Review of Sensor-Based Subgrade Distress Identifications.

The attributes of diversity and concealment pose formidable challenges in the accurate detection and efficacious management of distresses within subgrade structures. The onset of subgrade distresses may precipitate structural degradation, thereby amplifying the frequency of traffic incidents and instigating economic ramifications. Accurate and timely detection of subgrade distresses is essential for maintaining and repairing road sections with existing distresses. This helps to prolong the service life of road infrastructure and reduce financial burden. In recent years, the advent of numerous novel technologies and methodologies has propelled significant advancements in subgrade distress detection. Therefore, this review delineates a concentrated examination of subgrade distress detection, methodically consolidating and presenting various techniques while dissecting their respective merits and constraints. By furnishing comprehensive guidance on subgrade distress detection, this review facilitates the expedient identification and targeted treatment of subgrade distresses, thereby fortifying safety and enhancing durability. The pivotal role of this review in bolstering the construction and operational facets of transportation infrastructure is underscored.

An investigation of the pullout behaviors of tire strips embedded in tire-derived aggregate reinforced sand.

The recycling of scrap tires has become an important issue in the area of environmental protection in the past 20 years. In recent years, tire strips and tire-derived aggregates (TDA) have been used in geotechnical engineering projects. Both reinforcement methods are proved available to improve the horizontal resistance of stabilized structures. This study reported a new method which combined tire strips and TDA utilization in order to investigate if such combinations could further improve the stability of retaining structures. The shear properties of TDA reinforced sand with different tire content levels (0%, 10%, 20%, and 30%) were measured using direct shear tests. The pullout behaviors of tire strips with and without transverse ribs embedded in pure sand/TDA reinforced materials were then compared. Based on the obtained results, a new calculation method was proposed for the estimation of the peak pullout resistance of tire strips embedded in TDA-reinforced sand, with the interference of transverse ribs and different tire content levels of the TDA-reinforced sand taken into consideration. The test results revealed that a tire content level of 20% was the optimal proportion of TDA-reinforced sand. Meanwhile, the model tests proved that the end resistance provided by transverse ribs could largely enhance the ultimate pullout capacity of soil structures. Therefore, it was concluded that the proposed methods were feasible in scrap tire recycling projects, and the test results and proposed calculation method could potentially provide important references for the future designs and construction of tire strip stabilized retaining walls.

Determinants and Prediction of Injury Severities in Multi-Vehicle-Involved Crashes.

Multi-vehicle (MV) crashes, which can lead to great damages to society, have always been a serious issue for traffic safety. A further understanding of crash severity can help transportation engineers identify the critical reasons and find effective countermeasures to improve transportation safety. However, studies involving methods of machine learning to predict the possibility of injury-severity of MV crashes are rarely seen. Besides that, previous studies have rarely taken temporal stability into consideration in MV crashes. To bridge these knowledge gaps, two kinds of models: random parameters logit model (RPL), with heterogeneities in the means and variances, and Random Forest (RF) were employed in this research to identify the critical contributing factors and to predict the possibility of MV injury-severity. Three-year (2016-2018) MV data from Washington, United States, extracted from the Highway Safety Information System (HSIS), were applied for crash injury-severity analysis. In addition, a series of likelihood ratio tests were conducted for temporal stability between different years. Four indicators were employed to measure the prediction performance of the selected models, and four categories of crash-related characteristics were specifically investigated based on the RPL model. The results showed that the machine learning-based models performed better than the statistical models did when taking the overall accuracy as an evaluation indicator. However, the statistical models had a better prediction performance than the machine learning models had considering crash costs. Temporal instabilities were present between 2016 and 2017 MV data. The effect of significant factors was elaborated based on the RPL model with heterogeneities in the means and variances.

Real-Time Queue Length Detection with Roadside LiDAR Data.

Real-time queue length information is an important input for many traffic applications. This paper presents a novel method for real-time queue length detection with roadside LiDAR data. Vehicles on the road were continuously tracked with the LiDAR data processing procedures (including background filtering, point clustering, object classification, lane identification and object association). A detailed method to identify the vehicle at the end of the queue considering the occlusion issue and package loss issue was documented in this study. The proposed method can provide real-time queue length information. The performance of the proposed queue length detection method was evaluated with the ground-truth data collected from three sites in Reno, Nevada. Results show the proposed method can achieve an average of 98% accuracy at the six investigated sites. The errors in the queue length detection were also diagnosed.

Expression of hepatitis B virus 1.3-fold genome plasmid in an SV40 T-antigen-immortalized mouse hepatic cell line.

AIM: To investigate the expression of the hepatitis B virus (HBV) 1.3-fold genome plasmid (pHBV1.3) in an immortalized mouse hepatic cell line induced by SV40 T-antigen (SV40T) expression. METHODS: Mouse hepatic cells were isolated from mouse liver tissue fragments from 3-5 d old Kunming mice by the direct collagenase digestion method and cultured in vitro. The pRSV-T plasmid was transfected into mouse hepatic cells to establish an SV40LT-immortalized mouse hepatic cell line. The SV40LT-immortalized mouse hepatic cells were identified and transfected with the pHBV1.3 plasmid. The levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in the supernatant were determined by an electrochemiluminescence immunoassay at 24, 48, 72 and 96 h after transfection. The expressions of HBsAg and hepatitis B c antigen (HBcAg) in the cells were investigated by indirect immunofluorescence analysis. The presence of HBV DNA replication intermediates in the transfected cells and viral particles in the supernatant of the transfected cell cultures was monitored using the Southern hybridization assay and transmission electronic microscopy, respectively. RESULTS: The pRSV-T plasmid was used to immortalize mouse hepatocytes and an SV40LT-immortalized mouse hepatic cell line was successfully established. SV40LT-immortalized mouse hepatic cells have the same morphology and growth characteristics as primary mouse hepatic cells can be subcultured and produce albumin and cytokeratin-18 in vitro. Immortalized mouse hepatic cells did not show the characteristics of tumor cells, as alpha-fetoprotein levels were comparable (0.58 ± 0.37 vs 0.61 ± 0.31, P = 0.37). SV40LT-immortalized mouse hepatic cells were then transfected with the pHBV1.3 plasmid, and it was found that the HBV genome replicated in SV40LT-immortalized mouse hepatic cells. The levels of HBsAg and HBeAg continuously increased in the supernatant after the transfection of pHBV1.3, and began to decrease 72 h after transfection. The expressions of HBsAg and HBcAg were observed in the pHBV1.3-transfected cells. HBV DNA replication intermediates were also observed at 72 h after transfection, including relaxed circular DNA, double-stranded DNA and single-stranded DNA. Furthermore, a few 42 nm Dane particles, as well as many 22 nm subviral particles with a spherical or filamentous shape, were detected in the supernatant. CONCLUSION: SV40T expression can immortalize mouse hepatic cells, and the pHBV1.3-transfected SV40T-immortalized mouse hepatic cell line can be a new in vitro cell model.

Clinical progress and risk factors for death in severe fever with thrombocytopenia syndrome patients.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by the SFTS virus (SFTSV) with an average fatality rate of 12%. The clinical factors for death in SFTS patients remain unclear. METHODS: Clinical features and laboratory parameters were dynamically collected for 11 fatal and 48 non-fatal SFTS cases. Univariate logistic regression was used to evaluate the risk factors associated with death. RESULTS: Dynamic tracking of laboratory parameters revealed that during the initial fever stage, the viral load was comparable for the patients who survived as well as the ones that died. Then in the second stage when multi-organ dysfunction occurred, from 7-13 days after disease onset, the viral load decreased in survivors but it remained high in the patients that died. The key risk factors that contributed to patient death were elevated serum aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and creatine kinase fraction, as well as the appearance of CNS (central nervous system) symptoms, hemorrhagic manifestation, disseminated intravascular coagulation, and multi-organ failure. All clinical markers reverted to normal in the convalescent stage for SFTS patients who survived. CONCLUSIONS: We identified a period of 7-13 days after the onset of illness as the critical stage in SFTS progression. A sustained serum viral load may indicate that disease conditions will worsen and lead to death.

Person-to-person transmission of severe fever with thrombocytopenia syndrome bunyavirus through blood contact.

Severe fever with thrombocytopenia syndrome bunyavirus is a newly discovered bunyavirus with high pathogenicity to human. The transmission model has been largely uncharacterized. Investigation on a cluster of severe fever with thrombocytopenia syndrome cases provided evidence of person-to-person transmission through blood contact to the index patient with high serum virus load.