Automated Dilated Spatio-Temporal Synchronous Graph Modeling for Traffic Prediction

Accurate traffic prediction is a challenging task in intelligent transportation systems because of the complex spatio-temporal dependencies in transportation networks. Many existing works utilize sophisticated temporal modeling approaches to incorporate with graph convolution networks (GCNs) for capturing short-term and long-term spatio-temporal dependencies. However, these separated modules with complicated designs could restrict effectiveness and efficiency of spatio-temporal representation learning. Furthermore, most previous works adopt the fixed graph construction methods to characterize the global spatio-temporal relations, which limits the learning capability of the model for different time periods and even different data scenarios. To overcome these limitations, we propose an automated dilated spatio-temporal synchronous graph network, named Auto-DSTSGN for traffic prediction. Specifically, we design an automated dilated spatio-temporal synchronous graph (Auto-DSTSG) module to capture the short-term and long-term spatio-temporal correlations by stacking deeper layers with dilation factors in an increasing order. Further, we propose a graph structure search approach to automatically construct the spatio-temporal synchronous graph that can adapt to different data scenarios. Extensive experiments on four real-world datasets demonstrate that our model can achieve about 10% improvements compared with the state-of-art methods. Source codes are available at https://github.com/jinguangyin/Auto-DSTSGN

PHUIMUS: A Potential High Utility Itemsets Mining Algorithm Based on Stream Data with Uncertainty

High utility itemsets (HUIs) mining has been a hot topic recently, which can be used to mine the profitable itemsets by considering both the quantity and profit factors. Up to now, researches on HUIs mining over uncertain datasets and data stream had been studied respectively. However, to the best of our knowledge, the issue of HUIs mining over uncertain data stream is seldom studied. In this paper, PHUIMUS (potential high utility itemsets mining over uncertain data stream) algorithm is proposed to mine potential high utility itemsets (PHUIs) that represent the itemsets with high utilities and high existential probabilities over uncertain data stream based on sliding windows. To realize the algorithm, potential utility list over uncertain data stream (PUS-list) is designed to mine PHUIs without rescanning the analyzed uncertain data stream. And transaction weighted probability and utility tree (TWPUS-tree) over uncertain data stream is also designed to decrease the number of candidate itemsets generated by the PHUIMUS algorithm. Substantial experiments are conducted in terms of run-time, number of discovered PHUIs, memory consumption, and scalability on real-life and synthetic databases. The results show that our proposed algorithm is reasonable and acceptable for mining meaningful PHUIs from uncertain data streams

Co-expression of apoptin (VP3) and antibacterial peptide cecropin B mutant (ABPS1) genes induce higher rate of apoptosis in HepG2 and A375 cell lines

The antibacterial peptide cecropin B mutant (ABPS1) gene has a broad range of antibacterial and  antiproliferative properties. Apoptin (VP3), a chicken anaemia virus-encoded protein is known to induce  apoptosis in human transformed cells. To explore drug combination in human tumor cells, apoptin and ABPS1 eukaryotic expression vector pIRES2-EGFP-apoptin and pIRES2-EGFP-ABPS1 were constructed and their expression effect individually and in combinations were studied in HepG2 and A375 cells. The vector pIRES2-EGFP-ABPS1 and pIRES2-EGFP-apoptin were transfected into tumor cells HepG2 and A375 by the  lipofectamine-mediated DNA transfection procedure. At 48 h post transfection, the apoptotic rate obtained by flow cytometry and the morphological changes under light and scanning electron microscope of tumor cells  were significant. In contrast, the microvilli on the surface of the control cells were disrupted, decreased and even disappeared. The cell membrane was injured and intracellular substances leaked out. Furthermore, our  results indicate that the apoptotic rates of apoptin (27.32% in HepG2 and 9.34% in A375 cells), were higher  than ABPS1 (23.79% in HepG2 and 8.33% in A375 cells). Moreover, the co-expression of Apoptin and ABPS1  showed higher apoptotic rates which were 27.66 and 10.33% in HepG2 and A375 cells respectively. However, the apoptotic rates obtained in HepG2 cells treated with apoptin and apoptin and ABPS1 together were closely  similar, but, not in A375 cells. Therefore, the results of the present study showed that the combination of  Apoptin and ABPS1 has synergistic effect in HepG2 and A375 cell lines.Keys words: Apoptin, ABPS1, apoptosis, co-expression, HepG2, A375

Cu2O@PNIPAM core–shell microgels as novel inkjet materials for the preparation of CuO hollow porous nanocubes gas sensing layers

There has been long-standing interest in developing metal oxide-based sensors with high sensitivity, selectivity, fast response and low material consumption. Here we report for the first time the utilization of Cu2O@PNIPAM core–shell microgels with a nanocube-shaped core structure for construction of novel CuO gas sensing layers. The hybrid microgels show significant improvement in colloidal stability as compared to native Cu2O nanocubes. Consequently, a homogeneous thin film of Cu2O@PNIPAM nanoparticles can be engineered in a quite low solid content (1.5 wt%) by inkjet printing of the dispersion at an optimized viscosity and surface tension. Most importantly, thermal treatment of the Cu2O@PNIPAM microgels forms porous CuO nanocubes, which show much faster response to relevant trace NO2 gases than sensors produced from bare Cu2O nanocubes. This outcome is due to the fact that the PNIPAM shell can successfully hinder the aggregation of CuO nanoparticles during pyrolysis, which enables full utilization of the sensor layers and better access of the gas to active sites. These results point out great potential of such an innovative system as gas sensors with low cost, fast response and high sensitivitH. J. gratefully acknowledges financial support of the CSC scholarship. S. P. acknowledges funding from the Community of Madrid under grant number 2016-T1/AMB-1695

Diverse phylogeny and morphology of magnetite biomineralized by magnetotactic cocci

Magnetotactic bacteria (MTB) are diverse prokaryotes that produce magnetic nanocrystals within intracellular membranes (magnetosomes). Here, we present a large‐scale analysis of diversity and magnetosome biomineralization in modern magnetotactic cocci, which are the most abundant MTB morphotypes in nature. Nineteen novel magnetotactic cocci species are identified phylogenetically and structurally at the single‐cell level. Phylogenetic analysis demonstrates that the cocci cluster into an independent branch from other Alphaproteobacteria MTB, that is, within the Etaproteobacteria class in the Proteobacteria phylum. Statistical analysis reveals species‐specific biomineralization of magnetosomal magnetite morphologies. This further confirms that magnetosome biomineralization is controlled strictly by the MTB cell and differs among species or strains. The post‐mortem remains of MTB are often preserved as magnetofossils within sediments or sedimentary rocks, yet paleobiological and geological interpretation of their fossil record remains challenging. Our results indicate that magnetofossil morphology could be a promising proxy for retrieving paleobiological information about ancient MTB.This study was supported financially by the National Natural Science Foundation of China (grants 41920104009, 41890843 and 41621004), The Senior User Project of RVKEXUE2019GZ06 (Centre for Ocean Mega-Science, Chinese Academy of Sciences), The Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology (grant MGQNLM201704) and the Australian Research Council (grants DP140104544 and DP200100765)

Multinäre Metalloxide zur solaren Wasserspaltung : auf dem Weg zu hoher Effizienz und hoher Stabilität

The world has experienced an exponential increase in the demand for energy primarily coming from the consumption of fossil fuels, which is accompanied by the inevitable emission of carbon dioxide, causing global warming. Developing renewable and carbon-free sources is essential to reduce carbon dioxide emission and mitigate global warming. Among the renewable energy sources, solar energy has the greatest potential to meet our future energy demands. One crucial problem of solar energy utilization is its intermittency due to day and night cycles as well as fluctuations in weather. Solar water splitting provides a possible route to convert solar energy into more storable chemical energy—hydrogen. To ensure good efficiency and stability in photoelectrochemical water splitting, the photoelectrode materials must satisfy critical thermodynamic and kinetic requirements. Unfortunately, so far no material in nature can meet all these requirements. Therefore, exploring new materials and modifying the properties of the existing materials are the crucial tasks ahead for materials scientists. In this thesis, we demonstrate the development of CuBi2O4 as a photocathode material for hydrogen production and BiVO4 as a photoanode material for water oxidation. A new spray pyrolysis recipe is developed to deposit homogeneous CuBi2O4. The key to the synthesis is to use additives including (1) triethyl orthoformate to avoid rapid hydrolysis of the bismuth precursor in the spray solution and (2) polyethylene glycol to improve the spreading behavior of the droplets over the substrates. A comprehensive investigation of the structure, optical, electrical, and morphological properties of CuBi2O4 demonstrates its potential to be used as a photocathode material with the main limitations being poor charge separation efficiency and photo-corrosion. To address these limitations, we explore a new strategy of gradient self-doping by introducing a Cu vacancy gradient using a two-step-diffusion assisted spray pyrolysis process. The flat-band of the CuBi2O4 photocathodes can be tailored by varying the Cu : Bi ratio. Introducing a Cu : Bi gradient inside the film leads to a gradient in Cu vacancies and therefore a built-in electric field, which in turn enhances or reduces the photoelectrochemical performance depending on the direction of the gradient. Applying CdS/TiO2 as protection layers and Pt as a catalytic layer significantly improves the stability of the forward gradient CuBi2O4 photocathode. We also explore direct current magnetron sputtering as a potential scaling-up technique for the economical deposition of BiVO4 photoanodes. The role of stoichiometry on structure, grain size, diffusion length, and photoelectrocatalytic performance is investigated, revealing a strong relationship between the grain size and the electronic properties. Our self-designed solvent capture technique combined with attenuated total reflection infrared (ATR-IR) spectroscopy can be useful for in-situ analysis of the reaction mechanisms in solution. The strategies we utilized to improve the solution chemistry by adding additives might be applicable for developing solution-based recipe for the synthesis of other metal oxides. The concept of using self-gradient-doping to improve the charge separation efficiency in CuBi2O4 can be easily applied to other multinary metal oxide photoelectrodes. In addition, we demonstrate the potential of using direct current magnetron sputtering, a highly scalable technique, to produce multinary oxide photoelectrodes at high deposition rate and low cost.Der exponentiell ansteigende Weltenergiebedarf wird zurzeit hauptsächlich durch Fossile Brennstoffe gedeckt. Dies hat den unvermeidlichen Ausstoß von Kohlenstoffdioxid zur Folge, welches für den Klimawandel verantwortlich ist. Die Erschließung von erneuerbaren und kohlenstofffreien Energiequellen ist daher essenziell für die Reduktion des Kohlenstoffdioxidausstoßes und der Abschwächung des Klimawandels. Unter den erneuerbaren Energiequellen besitzt die Solarenergie das größte Potential den kommenden Bedarf zu decken. Die schwankende Verfügbarkeit von Solarenergie durch den Tag /Nachtzyklus oder Wettereinflüsse stellt jedoch ein großes Problem dar. Die solare Wasserspaltung könnte dieses Problem lösen, indem die Sonnenenergie in den besser speicherbaren chemischen Brennstoff Wasserstoff umgewandelt wird. Um eine hohe Effizienz und Stabilität bei der solaren Wasserspaltung zu gewährleisten, müssen die Materialien für die Photoelektroden wichtige thermodynamische und kinetische Anforderungen erfüllen. Leider kann bisher kein Material diese Vielzahl von Bedingungen erfüllen. Daher ist das Erforschen von neuen und die Modifikation von bestehenden Photoelektrodenmaterialien eine der wichtigsten Aufgaben für Materialwissenschaftler im Feld der solaren Wasserspaltung. In dieser Arbeit demonstrieren wir die Entwicklung von CuBi2O4 als Photokathodenmaterial für die Wasserstoffproduktion und BiVO4 als Photoanodenmaterial für die Sauerstofferzeugung. Ein wurde ein neues Spray-Pyrolyse Rezept entwickelt, das die Herstellung von homogenen CuBi2O4-Schichten ermöglicht. Die entscheidenden Schritte ist das Hinzufügen von (1) Triethyl-Orthoformiat, das die schnelle Hydrolyse von Bismut im Präkursor verhindert und (2) Polyethylenglykol, das das Verteilungsverhalten der Tropfen auf dem Substrat verbessert. Ein intensives Erforschen der Struktur, der optischen, elektrischen und morphologischen Eigenschaften von CuBi2O4-Schichten zeigt zum einem das Potential und zum anderen die limitierenden Eigenschaften für die Nutzung des Materials als Photokathode auf. Letztere liegen hauptsächlich im Bereich der Ladungstrennung und der Photokorrosion. Um diese Limitationen zu umgehen untersuchen wir die neue Strategie einer graduellen Selbst-Dotierung mittels einem Kupfer-Fehlstellen-Gradienten, der mit einem zweistufigen diffusionsgestützten Spray-Pyrolyse Prozess hergestellt wird. Das Flachbandpotential der Schichten kann durch Variation der Cu : Bi Verhältnisses kontrolliert werden. Das Einstellen eines Cu : Bi-Gradienten innerhalb des Films führt zu einem Kupfer-Fehlstellen-Gradienten und damit einem elektrischen Feld, das die photoelektrochemischen Eigenschaften je nach Richtung des Gradienten verbessert oder verschlechtert. Das Abscheiden von CdS/TiO2 als Schutzschichten und Pt als Katalysator verbessert die Stabilität der Vorwärts-Gradienten-CuBi2O4-Photokathode. Des Weiteren wurde Magnetron Sputtern als potentielles Scale-Up Verfahren für die wirtschaftliche Herstellung von BiVO4-Schichten untersucht. Der Einfluss der Stöchiometrie auf die Struktur, die Korngröße, Diffusionslänge und der photoelektrokatalytischen Leistung wurde näher betrachtet und eine starke Verknüpfung zwischen Korngröße und elektrischen Eigenschaften festgestellt. Unsere selbstentwickelte Lösemittelabscheidung Technik kombiniert mit ATR-IR Spektroskopie kann für die In-Situ Betrachtung von Reaktionsmechanismen innerhalb der Lösung hilfreich sein. Die verwendeten Strategien zur Beeinflussung der chemischen Vorgänge in der Lösung durch die Zugabe von Additiven könnten auf andere lösungsbasierte Synthesen von Metalloxiden übertragen werden. Das Konzept der selbst-dotierenden-Gradienten-Elektroden für die Verbesserung der Trennung von Ladungsträgern in CuBi2O4 könnte auch auf andere Mehrmetalloxide angewandt werden. Darüber hinaus demonstrieren wir das Potential des Gleichstrom-Magnetron-Sputterns als leicht skalierbare Herstellungsmethode von Mehrmetalloxid-Photoelektroden mit hohen Depositionsraten und geringen Kosten

Multinary Metal Oxides for Solar Water Splitting Towards High Efficiency and High Stability

The world has experienced an exponential increase in the demand for energy primarily coming from the consumption of fossil fuels, which is accompanied by the inevitable emission of carbon dioxide, causing global warming. Developing renewable and carbon free sources is essential to reduce carbon dioxide emission and mitigate global warming. Among the renewable energy sources, solar energy has the greatest potential to meet our future energy demands. One crucial problem of solar energy utilization is its intermittency due to day and night cycles as well as fluctuations in weather. Solar water splitting provides a possible route to convert solar energy into more storable chemical energy hydrogen. To ensure good efficiency and stability in photoelectrochemical water splitting, the photoelectrode materials must satisfy critical thermodynamic and kinetic requirements. Unfortunately, so far no material in nature can meet all these requirements. Therefore, exploring new materials and modifying the properties of the existing materials are the crucial tasks ahead for materials scientists. In this thesis, we demonstrate the development of CuBi2O4 as a photocathode material for hydrogen production and BiVO4 as a photoanode material for water oxidation. A new spray pyrolysis recipe is developed to deposit homogeneous CuBi2O4. The key to the synthesis is to use additives including 1 triethyl orthoformate to avoid rapid hydrolysis of the bismuth precursor in the spray solution and 2 polyethylene glycol to improve the spreading behavior of the droplets over the substrates. A comprehensive investigation of the structure, optical, electrical, and morphological properties of CuBi2O4 demonstrates its potential to be used as a photocathode material with the main limitations being poor charge separation efficiency and photo corrosion. To address these limitations, we explore a new strategy of gradient self doping by introducing a Cu vacancy gradient using a two step diffusion assisted spray pyrolysis process. The flat band of the CuBi2O4 photocathodes can be tailored by varying the Cu Bi ratio. Introducing a Cu Bi gradient inside the film leads to a gradient in Cu vacancies and therefore a built in electric field, which in turn enhances or reduces the photoelectrochemical performance depending on the direction of the gradient. Applying CdS TiO2 as protection layers and Pt as a catalytic layer significantly improves the stability of the forward gradient CuBi2O4 photocathode. We also explore direct current magnetron sputtering as a potential scaling up technique for the economical deposition of BiVO4 photoanodes. The role of stoichiometry on structure, grain size, diffusion length, and photoelectrocatalytic performance is investigated, revealing a strong relationship between the grain size and the electronic properties. Our self designed solvent capture technique combined with attenuated total reflection infrared ATR IR spectroscopy can be useful for in situ analysis of the reaction mechanisms in solution. The strategies we utilizedto improve the solution chemistry by adding additives might be applicable for developing solution based recipe for the synthesis of other metal oxides. The concept of using self gradient doping to improve the charge separation efficiency in CuBi2O4 can be easily applied to other multinary metal oxide photoelectrodes. In addition, we demonstrate the potential of using direct current magnetron sputtering, a highly scalable technique, to produce multinary oxide photoelectrodes at high deposition rate and low cos

ELK4 Promotes Cell Cycle Progression and Stem Cell-like Characteristics in HPV-associated Cervical Cancer by Regulating the FBXO22/PTEN Axis

Background:Cervical cancer (CC) is a prevalent gynecological carcinoma, and patients infected with human papillomavirus (HPV) have a higher morbidity rate.Aims:To explore the effects of ETS-like transcription factor 4 (ELK4) in patients with HPV+ CC.Study design:In vitro cell lines and human-sample study.Methods:The ELK4 levels in human tissue (65 HPV+ CC tissue and 25 HPV− normal cervical tissue) and cell lines (human cervical epithelial immortalized cell line H8 and CC cell lines HeLa [HPV18], CaSki [HPV16], and SiHa [HPV−]) were quantified using qRT-PCR and western blot assay. ELK4 knockdown transfection was effective and confirmed by western blotting. The MTT and EDU assays were used to evaluate cell viability and proliferation, respectively. Flow cytometry was used to detect the CC cell cycle stage. Stem cell markers, such as cluster of differentiation 133 (CD133), CD44, and aldehyde dehydrogenase 1, and the cervicospheres formed were measured. ChIP-qPCR and luciferase activity experiments were used to assess the bond between ELK4 and F-box protein 22 (FBXO22).Results:ELK4 was highly expressed in the HPV+ CC tissue. CC cells with ELK4 knockdown had lower viability and proliferation than the control cells. ELK4 knockdown blocked the progression of the cell cycle from G1 to S phase. ELK4 knockdown suppressed the stem cell-like characteristics of the HPV+ CC cells. ELK4 bonded with the FBXO22 promoter, inhibiting the levels of phosphatase and tensin homolog (PTEN).Conclusion:ELK4 facilitated cell cycle progression and stem cell-like characteristics by regulating the FBXO22/PTEN axis. Thus, ELK4 could be a potential therapeutic target to arrest the progress of HPV-associated CC