bluuebunny/crossref_metadata_2025 huggingface dataset:
Process intensification for O2‐dependent enzymatic transformations in continuous single‐phase pressurized flow
Authors: Bolivar Juan M. , Mannsberger Alexander , Thomsen Malene S. , Tekautz Günter , Nidetzky Bernd
Published: December 2018

Oxidative O2‐dependent biotransformations are promising for chemical synthesis, but their development to an efficiency required in fine chemical manufacturing has proven difficult. General problem for process engineering of these systems is that thermodynamic and kinetic limitations on supplying O2 to the enzymatic reaction combine to create a complex bottleneck on conversion efficiency. We show here that continuous‐flow microreactor technology offers a comprehensive solution. It does so by expanding the process window to the medium pressure range (here, ≤34 bar) and thus enables biotransformations to be conducted in a single liquid phase at boosted concentrations of the dissolved O2 (here, up to 43 mM). We take reactions of glucose oxidase and d‐amino acid oxidase as exemplary cases to demonstrate that the pressurized microreactor presents a powerful engineering tool uniquely apt to overcome restrictions inherent to the individual O2‐dependent transformation considered. Using soluble enzymes in liquid flow, we show reaction rate enhancement (up to six‐fold) due to the effect of elevated O2 concentrations on the oxidase kinetics. When additional catalase was used to recycle dissolved O2 from the H2O2 released in the oxidase reaction, product formation was doubled compared to the O2 supplied, in the absence of transfer from a gas phase. A packed‐bed reactor containing oxidase and catalase coimmobilized on porous beads was implemented to demonstrate catalyst recyclability and operational stability during continuous high‐pressure conversion. Product concentrations of up to 80 mM were obtained at low residence times (1–4 min). Up to 360 reactor cycles were performed at constant product release and near‐theoretical utilization of the O2 supplied. Therefore, we show that the pressurized microreactor is practical embodiment of a general reaction‐engineering concept for process intensification in enzymatic conversions requiring O2 as the cosubstrate.
Epigenetic regulation of gene expression in Chinese Hamster Ovary cells in response to the changing environment of a batch culture
Authors: Hernandez Inmaculada , Dhiman Heena , Klanert Gerald , Jadhav Vaibhav , Auer Norbert , Hanscho Michael , Baumann Martina , Esteve‐Codina Anna , Dabad Marc , Gómez Jessica , Alioto Tyler , Merkel Angelika , Raineri Emanuele , Heath Simon , Rico Daniel , Borth Nicole
Published: December 2018

The existence of dynamic cellular phenotypes in changing environmental conditions is of major interest for cell biologists who aim to understand the mechanism and sequence of regulation of gene expression. In the context of therapeutic protein production by Chinese Hamster Ovary (CHO) cells, a detailed temporal understanding of cell‐line behavior and control is necessary to achieve a more predictable and reliable process performance. Of particular interest are data on dynamic, temporally resolved transcriptional regulation of genes in response to altered substrate availability and culture conditions. In this study, the gene transcription dynamics throughout a 9‐day batch culture of CHO cells was examined by analyzing histone modifications and gene expression profiles in regular 12‐ and 24‐hr intervals, respectively. Three levels of regulation were observed: (a) the presence or absence of DNA methylation in the promoter region provides an ON/OFF switch; (b) a temporally resolved correlation is observed between the presence of active transcription‐ and promoter‐specific histone marks and the expression level of the respective genes; and (c) a major mechanism of gene regulation is identified by interaction of coding genes with long non‐coding RNA (lncRNA), as observed in the regulation of the expression level of both neighboring coding/lnc gene pairs and of gene pairs where the lncRNA is able to form RNA–DNA–DNA triplexes. Such triplex‐forming regions were predominantly found in the promoter or enhancer region of the targeted coding gene. Significantly, the coding genes with the highest degree of variation in expression during the batch culture are characterized by a larger number of possible triplex‐forming interactions with differentially expressed lncRNAs. This indicates a specific role of lncRNA‐triplexes in enabling rapid and large changes in transcription. A more comprehensive understanding of these regulatory mechanisms will provide an opportunity for new tools to control cellular behavior and to engineer enhanced phenotypes.
Proposing simulation model for multi‐wavelength source offering 40 Gbps WDM‐PON using AWG with a single laser
Authors: Ullah Rahat , Bo Liu , Ullah Sibghat , Yaya Mao , Tian Feng , Xiangjun Xin
Published: December 2018

In this paper, A new simulation model is proposed and implemented for cost effective optical line terminal (OLT) arrangements for wavelength division multiplexed passive optical network (WDM‐PON). The conventional setup at OLT side is replaced with a new arrangement containing single laser source in cascade with phase modulator and arrayed waveguide grating (AWG), whereas the phase modulator is tailored with one RF source. The phase modulator generates multicarrier signal and AWG splits the signal into multiple single wavelengths based on its routing configurations. AWG is actually used as a passing band periodical filter that routs the input wavelengths to four different wavelengths depending on its free spectral range, the frequency spacing between the generated wavelengths is 20 GHz. Across each routed wavelength, differential phase shift keying is used in downlink transmission for 10 Gbps, while intensity modulation is employed in the uplink transmission based on off‐keying. 40 Gbps full duplex transmission via 20 km fiber span is successfully achieved with minimum power loss and effective results. At ONU side, optical splitters divides the signal into two, half power of the signal is used in demodulation at ONU while half of the power is utilized for the uplink transmission, this way colorless transmission is achieved. Transmission performances are examined with negligible power penalties, better Q‐factors, and handsome eye openings, which confirm the deployment of proposed arrangement in the next generation access network. The proposed model is successfully implemented in the simulation environment provided by OptiSystem.
Volatile Composition and Biological Activities of the Leaf Essential Oil from Zanthoxylum limoncello Grown in Oaxaca, México
Authors: Villa‐Ruano Nemesio , Pacheco‐Hernández Yesenia , Zárate‐Reyes José Alejo , Cruz‐Durán Ramiro , Lozoya‐Gloria Edmundo
Published: December 2018

Zanthoxylum limoncello is a native plant from southern Mexico which is used as a timber source, condiment and as a traditional medicine. Herein, we report on the volatile content of the leaf essential oil and its biological activities. The annual essential oils (2015–2018) contained volatile organic compounds which exhibited a moderate growth inhibitory activity against H. pylori ATCC 53504 (MIC 121.4–139.7 μg mL−1), 26695 (MIC 85.5–94.9 μg mL−1) and J99 (MIC 94.7–110.4 μg mL−1). These hydrodistillates contained 2‐undecanone (31.6–36.8 %; MIC 185.3–199.2 μg mL−1) and 2‐undecenal (25.1–35.7 %; MIC 144.8–111.3 μg mL−1) as the most abundant compounds which were partially involved in the anti‐H. pylori activity. The human ornithine decarboxylase enzyme (ODC1), which shows increased activity in several cancer types, was non‐competitively inhibited (Vmax 2.7>0.8 Kcat s−1) by the essential oil of Z. limoncello as well as by 2‐undecanone and 2‐undecenal in accordance to in vitro kinetic studies. In silico calculations strongly suggest that the carbonyl group of these oxygenated hydrocarbons interacts with both Asn319 and Ala39 at the subunit A of ODC1. Considering that Ala39 is located close to Asn44, a crucial amino acid of the ODC's allosteric site, the non‐competitive inhibition of the enzyme by 2‐undecanone and 2‐undecenal is endorsed. Finally, the essential oil of Z. limoncello and its main volatiles showed a significant (p<0.01) and prolonged repellent effect against Aedes aegypti.
Manipulating DNA G‐Quadruplex Structures by Using Guanosine Analogues
Authors: Haase Linn , Karg Beatrice , Weisz Klaus
Published: December 2018

The ability to control the folding topology of DNA G‐quadruplexes allows for rational design of quadruplex‐based scaffolds for potential use in various therapeutic and technological applications. By exploiting the distinct conformational properties of some base‐ and sugar‐modified guanosine surrogates, conformational transitions can be induced through their judicious incorporation at specific sites in the quadruplex core. Changes may involve tetrad polarity inversions with conservation of the global fold or complete refolding to new topologies. Reliable predictions relating to low‐energy conformers formed upon specific chemical perturbations of the system and the rational design of modified sequences suffer from our still limited understanding of the subtle interplay of various favorable and unfavorable interactions within a particular quadruplex scaffold. However, aided by an increasing number of systematic substitution experiments and high‐resolution structures of modified quadruplex variants, critical interactions, in addition to glycosidic bond angle propensities, are starting to emerge as important contributors to modification‐driven quadruplex refolding.
Impact of coronary artery disease and percutaneous coronary intervention in women undergoing transcatheter aortic valve replacement: From the WIN‐TAVI registry
Authors: Guedeney Paul , Tchétché Didier , Petronio Anna Sonia , Mehilli Julinda , Sartori Samantha , Lefèvre Thierry , Presbitero Patrizia , Capranzano Piera , Iadanza Alessandro , Sardella Gennaro , Van Mieghem Nicolas M. , Sorrentino Sabato , Claessen Bimmer E. P. M. , Chandrasekhar Jaya , Vogel Birgit , Kalkman Deborah N. , Meliga Emanuele , Dumonteil Nicolas , Fraccaro Chiara , Trabattoni Daniela , Mikhail Ghada , Ferrer‐Grazia Maria‐Cruz , Naber Christoph , Kievit Peter , Baber Usman , Sharma Samin , Morice Marie‐Claude , Chieffo Alaide , Mehran Roxana ,   on behalf of WIN TAVI Investigators
Published: December 2018

Objectives

To evaluate the impact of coronary artery disease (CAD) with or without recent (≤ 30 days) percutaneous coronary intervention (PCI) in women undergoing transcatheter aortic valve replacement (TAVR).

Background

Although women display a specific risk‐profile for both PCI and TAVR, the impact of CAD and PCI in the setting of TAVR in women is unclear.

Methods

The multinational Women's International Transcatheter Aortic Valve implantation registry enrolled consecutive female patients undergoing contemporary TAVR in 19 centers between 2013 and 2015. Patients with available coronary angiography or CT scan in the pre‐operative assessment of TAVR were categorized as without CAD, with CAD but no recent PCI and CAD and recent PCI (≤30 days). All events were adjudicated according to the VARC‐2 criteria.

Results

A total of 787 patients were included in this analysis, among whom 459 (58.3%) had no CAD, 247 (31.4%) had CAD without recent PCI and 81 (10.3%) underwent recent PCI (≤ 30 days before TAVR). After multivariable adjustment, both groups of CAD patients, without and with recent PCI, presented with higher risk of death, myocardial infarction or stroke, compared with patients without CAD (adjHR 1.56, 95%CI 1.03–2.39, P = 0.038 and adjHR 1.96, 95% CI 1.1–3.5, P = .021, respectively). Patients with recent PCI had increased risk of all‐cause death (adjHR 1.89, 95% CI 1.0–3.5, P = 0.04) and stroke (adjHR 3.7, 95% CI 1.0–13.5, P = 0.046) compared with patients without CAD.

Conclusion

The presence of CAD in women undergoing TAVR, with or without recent PCI, was associated with long‐term poorer outcomes.
Role of Co2C in ZnO‐promoted Co Catalysts for Alcohol Synthesis from Syngas
Authors: Singh Joseph A. , Hoffman Adam S. , Schumann Julia , Boubnov Alexey , Asundi Arun S. , Nathan Sindhu S. , Nørskov Jens , Bare Simon R. , Bent Stacey F.
Published: December 2018

Controlling selectivity is a key goal in the design of a heterogeneous catalyst. Herein, we present detailed characterization and activity of silica‐supported cobalt catalysts modified by atomic layer deposition of ZnO. After reduction, the resulting catalysts exhibit substantial selectivity towards alcohol production during CO hydrogenation compared to catalysts containing only cobalt. The prepared catalysts have up to 46 % selectivity toward alcohols with 39 % of the alcohols corresponding to ethanol and other higher alcohols, albeit with reduced activity. In situ characterization of the catalyst by X‐ray diffraction and X‐ray absorption spectroscopy reveals details on the structural evolution in syngas, CO+H2, and shows that ZnO promotion of Co results in the formation of Co2C under catalytic conditions. A mechanism is proposed, supported by density functional theory calculations, which explains Co2C formation by the blocking of Co step sites by Zn species. The ZnO acts a dual promoter both by facilitating Co2C formation and by modifying the resulting Co2C. The Co2C formed from the ZnO‐promoted Co catalysts displays improved thermal stability and selectivity compared with similar Co2C catalysts without Zn.
Catalytic Activity of Ceramic Honeycombs in the Exhaust Gas Oxidation of a Waste Treatment Plant
Authors: Knoll Manuela , Schomäcker Reinhard , Bungert Bernd
Published: December 2018

The activity of ceramic honeycombs with varying material composition and degree of utilization is compared on a suitable model gas in a test plant. The tested honeycombs are standard products that have not been surface‐treated in any way. A propane‐air mixture was fed to the test plant and then oxidized in a high‐temperature furnace. The analysis of the conversion rate over the reaction temperature showed remarkable differences in activity. The honeycomb with the most promising results was further investigated with the exhaust gas from the drying process of a waste treatment plant. Finally, the activity of this honeycomb was assessed in a large‐scale trial in an existing running regenerative thermal oxidizer.
Enhanced Li‐Ion‐Storage Performance of MoS2 through Multistage Structural Design
Authors: Wang Mei , Xu Yunhua H. , Lu Fei , Zhu Zhian , Dong Jinyang Y. , Fang Daliang L. , Zhou Jian , Yang Yijun J. , Zhong Yeteng T. , Chen Shimou M. , Bando Yoshio , Golberg Dmitri , Wang Xi
Published: December 2018

Inspired by a folded protein, multistage structural MoS2 is designed as an advanced anode material for lithium‐ion batteries (LIBs). Density functional theory (DFT) calculations are initially performed, demonstrating that the ideal primary structure (P−MoS2) has saw‐tooth‐like edges terminated by Mo atoms and the desired secondary structure (C−MoS2) may form via crumpling. For the latter, more exposed (002) planes exist within the wrinkled parts, creating more active sites and promoting isotropic Li+ insertion. Importantly, the rate capability and capacity of a MoS2 anode are enhanced after such a P−MoS2 to C−MoS2 transition: a superb specific capacity of 1490 mAh/g for C−MoS2 at 0.1 A/g (vs. 1083 mAh/g for P−MoS2), an excellent cycling stability (858 mAh/g after 450 cycles at 0.5 A/g), and an improved rate capability of 591 mAh/g at 1 A/g (vs. 465 mAh/g) are documented. The curving effects and mechanical properties of a single C−MoS2 particle are further visualized by in situ TEM. Drastically enlarged spacing changes upon Li‐insertion and high elasticity are confirmed, which lead to enhanced LIB performances and the excellent mechanical strength of C−MoS2. The present multistage design of a MoS2 structure should pave the way toward high‐energy MoS2 anode materials for future LIBs.
Chemoselectivity for Alkene Cleavage by Palladium‐Catalyzed Intramolecular Diazo Group Transfer from Azide to Alkene
Authors: Frost Grant B. , Mittelstaedt Michaela N. , Douglas Christopher J.
Published: December 2018

Alkenes can be cleaved by means of the (3+2) cycloaddition and subsequent cycloreversion of 1,3‐dipoles, classically ozone (O3), but the azide (R−N3) variant is rare. Chemoselectivity for these azide to alkene diazo group transfers (DGT) is typically disfavored, thus limiting their synthetic utility. Herein, this work discloses a palladium‐catalyzed intramolecular azide to alkene DGT, which grants chemoselectivity over competing aziridination. The data support a catalytic cycloreversion mechanism distinct from other known metal‐catalyzed azide/alkene reactions: nitrenoid/metalloradical and (3+2) cycloadditions. Kinetics experiments reveal an unusual mechanistic profile in which the catalyst is not operative during the rate‐controlling step, rather, it is active during the product‐determining step. Catalytic DGT was used to synthesize N‐heterocyclic quinazolinones, a medicinally relevant structural core. We also report on the competing aziridination and subsequent ring expansion to another N‐heterocyclic core structure of interest, benzodiazepinones.
Lemon battery again – a clarification
Authors: Rosenberg Dominique , Rautenstrauch Hanne , Pöhls Christin , Böttger Sebastian , Busker Maike , Fittschen Ursula , Jansen Walter
Published: December 2018

Über die elektrochemischen Vorgänge in der sogenannten Zitronenbatterie mit Zink‐ bzw. Eisenelektroden und Kupferelektroden wird seit Jahrzehnten diskutiert. In diesem Artikel wird durch Versuche aufgezeigt, dass bei einer Eisen‐Kupfer‐Zelle nur die Reduktion des Luftsauerstoffs möglich ist, während bei einer Zink‐Kupfer‐Zelle unter bestimmten Bedingungen auch eine Reduktion von Wasserstoff‐Ionen erfolgen kann. Auch dazu wird in diesem Artikel ein Versuchsaufbau der Zitronenbatterie in einer sauerstofffreien Atmosphäre vorgestellt. In weiteren Untersuchungen wird mit Hilfe der Totalreflektions‐Röntgenfluoreszenzanalyse ebenso die Korrosionsgeschwindigkeit der Sauerstoffkorrosion des Kupfers in der Zitronensäure ermittelt und diskutiert.
The role of cytology in molecular testing and personalized medicine in lung cancer: A clinical perspective
Authors: Young Kelvin , da Cunha Santos Gilda , Card Paul , Leighl Natasha
Published: December 2018

Cytology is a viable and underused medium for obtaining molecular testing in lung cancer. There are various obstacles to the widespread adoption of molecular diagnostics using cytologic specimens, and these should be addressed to ensure optimal patient care.
Color segmentation in multicolor images using node‐growing self‐organizing map
Authors: Ouyang Wenbin , Xu Bugao , Yuan Xiaohui
Published: December 2018

This article presents a clustering algorithm based on node‐growing self‐organizing map (NGSOM) to classify colors on color images automatically and accurately partition the regions of different colors for color measurement. Based on the CIEDE2000 criterion, pixels in a multicolor image are grouped into a number of visually distinguishable color regions in which pixel distribution information is provided as the input of the NGSOM network for further segmentation. As an unsupervised clustering algorithm, the NGSOM randomly selects two initial nodes from the input source without a predefined network structure and grows nodes according to color differences between the first best matching unit (FBMU) and the second best matching unit (SBMU) of the current input data. Unlike a traditional SOM, the NGSOM utilizes learning rates varying with the pixel distributions of major color regions. The node‐growing procedure is terminated when all the input data are examined. Compared with some commonly used color clustering algorithms, the proposed algorithm possesses a better peak signal‐to‐noise ratio (PSNR) and higher time efficiency. The NGSOM can be used for a wide range of applications, including fabric colorfastness assessment, painting conservation, and scenic identification in aerial images.
Enhancing the security and performance of nodes in Internet of Vehicles
Authors: Vijayarangam S. , Chandra Babu Gokulnath , Ananda Murugan S. , Kalpana N. , Malarvizhi Kumar Priyan
Published: December 2018

Internet of Vehicles is recorded as an ever growing area for connected vehicles to exchange their information with other vehicles using vehicle‐to‐vehicle communication. Vehicle‐to‐vehicle communication is possible by forming vehicular ad hoc networks, with the help of roadside units using vehicle‐to‐roadside communications in the network. Internet of networks has many advantages such as road safety, traffic management, and sharing information on daily traffic and updating traffic information. For example, the Internet of Vehicles can be used to reduce traffic and deaths occurring due to road accidents, to reduce the fuel needed, and to reduce travel time. Interconnected vehicles rapidly learn about road conditions and traffic and respond to the driver; thus, necessary actions are taken. However, the attacker can modify the information in the connected vehicles and, thus, creates problem on the road. Data fascination is one of the main attacks on connected vehicles where connected vehicles take action based on information from the other vehicle. In this paper, first, a model has been proposed to detect the data fascination attack using the hashing technique to enhance the security in the interconnected vehicles by adjusting the size of the contention window to transfer original information to other interconnected vehicles at the correct time. Second, a model has been suggested to reduce the travel time in case of traffic congestion. The efficiency of the proposed model is checked using numerical methods obtained from the simulation results. From the obtained results, the proposed approach prevents data fascination attacks in interconnected vehicles and provides high throughput with lower delay.
Tetrakis(oxadiazolylphenyl)pyrazines: New St. Andrew′s Cross‐Shaped Liquid Crystals
Authors: Röder Nico , Marszalek Tomasz , Limbach Daniel , Pisula Wojciech , Detert Heiner
Published: December 2018

π‐Conjugated molecules with the shape of St. Andrew′s cross have been synthesized via fourfold Huisgen reaction. Four 2,5‐diaryl‐1,3,4‐oxadiazol arms are attached to a central pyrazine nucleus. These fluorescent stars, when decorated with a rim of eight alkoxy side chains are discotic liquid crystals. Depending on the substitution pattern, the width of the liquid phase varies within a broad range of 25 °C to 250 °C. In their liquid crystalline phase, the molecules assemble in a typical hexagonal columnar supramolecular arrangement.
Individual goal achievement in group psychotherapy: The roles of psychological mindedness and group process in interpretive and supportive therapy for complicated grief
Authors: Kealy David , Piper William E. , Ogrodniczuk John S. , Joyce Anthony S. , Weideman Rene
Published: December 2018

The ability to infer psychological meaning in behaviour—referred to as psychological mindedness—has been posited as a patient characteristic that contributes to the therapy process and consequently to therapeutic success. The present study was developed to examine the relationship between patients' psychological mindedness and improvement in patients' personal treatment goals in interpretive and supportive group therapies for complicated grief, along with patients' importance to group process. The study was conducted with a clinical sample of 109 patients (79% female; average 45 years old) receiving treatment for complicated grief. Patients provided severity of distress ratings for individual target objectives at pretreatment and posttreatment. Psychological mindedness was assessed prior to treatment using the video‐based, interviewer‐rated Psychological Mindedness Assessment Procedure. Patients' importance to the therapy process was rated by therapists and other patients in interpretive and supportive group therapy for complicated grief. Conditional process modelling tested whether psychological mindedness would contribute to patients' goal achievement through patients' importance to group process, moderated by type of therapy. A significant, conditional indirect effect was observed for psychological mindedness as a predictor of improvement in individual target objectives, through patients' importance to group process as rated by therapists, specifically in interpretive therapy. The findings indicate that patients' psychological mindedness significantly contributes to their achievement of individual goals through their contributions to group process in interpretive group therapy. Further research is needed to understand the facilitation of individual goal achievement in supportive therapy.
Differences in means‐end exploration between infants at risk for autism and typically developing infants in the first 15 months of life
Authors: Srinivasan Sudha M. , Bhat Anjana N.
Published: December 2018

Our study compared means‐end exploration in infants at risk (AR) for autism and typically developing (TD) infants using a nested box paradigm. Sixteen AR and 16 TD infants were observed at 9, 12, and 15 months with follow‐up at 18 and 24 months. We collected video data on three tasks involving retrieval of a small toy by opening (a) an opaque box, (b) a transparent box, and (c) two nested boxes. Dependent variables included hand bias, time to completion, bilateral hand use, problem‐solving strategies used, and tester assistance required. There were no group differences in terms of hand biases. Compared to TD infants, AR infants had lower bilateral hand use, poor problem solving skills, and required greater assistance. Both groups demonstrated age‐related improvements in motor and cognitive skills. Means‐end exploration provides a window into the bilateral coordination and motor planning/problem‐solving abilities of young infants at risk for autism. Lastly, object retrieval tasks could serve as important learning contexts for at‐risk infants.
Silk properties and overwinter survival in gregarious butterfly larvae
Authors: Duplouy Anne , Minard Guillaume , Lähteenaro Meri , Rytteri Susu , Saastamoinen Marjo
Published: December 2018

All organisms are challenged by encounters with parasites, which strongly select for efficient escape strategies in the host. The threat is especially high for gregarious species entering immobile periods, such as diapause. Larvae of the Glanville fritillary butterfly,Melitaea cinxia, spend the winter in diapause in groups of conspecifics each sheltered in a silk nest. Despite intensive monitoring of the population, we have little understanding of the ecological factors influencing larval survival over the winter in the field. We tested whether qualitative and quantitative properties of the silk nest contribute to larval survival over diapause. We used comparative proteomics, metabarcoding analyses, microscopic imaging, and in vitro experiments to compare protein composition of the silk, community composition of the silk‐associated microbiota, and silk density from both wild‐collected and laboratory‐reared families, which survived or died in the field. Although most traits assessed varied across families, only silk density was correlated with overwinter survival in the field. The silk nest spun by gregarious larvae before the winter acts as an efficient breathable physical shield that positively affects larval survival during diapause. Such benefit may explain how this costly trait is conserved across populations of this butterfly species and potentially across other silk‐spinning insect species.
Linking beaver dam affected flow dynamics to upstream passage of Arctic grayling
Authors: Cutting Kyle A. , Ferguson Jake M. , Anderson Michelle L. , Cook Kristen , Davis Stacy C. , Levine Rebekah
Published: December 2018

Beaver reintroductions and beaver dam structures are an increasingly utilized ecological tool for rehabilitating degraded streams, yet beaver dams can potentially impact upstream fish migrations. We collected two years of data on Arctic grayling movement through a series of beaver dams in a low gradient mountain stream, utilizing radio‐telemetry techniques, to determine how hydrology, dam characteristics, and fish attributes impeded passage and movement rates of spawning grayling. We compared fish movement between a “normal” flow year and a “low” flow year, determined grayling passage probabilities over dams in relation to a suite of factors, and predicted daily movement rates in relation to the number of dams each fish passed and distance between dams during upstream migration to spawning areas. We found that the average passage probability over unbreached beaver dams was 88%, though we found that it fell below 50% at specific dams. Upstream passage of grayling was affected by three main characteristics: (a) temperature, (b) breach status, and (c) hydrologic linkages that connect sections of stream above and below the dam. Other variables influence passage, but to a lesser degree. Cumulative passage varied with distance upstream and total number of dams passed in low versus normal flow years, while movement rates upstream slowed as fish swam closer to dams. Our findings demonstrate that upstream passage of fish over beaver dams is strongly correlated with hydrologic conditions with moderate controls by dam‐ and fish‐level characteristics. Our results provide a framework that can be applied to reduce barrier effects when and where beaver dams pose a significant threat to the upstream migration of fish populations while maintaining the diverse ecological benefits of beaver activity when dams are not a threat to fish passage.
Environmental gradients in old‐growth Appalachian forest predict fine‐scale distribution, co‐occurrence, and density of woodland salamanders
Authors: Baecher J. Alex , Richter Stephen C.
Published: December 2018

Woodland salamanders are among the most abundant vertebrate animals in temperate deciduous forests of eastern North America. Because of their abundance, woodland salamanders are responsible for the transformation of nutrients and translocation of energy between highly disparate levels of trophic organization: detrital food webs and high‐order predators. However, the spatial extent of woodland salamanders’ role in the ecosystem is likely contingent upon the distribution of their biomass throughout the forest. We sought to determine if natural environmental gradients influence the fine‐scale distribution and density of Southern Ravine Salamanders (Plethodon richmondi) and Cumberland Plateau Salamanders (P. kentucki). We addressed this objective by constructing occupancy, co‐occurrence, and abundance models from temporally replicated surveys within an old‐growth forest in the Cumberland Plateau region of Kentucky. We found that Plethodon richmondi had a more restricted fine‐scale distribution than P. kentucki (mean occupancy probability [] = 0.737) and exhibited variable density, from <250 to >1000 individuals per hectare, associated with increased soil moisture and reduced solar exposure due to slope face. While more ubiquitously distributed ( = 0.95), P. kentucki density varied from <400 to >1,000 individuals per hectare and was inversely related to increased solar exposure from canopy disturbance and landscape convexity. Our data suggest co‐occurrence patterns of P. richmondi and P. kentucki are influenced primarily by abiotic conditions within the forest, and that populations likely occur independently and without evidence of biotic interaction. Given the critical role that woodland salamanders play in the maintenance of forest health, regions that support large populations of woodland salamanders, such as those highlighted in this study—mesic forest stands on north‐to‐east facing slopes with dense canopy and abundant natural cover, may provide enhanced ecosystem services and support the stability of the total forest.
Chemical Insights into the Issues of Gd Retention in the Brain and Other Tissues Upon the Administration of Gd‐Containing MRI Contrast Agents
Authors: Gianolio Eliana , Gregorio Enza Di , Aime Silvio
Published: December 2018

Gadolinium bearing contrast agents (GBCA) are commonly used in clinical settings as they add relevant physiological information to the superb anatomical resolution of the MR images. Recently it has been found that tiny amounts of gadolinium can be retained in the brain and other tissues in patients treated with GBCAs. Much work has been devoted to address the main determinants of the fate of GBCAs in vivo. Particular attention is given to the characterization of the chemical form/s (intact GBCA, soluble and insoluble Gd‐containing species) and to the relationship with the hyperintensity shown in T1w MR images. The article compares results from the authors' work with relevant achievements from other labs aimed at shedding light on the complex bio‐inorganic problems that accompany Gd‐retention in living systems.
Carborane‐Substituted Bis(phosphino)hydrazines: Selective Formation of Six‐ and Twelve‐Membered P,N Heterocycles
Authors: Maulana Ilham , Lönnecke Peter , Hey‐Hawkins Evamarie
Published: December 2018

Six‐ and twelve‐membered heterocyclic carborane‐substituted bis(phosphino)hydrazines 1 and 2 were obtained selectively. Compound 1 was obtained as the major product in a 1:1 reaction, when the dilithiated o‐carborane was added to 1,2‐bis(dichlorophosphino)‐1,2‐diethylhydrazine, whereas the reverse addition led to 2 as the main product (2:2 reaction). Compound 1 was obtained only as the rac isomer, 2 as the RP,SP,SP,RP isomer. The rhodium(I) complex of 1, rac‐[{RhCl(η4‐C8H12)}2{cyclo‐1,2‐(NEt)2‐3,6‐(PCl)2‐4,5‐(ortho‐C2B10H10)‐κP,κP′}] (3), shows dynamic behavior due to a temperature‐dependent equilibrium. Preliminary studies showed the rhodium(I) complex generated in situ from 1 and [Rh(cod)2]BF4 (cod = 1,5‐cyclooctadiene) to be an active catalyst in the hydrogenation of dimethyl itaconate.
A Continuous Flow Strategy for the Facile Synthesis and Elaboration of Semi‐Saturated Heterobicyclic Fragments
Authors: Luise Nicola , Wyatt Eleanor W. , Tarver Gary J. , Wyatt Paul G.
Published: December 2018

An efficient hydrogenation protocol under continuous flow conditions was developed for the synthesis of underrepresented semi‐saturated bicyclic fragments containing highly sp3‐rich skeletons for fragment‐based drug discovery (FBDD) programs. Excellent yields were generally achieved by using Pd/C (10 % w/w) and RaNi at 25–150 °C under 4–100 bar of hydrogen pressure. The generated fragments, with appropriate physicochemical properties, present diverse hydrogen‐bonding pharmacophores and useful vectors for their synthetic elaboration in the optimization stage. Successive, simple functionalizations in continuous flow were accomplished to demonstrate the opportunity to develop multi‐step continuous flow synthesis of valuable starting points for FBDD campaigns. A conclusive quality control (QC) was essential to discard those structures which do not fit the typical fragment library parameters.
Nanopore sequencing: An enrichment‐free alternative to mitochondrial DNA sequencing
Authors: Zascavage Roxanne R. , Thorson Kelcie , Planz John V.
Published: December 2018

Mitochondrial DNA sequence data are often utilized in disease studies, conservation genetics and forensic identification. The current approaches for sequencing the full mtGenome typically require several rounds of PCR enrichment during Sanger or MPS protocols followed by fairly tedious assembly and analysis. Here we describe an efficient approach to sequencing directly from genomic DNA samples without prior enrichment or extensive library preparation steps. A comparison is made between libraries sequenced directly from native DNA and the same samples sequenced from libraries generated with nine overlapping mtDNA amplicons on the Oxford Nanopore MinION™ device. The native and amplicon library preparation methods and alternative base calling strategies were assessed to establish error rates and identify trends of discordance between the two library preparation approaches. For the complete mtGenome, 16 569 nucleotides, an overall error rate of approximately 1.00% was observed. As expected with mtDNA, the majority of error was detected in homopolymeric regions. The use of a modified basecaller that corrects for ambiguous signal in homopolymeric stretches reduced the error rate for both library preparation methods to approximately 0.30%. Our study indicates that direct mtDNA sequencing from native DNA on the MinION™ device provides comparable results to those obtained from common mtDNA sequencing methods and is a reliable alternative to approaches using PCR‐enriched libraries.
A numerical study on viscoelastic droplet migration on a solid substrate due to wettability gradient
Authors: Bai Fan , Li Yuke , Zhang Hongna , Joo Sang Woo
Published: December 2018

This study investigates the viscoelastic effects on droplet migration induced by a wettability gradient on a rigid substrate by a numerical simulation based on OpenFOAM with the volume‐of‐fluid method. The droplets are set with different rheological properties to investigate the effect of the elastic parameters. The Oldroyd‐B model was employed. Quantitative differences in the migration and deformation between Newtonian and viscoelastic droplets were investigated by changing the degree of elasticity. The droplet migration shows conspicuously higher mobility for high elasticity, especially during the accelerating period. Moreover, the displacement and velocity increased with the decrease of a viscoelasticity parameter, and the velocity enhancement was regulated by the elastic instability shown at a high Weissenberg number. In addition, the velocity of the droplet changes more significantly over the range of contact angles of 130° to 60° compared to other wettability‐gradient surfaces.
A smartphone‐based on‐site nucleic acid testing platform at point‐of‐care settings
Authors: Xu Xiayu , Wang Xuemin , Hu Jie , Gong Yang , Wang Lin , Zhou Wan , Li XiuJun , Xu Feng
Published: December 2018

We developed a smartphone‐based on‐site nucleic acid testing (NAT) platform that can image and analyze lateral flow nucleic acid assays at point‐of‐care settings. An inexpensive add‐on was devised to run lateral flow assays while providing homogeneous ambient light for imaging. In addition, an Android app with a user‐friendly interface was developed for the result analysis and management. Linear color calibration is implemented inside the app to minimize the colorimetric reaction difference between smartphones. A relationship function between nucleic acid concentration and colorimetric reaction was established and evaluated by leave‐one‐out cross validation. The predicted concentration and true concentration showed a good agreement with an R‐squared value of 0.96. This smartphone‐based NAT platform can be used to diagnose infectious diseases and monitor disease progression, and assess treatment efficacy, especially for resource‐limited settings.
A periodic mixed linear state‐space model to monthly long‐term temperature data
Authors: Costa M. , Monteiro M.
Published: December 2018

In recent decades, the world has been confronted with the consequences of global warming; however, this phenomenon is not reflected equally in every part of the globe. Thus, the warming phenomenon must be monitored in a more regional or local scale. This paper analyzes monthly long‐term time series of air temperatures in three Portuguese cities: Lisbon, Oporto, and Coimbra. We propose a periodic state‐space framework, associated with a suitable version of the Kalman filter; which allows for the estimation of monthly warming rates taking into account the seasonal behavior and serial correlation. Results about the monthly mean of the daily midrange temperature time series show that there are different monthly warming rates. The greatest annual mean rise was found in Oporto with 2.17°C, whereas in Lisbon and Coimbra, it was respectively 0.62°C and 0.55°C per century.
Loss of function, missense, and intronic variants in NOTCH1 confer different risks for left ventricular outflow tract obstructive heart defects in two European cohorts
Authors: Helle Emmi , Córdova‐Palomera Aldo , Ojala Tiina , Saha Priyanka , Potiny Praneetha , Gustafsson Stefan , Ingelsson Erik , Bamshad Michael , Nickerson Deborah , Chong Jessica X. ,   University of Washington Center for Mendelian Genomics, Ashley Euan , Priest James R.
Published: December 2018

Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in
NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function
NOTCH1 variants in 6% of individuals. Rare or low‐frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in
NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in
NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European‐ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non‐European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in
NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population‐based data sets in quantifying the specific risk of individual variants for disease‐related phenotypes.
Optimal matching between CO2 sources in Jiangsu province and sinks in Subei‐Southern South Yellow Sea basin, China
Authors: Zhu Qianlin , Wang Chuang , Fan Zhihan , Ma Jing , Chen Fu
Published: December 2018

An understanding of CO2 sources, sinks, and their optimal matching relationships is helpful when making an initial assessment or making decisions regarding CO2 sequestration. One of the most populous and developed provinces in China, Jiangsu, is facing tremendous pressure to reduce CO2 emissions. This study assessed CO2 emissions from large, stationary CO2 sources and the CO2 geological storage capacity for the Jiangsu province, and studied their optimal geographical matching relationships. The results of the study show that major, large, stationary sources have a total of 730.75 Mt/year CO2 emissions, and the majority of them are located in southern Jiangsu. The Subei‐Southern South Yellow Sea basin, with a total storage capacity of 5.21 × 104 Mt, can be subdivided into 28 storage blocks based on the faults. Source‐sink geographical matching shows that the locations of the sources and the matched sinks are approximately translational. When the entire Subei‐Southern South Yellow basin was chosen as an option for CO2 sinks, the sinks that matched to the northern Jiangsu CO2 sources were mainly located in the onshore northern Subei basin. The northern sources tended to match the north sinks of the northern Subei basin. The CO2 from the southern Jiangsu should be stored in the southern Subei basin and the offshore Southern South Yellow basin. When only the offshore storage blocks are optional CO2 sinks, the CO2 sources in the northern and central Jiangsu mainly match the sinks in the northwestern Southern South Yellow basin. The CO2 sources from southern Jiangsu mainly match the sinks in the southern and eastern Southern South Yellow basin. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.
Features of magnetic anomaly and distribution of igneous rock in the south‐western Tibetan Plateau
Authors: Zhang Chunguan , Zhang Minghua , Zhang Guoli
Published: December 2018

In order to study the magnetic characteristics and temporal and spatial distribution law of igneous rocks in the south‐western Tibetan Plateau, we calculated the RTP aeromagnetic anomaly based on the aeromagnetic anomaly data with scales of 1:200,000 and 1:1,000,000. Then, we separated the RTP aeromagnetic anomaly using the regularization filtering method and obtained the local magnetic anomaly and the regional magnetic anomaly in the study area. Combined with previous geological and geophysical studies, we analysed the features of the RTP aeromagnetic anomaly, the local magnetic anomaly, and the regional magnetic anomaly, studied the corresponding relationship between the igneous rocks and the magnetic anomalies, discussed the magnetic characteristics and temporal and spatial distribution law of igneous rocks, and determined the distribution of the concealed igneous rocks. The results showed that the ophiolites and the ultrabasic rocks display strong magnetic characteristics, and the basic rocks and the intermediate rocks display weak magnetic characteristics, and the acidic rocks display moderate‐strong magnetic characteristics in the study area. The study revealed that the magmatic activities display a decreasing tendency from south to north in the study area. There are five concealed Jurassic ophiolite belts in the Bangong‐Nujiang Suture Zone and the Yarlung Zangbo Suture Zone, and two concealed Jurassic ultrabasic rock belts in the Gangdise Block and the Qiangtang Block, and a lot of concealed acidic rocks are found in the Gangdise Block.
Stratigraphy and facies analysis of the La Chilca Formation, Central Precordillera: Insights on the postglacial Ordovician–Silurian boundary and Early Silurian deposits from Argentina
Authors: Asurmendi Estefanía , Sánchez María Lidia , Heredia Susana
Published: December 2018

The La Chilca Formation is exposed at the Poblete Norte and Ancha sections, Talacasto, Central Precordillera. Detailed facies analysis on field outcrops suggests a tide‐dominated tidal plain model on the Silurian siliciclastic ramp, integrated by supratidal to subtidal plain deposits. The lower part of the La Chilca Formation (upper supratidal plain) is herein attributed to reworked glaciomarine deposits that occurred during interglacial Hirnantian age, under conditions of sea rise and the action of tidal amplification. The intertidal–supratidal depositional environments are represented by tidal channels, scour and fill, tidal dunes, and hummocky cross‐stratified sandstones. The estimated tidal conditions for the tidal plain were mesotidal to macrotidal, under action of combined flows, attributed to the interaction of tidal currents and orbital low‐velocity waves. The identification of microbially induced sedimentary structures (MISS) in these deposits, such as petee polygonal structures, pitted texture, imploded sand volcanoes, Astropolithon sp., Manchuriophycus sp., domal build‐ups, biofilms, elephant skin, and trace fossils such as Chondrites sp., Zoophycos sp., Undichnia sp., Planolites sp., Monomorphichnus sp., and gastropod traces, may have played a protection and stabilization role on the clastic sediment surfaces against erosion of the La Chilca Formation deposits. The prolific growth of microbial mat on the intertidal to supratidal zone occurs explicitly at the turning points of transgression–regression cycles in shallow‐water environments under stable base‐level conditions. The middle‐upper section of the La Chilca Formation shows non‐cyclic rhythmites that are replaced by the cyclic rhythmites, suggesting an open tidal plain subject to an orbital/climatic rather than a tectonic control of cyclicity (Milankovitch cycles). The aggradation in this section indicates a shallowing towards the top of the formation. The La Chilca Formation records two third‐order transgressive events and a shallowing event. The transgressive events are found in the base and top of the formation and are marked by the presence of Fe‐oolites, while the shallowing event is determined by the presence of MISS.