bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractMittels 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

AbstractDer 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

AbstractEin 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

AbstractSecondary 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

AbstractSafe 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

AbstractVisible‐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

AbstractThe 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

Abstractm6A 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

ABSTRACTMammalian 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

AbstractIn 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

AbstractRapid 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

AbstractModeling 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

AbstractExtensive 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.
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

AbstractNear‐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

AbstractFurin, 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

AbstractCRISPR‐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 objectivesWhole 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.FindingsAn 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.ConclusionsThe 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 NoveltyIntrogression of specific genes for gluten proteins may positively impact baking quality of whole wheat.