12 research outputs found

    Classical Keggin intercalated into layered double hydroxides: facile preparation and catalytic efficiency in Knoevenagel condensation reaction

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    The family of polyoxometalate (POM) intercalated layered double hydroxides (LDHs) composite materials has shown great promise for the design of functional materials with numerous applications. It is known that intercalation of the classical Keggin polyoxometalate (POM) of [PW12O40]3- (PW12) into layered double hydroxides (LDHs) is very unlikely to take place by conventional ion exchange methods due to spatial and geometrical restrictions. In this paper, such intercalated compound of Mg0.73Al0.22(OH)2 [PW12O40]0.04•0.98H2O (Mg3Al-PW12) has been successfully obtained by adopting a spontaneous flocculation method. The Mg3Al-PW12 has been fully characterized using a wide range of methods (XRD, SEM, TEM, XPS, EDX, XPS, FT-IR, NMR, BET). XRD patterns of Mg3Al-PW12 exhibit no impurity phase usually observed next to the (003) diffraction peak. Subsequent application of the Mg3Al-PW12 as catalyst in Knoevenagel condensation reactions of various aldehydes and ketones with Z–CH2-Z‘ type substrates (ethyl-cyanoacetate and malononitrile) at 60 oC in mixed solvents (Vi-propanol:Vwater = 2 : 1) demonstrated highly efficient catalytic activity. The synergistic effect between the acidic and basic sites of the Mg3Al-PW12 composite proved to be crucial for the efficiency of the condensation reactions. Additionally, the Mg3Al-PW12 catalysed Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate demonstrated the highest turnover number (TON) of 47980 reported so far

    Tracking Objects as Pixel-wise Distributions

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    Multi-object tracking (MOT) requires detecting and associating objects through frames. Unlike tracking via detected bounding boxes or tracking objects as points, we propose tracking objects as pixel-wise distributions. We instantiate this idea on a transformer-based architecture, P3AFormer, with pixel-wise propagation, prediction, and association. P3AFormer propagates pixel-wise features guided by flow information to pass messages between frames. Furthermore, P3AFormer adopts a meta-architecture to produce multi-scale object feature maps. During inference, a pixel-wise association procedure is proposed to recover object connections through frames based on the pixel-wise prediction. P3AFormer yields 81.2\% in terms of MOTA on the MOT17 benchmark -- the first among all transformer networks to reach 80\% MOTA in literature. P3AFormer also outperforms state-of-the-arts on the MOT20 and KITTI benchmarks.Comment: Accepted in ECCV22 as an oral presentation paper. The code&project page is at https://github.com/dvlab-research/ECCV22-P3AFormer-Tracking-Objects-as-Pixel-wise-Distribution

    The change of intimate relationship between people with Alzheimer's disease and their adult child caregivers : An interpretative phenomenological analysis

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    This study aims to explore the change of intimate relationship between people with Alzheimer’s disease and their adult child caregivers as the disease progresses. Twelve adult child caregivers were recruited through purposive sampling. Explanatory phenomenological analysis was conducted to analyse data collected by semi-structured in-depth interviews. This study found a dynamically changing relationship between adult child caregivers and their parents with Alzheimer’s disease during care giving that evolved with the progress of the disease. The relationship was the most intimate in the middle stage of the disease for most caregivers and a new reciprocal relationship developed due to caregiving. Caregivers experienced different degrees of self-growth when providing care, though caregiver burdens were common. The positive experience and perception of caregivers were important for improving the quality of life for adult child caregivers of people with Alzheimer’s disease

    Influencing factors of psychological well-being of the non-designated hospital staff in China during the COVID-19 pandemic

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    Background: Recent studies report that hospital staff at the forefront of caring for COVID-19 patients experience increased psychological distress. To effectively manage the outbreak of COVID-19, China established COVID-19 designated and non-designated hospitals. To date, few studies have examined the impacts of COVID-19 on psychological health of staff working at non-designated hospitals. This study is to explore factors affecting psychological health of non-designated hospital staff in China during the COVID-19 pandemic. Methods: Data were collected through an online questionnaire between February and March 2020. The questionnaire consists of General Health Questionnaire (GHQ-20), Social Support Rating Scale (SSRS), Simplified Coping Style Questionnaire (SCSQ), sociodemographic characteristics, employment history, health status, and contact history of COVID-19. The questionnaire was distributed through hospital WeChat groups and work colleague referrals. A total of 470 non-designated hospital staff members completed the questionnaire. Multiple Linear Regression analysis was used to interpret the associations among social support, coping styles, sociodemographic factors, job roles, and psychological status. Data were analyzed using SPSS version 21.0.Results: The non-designated hospital staff differed significantly in anxiety and depression subscores of the GHQ-20 by their job roles, levels of social support, and history of mental disorders. Staff with medical job roles, good self-reported health status, no previous mental disorders, adequate social support, and positive coping styles scored lower in GHQ-20 total score, which indicated healthier psychological status. Conclusions: The results indicate that history of mental health disorders, non-medical job roles, and inadequate social support are associated with greater psychological distress. Personalized support should be provided to those who are vulnerable and in need of social and psychological support

    Cloning and Functional Characterization of Chalcone Isomerase Genes Involved in Anthocyanin Biosynthesis in Clivia miniata

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    Chalcone isomerase (CHI), catalyzing isomerization of chalcones, is a crucial enzyme in flavonoid biosynthesis. Three CHI genes were isolated from Clivia miniata and designated as CmCHI1, CmCHI2 and CmCHI3, respectively. Multiple sequence alignments and phylogenetic analysis showed that CmCHI1 and CmCHI2 were members of type I CHI proteins, whereas CmCHI3 belonged to type IV CHI proteins. Subcellular localization analysis found that all three CmCHIs had diffused distribution in the cytoplasm similar to green fluorescent protein (GFP). Anthocyanin biosynthesis and gene expression analysis demonstrated that CmCHIs were highly expressed in anthocyanin accumulated tissues. To further functionally characterize the role of CmCHIs, an in vitro enzymatic activity assay was carried out using the purified recombinant proteins. Results showed that CmCHI1 and CmCHI2 could completely convert the substrate naringenin chalcone (NC) into the product naringenin (NA), whereas CmCHI3 seemed nonfunctional as no increment of NA was detected. Further genetic transformation of Arabidopsis tt5-1 mutant validated that CmCHI1 and CmCHI2 rather than CmCHI3 could complement the chi deficient phenotypes. In summary, CmCHI1 and CmCHI2 are the real active CHI genes in Clivia miniata. The results not only broaden our knowledge on flavonoid biosynthesis in C. miniata but also lay a new foundation for further flavonoid modification in C. miniata

    Morphological, physiological and proteomic analyses provide insights into the improvement of castor bean productivity of a dwarf variety in comparing with a high-stalk variety

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    Ricinus communis displays a broad range of phenotypic diversity in size, with dwarf, common, and large-sized varieties. To better understand the differences in plant productivity between a high-stalk variety and a dwarf variety under normal growth conditions, we carried out a comparative proteomic study between Zhebi 100 (a high stalk variety) and Zhebi 26 (a dwarf variety) combined with agronomic and physiological analyses. Over 1000 proteins were detected, 38 of which differed significantly between the two varieties and were identified by mass spectrometry. Compared with Zhebi 100, we found that photosynthesis, energy, and protein biosynthesis related proteins decreased in abundance in Zhebi 26. The lower yield of the dwarf castor is likely related to its lower photosynthetic rate, therefore we hypothesize that the lower yield of the dwarf castor, in comparing to high stalk castor, could be increased by increasing planting density. Consequently, we demonstrated that at the higher planting density in Zhebi 26 (36,000 seedlings/hm²) can achieve a higher yield than that of Zhebi 100 (12,000 seedlings/hm²). Proteomic and physiological studies showed that for developing dwarf R. communis cultivar that is suitable for large scale-production (i.e. mechanical harvesting), it is imperative to identify the optimum planting density that will contribute to higher leaf area index, higher photosynthesis, and eventually higher productivity
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