129 research outputs found

    Aggregation‐induced emission luminogen: A new perspective in the photo‐degradation of organic pollutants

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    Both the variety and uniqueness of organic semiconductors has contributed to the rapid development of environmental engineering applications and renewable fuel production, typified by the photodegradation of organic pollutants or water splitting. This paper presents a rare example of an aggregation‐induced emission luminogen as a highly efficient photocatalyst for pollutant decomposition in an environmentally relevant application. Under irradiation, the tetraphenylethene‐based AIEgen (TPE‐Ca) exhibited high photo‐degradation efficiency of up to 98.7% of Rhodamine B (RhB) in aqueous solution. The possible photocatalytic mechanism was studied by electron paramagnetic resonance and X‐ray photoelectron spectroscopy spectra, electrochemistry, thermal imaging technology, ultra‐performance liquid chromatography and high‐definition mass spectrometry, as well as by density functional theory calculations. Among the many diverse AIEgens, this is the first AIEgen to be developed as a photocatalyst for the degradation of organic pollutants. This research will open up new avenues for AIEgens research, particularly for applications of environmental relevance

    Can integration reduce inequity in healthcare utilization?: evidence and hurdles in China

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    Background: Integration of medical insurance schemes has been prioritized as one of the key strategies to address inequity in China's health system. The first pilot attempt to integrate started in 2003 and later expanded nationwide. This study aims to assess its intended impact on inequity in inpatient service utilization and identify the main determinants contributing to ieffectiveness. Methods: A total of 49,365 respondents in the pilot integrated area and 77,165 respondents in the non-integration area were extracted from the Fifth National Health Services Survey. A comparative analysis was conducted between two types of areas. We calculate a concentration index (CI) and horizontal inequity index (HI) in inpatient service utilization and decompose the two indices. Results: Insurance integration played a positive role in reducing inequality in inpatient service utilization to some extent. A 13.23% lower in HI, a decrease in unmet inpatient care and financial barriers to inpatient care in the pilot integrated area compared with the non-integration area; decomposition analysis showed that the Urban-Rural Residents Basic Medical Insurance, a type of integrated insurance, contributed 37.49% to reducing inequality in inpatient service utilization. However, it still could not offset the strong negative effect of income and other insurance schemes that have increased inequality. Conclusions: The earlier pilot attempt for integrating medical insurance was not enough to counteract the influence of factors which increased the inequality in inpatient service utilization. Further efforts to address the inequality should focus on widening access to financing, upgrading the risk pool, reducing gaps within and between insurance schemes, and providing broader chronic disease benefit packages. Social policies that target the needs of the poor with coordinated efforts from various levels and agencies of the government are urgently needed

    Near-real-time monitoring of global CO₂ emissions reveals the effects of the COVID-19 pandemic

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    The COVID-19 pandemic is impacting human activities, and in turn energy use and carbon dioxide (CO₂) emissions. Here we present daily estimates of country-level CO2 emissions for different sectors based on near-real-time activity data. The key result is an abrupt 8.8% decrease in global CO₂ emissions (−1551 Mt CO₂) in the first half of 2020 compared to the same period in 2019. The magnitude of this decrease is larger than during previous economic downturns or World War II. The timing of emissions decreases corresponds to lockdown measures in each country. By July 1st, the pandemic’s effects on global emissions diminished as lockdown restrictions relaxed and some economic activities restarted, especially in China and several European countries, but substantial differences persist between countries, with continuing emission declines in the U.S. where coronavirus cases are still increasing substantially

    Climate change : strategies for mitigation and adaptation

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    The sustainability of life on Earth is under increasing threat due to humaninduced climate change. This perilous change in the Earth's climate is caused by increases in carbon dioxide and other greenhouse gases in the atmosphere, primarily due to emissions associated with burning fossil fuels. Over the next two to three decades, the effects of climate change, such as heatwaves, wildfires, droughts, storms, and floods, are expected to worsen, posing greater risks to human health and global stability. These trends call for the implementation of mitigation and adaptation strategies. Pollution and environmental degradation exacerbate existing problems and make people and nature more susceptible to the effects of climate change. In this review, we examine the current state of global climate change from different perspectives. We summarize evidence of climate change in Earth’s spheres, discuss emission pathways and drivers of climate change, and analyze the impact of climate change on environmental and human health. We also explore strategies for climate change mitigation and adaptation and highlight key challenges for reversing and adapting to global climate change

    Effect of Flammulina velutipes (golden needle mushroom, eno-kitake) polysaccharides on constipation

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    Flammulina velutipes, (Curt. ex Fr.) Sing, a popularly edible fungus, has been widely used both as a restorative drug and a tonic food in China. In the current study, the effect of F. velutipes polysaccharides was evaluated with a constipated rat model induced by loperamide hydrochloride. The rats were divided into six groups: normal group, model group, positive control group, F. velutipes polysaccharides high, moderate and low dose groups. Rats were given 2 mL of Loperamide hydrochloride (3 mg·kg·d), by intragastric administration 2 times per day for 10 days. F. velutipes polysaccharides at the doses of 600, 400 and 200 mg/kg (1 mL/100g weight) were administered to treat rats with constipation for 7 days. The gastrointestinal hormones, including motilin (MTL), gastrin (GAS), substance P (SP), somatostatin (SS), and intestinal propulsive rate and feces weight at 24 hours after treatment were used as the indexes to evaluate the effects of F. velutipes polysaccharides on constipation. The levels of MTL, GAS and SP in serum significantly increased and the levels of SS in serum of rats significantly decreased after the treatment of rats with F. velutipes polysaccharides as compared with those of rats in the model group

    Dynamic Changes of Secondary Metabolites and Antioxidant Activity of Ligustrum lucidum During Fruit Growth

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    There are a number of secondary metabolites having medicinal values in Ligustri Lucidi Fructus. In this study, the target analytes salidroside, ligustroflavone, specnuezhenide, oleuropein, oleanolic acid and ursolic acid were chosen, aiming to establish a method to investigate the content of six compounds during eight growth stages of Ligustri Lucidi Fructus. Even though the results indicated that the contents of six compounds in different growth periods reached their maximum value, they displayed a downward trend. The antioxidant activity of the analyzed samples also decreased along with the growth period. The relationship between the content of six secondary metabolites and the activity has been elucidated. Hence, this research provides a theoretical basis for guiding efficient use of Ligustri Lucidi Fructus

    Screening the Marker Components in <i>Psoralea corylifolia</i> L. with the Aids of Spectrum-Effect Relationship and Component Knock-Out by UPLC-MS<sup>2</sup>

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    Psoralea corylifolia L., (P. corylifolia), which is used for treating vitiligo in clinic, shows inhibitory and activating effects on tyrosinase, a rate-limiting enzyme of melanogenesis. This study aimed to determine the active ingredients in the ethenal extracts of P. corylifolia on tyrosinase activity. The spectrum-effect relationship and knock-out method were established to predict the active compounds. Their structures were then identified with the high resolution mass spectra. A high performance liquid chromatography method was established to obtain the specific chromatograms. Tyrosinase activity in vitro was assayed by the method of oxidation rate of levodopa. Partial least squares method was used to test the spectrum-effect relationships. Chromatographic peaks P2, P4, P9, P10, P11, P13, P21, P26, P28, and P30 were positively related to the activating effects on tyrosinase activity in PE, whereas chromatographic peaks P1, P3, P6, P14, P16, P19, P22, and P29 were negatively related to the activating effects on tyrosinase in the P. corylifolia (PEs). When the sample concentration was 0.5 g&#183;mL&#8722;1, equal to the amount of raw medicinal herbs, the target components were daidzein (P2), psoralen (P5), neobavaisoflavone (P13), and psoralidin (P20), which were consistent with the results of spectrum-effect relationships

    Redox Properties of Tryptophan Metabolism and the Concept of Tryptophan Use in Pregnancy

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    During pregnancy, tryptophan (Trp) is required for several purposes, and Trp metabolism varies over time in the mother and fetus. Increased oxidative stress (OS) with high metabolic, energy and oxygen demands during normal pregnancy or in pregnancy-associated disorders has been reported. Taking the antioxidant properties of Trp and its metabolites into consideration, we made four hypotheses. First, the use of Trp and its metabolites is optional based on their antioxidant properties during pregnancy. Second, dynamic Trp metabolism is an accommodation mechanism in response to OS. Third, regulation of Trp metabolism could be used to control/attenuate OS according to variations in Trp metabolism during pregnancy. Fourth, OS-mediated injury could be alleviated by regulation of Trp metabolism in pregnancy-associated disorders. Future studies in normal/abnormal pregnancies and in associated disorders should include measurements of free Trp, total Trp, Trp metabolites, and activities of Trp-degrading enzymes in plasma. Abnormal pregnancies and some associated disorders may be associated with disordered Trp metabolism related to OS. Mounting evidence suggests that the investigation of the use of Trp and its metabolites in pregnancy will be meanful

    Cascade C‒H-Activated Polyannulations toward Ring-Fused Heteroaromatic Polymers for Intracellular pH Mapping and Cancer Cell Killing

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    The development of straightforward and efficient synthetic methods toward ring-fused heteroaromatic polymers with attractive functionalities has great significance in both chemistry and materials science. Herein, we develop a facile cascade C-H-activated polyannulation route that can in situ generate multiple ring-fused aza-heteroaromatic polymers from readily available monomers in an atom-economical manner. A series of complex polybenzimidazole derivatives with high absolute molecular weights of up to 24000 are efficiently produced in high yields within 2 hours. Benefiting from their unique imidazole-containing ring-fused structures with multiple aryl pendants, the obtained polymers show excellent thermal and morphological stability, good solution processability, high refractive index, small chromic dispersion, as well as remarkable acid-base-responsive fluorescence. Taking advantage of the ratiometric fluorescence response of the triphenylamine-substituted heteroaromatic polymer to pH variations, we successfully apply it as a sensitive fluorescence probe for the mapping and quantitative analysis of intracellular pH changes in live cells. Furthermore, through the simple N-methylation reaction of the ring-fused polybenzimidazoles, diverse azonia-containing polyelectrolytes are readily produced, which can efficiently kill cancer cells via the synergistic effects of dark toxicity and photo-toxicity
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