bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrooxidative and Regioselective C−H Azolation of Phenol and Aniline Derivatives
Authors: Feng Pengju , Ma Guojian , Chen Xiaoguang , Wu Xing , Lin Ling , Liu Peng , Chen Tianfeng
Published: March 2019

A general and practical protocol was developed for the regioselective C−H azolation of phenol and aniline derivatives by electrooxidative cross‐coupling. The reaction occurs under metal‐, oxidant‐, and reagent‐free conditions, allowing access to a wide variety of synthetically useful heteroarene derivatives. The reaction also tolerates a broad range of functional groups and is amenable to gram‐scale synthesis. Finally, a preliminary mechanistic study indicated that a radical–radical‐combination pathway might be involved in the coupling reaction.
Multivalent Chelators for In Vivo Protein Labeling
Authors: Wieneke Ralph , Tampé Robert
Published: March 2019

With the advent of single‐molecule methods, chemoselective and site‐specific labeling of proteins evolved to become a central aspect in chemical biology as well as cell biology. Protein labeling demands high specificity, rapid as well as efficient conjugation, while maintaining low concentration and biocompatibility under physiological conditions. Generic methods that do not interfere with the function, dynamics, subcellular localization of proteins, and crosstalk with other factors are crucial to probe and image proteins in vitro and in living cells. Alternatives to enzyme‐based tags or autofluorescent proteins are short peptide‐based recognition tags. These tags provide high specificity, enhanced binding rates, bioorthogonality, and versatility. Here, we report on recent applications of multivalent chelator heads, recognizing oligohistidine‐tagged proteins. The striking features of this system has facilitated the analysis of protein complexes by single‐molecule approaches.
Electron Decoupling with Chirped Microwave Pulses for Rapid Signal Acquisition and Electron Saturation Recovery
Authors: Alaniva Nicholas , Saliba Edward P. , Sesti Erika L. , Judge Patrick T. , Barnes Alexander B.
Published: March 2019

Dynamic nuclear polarization (DNP) increases NMR sensitivity by transferring polarization from electron to nuclear spins. Herein, we demonstrate that electron decoupling with chirped microwave pulses enables improved observation of DNP‐enhanced13C spins in direct dipolar contact with electron spins, thereby leading to an optimal delay between transients largely governed by relatively fast electron relaxation. We report the first measurement of electron longitudinal relaxation time (T1e) during magic angle spinning (MAS) NMR by observation of DNP‐enhanced NMR signals (T1e=40±6 ms, 40 mMtrityl, 4.0 kHz MAS, 4.3 K). With a 5 ms DNP period, electron decoupling results in a 195 % increase in signal intensity. MAS at 4.3 K, DNP, electron decoupling, and short recycle delays improve the sensitivity of13C in the vicinity of the polarizing agent. This is the first demonstration of recovery times between MAS‐NMR transients being governed by short electron T1and fast DNP transfer.
Chemoenzymatic Total Synthesis of Deoxy‐, epi‐, and Podophyllotoxin and a Biocatalytic Kinetic Resolution of Dibenzylbutyrolactones
Authors: Lazzarotto Mattia , Hammerer Lucas , Hetmann Michael , Borg Annika , Schmermund Luca , Steiner Lorenz , Hartmann Peter , Belaj Ferdinand , Kroutil Wolfgang , Gruber Karl , Fuchs Michael
Published: March 2019

Podophyllotoxin is probably the most prominent representative of lignan natural products. Deoxy‐, epi‐, and podophyllotoxin, which are all precursors to frequently used chemotherapeutic agents, were prepared by a stereodivergent biotransformation and a biocatalytic kinetic resolution of the corresponding dibenzylbutyrolactones with the same 2‐oxoglutarate‐dependent dioxygenase. The reaction can be conducted on 2 g scale, and the enzyme allows tailoring of the initial, “natural” structure and thus transforms various non‐natural derivatives. Depending on the substitution pattern, the enzyme performs an oxidative C−C bond formation by C−H activation or hydroxylation at the benzylic position prone to ring closure.
Isomeric Effect on the anticancer Behavior of two Zinc (II) complexes based on 3,5‐bis(1‐imidazoly) pyridine: Experimental and Theoretical Approach
Authors: Zhu Mingchang , Song Da , Liu Ning , Wang Kehua , Su Junqi , Xiong Meng , Zhang Xi , Xu Yuang , Gao Enjun
Published: March 2019

Two isomeric Zinc (II) complexes constructed by 3,5‐bis(1‐imidazoly) pyridine has been synthesized and characterized by single crystal X‐ray diffraction, elemental analyses and infrared spectroscopy. The binding mode and ability of complex 1–2 with CT‐DNA were studied by UV and fluorescence spectra. The intrinsic binding constant Kb (Kb1 = 2.305 × 104 M−1, Kb2 = 3.095 × 104 M−1) and the observed association constant Kobs (Kobs1 = 1.523*106 M−1, Kobs2 = 2.057*106 M−1) indicated that the insertion ability of complex 2 with CT‐DNA is stronger than complex 1. Gel electrophoresis showed that complexes have a good ability to hydrolyze cleavage pBR322 plasmid DNA. The cytotoxicity and apoptosis studies showed that complexes exhibited excellent cytotoxic activity against HeLa cells, especially complex 2 had better growth inhibition than Cisplatin. Molecular docking study simulated the binding model of complexes with DNA (PDB:4av1), showing an imidazole plane of complex 2 can be inserted into a DNA base pair in relative parallel. Both complexes can be used as potential anticancer agents.
Fe3O4‐supported Schiff‐base copper (II) complex: A valuable heterogeneous nanocatalyst for one‐pot synthesis of new pyrano[2,3‐b]pyridine‐3‐carboxamide derivatives
Authors: Mahmoudi‐GomYek Samaneh , Azarifar Davood , Ghaemi Masoumeh , Keypour Hassan , Mahmoudabadi Masoumeh
Published: March 2019

A novel Cu (II) Schiff‐base complex immobilized on core‐shell magnetic Fe3O4nanoparticles (Fe3O4@SPNC) was successfully designed and synthesized. The structural features of these nanoparticles were studied and confirmed by using various techniques including FT‐IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy‐dispersive X‐ray spectroscopy (EDS), vibrating sample magnetometer (VSM), X‐Ray diffraction (XRD), wavelength dispersive X‐ray spectroscopy (WDX), and inductively coupled plasma (ICP). These newly synthesized nanoparticles have been used as efficient heterogeneous catalytic system for one‐pot multicomponent synthesis of new pyrano[2,3‐b]pyridine‐3‐carboxamide derivatives. Notably, the catalyst could be easily separated from the reaction mixture by using an external magnet and reused for several successive reaction runs with no significant loss of activity or copper leaching. The present protocol benefits from a hitherto unreported MNPs‐immobilized Cu (II) Schiff‐base complex as an efficient nanocatalyst for the synthesis of newly reported derivatives of pyrano[2,3‐b]pyridine‐3‐carboxamide from one‐pot multicomponent reactions.
Synthesis and CO2 separation of novel polyurethane membranes containing urea linkages
Authors: Zheng Yayun , Hu Yaofang , Yang Xing , Yuan Meng , Zhang Jie , Zhang Yaodong , Luo Jujie
Published: March 2019

We synthesized novel polyurethane (PU) membranes from isophorone diisocyanate (IPDI), poly(ethylene glycol) (PEG) with a molecular weight of 2000, aminopropyl‐terminated poly(dimethyl siloxane) (PDMS) with a molecular weight of 2000, and 1,4‐butanediol (BDO) via a two‐step polymerization. The structure of each synthesized membrane was studied through Fourier transform infrared spectroscopy and gel permeation chromatography. The effect of the thermal behavior was determined by differential scanning calorimetry and thermogravimetric analysis. The gas‐permeability characteristics of the PU membranes were then tested for a single gas. The results show that the permeability of CO2 (PCO2) gradually increased with PDMS content. Among these PU membranes, PU‐d (PEG/PDMS = 1:1, PEG/PDMS/IPDI/BDO = 1:3:2) showed the best PCO2 (132.6 Barrer) at 25°C and 1 bar pressure. The gas‐permeability coefficients of each PU membrane at different operating temperatures were investigated, and the results show that PCO2 reached 302.6 Barrer at 65°C and 1 bar. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47723.
Community participation in the development of the Ōngātoro/Maketū Estuary project: The socio‐ecological dimensions of restoring an interconnected ecosystem
Authors: Barrett Patrick , Kurian Priya , Simmonds Naomi , Cretney Raven
Published: March 2019

The restoration of the Ōngātoro/Maketū Estuary involves the reconnection of freshwater and estuarine habitats through the rediversion of the Kaituna River and is an innovative attempt to manage interconnected ecosystems to improve ecological health and conservation outcomes.

Flood and drainage works in the 1950s severed the connection between fresh‐ and salt‐water systems, leading to sedimentation, algal growth and anoxic conditions, and the loss of saltmarsh and other vegetated wetland habitat.

Following decades of trenchant debate about the causes, consequences and possible solutions to estuary degradation, a 3‐year consultation process between 2006 and 2009 established Māori and community support to restore water flows, re‐establish wetlands and other estuarine habitats, and promote kaitiakitanga (guardianship) and local people's stewardship.

Having secured widespread community support, a restoration plan informed by technical assessments and local traditional knowledge was co‐developed.

Analysis of the socio‐ecological dimensions of this aquatic conservation initiative uncovers implementation success factors in conservation planning: resource and governance system factors, historically contingent events, the opportunity to develop a shared understanding across stakeholder and iwi (indigenous) groups, the negotiation of a collective vision, and including diverse social actors who reflect a variety of viewpoints and values.
Structural Transformation Pathways of Alkaline Earth Family Coordination Polymers Containing 3,3′,5,5′‐Biphenyl Tetracarboxylic Acid
Authors: Lu Guo‐Dong , Zhang Zhi‐Hui , Tong Ya‐Yan , Liu Xiao‐Meng , Ma Xiao‐Fan , Xuan Xiao‐Peng
Published: March 2019

The understanding of crystal stepwise transformation is very important to enclose the “black box” in the preparation of crystal materials. In this work, different structural intermediates were isolated prior to the formation of the final alkali earth coordination polymers (CPs) during the preparation of three pairs of alkali earth CPs through solvothermal method and convenient oil‐bath reactions. Single crystal X‐ray diffraction analysis demonstrated the structural transformation from a 0 D to 1 D inorganic connectivity for the Ca‐CPs and Sr‐CPs, but a 1 D to 0 D inorganic connectivity for Ba‐CPs, involving the breakage/formation of chemical bonds in the reaction solutions. Further analyses indicated that these two different structural transformation pathways are determined by the deprotonation of organic acid, competitive balance between the inorganic and organic connectivity, and the twist of the linker. FT‐IR spectra, thermogravimetric and luminescence behaviors agree with their structural characteristics.
The constellations and spacetime concept according to the Inkas
Authors: Gamarra M. R. , Zen Vasconcellos C. A.
Published: March 2019

This paper tries to identify some of the main stellar constellations supposedly identified by the Inkas and their conception of space and time in the context of archaeoastronomy. Archaeoastronomy is not hard science; but it is still of transcendental importance in seeking to establish a bridge between the past and the present of astronomy and related sciences. “Archaeoastronomy is a discipline devoted to the study of the astronomical observations preceding the invention of the telescope. It has highlighted the great importance that ancient civilizations attributed to celestial phenomena and demonstrated how the analysis of the testimonies of this interest can greatly help us in the understanding of the past history of mankind”. Based on this conception, these constellations were collected through the study of manuscripts, documents, chronicles, interviews, and the oral tradition of different Quéchua‐speaking peoples in the Andes as well as their conceptions about space and time.
High energy processes in Wolf‐Rayet stars
Authors: Skinner S. L. , Schmutz W. , Güdel M. , Zhekov S.
Published: March 2019

Wolf‐Rayet (WR) stars are massive (≥10 M⊙) evolved stars undergoing advanced nuclear burning in their cores, rapidly approaching the end of their lives as supernovae. Their powerful winds enrich the interstellar medium with heavy elements, providing raw material for future generations of stars. We briefly summarize high‐energy processes in WR stars, focusing mainly on their X‐ray emission. We present new results from Chandra observations of the eclipsing WR + O binary CQ Cep covering a full orbit which stringently test X‐ray emission models.
Investigating the physics of ultrahigh‐energy neutrinos in neutrino telescope experiments
Authors: Machado M. V. T.
Published: March 2019

In this paper, we compute the corresponding number of events for PeV‐energy neutrinos for typical neutrino telescopes as in the IceCube experiment. We consider different parametrizations for the νN cross‐section, including predictions from the geometric scaling phenomenon. The theoretical uncertainty for the number of events is investigated and compared with usual quantum chromodynamics (QCD) calculations.
Entropy and creation cold dark matter models
Authors: Valentim R. , Jesus J. F.
Published: March 2019

Entropy is a fundamental concept from thermodynamics, and it can be used to study models in the context of the creation cold dark matter. A general feature of these models is that thermodynamic equilibrium is reached at last at the de Sitter era. Total Universe's entropy is calculated based on three terms: apparent horizon (Sh), entropy of matter (Sm), and entropy of radiation (Sγ). The constraints from total entropy come from the first and second derivatives (S′ ≥ 0 and S″ < 0) to estimate the parameters of the model with the general matter creation rate. The preliminary outcomes suggest limits for these parameters.
Non‐geodesic corrections to mass‐spin estimates for Galactic microquasars implied by quasiperiodic oscillation models
Authors: Kotrlová A. , Šrámková E. , Török G. , Goluchová K. , Horák J. , Straub O.
Published: March 2019

We study frequencies of axisymmetric and non‐axisymmetric epicyclic modes of accretion disk oscillations and explore the influence of pressure forces present in the disk. We utilize both approximate analytic methods and methods dealing with exact numerical solutions. Our investigation implies consequences for estimations of black hole spin in the three Galactic microquasars, namely GRS 1915+105, GRO J1655‐40, and XTE J1550‐564, which have been carried out based on several models of 3:2 high‐frequency quasiperiodic oscillations (QPOs). In the particular case of 3:2 epicyclic resonance model, the presence of pressure forces affects the predicted QPO frequencies only slightly when a < 0.9. On the contrary, when a > 0.9, the influence of pressure forces is nonnegligible. Our findings indicate that for several models this influence can be quite significant even for low values of spin.
Double tidal disruption events with supermassive black hole binaries
Authors: Wu X.‐J. , Yuan Y.‐F.
Published: March 2019

The two stars of stellar binaries can be tidally disrupted by supermassive black holes (SMBHs) or supermassive black hole binaries (SMBHBs) in sequence. In this contribution, we review our recent study about double tidal disruption events (DTDEs) with SMBHBs. With the help of scattering experiments, we find that the time interval between two successive tidal disruption events (TDEs) depend on the semimajor axis of incident stellar binaries. For stellar binaries with 1 M⊙ for each companion star and a semimajor axis less than 100 au, the maximum time interval is about 150 days when the stellar binary is tidally disrupted by an SMBH. However, for an SMBHB, the time intervals can be very large, and the maximum can exceed 10,000 years. Moreover, we also compare the probabilities of a DTDE with the time interval larger than 150 days by the SMBHB and of two separate TDEs by the SMBH with the same time interval. We find that, for the time interval of 150 days to 15 years, the probability of DTDEs by the SMBHB with a large mass ratio (i.e., qbhb ≳ 0.1) is larger than that of the SMBH scenario. Finally, according to our results, we suggest that DTDEs with the time interval of 150 days to 15 years could be useful tools for finding SMBHB candidates with the mass ratio qbhb ≳ 0.1 at galactic centers.
Inflation, dark energy, and dark matter in supergravity
Authors: Ketov S. V. , Aldabergenov Y.
Published: March 2019

We discuss the physical applications of supergravity to the dark side of our universe, comprising cosmological inflation, dark energy, and dark matter (DM). Supergravity is the meeting point of cosmology, gravity, and high‐energy physics of elementary particles, which makes it the natural framework to unify fundamental interactions and fundamental scales under Planck scale. In order to make our presentation accessible to a larger audience, we skip all technical details about supergravity theory and concentrate on the conceptual issues of supergravity applications to cosmology. We conjecture the gravitational origin of the cosmological inflation (in the modified gravity), the dark energy (as the positive cosmological constant), and the DM (made of gravitino particles) in supergravity.
Constraints on axionic dark matter in the 3‐3‐1 model
Authors: Romero Castellanos Ana R. , Alvarez‐Salazar C. E. , Sánchez‐Vega B. L.
Published: March 2019

Dark matter in the form of axions can be included in models with SU(3)C ⊗ SU(3)L ⊗ U(1)X symmetry with right‐handed neutrinos, where the strong charge‐parity (CP) problem can be solved. Different versions of the model have the appealing characteristic of giving the observed dark matter abundance, measured by the Planck collaboration, for suitable values of the parameters. We studied the constraints on the parameter space of the model obtained when the axion mass is calculated taking into account both quantum chromodynamics (QCD) effects and gravitationally induced operators, making a comparison of three different models.
The dark matter puzzle in a class of models with gauge symmetry SU(3)C ⊗ SU(3)L ⊗ U(1)N
Authors: Alvarez‐Salazar C. E. , Peres O. L. G. , Sánchez‐Vega B. L.
Published: March 2019

We analyze the dark matter (DM) puzzle in a class of models with gauge symmetry SU(3)C ⊗ SU(3)L ⊗ U(1)N, taking into account the constraints coming from Planck observations of the DM relic density, direct detection searches with Xenon1T, and indirect detection using Fermi‐LAT data. The model has two possible candidates, a fermion and a scalar, which require, to evade the constraints set by Xenon1T and Fermi‐LAT, and have relic densities in the range measured by the Planck collaboration, a minimum vacuum expectation value to break the SU(3)L symmetry of 10 and 15 TeV, respectively. In this case, these particles have masses of order 1 TeV, for the fermion, and between 500 and 600 GeV, for the scalar.
Numerical analysis of magnetogenesis' primordial mechanism
Authors: Garrison D.
Published: March 2019

We present the results of Relativistic Magnetohydrodynamic simulations utilizing initial conditions from both the Electroweak and quantum chromodynamics phase transitions to see if seed magnetic fields may be generated via the Biermann battery mechanism of magnetogensis. These simulations occur in a simulated early universe between 10−11 s and 10–3 s after the Big Bang. We find that magnetic fields on the order of 10−19 G are generated on small scales and magnetic fields of 10−25 G are generated on the Mpc scale. Further work is needed to understand how these fields may have impacted the large‐scale structures we observe today.
On the phase diagram of the Nambu–Jona‐Lasinio Lagrangian
Authors: Aichelin J. , Torres‐Rincon J.
Published: March 2019

The (Polyakov) Nambu–Jona‐Lasinio approach is an effective theory for low energies, which shares with Quantumchromodynamics the global symmetries. This approach is easy to handle and allows for analytical results for many of the observables that are of interest for the studies of ultrarelativistic heavy ion collisions but also for the merger and collisions of neutron stars. It allows in particular to study the density and temperature dependence of quark masses and of the masses of mesons and baryons as well as the chiral phase transition. In recent times, this transition came in the focus of interest because it is expected that the upcoming experiments at the Fair (Germany) and Nuclotron‐based Ion Collider fAcility (Russia) facilities will observe a Quark‐Gluon‐Plasma at finite baryon chemical potential.
A novel sensitive laccase biosensor using gold nanoparticles and poly L‐arginine to detect catechol in natural water
Authors: Maleki Nasim , Kashanian Soheila , Nazari Maryam , Shahabadi Nahid
Published: March 2019

In this study, the simple, green, and fast layer‐by‐layer modification of the glassy carbon electrode was mainly performed by electrodeposition of gold nanoparticles and then, poly‐l‐arginine, and finally, laccase was covalently bonded to poly‐l‐arginine using glutaraldehyde. This type of fabrication is used for the first time for catechol detection, which provides a bioelectrocatalytic cycle for electron transport in the presence of laccase that results in sensitive and fast detection of catechol. The scanning electron microscopy, Fourier‐transform infrared spectroscopy, and electrochemical studies were performed to confirm successful immobilization of the enzyme. The biosensor response was linear in a wide range of catechol trace concentrations, 24.90–274.00 nM, with the detection limit of 18.00 nM. Values of Km, α, n, and Ks for the immobilized enzyme were calculated to be 1.25 × 10−2 µM, 0.56, 3.19, and 0.28 Sec−1, respectively. It was examined in real sample successfully confirming it is capable of measuring catechol in natural water.
Techno‐economic and greenhouse gas analyses of lignin valorization to eugenol and phenolic products in integrated ethanol biorefineries
Authors: Martinez‐Hernandez Elias , Cui Xinguang , Scown Corinne D. , Amezcua‐Allieri Myriam A. , Aburto Jorge , Simmons Blake A.
Published: March 2019

This work presents techno‐economic and greenhouse gas (GHG) analyses of an ethanol biorefinery integrating lignin conversion into eugenol and other phenolics. Catalytic hydrogenolysis assisted by isopropanol (IPA) is used to convert the lignin recovered after ionic liquid (IL) pretreatment, saccharification, and fermentation. This process was compared to a biorefinery using lignin for energy generation and simulated in SuperPro Designer. Spatial analysis was performed to determine biorefinery locations and capacities in a Mexican state with potential for lignocellulosic biomass, including corn stover, sorghum stubble, and Jatropha fruit shells. Relative to the base case, diverting 50% of lignin to phenolics decreased the ethanol cost of production significantly due to the high market value of the co‐products. The minimum ethanol selling price (MESP) for this case was $2.02 gal−1. The resulting cradle‐to‐gate GHG footprint of bioethanol was 21 g CO2‐eq MJ−1, a 78% reduction with respect to gasoline when system expansion is used for allocation. Using market value‐based allocation resulted in 82% GHG reduction. Analysis of scenarios showed that a biorefinery processing 3000 t day−1 biomass and diverting 80% of lignin to phenolics can potentially yield an MESP lower than $1.5 gal−1. To achieve this, research should target a reduction in IL input by 30% and IPA input by 40%, together with more energy‐efficient separation processes. The reduction in IL and IPA can be achieved by decreasing their loading rates and increasing recycling. Sensitivity analysis showed that, for biomass prices higher than $45 t−1, biorefinery capacities must exceed 5000 t d−1 biomass input. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd
Development of a Korean‐specific virtual population for physiologically based pharmacokinetic modelling and simulation
Authors: Kim Yun , Hatley Oliver , Rhee Su‐jin , Yi Sojeong , Lee Hyun A. , Yoon Sumin , Chung Jae‐Yong , Yu Kyung‐Sang , Lee Howard
Published: March 2019

Physiologically based pharmacokinetic (PBPK) modelling and simulation is a useful tool in predicting the PK profiles of a drug, assessing the effects of covariates such as demographics, ethnicity, genetic polymorphisms and disease status on the PK, and evaluating the potential of drug–drug interactions. We developed a Korean‐specific virtual population for the SimCYP® Simulator (version 15 used) and evaluated the population's predictive performance using six substrate drugs (midazolam, S‐warfarin, metoprolol, omeprazole, lorazepam and rosuvastatin) of five major drug metabolizing enzymes (DMEs) and two transporters. Forty‐three parameters including the proportion of phenotypes in DMEs and transporters were incorporated into the Korean‐specific virtual population. The simulated concentration–time profiles in Koreans were overlapped with most of the observed concentrations for the selected substrate drugs with a < 2‐fold difference in clearance. Furthermore, we found some drug models within the SimCYP® library can be improved, e.g., the minor allele frequency of ABCG2 and the fraction metabolized by UGT2B15 should be incorporated for rosuvastatin and lorazepam, respectively. The Korean‐specific population can be used to evaluate the impact of ethnicity on the PKs of a drug, particularly in various stages of drug development.
Fetal cardiac intervention for right sided heart disease: Pulmonary atresia with intact ventricular septum
Authors: Strainic James
Published: March 2019

Congenital heart disease (CHD), the most common of birth defects, can be serious enough to require a lifetime of medical care including multiple surgeries or other interventions. Advances in ultrasound technology and a better understanding of the progression of CHDs have made it possible to intervene in utero. This early stage intervention allows the still plastic cardiovascular system to return to a more normal trajectory thus sparing the newborn from negative consequences to morbidity and mortality. Fetal cardiac intervention (FCI) has been successful for the alleviation of left ventricular dysfunction resulting in remarkably positive outcomes for many families. Promising results support that FCI may also be useful in alleviating right ventricular dysfunction. This bodes well for expanding the use of FCI to lead to better postnatal adaptation and improved long‐term function for more children with CHD.
Stress‐Induced Evolutionary Innovation: A Mechanism for the Origin of Cell Types
Authors: Wagner Günter P. , Erkenbrack Eric M. , Love Alan C.
Published: March 2019

Understanding the evolutionary role of environmentally induced phenotypic variation (i.e., plasticity) is an important issue in developmental evolution. A major physiological response to environmental change is cellular stress, which is counteracted by generic stress reactions detoxifying the cell. A model, stress‐induced evolutionary innovation (SIEI), whereby ancestral stress reactions and their corresponding pathways can be transformed into novel structural components of body plans, such as new cell types, is described. Previous findings suggest that the cell differentiation cascade of a cell type critical to pregnancy in humans, the decidual stromal cell, evolved from a cellular stress reaction. It is hypothesized that the stress reaction in these cells was elicited ancestrally via inflammation caused by embryo attachment. The present study proposes that SIEI is a distinct form of plasticity‐based evolutionary change leading to the origin of novel structures rather than adaptive transformation of pre‐existing characters.
Elevated Mutagenicity in Meiosis and Its Mechanism
Authors: Arbel‐Eden Ayelet , Simchen Giora
Published: March 2019

Diploid germ cells produce haploid gametes through meiosis, a unique type of cell division. Independent reassortment of parental chromosomes and their recombination leads to ample genetic variability among the gametes. Importantly, new mutations also occur during meiosis, at frequencies much higher than during the mitotic cell cycles. These meiotic mutations are associated with genetic recombination and depend on double‐strand breaks (DSBs) that initiate crossing over. Indeed, sequence variation among related strains is greater around recombination hotspots than elsewhere in the genome, presumably resulting from recombination‐associated mutations. Significantly, enhanced mutagenicity in meiosis may lead to faster divergence during evolution, as germ‐line mutations are the ones that are transmitted to the progeny and thus have an evolutionary impact. The molecular basis for mutagenicity in meiosis may be related to the repair of meiotic DSBs by polymerases, or to the exposure of single‐strand DNA to mutagenic agents during its repair.
Baseline findings of the population-based, randomized, multifaceted Danish cardiovascular screening trial (DANCAVAS) of men aged 65–74 years
Authors: Lindholt J S , Rasmussen L M , Søgaard R , Lambrechtsen J , Steffensen F H , Frost L , Egstrup K , Urbonaviciene G , Busk M , Olsen M H , Hallas J , Diederichsen A C
Published: March 2019

Background

The challenge of managing age-related diseases is increasing; routine checks by the general practitioner do not reduce cardiovascular mortality. The aim here was to reduce cardiovascular mortality by advanced population-based cardiovascular screening. The present article reports the organization of the study, the acceptability of the screening offer, and the relevance of multifaceted screening for prevention and management of cardiovascular disease.

Methods

Danish men aged 65–74 years were invited randomly (1 : 2) to a cardiovascular screening examination using low-dose non-contrast CT, ankle and brachial BP measurements, and blood tests.

Results

In all, 16 768 of 47 322 men aged 65–74 years were invited and 10 471 attended (uptake 62·4 per cent). Of these, 3481 (33·2 per cent) had a coronary artery calcium score above 400 units. Thoracic aortic aneurysm was diagnosed in the ascending aorta (diameter 45 mm or greater) in 468 men (4·5 per cent), in the arch (at least 40 mm) in 48 (0·5 per cent) and in the descending aorta (35 mm or more) in 233 (2·2 per cent). Abdominal aortic aneurysm (at least 30 mm) and iliac aneurysm (20 mm or greater) were diagnosed in 533 (5·1 per cent) and 239 (2·3 per cent) men respectively. Peripheral artery disease was diagnosed in 1147 men (11·0 per cent), potentially uncontrolled hypertension (at least 160/100 mmHg) in 835 (8·0 per cent), previously unknown atrial fibrillation confirmed by ECG in 50 (0·5 per cent), previously unknown diabetes mellitus in 180 (1·7 per cent) and isolated severe hyperlipidaemia in 48 men (0·5 per cent).

In all, 4387 men (41·9 per cent), excluding those with potentially uncontrolled hypertension, were referred for additional cardiovascular prevention. Of these, 3712 (35·5 per cent of all screened men, but 84·6 per cent of those referred) consented and were started on medication.

Conclusion

Multifaceted cardiovascular screening is feasible and may optimize cardiovascular disease prevention in men aged 65–74 years. Uptake is lower than in aortic aneurysm screening.
Randomized clinical trial of liposomal bupivacaine transverse abdominis plane block versus intrathecal analgesia in colorectal surgery
Authors: Colibaseanu D T , Osagiede O , Merchea A , Ball C T , Bojaxhi E , Panchamia J K , Jacob A K , Kelley S R , Naessens J M , Larson D W
Published: March 2019

Background

Transverse abdominis plane (TAP) block is considered an effective alternative to neuraxial analgesia for abdominal surgery. However, limited evidence supports its use over traditional analgesic modalities in colorectal surgery. This study compared the analgesic efficacy of liposomal bupivacaine TAP block with intrathecal (IT) opioid administration in a multicentre RCT.

Methods

Patients undergoing elective small bowel or colorectal resection were randomized to receive TAP block or a single injection of IT analgesia with hydromorphone. Patients were assessed at 4, 8, 16, 24 and 48 h after surgery. Primary outcomes were mean pain scores and morphine milligram equivalents (MMEs) administered within 48 h after surgery. Secondary outcomes included duration of hospital stay, incidence of postoperative ileus and use of intravenous patient-controlled analgesia.

Results

In total, 209 patients were recruited and 200 completed the trial (TAP 102, IT 98). The TAP group had a 1·6-point greater mean pain score than the IT group at 4 h after surgery, and this difference lasted for 16 h after operation. The TAP group received more MMEs within the first 24 h after surgery than the IT group (median difference in MMEs 10·0, 95 per cent c.i. 3·0 to 20·5). There were no differences in MME use at 24 and 48 h, or with respect to secondary outcomes.

Conclusion

IT opioid administration provided better immediate postoperative pain control than TAP block. Both modalities resulted in low pain scores in patients undergoing elective colorectal surgery and should be considered in multimodal postoperative analgesic plans. Registration number: NCT02356198 ( http://www.clinicaltrials.gov).
MnOx–Carbon Black‐embedded LiFePO4 (MnOx/C‐LFP) as a Cathode Material for High‐Power Li‐Ion Batteries
Authors: Kim Su Jin , Cho Jae‐Hyun , Lee Kwan‐Young , Cho Byung Won , Chung Kyung Yoon , Kim Ji‐Young
Published: March 2019

LiFePO4 is a promising, cost‐effective, and safe material for large‐scale energy‐storage applications, however its low intrinsic conductivity requires improvement. In order to address this issue, herein, we describe the successful sol‐gel synthesis of MnOx–carbon black‐embedded LiFePO4 (MnOx/C‐LFP). Bare LiFePO4 and MnOx/C‐LFP composites were characterized by scanning electron and high‐resolution transmission electron microscopies, as well as X‐ray diffraction, which revealed LiFePO4 particles embedded in the cross‐linked MnOx/C matrix. Electrochemical studies show that the composite has a superior initial discharge capacity of 151.4 mAh/g at 1C, and a good capacity retention of 96.6% after 100 cycles, compared to the bare material (141.2 mAh/g and 92%). The improvement in electrochemical performance is attributed to facile lithium‐ion diffusion through MnOx/C nanoparticles on the surface of the LiFePO4 cathode material. The co‐coating of MnOx and carbon black is an effective way of improving the electrochemical kinetics of cathode materials.
Plagiarism or not? investigation of Turnitin®‐detected similarity hits in biology laboratory reports
Authors: Bertram Gallant Tricia , Picciotto Madeleine , Bozinovic Goran , Tour Ella
Published: March 2019

In undergraduate biology laboratory courses, laboratory reports can be a useful tool for teaching scientific writing, integration of source material, and information literacy; however, these teaching objectives are at times undermined by students' plagiarism. Laboratory instructors often use similarity‐matching software to detect plagiarism in laboratory reports, yet similarity hits detected with such software remain poorly characterized. In the upper division molecular biology laboratory course described here, Turnitin® routinely detected dozens of similarity hits in laboratory reports. To determine whether this abundance of similarity hits was indicative of widespread plagiarism, we analyzed similarity hits detected in 255 laboratory reports written by 135 students. Only a small minority of Turnitin® similarity matches were problematic, but over half of the laboratory reports contained at least one problem with incorporation of scientific sources (e.g., laboratory manual and scientific articles). We identified four common types of such writing problems: patchwriting, technical parroting, copying, and falsification of sources. In 18% of the laboratory reports, we detected an alarmingly superficial use of primary literature. Most of the source incorporation problems did not rise to the level of plagiarism. As a result of this study, we recommend changes in scientific writing instruction and a transition to laboratories providing more authentic research experiences. © 2019 International Union of Biochemistry and Molecular Biology, 47(4):370–379, 2019.
Incorporating a Monofluoroalkene into the Backbones of Short Peptides: Evaluating the Impact on Local Hydrophobicity
Authors: Drouin Myriam , Laxio Arenas José , Paquin Jean‐François
Published: March 2019

The local hydrophobicity of an amino acid residue in a peptide sequence can be determined by measuring the hydrophobicity index (φ0) by reversed‐phase (RP) HPLC. Herein, the impact on the local hydrophobicity of the replacement of an amide by a monofluoroalkene unit in short peptides is discussed. Monofluoroalkene‐containing dipeptides and tripeptides were synthesized, as well as their natural parent compounds, and the hydrophobicity indexes of these short peptides and peptidomimetics were determined. Comparison between the natural parent peptides and their alkene‐containing analogues was made, and the dependence of the peptidomimetic analogues’ behaviour on the pH and the solvent was studied. It was found that the presence of a monofluoroalkene unit enhanced a peptide's hydrophobicity.
Human Macrophage Galactose‐Type Lectin (MGL) Recognizes the Outer Core of Escherichia coli Lipooligosaccharide
Authors: Maalej Meriem , Forgione Rosa Ester , Marchetti Roberta , Bulteau François , Thépaut Michel , Lanzetta Rosa , Laguri Cedric , Simorre Jean‐Pierre , Fieschi Franck , Molinaro Antonio , Silipo Alba
Published: March 2019

Carbohydrate–lectin interactions intervene in and mediate most biological processes, including a crucial modulation of immune responses to pathogens. Despite growing interest in investigating the association between host receptor lectins and exogenous glycan ligands, the molecular mechanisms underlying bacterial recognition by human lectins are still not fully understood. Herein, a novel molecular interaction between the human macrophage galactose‐type lectin (MGL) and the lipooligosaccharide (LOS) of Escherichia coli strain R1 is described. Saturation transfer difference NMR spectroscopy analysis, supported by computational studies, demonstrated that MGL bound to the purified deacylated LOSR1 mainly through recognition of its outer core and established crucial interactions with the terminal Galα(1,2)Gal epitope. These results assess the ability of MGL to recognise glycan moieties exposed on Gram‐negative bacterial surfaces.
Design of an Ultrafast G Protein Switch Based on a Mouse Melanopsin Variant
Authors: Tennigkeit Stefan Alexander , Karapinar Raziye , Rudack Till , Dreier Max‐Aylmer , Althoff Philipp , Eickelbeck Dennis , Surdin Tatjana , Grömmke Michelle , Mark Melanie D. , Spoida Katharina , Lübben Mathias , Höweler Udo , Herlitze Stefan , Gerwert Klaus
Published: March 2019

The primary goal of optogenetics is the light‐controlled noninvasive and specific manipulation of various cellular processes. Herein, we present a hybrid strategy for targeted protein engineering combining computational techniques with electrophysiological and UV/visible spectroscopic experiments. We validated our concept for channelrhodopsin‐2 and applied it to modify the less‐well‐studied vertebrate opsin melanopsin. Melanopsin is a promising optogenetic tool that functions as a selective molecular light switch for G protein‐coupled receptor pathways. Thus, we constructed a model of the melanopsin Gq protein complex and predicted an absorption maximum shift of the Y211F variant. This variant displays a narrow blue‐shifted action spectrum and twofold faster deactivation kinetics compared to wild‐type melanopsin on G protein‐coupled inward rectifying K+ (GIRK) channels in HEK293 cells. Furthermore, we verified the in vivo activity and optogenetic potential for the variant in mice. Thus, we propose that our developed concept will be generally applicable to designing optogenetic tools.
Coronary artery disease and reasonably incomplete coronary revascularization in high‐risk patients undergoing transcatheter aortic valve implantation
Authors: Saia Francesco , Palmerini Tullio , Compagnone Miriam , Battistini Paola , Moretti Carolina , Taglieri Nevio , Marcelli Chiara , Bruno Antonio G. , Ghetti Gabriele , Corsini Anna , Bacchi Reggiani Maria‐Letizia , Marrozzini Cinzia , Rapezzi Claudio
Published: March 2019

Objectives

To evaluate the long‐term impact of coronary artery disease (CAD) and heart team‐guided incomplete coronary revascularization in patients undergoing transcatheter aortic valve implantation (TAVI).

Background

Revascularization strategy of CAD diagnosed with routine coronary angiography before TAVI is uncertain.

Methods

Five hundred and forty consecutive TAVI patients were classified as having CAD or normal coronary arteries (no‐CAD). Within the CAD group, patients were further classified as those with complete (CR) versus incomplete revascularization (IR). Revascularization strategy was guided by the Heart Team following an algorithm largely based on current guidelines. Main outcome of interest was the incidence of 5‐year cardiovascular (CV) death.

Results

Prevalence of CAD was 53.9%. CAD patients showed significantly lower left ventricular ejection fraction (LVEF: 55.8 ± 13.4% CAD vs. 61.4% ± 12.1 no‐CAD, p < .0001), lower gradients, and larger ventricular volumes in comparison with the no‐CAD group. Within the CAD group, 138 patients (47.4%) received CR and 153 (52.6%) IR. In‐hospital mortality was 3.9%, without significant difference between groups (4.0% no‐CAD vs. 3.8% CAD, p = .88; 2.9% CR vs. 4.6% IR, p = .45). Median follow‐up was 57.8 months. Five‐year survival free from CV death was 79.6% in the CAD versus 77.9% in the no‐CAD group (p = .98), and 84.3% in the CR versus 74.3% in the IR groups (p = .25). These results were confirmed excluding patients with previous revascularization. At multivariable analyses, presentation with acute coronary syndrome (ACS) was significantly associated with 5‐year CV death.

Conclusions

CAD is frequent in patients undergoing TAVI but portends an adverse prognosis only when presenting with ACS. Heart‐team directed complete or reasonably incomplete revascularization was associated with comparable outcomes.
Elaborate Tuning in Ligand Makes a Big Difference in Catalytic Performance: Bulky Nickel Catalysts for (Co)polymerization of Ethylene with Promising Vinyl Polar Monomers
Authors: Zhang Yanping , Mu Hongliang , Wang Xuling , Pan Li , Li Yuesheng
Published: March 2019

To reveal effect of electronic or steric modification of phosphino‐phenolate nickel complex for preparing optimized catalysts, we take elaborated studies on structure‐performance relationship by finely modifying substituents on ortho‐phenoxy position or phosphorus moiety of this catalyst. It reveals that these newly synthesized complexes are thermally robust, and exhibits very high activity (up to 107 g molNi−1 h−1) in ethylene polymerization even at 120 °C. Associated with stoichiometric experiments, experimental results prove that nickel complexes bearing electron‐withdrawing substituents on ortho‐phenoxy position or electron‐donating substituents on phosphorus atom show higher activity than contrastive catalysts toward ethylene polymerization and ethylene–methyl acrylate (MA) copolymerization. Among these catalysts, 3 g bearing a strong electron‐withdrawing substituent on ortho‐phenoxy position exhibits the highest activity, and produces copolymers with the highest molecular weight and analogous MA incorporation. Various challenging polar vinyl monomers, like polyethylene glycol monomethyl ether acrylate, can be efficiently copolymerized with ethylene.
In Situ Hydrogenation of CO2 by Al/Fe and Zn/Cu Alloy Catalysts under Mild Conditions
Authors: Sun Yufan , Hu Hanjun , Wang Yutian , Gao Jia , Tang Yang , Wan Pingyu , Hu Qing , Lv Jianjun , Zhang Tianshu , Yang Xiao Jin
Published: March 2019

The development of efficient metal catalysts for in situ hydrogenation of CO2 in water under mild conditions has gained considerable attention. Three Al alloys (Al/Fe, Al/Fe/Cu, Al/Cu) and three Zn/Cu alloys for in situ hydrogenation of CO2 in aqueous bicarbonate solutions were investigated. Hydrogen was generated by reaction of Al, Fe, and Zn in the alloys with water. In situ hydrogenation of CO2 was likely to be catalyzed by intermetallic compounds and generated metal oxides. Al alloys catalyzed the hydrogenation to methane while Zn/Cu alloys produced CO and formic acid. Zn/Cu5 possessed the highest catalytic activity, which was attributed to the CuZn5 crystal planes in the alloys. Insights are provided into the importance of compositions and structures of alloys for the selectivity for in situ hydrogenation of CO2 in aqueous bicarbonate solutions.
Influence of the Nature of Boron‐Doped Diamond Anodes on the Dehydrogenative Phenol‐Phenol Cross‐Coupling
Authors: Gleede Barbara , Yamamoto Takashi , Nakahara Kenshin , Botz Alexander , Graßl Tobias , Neuber Rieke , Matthée Thorsten , Einaga Yasuaki , Schuhmann Wolfgang , Waldvogel Siegfried R.
Published: March 2019

Boron‐doped diamond (BDD) represents a powerful and innovative electrode material. In particular, in combination with fluorinated solvents such as 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP), the system exhibits the largest known electrochemical window of approximately 5 V in protic media. Furthermore, the anodic treatment allows the direct formation of oxyl radicals, which are known to exhibit specific reactivity. The electrochemical dehydrogenative phenol‐phenol cross‐coupling is a versatile and useful transformation to non‐symmetric biphenols. This electro‐organic conversion can be divided into two regimes: initial oxidation at the anode and the electrolyte‐controlled follow‐up reaction. This work intends to provide an answer about the influence of BDD electrodes on oxidation reactions in electrosynthesis. Depending on the electro‐organic transformation, the support material of BDD, its boron content, and its fabrication method have a significant influence on the electrosynthetic efficiency.
Lubricin on Platinum Electrodes: A Low‐Impedance Protein‐Resistant Surface Towards Biomedical Implantation
Authors: Silva Saimon M. , Quigley Anita F. , Kapsa Robert M. I. , Greene George W. , Moulton Simon E.
Published: March 2019

Biofouling on surfaces compromises the function of biomedical devices whose function involves contact with biological fluids. In the context of electrochemical devices, proteins are attracted to the surface via coaction of various forces (hydrogen bond, hydrophobic effect, and other polar interactions) and protein interaction with the surface can significantly alter the surface chemistry. In response to this issue, we have developed an efficient anti‐biofouling surface that employs a glycoprotein, lubricin (LUB), and which generates low impedance layers compatible with electrochemical applications. Herein, we investigate how different LUB densities on platinum (Pt) electrodes affect the surface electrochemistry and its ability to prevent nonspecific adsorption of protein to the surface. Surfaces with higher densities of LUB were more resistant to protein adsorption. The LUB modified Pt electrodes were challenged in artificial perilymph (AP) media under passive and electrically stimulated conditions over 7‐day periods throughout which the LUB layer retained its anti‐biofouling and surface coating stability.