bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixtures of QSAR models: Learning application domains of pKpredicto rs
Authors: Dörgő Gyula , Péter Hamadi Omar , Varga Tamás , Abonyi János 
Published: February 2020

AbstractQuantitative structure‐activity relationship models (QSAR models) predict the physical properties or biological effects based on physicochemical properties or molecular descriptors of chemical structures. Our work focuses on the construction of optimal linear and nonlinear weighted mixes of individual QSAR models to more accurately predict their performance. How the splitting of the application domain by a nonlinear gating network in a “mixture of experts” model structure is suitable for the determination of the optimal domain‐specific QSAR model and how the optimal QSAR model for certain chemical groups can be determined is highlighted. The input of the gating network is arbitrarily formed by the various molecular structure descriptors and/or even the prediction of the individual QSAR models. The applicability of the method is demonstrated on the pKvalues of the OASIS database (1912 chemicals) by the combination of four acidic pKpredictions of the OECD QSAR Toolbox. According to the results, the prediction performance was enhanced by more than 15% (root‐mean‐square error [RMSE] value) compared with the predictions of the best individual QSAR model.
An ensemble just‐in‐time learning soft‐sensor model for residual lithium concentration prediction of ternary cathode materials
Authors: Chen Jiayao , Gui Weihua , Dai Jiayang , Yuan Xiaofeng , Chen Ning 
Published: February 2020

AbstractThe surface‐free lithium content, which is a critical index that reflecting the quality of ternary cathode materials, usually cannot be monitored in real time due to technical restriction. To this end, soft sensor technique is applied to predict the surface‐free lithium content by readily available process variables, making timely control on operation parameters. In this paper, a modeling method based on ensemble just‐in‐time learning (JITL) soft‐sensor is developed. In the model, data feature indices are firstly designed to properly extract the real‐time and short‐time features between the batching and the loading procedure. Accordingly, ensemble JITL soft‐sensor model is constructed with the semisupervised local weighted probability principal component regression. Moreover, considering varying working conditions, an adaptive moving window technique is adopted to improve the adaptability of the model. The validation and the flexibility of the developed modeling method are testified with the practical manufacturing data.
Coordinatively Unsaturated Metal–Nitrogen Active Sites at Twisted Surfaces in Metallic Porous Nitride Single Crystals Delivering Enhanced Electrocatalysis Activity
Authors: Zhang Feiyan , Jin Lu , Li Hao , Xie Kui 
Published: February 2020

AbstractTo create active sites on surfaces, the identification of structural features that could confine the local‐defect structure in the lattice is required. Porous nitride single crystals, combining the advantages of porosity and structural coherence, provide the possibility to create coordinatively unsaturated metal–nitrogen active sites confined on surfaces. For the first time, ordered active sites and tailor the atomically resolved Fe−N and Co−N local structures are created through control of the unsaturated nitrogen coordination at twisted surfaces in porous single‐crystalline FenN (n=2–4) and ConN (n=1–3) nanocubes. The precise tailoring of the electronic structures of these coordinatively unsaturated active sites therefore engineer the catalytic activity. Optimum electrocatalysis performances are observed with the porous Fe4N and Co3N nanocubes with highly unsaturated nitrogen coordination for selective nitrate reduction to ammonia and nitrobenzene amination to aminobenzene, while the structural coherence of these porous nitride single crystals delivers excellent durability.
Asymmetric Organocatalyzed Aza‐Henry Reaction of Hydrazones: Experimental and Computational Studies
Authors: Sonsona Isaac G. , Alegre‐Requena Juan V. , Marqués‐López Eugenia , Gimeno M. Concepción , Herrera Raquel P. 
Published: February 2020

AbstractThe first asymmetric catalyzed aza‐Henry reaction of hydrazones is presented. In this process, quinine was used as the catalyst to synthesize different alkyl substituted β‐nitrohydrazides with ee up to 77 %. This ee was improved up to 94 % by a further recrystallization and the opposite enantiomer can be obtained by using quinidine as the catalyst, opening exciting possibilities in fields in which the control of chirality is vital, such as the pharmaceutical industry. Additionally, experimental and ab initio studies were performed to understand the reaction mechanism. The experimental results revealed an unexpected secondary kinetic isotope effect (KIE) that is explained by the calculated reaction pathway, which shows that the protonation of the initial hydrazone and the C−C bond forming reaction occur during a concerted process. This concerted mechanism makes the catalysis conceptually different to traditional base‐promoted Henry and aza‐Henry reactions.
Identification of the regime boundaries in bubble columns based on the degree of randomness in the signals†
Authors: Nedeltchev Stoyan , Top Yasin , Hlawitschka Mark W. , Schubert Markus , Bart Hans‐Jörg 
Published: February 2020

AbstractA new parameter (degree of randomness (DR)) was defined for the identification of the main transition velocities, U
trans. The new method reconstructs the time series into multiple state vectors, thus generating non‐overlapping vector pairs and then compares the distance between them with a pre‐selected cut‐off length. The DR values were extracted from gauge and differential pressure fluctuations as well as x‐ray tomographic scans. At every U
trans value, the DR index exhibited a well‐pronounced local minimum. Three cylindrical bubble columns (BCs) with various diameters (0.1, 0.14, and 0.45 m in ID) and one rectangular BC (width = 0.2 m, depth = 0.04 m) were used. They were aerated by means of different perforated plate gas distributors. It was found that in the cylindrical BCs the disintegration of the bubbly flow regime took place always at U
trans = 0.04 m/s. In the case of the rectangular BC the first critical velocity appeared at U
trans = 0.012 m/s. The lower boundary of the churn‐turbulent regime was identified at U
trans = 0.11 m/s in the smallest cylindrical BC and at about U
trans = 0.095 m/s in the other two cylindrical BCs. In the case of the rectangular BC, the second critical velocity was identified at U
trans = 0.039 m/s. The low U
trans in the rectangular BC imply that the hydrodynamic regimes are less stable in this particular column due to higher degree of liquid turbulence. The calculated DR values from the gauge pressure fluctuations successfully distinguished the upper boundary of the gas maldistribution and the first transition sub‐regime.
Use of empiric methods to inform prostate cancer health disparities: Comparison of neighborhood‐wide association study “hits” in black and white men
Authors: Lynch Shannon M. , Sorice Kristen , Tagai Erin K. , Handorf Elizabeth A. 
Published: February 2020

BackgroundBlack men are more likely to die of prostate cancer (PCa) compared with white men. Factors ranging from genetics to neighborhood environment contribute to these disparities. However, unlike genetics, agnostic investigations that identify candidate variables from large‐scale data, and that allow for empiric investigations into differential associations between neighborhood and PCa by race/ethnicity, to the authors' knowledge have not been well explored. Thus, herein, the authors built on their previously developed, empiric neighborhood‐wide association study (NWAS) in white men and conducted a NWAS in black men to determine whether findings differed by race.MethodsPennsylvania Cancer Registry data were linked to US Census data. For the NWAS in non‐Hispanic black men, the authors evaluated the association between 14,663 neighborhood census variables and advanced PCa (11 high‐stage and/or high‐grade cases and 8632 low‐stage and/or low‐grade cases), adjusting for age, diagnosis year, spatial correlation, and multiple testing. Odds ratios and 95% credible intervals were reported. Replication of NWAS findings across black and white races was assessed using Bayesian mixed effects models.ResultsFive variables related to housing (3 variables), education (1 variable), and employment and/or transportation (1 variable) were found to be significantly associated with advanced PCa in black men compared with 17 socioeconomic variables (mostly related to poverty and/or income) in white men. The top hit in black men was related to crowding in renter‐occupied housing (odds ratio, 1.10; 95% credible interval, 1.001‐1.12). Nine of 22 NWAS hits (4 of 5 hits in black men) were replicated across racial/ethnic groups.ConclusionsDifferent neighborhood variables, or “candidates,” were identified across race‐specific NWASs. These findings and empiric approaches warrant additional study and may inform PCa racial disparities, particularly future gene‐environment studies aimed at identifying patients and/or communities at risk of advanced PCa.
Metabolic syndrome, metabolic components, and their relation to the risk of pancreatic cancer
Authors: Park Sung Keun , Oh Chang‐Mo , Kim Min‐Ho , Ha Eunhee , Choi Yong‐Sung , Ryoo Jae‐Hong 
Published: February 2020

BackgroundComponents of the metabolic syndrome (MetS), such as elevated fasting glucose levels and abdominal obesity, have been suggested as potential risk factors for pancreatic cancer. However, data are still insufficient to assure the influence of MetS on incident pancreatic cancer. The objective of the current study was to investigate the association between MetS, metabolic components, and the risk of pancreatic cancer.MethodsIn the Korea National Health Information Database, 223,138 individuals who were without pancreatic cancer in 2009 were enrolled and followed until 2013. They were categorized into 4 groups according to the number of baseline metabolic components (0, 1, 2, 3, and 4‐5). A multivariate Cox proportional hazard model was used to calculate the adjusted hazard ratios (HRs) and 95% CIs for incident pancreatic cancer according to the presence of MetS and the number of metabolic components. In addition, the risk of pancreatic cancer was evaluated in individuals who had a single metabolic component.ResultsThe presence of MetS was significantly associated with incident pancreatic cancer (adjusted HR, 1.47; 95% CI, 1.19‐1.81). The group with 4 or 5 baseline metabolic components had a higher risk of pancreatic cancer than the other groups (0 components: reference category; 1 component: adjusted HR, 0.94 [95% CI, 0.61‐1.45]; 2 components: adjusted HR, 1.03 [95% CI, 0.68‐1.56]; 3 components: adjusted HR, 1.35 [95% CI, 0.89‐2.04]; 4‐5 components: adjusted HR, 1.64 [95% CI, 1.06‐2.51]). Regarding associations between the individual metabolic components and pancreatic cancer, no metabolic component alone had a statistically significant association with pancreatic cancer.ConclusionsMetS is a potential risk factor for pancreatic cancer. The presence of ≥4 metabolic components leads to a higher risk of pancreatic cancer even within categories of the MetS.
Preoperative bronchial cytology for the assessment of tumor spread through air spaces in lung adenocarcinoma resection specimens
Authors: Medina Mayra A. , Onken Allison M. , de Margerie‐Mellon Constance , Heidinger Benedikt H. , Chen Yigu , Bankier Alexander A. , VanderLaan Paul A. 
Published: February 2020

BackgroundTumor spread through air spaces (STAS), a significant prognostic indicator, has been described recently as a pattern of invasion in pulmonary carcinomas. However, questions remain regarding preoperative identification of STAS and whether it represents an in vivo phenomenon versus an ex vivo artifact.MethodsWe retrospectively reviewed 67 paired preoperative bronchoalveolar lavage (BAL) or bronchial washing (BW) cytology specimens with the subsequent lung adenocarcinoma surgical resection specimen to determine whether preoperative cytology could predict STAS. Other clinical, radiologic, and pathologic features of the resected lesions were also correlated with preoperative bronchial cytology results.ResultsPositive bronchial cytology was observed in 28 cases (41.8%), 24 of which had STAS (85.7%); however, negative BAL/BW cytology was observed in 39 cases (58.2%), 29 of which had STAS (74.4%) (x2 = 1.27, P = .26, not significant). High‐STAS burden was observed in 44 cases (83.0%), 21 (47.7%) with negative BAL/BW and 23 (52.3%) with positive BAL/BW. Low‐STAS burden was observed in 9 cases (17.0%), 8 (88.9%) with negative BAL/BW and only 1 (11.1%) with positive BAL/BW (x2 = 5.11, P = .024, significant). For tumors with STAS, a statistically significant difference was identified in the maximal STAS distance from the main tumor edge between BAL/BW‐positive and BAL/BW‐negative groups (P = .007). Of the remaining clinicopathologic and radiologic features, only visceral pleural invasion was significantly associated with BAL/BW positivity.ConclusionPresurgical bronchial cytology alone cannot adequately predict tumor STAS; however, it may provide useful information regarding the extent and overall burden of STAS on the subsequent resection specimen.
Electrochemical Synthesis of Spiro[4.5]trienones through Radical‐Initiated Dearomative Spirocyclization
Authors: Hua Jiawei , Fang Zheng , Bian Mixue , Ma Tao , Yang Man , Xu Jia , Liu ChengKou , He Wei , Zhu Ning , Yang Zhao , Guo Kai 
Published: February 2020

AbstractA novel and green route has been developed for the electrochemical synthesis of spiro[4.5]trienones through radical‐initiated dearomative spirocyclization of alkynes with diselenides. This metal‐free and oxidant‐free electrosynthesis reaction was performed in an undivided cell under mild conditions. A variety of selenation spiro[4.5]trienones products were prepared in moderate‐to‐good yields, showing a broad scope and functional group tolerance. Moreover, the developed continuous‐flow system combined with electrosynthesis possesses the potential to achieve scaled‐up reactions, overcoming the low efficiency of conventional electrochemical scaled‐up reactions.
Native honeybees as flower visitors and pollinators in wild plant communities in a biodiversity hotspot
Authors: Stanley Dara A. , Msweli Simangele M. , Johnson Steven D. 
Published: February 2020

AbstractWestern honeybees (Apis mellifera L.), native to Europe and Africa, have been transported worldwide and are now one of the most important global crop pollinator species. Although the relative contribution of honeybees to global crop pollination is increasingly recognized, relatively little is known about their importance as pollinators in wild plant communities. The only remaining wild and unmanaged western honeybee populations are in Africa. We investigated the importance of honeybees as pollinators of diverse wild plant communities in two protected areas within the Maputaland–Pondoland–Albany biodiversity hotspot in South Africa. Sites were far from any known areas of beekeeping, and so all honeybees were most likely from wild colonies. Honeybees visited a large proportion of flowering plant species within these two communities (40% and 35%) and also provided a substantial proportion of visits to the plants they visited (40% and 32%, respectively). However, when pollinator importance indices (based on abundance and the size and purity of pollen loads) were calculated for a small subset of plants, honeybees were only important pollinators of 29% of the plants they visited. Our data provide a first step in determining the importance of honeybees as flower visitors and pollinators in wild plant communities and the potential impacts of honeybee declines on these highly diverse grassland ecosystems. Our work suggests that many plants in the grassland systems studied are visited by non‐Apis flower visitors and therefore that conservation efforts should also focus on these pollinator groups.
Gaps present a trade‐off between dispersal and establishment that nourishes species diversity
Authors: Terborgh John , Huanca Nuñez Nohemi , Feeley Kenneth , Beck Harald 
Published: February 2020

AbstractWe took advantage of two natural experiments to investigate processes that regulate tree recruitment in gaps. In the first, we examined the recruitment of small and large saplings and trees into 31 gaps resulting from treefalls occurring between 1984 and 2015 in the 2.25‐ha core area of a 4‐ha tree plot at Cocha Cashu in Perú. In the second, we identified the tallest saplings recruiting into 69 gaps created during a violent wind storm in February 2000. In the established tree plot, we were able to compare the composition of saplings in the disturbance zones of gaps prior to, during, and subsequent to the period of gap formation. Recruitment in gaps was compared with that in “nofall” zones, areas within the plot that had not experienced a treefall at least since the early 1980s. Our results confirmed earlier findings that a consistently high proportion (~60%) of established saplings survived gap formation. Light demanding species, as proxied by mortality rates, recruited under all conditions, but preferentially during periods of gap formation, a pattern that was especially strong among gap pioneers. Similar results were noted, separately, for small and large saplings and trees recruiting at ≥10 cm dbh. One hundred percent of previously untagged trees recruiting into gaps in the first post‐disturbance census were gap pioneers, suggesting rapid development. This conclusion was strongly supported in a follow‐up survey taken of 69 gaps 19 months after they had been synchronously created in a wind storm. Ten species of gap pioneers, eight of which are not normally present in the advance regeneration, had attained heights of 6–10 m in 19 months. The 10 gap pioneers were dispersed, variously, by primates, bats, birds, and wind and reached maximum frequency in different‐sized gaps (range <100 m2 to >1,000 m2). Both gap size and limited dispersal of zoochorous species into gaps serve as filters for establishment, creating a complex mosaic of conditions that enhances species diversity.
Syncytin‐1/HERV‐W envelope is an early activation marker of leukocytes and is upregulated in multiple sclerosis patients
Authors: Garcia‐Montojo Marta , Rodriguez‐Martin Eulalia , Ramos‐Mozo Priscila , Ortega‐Madueño Isabel , Dominguez‐Mozo Maria Inmaculada , Arias‐Leal Ana , García‐Martínez Maria Ángel , Casanova Ignacio , Galan Victoria , Arroyo Rafael , Álvarez‐Lafuente Roberto , Villar Luisa María 
Published: February 2020

AbstractSyncytin‐1 is the envelope protein of the human endogenous retrovirus W (HERV‐W). It has been related to multiple sclerosis (MS) but its role in cellular immunity and its pathogenic mechanism in the autoimmune context are not fully understood. We analyzed syncytin‐1 levels in peripheral blood mononuclear cells (PBMC) subsets from healthy donors, MS patients in relapse or remission, and patients with acute infections by flow cytometry. PBMC cultures were also prepared to analyze protein expression kinetics. MS patients had higher levels of syncytin‐1 levels than controls. We found that syncytin‐1 is elevated in monocytes during MS relapses and infections. Cells expressing syncytin‐1, including monocytes, T and B lymphocytes, and NKs presented mainly an activated phenotype and, upon stimulation with LPS, its levels increased rapidly on antigen‐presenting cells. Syncytin‐1 ligation promoted the activation of monocytes, as demonstrated by the upregulation of CD80 and the nonclassical subset CD14low CD16+. Our results suggest an important role for syncytin‐1 in the activation of leukocytes. Given that the expression of syncytin‐1 is upregulated in MS patients, this protein might be contributing to the autoimmune cascade in the disease.
Electrokinetic‐vortex formation near a two‐part cylinder with same‐sign zeta potentials in a straight microchannel
Authors: Wang Chengfa , Song Yongxin , Pan Xinxiang 
Published: February 2020

AbstractVortex formation near a two‐part cylinder with zeta potentials of different values but the same sign under an external DC electric field is numerically investigated in this paper. The cylinder, inserted in a straight microchannel filled with an aqueous solution, is composed of an upstream part and a downstream part. When a DC electric field is applied in the channel, under certain conditions, the vortex will form near the cylinder due to the different velocities of electroosmotic flow generated on the cylinder surface. The numerical results reveal that the larger the velocity difference of electroosmotic flow generated on the two‐part cylinder and the smaller the channel width, the more conducive to vortex formation in the channel. In addition, if the zeta potential ratios of cylinder downstream part to upstream part and channel wall to cylinder upstream part are unchanged, the DC electric field strength and the zeta potential value do not affect the pattern of vortices formed in the channel. This study provides a way for vortex formation in microchannels and has the potential application in microfluidic devices.
Simulation of steady and unsteady flows through a small‐size Kaplan turbine
Authors: Ghenaiet Adel , Bakour Mustapha 
Published: February 2020

AbstractThe increasing demand for electric energy has pushed to rely on the microhydropower as one of the most cost‐effective technologies to improve the grid stability in rural localities. This article investigates the steady and unsteady flows in a complete small Kaplan turbine by means of the solver ANSYS‐CFX. Examination of the basic design parameters in terms of blade setting, vane opening, and interdistance has revealed the best operating parameters and the potentiality of performance improvement. Moreover, the Fast Fourier Transform of static pressure fluctuations recorded at different monitor points allowed analyzing the flow unsteadiness arising from the stator‐rotor interactions (RSI). The prevailing harmonics coinciding with the modes of RSI were determined and compared with the analytically predicted main diametrical modes and frequencies of the pressure waves. The found results in this category of low‐head small Kaplan turbine may serve in developing similar hydroturbines suitable for the microhydropower.