bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iridium‐Catalyzed and Ligand‐Controlled Carbonylative Synthesis of Flavones from Simple Phenols and Internal Alkynes
Authors: Zhu Fengxiang , Wang Zechao , Li Yahui , Wu Xiao‐Feng 
Published: January 2017

AbstractFlavones are important natural products with diverse biological activities. In this study, a novel procedure for the carbonylative synthesis of flavones has been developed by using simple phenols and internal alkynes as the substrates. Various flavones were isolated in moderate to good yields with excellent regioselectivity and functional group tolerance by using an iridium catalyst system. Notably, this is the first example of direct carbonylative annulation of non‐preactivated phenols and alkynes to produce flavones, with the choice of ligand proving to be critical for the success of this transformation.
Impact of rotor temperospatial stability on acute and one‐year atrial fibrillation ablation outcomes
Authors: Balouch Muhammad , Gucuk Ipek Esra , Chrispin Jonathan , Bajwa Rizma J. , Zghaib Tarek , Berger Ronald D. , Ashikaga Hiroshi , Nazarian Saman , Marine Joseph E. , Calkins Hugh , Spragg David D. 
Published: January 2017

BackgroundThe utility of rotor ablation using commercially available systems as an adjunct to pulmonary vein isolation (PVI) is controversial. Variable results may stem from heterogeneous practice patterns. We investigated whether a prespecified protocol to determine temperospatial rotor stability improved acute and intermediate outcomes following rotor ablation.HypothesisProtocolized rotor mapping and ablation, with prespecified metrics to determine temporal rotor stability prior to ablation, will improve short‐ and long‐term PVI/rotor ablation outcomes.MethodsPatients undergoing PVI plus rotor ablation at Johns Hopkins during 2015 were included. The first cohort underwent rotor mapping and ablation at the operator's discretion, whereas the second cohort underwent protocolized rotor mapping, with ablation limited to temperospatially stable rotors. Both cohorts underwent PVI. Acute results (rotor elimination, atrial fibrillation [AF] termination), procedural data, and 1‐year outcomes were assessed.ResultsTwenty‐seven patients underwent ablation (mean age, 64.4 ± 9 years, male 81.5%, persistent AF 85.2%, long‐standing persistent AF 14.8%, mean AF duration 4.4 ± 4 years, repeat cases 51.8%, and mean LA size 4.6 ± 0.8 cm). In the protocolized cohort, rotors were reproducible in 83% (10/12) of cases in at least 1 chamber. Acute rhythm change was achieved in 8/27 (29.6%) patients. Sinus rhythm on presentation (62.5% vs 15.8%, P = 0.03) and higher total targeted rotors (3.8 ± 1.7 vs 2.5 ± 1.0, P = 0.02) predicted acute change. At 12 months, freedom from AF/atrial tachycardia was achieved in 5/15 (33.3%) patients in the first cohort and 5/11 patients in the protocolized cohort (45.5%; P = 0.53 for comparison).ConclusionsAcute and intermediate results did not change with protocolized mapping designed to identify temperospatially stable rotors. Outcomes at 12 months were similar in both groups.
Optimizing in Vitro Impedance and Physico‐Chemical Properties of Neural Electrodes by Electrophoretic Deposition of Pt Nanoparticles
Authors: Koenen Sven , Rehbock Christoph , Heissler Hans E. , Angelov Svilen D. , Schwabe Kerstin , Krauss Joachim K. , Barcikowski Stephan 
Published: January 2017

AbstractNeural electrodes suffer from an undesired incline in impedance when in permanent contact with human tissue. Nanostructures, induced by electrophoretic deposition (EPD) of ligand‐free laser‐generated nanoparticles (NPs) on the electrodes are known to stabilize impedance in vivo. Hence, Pt surfaces were systematically EPD‐coated with Pt NPs and evaluated for impedance as well as surface coverage, contact angle, electrochemically active surface area (ECSA) and surface oxidation. The aim was to establish a systematic correlation between EPD process parameters and physical surface properties. The findings clearly reveal a linear decrease in impedance with increasing surface coverage, which goes along with a proportional reduction of the contact angle and an increase in ECSA and surface oxidation. EPD process parameters, prone to yield surface coatings with low impedance, are long deposition times (40–60 min), while high colloid concentrations (>250 μg mL−1) and electric field strengths (>25 V cm−1) should be avoided due to detrimental NP assemblage effects.
Heterostructured WS2‐MoS2 Ultrathin Nanosheets Integrated on CdS Nanorods to Promote Charge Separation and Migration and Improve Solar‐Driven Photocatalytic Hydrogen Evolution
Authors: Reddy D. Amaranatha , Park Hanbit , Ma Rory , Kumar D. Praveen , Lim Manho , Kim Tae Kyu 
Published: January 2017

AbstractSolar‐driven photocatalytic hydrogen evolution is important to bring solar‐energy‐to‐fuel energy‐conversion processes to reality. However, there is a lack of highly efficient, stable, and non‐precious photocatalysts, and catalysts not designed completely with expensive noble metals have remained elusive, which hampers their large‐scale industrial application. Herein, for the first time, a highly efficient and stable noble‐metal‐free CdS/WS2‐MoS2 nanocomposite was designed through a facile hydrothermal approach. When assessed as a photocatalyst for water splitting, the CdS/WS2‐MoS2 nanostructures exhibited remarkable photocatalytic hydrogen‐evolution performance and impressive durability. An excellent hydrogen evolution rate of 209.79 mmol g−1 h−1 was achieved under simulated sunlight irradiation, which is higher than the values for CdS/MoS2 (123.31 mmol g−1 h−1) and CdS/WS2 nanostructures (169.82 mmol g−1 h−1) and the expensive CdS/Pt benchmark catalyst (34.98 mmol g−1 h−1). The apparent quantum yield reached 51.4 % at λ=425 nm in 5 h. Furthermore, the obtained hydrogen evolution rate was better than those of several noble‐metal‐free catalysts reported previously. The observed high rate of hydrogen evolution and remarkable stability may be a result of the ultrafast separation of photogenerated charge carriers and transport between the CdS nanorods and the WS2‐MoS2 nanosheets, which thus increases the number of electrons involved in hydrogen production. The proposed designed strategy is believed to potentially open a door to the design of advanced noble‐metal‐free photocatalytic materials for efficient solar‐driven hydrogen production.
Parameters self‐tuning PID controller circuit with memristors
Authors: Lu Yimin , Liang Qianqian , Huang Xianfeng 
Published: January 2017

SummaryTo achieve the satisfactory control performance of a dynamic system using a proportion‐integration‐differentiation (PID) controller, it is necessary that the three parameters of the PID controller are set to values that suit the system to be controlled. Most current applications employ fixed setting parameters that are not adequate for nonlinear time varying systems with uncertainty and disturbances. In this paper, we use neuron weighted tuning functions to develop self‐tuning methods that can automatically tune the parameters of PID controllers. The weighting processes performed using voltage‐controlled memristors and current‐controlled memristor are discussed. It is proven that the output tracking error of a closed‐loop system controlled by the proposed controllers and the weight update rules governed by the memristors descends toward its minimum. A simulation and experimental verification of the performances of these controllers in linear and nonlinear systems are included. This proposed PID controllers are shown to be more robust than conventional PID controllers. Copyright © 2017 John Wiley & Sons, Ltd.
An 8‐item short form of the Eating Disorder Examination‐Questionnaire adapted for children (ChEDE‐Q8)
Authors: Kliem Sören , Schmidt Ricarda , Vogel Mandy , Hiemisch Andreas , Kiess Wieland , Hilbert Anja 
Published: January 2017

AbstractEating disturbances are common in children placing a vulnerable group of them at risk for full‐syndrome eating disorders and adverse health outcomes. To provide a valid self‐report assessment of eating disorder psychopathology in children, a short form of the child version of the Eating Disorder Examination (ChEDE‐Q) was psychometrically evaluated. Similar to the EDE‐Q, the ChEDE‐Q provides assessment of eating disorder psychopathology related to anorexia nervosa, bulimia nervosa, and binge‐eating disorder; however, the ChEDE‐Q does not assess symptoms of avoidant/restrictive food intake disorder, pica, or rumination disorder. In 1,836 participants ages 7 to 18 years, recruited from two independent population‐based samples, the factor structure of the recently established 8‐item short form EDE‐Q8 for adults was examined, including measurement invariance analyses on age, gender, and weight status derived from objectively measured weight and height. For convergent validity, the ChEDE‐Q global score, body esteem scale, strengths and difficulties questionnaire, and sociodemographic characteristics were used. Item characteristics and age‐ and gender‐specific norms were calculated. Confirmatory factor analysis revealed good model fit for the 8‐item ChEDE‐Q. Measurement invariance analyses indicated strict invariance for all analyzed subgroups. Convergent validity was provided through associations with well‐established questionnaires and age, gender, and weight status, in expected directions. The newly developed ChEDE‐Q8 proved to be a psychometrically sound and economical self‐report assessment tool of eating disorder psychopathology in children. Further validation studies are needed, particularly concerning discriminant and predictive validity.
Climate changes and wildfire alter vegetation of Yellowstone National Park, but forest cover persists
Authors: Clark Jason A. , Loehman Rachel A. , Keane Robert E. 
Published: January 2017

AbstractWe present landscape simulation results contrasting effects of changing climates on forest vegetation and fire regimes in Yellowstone National Park, USA, by mid‐21st century. We simulated potential changes to fire dynamics and forest characteristics under three future climate projections representing a range of potential future conditions using the FireBGCv2 model. Under the future climate scenarios with moderate warming (>2°C) and moderate increases in precipitation (3–5%), model simulations resulted in 1.2–4.2 times more burned area, decreases in forest cover (10–44%), and reductions in basal area (14–60%). In these same scenarios, lodgepole pine (Pinus contorta) decreased in basal area (18–41%), while Douglas‐fir (Pseudotsuga menziesii) basal area increased (21–58%). Conversely, mild warming (<2°C) coupled with greater increases in precipitation (12–13%) suggested an increase in forest cover and basal area by mid‐century, with spruce and subalpine fir increasing in abundance. Overall, we found changes in forest tree species compositions were caused by the climate‐mediated changes in fire regime (56–315% increase in annual area burned). Simulated changes in forest composition and fire regime under warming climates portray a landscape that shifts from lodgepole pine to Douglas‐fir caused by the interaction between the magnitude and seasonality of future climate changes, by climate‐induced changes in the frequency and intensity of wildfires, and by tree species response.
Predicting trait‐environment relationships for venation networks along an Andes‐Amazon elevation gradient
Authors: Blonder Benjamin , Salinas Norma , Patrick Bentley Lisa , Shenkin Alexander , Chambi Porroa Percy O. , Valdez Tejeira Yolvi , Violle Cyrille , Fyllas Nikolaos M. , Goldsmith Gregory R. , Martin Roberta E. , Asner Gregory P. , Díaz Sandra , Enquist Brian J. , Malhi Yadvinder 
Published: January 2017

AbstractUnderstanding functional trait‐environment relationships (TERs) may improve predictions of community assembly. However, many empirical TERs have been weak or lacking conceptual foundation. TERs based on leaf venation networks may better link individuals and communities via hydraulic constraints. We report measurements of vein density, vein radius, and leaf thickness for more than 100 dominant species occurring in ten forest communities spanning a 3,300 m Andes‐Amazon elevation gradient in Peru. We use these data to measure the strength of TERs at community scale and to determine whether observed TERs are similar to those predicted by physiological theory. We found strong support for TERs between all traits and temperature, as well weaker support for a predicted TER between maximum abundance‐weighted leaf transpiration rate and maximum potential evapotranspiration. These results provide one approach for developing a more mechanistic trait‐based community assembly theory.
Traffic‐aware overload control scheme in 5G ultra‐dense M2M networks
Authors: He Hongliang , Ren Pinyi , Du Qinghe , Sun Li , Wang Yichen 
Published: January 2017

AbstractDue to a huge number of M2M devices expected to access the network simultaneously, congestion and overload of networks are the core challenges to the 5G ultra‐dense M2M networks design. In this paper, an optimal traffic‐load control scheme is proposed to overcome the challenges. Since the base station lacks accurate information about the traffic‐load of network resulting in an unachievable solution to the optimal control scheme in practice, we propose two different traffic‐load estimation schemes corresponding to the two different access protocols. For the first protocol that the collision devices are not barred by an access probability, we propose a markov‐chain based estimation scheme according to the collision state of network. For the second protocol that the collision devices are barred by an access probability, we estimate the traffic‐load using the number of success devices and the average number of new active devices in each slot. Both estimation schemes ensure that the practical control schemes are very close to the theoretical optimal control scheme. In addition, we prove that the optimal performances of the two protocols are exactly the same in theory. Finally, the simulation results exhibit our conclusion and show the superior performances of our proposed scheme.
Prioritization of pharmaceuticals based on risks to aquatic environments in Kazakhstan
Authors: Aubakirova Bakhyt , Beisenova Raikhan , Boxall Alistair BA 
Published: January 2017

Abstract

Over the last 20 years, there has been increasing interest in the occurrence, fate, effects, and risk of pharmaceuticals in the natural environment. However, we still have only limited or no data on ecotoxicological risks of many of the active pharmaceutical ingredients (APIs) currently in use. This is partly due to the fact that the environmental assessment of an API is an expensive, time-consuming, and complicated process. Prioritization methodologies, which aim to identify APIs of most concern in a particular situation, could therefore be invaluable in focusing experimental work on APIs that really matter. The majority of approaches for prioritizing APIs require annual pharmaceutical usage data. These methods cannot therefore be applied to countries, such as Kazakhstan, that have very limited data on API usage. The present paper therefore offers an approach for prioritizing APIs in surface waters in information-poor regions such as Kazakhstan. Initially data were collected on the number of products and active ingredients for different therapeutic classes in use in Kazakhstan and on the typical doses. These data were then used alongside simple exposure modeling approaches to estimate exposure indices for active ingredients (about 240 APIs) in surface waters in the country. Ecotoxicological effects data were obtained from the literature or predicted. Risk quotients were then calculated for each pharmaceutical based on the exposure and the substances were ranked in order of risk quotient. Highest exposure indices were obtained for benzylpenicillin, metronidazole, sulbactam, ceftriaxone, and sulfamethoxazole. The highest risk was estimated for amoxicillin, clarithromycin, azithromycin, ketoconazole, and benzylpenicillin. In the future, the approach could be employed in other regions where usage information is limited. Integr Environ Assess Manag 2017;13:832–839. © 2017 SETAC

Key Points
This is the first study to prioritize pharmaceuticals in the aquatic environment in Kazakhstan. Benzylpenicillin, metronidazole, sulbactam, ceftriaxone, and sulfamethoxazole were predicted to have the highest exposure in surface waters, whereas in fish plasma the compounds with highest predicted exposure were lisinopril, telmisartan, orlistat, drotaverine, and terbinafine. The most highly ranked substances based on the apical ecotoxicological endpoints were amoxicillin, clarithromycin, azythromycin, sulphamethoxazole, and ketoconazole. The most highly ranked compounds based on the nonapical assessment were lisinopril, orlistat, estradiol valerate, cinnarizine, and drotaverine.
European Union regulators and industry agree on improving specific environmental release categories: Report from the exchange network for exposure scenarios specific environmental release category workshop on May 13, 2016
Authors: Ahrens Andreas , Moilanen Marianne , Martin Sara , Garcia-John Enrique , Sättler Daniel , Bakker Joost , Reihlen Antonia , Wind Thorsten , Tolls Johannes 
Published: January 2017

Abstract

Specific environmental release categories (SPERCs) are an instrument for lower-tier environmental emissions assessments. They support chemical safety assessments under the European Union (EU) regulation Registration, Evaluation, Authorisation, and Restriction of Chemicals. SPERCs have been developed by industry and subjected to regulatory review. Within the framework of the Chemical Safety Report/Exposure Scenario Roadmap, the EU Chemicals Agency (ECHA), the EU Member State authorities, and European industry sector associations collaborate to improve the quality of the SPERCs. Following up on the outcome of ECHA's SPERC Best Practice Project, industry, together with ECHA, developed an updated SPERC factsheet template and guidance on how to fill it out. In addition, industry developed 2 sets of SPERC factsheet examples and the corresponding SPERC background documents. These documents were submitted to a multistakeholder review process. The comments from the review were discussed at a workshop in spring 2016. The workshop participants acknowledged the revised factsheet format including the corresponding guidance, the 2 SPERC factsheets, and the 2 SPERC background documents as best practice examples. The package is expected to support further improvement of the quality of the SPERCs. A common understanding was achieved of the need to match the level of detail of the use conditions description with the risk to be controlled (i.e., the emission intensity and hazard profile of the substances) and with the level of conservatism of SPERC release factors. The complete and transparent documentation of the derivation of the release factors and of their conservatism is conceived as crucial for the credibility of the SPERCs, such that they can be trusted by partners in the chemicals supply chain and by regulators. To that end, background documents will include a dedicated section describing the conservatism of SPERCs. The workshop concluded with an outline of the practical way forward for the improvement of SPERC documentation. Integr Environ Assess Manag 2017;13:815–820. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC)

Key Points
EU regulators and industry have agreed on standards to document the assessment of emissions for environmental risk assessment of chemicals, with particular attention paid to balancing the degree of detail in the documentation with the degree of conservatism in the emission assessment.
Graphene oxide nanolayers as nanoparticle anchors on biomaterial surfaces with nanostructures and charge balance for bone regeneration
Authors: Xie Chaoming , Sun Honglong , Wang Kefeng , Zheng Wei , Lu Xiong , Ren Fuzeng 
Published: January 2017

AbstractGraphene oxide (GO) is a carbon‐based nanomaterial with high surface area and abundant functional groups, providing various sites for binding and immobilization of growth factor vehicles. This study used GO nanolayer as an anchor for the immobilization of bone morphogenetic protein‐2 (BMP‐2)‐encapsulated bovine serum albumin nanoparticles (NPs) on the hydroxyapatite (HA) and tricalcium phosphate (TCP) scaffolds by electrostatic interaction between the positive charges of the NPs and negative charges of GO. GO nanolayers prevented the rapid degradation of TCP scaffolds. Moreover, GO nanolayers promoted NP adsorption on these scaffolds, and realized BMP‐2 sustained release. NPs endowed the scaffold surfaces with a nanostructure similar to that of the extracellular matrix (ECM), improving bone marrow stromal cell (BMSC) attachment. Furthermore, the positive charged NPs and negative charged GO nanolayers constructed a charge‐balanced surface on the scaffolds, enhancing BMSC proliferation. The nanostructure, charge balance and BMP‐2 sustained release capability synergistically improved BMSC differentiation and bone regeneration. In summary, GO is a potential candidate to modify biomaterial surfaces as an anchor for efficient immobilization of growth factor vehicles. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1311–1323, 2017.
Collagen/heparin sulfate scaffolds fabricated by a 3D bioprinter improved mechanical properties and neurological function after spinal cord injury in rats
Authors: Chen Chong , Zhao Ming‐liang , Zhang Ren‐kun , Lu Gang , Zhao Chang‐yu , Fu Feng , Sun Hong‐tao , Zhang Sai , Tu Yue , Li Xiao‐hong 
Published: January 2017

AbstractEffective treatments promoting axonal regeneration and functional recovery for spinal cord injury (SCI) are still in the early stages of development. Most approaches have been focused on providing supportive substrates for guiding neurons and overcoming the physical and chemical barriers to healing that arise after SCI. Although collagen has become a promising natural substrate with good compatibility, its low mechanical properties restrict its potential applications. The mechanical properties mainly rely on the composition and pore structure of scaffolds. For the composition of a scaffold, we used heparin sulfate to react with collagen by crosslinking. For the structure, we adopted a three‐dimensional (3D) printing technology to fabricate a scaffold with a uniform pore distributions. We observed that the internal structure of the scaffold printed with a 3D bioprinter was regular and porous. We also found that both the compression modulus and strengths of the scaffold were significantly enhanced by the collagen/heparin sulfate composition compared to a collagen scaffold. Meanwhile, the collagen/heparin sulfate scaffold presented good biocompatibility when it was co‐cultured with neural stem cells in vitro. We also demonstrated that heparin sulfate modification significantly improved bFGF immobilization and absorption to the collagen by examining the release kinetics of bFGF from scaffolds. Two months after implantating the scaffold into transection lesions in T10 of the spinal cord in rats, the collagen/heparin sulfate group demonstrated significant recovery of locomotor function and according to electrophysiological examinations. Parallel to functional recovery, collagen/heparin sulfate treatment further ameliorated the pathological process and markedly increased the number of neurofilament (NF) positive cells compared to collagen treatment alone. These data suggested that a collagen/heparin sulfate scaffold fabricated by a 3D bioprinter could enhance the mechanical properties of collagen and provide continuous guidance channels for axons, which would improve the neurological function after SCI. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1324–1332, 2017.