bluuebunny/crossref_metadata_2025_split huggingface dataset:
Steady‐State Kinetic Analysis of DNA Polymerase Single‐Nucleotide Incorporation Products
Authors: O'Flaherty Derek K. , Guengerich F. Peter 
Published: December 2014

AbstractThis unit describes the experimental procedures for the steady‐state kinetic analysis of DNA synthesis across DNA nucleotides (native or modified) by DNA polymerases. In vitro primer extension experiments with a single nucleoside triphosphate species followed by denaturing polyacrylamide gel electrophoresis of the extended products is described. Data analysis procedures and fitting to steady‐state kinetic models is presented to highlight the kinetic differences involved in the bypass of damaged versus undamaged DNA. Moreover, explanations concerning problems encountered in these experiments are addressed. This approach provides useful quantitative parameters for the processing of damaged DNA by DNA polymerases. © 2014 by John Wiley & Sons, Inc.
Olefin Cross‐Metathesis for the Synthesis of Alkenyl Acyclonucleoside Phosphonates
Authors: Bessières Maxime , De Schutter Coralie , Roy Vincent , Agofoglio Luigi A. 
Published: December 2014

AbstractThe detailed synthetic protocol for the straightforward, efficient synthesis of various alkenyl acyclonucleosides, including challenging trisubstituted alkenyl acyclonucleoside phosphonates, is described. The key step of those syntheses is an olefin cross‐metathesis reaction between two olefins selected based on their reactivity using well‐defined ruthenium alkylidene catalysts. © 2014 by John Wiley & Sons, Inc.
Practical Synthesis of 4′‐Thioribonucleosides Starting from D‐Ribose
Authors: Minakawa Noriaki , Matsuda Akira 
Published: December 2014

AbstractA practical synthesis of 4′‐thioribonucleosides, i.e., 4′‐thiouridine, ‐cytidine, ‐adenosine, and ‐guanosine, which are versatile units for nucleic acids–based therapeutics, is described. Large‐scale synthesis of 4‐thiosugar starting from D‐ribose was achieved (33%) in eight steps and with only three chromatographic purifications. After the appropriate chemical conversion of the 4‐thiosugar, the resulting sulfoxide was subjected to the Pummerer reaction in the presence of silylated nucleobases. In reactions with silylated pyrimidine bases, the desired 4′‐thioribonucleoside derivatives were obtained in good yield and β‐selectively. On the other hand, N‐7 isomers were obtained mainly in the Pummerer reaction with purine bases under the same conditions. However, the desired N‐9 isomers were obtained in moderate yields when the reaction mixtures were subsequently heated under reflux. As a result, effective synthesis of 4′‐thioribonucleosides was accomplished. © 2014 by John Wiley & Sons, Inc.
Opposite hemispheric asymmetries during the ionospheric storm of 29–31 August 2004
Authors: Astafyeva Elvira , Zakharenkova Irina , Doornbos Eelco 
Published: December 2014

AbstractBy making use of multiple ground‐based and spaceborne instruments, we study ionospheric and thermospheric behavior during the moderately intense geomagnetic storm of 29–31 August 2004 (minimum Dst excursion of −128 nT). Although this storm was far from the strongest in solar cycle 23, it provoked quite interesting effects in the ionosphere, such as opposite hemispheric asymmetries in the ionospheric F layer and in the topside ionosphere and a development of the ionospheric superfountain effect in the postsunset sector. Data from ground‐based GPS receivers and ionosondes revealed large increase in total electron content (TEC) and in NmF2 in the southern hemisphere, whereas in the northern hemisphere, very weak or no effect was observed. On the contrary, the topside measurements indicated the occurrence of a positive storm in the northern hemisphere. Overall, the strongest storm time disturbances were observed in the postsunset sector (~20:30–21:30 LT), where satellite radar altimeters TOPEX and Jason 1, along with the CHAMP satellite showed ~250–400% TEC increase in the middle‐ and low‐latitude regions. The signatures of the ionospheric plasma enhancement were seen up to the height of the Defense Meteorological Satellite Program (DMSP) satellites (~840 km). As for the thermospheric storm, data of the Gravity Recovery and Climate Experiment (GRACE) satellite mission revealed no asymmetry in neutral density data in the evening sector (~17 UT); however, very strong hemispheric asymmetry was observed in the postsunset sector by CHAMP (~21 UT). Overall, neutral density increase in the postsunset sector was found to be much stronger than in the evening sector.
The effects of sediment transport, weathering, and aeolian mechanisms on soil evolution
Authors: Cohen Sagy , Willgoose Garry , Svoray Tal , Hancock Greg , Sela Shai 
Published: December 2014

AbstractAeolian‐derived soils are found throughout the world. Soil evolution processes in aeolian‐dominated landscapes differ from processes in bedrock‐weathering landscapes by a number of key aspects including the lack of (1) soil production depth dependency, (2) surface armoring, and (3) grain size self‐organization in the soil profile. We use here a soil evolution model (mARM5D) to study the differences between aeolian and bedrock‐weathering‐dominated landscapes by analyzing soil evolution on a hillslope under various aeolian and bedrock‐soil supply settings subject to fluvial and diffusive sediment transport. The model simulates spatial and temporal variation in soil particle size distribution (PSD) and profile depth for each grid cell on the landscape, as a function of physical weathering, aeolian deposition, and diffusive and fluvial sediment transport. Our results indicate that surface armoring plays a major role in soil evolution. Under bedrock‐weathering‐dominated conditions, armoring reduces soil erosion and in conjunction with depth‐dependent soil production, leads to steady state soil grading and depth and a relatively uniform soil distribution. In contrast, aeolian‐dominated landscapes tend to have considerable spatial variability in soil depth and PSD. Our results also indicate that in contrast with diffusive transport, which is assumed to be PSD independent, fluvial sediment transport is strongly influenced by the soil production mechanism (aeolian or bedrock weathering). Based on the results presented here, we propose that aeolian‐dominated landscapes are more responsive to environmental changes (e.g., climatic and anthropogenic) compared with bedrock‐weathering landscapes. We further propose that this sensitivity may help explain the patchy soil distribution that is often observed in aeolian‐dominated regions.
Seasonal and diurnal variations in net carbon dioxide flux throughout the year from soil in paddy field
Authors: Nishimura Seiichi , Yonemura Seiichiro , Minamikawa Kazunori , Yagi Kazuyuki 
Published: December 2014

AbstractIn contrast to upland croplands, carbon dioxide (CO2) emission from soils has rarely been investigated previously in fields with paddy rice cultivation. In this study, we hypothesized that CO2 emission from paddy soils is suppressed to be a low level due the soil submergence for months for paddy rice cultivation and conducted a continuous measurement of net CO2 flux from the soil/water surface of a paddy field throughout the year, including both the submerged and drained periods. The net CO2 flux was generally near zero during the submerged period with paddy rice cultivation and showed a slight CO2 influx in the daytime and efflux at nighttime, indicating dominance of photosynthetic CO2 uptake and respiratory CO2 release by aquatic weeds and algae in paddy water. The diurnal variations in net CO2 flux and dissolved CO2 concentration had negative correlations with the pH of paddy water. A remarkably high CO2 efflux was observed during the period with intermittent drainage in summer. Unexpectedly, the cumulative CO2 emissions throughout the year were not considerably lower than those reported in upland croplands ranging from 1309 to 2160 g CO2 m−2 yr−1, of which 41–48% was emitted from the first drainage in summer to the rice harvest in autumn. In summary, in this study, we revealed that CO2 emission from soil in paddy fields is strictly suppressed during the submerged period, but considerably enhanced by the succeeding drainage, which may negate the suppressed CO2 emission during the submerged period.
Metal‐Organic Frameworks: Harmful Gas Removal
Authors: Liu Jian , McGrail B. Peter , Strachan Denis M. , Liu Jun , Tian Jian , Thallapally Praveen K. 
Published: December 2014

Abstract

Metal–organic frameworks (MOFs) have been considered to be novel adsorbents for a variety of applications, because of their high surface areas, large pore volumes, tunable pore geometries, and versatile chemical compositions. Besides their applications in energy gas storage, such as H
2
and CH
4
, harmful gas removal has become an important potential area for MOFs applications. This chapter reviews recent research related to four different types of harmful gas adsorption in MOFs, including greenhouse gases such as CO
2
, inorganic toxic gases such as SO

x

, NO

x

, and NH
3
; volatile organic compounds such as benzene and formaldehyde; and radioactive gases such as Xe, Kr, and I
2
. This information is organized in a way that will attempt to introduce this attractive research area to a broad audience, as well as to reveal some trends and significant discoveries to the researchers who are interested in this area. Obviously, removing harmful gases can provide a cleaner and safer living environment to human beings and other creatures. MOFs as novel adsorbents possess advantages, such as high gas adsorption capacities and selectivities, as well as adjustable properties to suit specific needs. However, more fundamental work is still necessary to understand this topic better, and some challenges, such as cost and stability, are in the way of applying MOFs to practical applications.
Metal‐Organic Frameworks: Photoreactive Frameworks
Authors: Chanthapally Anjana , Vittal Jagadese J. 
Published: December 2014

AbstractThis chapter deals with various photoreactive coordination polymers (CPs) and metal‐organic frameworks (MOFs) that undergo [2+2] cycloaddition reactions in the solid state, solid‐state structural transformations, post‐synthetic modification of surfaces creating reactive sites, radicals that are not possible by conventional synthetic routes, polymerization on the surfaces,cis‐transisomerization of the guest molecules in the cavities as well as the dynamic behavior of the CP and MOF structures. Further the formation of these compounds by photochemical methods is also discussed. The three‐dimensional (3D) structural characterization of the products of a number of photochemical and photo‐polymerization reactions were hampered by the lack of a suitable structural tool other than single crystal X‐ray crystallography. On the other hand, most of the examples discussed in this chapter do maintain single crystals at the end of the reactions such that 3D structural elucidation is possible by single crystal X‐ray crystallography to understand the reactivity completely. A few examples have been illustrated where [2+2] cycloaddition reaction has been used to monitor the formation of ladder structures in the solid state in the absence of crystal structures.
Metal–Organic Frameworks: Functional Magnetic Materials with Formate
Authors: Shang Ran , Chen Sa , Wang Zhe‐Ming , Gao Song 
Published: December 2014

AbstractIn this chapter, the state of art of the functional magnetic materials based on metal formate frameworks (MFFs), mainly developed in the past decade, is provided. These materials, belonging to a relatively small yet fundamentally important class of metal‐organic frameworks (MOFs), possess various structures and interesting properties. The binary or ternary dense MFFs display complicated structures and various magnetic behaviors though their constituents are simple. MFFs with ammonium components exhibited abundant and interesting magnetism, di‐/ferro‐/antiferroelectric and mechanical properties, structural phase transitions, and critical phenomena triggered by various order–disorder transitions of ammoniums, and the chirality, as well as the possible combinations such as multiferroics. These ammonium MFFs mimic the traditional inorganic materials such as perovskite, niccolite, and diamond. The porous diamondoid MFFs of [M3(HCOO)6] possess a wide spectrum of gas and guest inclusion behaviors. They thus show guest‐modulated magnetism, guest‐induced chirality, and guest‐based electric polarization. Mixing formate with coligands has provided MFFs with not only beautiful and fantastic structures but also interesting and appealing magnetic properties and others. It has been demonstrated that the formate, being the smallest and simple carboxylate, cheap and less toxic thus more biocompatible and environment‐friendly, and having been more or less ignored before, now comes back to our sight and awareness with its important role, having been verified, in the construction of promising MOF materials, and provides new materials with interesting properties.
Metal‐Organic Frameworks: Single‐Crystal‐to‐Single‐Crystal Transformations
Authors: Neogi Subhadip 
Published: December 2014

Abstract
Remarkable advances in the development of metal‐organic framework (MOF) structures have paved the way toward new multifunctional materials with various potential applications. Porous MOFs having flexible and dynamic properties, resulting from the cooperative action of organic and inorganic moieties, represent an important subclass. Changes between the solid phases under external stimuli are particularly intriguing especially when crystallinity is maintained, allowing direct visualization of such changes via X‐ray crystallography. This chapter is concerned with such changes under different types of external stimuli in single‐crystal to single‐crystal (SC–SC) manner, with an ultimate hope to open up new dimensions in materials chemistry.
Nasal and bronchial response to exercise in children with seasonal allergic rhinitis out of the pollen season
Authors: Harmancı Koray , Urhan Barıs , Anıl Hülya , Kocak Abdulkadır 
Published: December 2014

BackgroundAllergic rhinitis is a type I allergic disease of the nasal mucosa, and is characterized by paroxysmal sneezing, watery rhinorrhea, and nasal blockage. In seasonal allergic rhinitis subjects, even subthreshold allergen doses have been found to cause inflammatory cell infiltration in the nasal mucosa. This study aimed to investigate the presence of nasal obstructions and symptoms in seasonal allergic rhinitis subjects by assessing an exercise challenge test (ECT) outside of the pollen season.MethodsTwenty patients and 20 healthy children who were admitted to the Osmangazi University Medical School Pediatric Allergy Clinic were included in the study in a pollen free season. The total nasal airflow and visual analog scale (for rhinorrhea, nasal congestion, sneezing, and itching) and pulmonary function tests were evaluated before and after each ECT. The nasal airflow and resistance changes were evaluated with anterior rhinomanometry.ResultsEight patients and one healthy child had nasal obstructions after the ECT. There was a significant difference in the exercise‐induced nasal obstructions between the 2 groups (p = 0.02). Eighteen children with exposure to tobacco smoke in the patient and control groups had lower forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and forced expiratory flow 25% to 75% (FEF25‐75) values than the children without exposure to tobacco smoke.ConclusionThe prevalence of exercise‐induced nasal obstruction in children with seasonal rhinitis out of the pollen season is 40%. We showed that minimal persistent inflammation and nasal symptoms can also be diagnosed in rhinitis children in a symptom‐free period.
Covalent Modification of a Cysteine Residue in the XPB Subunit of the General Transcription Factor TFIIH Through Single Epoxide Cleavage of the Transcription Inhibitor Triptolide
Authors: He Qing‐Li , Titov Denis V. , Li Jing , Tan Minjia , Ye Zhaohui , Zhao Yingming , Romo Daniel , Liu Jun O. 
Published: December 2014

AbstractTriptolide is a key component of the traditional Chinese medicinal plant Thunder God Vine and has potent anticancer and immunosuppressive activities. It is an irreversible inhibitor of eukaryotic transcription through covalent modification of XPB, a subunit of the general transcription factor TFIIH. Cys342 of XPB was identified as the residue that undergoes covalent modification by the 12,13‐epoxide group of triptolide. Mutation of Cys342 of XPB to threonine conferred resistance to triptolide on the mutant protein. Replacement of the endogenous wild‐type XPB with the Cys342Thr mutant in a HEK293T cell line rendered it completely resistant to triptolide, thus validating XPB as the physiologically relevant target of triptolide. Together, these results deepen our understanding of the interaction between triptolide and XPB and have implications for the future development of new analogues of triptolide as leads for anticancer and immunosuppressive drugs.
Near‐IR Phosphorescent Ruthenium(II) and Iridium(III) Perylene Bisimide Metal Complexes
Authors: Schulze Marcus , Steffen Andreas , Würthner Frank 
Published: December 2014

AbstractThe phosphorescence emission of perylene bisimide derivatives has been rarely reported. Two novel ruthenium(II) and iridium(III) complexes of an azabenz‐annulated perylene bisimide (ab‐PBI), [Ru(bpy)2(ab‐PBI)][PF6]2 1 and [Cp*Ir(ab‐PBI)Cl]PF6 2 are now presented that both show NIR phosphorescence between 750–1000 nm in solution at room temperature. For an NIR emitter, the ruthenium complex 1 displays an unusually high quantum yield (Φp) of 11 % with a lifetime (τp) of 4.2 μs, while iridium complex 2 exhibits Φp<1 % and τp=33 μs. 1 and 2 are the first PBI‐metal complexes in which the spin–orbit coupling is strong enough to facilitate not only the Sn→Tn intersystem crossing of the PBI dye, but also the radiative T1→S0 transition, that is, phosphorescence.
Reactions of Difunctional Electrophiles with Functionalized Aryllithium Compounds: Remarkable Chemoselectivity by Flash Chemistry
Authors: Nagaki Aiichiro , Imai Keita , Ishiuchi Satoshi , Yoshida Jun‐ichi 
Published: December 2014

AbstractFlash chemistry using flow microreactors enables highly chemoselective reactions of difunctional electrophiles with functionalized aryllithium compounds by virtue of extremely fast micromixing. The approach serves as a powerful method for protecting‐group‐free synthesis using organolithium compounds and opens a new possibility in the synthesis of polyfunctional organic molecules.
Screening for Protein Phosphorylation Using Nanoscale Reactions on Microdroplet Arrays
Authors: Küster Simon K. , Pabst Martin , Zenobi Renato , Dittrich Petra S. 
Published: December 2014

AbstractWe present a novel and straightforward screening method to detect protein phosphorylations in complex protein mixtures. A proteolytic digest is separated by a conventional nanoscale liquid chromatography (nano‐LC) separation and the eluate is immediately compartmentalized into microdroplets, which are spotted on a microarray MALDI plate. Subsequently, the enzyme alkaline phosphatase is applied to every second microarray spot to remove the phosphate groups from phosphorylated peptides, which results in a mass shift of n×−80 Da. The MALDI‐MS scan of the microarray is then evaluated by a software algorithm to automatically identify the phosphorylated peptides by exploiting the characteristic chromatographic peak profile induced by the phosphatase treatment. This screening method does not require extensive MS/MS experiments or peak list evaluation and can be easily extended to other enzymatic or chemical reactions.
Highly Regio‐ and Enantioselective Synthesis of N‐Substituted 2‐Pyridones: Iridium‐Catalyzed Intermolecular Asymmetric Allylic Amination
Authors: Zhang Xiao , Yang Ze‐Peng , Huang Lin , You Shu‐Li 
Published: December 2014

AbstractThe first iridium‐catalyzed intermolecular asymmetric allylic amination reaction with 2‐hydroxypyridines has been developed, thus providing a highly efficient synthesis of enantioenriched N‐substituted 2‐pyridone derivatives from readily available starting materials. This protocol features a good tolerance of functional groups in both the allylic carbonates and 2‐hydroxypyridines, thereby delivering multifunctionalized heterocyclic products with up to 98 % yield and 99 % ee.
Effect of treatment pressure on structures and properties of PMIA fiber in supercritical carbon dioxide fluid
Authors: Zheng Huanda , Zhang Juan , Du Bing , Wei Qufu , Zheng Laijiu 
Published: December 2014

ABSTRACTThe effects of treatment pressure on the structures and properties of PMIA fiber were investigated by Scanning electron microscopy, Dynamic wetting measurements, Fourier transform infrared spectrometry, X‐ray diffraction, thermogravimetric analysis, and mechanical properties test technology in supercritical carbon dioxide. The results indicated that the surface morphology, the water contact angle, the interaction of macromolecules, the crystal structure, the thermal property, and tensile strength of PMIA fibers were changed during supercritical carbon dioxide treatment, particularly the surface morphology and the wettability of fiber changed the most obviously with the increase of treatment pressure. Furthermore, the thermal property and tensile strength of treated PMIA fiber sample were improved in comparison with those of untreated sample. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41756.