Gradual Generalization of Nautical Chart Contours with a Cube B-Spline Snake Model

—B-spline snake methods have been used in cartographic generalization in the past decade, particularly in the generalization of navigational charts where this method yields good results with respect to the shoal-bias rules for generalization of chart contours. However, previous studies only show generalization results at particular generalization (or scale) levels, and the user can only see two conditions: before the generalization and after generalization, but nothing in between. This paper presents an improved method of using B-spline snakes for generalization in the context of nautical charts, where the generalization process is done gradually, and the user can see the complete process of the generalization

Bottom-up photochemical synthesis of structurally defined graphene nanoribbons and conjugated Polymers

Le graphène peut être considéré comme l'un des matériaux les plus prometteurs pour les composants électroniques pratiques en raison de ses excellentes propriétés de transport de charge, de sa surface spécifique très élevée, de sa conductivité thermique excellente et de sa grande résistance mécanique. Cependant, ce graphène bidimensionnel est un semiconducteur à bande interdite nulle, ce qui limite son application pratique dans les dispositifs électroniques. L'une des méthodes les plus prometteuses pour ouvrir une bande interdite est le confinement structurel du graphène en bandes étroites, définies comme des nanorubans de graphène (GNR). La bande interdite des GNR peut être contrôlée avec précision par la largeur et la configuration des bords, ce qui donne aux GNR des propriétés optiques et électroniques réglables. La synthèse ascendante en solution est l’une des stratégies les plus prometteuses pour préparer des GNR structurellement bien définis avec des propriétés optiques et électroniques ajustables. Contrairement aux méthodes descendantes, la stratégie ascendante permet un contrôle précis de la largeur et de la configuration des bords des GNR. Une stratégie couramment utilisée, la réaction de cyclodéshydrogénation catalysée par l'acide de Lewis, appelée réaction de Scholl, a été largement utilisée pour synthétiser une grande variété de GNR bien définis sur des précurseurs de polyphénylène. Cependant, la réaction de Scholl présente de sérieux inconvénients qui limitent la portée et la polyvalence de cette réaction. Le premier est sa faible régiosélectivité qui entraîne des défauts de structure et affecte les propriétés des GNR. Ensuite, les réarrangements indésirables et l'utilisation d'un catalyseur métallique peuvent conduire à la formation de sous-produits. De plus, l'introduction de groupes fonctionnels sensibles aux oxydants et d'hétérocycles riches en électrons est difficile à réaliser en raison des conditions de réaction difficiles, qui limitent la diversité des propriétés structurelles et électroniques des GNR. Notre groupe a récemment développé une synthèse de nanographènes et de GNR à l'aide de la réaction de cyclodéhydrochloration photochimique (CDHC) sur des précurseurs de polyphénylène polychlorés. La réaction CDHC possède une haute régiosélectivité et se déroule sans réarrangement ni formation de sous-produits. De plus, la réaction CDHC est conduite sans catalyseur métallique ni oxydant dans des conditions très douces, permettant ainsi l’introduction de différents groupes fonctionnels et hétérocycles sur le GNR afin de moduler leurs propriétés optoélectroniques. En comparant avec la réaction de Scholl, la réaction CDHC permet de mieux contrôler les configuration de bord des GNR. Cette thèse présente en détail l'utilisation de la réaction CDHC pour la préparation de GNR et étudie avec soin les propriétés structurelles et optoélectroniques des GNR produits. Tout d'abord, les GNR asymétriques et latéralement symétriques ont été préparés pour démontrer la régiosélectivité, le contrôle des configuration de bord et l'efficacité de la réaction photochimique CDHC. Ensuite, les GNR à bord thiophène ont été synthétisés pour montrer la polyvalence de la réaction CDHC et étudier l'influence de l'introduction de groupes fonctionnels riches en électrons sur les structures et les propriétés optoélectroniques des GNR. Ensuite, les polymères échelle conjugués (CLP) contenant des unités pyrrole riches en électrons ont été synthétisés pour montrer la compatibilité de la réaction du CDHC avec des groupes fonctionnels très riches en électrons et le rendement élevé de la réaction du CDHC. Enfin, divers dérivés d'ullazine fusionnés avec des hétérocycles riches en électrons ou pauvres en électrons ont été préparés et une série de polymères donneurs-accepteurs conjugués (D-A CP) ont été synthétisés et ces polymères ont été utilisés avec succès dans les cellules solaires à polymères et ont présenté des performances très prometteuse, indiquant l’efficacité, la polyvalence et le caractère pratique de la réaction photochimique CDHCGraphene is considered as one of the most promising materials for practical electronic components because of its outstanding charge transport properties, very high specific surface area, excellent thermal conductivity, and high mechanical strength. However, this two dimensional graphene is a zero band gap semiconductor, which limits its practical application in electronic devices. One of the most promising methods to open a band gap is the structural confinement of graphene into narrow strips, which is defined as graphene nanoribbons (GNRs). The band gap of GNRs can be precisely controlled by the width and edge configuration, providing GNRs with tunable optical and electronic properties. Bottom-up, solution-phase synthesis is one of the most promising strategies to prepare structurally well-defined GNRs with tunable optical and electronic properties. Unlike the top-down methods, the bottom-up strategy allows a precise control over the width and edge configuration of GNRs. One of the most commonly used strategy, the Lewis acid catalyzed cyclodehydrogenation reaction, known as the Scholl reaction, has been widely used to synthesize a large variety of well-defined GNRs on polyphenylene precursors. However, the Scholl reaction possesses some serious drawbacks that limit the scope and versatility of this reaction. First is its poor regioselectivity that results in structural defects to affect the properties of GNRs. Then the undesired rearrangements and the use of a metal catalyst can lead to the formation of by-products. Moreover, the introduction of oxidant-sensitive functional groups and electron-rich heterocycles is difficult to achieve due to the harsh reaction conditions, which limits the diversity of structural and electronic properties of GNRs. Recently, our group reported the synthesis of nanographenes and GNRs using the photochemical cyclodehydrochlorination (CDHC) reaction on polychlorinated polyphenylene precursors. The CDHC reaction possesses high regioselectivity and it proceeds without rearrangements or the formation of side-products. Furthermore, the CDHC reaction is conducted without metal catalyst and oxidant under very mild conditions, thus enabling the introduction of different functional groups and heterocycles onto the GNRS to modulate their optoelectronic properties. And comparing with the Scholl reaction, the CDHC reaction provides better cont rol over the edge configuration of the GNRs. This paper investigates in detail the usefulness of the CDHC reaction for the preparation of GNRs and carefully studies the structur al and optoelectronic properties of the GNRs produced. First the laterally symmetrical and unsymmetrical GNRs were prepared to demonstrate the regioselectivity edge configuration control, and efficiency of the photochemical CDHC reaction. Then the thiophene edged GNRs were synthesized to show the versatility of the CDHC reaction and study the i nfluence of the introduction of electron rich functional groups on the structures and optoelectronic properties of GNRs. Then, the conjugated ladder polymers (CLPs) containing electron rich pyrrole units were synthesized to show the compatibility of the CDHC reaction with very electron rich functional groups and the high efficiency of the CDHC reaction. Finally various extended ullazine derivatives fused with electron rich or electron poor heterocycles were prepared and a series of conjugated donor acceptor polymers (D A CPs) were synthesized and these polymers were successfully employed in the polymer solar cells and exhibited very promising performances, indicating the efficiency, versatility and practicality of the photochemical CDHC reactio

Gradual Generalization of Nautical Chart Contours with a B-Spline Snake Method

B-spline snake methods have been used in cartographic generalization in the past decade, particularly in the generalization of nautical charts where these methods yield good results with respect to the shoal-bias rules for the generalization of chart contours. However, previous studies only show generalization results at particular generalization (or scale) levels, and show only two states of the algorithm: before and after generalization, but nothing in between. This thesis presents an improved method of using B-spline snakes and other auxiliary functions and workflows for generalization in the context of nautical charts which can generalize multiple nautical chart features from large scale to small scale without creating any invalid intermediate features that require special processing to resolve. This process allows users to generate charts at any intermediate scale without cartographic irregularities, and is capable of extension to include more specialized generalization operators

Photochemical synthesis of p-extended ullazine derivatives as new electron donor for efficient conjugated D–A polymers

We report the synthesis of π-extended ullazine derivatives annulated with either electron-poor pyridine or electron-rich thiophene units through a metal-free, photochemical cyclodehydrochlorination (CDHC) reaction. The strongest electron-donor derivative, 7-tetradecylthieno[3′,2′:7,8]indolizino[6,5,4,3-ija]thieno[2,3-c]quinolone, was copolymerized with electron-deficient thienopyrroledione (TPD), isoindigo (IID), and diketopyrrolopyrrole (DPP) derivatives to provide three donor–acceptor conjugated polymers (D–A CPs). Their photophysical, electrochemical and photovoltaic (PV) properties were investigated. The polymers showed broad UV-vis-NIR absorption bands with λmax values of 612 nm, 698 nm, 788 nm in chloroform and exhibited optical bandgap (Eoptg) of 1.58 eV, 1.41 eV, 1.24 eV measured as films. Inverted bulk heterojunction polymer solar cells (BHJ-PSCs) were fabricated using these polymers as host and light-harvesting materials. The device based on P3:PC70BM blends shows the best power conversion efficiency (PCE) of 2.23% (Voc = 0.55 V, Jsc = 7.86 mA cm−2, FF = 52%). These promising results demonstrate that π-extended ullazine derivatives can be used as electron-rich building blocks for the construction of D–A CPs for efficient PSCs applications

Unblinding at disease progression in double-blinded randomized controlled cancer drug clinical trials: A controversy requires more attention

Unblinding at disease progression in double-blinded randomized controlled cancer drug clinical trials is ethical to the patient by ensuring optimal subsequent treatment, but the effect of study treatment on overall survival may be confounded. The views of science and ethics in this issue are controversial and the unblinding procedures should be well-designed. In real world settings, a lack of use of this unblinding process in protocol was observed in the analysis of 134 double-blind randomized controlled anticancer drug clinical trials conducted in China from 2018 to 2021. Unblinding at disease progression was allowed in only 26 (18.2%) trials. Among them, Only 9 (34.6%) trials involved patient-level unblinding. None of the 134 included trials accounted for the risk of blind-maintenance after disease progression. Based on the analysis and case studies, we believe that unblinding at disease progression should be stated in the protocol when the treatment assignment directly affected the choice of subsequent regimen, in which the drug category, control group design, standard of care of further-line therapy and primary endpoint together play a role. When unblinding at disease progression is adopted, the sensitivity analytics are recommended to understand the true effect of study drug on overall survival. The notification of treatment allocation after unblinding and the informed consent also require attention. A decision-making framework is established to help understand this controversy, which should be carefully discussed by the investigator and the sponsor

The impact of the 2016 flood event in Anhui Province, China on infectious diarrhea disease: An interrupted time-series study.

Climate change may bring more frequent and severe floods which will heighten public health problems, including an increased risk of infectious diarrhea in susceptible populations. Affected by heavy rainfall and an El Niño event, a destructive flood occurred in Anhui province, China on 18th June 2016. This study investigates the impact of this severe flood on infectious diarrhea at both city-level and provincial level, and further to identify modifying factor. We obtained information on infectious diarrheal cases during 2013-2017 from the National Disease Surveillance System. An interrupted time-series design was used to estimate effects of the flood event on diarrhea in 16 cities. Then we applied a meta-analysis to estimate the area-level pooled effects of the flood in both flooded areas and non-flooded areas. Finally, a meta-regression was applied to determine whether proximity to flood was a predictor of city-level risks. Stratified analyses by gender and age group were also conducted for flooded areas. A significant increase in infectious diarrhea risk (RR = 1.11, 95% CI: 1.01, 1.23) after the flood event was found in flooded area with variation in risks across cities, while there was no increase in non-flooded areas. Diarrheal risks post-flood was progressively higher in cities with greater proximity to the Yangtze River. Children aged 5-14 were at highest risk of diarrhea post-flood in the flooded areas. Our study provides strong evidence that the 2016 severe flood significantly increased infectious diarrheal risk in exposed populations. Local public health agencies are advised to develop intervention programs to prevent and control infectious diarrhea risk when a major flood occurs, especially in areas close to water bodies and among vulnerable populations

GPX8 regulates pan-apoptosis in gliomas to promote microglial migration and mediate immunotherapy responses

IntroductionGliomas have emerged as the predominant brain tumor type in recent decades, yet the exploration of non-apoptotic cell death regulated by the pan-optosome complex, known as pan-apoptosis, remains largely unexplored in this context. This study aims to illuminate the molecular properties of pan-apoptosis-related genes in glioma patients, classifying them and developing a signature using machine learning techniques.MethodsThe prognostic significance, mutation features, immunological characteristics, and pharmaceutical prediction performance of this signature were comprehensively investigated. Furthermore, GPX8, a gene of interest, was extensively examined for its prognostic value, immunological characteristics, medication prediction performance, and immunotherapy prediction potential. ResultsExperimental techniques such as CCK-8, Transwell, and EdU investigations revealed that GPX8 acts as a tumor accelerator in gliomas. At the single-cell RNA sequencing level, GPX8 appeared to facilitate cell contact between tumor cells and macrophages, potentially enhancing microglial migration. ConclusionsThe incorporation of pan-apoptosis-related features shows promising potential for clinical applications in predicting tumor progression and advancing immunotherapeutic strategies. However, further in vitro and in vivo investigations are necessary to validate the tumorigenic and immunogenic processes associated with GPX8 in gliomas

A heterozygous moth genome provides insights into herbivory and detoxification

How an insect evolves to become a successful herbivore is of profound biological and practical importance. Herbivores are often adapted to feed on a specific group of evolutionarily and biochemically related host plants1, but the genetic and molecular bases for adaptation to plant defense compounds remain poorly understood2. We report the first whole-genome sequence of a basal lepidopteran species, Plutella xylostella, which contains 18,071 protein-coding and 1,412 unique genes with an expansion of gene families associated with perception and the detoxification of plant defense compounds. A recent expansion of retrotransposons near detoxification-related genes and a wider system used in the metabolism of plant defense compounds are shown to also be involved in the development of insecticide resistance. This work shows the genetic and molecular bases for the evolutionary success of this worldwide herbivore and offers wider insights into insect adaptation to plant feeding, as well as opening avenues for more sustainable pest management.Minsheng You … Simon W Baxter … et al

Effect of Y-TZP addition on the microstructure and properties of titania-based composites

To maintain the bioactivity and improve the mechanical properties of titania, both pure titania ceramics and titania-yttria-stabilized tetragonal zirconia (Y-TZP) composites with 5, 10, and 15 vol% Y-TZP were prepared via a sol-gel precipitation method. A titania precursor (titanium butoxide) was mixed with a submicron-sized Y-TZP powder, followed by hydrolysis-condensation reactions, green compact forming, and sintering in air at 1200 degrees Celsius to 1350 degrees Celsius. It was found that the addition of Y-TZP resulted in reduced rutile titania grain size from 13 um to 3 um. The Y-TZP tetragonal phase also resulted in improved mechanical properties of the titania-Y-TZP composites. For instance, the titania-15vol%Y-TZP composite had a hardness value of 983 kg/mm2, a bending strength of 160 MPa, and a fracture toughness of 3.79 MPa.m0.5. While the addition of Y-TZP increased the mechanical properties, it also decreased the bioactivity of the composites

Research on fault detection of belt conveyor drum based on improved YOLOv5s

At present, the detection efficiency of belt conveyor drum fault detection methods is low, the recognition accuracy is not high, and the feature extraction capability is poor. In order to solve the above problems, a belt conveyor drum fault detection method based on improved YOLOv5s is proposed. A small-sized detection layer has been added to the YOLOv5s network model, making it easier to detect smaller drum faults. The method introduces the convolutional block attention module (CBAM) between the Backbone and Neck to improve the accuracy of target detection. The method introduces efficient channel attention mechanism (ECA) in Neck to enhance feature extraction capabilities for drum faults. The experimental results show the following points. ① On the premise of meeting the real-time detection requirements, the average recognition accuracy of the improved YOLOv5s network model reaches 94.46%, which is 1.65% higher than before the improvement. ② The average accuracy of the improved YOLOv5s network model for detecting drum opening, rubber coating wear, and rubber coating detachment are 95.29%, 96.43%, and 91.65%, respectively, which are 1.56%, 0.89%, and 2.50% higher than before the improvement. A belt conveyor drum fault detection system based on improved YOLOv5s is designed and validated. ① The experimental platform test results show that the average accuracy of the belt conveyor drum fault detection system based on improved YOLOv5s for drum welding, rubber coating wear, and rubber coating detachment detection reach 95.29%, 96.43%, and 91.65%, respectively. The average accuracy of the three types of faults reaches 94.46%, and the detection speed is about 14 frames/s. ② The on-site test results show that the confidence levels for rubber coating wear and rubber coating detachment are 0.92 and 0.97, respectively. The fault type and location of the drum can be accurately identified. This indicates that the improved YOLOv5s-based belt conveyor drum fault detection system is feasible