bluuebunny/crossref_metadata_2025 huggingface dataset:
Adult acute rhinosinusitis guidelines worldwide: similarities and disparities
Authors: Gluck Ofer , Marom Tal , Shemesh Shay , Tamir Sharon Ovnat
Published: May 2018

Background

Acute rhinosinusitis (ARS) is a common respiratory infection that poses a major public healthcare burden with respect to antibiotic consumption and related morbidity. Position statements and national ARS guidelines have been published worldwide, aiming to define diagnostic criteria and outline treatment options. Our objective was to analyze the similarities and disparities between such guidelines.

Methods

We conducted an electronic database search for ARS guidelines using relevant keywords between January 1, 1989, through December 31, 2017. Overall, 25 guidelines from 39 countries were retrieved: 8 from 8 developed countries, and 17 from 31 developing countries. Representative guidelines from developing and developed countries from America, Europe, Africa, Asia, and Oceania were evaluated. We compared the bibliographic data, diagnostic criteria, and treatment recommendations of selected guidelines.

Results

In most developed countries, otorhinolaryngological societies published ARS guidelines, whereas the Ministry of Health formulated the guidelines or adopted generic guidelines prepared by an international organization in developing countries. Many similarities in the diagnostic criteria were found, such as purulent nasal discharge and nasal obstruction sensation. In contrast, maxillary culture as a diagnostic tool was mentioned in developed countries, while it was generally ignored in developing countries. The watchful waiting (WW) policy and abstaining from immediate antibiotics was unanimously adopted in developed countries, which was only partly embraced in developing countries. The recommended universal first‐line antibiotic therapy is amoxicillin, with or without clavulanic acid, whereas options for second‐line and third‐line antibiotic therapies varied.

Conclusion

ARS guidelines from different countries have many similarities. Specific recommendations are tailored to local epidemiology and healthcare accessibility.
Randomized controlled trial comparing the supraglottic airway to use of an endotracheal tube in sinonasal surgery
Authors: Adams Austin S. , Wannemuehler Todd J. , Hull Benjamin , Wu Jeffanie , Chandra Rakesh K. , VonWahlde Kate , Shotwell Matthew S. , Harvey Stephen , Higgins Michael , McQueen Kelly , Turner Justin H.
Published: May 2018

Background

The supraglottic airway (SGA) represents an alternative to endotracheal intubation (endotracheal tube [ETT]) in many types of ambulatory surgery. Adoption of the SGA has progressed slowly in sinonasal surgery due to concerns about airway protection. The purpose of this study was to compare quality of life measures and indices of airway protection between patients undergoing sinonasal surgery who were ventilated via an SGA or ETT.

Methods

Patients undergoing outpatient sinonasal surgery were enrolled into a randomized, single‐blind study in which patients would be ventilated with either an SGA or ETT. At the first postoperative visit, a symptom severity and quality of life questionnaire was completed. Additional objective metrics were extracted from the anesthesia record.

Results

A total of 102 patients were enrolled; 49 assigned to the SGA group and 53 assigned to the ETT group. No significant differences in swallowing function or cough were identified. SGA patients reported more difficulty returning to a normal diet (p = 0.03) with a trend toward reduced throat pain (p = 0.07) and improved phonation (p = 0.06). No significant difference in perioperative oxygen desaturations, emesis, recovery time, or airway blood penetration were identified.

Conclusion

While the use of the SGA results in patient diet modification postoperatively, it may also be associated with a reduction in throat pain and dysphonia. SGA use had no appreciable effect on postanesthesia recovery times, oxygen desaturations, or emesis. Use of the SGA in sinonasal surgery appears to be a safe and reliable option for airway management in selected adult patients undergoing routine ambulatory sinonasal surgery.
A novel blowing agent polyelectrolyte for fabricating intumescent multilayer coating that retards fire on cotton fabric
Authors: Pan Ying , Zhao Hongting
Published: May 2018

Sulfonated melamine‐formaldehyde (SMF) resin was successfully synthesized with a mixture of formaldehyde, melamine, and NaHSO3 in an aqueous solution. Then the SMF was used as the blowing agent to combine with chitosan and phytic acid for fabricating the intumescent flame retardant coating on the surface of the cotton fabric by layer‐by‐layer (LbL) self‐assembled technology. As characterized by X‐ray photoelectron spectroscopy, scanning electron microscopy, and attenuated total reflection Fourier transform infrared spectroscopy, the (chitosan/SMF + phytic acid)n coating was successfully deposited on the surfaces of cotton fibers. Thermogravimetric analysis results exhibited that the thermal stabilities of coated cotton fabrics under nitrogen and air atmosphere were enhanced at temperatures ranging from 400 to 700 °C compared with pure cotton fabric. At 700 °C, the char residues of cotton‐5BL and cotton‐10BL under a nitrogen atmosphere were improved 25.9 and 32 wt % than that of pure cotton fabric, respectively. In the vertical flame test, the self‐extinguishing could be obtained for the cotton‐10BL sample. This work first utilized SMF as negative polyelectrolyte to fabricate intumescent flame retardant coating by LbL self‐assembled technology on cotton fabric to strengthen its thermal stability and flame resistance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46583.
Synthesis and characterization of lignin‐based cationic dye‐flocculant
Authors: Kajihara Masaru , Aoki Dan , Matsushita Yasuyuki , Fukushima Kazuhiko
Published: May 2018

Kraft lignin derivatives having cationic poly 2‐(trimethylamino)ethyl methacrylate side chains were synthesized and their property as dye‐flocculant was investigated. Lignin‐based flocculants having three types of side chain densities and three types of side chain lengths were synthesized by esterification of the lignin hydroxyl groups with bromoisobutyryl groups, atom transfer radical polymerization using 2‐(dimethylamino)ethyl methacrylate, and quaternization of the amino groups. Dye removal test was performed using three organic dyes and the obtained lignin‐based flocculants. The results indicated that the density and the length of the side chains obviously affected the flocculation behavior. When the flocculants containing the same nitrogen amount were compared, the flocculation performance was improved with the increase of the side chain length within the samples having low and middle side chain densities. In the case of the samples having high side chain density, the most efficient sample was not the sample having the longest side chain. Most of the lignin‐based flocculants removed dyes more efficiently than the poly 2‐(trimethylamino)ethyl methacrylate homopolymer. From these results, it was suggested that lignin has a potential character as the core molecule to design the high‐efficient dye‐flocculant. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46611.
Insurance Plus Futures: Agricultural Commodity Price Reform in China
Authors: Kenderdine Tristan
Published: May 2018

China's agricultural support policies are moving towards market institutions through a quasi‐market transition. Ten years of direct minimum purchase price procurement on agricultural commodities resulted in overcapacity, oversupply, mixed‐market signals and grey‐market imports. The Insurance Plus Futures (保险 + 期货) policy pilot in agricultural price reform is a leading indicator of reform in China's agricultural production and rural finance architecture. State procurement of staple crops is now ending, and an interim governance structure is in place for the transition to market prices. This article assesses the historical institutional development of three key economic institutions in Chinese agricultural production: agricultural prices, insurance and futures. It examines government plans to move from a centrally procured to a provincially variable agricultural production model, examines the provincial sectoral target‐price mechanisms constructed in 2016–2018 as interim price‐setting mechanisms, looks at the emergence of government mandated agricultural insurance as a measure to cover the subsidy previously served by the minimum purchase price system and assesses the prospects for institutional development of futures contracts, commodities exchanges and price formation institutions in China.
A simulation approach for power calculation in large cohort studies based on multistate models
Authors: Jenny Bastian , Beyersmann Jan , Schumacher Martin
Published: May 2018

Realistic power calculations for large cohort studies and nested case control studies are essential for successfully answering important and complex research questions in epidemiology and clinical medicine. For this, we provide a methodical framework for general realistic power calculations via simulations that we put into practice by means of an R‐based template. We consider staggered recruitment and individual hazard rates, competing risks, interaction effects, and the misclassification of covariates. The study cohort is assembled with respect to given age‐, gender‐, and community distributions. Nested case‐control analyses with a varying number of controls enable comparisons of power with a full cohort analysis. Time‐to‐event generation under competing risks, including delayed study‐entry times, is realized on the basis of a six‐state Markov model. Incidence rates, prevalence of risk factors and prefixed hazard ratios allow for the assignment of age‐dependent transition rates given in the form of Cox models. These provide the basis for a central simulation‐algorithm, which is used for the generation of sample paths of the underlying time‐inhomogeneous Markov processes. With the inclusion of frailty terms into the Cox models the Markov property is specifically biased. An “individual Markov process given frailty” creates some unobserved heterogeneity between individuals. Different left‐truncation‐ and right‐censoring patterns call for the use of Cox models for data analysis. p‐values are recorded over repeated simulation runs to allow for the desired power calculations. For illustration, we consider scenarios with a “testing” character as well as realistic scenarios. This enables the validation of a correct implementation of theoretical concepts and concrete sample size recommendations against an actual epidemiological background, here given with possible substudy designs within the German National Cohort.
Characteristics and Antioxidant Activity of Lignans in Schisandra chinensis and Schisandra sphenanthera from Different Locations
Authors: Wang Xinting , Yu Jiahui , Li Wei , Wang Chunmei , Li He , Ju Wenbo , Chen Jianguang , Sun Jinghui
Published: April 2018

Twenty Schisandra samples were collected from different locations. Contents of 7 lignans in the samples were determined and analyzed by HPLC method coupled with hierarchical clustering analysis (HCA) and principal component analysis (PCA), and the antioxidant capacity of Schisandra from the different locations was evaluated by reducing power, ferric thiocyanate (FTC) and 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH) assay. The results showed that there was a significant difference in the content of lignans between Schisandra chinensis and Schisandra sphenanthera. The Schisandra sphenanthera samples in the southwest of China were significantly different from those from the other locations. The antioxidant capacity of Schisandra chinensis was significantly superior to that of Schisandra sphenanthera, and the main antioxidant components were schisandrol A, schisandrol B and schisandrin B based on the result of discrimination analyses. The differences in the chemical composition and antioxidant activity of lignans in Schisandra chinensis and Schisandra sphenanthera from the different locations were investigated in this study, which may provide an experimental basis for the quality control of Schisandra.
A Carbapenem‐Based Off–On Fluorescent Probe for Specific Detection of Metallo‐β‐Lactamase Activities
Authors: Mao Wuyu , Wang Yaqun , Qian Xiana , Xia Lingying , Xie Hexin
Published: May 2018

Metallo‐β‐lactamase is one of the major clinical threats because this β‐lactam‐hydrolyzing enzyme confers significant resistance to most β‐lactam antibiotics, including carbapenems, among bacterial pathogens. Reported herein is a novel fluorogenic sensor for the specific detection of metallo‐β‐lactamase activities. This carbapenem‐based reagent exhibits excellent selectivity to metallo‐β‐lactamase over other serine‐β‐lactamases, including serine carbapenemases. The usefulness of this probe was further demonstrated in the rapid identification of metallo‐β‐lactamase‐expressing pathogenic bacteria.
Heterologous Biosynthesis of Fungal Indole Sesquiterpene Sespendole
Authors: Kudo Kosei , Liu Chengwei , Matsumoto Tomoyuki , Minami Atsushi , Ozaki Taro , Toshima Hiroaki , Gomi Katsuya , Oikawa Hideaki
Published: May 2018

Indole sesquiterpene sespendole, which has been isolated from the filamentous fungus Pseudobotrytis terrestris FKA‐25, is a specific inhibitor of lipid droplet synthesis in mouse macrophages. The biosynthetic pathway that involves genes encoding six enzymes (spdEMBQHJ) was elucidated through heterologous expression of spd genes in Aspergillus oryzae, biotransformation experiments, and in vitro enzymatic reactions with a recombinant protein, thereby revealing the mechanism underlying the characteristic modification on the indole ring, catalyzed by a set of prenyltransferase (SpdE)/cytochrome P450 (SpdJ) enzymes. Functional analysis of the homologous genes encoding these enzymes involved in the biosynthesis of lolitrem allowed a biosynthetic pathway for the bicyclic ring skeleton fused to the indole ring to be proposed.
Effect of Catalyst Supports on Water‐Gas Shift Reaction at Ultrahigh Temperatures Using Syngas
Authors: Chein Rei-Yu , Fang Chien-Min , Chyou Yau-Ping , Chang Shih-Hsien
Published: May 2018

Monometallic and bimetallic catalysts (Pt, Ni, and Pt‐Ni) with single support (Al2O3, TiO2) and composite support (CeO2/Al2O3, CeO2/TiO2) were prepared and tested for water‐gas shift reaction in a tubular quartz reactor. Syngas and steam with different steam‐to‐carbon ratios served as feedstock. The operating pressure was fixed while the reaction temperature was varied. The measured results indicated that the monometallic Ni/Al2O3 catalyst exhibits the lowest CO conversion and H2 yield as compared with other catalysts. About the same CO conversion can be obtained from Pt and Pt‐Ni catalysts with single or composite support. However, higher H2 yield can be achieved from the TiO2‐supported catalyst compared with those supported by Al2O3. The experimental data also indicated that good thermal stability can be reached for the Pt‐based catalysts studied.
An Exceptionally Efficient Co−Co2P@N, P‐Codoped Carbon Hybrid Catalyst for Visible Light‐Driven CO2‐to‐CO Conversion
Authors: Xu Yong , Mo Jiang , Fu Zi‐Cheng , Liu Su , Yang Zhi , Fu Wen‐Fu
Published: May 2018

Artificial photosynthesis has attracted wide attention, particularly the development of efficient solar light‐driven methods to reduce CO2 to form energy‐rich carbon‐based products. Because CO2 reduction is an uphill process with a large energy barrier, suitable catalysts are necessary to achieve this transformation. In addition, CO2 adsorption on a catalyst and proton transfer to CO2 are two important factors for the conversion reaction, and catalysts with high surface area and more active sites are required to improve the efficiency of CO2 reduction. Here, a visible light‐driven system for CO2‐to‐CO conversion is reported, which consists of a heterogeneous hybrid catalyst of Co and Co2P nanoparticles embedded in carbon nanolayers codoped with N and P (Co‐Co2P@NPC) and a homogeneous RuII‐based complex photosensitizer. The average generation rate of CO of the system was up to 35 000 μmol h−1 g−1 with selectivity of 79.1 % in 3 h. Linear CO production at an exceptionally high rate of 63 000 μmol h−1 g−1 was observed in the first hour of reaction. Inspired by this highly active catalyst, Co@NC and Co2P@NPC materials were also synthesized and their structure, morphology, and catalytic properties for CO2 photoreduction were explored. The results showed that the nanoparticle size, partially adsorbed H2O molecules on the catalyst surface, and the hybrid nature of the systems influenced their photocatalytic CO2 reduction performance.
High‐Level Ab Initio Calculations of Intermolecular Interactions: Heavy Main‐Group Element π‐Interactions
Authors: Krasowska Małgorzata , Schneider Wolfgang B. , Mehring Michael , Auer Alexander A.
Published: May 2018

This work reports high‐level ab initio calculations and a detailed analysis on the nature of intermolecular interactions of heavy main‐group element compounds and π systems. For this purpose we have chosen a set of benchmark molecules of the form MR3, in which M=As, Sb, or Bi, and R=CH3, OCH3, or Cl. Several methods for the description of weak intermolecular interactions are benchmarked including DFT‐D, DFT‐SAPT, MP2, and high‐level coupled cluster methods in the DLPNO‐CCSD(T) approximation. Using local energy decomposition (LED) and an analysis of the electron density, details of the nature of this interaction are unraveled. The results yield insight into the nature of dispersion and donor–acceptor interactions in this type of system, including systematic trends in the periodic table, and also provide a benchmark for dispersion interactions in heavy main‐group element compounds.
Reductive Coupling and Loss of N2 from Magnesium Diazomethane Derivatives
Authors: Zhou Jiliang , Liu Liu Leo , Cao Levy L. , Stephan Douglas W.
Published: May 2018

The reductive coupling of two diazomethanes is affected by reaction with [(NacNacMes)Mg]2 affording the species [(NacNacMes)Mg(N2CPh2)]2 2 and [(NacNacMes)Mg(N2C(C6H4)2)]2 3. These species containing N4 linkages readily evolve the central N2 at 50 and 75 °C to give the Mg–imide products [(NacNacMes)Mg(NCPh2)]2 (4) and [(NacNacMes)Mg(NC(C6H4)2)]2 (5), respectively. The mechanism for the loss of N2 was considered computationally. Compounds 2 and 3 reacted with O2 to liberate the tetrazene (Ph2N2)2 6 and the hydrazine ((C6H4)2CN)2 7, whereas reactions with Me3SiOSO2CF3 or Me3SiCl with 2 and 3 provide the related silyl imines 8 and 9, respectively.
Spin precession: A spin‐1 case study using irreducible tensor operators
Authors: Siminovitch David J.
Published: April 2018

Using a Cartesian operator basis set, precession equations have previously been derived for spin‐1 systems using some 23 Cartesian operator commutators. We avoid the explicit evaluation of these commutators, and use instead fundamental properties of irreducible tensor operators (ITO)to obtain these precession equations. First, advantage is taken of the angle‐axis parametrization of the rotation matricesthat transform second‐rankITOunder rotation to define the unitarily equivalent rotation matrixthat transforms second‐rank Cartesian tensors. From this latter transformation, and using simple matrix analysis techniques, all the equations that describe spin‐1 precession in the presence of radiofrequency fields and resonance offsets are obtained. Second, information on theITOcommutation relationscan be encoded in angular momentum coupling coefficients in a generalized spin precession equation. In the case of spin‐1, this leads to a set of coupled differential equations for the statistical tensor components. After transformation of these components to their Cartesian counterparts, the corresponding vector differential equations that define the time evolution of the Cartesian operator expectation values are easily solved, again using simple matrix analysis. This solution yields all the equations that describe spin‐1 precession in the presence of radiofrequency fields, resonance offsets, and the quadrupolar interaction.
Solid‐state nuclear magnetic resonance and nuclear quadrupole resonance as complementary tools to study quadrupolar nuclei in solids
Authors: Szell Patrick M.J. , Bryce David L.
Published: April 2018

Solid‐state nuclear magnetic resonance (SSNMR) spectroscopy has largely overtaken nuclear quadrupole resonance (NQR) spectroscopy for the study of quadrupolar nuclei. In addition to information on the electric field gradient, SSNMR spectra may offer additional information concerning other NMR interactions such as magnetic shielding. With continued technological advances contributing to developments such as higher magnetic fields, SSNMR boasts several practical advantages over NQR. However, NQR is still a relevant technique, as it may often be the most practical approach in cases of extremely large quadrupolar coupling constants. Here, we discuss the advantages and disadvantages of SSNMR and NQR spectroscopies, with the quadrupolar halogens serving as examples. The purpose of this article is to serve as a guide on using SSNMR and NQR as complementary tools, covering some of their practicalities, limitations, and experimental challenges.
Introduction to average Hamiltonian theory. I. Basics
Authors: Brinkmann Andreas
Published: April 2018

Understanding the dynamics of electron or nuclear spins during a magnetic resonance experiment requires to solve the Schrödinger equation for the spin system considering all contributions to the Hamiltonian from interactions of the spins with each other and their surroundings. In general, this is a difficult task as these interaction terms can be both time‐dependent and might not commute with each other. A powerful tool to analytically approximate the time evolution is average Hamiltonian theory, in which a time‐independent effective Hamiltonian is taking the place of the time‐dependent Hamiltonian. The effective Hamiltonian is subjected to the Magnus expansion, allowing to calculate the effective Hamiltonian to a certain order. The goal of this paper is to introduce average Hamiltonian theory in a rigorous but educational manner. The application to two composite pulses in NMR spectroscopy is used to demonstrate important aspects of average Hamiltonian theory.
Evolutionary algorithms and nuclear magnetic resonance of oriented molecules
Authors: Burnell E. Elliott , de Lange Cornelis A. , Dong Ronald Y. , Meerts W. Leo , Weber Adrian C. J.
Published: April 2018

In this article, we discuss the progress achieved with the use of evolutionary algorithms for the analysis of 1H Nuclear Magnetic Resonance spectra of solutes in orientationally ordered liquids. With these tools the analysis of extremely complex spectra that were hitherto impossible to solve has now become eminently feasible. We discuss applications to 2 molecules of special interest: (a) hexamethylbenzene, which is a text book example of steric hindrance between adjacent rotating methyl groups; and (b) cyclohexane which is the standard example of interconversion between various molecular conformations. New interesting physics is obtained in both cases.
Two‐pulse frequency‐hopped excitation
Authors: Michal Carl A. , Dong Ronald Y.
Published: April 2018

The use of frequency‐hopped pulse pairs and pulse pair trains for exciting NMR signals is introduced. Pairs of pulses, each pair lasting one nutation period about the effective field in the rotating frame, can be used to efficiently tip nuclear spin magnetization. In the limit where the frequency difference between the partners in a pair is large, the magnetization dynamics mimic those of an ordinary rectangular rf pulse with rf amplitude scaled down by a factor of π/2. When the amplitude of the applied rf begins to approach the offset frequency however, the excitation bandwidth broadens dramatically in a manner reminiscent of a composite pulse. The effects of the frequency‐hopped pulse pairs is described with analytical calculations and numerical simulations, and are shown to agree well with experiment.
A tribute to Alexander Davidson Bain: An NMR pioneer and mentor at McMaster University
Authors: Anand Christopher , Berno Bob , Boulton Stephen , Brook Michael A. , Epand Richard , Field Timothy R. , Goward Gillian R. , Hazendonk Paul , Melacini Giuseppe
Published: April 2018

In this tribute to our friend, mentor and colleague Alexander Davidson Bain we have collectively recapitulated the milestones of his career at McMaster university. We start from Alex's scientific and educational achievements and continue with his accomplishments as a community and infrastructure builder. We attempt to provide a sense of the breadth and depth of his seemingly endless scientific contributions while at McMaster by briefly summarizing selected representative examples from his body of work. Following Alex's lead, the scientific account is mixed with anecdotes and “bits of wisdom” we fondly remember from our interactions and collaborations with him. We also touch upon his brilliant and nurturing educational style and his “aggregator” role within the McMaster and wider NMR communities. We conclude with a more personal picture of Alex D. Bain, in which his scientific excellence and profound intellect are inextricably tied to his kind, nurturing and optimistic character and to his uniquely wry humor. He was not just a “good guy,” he was the epitome of the “good guy.”
Dependence of electron paramagnetic resonance spectral lineshapes on molecular tumbling: Nitroxide radical in water:glycerol mixtures
Authors: Clark Ashley , Sedhom Jessica , Elajaili Hanan , Eaton Gareth R. , Eaton Sandra S.
Published: April 2018

Electron paramagnetic resonance spectra of nitroxide radicals are reporters of molecular tumbling correlation times. The concepts of electron paramagnetic resonance and molecular tumbling are demonstrated by examination of spectra of the radical tempol (4‐hydroxy‐2,2,6,6‐tetramethylpiperidin‐1‐oxyl) in water:glycerol mixtures. Analysis of the spectral line shapes with the Kivelson model and computer simulation with EasySpin are discussed. Values of the tumbling correlation times obtained by the two methods are shown to be in good agreement. Comparison of the experimental tumbling correlation times with values calculated with the Stokes‐Einstein model indicates a slip coefficient of 0.066, which is consistent with other reports for nitroxides in various solvents.
Unusually large scalar coupling between geminal protons in a saturated pyrimidine
Authors: Mazzola Eugene P. , Gutierrez Osvaldo , Fraenkel Gideon A. , Chow Albert , Doyle Michael P. , Mandler Michael D. , Dykstra Ryan , Garg Deeya , Ridge Clark D.
Published: April 2018

An unusually large geminal coupling has been observed in a stereochemically rigid system that permits a favorable coupling alignment between the methylene protons and an adjacent carbon‐carbon double bond. Such couplings have been found to depend on both the alignment of a line connecting the geminal hydrogens and the nodal plane of the adjacent double bond, and the orientation of lone‐pair electrons on adjacent heteroatoms. Electron withdrawal from symmetrical bonding orbitals results in more slightly positive geminal coupling constants while that from antisymmetrical bonding orbitals produces more negative coupling constants, which has been found to be very large in certain rigid systems.
Systematic image alteration due to phase accumulation during RF pulse excitation in pure phase encode magnetic resonance imaging
Authors: McDonald Tess , MacMillan Bryce , Newling Ben , Balcom Bruce J.
Published: April 2018

The SPI/SPRITE class of techniques in magnetic resonance imaging are pure phase encode methods that are well established for systems with short transverse signal lifetimes. Applying a broadband radio‐frequency pulse in the presence of a magnetic field gradient is unconventional in MRI but fundamental to these methods. Ordinarily, it is assumed that the excitation is instantaneous and any possible phase evolution during the RF pulse is ignored. High quality, quantitative imaging of a variety of samples over many years suggests that the off‐resonance effects of the RF pulse, with consequent phase accumulation during the pulse, are not significant. However, a reconsideration of the RF pulse behavior in related work has shown that phase accumulation during the pulse may be non‐negligible in some circumstances.

The effect of phase accumulation during the RF pulse is investigated through simulation of one‐dimensional SPI experiments and is shown to manifest as a systematic scaling of the image field‐of‐view (FOV). The FOV scaling effect is also verified experimentally. One‐dimensional profiles of a cylindrical elastomer sample were acquired employing a 2.4 T horizontal bore magnet. Experiments were undertaken with variation of the experimental RF pulse duration. Under typical experimental parameters, neglecting the phase accumulation during the RF pulse is acceptable.
Sustainable facility location‐allocation problem under uncertainty
Authors: Wang Cheng , Hu Zhuo , Xie Ming , Bian Yuxiang
Published: April 2018

This paper addresses a sustainable facility location‐allocation problem under uncertain environment with considering economic and sustainable dimensions simultaneously. We establish three types of belief degree constrained mathematical models to investigate the problem under the optimistic value criterion, the pessimistic value criterion, and the Hurwicz criterion. The corresponding crisp determinants of the models are derived, and several properties of the models are also discussed. The theoretical analysis demonstrates that the optimal objective values of the models crucially depend on the predetermined confidence level given by decision makers. What's more, the total cost of the problem in the belief degree constrained Hurwicz criterion model decreases as Hurwicz coefficient becomes larger. To evaluate the performance of our novel models, several numerical examples are conducted. The numerical results are obtained by using the standard optimization software LINGO.
Monotherapy Is Good Enough for Patients With Mild‐to‐Moderate Alzheimer's Disease: A Network Meta‐Analysis of 76 Randomized Controlled Trials
Authors: Tsoi Kelvin K.F. , Chan Joyce Y.C. , Chan Felix C.H. , Hirai Hoyee W. , Kwok Timothy C.Y. , Wong Samuel Y.S.
Published: May 2018

Memantine and the acetylcholinesterase inhibitors (AChEIs) are two classes of drugs that are used to treat patients with Alzheimer's disease (AD). We conducted a network meta‐analysis of randomized controlled trials to compare the treatment effectiveness of monotherapy or combination therapy A total of 23,707 AD patients in 76 randomized trials were identified. In patients with mild‐to‐moderate AD, monotherapy with donepezil, galantamine, or rivastigmine were superior to placebo in enhancing cognitive functions and activities of daily living, whereas monotherapy with donepezil or memantine were superior to placebo in improving behavioral symptoms. However, combination therapy with AChEIs and memantine did not show additional benefit than monotherapy. In patients with moderate‐to‐severe AD, neither monotherapy nor combination therapy were superior to placebo in any domain measurement. Combination therapy with memantine and AChEIs is confirmed to have no additional benefits over monotherapy.
Weak interspecific interactions in a sagebrush steppe? Conflicting evidence from observations and experiments
Authors: Adler Peter B. , Kleinhesselink Andrew , Hooker Giles , Taylor Joshua B. , Teller Brittany , Ellner Stephen P.
Published: April 2018

Stable coexistence requires intraspecific limitations to be stronger than interspecific limitations. The greater the difference between intra‐ and interspecific limitations, the more stable the coexistence, and the weaker the competitive release any species should experience following removal of competitors. We conducted a removal experiment to test whether a previously estimated model, showing surprisingly weak interspecific competition for four dominant species in a sagebrush steppe, accurately predicts competitive release. Our treatments were (1) removal of all perennial grasses and (2) removal of the dominant shrub, Artemisia tripartita. We regressed survival, growth, and recruitment on the locations, sizes, and species identities of neighboring plants, along with an indicator variable for removal treatment. If our “baseline” regression model, which accounts for local plant–plant interactions, accurately explains the observed responses to removals, then the removal coefficient should be non‐significant. For survival, the removal coefficients were never significantly different from zero, and only A. tripartita showed a (negative) response to removals at the recruitment stage. For growth, the removal treatment effect was significant and positive for two species, Poa secunda and Pseudoroegneria spicata, indicating that the baseline model underestimated interspecific competition. For all three grass species, population models based on the vital rate regressions that included removal effects projected 1.4‐ to 3‐fold increases in equilibrium population size relative to the baseline model (no removal effects). However, we found no evidence of higher response to removal in quadrats with higher pretreatment cover of A. tripartita, or by plants experiencing higher pre‐treatment crowding by A. tripartita, raising questions about the mechanisms driving the positive response to removal. While our results show the value of combining observations with a simple removal experiment, more tightly controlled experiments focused on underlying mechanisms may be required to conclusively validate or reject predictions from phenomenological models.
Drivers of leaf carbon exchange capacity across biomes at the continental scale
Authors: Smith Nicholas G. , Dukes Jeffrey S.
Published: April 2018

Realistic representations of plant carbon exchange processes are necessary to reliably simulate biosphere–atmosphere feedbacks. These processes are known to vary over time and space, though the drivers of the underlying rates are still widely debated in the literature. Here, we measured leaf carbon exchange in >500 individuals of 98 species from the Neotropics to high boreal biomes to determine the drivers of photosynthetic and dark respiration capacity. Covariate abiotic (long‐ and short‐term climate) and biotic (plant type, plant size, ontogeny, water status) data were used to explore significant drivers of temperature‐standardized leaf carbon exchange rates. Using model selection, we found the previous week's temperature and soil moisture at the time of measurement to be a better predictor of photosynthetic capacity than long‐term climate, with the combination of high recent temperatures and low soil moisture tending to decrease photosynthetic capacity. Non‐trees (annual and perennials) tended to have greater photosynthetic capacity than trees, and, within trees, adults tended to have greater photosynthetic capacity than juveniles, possibly as a result of differences in light availability. Dark respiration capacity was less responsive to the assessed drivers than photosynthetic capacity, with rates best predicted by multi‐year average site temperature alone. Our results suggest that, across large spatial scales, photosynthetic capacity quickly adjusts to changing environmental conditions, namely light, temperature, and soil moisture. Respiratory capacity is more conservative and most responsive to longer‐term conditions. Our results provide a framework for incorporating these processes into large‐scale models and a data set to benchmark such models.
Habitat availability and ontogenetic shifts alter bottlenecks in size‐structured fish populations
Authors: Cantin Ariane , Post John R.
Published: April 2018

For species that utilize different habitats throughout their life cycle, the habitat limitation at a given stage can act as a bottleneck on population abundance, impacting density‐dependent processes such as individual growth and survival. We explore the influence of habitat limitation on population dynamics by developing a multi‐stage population model based on lake‐dwelling rainbow trout (Oncorhynchus mykiss) populations where adults occupy the lake habitat but use tributaries for spawning and juvenile rearing. The model details density‐dependent ecological processes and ontogenetic habitat shifts, harvest mortality, and the impact of climate on growth. We ran model simulations using a range of early life stage habitat availabilities and climatic conditions representative of the native range of rainbow trout in Canada and compared the results to empirical data. The results suggest that (1) increases in early life stage habitat leads to increases in population abundance but, due to density‐dependent processes, also results in slower growing stunted populations; (2) population bottlenecks can occur at any life stage, even at the adult stage if spawning and rearing habitats are abundant; (3) when the level of competition for early life stages is increased, inter‐cohort competition can lead to population cycles. The model's conclusions are further reinforced by empirical data showing a similar trend in the relationship between fish density and maximum size and providing evidence that limited early life stage habitat leads to lower fish densities and larger fish size. We provide a model that links environmental conditions to population dynamics and is useful for fisheries management and habitat conservation decisions.
Large‐Scale Transdisciplinary Collaboration for Adaptation Research: Challenges and Insights
Authors: Cundill Georgina , Harvey Blane , Tebboth Mark , Cochrane Logan , Currie‐Alder Bruce , Vincent Katharine , Lawn Jon , Nicholls Robert. J. , Scodanibbio Lucia , Prakash Anjal , New Mark , Wester Philippus , Leone Michele , Morchain Daniel , Ludi Eva , DeMaria‐Kinney Jesse , Khan Ahmed , Landry Marie‐Eve
Published: May 2018

An increasing number of research programs seek to support adaptation to climate change through the engagement of large‐scale transdisciplinary networks that span countries and continents. While transdisciplinary research processes have been a topic of reflection, practice, and refinement for some time, these trends now mean that the global change research community needs to reflect and learn how to pursue collaborative research on a large scale. This paper shares insights from a seven‐year climate change adaptation research program that supports collaboration between more than 450 researchers and practitioners across four consortia and 17 countries. The experience confirms the importance of attention to careful design for transdisciplinary collaboration, but also highlights that this alone is not enough. The success of well‐designed transdisciplinary research processes is also strongly influenced by relational and systemic features of collaborative relationships. Relational features include interpersonal trust, mutual respect, and leadership styles, while systemic features include legal partnership agreements, power asymmetries between partners, and institutional values and cultures. In the new arena of large‐scale collaborative science efforts, enablers of transdisciplinary collaboration include dedicated project coordinators, leaders at multiple levels, and the availability of small amounts of flexible funds to enable nimble responses to opportunities and unexpected collaborations.
The magma evolution sequence and geodynamic setting in the Qibaoshan ore area, Wulian County, Shandong Province, China
Authors: Yu Guang‐Yuan , Wang Zhi‐Gao , Wang Ke‐Yong , Li Jian‐Feng , Wang Cheng‐Yang
Published: May 2018

The Qibaoshan ore area is located in Wulian town, Shandong Province, which is an important polymetallic metallogenic zone containing gold, copper, lead, and zinc. The polymetallic mineralization is mostly related to the Qibaoshan complex. The Qibaoshan complex is composed mainly of pyroxene diorite, andesitic porphyrite, pyroxene andesite porphyrite, amphibole andesite porphyrite, diorite porphyrite, and granodiorite porphyry, among which granodiorite–porphyry is the main wall rock of gold and copper ore body, whereas lead and zinc mineralization is closely related to diorite porphyrite. A combined study of laser ablation–inductively coupled plasma–mass spectrometry zircon U–Pb dating and geochemical analyses (major and trace elements) for 5 Mesozoic plutons from the Qibaoshan complex was carried out to determine their ages, petrogenesis, and tectonic setting. The U–Pb zircon ages measured by laser ablation–inductively coupled plasma–mass spectrometry indicate that the Qibaoshan complex was emplaced in 3 stages, represented by the ~175 Ma pyroxene diorite, ~129 Ma andesitic porphyrite/ porphyrite, ~125 Ma granodiorite‐porphyry, and ~112 Ma diorite porphyrite. Systematic diagenetic chronology and rock geochemistry show that formation of ~175 Ma pyroxene diorite in Qibaoshan ore‐concentrated area is possibly related to the transformation environment from compression to extension of the Sulu orogenic belt and/or of the subduction of the Pacific Plate, whereas the formation of the Early Cretaceous subvolcanic rock has a volcanic arc affinity related to subduction of the Pacific Plate. Based on the previous studies, this paper argues that the metallogenic age of Qibaoshan polymetallic ore‐concentrated area is 125–105 Ma, which is formed in the volcanic arc dynamics environment of the Pacific Plate subduction in the Late Yanshanian. In addition, a small amount of 610–799 Ma and 1.8 Ga was developed in the samples of the pyroxene diorite and andesitic porphyrite, suggesting their source may have great affinities with South China.
The impact of institutions on the competitive advantage of publicly listed family firms in emerging markets
Authors: Duran Patricio , van Essen Marc , Heugens Pursey P. M. A. R. , Kostova Tatiana , Peng Mike W.
Published: May 2018

Research Summary: We develop an institutional explanation for the finding that the competitive advantage publicly listed family firms (PFFs) enjoy over other publicly listed firms varies across emerging markets. We propose that PFF performance is contingent on the state of four types of institutions—formal constraining, informal constraining, formal enabling, and informal enabling institutions. We test these ideas with a meta‐analysis of 177 primary studies, situated in 49 countries. Our results show that the competitive advantage PFFs enjoy is stronger when formal constraining institutions are less developed and when suitable informal enabling institutions are present. However, their competitive advantage is weaker when formal enabling and informal constraining institutions are less developed. We conclude that the competitive advantage of PFFs in emerging markets is contingent on local institutional conditions.

Managerial Summary: We develop a framework to improve our understanding of how institutions impact the competitive advantage of publicly listed family firms (PFFs) in 49 emerging markets. The framework informs the decisions of PFF owners and managers concerning where to compete and when to invest in distinctive characteristics of family involvement, like a long‐term orientation, familial control, stewardship, and reputational capital. While our baseline expectation is that PFFs enjoy a competitive advantage in emerging markets, the model also specifies in which contexts the competitiveness of PFFs will be compromised. Our framework offers guidance to policymakers interested in increasing the economic contribution PFFs make to their jurisdictions, which they can ensure by developing PFF‐favoring institutions that strengthen the competitive advantage of these firms.
Estimation of vocational aptitudes using functional brain networks
Authors: Sung Yul‐Wan , Kawachi Yousuke , Choi Uk‐Su , Kang Daehun , Abe Chihiro , Otomo Yuki , Ogawa Seiji
Published: May 2018

The success of human life in modern society is highly dependent on occupation. Therefore, it is very important for people to identify and develop a career plan that best suits their aptitude. Traditional test batteries for vocational aptitudes are not oriented to measure developmental changes in job suitability because repeated measurements can introduce bias as the content of the test batteries is learned. In this study, we attempted to objectively assess vocational aptitudes by measuring functional brain networks and identified functional brain networks that intrinsically represented vocational aptitudes for 19 job divisions in a General Aptitude Test Battery. In addition, we derived classifiers based on these networks to predict the aptitudes of our test participants for each job division. Our results suggest that the measurement of brain function can indeed yield an objective evaluation of vocational aptitudes; this technique will enable a person to follow changes in one's job suitability with additional training or learning, paving a new way to advise people on career development.
Learning from failure in healthcare: Dynamic panel evidence of a physician shock effect
Authors: Van Gestel Raf , Müller Tobias , Bosmans Johan
Published: May 2018

Procedural failures of physicians or teams in interventional healthcare may positively or negatively predict subsequent patient outcomes. We identify this effect by applying (non)linear dynamic panel methods to data from the Belgian transcatheter aorta valve implantation registry containing information on the first 860 transcatheter aorta valve implantation procedures in Belgium. We find that a previous death of a patient positively and significantly predicts subsequent survival of the succeeding patient. We find that these learning from failure effects are not long‐lived and that learning from failure is transmitted across adverse events.
Design of A Metabolically Stable Tritium‐Tracer of the PI3Kδ‐Inhibitor CDZ173 (Leniolisib) as a Tool to Study Liver Metabolites
Authors: Bauer Carsten , Luu Tong , Eggimann Fabian , Bross Patrick , Gertsch Werner , Hu Cheng , Ramstein Philippe , Bourgailh Julien , Glänzel Albrecht , Dix Ina , Guenat Christian , Soldermann Nicolas , Litherland Karine , Desrayaud Sandrine , Hengy Jean‐Claude , Pearson David , Blanz Joachim , Burkhart Christoph
Published: April 2018

In this disclosure, we summarize the preliminary metabolic profiling of the PI3Kδ inhibitor CDZ173 (leniolisib, 1a) obtained from incubations of the unlabeled compound and the synthesis of its metabolically stable tritium isotopologue 1b used for metabolite structure confirmation. Access to 1b was achieved when a halogenated precursor was subject to Hal/3H‐exchange. Hence, [3H]CDZ173 with specific activity 630 GBq/mmol, HPLC‐RA 97% and ee = 99.2% was obtained. Synthetic key to the precursor was using a bis‐halo‐pyridine in a Pd‐catalyzed mono‐amination of the tetrahydropyrido‐pyrimidine core. Stereochemistry of the synthetic precursors were confirmed by X‐ray analysis of the unlabeled bis‐halo‐pyridines and chiral HPLC of the tritiated material. The correct position of tritium label in the target, was confirmed by 3H‐NMR difference spectroscopy. Besides, we report on the validation of the radiotracer as a tool for pre‐clinical ADME in incubations with hepatocytes. Based on this data, we present a quantitative metabolite profile of leniolisib which was confirmed by independently synthesized metabolite references. The conformation of CDZ173 was investigated by NMR suggesting two different amide backbones each with specific pyrrolidine puckerings.