bluuebunny/crossref_metadata_2025 huggingface dataset:
Sodium and Sodium‐Ion Batteries: 50 Years of Research
Authors: Delmas Claude
Published: February 2018

This paper gives an overview of the research carried out on sodium batteries in the last 50 years. The discovery of the very high Na+ ion conductivity in β‐Al2O3 opened the way to high‐energy batteries (sodium/sulfur and sodium/NiCl2) for load leveling and electrical vehicles. Then, the liquid electrolyte batteries were considered with intercalation‐based electrodes and lithium and sodium as mobile ions. When Sony proposed the lithium‐ion batteries, most research moved to lithium systems, exhibiting a higher energy density. These are now currently used in electronic devices, hybrid electrical vehicle (HEV) and electrical vehicle (EV). The development of renewable energies, which have an intermittent character, requires very large batteries for frequency regulation and peak production shift. For these stationary applications the most important parameters are the lifetime, the power, the price, and the material availability. Since sodium ion batteries are able to satisfy these criteria, these new material families now concern a large part of the scientific community. This article gives a general introduction and an overview of the research carried out on the materials that are presented in detail, in the articles within this special issue on sodium batteries.
Boosting Fast Sodium Storage of a Large‐Scalable Carbon Anode with an Ultralong Cycle Life
Authors: Qian Ji , Wu Feng , Ye Yusheng , Zhang Menglu , Huang Yongxin , Xing Yi , Qu Wei , Li Li , Chen Renjie
Published: February 2018

Sodium‐ion batteries (SIBs) are considered to be a promising alternative for large‐scale electricity storage. However, it is urgent to develop new anode materials with superior ultralong cycle life performance at high current rates. Herein, a low‐cost and large‐scalable sulfur‐doped carbon anode material that exhibits the best high‐rate cycle performance and the longest cycle life ever reported for carbon anodes is developed. The material delivers a reversible capacity of 142 mA h g−1 at a current rate up to 10 A g−1. After 10 000 cycles the capacity is remained at 126.5 mA h g−1; 89.1% of the initial value. Density functional theory computations demonstrate that the sulfur‐doped carbon has a strong binding affinity for sodium which promotes sodium storage. Meanwhile, the kinetics analysis identifies the capacitive charge storage as a large contributor to sodium storage, which favors ultrafast storage of sodium ions. These results demonstrate a new way to design carbon‐based SIBs anodes for next‐generation large‐scale electricity storage.
Unassisted Water Splitting Using a GaSbxP(1−x) Photoanode
Authors: Martinez‐Garcia Alejandro , Russell Harry B. , Paxton William , Ravipati Srikanth , Calero‐Barney Sonia , Menon Madhu , Richter Ernst , Young James , Deutsch Todd , Sunkara Mahendra K.
Published: February 2018

Here, unbiased water splitting with 2% solar‐to‐hydrogen efficiency under AM 1.5 G illumination using new materials based on GaSb0.03P0.97 alloy is reported. Freestanding GaSbxP1−x is grown using halide vapor phase epitaxy. The native conductivity type of the alloy is modified by silicon doping, resulting in an open‐circuit potential (OCP) of 750 mV, photocurrents of 7 mA cm−2 at 10 sun illumination, and corrosion resistance in an aqueous acidic environment. Alloying GaP with Sb at 3 at% improves the absorption of high‐energy photons above 2.68 eV compared to pure GaP material. Electrochemical Impedance Spectroscopy and illuminated OCP measurements show that the conduction band of GaSbxP1−x is at −0.55 V versus RHE irrespective of the Sb concentration, while photocurrent spectroscopy indicates that only radiation with photon energies greater than 2.68 eV generate mobile and extractable charges, thus suggesting that the higher‐laying conduction bands in the Γ 1 valley of the alloys are responsible for exciton generation.
Carbon Incorporation and Anion Dynamics as Synergistic Drivers for Ultrafast Diffusion in Superionic LiCB11H12 and NaCB11H12
Authors: Dimitrievska Mirjana , Shea Patrick , Kweon Kyoung E. , Bercx Marnik , Varley Joel B. , Tang Wan Si , Skripov Alexander V. , Stavila Vitalie , Udovic Terrence J. , Wood Brandon C.
Published: February 2018

The disordered phases of LiCB11H12 and NaCB11H12 possess superb superionic conductivities that make them suitable as solid electrolytes. In these materials, cation diffusion correlates with high orientational mobilities of the CB11H12− anions; however, the precise relationship has yet to be demonstrated. In this work, ab initio molecular dynamics and quasielastic neutron scattering are combined to probe anion reorientations and their mechanistic connection to cation mobility over a range of timescales and temperatures. It is found that anions do not rotate freely, but rather transition rapidly between orientations defined by the cation sublattice symmetry. The symmetry‐breaking carbon atom in CB11H12− also plays a critical role by perturbing the energy landscape along the instantaneous orientation of the anion dipole, which couples fluctuations in the cation probability density directly to the anion motion. Anion reorientation rates exceed 3 × 1010 s−1, suggesting the underlying energy landscape fluctuates dynamically on diffusion‐relevant timescales. Furthermore, carbon is found to modify the orientational preferences of the anions and aid rotational mobility, creating additional symmetry incompatibilities that inhibit ordering. The results suggest that synergy between the anion reorientational dynamics and the carbon‐modified cation–anion interaction accounts for the higher ionic conductivity in CB11H12− salts compared with B12H122−.
Sub‐3 nm Ultrafine Monolayer Layered Double Hydroxide Nanosheets for Electrochemical Water Oxidation
Authors: Zhao Yufei , Zhang Xin , Jia Xiaodan , Waterhouse Geoffrey I. N. , Shi Run , Zhang Xuerui , Zhan Fei , Tao Ye , Wu Li‐Zhu , Tung Chen‐Ho , O'Hare Dermot , Zhang Tierui
Published: February 2018

This study reports the synthesis of ultrafine NiFe‐layered double hydroxide (NiFe‐LDH) nanosheets, possessing a size range between 1.5 and 3.0 nm with a thickness of 0.6 nm. Abundant metal and oxygen vacancies impart the ultrafine nanosheets with semi‐metallic character, and thus superior charge transfer properties and electrochemical water oxidation performance with overpotentials (η) of 254 mV relative to monolayer LDH nanosheets (η of 280 mV) or bulk LDH materials (η of 320 mV) at 10 mA cm−2. These results are highly encouraging for the future application of ultrafine monolayer LDH nanosheets in electronics, solar cells, and catalysis.
Probabilistic Design space determination in pharmaceutical product development: A Bayesian/latent variable approach
Authors: Bano Gabriele , Facco Pierantonio , Bezzo Fabrizio , Barolo Massimiliano
Published: February 2018

To find the design space (DS) of a pharmaceutical process, quantification of the “assurance of quality” for the product under development is required. In this study, latent‐variable modeling is combined with multivariate Bayesian regression to identify a subset of input combinations (process operating conditions and raw materials properties) within which the DS of the product will lie at a probability equal to, or greater than, an assigned threshold. Partial least‐squares regression is used to obtain a linear transformation between the original multidimensional input space and a low‐dimensional latent space. The input domain is then discretized on its lower dimensional representation and a Bayesian posterior predictive approach is used to quantify the probability that the critical quality attributes of the product will meet their specifications for each discretization point. The methodology is tested on two case studies taken from the literature, one of which involving experimental data. The ability of the proposed approach to obtain a probabilistic identification of the DS, while simultaneously reducing the computational burden for the discretization of the input domain and providing a simple graphical representation of the DS, is shown. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2438–2449, 2018
Shifts in gene expression profiles are associated with weak and strong Crassulacean acid metabolism
Authors: Heyduk Karolina , Ray Jeremy N. , Ayyampalayam Saravanaraj , Leebens‐Mack James
Published: February 2018

Premise of the Study

The relative ease of high throughput sequencing is facilitating comprehensive phylogenomic and gene expression studies, even for nonmodel groups. To date, however, these two approaches have not been merged; while phylogenomic methods might use transcriptome sequences to resolve relationships, assessment of gene expression patterns in a phylogenetic context is less common. Here we analyzed both carbon assimilation and gene expression patterns of closely related species within the Agavoideae (Asparagaceae) to elucidate changes in gene expression across weak and strong phenotypes for Crassulacean acid metabolism (CAM).

Methods

Gene expression patterns were compared across four genera: Agave (CAM), which is paraphyletic with Polianthes (weak CAM) and Manfreda (CAM), and Beschorneria (weak CAM). RNA‐sequencing was paired with measures of gas exchange and titratable acidity. Climate niche space was compared across the four lineages to examine abiotic factors and their correlation to CAM.

Key Results

Expression of homologous genes showed both shared and variable patterns in weak and strong CAM species. Network analysis highlights that despite shared expression patterns, highly connected genes differ between weak and strong CAM, implicating shifts in regulatory gene function as key for the evolution of CAM. Variation in carbohydrate metabolism between weak and strong CAM supports the importance of sugar turnovers for CAM physiology.

Conclusions

Integration of phylogenetics and RNA‐sequencing provides a powerful tool to study the evolution of CAM photosynthesis across closely related but photosynthetically variable species. Our findings regarding shared or shifted gene expression and regulation of CAM via carbohydrate metabolism have important implications for efforts to engineer the CAM pathway into C3 food and biofuel crops.
Non‐invasive genetic censusing and monitoring of primate populations
Authors: Arandjelovic Mimi , Vigilant Linda
Published: February 2018

Knowing the density or abundance of primate populations is essential for their conservation management and contextualizing socio‐demographic and behavioral observations. When direct counts of animals are not possible, genetic analysis of non‐invasive samples collected from wildlife populations allows estimates of population size with higher accuracy and precision than is possible using indirect signs. Furthermore, in contrast to traditional indirect survey methods, prolonged or periodic genetic sampling across months or years enables inference of group membership, movement, dynamics, and some kin relationships. Data may also be used to estimate sex ratios, sex differences in dispersal distances, and detect gene flow among locations. Recent advances in capture‐recapture models have further improved the precision of population estimates derived from non‐invasive samples. Simulations using these methods have shown that the confidence interval of point estimates includes the true population size when assumptions of the models are met, and therefore this range of population size minima and maxima should be emphasized in population monitoring studies. Innovations such as the use of sniffer dogs or anti‐poaching patrols for sample collection are important to ensure adequate sampling, and the expected development of efficient and cost‐effective genotyping by sequencing methods for DNAs derived from non‐invasive samples will automate and speed analyses.
Memory complaints, dementia, and neuropathology in older blacks and whites
Authors: Arvanitakis Zoe , Leurgans Sue E. , Fleischman Debra A. , Schneider Julie A. , Rajan Kumar B. , Pruzin Jeremy J. , Shah Raj C. , Evans Denis A. , Barnes Lisa L. , Bennett David A.
Published: February 2018

Objective

To determine relationships of memory complaints to cognitive function and decline, incident dementia, and neurodegenerative and other neuropathologies, as well as the population‐attributable risk for dementia in older black and white persons.

Methods

A total of 4,015 community‐based persons (28% black; 74% women; mean baseline age = 78 years) were enrolled in 1 of 4 longitudinal cohort studies, and another 2,937 in a population‐based cohort. Memory scores, assessed using 2 questions (5‐point Likert scales) were categorized as complaints present or absent. Global cognition and 5 cognitive domains were derived from annual neuropsychological tests. Dementia was assessed from these tests and additional data. Neuropathologic data were available for 1,350 deceased subjects with brain autopsies. Regression and mixed effects models were used to examine relationships of memory complaints to cognition and neuropathology.

Results

Baseline memory complaints (n = 1,310; 33% of 4,015) were associated with lower cognition and faster decline in all domains (global score estimate = −0.032, standard error = 0.004, p < 0.0001), during a mean follow‐up of 6 (standard deviation = 2) years. Persons with memory complaints had higher dementia risk (hazard ratio = 1.64, 95% confidence interval [CI] = 1.42–1.89) and odds of pathologic Alzheimer disease (odds ratio [OR] = 1.96, 95% CI = 1.51–2.54), neocortical Lewy bodies (OR = 2.47, 95% CI = 1.54–3.96), and other neurodegenerative pathologies. Results for dementia risk were similar among blacks and whites. Among 2,937 older persons in a population‐based cohort with similar data, the population‐attributable risk for incident dementia due to memory complaints was 14.0% (95% CI = 2.6–23.0), and did not vary between the black and white groups.

Interpretation

Memory complaints are common in older black and white persons, and relate to cognitive decline, dementia risk, and neurodegenerative pathologies. Ann Neurol 2018;83:718–729
Einblicke in die Verteilung von CO2‐Molekülen und deren zeitliche Entwicklung durch Mikro‐Bildgebung mittels IR‐Spektroskopie und molekulardynamische Modellierung
Authors: Hwang Seungtaik , Semino Rocio , Seoane Beatriz , Zahan Marufa , Chmelik Christian , Valiullin Rustem , Bertmer Marko , Haase Jürgen , Kapteijn Freek , Gascon Jorge , Maurin Guillaume , Kärger Jörg
Published: February 2018

Mittels IR‐Mikro‐Bildgebung wurde die Entwicklung der CO2‐Konzentration einer ZIF‐8@6FDA‐DAM‐Mixed‐Matrix‐Membran während des Adsorptionsvorgangs räumlich und zeitlich aufgelöst aufgezeichnet. Indem die Entwicklung der CO2‐Konzentration aufgelöst wird, wird beobachtet, dass die CO2‐Moleküle vom ZIF‐8‐Füllstoff, der als “Schnellstraße” des Stofftransports wirkt, in das umgebende Polymer gelangen. Es bildet sich eine Schicht hoher CO2‐Konzentration an der MOF/Polymer‐Zwischenschicht, die sich bei hohen CO2‐Gasdrücken stärker ausbildet. Eine mikroskopische Erklärung des Ursprungs dieses Phänomens wird auf der Basis molekularer Simulation vorgeschlagen. Indem eine Rechenmethode eingesetzt wird, die auf quantenmechanischen und Kraftfeld‐basierten Berechnungen fußt, wird die Bildung von Mikro‐Hohlräumen in der MOF/Polymer‐Zwischenschicht vorhergesagt. Großkanonische Monte‐Carlo‐Simulationen zeigen weiterhin, dass die CO2‐Moleküle dazu neigen, sich bevorzugt in diesen Mikro‐Hohlräumen aufzuhalten, woraus man schließen kann, dass dies die CO2‐Anreicherung in der Zwischenschicht erleichtert.
Eisenkatalysierte Kreuzkupplungen in der Synthese von Pharmazeutika: Streben nach Nachhaltigkeit
Authors: Piontek Aleksandra , Bisz Elwira , Szostak Michal
Published: February 2018

Der Mangel an Edelmetallen hat eine Suche nach nachhaltigen Strategien für metallkatalysierte Kreuzkupplungen ausgelöst. Die Entwicklung neuer Katalysemethoden unter Verwendung von Eisen ist wegen der geringen Kosten, leichten Verfügbarkeit und sehr geringen Toxizität von Eisen hoch attraktiv. In den letzten Jahren haben nachhaltige Methoden für eisenkatalysierte Kreuzkupplungen den kritischen Bereich der pharmazeutischen Forschung erreicht. Insbesondere ist Eisen eines der sehr wenigen unedlen Metalle, deren praktischer Einsatz in industriellen Kreuzkupplungen im Kilogrammmaßstab erfolgreich erprobt wurde. In diesem Kurzaufsatz wollen wir die strategischen Vorteile der Verwendung von Eisenkatalysatoren als umweltfreundliche und nachhaltige Alternative zu Edelmetallen in Kreuzkupplungen für die Synthese von Pharmazeutika kritisch beleuchten. Wir bieten eine Einführung in die grundlegenden Aspekte der Eisenkatalyse, heben Bereiche mit Verbesserungspotenzial hervor und zeigen neue Richtungen auf, die in Zukunft erforscht werden sollten.
Beispielloses dearomatisiertes Spirocyclopropan in einer sequenziellen Rhodium(III)‐katalysierten C‐H‐Aktivierung und Umlagerungsreaktion
Authors: Wang Xiaoming , Li Yingzi , Knecht Tobias , Daniliuc Constantin G. , Houk K. N. , Glorius Frank
Published: February 2018

Ein beispielloses dearomatisiertes Spirocyclopropanintermediat wurde in einer sequenziellen Cp*RhIII‐katalysierten C‐H‐Aktivierung, gefolgt von einer Variante der Wagner‐Meerwein‐Umlagerung, entdeckt. Wie die O‐N‐Bindung oxidativ gespalten wird und welche Rolle dabei HOAc spielt, wurde in dieser Studie aufgedeckt. Darüber hinaus wurde eine Cp*RhIII‐katalysierte Dearomatisierungsreaktion von N‐(Naphthalin‐1‐yloxy)acetamid mit gespannten Olefinen entwickelt, die eine Vielzahl von Spirocyclopropanen lieferte.
Chiral 1,3,2‐Diazaphospholenes as Catalytic Molecular Hydrides for Enantioselective Conjugate Reductions
Authors: Miaskiewicz Solène , Reed John H. , Donets Pavel A. , Oliveira Caio C. , Cramer Nicolai
Published: February 2018

Secondary 1,3,2‐diazaphospholenes have a polarized P−H bond and are emerging as molecular hydrides. Herein, a class of chiral, conformationally restricted methoxy‐1,3,2‐diazaphospholene catalysts is reported. We demonstrate their catalytic potential in asymmetric 1,4‐reductions of α,β‐unsaturated carbonyl derivatives, including enones, acyl pyrroles, and amides, which proceeded in enantioselectivities of up to 95.5:4.5 e.r.
Highly Stable Lithium Metal Batteries Enabled by Regulating the Solvation of Lithium Ions in Nonaqueous Electrolytes
Authors: Zhang Xue‐Qiang , Chen Xiang , Cheng Xin‐Bing , Li Bo‐Quan , Shen Xin , Yan Chong , Huang Jia‐Qi , Zhang Qiang
Published: February 2018

Safe and rechargeable lithium metal batteries have been difficult to achieve because of the formation of lithium dendrites. Herein an emerging electrolyte based on a simple solvation strategy is proposed for highly stable lithium metal anodes in both coin and pouch cells. Fluoroethylene carbonate (FEC) and lithium nitrate (LiNO3) were concurrently introduced into an electrolyte, thus altering the solvation sheath of lithium ions, and forming a uniform solid electrolyte interphase (SEI), with an abundance of LiF and LiNxOy on a working lithium metal anode with dendrite‐free lithium deposition. Ultrahigh Coulombic efficiency (99.96 %) and long lifespans (1000 cycles) were achieved when the FEC/LiNO3 electrolyte was applied in working batteries. The solvation chemistry of electrolyte was further explored by molecular dynamics simulations and first‐principles calculations. This work provides insight into understanding the critical role of the solvation of lithium ions in forming the SEI and delivering an effective route to optimize electrolytes for safe lithium metal batteries.
Visible‐Light Photocatalysis: Does It Make a Difference in Organic Synthesis?
Authors: Marzo Leyre , Pagire Santosh K. , Reiser Oliver , König Burkhard
Published: February 2018

Visible‐light photocatalysis has evolved over the last decade into a widely used method in organic synthesis. Photocatalytic variants have been reported for many important transformations, such as cross‐coupling reactions, α‐amino functionalizations, cycloadditions, ATRA reactions, or fluorinations. To help chemists select photocatalytic methods for their synthesis, we compare in this Review classical and photocatalytic procedures for selected classes of reactions and highlight their advantages and limitations. In many cases, the photocatalytic reactions proceed under milder reaction conditions, typically at room temperature, and stoichiometric reagents are replaced by simple oxidants or reductants, such as air, oxygen, or amines. Does visible‐light photocatalysis make a difference in organic synthesis? The prospect of shuttling electrons back and forth to substrates and intermediates or to selectively transfer energy through a visible‐light‐absorbing photocatalyst holds the promise to improve current procedures in radical chemistry and to open up new avenues by accessing reactive species hitherto unknown, especially by merging photocatalysis with organo‐ or metal catalysis.
On‐Demand Production of Flow‐Reactor Cartridges by 3D Printing of Thermostable Enzymes
Authors: Maier Manfred , Radtke Carsten P. , Hubbuch Jürgen , Niemeyer Christof M. , Rabe Kersten S.
Published: February 2018

The compartmentalization of chemical reactions is an essential principle of life that provides a major source of innovation for the development of novel approaches in biocatalysis. To implement spatially controlled biotransformations, rapid manufacturing methods are needed for the production of biocatalysts that can be applied in flow systems. Whereas three‐dimensional (3D) printing techniques offer high‐throughput manufacturing capability, they are usually not compatible with the delicate nature of enzymes, which call for physiological processing parameters. We herein demonstrate the utility of thermostable enzymes in the generation of biocatalytic agarose‐based inks for a simple temperature‐controlled 3D printing process. As examples we utilized an esterase and an alcohol dehydrogenase from thermophilic organisms as well as a decarboxylase that was thermostabilized by directed protein evolution. We used the resulting 3D‐printed parts for a continuous, two‐step sequential biotransformation in a fluidic setup.
Enzymatic or In Vivo Installation of Propargyl Groups in Combination with Click Chemistry for the Enrichment and Detection of Methyltransferase Target Sites in RNA
Authors: Hartstock Katja , Nilges Benedikt S. , Ovcharenko Anna , Cornelissen Nicolas V. , Püllen Nikolai , Lawrence‐Dörner Ann‐Marie , Leidel Sebastian A. , Rentmeister Andrea
Published: February 2018

m6A is the most abundant internal modification in eukaryotic mRNA. It is introduced by METTL3‐METTL14 and tunes mRNA metabolism, impacting cell differentiation and development. Precise transcriptome‐wide assignment of m6A sites is of utmost importance. However, m6A does not interfere with Watson–Crick base pairing, making polymerase‐based detection challenging. We developed a chemical biology approach for the precise mapping of methyltransferase (MTase) target sites based on the introduction of a bioorthogonal propargyl group in vitro and in cells. We show that propargyl groups can be introduced enzymatically by wild‐type METTL3‐METTL14. Reverse transcription terminated up to 65 % at m6A sites after bioconjugation and purification, hence enabling detection of METTL3‐METTL14 target sites by next generation sequencing. Importantly, we implemented metabolic propargyl labeling of RNA MTase target sites in vivo based on propargyl‐l‐selenohomocysteine and validated different types of known rRNA methylation sites.
Central and Peripheral Expression of DNA Double‐Strand Breaks in Human and Mouse Tissues
Authors: Castiglione Mia P. , Ramos Raddy L. , Leheste Joerg R. , Torres German
Published: February 2018

Mammalian cells accumulate DNA lesions when they undergo phases of the cell cycle or during normal cellular activity. In this regard, several DNA repair signaling pathways have evolved to maintain genome stability and avoid the potential acquisition of mutations. To define and further characterize the expression of DNA double‐strand breaks in humans and mice, we used immunocytochemistry to localize a DNA damage signal within the spatial confines of the cell nucleus. We show that DNA double‐strand breaks are abundantly expressed in postmitotic neurons of the human and mouse brain. Notably, DNA double‐strand breaks are present in human hypothalamic and mouse striatal and hippocampal cells, with stable expression of the nuclear signal detected throughout the mammalian brain. Analysis of the mouse tongue, heart, and testis shows that expression of DNA double‐strand breaks is only demonstrated in circumscribed populations of peripheral cells. These data suggest that levels of DNA double‐strand breaks are tissue‐specific with the tongue, heart and testicular tissue having different thresholds of DNA repair and DNA damage from those outlined at the brain level. Anat Rec, 301:1251–1257, 2018. © 2018 Wiley Periodicals, Inc.
Techno‐economic analysis of various biochemical conversion platforms for biosugar production: Trade‐offs of co‐producing biopower versus pellets for either a greenfield, repurpose, or co‐location siting context
Authors: Reeb Carter , Phillips Richard , Venditti Richard , Treasure Trevor , Daystar Jesse , Gonzalez Ronalds , Jameel Hasan , Kelley Stephen
Published: February 2018

In theory, biosugar for conversion to bioproducts can be produced economically from a variety of biomass types in many different technological, co‐production, and biorefinery siting contexts. In this paper, process modeling and financial analysis were conducted for all permutations of biochemical conversion pathways, global biomass types, co‐product options, and biorefinery siting contexts for biosugar production. Minimum sugar revenue (MSR) required to achieve a 15% internal rate of return values for scenarios examined ranged from $150–$748 per tonne. The scenarios with the lowest MSRs were sugarcane in South America and Asia, assuming hot water cook and co‐location or repurpose siting contexts. Another financially optimized scenario is corn grain, also assuming hot water cook, co‐producing distiller’s dry grains and solubles (DDGS), in a repurpose siting context. Against a benchmark sugar price of $408 per metric tonne, an internal rate of return on investment of >15% can typically only be achieved via previously demonstrated conversion pathways using sugar cane and corn grain. Major cost drivers were feedstock cost per metric tonne of carbohydrate, sugar yield, capital investment per annual metric tonne of sugar produced, residue value, and siting context. Near‐term promising technologies include autohydrolysis and dilute acid pathways. Generally, scenarios are financially enhanced by co‐location or repurposing, reducing capital expenditure (CAPEX) by about 33% and 50%, respectively, with negligible impact on cash cost. Conversion process complexity drives capital investment, making some scenarios infeasible despite high sugar yields. Any of the five major cost drivers can impact the order of financial attraction of scenarios, with the outcome of the analysis typically not obvious in advance. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd
Fluorescent nanodiamond‐bacteriophage conjugates maintain host specificity
Authors: Trinh Jimmy T. , Alkahtani Masfer H. , Rampersaud Isaac , Rampersaud Arfaan , Scully Marlan , Young Ryland F. , Hemmer Philip , Zeng Lanying
Published: February 2018

Rapid identification of specific bacterial strains within clinical, environmental, and food samples can facilitate the prevention and treatment of disease. Fluorescent nanodiamonds (FNDs) are being developed as biomarkers in biology and medicine, due to their excellent imaging properties, ability to accept surface modifications, and lack of toxicity. Bacteriophages, the viruses of bacteria, can have exquisite specificity for certain hosts. We propose to exploit the properties of FNDs and phages to develop phages conjugated with FNDs as long‐lived fluorescent diagnostic reagents. In this study, we develop a simple procedure to create such fluorescent probes by functionalizing the FNDs and phages with streptavidin and biotin, respectively. We find that the FND‐phage conjugates retain the favorable characteristics of the individual components and can discern their proper host within a mixture. This technology may be further explored using different phage/bacteria systems, different FND color centers and alternate chemical labeling schemes for additional means of bacterial identification and new single‐cell/virus studies.
High school biology students use of visual molecular dynamics as an authentic tool for learning about modeling as a professional scientific practice
Authors: Burgin Stephen R. , Oramous Jennifer , Kaminski Michael , Stocker Linda , Moradi Mahmoud
Published: February 2018

Modeling is a practice of science that is underemphasized in biology classrooms in comparison to its central focus in the physical sciences. Visualizations of the submicroscopic world of molecules are becoming increasingly sophisticated with the evolution of new technologies. With this in mind, we introduced high school biology classrooms to a professional molecular modeling software program used by research biochemists to visualize proteins and other macromolecules. Analysis of surveys completed before and after the use of the program revealed significant student gains in their understandings of the nature of models. Student and teacher perceptions of the program showed an appreciation for the real/authentic nature of the program, and its affordances when utilizing the three‐dimensional rendering of proteins. The teachers did report a general level of frustration regarding their lack of experience with the program and their inability to unlock its full potential due to not being able to access all of the program's features. However, we believe that the evidence at hand indicates that the value of introducing students to authentic molecular modeling tools in high school science classrooms outweighs the potential limitations. © 2018 by The International Union of Biochemistry and Molecular Biology, 46(3):230–236, 2018.
Development and validation of a LC‐MS/MS method for quantitation of fosfomycin – Application to in vitro antimicrobial resistance study using hollow‐fiber infection model
Authors: Gandhi Adarsh , Matta Murali , Garimella Narayana , Zere Tesfalem , Weaver James
Published: February 2018

Extensive use and misuse of antibiotics over the past 50 years has contributed to the emergence and spread of antibiotic‐resistant bacterial strains, rendering them as a global health concern. To address this issue, a dynamic in vitro hollow‐fiber system, which mimics the in vivo environment more closely than the static model, was used to study the emergence of bacterial resistance of Escherichia coli against fosfomycin (FOS). To aid in this endeavor we developed and validated a liquid chromatography–tandem mass spectrometry (LC‐MS/MS) assay for quantitative analysis of FOS in lysogeny broth. FOS was resolved on a Kinetex HILIC (2.1 × 50 mm, 2.6 μm) column with 2 mm ammonium acetate (pH 4.76) and acetonitrile as mobile phase within 3 min. Multiple reaction monitoring was used to acquire data on a triple quadrupole mass spectrometer. The assay was linear from 1 to 1000 μg/mL. Inter‐ and intra‐assay precision and accuracy were <15% and between ±85 and 115% respectively. No significant matrix effect was observed when corrected with the internal standard. FOS was stable for up to 24 h at room temperature, up to three freeze–thaw cycles and up to 24 h when stored at 4°C in the autosampler. In vitro experimental data were similar to the simulated plasma pharmacokinetic data, further confirming the appropriateness of the experimental design to quantitate antibiotics and study occurrence of antimicrobial resistance in real time. The validated LC‐MS/MS assays for quantitative determination of FOS in lysogeny broth will help antimicrobial drug resistance studies.
Development of a novel affinity chromatography resin for platform purification of bispecific antibodies with modified protein a binding avidity
Authors: Tustian Andrew D. , Laurin Linus , Ihre Henrik , Tran Travis , Stairs Robert , Bak Hanne
Published: February 2018

There is strong interest in the production of bispecific monoclonal antibodies that can simultaneously bind two distinct targets or epitopes to achieve novel mechanisms of action and efficacy. Regeneron's bispecific technology, based upon a standard IgG, consists of a heterodimer of two different heavy chains, and a common light chain. Coexpression of two heavy chains leads to the formation of two parental IgG impurities, the removal of which is facilitated by a dipeptide substitution in the Fc portion of one of the heavy chains that ablates Fc Protein A binding. Therefore, the affinity capture (Protein A) step of the purification process must perform both bulk capture and high resolution of these mAb impurities, a task current commercially available resins are not designed for. Resolution can be further impaired by the ability of Protein A to bind some antibodies in the variable region of the heavy chain (VH). This article details development of a novel Protein A resin. This resin combines an alkali stable ligand with a base matrix exhibiting excellent mass transfer properties to allow high capacity single step capture and resolution of bispecific antibodies (bsAbs) with high yields. The developed resin, named MabSelect SuRe™ pcc, is implemented in GMP production processes for several bsAbs. © 2018 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 34:650–658, 2018
Selective extraction of lipase and amylase from enzyme mixture by employing liquid emulsion membrane
Authors: Priyanka B.S. , Rastogi Navin K.
Published: February 2018

This work deals with the extraction of lipase and amylase from enzyme mixture by employing liquid emulsion membranes (LEM). The electrostatic interaction between enzymes and reverse micellar surfactant polar head group plays an important role for selective extraction of two different enzymes having different isoelectric points. The optimized conditions for lipase extraction (pH 7.0) resulted in the purification fold and activity recovery of 5.43 fold and 89.53%, respectively, whereas, in case of amylase (pH 9.0) the purification fold and activity recovery were 6.58 and 94.32%, respectively. The results were compared with the control sample (containing individual enzymes) and mixture of enzymes lipase and amylase and it was shown that for optimum conditions the activity recovery and purification fold was higher for the individual enzymes as compared to their mixture. Downstream processing involving LEM was shown to be a feasible method for selective extraction of enzymes. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:721–729, 2018
Near‐Infrared Light‐Controlled Gene Expression and Protein Targeting in Neurons and Non‐neuronal Cells
Authors: Redchuk Taras A. , Karasev Maksim M. , Omelina Evgeniya S. , Verkhusha Vladislav V.
Published: February 2018

Near‐infrared (NIR) light‐inducible binding of bacterial phytochrome BphP1 to its engineered partner, QPAS1, is used for optical protein regulation in mammalian cells. However, there are no data on the application of the BphP1–QPAS1 pair in cells derived from various mammalian tissues. Here, we tested the functionality of two BphP1–QPAS1‐based optogenetic tools—an NIR‐ and blue‐light‐sensing system for control of protein localization (iRIS) and an NIR light‐sensing system for transcription activation (TA)—in several cell types, including cortical neurons. We found that the performance of these optogenetic tools often relied on physiological properties of a specific cell type, such as nuclear transport, which could limit the applicability of the blue‐light‐sensitive component of iRIS. In contrast, the NIR‐light‐sensing component of iRIS performed well in all tested cell types. The TA system showed the best performance in cervical cancer (HeLa), bone cancer (U‐2 OS), and human embryonic kidney (HEK‐293) cells. The small size of the QPAS1 component allowed the design of adeno‐associated virus (AAV) particles, which were applied to deliver the TA system to neurons.
Targeted Delivery of an Activatable Fluorescent Probe for the Detection of Furin Activity in Living Cells
Authors: Zhao Xueyu , Lv Gaochao , Peng Ying , Liu Qingzhu , Li Xi , Wang Shanshan , Li Ke , Qiu Ling , Lin Jianguo
Published: February 2018

Furin, a protein convertase, plays a crucial role in the progression of tumors. In this work, a new fluorescent probe consisting of a peptide, Arg‐Val‐Arg‐Arg (RVRR), and an aminoluciferin fluorophore was designed and prepared for the responsive and activatable detection of furin activity in vitro and in living cells. We demonstrated that this probe could be responsive toward furin with an “off–on” florescence signal and generated an approximately 3.58‐fold enhancement in the fluorescence intensity in vitro. Fluorescence imaging in MDA‐MB‐468 and LoVo cells showed that the probe could be cleaved by overexpressed furin with fluorescence turn‐on in MDA‐MB‐468 cells, and this probe was also found to be capable of discriminating between furin‐overexpressing and furin‐deficient cell lines. Our research indicates that this probe has great potential for the detection of furin activity in living cells.
Comparative analysis of lipid‐mediated CRISPR‐Cas9 genome editing techniques
Authors: Ringer Kelsey P. , Roth Mark G. , Garey Mitchell S. , Piorczynski Ted B. , Suli Arminda , Hansen Jason M. , Alder Jonathan K.
Published: February 2018

CRISPR‐Cas technology has revolutionized genome engineering. While Cas9 was not the first programmable endonuclease identified, its simplicity of use has driven widespread adoption in a short period of time. While CRISPR‐Cas genome editing holds enormous potential for clinical applications, its use in laboratory settings for genotype‐phenotype studies and genome‐wide screens has led to breakthroughs in the understanding of many molecular pathways. Numerous protocols have been described for introducing CRISPR‐Cas components into cells, and here we sought to simplify and optimize a protocol for genome editing using readily available and inexpensive tools. We compared plasmid, ribonucleoprotein (RNP), and RNA transfection to determine which was method was most optimal for editing cells in a laboratory setting. We limited our comparison to lipofection‐mediated introduction because the reagents are widely available. To facilitate optimization, we developed a novel reporter assay to measure gene disruption and the introduction of a variety of exogenous DNA tags. Each method efficiently disrupted endogenous genes and was able to stimulate the introduction of foreign DNA at specific sites, albeit to varying efficiencies. RNP transfection produced the highest level of gene disruption and was the most rapid and efficient method overall. Finally, we show that very short homology arms of 30 base pairs can mediate site‐specific editing. The methods described here should broaden the accessibility of RNP‐mediated lipofection for laboratory genome‐editing experiments.
Effect of a gene for high dough strength on whole wheat baking parameters of hard white spring wheat
Authors: Sherman Jamie D. , Varella Andrea C. , Lanning Susan P. , Martin John M. , Heo Hwa‐Young , Nash Deanna , Blake Nancy K. , Cook Jason P. , Talbert Luther E.
Published: February 2018

Background and objectives

Whole wheat flour has weaker mixing properties and produces bread with smaller loaf volume than bread made from white flour. The objective of this research was to test the effect of an allele for increased dough strength on the quality of bread made from whole wheat flour.

Findings

An allele for increased strength at the Gli‐B1 locus was introduced by backcrossing into four hard white spring wheat backgrounds. Whole wheat flour was used for a mill and bake analysis with near‐isogenic lines containing alternative alleles at Gli‐B1 grown in dryland and irrigated environments. The allele for strong gluten did not impact flour protein. However, the strong gluten allele resulted in increased dough strength and greater loaf volume in near‐isogenic lines from different genetic backgrounds and under multiple environments.

Conclusions

The allele for strong gluten at Gli‐B1 may be useful to improve the end‐use quality of hard white wheat for the purpose of making whole wheat leavened bread.

Significance and Novelty

Introgression of specific genes for gluten proteins may positively impact baking quality of whole wheat.
Reaching Highly Stable Specific Capacity with Integrated 0.6Li2MnO3 : 0.4LiNi0.6Co0.2Mn0.2O2 Cathode Materials
Authors: Penki Tirupathi Rao , Nayak Prasant Kumar , Levi Elena , Grinblat Judith , Elias Yuval , Luski Shalom , Markovsky Boris , Aurbach Doron
Published: February 2018

The work described herein was performed to find guidelines for the optimal selection of high‐specific‐capacity cathode materials for Li‐ion batteries. In this study, we compared the electrochemical behavior of three cathode materials working over wide potential domains in Li cells: Li1.2Ni0.24Co0.08Mn0.48O2 (0.6Li2MnO3 : 0.4LiNi0.6Co0.2Mn0.2O2), Li1.2Ni0.16Co0.08Mn0.56O2 (0.6Li2MnO3 : 0.4LiNi0.4Co0.2Mn0.4O2), and LiNi0.6Co0.2Mn0.2O2 (as a reference material). The first two compositions are Li‐ and Mn‐rich cathode materials that contain Li2MnO3 and LiNixCo1‐x‐yMnyO2 components, as established by structural analysis using X‐ray and electron diffraction. The main focus was the possibility to obtain a stable capacity and average voltage while working over a wide potential domain, in order to extract high specific capacity. The three materials were prepared through the self‐combustion reaction and were characterized by using SEM, ICP, HRTEM, and electrochemical techniques. Li1.2Ni0.24Co0.08Mn0.48O2 cathodes operating over the potential range 2.0–4.6 V vs. Li demonstrated stable specific capacities greater than 200 mAh g−1 and stable average voltages, thus rivaling LiNi0.6Co0.2Mn0.2O2 and Li1.2Ni0.16Co0.08Mn0.56O2 cathodes in terms of electrochemical performance. The consequences of these findings are discussed herein. Li‐ and Mn‐rich cathode materials may be advantageous compared to Ni‐rich cathode materials in terms of cost and safety.
Nitrogen and Phosphorus Co‐doped Hollow Carbon Spheres as Efficient Metal‐Free Electrocatalysts for the Oxygen Reduction Reaction
Authors: Zhang Chunmei , Hou Lin , Cheng Chunfeng , Zhuang Zhihua , Zheng Fuqin , Chen Wei
Published: February 2018

Replacement of rare‐ and noble‐metal catalysts with earth‐abundant, low‐cost, stable, and efficient metal‐free catalyst substitutes is highly desirable, but full of challenges for the oxygen reduction reaction (ORR). Herein, N, P co‐doped hollow carbon spheres (N,P‐HCS) are prepared through a simple pyrolysis method, using hollow carbon spheres (HCS), melamine, and phytic acid (PA) as the C, N, and P sources, respectively. Compared to the N‐doped HCS (N‐HCS) and P‐doped HCS (P‐HCS), the N, P co‐doped sample exhibited much higher ORR catalytic activity. Moreover, in comparison with commercial Pt/C, the as‐prepared N,P‐HCS showed comparable ORR activity, but stronger endurance to methanol and higher durability in alkaline solution. The high performance of N,P‐HCS can be primarily ascribed to the large surface area, high conductivity, porous carbon structure, and high content of heteroatoms (N and P). Considering the excellent catalytic activity and durability, after further structural optimization, N,P‐HCS could be a promising metal‐free catalyst candidate for the ORR in fuel cells.
Synergistic Hematite–Fullerene Electron‐Extracting Layers for Improved Efficiency and Stability in Perovskite Solar Cells
Authors: Hou Qinzhi , Ren Jing , Chen Haijun , Yang Pan , Shao Qian , Zhao Min , Zhao Xiaochong , He Hongcai , Wang Ning , Luo Qiang , Guo Zhanhu
Published: February 2018

The front cover artwork is provided by Prof. Zhanhu Guo from the University of Tennessee, Knoxville (USA) and Profs. Ning Wang and Qiang Luo from the University of Electronic Science and Technology of China. The image shows that inorganic hematite can synergistically work with organic fullerene as an electron‐extracting material for efficient and stable heterojunction perovskite solar cells. Read the full text of the Communication at 10.1002/celc.201701054.
Recent Advances in the Cycloisomerizations of Methylenecyclopropanes using Gold Catalysis
Authors: Fang Wei , Shi Min
Published: February 2018

During the past decades, cycloisomerizations of methylenecyclopropanes using gold catalysis have attracted much attention from organic chemists. The different patterns of gold(I)‐catalyzed cycloisomerizations of methylenecyclopropanes have been developed, and they can be classified as ring‐opening and ring‐expansion reaction patterns. This synthetic methodology provides a new approach to novel cyclic‐ or polycyclic compounds. The corresponding products have great potential for material science, medicinal chemistry and total synthesis. This Concept article will mainly focus on the recent advances in the cycloisomerizations of methylenecyclopropanes in the past four years.
Constrained Chemical Dynamics of CO Dissociation/Hydrogenation on Rh Surfaces
Authors: Kraus Peter , Frank Irmgard
Published: February 2018

Among noble metal catalysts, rhodium (Rh) is unique in its ability to perform a one‐step synthesis of ethanol from syngas. The first steps following the adsorption of syngas on Rh surfaces are assumed to be responsible for the conversion of CO and the selectivity effects between C1, C2, and oxygenated species. In the current work, constrained ab initio molecular dynamics are applied to investigate the kinetics of CO dissociation and hydrogenation over flat and stepped Rh surfaces. The obtained barriers for the Rh(111) surface are in good agreement with the literature data. On the stepped Rh(211) surface, a large site‐dependent variation in barrier height is shown, with the upper terrace exhibiting behavior comparable to the Rh(111) surface, whereas the barriers over the lower terrace site are generally significantly lower. The rate constants are calculated using transition state theory for both surfaces, and are applied successfully in a microkinetic model, confirming the predicted impact on CO conversion and CH4/C1‐oxygenate/C2Hn selectivity. In addition to the high‐accuracy energetics and rate constants reported for CO dissociation/hydrogenation and the presentation of an updated microkinetic mechanism for Rh catalysts, the applicability of constrained molecular dynamics for reaction barrier calculation is confirmed, and sensitive pathways affecting the selectivity between formaldehyde/methanol over Rh catalysts are highlighted.
Organoactinide‐Catalyzed Monohydroboration of Carbodiimides
Authors: Liu Heng , Kulbitski Kseniya , Tamm Matthias , Eisen Moris S.
Published: February 2018

The organoactinide‐catalyzed monohydroboration of carbodiimides is reported herein. The catalytic reactions proceed under very mild conditions in a highly atom‐efficient and highly selective fashion to afford the corresponding monohydroborated N‐borylformamidine products in high yields. A plausible mechanism is proposed based on stoichiometric and kinetic studies.
Chemoselective Glycosylation of Peptides through S‐Alkylation Reaction
Authors: Calce Enrica , Digilio Giuseppe , Menchise Valeria , Saviano Michele , De Luca Stefania
Published: February 2018

An efficient and rapid procedure for synthesizing S‐linked glycopeptides is reported. The approach uses activated molecular sieves as a base to promote the selective S‐alkylation of readily prepared cysteine‐containing peptides, upon reaction of appropriate glycosyl halides. Considering the very mild conditions employed, the chemoselective linkage of the electrophilic sugar with a peptide sulfhydryl group occurred in satisfactory yield, allowing the incorporation of mono and disaccharide moieties. The sugar–peptide conjugates obtained from α‐d‐glycosyl derivatives adopt a β‐S‐configuration, indicating the high stereoselectivity of the substitution reaction.