jaehan , Kim Seoni , Kim Seonghwan , Yoon Jeyong
Published: August 2017

Securing lithium resources is an emerging issue owing to the widespread use of lithium‐ion batteries. Recently, an electrochemical lithium recovery method based on the principle of a lithium‐ion battery using a lithium‐capturing electrode and silver as a negative electrode was proposed to meet the increased demand for lithium. However, the high cost of silver is one hindrance to facilitating the practical use of this electrochemical lithium recovery. In this study, zinc, which has a low price, large capacity, and stable redox potential, was proposed as an alternative negative electrode material. Using a LiMn2O4–zinc (LMO‐Zn) battery system, lithium was selectively recovered with an energy consumption of 6.3 Wh mol−1 of lithium recovered. Zinc was reversibly oxidized and reduced during the lithium‐recovery process without side reactions and weight loss.
Flume tests on fluvial erosion mechanisms in till‐bed channels
Authors: Pike Leila , Gaskin Susan , Ashmore Peter
Published: August 2017

Semi‐alluvial stream channels eroded into till and other glacial sediments are common in areas of extensive glacial deposition such as the Great Lakes region and northern interior plains of North America. The mechanics of erosion and erosional weakness of till results in the dominance of fluvial scour and mass erosion due to spontaneous fracture at planes of weakness under shearing flow. There have been few controlled tests looking at erosional mechanisms and resistance of till in river channels. We subjected small blocks of till to unidirectional flows in a laboratory flume to measure the threshold shear stress for erosion and observed the erosion mechanics. Critical shear stress for erosion varied from 7 to 8 Pa for samples with initial saturated moisture content in which a combination of fluvial scour and mass cracking/block erosion dominated. When dried, micro‐fissures occurred in the sample and erosional resistance of the till was extremely low at <1 Pa with erosion appearing to be by fluvial scour. When mobile gravel was added to the test conditions, the gravel reduced the erosion threshold slightly because of the enhanced scour around and below the gravel particles and the tendency for the gravel to aid in crack enlargement. Thus a partial or thin gravel cover over the till may provide no protection from erosion. The erosion processes and effects reflect the complex and contingent mechanics and properties of till, and suggest that the erosion characteristics of till bed semi‐alluvial channels differ from abrasion or plucking dominated processes in more resistant bedrock. Copyright © 2017 John Wiley & Sons, Ltd.
Summary of the development the US Environmental Protection Agency's Medaka Extended One Generation Reproduction Test (MEOGRT) using data from 9 multigenerational medaka tests
Authors: Flynn Kevin , Lothenbach Doug , Whiteman Frank , Hammermeister Dean , Touart Leslie W. , Swintek Joe , Tatarazako Norihisa , Onishi Yuta , Iguchi Taisen , Johnson Rodney
Published: August 2017

In response to various legislative mandates, the US Environmental Protection Agency (USEPA) formed its Endocrine Disruptor Screening Program (EDSP), which in turn, formed the basis of a tiered testing strategy to determine the potential of pesticides, commercial chemicals, and environmental contaminants to disrupt the endocrine system. The first tier of tests is intended to detect the potential for endocrine disruption mediated through estrogen, androgen, or thyroid pathways, whereas the second tier is intended to further characterize the effects on these pathways and to establish a dose–response relationship for adverse effects. One of these tier 2 tests, the Medaka Extended One Generation Reproduction Test (MEOGRT), was developed by the USEPA for the EDSP and, in collaboration with the Japanese Ministry of the Environment, for the Guidelines for the Testing of Chemicals of the Organisation for Economic Co-operation and Development (OECD). The MEOGRT protocol was iteratively modified based on knowledge gained after the successful completion of 9 tests with variations in test protocols. The present study describes both the final MEOGRT protocol that has been published by the USEPA and the OECD, and the iterations that provided valuable insights into nuances of the protocol. The various tests include exposure to 17β-estradiol, 4-t-octylphenol, o,p′- dichlorodiphenyltrichloroethane, 4-chloro-3-methylphenol, tamoxifen, 17β-trenbolone, vinclozolin, and prochloraz. Environ Toxicol Chem 2017;36:3387–3403. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Well‐balanced discontinuous Galerkin method and finite volume WENO scheme based on hydrostatic reconstruction for blood flow model in arteries
Authors: Li Gang , Delestre Olivier , Yuan Li
Published: August 2017

The blood flow model in arteries admits the steady state solutions, for which the flux gradient is nonzero, and is exactly balanced by the source term. In this paper, by means of hydrostatic reconstruction, we construct a high order discontinuous Galerkin method, which exactly preserves the dead‐man steady state, which is characterized by a discharge equal to zero (analogue to hydrostatic equilibrium). Moreover, the method maintains genuine high order of accuracy. Subsequently, we apply the key idea to finite volume weighted essentially non‐oscillatory schemes and obtain a well‐balanced finite volume weighted essentially non‐oscillatory scheme. Extensive numerical experiments are performed to verify the well‐balanced property, high order accuracy, as well as good resolution for smooth and discontinuous solutions.
Rare earth elements geochemistry characteristics and their geological implications of lacustrine oil shale from Chang 7 oil layer in southern Ordos Basin, China
Authors: Li Delu , Li Rongxi , Zhu Zengwu , Wu Xiaoli , Zhao Bangsheng , Cheng Jinghua , Liu Futian
Published: August 2017

Located in the middle‐western area of China, Ordos Basin is a large continental basin with vast petroleum resources. Oil shale of Chang 7 oil layer from Triassic Yanchang Formation represents the typical lacustrine oil shale in China. Oil shale samples were collected from Chang 7 oil layer to study the characteristics of elements geochemistry. The rare earth elements (REEs) concentration of oil shale samples varies from 138.51 to 206.36 μg/g with an average of 162.64 μg/g, close to the average REEs content of the North American shale Composite and slightly higher than the upper continental crust. The chondrite‐normalized and North American shale composite‐normalized REEs distribution patterns explain that oil shale samples, together with silty mudstone samples, may have been derived from a similar terrigenous source. The oil shale deposited mainly in early diagenetic stage B period and the paleoclimate condition was warm and humid with moderate chemical weathering. The whole sedimentary rate of oil shale was low. The source rocks of oil shale were mainly from the felsic rocks and deposited in the continental island arc tectonic setting. The total REE of oil shale samples show positive correlations with Al, Si, K, and ash yield concentration and negative correlations with oil yield, Fe, P, and total sulfur concentration, illustrating that REEs concentration in clay minerals is more than that in organic matter. In addition, the light REEs and heavy REEs are both present in clay minerals and controlled by land‐derived detritus.
Early Paleozoic Tarim Orocline: Insights from paleogeography and tectonic evolution in the Tarim Basin
Authors: Wang Qian , Li Sanzhong , Zhao Shujuan , Mu Dunling , Guo Runhua , Somerville Ian
Published: August 2017

The Tarim Basin, situated between the Paleo‐Asian tectonic domain and the Proto‐Tethys tectonic domain, has undergone a complex tectonic evolutionary process under various geodynamic conditions and has provided abundant information about the dynamic evolution of the peripheral orogens. From the Sinian to Early Ordovician, the Tarim–Qaidam Block was under a regional extensional setting. A carbonate platform developed widely in the basin, flanked by a passive continental margin setting. As the extension enhanced, the spreading of the Proto‐Tethys Ocean was accompanied by subduction and collision, which resulted in a nearly linear subduction zone. Since the Late Cambrian, a continuous oblique subduction and induced sinistral shearing produced an initial bending of the Proto‐Tethys subduction zone, leading to rotation and bend of the original Tarim–Qaidam Block and internal long striped subaqueous paleo‐uplift. During the Middle and Late Ordovician, the Altyn–Qilian Orogen underwent continent–continent collision and continental crust deep subduction. The buckling of the subduction system enhanced under the sinistral transpressional field, resulted in the bending of the Altyn–Qilian Orogen to an S‐shape. The subaqueous uplift areas in the basin were further elevated, rotated, and eroded to show an S‐shape distribution and an unconformity developed between the Silurian sediments and underlying strata. The extent of the carbonate platform decreased, around which developed a high‐energy facies in a platform margin and formed important oil–gas reservoirs. In the Silurian to Middle Devonian, the Tarim Basin evolved into a “two uplifts with a depression” framework under the dual‐directional compressional field. Near the end of the Late Devonian, the S‐shape distribution pattern of paleo‐uplifts was covered by the Upper Devonian and Carboniferous sequence in an angular unconformity. Moreover, the planar distribution of thrust faults with strike‐slip property around the paleo‐uplifts also showed an S‐shape. Accompanying small‐scale strike‐slip faults presented as the radial axial cleavages of plunging vertical folds around a vertical hinge, which indicated that the pre‐existing thrust faults bent around a vertical axis resulting from late strike‐slip faults, demonstrating a coupling between the Tarim Basin and orocline of the Early Paleozoic orogens in the Proto‐Tethys Ocean, called the Tarim Orocline.
Cholesterol regulates polymodal sensory transduction in Müller glia
Authors: Lakk Monika , Yarishkin Oleg , Baumann Jackson M. , Iuso Anthony , Križaj David
Published: August 2017

Over‐ and underexposure to cholesterol activates glia in neurodegenerative brain and retinal diseases but the molecular targets of cholesterol in glial cells are not known. Here, we report that disruption of unesterified membrane cholesterol content modulates the transduction of chemical, mechanical and temperature stimuli in mouse Müller cells. Activation of TRPV4 (transient receptor potential vanilloid type 4), a nonselective polymodal cation channel was studied following the removal or supplementation of cholesterol using the methyl‐beta cyclodextrin (MβCD) delivery vehicle. Cholesterol extraction disrupted lipid rafts and caveolae without affecting TRPV4 trafficking or membrane localization protein. However, MβCD suppressed agonist (GSK1016790A)‐ and temperature‐evoked elevations in [Ca2+]i, and suppressed transcellular propagation of Ca2+ waves. Lowering the free membrane cholesterol content markedly prolonged the time‐course of the glial swelling response, whereas MβCD:cholesterol supplementation enhanced agonist‐ and temperature‐induced Ca2+ signals and shortened the swelling response. Taken together, these data show that membrane cholesterol modulates polymodal transduction of agonists, swelling and temperature stimuli in retinal radial glia and suggest that dyslipidemic retinas might be associated with abnormal glial transduction of ambient sensory inputs.
An econometric method for estimating population parameters from non‐random samples: An application to clinical case finding
Authors: Burger Rulof P. , McLaren Zoë M.
Published: August 2017

The problem of sample selection complicates the process of drawing inference about populations. Selective sampling arises in many real world situations when agents such as doctors and customs officials search for targets with high values of a characteristic. We propose a new method for estimating population characteristics from these types of selected samples. We develop a model that captures key features of the agent's sampling decision. We use a generalized method of moments with instrumental variables and maximum likelihood to estimate the population prevalence of the characteristic of interest and the agents' accuracy in identifying targets. We apply this method to tuberculosis (TB), which is the leading infectious disease cause of death worldwide. We use a national database of TB test data from South Africa to examine testing for multidrug resistant TB (MDR‐TB). Approximately one quarter of MDR‐TB cases was undiagnosed between 2004 and 2010. The official estimate of 2.5% is therefore too low, and MDR‐TB prevalence is as high as 3.5%. Signal‐to‐noise ratios are estimated to be between 0.5 and 1. Our approach is widely applicable because of the availability of routinely collected data and abundance of potential instruments. Using routinely collected data to monitor population prevalence can guide evidence‐based policy making.
Therapies for patients with hepatocellular carcinoma awaiting liver transplantation: A systematic review and meta‐analysis
Authors: Kulik Laura , Heimbach Julie K. , Zaiem Feras , Almasri Jehad , Prokop Larry J , Wang Zhen , Murad M. Hassan , Mohammed Khaled
Published: August 2017

Patients with hepatocellular carcinoma (HCC) who are listed for liver transplantation (LT) are often treated while on the waiting list with locoregional therapy (LRT), which is aimed at either preventing progression of HCC or reducing the measurable disease burden of HCC in order to receive increased allocation priority. We aimed to synthesize evidence regarding the effectiveness of LRT in the management of patients with HCC who were on the LT waitlist. We conducted a comprehensive search of multiple databases from 1996 to April 25, 2016, for studies that enrolled adults with cirrhosis awaiting LT and treated with bridging or down‐staging therapies before LT. Therapies included transcatheter arterial chemoembolization, transarterial radioembolization, ablation, and radiotherapy. We included both comparative and noncomparative studies. There were no randomized controlled trials identified. For adults with T1 HCC and waiting for LT, there were only two nonrandomized comparative studies, both with a high risk of bias, which reported the outcome of interest. In one series, the rate of dropout from all causes at 6 months in T1 HCC patients who underwent LRT was 5.3%, while in the other series of T1 HCC patients who did not receive LRT, the dropout rate at median follow‐up of 2.4 years and the progression rate to T2 HCC were 30% and 88%, respectively. For adults with T2 HCC awaiting LT, transplant with any bridging therapy showed a nonsignificant reduction in the risk of waitlist dropout due to progression (relative risk [RR], 0.32; 95% confidence interval [CI], 0.06‐1.85; I
2 = 0%) and of waitlist dropout from all causes (RR, 0.38; 95% CI, 0.060‐2.370; I
2 = 85.7%) compared to no therapy based on three comparative studies. The quality of evidence is very low due to high risk of bias, imprecision, and inconsistency. There were five comparative studies which reported on posttransplant survival rates and 10 comparative studies which reported on posttransplant recurrence, and there was no significant difference seen in either of these endpoints. For adults initially with stage T3 HCC who received LRT, there were three studies reporting on transplant with any down‐staging therapy versus no downstaging, and this showed a significant increase in 1‐year (two studies, RR, 1.11; 95% CI, 1.01‐1.23) and 5‐year (1 study, RR, 1.17; 95% CI, 1.03‐1.32) post‐LT survival rates for patients who received LRT. The quality of evidence is very low due to serious risk of bias and imprecision. Conclusion: In patients with HCC listed for LT, the use of LRT is associated with a nonsignificant trend toward improved waitlist and posttransplant outcomes, though there is a high risk of selection bias in the available evidence. (Hepatology 2018;67:381‐400).