This paper introduces computational fluid used in aerospace engineering, to deal with surface physical and mathematical foundations of CFD, this traffic problems such as queue/platoon distribution, dynamics （CFD）, a...This paper introduces computational fluid used in aerospace engineering, to deal with surface physical and mathematical foundations of CFD, this traffic problems such as queue/platoon distribution, dynamics （CFD）, a numerical traffic flow related problems. approach widely and successfully After a brief introduction of the paper develops CFD implementation methodology for modeling shockwave propagation, and prediction of system performance. Some theoretical and practical applications are discussed in this paper to illustrate the implementation methodology. It is found that CFD approach can facilitate a superior insight into the formation and propagation of congestion, thereby supporting more effective methods to alleviate congestion. In addition, CFD approach is found capable of assessing freeway system performance using less ITS detectors, and enhancing the coverage and reliability of a traffic detection system.展开更多
In this study, the factors influencing phone-related driving safety and drivers＇ perceptions of cell phone usage were analyzed. A representative sample of more than 500 licensed drivers in Texas who own a cell phone ...In this study, the factors influencing phone-related driving safety and drivers＇ perceptions of cell phone usage were analyzed. A representative sample of more than 500 licensed drivers in Texas who own a cell phone was interviewed based on a well-design questionnaire. Logistic regression model showed that the impact of using cell phone on driving safety varies depending on the characteristics of drivers, such as gender, age, driving experience, and use intensity. Additionally, the results indicated that the strong determinants of phone-related hazard are different from that of phone-related accidents. Regarding the drivers＇ perception of cell phone usage, there are two key findings. First, there is no explicit belief among the drivers about whether cell phone usage impairs driving safety regardless of the drivers＇ age, gender, driving education experience etc. Second, most of drivers have not realized that cell phone use while driving would increase their perception reaction time. Based on the analysis of these results, implications of cell phone use on driving safety along with some safety countermeasures, such as selective bans and non-cell phone zones, are discussed in the paper.展开更多
<i><span style="font-family:;" "="">Solanum nigrum</span></i><span style="font-family:;" "=""> L. has a delightful prospect as a hyperacc...<i><span style="font-family:;" "="">Solanum nigrum</span></i><span style="font-family:;" "=""> L. has a delightful prospect as a hyperaccumulation plant for cadmium pollution remediation, and microplastic is a new type of pollution that has received wide attention. In this study, the effects of polyethylene microplastics (LDPE) (0.135, 0.27, 0.81 and 1.35 mg·kg<sup>-1</sup>) and cadmium (20 mg·kg<sup>-1</sup>) on the growth indexes and soil physical and chemical properties of <i>Solanum nigrum</i> L. were investigated in a 17-day microcosm experiment. The results showed that single LDPE contamination showed a trend of low concentration promotion and medium-high concentration inhibited the growth index of <i>Solanum nigrum</i> L. and soil physicochemical index, and single Cd contamination was more stressful to plants than single LDPE contamination, while low concentration of LDPE could reduce the effect of Cd on soil physical and chemical properties and promote plant growth and uptake of soil nutrients. These findings suggest that high concentrations of microplastics can inhibit the growth of <i>Solanum nigrum</i> L. alone or in combination with Cd, rather than reducing the toxicity of Cd.</span>展开更多
Inorganic nanomaterials exhibit superior friction-reduction and anti-wear properties in oils. In this study, 2D layered α-zirconium phosphate (α-ZrP) nanosheets intercalated with different amines have been synthesiz...Inorganic nanomaterials exhibit superior friction-reduction and anti-wear properties in oils. In this study, 2D layered α-zirconium phosphate (α-ZrP) nanosheets intercalated with different amines have been synthesized to study their dispersion stabilities in lubricating oil and tribological applications. The intercalated amines should be sufficiently long and lipophilic to provide stabilization to α-ZrP nanosheets in mineral oil. The results of tribological tests illustrate that with the addition of well-dispersed nanosheets, the coefficient of friction (COF) and pin volume loss reduce by ~47% and 75%, respectively. The excellent dispersion stability enables the nanosheets to flow into the contact area at the beginning, and thereby protect the rubbing surface. A reduction in the van der Waals forces between the adjacent layers induced by the intercalated amines transforms the friction between adjacent layers from pin disk to sliding, leading to a decrease in the COF under hydrodynamic lubrication. The study provides a new method to enhance the tribological properties via tuning the dispersion stabilities of nanomaterials in oils.展开更多
The functional recovery of peripheral nerve injury(PNI)is unsatisfactory,whereas diabetes mellitus(DM)and its related complications further attenuate the restoration of diabetic PNI(DPNI).Adipose-derived stem cells(AD...The functional recovery of peripheral nerve injury(PNI)is unsatisfactory,whereas diabetes mellitus(DM)and its related complications further attenuate the restoration of diabetic PNI(DPNI).Adipose-derived stem cells(ADSCs)are promising candidates for treatment of DPNI due to their abundant source,excellent differentiation and paracrine ability.Our results showed that ADSCs remarkably enhanced the proliferation and migration of Schwann cells and endothelial cells,and tube formation.Mechanistically,ADSCs could regulate Nrf2/HO-1,NF-κB and PI3K/AKT/mTOR signaling pathways,showing multiple functions in reducing oxidative stress and inflammation,and regulating cell metabolism,growth,survival,proliferation,angiogenesis,differentiation of Schwann cell and myelin formation.In current study,novel graphene foam(GF)/hydrogel-based scaffold was developed to deliver ADSCs for treatment of DPNI.GF/hydrogel scaffold exhibited excellent mechanical strength,suitable porous network,superior electrical conductivity,and good biocompatibility.In vitro results revealed that GF/hydrogel scaffold could obviously accelerate proliferation of Schwann cells.Moreover,in vivo experiments demonstrated that ADSCs-loaded GF/hydrogel scaffold significantly promoted the recovery of DPNI and inhibited the atrophy of targeted muscles,thus providing a novel and attractive therapeutic approach for DPNI patients.展开更多
Objective This study aims to explore the application value of multimodal magnetic resonance imaging(MRI)in the diagnosis of atypical hepatocellular carcinoma(HCC).Methods 80 patients with atypical HCC who were admitte...Objective This study aims to explore the application value of multimodal magnetic resonance imaging(MRI)in the diagnosis of atypical hepatocellular carcinoma(HCC).Methods 80 patients with atypical HCC who were admitted to our hospital from August 2018 to February 2020 were selected as the research subjects.All patients underwent dynamic computed tomography(CT)enhancement scans,and then multimodal MRI scans,including an MRI plain scan,dynamic contrastenhancement(DCE),and diffusion-weighted imaging(DWI).Then,the image data were analyzed.Results The diagnostic accuracy of the observation group(95.00%)was significantly higher than that of the control group(75.00%).This difference was statistically significant(χ2=6.128,P<0.05).With the increase of the b value,the apparent diffusion coefficient(ADC)values of the liver tissue and liver cancer tissue gradually decreased.Compared with normal liver tissue,the ADC value of liver cancer tissue was significantly lower than that of normal liver tissue(P<0.05).A plain MRI scan of 89 lesions,DCE examination of 93 lesions,(1)7 lesions were slow-rising and fast-falling;(2)72 lesions were fast-rising and fast-falling;(3)10 were platform-type lesions;(4)4 lesions had no enhancement.Conclusion The diagnostic efficiency of a multimodal MRI in the diagnosis of atypical HCC is high,and it has particular clinical application value.展开更多
文摘This paper introduces computational fluid used in aerospace engineering, to deal with surface physical and mathematical foundations of CFD, this traffic problems such as queue/platoon distribution, dynamics （CFD）, a numerical traffic flow related problems. approach widely and successfully After a brief introduction of the paper develops CFD implementation methodology for modeling shockwave propagation, and prediction of system performance. Some theoretical and practical applications are discussed in this paper to illustrate the implementation methodology. It is found that CFD approach can facilitate a superior insight into the formation and propagation of congestion, thereby supporting more effective methods to alleviate congestion. In addition, CFD approach is found capable of assessing freeway system performance using less ITS detectors, and enhancing the coverage and reliability of a traffic detection system.
文摘In this study, the factors influencing phone-related driving safety and drivers＇ perceptions of cell phone usage were analyzed. A representative sample of more than 500 licensed drivers in Texas who own a cell phone was interviewed based on a well-design questionnaire. Logistic regression model showed that the impact of using cell phone on driving safety varies depending on the characteristics of drivers, such as gender, age, driving experience, and use intensity. Additionally, the results indicated that the strong determinants of phone-related hazard are different from that of phone-related accidents. Regarding the drivers＇ perception of cell phone usage, there are two key findings. First, there is no explicit belief among the drivers about whether cell phone usage impairs driving safety regardless of the drivers＇ age, gender, driving education experience etc. Second, most of drivers have not realized that cell phone use while driving would increase their perception reaction time. Based on the analysis of these results, implications of cell phone use on driving safety along with some safety countermeasures, such as selective bans and non-cell phone zones, are discussed in the paper.
文摘<i><span style="font-family:;" "="">Solanum nigrum</span></i><span style="font-family:;" "=""> L. has a delightful prospect as a hyperaccumulation plant for cadmium pollution remediation, and microplastic is a new type of pollution that has received wide attention. In this study, the effects of polyethylene microplastics (LDPE) (0.135, 0.27, 0.81 and 1.35 mg·kg<sup>-1</sup>) and cadmium (20 mg·kg<sup>-1</sup>) on the growth indexes and soil physical and chemical properties of <i>Solanum nigrum</i> L. were investigated in a 17-day microcosm experiment. The results showed that single LDPE contamination showed a trend of low concentration promotion and medium-high concentration inhibited the growth index of <i>Solanum nigrum</i> L. and soil physicochemical index, and single Cd contamination was more stressful to plants than single LDPE contamination, while low concentration of LDPE could reduce the effect of Cd on soil physical and chemical properties and promote plant growth and uptake of soil nutrients. These findings suggest that high concentrations of microplastics can inhibit the growth of <i>Solanum nigrum</i> L. alone or in combination with Cd, rather than reducing the toxicity of Cd.</span>
基金This work was supported by the start-up funding from the Southern University of Science and Technology(SUSTech),"The Recruitment Program of Global Youth Experts of China"the Foundation of Shenzhen Science and Technology Innovation Committee(Grant Nos.JCYJ20160315164631204 and KQJSCX20170726145415637).
文摘Inorganic nanomaterials exhibit superior friction-reduction and anti-wear properties in oils. In this study, 2D layered α-zirconium phosphate (α-ZrP) nanosheets intercalated with different amines have been synthesized to study their dispersion stabilities in lubricating oil and tribological applications. The intercalated amines should be sufficiently long and lipophilic to provide stabilization to α-ZrP nanosheets in mineral oil. The results of tribological tests illustrate that with the addition of well-dispersed nanosheets, the coefficient of friction (COF) and pin volume loss reduce by ~47% and 75%, respectively. The excellent dispersion stability enables the nanosheets to flow into the contact area at the beginning, and thereby protect the rubbing surface. A reduction in the van der Waals forces between the adjacent layers induced by the intercalated amines transforms the friction between adjacent layers from pin disk to sliding, leading to a decrease in the COF under hydrodynamic lubrication. The study provides a new method to enhance the tribological properties via tuning the dispersion stabilities of nanomaterials in oils.
基金This study is financially supported by the National Natural Science Foundation of China(Nos.81971758,51890892,81971712,81870346,and 81700432)the Natural Science Foundation of Shanghai Science and Technology Committee(No.20ZR1431600)+7 种基金This research is also supported by the National Natural Science Foundation of China(No.11761161004)Z.L.acknowledge supports by the National Natural Science Foundation of China-Research Grants Council Joint Research Scheme(Nos.11761161004 and N_HKUST607/17)the IER foundation(No.HT-JD-CXY-201907)“International science and technology cooperation projects”of Science and Technological Bureau of Guangzhou Huangpu District(No.2019GH06)Guangdong Science and Technology Department(No.2020A0505090003)Research Fund of Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology(No.2020B1212030010)Technical assistance from the Materials Characterization and Preparation Facilities of The Hong Kong University Of Science And Technology is greatly appreciatedWe also acknowledge the support of Guangdong Provincial Key Laboratory Program(No.2021B1212040001)from the Department of Science and Technology of Guangdong Province.
文摘The functional recovery of peripheral nerve injury(PNI)is unsatisfactory,whereas diabetes mellitus(DM)and its related complications further attenuate the restoration of diabetic PNI(DPNI).Adipose-derived stem cells(ADSCs)are promising candidates for treatment of DPNI due to their abundant source,excellent differentiation and paracrine ability.Our results showed that ADSCs remarkably enhanced the proliferation and migration of Schwann cells and endothelial cells,and tube formation.Mechanistically,ADSCs could regulate Nrf2/HO-1,NF-κB and PI3K/AKT/mTOR signaling pathways,showing multiple functions in reducing oxidative stress and inflammation,and regulating cell metabolism,growth,survival,proliferation,angiogenesis,differentiation of Schwann cell and myelin formation.In current study,novel graphene foam(GF)/hydrogel-based scaffold was developed to deliver ADSCs for treatment of DPNI.GF/hydrogel scaffold exhibited excellent mechanical strength,suitable porous network,superior electrical conductivity,and good biocompatibility.In vitro results revealed that GF/hydrogel scaffold could obviously accelerate proliferation of Schwann cells.Moreover,in vivo experiments demonstrated that ADSCs-loaded GF/hydrogel scaffold significantly promoted the recovery of DPNI and inhibited the atrophy of targeted muscles,thus providing a novel and attractive therapeutic approach for DPNI patients.
文摘Objective This study aims to explore the application value of multimodal magnetic resonance imaging(MRI)in the diagnosis of atypical hepatocellular carcinoma(HCC).Methods 80 patients with atypical HCC who were admitted to our hospital from August 2018 to February 2020 were selected as the research subjects.All patients underwent dynamic computed tomography(CT)enhancement scans,and then multimodal MRI scans,including an MRI plain scan,dynamic contrastenhancement(DCE),and diffusion-weighted imaging(DWI).Then,the image data were analyzed.Results The diagnostic accuracy of the observation group(95.00%)was significantly higher than that of the control group(75.00%).This difference was statistically significant(χ2=6.128,P<0.05).With the increase of the b value,the apparent diffusion coefficient(ADC)values of the liver tissue and liver cancer tissue gradually decreased.Compared with normal liver tissue,the ADC value of liver cancer tissue was significantly lower than that of normal liver tissue(P<0.05).A plain MRI scan of 89 lesions,DCE examination of 93 lesions,(1)7 lesions were slow-rising and fast-falling;(2)72 lesions were fast-rising and fast-falling;(3)10 were platform-type lesions;(4)4 lesions had no enhancement.Conclusion The diagnostic efficiency of a multimodal MRI in the diagnosis of atypical HCC is high,and it has particular clinical application value.
