bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic diversity increases with depth in red gorgonian populations of the Mediterranean Sea and the Atlantic Ocean
Authors: Pilczynska Joanna , Cocito Silvia , Boavida Joana , Serrão Ester A. , Assis Jorge , Fragkopoulou Eliza , Queiroga Henrique 
Published: May 2019

BackgroundIn the ocean, the variability of environmental conditions found along depth gradients exposes populations to contrasting levels of perturbation, which can be reflected in the overall patterns of species genetic diversity. At shallow sites, resource availability may structure large, persistent and well-connected populations with higher levels of diversity. In contrast, the more extreme conditions, such as thermal stress during heat waves, can lead to population bottlenecks and genetic erosion, inverting the natural expectation. Here we examine how genetic diversity varies along depth for a long-lived, important ecosystem-structuring species, the red gorgonian,Paramuricea clavata.MethodsWe used five polymorphic microsatellite markers to infer differences in genetic diversity and differentiation, and to detect bottleneck signs between shallow and deeper populations across the Atlantic Ocean and the Mediterranean Sea. We further explored the potential relationship between depth and environmental gradients (temperature, ocean currents, productivity and slope) on the observed patterns of diversity by means of generalized linear mixed models.ResultsAn overall pattern of higher genetic diversity was found in the deeper sites of the Atlantic Ocean and the Mediterranean Sea. This pattern was largely explained by bottom temperatures, with a linear pattern of decreasing genetic diversity with increasing thermal stress. Genetic differentiation patterns showed higher gene flow within sites (i.e., shallow vs. deeper populations) than between sites. Recent genetic bottlenecks were found in two populations of shallow depths.DiscussionOur results highlight the role of deep refugial populations safeguarding higher and unique genetic diversity for marine structuring species. Theoretical regression modelling demonstrated how thermal stress alone may reduce population sizes and diversity levels of shallow water populations. In fact, the examination of time series on a daily basis showed the upper water masses repeatedly reaching lethal temperatures forP. clavata. Differentiation patterns showed that the deep richer populations are isolated. Gene flow was also inferred across different depths; however, not in sufficient levels to offset the detrimental effects of surface environmental conditions on genetic diversity. The identification of deep isolated areas with high conservation value for the red gorgonian represents an important step in the face of ongoing and future climate changes.
Inverted papilloma with multifocal attachment is associated with increased recurrence
Authors: Tong Charles C. L. , Patel Neil N. , Maina Ivy W. , Triantafillou Vasiliki , Yan Carol H. , Kuan Edward C. , Kohanski Michael A. , Papagiannopoulos Peter , Workman Alan D. , Cohen Noam A. , Kennedy David W. , Adappa Nithin D. , Palmer James N. 
Published: May 2019

BackgroundInverted papilloma (IP) is a benign sinonasal tumor with a well‐known propensity to recur, especially at its bony attachment site. Anecdotal evidence suggests lower rate of recurrence in primary resection. We also aimed to evaluate the effect of multifocal vs single focus of attachment in disease control.MethodsThis work is a retrospective review of 535 IP resections performed during the period from 2006 to 2016 at a tertiary‐care center. Demographic data, tumor location and attachment sites, and follow‐up duration data were obtained.ResultsTwo hundred ten patients were eligible for analysis. The mean age was 57 years, with an average postoperative surveillance of 36.4 months. Patients who had a previous procedure at an outside institution have a recurrence rate of 22.3%, compared with 12.4% for patients who had primary surgery at our institution. The most common site of attachment was maxillary sinus (47.6%), followed by ethmoid sinus (39%). Individual tumor review showed 50% of the patients to have multifocal attachment disease, of which there is a higher prevalence in secondary cases when compared with primary cases (53.7% vs 44.9%). Multiple tumor attachment sites had a significant effect on recurrence (odds ratio, 3.5; 95% confidence interval, 1.6‐7.6; p = 0.002).ConclusionPrimary resection and single‐focus attachment of inverted papilloma are associated with lower recurrence rates at 3‐year follow‐up.
Produktive Modifikationen von Cyaninfarbstoff‐π‐Netzwerken
Authors: Usama Syed Muhammad , Thompson Tye , Burgess Kevin 
Published: May 2019

AbstractPolymethinbrücken in Cyaninfarbstoffen können durch Einbau in kantenverknüpfte Ringsysteme sterisch fixiert oder aber durch Konjugation mit Heterocyclen expandiert werden. Neuere Studien haben gezeigt, dass solche Modifikationen zu deutlich helleren Farbstoffen mit rotverschobenen Absorptions‐ und Emissionsmaxima führen können.
Electrolytes for Rechargeable Lithium–Air Batteries
Authors: Lai Jingning , Xing Yi , Chen Nan , Li Li , Wu Feng , Chen Renjie 
Published: May 2019

AbstractLithium–air batteries are promising devices for electrochemical energy storage because of their ultrahigh energy density. However, it is still challenging to achieve practical Li–air batteries because of their severe capacity fading and poor rate capability. Electrolytes are the prime suspects for cell failure. In this Review, we focus on the opportunities and challenges of electrolytes for rechargeable Li–air batteries. A detailed summary of the reaction mechanisms, internal compositions, instability factors, selection criteria, and design ideas of the considered electrolytes is provided to obtain appropriate strategies to meet the battery requirements. In particular, ionic liquid (IL) electrolytes and solid‐state electrolytes show exciting opportunities to control both the high energy density and safety.
Zusätzliche Schienenspannungen aus Langzeitverformungen von Eisenbahnbrücken mit Fester Fahrbahn – Modell und Realität
Authors: Wenner Marc , Marx Steffen , Koca Matthias 
Published: May 2019

AbstractDie Langzeitverformungen des Überbaus aus Temperaturänderungen sowie aus Kriechen und Schwinden bei Betonbrücken sind für einen wesentlichen Teil der zusätzlichen Schienenspannungen bei lückenloser Führung der Schiene über die Brücke verantwortlich. In diesem Aufsatz werden die Ergebnisse umfangreicher Messungen an langen Talbrücken mit Fester Fahrbahn analysiert, um die aktuellen Modelle zur Berechnung der zusätzlichen Schienenspannungen auf Brücken zu überprüfen. In einem ersten Schritt werden der Umfang und die Konzeption der Messung sowie die Methodik der Auswertung und die Plausibilisierung der Daten vorgestellt. Im nächsten Schritt werden die Daten in Hinblick auf die in der Berechnung anzusetzenden Temperaturen analysiert. Der Schwerpunkt des Aufsatzes liegt auf der Auswertung der über fast zwei Jahre erfassten Langzeitdaten der Schienenspannungen und ‐verschiebungen sowie auf deren Vergleich mit den Modellen. Durch das gewählte Messlayout konnten aus den Messergebnissen auch Rückschlüsse auf den sich einstellenden Längsverschiebewiderstand unter den Realbedingungen der Strecke, der bei der Festen Fahrbahn den maßgebenden Parameter für die auftretenden Schienenspannungen darstellt, gezogen werden. Die im Aufsatz vorgestellten Ergebnisse liefern wichtige Erkenntnisse über die Berechnung der zusätzlichen Schienenspannungen bei Fester Fahrbahn.
Stabilization of cyclohexanone monooxygenase by computational and experimental library design
Authors: Fürst Maximilian J. L. J. , Boonstra Marjon , Bandstra Selle , Fraaije Marco W. 
Published: May 2019

AbstractEnzymes often by far exceed the activity, selectivity, and sustainability achieved with chemical catalysts. One of the main reasons for the lack of biocatalysis in the chemical industry is the poor stability exhibited by many enzymes when exposed to process conditions. This dilemma is exemplified in the usually very temperature‐sensitive enzymes catalyzing the Baeyer–Villiger reaction, which display excellent stereo‐ and regioselectivity and offer a green alternative to the commonly used, explosive peracids. Here we describe a protein engineering approach applied to cyclohexanone monooxygenase from Rhodococcus sp. HI‐31, a substrate‐promiscuous enzyme that efficiently catalyzes the production of the nylon‐6 precursor ε‐caprolactone. We used a framework for rapid enzyme stabilization by computational libraries (FRESCO), which predicts protein‐stabilizing mutations. From 128 screened point mutants, approximately half had a stabilizing effect, albeit mostly to a small degree. To overcome incompatibility effects observed upon combining the best hits, an easy shuffled library design strategy was devised. The most stable and highly active mutant displayed an increase in unfolding temperature of 13°C and an approximately 33x increase in half‐life at 30°C. In contrast to the wild‐type enzyme, this thermostable 8x mutant is an attractive biocatalyst for biotechnological applications.
Effect of UV Radiation on Fluorescent RNA Aptamers’ Functional and Templating Ability
Authors: Saha Ranajay , Chen Irene A. 
Published: May 2019

AbstractDamage from ultraviolet (UV) radiation was likely to be an important selection pressure during the origin of life. RNA is believed to have been central to the origin of life and might form the basis for simple synthetic cells. Although photodamage of DNA has been extensively studied, photodamage is highly dependent on local molecular context, and damage to functional RNAs has been relatively under‐studied. We irradiated two fluorescent RNA aptamers and monitored the loss of activity, folding, and the kinetics of lesion accumulation. The loss of activity differed depending on the aptamer, with the Spinach2 aptamer retaining substantial activity after long exposure times. The binding pocket was particularly susceptible to damage, and melting of the duplex regions increased susceptibility; this is consistent with the view that duplex formation is protective. At the same time, susceptibility varied greatly depending on context, thus emphasizing the importance of studying many different RNAs to understand UV hardiness.
Trichogin GA IV Alignment and Oligomerization in Phospholipid Bilayers
Authors: Salnikov Evgeniy S. , De Zotti Marta , Bobone Sara , Mazzuca Claudia , Raya Jesus , Siano Alvaro S. , Peggion Cristina , Toniolo Claudio , Stella Lorenzo , Bechinger Burkhard 
Published: May 2019

AbstractTrichogin GA IV is a short peptaibol with antimicrobial activity. This uncharged, but amphipathic, sequence is aligned at the membrane interface and undergoes a transition to an aggregated state that inserts more deeply into the membrane, an assembly that predominates at a peptide‐to‐lipid ratio (P/L) of 1:20. In this work, the natural trichogin sequence was prepared and reconstituted into oriented lipid bilayers. The 15N NMR chemical shift is indicative of a well‐defined alignment of the peptide parallel to the membrane surface at P/Ls of 1:120 and 1:20. When the P/L is increased to 1:8, an additional peptide topology is observed that is indicative of a heterogeneous orientation, with helix alignments ranging from around the magic angle to perfectly in‐plane. The topological preference of the trichogin helix for an orientation parallel to the membrane surface was confirmed by attenuated total reflection FTIR spectroscopy. Furthermore, 19F CODEX experiments were performed on a trichogin sequence with 19F‐Phe at position 10. The CODEX decay is in agreement with a tetrameric complex, in which the 19F sites are about 9–9.5 Å apart. Thus, a model emerges in which the monomeric peptide aligns along the membrane surface. When the peptide concentration increases, first dimeric and then tetrameric assemblies form, made up from helices oriented predominantly parallel to the membrane surface. The formation of these aggregates correlates with the release of vesicle contents including relatively large molecules.
Utilizing the Alterable Solubility of Chitosan in Aqueous Solution to Synthesize Nanosized Sulfur for High Performance Li–S Batteries
Authors: Zhang Yu , Li Wen‐Cui , He Bin , Yu Xiao‐Fei , Hou Lu , Lu An‐Hui 
Published: May 2019

Summary of main observation and conclusionWe demonstrate the synthesis of cathode material with nanosized sulfur by a precipitation method making use of the alterable solubility of chitosan (CTS) in aqueous solution. Mesoporous Ketjen Black (KB) and carbon nanotube (CNT) are added as conductive agents to provide the three‐dimensional electric channels. This method can reduce the size of the sulfur particles, thus the nanosized sulfur obtained can fully contact with the conductive agent, which could increase the utilization of sulfur and improve the capacity of Li‐S batteries. Moreover, CTS with abundant hydroxyl and amine groups has strong interaction with polysulfides, which can improve the stability of Li‐S batteries. As a result, the obtained CTS/C‐S cathode containing 76 wt% sulfur delivers an impressively initial discharge specific capacity of 1141.6 mA·h·g–1 at 0.5 C and maintains a capacity of 842.3 mA·h·g–1 after 300 cycles. Our finding paves a way for the rational design of high‐performance sulfur cathodes for advanced Li‐S batteries.
Multifunctional Ultra‐Small Nanocomplexes Capping Mesoporous Silica Nanoparticles for Multimodal Imaging and Chemo‐Photothermal Therapy
Authors: Li Xianglong , Luo Kai , Lin Xucong , Zhu Chunling 
Published: May 2019

AbstractTo achieve the clinical application of photothermal nanomaterials in tumor treatment, developing photothermal therapeutic agents with a strong photothermal therapeutic effect, good photostability and rapid clearance or dissociation abilities are urgently desired. Herein, epigallocatechin gallate‐iron coordination nanocomplexes with high photothermal conversion capability, magnetic resonance (MR)/photoacoustic (PA) imaging ability and rapid degradation ability under high GSH condition were prepared. (abbreviated as EGCG‐Fe/PVP NCs). The EGCG‐Fe/PVP NCs were composed through a coordination reaction between Fe3+ and EGCG upon the protection of polyvinyl pyrrolidone (PVP). For its application in the biomedical field, using electronegativity from the polyhydroxy characteristics of EGCG, these complexes were controlled to cap the pores of the DOX‐loaded and aminated mesoporous silica nanoparticles via electrostatic attraction to form a multimodal imaging‐guided combined chemo and photothermal therapy nanoplatform (abbreviated as MDEF NPs). The prepared MDEF NPs exhibit high drug loading efficiency and favorable pH‐dependent drug release capacity. In vitro cytotoxicity data showed that MDEF NPs in the laser exposure group exhibited stronger cytotoxicity than other groups. Therefore, this work may expand the application of MSNs and EGCG‐Fe/PVP NCs in the biological field.
A generic paradigm for mining human mobility patterns based on the GPS trajectory data using complex network analysis
Authors: Wang Shuangyan , Mei Gang , Cuomo Salvatore 
Published: May 2019

SummaryThe mining of human mobility can be exploited to support the design of traffic planning, route recommendations, urban planning, emergency management, and land use. Currently, various methods such as the machine learning algorithms, statistical methods, and semantic analysis are widely applied to identify and extract human mobility patterns. In this paper, we propose a simple and generic paradigm for mining human mobility patterns based on the GPS trajectory data using complex network analysis. The essential ideas behind the proposed paradigm mainly include (1) creating weighted complex networks of GPS trajectories and (2) extracting the human mobility patterns by analyzing the structures and metrics of the created complex networks of GPS trajectories. To evaluate the performance of the proposed paradigm, we design five groups of experiments and identify the mobility patterns of the selected five persons based on the selected five network analysis metrics. Experimental results indicate that (1) the proposed paradigm is effective and (2) the quite interesting potential information about the human mobility can be mined easily. The proposed paradigm is simple and generic, which can be employed to rapidly identify the human mobility patterns based on the GPS trajectory data.
Privacy protection based on many‐objective optimization algorithm
Authors: Zhang Jiangjiang , Xue Fei , Cai Xingjuan , Cui Zhihua , Chang Yu , Zhang Wensheng , Li Wuzhao 
Published: May 2019

SummaryIt is difficult to protect users' privacy and to process private information due to the complexity and uncertainty of such information. To protect private information quickly and accurately, a many‐objective optimization algorithm framework based on the hybrid elite selection strategy is proposed in this paper. First, a mating selection mechanism combined with the achievement scale function and angle information index is used to generate elite offspring of the internal population. Then, the balanceable fitness estimation method is employed to select and update the external archive. To test performance, the proposed algorithm is tested on many‐objective optimization problems (MaOPs) and compared with five state‐of‐the‐art algorithms. Experimental simulation results show that the proposed algorithm is more effective in solving MaOPs and can inspire development of a better privacy protection strategy.
Strong Pancake 2e/12c Bond in π‐Stacking Phenalenyl Derivatives Avoiding Bond Conversion
Authors: Zhong Rong‐Lin , Gao Feng‐Wei , Xu Hong‐Liang , Su Zhong‐Min 
Published: May 2019

AbstractThe nature of the 2e/12c bond and its conversion to a carbon‐carbon single bond in phenalenyl dimers have prompted a great deal of interests recently. In this work, we theoretically investigated a series of π‐stacking phenalenyl derivatives with 2e/12c bonding character by density functional theory (DFT) calculations to elucidate origin of this unusual bond conversion. Results show that bond‐conversion of the phenalenyl dimer easily occurs at room‐temperature both dynamically and thermodynamically. However, bond‐conversion of hetero π‐stacking adducts, in which the two center carbon atoms were substituted by boron and nitrogen atoms, respectively, is much more difficult, because the 2e/12c bond is stabilized by its charge transfer character. Consequently, the bond‐conversion is an endothermic process, albeit with a low conversion barrier. Interestingly, Lewis acid‐base interactions would be induced by substitution of the center nitrogen atom to phosphorus atom. The 2e/12c bond is further stabilized by 5.9 kcal mol−1 and its conversion is also thermodynamically unfavorable.
Binary Colloidal Nanoparticles with a Large Size Ratio in Analytical Ultracentrifugation
Authors: Xu Xufeng , Cölfen Helmut 
Published: May 2019

AbstractSedimenting colloidal particles may feel a surprisingly strong buoyancy in a mixture with other particles of a considerably larger size. In this paper we investigated the buoyancy of colloidal particles in a concentrated binary suspension in situ in a centrifugal field. After dispersing two different fluorescence‐labeled silica nanoparticles with a large size ratio (90 nm and 30 nm, size ratio: 3) in a refractive index matching solvent, we used a multi‐wavelength analytical ultracentrifuge to measure the concentration gradients of both particles in situ. The concentration of the 90 nm silica nanoparticles was used to calculate the effective solvent density for the 30 nm silica nanoparticles. The exponential Boltzmann equation for the sedimentation‐diffusion equilibrium with locally varying effective solvent density was then used to theoretically predict the concentration gradient of 30 nm silica nanoparticles, which describes the experimental results very well. This finding proves the validity of effective buoyancy in colloidal mixtures and provides a good model to study sedimenting polydisperse colloids.
Engineering the Surface of a Polymeric Photocatalyst for Stable Solar‐to‐Chemical Fuel Conversion from Seawater
Authors: Mishra Biswajit , Mishra Sabyasachi , Satpati Biswarup , Chaudhary Yatendra S. 
Published: May 2019

AbstractThe design of an efficient and highly selective organic polymeric semiconductor photocatalyst consisting of Earth‐abundant elements for solar fuel generation using seawater, and also deionized water, as a proton source is reported. The mesoporous g‐C3N4 synthesized using a conventional precursor (urea) shows significant H2 generation (ca. 33 000 μmol h−1 g−1) and drives the photoreduction of CO2 to CH4, along with trace amount of methanol. However, when the chosen precursor cyanamide is used, drastic improvement in H2 generation (ca. 41 600 μmol h−1 g−1) and CO2 photoreduction is observed. The introduction of a surface nitrogen deficiency and modification of the surface with Cu0 further enhances solar H2 generation (ca. 50 000 μmol h−1 g−1) and CO2 photoreduction (3.12 μmol h−1 g−1) activity, respectively, owing to improvement in light harvesting and charge separation, as revealed by a shorter average lifetime of 3.52 ns and higher Stern–Volmer quenching constant value of approximately 11.2 m−1. In addition, improved selectivity in CO2 photoreduction to only CH4 is also observed. The designed photocatalytic system is stable, with the solar H2 generation rate increasing even after 20 h under continuous illumination with a turnover number of 6500. When seawater used instead of deionized water, the overall solar fuel generation efficiencies of all photocatalysts marginally decreased owing to a decrease in the photogenerated charge‐carrier separation efficacy.
Hox genes: Downstream “effectors” of retinoic acid signaling in vertebrate embryogenesis
Authors: Nolte Christof , De Kumar Bony , Krumlauf Robb 
Published: May 2019

SummaryOne of the major regulatory challenges of animal development is to precisely coordinate in space and time the formation, specification, and patterning of cells that underlie elaboration of the basic body plan. How does the vertebrate plan for the nervous and hematopoietic systems, heart, limbs, digestive, and reproductive organs derive from seemingly similar population of cells? These systems are initially established and patterned along the anteroposterior axis (AP) by opposing signaling gradients that lead to the activation of gene regulatory networks involved in axial specification, including the Hox genes. The retinoid signaling pathway is one of the key signaling gradients coupled to the establishment of axial patterning. The nested domains of Hox gene expression, which provide a combinatorial code for axial patterning, arise in part through a differential response to retinoic acid (RA) diffusing from anabolic centers established within the embryo during development. Hence, Hox genes are important direct effectors of retinoid signaling in embryogenesis. This review focuses on describing current knowledge on the complex mechanisms and regulatory processes, which govern the response of Hox genes to RA in several tissue contexts including the nervous system during vertebrate development.