32 research outputs found

    Novel photobase generators for photoinduced polymerization and pH regulation

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    Photochemistry encompasses the investigation of chemical processes instigated by light absorption. As important branches of photochemistry, photosensitive and optical materials have attracted extensive research interests in both academia and industry. Photosensitive and optical materials are composed of polymers / small molecules with photo-responsive properties. These materials not only can absorb light in the desired energy spectrum, but also exhibit chemical / physical reactions, which can be applied to different fields such as photoredox, photo-heat, phototherapy, solar cells, diodes, etc. Among them, photobase generators (PBGs) are a series of photosensitive compounds, which absorb the incident light, then release the basic species that can trigger the consequent reactions such as thiol-Michael reaction and ring-opening polymerization reactions. Boron-dipyrromethene (BODIPY)-based chromophores have emerged as highly intriguing moieties within the realm of chromophores. The prominence is attributed to its remarkable properties, including a high fluorescent quantum yield, pronounced chemical stability, and minimal Stokes shift. The core structures of BODIPY have been subject to thorough investigations and refinements, resulting in the development of a spectrum of BODIPY derivatives that find applications within the domain of chemical synthesis and biological science. In this work, three projects about BODIPY-based photobase generators are included with demonstration and discussion of their bio-applications. Firstly, BODIPY based PBGs are synthesized and the photochemical/photophysical properties are characterized. Secondly, the applications of BODIPY based PBGs in photoinduced thiol Michael reaction and ring-opening reaction are explored. Thirdly, the feasibility of using PBGs in lysosome pH regulation light is demonstrated and the potential usage in cancer therapy is discussed

    Potential role of macrophage migration inhibitory factor in the pathogenesis of Marek’s disease

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    Marek’s disease virus (MDV) can cause malignant T-cell lymphomas and immunosuppression in chickens. Macrophage migration inhibitory factor (MIF) not only plays a critical role in inhibiting T-cell responses, but also contributes to multiple aspects of tumour progression. The aim of this study was to reveal the potential role of MIF in the pathogenesis of MDV infection

    Prognostic and clinicopathological value of Beclin-1 expression in hepatocellular carcinoma: a meta-analysis

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    Abstract Background The abnormal expression of Beclin-1 has recently been investigated in a variety of tumors. However, previous studies have obtained contradicting results regarding the clinical and prognostic value of Beclin-1 in hepatocellular carcinoma (HCC). We performed a meta-analysis to clarify the prognostic value of Beclin-1 and its correlations with clinical pathological parameters in HCC. Methods Relevant studies were systematically retrieved from PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), Wan Fang and Chinese VIP databases. We used the Newcastle-Ottawa scale (NOS) to estimate the quality of the involved studies. Results Ten eligible studies with 1086 HCC patients were included in this study. Our results showed that decreased Beclin-1 expression in HCC related to histological grade [poor-undifferentiated vs. well-moderate: odds ratio (OR) = 2.34, 95% confidence interval (CI) = 1.65–3.32, P < 0.00001]. The pooled hazard ratio (HR) (HR = 1.43, 95% CI = 1.17–1.75, P = 0.0004) indicated that decreased Beclin-1 expression correlated with poor overall survival (OS). Conclusions This meta-analysis indicated that decreased Beclin-1 expression might relate to poor differentiation and unfavorable outcome in HCC

    Spatial and Seasonal Characteristics of Air Pollution Spillover in China

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    Air pollution spillover can cause air pollution to negatively affect neighboring regions. The structure of air pollution spillover varies with changes in season and space. Researching the spatial and seasonal characteristics of air pollution spillover is beneficial for determining air pollution prevention and control policies. First, this paper uses the GARCH-BEKK model to correlate the air pollution spillover among cities. Second, a complex network is constructed, and cities that have stronger spillover correlations are grouped into the same region. Finally, motifs are analyzed regarding the spillover relationships among regions. This paper also compares the structure of air pollution spillover during various seasons. This study determines that every season has a core region where the air pollution spillover exits the region. The core region in the spring is western East China, in the summer it is northern East China, in the autumn it is northern East China, and in the winter it is northern North China. These regions interact with most other regions. Furthermore, in spring and winter, the phenomena of air pollution spillover between regions are stronger than those in summer and autumn. We can weaken the air pollution spillover by controlling the air pollution in core regions

    Prediction of phosphate concentrate grade based on artificial neural network modeling

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    In order to determine the grade of phosphate concentrate rapidly and accurately on-line, first, the surface color parameters of primary ore, concentrated and tailing of phosphate rock was collected and extracted based on a self-designing surface color acquisition device. Then these parameters were modeled by artificial neural network. The results showed that the 5-12-1 BP model established by artificial neural network could achieve better prediction results with error less than 5%, which provided theoretical support for realizing the on-line soft measurement of flotation concentrate grade. Keywords: Artificial neural network, Phosphate concentrate, Grade prediction, Color senso

    Rapid and Quantitative Determination of Soil Water-Soluble Nitrogen Based on Surface-Enhanced Raman Spectroscopy Analysis

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    An accurate and rapid determination of soil water-soluble nitrogen is conducive to scientific fertilization in precision agriculture. Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive fingerprint with the advantages of simple operation and high detection efficiency. In this paper, partial least squares (PLS), principal components analysis (PCA), and least squares supports vector machine (LS-SVM) were applied to analyze the relationship between soil water-soluble nitrogen concentration and SERS. The results showed that the SERS-enhancing effect based on Opto Trace Raman 202 (OTR 202) was better than that of silver nanosubstrate and gold nanosubstrate. In addition, the prediction accuracy of soil water-soluble nitrogen in PLS was the highest ( R p 2 = 0.91 , &nbsp; RMSE p = 8.76 &nbsp; mg / L , R P D = 3.00 ) when the original spectra were preprocessed with first-derivative. Moreover, 1028, 1370, 1436, and 1636 cm&minus;1 could be determined as characteristic peaks of soil water-soluble nitrogen, the association between soil water-soluble nitrogen concentration and a SERS intensity of 1370 cm&minus;1 was the highest &nbsp; ( R p 2 = 0.94 ) , and the regression equation was y = 93.491x + 1771.5. Beyond that, the prediction accuracy of distinguishing between a low soil water-soluble nitrogen concentration (22.7&ndash;63.7 mg/L) and a high soil water-soluble nitrogen concentration (70.5&ndash;118.3 mg/L) based on PCA and LS-LVM was 86.67%. In conclusion, soil water-soluble nitrogen could be detected rapidly and quantitatively using SERS, which was beneficial to provide a rapid, accurate, and reliable scheme for scientific and precise fertilization

    miR-4443 promotes radiation resistance of esophageal squamous cell carcinoma via targeting PTPRJ

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    Abstract Background Radiotherapy is one of the main treatments for esophageal squamous cell carcinoma (ESCC), but its efficacy is limited by radioresistance. MicroRNAs play a crucial role in posttranscriptional regulation, which is linked to the cancer response to radiation. Methods We successfully established a radioresistant cell line model by using fractionated irradiation. qRT-PCR was adopted to detect the expression of miR-4443 in human normal esophageal cell lines, tumor cells, and radioresistant cells. Next, CCK-8, colony formation, apoptosis, and cell cycle assays were used to assess the biological effect of miR-4443. Weighted gene coexpression network analysis (WGCNA) was performed to identify potential radiosensitivity-related genes. Additionally, we predicted the probable targets of the miRNA using bioinformatic methods and confirmed them using Western blot. Results miR-4443 was significantly upregulated in radioresistant ESCC cells. Enhancement of miR-4443 further decreased the radiosensitivity of ESCC cells, while inhibition of miR-4443 increased the radiosensitivity of ESCC cells. Notably, miR-4443 modulated radiosensitivity by influencing DNA damage repair, apoptosis, and G2 cycle arrest. By using WGCNA and experimental validation, we identified PTPRJ as a key target for miRNA-4443 to regulate radiosensitivity. The effects of miR-4443 overexpression or inhibition could be reversed by increasing or decreasing PTPRJ expression. Conclusion In this study, miR-4443 is found to promote radiotherapy resistance in ESCC cells by regulating PTPRJ expression, which provides a new perspective and clue to alleviate radioresistance

    Association between the traditional Chinese medicine constitution and metabolic dysfunction-associated fatty liver disease in older people: A cross-sectional study

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    Background: Few studies have focused on the relationship between the traditional Chinese medicine constitution (TCMC) and metabolic dysfunction-associated fatty liver disease (MAFLD) in older populations. We sought to investigate the distribution of MAFLD and the TCMC in older people, and provide a theoretical basis for TCMC-based management of MAFLD in this population. Methods: A cross-sectional study was conducted among older (≥65 years) individuals in Zhongshan, China. Information on common sociodemographic characteristics, medical history, anthropometric measurements, and the TCMC was collected. The chi-square test, multivariable logistic regression analysis, subgroup analysis, and inverse probability weighting of the propensity score were used to explore the relationship between MAFLD and the TCMC. Results: Of 7085 participants, 1408 (19.9 %) had MAFLD. The three most common TCMC types in MAFLD patients were “phlegm-dampness”, “gentleness”, and “yin-deficiency”. After adjustment for gender, age, tobacco smoking, alcohol consumption, body mass index, abnormal waist-to-hip ratio, hypertension, diabetes mellitus, and dyslipidemia, MAFLD was positively associated with the phlegm-dampness constitution (PDC) (ORadjusted (95 % CI) = 1.776 (1.496–2.108), P < 0.001), and negatively correlated with the qi-depression constitution (0.643 (0.481–0.860), 0.003). A stronger correlation between the PDC and MAFLD was observed in men compared with women (ORadjusted = 2.04 (95%CI = 1.47–2.84) vs. 1.70 (95%CI = 1.39–2.08), Pinteraction = 0.003) as well as between people who smoked tobacco and non-tobacco-smoking individuals (2.11 (1.39–3.21) vs. 1.75 (1.45–2.12), 0.006). Conclusions: A positive relationship was observed between MAFLD and the PDC in older people living in Zhongshan. Early detection and treatment of the PDC (especially in men and smokers) could prevent the occurrence and development of MAFLD

    Efficient Synthesis of 3-<i>R</i>-Boc-amino-4-(2,4,5-trifluorophenyl)butyric Acid

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    <div><p></p><p>3-<i>R</i>-Boc-amino-4-(2,4,5-trifluorophenyl)butyric acid (<b>9</b>) was obtained from <i>L</i>-methionine in six steps with a total yield of 32%. The α-amino acid segment of <i>L</i>-methionine was transferred to chiral aziridine by amino protection, reduction, hydroxyl derivation, and cyclization. After ring opening of 2,4,5-trifluoro-phenyl magnesium bromide, the methylthiomethyl group was then hydrolyzed to β-amino alcohol and oxidized to the target β-amino acid.</p></div
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