Learning Outcomes of African Engineering Students in a Chinese Context: A Qualitative Study

China’s ‘One Belt, One Road’ national strategy has brought about both opportunities and challenges to its higher education system and that of neighbouring countries. Increased internationalisation of higher education has resulted in Chinese universities attracting a large number of international students, including those from Africa. However, few studies have been conducted to assess the learning outcomes of African students in a Chinese context. This article provides insight into African engineering students’ self-reported learning outcomes and experiences after studying in China. The fndings reveal that academic and cultural knowledge, cross-cultural communication skills, teamwork skills and changes in personalities and professional vision are common areas of development. The article concludes with recommendations for the design of effective learning experiences. La stratégie nationale chinoise “une ceinture, une route” a généré des opportunités et des défs pour son système d’enseignement supérieur et celui des pays voisins. Avec l’internationalisation croissante de l’enseignement supérieur, les universités chinoises attirent un grand nombre d’étudiants internationaux, y compris des étudiants en provenance d’Afrique. Cependant, peu d’études ont tenté d’évaluer les acquis de l’apprentissage des étudiants africains dans le contexte chinois. Cet article offre un aperçu des acquis autodéclarés des étudiants ingénieurs africains et de leur expérience des études en Chine. Les résultats de ce projet exposent plusieurs domaines communs de développement : les connaissances académiques et culturelles, les compétences de communication interculturelle, la capacité à travailler en équipe et des changements de visions professionnelle et académique. Cet article conclut par des recommandations visant à créer des expériences d’apprentissage efcaces

Recent Progress on MOF-Derived Nanomaterials as Advanced Electrocatalysts in Fuel Cells

Developing a low cost, highly active and durable cathode material is a high-priority research direction toward the commercialization of low-temperature fuel cells. However, the high cost and low stability of useable materials remain a considerable challenge for the widespread adoption of fuel cell energy conversion devices. The electrochemical performance of fuel cells is still largely hindered by the high loading of noble metal catalyst (Pt/Pt alloy) at the cathode, which is necessary to facilitate the inherently sluggish oxygen reduction reaction (ORR). Under these circumstances, the exploration of alternatives to replace expensive Pt-alloy for constructing highly efficient non-noble metal catalysts has been studied intensively and received great interest. Metal–organic frameworks (MOFs) a novel type of porous crystalline materials, have revealed potential application in the field of clean energy and demonstrated a number of advantages owing to their accessible high surface area, permanent porosity, and abundant metal/organic species. Recently, newly emerging MOFs materials have been used as templates and/or precursors to fabricate porous carbon and related functional nanomaterials, which exhibit excellent catalytic activities toward ORR or oxygen evolution reaction (OER). In this review, recent advances in the use of MOF-derived functional nanomaterials as efficient electrocatalysts in fuel cells are summarized. Particularly, we focus on the rational design and synthesis of highly active and stable porous carbon-based electrocatalysts with various nanostructures by using the advantages of MOFs precursors. Finally, further understanding and development, future trends, and prospects of advanced MOF-derived nanomaterials for more promising applications of clean energy are presented

Study of ZnS Nanostructures Based Electrochemical and Photoelectrochemical Biosensors for Uric Acid Detection

Uric acid (UA) is a kind of purine metabolism product and important in clinical diagnosis. In this work, we present a study of ZnS nanostructures-based electrochemical and photoelectrochemical biosensors for UA detection. Through a simple hydrothermal method and varying the ratio of reaction solvents, we obtained ZnS nanomaterials of one-dimensional to three-dimensional morphologies and they were characterized using field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). To fabricate the UA biosensor and study the effect of material morphology on its performance, ZnS nanomaterials were deposited on indium tin oxide (ITO) conducting glass and then coated with uricase by physical absorption. Three kinds of working electrodes were characterized by cyclic voltammetry method. The effect of material morphology on performance of UA detection was investigated via amperometric response based electrochemical method based on enzymatic reaction. The ZnS urchin-like nanostructures electrode shows better sensitivity compared with those made of nanoparticles and nanoflakes because of its high surface-area-to-volume ratio. The photoelectrochemical method for detection of UA was also studied. The sensitivity was increased 5 times after irradiation of 300 nm UV light. These results indicate that ZnS nanostructures are good candidate materials for developing enzyme-based UA biosensors

An LED-Driven AuNPs-PDMS Microfluidic Chip and Integrated Device for the Detection of Digital Loop-Mediated Isothermal DNA Amplification

The sensitive quantification of low-abundance nucleic acids holds importance for a range of clinical applications and biological studies. In this study, we describe a facile microfluidic chip for absolute DNA quantifications based on the digital loop-mediated isothermal amplification (digital LAMP) method. This microfluidic chip integrates a cross-flow channel for droplet generation with a micro-cavity for droplet tiling. DNA templates in the LAMP reagent were divided into ~20,000 water-in-oil droplets at the cross-flow channel. The droplets were then tiled in the micro-cavity for isothermal amplification and fluorescent detection. Different from the existing polydimethylsiloxane (PDMS) microfluidic chips, this study incorporates gold nanoparticles (AuNPs) into PDMS substrate through silica coating and dodecanol modification. The digital LAMP chip prepared by AuNPs-PDMS combines the benefits of the microstructure manufacturing performance of PDMS with the light-to-heat conversion advantages of AuNPs. Upon illumination with a near infrared (NIR) LED, the droplets were stably and efficiently heated by the AuNPs in PDMS. We further introduce an integrated device with a NIR heating unit and a fluorescent detection unit. The system could detect HBV (hepatitis B virus)-DNA at a concentration of 1 × 101 to 1 × 104 copies/μL. The LED-driven digital LAMP chip and the integrated device; therefore, demonstrate high accuracy and excellent performance for the absolute quantification of low-abundance nucleic acids, showing the advantages of integration, miniaturization, cost, and power consumption

FUELCELL2006-97192 SINGLE CELL PERFORMANCE OF CATALYST COATED MEMBRANE BASED ON SUPERTHIN PROTON EXCHANGE MEMBRANE

ABSTRACT The superthin PEM (≤ 30µm in thickness) can be used in CCMs(Catalyst coated membranes) and helpful to lower the cost of fuel cells. In this paper, the CCM based on Nafion NRE® 211 membrane (thickness ~25µm) was prepared and assembled into a single fuel cell. The activation time, the V-I curves and the voltage vs time plot were used to characterize the performance of CCMs under variuos hydrogen/air humidifying conditions at ambient pressure. The experimental results showed that the fuel cell with CCMs based on NRE® 211 membrane had a shorter activation time and higher performance under humidifying conditions compared to that based on nafion NRE® 212 membrane (thickness ~50µm). However, it's important to remove water from anode in order to maintain a stable performance of fuel cell. Moreover, the performance of the single fuel cell using superthin membranes could be improved at a high current density under non-humidifying conditions

Electrocatalytic activity and stability of carbon nanotubes-supported Pt-on-Au, Pd-on-Au, Pt-on-Pd-on-Au, Pt-on-Pd, and Pd-on-Pt catalysts for methanol oxidation reaction

For optimizing both the activity and stability of Pt-based catalysts for methanol oxidation reaction (MOR), several carbon nanotubes(CNTs)-supported catalysts such as Pt-on-Au/CNTs, Pd-on-Au/CNTs, Pt-on-Pdon- Au/CNTs, Pt-on-Pd/CNTs, and Pd-on-Pt/CNTs catalysts are synthesized mainly through electrodeposition method. The activity and stability comparisons show that Pt-on-Au/CNTs has a higher MOR activity but a lower stability than Pd-on-Au/CNTs. To utilize the merits of the Pt and Pd components, Pt-on-Pd-on- Au/CNTs and Pt-on-Pd/CNTs catalysts are synthesized. The Pt-on-Pd-on-Au/CNTs and Pt-on-Pd/CNTs catalysts shows higher MOR activity than Pd-on-Au/CNTs and Pd/CNTs catalysts and higher stability than Pt-on-Au/CNTs, suggesting a synergistic interaction between Pt and Pd in catalyzing methanol oxidation reaction. Calculation shows that the total mass activity of Pt-on-Pd/CNTs with quite low Pt amount is on a similar level as that of Pt/CNTs for MOR oxidation, indicating the Pt-on-Pd catalyst could have promising potential as a low-Pt catalyst for MOR in alkaline media.Peer reviewed: YesNRC publication: Ye

The Shuganhuazheng Formula in Triple-Negative Breast Cancer: A Study Based on Network Pharmacology and In Vivo Experiments

Breast cancer is the most common cancer in women. Among breast cancer subtypes, triple-negative breast cancer (TNBC) has the highest degree of malignancy and the worst prognosis. The Shuganhuazheng formula (SGHZF) is a traditional Chinese herbal formula for the treatment of TNBC, but the mechanism of SGHZF in the treatment of TNBC remains unclear. In this study, the therapeutic effect and mechanism of SGHZF against TNBC were preliminarily determined based on in vivo experimental verification and network pharmacology. In terms of therapeutic effects, the antitumour effect was verified by measuring and calculating tumour volume, and the expression of proto-oncogene c-Myc was verified by PCR. In terms of the mechanism, potential therapeutic targets were identified by overlapping the SGHZF-related and TNBC-related targets. After comprehensively analysing the results of the protein-protein interaction (PPI), gene ontology (GO) function, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, Akt and HIF-1α were selected for verification by using immunohistochemical and Western blot analyses. The results of the study indicated that SGHZF can inhibit breast tumour growth in mice and that the mechanism may be related to the inhibition of Akt and HIF-1α expression

Centrifugal Microfluidic System for Nucleic Acid Amplification and Detection

We report here the development of a rapid PCR microfluidic system comprising a double-shaft turntable and centrifugal-based disc that rapidly drives the PCR mixture between chambers set at different temperatures, and the bidirectional flow improved the space utilization of the disc. Three heating resistors and thermistors maintained uniform, specific temperatures for the denaturation, annealing, and extension steps of the PCR. Infrared imaging showed that there was little thermal interference between reaction chambers; the system enabled the cycle number and reaction time of each step to be independently adjusted. To validate the function and efficiency of the centrifugal microfluidic system, a 350-base pair target gene from the hepatitis B virus was amplified and quantitated by fluorescence detection. By optimizing the cycling parameters, the reaction time was reduced to 32 min as compared to 120 min for a commercial PCR machine. DNA samples with concentrations ranging from 10 to 106 copies/mL could be quantitatively analyzed using this system. This centrifugal-based microfluidic platform is a useful system and possesses industrialization potential that can be used for portable diagnostics