bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalized radiation model for human migration
Authors: Alis Christian , Legara Erika Fille , Monterola Christopher
Published: November 2021

One of the main problems in the study of human migration is predicting how many people will migrate from one place to another. An important model used for this problem is the radiation model for human migration, which models locations as attractors whose attractiveness is moderated by distance as well as attractiveness of neighboring locations. In the model, the measure used for attractiveness is population which is a proxy for economic opportunities and jobs. However, this may not be valid, for example, in developing countries, and fails to take into account people migrating for non-economic reasons such as quality of life. Here, we extend the radiation model to include the number of amenities (offices, schools, leisure places, etc.) as features aside from population. We find that the generalized radiation model outperforms the radiation model by as much as 10.3% relative improvement in mean absolute percentage error based on actual census data five years apart. The best performing model does not even include population information which suggests that amenities already include the information that we get from population. The generalized radiation model provides a measure of feature importance thus presenting another avenue for investigating the effect of amenities on human migration.
CinE caRdiac magneTic resonAnce to predIct veNTricular arrhYthmia (CERTAINTY)
Authors: Krebs Julian , Mansi Tommaso , Delingette Hervé , Lou Bin , Lima Joao A. C. , Tao Susumu , Ciuffo Luisa A. , Norgard Sanaz , Butcher Barbara , Lee Wei H. , Chamera Ela , Dickfeld Timm-Michael , Stillabower Michael , Marine Joseph E. , Weiss Robert G. , Tomaselli Gordon F. , Halperin Henry , Wu Katherine C. , Ashikaga Hiroshi
Published: November 2021

Better models to identify individuals at low risk of ventricular arrhythmia (VA) are needed for implantable cardioverter-defibrillator (ICD) candidates to mitigate the risk of ICD-related complications. We designed the CERTAINTY study (CinE caRdiac magneTic resonAnce to predIct veNTricular arrhYthmia) with deep learning for VA risk prediction from cine cardiac magnetic resonance (CMR). Using a training cohort of primary prevention ICD recipients (n = 350, 97 women, median age 59 years, 178 ischemic cardiomyopathy) who underwent CMR immediately prior to ICD implantation, we developed two neural networks:Cine Fingerprint ExtractorandRisk Predictor. The former extracts cardiac structure and function features from cine CMR in a form of cine fingerprint in a fully unsupervised fashion, and the latter takes in the cine fingerprint and outputs disease outcomes as a cine risk score. Patients with VA (n = 96) had a significantly higher cine risk score than those without VA. Multivariate analysis showed that the cine risk score was significantly associated with VA after adjusting for clinical characteristics, cardiac structure and function including CMR-derived scar extent. These findings indicate that non-contrast, cine CMR inherently contains features to improve VA risk prediction in primary prevention ICD candidates. We solicit participation from multiple centers for external validation.
Retentive capacity of power output and linear versus non-linear mapping of power loss in the isotonic muscular endurance test
Authors: Xu Hong-qi , Xue Yong-tai , Zhou Zi-jian , Koh Koon Teck , Xu Xin , Shi Ji-peng , Zhang Shou-wei , Zhang Xin , Cai Jing
Published: November 2021

The limit of dynamic endurance during repetitive contractions has been referred to as the point of muscle fatigue, which can be measured by mechanical and electrophysiological parameters combined with subjective estimates of load tolerance for revealing the human real-world capacity required to work continuously. In this study, an isotonic muscular endurance (IME) testing protocol under a psychophysiological fatigue criterion was developed for measuring the retentive capacity of the power output of lower limb muscles. Additionally, to guide the development of electrophysiological evaluation methods, linear and non-linear techniques for creating surface electromyography (sEMG) models were compared in terms of their ability to estimate muscle fatigue. Forty healthy college-aged males performed three trials of an isometric peak torque test and one trial of an IME test for the plantar flexors and knee and hip extensors. Meanwhile, sEMG activity was recorded from the medial gastrocnemius, lateral gastrocnemius, vastus medialis, rectus femoris, vastus lateralis, gluteus maximus, and biceps femoris of the right leg muscles. Linear techniques (amplitude-based parameters, spectral parameters, and instantaneous frequency parameters) and non-linear techniques (a multi-layer perception neural network) were used to predict the time-dependent power output during dynamic contractions. Two mechanical manifestations of muscle fatigue were observed in the IME tests, including power output reduction between the beginning and end of the test and time-dependent progressive power loss. Compared with linear mapping (linear regression) alone or a combination of sEMG variables, non-linear mapping of power loss during dynamic contractions showed significantly higher signal-to-noise ratios and correlation coefficients between the actual and estimated power output. Muscular endurance required in real-world activities can be measured by considering the amount of work produced or the activity duration via the recommended IME testing protocol under a psychophysiological termination criterion. Non-linear mapping techniques provide more powerful mapping of power loss compared with linear mapping in the IME testing protocol.
Tissue and salinity specific Na+/Cl− cotransporter (NCC) orthologues involved in the adaptive osmoregulation of sea lamprey (Petromyzon marinus)
Authors: Barany A. , Shaughnessy C. A. , Pelis R. M. , Fuentes J. , Mancera J. M. , McCormick S. D.
Published: November 2021

Two orthologues of the gene encoding the Na+-Cl− cotransporter (NCC), termed ncca and nccb, were found in the sea lamprey genome. No gene encoding the Na+-K+-2Cl− cotransporter 2 (nkcc2) was identified. In a phylogenetic comparison among other vertebrate NCC and NKCC sequences, the sea lamprey NCCs occupied basal positions within the NCC clades. In freshwater, ncca mRNA was found only in the gill and nccb only in the intestine, whereas both were found in the kidney. Intestinal nccb mRNA levels increased during late metamorphosis coincident with salinity tolerance. Acclimation to seawater increased nccb mRNA levels in the intestine and kidney. Electrophysiological analysis of intestinal tissue ex vivo showed this tissue was anion absorptive. After seawater acclimation, the proximal intestine became less anion absorptive, whereas the distal intestine remained unchanged. Luminal application of indapamide (an NCC inhibitor) resulted in 73% and 30% inhibition of short-circuit current (Isc) in the proximal and distal intestine, respectively. Luminal application of bumetanide (an NKCC inhibitor) did not affect intestinal Isc. Indapamide also inhibited intestinal water absorption. Our results indicate that NCCb is likely the key ion cotransport protein for ion uptake by the lamprey intestine that facilitates water absorption in seawater. As such, the preparatory increases in intestinal nccb mRNA levels during metamorphosis of sea lamprey are likely critical to development of whole animal salinity tolerance.
A SEER-based nomogram accurately predicts prognosis in Ewing’s sarcoma
Authors: Zhan Haibo , Mo Fengbo , Zhu Meisong , Xu Xiaoyu , Zhang Bin , Liu Hucheng , Dai Min
Published: November 2021

Ewing's sarcoma is a high-grade malignancy bone and soft tissue tumor that most commonly occurs in children and adolescents. Although the overall prognosis of Ewing's sarcoma has improved, the 5-year survival rate has not improved significantly. The study aimed to determine the risk factors independently associated with the prognosis of Ewing's sarcoma and to construct a nomogram to predict patient survival. Patients diagnosed with Ewing's sarcoma were collected from the Surveillance, Epidemiology, and End Results program database between 2004 and 2015 and further divided into training and validation cohort. Univariate and multivariate Cox regression analyses were used to identify meaningful independent prognostic factors. The nomogram was used to predict 3- and 5-year overall survival (OS) and cancer-specific survival (CSS). Finally, the nomogram was verified internally and externally through the training and validation cohorts, and the predictive capability was evaluated using the receiver operating characteristic (ROC) curve, C-index, and calibration curve and compared with that of the 7th TNM stage. A total of 1120 patients were divided into training (n = 713) and validation (n = 407) cohorts. Based on the multivariate analysis of the training cohort, a nomogram that integrated age, tumor size, primary site, N stage, and M stage was constructed (P < 0.05). The predicted C-indexes of OS and CSS of the training cohort were 0.744 (95% CI 0.717–0.771) and 0.743 (95% CI 0.715–0.770), respectively. However, the TNM stage had a C-index of 0.695 (95% CI 0.666–0.724) and 0.698 (95% CI 0.669–0.727) for predicting OS and CSS, respectively. The nomogram showed higher C-indexes than those in the TNM stage. Furthermore, the internal and external calibration curves showed good consistency between the predicted and observed values. Age, tumor size, primary site, N stage, and M stage are independent risk factors affecting the OS and CSS in Ewing’s sarcoma patients. Compared with the 7th TNM staging, the nomogram consisting of these factors was more accurate for risk assessment and survival prediction in patients with Ewing’s sarcoma, thus providing a novel reliable tool for risk assessment and survival prediction in Ewing’s sarcoma patients.
Circulating bile acids concentration is predictive of coronary artery disease in human
Authors: Chong Nguyen Caroline , Duboc Denis , Rainteau Dominique , Sokol Harry , Humbert Lydie , Seksik Philippe , Bellino Adèle , Abdoul Hendy , Bouazza Naïm , Treluyer Jean-Marc , Saadi Malika , Wahbi Karim , Soliman Heithem , Coffin Benoit , Bado André , Le Gall Maude , Varenne Olivier , Duboc Henri
Published: November 2021

Synthetized by the liver and metabolized by the gut microbiota, BA are involved in metabolic liver diseases that are associated with cardiovascular disorders. Animal models of atheroma documented a powerful anti-atherosclerotic effect of bile acids (BA). This prospective study examined whether variations in circulating BA are predictive of coronary artery disease (CAD) in human. Consecutive patients undergoing coronary angiography were enrolled. Circulating and fecal BA were measured by high pressure liquid chromatography and tandem mass spectrometry. Of 406 screened patients, 80 were prospectively included and divided in two groups with (n = 45) and without (n = 35) CAD. The mean serum concentration of total BA was twice lower in patients with, versus without CAD (P = 0.005). Adjusted for gender and age, this decrease was an independent predictor of CAD. In a subgroup of 17 patients, statin therapy doubled the serum BA concentration. Decreased serum concentrations of BA were predictors of CAD in humans. A subgroup analysis showed a possible correction by statins. With respect to the anti-atherosclerotic effect of BA in animal models, and their role in human lipid metabolism, this study describe a new metabolic disturbance associated to CAD in human.
GABAergic basal forebrain projections to the periaqueductal gray promote food consumption, reward and predation
Authors: Roman-Ortiz Ciorana , Guevara Jessica A. , Clem Roger L.
Published: November 2021

Behaviors central to the procurement and consumption of food are among those most fundamental to survival, but their inappropriate expression can lead to overeating and obesity. Nevertheless, we have a poor understanding of circuits that promote feeding independent of physiological demand. Here we demonstrate that activation of basal forebrain (BF) GABAergic neurons results in consumption of food as well as non-food items in well-fed mice, and performance of fictive eating in the absence of ingestible materials. In addition, stimulation of these cells disrupts defensive threat responses and elicits reward-like motivational effects. Finally, BF GABAergic activity triggers skilled predatory attacks of live prey and prey-like objects, but not social targets. These effects were entirely recapitulated by selective stimulation of BF GABAergic projections to the periaqueductal gray (PAG). Our results outline a potent circuit mechanism for increased feeding through recruitment of distinct but synergistic behaviors, and add to growing evidence that PAG is an important integrator of feeding-related activity.
Variation in fine root traits with thinning intensity in a Chinese fir plantation insights from branching order and functional groups
Authors: Wang Zuhua , Liu Min , Chen Fen , Li Haibo
Published: November 2021

Thinning is a widely used practice in forest management, but the acclimation mechanisms of fine roots to forest thinning are still unclear. We examined the variations in fine root traits of different branching orders and functional groups along a thinning intensity gradient in a 26-year-old Chinese fir (Cunninghamia lanceolata) plantation. With increasing thinning intensity, the root C concentration (RCC), root N concentration (RNC), specific root area (SRA), and specific root length (SRL) of the absorptive roots (the first two orders) significantly decreased, while root abundance (root biomass and root length density) and root tissue density (RTD) significantly increased. Fifty-four percent of the variation in the absorptive root traits could be explained by the soil N concentration and the biomass and diversity of the understorey vegetation. Conversely, transport root (third- and higher-order) traits did not vary significantly among different thinning intensities. The covariation of absorptive root traits across thinning intensities regarding two dimensions was as follows: the first dimension (46% of the total variation) represented changes in root abundance and chemical traits (related to RCC, RNC), belonging to an extensive foraging strategy; the second dimension (41% of the total variation) represented variations in root morphological traits (related to RTD, SRL and SRA), which is an intensive foraging strategy (i.e., root economic spectrum). These results suggested that the absorptive roots of Chinese fir adopt two-dimensional strategies to acclimate to the altered surroundings after thinning.
FLT3-ITD transduces autonomous growth signals during its biosynthetic trafficking in acute myelogenous leukemia cells
Authors: Yamawaki Kouhei , Shiina Isamu , Murata Takatsugu , Tateyama Satoru , Maekawa Yutarou , Niwa Mariko , Shimonaka Motoyuki , Okamoto Koji , Suzuki Toshihiro , Nishida Toshirou , Abe Ryo , Obata Yuuki
Published: November 2021

FMS-like tyrosine kinase 3 (FLT3) in hematopoietic cells binds to its ligand at the plasma membrane (PM), then transduces growth signals. FLT3 gene alterations that lead the kinase to assume its permanently active form, such as internal tandem duplication (ITD) and D835Y substitution, are found in 30–40% of acute myelogenous leukemia (AML) patients. Thus, drugs for molecular targeting of FLT3 mutants have been developed for the treatment of AML. Several groups have reported that compared with wild-type FLT3 (FLT3-wt), FLT3 mutants are retained in organelles, resulting in low levels of PM localization of the receptor. However, the precise subcellular localization of mutant FLT3 remains unclear, and the relationship between oncogenic signaling and the mislocalization is not completely understood. In this study, we show that in cell lines established from leukemia patients, endogenous FLT3-ITD but not FLT3-wt clearly accumulates in the perinuclear region. Our co-immunofluorescence assays demonstrate that Golgi markers are co-localized with the perinuclear region, indicating that FLT3-ITD mainly localizes to the Golgi region in AML cells. FLT3-ITD biosynthetically traffics to the Golgi apparatus and remains there in a manner dependent on its tyrosine kinase activity. Tyrosine kinase inhibitors, such as quizartinib (AC220) and midostaurin (PKC412), markedly decrease FLT3-ITD retention and increase PM levels of the mutant. FLT3-ITD activates downstream in the endoplasmic reticulum (ER) and the Golgi apparatus during its biosynthetic trafficking. Results of our trafficking inhibitor treatment assays show that FLT3-ITD in the ER activates STAT5, whereas that in the Golgi can cause the activation of AKT and ERK. We provide evidence that FLT3-ITD signals from the early secretory compartments before reaching the PM in AML cells.
Endophytic bacterial communities are associated with leaf mimicry in the vine Boquila trifoliolata
Authors: Gianoli Ernesto , González-Teuber Marcia , Vilo Claudia , Guevara-Araya María J. , Escobedo Víctor M.
Published: November 2021

The mechanisms behind the unique capacity of the vineBoquila trifoliolatato mimic the leaves of several tree species remain unknown. A hypothesis in the original leaf mimicry report considered that microbial vectors from trees could carry genes or epigenetic factors that would alter the expression of leaf traits inBoquila. Here we evaluated whether leaf endophytic bacterial communities are associated with the mimicry pattern. Using 16S rRNA gene sequencing, we compared the endophytic bacterial communities in three groups of leaves collected in a temperate rainforest: (1) leaves from the model treeRhaphithamnus spinosus(RS), (2)Boquilaleaves mimicking the tree leaves (BR), and (3)Boquilaleaves from the same individual vine but not mimicking the tree leaves (BT). We hypothesized that bacterial communities would be more similar in the BR–RS comparison than in the BT–RS comparison. We found significant differences in the endophytic bacterial communities among the three groups, verifying the hypothesis. Whereas non-mimeticBoquilaleaves and tree leaves (BT–RS) showed clearly different bacterial communities, mimeticBoquilaleaves and tree leaves (BR–RS) showed an overlap concerning their bacterial communities. The role of bacteria in this unique case of leaf mimicry should be studied further.
The influence law of concrete aggregate particle size on acoustic emission wave attenuation
Authors: Wu Xin , Yan Qiao , Hedayat Ahmadreza , Wang Xuemei
Published: November 2021

Elastic waves have different attenuation laws when propagating in various materials, which is one of the important challenges in the application of non-destructive testing methods, such as acoustic emission (AE) technology in geotechnical engineering. The study presented in this paper investigated the influence mechanism of concrete composition materials and parameters on the propagation law of elastic waves using concrete specimens produced in six different particle sizes of sand or gravel. The burst AE signal was generated through the lead-breaking experiment, and ceramic piezoelectric sensors were used to record the signal waveform at different propagation distances. Through parameter analysis, spectrum analysis, and pattern recognition techniques, the influence of the concrete aggregate particle size on AE wave propagation and attenuation was revealed. The results show that the attenuation of elastic wave amplitude, energy spectral density, and frequency all were positively correlated with the aggregate particle size, and the elastic wave spectrum center of gravity generally decreased with the propagation distance. The ring count gradually decreased with the propagation distance, and the specimens with a larger aggregate particle size underwent a relatively faster ring count attenuation rate. The rise time increased rapidly with the propagation of the elastic wave, and the specimens with a larger aggregate particle size experienced a relatively rapid increase in rise time. In addition, in the feature spaces of ring count-amplitude and rise time–amplitude, the size of aggregate has an obvious influence on the distribution of these feature vector.
MUC1 ectodomain is a flagellin-targeting decoy receptor and biomarker operative during Pseudomonas aeruginosa lung infection
Authors: Verceles Avelino C. , Bhat Pavan , Nagaria Zain , Martin Destiny , Patel Harsh , Ntem-Mensah Afua , Hyun Sang W. , Hahn Andrea , Jeudy Jean , Cross Alan S. , Lillehoj Erik P. , Goldblum Simeon E.
Published: November 2021

We previously reported that flagellin-expressing Pseudomonas aeruginosa (Pa) provokes NEU1 sialidase-mediated MUC1 ectodomain (MUC1-ED) desialylation and MUC1-ED shedding from murine lungs in vivo. Here, we asked whether Pa in the lungs of patients with ventilator-associated pneumonia might also increase MUC1-ED shedding. The levels of MUC1-ED and Pa-expressed flagellin were dramatically elevated in bronchoalveolar lavage fluid (BALF) harvested from Pa-infected patients, and each flagellin level, in turn, predicted MUC1-ED shedding in the same patient. Desialylated MUC1-ED was only detected in BALF of Pa-infected patients. Clinical Pa strains increased MUC1-ED shedding from cultured human alveolar epithelia, and FlaA and FlaB flagellin-expressing strains provoked comparable levels of MUC1-ED shedding. A flagellin-deficient isogenic mutant generated dramatically reduced MUC1-ED shedding compared with the flagellin-expressing wild-type strain, and purified FlaA and FlaB recapitulated the effect of intact bacteria. Pa:MUC1-ED complexes were detected in the supernatants of alveolar epithelia exposed to wild-type Pa, but not to the flagellin-deficient Pa strain. Finally, human recombinant MUC1-ED dose-dependently disrupted multiple flagellin-driven processes, including Pa motility, Pa biofilm formation, and Pa adhesion to human alveolar epithelia, while enhancing human neutrophil-mediated Pa phagocytosis. Therefore, shed desialylated MUC1-ED functions as a novel flagellin-targeting, Pa-responsive decoy receptor that participates in the host response to Pa at the airway epithelial surface.
Small berries as health-promoting ingredients: a review on anti-aging effects and mechanisms inCaenorhabditis elegans
Authors: Li Rong , Tao Mingfang , Xu Tingting , Pan Siyi , Xu Xiaoyun , Wu Ting
Published: November 2021

The topic discussed in this review is about the anti-aging effects of small berries including small berries type, effective concentration of small berry extracts or their components, and the potential molecular mechanisms inC. elegansmodel.
Impact of following a healthy dietary pattern with co-consuming wolfberry on number and function of blood outgrowth endothelial cells from middle-aged and older adults
Authors: Xia Xuejuan , Toh Darel Wee Kiat , Ng Shi Ling , Zharkova Olga , Poh Kian Keong , Foo Roger S. Y. , Wang Jiong-Wei , Kim Jung Eun
Published: November 2021

This study investigates the effect of a healthy dietary pattern with or without wolfberry consumption on the number and function of BOECs in middle-aged and older adults.
Lactobacillus plantarum SHY130 isolated from yak yogurt attenuates hyperglycemia in C57BL/6J mice by regulating the enteroinsular axis
Authors: Wang Guangqi , Song Jiajia , Huang Yechuan , Li Xueqiong , Wang Hongwei , Zhang Yu , Suo Huayi
Published: November 2021

L. plantarum SHY130 isolated from yak yogurt attenuates hyperglycemia in C57BL/6J mice by regulating the enteroinsular axis.
1D alignment of Co(ii) metalated porphyrin–napthalimide based self-assembled nanowires for photocatalytic hydrogen evolution
Authors: Bhavani Botta , Chanda Nageshwarrao , Kotha Vishal , Reddy Govind , Basak Pratyay , pal Ujjwal , Giribabu Lingamallu , Prasanthkumar Seelam
Published: November 2021

Cobalt(ii) metalated porphyrin–napthalimide acts as donor–acceptor motif, which undergoes self-assembly leading to well-aligned one-dimensional nanowires promotes as an efficient photocatalyst for hydrogen evolution.
Oxidative esterification of aliphatic α,ω-diols, an alternative route to polyester precursors for the synthesis of polyurethanes
Authors: Gosecki Mateusz , Gosecka Monika , Urbaniak Malgorzata
Published: November 2021

Aliphatic α,ω-diols are converted into polyester polyols in water in the presence ofin situgenerated BrOH. The extent of the reaction is controlled by the BrOH to hydroxymethyl group molar ratio.
Palladium-catalysed stereoselective [3 + 2] annulation of vinylethylene carbonates and tryptanthrin-based ketones
Authors: Fan Yang , Li Qing-Zhu , Li Jun-Long , Zhang Bin , Dai Zhen , Xie Ke , Zeng Rong , Zou Liang , Zhang Xiang
Published: November 2021

The first example of palladium-catalysed [3 + 2] annulation of VECs and ketones has been developed, allowing the efficient synthesis of indoloquinazolinones in generally excellent yields with good stereoselectivity.
A multifaceted approach towards understanding the peculiar behavior of (α)-hydroxyiminophosphonates
Authors: Toupy Thomas , Kune Christopher , Van Hecke Kristof , Quinton Loïc , Monbaliu Jean-Christophe M.
Published: November 2021

A unique multifaceted approach involving the interplay of NMR, XRD, LC, DFT and MS/IM-MS techniques toward the understanding of the peculiar isomer-selective reduction of (α)-hydroxyiminophosphonates into (α)-hydroxyaminophosphonate derivatives.
Strongly diluted dimethyl-imidazolium chloride–alcohol solutions: solvents are structurally different but dynamic heterogeneities are similar
Authors: Atamas N. A. , Lazarenko M. M. , Yablochkova K. S. , Taranyik G.
Published: November 2021

The increase of the alkyl chain length of the alcohol molecule does not affect the motion of the ionic liquid components.
Synthesis of calixresorcarenes using magnetic poly triazine-benzene sulfonamide-SO3H
Authors: Gharehkhani Alireza , Ghorbani-vaghei Ramin , Alavinia Sedigheh
Published: November 2021

Magnetic poly triazine-benzene sulfonamide-SO3H was investigated for the synthesis of calixresorcarenes.
Novel alkylaminoethyl derivatives of androstane 3-oximes as anticancer candidates: synthesis and evaluation of cytotoxic effects
Authors: Ajduković Jovana J. , Jakimov Dimitar S. , Rárová Lucie , Strnad Miroslav , Dzichenka Yaraslau U. , Usanov Sergey , Škorić Dušan Đ. , Jovanović-Šanta Suzana S. , Sakač Marija N.
Published: November 2021

Novel steroidO-alkylated 3-oxyimino derivatives were synthesized and evaluatedin vitrofor their antitumor properties. The obtained data indicate the potential of these functionalities for the development of new candidates for tumor treatment.
Spatiotemporal dynamics of self-assembled structures in enzymatically induced agonistic and antagonistic conditions
Authors: Priyanka  , Shandilya Ekta , Brar Surinder Kaur , Mahato Rishi Ram , Maiti Subhabrata
Published: November 2021

We have shown ATP-driven spatiotemporally distinct self-organization pattern of a surfactant in a two-dimensional space using enzymes, demonstrating a new route for obtaining ‘spatial’ organizational adaptability among interacting components.
Hydroxyl-anchored covalent organic crown-based polymers for CO2 fixation into cyclic carbonates under mild conditions
Authors: Hao Yongjing , Yan Xiuli , Chang Tao , Liu Xiaohuan , Kang Lianwei , Zhu Zheng , Panchal Balaji , Qin Shenjun
Published: November 2021

A series of covalent organic crown-based polymers coordinated with KI exhibit high activity. The synergetic effect plays an important role in accelerating the reaction rate.
Electrocatalytic reduction of protons to dihydrogen by the cobalt tetraazamacrocyclic complex [Co(N4H)Cl2]+: mechanism and benchmarking of performances
Authors: Li Cheng-Bo , Bagnall Andrew J. , Sun Dongyue , Rendon Julia , Koepf Matthieu , Gambarelli Serge , Mouesca Jean-Marie , Chavarot-Kerlidou Murielle , Artero Vincent
Published: November 2021

The mechanism of H2 evolution catalyzed by the [Co(N4H)Cl2]+ complex is elucidated with quantitative determination of the rate-constants for the various protonation steps, and the identification of the aliphatic amine to act as a proton relay.
Three-dimensional compaction of soft granular packings
Authors: Cárdenas-Barrantes Manuel , Cantor David , Barés Jonathan , Renouf Mathieu , Azéma Emilien
Published: November 2021

This paper analyzes the compaction behavior of assemblies composed of soft (elastic) spherical particles beyond the jammed state, using three-dimensional non-smooth contact dynamic simulations.
Commentary on “Urinary L-erythro-β-hydroxyasparagine - a novel serine racemase inhibitor and substrate of the Zn2+-dependent D-serine dehydratase”
Authors: Tamaki Fabio Kendi
Published: November 2021

The analysis of the urine contents can be informative of physiological homeostasis, and it has been speculated that the levels of urinary D-serine (D-ser) could inform about neurological and renal disorders. By analysing the levels of urinary D-ser using a D-ser dehydratase (DSD) enzyme, Ito et al. have described abundant levels of L-β-EHAsn, a non-proteogenic amino acid which is also a newly described substrate for DSD. The data presented supports the endogenous production L-β-EHAsn, with its concentration significantly correlating with the concentration of creatinine in urine. Taken together, these results could raise speculations that L-β-EHAsn might have unexplored important biological roles. It has been demonstrated that L-β-EHAsn also inhibits serine racemase with Ki values (40 μM) similar to its concentration in urine (50 μM). Given that serine racemase is the enzyme involved in the synthesis of D-ser, and L-β-EHAsn is also a substrate for DSD, further investigations could verify if this amino acid would be involved in the metabolic regulation of pathways involving D-ser.
Adversarial attack and defense methods for neural network based state estimation in smart grid
Authors: Tian Jiwei , Wang Buhong , Li Jing , Konstantinou Charalambos
Published: November 2021

Deep learning has been recently used in safety‐critical cyber‐physical systems (CPS) such as the smart grid. The security assessment of such learning‐based methods within CPS algorithms, however, is still an open problem. Despite existing research on adversarial attacks against deep learning models, only few works are concerned about safety‐critical energy CPS, especially the state estimation routine. This paper investigates security issues of neural network based state estimation in the smart grid. Specifically, the problem of adversarial attacks against neural network based state estimation is analysed and an efficient adversarial attack method is proposed. To thwart this attack, two defense methods based on protection and adversarial training, respectively, are proposed further. The experiments demonstrate that the proposed attack method poses a major threat to neural network based state estimation models. In addition, our results present that defense methods can improve the ability of neural network models to defend against such adversarial attacks.
The SAPP pipeline for the determination of stellar abundances and atmospheric parameters of stars in the core program of the PLATO mission
Authors: Gent Matthew Raymond , Bergemann Maria , Serenelli Aldo , Casagrande Luca , Gerber Jeffrey M. , Heiter Ulrike , Kovalev Mikhail , Morel Thierry , Nardetto Nicolas , Adibekyan Vardan , Silva Aguirre Víctor , Asplund Martin , Belkacem Kevin , del Burgo Carlos , Bigot Lionel , Chiavassa Andrea , Rodríguez Díaz Luisa Fernanda , Goupil Marie-Jo , González Hernández Jonay I. , Mourard Denis , Merle Thibault , Mészáros Szabolcs , Marshall Douglas J. , Ouazzani Rhita-Maria , Plez Bertrand , Reese Daniel , Trampedach Regner , Tsantaki Maria
Published: November 2021

We introduce the SAPP (Stellar Abundances and atmospheric Parameters Pipeline), the prototype of the code that will be used to determine parameters of stars observed within the core program of the PLATO space mission. The pipeline is based on the Bayesian inference and provides effective temperature, surface gravity, metallicity, chemical abundances, and luminosity. The code in its more general version has a much wider range of potential applications. It can also provide masses, ages, and radii of stars and can be used with stellar types not targeted by the PLATO core program, such as red giants. We validate the code on a set of 27 benchmark stars that includes 19 FGK-type dwarfs, 6 GK-type subgiants, and 2 red giants. Our results suggest that combining various observables is the optimal approach, as this allows the degeneracies between different parameters to be broken and yields more accurate values of stellar parameters and more realistic uncertainties. For the PLATO core sample, we obtain a typical uncertainty of 27 (syst.) ± 37 (stat.) K for Teff, 0.00 ± 0.01 dex for log g, 0.02 ± 0.02 dex for metallicity [Fe/H], −0.01 ± 0.03 R⊙ for radii, −0.01 ± 0.05 M⊙ for stellar masses, and −0.14 ± 0.63 Gyr for ages. We also show that the best results are obtained by combining the νmax scaling relation with stellar spectra. This resolves the notorious problem of degeneracies, which is particularly important for F-type stars.
Comparative analysis between methane and hydrogen regarding ignition and combustion in diffusive mode
Authors: Mihăescu Lucian , Stanciu Dorin , Lăzăroiu Gheorghe , Pîșă Ionel , Negreanu Gabriel
Published: November 2021

The hydrogen is expected to become the energy vector of the future. If for environmental protection this concept it is obvious, the data for the design of hydrogen combustion facilities are still insufficient. This paper discusses the fundamental actions related to the design of a hydrogen burner. Numerical modelling researches using the Ansys-Fluent software has shown the link between the flow velocity in combustible gas jets together with the required air and the combustion rates. Combustion models (both analytical and numerical) allowed finding the optimal ratios between the two specified velocities (combustion and flow) compared to those for methane combustion, correlated also with the classical directions and recommendations for the burner design.
Energy and economic analysis of an ORC combined to steam boiler
Authors: Mocanu Gabriel , Ion Ion V. , Iosifescu Cristian
Published: November 2021

Energy and economic performance of an organic Rankine cycle (ORC) system designed to recycle waste heat of a steam boiler was analysed. Optimisation of ORC system was performed by using the Cycle-Tempo software and the REFPROP program. The selected working fluid was R245fa. For the exhaust gases temperature of 163°C and mass flow rate of 11.83 kg/s, cooling water temperature of 20°C resulted a gross efficiency of 21.02% and a cost of 2987 €/kW, an electricity levelised cost of 102 €/kWh and a payback period of 5.5 years.
Modelling and numerical simulation of the transport phenomena in water thermal energy storage tanks
Authors: Kaloyanov Nikola , Tsecov Rosen , Penkova Nina
Published: November 2021

Mathematical model for numerical simulation of the transient heat transfer and fluid flows in water thermal energy storage tanks is developed. The model allows analysis of the thermal fields in the accumulators at different schemes and modes of charging and discharging. It was verified and validated based on experimentally obtained information about the temperature stratification at charging of a thermal accumulator at a laboratory solar system. The proposed approach for numerical study of the thermal energy storage is convenient for parametrical estimation and improvement of the efficiency of the thermal systems.
Thermal-hydraulic analysis of a VVER-1000 core in MSLB conditions
Authors: Mitkov Svetlomir , Spasov Ivan , Kolev Nikola
Published: November 2021

The objective of this paper is to analyze the ability of a VVER-1000 core and its control system to cope with a hypothetical main steam line break (MSLB) accident in case of multiple equipment failures. The study involves the use of advanced 3D core calculation models benchmarked and validated for reactivity accidents in preceding studies. A MSLB core boundary condition problem is solved on a coarse (nodal) mesh with the coupled COBAYA/CTF neutronic/thermal hydraulic codes. The core thermal-hydraulic boundary conditions are obtained from a preceding full-plant MSLB simulation. The assessment of the core safety parameters is supplemented by a fine-mesh (sub-channel) thermal-hydraulic analysis of the hottest assemblies with the CTF code using information from the 3D nodal COBAYA/CTF calculations. Thirteen variants of a pessimistic MSLB scenario are considered, each of them assuming a number of equipment failures aggravated by eight control rods stuck out of the core after scram at different locations in the overcooled sector. The results (within the limitations of the adopted modeling assumptions) show that the core safety parameters do not exceed the safety limits in the simulated aggravated reactivity accidents.
Thermodynamic and kinetic parameters of biomass from black pine (PINUS NIGRA ARN.)
Authors: Tasheva Stanislava , Dimov Milen , Fidan Hafize , Stankov Stanko , Lazarov Lazar , Bozadzhiev Bozidar , Simitchiev Apostol , Stoyanova Albena
Published: November 2021

The aim of the present study was to determine the thermodynamic and kinetic parameters of biomass obtained from black pine (Pinus nigra Arn.). The biomass, consisting of twigs with needles and needles alone of black pine, was used. Ultimate analysis with the elemental composition of the biomass with respect to the main components such as carbon (C), hydrogen (H), nitrogen (N), and sulfur (S) of the biomass before and after water distillation was made. The high heating value (HHV) and low heating value (LHV), energy density and fuel value index were determined. Thermodynamic (Gibbs energy, enthalpy, and entropy) and kinetic (activation energy, the rate constant of the process, and reaction order) parameters of the biomass were calculated.
Renewable energies projects selection: block criteria systematization with AHP and Entropy-MOORA methods in MCDM
Authors: Petrov Iliyan
Published: November 2021

EU countries face two major challenges in the energy sector – the control of carbon emissions and the high dependence on imported primary energy sources. Both European Commission and national governments actively develop, update and upgrade strategies and plans for the energy sector. They aim to ensure the gradual reaching of consecutive targets for increasing the weight of Renewable Energies (RE) in the European primary energy mix. The selection of Renewable Energy investment projects in these sectors involves different groups of experts who have to consider the specifics of different countries, regions, and technologies. The Decision-making process becomes more complicated, as in addition to political goals it has to ensure the efficiency and competitiveness of European economies. Several conflicting objectives have to be balanced with complex social, economic, technological, and environmental factors. Our study explores the application of combined methods and evaluation techniques for improving the assessment and selection of prospective RE projects. We implement an innovative integration of the Analytical Hierarchy Process (AHP) for block criteria systematization combined with objective Shannon Entropy in the MOORA evaluation.
A design of solar battery cleaning system by modularity method
Authors: Dien L.K. , Antonov Svetlin
Published: November 2021

According to the World Bank statistical report, Vietnam has an average of 1,600-2,700 hours of sunshine and normal direct radiation averaging 4-5 kWh per square meter a day. Before 2017, solar energy was considered worthless in Vietnam's energy development strategy, but by the end of 2019, Vietnam overtook Malaysia and Thailand to become the country with the largest solar panel installation capacity in Southeast Asia. The photovoltaic projects in Vietnam has reached 5 gigawatts (GW), far exceeding from the target of 1 GW that proposed by the Government in 2020 [1]. The strong development of solar energy from industry to civil activities has led to the development of ancillary services such as installation, maintenance and commerce. To ensure the productivity, all solar panels must be cleaned to absorb solar energy as much as possible. In the paper, we mention on the design of a solar panel cleaning robot that has a compact size, easy to move through the panels, taking advantage of domestic factors to have an edge price. The highlight point in that work is our application of the modularity method to gain the best competition with the other existing products on the market.
Determination of the optimal air-fuel ratio for upgraded biogas engine operation
Authors: Dimitrov Radostin , Zlateva Penka
Published: November 2021

The paper reveals a study about air-fuel ratio variation of spark-ignition engine running on upgraded biogas (biomethane). Using biogas as internal combustion engine fuel and external mixture formation is a new approach to decrease harmful exhaust gas emissions. Тo obtain minimum concentrations of exhaust gases harmful emissions the engine must work with optimal air-fuel ratio. This research contains analysis of many test engine adjusting characteristics to determine optimal air-fuel ratio for each working regime and to obtain maximum effective working process by the use of biomethane as a fuel. Three-dimensional graphics of air-fuel ratio variation across the rpm and load range were made. In conclusion based on performed experiments, a table with values of air-fuel ratio for all engine operating modes and dependence on rpm and load of the engine is proposed.
GA-tuning of Multivariable PID Controller for Electrohydraulic Load-Sensing Servo System
Authors: Mitov Alexander , Slavov Tsonyo , Kralev Jordan , Angelov Ilcho
Published: November 2021

The main purpose of this article is to present the design, optimal setting and experimental study of a multivariable PID controller supposed for electrohydraulic power steering system with load-sensing function. The set of the controller is performed through an optimization procedure based on a genetic algorithm. The PID controller is embedded into a microcontroller for mobile machinery used in laboratory test rig for investigation of an electrohydraulic servo steering system. Results obtained in conditions of physical experiment and numerical simulation with the optimally tuned PID controller are presented. An analysis of the control performance, as well as some features of the used method for setting the PID controller.
Design of direct acting differential pressure control valve test bench
Authors: Bekriev Ognyan , Asenov Radoslav
Published: November 2021

This article aims to acquaint readers with a designed test bench for direct acting differential pressure control valves. These control valves are used in district heating systems. The conformity of the construction of the test bench with the international standard IEC 60534-2-3:2015 is evaluate and the results of an experimental study of the control valve AVPB DN20 Kvs 6.3 PN16 are present.
Investigations of a vertical axis wind turbine with frontal cylindrical guide vane unit
Authors: Obretenov Valentin , Iliev Rossen
Published: November 2021

The paper presents the results of an experimental study of a vertical wind turbine type Darrieus with frontal cylindrical guide vane unit. The main goal of the research is to analyze the influence of the geometry of a classical cylindrical guide vane unit on the active and passive zone of the wind turbine. The aerodynamic scheme is synthesized by a classic runner and frontal cylindrical guide vanes. Three different guiding devices of a model vertical wind turbine with frontally located guide vanes have been studied. Their influence on the characteristics of the turbine has been examined. The reasons of the differences in the characteristics of the three studied variants of the guiding devices are clarified by numerical study of the flow through the blade cascades of the guide vanes and the runner. The results of the study shows what is the reason for the positive effect of the cylindrical vane guide device on the wind turbine’s runner.
Modelling indoor pollutant distribution via passive scalar and virtual box approach
Authors: Pitchurov George , Markov Detelin , Simova Iskra , Velichkova Rositsa , Stankov Peter , Angelova Radostina
Published: November 2021

The distribution of PM2.5 around a thermal manikin with realistic female body shape in a naturally ventilated room has been modelled. The health risk (HR) due to inhalation of the PM2.5 has been quantified by integrating the pollutants mass flux over the boundaries of a virtual box around the mannequin’s head (the breathing zone). By the same approach HR is evaluated over the boundaries of another virtual box that surrounds the manikins body and defines the occupied zone. The paper focuses on the peculiarities of creating and meshing a virtual geometry, as well as on the application of user-defined functions (UDF) for defining a pollutant source within the room using Ansys Fluent modelling package.
The influence of the structure of laminar flows on the characteristics of equipment
Authors: Arsirii Vasyl , Kravchenko Oleg , Savchuk Bohdan , Arsirii Olena
Published: November 2021

The new method of visual diagnostics of liquid motion processes in physical models showed a high degree of the flow structure organization. Visual pictures made it possible to develop a hydraulic experiment to reveal the dimensions of the transverse structure in the form of layers and zones of flow separation from the channel walls. Visual diagnostics is the basis for comprehensive equipment design. Visual studies of the flow structure provide information for improving equipment by changing the geometry of the flow paths. Hydraulic studies show the change in the resistance of the equipment channels. Based on the results of visual and hydraulic studies, the wave character of the distribution of the pulsation velocity components was revealed. The regularities of the velocity distribution allow predicting the minimum or maximum values of the resistances of the flow paths of the equipment.
A Research on The Formability of PVC Sheet in Single Point Incremental Forming (SPIF) Technology
Authors: Thanh Nam Nguyen , Hoang Hiep Nguyen , Tan Hung Nguyen , Trong Hy Tran , Huu Han Ho
Published: November 2021

Nowadays Single Point Incremental Forming (SPIF) is really a new technology of forming metal sheet after its formation and long development in about five decades. Although it was invented in, 1967 by Leszak, an American inventor, but the applications of the innovative technology have just been popular from 1990 because of the advance of controlling technology. This technology is especially adapted to small batch, unique or single productions. In almost all cases, the workpiece material sheets are metal such as aluminum alloys, bronze, mild steel, stainless steel and even Titanium with lot of researches, papers and thesis... Nonmetal sheets are rarely applied in this technology because of rare application. Nowadays, on the rise of the development of composite materials such as, PVC, thermoplastic resins... that have been a lot of applications on living life and technology. In this paper, we dedicate all of our work in the examination some parameters of forming that influence on the deformable ability of PVC plastic by empirical method under the support of DOE and Minitab software. This paper also provides our own experiences in forming PVC sheet that we had performed in the recent decade.
Der selektive Nachweis von HLA-spezifischen B-Gedächtniszellen
Authors: Simper Gwendolin , Schleumann Philipp , Seidel Sarah , Ho Gia-Gia Toni , Placzko Susann , Bade-Döding Christina
Published: November 2021

In der Transplantationsdiagnostik werden die Seren der Patienten auf der Warteliste jedes Quartal auf präexistierende Anti-HLA-Antikörper untersucht. Jedoch kann die Existenz von zirkulierenden peripheren Antikörpern, die von knochenmarkresidierenden Plasmazellen sezerniert wurden, keine zuverlässige Information über das Zellkompartment von B-Gedächtniszellen geben. Die Exposition mit einem inkompatiblen HLA-Antigen kann immer die Aktivierung vorhandener B-Gedächtniszellen auslösen. Die Analyse von B-Gedächtniszellen ermöglicht die Erhebung von belastbaren Daten über den individuellen Immunstatus eines Patienten.