bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Sodium Cation on Metallacycle β‐Hydride Elimination in CO2–Ethylene Coupling to Acrylates
Authors: Jin Dong , Williard Paul G. , Hazari Nilay , Bernskoetter Wesley H. 
Published: February 2014

AbstractThe catalytic conversion of carbon dioxide and olefins into acrylates has been a long standing target, because society attempts to synthesize commodity chemicals in a more economical and sustainable fashion. Although nickel complexes have been known to successfully couple CO2 and ethylene for decades, a key β‐hydride elimination step has proven a major obstacle to the development of a catalytic process. Recent studies have shown that Lewis acid additives can be used to create a lower‐energy pathway for β‐hydride elimination and facilitate a low number of catalytic turnovers. However, the exact manner, in which the Lewis acid promotes β‐hydride elimination remains to be elucidated. Herein, we describe the kinetic and thermodynamic role that commercially relevant and weakly Lewis acidic sodium salts play in promoting β‐hydride elimination from nickelalactones synthesized from CO2 and ethylene. This process is compared to a non‐Lewis acid promoted pathway, and DFT calculations were used to identify differences between the two systems. The sodium‐free isomerization reaction gave a rare CO2‐derived β‐nickelalactone complex, which was structurally characterized.
New Functional Cyclic Aminomethylphosphine Ligands for the Construction of Catalysts for Electrochemical Hydrogen Transformations
Authors: Musina Elvira I. , Khrizanforova Vera V. , Strelnik Igor D. , Valitov Murad I. , Spiridonova Yulia S. , Krivolapov Dmitry B. , Litvinov Igor A. , Kadirov Marsil K. , Lönnecke Peter , Hey‐Hawkins Evamarie , Budnikova Yulia H. , Karasik Andrey A. , Sinyashin Oleg G. 
Published: February 2014

AbstractEight‐membered cyclic functional bisphosphines, namely 1,5‐di‐aryl‐3,7‐di(2‐pyridyl)‐1,5‐diaza‐3,7‐diphosphacyclooctanes (aryl=2‐pyridyl, m‐tolyl, p‐tolyl, diphenylmethyl, benzyl, (R)‐(+)‐(α‐methyl)benzyl), with 2‐pyridyl substituents on the phosphorus atoms have been synthesized by condensation of 2‐pyridylphosphine, formaldehyde, and the corresponding primary amine. The structures of some of these bisphosphines have been investigated by X‐ray crystallography. The bisphosphines readily form neutral P,P‐chelate complexes [(κ2‐P,P‐L)MCl2], cationic bis‐P,P‐chelate complexes [(κ2‐P,P‐L)2M]2+, or a five‐coordinate complex [(κ2‐P,P‐L)2NiBr]Br. The electrochemical behavior of two of the nickel complexes, and their catalytic activities in electrochemical hydrogen evolution and hydrogen oxidation, including the fuel‐cell test, have been studied.
Nitrogen and Phosphorus Dual‐Doped Hierarchical Porous Carbon Foams as Efficient Metal‐Free Electrocatalysts for Oxygen Reduction Reactions
Authors: Jiang Hongliang , Zhu Yihua , Feng Qian , Su Yunhe , Yang Xiaoling , Li Chunzhong 
Published: February 2014

AbstractDespite tremendous progress in developing doped carbocatalysts for the oxygen reduction reaction (ORR), the ORR activity of current metal‐free carbocatalysts is still inferior to that of conventional Pt/C catalysts, especially in acidic media and neutral solution. Moreover, it also remains a challenge to develop an effective and scalable method for the synthesis of metal‐free carbocatalysts. Herein, we have developed nitrogen and phosphorus dual‐doped hierarchical porous carbon foams (HP‐NPCs) as efficient metal‐free electrocatalysts for ORR. The HP‐NPCs were prepared for the first time by copyrolyzing nitrogen‐ and phosphorus‐containing precursors and poly(vinyl alcohol)/polystyrene (PVA/PS) hydrogel composites as in situ templates. Remarkably, the resulting HP‐NPCs possess controllable nitrogen and phosphorus content, high surface area, and a hierarchical interconnected macro‐/mesoporous structure. In studying the effects of the HP‐NPCs on the ORR, we found that the as‐prepared HP‐NPC materials exhibited not only excellent catalytic activity for ORR in basic, neutral, and acidic media, but also much better tolerance for methanol oxidation and much higher stability than the commercial, state‐of‐the‐art Pt/C catalysts. Because of all these outstanding features, it is expected that the HP‐NPC material will be a very suitable catalyst for next‐generation fuel cells and lithium–air batteries. In addition, the novel synthetic method described here might be extended to the preparation of many other kinds of hierarchical porous carbon materials or porous carbon that contains metal oxide for wide applications including energy storage, catalysis, and electrocatalysis.
Pseudotetrahedral Rhodium(I) Complexes
Authors: Geer Ana M. , Julián Alejandro , López José A. , Ciriano Miguel A. , Tejel Cristina 
Published: February 2014

AbstractA combination of four‐electron donors, such as alkynes, with strongly donating and strong‐field scorpionate ligands is appropriate to create pseudotetrahedral rhodium(I) environments, as found in [Rh(PhBP3)(HCCPh)], which promotes HC bond activation and CC coupling reactions under very smooth conditions.
Stereocontrol by Quaternary Centres: A Stereoselective Synthesis of (−)‐Luminacin D
Authors: Bartlett Nathan , Gross Leona , Péron Florent , Asby Daniel J. , Selby Matthew D. , Tavassoli Ali , Linclau Bruno 
Published: February 2014

AbstractVery high diastereoselectivity can be achieved by 1,3‐chelation‐controlled allylation of aldehydes that possess a non‐chelating α‐ether substituent, even if the α‐position is a quaternary centre and/or a spiro‐epoxide. This reaction was used as a key step in an enantioselective synthesis of the angiogenesis inhibitor luminacin D.
A NLCG 3‐D Inversion Method of Magnetotellurics with Parallel Structure
Authors: Kun ZHANG , Hao DONG , Jia‐Yong YAN , Qing‐Tian LÜ , Wen‐Bo WEI , Yu‐Xian HE 
Published: February 2014

AbstractIn this paper, we improve and verify the inversion algorithm and parallel computing program of three‐dimensional magnetotelluric sounding, and the program does not require much physical memory and CPU quantity. It makes possible to do three‐dimensional inversion on ordinary PC computers. Throughout nonlinear conjugate gradient algorithm proposed by Newman and Alumbaugh (2000) and preconditioning method proposed by Rodi and Mackie (2001), we improve the preconditioning method add parallel structure, and verify the program with theoretical models. According to the inversion results of measured data in Japanese KAYABE area, we demonstrate the practicality of the algorithm.
Edge Detection in Potential Fields Using Optimal Auto‐Ratios of Vertical Gradients
Authors: Yan‐Guo WANG , Feng‐Xu ZHANG , Cai LIU , Zhu‐Wen WANG , Jin ZHANG 
Published: February 2014

AbstractDerivative calculation of potential‐fields is widely used in edge detection of geologic bodies. However, the traditional gradient methods are susceptible to noise disturbance, and can lead to instability of results. Besides, the edges of small‐sized geologic bodies are difficult to be detected because of superimposed anomalies. In this paper, we give the definition of auto‐ratios and present a new method for edge detection by using optimal auto‐ratios of vertical derivatives, and elaborate mathematical implication and physical meaning of this method. The model test shows that the method using optimal auto‐ratios of vertical gradients can greatly suppress noise disturbance and accurately detect the edges of geologic bodies which cannot be recognized by traditional edge detection methods. In application, we choose gravity data of the Yalujiang Basin where geological conditions are very complex to test the optimal auto‐ratio method. The results show that the tectonic boundaries recognized by the optimal auto‐ratios of the third‐order vertical derivatives correspond well to distribution characteristics of real geologic bodies, which are in agreement with previous work. And the negative anomaly zones delineated by the auto‐ratios reflect the work area of the Hunjiang coalfield rather well.
Highlights From the 2013 ACCF/AHA Guidelines for the Management of ST‐Elevation Myocardial Infarction and Beyond
Authors: Tamis‐Holland Jacqueline E. , O'Gara Patrick 
Published: February 2014

AbstractST‐segment elevation myocardial infarction (STEMI) is considered a cardiology emergency requiring immediate recognition and treatment aimed at successful and early reperfusion to ensure optimal outcomes. The American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) have issued guidelines for the diagnosis and management of patients with acute myocardial infarction since 1990. These guidelines are based on clinical research exploring reperfusion modalities and adjunctive therapies. They are further supported by expert opinion where randomized trial evidence is lacking. In January 2013, the ACCF/AHA released the most recent guidelines for the management of patients with STEMI. This review focuses on the newest and most important recommendations taken from the 2013 ACCF/AHA Guidelines for the Management of STEMI and highlight important new studies that have emerged over the past year.
Removal of Benzoic Acid from Water by Reactive Extraction Using Hollow Fiber Membrane Contactor: Experiment and Modeling
Authors: Agrahari Gunjan Kumar , Verma Nishith , Bhattacharya Prashant K. 
Published: February 2014

AbstractA commercially available hydrophobic polypropylene based hollow fiber membrane contactor (HFMC: Liquicel® module) was used for the removal of dissolved benzoic acid (BA) from water. The module was operated in liquid–liquid extraction (LLE) mode using BA‐laden water as feed on the lumen side and trioctylamine (TOA) diluted in 1‐octanol as extractant on the shell side of the module. The aqueous and organic streams flowed counter‐currently within the HFMC module. Experiments were carried out under different operating conditions, that is, feed flow rates, extractant flow rates, and initial BA concentrations in the feed. The synthetic wastewater was prepared using BA at concentrations ranging from 150 to 2700 ppm in water, whereas the extractant solution consisted of 0.12 M TOA in 1‐octanol. BA reacted with TOA at the interface of the aqueous and membrane phases, forming a complex that was removed by the organic extractant flowing on the shell side of the module. In this study, up to 95% removal efficiency was obtained using the HFMC operated in the LLE mode. A mathematical model was developed that simulated transport of the bulk aqueous phase and within the pores of the membrane. The model simulation results were found to be in reasonable agreement with the experimental data.
Discovery of 5‐(2‐(Phenylamino)pyrimidin‐4‐yl)thiazol‐2(3H)‐one Derivatives as Potent Mnk2 Inhibitors: Synthesis, SAR Analysis and Biological Evaluation
Authors: Diab Sarah , Teo Theodosia , Kumarasiri Malika , Li Peng , Yu Mingfeng , Lam Frankie , Basnet Sunita K. C. , Sykes Matthew J. , Albrecht Hugo , Milne Robert , Wang Shudong 
Published: February 2014

AbstractPhosphorylation of eIF4E by human mitogen‐activated protein kinase (MAPK)‐interacting kinases (Mnks) is crucial for human tumourigenesis and development. Targeting Mnks may provide a novel anticancer therapeutic strategy. However, the lack of selective Mnk inhibitors has so far hampered pharmacological target validation and clinical drug development. Herein, we report, for the first time, the discovery of a series of 5‐(2‐(phenylamino)pyrimidin‐4‐yl)thiazole‐2(3H)‐one derivatives as Mnk inhibitors. Several derivatives demonstrate very potent Mnk2 inhibitory activity. The most active and selective compounds were tested against a panel of cancer cell lines, and the results confirm the cell‐type‐specific effect of these Mnk inhibitors. Detailed cellular mechanistic studies reveal that Mnk inhibitors are capable of reducing the expression level of anti‐apoptotic protein Mcl‐1, and of promoting apoptosis in MV4‐11 acute myeloid leukaemia cells.
Multi‐institutional, randomized, double‐blind, placebo‐controlled trial to assess the efficacy of a mucoadhesive hydrogel (MuGard) in mitigating oral mucositis symptoms in patients being treated with chemoradiation therapy for cancers of the head and neck
Authors: Allison Ron R. , Ambrad Aaron A. , Arshoun Youssef , Carmel Richard J. , Ciuba Doug F. , Feldman Elizabeth , Finkelstein Steven E. , Gandhavadi Ranjini , Heron Dwight E. , Lane Steven C. , Longo John M. , Meakin Charles , Papadopoulos Dimitrios , Pruitt David E. , Steinbrenner Lynn M. , Taylor Michael A. , Wisbeck William M. , Yuh Grace E. , Nowotnik David P. , Sonis Stephen T. 
Published: February 2014

BACKGROUNDThe objective of this trial was to determine how a mucoadhesive hydrogel (MuGard), a marketed medical device, would fare when tested with the strictness of a conventional multi‐institutional, double‐blind, randomized, placebo‐controlled study format.METHODSA total of 120 subjects planned to receive chemoradiation therapy (CRT) for treatment of head and neck cancers were randomized to receive either MuGard or sham control rinse (SC) during CRT. Subjects completed the validated Oral Mucositis Daily Questionnaire. Weight, opiate use, and World Health Organization (WHO) oral mucositis (OM) scores were recorded. Subjects who dosed at least once daily during the first 2.5 weeks of CRT were included in the efficacy analysis.RESULTSOf 120 subjects enrolled, 78 (SC, N = 41; MuGard, N = 37) were eligible for efficacy analysis. Both cohorts were similar in demographics, baseline characteristics, primary tumor type, and planned CRT regimen. MuGard effectively mitigated OM symptoms as reflected by area under the curve of daily patient‐reported oral soreness (P = .034) and WHO scores on the last day of radiation therapy (P = .038). MuGard was also associated with nonsignificant trends related to therapeutic benefit including opioid use duration, and OM scores (WHO criteria) at CRT week 4. Rinse compliance was identical between cohorts. No significant adverse events were reported, and the adverse event incidence was similar between cohorts.CONCLUSIONSTesting MuGard, a rinse marketed as a device, in a standard clinical trial format demonstrated its superiority to SC in mitigating OM symptoms, delaying OM progression, and its safety and tolerability. Cancer 2014;120:1433–1440. © 2014 Access Pharmaceuticals, Inc. Cancer published by Wiley Periodicals. Inc. on behalf of American Cancer Society.
Identification of underserved areas for urologic cancer care
Authors: Mossanen Matthew , Izard Jason , Wright Jonathan L. , Harper Jonathan D. , Porter Michael P. , Daratha Kenn B. , Holt Sarah K. , Gore John L. 
Published: February 2014

BACKGROUNDThe delivery of urologic oncology care is susceptible to regional variation. In the current study, the authors sought to define patterns of care for patients undergoing genitourinary cancer surgery to identify underserved areas for urologic cancer care in Washington State.METHODSThe authors accessed the Washington State Comprehensive Hospital Abstract Reporting System from 2003 through 2007. They identified patients undergoing radical prostatectomy, radical cystectomy (RC), partial nephrectomy (PN), radical nephrectomy, and transurethral resection of the prostate (TURP). TURP was included for comparison as a reference procedure indicative of access to urologic care. Hospital service areas (HSAs) are where the majority of local patients are hospitalized; hospital referral regions (HRR) are where most patients receive tertiary care. The authors created multivariate hierarchical logistic regression models to examine patient and HSA characteristics associated with the receipt of urologic oncology care out of the HRR for each procedure.RESULTSGreater than one‐half of patients went out of their HRR in 7 HSAs (11%) for radical prostatectomy, 3 HSAs (5%) for radical nephrectomy, 10 HSAs (15%) for PN, and 14 HSAs (22%) for RC. No HSAs had high export rates for TURP. Few patient factors were found to be associated with surgical care out of the HRR. High‐export HSAs for PN and RC exhibited lower socioeconomic characteristics than low‐export HSAs, adjusting for HSA population, race, and HSA procedure rates for PN and RC.CONCLUSIONSPatients living in areas with lower socioeconomic status have a greater need to travel for complex urologic surgery. Consideration of geographic delineation in the delivery of urologic oncology care may aid in regional quality improvement initiatives. Cancer 2014;120:1565–1571. © 2014 American Cancer Society.
Natural and lesion‐induced decrease in cell proliferation in the medial nucleus of the trapezoid body during hearing development
Authors: Saliu Aminat , Adise Shana , Xian Sandy , Kudelska Kamila , Rodríguez‐Contreras Adrián 
Published: February 2014

ABSTRACTThe functional interactions between neurons and glial cells that are important for nervous system function are presumably established during development from the activity of progenitor cells. In this study we examined proliferation of progenitor cells in the medial nucleus of the trapezoid body (MNTB) located in the rat auditory brainstem. We performed DNA synthesis labeling experiments to demonstrate changes in cell proliferation activity during postnatal stages of development. An increase in cell proliferation correlated with MNTB growth and the presence of S100β‐positive astrocytes among MNTB neurons. In additional experiments we analyzed the fate of newly born cells. At perinatal ages, newly born cells colabeled with the astrocyte marker S100β in higher numbers than when cells were generated at postnatal day 6. Furthermore, we identified newly born cells that were colabeled with caspase‐3 immunohistochemistry and performed comparative experiments to demonstrate that there is a natural decrease in cell proliferation activity during postnatal development in rats, mice, gerbils, and ferrets. Lastly, we found that there is a stronger decrease in MNTB cell proliferation after performing bilateral lesions of the auditory periphery in rats. Altogether, these results identify important stages in the development of astrocytes in the MNTB and provide evidence that the proliferative activity of the progenitor cells is developmentally regulated. We propose that the developmental reduction in cell proliferation may reflect coordinated signaling between the auditory brainstem and the auditory periphery. J. Comp. Neurol. 522:971–985, 2014. © 2013 Wiley Periodicals, Inc.
Graphite Felt Modified with Bismuth Nanoparticles as Negative Electrode in a Vanadium Redox Flow Battery
Authors: Suárez David J. , González Zoraida , Blanco Clara , Granda Marcos , Menéndez Rosa , Santamaría Ricardo 
Published: February 2014

AbstractA graphite felt decorated with bismuth nanoparticles was studied as negative electrode in a vanadium redox flow battery (VRFB). The results confirm the excellent electrochemical performance of the bismuth modified electrode in terms of the reversibility of the V3+/V2+ redox reactions and its long‐term cycling performance. Moreover a mechanism that explains the role that Bi nanoparticles play in the redox reactions in this negative half‐cell is proposed. Bi nanoparticles favor the formation of BiHx, an intermediate that reduces V3+ to V2+ and, therefore, inhibits the competitive irreversible reaction of hydrogen formation (responsible for the commonly observed loss of Coulombic efficiency of VRFBs). Thus, the total charge consumed during the cathodic sweep in this electrode is used to reduce V3+ to V2+, resulting in a highly reversible and efficient process.
Energetics of Defects on Graphene through Fluorination
Authors: Xiao Jie , Meduri Praveen , Chen Honghao , Wang Zhiguo , Gao Fei , Hu Jianzhi , Feng Ju , Hu Mary , Dai Sheng , Brown Suree , Adcock Jamie L. , Deng Zhiqun , Liu Jun , Graff Gordon L. , Aksay Ilhan A. , Zhang Ji‐Guang 
Published: February 2014

AbstractFunctionalized graphene sheets (FGSs) comprise a unique member of the carbon family, demonstrating excellent electrical conductivity and mechanical strength. However, the detailed chemical composition of this material is still unclear. Herein, we take advantage of the fluorination process to semiquantitatively probe the defects and functional groups on graphene surface. Functionalized graphene sheets are used as substrate for low‐temperature (<150 °C) direct fluorination. The fluorine content has been modified to investigate the formation mechanism of different functional groups such as CF, CF2, OCF2 and (CO)F during fluorination. The detailed structure and chemical bonds are simulated by density functional theory (DFT) and quantified experimentally by nuclear magnetic resonance (NMR). The electrochemical properties of fluorinated graphene are also discussed extending the use of graphene from fundamental research to practical applications.
Temperature thresholds of physically dormant seeds and plant functional response to fire: variation among species and relative impact of climate change
Authors: Ooi Mark K. J. , Denham Andrew J. , Santana Victor M. , Auld Tony D. 
Published: February 2014

AbstractVariation in dormancy thresholds among species is rarely studied but may provide a basis to better understand the mechanisms controlling population persistence. Incorporating dormancy‐breaking temperature thresholds into existing trait frameworks could improve predictions regarding seed bank persistence, and subsequently species resilience in response to fire, climate change and anthropogenic management. A key ecological strategy for many species from fire‐prone ecosystems is the possession of a long‐lived seed bank, ensuring recovery after fire. Physical dormancy is dominant in these ecosystems and maintaining this dormancy is directly linked to seed bank persistence. We identified a suite of seed‐related factors relevant to maintaining populations in fire‐prone regions for 14 co‐occurring physically dormant species. We measured variation in initial levels of dormancy and then applied experimental heating treatments, based on current seasonal temperatures and those occurring during fires, to seeds of all study species. Additionally, higher seasonal temperature treatments were applied to assess response of seeds to temperatures projected under future climate scenarios. Levels of germination response and mortality were determined to assess how tightly germination response was bound to either fire or seasonal cues. Six species were found to have dormancy cues bound to temperatures that only occur during fires (80°C and above) and were grouped as having obligate pyrogenic dormancy release. The remaining species, classified as having facultative pyrogenic dormancy, had lower temperature dormancy thresholds and committed at least 30% of seeds to germinate after summer‐temperature treatments. Evidence from this study supports including dormancy‐breaking temperature thresholds as an attribute for identifying functional types. High temperature thresholds for breaking dormancy, found in our obligate pyrogenic group, appear to be a fire‐adapted trait, while we predict that species in the facultative group are most at risk to increased seed bank decay resulting from elevated soil temperatures under projected climate change.