684 research outputs found

    A systematic review on sustainability assessment of internal combustion engines

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    Internal combustion engines (ICEs) have served as the primary powertrain for mobile sources since the 1890s and also recognized as significant contributors to CO2 emissions in the transportation sector. In order to achieve "carbon neutrality" for transportation sectors, ICE vehicles (ICEVs) are facing substantial challenges in meeting CO2 regulations and intense competition from battery electric vehicles and fuel cell vehicles. Consequently, new technologies of ICEs are continually emerging to enhance competitiveness in reducing environmental impacts. However, the limited studies on the life cycle assessment (LCA) of ICEs make it difficult to evaluate the actual contributions of the emerging technologies from a life cycle perspective. Conducting a systematic review of ICEs LCA studies could identify weaknesses and gaps in these studies for new scenarios. Therefore, this article presents the first systematic review of the LCA of ICEs to provide an overview of the current state of knowledge. A total of 87 life cycle assessment studies between 2017 and 2023 using the Scopus database were identified after searching for the keywords "Sustainability assessment" OR "Life cycle assessment" AND "Internal combustion engine*" OR "ICE*" and carefully screening, and then classified and analyzed by six aspects including sustainability indicators, life cycle phases, life cycle inventories, ICE technologies (including alternative fuels), types of mobile sources and powertrain systems. It is concluded that there are quite limited studies solely focusing on LCA of ICEs, and the LCA assessment lacks consideration of: 1. environmental pollution, human health and socio-economic aspects, 2. fuel production process and maintenance & repair phase, 3. small and developing countries, 4. the emerging ICE technologies and zero carbon/carbon-neutral fuels, 5. large and high-power mobile sources and heavy-duty hybrid technologies

    MST: Adaptive Multi-Scale Tokens Guided Interactive Segmentation

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    Interactive segmentation has gained significant attention for its application in human-computer interaction and data annotation. To address the target scale variation issue in interactive segmentation, a novel multi-scale token adaptation algorithm is proposed. By performing top-k operations across multi-scale tokens, the computational complexity is greatly simplified while ensuring performance. To enhance the robustness of multi-scale token selection, we also propose a token learning algorithm based on contrastive loss. This algorithm can effectively improve the performance of multi-scale token adaptation. Extensive benchmarking shows that the algorithm achieves state-of-the-art (SOTA) performance, compared to current methods. An interactive demo and all reproducible codes will be released at https://github.com/hahamyt/mst.Comment: 11 pages, 10 figure

    Analysis on the Correlation Degree between the Driver’s Reaction Ability and Physiological Parameters

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    In this paper, the correlation degree between driver’s reaction time and the physiological signal is analyzed. For this purpose, a large number of road experiments are performed using the biopac and the reaction time test systems to collect data. First, the electroencephalograph (EEG) signal is processed by using the fast Fourier and the inverse Fourier transforms. Then, the power spectrum densities (PSD) of α, β, δ, and EEG wave are calculated by Welch procedure. The average power of the power spectrum of α, β, and θ is calculated by the biopac software and two ratio formulas, (α+θ)/β and α/β, are selected to be the impact factors. After that the heart rate and the standard deviation of RR interval are calculated from the electrocardiograph (ECG) signal. Lastly, the correlation degree between the eight impact factors and the reaction time are analyzed based on the grey correlation analysis. The results demonstrate that α/β has the greatest correlation to the reaction time except EEG-PSD. Furthermore, two mathematical models for the reaction time-driving time and the α/β-driving time are developed based on the Gaussian function. These mathematical models are then finally used to establish the functional relation of α/β-the reaction time

    Chemokine CXCL12 and its receptor CXCR4 expression are associated with perineural invasion of prostate cancer

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    <p>Abstract</p> <p>Objective</p> <p>To identify the roles of CXCL12 and CXCR4 and the associated mechanism involved in perineural invasion of prostate cancer.</p> <p>Methods</p> <p>The distribution and expression of CXCL12, CXCR4, MMP-2 and MMP-9 in human prostate cancer and in tumor cells invading nerve tissue were studied with immunohistochemical staining. The effects of exogenous CXCL12 and CXCR4 antagonist AMD3100 on PC3 prostate cancer cells invasiveness were assessed in vitro and in vivo.</p> <p>Results</p> <p>The expression of CXCL12, CXCR4, MMP-2, and MMP-9 in human prostate cancer were higher than those in hyperplastic prostate tissues (<it>P </it>< 0.05). In vitro CXCL12 could stimulate the PC3 cells invasiveness (<it>P </it>< 0.05) while AMD3100 could inhibit invasiveness. In vivo, the number of nerves around the tumor tissue in the group treated with CXCL12 was significantly higher than that found in the control group (<it>P </it>< 0.05). Both the control group and the CXCL12-treated group had more nerves number near the tumor tissue than it found in the AMD3100-treated group. The positive cell number of CXCL12, CXCR4, MMP-2, MMP-9, and NGF expression ranked from highest to lowest, were the CXCL12-treated, the control, and the AMD3100-treated group(<it>P </it>< 0.05).</p> <p>Conclusion</p> <p>CXCL12 and its receptor CXCR4 along with MMP-2 and MMP-9 are related with prostate cancer perineural invasion.</p

    The Signaling Pathways Involved in Chondrocyte Differentiation and Hypertrophic Differentiation

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    Chondrocytes communicate with each other mainly via diffusible signals rather than direct cell-to-cell contact. The chondrogenic differentiation of mesenchymal stem cells (MSCs) is well regulated by the interactions of varieties of growth factors, cytokines, and signaling molecules. A number of critical signaling molecules have been identified to regulate the differentiation of chondrocyte from mesenchymal progenitor cells to their terminal maturation of hypertrophic chondrocytes, including bone morphogenetic proteins (BMPs), SRY-related high-mobility group-box gene 9 (Sox9), parathyroid hormone-related peptide (PTHrP), Indian hedgehog (Ihh), fibroblast growth factor receptor 3 (FGFR3), and -catenin. Except for these molecules, other factors such as adenosine, O 2 tension, and reactive oxygen species (ROS) also have a vital role in cartilage formation and chondrocyte maturation. Here, we outlined the complex transcriptional network and the function of key factors in this network that determine and regulate the genetic program of chondrogenesis and chondrocyte differentiation

    A Magnetically and Thermally Controlled Liquid Metal Variable Stiffness Material

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    Smart materials that can actively tune their stiffness are of great interest to many fields, including the construction industry, medical devices, industrial machines, and soft robotics. However, developing a material that can offer a large range of stiffness change and rapid tuning remains a challenge. Herein, a liquid metal variable stiffness material (LMVSM) that can actively and rapidly tune its stiffness by applying an external magnetic field or by changing the temperature is developed. The LMVSM is composed of three layers: a gallium–iron magnetorheological fluid (Ga–Fe MRF) layer for providing variable stiffness, a nickel–chromium wire layer for Joule heating, and a soft heat dissipation layer for accelerating heating and rapid cooling. The stiffness can be rapidly increased by 4 times upon the application of a magnetic field or 10 times by solidifying the Ga–Fe MRF. Finally, the LMVSM is attached to a pneumatically controlled soft robotic gripper to actively tune its load capacity, demonstrating its potential to be further developed into smart components that can be widely adopted by smart devices

    Preparation of lactose-free pasteurized milk with a recombinant thermostable β-glucosidase from Pyrococcus furiosus

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    Abstract Background Lactose intolerance is a common health concern causing gastrointestinal symptoms and avoidance of dairy products by afflicted individuals. Since milk is a primary source of calcium and vitamin D, lactose intolerant individuals often obtain insufficient amounts of these nutrients which may lead to adverse health outcomes. Production of lactose-free milk can provide a solution to this problem, although it requires use of lactase from microbial sources and increases potential for contamination. Use of thermostable lactase enzymes can overcome this issue by functioning under pasteurization conditions. Results A thermostable β-glucosidase gene from Pyrococcus furiosus was cloned in frame with the Saccharomyces cerecisiae a-factor secretory signal and expressed in Pichia pastoris strain X-33. The recombinant enzyme was purified by a one-step method of weak anion exchange chromatography. The optimum temperature and pH for this β-glucosidase activity was 100°C and pH 6.0, respectively. The enzyme activity was not significantly inhibited by Ca2+. We tested the additive amount, hydrolysis time, and the influence of glucose on the enzyme during pasteurization and found that the enzyme possessed a high level of lactose hydrolysis in milk that was not obviously influenced by glucose. Conclusions The thermostablity of this recombinant β-glucosidase, combined with its neutral pH activity and favorable temperature activity optima, suggest that this enzyme is an ideal candidate for the hydrolysis of lactose in milk, and it would be suitable for application in low-lactose milk production during pasteurization. </jats:sec

    Non-invasive methods to evaluate liver fibrosis in patients with non-alcoholic fatty liver disease

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    Non-alcoholic Fatty Liver Disease (NAFLD) is a chronic liver disease that is strongly related to insulin resistance and metabolic syndrome, and it has become the most common liver disorder in developed countries. NAFLD embraces the full pathological process of three conditions: steatosis, non-alcoholic steatohepatitis, and finally, cirrhosis. As NAFLD progresses, symptoms will become increasingly severe as fibrosis develops. Therefore, evaluating the fibrosis stage is crucial for patients with NAFLD. A liver biopsy is currently considered the gold standard for staging fibrosis. However, due to the limitations of liver biopsy, non-invasive alternatives were extensively studied and validated in patients with NAFLD. The advantages of non-invasive methods include their high safety and convenience compared with other invasive approaches. This review introduces the non-invasive methods, summarizes their benefits and limitations, and assesses their diagnostic performance for NAFLD-induced fibrosis
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