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Roadway multi-fatality crashes have always been a vital issue for traffic safety. This study aims to explore the contributory factors and interdependent characteristics of multi-fatality crashes using a novel framework combining association rules mining and rules graph structures. A case study is conducted using data from 1068 severe fatal crashes in China from 2015 to 2020, and 1452 interesting rules are generated using an association rule mining approach. Several modular rules graph structures are constructed based on graph theory to reflect the interactions and patterns between different variables. The results indicate that multi-fatality crashes are highly associated with improper operations, passenger overload, fewer lanes, mountainous terrain, and run-off-the-road crashes, representing the key variables of factors concerning driver, vehicle, road, environment, and accident, respectively. Furthermore, crashes involving different severity levels, road categories, and terrain are verified to possess unique association rules and independent crash patterns. Moreover, the proportion of severe crashes caused by a combination of human-vehicle-road-environment factors (43%) is much higher than that of normal crashes (3%). This study reveals that the hidden associations between various factors contribute to the overrepresentation and severity of multi-fatality crashes. It also demonstrates that the crash mechanisms involving multi-fatality crashes and their interactions are more complex at the system level than those for normal crashes. The proposed framework can effectively map the intrinsic link between multiple crash factors and potential risks, providing transportation agencies with helpful insights for targeted safety measures and preventive strategies. [ABSTRACT FROM AUTHOR]

Iron deficiency anemia (IDA) in pregnant women was associated with increased risks of both maternal and neonatal adverse outcomes. This study aimed to investigate the prevalence of IDA and identify the associated factors of IDA among pregnancy woman in Fuyang, China. The cross-sectional study was carried out in 789 pregnant women using simple random sampling method living in Fuyang, China from August 2017 to May 2018. Overall, the prevalence of IDA was 39.8%. 1-unit increment in maternal age was associated with a 5% increased risk of IDA, and 1-unit increased in BMI was associated with a 6% decreased risk of IDA (all P <.01). When compared with exercise for <30 minutes, 30–60 minutes of daily exercise was associated with a lower risk of IDA (P =.02). Similarly, when compared with a low frequency intake of iron-rich food, intake≥once/week was associated with a lower risk of IDA (P <.0001). However, vitamin C-rich food intake ≥twice/day was associated with a higher risk of IDA (P =.01) and a normal or bad appetite increased the risk of IDA when compared with a good appetite (P <.01). Our findings suggested that high frequency of iron-rich food intake, good appetite, and moderate physical activity were important for the prevention of IDA during pregnancy. [ABSTRACT FROM AUTHOR]

Predicting vehicle carbon emissions on vertical curve sections can provide guidance for low-carbon vertical profile designs. Given that the influence of vertical curve design indicators on the fuel consumption and CO2 emissions of vehicles are underexplored, this study filled this research gap by establishing a theoretical carbon emission model of vehicles on vertical curve sections. The carbon emission model was established based on Xu's vehicle energy conversion model, the conversion model of energy, fuel consumption, and CO2 emissions. The accuracy of the theoretical carbon emission model and the CO2 emission rules on vertical curve sections were verified by field test results. Field tests were carried out on flat sections, longitudinal slope sections, and various types of vertical curve sections, with five common types of vehicles maintaining cruising speed. The carbon emission rate effects on the vertical curve are closely related to the gradient and irrelevant of the radius. On the vertical profile composed with downhill/asymmetric/symmetrical vertical curve with a gradient greater than the balance gradient, the carbon emission rate is determined by the gradient and radius. The influence of the gradient on carbon emissions of vehicle on these vertical profiles was more significant than the radius. The radius is irrelevant to the carbon emission rate on the other forms of vertical profile. These results may benefit highway designers and engineers by providing guidelines regarding the environmental effects of highway vertical curve indexes. [ABSTRACT FROM AUTHOR]

Carbon emissions are the primary reason that contributes to global warming. The gradient has a significant impact on the carbon dioxide (CO2) emissions produced by trucks. The aim of the current paper is to propose a carbon emission quantification model for diesel trucks on longitudinal slope sections and investigate the influence of gradient on the carbon emissions of trucks for use in the low-carbon highway design. The law of conservation of mechanical energy, the first law of thermodynamics, and the vehicle longitudinal dynamics theory were adopted for deriving the carbon emission model of the trucks on the flat, uphill, downhill and round-trip longitudinal slope segments. Three kinds of common trucks were chosen to conduct the field test. Following the test data, the model demonstrates a high accuracy. The minimum gradient which is expected to impact carbon emissions of trucks on the round-trip longitudinal slope sections was the balance gradient as revealed. The gradient of the longitudinal slope is required to be avoided to be greater in comparison with the balance gradient for the achievement of the two-way traffic low carbon operation on a highway. The results of this study are valuable to researchers interested in low carbon road design and low carbon transportation control. [ABSTRACT FROM AUTHOR]

Truck's climbing performance is an important consideration in traffic safety, efficiency, and highway geometric design. With the infrastructure development in high-altitude area in China, more attention needs to be paid on truck's climbing performance in such area. In this article, truck's climbing speed in high-altitude area was examined through field tests on different grade sections at different altitudes. Truck's speed-distance curves were built at different altitudes and the impact of altitude on truck's climbing speed was explored based on the test results. It was shown that, within the altitude range of 3000~5000m, altitude had an obvious influence on test truck's decelerating and accelerating performance. Truck's speed decreased faster on steep grades and increased slower on gentle grades with the increase of the altitude. Also, the stable speed that test truck could maintain on a certain grade was lower at a higher altitude. In addition, test truck's theoretical speed-distance curves at the sea level were estimated through truck's dynamic model. Compared with the theoretical crawl speed, a negative effect of altitude change (from 0 to the altitude above 3000 m) was found on truck's climbing performance. [ABSTRACT FROM AUTHOR]

Traditional automatic incident detection methods such as artificial neural networks, backpropagation neural network, and Markov chains are not suitable for addressing the incident detection problem of rural roads in China which have a relatively high accident rate and a low reaction speed caused by the character of small traffic volume. This study applies the support vector machine (SVM) and parameter sensitivity analysis methods to build an accident detection algorithm in a rural road condition, based on real-time data collected in a field experiment. The sensitivity of four parameters (speed, front distance, vehicle group time interval, and free driving ratio) is analyzed, and the data sets of two parameters with a significant sensitivity are chosen to form the traffic state feature vector. The SVM and k-fold cross validation (K-CV) methods are used to build the accident detection algorithm, which shows an excellent performance in detection accuracy (98.15% of the training data set and 87.5% of the testing data set). Therefore, the problem of low incident reaction speed of rural roads in China could be solved to some extent. [ABSTRACT FROM AUTHOR]

Background The objective of this study was to describe a cosmetic skin incision for resection of large anterior mediastinal masses, and to review our experience with this technique. Methods From 1999 to 2010, 55 patients with a diagnosis of large anterior mediastinal masses underwent 'goblet'-shaped skin incision with midline sternotomy. The complications, mortality, details of surgery, and duration of hospital stay were observed from review. Patients were monitored via follow-up for a duration of one year after surgery. Results The mean hospital stay was nine days. Wound complications of infection were observed in one patient. There were no other complications, such as hematoma formation, necrosis of skin flap, split or infection of the sternum. No related mortality was recorded within the 30-day postoperative period. All of the patients verbalized the benefits of this technique, particularly the possibility of wearing open-collared clothing, as a result of the cosmetic chest wall and a camouflaging scar below the angle of Louis. At the follow-up periods, 52 of the patients were found to be well. Three patients did not complete follow-up at our facility. Conclusion Our primary experience with this procedure proved it was safe. The technique allows excellent access to the mediastinum and complete removal of large anterior mediastinal masses that are complicated with adjacent midline cardiovascular structures. This technique also provides a better cosmetic result than the standard vertical incision. [ABSTRACT FROM AUTHOR]

Background: To investigate the prevalence and risk factors of premature thelarche (PT) in girls and gynecomastia (GM) in boys in Southern China.Methods: We conducted a cross-sectional study of preschool children across 9 cities in Zhejiang province. A total of 6273 children in the age-group of 2-7 years were recruited from January 2014 to March 2015. Relevant information was collected from mothers through face-to-face interviews. Logistic regression models were used to examine the correlates of PT and GM. Odds ratios (ORs) with 95% confidence intervals (CIs) are reported.Results: The prevalence of PT among girls was 4.8% and that of GM among boys was 0.8%. One hundred girls were diagnosed with PT before the age of 2 years; 69 (69.0%) of these girls experienced spontaneous resolution of PT. Twenty-four boys were diagnosed with GM before the age of 2 years; 10 (41.7%) of these experienced spontaneous resolution of GM. Children borne of mothers with early onset of menarche and those belonging to high-income families were at a higher risk of premature breast development. Greater consumption of eggs was associated with premature breast development in early childhood.Conclusions: Socioeconomic status of family, early onset of menarche in mother, and consumption of eggs were strongly associated with premature breast development in early childhood. [ABSTRACT FROM AUTHOR]

• A roadmap is proposed to reach the limit efficiency. • The roadmap reflected in general analysis and practical analysis of sCO 2 cycle. • TC achieves the second largest contribution for efficiency increment after RH. • The limited efficiency for sCO 2 coal fired power plant is over 51%. The Chinese Government has issued a series of documents to explain China's control over the carbon dioxide (CO 2) emission. One of the major tasks is to develop higher efficiency coal fired power plant, compared with current running power plant. In this paper, we aim to explore the roadmap to reach the efficiency limit for coal fired power plant using supercritical carbon dioxide cycle (sCO 2 cycle). Referenced to Carnot cycle, the proposed roadmap is to increase the cycle efficiency by elevating average heat absorption temperature (T ave, h) and lowering average heat release temperature (T ave, l). In contrast to recompression cycle (RC), tri-compression cycle (TC) is introduced. Due to the increased T ave,h , TC achieves the second largest contribution for efficiency increment, followed by the reheating technique. Then, TC, double reheating (DRH) and intercooling (IC) are integrated as TC + DRH + IC in the power plant. To completely absorb flue gas energy over entire temperature range of (1500 ∼ 120) °C. A top cycle and a bottom cycle are connected for cascade utilization of flue gas energy. Overlap energy utilization is further utilized to fill the efficiency gap between top and bottom cycles. The proposed cycle also integrates the module boiler design to suppress the pressure drop penalty, and the flue gas recirculation to keep the heater surface temperature in an accepted level. A numerical model is developed for the comprehensive sCO 2 cycle. At the main vapor parameters of 35 MPa/630 °C, the sCO 2 coal fired power plant reaches the net power generation efficiency of 51.03%, which is higher than 48.12% for a supercritical water-steam power plant at the same capacity. Such efficiency improvement saves 175.2 kilotons of coal and reduces 396.4 kilotons of CO 2 emission for 1000 MW capacity in a fascial year. Our work provides the guideline for the design and operation of large scale sCO 2 coal fired power plant. [ABSTRACT FROM AUTHOR]

The design hourly volume (DHV) of traffic based on the 30th highest hourly volume (30 HV) of the year has been widely applied in expressway design in various countries to balance the benefit and economy of expressway engineering. However, this design method has barely changed since it was first adopted in China, which may be contrary to the rapidly changing traffic macroenvironment. In this study, annual hourly traffic volume (HV) data pertaining to expressways in East China, Southwest China and Northwest China were collected. Based on the descending order of the obtained HV and HV factor data, the distribution patterns of the traffic demand throughout the year and peak hours were analyzed. The distribution characteristics of the HV, typicality of 30 HV and applicability of the DHV factor were investigated. It was found that severe polarization occurred in the HV distribution in China. The actual 30 HV factor is more than 0.5 times the recommended value in the specification. Continued use of the current DHV would result in more than 200 h of inefficient travel time, 5.7 times more than expected, with the DHV factor is currently no longer applicable in China. Furthermore, the annual 30 HV value loses its typical status. Depending on the level of local economic development, using 10 HV factor or 80 HV factor as the new DHV factor can better alleviate the congestion problem. This study determines the reasons for the widespread congestion issues in China from the perspective of expressway design, which is beneficial to adjust the basis of expressway design in China.

Icy bridge deck in winter has tremendous consequences for expressway traffic safety, which is closely related to the bridge pavement temperature. In this paper, the critical meteorological conditions of icy bridge deck were predicted by multiple linear regression and BP neural network respectively. Firstly, the main parameters affecting the bridge pavement temperature were determined by Pearson partial correlation analysis based on the three-year winter meteorological data of the traffic meteorological monitoring station on the bridge in Shandong province. Secondly, the bridge pavement temperature is selected as the dependent variable, while air temperature, wind speed, relative humidity, dew point temperature, wet bulb temperature and wind cold temperature were selected as independent variables, and the bridge pavement temperature prediction models of linear regression and 5-layer hidden layer classical BP neural network regression were established respectively based on whether the variables are linear or not. Finally, the prediction accuracy of the above models was compared by using the measured data. The results show that the linear regression model could be established only with air temperature, relative humidity and wind speed, owing to collinearity problem. Compared with multiple linear regression model, the predicted value of the BP neural network has a higher degree of fitting with the measured data, and the coefficient of determination reaches 0.7929. Using multiple linear regression and BP neural network, the critical meteorological conditions of bridge deck icing in winter can be effectively predicted even when the sample size is insufficient., Competing Interests: The authors have declared that no competing interests exist.

Context: Gonadotropin-releasing hormone analogues (GnRHa) and recombinant human growth hormone (rhGH) have been widely used to treat idiopathic central precocious puberty (CPP) or early and fast puberty (EFP). However, large-scale studies to evaluate the treatment effects on final adult height (FAH) are still lacking., Objective: To assess the effects of long-term treatment for CPP/EFP on FAH and its main influencing factors., Design and Setting: Retrospective, multicenter observational study from 1998 to 2017., Participants: Four hundred forty-eight Chinese girls with CPP/EFP received GnRHa and rhGH treatment (n = 118), GnRHa alone (n = 276), or no treatment (n = 54)., Main Outcome Measures: FAH, target height (Tht), and predictive adult height (PAH)., Results: The height gain (FAH-PAH) was significantly different among the GnRHa and rhGH treatment, GnRHa alone, and no treatment groups (P < 0.05; 9.51 ± 0.53, 8.07 ± 0.37, and 6.44 ± 0.91 cm, respectively). The genetic height gain (FAH-Tht) was 4.0 ± 0.5 cm for the GnRHa + rhGH group and 2.0 ± 0.27 cm for the GnRHa group, while the control group reached their Tht. In addition, 5 critical parameters derived from PAH, bone age, and Tht, showed excellent performance in predicting which patients could gain ≥5 cm (FAH-PAH), and this was further validated using an independent study., Conclusions: The overall beneficial effect of GnRHa + rhGH or GnRHa on FAH was significant. The control group also reached their genetic target height. Clinicians are recommended to consider both the potential gains in height and the cost of medication., (© Endocrine Society 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Heavy-duty trucks contribute a significant component of all transportation in cargo terminals, such as Shaanxi Province, China. The emissions from these vehicles are the primary source of carbon emissions during highway operations. While several studies have attempted to address emission issues by improving traffic operations, a few focused on the relationship between emissions and highway geometric design, especially for heavy-duty trucks. The primary goal of this research was to understand the impact of circular curve on carbon dioxide (CO 2 ) emissions produced by heavy-duty diesel trucks. Firstly, appropriate parameters were specified in MOVES (motor vehicle emission simulator) model according to the geometrical characteristics. Fuel consumption, speed and location data were collected by hiring five skilled drivers on the automotive proving ground located at Chang'an University, Shaanxi Province. The associated carbon emission data were derived from fuel consumption data by applying the IPCC (Intergovernmental Panel on Climate Change) method. After this, the applicability of MOVES model was verified by the field experiment. Moreover, a multiple regression model for CO 2 emissions incorporated with roadway segment radius, circular curve length, and initial vehicle speed was established with data generated by the MOVES model. The proposed CO 2 emission model was also verified by field experiment with relative error of 6.17%. It was found that CO 2 emission had monotone decreasing property with radius increasing, and the minimum radius that influenced diesel CO 2 emission was 550 m. The proposed quantitative CO 2 emission model can provide a reference for low-carbon highway design, leading to environment-friendly transportation construction.

Objectives: To explore the rule of subcarinal lymph node metastasis in thoracic oesophageal cancer and its clinical significance in the radical resection of oesophageal cancer., Methods: We retrospectively analysed 2223 patients with oesophageal cancer who were admitted to Henan Cancer Hospital during 2004-2011 and underwent surgery as the first treatment option. Routine subcarinal lymph node dissections were performed, and the sections from the resected lymph nodes were embedded in paraffin for routine pathological examination., Results: Subcarinal lymph node metastasis was observed in 200 patients (9%). Logistic regression analysis identified the following risk factors (P < 0.05): tumour location, depth of invasion into the oesophageal wall, tissue type, number of lymph node metastases, paraoesophageal lymph node metastasis (level 8 lymph nodes), left gastric cardiac lymph node metastasis. Unpaired t-test and χ(2)-test showed that more lymph node metastases, longer tumour length, deeper tumour invasion, middle oesophageal cancer, squamous-cell carcinoma, lower degree of differentiation, paraoesophageal lymph node metastasis and left gastric cardiac lymph node metastasis were associated with a higher frequency of subcarinal lymph node metastases (P < 0.05). Using the Kaplan-Meier method, recurrence and metastasis were shown to be more likely with solitary subcarinal lymph node metastasis than with solitary paraoesophageal lymph node metastasis (P = 0.001)., Conclusions: Tumour location, depth of invasion, pathological type, degree of differentiation and other factors are closely associated with subcarinal lymph node metastasis. Recurrence and metastasis after oesophageal dissection are more likely with subcarinal lymph node metastasis.