bluuebunny/crossref_metadata_2025 huggingface dataset:
Modellsystem Honigbiene
Authors: Reiter Christian , Kühn Ralph , Nerdel Claudia
Published: June 2019

Im Kontext Honigbiene lässt sich eine nahezu unüberschaubare Bandbreite an Fragestellungen aus unterschiedlichen Perspektiven synergistisch vereinen. Für die Lehre an Schule und Hochschule im Fach Biologie eröffnet das Modellsystem Honigbiene damit einen inhaltlichen Rahmen zur Vernetzung fachlicher Inhalte sowie zur Abstimmung fachlicher, fachdidaktischer, erziehungswissenschaftlicher und schulpraktischer Aspekte und damit zur horizontalen und vertikalen Verknüpfung der Betrachtungsebenen. Im Beitrag werden vier Schülerforschungsprojekte mit dem Modellorganismus Honigbiene aus unterschiedlichen Themenbereichen der Biologie jeweils mit Fokus auf die Bearbeitung authentischer Forschungsfragen vorgestellt.
Das ungewöhnliche Plastidengenom von Balanophora
Authors: Sander Johannes
Published: June 2019

Parasiten weisen oft viele Anpassungen auf, die ihrer spezielle Lebensweise geschuldet sind. Besonders interessant sind aber die Sonderlinge unter den Sonderlingen. Beispiele hierfür sind die Plastidengenome zweier Balanophora‐Pflanzen, die sich durch die Kombination von zahlreichen ungewöhnlichen Eigenschaften von den Plastidengenomen anderer parasitischer Blütenpflanzen abheben.
Das Mendelianum des Mährischen Landesmuseums in Brünn, Tschechien
Authors: Simunek Michal V. , Sekerak Jiri
Published: June 2019

Authentische Räume in Verbindung mit zeitgenössischen Objekten und einem höchstmodernen Labor bietet die neue Daueraustellung zur Geschichte der Genetik des Mendelianums des Mährischen Landesmuseums in Brünn (Tschechien) an. Es ist ein Ort der interaktiven Informationsvermittlung zur Geschichte sowie zum aktuellen Stand einer der wichtigsten biologischen Disziplinen unserer Gegenwart.
Aminotenuazonic Acid: Isolation, Structure Elucidation, Total Synthesis and Herbicidal Activity of a New Tetramic Acid from Fruiting Bodies of Laccaria Species
Authors: Schrey Hedda , Backenköhler Jana , Kogler Herbert , Plaumann Markus , Spiteller Peter
Published: June 2019

(5S,6S)‐Aminotenuazonic acid, a new 3‐acyltetramic acid, related to the well‐known mycotoxin tenuazonic acid has been isolated from fruiting bodies of Laccaria bicolor. Its structure was mostly established by analysis of its 2D NMR and HR‐(+)‐ESI‐MS spectra. A total synthesis starting from N‐Boc‐l‐isoleucine gave (5S,6S)‐aminotenuazonic acid in 8 % yield over nine steps (67 % de). The key steps of the total synthesis are a light‐initiated Hofmann–Löffler–Freytag radical chain reaction and a Dieckmann cyclisation. The relative and absolute configurations of the natural product were determined by comparison of its NMR and CD spectra with those of the corresponding enantiopure synthetic compounds. Metabolic profiling of crude extracts of different mushrooms showed that aminotenuazonic acid is present in all four of the investigated Laccaria species. Aminotenuazonic acid shows phytotoxic activities against the root and shoot growth of Lepidium sativum, Pinus sylvestris and Arabidopsis thaliana comparable to those of tenuazonic acid.
Photoinitiated Charge Transfer in a Triangular Silver(I) Hydride Complex and Its Oxophilicity
Authors: Kruppa Sebastian V. , Groß Cedric , Gui Xin , Bäppler Florian , Kwasigroch Björn , Sun Yu , Diller Rolf , Klopper Wim , Niedner‐Schatteburg Gereon , Riehn Christoph , Thiel Werner R.
Published: June 2019

The photoexcitation of a triangular silver(I) hydride complex, [Ag3(μ3‐H)(μ2‐dcpm)3](PF6)2 ([P](PF6)2, dcpm=bis(dicyclohexylphosphino)methane), designed with “UV‐silent” bis‐phosphine ligands, provokes hydride‐to‐Ag3 single and double electron transfer. The nature of the electronic transitions has been authenticated by absorption and photodissociation spectroscopy in parallel with high‐level quantum‐chemical computations utilizing the GW method and Bethe–Salpeter equation (GW‐BSE). Specific photofragments of mass‐selected [P]2+ ions testify to charge transfer and competing pathways resulting from the unique [Ag3(μ3‐H)]2+ scaffold. This structural motif of [P](PF6)2 has been unequivocally verified by 1H NMR spectroscopy in concert with DFT and X‐ray diffraction structural analysis, which revealed short equilateral Ag–Ag distances (dAgAg=3.08 Å) within the range of argentophilic interactions. The reduced radical cation [P].+ exhibits strong oxophilicity, forming [P+O2].+,which is a model intermediate for silver oxidation catalysis.
An Electron‐Rich Helical Host for the Exclusive Removal of a Planar Electron‐Deficient Organic Compound
Authors: Kumar Rajesh , Aggarwal Himanshu , Bhowal Rohit , Chopra Deepak , Srivastava Aasheesh
Published: June 2019

In this study, a series of electron‐rich helical hosts, viz. Pyr‐HAC, Anth‐HAC and Ben‐HAC, containing pyrene, anthracene and benzene residues, respectively, at their periphery, were screened for their interaction with different planar electron‐deficient organic guests (PEDOGs). A strong and highly selective charge‐transfer interactions (CTI) was observed between the host Pyr‐HAC and the guest 1,2,4,5‐tetracyano‐benzene (TCNB), leading to a yellow‐to‐bright‐red color change in both the solubilized and the solid state. The interaction between Pyr‐HAC and TCNB also induced profound structural and morphological changes. Pyr‐HAC self‐assembled into belt‐like morphology created by homochiral stacking of the host molecules, but in the Pyr‐HAC⊃TCNB complex, square bipyramids containing intertwined heterochiral C2‐double helices of Pyr‐HAC were observed. Other PEDOGs did not induce any of the above changes in Pyr‐HAC. Detailed UV/Vis absorption and fluorescence spectroscopy, NMR, and X‐ray diffraction studies confirmed this selectivity, which arises due to CTI assisted by complementary, directional intermolecular hydrogen bonding (DIHB) between Pyr‐HAC and TCNB. This allowed for the exclusive extraction of TCNB from a solution enriched in other PEDOGs. Thus, this study provides a ground work for designing responsive helical hosts towards CTI‐driven selective “catch‐and‐release” of guests.
Structure–Affinity Relationships of Fluorinated Spirocyclic σ2 Receptor Ligands with an Exocyclic Benzylamino Moiety
Authors: Bergkemper Melanie , Kronenberg Elisabeth , Schepmann Dirk , Ludwig Friedrich‐Alexander , Brust Peter , Wünsch Bernhard
Published: June 2019

To identify a potent and selective σ2 receptor ligand appropriate for development as a positron emission tomography (PET) tracer, several fluorinated analogues of the spirocyclic lead compounds trans‐ and cis‐6 (N‐(2,4‐dimethylbenzyl)‐3‐methoxy‐3,4‐dihydrospiro[[2]benzopyran‐1,1′‐cyclohexan]‐4′‐amine) were designed. In multistep syntheses, a fluorine atom was introduced directly or as a 2‐fluoroethoxy moiety on the 2‐benzopyran scaffold, on the dimethylbenzylamino moiety, or on the central amino moiety. The σ1 and σ2 receptor affinity was determined in receptor binding studies with radioligands. With respect to σ2 affinity and σ2/σ1 selectivity, cis‐N‐(2,4‐dimethylbenzyl)‐5‐fluoro‐3‐methoxy‐3,4‐dihydrospiro[[2]benzopyran‐1,1′‐cyclohexan]‐4′‐amine (cis‐15 c, Ki(σ2)=51 nm) and cis‐N‐[4‐(fluoromethyl)‐2‐methylbenzyl]‐3‐methoxy‐3,4‐dihydrospiro[[2]benzopyran‐1,1′‐cyclohexan]‐4′‐amine (cis‐28 e, Ki(σ2)=57 nm) are the most promising ligands. The combination of both structural elements in one molecule, cis‐N‐[4‐(fluoromethyl)‐2‐methylbenzyl]‐5‐fluoro‐3‐methoxy‐3,4‐dihydrospiro[[2]benzopyran‐1,1′‐cyclohexan]‐4′‐amine (cis‐28 c: Ki(σ2)=874 nm), resulted in decreased σ2 and σ1 affinity. Methylation of secondary amines led to three tertiary methylamines with moderate affinity for both σ receptor subtypes.
Physiology of Electrolyte Transport in the Gut: Implications for Disease
Authors: Rao Mrinalini C.
Published: June 2019

We now have an increased understanding of the genetics, cell biology, and physiology of electrolyte transport processes in the mammalian intestine, due to the availability of sophisticated methodologies ranging from genome wide association studies to CRISPR‐CAS technology, stem cell‐derived organoids, 3D microscopy, electron cryomicroscopy, single cell RNA sequencing, transgenic methodologies, and tools to manipulate cellular processes at a molecular level. This knowledge has simultaneously underscored the complexity of biological systems and the interdependence of multiple regulatory systems. In addition to the plethora of mammalian neurohumoral factors and their cross talk, advances in pyrosequencing and metagenomic analyses have highlighted the relevance of the microbiome to intestinal regulation. This article provides an overview of our current understanding of electrolyte transport processes in the small and large intestine, their regulation in health and how dysregulation at multiple levels can result in disease. Intestinal electrolyte transport is a balance of ion secretory and ion absorptive processes, all exquisitely dependent on the basolateral Na+/K+ATPase; when this balance goes awry, it can result in diarrhea or in constipation. The key transporters involved in secretion are the apical membrane Cl−channels and the basolateral Na+‐K+‐2Cl−cotransporter, NKCC1 and K+channels. Absorption chiefly involves apical membrane Na+/H+exchangers and Cl−/HCO3−exchangers in the small intestine and proximal colon and Na+channels in the distal colon. Key examples of our current understanding of infectious, inflammatory, and genetic diarrheal diseases and of constipation are provided. © 2019 American Physiological Society.Compr Physiol9:947‐1023, 2019.
CO2‐Tonnagen und Wärmespeichereffekte über den Lebenszyklus von Gebäuden
Authors: Pohl Sebastian , Schöttner Robin
Published: June 2019

The study outlined in this article was intended to quantify the lifecycle assessment effects resulting from the different thermal storage capacities of the market‐relevant construction methods masonry, reinforced concrete and timber frame. Independently reviewed and verified life cycle assessments of representative model homes were the starting point of this study. But the findings of available computer simulations concerning the thermal behaviour of the model homes suggest that different thermal storage capacities of construction materials induce significant deviations of the heating demand, which should also precipitate significant lifecycle assessment differences – because the overall lifecycle assessment results of a building are generally substantially determined by the energy demand during its use phase.
Setting expected timelines of fished population recovery for the adaptive management of a marine protected area network
Authors: Kaplan Katherine A. , Yamane Lauren , Botsford Louis W. , Baskett Marissa L. , Hastings Alan , Worden Sara , White J. Wilson
Published: June 2019

Adaptive management of marine protected areas (MPAs) requires developing methods to evaluate whether monitoring data indicate that they are performing as expected. Modeling the expected responses of targeted species to an MPA network, with a clear timeline for those expectations, can aid in the development of a monitoring program that efficiently evaluates expectations over appropriate time frames. Here, we describe the expected trajectories in abundance and biomass following MPA implementation for populations of 19 nearshore fishery species in California. To capture the process of filling in the age structure truncated by fishing, we used age‐structured population models with stochastic larval recruitment to predict responses to MPA implementation. We implemented both demographically open (high larval immigration) and closed (high self‐recruitment) populations to model the range of possible trajectories as they depend on recruitment dynamics. From these simulations, we quantified the time scales over which anticipated increases in abundance and biomass inside MPAs would become statistically detectable. Predicted population biomass responses range from little change, for species with low fishing rates, to increasing by a factor of nearly seven, for species with high fishing rates before MPA establishment. Increases in biomass following MPA implementation are usually greater in both magnitude and statistical detectability than increases in abundance. For most species, increases in abundance would not begin to become detectable for at least 10 years after implementation. Overall, these results inform potential indicator metrics (biomass), potential indicator species (those with a high fishing : natural mortality ratio), and time frame (>10 yr) for MPA monitoring assessment as part of the adaptive management process.
Refinement of eDNA as an early monitoring tool at the landscape‐level: study design considerations
Authors: Mize E. L. , Erickson R. A. , Merkes C. M. , Berndt N. , Bockrath K. , Credico J. , Grueneis N. , Merry J. , Mosel K. , Tuttle‐Lau M. , Von Ruden K. , Woiak Z. , Amberg J. J. , Baerwaldt K. , Finney S. , Monroe E.
Published: June 2019

Natural resource managers use data on the spatial range of species to guide management decisions. These data come from survey or monitoring efforts that use a wide variety of tools. Environmental DNA (eDNA) is a surveillance tool that uses genetic markers for detecting species and holds potential as a tool for large‐scale monitoring programs. Two challenges of eDNA‐based studies are uncertainties created by imperfect capture of eDNA in collection samples (e.g., water field samples) and imperfect detection of eDNA using molecular methods (e.g., quantitative PCR). Occurrence models can be used to address these challenges, thus we use an occurrence model to address two objectives: first, to determine how many samples were required to detect species using eDNA; second, to examine when and where to take samples. We collected water samples from three different habitat types in the Upper Mississippi River when both Bighead Carp and Silver Carp were known to be present based on telemetry detections. Each habitat type (backwater, tributary, and impoundment) was sampled during April, May, and November. Detections of eDNA for both species varied across sites and months, but were generally low, 0–19.3% of samples were positive for eDNA. Overall, we found that eDNA‐based sampling holds promise to be a powerful monitoring tool for resource managers; however, limitations of eDNA‐based sampling include different biological and ecological characteristics of target species such as seasonal habitat usage patterns as well as aspects of different physical environments that impact the implementation of these methods such as water temperature.
Ultraconserved element (UCE) probe set design: Base genome and initial design parameters critical for optimization
Authors: Gustafson Grey T. , Alexander Alana , Sproul John S. , Pflug James M. , Maddison David R. , Short Andrew E. Z.
Published: June 2019

Targeted capture and enrichment approaches have proven effective for phylogenetic study. Ultraconserved elements (UCEs) in particular have exhibited great utility for phylogenomic analyses, with the software package phyluce being among the most utilized pipelines for UCE phylogenomics, including probe design. Despite the success of UCEs, it is becoming increasing apparent that diverse lineages require probe sets tailored to focal taxa in order to improve locus recovery. However, factors affecting probe design and methods for optimizing probe sets to focal taxa remain underexplored. Here, we use newly available beetle (Coleoptera) genomic resources to investigate factors affecting UCE probe set design using phyluce. In particular, we explore the effects of stringency during initial design steps, as well as base genome choice on resulting probe sets and locus recovery. We found that both base genome choice and initial bait design stringency parameters greatly alter the number of resultant probes included in final probe sets and strongly affect the number of loci detected and recovered during in silico testing of these probe sets. In addition, we identify attributes of base genomes that correlated with high performance in probe design. Ultimately, we provide a recommended workflow for using Phyluce to design an optimized UCE probe set that will work across a targeted lineage, and use our findings to develop a new, open‐source UCE probe set for beetles of the suborder Adephaga.
Quantifying carbon and species dynamics under different fire regimes in a southeastern U.S. pineland
Authors: Flanagan Steven A. , Bhotika Smriti , Hawley Christie , Starr Gregory , Wiesner Susanne , Hiers J. Kevin , O'Brien Joseph J. , Goodrick Scott , Callaham Mac A. , Scheller Robert M. , Klepzig Kier D. , Taylor R. Scott , Loudermilk E. Louise
Published: June 2019

Forests have a prominent role in carbon sequestration and storage. Climate change and anthropogenic forcing have altered the dominant characteristics of some forested ecosystems through changes to their disturbance regimes, particularly fire. Ecosystems that historically burned frequently, like pinelands in the southeastern United States, risk changes in their structure and function when the fire regime they require is altered. Although the carbon storage potential in an unburned southeastern U.S. forest would be larger, this scenario is unrealistic due to the likelihood of wildfire. Additionally, fire exclusion can have negative consequences on these forests health, biodiversity, and species endemism. There is a need, specifically for the southeast, to estimate carbon and species dynamics based on the differences between various fire regimes, and particularly the differences between prescribed fire and wildfire. These are important factors to consider given that prescribed fire is a common tool used in the southeast, and wildfires are ever more present. Field data from an experimentalPinus palustris(longleaf pine) forest of southwest Georgia were used to parametrize the forest landscape modelLANDIS‐II. The model simulated how carbon and species dynamics differ under a fire exclusion, a prescribed fire, and multiple wildfire scenarios. All scenarios except fire exclusion resulted in net emissions to the atmosphere, but prescribed fire produced the least carbon emissions from fire and maintained the most stable aboveground biomass compared to wildfire scenarios. Removing fire for approximately a century was necessary to obtain an average stand‐level biomass greater than that of prescribed fire and net emissions less than that of prescribed fire. The prescribed fire scenario produced a longleaf pine‐dominated forest, the exclusion scenario converted to predominantly oak speciesQuercus virginiana(live oak),Q. stellata(post oak), andQ. margaretta(sand post oak), while scenarios with intermediate wildfire regimes supported a mix of other fire‐facilitator hardwoods and pine species, such asQ. incana(bluejack oak) andPinus elliotti(slash pine). Overall, this study supports prescribed fire regimes in southeastern U.S. pinelands to both minimize carbon emissions and preserve native biodiversity.
Pyridylbenzimidazole‐Based Gold(III) Complexes: Lysozyme Metalation, DNA Binding Studies, and Biological Activity
Authors: Mansour Ahmed M. , Shehab Ola R.
Published: June 2019

The lysozyme binding affinity of new Au(III) complexes, bearing pyridylbenzimidazole ligands, was investigated by ESI‐MS and UV/Vis. Metalation of lysozyme happened mainly by {Au}n+, {AuCl}0/n+ and {AuCl2}n+/–. The appendage sulfonate group of pyridylbenzimidazole ligand system played a role in determining the products of interaction of HEWL with Au(III) complexes. The hydrophilic sulfonate group inhibited the ligand cleavage via the participation in several coulombic and H‐bond interactions giving several AuLn+ containing adduct peaks (L = 1‐[(pyridin‐2‐yl) benzimidazole]‐propyl‐sulfonic acid). The stability of the complexes in presence of ascorbic acid was examined by UV/Vis and 13C NMR. To recognize if His15 side‐chain is the metalation site of HEWL, the interactions between the complexes and imidazole, as a simple model of histidine, were investigated by 1H and 13C NMR. The DNA binding studies of the complexes were reported. For this class of Au(III) complexes, it is preferred to decorate the pyridylbenzimidazole system with ethyl group rather than sulfonate and phthalimido group to have a complex with interesting antifungal activity against Candida albicans and Cryptococcus neoformans var. grubii. Au(III) complex, having sulfonate group, is noncytotoxic to non‐malignant cells (human embryonic kidney cells (HEK293)), shows negligible hemoglobin release and is safe to the normal cells if applicable.
The Influence of Active Biomolecules in Plant Extracts on the Performance of Au/TS‐1 Catalysts in Propylene Epoxidation
Authors: Lian Ting , Zeng Wei , Liu Hai , Yu Jing , Huang Jiale , Wang Haitao , Sun Daohua
Published: June 2019

An extract of Cinnamomum camphora (CC) leaves was adopted to prepare a Au/TS‐1 catalyst for vapor‐phase epoxidation of propylene. To explore the relationship between the active components in the extract and the performance of the resulting catalysts, the extract was roughly separated by silica gel column chromatography, and the separated samples were used to obtain a series of Au/TS‐1 catalysts. Carbohydrates, polyphenols, and flavonoids were found to be the main active components involved in the biosynthesis of Au catalysts. The catalyst prepared with flavonoids showed better performance than that prepared with polyphenols or carbohydrates. XPS spectra showed that the catalyst prepared with flavonoids was only loaded with Au0 because flavonoids have the strongest reducing power among the three natural components. XRD and TEM results indicated no obvious size variation of Au NPs after calcination resulting from the presence of –COOH. In addition, the high surface hydrophobicity of the catalyst is helpful in improving its activity toward vapor‐phase epoxidation of propylene. The catalyst was not deactivated by the blocking of its active sites with carbonaceous deposits. The catalyst prepared with polyphenol and flavonoid components demonstrated remarkable stability, because the –COOH in these components tended to prevent Au NPs from agglomerating.
Enhancement of Lipase CAL‐A Selectivity by Protein Engineering for the Hydrolysis of Erucic Acid from Crambe Oil
Authors: Oroz‐Guinea Isabel , Zorn Katja , Bornscheuer Uwe T.
Published: June 2019

The aim of this study is to pursue the identification and characterization of different CAL‐A variants displaying higher specificity toward erucic acid than CAL‐A wild type (wt). A careful analysis of the data generated from previously created site‐directed saturation libraries reveals several variants that display a higher preference for the hydrolysis of p‐nitrophenyl (pNP)‐erucate over pNP‐oleate than the wt. The best three candidates (CAL‐A V238D, V238Y, and V286N) are applied in biocatalysis using both Crambe oil and ethyl ester derivatives. When acting on Crambe oil, these CAL‐A variants are as efficient as CAL‐A wt in terms of C22:1 enrichment and product recovery independently of the temperature (enrichment and recovery values between 70–76% and 67–79% at 37 °C, and between 71–73% and 61–75% at 50 °C). In contrast, hydrolysis of Crambe ethyl esters leads to substantially increased accumulations of C22:1 and recovery values (V238Y: 78% enrichment and 92% recovery; V286N: 83% enrichment and 91% recovery) when using CAL‐A V238Y and CAL‐A V286N compared to CAL‐A wt (78% enrichment, 60% recovery) in the free fatty acid fraction.

Practical Applications: This study describes the enhancement of lipase CAL‐A selectivity for the isolation and recovery of erucic acid (C22:1) from plant oil or its ethyl ester derivatives. Hence, this approach could represent a more eco‐friendly alternative for its application in processes where the erucic acid is used as building block, such as the production of surfactants or polymers.
Mild and Regioselective Bromination of Phenols with TMSBr
Authors: Ma Xiantao , Yu Jing , Jiang Mengyuan , Wang Mengyu , Tang Lin , Wei Mengmeng , Zhou Qiuju
Published: June 2019

In this work, an unexpected promoting effect of by‐product thioether was observed, leading to a mild and regioselective bromination of phenols with TMSBr. This method can tolerate a series of functional groups such as the reactive methoxyl, amide, fluoro, chloro, bromo, aldehyde, ketone and ester groups, and has the potential to recycle the by‐product thioether and isolate the desired product under column chromatography‐free conditions. Mechanism studies revealed that O–H···S hydrogen bond may be formed between phenol and by‐product thioether. Possibly owing to the steric hindrance effect from by‐product thioether, the electrophilic bromination at para‐position of phenols is much favorable.
Diamond Electrodes for High Sensitivity Mercury Detection in the Aquatic Environment: Influence of Surface Preparation and Gold Nanoparticle Activity
Authors: McLaughlin Maeve H. S. , Pakpour‐Tabrizi Alexander C. , Jackman Richard B.
Published: June 2019

This work compares polished and unpolished boron doped diamond (BDD) electrodes decorated with two sizes of gold nanoparticles (AuNPs) for use as robust mercury sensors in aquatic environments. The size of the catalytically active AuNPs on the electrode surfaces was demonstrated to have a less significant effect on the sensitivity for mercury detection than the surface preparation of the BDD. The lowest limits of detection were achieved with the polished BDD electrodes, which both detected mercury at a concentration of 1 pM, six orders of magnitude greater sensitivity than the lowest detection limit of 5 μM achieved with an unpolished BDD electrode, and high in comparison with other reported electrode systems.
The Electrochemical Oxidation of Sulphite on Gold Electrodes
Authors: Cai Xiaosheng , Lin Chuhong , Foord John S. , Compton Richard G.
Published: June 2019

The electro‐oxidation of sulphite is studied in acid media on gold macroelectrodes and Au particle array modified boron doped diamond electrodes. The sulphite oxidation proceeds through a one‐electron transfer process followed by a chemical step of second order (EC2 mechanism), as evidenced by experimental voltammetry and digital simulation for both gold macroelectrodes and gold particle modified substrates. The diffusion coefficient of sulphite is calculated consistently for both cases at about 4×10−9 m2 s−1, with the reverse peak behaviour concentration dependent. The arrays are made by electrodeposition and show a morphological transition from a quasi‐spherical to a star shape as the growth time of the particles increases. Kinetic parameters inferred from the electro‐oxidation at the macroelectrode can be successfully applied to model the gold particle modified electrode data to confirm the EC2 mechanism, whilst recognising the overlapping diffusion layers of adjacent gold particles.
Tuna Consumption, Mercury Exposure, and Knowledge about Mercury Exposure Risk from Tuna Consumption in University Students
Authors: Murata Yasuhiko , Finkelstein Doreen B. , Lamborg Carl H. , Finkelstein Myra E.
Published: June 2019

We examined the relationships among tuna consumption, hair mercury levels, and knowledge of mercury exposure risk from tuna consumption in university students that were offered tuna daily at university-run dining halls. Hair total mercury levels in tuna consumers were higher than those in non-tuna consumers (average = 0.466 µg/g ± 0.328 standard deviation [SD], n = 20 vs 0.110 µg/g ± 0.105 SD, n = 33, respectively; p < 0.0001, Mann–Whitney U test), with tuna eaters exhibiting a positive relationship between self-reported tuna consumption at dining halls and hair mercury levels (R2 = 0.868, p < 0.0001, n = 17, linear regression). For all tuna eaters surveyed, more than half (54%) self-reported eating ≥3 tuna meals/wk, potentially exceeding the US Environmental Protection Agency's reference dose for methylmercury of 0.1 µg/kg body weight/d. Seven percent of study participants reported they consumed >20 tuna meals/wk, which was related to hair mercury levels >1 µg/g, a level of concern. Study participants had an overall lack of knowledge and confidence in their knowledge about mercury exposure risk from tuna consumption, with >99% of participants reporting low knowledge and low confidence in survey answers. Our study highlights the importance of education about the risks of tuna consumption, particularly in institutional settings where individuals have unlimited access to tuna products. Environ Toxicol Chem 2019;38:1988–1994. © 2019 SETAC.

Abstract

University students were served tuna daily at dining hall facilities, and their hair mercury concentrations were positively related to the number of tuna meals eaten/wk. The majority (>99%) of students had a lack of knowledge with respect to mercury exposure risk from tuna consumption.
Coupled Application of Antioxidant Defense Response and Embryo Development in Amphipod Crustaceans in the Assessment of Sediment Toxicity
Authors: Berezina Nadezhda A. , Lehtonen Kari K. , Ahvo Aino
Published: June 2019

Survival rate, frequency of malformed embryos, and antioxidant defense system responses in the benthic amphipod Gmelinoides fasciatus from the Baltic Sea were measured to examine the effects of toxic sediments, and to assess the usefulness of these endpoints in sediment toxicity biotesting. A highly contaminated sediment sample from the Baltic Sea was diluted with sediment from a clean site to come up with a series of 5 test sediments with dilutions from 1:32 to 1:1024, and the reference sediment. The 1:32 dilution of the test sediment was analyzed for organotins (2862 µg tin [Sn] kg dry wt –1), polycyclic aromatic hydrocarbons (6064 µg kg dry wt –1), and selected trace metals (e.g., copper 352 mg kg dry wt –1). The survival rate of G. fasciatus (10-d toxicity test) was 100% in the reference and 1:1024 treatments, and began to decline from the 1:256 dilution onward. In a 28-d experiment, various types of morphological malformations were observed in 11 to 80% of the amphipod embryos in the 1:64, 1:128, and 1:256 dilutions, with only <5% in the reference treatment. Also, elevated activities in the antioxidant defense system enzymes glutathione S-transferase and catalase were observed in amphipods exposed to the contaminated sediments compared with the reference treatment, with responses at lower contamination levels compared with the appearance of malformations in the embryos. The results obtained illustrate the effectiveness of the combined application of embryonic malformations and antioxidant defense system biomarkers in amphipods in the assessment of sediment toxicity, and potentially also of sublethal effects of chemical contamination in aquatic ecosystems. Environ Toxicol Chem 2019;38:2020–2031. © 2019 SETAC.
A rapid method of screening ceramic artefacts to reject unlikely hypotheses of provenance
Authors: Saiano Filippo , Pantani Ottorino‐Luca , Scalenghe Riccardo
Published: June 2019

This study was aimed at testing a cost‐effective method based on comparing the rare earth element patterns in artefacts of known origin with patterns of potential raw materials, thus allowing the restriction/exclusion of working hypotheses on provenance, and consequently a better focus of research funding. The method targets ceramics/materials of terrigenous origin. Lanthanoids and yttrium patterns were determined in 26 wine amphorae that had a well‐established geographical origin from the Nuovo Mercato Testaccio in Rome, and these patterns were compared to plausible terrigenous materials from various ancient Roman regions. The point was not to pinpoint the origins of the material, but rather to rule out possible areas of origin. On both a national and a regional scale, we were able to exclude some regions of origin for these amphorae that would otherwise have been largely plausible. This method does not require sampling from already known kiln/extraction sites. Moreover, if maps of all rare earth elements in soils become available on a regional scale, it could be possible to obtain a level of discriminatory detail in the range of a few tens of kilometres.
Longitudinal associations between white matter maturation and cognitive development across early childhood
Authors: Dai Xiongtao , Hadjipantelis Pantelis , Wang Jane‐Ling , Deoni Sean C. L. , Müller Hans‐Georg
Published: June 2019

From birth to 5 years of age, brain structure matures and evolves alongside emerging cognitive and behavioral abilities. In relating concurrent cognitive functioning and measures of brain structure, a major challenge that has impeded prior investigation of their time‐dynamic relationships is the sparse and irregular nature of most longitudinal neuroimaging data. We demonstrate how this problem can be addressed by applying functional concurrent regression models (FCRMs) to longitudinal cognitive and neuroimaging data. The application of FCRM in neuroimaging is illustrated with longitudinal neuroimaging and cognitive data acquired from a large cohort (n= 210) of healthy children, 2–48 months of age. Quantifying white matter myelination by using myelin water fraction (MWF) as imaging metric derived from MRI scans, application of this methodology reveals an early period (200–500 days) during which whole brain and regional white matter structure, as quantified by MWF, is positively associated with cognitive ability, while we found no such association for whole brain white matter volume. Adjusting for baseline covariates including socioeconomic status as measured by maternal education (SES‐ME), infant feeding practice, gender, and birth weight further reveals an increasing association between SES‐ME and cognitive development with child age. These results shed new light on the emerging patterns of brain and cognitive development, indicating that FCRM provides a useful tool for investigating these evolving relationships.
Omission of temporal nuisance regressors from dual regression can improve accuracy of fMRI functional connectivity maps
Authors: Kelly Robert E. , Hoptman Matthew J. , Alexopoulos George S. , Gunning Faith M. , McKeown Martin J.
Published: June 2019

Functional connectivity (FC) maps from brain fMRI data can be derived with dual regression, a proposed alternative to traditional seed‐based FC (SFC) methods that detect temporal correlation between a predefined region (seed) and other regions in the brain. As with SFC, incorporating nuisance regressors (NR) into the dual regression must be done carefully, to prevent potential bias and insensitivity of FC estimates. Here, we explore the potentially untoward effects on dual regression that may occur when NR correlate highly with the signal of interest, using both synthetic and real fMRI data to elucidate mechanisms responsible for loss of accuracy in FC maps. Our tests suggest significantly improved accuracy in FC maps derived with dual regression when highly correlated temporal NR were omitted. Single‐map dual regression, a simplified form of dual regression that uses neither spatial nor temporal NR, offers a viable alternative whose FC maps may be more easily interpreted, and in some cases be more accurate than those derived with standard dual regression.
Short Syntheses of some ‘Decalin‐1,8‐diones’ and their Derivatives: Breaking the Pretended Symmetry
Authors: Knorr Rudolf , Nadolny Annette , Hauer Hermann , Böhrer Petra
Published: June 2019

A cheap synthesis of the so‐called ‘decalin‐1,8‐diones’ started with the conjugate (1,4‐) addition of cyclohex‐2‐en‐1‐one derivatives to the γ‐position of the dilithium derivative (buta‐1,3‐diene‐1,1‐bis(olate)) of crotonic acid. Hydrogenation of these ‘1,4‐γ’ adducts and final cyclization afforded the enol tautomers of decalin‐1,8‐diones. Nucleophilic substitutions at these 3‐oxoenols by NH3 or primary amines created only monoamino products (namely, 3‐oxoenamines) whose reactions with OPCl3 yielded dihydro(1,3,2)oxazaphosphinin‐2‐one derivatives. The two regioisomers of a trimethyl‐3‐oxoenamine served as models for the constitutional assignments of the two rapidly interconverting (hence, individually NMR‐invisible), tautomeric trimethyl‐3‐oxoenols. Such methyl substitutions served to break the ‘pretended’ symmetry of ‘decalin‐1,8‐dione’. Hydrazine and 3‐oxoenols furnished oxygen‐free indazole derivatives whose N−H bonds exchanged with t1/2=ca. 0.00035 s at ca. −58(9) °C.
Liquid biopsy in non‐Hodgkin's lymphoma
Authors: Melani Christopher , Wilson Wyndham H. , Roschewski Mark
Published: June 2019

ctDNA provides an important new strategy that will aid in the treatment of non‐Hodgkin's lymphoma. Immunoglobulin sequencing provides a tumor specific marker for disease activity with a sensitivity equivalent to one tumor cell per 10‐6. Furthermore, it can provide an estimate of tumor bulk and tumor response dynamics during treatment. Interim monitoring can identify patients at high risk of treatment failure and surveillance monitoring can identify patients months before radiographic disease progression. Tumor specific mutations can also be detected in ctDNA and may reflect an averaging of mutations present within multiple tumor masses. Such analysis may aid in the molecular characterization of tumors and selection of targeted treatments for precision medicine.
Treating Hodgkin lymphoma in the new millennium: Relapsed and refractory disease
Authors: LaCasce Ann S.
Published: June 2019

Although the majority of patients with Hodgkin lymphoma are cured with initial therapy, 10% to 15% of patients with early stage disease and 15% to 30% of patients with advanced disease have primary refractory or relapsed lymphoma. For younger patients whose disease is sensitive to second‐line therapy, more than half of patients will experience long‐term disease control with high‐dose chemotherapy/autologous stem cell rescue (ASCT). For those patients who are chemotherapy refractory, relapse after, or are ineligible for ASCT, brentuximab vedotin, and checkpoint, inhibitors are highly active, although the majority of patients will ultimately experience recurrent lymphoma. Allogeneic transplant is curative in a subset of patients but may be associated with significant toxicity. Novel targeted and immunotherapy approaches, including chimeric antigen receptor T‐cell therapy, are currently being studied in clinical trials with promising early results.
Self‐Assembly of Multiblock Copolymers
Authors: Qiang Xiaolian , Chakroun Ramzi , Janoszka Nicole , Gröschel André H.
Published: June 2019

Block copolymers (BCPs) are a subclass of soft matter extensively used in materials science and nanomedicine. They consist of two or more incompatible segments and are prone to self‐assemble into nanostructures with a characteristic size of 10–100 nm. BCPs thus naturally address the structural dimension between molecular and colloidal scales. This review gives a brief overview of recent developments in BCP self‐assembly under various conditions. Special emphasis is put on linear BCPs with three or more sequentially linked blocks, i. e. ABC triblock terpolymers, ABAC tetrablock terpolymers, and so on. We discuss their microphase separation in bulk, in the confinement of nanoemulsion droplets, and their hierarchical self‐assembly to multicompartment nanostructures in selective solvents. Regarding applications, block copolymers are widely used in templating and drug delivery, but their inherent asymmetry is also particularly useful for the synthesis of Janus nanoparticles.
Clonal dominance of a donor‐derived del(20q) clone after allogeneic hematopoietic stem cell transplantation in an acute myeloid leukemia patient with del(20q)
Authors: Yoon Jung , Yun Jae Won , Jung Chul Won , Kim Hee‐Jin , Kim Sun‐Hee
Published: June 2019

Del(20q) is the most frequently detected large structural genetic mosaicism alteration in the healthy aging population, occurring in approximately 0.1% of older persons. Age‐related clonal hematopoiesis of copy number variations (CNVs) is linked to an increased risk of hematologic malignancies, but the clinical impact of hematopoietic stem cells (HSCs) harboring such CNVs, such as del(20q), is not clearly understood. Here, we report an acute myeloid leukemia (AML) patient with known del(20q) who acquired donor‐derived del(20q) after allogeneic hematopoietic stem cell transplantation (HSCT). The HSCs with del(20q) engrafted and expanded over time, but the patient did not clinically progress to myeloid neoplasm. Although donor‐derived del(20q) from a healthy donor has been reported previously, our case is the first to review the clonal dynamics of a del(20q) clone and its post‐transplantation impact. Since recurrent hematology neoplasm‐associated CNVs, including del(20q), may not be rare among aged HSCT donors, identifying the origin of such a CNV is necessary for clinical decisions when clonal abnormality appears after HSCT, even in recipients who previously had the same abnormality.
Circle RNA hsa_circRNA_100290 serves as a ceRNA for miR‐378a to regulate oral squamous cell carcinoma cells growth via Glucose transporter‐1 (GLUT1) and glycolysis
Authors: Chen Xing , Yu Jianjun , Tian Hao , Shan Zhenfeng , Liu Wei , Pan Zhen , Ren Jihao
Published: June 2019

Aerobic glycolysis (the Warburg effect) is a robust metabolic hallmark of most tumors, including oral squamous cell carcinoma (OSCC). Glucose transporter 1 (GLUT1), a major glucose transporter regulating the glucose uptake, is upregulated in OSCC and participated in the cell glycolysis of OSCC. The deregulation and function of noncoding RNAs in cancers have been widely reported. Reportedly, hsa_circular RNA (circRNA)_100290 (circ_SLC30A7) is significantly upregulated (fold change = 6.91, p < 0.0000001) in OSCC. According to online tools prediction (miRWalk, miRanda, and Targetscan), miR‐378a could simultaneously target circRNA_100290 and GLUT1. Herein, the expression of circRNA_100290 and GLUT1 remarkably increased in oral tumor tissue specimens and cells. In OSCC cell lines, cell proliferation and glycolysis could be remarkably downregulated by circRNA_100290 silence, which could be rescued by GLUT1 overexpression. Conversely, miR‐378a expression could be remarkably inhibited in tumor tissue specimens and cells. The effect of miR‐378a overexpression on OSCC cells was similar to those of circRNA_100290 silence. miR‐378a directly bound to circRNA_100290 and GLUT1 3′‐untranslated region, circRNA_100290 could remarkably relieve miR‐378a‐induced inhibition on GLUT1 via acting as a competing endogenous RNA (ceRNA). miR‐378a inhibition remarkably attenuated the effect of circRNA_100290 silence on cell proliferation and glycolysis in OSCC cell lines. In summary, circRNA_100290 serves as a ceRNA to counteract miR‐378a‐mediated GLUT1 suppression, thus promoting glycolysis and cell proliferation in OSCC. We provide a reliable experimental basis for understanding the mechanism of cell growth and glycolysis deregulation in OSCC.
Potential antigen candidates for subunit vaccine development against Helicobacter pylori infection
Authors: Keikha Masoud , Eslami Majid , Yousefi Bahman , Ghasemian Abdolmajid , Karbalaei Mohsen
Published: June 2019

Helicobacter pylori (H. pylori) is a resident bacterium in the stomach that accounts for 75% cases of gastric cancer. In this review, we comprehensively studied published papers on H. pylori vaccines using Google Scholar and NCBI databases to gather information about vaccines against H. pylori. Considering the pivotal roles of the enzyme urease (in production of NH3 and neutralization of the acidic medium of the stomach), cytotoxin‐associated gene A, and vacuolating cytotoxin A proteins in H. pylori infection, they could be the best candidates for the construction of recombinant vaccines. The outer membrane porins (Hop), blood group antigen‐binding adhesin (BabA), sialic acid‐binding adhesin (SabA), and outer inflammatory protein A, play significant roles in binding of bacterium to human gastric tissues, and because binding is the first step in bacterial fixation and colonization, these antigens also can be considered as suitable candidates for designing vaccines. Likely, other significant bacterial antigens, such as NapA (chemotactic factor for recruitment of human neutrophils and monocytes to the site of infection), duodenal ulcer promoting protein A (to promote duodenal ulcer), and Hsp60 (as a molecular chaperon for activation of urease enzyme), can be used in the construction of subunit vaccines. New vaccines in use currently, such as DNA vaccines and subunit vaccines, can efficiently replace the dead and attenuated vaccines. Nonetheless, the results show that urease enzyme is most used compared with bacterial components in the designing and construction of recombinant vaccines. The BabA and SabA antigens belong to the outer membrane porins family in H. pylori and are required for binding and fixation of the bacterium to the human gastric tissues.
Propofol‐mediated cardioprotection dependent of microRNA‐451/HMGB1 against myocardial ischemia‐reperfusion injury
Authors: Li Yu‐mei , Sun Jin‐guo , Hu Li‐hua , Ma Xian‐chun , Zhou Gang , Huang Xi‐zhao
Published: June 2019

Administration of propofol at the time of reperfusion has shown to protect the heart from ischemia and reperfusion (I/R) injury. The aim of the present study was to investigate the molecular mechanism underling the cardioprotective effect of propofol against myocardial I/R injury (MIRI) in vivo and in vitro. Rat heart I/R injury was induced by ligation of the left anterior descending (LAD) artery for 30 min followed by 2‐hr reperfusion. Propofol pretreatment (0.01 mg/g) was performed 10 min before reperfusion. In vitro MIRI was investigated in cultured cardiomyocytes H9C2 following hypoxia/reoxygenation (H/R) injuries. Propofol pretreatment in vitro was achieved in the medium supplemented with 25 μmol/L propofol before H/R injuries. Propofol pretreatment significantly increased miRNA‐451 expression, decreased HMGB1 expression, reduced infarct size, and I/R‐induced cardiomyocyte apoptosis in rat hearts undergoing I/R injuries. Knockdown of miRNA‐451 48 hr before I/R injury was found to increase HMGB1 expression, infarct size, and I/R‐induced cardiomyocyte apoptosis in rat hearts in the presence of propofol pretreatment. These in vivo findings were reproduced in vivo that knockdown of miRNA‐451 48 hr before H/R injuries increased HMGB1 expression and H/R‐induced apoptosis in cultured H9C2 supplemented with propofol. In addition, luciferase activity assays and gain‐of‐function studies found that propofol could decrease HMGB1, the target of miRNA‐541. Taken together our findings provide a first demonstration that propofol‐mediated cardioprotection against MIRI is dependent of microRNA‐451/HMGB1. The study provides a novel target to prevent I/R injury during propofol anesthesia.
RETRACTED: LINC00339 promotes gastric cancer progression by elevating DCP1A expression via inhibiting miR‐377‐3p
Authors: Shi Chengmin , Liu Tonglei , Chi Junlin , Luo Huayou , Wu Zhizhong , Xiong Binghong , Liu Shuang , Zeng Yujian
Published: June 2019

Up to date, the mechanism of gastric cancer (GC) development is poorly understood. This study was to demonstrate the effects of LINC00339 on GC progression. Here, we found that LINC00339 was overexpressed expressed in GC tissues and predicted poor outcome. By CCK8, colony formation and Transwell assays, we showed LINC00339 knockdown suppressed GC cell proliferation, migration, and invasion in vitro. Flow cytometry analysis (FACS) indicated that LINC00339 knockdown induced tumor cell apoptosis. Besides, we utilized the xenograft assay and found that LINC00339 depletion led to decreased tumor growth in vivo. Mechanistically, miR‐377‐3p was found to be inhibited by LINC00339. And LINC00339 suppressed miR‐377‐3p to upregulate DCP1A, which consequently promoted GC progression. In conclusion, LINC00339 promotes gastric cancer progression by elevating DCP1A expression via inhibiting miR‐377‐3p.