bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aberrant repair initiated by the adenine-DNA glycosylase does not play a role in UV-induced mutagenesis inEscherichia coli
Authors: Zutterling Caroline , Mursalimov Aibek , Talhaoui Ibtissam , Koshenov Zhanat , Akishev Zhiger , Bissenbaev Amangeldy K. , Mazon Gerard , Geacintov Nicolas E. , Gasparutto Didier , Groisman Regina , Zharkov Dmitry O. , Matkarimov Bakhyt T. , Saparbaev Murat 
Published: December 2018

BackgroundDNA repair is essential to counteract damage to DNA induced by endo- and exogenous factors, to maintain genome stability. However, challenges to the faithful discrimination between damaged and non-damaged DNA strands do exist, such as mismatched pairs between two regular bases resulting from spontaneous deamination of 5-methylcytosine or DNA polymerase errors during replication. To counteract these mutagenic threats to genome stability, cells evolved the mismatch-specific DNA glycosylases that can recognize and remove regular DNA bases in the mismatched DNA duplexes. TheEscherichia coliadenine-DNA glycosylase (MutY/MicA) protects cells against oxidative stress-induced mutagenesis by removing adenine which is mispaired with 7,8-dihydro-8-oxoguanine (8oxoG) in the base excision repair pathway. However, MutY does not discriminate between template and newly synthesized DNA strands. Therefore the ability to remove A from 8oxoG•A mispair, which is generated via misincorporation of an 8-oxo-2′-deoxyguanosine-5′-triphosphate precursor during DNA replication and in which A is the template base, can induce A•T→C•G transversions. Furthermore, it has been demonstrated that human MUTYH, homologous to the bacterial MutY, might be involved in the aberrant processing of ultraviolet (UV) induced DNA damage.MethodsHere, we investigated the role of MutY in UV-induced mutagenesis inE. coli. MutY was probed on DNA duplexes containing cyclobutane pyrimidine dimers (CPD) and pyrimidine (6–4) pyrimidone photoproduct (6–4PP). UV irradiation ofE. coliinduces Save Our Souls (SOS) response characterized by increased production of DNA repair enzymes and mutagenesis. To study the role of MutY in vivo, the mutation frequencies to rifampicin-resistant (RifR) after UV irradiation of wild type and mutantE. colistrains were measured.ResultsWe demonstrated that MutY does not excise Adenine when it is paired with CPD and 6–4PP adducts in duplex DNA. At the same time, MutY excises Adenine in A•G and A•8oxoG mispairs. Interestingly,E. coli mutYstrains, which have elevated spontaneous mutation rate, exhibited low mutational induction after UV exposure as compared to MutY-proficient strains. However, sequence analysis of RifRmutants revealed that the frequencies of C→T transitions dramatically increased after UV irradiation in both MutY-proficient and -deficientE. colistrains.DiscussionThese findings indicate that the bacterial MutY is not involved in the aberrant DNA repair of UV-induced DNA damage.
High‐throughput isolation of circulating tumor DNA: a comparison of automated platforms
Authors: van Dessel Lisanne F. , Vitale Silvia R. , Helmijr Jean C. A. , Wilting Saskia M. , van der Vlugt‐Daane Michelle , Oomen‐de Hoop Esther , Sleijfer Stefan , Martens John W. M. , Jansen Maurice P. H. M. , Lolkema Martijn P. 
Published: December 2018

The emerging interest in circulating tumor DNA (ctDNA) analyses for clinical trials has necessitated the development of a high‐throughput method for fast, reproducible, and efficient isolation of ctDNA. Currently, the majority of ctDNA studies use the manual QIAamp (QA) platform to isolate DNA from blood. The purpose of this study was to compare two competing automated DNA isolation platforms [Maxwell (MX) and QIAsymphony (QS)] to the current ‘gold standard’ QA to facilitate high‐throughput processing of samples in prospective trials. We obtained blood samples from healthy blood donors and metastatic cancer patients for plasma isolation. Total cell‐free DNA (cfDNA) quantity was assessed by TERT quantitative PCR. Recovery efficiency was investigated by quantitative PCR analysis of spiked‐in synthetic plant DNA. In addition, a β‐actin fragmentation assay was performed to determine the amount of contamination by genomic DNA from lysed leukocytes. ctDNA quality was assessed by digital PCR for somatic variant detection. cfDNA quantity and recovery efficiency were lowest using the MX platform, whereas QA and QS showed a comparable performance. All platforms preferentially isolated small (136 bp) DNA fragments over large (420 and 2000 bp) DNA fragments. Detection of the number variant and wild‐type molecules was most comparable between QA and QS. However, there was no significant difference in variant allele frequency comparing QS and MX to QA. In summary, we show that the QS platform has comparable performance to QA, the ‘gold standard’, and outperformed the MX platform depending on the readout used. We conclude that the QS can replace the more laborious QA platform, especially when high‐throughput cfDNA isolation is needed.
Chloride promotes refolding of active Vibrio alkaline phosphatase through an inactive dimeric intermediate with an altered interface
Authors: Hjörleifsson Jens Guðmundur , Ásgeirsson Bjarni 
Published: December 2018

Most enzymes are homodimers or higher order multimers. Cold‐active alkaline phosphatase from Vibrio splendidus (VAP) transitions into a dimer with very low activity under mild denaturation conditions. The desire to understand why this dimer fails to efficiently catalyse phosphomonoester hydrolysis led us to investigate interfacial communication between subunits. Here, we studied in detail the unfolding mechanism at two pH values and in the presence or absence of sodium chloride. At pH 8.0, the denaturation model had to include an inactive dimer intermediate and follow the pathway: N2 → I2 → 2U. At pH 10.5, the model was of a two‐state nature. Enzyme activity was not recovered under several examined refolding conditions. However, in the presence of 0.5 m NaCl, the enzyme was nearly fully reactivated after urea treatment. Thermal inactivation experiments were biphasic where the inactivation could be detected using CD spectroscopy at 190–200 nm. By incorporating a bimane fluorescence probe at the dimer interface, we could monitor inactivation/denaturation at two distinct sites at the dimer interface. A change in bimane fluorescence at both sites was observed during inactivation, but prior to the global unfolding event. Furthermore, the rate of change in bimane fluorescence correlated with inactivation rates at 40 °C. These results indicate and support the hypothesis that the subunits of VAP are only functional in the dimeric state due to the cooperative nature of the reaction mechanism when proper crosstalk between subunits is facilitated.
Self‐Determination and Adult Transitions and Supports
Authors: Wehmeyer Michael L. , Shogren Karrie A. , Thompson James R. 
Published: December 2018

AbstractThis chapter describes the importance of self‐determination for transitions and supports for adults with disabilities. Self‐determination is defined and its application to the disability context examined, followed by an overview of a multicomponent model to engage adults with disabilities to self‐regulate problem solving to set and attain life and career goals and to enhance self‐determination.
Particulate Coatings with Optimized Haze Properties
Authors: Semmler Johannes , Bley Karina , Klupp Taylor Robin N. , Stingl Michael , Vogel Nicolas 
Published: December 2018

AbstractThe haze factor, which describes the fraction of light that is scattered when passing through a transparent material, is of general importance for any optical device, from milk glass shielding visibility while providing ambient lighting to solar cells that are optimized by sophisticated light management layers. Often, such active layers are fabricated from particulate materials that are deposited as thin films on a substrate. Here, the effect of structural arrangement, position, and orientation of particles on the resulting haze factor is investigated. A mathematical optimization model that iteratively alters the particle layer structure to maximize or minimize the haze factor for a range of optimization scenarios is designed. Colloidal self‐assembly techniques are then used to replicate typical particle structures found in the optimized designs and correlate the macroscopically measured haze values to the predictions of the optimization. The results indicate general design rules that control the haze value in particle layers. Non close‐packed structures with distributed scatterers and high degrees of order provide minimal haze values while chain‐like arrangements and small clusters maximize the haze of a particle layer. Finally, the findings are transferred to metal nanohole films as model transparent electrodes with controlled haze values.
DNA‐Based Biomaterials for Immunoengineering
Authors: Maeda Midori , Kojima Taisuke , Song Yang , Takayama Shuichi 
Published: December 2018

AbstractMan‐made DNA materials hold the potential to modulate specific immune pathways toward immunoactivating or immunosuppressive cascades. DNA‐based biomaterials introduce DNA into the extracellular environment during implantation or delivery, and subsequently intracellularly upon phagocytosis or degradation of the material. Therefore, the immunogenic functionality of biological and synthetic extracellular DNA should be considered to achieve desired immune responses. In vivo, extracellular DNA from both endogenous and exogenous sources holds immunoactivating functions which can be traced back to the molecular features of DNA, such as sequence and length. Extracellular DNA is recognized as damage‐associated molecular patterns (DAMPs), or pathogen‐associated molecular patterns (PAMPs), by immune cell receptors, activating either proinflammatory signaling pathways or immunosuppressive cell functions. Although extracellular DNA promotes protective immune responses during early inflammation such as bacterial killing, recent advances demonstrate that unresolved and elevated DNA concentrations may contribute to the pathogenesis of autoimmune diseases, cancer, and fibrosis. Therefore, addressing the immunogenicity of DNA enables immune responses to be engineered by optimizing their activating and suppressive performance per application. To this end, emerging biology relevant to the generation of extracellular DNA, DNA sensors, and its role concerning existing and future synthetic DNA biomaterials are reviewed.
Ultrathin Visible‐Light‐Driven Mo Incorporating In2O3–ZnIn2Se4 Z‐Scheme Nanosheet Photocatalysts
Authors: Chao Yuguang , Zhou Peng , Li Na , Lai Jianping , Yang Yong , Zhang Yelong , Tang Yonghua , Yang Wenxiu , Du Yaping , Su Dong , Tan Yisheng , Guo Shaojun 
Published: December 2018

AbstractInspired by natural photosynthesis, the design of new Z‐scheme photocatalytic systems is very promising for boosting the photocatalytic performance of H2 production and CO2 reduction; however, until now, the direct synthesis of efficient Z‐scheme photocatalysts remains a grand challenge. Herein, it is demonstrated that an interesting Z‐scheme photocatalyst can be constructed by coupling In2O3 and ZnIn2Se4 semiconductors based on theoretical calculations. Experimentally, a class of ultrathin In2O3–ZnIn2Se4 (denoted as In2O3–ZISe) spontaneous Z‐scheme nanosheet photocatalysts for greatly enhancing photocatalytic H2 production is made. Furthermore, Mo atoms are incorporated in the Z‐scheme In2O3–ZISe nanosheet photocatalyst by forming the MoSe bond, confirmed by X‐ray photoelectron spectroscopy, in which the formed MoSe2 works as cocatalyst of the Z‐scheme photocatalyst. As a consequence, such a unique structure of In2O3–ZISe–Mo makes it exhibit 21.7 and 232.6 times higher photocatalytic H2 evolution activity than those of In2O3–ZnIn2Se4 and In2O3 nanosheets, respectively. Moreover, In2O3–ZISe–Mo is also very stable for photocatalytic H2 production by showing almost no activity decay for 16 h test. Ultraviolet–visible diffuse reflectance spectra, photoluminescence spectroscopy, transient photocurrent spectra, and electrochemical impedance spectroscopy reveal that the enhanced photocatalytic performance of In2O3–ZISe–Mo is mainly attributed to its widened photoresponse range and effective carrier separation because of its special structure.
Roll‐to‐Roll (R2R) Production of Ultrasensitive, Flexible, and Transparent Pressure Sensors Based on Vertically Aligned Lead Zirconate Titanate and Graphene Nanoplatelets
Authors: Yildirim Armen , Rahimi Rahim , Shams Es‐haghi Siamak , Vadlamani Anand , Peng Fang , Oscai Mark , Cakmak Mukerrem 
Published: December 2018

AbstractDespite extensive advances in the use of piezoelectric materials in flexible electronics, they have numerous shortcomings, including low efficiency, limited flexibility, and lack of transparency. Additionally, the production of these materials is often limited to small batch processes which are difficult to scale up for mass production. A novel method to produce ultrasensitive, high performance, flexible, and transparent piezoelectric materials where both lead zirconate titanate nanoparticles, and graphene nanoplatelets are aligned together in polydimethylsiloxane under an AC electric field in the thickness (“Z”) direction, is reported here for the first time. The electric field alignment improves the piezoelectric response along with transparency and also reduces the amount of filler required to achieve outstanding piezoelectric properties. The resulting ultrasensitive piezoelectric film is able to sense the pressure of a bird feather (1.4 mg) dropped from a certain distance, whereas at the touch of a fingertip, it can generate up to 8.2 V signal. Moreover, the mass production compatibility of the system is also demonstrated by producing a 3 m long and 15 cm wide large‐area sample via a novel 44′ long roll‐to‐roll manufacturing line which is designed and developed by the group.
A Facile Realization Scheme for Tactile Sensing with a Structured Silver Nanowire‐PDMS Composite
Authors: Li Yunxia , Han Dongyan , Jiang Changjun , Xie Erqing , Han Weihua 
Published: December 2018

AbstractTo mimic the sensing function of human skin, the rational design of force‐sensitive materials is highly required for sensors. Here, a facile design of resistive‐type tactile sensors based on a structured silver nanowire‐polydimethylsiloxane composite is reported for applications in electronic skins and wearable electronics. The composite has a hollow microstructure of interconnected channels, and the inner surface of the channels is a conductive layer consisting of silver nanowires. The sensing function to external force is realized by measuring the resistance change upon deforming. The deforming causes the distance change of silver nanowires and the contact‐area change of the inner surfaces. Such a unique structure promises a robust mechanical property due to the half‐embedded silver nanowires which are free of peeling off, and also makes it possible to control the device sensitivity by its mechanical structure and the elastic property of the polydimethylsiloxane. The results show that the composite has steady‐state responses to various pressures and stretches, even to mouth blowing, a response time of ≈90 ms, and favorable repeatability over 2000 cycles of bending/unbending. The 3D structure enables pressing, bending, pulling and torsional force sensing, and promises real‐time monitoring of various human motions ranging from blood pulses to joint movements.
Double Helix Actuators
Authors: Shepherd David J. , Spinks Geoffrey M. 
Published: December 2018

AbstractTensile actuators that reversibly generate large length change strokes are of great interest in many biomedical and robotic applications. Guest–host composite materials comprising volume change guests with multi‐filament yarn hosts can be exploited as large stroke tensile actuators when the fiber host is formed into helices. Here, a new type of double helix actuator is introduced by plying two yarns together. The helical geometry suggests large length contractions are possible when the ply angle approaches the limit of 45° and when the yarn swells predominantly in the diameter direction as it occurs when reinforcing filaments are aligned in the yarn direction. Prototype double helix actuators are constructed from cotton yarn infused with a water‐swellable hydrogel. A series of actuator samples are made with differing ply angles and the length changes monitored during repeated hydration/dehydration cycles. Water swelling causes length contractions of up to 9% and it increases in magnitude with an increase in ply twist. The experimental results are in good agreement with those calculated using the helical geometry model.
Fano Resonance in Asymmetric Plasmonic Nanostructure: Separation of Sub‐10 nm Enantiomers
Authors: Cao Tun , Mao Libang , Qiu Yimei , Lu Li , Banas Agnieszka , Banas Krzysztof , Simpson Robert E. , Chui Hsiang‐Chen 
Published: December 2018

AbstractSeparating enantiomers is vital in chemical syntheses, life sciences, and physics. However, the usual chemical processes are inefficient. Recently, plasmonic nanostructures have drawn considerable attention for manipulating nanoparticles; however, only a few approaches are proposed to discriminate between entities that differ in terms of their handedness. This is because the chiral polarizability is much smaller than the electric polarizability, and therefore the non‐chiral gradient force dominates over the chiral gradient force. This limit means that the enantioselective sorting of chiral nanoparticles is a formidable challenge. A plasmonic nanostructure consisting of a disc‐double split ring resonator exhibiting a dipole–octupole (DO) Fano resonance (FR) is designed and fabricated. It is theoretically demonstrated that such a DO‐FR can markedly enhance the chiral gradient force on the paired enantiomers. The coaxial channel of the resonator possessing high chirality density gradients around the DO‐FR is derived. This provides an enhanced chiral gradient force that dominates over the non‐chiral gradient forces on sub‐10 nm chiral nanoparticles. Enantiomeric pairs can thus experience distinct potential wells in terms of signs. This proposed structure may advance the techniques of enantiopurification and enantioseparation, bringing a new perspective to state‐of‐the‐art all‐optical enantiopure synthesis.
Control of Barrier Width in Perovskite Multiple Quantum Wells for High Performance Green Light–Emitting Diodes
Authors: Yu Maotao , Yi Chang , Wang Nana , Zhang Liangdong , Zou Renmeng , Tong Yunfang , Chen Hong , Cao Yu , He Yarong , Wang Ying , Xu Mengmeng , Liu Yang , Jin Yizheng , Huang Wei , Wang Jianpu 
Published: December 2018

AbstractSolution‐processed, self‐organized multiple quantum well (MQW) perovskites possess good film coverage and high photoluminescence quantum efficiency, which are promising for high performance light‐emitting diodes (LEDs). However, due to the inclusion of insulating large organic cation as barrier layer, the charge transport in MQW perovskites is not as efficient as 3D perovskites, which limits the improvement of power conversion efficiency of MQW perovskite LEDs. Here, it is demonstrated that by molecular engineering, the conductivity of MQW perovskite film can be effectively increased by reducing the barrier width in QWs, thus leading to enhanced device performance. By controlling the constitution of the narrow‐barrier‐width MQW perovskites, one can achieve green LEDs with a high luminance of 30 000 cd m−2 at a low voltage of 6 V and a peak external quantum efficiency of 7.7%. Moreover, the green perovskite LEDs show a lifetime of 63 min with initial luminance of 1330 cd m−2, representing one of the best performing green perovskite LEDs. Here, a promising strategy is provided to further boost the efficiency, brightness, and stability of MQW perovskite LEDs.
Recent Developments in Enantioselective Metal‐Catalyzed Domino Reactions
Authors: Pellissier Hélène 
Published: December 2018

AbstractThis review collects the very recent developments in enantioselective metal‐catalyzed domino reactions published since the beginning of 2016. It illustrates that many types of enantioselective metal‐catalyzed domino processes continue to be developed, allowing an easy one‐pot access to complex molecular architectures from simple starting materials while providing economic advantages, such as avoiding costly protecting groups and time‐consuming purification procedures after each step.Abbreviations: acac: acetylacetonate; Ar: aryl; BINAP: 2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl; BINOL: 1,1′‐bi‐2‐naphthol; Bn: benzyl; Boc: tert‐butoxycarbonyl; Box: bisoxazoline; BOXAX: 2,2′‐bis(oxazolyl)‐1,1′‐binaphthyl; Bz: benzoyl; cod: cyclooctadiene; Cy: cyclohexyl; DBDMH: 1,3‐dibromo‐5,5‐dimethylhydantoin; DBU: 1,8‐diazabicyclo[5.4.0]undec‐7‐ene; DCE: dichloroethane; de: diastereomeric excess; DIPEA: diisopropylethylamine; dr: diastereomeric ratio; ee: enantiomeric excess; Hex: hexyl; L: ligand; MTBE: methyl tert‐butyl ether; Naph: naphthyl; Ms: mesyl; M.S.: molecular sieves; NMP: N‐methyl‐2‐pyrrolidone; Ns: nosyl; PG: protecting group; Phos: phosphinyl; PHOX: phosphinooxazoline; Phth: phthaloyl; Pin: pinacolato; Piv: pivaloyl; Pybox: 2,6‐bis(2‐oxazolyl)pyridine; r.t.: room temperature; TBS: tert‐butyldimethylsilyl; Tf: trifluoromethanesulfonyl; TFA: trifluoroacetic acid; THF: tetrahydrofuran; TMS: trimethylsilyl; Tol: tolyl; Ts: 4‐toluenesulfonyl (tosyl).magnified image
Biological One‐Way Functions for Secure Key Generation
Authors: Dodda Akhil , Wali Akshay , Wu Yang , Pannone Andrew , Reddy Likhith Kumar , Raha Arnab , Ozdemir Sahin Kaya , Ozbolat Ibrahim Tarik , Das Saptarshi 
Published: December 2018

AbstractDisorder is fundamental to nature and natural phenomena, providing countless information sources, which are astronomically difficult to duplicate, but have yet to be exploited for cryptographic applications. While the contemporary crypto systems, relying on the premise of abstract mathematical one‐way functions, are relatively difficult to decipher with reasonable and/or finite resources, the situation is bound to change with the advent of quantum computers, necessitating physically unclonable entropy sources. As such, inspiration is drawn from the disorder that is prevalent in nature and inherent to biological systems for designing disruptive mechanisms for cryptographic key generation. It is demonstrated that the spatiotemporal dynamics of an ensemble of living organisms such as T cells can be used for maximum entropy, high‐density, and high‐speed key generation. Further, such biology based one‐way functions are oblivious to any mathematical representations and are computationally expensive to decipher even if an adversary has an exhaustive knowledge of the key generation mechanisms, which include cell type, cell density, key sampling rate, and sampling instance. The introduction of such biological one‐way functions can greatly enhance the ability to protect information in the post quantum era.