bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Chromatography and Liquid Chromatography–Mass Spectrometry of Plants: Techniques and Applications
Authors: Doell Stefanie , Arens Nadja , Mock Hans‐Peter 
Published: June 2019

Abstract
Mass spectrometry coupled with LC (liquid chromatography) separation has developed into a technique routinely applied for targeted as well as for nontargeted analysis of complex biological samples, not only in plant biochemistry. Earlier on, LC‐MS (liquid chromatography–mass spectrometry) was mostly part of the efforts for identification of one or few unknown metabolites of interest as part of a phytochemical study. As a major strategy, unknown compounds had to be purified in sufficient quantities. The purified fractions were then subjected to LC‐MS/MS as part of the structural elucidation, mostly complemented by NMR (nuclear magnetic resonance) analysis. With the advance of mass spectrometry instrumentation, LC‐MS is now widely applied for analysis of crude plant extracts and large numbers (100s to 1000s) of samples. It has become an essential part of metabolomic studies (see Metabolomics), aiming at the comprehensive coverage of the metabolite profiles of cells, tissues, or organs. Owing to the huge chemical diversity of small molecules, conditions for the extraction will restrict the subfraction of the metabolome, which can be actually analyzed. The conditions for LC have to be adjusted to allow good separation of the particular metabolites from the respective extract. Major consideration will be the selection of an appropriate column and suitable eluents, the establishment of gradient profiles, temperature conditions, and so on.
Identification of Medicinal Plants Using
DNA
Barcoding Technique
Authors: Pang Xiaohui , Chen Shilin 
Published: June 2019

Abstract
Medicinal plants have been used in the health care system in China for thousands of years. The correct identification of these plants is a prerequisite for their safe application. At present, the traditional methods are insufficient to meet the demands of identification, and a rapid and accurate method for authentication of medicinal plants is needed. DNA barcoding, a technique aiming at detecting species‐specific differences in a short region of DNA, provides a new powerful tool toward addressing this problem. Recently, ITS2 (second internal transcribed spacer) barcode has been broadly recognized and widely applied in the discrimination of herbs, and a publically available DNA barcoding system for identifying herbs has been established. Principles for identification of herbs using DNA barcoding have been embodied into the Chinese Pharmacopoeia. In this article, we introduce the DNA barcoding technique and determine its usage in discriminating medicinal plants, as well as its advantages and limitations.
Boron: Inorganic Chemistry
Authors: Schubert David M. 
Published: June 2019

AbstractBoron is unique among the elements and displays remarkable chemistry in all of its compounds. It is widely distributed at low concentrations in the environment and is nearly always found bound to oxygen in its natural forms. Boron is roughly the tenth most abundant element in seawater, where it exists primarily as boric acid. In addition to amorphous boron, several crystalline allotropes exist, with the β‐rhombohedral phase being the most stable form of the element under standard conditions. The borospherene B40cluster and 2D borophenes are more recently documented forms of boron. Metal borides are important to electronics, thermoelectrics, and superhard materials. Most have high melting points, high hardnesses, and good resistance to chemical attack. Refractory boron materials, including boron carbides, nitrides, and phosphides are discussed, as well as molecular boron–nitrogen, boron–phosphorus, boron–sulfur, and boron halide compounds. Boron‐containing amorphous metals are used as master alloys in electrical devices and in strong magnets. The vast majority of industrial use of boron on a tonnage basis involves boron–oxygen compounds. Condensation of boric acid, B(OH)3, and its conjugate base, B(OH)4−, in aqueous solution results in polyborate anions which provide the basis for many industrial products. Boric acid reacts with alcohols to form esters having industrial uses. Reversible borate ester formation with 1,2‐ and 1,3‐diols provides the basis for adhesives and oilfield applications and is central to the bioinorganic chemistry of boron. Boron enters the life cycle of plants and animals, primarily as naturally occurring boric acid found at low concentrations in natural waters and soils. Boron is essential to plants, including important food crops, resulting in extensive use of borates as agricultural micronutrients to correct suboptimal soil boron levels. Borax pentahydrate (disodium tetraborate pentahydrate) is the world's largest volume boron chemical product, followed by boric acid. Major industrial applications of borates include the manufacture of glasses, ceramics, electronic displays, consumer products, construction materials, industrial fluids, fire retardants and in metallurgy, optoelectronics, and agriculture. Other commercially important compounds, such as zinc borates, are discussed.
Cadmium: Organometallic Chemistry
Authors: Bright Kochappi C. , Joseyphus R. Selwin 
Published: June 2019

Abstract
As a large, soft, heavy element, the chemistry of cadmium is marked by relatively weak bonding to carbon and other more electronegative atoms. Organocadmium compounds thus demonstrate diverse reaction chemistry. Furthermore, the large size and low valency of cadmium lead to interesting aggregated compounds. The reactivity and structural importance of organocadmium compounds find applications as nonlinear optical, thermal resistive, and dielectric materials.
Nitrogenase: Metal Cluster Models
Authors: Ohta Shun 
Published: June 2019

AbstractNitrogenases are metalloenzymes that are involved in the biological fixation of nitrogen. Nitrogenases contain the following metal–sulfur clusters: the [Fe4S4] cluster, the P‐cluster, and one of the FeMo‐cofactor, the FeV‐cofactor, or the FeFe‐cofactor. At present, structures of all clusters except for that of the FeFe‐cofactor have been determined by X‐ray diffraction studies of nitrogenases. The metal–sulfur clusters in nitrogenases have remained challenging synthetic targets due to their unique structural features. In addition, the elucidation of the properties of the cluster models, including their structural, spectroscopic, magnetic, and electronic characteristics, as well as their reactivity may further our understanding of the properties and functionality of nitrogenases. This article reviews hitherto reported structural models of nitrogenase metalloclusters. Although the synthesis of reliable structural models of the FeMo‐cofactor and the FeV‐cofactor remains challenging, high‐precision structural models have already been obtained for the [Fe4S4] cluster and the P‐cluster, which has allowed systematic investigations into their structures and redox properties. This article also summarizes the current state‐of‐the‐art regarding the functional modeling of nitrogenases with metal–sulfur clusters, which includes the reduction of hydrazine to ammonia and of C1‐substrates to hydrocarbons, and N2‐binding. Moreover, the reactivity of nitrogenase with a structural model inserted instead of the FeMo‐cofactor has recently been reported.
Tracking Metal Ions in Biology UsingX‐Ray Methods
Authors: James Simon A. , van der Ent Antony , Harris Hugh H. 
Published: June 2019

AbstractIn this article, we describe the current state‐of‐play and potential future developments for a set of experimental methods that rely on X‐rays to probe metal ions in biological systems, especially X‐ray fluorescence imaging (XFI) and X‐ray absorption spectroscopy (XAS), which are almost always performed at synchrotron light sources to give suitable sensitivity to biologically realistic concentrations of metal ions. We do not take a comprehensive viewpoint, but rather choose particular applications to illustrate where these methods shine, directly probing the native coordination environment where no other techniques can, providing a complementary picture to that provided by other methods, and acting as a vital sanity check on results derived from other less direct methods.
Degradable Inorganic Polymers
Authors: Teasdale Ian 
Published: June 2019

Abstract
This article provides an insight into the development of inorganic polymers as (bio)degradable materials. A particular focus is placed on recent advancements to prepare stable polymers showing stimuli‐responsive degradation, that is which degrade only upon exposure to certain stimuli, with the aim of producing materials, which are stable for their usage lifetime but degrade rapidly thereafter. Firstly, these works are placed in the context of biodegradable polymers in general, as well as state‐of‐the‐art organic polymers showing stimuli‐responsive degradation. Degradable polymers is a field which is currently of great importance, both in advanced biomedical applications for which polymeric materials have become indispensable, but also for ever‐growing societal and environmental concerns regarding the use of biopersistant polymers. The inclusion of inorganic components into polymers can lead to unique properties and responsiveness compared to traditional carbon‐based polymers, as is demonstrated by a number of examples herein including phosphorus and boron‐based polymers and metallopolymers, which degrade or depolymerize in response to specific triggers including visible light and oxidation.
Enabling Tailorable Optical Properties and Markedly Enhanced Stability of Perovskite Quantum Dots by Permanently Ligating with Polymer Hairs
Authors: Yoon Young Jun , Chang Yajing , Zhang Shuguang , Zhang Meng , Pan Shuang , He Yanjie , Lin Chun Hao , Yu Shengtao , Chen Yihuang , Wang Zewei , Ding Yong , Jung Jaehan , Thadhani Naresh , Tsukruk Vladimir V. , Kang Zhitao , Lin Zhiqun 
Published: June 2019

AbstractInstability of perovskite quantum dots (QDs) toward humidity remains one of the major obstacles for their long‐term use in optoelectronic devices. Herein, a general amphiphilic star‐like block copolymer nanoreactor strategy for in situ crafting a set of hairy perovskite QDs with precisely tunable size and exceptionally high water and colloidal stabilities is presented. The selective partition of precursors within the compartment occupied by inner hydrophilic blocks of star‐like diblock copolymers imparts in situ formation of robust hairy perovskite QDs permanently ligated by outer hydrophobic blocks via coprecipitation in nonpolar solvent. These size‐ and composition‐tunable perovskite QDs reveal impressive water and colloidal stabilities as the surface of QDs is intimately and permanently ligated by a layer of outer hydrophobic polymer hairs. More intriguingly, the readily alterable length of outer hydrophobic polymers renders the remarkable control over the stability enhancement of hairy perovskite QDs.
Nitrogen Vacancies on 2D Layered W2N3: A Stable and Efficient Active Site for Nitrogen Reduction Reaction
Authors: Jin Huanyu , Li Laiquan , Liu Xin , Tang Cheng , Xu Wenjie , Chen Shuangming , Song Li , Zheng Yao , Qiao Shi‐Zhang 
Published: June 2019

AbstractElectrochemical nitrogen reduction reaction (NRR) under ambient conditions provides an avenue to produce carbon‐free hydrogen carriers. However, the selectivity and activity of NRR are still hindered by the sluggish reaction kinetics. Nitrogen Vacancies on transition metal nitrides are considered as one of the most ideal active sites for NRR by virtue of their unique vacancy properties such as appropriate adsorption energy to dinitrogen molecule. However, their catalytic performance is usually limited by the unstable feature. Herein, a new 2D layered W2N3 nanosheet is prepared and the nitrogen vacancies are demonstrated to be active for electrochemical NRR with a steady ammonia production rate of 11.66 ± 0.98 µg h−1 mgcata−1 (3.80 ± 0.32 × 10−11 mol cm−2 s−1) and Faradaic efficiency of 11.67 ± 0.93% at −0.2 V versus reversible hydrogen electrode for 12 cycles (24 h). A series of ex situ synchrotron‐based characterizations prove that the nitrogen vacancies on 2D W2N3 are stable by virtue of the high valence state of tungsten atoms and 2D confinement effect. Density function theory calculations suggest that nitrogen vacancies on W2N3 can provide an electron‐deficient environment which not only facilitates nitrogen adsorption, but also lowers the thermodynamic limiting potential of NRR.
Integrating Flexible Filament Circuits for E‐Textile Applications
Authors: Komolafe Abiodun , Torah Russel , Wei Yang , Nunes‐Matos Helga , Li Menglong , Hardy Dorothy , Dias Tilak , Tudor Michael , Beeby Stephen 
Published: June 2019

AbstractPractical wearable e‐textiles must be durable and retain, as far as possible, the textile properties such as drape, feel, lightweight, breathability, and washability that make fabrics suitable for clothing. Early e‐textile garments were realized by inserting standard portable electronic devices into bespoke pockets and arranging interconnects and cabling across the garment. In these examples, the textile merely served as a vehicle to house the electronics and had no inherent electronic functionality. A reduction in electronic component size, the development of flexible circuits, and the ability to weave robust interconnects offer the potential for improved levels of electronic integration within the textile. The weaving of electronic circuit filaments less than 2 mm wide into fabrics such that the electronics are fully concealed in the textile and given extra protection by the surrounding textile fibers is introduced. The failure mechanisms for different filament circuit designs before and after integration into the textile are investigated with a 90° cyclical bending test. Results show that encapsulated filament circuits embedded within the textile survive 45 washing cycles and more than 1500 cycles of 90° bending around a bending radius of 10 mm, performing five times better than equivalent filament circuits before integration into the fabric.
High‐Resolution Scanning Probe Nanolithography of 2D Materials: Novel Nanostructures
Authors: Rani Ekta , Wong Lu Shin 
Published: June 2019

Abstract2D materials have attracted tremendous research interest since the isolation of graphene. Their remarkable optical, electronic, and mechanical properties show that they hold great potential across a range of technological applications. As a result, there is a growing demand for low‐cost, low‐energy, and high‐resolution lithography methods that will enable the integration of 2D materials into complex integrated circuitry, biomedical devices, and in the generation of quantum‐confined nanostructures. Recent advances in scanning probe nanolithography (SPL) techniques for the lithography of 2D materials such as graphene, black phosphorus, molybdenum disulfide, and tungsten diselenide are discussed, including the various physiochemical aspects of subtractive and additive lithography of these materials. Examples of 2D‐material‐based devices fabricated by SPL and their properties are also described. The comparative advantages of the individual SPL techniques are discussed along with the future outlook of SPL for 2D materials.
A Brief Review on Measuring Methods of Thermal Conductivity of Organic and Hybrid Thermoelectric Materials
Authors: Wang Hanfu , Chu Weiguo , Chen Guangming 
Published: June 2019

AbstractOrganic and hybrid thermoelectric (OHT) materials have attracted increasing research interest over the past decade. Thermal conductivity measurement plays a critical role in evaluating and improving the thermoelectric performance of various types of these novel materials, ranging from bulks to low‐dimensional structures. Commonly used and newly developed techniques for thermal conductivity measurement, most of which have been applied to OHT materials in recent years, are reviewed. They are categorized as steady‐state methods, time‐domain methods, or frequency‐domain methods. The operating principles, merits and limitations, technical issues, and application examples for each technique are also discussed.
Pentacoordinated Al3+‐Stabilized Active Pd Structures on Al2O3‐Coated Palladium Catalysts for Methane Combustion
Authors: Duan Huimei , You Rui , Xu Shutao , Li Zhaorui , Qian Kun , Cao Tian , Huang Weixin , Bao Xinhe 
Published: June 2019

AbstractSupported Pd catalysts are active in catalyzing the highly exothermic methane combustion reaction but tend to be deactivated owing to local hyperthermal environments. Herein we report an effective approach to stabilize Pd/SiO2 catalysts with porous Al2O3 overlayers coated by atomic layer deposition (ALD). 27Al magic angle spinning NMR analysis showed that Al2O3 overlayers on Pd particles coated by the ALD method are rich in pentacoordinated Al3+ sites capable of strongly interacting with adjacent surface PdOx phases on supported Pd particles. Consequently, Al2O3‐decorated Pd/SiO2 catalysts exhibit active and stable PdOx and Pd–PdOx structures to efficiently catalyze methane combustion between 200 and 850 °C. These results reveal the unique structural characteristics of Al2O3 overlayers on metal surfaces coated by the ALD method and provide a practical strategy to explore stable and efficient supported Pd catalysts for methane combustion.
Synthesis of Chiral Aldehyde Catalysts by Pd‐Catalyzed Atroposelective C−H Naphthylation
Authors: Liao Gang , Chen Hao‐Ming , Xia Yu‐Nong , Li Bing , Yao Qi‐Jun , Shi Bing‐Feng 
Published: June 2019

AbstractChiral aldehyde catalysis opens new avenues for the activation of simple amines. However, the lack of easy access to structurally diverse chiral aldehyde catalysts has hampered the development of this cutting‐edge field. Herein, we report a Pd‐catalyzed atroposelective C−H naphthylation with 7‐oxabenzonorbornadienes for the preparation of axially chiral biaryls with excellent enantioselectivities (up to >99 % ee). This reaction is scalable and robust, which serves as a key step to provide a rapid access to axially chiral aldehyde catalysts through a three‐step C−H functionalization sequence. These chiral aldehydes exhibit better activities and enantioselectivities than the previously reported organocatalysts in the asymmetric activation of glycine derived amides and dipeptides. Moreover, preliminary investigation also discloses that the aldehyde catalyst can effectively override the intrinsic facial selectivity of chiral dipeptide substrates, showcasing the strong chiral induction ability of this type of novel aldehyde catalysts.
Data‐Driven Identification of Hydrogen Sulfide Scavengers
Authors: Yang Chun‐tao , Wang Yingying , Marutani Eizo , Ida Tomoaki , Ni Xiang , Xu Shi , Chen Wei , Zhang Hui , Akaike Takaaki , Ichinose Fumito , Xian Ming 
Published: June 2019

AbstractHydrogen sulfide (H2S) is an important signaling molecule whose up‐ and down‐regulation have specific biological consequences. Although significant advances in H2S up‐regulation, by the development of H2S donors, have been achieved in recent years, precise H2S down‐regulation is still challenging. The lack of potent/specific inhibitors for H2S‐producing enzymes contributes to this problem. We expect the development of H2S scavengers is an alternative approach to address this problem. Since chemical sensors and scavengers of H2S share the same criteria, we constructed a H2S sensor database, which summarizes key parameters of reported sensors. Data‐driven analysis led to the selection of 30 potential compounds. Further evaluation of these compounds identified a group of promising scavengers, based on the sulfonyl azide template. The efficiency of these scavengers in in vitro and in vivo experiments was demonstrated.
Foam fractionation for enhancing silica gel adsorption of urokinase from human urine
Authors: Xu Na , Wang Lu , Dou Nongxiao , Zhang Lili , Guan Jing , Chang Yunkang , Li Rui 
Published: June 2019

AbstractIn this work, foam fractionation (FF), a cost‐effective method, was used to enhance the silica gel adsorption (SGA) of urokinase from human urine. The analysis of how FF enhanced the adsorption/desorption of urokinase onto silica gel was conducted. The results show that FF increased both the adsorption rate of urokinase onto silica gel and the activity concentration of urokinase adsorbed at silica gel by pre‐enriching urokinase from urine. It also reduced the activity loss of urokinase in the desorption process. Then, a coupled technology of FF and SGA was developed. The effects of pH, superficial air flow rate, beta‐cyclodextrin concentration, and amount of silica gel added on activity recovery yield and purification fold of urokinase were studied. At pH 7.5, superficial air flow rate 1.70 mm/s, beta‐cyclodextrin concentration 0.2 g/L, and amount of silica gel added 0.9%, the activity recovery and purification fold of urokinase reached 89.5% and 56.8 in the coupled technology, which were 25.3% and 79.2% higher than those obtained by SGA alone, respectively. Furthermore, the amount of silica gel added in the coupled technology was 40.0% lower than that in SGA alone. Therefore, FF effectively enhanced the SGA of urokinase from human urine.
Typical perceptual organization in autism: Perceptual grouping and spatial distortion
Authors: Avraam Ravit , Binur Nahal , Hadad Bat‐Sheva 
Published: June 2019

The extensive literature on global–local processing in people with autism spectrum disorder (ASD) has recently shifted from arguing for a processing impairment among those with ASD to positing an attenuated preference for global processing. One suggestion is that the fast extraction of the global gist is less efficient in ASD, in contrast to the superior attention‐driven processing of local elements. To examine this claim of attenuated global processing, the present study tested how perceptual grouping affected the global organization of visual scenes, specifically testing the claim of less mandatory, more optional global processing in ASD. Participants judged the distance between grouped and ungrouped elements in displays in which illusory distortions were inherent in configurations exemplifying the Gestalt principles of organization. Results from six experiments manipulating different Gestalt cues showed a consistent pattern, indicating that for individuals with ASD, as for typically developed (TD) individuals, grouping processes are organizational in nature, incorporating the grouping of related elements while parsing these from other unrelated elements. This parsing is accompanied by distortions in the spatial relationships perceived in the visual scene. ASD participants exhibited an overall larger tendency to overestimate the distances, but they also demonstrated typical perceptual organization processes that were robust and mandatory and, as in neurotypicals, affected the perception of the whole scene. Autism Res 2019. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryIt is known that individuals with autism spectrum disorder (ASD) perceive the world in a different way than their typically developed (TD) peers. While TD individuals exhibit strong bias toward processing the global structure of visual scenes, individuals with ASD exhibit enhanced perception of the local elements. We showed that when the local and global levels are not competing, individuals with autism demonstrate robust global organization that operates even when not directly instructed.