bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postsynthetic Improvement of the Physical Properties in a Metal–Organic Framework through a Single Crystal to Single Crystal Transmetallation
Authors: Grancha Thais , Ferrando‐Soria Jesús , Zhou Hong‐Cai , Gascon Jorge , Seoane Beatriz , Pasán Jorge , Fabelo Oscar , Julve Miguel , Pardo Emilio 
Published: April 2015

AbstractA single crystal to single crystal transmetallation process takes place in the three‐dimensional (3D) metal–organic framework (MOF) of formula MgII2{MgII4[CuII2(Me3mpba)2]3}⋅45 H2O (1; Me3mpba4−=N,N′‐2,4,6‐trimethyl‐1,3‐phenylenebis(oxamate)). After complete replacement of the MgII ions within the coordination network and those hosted in the channels by either CoII or NiII ions, 1 is transmetallated to yield two novel MOFs of formulae Co2II{CoII4[CuII2(Me3mpba)2]3}⋅56 H2O (2) and Ni2II{NiII4[CuII2(Me3mpba)2]3}⋅ 54 H2O (3). This unique postsynthetic metal substitution affords materials with higher structural stability leading to enhanced gas sorption and magnetic properties.
Palladium(0)/PAr3‐Catalyzed Intermolecular Amination of C(sp3)H Bonds: Synthesis of β‐Amino Acids
Authors: He Jian , Shigenari Toshihiko , Yu Jin‐Quan 
Published: April 2015

AbstractAn intermolecular C(sp3)H amination using a Pd0/PAr3 catalyst was developed. The reaction begins with oxidative addition of R2NOBz to a Pd0/PAr3 catalyst and subsequent cleavage of a C(sp3)H bond by the generated PdNR2 intermediate. The catalytic cycle proceeds without the need for external oxidants in a similar manner to the extensively studied palladium(0)‐catalyzed CH arylation reactions. The electron‐deficient triarylphosphine ligand is crucial for this C(sp3)H amination reaction to occur.
To what extent the presence of real‐strength tropical cyclones influences the estimation of atmospheric intraseasonal oscillation intensity?
Authors: Bi Mingyu , Li Tim , Shen Xinyong , Peng Melinda 
Published: April 2015

AbstractAn idealized dataset that contains a background seasonal mean state, a reference intraseasonal oscillation (ISO) state and real‐strength tropical cyclones (TCs) was constructed, in order to examine to what extent the presence of the real‐strength TCs may impact the overall ISO strength over the western North Pacific. The averaged ISO strength (measured by combined 850‐hPa zonal and meridional wind fields) increases by 9% when the realistic TCs are included. The percentage increase of the overall ISO strength depends on the variable used. It is doubled (reduced to 3%) when the vorticity (stream function) is used as the estimated variable.
Preparing augmented reality learning content should be easy: UNED ARLE—an authoring tool for augmented reality learning environments
Authors: Cubillo Joaquín , Martin Sergio , Castro Manuel , Boticki Ivica 
Published: April 2015

ABSTRACTThe purpose of this study was to investigate how an augmented reality learning environment system (UNED ARLE) can be used both by teachers and students to add virtual content into educational resources and how can it serve as a tool for acquiring knowledge, motivating and encouraging students. UNED ARLE is used to add contextualized virtual content (3D objects, animated 3D objects, videos, sound files and images) and the accompanying descriptions or narratives into printed material, thereby enriching existing content without any programming skills. This study recruited 44 students of advanced and intermediate cycles of vocational training and two teachers. It analyses UNED ARLE by examining the interaction between teachers and the system and by comparing the results of two groups of students. The study concludes that the students who used UNED ARLE show significantly better learning achievements compared to the traditional system. In regards to the teachers, the study shows that incorporating multimedia resources into augmented reality is directly influenced by their knowledge of this technology, due to the difficulty of developing new virtual objects. © 2015 Wiley Periodicals, Inc. Comput. Appl. Eng. Educ. Comput Appl Eng Educ 23:778–789, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21650
Photocatalytic CH Activation by Hydrogen‐Atom Transfer in Synthesis
Authors: Protti Stefano , Fagnoni Maurizio , Ravelli Davide 
Published: April 2015

AbstractThis minireview encompasses the most recent (since 2010) advancements in the field of photocatalytic hydrogen‐atom transfer (HAT) processes for CH bond functionalization. The direct HAT process promoted from the excited state of a photocatalyst is limited to the classes of polyoxometalates and aromatic ketones, but alternative photocatalytic strategies have recently been devised to alleviate this shortcoming, making use of indirect HAT reactions. The applications of these two approaches in organic synthesis, including the formation of CC, as well as Chalogen, CO (CO), and CN bonds, are presented herein.
Extension of the Rapid Design Algorithm for Twisted‐Tube Evaporative Fluid Coolers
Authors: Nasr Mohammad R. Jafari , Jafarifar Shima 
Published: April 2015

AbstractThe thermal analysis performance of evaporative fluid coolers (EFCs) is improved by replacing plain tubes by twisted oblong tubes. Results of the system are assessed by a rapid design algorithm (RDA) and compared to conventional plain‐tube EFCs and other traditional algorithms including the effectiveness number of transfer units (ϵ‐NTU). Based on the RDA, a relationship between heat transfer coefficients, pressure drops, heat transfer area, and mass transfer coefficient is derived. Using the maximum allowable pressure drops in this algorithm, the minimum required heat transfer area can be determined. The algorithm is validated by comparing the plain‐tube EFC design with twisted‐tube design. The RDA‐designed EFCs with twisted tubes provide higher efficiency compared with the traditional designs with plain tubes in such that the new design needs a lower heat transfer area for a given heat load.
Synthesis of a Tricyclic Bisguanidine Compound Structurally Related to Saxitoxin and its Identification in Paralytic Shellfish Toxin‐Producing Microorganisms
Authors: Tsuchiya Shigeki , Cho Yuko , Konoki Keiichi , Nagasawa Kazuo , Oshima Yasukatsu , Yotsu‐Yamashita Mari 
Published: April 2015

AbstractWe recently reported the chemical synthesis and identification of the genetically predicted biosynthetic intermediates of saxitoxin (STX), including a 2‐aminoimidazole‐bearing monoguanidine compound (Int‐C′2) in two paralytic shellfish toxin (PST)‐producing microorganisms. In this study, we achieved the direct conversion of Int‐C′2 into a tricyclic bisguanidine compound (called Cyclic‐C′), which is structurally related to STX, through oxidative intramolecular guanidine transfer to 2‐aminoimidazole catalyzed by Pd/C under basic conditions in air. By using HPLC‐MS analysis, Cyclic‐C′ was also identified in the PST‐producing microorganisms, suggesting that Cyclic‐C′ is either another biosynthetic intermediate or a shunt product of PSTs. In addition, a weak inhibitory activity of Cyclic‐C′ to the voltage‐gated sodium channels was detected by using a cell‐based assay.
Practical communication guidance to improve phase 1 informed consent conversations and decision‐making in pediatric oncology
Authors: Johnson Liza‐Marie , Leek Angela C. , Drotar Dennis , Noll Robert B. , Rheingold Susan R. , Kodish Eric D. , Baker Justin N. 
Published: April 2015

BACKGROUNDIt can be difficult to explain pediatric phase 1 oncology trials to families of children with refractory cancer. Parents may misunderstand the information presented to them, and physicians may assume that certain topics are covered in the informed consent document and need not be discussed. Communication models can help to ensure effective discussions.METHODSSuggestions for improving the informed consent process were first solicited from phase 1 study clinicians via questionnaire. Eight parents who had enrolled their child on a phase 1 pediatric oncology trial were recruited for an advisory group designed to assess the clinicians' suggestions and make additional recommendations for improving informed consent for pediatric phase 1 trials.RESULTSA phase 1 communication model was designed to incorporate the suggestions of clinicians and families. It focused on educating parents/families about phase 1 trials at specific time points during a child's illness, but specifically at the point of disease recurrence. An informative phase 1 fact sheet that can be distributed to families was also presented.CONCLUSIONSFamilies who will be offered information regarding phase 1 clinical trials can first receive a standardized fact sheet explaining the general purpose of these early‐phase clinical trials. Parental understanding may be enhanced further when oncologists address key themes, beginning at the time of diagnosis and continuing through important decision points during the child's illness. This model should be prospectively evaluated. Cancer 2015;121:2439–2448. © 2015 American Cancer Society.
Effect of age on the efficacy of adjuvant chemotherapy for resected non–small cell lung cancer
Authors: Ganti Apar Kishor , Williams Christina D. , Gajra Ajeet , Kelley Michael J. 
Published: April 2015

BACKGROUNDAdjuvant chemotherapy after surgical resection improves outcomes for patients with early‐stage non–small cell lung cancer (NSCLC). To the authors' knowledge, there are no published prospective trials to date of adjuvant chemotherapy after surgical resection administered exclusively in older patients. In the current study, the authors sought to evaluate the efficacy of adjuvant chemotherapy in older patients in a Veterans Health Administration cohort.METHODSPatients who underwent surgical resection for American Joint Committee on Cancer stages IB to III NSCLC between 2001 and 2011 were analyzed. Data regarding patient demographics and comorbidities, tumor characteristics, and primary treatment were collected. Patients were divided into 2 groups based on age at diagnosis: those aged <70 years and those aged ≥70 years. The primary exposure was use of adjuvant chemotherapy. A Cox proportional hazards model was used to estimate the significance of patient characteristics. Survival curves were estimated using the Kaplan‐Meier method and group comparisons were performed using the log‐rank test.RESULTSThe analysis included 7593 patients who underwent surgical resection for stage IB to stage III NSCLC. Among these, 2897 patients (38%) were aged ≥70 years. The percentage of older patients who received adjuvant chemotherapy was approximately one‐half that of younger patients who did so (15.3% vs 31.6%; P<.0001). Carboplatin‐based doublets were used most often in all patients (64.6%). Both younger patients (hazard ratio, 0.79; 95% confidence interval, 0.72‐0.86) and older patients (hazard ratio, 0.81; 95% confidence interval, 0.71‐0.92) were found to have a lower risk of death with receipt of adjuvant chemotherapy.CONCLUSIONSOlder patients derive a similar magnitude of benefit from adjuvant chemotherapy as younger patients and therefore adjuvant chemotherapy should not be withheld based on age alone. Cancer 2015;121:2578–2585. © 2015 American Cancer Society.
Epidemiology of meningiomas post‐Public Law 107‐206: The Benign Brain Tumor Cancer Registries Amendment Act
Authors: Dolecek Therese A. , Dressler Emily Van Meter , Thakkar Jigisha P. , Liu Meng , Al‐Qaisi Abeer , Villano John L. 
Published: April 2015

BACKGROUNDThe current analysis follows the implementation of Public Law 107‐260, the Benign Brain Tumor Cancer Registries Amendment Act, which mandated the collection of nonmalignant brain tumors.METHODSMeningiomas were selected from the Surveillance, Epidemiology, and End Results (SEER) Program database for the years 2004 to 2011. Demographic and clinical characteristics, initial treatment patterns, and survival outcomes were evaluated using surveillance epidemiology statistical methods.RESULTSThe average annual age‐adjusted incidence rate per 100,000 population was 7.62 (95 % confidence interval [CI], 7.55‐7.68) for all meningiomas, 7.18 (95% CI, 7.12‐7.25) for benign meningiomas, 0.32 (95% CI, 0.31‐0.33) for borderline malignant meningiomas, and 0.12 (95% CI, 0.11‐0.12) for malignant meningiomas. The annual rates increased for benign and borderline malignant tumors but decreased for malignant tumors. The rates for women exceeded those for men, especially for those with benign meningiomas. Black race was associated with significantly higher rates as was advancing age. Greater than 80% of tumors were located in cerebral meninges. Diagnostic confirmation through pathology occurred for approximately 50% of benign tumors, 90% of borderline malignant tumors, and 80% of malignant tumors. No initial treatment was reported for greater than 60% of benign tumors, 29% of borderline malignant tumors, or 31% of malignant tumors. The 5‐year relative survival estimates for benign tumors, borderline malignant tumors, and malignant tumors were 85.6% (95% confidence interval [CI], 85%‐86.2%), 82.3% (95% CI, 79.3%‐84.8%), and 66% (95% CI, 60.6%‐70.9%), respectively. Predictors of poorer survival were advanced age, being male gender, black race, no initial treatment, and malignant tumor behavior.CONCLUSIONSThe current analysis demonstrates that there is an increasing incidence of nonmalignant meningiomas, probably because of reporting learning curves associated with the implementation of Public Law 107‐260. The high proportion of cases who receive no initial treatment is a survival outcome concern, especially for patients with malignant meningiomas. Cancer 2015;121:2400–2410. © 2015 American Cancer Society.
Changing prognostic significance of tumor stage and nodal stage in patients with squamous cell carcinoma of the oropharynx in the human papillomavirus era
Authors: Keane Florence K. , Chen Yui‐Hui , Neville Bridget A. , Tishler Roy B. , Schoenfeld Jonathan D. , Catalano Paul J. , Margalit Danielle N. 
Published: April 2015

BACKGROUNDAlthough human papillomavirus (HPV)–associated oropharyngeal squamous cell carcinoma (OPSCC) tends to present at an advanced nodal stage (N stage), the prognosis is generally better than that for HPV‐negative OPSCC. Prior work has demonstrated the increasing incidence of HPV‐related OPSCC in the United States. This study was designed to determine whether the changing epidemiology of OPSCC is reflected in changes in the prognostic significance of the tumor stage (T stage) and the N stage in a population‐based cohort.METHODSThe Surveillance, Epidemiology, and End Results program was used to identify 13,328 patients who were 18 years old or older and were diagnosed with OPSCC from 1997 to 2008. The Kaplan‐Meier method was used to estimate head and neck cancer–specific survival. Cox proportional hazards models were used to evaluate the associations between head and neck cancer–specific mortality (HNCSM) and T and N stages and the interaction of variables with the year of diagnosis.RESULTSWith a median follow‐up of 67 months, there were 4099 head and neck cancer deaths. There was a significant interaction between the T stage and time (Pfor interaction = .01), with the effect of the T stage on HNCSM increasing from 1997 to 2008. The T stage retained a linear relationship with HNCSM. The effect of the N stage on HNCSM declined over time (Pfor interaction = .0004). The current American Joint Committee on Cancer (AJCC) staging system did not subdivide distinct prognostic subgroups for HNCSM by overall stage.CONCLUSIONSIn this population‐based study of OPSCC, the effect of the N stage on cancer‐specific mortality decreased over time as the impact of the T stage increased. The current AJCC staging system did not distinguish prognostic subgroups. These changes may reflect the increasing prevalence of HPV‐related OPSCC. Further study in HPV‐defined cohorts is needed to tailor the AJCC staging system to better reflect HNCSM risk.Cancer2015;121:2594–2602. ©2015 American Cancer Society.
Theoretical Studies of the Reactions CFxH3−xCOOR+Cl and CF3COOCH3+OH
Authors: Bai Feng‐Yang , Zhu Xiao‐Le , Jia Zi‐Man , Wang Xu , Sun Yan‐Qiu , Wang Rong‐Shun , Pan Xiu‐Mei 
Published: April 2015

AbstractThe mechanism and kinetics of the reactions of CF3COOCH2CH3, CF2HCOOCH3, and CF3COOCH3 with Cl and OH radicals are studied using the B3LYP, MP2, BHandHLYP, and M06‐2X methods with the 6‐311G(d,p) basis set. The study is further refined by using the CCSD(T) and QCISD(T)/6‐311++G(d,p) methods. Seven hydrogen‐abstraction channels are found. All the rate constants, computed by a dual‐level direct method with a small‐curvature tunneling correction, are in good agreement with the experimental data. The tunneling effect is found to be important for the calculated rate constants in the low‐temperature range. For the reaction of CF3COOCH2CH3+Cl, H‐abstraction from the CH2 group is found to be the dominant reaction channel. The standard enthalpies of formation for the species are also calculated. The Arrhenius expressions are fitted within 200–1000 K as kT(1)=8.4×10−20T 2.63exp(381.28/T), kT(2)=2.95×10−21T 3.13exp(−103.21/T), kT(3)=1.25×10−23T 3.37exp(791.98/T), and kT(4)=4.53×10−22T 3.07exp(465.00/T).
Study of Electronic, Optical Absorption and Emission in Pure and Metal‐Decorated Graphene Nanoribbons (C29H14‐X; X=Ni, Fe, Ti, Co+, Al+, Cu+): First Principles Calculations
Authors: Chopra Siddheshwar 
Published: April 2015

AbstractDensity functional theory (DFT) and time‐dependent density functional theory (TDDFT) calculations were performed with the basis sets 6‐31G for DFT and 6‐31G(d), 6‐31+G(d,p) for TDDFT on pure graphene nanoribbon (GNR) C30H14 and metal‐decorated C29H14‐X (MGNRs; X=Ni, Fe, Ti, Co+, Al+, and Cu+). The metal/carbon ratio (X:C 3.45 %) and the doping site were fixed. Electronic properties, that is, the dipole moment, binding energy, and HOMO–LUMO gaps, were calculated. The absorption and emission properties in the visible range (λ=400–720 nm) were determined. Optical gaps, absorption and emission wavelengths, oscillator strengths, and dominant transitions were calculated. Pure graphene was found to be the most stable form. However, of the MGNRs, C29H14Co+ and C29H14Al+ were found to be the most and least stable, respectively. All GNRs were found to have semiconducting nature. The optical absorption of pure graphene undergoes a shift on metal doping. Emission from the pure graphene followed Kasha′s rule, unlike the metal‐doped GNRs.
Photoelectrochemical Reaction for the Efficient Production of Hydrogen and High‐Value‐Added Oxidation Reagents
Authors: Fuku Kojiro , Wang Nini , Miseki Yugo , Funaki Takashi , Sayama Kazuhiro 
Published: April 2015

AbstractA porous and thick photoelectrode of WO3 in the monoclinic phase was prepared to realize the recovery of H2 and high‐value‐added oxidation reagents with efficient solar energy conversion. The WO3 photoelectrode enabled the efficient production and accumulation of O2, S2O82−, Ce4+, and IO4− as oxidation products. Most notably, S2O82−, which possesses the highest oxidizability among all the peroxides, was generated with high applied bias photon‐to‐current efficiency (2.2 %) and faraday efficiency (≈100 %) upon irradiation from the back side of the photoelectrode. The design of a tandem photoelectrode system combining a dye‐sensitized solar cell (DSSC) was also challenged for the realization of this photoelectrode system without external bias. A high solar energy conversion efficiency (5.2 %) was achieved in the tandem system comprising the WO3 photoelectrode connected to two DSSCs with a near‐IR‐utilizing dye in series for the production of H2 and S2O82−.
A Critical View on Catalytic Pyrolysis of Biomass
Authors: Venderbosch R. H. 
Published: April 2015

AbstractThe rapid heating of biomass in an oxygen‐free environment optimizes the yield of fast‐pyrolysis liquids. This liquid comprises a mix of acids, (dehydrated) carbohydrates, aldehydes, ketones, lignin fragments, aromatics, and alcohols, limiting its use. Deoxygenation of these liquids to replace hydrocarbons represents significant challenges. Catalytic pyrolysis is seen as a promising route to yield liquids with a higher quality. In this paper, literature data on catalytic fast pyrolysis of biomass are reviewed and deoxygenation results correlated with the overall carbon yield. Evidence is given that in an initial stage of the catalytic process reactive components are converted to coke, gas, and water, and only to a limited extent to a liquid product. Catalysts are not yet good enough, and an appropriate combination of pyrolysis conditions, reactive products formed, and different reactions to take place to yield improved quality liquids may be practically impossible.
Recyclable Bifunctional Polystyrene and Silica Gel‐Supported Organocatalyst for the Coupling of CO2 with Epoxides
Authors: Kohrt Christina , Werner Thomas 
Published: April 2015

AbstractA bifunctional ammonium salt covalently bound to a polystyrene or silica support proved to be an efficient and recyclable catalyst for the solvent‐free synthesis of cyclic carbonates from epoxides and CO2. The catalyst can be easily recovered by simple filtration after the reaction and reused in up to 13 consecutive runs with retention of high activity and selectivity even at 90 °C. The scope and limitations of the reaction has been evaluated in terms of reaction conditions and substrate scope.
Improved Synthesis of a Zirconium(IV) Muconate Metal–Organic Framework: Characterization, Stability and Gas Sorption Properties
Authors: Buragohain Amlan , Biswas Shyam 
Published: April 2015

AbstractThe formerly reported ZrIV trans,trans‐muconate framework material (1) was synthesized by using an improved synthetic protocol. Instead of using the noncommercial Zr6‐methacrylate oxido cluster as the metal source, the same MOF was successfully synthesized by using commercially available ZrCl4 as the Zr source. Small amounts of H2O (1‐H2O‐AS; AS = as‐synthesized) or concd. aqueous HCl (1‐HCl‐AS) were used as additives in N,N‐dimethylformamide (DMF) in order to enhance the crystallinity of the compounds. The guest molecules were removed from the pores by heating the as‐synthesized compounds under vacuum, resulting in the empty‐pore forms of the compounds. The as‐synthesized and thermally activated compounds were characterized by X‐ray powder diffraction (XRPD), Fourier transform infrared (FTIR), thermogravimetric (TG) and elemental analyses. Thermogravimetric analyses suggest that the two compounds are stable up to ca. 250 °C in an air atmosphere. As verified by the XRPD experiments, the 1‐HCl compounds gradually lose their crystallinity when exposed to water and moisture. As confirmed by the N2 sorption analyses, the optimally activated 1‐HCl compound displayed a BET surface area of 557 m2 g–1, which is lower than the isostructural UiO‐66 (950 m2 g–1) but it is close to the literature value (705 m2 g–1). The moderate physiochemical stability paired with considerable porosity renders the material a promising candidate for gas storage and separation.