Publications by authors named "Chaoran Liu"

27 Publications

  • Page 1 of 1

Anti-cancer Substances and Safety of Lactic Acid Bacteria in Clinical Treatment.

Front Microbiol 2021 12;12:722052. Epub 2021 Oct 12.

College of Animal Science and Technology, Southwest University, Chongqing, China.

Lactic acid bacteria (LAB) are a kind of Gram-positive bacteria which can colonize in the biological gastrointestinal tract and play a variety of probiotic roles. LAB have a wide range of applications in industry, animal husbandry, planting, food safety, and medical science fields. Previous studies on LAB have typically concentrated on their effects on improving the digestion and absorption of the gastrointestinal tract, regulating the balance of the microflora, and inhibiting the production and accumulation of toxic substances. The resistance of LAB to cancer is a topic of growing interest and relevance. This paper provided a summary of bio-active substances of LAB when they act against cancer, as well as the safety of LAB in clinical cancer treatment. Moreover, this paper further discussed several possible directions for future research and the potential application of LAB as anti-cancer therapy.
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http://dx.doi.org/10.3389/fmicb.2021.722052DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8548880PMC
October 2021

Understanding the gut microbiota and sarcopenia: a systematic review.

J Cachexia Sarcopenia Muscle 2021 Sep 14. Epub 2021 Sep 14.

Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR, China.

Background: Gut microbiota dysbiosis and sarcopenia commonly occur in the elderly. Although the concept of the gut-muscle axis has been raised, the casual relationship is still unclear. This systematic review analyses the current evidence of gut microbiota effects on muscle/sarcopenia.

Methods: A systematic review was performed in PubMed, Embase, Web of Science, and The Cochrane Library databases using the keywords (microbiota* OR microbiome*) AND (sarcopen* OR muscle). Studies reporting the alterations of gut microbiota and muscle/physical performance were analysed.

Results: A total of 26 pre-clinical and 10 clinical studies were included. For animal studies, three revealed age-related changes and relationships between gut microbiota and muscle. Three studies focused on muscle characteristics of germ-free mice. Seventy-five per cent of eight faecal microbiota transplantation studies showed that the recipient mice successfully replicated the muscle phenotype of donors. There were positive effects on muscle from seven probiotics, two prebiotics, and short-chain fatty acids (SCFAs). Ten studies investigated on other dietary supplements, antibiotics, exercise, and food withdrawal that affected both muscle and gut microbiota. Twelve studies explored the potential mechanisms of the gut-muscle axis. For clinical studies, 6 studies recruited 676 elderly people (72.8 ± 5.6 years, 57.8% female), while 4 studies focused on 244 young adults (29.7 ± 7.8 years, 55.4% female). The associations of gut microbiota and muscle had been shown in four observational studies. Probiotics, prebiotics, synbiotics, fermented milk, caloric restriction, and exercise in six studies displayed inconsistent effects on muscle mass, function, and gut microbiota.

Conclusions: Altering the gut microbiota through bacteria depletion, faecal transplantation, and various supplements was shown to directly affect muscle phenotypes. Probiotics, prebiotics, SCFAs, and bacterial products are potential novel therapies to enhance muscle mass and physical performance. Lactobacillus and Bifidobacterium strains restored age-related muscle loss. Potential mechanisms of microbiome modulating muscle mainly include protein, energy, lipid, and glucose metabolism, inflammation level, neuromuscular junction, and mitochondrial function. The role of the gut microbiota in the development of muscle loss during aging is a crucial area that requires further studies for translation to patients.
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http://dx.doi.org/10.1002/jcsm.12784DOI Listing
September 2021

High-sensitivity tactile sensor based on TiC-PDMS sponge for wireless human-computer interaction.

Nanotechnology 2021 Apr 30;32(29). Epub 2021 Apr 30.

Ministry of Education Key Lab. of RF Circuits and Systems, College of Electronics and Information, Hangzhou Dianzi University, Hangzhou, 310018, People's Republic of China.

Tremendous attention has been paid to high-performance flexible tactile sensors owing to their potential applications in bionic skin, wearable electronics, the Internet of Things, etcHowever, the majority of pressure sensors require an intricately designed nanostructure requiring a high-cost complex manufacturing process. Therefore, the high-throughput and low-cost technology to produce high-sensitivity, flexible, pressure-sensitive materials with a large responding range is urgently needed. Herein, a novel flexible piezoresistive tactile sensor is fabricated based on the TiC-PDMS sponge as the conductive elastomer. The sensor exhibits a high sensitivity of 279 kPain a wide pressure range (0-34.4 kPa). The response time is as fast as 0.45 s with excellent durability over 4,000 cycles. Moreover, a 16-pixel wireless sensor system is fabricated and a series of applications have been demonstrated, including real-time force perception and pressure morphology feedback, which promote the potential applications in the visualizing of pressure distribution, human-machine communication and wearable devices.
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http://dx.doi.org/10.1088/1361-6528/abf59eDOI Listing
April 2021

A supersensitive silicon nanowire array biosensor for quantitating tumor marker ctDNA.

Biosens Bioelectron 2021 Jun 5;181:113147. Epub 2021 Mar 5.

Ministry of Education Engineering Research Center of Smart Microsensors and Microsystems, College of Electronics and Information, Hangzhou Dianzi University, Hangzhou, 310018, China. Electronic address:

Cancer has become one of the major diseases threatening human health and life. Circulating tumor DNA (ctDNA) testing, as a practical liquid biopsy technique, is a promising method for cancer diagnosis, targeted therapy and prognosis. Here, for the first time, a field effect transistor (FET) biosensor based on uniformly sized high-response silicon nanowire (SiNW) array was studied for real-time, label-free, super-sensitive detection of PIK3CA E542K ctDNA. High-response 120-SiNWs array was fabricated on a (111) silicon-on-insulator (SOI) by the complementary metal oxide semiconductor (CMOS)-compatible microfabrication technology. To detecting ctDNA, we modified the DNA probe on the SiNWs array through silanization. The experimental results demonstrated that the as-fabricated biosensor had significant superiority in ctDNA detection, which achieved ultralow detection limit of 10 aM and had a good linearity under the ctDNA concentration range from 0.1 fM to 100 pM. This biosensor can recognize complementary target ctDNA from one/two/full-base mismatched DNA with high selectivity. Furthermore, the fabricated SiNW-array FET biosensor successfully detected target ctDNA in human serum samples, indicating a good potential in clinical applications in the future.
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http://dx.doi.org/10.1016/j.bios.2021.113147DOI Listing
June 2021

The role of gut microbiota in bone homeostasis.

Bone Joint Res 2021 Jan;10(1):51-59

Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Hong Kong, Hong Kong.

Aims: The effect of the gut microbiota (GM) and its metabolite on bone health is termed the gut-bone axis. Multiple studies have elucidated the mechanisms but findings vary greatly. A systematic review was performed to analyze current animal models and explore the effect of GM on bone.

Methods: Literature search was performed on PubMed and Embase databases. Information on the types and strains of animals, induction of osteoporosis, intervention strategies, determination of GM, assessment on bone mineral density (BMD) and bone quality, and key findings were extracted.

Results: A total of 30 studies were included, of which six studies used rats and 24 studies used mice. Osteoporosis or bone loss was induced in 14 studies. Interventions included ten with probiotics, three with prebiotics, nine with antibiotics, two with short-chain fatty acid (SCFA), six with vitamins and proteins, two with traditional Chinese medicine (TCM), and one with neuropeptide Y1R antagonist. In general, probiotics, prebiotics, nutritional interventions, and TCM were found to reverse the GM dysbiosis and rescue bone loss.

Conclusion: Despite the positive therapeutic effect of probiotics, prebiotics, and nutritional or pharmaceutical interventions on osteoporosis, there is still a critical knowledge gap regarding the role of GM in rescuing bone loss and its related pathways. Cite this article:  2021;10(1):51-59.
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http://dx.doi.org/10.1302/2046-3758.101.BJR-2020-0273.R1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7845471PMC
January 2021

Micro Direct Methanol Fuel Cell Based on Reduced Graphene Oxide Composite Electrode.

Micromachines (Basel) 2021 Jan 11;12(1). Epub 2021 Jan 11.

Institute of Flexible Electronics Technology of THU, Jiaxing 31400, China.

The effect of an anode composite electrode on the performance of a micro direct methanol fuel cell (μDMFC) is analyzed from sample preparation configurations and discussed in detail, with a specific focus on the catalyst layer and the micro-porous layer on the anode composite electrode. This study investigates the effects of Pt content, Pt-Ru molar ratio, Nafion content, catalyst support, and preparation method in the catalyst layer, along with the carbon loading and polytetrafluoroethylene (PTFE )content in the micro-porous layer, on the performance of the anode composite electrode. The results show that the anode composite electrode delivers the best performance with 30% Pt content, a 1:1.5 Pt-Ru molar ratio, 10% Nafion content on reduced graphene oxide as the catalyst support. The synthesis is optimized with the impregnation reduction method using NaBH as the reducing agent, with the addition of 1.5 mg/cm carbon loading and 5% PTFE.
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http://dx.doi.org/10.3390/mi12010072DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7827227PMC
January 2021

Skeleton-Based Emotion Recognition Based on Two-Stream Self-Attention Enhanced Spatial-Temporal Graph Convolutional Network.

Sensors (Basel) 2020 Dec 30;21(1). Epub 2020 Dec 30.

Graduate School of Engineering Science, Osaka University, Osaka 565-0871, Japan.

Emotion recognition has drawn consistent attention from researchers recently. Although gesture modality plays an important role in expressing emotion, it is seldom considered in the field of emotion recognition. A key reason is the scarcity of labeled data containing 3D skeleton data. Some studies in action recognition have applied graph-based neural networks to explicitly model the spatial connection between joints. However, this method has not been considered in the field of gesture-based emotion recognition, so far. In this work, we applied a pose estimation based method to extract 3D skeleton coordinates for IEMOCAP database. We propose a self-attention enhanced spatial temporal graph convolutional network for skeleton-based emotion recognition, in which the spatial convolutional part models the skeletal structure of the body as a static graph, and the self-attention part dynamically constructs more connections between the joints and provides supplementary information. Our experiment demonstrates that the proposed model significantly outperforms other models and that the features of the extracted skeleton data improve the performance of multimodal emotion recognition.
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http://dx.doi.org/10.3390/s21010205DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7795329PMC
December 2020

Multi-Modality Emotion Recognition Model with GAT-Based Multi-Head Inter-Modality Attention.

Sensors (Basel) 2020 Aug 29;20(17). Epub 2020 Aug 29.

Advanced Telecommunications Research Institute International, Kyoto 619-0288, Japan.

Emotion recognition has been gaining attention in recent years due to its applications on artificial agents. To achieve a good performance with this task, much research has been conducted on the multi-modality emotion recognition model for leveraging the different strengths of each modality. However, a research question remains: what exactly is the most appropriate way to fuse the information from different modalities? In this paper, we proposed audio sample augmentation and an emotion-oriented encoder-decoder to improve the performance of emotion recognition and discussed an inter-modality, decision-level fusion method based on a graph attention network (GAT). Compared to the baseline, our model improved the weighted average F1-scores from 64.18 to 68.31% and the weighted average accuracy from 65.25 to 69.88%.
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http://dx.doi.org/10.3390/s20174894DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7506856PMC
August 2020

A self-cleaning and photocatalytic cellulose-fiber- supported "[email protected]@MOF- cloth'' membrane for complex wastewater remediation.

Carbohydr Polym 2020 Nov 25;247:116691. Epub 2020 Jun 25.

National Demonstration Center for Experimental Light Chemistry Engineering Education, College of Bioresources Chemical and Materials Engineering, Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, Shaanxi University of Science and Technology, Xi'an, 710021, China; Department of Chemical Engineering, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.

Membrane technology is one of the most promising technologies for wastewater remedy. However, it remains challenging to prepare high-performance membrane matrix for complex pollutants, e.g. containing both oil and organic dye. In this work, we facilely fabricate a cellulose-fiber-supported MOF photocatalytic membrane, namely [email protected]@MIL-100(Fe)/CCF, which was prepared via carboxymethylation of cotton fabric (CCF) as scaffold and in-situ synthesis of MOF derivative as photocatalyst. The carboxymethylation significantly improves the hydrophilicity of cotton fabric and the deposition amount of MIL-100(Fe). The high hydrophilicity of modified CCF and porous MIL-100(Fe) further enable the membrane with an efficient adsorption capacity of dyes and underwater oleophobicity against oils. The photocatalysts [email protected] nanoparticles anchored onto MIL-100(Fe) promote the photocatalytic activity. As a result, the membrane shows simultaneous high removal efficiency towards dyes (97.3 %) and oils (99.64 %). Additionally, thanks to the good photocatalytic activity against organic pollutants, the membrane exhibits excellent self-cleaning and a long-term reuse capacity.
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http://dx.doi.org/10.1016/j.carbpol.2020.116691DOI Listing
November 2020

Facile synthesis of Ag [email protected] MIL-100(Fe)/ guar gum hybrid hydrogel as a versatile photocatalyst for wastewater remediation: Photocatalytic degradation, water/oil separation and bacterial inactivation.

Carbohydr Polym 2020 Feb 19;230:115642. Epub 2019 Nov 19.

College of Bioresources Chemical and Materials Engineering, Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science and Technology, Xi'an, 710021, China; Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada.

3D Hydrogel is one of the most popular adsorbents for water remediation due to its excellent concentration/ adsorption capacity. However, it remains a challenge to use the hydrogel alone for treating complex wastewater. In this work, we designed and fabricated a versatile bio-based hybrid hydrogel consisting of Ag [email protected] MIL-100(Fe) photocatalysts and guar gum (GG) via facile blending and self-crosslinking. The hybrid hydrogel integrated with multifunctions of dye adsorption and degradation, oil/water separation and antibacterial properties, thus enabling its applications in complex wastewater remediation process. The presence of Ag nanoparticles (Ag NPs) not only enhanced the photocatalytic activity of MIL-100(Fe), but also imparted the antibacterial activity of Ag [email protected](Fe)/ GG hydrogel. Particularly, the bio-based GG hydrogel scaffold showed excellent injectable, remodeling, and self-healing properties, which enabled an effective oil/water separation ability (silicone oil, cyclohexane and canola oil) and facilitated the recyclability/sustainability of the nano-photocatalyst powders. This novel multifunctional 3D hybrid hydrogel provides new opportunities for wastewater remediation purpose.
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http://dx.doi.org/10.1016/j.carbpol.2019.115642DOI Listing
February 2020

A Silicon Nanowire Array Biosensor Fabricated by Complementary Metal Oxide Semiconductor Technique for Highly Sensitive and Selective Detection of Serum Carcinoembryonic Antigen.

Micromachines (Basel) 2019 Nov 11;10(11). Epub 2019 Nov 11.

College of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China.

In this paper, we present a highly sensitive and selective detection of serum carcinoembryonic antigen (CEA) based on silicon nanowire (SiNW) array device. With the help of traditional microfabrication technology, low-cost and highly controllable SiNW array devices were fabricated. After a series of surface modification processes, SiNW array biosensors show rapid and reliable response to CEA; the detection limit of serum CEA was 10 fg/mL, the current signal is linear with the logarithm of serum CEA concentration in the range of 10 fg/mL to 100 pg/mL. In this work, SiNW array biosensors can obtain strong signal and high signal-to-noise ratio; these advantages can reduce the production cost of the SiNW-based system and promote the application of SiNWs in the field of tumor marker detection.
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http://dx.doi.org/10.3390/mi10110764DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6915592PMC
November 2019

Immunomodulatory Effect of Structurally Characterized Mushroom Sclerotial Polysaccharides Isolated from on Bone Marrow Dendritic Cells.

J Agric Food Chem 2019 Oct 16;67(43):12137-12143. Epub 2019 Oct 16.

Food and Nutritional Sciences, School of Life Sciences , The Chinese University of Hong Kong , Shatin , New Territories , Hong Kong Special Administrative Region of the People's Republic of China.

This study evaluated the immunomodulatory effects of two high-molecular-weight and structurally different mushroom polysaccharides, an alkali-soluble polysaccharide (mPRSon) and a water-soluble polysaccharide-protein complex (PRW), isolated previously from the sclerotia of , on the maturation of murine bone-marrow-derived dendritic cells (BMDCs). The effects of mPRSon and PRW on the expression of morphological change, surface molecules, phagocytic activity, and cytokine release in BMDCs were determined by flow cytometry and a mouse cytokine array. The results showed that both mPRSon and PRW could induce phenotypic and functional maturation of BMDCs. At the same time, mPRSon upregulated the expression of membrane phenotypic marker CD86 and PRW markedly upregulated CD40, CD80, and CD86. In addition, mPRSon could bind to the dectin-1 receptor and stimulate the release of MIP-1α, MIP-2, and IL-2, while PRW could bind to complement receptor 3 and toll-like receptor 2 with an upregulation of the expression of IL-2, IL-6, MIP-1α, MIP-2, RANTES, IL-12p40p70, IL-12p70, TIMP-1, IFN-γ, KC, MCP-1, and GCSF. The study provides additional information on how structural differences in sclerotial polysaccharides influence their immunomodulatory activities on BMDCs involving different PAMP receptors. It is anticipated that more understanding of the interactions between the sclerotial polysaccharides and their receptors in immune cells can facilitate their future application for cancer immunotherapy.
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http://dx.doi.org/10.1021/acs.jafc.9b03294DOI Listing
October 2019

Structure and Immunomodulatory Activity of Microparticulate Mushroom Sclerotial β-Glucan Prepared from .

J Agric Food Chem 2019 Aug 5;67(32):9070-9078. Epub 2019 Aug 5.

Food and Nutritional Sciences, School of Life Sciences , The Chinese University of Hong Kong , Shatin , New Territories , Hong Kong Special Administrative Region of the People's Republic of China.

In this study, an immunologically active novel microparticulate mushroom β-glucan (PRA-1p) was prepared using an alkali-soluble glucan PRA-1 by an emulsification and cross-linking method. PRA-1 was a hyperbranched (1→3),(1→6)-β-d-glucan with a degree of branching of 0.89, isolated from the sclerotia of . PRA-1 had a rod-like conformation, while PRA-1p exhibited a monodisperse and homogeneous spherical conformation with a diameter ranging from 0.3 to 2.0 μm in water. PRA-1p significantly induced nitric oxide and reactive oxygen species production as well as morphological changes of murine macrophages (RAW 264.7 cells) and upregulated their phagocytic activity. Furthermore, PRA-1p treatment markedly enhanced the secretion of cytokines, including cutaneous T cell-attracting chemokine 27, granulocyte-colony-stimulating factor, monocyte chemoattractant protein 1, macrophage inflammatory protein 1α, macrophage inflammatory protein 2, regulated on activation, normal T cell expressed and secreted, soluble tumor necrosis factor receptor 1, and tissue inhibitors of metalloproteinases. Activation of RAW 264.7 cells triggered by PRA-1p was associated with activation of inducible nitric oxide synthase, nuclear factor κB, extracellular signal-regulated kinase, and protein kinase B. This work suggests that novel PRA-1p derived from the mushroom sclerotia of has potential application as an immunostimulatory agent.
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http://dx.doi.org/10.1021/acs.jafc.9b03206DOI Listing
August 2019

Carbohydrates-rich corncobs supported metal-organic frameworks as versatile biosorbents for dye removal and microbial inactivation.

Carbohydr Polym 2019 Oct 2;222:115042. Epub 2019 Jul 2.

College of Bioresources Chemical and Materials Engineering, Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science and Technology, Xi'an, 710021, China; Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, E3B 5A3, New Brunswick, Canada.

In this work, biodegradable cellulose-based biosorbents (MOFs/OCBs) with dual function of dye removal and microbial inactivation were fabricated by in situ anchoring metal-organic frameworks (MOFs) on the TEMPO oxidized corncobs (OCBs). Results showed that delignification and oxidation can develop the OCBs with more cellulose content, carboxyl groups and specific surface area, thus facilitating the deposition of MOFs. The porous and carbohydrate-rich OCBs can serve as supports and stabilizers for MOFs, allowing for enhanced stability and recyclability of MOFs powders. The MOFs, namely HKUST-1 and ZIF-8, can endow the OCBs multiple functions of good adsorption capacity to methyl orange (from 8% of OCBs to 55% of HKUST-1/OCBs and 84% of ZIF-8/OCBs) and excellent antibacterial activity (from 0 of OCBs to 90.2% of HKUST-1/OCBs and 44.8% of ZIF-8/OCBs). Such a concept may offer a new pathway for preparing economical and efficient biosorbents for environmental remedy purposes.
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http://dx.doi.org/10.1016/j.carbpol.2019.115042DOI Listing
October 2019

Magnetic solid-phase extraction of benzoylurea insecticides in tea samples with Fe O -hyperbranched polyester magnetic composite as sorbent.

J Sep Sci 2019 Apr 6;42(8):1610-1619. Epub 2019 Mar 6.

Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, P. R. China.

In this work, a method for the analysis of benzoylurea insecticides, including hexaflumuron, flufenoxuron, lufenuron and chlorfluazuron, in tea samples by high-performance liquid chromatography with Fe O -hyperbranched polyester nanocomposite as the adsorbent for magnetic solid-phase extraction was developed. The magnetic nanocomposite was prepared and characterized by infrared spectroscopy, vibrating sample magnetometry, and scanning electron microscopy. The as-prepared nanocomposite was used as a sorbent for the extraction and preconcentration of pesticide residues in tea samples. The extraction and desorption conditions, including mass ratios of raw materials, amount of sorbent, pH value, extraction time, and desorption time, were investigated. Under the final conditions chosen for the analysis, good linearity was obtained for all the tested compounds, with R values of at least 0.9979. The limits of detection were determined in the range of 0.15-0.3 μg/L. The recovery obtained from the analysis of tea samples with various spiked concentrations was between 90.7 and 98.4%, with relative standard deviations (n = 4) lower than 4.1%. Furthermore, the present approach was successfully applied to the quantitative determination of residues of benzoylurea insecticides in real samples.
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http://dx.doi.org/10.1002/jssc.201801159DOI Listing
April 2019

Self-propelled droplet-based electricity generation.

Nanoscale 2018 Dec 5;10(48):23164-23169. Epub 2018 Dec 5.

Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China.

Droplets are ubiquitous in nature and the preferential control of droplet transport offers limitless potential for efficient mass and momentum transfer as well as energy conversion. In this work, we show that even without the need for any external energy input, the self-propelled motion of droplets driven by a surface wetting gradient can lead to reliable electricity generation. Simple analytical analysis demonstrates that the output voltage results from the modulation of the surface charge distribution on the dynamically changing solid/liquid interfaces, which can be programmed by tailoring the wetting gradient and the size of the droplet. We demonstrate that a self-propelled 25 μL droplet can generate a peak current of 93.5 nA and a maximum output power of 2.4 nW. This work provides a new angle for optimizing energy harvesting devices based on liquid-solid interfaces.
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http://dx.doi.org/10.1039/c8nr08772eDOI Listing
December 2018

Low-Cost Method Generating In Situ Anaerobic Conditions on a 96-Well Plate for Microbial Fermentation in Food Research.

J Agric Food Chem 2018 Nov 24;66(44):11839-11845. Epub 2018 Oct 24.

Food and Nutritional Sciences Program, School of Life Sciences , The Chinese University of Hong Kong , Shatin , New Territory , Hong Kong.

Commercial tools and instruments have been developed for a screening study of microbial fermentation, but they are expensive and mostly confined to aerobic fermentation only. There is little development on the generation of anaerobic conditions directly on a 96-well plate. This report proposed a simple and versatile microbial fermentation system known as OVAMO that makes use of Oxyrase, vacuum, and mineral oil to generate an in situ anaerobic environment on a 96-well plate for at least 48 h. The practicality of OVAMO in anaerobic fermentation experiments used for functional food research was validated by a prebiotic screening study of different carbohydrates by Bifidobacterium longum subsp. infantis. The OVAMO system provides a less expensive but effective way to conduct a microbial fermentation screening study that requires anaerobic conditions without the need for atmospheric control by external devices.
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http://dx.doi.org/10.1021/acs.jafc.8b04888DOI Listing
November 2018

Determination of four pyrethroid insecticides in water samples through membrane emulsification-assisted liquid-liquid microextraction based on solidification of floating organic droplets.

J Chromatogr A 2018 Jul 13;1559:86-94. Epub 2018 Apr 13.

Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing 100194, China. Electronic address:

A novel membrane emulsification-assisted liquid-liquid microextraction method based on the solidification of floating organic drops was used to detect four pyrethroid pesticides (deltamethrin, etofenprox, fenpropathrin, and bifenthrin). In this method, [P]Br was used as a surfactant that could be removed from water via the addition of KPF. The extraction solvent was separated after centrifugation and solidification on the water surface. The parameters affecting the recovery of the target compounds, including the surfactant amount, [P]Br-to-KPF molar ratio, addition of salt, extraction solvent volume, and temperature, were individually optimized and further analyzed through an orthogonal array design (OAD) experiment. The optimized conditions were based on the results of the OAD experiment and single-factor analysis. Using these experimental conditions, the recovery of the four pyrethroids ranged from 91.3% to 98.1% with relative standard deviation (RSD) values ranging from 1.7 to 2.2%. Good linearity was observed, with values from 0.9982 to 0.9997, and the linear range was between 1 and 500 μg/L (5-500 μg/L for fenpropathrin). The limit of detection (LOD) values based on a signal-to-noise ratio (S/N) of 3:1 were 0.37-0.75 μg/L. The enrichment factor ranged from 90 to 96. Therefore, this method is suitable for the determination of pyrethroid pesticides in environmental water samples.
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http://dx.doi.org/10.1016/j.chroma.2018.04.031DOI Listing
July 2018

Stable and Biocompatible Mushroom β-Glucan Modified Gold Nanorods for Cancer Photothermal Therapy.

J Agric Food Chem 2017 Nov 20;65(43):9529-9536. Epub 2017 Oct 20.

School of Life Sciences, The Chinese University of Hong Kong , Shatin, New Territories, Hong Kong, China.

Naturally occurring β-glucans have been widely regarded as a natural source for functional foods and pharmaceuticals due to their immunomodulatory property and antitumor activity. However, physicochemically stable and biocompatible β-glucans are rarely explored as a carrier for nanomaterials to overcome the problems of aggregation and nanotoxicity. Here, we developed highly stable and biocompatible mushroom β-glucan coated gold nanorods (AuNR-Glu) for cancer photothermal therapy by integrating Pleurotus tuber-regium sclerotial β-glucan (Glu) and plasmonic gold nanorods (AuNRs) possessing photothermal property in the second near-infrared (NIR-II) window. AuNR-Glu showed high colloidal stability in various biological media, even in simulated gastric fluid. Moreover, AuNR-Glu had low cytotoxicity and high photothermal stability, which are excellent characteristics for photothermal agents for cancer therapy. In vitro experiments showed that AuNR-Glu nanohybrid was effective against MCF-7 (only 4.5 ± 0.9% viability) at a low dose of 20 μg/mL under NIR-II at a safe laser power density (0.75 W/cm). Natural mushroom β-glucans are potential functional polymers that can be used to fabricate nanohybrids for biomedical applications.
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http://dx.doi.org/10.1021/acs.jafc.7b03895DOI Listing
November 2017

Long-range spontaneous droplet self-propulsion on wettability gradient surfaces.

Sci Rep 2017 08 8;7(1):7552. Epub 2017 Aug 8.

Science and Technology on Microsystem Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China.

The directional and long-range droplet transportation is of great importance in microfluidic systems. However, it usually requires external energy input. Here we designed a wettability gradient surface that can drive droplet motion by structural topography. The surface has a wettability gradient range of over 150° from superhydrophobic to hydrophilic, which was achieved by etching silicon nanopillars and adjusting the area of hydrophilic silicon dioxide plane. We conducted force analysis to further reveal the mechanism for droplet self-propulsion, and found that the nanostructures are critical to providing a large driving force and small resistance force. Theoretical calculation has been used to analyze the maximal self-propulsion displacement on different gradient surfaces with different volumes of droplets. On this basis, we designed several surfaces with arbitrary paths, which achieved directional and long-range transportation of droplet. These results clarify a driving mechanism for droplet self-propulsion on wettability gradient surfaces, and open up new opportunities for long-range and directional droplet transportation in microfluidic system.
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http://dx.doi.org/10.1038/s41598-017-07867-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5548791PMC
August 2017

Centrifuge-less dispersive liquid-liquid microextraction base on the solidification of switchable solvent for rapid on-site extraction of four pyrethroid insecticides in water samples.

J Chromatogr A 2016 Nov 11;1472:1-9. Epub 2016 Oct 11.

Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Laboratory of Quality & Safety Risk Assessment for Vegetable Products (Beijing), Ministry of Agriculture, NO.12 Zhongguancun South St., Haidian District, Beijing 100081, China. Electronic address:

An on-site dispersive liquid liquid microextraction base on the solidification of switchable solvent has been developed as a simple, rapid and eco-friendly sample extraction method for the fast determination of pyrethroid insecticides in aqueous samples using high-performance liquid chromatography with ultraviolet detection. In this extraction method, medium-chain saturated fatty acids (n≥10), which can rapidly solidify at low temperatures (<20°C), were investigated as switchable hydrophilic solvents. The fatty acids were converted into the hydrophilic form by adding sodium hydroxide. Microdroplets of the fatty acids were generated when injected into an acidic sample that had been pretreated by the addition of sulfuric acid. The formed cloudy solution was cooled to a low temperature to turn the fatty acids into a solid, which was then separated by filtration, thus avoiding the time-consuming step of centrifugation. The microextraction process was performed in a 10mL syringe and the pretreatment process could thus be finished in 5min. No external energy resources were required in this method, which makes it a potential method for on-site extraction. The optimal experimental parameters were as follows: 350μL of decanoic acid (1mol/L) was used as the extraction solvent, 150μL of sulfuric acid (2mol/L) was used to decrease the pH of the samples, no salt was added, and the temperature of the samples was in the range of 20-40°C. Finally, the sample was cooled in an ice bath for three minutes. Under these optimal conditions, good responses for four pyrethroid insecticides were obtained in the concentration ranges of 1-500μg/L, with coefficients of determination greater than 0.9993. The recoveries of the four pyrethroid insecticides ranged from 84.7 to 95.3%, with relative standard deviations ranging from 1.6 to 4.6%. The limits of detection based on a signal-to-noise ratio of 3 were in the range of 0.24-0.68μg/L, and the enrichment factors were in the range of 121-136. The results demonstrate that this method was successfully applied to determine pyrethroid insecticides in real water samples. No centrifugation or any special apparatus are required, make this a promising method for rapid field-sampling procedures.
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http://dx.doi.org/10.1016/j.chroma.2016.10.013DOI Listing
November 2016

Immunomodulatory Activity of Polysaccharide-Protein Complex from the Mushroom Sclerotia of Polyporus rhinocerus in Murine Macrophages.

J Agric Food Chem 2016 Apr 18;64(16):3206-14. Epub 2016 Apr 18.

Food and Nutritional Sciences, School of Life Sciences, The Chinese University of Hong Kong , Shatin, New Territories, Hong Kong SAR (HKSAR), China.

A novel water-soluble polysaccharide-protein complex (PRW1) isolated from the sclerotia of an edible mushroom Polyporus rhinocerus which was purified by membrane ultrafiltration could significantly activate murine macrophages RAW264.7 in vitro. PRW1 had a molecular weight of less than 50 kDa and was found to be a highly branched heteropolysaccharide-protein complex composed of 45.7 ± 0.97% polysaccharide and 44.2 ± 0.41% protein. Based on the results of total acid hydrolysis, methylation analysis, and Fourier transform infrared spectroscopy, the carbohydrate moiety of PRW1 was found to be a β-d-mannoglucan with its backbone containing →1)-d-Glcp-(4→, →1)-d-Glcp-(6→, and →1)-d-Manp-(2→ residues (molar ratio of 5:4:6) and having terminal d-Glcp as side chain (degree of branching of 0.62). In vitro studies showed that PRW1 significantly induced NO production and enhanced the release of a variety of cytokines including G-CSF, GM-CSF, IL-6, IL12p40/70, MCP-1, MCP-5, MIP-1-α, MIP-2, RANTES, sTNFRI, and TNF-α. Mechanistically, PRW1 treatment triggered ERK phosphorylation to activate macrophages within 15 min and significantly increased the expression level of inducible NOS after 6 h. In summary, this study indicates that PRW1 derived from the sclerotia of P. rhinocerus is a potential immunomodulatory agent for cancer immunotherapy.
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http://dx.doi.org/10.1021/acs.jafc.6b00932DOI Listing
April 2016

Epidemics in interconnected small-world networks.

PLoS One 2015 23;10(3):e0120701. Epub 2015 Mar 23.

School of Reliability and Systems Engineering, Beihang University, Beijing, China; Science and Technology on Reliability and Environmental Engineering Laboratory, Beijing, China.

Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks has rarely been considered. Here, we study the susceptible-infected-susceptible (SIS) model of epidemic spreading in a system comprising two interconnected small-world networks. We find that the epidemic threshold in such networks decreases when the rewiring probability of the component small-world networks increases. When the infection rate is low, the rewiring probability affects the global steady-state infection density, whereas when the infection rate is high, the infection density is insensitive to the rewiring probability. Moreover, epidemics in interconnected small-world networks are found to spread at different velocities that depend on the rewiring probability.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0120701PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4370840PMC
December 2015

A modeling framework for system restoration from cascading failures.

PLoS One 2014 4;9(12):e112363. Epub 2014 Dec 4.

School of Reliability and Systems Engineering, Beihang University, Beijing, China; Science and Technology on Reliability and Environmental Engineering Laboratory, Beijing, China.

System restoration from cascading failures is an integral part of the overall defense against catastrophic breakdown in networked critical infrastructures. From the outbreak of cascading failures to the system complete breakdown, actions can be taken to prevent failure propagation through the entire network. While most analysis efforts have been carried out before or after cascading failures, restoration during cascading failures has been rarely studied. In this paper, we present a modeling framework to investigate the effects of in-process restoration, which depends strongly on the timing and strength of the restoration actions. Furthermore, in the model we also consider additional disturbances to the system due to restoration actions themselves. We demonstrate that the effect of restoration is also influenced by the combination of system loading level and restoration disturbance. Our modeling framework will help to provide insights on practical restoration from cascading failures and guide improvements of reliability and resilience of actual network systems.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0112363PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4256303PMC
August 2015

Microwave-assisted synthesis of arene ruthenium(II) complexes that induce S-phase arrest in cancer cells by DNA damage-mediated p53 phosphorylation.

Eur J Med Chem 2013 May 8;63:57-63. Epub 2013 Feb 8.

School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, China.

A series of arene ruthenium(II) complexes coordinated by phenanthroimidazole derivates, [(C6H6)Ru(L)Cl]Cl·2H2O (1b L = IP, 2b L = p-NMe2PIP, 3b L = p-MeOPIP, 4b L = p-HOPIP, 5b L = p-COOHPIP, 6b L = p-CF3PIP, 7b L = p-BrPIP) have been synthesized in yields of 89-92% under microwave irradiation in 30 min, and the crystal structure of 1b by XRD gives a typical "piano stool" conformation. The antitumor activity of these complexes against various tumor cells have been evaluated by MTT assay, and the results show that this type of arene Ru(II) complexes exhibit acceptable inhibitory effect against all of these tumor cells, especially osteosarcoma MG-63 cells, but with low toxicity toward HK-2 human normal cells. Studies on the mechanism revealed that cell cycle arrest at S-phase in MG-63 cells induced by the arene Ru(II) complex 2b, which was confirmed by the increase in the percentage of cells at S-phase and down-regulator of cyclin A. The further studies by Comet assay at single cell level indicated that DNA damage in MG-63 cells was triggered by 2b, following with the up-regulation of phosphorylated p53 and histone. The studies by spectroscopy in vitro also indicate that 2b bind to DNA molecule by intercalative mode to disturb the bio-function of tumor cells. In conclusion, the synthetic arene Ru(II) complexes could serve as novel p53 activator with potential application in cancer chemotherapy.
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http://dx.doi.org/10.1016/j.ejmech.2013.01.037DOI Listing
May 2013

Enhancement of auranofin-induced apoptosis in MCF-7 human breast cells by selenocystine, a synergistic inhibitor of thioredoxin reductase.

PLoS One 2013 14;8(1):e53945. Epub 2013 Jan 14.

Department of Chemistry, Jinan University, Guangzhou, China.

Thioredoxin system plays an important role in regulation of intracellular redox balance and various signaling pathways. Thioredoxin reductase (TrxR) is overexpressed in many cancer cells and has been identified as a potential target of anticancer drugs. Auranofin (AF) is potent TrxR inhibitor with novel in vitro and in vivo anticancer activities. Selenocystine (SeC) is a nutritionally available selenoamino acid with selective anticancer effects through induction of apoptosis. In the present study, we demonstrated the synergistic effects and the underlying molecular mechanisms of SeC in combination with AF on MCF-7 human breast cancer cells. The results showed that SeC and AF synergistically inhibited the cancer cell growth through induction of ROS-dependent apoptosis with the involvement of mitochondrial dysfunction. DNA damage-mediated p53 phosphorylation and down-regulation of phosphorylated AKT and ERK also contributed to cell apoptosis. Moreover, we demonstrated the important role of TrxR activity in the synergistic action of SeC and AF. Taken together, our results suggest the strategy to use SeC and AF in combination could be a highly efficient way to achieve anticancer synergism by targeting TrxR.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0053945PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3544722PMC
July 2013

The reversal of cisplatin-induced nephrotoxicity by selenium nanoparticles functionalized with 11-mercapto-1-undecanol by inhibition of ROS-mediated apoptosis.

Biomaterials 2011 Dec 23;32(34):9068-76. Epub 2011 Aug 23.

Department of Chemistry, Jinan University, Guangzhou, China.

Although cisplatin is still one of the most effective chemotherapy agents for human cancers, its clinical use is limited by serious side effects, especially nephrotoxicity. Oxidative stress is an important mediator of cisplatin-induced nephrotoxicity. In the present study, a simple method for functionalization of selenium nanoparticles by self-assembly of 11-mercapto-1-undecanol ([email protected]) to achieve enhanced antioxidant activity and antagonis against cisplatin-induced nephrotoxicity has been demonstrated. The chemical structure of the nanoparticles was characterized by various microscopic and spectroscopic methods. The results revealed that the spherical nanoparticles were capped with MUN on the surface through formation of Se-S bond. The in vitro protective effects of [email protected] on HK-2 proximal tubular cells against cisplatin-induced nephrotoxicity and the underlying mechanisms were also investigated. [email protected] exhibited free radical scavenging activity and higher cellular uptake in human normal cells by comparing with SeNPs. [email protected] significantly attenuated cisplatin-induced reduction in cell viability, appearance of Sub-G1 peak, nuclear condensation and DNA fragmentation in HK-2 cells. Activation of caspase-3 in cells exposed to cisplatin was also effectively blocked by [email protected] Moreover, [email protected] significantly prevented the cisplatin-induced overproduction of intracellular ROS. Our findings suggest that [email protected] is a promising selenium species with potential application in prevention of cisplatin-induced renal injury.
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http://dx.doi.org/10.1016/j.biomaterials.2011.08.001DOI Listing
December 2011
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