bluuebunny/crossref_metadata_2025 huggingface dataset:
Proteome Expression: The Subcellular Organisation of Protein Synthesis
Authors: Hsu Jack C‐C , Nicchitta Christopher V
Published: June 2018

Proteome expression is the integrated output of gene transcription, messenger ribonucleic acid (mRNA) stability, mRNA translation and protein stability, and varies between cells, tissues and organs. Proteome expression is dynamic and can be readily modified in response to stress, cell cycle progression, pathogenic infection and malignant transformation. With recent advances in single molecule optical imaging and high‐resolution genomic analyses, increased attention has turned to the spatiotemporal regulation of proteome expression at the subcellular level. With this interest has come a reinvestigation of a fundamental question in cell biology – the subcellular organisation of mRNA transcriptome expression. Although it is widely accepted that eukaryotic cells partition proteome expression, with soluble proteins being synthesised on cytoplasmic ribosomes and secretory/integral membrane proteins on endoplasmic reticulum (ER)‐bound ribosomes, recent data indicate a far broader role for the ER in proteome expression.

Key Concepts

Ribosomes, the cellular machines that perform protein synthesis, are present in the two primary protein synthesis compartments of the eukaryotic cell, the cytosol and endoplasmic reticulum (ER).

mRNAs are largely partitioned between the cytosol and the ER on the basis of their encoded gene product, with cytosolic protein‐encoding mRNAs being translated by cytoplasmic ribosomes and secretory/membrane protein‐encoding mRNAs undergoing translation on ER‐bound ribosomes.

The mechanisms governing mRNA and ribosome partitioning between the cytosol and ER compartments are largely unknown.

Recent studies have revealed that ER‐bound ribosomes are broadly engaged in the translation of the mRNA transcriptome.

A role for the ER in the expression of the cellular proteome can now be considered.
Endosperm Development
Authors: Tonosaki Kaoru , Kinoshita Tetsu
Published: June 2018

Endosperm is a tissue in the seeds of many plants and supports embryonic and seedling growth by providing nutrients stored in its cells. As the stored products, starches, proteins and oils are valuable to humans for nutrition and as industrial materials, endosperm development has been well documented, particularly in cereal plants such as maize, barley and rice. Molecular genetics and genomics analyses have also been widely applied to the model plant
Arabidopsis thaliana
. Although the structures and amounts of endosperm within mature seeds vary considerably among plant species, most of the developmental events, such as genetic and epigenetic controls, are conserved.

Key Concepts

The programme of endosperm development varies among plant species.

In most angiosperm species, seeds have three genetically distinct tissues: maternal diploid seed coat, fertilised diploid embryo and triploid endosperm.

Endosperm consists of differentiated tissues that have distinct roles.

Roles of parental genomes in the endosperm (2 maternal and 1 paternal) are not equivalent owing to asymmetric epigenetic modifications, similar to those in the mammalian placenta.

Hybridisation barrier can be seen in the endosperm.
M
arjory
S
tephenson (1885–1948)
Authors: Štrbáňová Soňa
Published: June 2018

The year 2018 marks the seventieth death anniversary of a significant yet almost forgotten British biochemist and microbiologist Marjory Stephenson, who was institutionally linked to the Medical Research Council and the Sir William Dunn Institute of Biochemistry in Cambridge. Stephenson's research concerned especially biochemistry of microorganisms, namely organisation and control of biochemical processes in the cells, and played a founding role in formation of chemical microbiology and microbial biochemistry, considered predecessors of molecular biology. Stephenson was elected in 1945 as one of the first two women fellows of the Royal Society and in 1947 as the second president (after Sir Alexander Fleming) of the Society for General Microbiology. She belonged to the few women in science of her time who pioneered new fields and managed research teams; in spite of that, she had to cope most of her life with practices of undeclared discrimination.
Extensive Viewing: Extra‐Curricular Language Learning Outside the Classroom Walls
Authors: Rodgers Michael P. H.
Published: June 2018

The benefits of exposing language learners to large amounts of input through extensive reading programs continues to receive attention in English as a foreign or second language teaching situations. However, reading only provides learners with written input but exposure to aural input may be even more vital and hard to come by for learners. A potential source of aural input that can provide learners with opportunities to encounter the large amount of spoken input needed to improve their listening skills is viewing television program episodes. With appropriate guidance from teachers, learners can be pointed toward best practice in choosing and viewing television episodes leading to increased language learning opportunities and learner autonomy outside of the classroom. This entry outlines the potential benefits of viewing television, then presents a principle‐based framework for implementing an extensive viewing program. Finally, areas of research into learning through television that need further investigation are suggested.
Dynamic Assessment forESL
Authors: Smith Sara A.
Published: June 2018

Dynamic Assessment (DA), an assessment method rooted in Vygotsky's Zone of Proximal Development, incorporates the assessor into the testing process to scaffold and mediate, resulting in a process‐oriented form of assessment. With DA, assessment is productive learning time during which learners develop language skills, metacognitive strategies, and problem‐solving insights. As recently as the 1990s, DA was considered prohibitively costly in time and money, but contemporary technological and social developments have brought DA to the forefront. As traditional testing methods increasingly fall out of favor, DA for English Language Teaching (ELT) is poised to increase dramatically. The current entry will describe DA for the ELT context, discuss methods, and review previous research on effective DA use. The unique opportunities DA offers for assessing English learner populations poorly served by standardized testing are discussed, followed by suggestions for adding DA to ELT curriculum and teacher training.
The Compound‐Coordinate Bilingual
Authors: Heredia Roberto R. , Ciesślicka Anna B.
Published: June 2018

This entry provides a theoretical and empirical overview of some of the issues related to thecompound‐coordinatebilingual distinction, and suggests some possibilities on how best to study it. It is argued that if, during the bilingual learning process, language‐dependent memories are acquired or stored in episodic memory, the episodic memory trace will be more accessible, as explained by theencoding specificity principle. That is, if the episodic memory trace is available (i.e., present), it should be possible to retrieve it, provided that the contextual cues (e.g., language, mental process, and task demands) utilized during the learning process are matched during retrieval. Finally, pedagogical implications of bilingual memory research are discussed.
Regulated Dewetting for Patterning Organic Single Crystals with Pure Crystallographic Orientation toward High Performance Field‐Effect Transistors
Authors: Zhao Yuyan , Fan Xiaoyu , Feng Jiangang , Wang Xuedong , Wu Yuchen , Su Bin , Jiang Lei
Published: June 2018

Fabrication of high‐quality organic single‐crystalline semiconductors and their deterministic patterning are core opportunities as well as challenges for large‐scale integration of functional devices with high efficiency and boosted performance. Previous approaches on solution patterning of organic semiconductors have achieved efficient and versatile control of the position, alignment, and size of organic structures. However, the poorly controllable dewetting dynamics of organic solution gives rise to low crystallinity and disordered crystallographic orientation of generated organic architectures that limit their device performance. Here, 1D organic single‐crystal arrays with high crystallinity, strict crystallographic alignment, precise position, tunable, and homogeneous size are fabricated by exploiting an asymmetric‐wettability topographical template. Periodically arranged micropillars with lyophobic sidewalls and lyophilic tops permit the generation of capillary bridges, which enable unidirectional dewetting of organic solution and ordered packing of molecules. The 1D arrays present pure (100) crystallographic orientation with π–π stacking of molecules in the optimal direction of carrier transport, leading to high carrier mobility of 8.7 cm2 V−1 s−1 in the field‐effect transistor measurements. A facile pressure sensor based on the patterned belt arrays is fabricated, exhibiting high sensitivity and long‐term stability.
Bio‐Inspired Superhydrophobic Closely Packed Aligned Nanoneedle Architectures for Enhancing Condensation Heat Transfer
Authors: Wang Rui , Zhu Jie , Meng Kaixin , Wang Hao , Deng Tao , Gao Xuefeng , Jiang Lei
Published: June 2018

Bionic condensate microdrop self‐propelling (CMDSP) surfaces are attracting intensive interest due to their academic and commercial values. Up to now, it is still a great challenge to design and fabricate CMDSP nanostructures with superior condensation heat transfer (CHT) efficiency. Here, it is reported that the CHT coefficient of copper surfaces can be enhanced maximally ≈320% via in situ growth and geometric regulation of closely packed aligned nanoneedles with CMDSP function. These experiments and theoretical analyses indicate that reducing the interspaces of nanoneedles can help reduce the departure diameters of condensate microdrops and increase their nucleation density, both of which are beneficial to enhance CHT. In contrast, increasing the tip size and height of nanoneedles can increase drop departure diameters and film‐layer thermal resistance, respectively, either of which is disadvantageous to enhance CHT. Clearly, only considering superhydrophobic effect is insufficient and both choosing ideal nanoarchitectures and optimizing their geometric parameters are very crucial to realize high‐efficiency CHT, which optimization can be achieved via simply controlling growth time of nanostructures. These findings offer new insights into the design and development of first‐rank CHT interface nanomaterials.
A Controllable Surface Etching Strategy for Well‐Defined Spiny Yolk@Shell CuO@CeO2 Cubes and Their Catalytic Performance Boost
Authors: Li Wang , Feng Xilan , Zhang Zheng , Jin Xin , Liu Dapeng , Zhang Yu
Published: June 2018

Herein, an effective top‐down etching route is presented to in situ fabricate CuO/CeO2 nanohybrids on the surface of Cu2O microcube templates. This method has well taken into account the factors both in thermodynamics and in kinetics, including surface structural nanocrystallization, construction of mesopores, formation of stable core@shell structures, and strengthened synergistic effects, in order to realize the structural design and hence greatly improve catalytic performance caused by surface nanocrystallization of Cu2O cubes. After etched by aid of ammonia and Ce3+ ions the final products are in a well‐defined spiny yolk@shell structures, in which the unetched part of Cu2O cubes serves as the core and the shell is composed by the CuO nanothorns encapsulated by CeO2 nanoparticles. Systematical characterizations including scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, H2‐temperature programmed reduction, N2 sorption, firmly disclose the relationship between the catalytic properties and the structures of samples. By simply tuning the usage amount of ammonia and Ce3+ ions, the samples show a typical volcano curve in the model reaction of catalytic CO oxidation. Sample CuO@CeO2‐0.05 exhibits the optimal catalytic activity and stability. It is believed that this top‐down strategy has shown promising future to design high‐performance catalysts for the practical need of application.
Transparent Polycrystalline Magnesium Aluminate Spinel Fabricated by Spark Plasma Sintering
Authors: Sokol Maxim , Ratzker Barak , Kalabukhov Sergey , Dariel Moshe Peter , Galun Ehud , Frage Nachum
Published: June 2018

Polycrystalline magnesium aluminate (MgAl2O4) spinel (PMAS) exhibits a unique combination of physical, chemical, mechanical, and optical properties, which makes it useful for a wide range of applications, including UV lenses for lithography, electroinsulation, and structural windows for both VIS and IR region radiation and armor applications. Conventional two‐stage processing of PMAS involves prolonged pressureless sintering followed by hot isostatic pressing. The costly processing of high‐quality transparent PMAS ceramic is the main reason for the limited usage of this material in industry. Spark plasma sintering (SPS) is a relatively novel one‐stage, rapid, and cost‐effective sintering technique, which holds great potential for producing high‐quality optical materials. Here, recent advances in the fabrication of transparent PMAS by the SPS approach, the influence of sintering parameters on microstructure evolution during densification, and their effects on the optical and mechanical properties of the material are reviewed.
Functional Enzyme Mimics for Oxidative Halogenation Reactions that Combat Biofilm Formation
Authors: Herget Karoline , Frerichs Hajo , Pfitzner Felix , Tahir Muhammad Nawaz , Tremel Wolfgang
Published: June 2018

Transition‐metal oxide nanoparticles and molecular coordination compounds are highlighted as functional mimics of halogenating enzymes. These enzymes are involved in halometabolite biosynthesis. Their activity is based upon the formation of hypohalous acids from halides and hydrogen peroxide or oxygen, which form bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities in follow‐up reactions. Therefore, enzyme mimics and halogenating enzymes may be valuable tools to combat biofilm formation. Here, halogenating enzyme models are briefly described, enzyme mimics are classified according to their catalytic functions, and current knowledge about the settlement chemistry and adhesion of fouling organisms is summarized. Enzyme mimics with the highest potential are showcased. They may find application in antifouling coatings, indoor and outdoor paints, polymer membranes for water desalination, or in aquacultures, but also on surfaces for food packaging, door handles, hand rails, push buttons, keyboards, and other elements made of plastic where biofilms are present. The use of natural compounds, formed in situ with nontoxic and abundant metal oxide enzyme mimics, represents a novel and efficient “green” strategy to emulate and utilize a natural defense system for preventing bacterial colonization and biofilm growth.
“Dual Lock‐and‐Key”‐Controlled Nanoprobes for Ultrahigh Specific Fluorescence Imaging in the Second Near‐Infrared Window
Authors: Tang Yufu , Li Yuanyuan , Hu Xiaoming , Zhao Hui , Ji Yu , Chen Liang , Hu Wenbo , Zhang Wansu , Li Xiang , Lu Xiaomei , Huang Wei , Fan Quli
Published: June 2018

Fluorescence imaging in the second near‐infrared window (NIR‐II) is a new technique that permits visualization of deep anatomical features with unprecedented spatial resolution. Although attractive, effectively suppressing the interference signal of the background is still an enormous challenge for obtaining target‐specific NIR‐II imaging in the complex and dynamic physiological environment. Herein, dual‐pathological‐parameter cooperatively activatable NIR‐II fluorescence nanoprobes (HISSNPs) are developed whereby hyaluronic acid chains and disulfide bonds act as the “double locks” to lock the fluorescence‐quenched aggregation state of the NIR‐II fluorescence dyes for performing ultrahigh specific imaging of tumors in vivo. The fluorescence can be lit up only when the “double locks” are opened by reacting with the “dual smart keys” (overexpressed hyaluronidase and thiols in tumor) simultaneously. In vivo NIR‐II imaging shows that they reduce nonspecific activitation and achieve ultralow background fluorescence, which is 10.6‐fold lower than single‐parameter activatable probes (HINPs) in the liver at 15 h postinjection. Consequently, these “dual lock‐and‐key”‐controlled HISSNPs exhibit fivefold higher tumor‐to‐normal tissue ratio than “single lock‐and‐key”‐controlled HINPs at 24 h postinjection, attractively realizing ultrahigh specificity of tumor imaging. This is thought to be the first attempt at implementing ultralow background interference with the participation of multiple pathological parameters in NIR‐II fluorescence imaging.
Hierarchical Nanoporous Copper Fabricated by One‐Step Dealloying Toward Ultrasensitive Surface‐Enhanced Raman Sensing
Authors: Song Ruirui , Zhang Ling , Zhu Fan , Li Wei , Fu Zhenchuang , Chen Bin , Chen Mingwei , Zeng Heping , Pan Deng
Published: June 2018

Geometry‐tunable substrates with abundant plasmon resonant structure are ideal to proffer high surface‐enhanced Raman scattering (SERS) activity for trace sensing including pollutants and toxics, whereas great challenge remains in creating high‐density “hotspots” in these structures for further improving Raman signals and detection sensitivity. Herein, one‐step dealloying strategy is proposed to fabricate free‐standing copper membranes with hierarchical porous architecture where a high density of inherent “hotspots” is built in the vicinity of secondary pores in 3D ligaments. The hierarchical nanoporous copper shows excellent SERS activity with an average enhancement factor of 6.4 × 109, originating from strong electromagnetic coupling effects induced by its highly dense “hotspots” and highly accessible surface. Moreover, the proposed one‐step dealloying strategy of dual‐phase binary alloys propounds an inexpensive yet effective route to construct ultrasensitive SERS substrate for trace detection and molecular diagnosis.
Dynamic Impact of Electrode Materials on Interface of Single‐Crystalline Methylammonium Lead Bromide Perovskite
Authors: Tisdale Jeremy T. , Muckley Eric , Ahmadi Mahshid , Smith Travis , Seal Cody , Lukosi Eric , Ivanov Ilia N. , Hu Bin
Published: June 2018

One of the current challenges in methylammonium lead halide (MAPbX3) perovskite application research is understanding contact formation and interfacial phenomena for highly efficient and stable device performance. For semiconductors, development of contact formation is inseparable from device performance and stability. Single‐crystalline MAPbX3 has become of great interest for perovskite devices in photodetectors, light‐emitting diodes, and more recently in high‐energy radiation detection. Deeper research is required to understand interfacial interactions in single‐crystalline MAPbX3. This article focuses on the dynamic impact of electrode metal (Au and Cr) on methylammonium lead bromide (MAPbBr3) single crystals. It is studied how charge transport properties of single crystal MAPbBr3 can be tuned via electrode material selection at the metal/MAPbBr3 interface to improve device performance with proper contact formation. The ability to create an ohmic‐like or nonohmic contact by switching the electrode metal from Cr to Au, respectively, is demonstrated. It is observed that the interfacial charge transfer resistance (recombination resistance) of the Cr/MAPbBr3 interface is 1.79  ×  109 Ω, compared to 1.32  ×  107 Ω for the Au/MAPbBr3. Cr contacts can reduce hysteretic behavior by reducing interfacial recombination and interfacial polarization. These studies provide insight to metal/MAPbX3 interfacial interactions toward device engineering for hole transport layer‐free MAPbX3 device structures.
The effects of plant sexual system and latitude on resistance to herbivores
Authors: Rivkin L. R. , Barrett Spencer C. H. , Johnson Marc T. J.
Published: June 2018

Premise of the Study

The strength of plant‐herbivore interactions varies in space and time, but the factors that explain this variation are poorly understood. Several lines of research suggest that variation in plant reproductive systems and latitude may explain resistance against herbivores, but how these factors jointly affect plant‐herbivore interactions has not been investigated in detail. We examined the effects of latitude, sexual system, and plant gender on herbivory in Sagittaria latifolia, an aquatic plant in which populations are typically monoecious (separate female and male flowers) or dioecious (separate female and male plants).

Methods

We surveyed 43 populations of S. latifolia between 42 and 48° N in Ontario, Canada. In each population, we recorded the sexual system and obtained estimates of herbivore damage to ramets of known gender (i.e. female, male, or hermaphrodite) by the weevil Listronotus appendiculatus, the principal herbivore of S. latifolia. Herbivore damage was quantified as the percent leaf area removed by adult L. appendiculatus weevils, and the abundance of larvae feeding within flowering stalks, which was correlated with the amount of damage by herbivores to the inflorescence.

Key Results

Leaf herbivory significantly decreased with increasing latitude but did not vary with sexual system or plant gender. By contrast, larvae were more abundant in dioecious populations and on female plants, corresponding to increased stem damage, providing evidence for sex‐biased larval abundance in S. latifolia. These effects of sexual system and gender on larval abundance were strongest at lower latitudes.

Conclusions

Our study found latitudinal variation in leaf herbivory and sex‐biased resistance to weevil larvae that feed on the reproductive tissues of S. latifolia, which is predicted to be a necessary condition for herbivory to influence the evolution of dioecy.
Iron Porphyrins Embedded into a Supramolecular Porous Organic Cage for Electrochemical CO2 Reduction in Water
Authors: Smith Peter T. , Benke Bahiru Punja , Cao Zhi , Kim Younghoon , Nichols Eva M. , Kim Kimoon , Chang Christopher J.
Published: June 2018

A porous organic cage composed of six iron tetraphenylporphyrins was used as a supramolecular catalyst for electrochemical CO2‐to‐CO conversion. This strategy enhances active site exposure and substrate diffusion relative to the monomeric catalyst, resulting in CO generation with near‐quantitative Faradaic efficiency in pH 7.3 water, with activities reaching 55 250 turnovers. These results provide a starting point for the design of supramolecular catalysts that can exploit the properties of the surrounding matrix yet retain the tunability of the original molecular unit.
Precise Activation of Ammonia and Carbon Dioxide by an Iminodisilene
Authors: Wendel Daniel , Szilvási Tibor , Henschel Daniel , Altmann Philipp J. , Jandl Christian , Inoue Shigeyoshi , Rieger Bernhard
Published: June 2018

The activation of NH3 and CO2 is still an ambitious target for multiply bonded sub‐valent silicon compounds. Now, the precise splitting of the N−H bond of ammonia by (Z)‐imino(silyl)disilene 1 to give trans‐1,2‐adduct 2 a at low temperatures (−78 °C) is presented. According to DFT calculations, the stereospecific hydroamination follows a similar mechanism as the recently reported anti‐addition of H2 to the Si=Si bond of 1. The aminosilane 2 b could also be obtained as the formal silylene addition product under thermodynamic reaction control. By applying low temperatures, the activation of CO2 with 1 selectively afforded the cis‐oxadisilacyclobutanone 7‐c as [2+2] cycloadduct. By performing the reaction directly at ambient temperatures, a mixture of three different‐sized silacycles (4–6) was observed. Their formation was investigated theoretically and their structures were revealed with separate experiments using 1 and the oxygenation agents N2O and O2.
Efficient Oxygen Reduction Reaction (ORR) Catalysts Based on Single Iron Atoms Dispersed on a Hierarchically Structured Porous Carbon Framework
Authors: Zhang Zhengping , Sun Junting , Wang Feng , Dai Liming
Published: June 2018

Single Fe atoms dispersed on hierarchically structured porous carbon (SA‐Fe‐HPC) frameworks are prepared by pyrolysis of unsubstituted phthalocyanine/iron phthalocyanine complexes confined within micropores of the porous carbon support. The single‐atom Fe catalysts have a well‐defined atomic dispersion of Fe atoms coordinated by N ligands on the 3D hierarchically porous carbon support. These SA‐Fe‐HPC catalysts are comparable to the commercial Pt/C electrode even in acidic electrolytes for oxygen reduction reaction (ORR) in terms of the ORR activity (E1/2=0.81 V), but have better long‐term electrochemical stability (7 mV negative shift after 3000 potential cycles) and fuel selectivity. In alkaline media, the SA‐Fe‐HPC catalysts outperform the commercial Pt/C electrode in ORR activity (E1/2=0.89 V), fuel selectivity, and long‐term stability (1 mV negative shift after 3000 potential cycles). Thus, these nSA‐Fe‐HPCs are promising non‐platinum‐group metal ORR catalysts for fuel‐cell technologies.
E5M7+ (E=C–Pb, M=Li–Cs): A Source of Viable Star‐Shaped Clusters
Authors: Vásquez‐Espinal Alejandro , Palacio‐Rodríguez Karen , Ravell Estefanía , Orozco‐Ic Mesías , Barroso Jorge , Pan Sudip , Tiznado William , Merino Gabriel
Published: June 2018

Herein we report the systematic exploration of the potential energy surfaces of a series of clusters with formula E5M7+ (E=C‐Pb and M=Li‐Cs). Fifteen of these combinations adopt a D5h three‐dimensional seven‐pointed star‐like structure in a singlet state, where M atoms interact electrostatically with the E5 ring. The determining factors in the relative preference of having the D5h structure over the most competitive isomer or vice‐versa are analyzed. These star‐shaped systems satisfy the 4n+2 Hückel's rule and exhibit a strong diatropic (σ and π) response to an external magnetic field.
Developing a Self‐Healing Supramolecular Nucleoside Hydrogel Based on Guanosine and Isoguanosine
Authors: Tang Fan , Feng Hui , Du Yuqi , Xiao Yandi , Dan Hongxia , Zhao Hang , Chen Qianming
Published: June 2018

Recently, supramolecular hydrogels have attracted increasing interest owing to their tunable stability and inherent biocompatibility. However, only few studies have been reported in the literature on self‐healing supramolecular nucleoside hydrogels, compared to self‐healing polymer hydrogels. In this work, we successfully developed a self‐healing supramolecular nucleoside hydrogel obtained by simply mixing equimolar amounts of guanosine (G) and isoguanosine (isoG) in the presence of K+. The gelation properties have been studied systematically by comparing different alkali metal ions as well as mixtures with different ratios of G and isoG. To this end, rheological and phase diagram experiments demonstrated that the co‐gel not only possessed good self‐healing properties and short recovery time (only 20 seconds) but also could be formed at very low concentrations of K+. Furthermore, nuclear magnetic resonance (NMR), powder X‐ray diffraction (PXRD), and circular dichroism (CD) spectroscopy suggested that possible G2isoG2‐quartet structures occurred in this self‐healing supramolecular nucleoside hydrogel. This co‐gel, to some extent, addressed the problem of isoguanosine gels for the applications in vivo, which showed the potential to be a new type of drug delivery system for biomedical applications in the future.
EISA (Energy Independence and Security Act) compliant ethanol fuel from corn stover in a depot‐based decentralized system
Authors: Kim Seungdo , Zhang Xuesong , Dale Bruce E. , Reddy Ashwan D. , Jones Curtis D. , Izaurralde Roberto C.
Published: June 2018

Cellulosic biofuels face significant problems of feedstock aggregation and logistics leading to poor economies of scale. The current model is for relatively small biorefineries using feedstock gathered locally. Here a depot‐based decentralized biorefinery system is explored to estimate the US Energy Independence and Security Act (EISA) compliant corn stover ethanol production potential in the US Midwest. Depots serve to aggregate, pretreat, and densify biomass (via pellets) and thereby enable very large biorefineries using a decentralized system to collect these pellets. Such a corn‐stover based decentralized system using depots would establish one or two very large‐scale decentralized biorefineries capable of processing about 8–12% of the total corn stover available in the US Midwest. These decentralized biorefineries are economically competitive with the centralized biorefineries. About 55–153 depots could supply the pretreated pellets to the individual decentralized biorefineries leading to an annual production of 1.02–2.91 billion liters of cellulosic ethanol fuel. Most of the participating depots are located in Illinois and Iowa. The total EISA‐compliant ethanol fuel produced in the decentralized system is 2.82–4.07 billion liters per year. The ethanol selling price in the depot‐based decentralized biorefinery system varies between US$0.67 and US$0.72 L−1. The greenhouse gas (GHG) savings from cellulosic ethanol in the decentralized system compared to gasoline are 3.35–4.84 Tg CO2 year−1. Importantly, the total capital investment per annual volume of ethanol in the decentralized biorefinery ranges from US$0.71 L1 to US$1.15 L1, while the total capital investment per annual ethanol volume in the centralized biorefinery is US$1.98 L−1. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd
Development and validation of a high‐throughput assay for the quantification of multiple green tea‐derived catechins in human plasma
Authors: Mawson Deborah H. , Jeffrey Keon L. , Teale Philip , Grace Philip B.
Published: June 2018

A rapid, accurate and robust method for the determination of catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin gallate (Cg), epicatechin gallate (ECg), gallocatechin gallate (GCg) and epigallocatechin gallate (EGCg) concentrations in human plasma has been developed. The method utilizes protein precipitation following enzyme hydrolysis, with chromatographic separation and detection using reversed‐phase liquid chromatography–tandem mass spectrometry (LC–MS/MS). Traditional issues such as lengthy chromatographic runtimes, sample and extract stability, and lack of suitable internal standards have been addressed. The method has been evaluated using a comprehensive validation procedure, confirming linearity over appropriate concentration ranges, and inter/intra‐batch precision and accuracies within suitable thresholds (precisions within 13.8% and accuracies within 12.4%). Recoveries of analytes were found to be consistent between different matrix samples, compensated for using suitable internal markers and within the performance of the instrumentation used. Similarly, chromatographic interferences have been corrected using the internal markers selected. Stability of all analytes in matrix is demonstrated over 32 days and throughout extraction conditions. This method is suitable for high‐throughput sample analysis studies.
Carboxylesterase and UDP‐glucuronosyltransferases mediated metabolism of irinotecan: In vitro and in vivo insights from quantitative ultra‐performance liquid chromatography–mass spectrometry analysis
Authors: Qin Yifeng , Kang An , Zhou Guisheng , Wang Huan , Wei Wei , Cao Yujie , Chen Yanyan , Wang Jing , Shi Yajun , Tang Yuping , Jiang Jianqin
Published: June 2018

Carboxylesterase and UDP‐glucuronosyltransferase‐mediated metabolism of irinotecan (CPT‐11) has long been proposed to be responsible for its anti‐tumor activity and toxicity, like delayed‐onset diarrhea. However, recent studies failed to gain more comprehensive in vivo and in vitro pharmacokinetic profiles of irinotecan. Herein, we use rat plasma, human liver microsomes and immortalized HepG2 cell as experimental subjects to describe a sensitive and versatile UHPLC–MS/MS method for simultaneously quantifying CPT‐11 and its metabolites, including SN‐38 and SN‐38G. The method was applied to investigate the pharmacokinetic and metabolic behavior of CPT‐11 in the biological samples. Calibration curves for all bio‐matrices showed acceptable linearity (r2 > 0.99). The intra‐ and inter‐day precisions (RSD, %) were within 15% and the excellent accuracy (RE) was between 2.96 and 14.12%. In addition, the specificity, matrix effect and extraction recovery all met the requirements of biological sample analysis. We successfully applied this method to investigate the pharmacokinetics of irinotecan in various biological samples, mediated by carboxylesterase and UDP‐glucuronosyltransferase. This method could be employed in monitoring the metabolic status and clinical efficacy of irinotecan in the future.
Anti‐apoptotic effects of adipose‐derived adherent stromal cells in mesenchymal stem cells exposed to oxidative stress
Authors: Shin Sunhye , Choi Jung‐Won , Lim Soyeon , Lee Seahyoung , Jun Eun‐Young , Sun Hyun‐Min , Kim Il‐Kwon , Lee Hoon‐Bum , Kim Sang Woo , Hwang Ki‐Chul
Published: June 2018

Adipose‐derived stromal vascular fractions (SVFs) are a heterogeneous collection of cells, and their regenerative modality has been applied in various animal experiments and clinical trials. Despite the attractive advantages of SVFs in clinical interventions, the recent status of clinical studies involving the application of SVFs in many diseases has not been fully evaluated. Mesenchymal stem cells (MSCs) are multipotent stromal cells that can differentiate into a variety of cell types despite their low numbers in heart tissue. Here, we sought to determine if SVF implantation into impaired heart tissue affected endogenous MSCs in the heart. Therefore, we investigated the expression levels of proteins associated with oxidation, inflammation, and apoptosis in MSCs co‐cultured with adipose‐derived adherent stromal cells (ADASs) from 6 donors' SVFs under oxidative stress conditions for their roles in many physiological processes in the heart. Interestingly, p53 pathway proteins and mitogen‐activated protein kinase (MAPK) signalling pathway components were up‐regulated by H2O2 but exhibited a downward trend in MSCs co‐cultured with ADASs. These data suggest that ADASs may inhibit oxidative stress‐induced apoptosis in MSCs via the p53 and MAPK pathways. Our findings also suggest that the positive effects of SVF implantation into damaged heart tissue may be attributed to the various responses of MSCs. This finding may provide new insights for the clinical application of adipose‐derived SVF transplantation in cardiac diseases.

Significance of the study

We investigated the expression levels of proteins associated with oxidation, inflammation, and apoptosis in MSCs co‐cultured with isolated ADASs from 6 donors' SVFs under oxidative stress conditions. Our results imply that isolated ADASs from SVFs may inhibit oxidative stress‐induced cell cycle arrest and/or apoptosis in MSCs via a p53‐dependent pathway. Furthermore, we identified an anti‐apoptotic mechanism involving oxidative stress‐induced apoptosis by adipose‐derived ADASs in MSCs for the first time. Our findings suggest that the positive effects of SVF implantation into damaged heart tissue may be attributed to the various actions of MSCs.
Effect of breadmaking process on mycotoxin content in white and whole wheat breads
Authors: Tibola Casiane Salete , de Miranda Martha Zavariz , Paiva Flávia Fernandes , Fernandes José Mauricio Cunha , Guarienti Eliana Maria , Nicolau Marcio
Published: June 2018

Background and objectives

Fusarium graminearum may reduce the wheat flour yield, technological quality, and breadmaking performance. The objective was to evaluate the effect of breadmaking on the mycotoxin content in white and whole wheat breads to obtain information about the safety of wheat products. The wheat samples were contaminated via the addition of Fusarium‐damaged kernels to produce different levels of deoxynivalenol (DON), ranging from <500 to >5,000 μg/kg.

Findings

Because of the breadmaking process, a significant reduction in the DON concentration was observed in both the white and whole wheat breads at the upper DON levels (>2,000 μg/kg) compared with the flours. The DON reduction was 49% and 39%, respectively, in whole and white breads, compared with the original flours. ZON was only detected in the two higher levels of DON in the whole wheat flour (mean 33.1 μg/kg) and in the two whole wheat breads (mean 42.4 μg/kg).

Conclusions

The breadmaking process can be a complementary strategy to reduce the mycotoxin content in wheat products.

Significance and novelty

These results are important for wheat supply chain to meet the legislation requirements and to produce safer foods.
Redox‐Driven Transformation of a Discrete Molecular Cage into an Infinite 3D Coordination Polymer
Authors: Szalóki György , Krykun Serhii , Croué Vincent , Allain Magali , Morille Yohann , Aubriet Frédéric , Carré Vincent , Voitenko Zoia , Goeb Sébastien , Sallé Marc
Published: June 2018

Two M12L6 redox‐active self‐assembled cages constructed from an electron‐rich ligand based on the extended tetrathiafulvalene framework (exTTF) and metal complexes with a linear geometry (PdII and AgI) are depicted. Remarkably, based on a combination of specific structural and electronic features, the polycationic self‐assembled AgI coordination cage undergoes a supramolecular transformation upon oxidation into a three‐dimensional coordination polymer, that is characterized by X‐ray crystallography. This redox‐controlled change of the molecular organization results from the drastic conformational modifications accompanying oxidation of the exTTF moiety.
Lewis‐Base‐Induced Disproportionation of a Dialane
Authors: Hofmann Alexander , Lamprecht Anna , Jiménez‐Halla J. Oscar C. , Tröster Tobias , Dewhurst Rian D. , Lenczyk Carsten , Braunschweig Holger
Published: June 2018

The reaction of a pentamethylcyclopentadienyl‐substituted dialane with a variety of Lewis bases results in unexpected disproportionation of the dialane into AlI and AlIII species. Use of a transition‐metal Lewis base allows for the formation of metal‐only Lewis pairs. Furthermore, the synthesis of a Lewis base bis‐adduct was successful with the Lewis base 4‐dimethylaminopyridine.
Bifunctional Brønsted Base Catalyzed Mannich Reaction of β‐Alkoxy α‐Keto Amides: Stereocontrolled Entry to Functionalized Amino Diols
Authors: Echave Haizea , Bastida Iñaki , López Rosa , Palomo Claudio
Published: June 2018

The potential of β‐alkoxy α‐keto amides as pronucleophiles in the enantioselective Mannich type reaction with p‐nosyl imines is presented. The proper combination of β‐alkoxy α‐keto amides and a squaramide‐based Brønsted base catalyst produced highly enantioenriched Mannich adducts, which may be transformed into functionalized amino diols.
iSPAAC: Isomer‐Free Generation of a Bcl‐xL‐Inhibitor in Living Cells
Authors: Lis Christian , Rubner Stefan , Gröst Corinna , Hoffmann Ralf , Knappe Daniel , Berg Thorsten
Published: June 2018

Strain‐promoted azide–alkyne cycloadditions (SPAAC) have proven extremely useful for labeling of biomolecules, but typically produce isomeric mixtures. This is not appropriate for the formation of bioactive molecules in living cells. Here, the first use of SPAAC for the isomer‐free synthesis of a bioactive molecule is reported both in vitro and inside cultured cells. We developed the symmetrical cyclooctyne SYPCO and used it for the generation of a chemically uniform triazole inhibitor of protein–protein interactions mediated by Bcl‐xL via isomer‐free SPAAC (iSPAAC). Tumor cells treated with the reactants of the iSPAAC reaction contained higher concentrations of triazole, and displayed higher apoptosis levels, than cells treated with pre‐synthesized triazole. We envision iSPAAC as a broadly applicable method for modulating intracellular targets with organic molecules with molecular weights prohibitively large for cellular uptake, via smaller and thus more cell‐permeable components.
A Discrete Self‐Assembled Pd12 Triangular Orthobicupola Cage and its Use for Intramolecular Cycloaddition
Authors: Bhat Imtiyaz Ahmad , Devaraj Anthonisamy , Zangrando Ennio , Mukherjee Partha Sarathi
Published: June 2018

Water‐soluble Pd12L6 coordination cage TC‐1 was synthesized by coordination‐driven self‐assembly of symmetrical tetrapyridyl donor L with 90° ditopic acceptor cis‐[Pd(NO3)2(tmeda)] [tmeda=N,N,N′,N′‐tetramethylethane‐1,2‐diamine]. The Pd12L6 coordination assembly is an uncommon example of a coordination cage having triangular orthobicupola‐like geometry. It was characterized by multinuclear NMR spectroscopy, ESI‐MS, and single‐crystal X‐ray diffraction. Self‐assembly of a tetratopic donor with a cis‐blocked 90° ditopic acceptor generally yields tri‐/tetra‐/hexagonal barrels or closed cubic cages. However, in the present case the donor and acceptor are arranged in an unusual fashion to generate an orthobicupola geometry in which two triangular cupola share a common irregular hexagonal face. The cage was used to perform intramolecular cycloaddition reactions of O‐propargylated benzylidinebarbituric acid derivatives in nitromethane. Several penta‐/tetracyclouracil derivatives were synthesized through cage‐catalyzed [4+2] cycloaddition reactions in a concerted manner with good to high conversion under mild reaction conditions, whereas in the absence of cage TC‐1 similar reactions led to lower conversion to the cyclized products in organic solvent. This approach is of particular importance compared to the literature reports on the synthesis of similar compounds under high‐temperature reflux conditions with high catalyst loading.
Extraction of wax‐like materials from cereals
Authors: Pham Thi‐Can‐Tho , Angers Paul , Ratti Cristina
Published: June 2018

In this study, a comparison of the wax extraction process from rice, sorghum, and wheat using liquid nitrogen was done with respect to the traditional solvent extraction method using n‐hexane. For this purpose, these cereals were immersed in liquid nitrogen (1–4 cycles with different time intervals and different rest times between cycles). The results showed that waxes could be extracted by liquid nitrogen, but with a lower yield. When compared to the n‐hexane extraction method, the extracted amounts of waxes with liquid nitrogen were 5, 7.5, and 9.3 times lower, but the extraction times were 2.3, 5.5, and 11.25 times shorter for wheat, rice, and sorghum, respectively. No residue was left in wax‐like materials extracted with liquid nitrogen. While SEM depicted that the outer layer of waxes on the grains could be extracted by liquid nitrogen, GC‐MS and GC‐FID showed that the extracted waxes had similar compositions in both cycle extraction methods. These results could point out a novel environmentally‐friendly method to extract waxes from cereals that could be useful for certain applications.
Design of field‐scale cyclic solvent injection processes for post‐CHOPS applications
Authors: Martinez Gamboa Juan J. , Leung Juliana Y.
Published: June 2018

Oil recovery factors in cold heavy oil production with sand (CHOPS) are typically lower than 15 %. Solvent‐aided processes, such as cyclic solvent injection (CSI) are common post‐CHOPS approaches, where wormhole networks could offer increased reservoir contact. However, grid block sizes in field‐scale simulations are much larger than the wormhole scale and large‐scale dispersivity values are assigned arbitrarily based on history matching. This work implements a statistical scale‐up workflow that facilitates the construction of coarse‐scale models for CSI simulation, whose relevant parameters are calibrated against simulation results using high‐resolution wormhole networks. The formulated workflow can be integrated with commercial reservoir simulators to effectively simulate solvent processes at multiple scales.

Multiple injection scenarios are analyzed. Extended soaking periods may positively impact the ultimate recovery with a slower decline at later times, while a lower initial rate is observed. Interestingly, when an economic limit is imposed, the optimal soaking time is not necessarily the longest one. It depends on the trade‐off between extracting additional oil recovery at late times versus producing at a higher rate at early times. The analysis also reveals that the initial cycles contribute the most to the final recovery. In addition, when the amount of solvent available is limited, the results would support the strategy of injecting all the solvent in 1 single cycle, with an extended soaking period, rather than performing shorter consecutive cycles.
Asymmetric Synthesis of the Ring A Substructure of Genkwadane A
Authors: Feng Jing , Yin Hongli , Man Yi , Fu Shaomin , Liu Bo
Published: June 2018

A practical approach to the asymmetric synthesis of the ring A substructure of genkwadane A, a daphnane diterpenoid, was developed. This synthesis features the Mukaiyama aldol reaction to introduce the quaternary stereogenic center at C4 and VO(acac)2‐catalyzed Jackson‐Ellman‐Bolm sulfoxidation to deliver the corresponding sulfoxide. The Dieckmann‐type condensation was efficiently promoted by KHMDS and the ring A substructure was finally accomplished through Barton iodination condition.
Pharmacokinetics, Pharmacodynamics, and Safety of Subcutaneous Bapineuzumab: A Single‐Ascending‐Dose Study in Patients With Mild to Moderate Alzheimer Disease
Authors: Lu Ming , Brashear H. Robert
Published: June 2018

This study was designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending subcutaneous doses of bapineuzumab in patients with mild to moderate Alzheimer disease. Forty patients were randomized across 5 cohorts (5 mg, 10 mg, 20 mg, 40 mg, 80 mg; 8 patients each [bapineuzumab 6; placebo 2]). The incidence of treatment‐emergent adverse events (TEAEs) was higher in pooled bapineuzumab cohorts (83%) than in the pooled placebo group (27.7%). Most common TEAEs in the bapineuzumab group were gastrointestinal disorders and musculoskeletal and connective tissue disorders (bapineuzumab 17% each; placebo 0%). Serious TEAEs were observed in 7% of bapineuzumab‐treated patients without any deaths or adverse event–related discontinuation. The median times to reach peak measurable concentration (Cmax) of bapineuzumab were 14 days for 5‐, 10‐, and 20‐mg cohorts, 11 days for 40‐mg, and 7 days for 80‐mg cohorts. The apparent volume of distribution of bapineuzumab was 134.29 to 204.68 mL/kg. The total body clearance was consistent at 10 to 80 mg. The average terminal half‐life ranged from 26 to 46 days (5‐ to 80‐mg groups). Exposure to bapineuzumab increased dose‐proportionally from 10 to 80 mg. There was a positive correlation between Cmax and area under the concentration‐time curve to the last measurable concentration (AUClast) of plasma amyloid‐β, and between the Cmax and AUClast of serum bapineuzumab.
Pharmacogenetics of Clopidogrel Therapy and Neurointerventional Procedures: We Need Precision Data for Precision Medicine
Authors: Rakicevic Ljiljana , Nestorovic Aleksandra
Published: June 2018

Genetics has given a real boost to personalized and precision medicine, providing data used either for precise diagnostics, prediction of the course of illness, or for selecting therapy and tailoring it. Pharmacogenetics, as a discipline researching connection between genetic background of an individual and the effect of a certain drug, has created new possibilities in medicine. One of the most researched drugs in pharmacogenetics is certainly clopidogrel.