bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine Learning and Deep Learning Methods for Intrusion Detection Systems: A Survey
Authors: Liu Hongyu , Lang Bo
Published: October 2019

Networks play important roles in modern life, and cyber security has become a vital research area. An intrusion detection system (IDS) which is an important cyber security technique, monitors the state of software and hardware running in the network. Despite decades of development, existing IDSs still face challenges in improving the detection accuracy, reducing the false alarm rate and detecting unknown attacks. To solve the above problems, many researchers have focused on developing IDSs that capitalize on machine learning methods. Machine learning methods can automatically discover the essential differences between normal data and abnormal data with high accuracy. In addition, machine learning methods have strong generalizability, so they are also able to detect unknown attacks. Deep learning is a branch of machine learning, whose performance is remarkable and has become a research hotspot. This survey proposes a taxonomy of IDS that takes data objects as the main dimension to classify and summarize machine learning-based and deep learning-based IDS literature. We believe that this type of taxonomy framework is fit for cyber security researchers. The survey first clarifies the concept and taxonomy of IDSs. Then, the machine learning algorithms frequently used in IDSs, metrics, and benchmark datasets are introduced. Next, combined with the representative literature, we take the proposed taxonomic system as a baseline and explain how to solve key IDS issues with machine learning and deep learning techniques. Finally, challenges and future developments are discussed by reviewing recent representative studies.
Deep Convolutional Neural Network-Based Approaches for Face Recognition
Authors: Almabdy Soad , Elrefaei Lamiaa
Published: October 2019

Face recognition (FR) is defined as the process through which people are identified using facial images. This technology is applied broadly in biometrics, security information, accessing controlled areas, keeping of the law by different enforcement bodies, smart cards, and surveillance technology. The facial recognition system is built using two steps. The first step is a process through which the facial features are picked up or extracted, and the second step is pattern classification. Deep learning, specifically the convolutional neural network (CNN), has recently made commendable progress in FR technology. This paper investigates the performance of the pre-trained CNN with multi-class support vector machine (SVM) classifier and the performance of transfer learning using the AlexNet model to perform classification. The study considers CNN architecture, which has so far recorded the best outcome in the ImageNet Large-Scale Visual Recognition Challenge (ILSVRC) in the past years, more specifically, AlexNet and ResNet-50. In order to determine performance optimization of the CNN algorithm, recognition accuracy was used as a determinant. Improved classification rates were seen in the comprehensive experiments that were completed on the various datasets of ORL, GTAV face, Georgia Tech face, labelled faces in the wild (LFW), frontalized labeled faces in the wild (F_LFW), YouTube face, and FEI faces. The result showed that our model achieved a higher accuracy compared to most of the state-of-the-art models. An accuracy range of 94% to 100% for models with all databases was obtained. Also, this was obtained with an improvement in recognition accuracy up to 39%.
Support Vector Machine-Based EMG Signal Classification Techniques: A Review
Authors: Toledo-Pérez Diana C. , Rodríguez-Reséndiz Juvenal , Gómez-Loenzo Roberto A. , Jauregui-Correa J. C.
Published: October 2019

This paper gives an overview of the different research works related to electromyographic signals (EMG) classification based on Support Vector Machines (SVM). The article summarizes the techniques used to make the classification in each reference. Furthermore, it includes the obtained accuracy, the number of signals or channels used, the way the authors made the feature vector, and the type of kernels used. Hence, this article also includes a compilation about the bands used to filter signals, the number of signals recommended, the most commonly used sampling frequencies, and certain features that can create the characteristics of the vector. This research gathers articles related to different kinds of SVM-based classification and other tools for signal processing in the field.
Microscopic Imaging Spray Diagnostics under High Temperature Conditions: Application to Urea–Water Sprays
Authors: Lieber Christian , Koch Rainer , Bauer Hans-Jörg
Published: October 2019

The quantitative investigation of droplet laden turbulent flows at high temperature conditions is of great importance for numerous applications. In this study, an experiment was set up for investigation of evaporating urea–water sprays, which are relevant for the effective reduction of nitrogen oxide emissions of diesel engines using Selective Catalytic Reduction. A shadowgraphy setup is pushed to its limits in order to detect droplet diameters as small as 4 μ m and droplet velocities up to 250 m s − 1 . In addition, the operating conditions of the gaseous flow of up to 873 K and 0.6 M Pa are an additional challenge. Due to the high temperature environment, image quality is prone to be compromised by Schlieren effects and astigmatism phenomena. A water-cooled window and an astigmatism correction device are installed in order to correct these problems. The results to be presented include characteristics of the turbulent gas flow as well as detailed spray characteristics at different positions downstream of the atomiser. It is demonstrated that the velocity of the gas can be approximated by the velocity of the smallest detectable droplets with sufficient accuracy. Furthermore, the statistical analysis of velocity fluctuations provides data for predicting the turbulent dispersion of the droplets.
Impacts of the Desiccated Lake System on Precipitation in the Basin of Mexico City
Authors: López-Espinoza Erika , Ruiz-Angulo Angel , Zavala-Hidalgo Jorge , Romero-Centeno Rosario , Escamilla-Salazar Josefina
Published: October 2019

Mexico City constitutes one of the largest concentrations of population on the planet and is settled in a valley that, before the 16th century, had a lake system. The lakes were desiccated artificially, and currently, only small lakes remain. The impact of the lake system desiccation on precipitation was studied by performing numerical experiments: with the ancient lake system and without it. The experiments were carried out with the Weather Research and Forecasting (WRF) model coupled with a lake model for two months, using identical initial and boundary conditions, where only the system and lake physics were changed. The mean daily accumulated precipitation reduced when the system was removed. Additionally, the hourly distribution of rainfall changed from a relatively small diurnal variability when there was a lake system to a larger variability with a peak in the afternoon when the system was removed. Extreme precipitation events became more intense in the simulations with lakes. When the lakes were removed, the diurnal temperature range increased, and the boundary layer height became more variable, with a higher daily maximum. The results presented here show that the WRF-Lake model leads to opposite results compared to those with a non-coupled lake.
Quantemol Electron Collisions (QEC): An Enhanced Expert System for Performing Electron Molecule Collision Calculations Using the R-Matrix Method
Authors: Cooper Bridgette , Tudorovskaya Maria , Mohr Sebastian , O’Hare Aran , Hanicinec Martin , Dzarasova Anna , Gorfinkiel Jimena , Benda Jakub , Mašín Zdeněk , Al-Refaie Ahmed , Knowles Peter , Tennyson Jonathan
Published: October 2019

Collisions of low energy electrons with molecules are important for understanding many aspects of the environment and technologies. Understanding the processes that occur in these types of collisions can give insights into plasma etching processes, edge effects in fusion plasmas, radiation damage to biological tissues and more. A radical update of the previous expert system for computing observables relevant to these processes, Quantemol-N, is presented. The new Quantemol Electron Collision (QEC) expert system simplifyies the user experience, improving reliability and implements new features. The QEC graphical user interface (GUI) interfaces the Molpro quantum chemistry package for molecular target setups, and the sophisticated UKRmol+ codes to generate accurate and reliable cross-sections. These include elastic cross-sections, super elastic cross-sections between excited states, electron impact dissociation, scattering reaction rates, dissociative electron attachment, differential cross-sections, momentum transfer cross-sections, ionization cross sections, and high energy electron scattering cross-sections. With this new interface we will be implementing dissociative recombination estimations, vibrational excitations for neutrals and ions, and effective core potentials in the near future.
Deduction in Non-Fregean Propositional Logic SCI
Authors: Golińska-Pilarek Joanna , Welle Magdalena
Published: October 2019

We study deduction systems for the weakest, extensional and two-valued non-Fregean propositional logic SCI . The language of SCI is obtained by expanding the language of classical propositional logic with a new binary connective ≡ that expresses the identity of two statements; that is, it connects two statements and forms a new one, which is true whenever the semantic correlates of the arguments are the same. On the formal side, SCI is an extension of classical propositional logic with axioms characterizing the identity connective, postulating that identity must be an equivalence and obey an extensionality principle. First, we present and discuss two types of systems for SCI known from the literature, namely sequent calculus and a dual tableau-like system. Then, we present a new dual tableau system for SCI and prove its soundness and completeness. Finally, we discuss and compare the systems presented in the paper.
Effect of Marination Time on the Antioxidant Properties of Peptides Extracted from Organic Dry-Fermented Beef
Authors: Kęska Paulina , Wójciak Karolina M. , Stadnik Joanna
Published: October 2019

In this study, we evaluated the effect of marination time on changes in the antioxidant properties of peptides extracted from bovine semimembranosus muscle. We measured antiradical scavenging capacity and reducing power of the peptides using a spectrophotometric decolorization method; inhibition of lipid oxidation was also assessed by estimating the level of malondialdehyde formed. According to our results, there was no benefit from the doubling of marinating time (from 24 to 48 h) as part of the preprocessing of beef. Samples from S1 batch (24 h marination) showed better antioxidant properties than those from S2 batch. We also tested various color parameters as a reflection of the inhibition of oxidative processes, in which case, the most favorable parameters from the consumer point of view were found to be lightness and redness. The effect of marination time on the degree of proteolytic changes was estimated using peptidomic approach. The degradation of myoglobin, hemoglobin, creatine kinase-type M, and beta-enolase—as the most sensitive proteins to proteolytic degradation—was observed during the 62 days of processing. It seems that the prolongation of marination time as a preprocessing step intensifies the hydrolytic degradation of proteins and peptides during the processing step. This results in the loss (or it has no effect) of antioxidative properties in organic dry-fermented beef.
Parvifloron D from Plectranthus strigosus: Cytotoxicity Screening of Plectranthus spp. Extracts
Authors: Garcia Catarina , Ntungwe Epole , Rebelo Ana , Bessa Cláudia , Stankovic Tijana , Dinic Jelena , Díaz-Lanza Ana , P. Reis Catarina , Roberto Amílcar , Pereira Paula , Cebola Maria-João , Saraiva Lucília , Pesic Milica , Duarte Noélia , Rijo Patrícia
Published: October 2019

The Plectranthus genus is commonly used in traditional medicine due to its potential to treat several illnesses, including bacterial infections and cancer. As such, aiming to screen the antibacterial and cytotoxic activities of extracts, sixteen selected Plectranthus species with medicinal potential were studied. In total, 31 extracts obtained from 16 Plectranthus spp. were tested for their antibacterial and anticancer properties. Well diffusion method was used for preliminary antibacterial screening. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the five most active acetonic extracts (P. aliciae, P. japonicus, P. madagascariensis var. “Lynne”, P. stylesii, and P. strigosus) were determined. After preliminary toxicity evaluation on Artemia salina L., their cytotoxic properties were assessed on three human cancer cell lines (HCT116, MCF-7, and H460). These were also selected for mechanism of resistance studies (on NCI-H460/R and DLD1-TxR cells). An identified compound—parvifloron D—was tested in a pair of sensitive and MDR-Multidrug resistance cancer cells (NCI-H460 and NCI-H460/R) and in normal bronchial fibroblasts MRC-5. The chemical composition of the most active extract was studied through high performance liquid chromatography with a diode array detector (HPLC-DAD/UV) and liquid chromatography–mass spectrometry (LC–MS). Overall, P. strigosus acetonic extract showed the strongest antimicrobial and cytotoxic potential that could be explained by the presence of parvifloron D, a highly cytotoxic diterpene. This study provides valuable information on the use of the Plectranthus genus as a source of bioactive compounds, namely P. strigosus with the potential active ingredient the parvifloron D.
Identification and Isolation of Active Compounds from Astragalus membranaceus that Improve Insulin Secretion by Regulating Pancreatic β-Cell Metabolism
Authors: Lee Dahae , Lee Da , Choi Sungyoul , Lee Jin , Jang Dae , Kang Ki
Published: October 2019

In type 2 diabetes (T2D), insufficient secretion of insulin from the pancreatic β-cells contributes to high blood glucose levels, associated with metabolic dysregulation. Interest in natural products to complement or replace existing antidiabetic medications has increased. In this study, we examined the effect of Astragalus membranaceus extract (ASME) and its compounds 1–9 on glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells. ASME and compounds 1–9 isolated from A. membranaceus stimulated insulin secretion in INS-1 cells without inducing cytotoxicity. A further experiment showed that compounds 2, 3, and 5 enhanced the phosphorylation of total insulin receptor substrate-2 (IRS-2), phosphatidylinositol 3-kinase (PI3K), and Akt, and activated pancreatic and duodenal homeobox-1 (PDX-1) and peroxisome proliferator-activated receptor-γ (PPAR-γ), which are associated with β-cell function and insulin secretion. The data suggest that two isoflavonoids (2 and 3) and a nucleoside (compound 5), isolated from the roots of A. membranaceus, have the potential to improve insulin secretion in β-cells, representing the first step towards the development of potent antidiabetic drugs.
Beyond Chelation: EDTA Tightly Binds Taq DNA Polymerase, MutT and dUTPase and Directly Inhibits dNTPase Activity
Authors: Lopata Anna , Jójárt Balázs , Surányi Éva V. , Takács Enikő , Bezúr László , Leveles Ibolya , Bendes Ábris Á. , Viskolcz Béla , Vértessy Beáta G. , Tóth Judit
Published: October 2019

EDTA is commonly used as an efficient chelator of metal ion enzyme cofactors. It is highly soluble, optically inactive and does not interfere with most chemicals used in standard buffers making EDTA a common choice to generate metal-free conditions for biochemical and biophysical investigations. However, the controversy in the literature on metal-free enzyme activities achieved using EDTA or by other means called our attention to a putative effect of EDTA beyond chelation. Here, we show that EDTA competes for the nucleotide binding site of the nucleotide hydrolase dUTPase by developing an interaction network within the active site similar to that of the substrate. To achieve these findings, we applied kinetics and molecular docking techniques using two different dUTPases. Furthermore, we directly measured the binding of EDTA to dUTPases and to two other dNTPases, the Taq polymerase and MutT using isothermal titration calorimetry. EDTA binding proved to be exothermic and mainly enthalpy driven with a submicromolar dissociation constant considerably lower than that of the enzyme:substrate or the Mg:EDTA complexes. Control proteins, including an ATPase, did not interact with EDTA. Our findings indicate that EDTA may act as a selective inhibitor against dNTP hydrolyzing enzymes and urge the rethinking of the utilization of EDTA in enzymatic experiments.
Association of Polygenic Liability for Alcohol Dependence and EEG Connectivity in Adolescence and Young Adulthood
Authors: Meyers Jacquelyn L. , Chorlian David B. , Johnson Emma C. , Pandey Ashwini K. , Kamarajan Chella , Salvatore Jessica E. , Aliev Fazil , Subbie-Saenz de Viteri Stacey , Zhang Jian , Chao Michael , Kapoor Manav , Hesselbrock Victor , Kramer John , Kuperman Samuel , Nurnberger John , Tischfield Jay , Goate Alison , Foroud Tatiana , Dick Danielle M. , Edenberg Howard J. , Agrawal Arpana , Porjesz Bernice
Published: October 2019

Differences in the connectivity of large-scale functional brain networks among individuals with alcohol use disorders (AUD), as well as those at risk for AUD, point to dysfunctional neural communication and related cognitive impairments. In this study, we examined how polygenic risk scores (PRS), derived from a recent GWAS of DSM-IV Alcohol Dependence (AD) conducted by the Psychiatric Genomics Consortium, relate to longitudinal measures of interhemispheric and intrahemispheric EEG connectivity (alpha, theta, and beta frequencies) in adolescent and young adult offspring from the Collaborative Study on the Genetics of Alcoholism (COGA) assessed between ages 12 and 31. Our findings indicate that AD PRS (p-threshold < 0.001) was associated with increased fronto-central, tempo-parietal, centro-parietal, and parietal-occipital interhemispheric theta and alpha connectivity in males only from ages 18–31 (beta coefficients ranged from 0.02–0.06, p-values ranged from 10−6–10−12), but not in females. Individuals with higher AD PRS also demonstrated more performance deficits on neuropsychological tasks (Tower of London task, visual span test) as well as increased risk for lifetime DSM-5 alcohol and opioid use disorders. We conclude that measures of neural connectivity, together with neurocognitive performance and substance use behavior, can be used to further understanding of how genetic risk variants from large GWAS of AUD may influence brain function. In addition, these data indicate the importance of examining sex and developmental effects, which otherwise may be masked. Understanding of neural mechanisms linking genetic variants emerging from GWAS to risk for AUD throughout development may help to identify specific points when neurocognitive prevention and intervention efforts may be most effective.
A Study on Parametric Design Application to Hospital Retrofitting for Improving Energy Savings and Comfort Conditions
Authors: Gaspari Jacopo , Fabbri Kristian , Gabrielli Linda
Published: October 2019

The scientific literature offers a wide range of studies evidencing the progress done in the retrofit actions dealing with the current building stock; however, renovations of hospitals are still an open field of research due to their typical complexity that is usually associated with a very challenging updating processes to maintain or increase operational level. The paper provides a synthesis of a study developed by a team of the Department of Architecture for Saint Orsola Hospital in Bologna with the scope to explore innovative retrofitting strategies. The brief provided by the management unit of the hospital was connected to the general renovation plan involving the entire site and particularly some existing buildings taking into account some limitations concerning budget availabilities and everyday activities needed to ensure acceptable service level for the end users. The design approach starts from defining a basic unit (a typical hospital room) that is deeply analyzed to report the starting conditions (indoor environmental parameters) and then used to simulate the potential impacts of retrofitting actions on its performances. The results allowed to parametrically develop a step by step strategy scaled on each building sector and on the building as a whole to evaluate the global impact on energy performances while considering time and costs of each retrofitting options.
Clinical Application of Next-Generation Sequencing as A Liquid Biopsy Technique in Advanced Colorectal Cancer: A Trick or A Treat?
Authors: Kastrisiou Myrto , Zarkavelis George , Pentheroudakis George , Magklara Angeliki
Published: October 2019

Owing to its advantages over prior relevant technologies, massive parallel or next-generation sequencing (NGS) is rapidly evolving, with growing applications in a wide range of human diseases. The burst in actionable molecular alterations in many cancer types advocates for the practicality of using NGS in the clinical setting, as it permits the parallel characterization of multiple genes in a cost- and time-effective way, starting from low-input DNA. In advanced clinical practice, the oncological management of colorectal cancer requires prior knowledge of KRAS, NRAS, and BRAF status, for the design of appropriate therapeutic strategies, with more gene mutations still surfacing as potential biomarkers. Tumor heterogeneity, as well as the need for serial gene profiling due to tumor evolution and the emergence of novel genetic alterations, have promoted the use of liquid biopsies—especially in the form of circulating tumor DNA (ctDNA)—as a promising alternative to tissue molecular analysis. This review discusses recent studies that have used plasma NGS in advanced colorectal cancer and summarizes the clinical applications, as well as the technical challenges involved in adopting this technique in a clinically beneficial oncological practice.
Prediction of BAP1 Expression in Uveal Melanoma Using Densely-Connected Deep Classification Networks
Authors: Sun Muyi , Zhou Wei , Qi Xingqun , Zhang Guanhong , Girnita Leonard , Seregard Stefan , Grossniklaus Hans , Yao Zeyi , Zhou Xiaoguang , Stålhammar Gustav
Published: October 2019

Uveal melanoma is the most common primary intraocular malignancy in adults, with nearly half of all patients eventually developing metastases, which are invariably fatal. Manual assessment of the level of expression of the tumor suppressor BRCA1-associated protein 1 (BAP1) in tumor cell nuclei can identify patients with a high risk of developing metastases, but may suffer from poor reproducibility. In this study, we verified whether artificial intelligence could predict manual assessments of BAP1 expression in 47 enucleated eyes with uveal melanoma, collected from one European and one American referral center. Digitally scanned pathology slides were divided into 8176 patches, each with a size of 256 × 256 pixels. These were in turn divided into a training cohort of 6800 patches and a validation cohort of 1376 patches. A densely-connected classification network based on deep learning was then applied to each patch. This achieved a sensitivity of 97.1%, a specificity of 98.1%, an overall diagnostic accuracy of 97.1%, and an F1-score of 97.8% for the prediction of BAP1 expression in individual high resolution patches, and slightly less with lower resolution. The area under the receiver operating characteristic (ROC) curves of the deep learning model achieved an average of 0.99. On a full tumor level, our network classified all 47 tumors identically with an ophthalmic pathologist. We conclude that this deep learning model provides an accurate and reproducible method for the prediction of BAP1 expression in uveal melanoma.
Current Concepts of Non-Coding RNAs in the Pathogenesis of Non-Clear Cell Renal Cell Carcinoma
Authors: Barth Dominik A. , Slaby Ondrej , Klec Christiane , Juracek Jaroslav , Drula Rares , Calin George A. , Pichler Martin
Published: October 2019

Renal cell carcinoma (RCC) is a relatively rare malignancy of the urinary tract system. RCC is a heterogenous disease in terms of underlying histology and its associated underlying pathobiology, prognosis and treatment schedule. The most prevalent histological RCC subtype is clear-cell renal cell carcinoma (ccRCC), accounting for about 70–80% of all RCCs. Though the pathobiology and treatment schedule for ccRCC are well-established, non-ccRCC subtypes account for 20%–30% of RCC altogether, and their underlying molecular biology and treatment options are poorly defined. The class of non-coding RNAs—molecules that are generally not translated into proteins—are new cancer drivers and suppressors in all types of cancer. Of these, small non-coding microRNAs (miRNAs) contribute to carcinogenesis by regulating posttranscriptional gene silencing. Additionally, a growing body of evidence supports the role of long non-coding RNAs (lncRNAs) in cancer development and progression. Most studies on non-coding RNAs in RCC focus on clear-cell histology, and there is a relatively limited number of studies on non-ccRCC subtypes. The aim of this review is to give an overview of the current knowledge regarding the role of non-coding RNAs (including short and long non-coding RNAs) in non-ccRCC and to highlight possible implications as diagnostic, prognostic and predictive biomarkers.
The Novel Phosphatidylinositol-3-Kinase (PI3K) Inhibitor Alpelisib Effectively Inhibits Growth of PTEN-Haploinsufficient Lipoma Cells
Authors: Kirstein Anna S. , Augustin Adrien , Penke Melanie , Cea Michele , Körner Antje , Kiess Wieland , Garten Antje
Published: October 2019

Germline mutations in the tumor suppressor gene PTEN cause PTEN Hamartoma Tumor Syndrome (PHTS). Pediatric patients with PHTS frequently develop lipomas. Treatment attempts with the mTORC1 inhibitor rapamycin were unable to reverse lipoma growth. Recently, lipomas associated with PIK3CA-related overgrowth syndrome were successfully treated with the novel PI3K inhibitor alpelisib. Here, we tested whether alpelisib has growth-restrictive effects and induces cell death in lipoma cells. We used PTEN-haploinsufficient lipoma cells from three patients and treated them with alpelisib alone or in combination with rapamycin. We tested the effect of alpelisib on viability, proliferation, cell death, induction of senescence, adipocyte differentiation, and signaling at 1–100 µM alpelisib. Alpelisib alone or in combination with rapamycin reduced proliferation in a concentration- and time-dependent manner. No cell death but an induction of senescence was detected after alpelisib incubation for 72 h. Alpelisib treatment led to a reduced phosphorylation of AKT, mTOR, and ribosomal protein S6. Rapamycin treatment alone led to increased AKT phosphorylation. This effect could be reversed by combining rapamycin with alpelisib. Alpelisib reduced the size of lipoma spheroids by attenuating adipocyte differentiation. Since alpelisib was well tolerated in first clinical trials, this drug alone or in combination with rapamycin is a potential new treatment option for PHTS-related adipose tissue overgrowth.
Fischer-Tropsch Synthesis: Cd, In and Sn Effects on a 15%Co/Al2O3 Catalyst
Authors: Ma Wenping , Jacobs Gary , Shafer Wilson , Ji Yaying , Klettlinger Jennifer , Khalid Syed , Hopps Shelley , Davis Burtron
Published: October 2019

The effects of 1% of Cd, In and Sn additives on the physicochemical properties and Fischer-Tropsch synthesis (FTS) performance of a 15% Co/Al2O3 catalyst were investigated. The fresh and spent catalysts were characterized by BET, temperature programmed reduction (TPR), H2-chemisorption, NH3 temperature programmed desorption (TPD), X-ray absorption near edge spectroscopy (XANES), and X ray diffraction (XRD). The catalysts were tested in a 1 L continuously stirred tank reactor (CSTR) at 220 °C, 2.2 MPa, H2/CO = 2.1 and 20–55% CO conversion. Addition of 1% of Cd or In enhanced the reduction degree of 15%Co/Al2O3 by ~20%, while addition of 1% Sn slightly hindered it. All three additives adversely impacted Co dispersion by 22–32% by increasing apparent Co cluster size based on the H2-chemisorption measurements. However, the decreased Co active site density resulting from the additives did not result in a corresponding activity loss; instead, the additives decreased the activity of the Co catalysts to a much greater extent than expected, i.e., 82–93%. The additional detrimental effect on catalyst activity likely indicates that the Cd, In and Sn additives migrated to and covered active sites during reaction and/or provided an electronic effect. XANES results showed that oxides of the additives were present during the reaction, but that a fraction of metal was also likely present based on the TPR and reaction testing results. This is in contrast to typical promoters that become metallic at or below ~350 °C, such as noble metal promoters (e.g., Pt, Ru) and Group 11 promoters (e.g., Ag, Au) on Co catalysts in earlier studies. In the current work, all three additives remarkably increased CH4 and CO2 selectivities and decreased C5+ selectivity, with the Sn and In additives having a greater effect. Interestingly, the Cd, In, or Sn additives were found to influence hydrogenation and isomerization activities. At a similar conversion level (i.e., in the range of 40–50%), the additives significantly increased 2-C4 olefin content from 3.8 to 10.6% and n-C4 paraffin from 50 to 61% accompanied by decreases in 1-C4 olefin content from 48 to 30%. The Sn contributed the greatest impact on the secondary reactions of 1-olefins, followed by the In and Cd. NH3-TPD results suggest enhanced acid sites on cobalt catalysts resulting from the additives, which likely explains the change in selectivities for the different catalysts.
The Combination of Lewis Acid with N-Heterocyclic Carbene (NHC) Catalysis
Authors: Jia Qianfa , Li Yaqiong , Lin Yinhe , Ren Qiao
Published: October 2019

In the last ten years, the combination of Lewis acid with N-heterocyclic carbene (NHC) catalysis has emerged as a powerful strategy in a variety of important asymmetric synthesis, due to the ready availability of starting materials, operational simplicity and mild reaction conditions. Recent findings illustrate that Lewis acid could largely enhance the efficiency and enantioselectivity, reverse the diastereoselectivity, and even influence the pathway of the same reaction partners. Herein, this review aims to reveal the recent advances in NHC-Lewis acid synergistically promoted enantioselective reactions for the expeditious assembly of versatile biologically important chiral pharmaceuticals and natural products.
Arp2/3-Branched Actin Maintains an Active Pool of GTP-RhoA and Controls RhoA Abundance
Authors: Huang Yuxing , Yi Xin , Kang Chenlu , Wu Congying
Published: October 2019

Small GTPases regulate cytoskeletal dynamics, cell motility, and division under precise spatiotemporal control. Different small GTPases exhibit cross talks to exert feedback response or to act in concert during signal transduction. However, whether and how specific cytoskeletal components’ feedback to upstream signaling factors remains largely elusive. Here, we report an intriguing finding that disruption of the Arp2/3-branched actin specifically reduces RhoA activity but upregulates its total protein abundance. We further dissect the mechanisms underlying these circumstances and identify the altered cortactin/p190RhoGAP interaction and weakened CCM2/Smurf1 binding to be involved in GTP-RhoA reduction and total RhoA increase, respectively. Moreover, we find that cytokinesis defects induced by Arp2/3 inhibition can be rescued by activating RhoA. Our study reveals an intricate feedback from the actin cytoskeleton to the small GTPase. Our work highlights the role of Arp2/3-branched actin in signal transduction aside from its function in serving as critical cytoskeletal components to maintain cell morphology and motility.
Postnatal Development of the Subcellular Structures and Purinergic Signaling of Deiters’ Cells along the Tonotopic Axis of the Cochlea
Authors: Berekméri Eszter , Fekete Ádám , Köles László , Zelles Tibor
Published: October 2019

Exploring the development of the hearing organ helps in the understanding of hearing and hearing impairments and it promotes the development of the regenerative approaches-based therapeutic efforts. The role of supporting cells in the development of the organ of Corti is much less elucidated than that of the cochlear sensory receptor cells. The use of our recently published method of single-cell electroporation loading of a fluorescent Ca2+ probe in the mouse hemicochlea preparation provided an appropriate means to investigate the Deiters’ cells at the subcellular level in two different cochlear turns (apical, middle). Deiters’ cell’s soma and process elongated, and the process became slimmer by maturation without tonotopic preference. The tonotopically heterogeneous spontaneous Ca2+ activity less frequently occurred by maturation and implied subcellular difference. The exogenous ATP- and UTP-evoked Ca2+ responses were maturation-dependent and showed P2Y receptor dominance in the apical turn. By monitoring the basic structural dimensions of this supporting cell type as well as its spontaneous and evoked purinergic Ca2+ signaling in the hemicochlea preparation in different stages in the critical postnatal P5-25 developmental period for the first time, we showed that the soma and the phalangeal process of the Deiters’ cells go through age- and tonotopy-dependent changes in the morphometric parameters and purinergic signaling.
Microwave Enthrakometric Labs-On-A-Chip and On-Chip Enthrakometric Catalymetry: From Non-Conventional Chemotronics Towards Microwave-Assisted Chemosensors
Authors: Gradov Oleg V. , Gradova Margaret A.
Published: October 2019

A unique chemical analytical approach is proposed based on the integration of chemical radiophysics with electrochemistry at the catalytically-active surface. This approach includes integration of: radiofrequency modulation polarography with platinum electrodes, applied as film enthrakometers for microwave measurements; microwave thermal analysis performed on enthrakometers as bolometric sensors; catalytic measurements, including registration of chemical self-oscillations on the surface of a platinum enthrakometer as the chemosensor; measurements on the Pt chemosensor implemented as an electrochemical chip with the enthrakometer walls acting as the chip walls; chemotron measurements and data processing in real time on the surface of the enthrakometric chip; microwave electron paramagnetic resonance (EPR) measurements using an enthrakometer both as a substrate and a microwave power meter; microwave acceleration of chemical reactions and microwave catalysis оn the Pt surface; chemical generation of radio- and microwaves, and microwave spin catalysis; and magnetic isotope measurements on the enthrakometric chip. The above approach allows one to perform multiparametric physical and electrochemical sensing on a single active enthrakometric surface, combining the properties of the selective electrochemical sensor and an additive physical detector.
Thin Films of Tolane Aggregates for Faraday Rotation: Materials and Measurement
Authors: Eerdekens Maarten , López-Duarte Ismael , Hennrich Gunther , Verbiest Thierry
Published: October 2019

We present organic, diamagnetic materials based on structurally simple (hetero-)tolane derivatives. They form crystalline thin-film aggregates that are suitable for Faraday rotation (FR) spectroscopy. The resulting new materials are characterized appropriately by common spectroscopic (NMR, UV-Vis), microscopy (POM), and XRD techniques. The spectroscopic studies give extremely high FR activities, thus making these materials promising candidates for future practical applications. Other than a proper explanation, we insist on the complexity of designing efficient FR materials starting from single molecules.
The Crystal Structure of the Plasmodium falciparum PdxK Provides an Experimental Model for Pro-Drug Activation
Authors: Gao Kai , Wang Wenjia , Kronenberger Thales , Wrenger Carsten , Groves Matthew R.
Published: October 2019

Pyridoxine/pyridoxal kinase (PdxK), belongs to the ribokinase family and is involved in the vitamin B6 salvage pathway by phosphorylating 5-pyridoxal (PL) into an active form. In the human malaria parasite, Plasmodium falciparum, PfPdxK functions to salvage vitamin B6 from both itself and its host. Here, we report the crystal structure of PfPdxK from P. falciparum in complex with a non-hydrolyzable ATP analog (AMP-PNP) and PL. As expected, the fold is retained and both AMP-PNP and PL occupy the same binding sites when compared to the human ortholog. However, our model allows us to identify a FIxxIIxL motif at the C terminus of the disordered repeat motif (XNXH)m that is implicated in binding the WD40 domain and may provide temporal control of PfPdxK through an interaction with a E3 ligase complex. Furthermore, molecular docking approaches based on our model allow us to explain differential PfPdxK phosphorylation and activation of a novel class of potent antimalarials (PT3, PT5 and PHME), providing a basis for further development of these compounds. Finally, the structure of PfPdxK provides a high-quality model for a better understanding of vitamin B6 synthesis and salvage in the parasite.
Raman Scattering in Non-Stoichiometric Lithium Niobate Crystals with a Low Photorefractive Effect
Authors: Sidorov Nikolay , Palatnikov Mikhail , Kadetova Alexandra
Published: October 2019

Raman spectra of lithium niobate single crystals strongly doped by zinc and magnesium, it has been established, contain low-intense bands with frequencies 209, 230, 298, 694, and 880 cm−1. Ab ignition calculations fail to attribute these bands to fundamental vibrations of A2 symmetry type unambiguously. Such vibrations are prohibited by the selection rules in the space group C3V6 (R3c). Ab initio calculations also proved that low-intense “extra” bands with frequencies 104 and 119 cm−1 definitely do not correspond to vibrations of A2 symmetry type. We have paid special attention to these extra bands that appear in LiNbO3 single crystals Raman spectra despite the fact that they are prohibited by the selection rules. In order to do so, we have studied a number of lithium niobate single crystals, both nominally pure and doped, by Raman spectroscopy. We have assumed that some “extra” bands correspond to two-particle states of acoustic phonons with a total wave vector equal to zero. We have also detected a Zn concentration area (0.05–0.94 mol.% ZnO in a crystal) where doped crystal structure is more ordered: The order of alternation of the main, doping cations, and vacancies along the polar axis is increased, and oxygen octahedra are less distorted.
Soil Organic Carbon Shapes AMF Communities in Soils and Roots of Cynodon dactylon under Anti-Seasonal Drying-Wetting Cycles
Authors: Luo Xie , He Xinhua , Luo Xiumei , Liu Yining , Wang Junqi , Dong Jinyan
Published: October 2019

Anti-seasonal drying-wetting cycles since 2010 have substantially altered its soil and vegetation status in the drawdown zone of China’s Three Gorges Reservoir (TGR). Such alternations may thus affect the composition and functioning of soil microbial communities, including the beneficial arbuscular mycorrhizal fungi (AMF), which enhance plant performance. Moreover, limited information is available if AMF communities are different in soils and roots, particularly under contrasting land-use changes. By combining the Illumina Miseq sequencing with bioinformatics analyses, AMF communities in both rhizosphere soils and roots of a stoloniferous and rhizomatous C4 perennial of Cynodon dactylon were characterized under three land-use types: (1) crop cultivated, (2) non-cultivated non-disturbed, and (3) disturbed non-cultivated land. A total of 35 and 26 AMF taxa were respectively detected from C. dactylon rhizosphere soils and roots from these three land-use types, which had endured four anti-seasonal drying/summer-wetting/winter cycles. Contrasting differentiations in the AMF community composition and structure were displayed in the C. dactylon rhizosphere soils and roots, and between land-use types. Nonmetric multidimensional scaling analyses revealed that AMF communities significantly correlated to soil organic carbon in the rhizosphere soils and roots of C. dactylon, to land-use types only in rhizosphere soils, whereas to soil moisture only in roots. Our results highlight the effects of soil nutrients and land-use changes on AMF community composition and diversity under the canopy of C. dactylon in TGR. The identified dominant AMF taxa can be employed to vegetation restoration in such degraded habitats globally.
Prediabetes/Diabetes Can Be Screened at the Dental Office by a Low-Cost and Fast Chair-Side/Point-of-Care aMMP-8 Immunotest
Authors: Grigoriadis Andreas , Sorsa Timo , Räisänen Ismo , Pärnänen Pirjo , Tervahartiala Taina , Sakellari Dimitra
Published: October 2019

Pre-diabetes and diabetes are strongly associated with periodontal disease (gingivitis and periodontitis), and these conditions are known to upregulate aMMP-8 in inflamed gingiva and oral fluids. Thus, it would be feasible to screen for prediabetes and diabetes at the dental office by chairside tests. Chair-side assessment of HbA1c and a quantitative point-of-care (PoC) active matrix metalloproteinase (aMMP)-8 oral rinse immunotest developed for periodontal diseases, were performed on patients (n = 69) attending a Periodontology University Clinic who fulfilled the criteria for testing according to the screening questionnaire of the Centers for Disease Control and Prevention, USA. Clinical parameters of periodontal disease were also recorded with an automated probe. Twenty seven-point-five percent of the subjects were found with previously unknown hyperglycemia (HbA1c ≥ 5.7%). There was a statistically-significant positive association between the aMMP-8test and prediabetes (p < 0.05, unadjusted and adjusted for BMI and age ≥ 45 years logistic regression models). The dental setting is suitable for opportunistic screening for undiagnosed diabetes and pre-diabetes and point-of-care HbA1c, especially when combined with aMMP-8 assessment by dental professionals, being convenient and effective.
Multiscale Horizontal Visibility Graph Analysis of Higher-Order Moments for Estimating Statistical Dependency
Authors: Dong Keqiang , Che Haowei , Zou Zhi
Published: October 2019

The horizontal visibility graph is not only a powerful tool for the analysis of complex systems, but also a promising way to analyze time series. In this paper, we present an approach to measure the nonlinear interactions between a non-stationary time series based on the horizontal visibility graph. We describe how a horizontal visibility graph may be calculated based on second-order and third-order statistical moments. We compare the new methods with the first-order measure, and then give examples including stock markets and aero-engine performance parameters. These analyses suggest that measures derived from the horizontal visibility graph may be of particular relevance to the growing interest in quantifying the information exchange between time series.
A Comparison of the Maximum Entropy Principle Across Biological Spatial Scales
Authors: Cofré Rodrigo , Herzog Rubén , Corcoran Derek , Rosas Fernando E.
Published: October 2019

Despite their differences, biological systems at different spatial scales tend to exhibit common organizational patterns. Unfortunately, these commonalities are often hard to grasp due to the highly specialized nature of modern science and the parcelled terminology employed by various scientific sub-disciplines. To explore these common organizational features, this paper provides a comparative study of diverse applications of the maximum entropy principle, which has found many uses at different biological spatial scales ranging from amino acids up to societies. By presenting these studies under a common approach and language, this paper aims to establish a unified view over these seemingly highly heterogeneous scenarios.
Residual Predictive Information Flow in the Tight Coupling Limit: Analytic Insights from a Minimalistic Model
Authors: Wahl Benjamin , Feudel Ulrike , Hlinka Jaroslav , Wächter Matthias , Peinke Joachim , Freund Jan A.
Published: October 2019

In a coupled system, predictive information flows from the causing to the caused variable. The amount of transferred predictive information can be quantified through the use of transfer entropy or, for Gaussian variables, equivalently via Granger causality. It is natural to expect and has been repeatedly observed that a tight coupling does not permit to reconstruct a causal connection between causing and caused variables. Here, we show that for a model of interacting social groups, carried from the master equation to the Fokker–Planck level, a residual predictive information flow can remain for a pair of uni-directionally coupled variables even in the limit of infinite coupling strength. We trace this phenomenon back to the question of how the synchronizing force and the noise strength scale with the coupling strength. A simplified model description allows us to derive analytic expressions that fully elucidate the interplay between deterministic and stochastic model parts.
Teachers Co-Designing and Implementing Career-Related Instruction
Authors: Salonen Anssi , Kärkkäinen Sirpa , Keinonen Tuula
Published: October 2019

Teachers encounter the challenge of how to provide students adequate awareness of science-related careers. Therefore, innovative teaching material for promoting science-related careers needs to be designed. Educational innovations can be successful if teachers experience ownership and agency towards the designed teaching material. In this case study, a multi-professional group of two science teachers, a researcher, and a dentist co-designed instruction including a career presentation and relevant information about field-specific education and skills needed by a professional in that field. We refer to this as career-related instruction. The designed learning unit includes a scenario, inquiries and career-related activities. Teachers’ perceptions about co-designing and implementing the learning unit in science education are examined as well as students’ perceptions about the scenario. Data consists of teacher interviews and discussions and student questionnaires. A content analysis reveals the teachers’ high ownership and agency in co-designing the instruction, which was relevant, interesting and informative for students. It was easy for teachers to implement the learning unit even though they were not involved in every phase of the design process. We conclude that by strengthening teachers’ ownership and agency through multi-professional co-designing, relevant and interesting career-related instruction can be designed and implemented.