bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper‐Containing Nitrite Reductase Employing Proton‐Coupled Spin‐Exchanged Electron‐Transfer and Multiproton Synchronized Transfer to Reduce Nitrite
Authors: Qin Xin , Deng Li , Hu Caihong , Li Li , Chen Xiaohua 
Published: August 2017

AbstractThe possible catalytic mechanism of the reduction of nitrite by copper‐containing nitrite reductases (CuNiRs) is examined by using the M06 function according to two copper models, which include type‐one copper (T1Cu) and type‐two copper (T2Cu) sites. Examinations confirm that the protonation of two residues, His255 and Asp98, near the T2Cu site, can modulate the redox states of T1Cu and T2Cu, but cannot directly cause electron transfer from T1Cu to T2Cu. The electron hole remains at the T2Cu site when only one residue, His255 or Asp98, is protonated. However, the hole resides at the T1Cu site when both His255 and Asp98 are protonated. Then, the first protonation of nitrite takes place through indirect proton transfer from protonated His255 through the bridging H2O and Asp98 with three protons moving together, which cannot cause the cleavage of the HO−NO bond. Subsequently, the substrate is required to obtain another proton from reprotonated His255 through the bridging H2O. The reprotonation of nitrite induces the generation of nitric oxide (NO) and H2O at the T2Cu site through a special double‐proton‐coupled spin‐exchanged electron‐transfer mechanism with indirect proton transfer from His255 to the substrate, a beta‐electron of T2CuI shift to the NO cation, and the remaining alpha‐electron changing spin direction at the same time. These results may provide useful information to better understand detailed proton‐/electron‐transfer reactions for the catalytic processes of CuNiR.
A Recyclable Metal–Organic Framework as a Dual Detector and Adsorbent for Ammonia
Authors: Gładysiak Andrzej , Nguyen Tu N. , Navarro Jorge A. R. , Rosseinsky Matthew J. , Stylianou Kyriakos C. 
Published: August 2017

AbstractRecyclable materials for simultaneous detection and uptake of ammonia (NH3) are of great interest due to the hazardous nature of NH3. The structural versatility and porous nature of metal–organic frameworks (MOFs) make them ideal candidates for NH3 capture. Herein, the synthesis of a water‐stable and porous 3‐dimensional CuII‐based MOF (SION‐10) displaying a ship‐in‐a‐bottle structure is reported; the pores of the host SION‐10 framework accommodate mononuclear CuII‐complexes. SION‐10 spontaneously uptakes NH3 as a result of two concurrent mechanisms: chemisorption due to the presence of active CuII sites and physisorption (bulk permanent porosity). The color of the material changes from green to blue upon NH3 capture, with the shifts of the UV/Vis absorption bands clearly seen at NH3 concentrations as low as 300 ppm. SION‐10 can be recovered upon immersion of SION‐10⊃NH3 in water and can be further reused for NH3 capture for at least three cycles.
Ultrathin Layers of PdPX (X=S, Se): Two Dimensional Semiconductors for Photocatalytic Water Splitting
Authors: Jing Yu , Ma Yandong , Wang Yu , Li Yafei , Heine Thomas 
Published: August 2017

AbstractOn grounds of first principles calculations we propose two‐dimensional semiconductors, ultrathin mono‐, bi‐ and trilayers of PdPX (X=S, Se), as photocatalysts with band gaps suitable for harvesting the visible part of the solar spectrum and band edge energies matching the electrochemical potentials required for water splitting reaction. Layered bulk palladium phosphochalcogenides, among them the title compounds, have been known since 1971. The cleavage energy of ≈0.6 J m−2 suggests that single and few layer PdPX can be produced by exfoliation from the bulk phase. PdPX monolayer possesses a moderate band gap of 2.12 (1.97) eV for PdPS (PdPSe) and shows high, albeit anisotropic, carrier motilities. Bandgap (and edge) engineering is possible by applying strain (in the range of 1.5∼2.3 eV), and by varying the number of layers, that is, to 1.95(1.80) eV for the bi‐ and 1.75 (1.62) eV for the trilayer, to 1.70 (1.43) eV in the bulk.
Three‐year cytohistological correlation of salivary gland FNA cytology at a tertiary center with the application of the Milan system for risk stratification
Authors: Rohilla Manish , Singh Priya , Rajwanshi Arvind , Gupta Nalini , Srinivasan Radhika , Dey Pranab , Vashishta Rakesh K. 
Published: August 2017

BACKGROUNDFine‐needle aspiration (FNA) cytology of salivary glands is a well‐established technique that plays a critical role in the preoperative diagnosis of lesions. A risk stratification of FNA diagnostic categories has been recently proposed to be useful in reporting. The aims of this study were to evaluate the diagnostic accuracy of salivary gland FNA and to apply the proposed Milan system for reporting salivary gland lesions.METHODSA retrospective audit of FNA specimens of salivary gland lesions reported from 2014 to 2016 was performed. A correlation with the follow‐up histopathology, wherever it was available, was performed. The aspirates were then categorized according to the Milan system as follows: nondiagnostic, nonneoplastic, atypical, benign neoplasm, neoplasm of uncertain malignant potential (NUMP), suspicious for malignancy, or positive for malignancy. Furthermore, the risk of malignancy and the risk of high‐grade malignancy were calculated for all diagnostic categories.RESULTSA total of 631 salivary gland aspirates were evaluated: 2.2% were nondiagnostic, 55.8% indicated nonneoplastic lesions, and 40.4% indicated neoplastic lesions. Histopathology was available for 94 cases (14.9%). FNA had a sensitivity of 79.4% and a specificity of 98.3% with an overall diagnostic accuracy of 91.4% for differentiating malignant tumors from benign tumors. The overall risk of malignancy was 17.4% for the nonneoplastic category, 100% for the atypical category, 7.3% for the benign neoplasm category, 50% for the NUMP category, and 96% for the positive‐for‐malignancy category.CONCLUSIONSSalivary gland FNA continues to have high diagnostic accuracy and is thus helpful for guiding management. Neoplasms with classic cytomorphology are easily diagnosed; however, in difficult cases showing overlapping features, the use of the Milan system could be beneficial. Cancer Cytopathol 2017;125:767‐75. © 2017 American Cancer Society.
Excitation Power Modulates Energy‐Transfer Dynamics in a Supramolecular RuII‐FeII‐RuII Triad
Authors: Kübel Joachim , Wächtler Maria , Dietzek Benjamin 
Published: August 2017

AbstractMultichromophoric arrays are key to light harvesting in natural and artificial photosynthesis. A trinuclear, symmetric RuII‐FeII‐RuII triad may resemble a light‐harvesting model system in which excitation energy from donor units (Ru‐terpyridine fragments) is efficiently transferred to the acceptor (the Fe‐terpyridine fragment). The photoinduced dynamics after simultaneous excitation of more than a single chromophoric unit (donor/acceptor) at varying excitation fluence is investigated in this contribution. Data suggests that energy transfer is decelerated if the acceptor states (on the FeII unit) are not depopulated fast enough. As a consequence, the lifetime of a high‐lying excited state (centered on either of the RuII units) is prolonged. A kinetic model is suggested to account for this effect. Although the proposed model is specifically adopted to account for the experimental data reported here, it might be generalized to other situations in which multiple energy or electron donors are covalently linked to a single acceptor site, a situation of interest in contemporary artificial photosynthesis.
A Zinc(II) Porous Metal–Organic Framework and Its Morphologically Controlled Catalytic Properties in the Knoevenagel Condensation Reaction
Authors: Wang Jiajia , Wang Xiaoxiao , Xu Haitao , Zhao Xi , Zheng Zhizhong , Xu Zhen‐liang 
Published: August 2017

AbstractA new metal–organic framework (MOF), {Zn(oba)(3‐bpdh)0.5}∝⋅2 H2O (1 Zn; oba=4,4′‐oxybis(benzoic acid), 3‐bpdh=N,N′‐bis(1‐pyridine‐3‐yl‐ethylidene)hydrazine), was successfully assembled in a solvothermal system. The Zn2+ ion center located in a five‐coordinate environment combined with oba to produce a layer‐like structure, which is again linked with 3‐bpdh to yield a 3D channel framework. MOF 1 Zn microcrystals with different morphologies were synthesized through coordination modulation and solvent‐dependent methods. The effects of the concentration of the modulator, the reaction temperature, and the volume ratio of mixed solvents have been investigated. Furthermore, the catalytic performance in Knoevenagel condensation was studied for different morphologies of 1 Zn microcrystals; this revealed that the MOF microcrystals exhibited excellent and morphology‐dependent catalytic properties.
Dehydrogenase‐Catalyzed Oxidation of Furanics: Exploitation of Hemoglobin Catalytic Promiscuity
Authors: Jia Hao‐Yu , Zong Min‐Hua , Yu Hui‐Lei , Li Ning 
Published: August 2017

AbstractThe catalytic promiscuity of hemoglobin (Hb) was explored for regenerating oxidized nicotinamide cofactors [NAD(P)+]. With H2O2 as oxidant, Hb efficiently oxidized NAD(P)H into NAD(P)+ within 30 min. The new NAD(P)+ regeneration system was coupled with horse liver alcohol dehydrogenase (HLADH) for the oxidation of bio‐based furanics such as furfural and 5‐hydroxymethylfurfural (HMF). The target acids (e.g., 2,5‐furandicarboxylic acid, FDCA) were prepared with moderate‐to‐good yields. The enzymatic regeneration method was applied in l‐glutamic dehydrogenase (DH)‐mediated oxidative deamination of lglutamate and for l‐lactic‐DH‐mediated oxidation of l‐lactate, which furnished α‐ketoglutarate and pyruvate in yields of 97 % and 81 %, respectively. A total turnover number (TTON) of up to approximately 5000 for cofactor and an E factor of less than 110 were obtained in the bi‐enzymatic cascade synthesis of α‐ketoglutarate. Overall, a proof‐of‐concept based on catalytic promiscuity of Hb was provided for in situ regeneration of NAD(P)+ in DH‐catalyzed oxidation reactions.
Insights into the Hydrothermal Stability of Triamine‐Functionalized SBA‐15 Silica for CO2 Adsorption
Authors: Jahandar Lashaki Masoud , Ziaei‐Azad Hessam , Sayari Abdelhamid 
Published: August 2017

AbstractThe hydrothermal stability of triamine‐grafted, large‐pore SBA‐15 CO2 adsorbents was studied by using steam stripping. Following two 3 h cycles of steam regeneration, lower CO2 uptakes, lower CO2/N ratios, and slower adsorption kinetics were observed relative to fresh samples, particularly at the lowest adsorption temperature (25 °C). CO2 adsorption measurements for a selected sample exposed to 48 h of steam stripping depicted that after the initial loss during the first exposure to steam (3–6 h), the adsorptive properties stabilized. For higher adsorption temperatures (i.e., 50 and 75 °C), however, all adsorptive properties remained almost unchanged after steaming, indicating the significance of diffusional limitations. Thermogravimetric analysis and FTIR spectroscopy on grafted samples before and after steam stripping showed no amine leaching and no change in the chemical nature of the amine groups, respectively. Also, a six‐cycle CO2 adsorption/desorption experiment under dry conditions showed no thermal degradation. However, N2 adsorption measurement at 77 K showed significant reductions in the BET surface area of the grafted samples following steaming. Based on the pore size distribution of calcined, grafted samples before and after steaming, it is proposed that exposure to steam restructured the grafted materials, causing mass transfer resistance. It is inferred that triamine‐grafted, large‐pore SBA‐15 adsorbents are potential candidates for CO2 capture at relatively high temperatures (50–75 °C; for example, flue gas) combined with steam regeneration.
Is the tier-1 effect assessment for herbicides protective for aquatic algae and vascular plant communities?
Authors: van Wijngaarden René P.A. , Arts Gertie H.P. 
Published: August 2017

Abstract

In the aquatic tier-1 effect assessment for plant protection products with an herbicidal mode of action in Europe, it is usually algae and/or vascular plants that determine the environmental risks. This tier includes tests with at least 2 algae and 1 macrophyte (Lemna). Although such tests are considered to be of a chronic nature (based on the duration of the test in relation to the life cycle of the organism), the measurement endpoints derived from the laboratory tests with plants (including algae) and used in the first-tier effect assessment for herbicides are acute effect concentrations affecting 50% of the test organisms (EC50 values) and not no-observed-effect concentrations (NOECs) or effect concentrations affecting 10% of the test organisms (EC10) values. Other European legislative frameworks (e.g., the Water Framework Directive) use EC10 values. The present study contributes to a validation of the tiered herbicide risk assessment approach by comparing the standard first-tier effect assessment with results of microcosm and mesocosm studies. We evaluated EC50 and EC10 values for standard test algae and macrophytes based on either the growth rate endpoint (ErC50) or the lowest available endpoint for growth rate or biomass/yield (Er/EyC50). These values were compared with the regulatory acceptable concentrations for the threshold option as derived from microcosm and mesocosm studies. For these studies, protection is maintained if growth rate is taken as the regulatory endpoint instead of the lowest value of either growth rate or biomass/yield in conjunction with the standard assessment factor of 10. Based on a limited data set of 14 herbicides, we did not identify a need to change the current practice. Environ Toxicol Chem 2018;37:175–183. © 2017 SETAC
Enantiomer-specific measurements of current-use pesticides in aquatic systems
Authors: Ulrich Elin M. , TenBrook Patti L. , McMillan Larry M. , Wang Qianheng , Lao Wenjian 
Published: August 2017

Abstract

Some current-use pesticides are chiral and have nonsuperimposable mirror images called enantiomers that exhibit identical physical–chemical properties but can behave differently when in contact with other chiral molecules (e.g., regarding degradation and uptake). These differences can result in variations in enantiomer presence in the environment and potentially change the toxicity of pesticide residues. Several current-use chiral pesticides are applied in urban and agricultural areas, with increased potential to enter watersheds and adversely affect aquatic organisms. The present study describes a stereoselective analytical method for the current-use pesticides fipronil, cis-bifenthrin, cis-permethrin, cypermethrin, and cyfluthrin. We show use of the method by characterizing enantiomer fractions in environmental sample extracts (sediment and water), and laboratory-dosed fish and concrete extracts previously collected by California organizations. Enantiomer fractions for most environmental samples are the same as racemic standards (equal amounts of enantiomers, enantiomer fraction = 0.5) and therefore are not expected to differ in toxicity from racemic mixtures typically tested. In laboratory-derived samples, enantiomer fractions are more frequently nonracemic and favor the less toxic enantiomer; permethrin enantiomer fractions range from 0.094 to 0.391 in one type of concrete runoff and enantiomer fractions of bifenthrin in dosed fish range from 0.378 to 0.499. We use enantiomer fractions as a screening tool to understand environmental exposure and explore ways this uncommon measurement could be used to better understand toxicity and risk. Environ Toxicol Chem 2018;37:99–106. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Abstract
Permethrin enantiomer fractions (EFs) measured in water runoff from concrete (red) show differences in applied pesticide formulation. Bifenthrin enantiomer fractions measured in dosed fish over 3 d show a strong nonracemic signature, typical of biological processes.
Radio resource allocation in heterogeneous cellular networks based on effective capacity maximization: Perspective mobile data offloading
Authors: Gholami Mohamad Hassan , Azmi Paeiz , Mokari Nader , Forouzesh Moslem 
Published: August 2017

AbstractIn this paper, a new radio resource allocation approach for mobile data offloading, by means of a local access point (LAP) in the heterogeneous cellular networks is proposed. We consider the uplink path in a single‐carrier frequency‐division multiple access–based multiuser system in a 2‐tier cellular network with a macro base station (BS) and set of LAPs. We assume that there is no internetwork interference between macro BS and LAPs due to the use of 2 different sets of frequencies. Our aim is to allocate resources to determine the best strategy for providing the required quality of service with the criterion of minimum delay in terms of effective capacity maximization. The basis of this work is optimization for the strategy selection. In other words, the selection of the best station and power allocation for offloading in a single‐carrier frequency‐division multiple access multiuser system and solving the problems using the nonlinear optimization with the mesh adaptive direct algorithm solver and the dual decomposition method, respectively. The numerical results validate our analytical outcomes. For example, system delay decreases approximately 10 times if the traffic load of macro BS is decreased by 50%. In addition, we present a comparison of the impact of traffic reduction and consumed bandwidth due to offloading by means of LAPs on the cellular network, which confirms the efficiency of the proposed approach.
Study of the relationship between thermal insulation behavior and microstructure of a fire‐resistant gel containing silica during heating
Authors: Liu Wei , Ge Xinguo , Zhang Zejiang 
Published: August 2017

SummaryAdding a transparent gel containing silica between 2 sheets of glass could improve the fire resistance of laminated glazing by its thermal intumescent behavior at high temperature. In this study, a custom fire test shows that the glazing reaches the highest thermal insulation rating of 40 minutes when the molar ratio of SiO2 and Na2O in the gel is 4.0, but above this ratio, the thermal insulation rating of the glazing decreases with the increasing silica content. Thermal and scanning electron microscopic analyses have been used to investigate the thermal behavior and microstructure of the residual layer, respectively. The results indicate that, although the high silica content is responsible for the high amount of residue that is essential in the formation of a protection barrier between fire‐exposed and unexposed sides of the glass, it is not the only factor that resulted in the improved thermal insulation of the glazing.
Flexible transparent flame‐retardant membrane based on a novel UV‐curable phosphorus‐containing acrylate
Authors: Wang Xiaomeng , Liu Xueqing , Peng Sha , Peng Panrui , Zou Liyong , Chen Jia , Liu Jiyan 
Published: August 2017

SummaryA novel phosphorus‐containing acrylate monomer (AOPA) was synthesized starting from 2‐methy‐2,5‐dioxo‐1,2‐oxaphospholane and hydroxyethyl acrylate. The structure of AOPA was characterized with FTIR and 1H NMR. AOPA shows good compatibility with polyethylene glycol diacrylate (PEGDA) and can polymerize with PEGDA under UV light irradiation at different mass ratios to form membranes with high transparency (above 88.9% of light transmittance in the range of 400‐800 nm) and flexibility. Incorporating 20 wt% of AOPA in PEGDA reduced the total heat release and peak rate by 50.3% and 38.4%, respectively, as measured by micro combustion calorimeter. The membrane containing 40 wt% of AOPA with 0.4 mm thickness can pass the UL94 V0 rating, and limiting oxygen index reaches 33.4%. TG‐FTIR and SEM‐EDX analysis show that the presence of AOPA depresses the thermal degradation and promotes the char formation.
Geochronology, geochemistry, and zircon Hf isotopes of the Mo‐bearing granitoids in the eastern Jilin‐Heilongjiang provinces, NE China: Petrogenesis and tectonic implications
Authors: Hou Xue‐Gang , Sun De‐You , Gou Jun , Yang Dong‐Guang 
Published: August 2017

In order to investigate their precise geochronological framework, petrogenesis, and tectonic implications, whole‐rock major and trace elements, together with zircon U–Pb and Hf isotope data, are reported for the Mo‐bearing granitoids from the eastern Jilin‐Heilongjiang provinces in the eastern segment of the Central Asian Orogenic Belt. Zircon U–Pb dating by LA–ICP–MS yields crystallization ages for the Liushengdian monzogranite porphyry (252.2 ± 1.6 Ma), the Luming monzogranite porphyry (197.1 ± 1.6 Ma), and the Baoshan granodiorite (164.4 ± 1.9 Ma) and quartz diorite (165.2 ± 1.7 Ma), respectively. This zircon U–Pb data, combined with previous ages, indicate that the eastern Jilin‐Heilongjiang provinces is dominated by 2 stages of ore‐related granitic magmatism and associated Mo mineralization, that is, Late Permian (259–252 Ma) and Early‐Middle Jurassic (200–165 Ma). Geochemically, these Mo‐bearing granitoids have high SiO2 (60.78–74.67 wt.%) and K2O (2.85–6.23 wt.%), low MgO (0.17–2.85 wt.%) and CaO (0.66–4.38 wt.%) contents, with A/NCK and δEu values of 0.87–1.08 and 0.19–1.07, respectively; we infer that they belong to high‐K calc‐alkaline series and are metaluminous to peraluminous in nature. They are characterized by enrichment in large ion lithophile elements and light rare earth elements, and weak depletion in high field strength elements and heavy rare earth elements, consistent with the geochemical signatures of subduction‐related genesis. In addition, in situ Hf isotopic analyses of zircons from 4 dated samples reveal that they have εHf(t) values of −0.4 to +10.3, with 2‐stage model ages varying from 551 to 1,261 Ma, indicating that they probably originated from the partial melting of a dominantly Mesoproterozoic–Neoproterozoic crustal source. On the basis of the geochemical data and regional geological investigations, we propose that the formation of the Late Permian Mo‐bearing granite was related to the subduction of the Paleo‐Asian Ocean plate, whereas the generation of the Early‐Middle Jurassic Mo‐bearing granitoids was associated with the subduction of the Paleo‐Pacific Plate beneath the Eurasian continent.