Displaying publications 61 - 80 of 309 in total

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  1. Adsorption and desorption characteristics of flavonoids from white tea using macroporous adsorption resin
    Yang Y, Liang Q, Zhang B, Zhang J, Fan L, Kang J, et al.
    J Chromatogr A, 2024 Jan 25;1715:464621.
    PMID: 38198876 DOI: 10.1016/j.chroma.2023.464621
    White tea contains the highest flavonoids compared to other teas. While there have been numerous studies on the components of different tea varieties, research explicitly focusing on the flavonoid content of white tea remains scarce, making the need for a good flavonoid purification process for white tea even more important. This study compared the adsorption and desorption performance of five types of macroporous resins: D101, HP20, HPD500, DM301, and AB-8. Among the tested resins, AB-8 was selected based on its best adsorption and desorption performance to investigate the static adsorption kinetics and dynamic adsorption-desorption purification of white tea flavonoids. The optimal purification process was determined: adsorption temperature 25 °C, crude tea flavonoid extract pH 3, ethanol concentration 80 %, sample loading flow rate and eluent flow rate 1.5 BV/min, and eluent dosage 40 BV. The results indicated that the adsorption process followed pseudo-second-order kinetics. Under the above purification conditions, the purity of the total flavonoids in the purified white tea flavonoid increased from approximately 17.69 to 46.23 %, achieving a 2.61-fold improvement, indicating good purification results. The purified white tea flavonoid can be further used for nutraceutical and pharmaceutical applications.
  2. Fulltext Exergy intensity and environmental consequences of the medical face masks curtailing the COVID-19 pandemic: Malign bodyguard?
    Tabatabaei M, Hosseinzadeh-Bandbafha H, Yang Y, Aghbashlo M, Lam SS, Montgomery H, et al.
    J Clean Prod, 2021 Sep 01;313:127880.
    PMID: 34131367 DOI: 10.1016/j.jclepro.2021.127880
    On January 30, 2020, the World Health Organization identified SARS-CoV-2 as a public health emergency of global concern. Accordingly, the demand for personal protective equipment (PPE), including medical face masks, has sharply risen compared with 2019. The new situation has led to a sharp increase in energy demand and the environmental impacts associated with these product systems. Hence, the pandemic's effects on the environmental consequences of various PPE types, such as medical face masks, should be assessed. In light of that, the current study aimed to identify the environmental hot-spots of medical face mask production and consumption by using life cycle assessment (LCA) and tried to provide solutions to mitigate the adverse impacts. Based on the results obtained, in 2020, medical face masks production using fossil-based plastics causes the loss of 2.03 × 103 disability-adjusted life years (DALYs); 1.63 × 108 PDF*m2*yr damage to ecosystem quality; the climate-damaging release of 2.13 × 109 kg CO2eq; and 5.65 × 1010 MJ damage to resources. Besides, annual medical face mask production results in 5.88 × 104 TJ demand for exergy. On the other hand, if used makes are not appropriately handled, they can lead to 4.99 × 105 Pt/yr additional damage to the environment in 2020 as determined by the EDIP 2003. Replacement of fossil-based plastics with bio-based plastics, at rates ranging from 10 to 100%, could mitigate the product's total yearly environmental damage by 4-43%, respectively. Our study calls attention to the environmental sustainability of PPE used to prevent virus transmission in the current and future pandemics.
  3. Fulltext Peginterferon alfa-2b in the treatment of Chinese patients with HBeAg-positive chronic hepatitis B: a randomized trial
    Cheng J, Wang Y, Hou J, Luo D, Xie Q, Ning Q, et al.
    J Clin Virol, 2014 Dec;61(4):509-16.
    PMID: 25200354 DOI: 10.1016/j.jcv.2014.08.008
    In mainland China, peginterferon (PEG-IFN) alfa-2b 1.0μg/kg/wk for 24 weeks is the approved treatment for HBeAg-positive chronic hepatitis B.
  4. Risk factors for lower extremity amputation among patients with diabetes in Singapore
    Yang Y, Østbye T, Tan SB, Abdul Salam ZH, Ong BC, Yang KS
    J Diabetes Complications, 2011 Nov-Dec;25(6):382-6.
    PMID: 21983153 DOI: 10.1016/j.jdiacomp.2011.08.002
    BACKGROUND:
    Among other risk factors, renal disease and ethnicity have been associated with diabetic lower extremity amputation (LEA) in Western populations. However, little is known about risk factors for LEA among Asian patients.

    OBJECTIVE:
    The objective was to assess the proportion of hospitalized patients with diabetes who have a LEA among all hospital patients with diabetes mellitus (DM) and to investigate risk factors for diabetic LEA (especially renal disease and ethnicity) using hospital discharge database.

    METHOD:
    A retrospective study of hospital discharge database (2004-2009) was performed to identify patients with DM, LEA and renal disease using the International Statistical Classification of Diseases and Related Health Problems, Ninth Revision, Australian Modification codes.

    RESULTS:
    Of 44 917 hospitalized patients with DM during the 6 years, 7312 (16.3%) patients had renal disease, and 1457 (3.2%) patients had LEA. DM patients with renal disease had significant higher rates of LEA (7.1%) compared to DM patients without renal disease (2.5%, P < .001). The differences were present for foot (2.7% vs. 1.2%), ankle or leg (2.8% vs. 0.9%), and knee or above amputation (1.6% vs. 0.4%, all P
  5. Chemistry and bioactivity of plants from the genus Amomum
    Cai R, Yue X, Wang Y, Yang Y, Sun D, Li H, et al.
    J Ethnopharmacol, 2021 Dec 05;281:114563.
    PMID: 34438033 DOI: 10.1016/j.jep.2021.114563
    ETHNOPHARMACOLOGICAL RELEVANCE: The genus Amomum belonging to the family Zingiberaceae, is mainly distributed in tropical regions of Asia and Oceania. Their fruits and seeds are valuable traditional medicine and used extensively, particularly in South China, India, Malaysia, and Vietnam. The genus Amomum has long been used for treating gastric diseases, digestive disorder, cancer, hepatopathy, malaria, etc. AIMS OF THE REVIEW: The main purpose of this review is to provide the available information on the traditional medicinal uses, phytochemistry, and pharmacology aspects of the genus Amomum in order to explore the trends and perspectives for further studies on its non-volatile constituents.

    MATERIALS AND METHODS: The present review collected the literatures published prior to 2020 on the traditional medicinal uses, phytochemistry, and pharmacology of the genus Amomum. The available literatures were extracted from scientific databases, such as Sci-finder, PubMed, Web of Science, Google Scholar, Baidu Scholar, and CNKI, books, and others.

    RESULTS: Herein, we summarize all 166 naturally occurring non-volatile compounds from 16 plants of the genus Amomum reported in 171 references, including flavonoids, terpenoids, diarylheptanoids, coumarins, etc. Triterpenes and flavonoids are the main constituents among these compounds and maybe play an important role in the activities directly or indirectly. As traditional medicine, the plants from the genus Amomum have been usually used in some traditional herbal prescriptions, and pharmacological researches in vitro and in vivo revealed that the extracts possessed significant antioxidant, anti-inflammatory, anti-allergic activities, etc. CONCLUSION: The review systematically summarizes current studies on traditional medicinal uses, phytochemistry, pharmacological activity on the plants from the genus Amomum. To date, the majority of publications still focused on the research of volatile constituents. However, the promising preliminary data of non-volatile constituents indicated the research potential of this genus in phytochemical and pharmacological aspects. Furthermore, the further in-depth investigations on the safety, efficacy, as well as the stereo-chemistry and structure-activity relationships of pure compounds from this genus are essential in the future.

  6. Asian consensus on the relationship between obesity and gastrointestinal and liver diseases
    Koh JC, Loo WM, Goh KL, Sugano K, Chan WK, Chiu WY, et al.
    J Gastroenterol Hepatol, 2016 Aug;31(8):1405-13.
    PMID: 27010240 DOI: 10.1111/jgh.13385
    The incidence of obesity is increasing in Asia, with implications on gastrointestinal (GI) and liver diseases. The Gut and Obesity in Asia Workgroup comprises regional experts with the aim of studying relationship between obesity and the GI and liver diseases in Asia. Through literature review and the modified Delphi process, consensus statements examining the impact of obesity on esophageal, gastric, pancreatic, colorectal, and liver diseases, exploring relationship between gut microbiome and obesity, and assessing obesity therapies have been produced by the Gut and Obesity in Asia Workgroup. Sixteen experts participated with 9/15 statements having strong consensus (>80% agreement). The prevalence of obesity in Asia is increasing (100% percentage agreement in brackets), and this increased prevalence of obesity will result in a greater burden of obesity-related GI and liver diseases (93.8%). There was consensus that obesity increases the risk of gastric cancer (75%) and colorectal neoplasia (87.5%). Obesity was also associated with Barrett's esophagus and esophageal adenocarcinoma (66.7%) and pancreatic cancer (66.7%) in Asia. The prevalence of non-alcoholic fatty liver disease (NAFLD) in Asia is on the rise (100%), and the risk of NAFLD in Asia (100%) is increased by obesity. Obesity is a risk factor for the development of hepatocellular carcinoma (93.8%). Regarding therapy, it was agreed that bariatric surgery was an effective treatment modality for obesity (93.8%) but there was less agreement on its benefit for NAFLD (62.5%). These experts' consensus on obesity and GI diseases in Asia forms the basis for further research, and its translation into addressing this emerging issue.
  7. Mitigation of indoor air pollution: A review of recent advances in adsorption materials and catalytic oxidation
    Yue X, Ma NL, Sonne C, Guan R, Lam SS, Van Le Q, et al.
    J Hazard Mater, 2021 03 05;405:124138.
    PMID: 33092884 DOI: 10.1016/j.jhazmat.2020.124138
    Indoor air pollution with toxic volatile organic compounds (VOCs) and fine particulate matter (PM2.5) is a threat to human health, causing cancer, leukemia, fetal malformation, and abortion. Therefore, the development of technologies to mitigate indoor air pollution is important to avoid adverse effects. Adsorption and photocatalytic oxidation are the current approaches for the removal of VOCs and PM2.5 with high efficiency. In this review we focus on the recent development of indoor air pollution mitigation materials based on adsorption and photocatalytic decomposition. First, we review on the primary indoor air pollutants including formaldehyde, benzene compounds, PM2.5, flame retardants, and plasticizer: Next, the recent advances in the use of adsorption materials including traditional biochar and MOF (metal-organic frameworks) as the new emerging porous materials for VOCs absorption is reviewed. We review the mechanism for mitigation of VOCs using biochar (noncarbonized organic matter partition and adsorption) and MOF together with parameters that affect indoor air pollution removal efficiency based on current mitigation approaches including the mitigation of VOCs using photocatalytic oxidation. Finally, we bring forward perspectives and directions for the development of indoor air mitigation technologies.
  8. Phytoremediation of radionuclides in soil, sediments and water
    Yan L, Le QV, Sonne C, Yang Y, Yang H, Gu H, et al.
    J Hazard Mater, 2021 04 05;407:124771.
    PMID: 33388721 DOI: 10.1016/j.jhazmat.2020.124771
    Soil and water contaminated with radionuclides threaten the environment and public health during leaks from nuclear power plants. Remediation of radionuclides at the contaminated sites uses mainly physical and chemical methods such as vitrification, chemical immobilization, electro-kinetic remediation and soil excavation, capping and washing being among the preferred methods. These traditional technologies are however costly and less suitable for dealing with large-area pollution. In contrast to this, cost-effective and environment-friendly alternatives such as phytoremediation using plants to remove radionuclides from polluted sites in situ represent promising alternatives for environmental cleanup. Understanding the physiology and molecular mechanisms of radionuclides accumulation in plants is essential to optimize and improve this new remediation technology. Here, we give an overview of radionuclide contamination in the environment and biochemical characteristics for uptake, transport, and compartmentation of radionuclides in plants that characterize phytoextraction and its efficiency. Phytoextraction is an eco-friendly and efficient method for environmental removal of radionuclides at contaminated sites such as mine tailings. Selecting the most proper plant for the specific purpose, however, is important to obtain the best result together with, for example, applying soil amendments such as citric acid. In addition, using genetic engineering and optimizing agronomic management practices including regulation of atmospheric CO2 concentration, reasonable measures of fertilization and rational water management are important as well. For future application, the technique needs commercialization in order to fully exploit the technique at mining activities and nuclear industries.
  9. A review on phytoremediation of contaminants in air, water and soil
    Wei Z, Van Le Q, Peng W, Yang Y, Yang H, Gu H, et al.
    J Hazard Mater, 2021 02 05;403:123658.
    PMID: 33264867 DOI: 10.1016/j.jhazmat.2020.123658
    There is a global need to use plants to restore the ecological environment. There is no systematic review of phytoremediation mechanisms and the parameters for environmental pollution. Here, we review this situation and describe the purification rate of different plants for different pollutants, as well as methods to improve the purification rate of plants. This is needed to promote the use of plants to restore the ecosystems and the environment. We found that plants mainly use their own metabolism including the interaction with microorganisms to repair their ecological environment. In the process of remediation, the purification factors of plants are affected by many conditions such as light intensity, stomatal conductance, temperature and microbial species. In addition the efficiency of phytoremediation is depending on the plants species-specific metabolism including air absorption and photosynthesis, diversity of soil microorganisms and heavy metal uptake. Although the use of nanomaterials and compost promote the restoration of plants to the environment, a high dose may have negative impacts on the plants. In order to improve the practicability of the phytoremediation on environmental restoration, further research is needed to study the effects of different kinds of catalysts on the efficiency of phytoremediation. Thus, the present review provides a recent update for development and applications of phytoremediation in different environments including air, water, and soil.
  10. Development of formaldehyde-free bio-board produced from mushroom mycelium and substrate waste
    Khoo SC, Peng WX, Yang Y, Ge SB, Soon CF, Ma NL, et al.
    J Hazard Mater, 2020 12 05;400:123296.
    PMID: 32947701 DOI: 10.1016/j.jhazmat.2020.123296
    Synthetic adhesives in the plywood industry are usually volatile compounds such as formaldehyde-based chemical which are costly and hazardous to health and the environment. This phenomenon promotes an interest in developing bio-boards without synthetic adhesives. This study proposed a novel application of natural mycelium produced during mushroom cultivation as natural bio-adhesive material that convert spent mushroom substrate (SMS) into high-performance bio-board material. Different types of spent mushroom substrates were compressed with specific designed mould with optimal temperature at 160 °C and 10 mPa for 20 min. The bio-board made from Ganoderma lucidum SMS had the highest internal bonding strength up to 2.51 mPa. This is far above the 0.4-0.8 range of China and US national standards. In addition, the material had high water and fire resistance, high bonding and densified structures despite free of any adhesive chemicals. These properties and the low cost one step procedure show the potential as a zero-waste economy chain for sustainable agricultural practice for waste and remediation.
  11. Pyrolysis of Aesculus chinensis Bunge Seed with Fe2O3/NiO as nanocatalysts for the production of bio-oil material
    Li Y, Shaheen SM, Rinklebe J, Ma NL, Yang Y, Ashraf MA, et al.
    J Hazard Mater, 2021 08 15;416:126012.
    PMID: 34492887 DOI: 10.1016/j.jhazmat.2021.126012
    The rapid thermal cracking technology of biomass can convert biomass into bio-oil and is beneficial for industrial applications. Agricultural and forestry wastes are important parts of China's energy, and their high-grade utilization is useful to solve the problem of energy shortages and environmental pollution. To the best of our knowledge, the impact of nanocatalysts on converting biowastes for bio-oil has not been studied. Consequently, we examined the production of bio-oil by pyrolysis of Aesculus chinensis Bunge Seed (ACBS) using nanocatalysts (Fe2O3 and NiO catalysts) for the first time. The pyrolysis products of ACBS include 1-hydroxy-2-propanone (3.97%), acetic acid (5.42%), and furfural (0.66%). These chemical components can be recovered for use as chemical feedstock in the form of bio-oil, thus indicating the potential of ACBS as a feedstock to be converted by pyrolysis to produce value-added bio-oil. The Fe2O3 and NiO catalysts enhanced the pyrolysis process, which accelerated the precipitation of gaseous products. The pyrolysis rates of the samples gradually increased at DTGmax, effectively promoting the catalytic cracking of ACBS, which is beneficial to the development and utilization of ACBS to produce high valorization products. Combining ACBS and nanocatalysts can change the development direction of high valorization agricultural and forestry wastes in the future.
  12. Omics technologies used in pesticide residue detection and mitigation in crop
    Goh MS, Lam SD, Yang Y, Naqiuddin M, Addis SNK, Yong WTL, et al.
    J Hazard Mater, 2021 10 15;420:126624.
    PMID: 34329083 DOI: 10.1016/j.jhazmat.2021.126624
    In agriculture, the convenience and efficacy of chemical pesticides have become inevitable to manage cultivated crop production. Here, we review the worldwide use of pesticides based on their categories, mode of actions and toxicity. Excessive use of pesticides may lead to hazardous pesticide residues in crops, causing adverse effects on human health and the environment. A wide range of high-tech-analytical methods are available to analyse pesticide residues. However, they are mostly time-consuming and inconvenient for on-site detection, calling for the development of biosensors that detect cellular changes in crops. Such new detection methods that combine biological and physicochemical knowledge may overcome the shortage in current farming to develop sustainable systems that support environmental and human health. This review also comprehensively compiles domestic pesticide residues removal tips from vegetables and fruits. Synthetic pesticide alternatives such as biopesticide and nanopesticide are greener to the environment. However, its safety assessment for large-scale application needs careful evaluation. Lastly, we strongly call for reversions of pesticide application trends based on the changing climate, which is lacking in the current scenario.
  13. A comparative study on physicochemical properties, pyrolytic behaviour and kinetic parameters of environmentally harmful aquatic weeds for sustainable shellfish aquaculture
    Azwar E, Chan DJC, Kasan NA, Rastegari H, Yang Y, Sonne C, et al.
    J Hazard Mater, 2022 02 15;424(Pt A):127329.
    PMID: 34601414 DOI: 10.1016/j.jhazmat.2021.127329
    Aquatic weeds pose hazards to aquatic ecosystems and particularly the aquatic environment in shellfish aquaculture due to its excessive growth covering entire freshwater bodies, leading to environmental pollution particularly eutrophication intensification, water quality depletion and aquatic organism fatality. In this study, pyrolysis of six aquatic weed types (wild and cultured species of Salvinia sp., Lemna sp. and Spirodella sp.) were investigated to evaluate its potential to reduce and convert the weeds into value-added chemicals. The aquatic weeds demonstrated high fixed carbon (8.7-47.3 wt%), volatile matter content (39.0-76.9 wt%), H/C ratio (1.5-2.0) and higher heating value (6.6-18.8 MJ/kg), representing desirable physicochemical properties for conversion into biofuels. Kinetic analysis via Coats-Redfern integral method obtained different orders for chemical reaction mechanisms (n = 1, 1.5, 2, 3), activation energy (55.94-209.41 kJ/mol) and pre-exponential factor (4.08 × 104-4.20 × 1017 s-1) at different reaction zones (zone 1: 150-268 °C, zone 2: 268-409 °C, zone 3: 409-600 °C). The results provide useful information for design and optimization of the pyrolysis reactor and establishment of the process condition to dispose this environmentally harmful species.
  14. Simultaneous removal of toxic ammonia and lettuce cultivation in aquaponic system using microwave pyrolysis biochar
    Su MH, Azwar E, Yang Y, Sonne C, Yek PNY, Liew RK, et al.
    J Hazard Mater, 2020 Sep 05;396:122610.
    PMID: 32298865 DOI: 10.1016/j.jhazmat.2020.122610
    This study examined an aquaponic approach of circulating water containing ammonia excretions from African catfish grown in an aquaculture tank for bacterial conversion into nitrates, which then acted as a nutrient substance to cultivate lettuce in hydroponic tank. We found that microwave pyrolysis biochar (450 g) having microporous (1.803 nm) and high BET surface area (419 m2/g) was suitable for use as biological carrier to grow nitrifying bacteria (63 g of biofilm mass) that treated the water quality through removing the ammonia (67%) and total suspended solids (68%), resulting in low concentration of remaining ammonia (0.42 mg/L) and total suspended solid (59.40 mg/L). It also increased the pH (6.8), converted the ammonia into nitrate (29.7 mg/L), and increased the nitrogen uptake by the lettuce (110 mg of nitrogen per plant), resulting in higher growth in lettuce (0.0562 %/day) while maintaining BOD5 level (3.94 mg/L) at acceptable level and 100% of catfish survival rate. Our results demonstrated that microwave pyrolysis biochar can be a promising solution for growing nitrifying bacteria in aquaponic system for simultaneous toxic ammonia remediation and generation of nitrate for growing vegetable in aquaculture industry.
  15. A new medical device applied in a case of acute fecal impaction with overflow diarrhea: a case report
    Huang Q, Zheng F, Wang H, Yang Y, Ma C, Zhu L
    J Med Case Rep, 2024 Mar 06;18(1):89.
    PMID: 38444013 DOI: 10.1186/s13256-024-04407-4
    BACKGROUND: Fecal impaction is a digestive system disease, that is most common in the elderly population and becomes more prevalent with increasing age. Manual removal can successfully remove the impaction in 80% of fecal impaction cases. In severe cases, endoscopy and surgery may be necessary.

    CASE PRESENTATION: A 78-year-old Han Chinese man living in a nursing home was diagnosed with fecal impaction; his initial symptom was overflow diarrhea, which is a rare occurrence with regard to fecal impaction. Nevertheless, we were able to effectively treat this situation by employing a new medical device that presents a novel method for addressing fecal impaction.

    CONCLUSION: Early identification of fecal impaction with atypical symptoms is crucial to provide proper emergency management. A safe and noninvasive treatment method, especially for elderly patients with fecal impaction, should be chosen.

  16. Artemisia argyi extract exerts antioxidant properties and extends the lifespan of Drosophila melanogaster
    Yang Y, Cao Y, Zhang J, Fan L, Huang Y, Tan TC, et al.
    J Sci Food Agric, 2024 May;104(7):3926-3935.
    PMID: 38252625 DOI: 10.1002/jsfa.13273
    BACKGROUND: Chinese mugwort (Artemisia argyi) possesses extensive pharmacological activities associated with anti-tumour, antioxidative and anti-inflammatory effects. The present study aimed to investigate the antioxidant and anti-ageing effects of A. argyi extract (AAE) on the fruit fly (Drosophila melanogaster) ageing model by detecting antioxidant enzyme activities and the mRNA level of antioxidant genes.

    RESULTS: AAE could significantly lengthen the mean lifespan, 50% survival days, and maximum lifespan of D. melanogaster, especially when the amount of AAE added reached 6.68 mg mL-1, the mean lifespan of both female and male flies increased by 23.74% and 22.30%, respectively, indicating the effective life extension effect of AAE. At the same time, AAE could improve the climbing ability and tolerance to hydrogen peroxide in D. melanogaster. In addition, the addition of AAE effectively increased the activities of copper-zinc-containing superoxide dismutase, manganese-containing superoxide dismutase and catalase in D. melanogaster and reduced the contents of malondialdehyde. Moreover, when reared with diets containing AAE, the expression of antioxidant-related genes SOD1, SOD2 and CAT was up-regulated in D. melanogaster and down-regulated for MTH genes.

    CONCLUSION: The study indicates that AAE effectively enhances the antioxidant capacity of D. melanogaster and has potential applications as an antioxidant and anti-ageing agent in the nutraceutical industry. © 2024 Society of Chemical Industry.

  17. Degradation of MicroRNA miR-466d-3p by Japanese Encephalitis Virus NS3 Facilitates Viral Replication and Interleukin-1β Expression
    Jiang H, Bai L, Ji L, Bai Z, Su J, Qin T, et al.
    J Virol, 2020 07 16;94(15).
    PMID: 32461319 DOI: 10.1128/JVI.00294-20
    Japanese encephalitis virus (JEV) infection alters microRNA (miRNA) expression in the central nervous system (CNS). However, the mechanism contributing to miRNA regulation in the CNS is not known. We discovered global degradation of mature miRNA in mouse brains and neuroblastoma (NA) cells after JEV infection. Integrative analysis of miRNAs and mRNAs suggested that several significantly downregulated miRNAs and their targeted mRNAs were clustered into an inflammation pathway. Transfection with miRNA 466d-3p (miR-466d-3p) decreased interleukin-1β (IL-1β) expression and inhibited JEV replication in NA cells. However, miR-466d-3p expression increased after JEV infection in the presence of cycloheximide, indicating that viral protein expression reduced miR-466d-3p expression. We generated all the JEV coding proteins and demonstrated NS3 helicase protein to be a potent miRNA suppressor. The NS3 proteins of Zika virus, West Nile virus, and dengue virus serotype 1 (DENV-1) and DENV-2 also decreased miR-466d-3p expression. Results from helicase-blocking assays and in vitro unwinding assays demonstrated that NS3 could unwind pre-miR-466d and induce miRNA dysfunction. Computational models and an RNA immunoprecipitation assay revealed arginine-rich domains of NS3 to be crucial for pre-miRNA binding and degradation of host miRNAs. Importantly, site-directed mutagenesis of conserved residues in NS3 revealed that R226G and R202W reduced the binding affinity and degradation of pre-miR-466d. These results expand the function of flavivirus helicases beyond unwinding duplex RNA to degrade pre-miRNAs. Hence, we revealed a new mechanism for NS3 in regulating miRNA pathways and promoting neuroinflammation.IMPORTANCE Host miRNAs have been reported to regulate JEV-induced inflammation in the CNS. We found that JEV infection could reduce expression of host miRNA. The helicase region of the NS3 protein bound specifically to miRNA precursors and could lead to incorrect unwinding of miRNA precursors, thereby reducing the expression of mature miRNAs. This observation led to two major findings. First, our results suggested that JEV NS3 protein induced miR-466d-3p degradation, which promoted IL-1β expression and JEV replication. Second, arginine molecules on NS3 were the main miRNA-binding sites, because we demonstrated that miRNA degradation was abolished if arginines at R226 and R202 were mutated. Our study provides new insights into the molecular mechanism of JEV and reveals several amino acid sites that could be mutated for a JEV vaccine.
  18. A comparative study of skin cell activities in collagen and fibrin constructs
    Law JX, Musa F, Ruszymah BH, El Haj AJ, Yang Y
    Med Eng Phys, 2016 Sep;38(9):854-61.
    PMID: 27349492 DOI: 10.1016/j.medengphy.2016.05.017
    Collagen and fibrin are widely used in tissue engineering due to their excellent biocompatibility and bioactivities that support in vivo tissue formation. These two hydrogels naturally present in different wound healing stages with different regulatory effects on cells, and both of them are mechanically weak in the reconstructed hydrogels. We conducted a comparative study by the growth of rat dermal fibroblasts or dermal fibroblasts and epidermal keratinocytes together in collagen and fibrin constructs respectively with and without the reinforcement of electrospun poly(lactic acid) nanofiber mesh. Cell proliferation, gel contraction and elastic modulus of the constructs were measured on the same gels at multiple time points during the 22 day culturing period using multiple non-destructive techniques. The results demonstrated considerably different cellular activities within the two types of constructs. Co-culturing keratinocytes with fibroblasts in the collagen constructs reduced the fibroblast proliferation, collagen contraction and mechanical strength at late culture point regardless of the presence of nanofibers. Co-culturing keratinocytes with fibroblasts in the fibrin constructs promoted fibroblast proliferation but exerted no influence on fibrin contraction and mechanical strength. The presence of nanofibers in the collagen and fibrin constructs played a favorable role on the fibroblast proliferation when keratinocytes were absent. Thus, this study exhibited new evidence of the strong cross-talk between keratinocytes and fibroblasts, which can be used to control fibroblast proliferation and construct contraction. This cross-talk activity is extracellular matrix-dependent in terms of the fibrous network morphology, density and strength.
  19. Electronic Transport and Possible Superconductivity at Van Hove Singularities in Carbon Nanotubes
    Yang Y, Fedorov G, Shafranjuk SE, Klapwijk TM, Cooper BK, Lewis RM, et al.
    Nano Lett., 2015 Dec 09;15(12):7859-66.
    PMID: 26506109 DOI: 10.1021/acs.nanolett.5b02564
    Van Hove singularities (VHSs) are a hallmark of reduced dimensionality, leading to a divergent density of states in one and two dimensions and predictions of new electronic properties when the Fermi energy is close to these divergences. In carbon nanotubes, VHSs mark the onset of new subbands. They are elusive in standard electronic transport characterization measurements because they do not typically appear as notable features and therefore their effect on the nanotube conductance is largely unexplored. Here we report conductance measurements of carbon nanotubes where VHSs are clearly revealed by interference patterns of the electronic wave functions, showing both a sharp increase of quantum capacitance, and a sharp reduction of energy level spacing, consistent with an upsurge of density of states. At VHSs, we also measure an anomalous increase of conductance below a temperature of about 30 K. We argue that this transport feature is consistent with the formation of Cooper pairs in the nanotube.
  20. Phylogenomics and the rise of the angiosperms
    Zuntini AR, Carruthers T, Maurin O, Bailey PC, Leempoel K, Brewer GE, et al.
    Nature, 2024 Apr 24.
    PMID: 38658746 DOI: 10.1038/s41586-024-07324-0
    Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5-7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.
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