bluuebunny/crossref_metadata_2025 huggingface dataset:
EvaluatingEucalyptusleaf colonization byBrasilonema octagenarum(Cyanobacteria, Scytonemataceae) usingin plantaexperiments and genomics
Authors: Alvarenga Danillo O. , Franco Maione W. , Sivonen Kaarina , Fiore Marli F. , Varani Alessandro M.
Published: May 2020

Background

Brasilonemais a cyanobacterial genus found on the surface of mineral substrates and plants such as bromeliads, orchids and eucalyptus.B. octagenarumstands out among cyanobacteria due to causing damage to the leaves of its host in an interaction not yet observed in other cyanobacteria. Previous studies revealed thatB. octagenaumUFV-E1 is capable of leading eucalyptus leaves to suffer internal tissue damage and necrosis by unknown mechanisms. This work aimed to investigate the effects ofB. octagenarumUFV-E1 inoculation onEucalyptus urograndisand to uncover molecular mechanisms potentially involved in leaf damage by these cyanobacteria using a comparative genomics approach.

Results

Leaves fromE. urograndissaplings were exposed for 30 days toB. octagenarumUFV-E1, which was followed by the characterization of its genome and its comparison with the genomes of four otherBrasilonemastrains isolated from phyllosphere and the surface of mineral substrates. While UFV-E1 inoculation caused an increase in root and stem dry mass of the host plants, the sites colonized by cyanobacteria on leaves presented a significant decrease in pigmentation, showing that the cyanobacterial mats have an effect on leaf cell structure. Genomic analyses revealed that all evaluatedBrasilonemagenomes harbored genes encoding molecules possibly involved in plant-pathogen interactions, such as hydrolases targeting plant cell walls and proteins similar to known virulence factors from plant pathogens. However, sequences related to the type III secretory system and effectors were not detected, suggesting that, even if any virulence factors could be expressed in contact with their hosts, they would not have the structural means to actively reach plant cytoplasm.

Conclusions

Leaf damage by this species is likely related to the blockage of access to sunlight by the efficient growth of cyanobacterial mats on the phyllosphere, which may hinder the photosynthetic machinery and prevent access to some essential molecules. These results reveal that the presence of cyanobacteria on leaf surfaces is not as universally beneficial as previously thought, since they may not merely provide the products of nitrogen fixation to their hosts in exchange for physical support, but in some cases also hinder regular leaf physiology leading to tissue damage.
Studies on Phytoplankton Composition of River Shinga Gombe State, Nigeria
Authors: Kiman H. S. , Kawu A. A. , Ummu R. A.
Published: May 2020

Studies on the phytoplankton composition of River Shinga, Yamaltu Deba Local Government Area, Gombe State, Nigeria was carried out from June-August, 2019. Samples were collected fortnightly for the period of three month. The objectives were to determine the physico-chemical parameters, assess the phytoplankton abundance and the relationship between physico-chemical parameters and phytoplankton abundance of the river. Phytoplankton was determined following the method described by Lee and Cundy and Anene. Physicochemical parameters were determined following the method described by APHA. The mean values of the physico-chemical parameters recorded include Air temperature (29.6±1.04), water temperature (26.8±0.86), Water pH (8.09±0.33), Turbidity and Transparency (10.17±0.66), water velocity (0.29±0.04) Dissolved oxygen (3.3±0.24) and electrical Conductivity (84.6±4.12). A total of 717 individuals and 21 species of phytoplankton’s were recorded. The dominant phytoplankton was Bacillariophyceae (46.03%), followed by order Chlorophyceae (30.82%), Cyanophyceae (15.48%) and Euglenophyceae (7.67%). The total number of phytoplanktons varies with month of sampling; a higher number was experienced during the rainy seasons. Pearson correlation co-efficient shows physico-chemical parameters are responsible for sharpening the structure of phytoplankton abundance. ANOVA and Simpson’s index (D) method was used to analyze the data.
Covid 19: Determination of the Relationship between Sex, Having Handkerchief or Staying Indoor and Facial Touch
Authors: Aderoju S. A. , Ajewole S. S. , Balogun O. S.
Published: May 2020

Background: Covid-19 outbreak is the current pandemic confronting nations in the world. The virus had caused so much loss of lives, loss of jobs and serious damages to global economy. One major way of preventing the spread of the virus and guide against being infected is to avoid face touching with unwashed hand(s).

Objective: The objective of this study is to investigate the association between sex, having handkerchief or staying indoor and number of time a person touches face (mouth, eyes or nose). 

Methodology: A sample size of n = 130 people were randomly selected and observed obliviously for 120 seconds. The number of times they touched their faces were recorded with other variables like sex, having handkerchief and staying indoor or outdoor. Since the response variable is count, appropriate models for such data were used.

Results and Conclusion: The Poisson results shown that there exist overdispersion, hence, a model that can account for the dispersion parameter was used to obtain accurate results. The results of the analysis shown that there is no association between the number of time a person touches face and sex, having handkerchief or staying indoor. The expected number time people touch their faces within 120 seconds is twice while the minimum and maximum number of times are zero and eight respectively.

Recommendation: It is recommended that there ought to be adequate public enlightenment and sensitization on the peril of the novel COVID-19 pandemic and the reason why individuals ought to stick carefully to the exhortation of abstaining from touching of faces (without washing with soap and water) so as to forestall its spread. If a person's hands are contaminated with the virus, he/she isn't infected until he/she touches the face (nose, eye or mouth) with the hands unwashed.
Bryozoa,
Cristatella Mucedo
: Body Cavities
Authors: Schwaha Thomas F.
Published: May 2020

This contribution describes the body cavities of the freshwater bryozoans
Cristatella mucedo
.
Cellulose II Aerogel‐Based Triboelectric Nanogenerator
Authors: Zhang Lei , Liao Yang , Wang Yi‐Cheng , Zhang Steven , Yang Weiqing , Pan Xuejun , Wang Zhong Lin
Published: May 2020

Cellulose‐based triboelectric nanogenerators (TENGs) have gained increasing attention. In this study, a novel method is demonstrated to synthesize cellulose‐based aerogels and such aerogels are used to fabricate TENGs that can serve as mechanical energy harvesters and self‐powered sensors. The cellulose II aerogel is fabricated via a dissolution–regeneration process in a green inorganic molten salt hydrate solvent (lithium bromide trihydrate), where. The as‐fabricated cellulose II aerogel exhibits an interconnected open‐pore 3D network structure, higher degree of flexibility, high porosity, and a high surface area of 221.3 m2 g−1. Given its architectural merits, the cellulose II aerogel‐based TENG presents an excellent mechanical response sensitivity and high electrical output performance. By blending with other natural polysaccharides, i.e., chitosan and alginic acid, electron‐donating and electron‐withdrawing groups are introduced into the composite cellulose II aerogels, which significantly improves the triboelectric performance of the TENG. The cellulose II aerogel‐based TENG is demonstrated to light up light‐emitting diodes, charge commercial capacitors, power a calculator, and monitor human motions. This study demonstrates the facile fabrication of cellulose II aerogel and its application in TENG, which leads to a high‐performance and eco‐friendly energy harvesting and self‐powered system.
Enhancing Spontaneous Droplet Motion on Structured Surfaces with Tailored Wedge Design
Authors: Wang Zhongzheng , Owais Ahmed , Neto Chiara , Pereira Jean‐Michel , Gan Yixiang
Published: May 2020

Spontaneous liquid transport has a wide variety of applications, including fog harvesting, microfluidics, and water‐oil separation. Understanding of the droplet movement dynamics on structured surfaces is essential for enhancing the transport performance. In this work, a theoretical model describing the movement process of droplets on surfaces with prescribed wedge shapes is developed. Agreement is observed between the predictions from the model and experimental results. Through theoretical analysis and quantitative comparison between the transport performance of different wedge shapes, the factors affecting the movement process are identified and guidelines for wedge shape optimization for spontaneous droplet transport are provided.
Controlling the Charge Transfer across Thin Dielectric Interlayers
Authors: Hurdax Philipp , Hollerer Michael , Puschnig Peter , Lüftner Daniel , Egger Larissa , Ramsey Michael G. , Sterrer Martin
Published: May 2020

Whether intentional or unintentional, thin dielectric interlayers can be found in technologies ranging from catalysis to organic electronics. While originally considered as passive decoupling layers, recently it has been shown that they can actively promote charge transfer from the underlying metal to adsorbates. This charging can have profound effects on the surface chemistry of atoms, atomic clusters, and molecules, their magnetic moments, and charge injection at the contacts of organic devices. Yet, controlled studies required to understand the charge transfer process in depth are still lacking. Here, a comprehensive analysis of the phenomenon of charge transfer using the atomically controlled system of pentacene on ultrathin MgO(100) films on Ag(100) is presented. It is shown that the charge transfer process is governed by the charged and uncharged molecular species with distinct energy levels in the first monolayer. The experimental approach applied in this work allows to observe and control their ratio through direct tuning of either the work function or the thickness of the dielectric interlayer.
Miura‐ori Metastructure Enhanced Conductive Elastomers
Authors: Hou Yue , Wang Yixin , Yu Miao , Wang Ziyu , Yu Hongyu
Published: May 2020

Electrically conductive nanocomposite elastomers are widely used in wearable electronics and for monitoring personal health owing to their great stretchability and flexibility. However, working as interconnectors to transmit signals, the conductive elastomer is limited due to the large resistance variation under deformation that results in inaccuracy and reliability issues of the whole system. Herein, a new technology employing a Miura‐ori metastructure, together with surface buckling structure, into the nanocomposite elastomer system to fabricate a highly electrically stable conductive elastomer under deformation is reported. As a comparison, conductive elastomers with three different structures, namely Miura‐ori, wavy, and plane structures, are fabricated from multi‐walled carbon nanotubes and Ecoflex. Metal films are deposited on top of these three structures to enhance the conductivity of the composite system and to further verify the attachment‐enhanced structural ability. The Miura‐ori structure, together with a buckled surface, is able to reduce stress concentration at local points under stretching, which helps provide the nanocomposite elastomers with highly improved electrical stability.
Solution–Liquid–Solid Growth and Catalytic Applications of Silica Nanorod Arrays
Authors: Fang Yaosi , Lv Kangxiao , Li Zhao , Kong Ning , Wang Shenghua , Xu Ao‐Bo , Wu Zhiyi , Jiang Fengluan , Li Chaoran , Ozin Geoffrey A. , He Le
Published: May 2020

As an analogue to the vapor–liquid–solid process, the solution–liquid–solid (SLS) method offers a mild solution‐phase route to colloidal 1D nanostructures with controlled sizes, compositions, and properties. However, direct growth of 1D nanostructure arrays through SLS processes remains in its infancy. Herein, this study shows that SLS processes are also suitable for the growth of nanorod arrays on the substrate. As a proof of concept, seedless growth of silica nanorod arrays on a variety of hydrophilic substrates such as pristine and oxide‐modified glass, metal sheets, Si wafers, and biaxially oriented polypropylene film are demonstrated. Also, the silica nanorod arrays can be used as a new platform for the fabrication of catalysts for photothermal CO2 hydrogenation and the reduction of 4‐nitrophenol reactions. This work offers some fundamental insight into the SLS growth process and opens a new avenue for the mild preparation of functional 1D nanostructure arrays for various applications.
STAT3‐mediated gene expression in colorectal cancer cells‐derived cancer stem‐like tumorspheres
Authors: Lin Hua‐Ching , Ho Ai‐Sheng , Huang Hsin‐Hung , Yang Bi‐Ling , Shih Bin‐Bin , Lin Hsin‐Chi , Yeh Chun , Hsu Chung‐Te , Cheng Chun‐Chia
Published: May 2020

STAT3 is a transcriptional factor involved in tumorigenesis and the initiation of cancer stemness property. However, the STAT3‐downstream regulatory gene expressions in the formation of colorectal cancer (CRC)‐derived tumorsphere is obscure. In this study, RNAseq was used to uncover the potential genes involved in the formation of colorectal HCT116‐ and HT29‐derived stem‐like tumorspheres, whereas HCT116 and HT29 overexpressed CD133. Furthermore, STAT3 was knockdowned and analyzed consequently by RNAseq for picking up the STAT3‐mediated genes associated with tumorspheres formation. Then, quantitative polymerase chain reaction was used for validating the expressions of selected driver genes in epidermal growth factor (EGF) treated‐ and in STAT3‐knockdowned HT29 cells. We found that 654 genes and 646 genes were upregulated in HCT116‐ and HT29‐derived tumorspheres, respectively. There were 103 genes simultaneously increased in both CRC tumorspheres, including, STAT3 selected as a driver gene by NetworkAnalyst (https://www.networkanalyst.ca/). Moreover, there were 139 genes downregulated in HT29shSTAT3 cells compared to HT29shLuc cells, 12 of the genes were overlapped with the overexpressed 103 genes from tumorspheres, including, NDRG1, ALDOC, BHLHE40, ATF3, C6orf223, JUND, ERRFI1, HK2, ITPKA, PLOD2, IDI1, and S100A14. Among them, BHLHE40, ATF3, ERRFI1, ITPKA, and S100A14 were validated and induced by EGF treatment, that were, otherwise, decreased in HT29shSTAT3 cells. We found and validated that STAT3 mediated the formation of CRC stemness tumorspheres, and STAT3‐downstram BHLHE40, ATF3, ERRFI1, ITPKA, and S100A14 may be involved in the stemness property.
Comparison of two routes for the bio‐based production of economically important C4 streams
Authors: Satam Chinmay C. , Realff Matthew J.
Published: May 2020

Four carbon compounds like 1,4‐butanediol (1,4‐BDO), succinic acid (SA) have been identified as platform chemicals for producing polymers from renewable resources. The successful commercialization of 1,3‐propanediol by Dupont Tate and Lyle Bioproducts and 1,4‐BDO by Genomatica Inc. has established the commercial viability of green chemicals. In this study, we present the analyses to produce four‐carbon compounds (C4s) like 1,4‐BDO, gamma butyrolactone, and tetrahydrofuran from dextrose through two separate routes: (a) single‐step bioconversion and (b) hydrogenation of bio‐based SA. It was concluded that for an extended process involving hydrogenation of SA, additional increases in SA titer values and productivity by genetically modifying the relevant organisms will be required to achieve viability especially in comparison with the single‐step bioconversion process for 1,4‐BDO. In addition, the single‐step bioconversion process has lower greenhouse gas emissions but has higher overall water usage. Overall, given the published state of technology, the direct bioconversion route produces C4s (1,4‐BDO) at $ 1.8/kg and is economically viable, while the SA hydrogenation process (C4s refinery) produces C4s at $ 3.6/kg and is not competitive with current production routes.
Double‐Shelled C@MoS2 Structures Preloaded with Sulfur: An Additive Reservoir for Stable Lithium Metal Anodes
Authors: Yuan Huadong , Nai Jianwei , Fang Yongjin , Lu Gongxun , Tao Xinyong , Lou Xiong Wen (David)
Published: May 2020

The growth of Li dendrites hinders the practical application of lithium metal anodes (LMAs). In this work, a hollow nanostructure, based on hierarchical MoS2 coated hollow carbon particles preloaded with sulfur (C@MoS2/S), was designed to modify the LMA. The C@MoS2 hollow nanostructures serve as a good scaffold for repeated Li plating/stripping. More importantly, the encapsulated sulfur could gradually release lithium polysulfides during the Li plating/stripping, acting as an effective additive to promote the formation of a mosaic solid electrolyte interphase layer embedded with crystalline hybrid lithium‐based components. These two factors together effectively suppress the growth of Li dendrites. The as‐modified LMA shows a high Coulombic efficiency of 98 % over 500 cycles at the current density of 1 mA cm−2. When matched with a LiFePO4 cathode, the assembled full cell displays a highly improved cycle life of 300 cycles, implying the feasibility of the proposed LMA.
Intramolekulare Reaktionen transienter Phosphenium‐ und Arsenium‐Ionen führen zur Bildung isolierbarer 9‐Phospha‐ und 9‐Arsena‐Fluorenium‐Ionen
Authors: Olaru Marian , Duvinage Daniel , Naß Yannik , Malaspina Lorraine A. , Mebs Stefan , Beckmann Jens
Published: May 2020

Transiente, aus Bis(m‐terphenyl)fluorpniktogenen durch Fluorid‐Abstraktion gebildete Phosphenium‐ und Arsenium‐Ionen vollzogen einen intramolekularen elektrophilen Angriff, gefolgt von einer Methylgruppenwanderung und bildeten isolierbare 9‐Phospha‐ und 9‐Arsena‐Fluorenium‐Ionen.
Improved Access to Organo‐Soluble Di‐ and Tetrafluoridochlorate(I)/(III) Salts
Authors: Pröhm P. , Schmid J. R. , Sonnenberg K. , Voßnacker P. , Steinhauer S. , Schattenberg C. J. , Müller R. , Kaupp M. , Riedel S.
Published: May 2020

A facile one‐pot gram‐scale synthesis of tetraalkylammonium tetrafluoridochlorate(III) [cat][ClF4] ([cat]=[NEt3Me]+, [NEt4]+) is described. An acetonitrile solution of the corresponding alkylammonium chloride salt is fluorinated with diluted fluorine at low temperatures. The reaction proceeds via the [ClF2]− anion which is structurally characterized for the first time. The potential application of [ClF4]− salts as fluorinating agents is evaluated by the reaction with diphenyl disulfide, Ph2S2, to pentafluorosulfanyl benzene, PhSF5. The CN moieties in acetonitrile and [B(CN)4]− are transferred in CF3 groups. Exposure of carbon monoxide, CO, leads to the formation of carbonyl fluoride, COF2, and elemental gold is dissolved under the formation of tetrafluoridoaurate [AuF4]−.
Intramolecular Reaction of Transient Phosphenium and Arsenium Ions Giving Rise to Isolable 9‐Phospha‐ and 9‐Arsena‐Fluorenium Ions
Authors: Olaru Marian , Duvinage Daniel , Naß Yannik , Malaspina Lorraine A. , Mebs Stefan , Beckmann Jens
Published: May 2020

Transient phosphenium and arsenium ions, generated by fluoride abstraction from bis(m‐terphenyl)fluoropnictogens, underwent intramolecular electrophilic attack prior to methyl group migration and gave rise to isolable 9‐phospha‐ and 9‐arsena‐fluorenium ions.
Ligand‐Facilitated Reductive Coupling of Benzyl Chlorides with Aryl Chlorides Catalyzed by Well‐Defined Heteroleptic Ni (II)‐NHC Complexes
Authors: Lu Gusheng , Li Ruipeng , Shen Zhengwang , Wu Qinjia , Sun Hongmei
Published: May 2020

Novel heteroleptic Ni (II) complexes bearing a highly hindered yet flexible IPr* ligand, Ni (IPr*)(PPh3)Br2 (1) and Ni (IPr*)(PCy3)Br2 (2) (IPr* = 1,3‐bis(2,6‐bis (diphenylmethyl)‐4‐methylphenyl)imidazol‐2‐ylidene), were easily prepared in 78% and 89% yield, respectively. Both were characterized by elemental analysis and NMR spectroscopy, and 1 was subjected to X‐ray crystallography. Compared with 2 and its analogue bearing a less sterically demanding IPr ligand (IPr = 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene), complex 1 exhibited superior catalytic activity in the magnesium‐mediated reductive coupling of benzyl chlorides with aryl chlorides, featuring outstanding tolerance of both coupling partners with steric demand. This study discloses a ligand‐facilitated reductive coupling of benzyl chlorides with aryl chlorides, which provides a new and practical synthetic tool for the synthesis of diarylmethanes.
Purification of cell‐derived Japanese encephalitis virus by dual‐mode chromatography
Authors: Zhang Fuliang , Luo Jun , Teng Man , Xing Guangxu , Guo Junqing , Zhang Yihua
Published: May 2020

Purification of the enveloped virus poses a challenge as one must retain viral infectivity to preserve immunogenicity. The traditional process of virus purification is time‐consuming, laborious and hard to scale up. Here, a rapid, simple and extensible laboratory program for the purification of Japanese encephalitis virus (JEV) was developed by using differential centrifugation, ultrafiltration, Sepharose 4 fast flow gel chromatography, and CaptoTM Core 700 chromatography. The entire process recovered 61.64% of the original virus, and the purified virus particles maintained good activity and immunogenicity. The purification process described has potential application in large‐scale production of high‐purity JEV.
A predictive dynamic yeast model based on component, energy, and electron carrier balances
Authors: La Angéla , Du Huan , Taidi Behnam , Perré Patrick
Published: May 2020

The present study describes a novel yeast model for the prediction of yeast fermentation. The proposed model considers the possible metabolic pathways of yeast. For each pathway, the time evolution of components, energy (ATP/ADP), and electron carriers (NAD+/NADH) are expressed with limitation factors for all quantities consumed by each respective pathway. In this manner, the model can predict the partition of these pathways based on the growth conditions and their evolution over time. Several biological pathways and their stoichiometric coefficients are well known from literature. It is important to note that most of the kinetic parameters have no effect as the actual kinetics are controlled by the balance of limiting factors. The few remaining parameters were adjusted and compared with the literature when the data set was available. The model fits our experimental data from yeast fermentation on glucose in a nonaerated batch system. The predictive ability of the model and its capacity to represent the intensity of each pathway over time facilitate an improved understanding of the interactions between the pathways. The key role of energy (ATP) and electron carrier (NAD+) to trigger the different metabolic pathways during yeast growth is highlighted, whereas the involvement of mitochondrial respiration not being associated with the TCA cycle is also shown.
Radiotranscriptomics signature‐based predictive nomograms for radiotherapy response in patients with nonsmall cell lung cancer: Combination and association of CT features and serum miRNAs levels
Authors: Fan Liyuan , Cao Qiang , Ding Xiuping , Gao Dongni , Yang Qiwei , Li Baosheng
Published: May 2020

Purpose

We aimed to establish radiotranscriptomics signatures based on serum miRNA levels and computed tomography (CT) texture features and develop nomogram models for predicting radiotherapy response in patients with nonsmall cell lung cancer (NSCLC).

Methods

We first used established radioresistant NSCLC cell lines for miRNA selection. At the same time, patients (103 for training set and 71 for validation set) with NSCLC were enrolled. Their pretreatment contrast‐enhanced CT texture features were extracted and their serum miRNA levels were obtained. Then, radiotranscriptomics feature selection was implemented with the least absolute shrinkage and selection operator (LASSO), and signatures were generated by logistic or Cox regression for objective response rate (ORR), overall survival (OS), and progression‐free survival (PFS). Afterward, radiotranscriptomics signature‐based nomograms were constructed and assessed for clinical use.

Results

Four miRNAs and 22 reproducible contrast‐enhanced CT features were used for radiotranscriptomics feature selection and we generated ORR‐, OS‐, and PFS‐ related radiotranscriptomics signatures. In patients with NSCLC who received radiotherapy, the radiotranscriptomics signatures were independently associated with ORR, OS, and PFS in both the training (OR: 2.94, P < .001; HR: 2.90, P < .001; HR: 3.58, P = .001) and validation set (OR: 2.94, P = .026; HR: 2.14, P = .004; HR: 2.64, P = .016). We also obtained a satisfactory nomogram for ORR. The C‐index values for the ORR nomogram were 0.86 [95% confidence interval (CI), 0.75 to 0.92] in the training set and 0.81 (95% CI, 0.69 to 0.89) in the validation set. The calibration‐in‐the‐large and calibration slope performed well. Decision curve analysis indicated a satisfactory net benefit.

Conclusions

The radiotranscriptomics signature could be an independent biomarker for evaluating radiotherapeutic responses in patients with NSCLC. The radiotranscriptomics signature‐based nomogram could be used to predict patients’ ORR, which would represent progress in individualized medicine.
Separating Growth from Nucleation for Facile Control over the Size and Shape of Palladium Nanocrystals
Authors: Janssen Annemieke , Shi Yifeng , Xia Younan
Published: May 2020

In order to maximize the performance of nanocrystals in a specific application, it is necessary to control both their size and shape. Here we report a one‐pot protocol that allows us to separate growth from nucleation for achieving better control over the size and shape of Pd nanocrystals. The two processes are temporally separated from each other, although the synthesis is carried out in the same reaction container. Size control is achieved by simply varying the ratio between the amounts of precursor allocated to the growth and nucleation processes. With the involvement of seeds at a fixed number, increasing the amount of precursor for growth leads to increasingly larger nanocrystals. Shape control is made possible by varying the capping agent, with bromide leading to a cubic shape and citrate inducing the formation of an octahedral shape. The synthesis can also be scaled up by at least tenfold without compromising the quality.
Fluorescent‐Labeled Octasilsesquioxane Nanohybrids as Potential Materials for Latent Fingerprinting Detection
Authors: Dare Enock O. , Vendrell‐Criado Victoria , Consuelo Jiménez M. , Pérez‐Ruiz Raúl , Díaz Díaz David
Published: May 2020

The recent demand for fluorescent‐labeled materials (FLMs) in forensic security concepts such as latent fingerprints (LFs) that encode information for anti‐counterfeiting and encryption of confidential data makes necessary the development of building new and innovative materials. Here, novel FLMs based on polyhedral oligomeric silsesquioxanes (POSS) functionalized with fluorophores via “click” reactions have been successfully synthesized and fully characterized. A comprehensive study of their photophysical properties has displayed large Stokes's shift together with good photostability in all cases, fulfilling the fundamental requisites for any legible LF detection on various surfaces. The excellent performance of the hetero‐bifunctional FLM in the visualization of LF is emphasized by their legibility, selectivity, sensitivity and temporal photostability. In this study, development mechanisms have been proposed and the overall concept constitute a novel approach for vis‐à‐vis forensic investigations to trace an individual's identity.
Catalytic Activity of Alkali Metal Cations for the Chemical Oxygen Reduction Reaction in a Biphasic Liquid System Probed by Scanning Electrochemical Microscopy
Authors: Rastgar Shokoufeh , Teixeira Santos Keyla , Angelucci Camilo Andrea , Wittstock Gunther
Published: May 2020

Chemical reduction of dioxygen in organic solvents for the production of reactive oxygen species or the concomitant oxidation of organic substrates can be enhanced by the separation of products and educts in biphasic liquid systems. Here, the coupled electron and ion transfer processes is studied as well as reagent fluxes across the liquid|liquid interface for the chemical reduction of dioxygen by decamethylferrocene (DMFc) in a dichloroethane‐based organic electrolyte forming an interface with an aqueous electrolyte containing alkali metal ions. This interface is stabilized at the orifice of a pipette, across which a Galvani potential difference is externally applied and precisely adjusted to enforce the transfer of different alkali metal ions from the aqueous to the organic electrolyte. The oxygen reduction is followed by H2O2 detection in the aqueous phase close to the interface by a microelectrode of a scanning electrochemical microscope (SECM). The results prove a strong catalytic effect of hydrated alkali metal ions on the formation rate of H2O2, which varies systematically with the acidity of the transferred alkali metal ions in the organic phase.
Reduced order methods for parametric optimal flow control in coronary bypass grafts, toward patient‐specific data assimilation
Authors: Zainib Zakia , Ballarin Francesco , Fremes Stephen , Triverio Piero , Jiménez‐Juan Laura , Rozza Gianluigi
Published: May 2020

Coronary artery bypass grafts (CABG) surgery is an invasive procedure performed to circumvent partial or complete blood flow blockage in coronary artery disease. In this work, we apply a numerical optimal flow control model to patient‐specific geometries of CABG, reconstructed from clinical images of real‐life surgical cases, in parameterized settings. The aim of these applications is to match known physiological data with numerical hemodynamics corresponding to different scenarios, arisen by tuning some parameters. Such applications are an initial step toward matching patient‐specific physiological data in patient‐specific vascular geometries as best as possible. Two critical challenges that reportedly arise in such problems are: (a) lack of robust quantification of meaningful boundary conditions required to match known data as best as possible and (b) high computational cost. In this work, we utilize unknown control variables in the optimal flow control problems to take care of the first challenge. Moreover, to address the second challenge, we propose a time‐efficient and reliable computational environment for such parameterized problems by projecting them onto a low‐dimensional solution manifold through proper orthogonal decomposition‐Galerkin.
File integrity monitoring tools: Issues, challenges, and solutions
Authors: Peddoju Suresh K. , Upadhyay Himanshu , Lagos Leonel
Published: May 2020

Ensuring integrity of sensitive files in file systems is imperative to computer systems. The vast majority of attacks work through unapproved or unauthorized access to sensitive files to take secret data like secret keys, passwords, credit card numbers, and so on. After that, attackers generally conceal their traces by subverting critical files like system logs. File system integrity monitoring is a well‐known way to deal with ensuring integrity of sensitive and critical files. The file system is at the heart of any computing system as it stores the data and executable programs. Malicious users or malwares might change the content of a sensitive data file or insert malicious payload in an executable. Hence, monitoring the integrity of the files in the file system is of utmost importance. Significant research work has been done on file integrity monitoring tools. This article presents the currently available tools for file integrity monitoring and their underlying approaches.
Towards unobtrusive patient‐centric access‐control for Health Information System
Authors: de Carvalho Junior Marcelo Antonio , Bandiera‐Paiva Paulo
Published: May 2020

Patient consent is currently a missing piece on Health Information Systems (HIS) access permission. The control is needed to ensure personal data as the property of the individual, not data controllers or health‐care service providers. This is a newly‐designed access‐decision flow for HIS secured by Role‐Based Access Control (RBAC) including patient‐centric control. It makes use of Colored Petri‐Nets (CPN) to model RBAC restrictions. A Discretionary Access Control (DAC) functionality is added to Electronic Health‐Records (EHR) control to convey a patient's explicit authorization to their data in a non‐obstructive access flow. Mutual exclusion was designed to incorporate patient needs so that they could authorize healthcare professionals to access EHR data. Additional information was supplied to a PERMS Access Control matrix and this enabled DAC to be mimicked using existing RBAC Core functions. A minimal addition is proposed to incorporate RBAC‐aware systems with no significant drawbacks when compared with previous CPN simulations. The article also discusses the limitations of this technique and the favorable conditions for implementing new features.
Photocatalytic Synthesis of Stilbenes via Cross‐Coupling of Alkenyl Boronic Acids and Arenediazonium Tetrafluoroborate Salts
Authors: Meyer Tim , Xu Jian‐Xing , Rabeah Jabor , Brückner Angelika , Wu Xiao‐Feng
Published: May 2020

In this article, we describe the development of a new method for the photocatalytic synthesis of (E)‐stilbenes by the coupling of alkenyl boronic acids and aryldiazonium salts. In our operatively simple and metal‐free system, visible light is used as an energy source and a “green” mixture of water and ethanol is used as solvent. A mechanistic explanation is presented which is supported by several control experiments. The reaction proceeds via a radical pathway, from both the diazonium salt and boronic acid in the presence of visible light.
Transition‐Metal Phosphorus Trisulfides and its Vacancy Defects: Emergence of a New Class of Anode Material for Li‐Ion Batteries
Authors: Jana Rajkumar , Chowdhury Chandra , Datta Ayan
Published: May 2020

In the search of suitable anode candidates with high specific capacity, favorable potential, and structural stability for lithium‐ion batteries (LIBs), transition‐metal phosphorus trisulfides (TMPS3) can be considered as one of the most promising alternatives to commercial graphite. Here, it was demonstrated that the limitations of commercial anode materials (i.e., low specific capacity, large volume change, and high lithium diffusion barrier as well as nucleation) can be circumvented by using TMPS3 monolayer surfaces. The study revealed that lithium binds strongly to TMPS3 monolayers (−2.31 eV) without any distortion of the surface, with Li@TMPS3 exhibiting enhanced stability compared with other 2D analogues (graphene, phosphorene, MXenes, transition‐metal sulfides and phosphides). The binding energy of lithium was overwhelmingly enhanced with vacancy defects. The vacancy‐mediated TMPS3 surfaces showed further amplification of Li binding energy from −2.03 to −2.32 eV and theoretical specific capacity of 441.65 to 484.34 mAh g−1 for MnPS3 surface. Most importantly, minimal change in volume (less than 2 %) after lithiation makes TMPS3 monolayers a very effective candidate for LIBs. Additionally, the ultralow lithium diffusion barrier (0.08 eV) compared with other existing commercial anode material proves the superiority of TMPS3.
Dietary complexity and hidden costs of prey switching in a generalist top predator
Authors: Moorhouse‐Gann Rosemary J. , Kean Eleanor F. , Parry Gareth , Valladares Sonia , Chadwick Elizabeth A.
Published: May 2020

Variation in predator diet is a critical aspect of food web stability, health, and population dynamics of predator/ prey communities. Quantifying diet, particularly among cryptic species, is extremely challenging, however, and differentiation between demographic subsets of populations is often overlooked.

We used prey remains and data takenpostmortemfrom otterLutra lutrato determine the extent to which dietary variation in a top predator was associated with biotic, spatial, and temporal factors.

Biotic data (e.g., sex, weight, and length) and stomach contents were taken from 610 otters found dead across England and Wales between 1994 and 2010. Prey remains were identified to species where possible, using published keys and reference materials. Multi‐model inference followed by model prediction was applied to test for and visualize the nature of associations.

Evidence for widespread decline in the consumption of eels (Anguilla anguilla) reflected known eel population declines. An association between eel consumption and otter body condition suggested negative consequences for otter nutrition. Consumption ofCottus gobioand stickleback spp. increased, but was unlikely to compensate (there was no association with body condition). More otters with empty stomachs were found over time. Otter sex, body length, and age‐class were important biotic predictors of the prey species found, and season, region, and distance from the coast were important abiotic predictors.

Our study is unique in its multivariate nature, broad spatial scale, and long‐term dataset. Inclusion of biotic data allowed us to reveal important differences in costs and benefits of different prey types, and differences between demographic subsets of the population, overlaid on spatial and temporal variation. Such complexities in otter diet are likely to be paralleled in other predators, and detailed characterization of diet should not be overlooked in efforts to conserve wild populations.
Low‐voltage charge pump circuit with double boost technique
Authors: Uemi Allex , Hino Shota , Masui Yoshihiro
Published: May 2020

In recent years, interest in IoT (Internet of Things) has been increasing, and energy harvesting has attracted attention. However, the power and voltage that can be harvested are very small. Therefore, a power supply circuit is required to solve this problem. In this paper, we have realized a boost circuit that does not require a coil with the aim of integrating all the circuits required for sensing on one chip.
Loss of core fucosylation enhances the anticancer activity of cytotoxic T lymphocytes by increasing PD‐1 degradation
Authors: Zhang Nianzhu , Li Ming , Xu Xing , Zhang Yingshu , Liu Yancheng , Zhao Meng , Li Peng , Chen Jun , Fukuda Tomohiko , Gu Jianguo , Jin Xun , Li Wenzhe
Published: May 2020

As an immune checkpoint, programmed cell death 1 (PD‐1) and its ligand (PD‐L1) pathway plays a crucial role in CD8+ cytotoxic T lymphocytes (CTL) activation and provides antitumor responses. The N‐glycans of PD‐1 and PD‐L1 are highly core fucosylated, which are solely catalyzed by the core fucosyltransferase (Fut8). However, the precise biological mechanisms underlying effects of core fucosylation of PD‐1 and PD‐L1 on CTL activation have not been fully understood. In this study, we found that core fucosylation was significantly upregulated in lung adenocarcinoma. Compared to those of Fut8+/+OT‐I mice, the lung adenocarcinoma formation induced by urethane was markedly reduced in Fut8−/−OT‐I mice. De‐core fucosylation of PD‐1 compromised its expression on Fut8−/− CTL, resulted in enhanced Fut8−/− CTL activation and cytotoxicity, leading to more efficient tumor eradication. Indeed, loss of core fucosylation significantly enhanced the PD‐1 ubiquitination and in turn led to the degradation of PD‐1 in the proteasome. Our current work indicates that inhibition of core fucosylation is a unique strategy to reduce PD‐1 expression for the antilung adenocarcinoma immune therapy in the future.
Preventing Undesirable Structure Flexibility in Pyromellitate Metal Organic Frameworks
Authors: Hayes Oliver G. , Warrender Stewart J. , Cordes David B. , Duncan Morven J. , Slawin Alexandra M. Z. , Morris Russell E.
Published: May 2020

Removal of coordinated water molecules from the porous Zn‐pyromellitate metal organic framework Zn5(OH)2(PMA)2(H2O)4·xH2O (PMA = pyromellitic acid or 1,2,4,5‐benzene tetracarboxylic acid) should generate coordinatively unsaturated metal sites suitable for gas adsorption. However, reports of instability towards dehydration have restricted the study and utility of this MOF. Here we examine in more detail the nature of the structural transformation that occurs upon dehydration. This study reveals that a fully reversible crystalline‐crystalline transformation from a porous to a non‐porous homologue takes place, proceeding through a partially dehydrated intermediate. We show that doping the structure with Ni2+ ions at greater than 30 % prevents structural rearrangement, thereby maintaining porosity, and rendering the material effective for gas (nitric oxide) adsorption applications. These results indicate that doping can be an effective means to increase the utility of otherwise unserviceable structures.
Discrete and Polymeric Cobalt Pyrophosphates Derived from Pyrophosphoric Acid Diester Ar2H2P2O7
Authors: Sharma Kamna , Gupta Sandeep K. , Murugavel Ramaswamy
Published: May 2020

While the structural elucidation and coordination chemistry of organo‐monophosphates have been well investigated, research on the simplest member of organo‐oligophosphates, viz. diorganopyrophosphates, is relatively rare due to the inherent hydrolytic instability of the ligand. Water elimination from the 2,6‐diisopropyl phenyl phosphate (dippH2) by the action of dicyclohexylcarbodiimide (DCC) results in the isolation of a diorganopyrophosphates ligand formulated as [O{P(OAr)(OH)(O)}2] (1 or pyrodippH2) (Ar = 2,6‐diisopropylphenyl). Due to the instability of 1, it has been transformed into its sodium salt [O{P(OAr)(ONa)(O)}2] (2), which has been used for further reactions to prepare cobalt pyrophosphate complexes 3–7. Reaction of 2 with anhydrous cobalt(II) chloride in the presence of N‐heterocyclic ligands results in the formation of [Co(pyrodipp)(imz)3] (3), [Co(pyrodipp)(bpy)2](CH3OH) (4) and [Co(pyrodipp)(phen)2] (5) (imz = imidazole; bpy = 2,2'‐bipyridine; phen = 1,10‐phenanthroline). Use of multidentate ancillary ligand such as 4‐pyridyl‐2,2':6',2''‐terpyridine (pyterpy) under similar reaction conditions leads to the formation of a one‐dimensional zig‐zag cobalt pyrophosphate coordination polymer [Co(pyrodipp)(pyterpy)(CH3OH)]n (6). In the absence of any ancillary ligand, the reaction between cobalt(II) chloride and 2 in acetonitrile results in the isolation of an interesting inorganic polymer [Co(pyrodipp)(CH3CN)2]n (7), whose backbone consists of a chain of spirocycles of CoP2O3 rings, joined at the cobalt centers. The newly synthesized cobalt pyrophosphates 3–7 have been characterized by both analytical and spectroscopic techniques, magnetic studies apart from single‐crystal X‐ray diffraction studies in each case. A striking and persistent structural feature in 3–7 is the presence of the cobalt pyrophosphate six‐membered metallacycle Co(OPOPO). While cobalt metal exists in trigonal bipyramidal geometry in complex 3, distorted octahedral coordination geometry is observed for cobalt centers in complexes 4–7.
Photo‐Difunctionalization and Photo‐Oxidative Cleavage of the C–C Double Bond of Styrenes in the Presence of Nanosized Cadmium Sulfide (CdS) as a Highly Efficient Photo‐Induced Reusable Nanocatalyst
Authors: Firoozi Somayeh , Hosseini‐Sarvari Mona
Published: May 2020

The synthesis of cyclic dithiocarbonates via photo‐difunctionalization of the C–C double bond of styrene and aryl aldehydes via photo‐oxidative cleavage of the C–C double bond of styrene was accomplished in the presence of CdS NPs at room temperature in air atmosphere under visible light irradiation without using any external oxidant. Some of the special advantages of these processes are the use of CdS NPs as a simple, accessible, safe, and visible‐light‐induced reusable catalyst, as well as the use of air as an easily attainable, inexpensive, and harmless oxidant, styrene as a readily accessible substrate, and visible‐light as a renewable and safe energy source.
New Electrochemical Sensor of Prolonged Application for Metformin Determination Based on Hydrated Ruthenium Dioxide‐Carbon Black‐Nafion Modified Glassy Carbon Electrode
Authors: Górska Anna , Paczosa‐Bator Beata , Wyrwa Jan , Piech Robert
Published: May 2020

Metformin (MET) is an antidiabetic drug most commonly used in treatment of diabetes mellitus type 2 (T2D). Adsorptive stripping voltammetric method using carbon black – hydrated ruthenium dioxide – Nafion modified glassy carbon electrode (CB‐RuO2‐Nafion GC electrode) have been developed for metformin determination in pharmaceutical formulations. By using ruthenium dioxide, electrode's lifespan was extended to at least 3 weeks (change of metrological parameters estimated as 3–4 %) what is an excellent result concerning other solutions previously described in the literature. Moreover the fabrication of the sensor is simple and fast. Deposition step was carried out at the potential 0 mV for 15 s. The best results were obtained in 0.05 M acetate buffer (pH 4.6). Important aspect was fixed MET : Cu(II) ratio equal to 1 : 8, otherwise linear dependence between register current and MET concentration could not be obtained. In addition, a significant improvement in the parameters of the calibration curve was obtained. Limit of detection was equal to 0.7 μM. Developed method was successfully applied in analysis of 2 pharmaceuticals products and in wastewater and river water. Accuracy of the method was estimated using recoveries, which were in the range 101–110 %. In order to adapt developed system into hydrodynamic conditions, amperometry in hydrodynamic transport conditions and flow injection analysis (FIA) measurements have been conducted. Conducted FIA measurements prove that developed method has potential for application in automized flow systems without frequent calibration.
Determination of Ethanol in Alcoholic Drinks: Flow Injection Analysis with Amperometric Detection Versus Portable Raman Spectrometer
Authors: Jashari Granit , Švancara Ivan , Sýs Milan
Published: May 2020

A flow injection analysis with integrated amperometric alcohol dehydrogenase biosensor and a handheld Mira‐DS Raman spectrometer have been compared for the determination of ethanol in different samples of alcoholic drinks. The biosensor was constructed from the commercial screen‐printed carbon electrode as amperometric transducer and covered by a thin layer comprising alcohol dehydrogenase, reduced single‐layer graphene oxide, rhodium(IV) dioxide, and glutaraldehyde. Both assemblies were tested on analysis of plum brandy, white rum, vodka, white and red wines, strong dark beer, and non‐alcoholic beer. The two principally different analytical methods were critically compared and some limitations found, especially in case of analysis of red wine and beers. Finally, some future improvements of both analytical tools under test outlined.