ABSTRACT
An unreasonable overtaking attempt on two-lane highways could cause drivers to suffer in terms of driving safety, comfort, and efficiency. Several external factors related to the traffic environment (e.g., speed and car type of surrounding vehicles), were found to be the significant factors in drivers' overtaking performance in the previous studies. However, the microscopic decision-making (e.g., the moments of the occupation of the opposite lane) mechanisms during overtaking, by means of which drivers react to changes in the external traffic environment and adjust their overtaking trajectories, are still need to be explored. Hence, this study had three goals: (i) To explore the spatial characteristics of micro-decisions (MDs) (such as the start and end point) in overtaking trajectories; (ii) To measure three types of performance indicators (i.e., safety, comfort, and efficiency) for the execution of overtaking maneuvers; (iii) To quantitatively explain the microscopic decision-making mechanism in overtaking. Data for overtaking trajectories were collected from driving a simulation experiment where 52 Chinese student drivers completed a series of overtaking maneuvers on a typical two-lane highway under different traffic conditions. Two analyses were conducted: firstly, the distributions of the relative distance between the ego and surrounding vehicles at four key points (i.e., the start, entry, back, and end) in the overtaking trajectory were investigated and clustered to uncover the spatial characteristics of the MDs. Secondly, the safety, comfort, and efficiency of the overtaking were measured by the aggregations of multi-targets collision risks, triaxial acceleration variances, and spatial consumptions respectively based on the Data Envelopment Analysis (DEA), which were further applied in a two-stage SEM model to reveal the quantitative interrelationships among the external factors, microscope decisions and performances in overtaking. We confirmed that the MDs could be considered as the mediating variables between the external factors and overtaking performances. In the presence of the more hazardous traffic environment (e.g., faster traffic flow and impeded by a truck), the safety, comfort and efficiency of overtaking would be deteriorated inevitably. But drivers would execute the overtaking under the longer passing sight distance, migrate their trajectories forward, and shorten the spatial duration to significantly improve the overtaking performances. Based on this mechanism, a overtaking trajectory optimization strategy for the advanced or automatic driving system, was confirmed and concluded that 1) the passing gap should be firstly planned according to the sight distance acceptance of different drivers, which directly determine the upper limit of the safety performance in the overtaking; 2) the trajectory forward migration and shortening the whole duration in overtaking could be effective to enhance the overtaking performances of the overtaking on the two-lane highway; 3) the guidance of the stable control of the steering wheel and gas/brake pedals is essential in the overtaking.
Subject(s)
Automobile Driving , Computer Simulation , Decision Making , Safety , Humans , Male , Young Adult , Female , Environment Design , Adult , Accidents, Traffic/prevention & controlABSTRACT
The plant root-associated microbiomes include root microbiome and rhizosphere microbiome, which are closely related to plant life activities. Nearly 30% of photosynthesis products of plants are used to synthesize root compounds, there is evidence that root compounds regulate and significantly affect the root microbiome Tanshinones are the main hydrophobic components in Salvia miltiorrhiza. In order to study whether these compounds can regulate the root-associated microbiomes of S. miltiorrhiza, our study first identified a white root S. miltiorrhiza(BG) which contains little tanshinones. Retain of the fifth intron of tanshinones synthesis key enzyme gene SmCPS1 leading to the early termination of the SmCPS1 gene, and a stable white root phenotype. Further, wild type(WT) and BG were planted in greenhouse with nutrient soil(Pindstrup, Denmark) and Shandong soil(collected from the S. miltiorrhiza base in Weifang, Shandong), then high-throughput sequencing was used to analyze the root-associated microbiomes. The results showed that the tanshinones significantly affected the root-associated microbiomes of S. miltiorrhiza, and the impact on root microbiomes was more significant. There are significant differences between WT and BG root microbiomes in species richness, dominant strains and co-occurrence network. Tanshinones have a certain repelling effect on Bacilli which belongs to Gram-positive, while specifically attract some Gram-negative bacteria such as Betaproteobacteria and some specific genus of Alphaproteobacteria. This study determined the important role of tanshinones in regulating the structure of root-associated microbiomes from multiple angles, and shed a light for further improving the quality and yield of S. miltiorrhiza through microenvironment regulation.
Subject(s)
Abietanes , Microbiota , Plant Roots , Salvia miltiorrhizaABSTRACT
Objective To investigate the effect of intervention nursing on the formation of pressure ulcer in hypoalbuminemia patients with renal transplantation.Methods From February 2011 to June 2015,the 134 cases of hypoalbuminemia patients with renal transplantation in our hospital were divided into the observation group (73 cases)and the control group (61 cases).The control group were given conven-tional nursing methods for prevention of pressure ulcers,and the observation group were given corresponding intervention nursing measures on the basis of pressure ulcer risk factors.Then assessed the risk factors of pressure ulcers,the occurrence of pressure ulcers,and the rate of nursing satisfaction.Results The incidence of pressure ulcer in the observation group was significantly lower than that in the control group (P <0.05).The rate of nursing satisfaction in the observation group were significantly higher than that in the control group (P <0.05).The risk factors for hypoalbuminemia patients with renal transplantation were decrease of sensory response,increase of moisture in the compressed part,and increase of friction and shear forces in the compressed part.The occurrence of these risks could be significantly decreased after inter-vention nursing.Conclusion Effective nursing care can significantly reduce the incidence of pressure sores in hypoalbuminemia patients with renal transplantation and improve the nursing satisfaction.This method can be recommended for clinical nursing care for prevention of periop-erative pressure ulcer.
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Objective To investigate the surgical reparation of large coloboma raw surface after facial tumour resection in elderly patients.Methods According to the position and characteristics of tumor as well as the age and tolerance of the patients, full thick skin graft, the skin flaps with subcutaneous pedicle and free skin flap were designed and used in the reparation.Results 24 cases with large coloboma raw surface (5 cm×7 cm-12 cm× 16 cm)were treated by the utilization of three approaches after tumor resection.The large coloboma raw surface in all patients achieved the healing with satisfactory appearance.Conclusions After facial tumour resection, the large coloboma raw surface can be repaired by using the skin graft, skin flaps after tumor resection or free skin flap if designed reasonably.The procedure of operation is simple and the therapeutic effect is satisfactory.
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<p><b>OBJECTIVE</b>To investigate the quality and spatial distribution features of semen and to evaluate the reproductive health of the males in the Chongqing section of the Three-Gorge Reservoir area.</p><p><b>METHODS</b>We collected semen samples by masturbation after 2 -7 days of abstinence from the men in Nan'an, Shapingba, Zhongxian, Wanzhou, Yunyang and Wushan of Chongqing, which are geographically and demographically representative of the Three-Gorge Reservoir area. We analyzed the semen quality of all the samples and evaluated the reproductive health of the men.</p><p><b>RESULTS</b>The mean value of the five semen parameters of the male subjects from the six districts was within the normal range, including semen volume, sperm concentration, total sperm count, rapid progressive motile sperm, and total motile sperm. Those from Shapingba, Yunyang and Zhongxian exhibited abnormal sperm motility. According to the WHO criteria, normal value of all the semen parameters was found in less than 50% of the semen samples from the six districts, in 47% of those from Yunyang, and only 16% of those from Wanzhou. Spatial distribution maps of the semen parameters revealed significant spatial differences in seminal quality among the six districts, the highest in Yunyang, and the lowest in Wanzhou and Wushan that are located in the middle and lower reaches of the Three-Gorge Reservoir area.</p><p><b>CONCLUSION</b>The mean value of semen parameters was low in a large proportion of men in the Chongqing section of the Three-Gorge Reservoir area, with spatial differences along the Changjiang river.</p>
Subject(s)
Adult , Humans , Male , China , Semen , Semen Analysis , Sperm Count , Sperm MotilityABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of smoking on sperm apoptosis and semen quality of healthy adult males in the main urban area of Chongqing.</p><p><b>METHODS</b>According to the smoking habit, we divided 235 healthy adult males into a non-smoking group (n = 89) and a smoking group (n = 146). Then we detected the routine semen parameters by the computer-assisted semen analysis system and obtained the parameters of sperm apoptosis (the ratios of AN-/PI-, AN+/PI-, AN+/PI+ and AN-/PI+ sperm) by flow cytometry combined with Annexin V-FITC/PI fluorescence staining.</p><p><b>RESULTS</b>The rate of early apoptotic sperm (AN+/PI-) was higher in the smoking than in the non-smoking group ([8.1 +/- 5.1]% vs [6.8 +/- 3.8]%; P = 0.039), but there were no significant differences between the two groups in the rate of late apoptotic sperm (AN+/PI+) ([5.6 +/- 5.2]% vs [5.5 +/- 5.1]%; P = 0.87), as well as in such routine semen indexes as semen volume, sperm density, sperm motility, sperm vitality and normal sperm morphology (P = 0.30, 0.82, 0.37, 0.81 and 0.84, respectively).</p><p><b>CONCLUSION</b>The rate of early apoptotic sperm is higher in smokers than in non-smokers, suggesting that smoking may induce early damage to sperm cells. Compared with routine semen parameters, sperm apoptosis is a more sensitive biomarker to reflect smoking-induced damage to sperm.</p>
Subject(s)
Humans , Male , Apoptosis , China , Semen , Semen Analysis , Smoking , Sperm Count , Sperm Motility , Spermatozoa , Cell BiologyABSTRACT
<p><b>OBJECTIVE</b>Data on traffic accident from year 2000 to 2002 were collected and testified. Epidemiological study was carried out to find the main risk factors of traffic accident.</p><p><b>METHODS</b>The spatial distribution was conducted by means of Geographic Information System (GIS) and were marked on Shanghai digitalized map with different layers by different colors.</p><p><b>RESULTS</b>Results showed that during 2000, 2001 and 2002, 69,669 , 68,894, and 47,088 traffic accident episodes occurred in Shanghai, resulting in 1747, 1724, 1557 deaths respectively with direct economic lost: 2.1, 2.4, 3.0 billion RMB. The main risk factors causing traffic accident deaths would include drinking alcohol before driving, fatigue and speeding. The leading causes of death were head injury and complex injury of body. GIS showed that there was a homocentric circle with more traffic accidents in downtown city, but more deaths in the urban city. Disease burden caused by traffic accident was very heavy.</p><p><b>CONCLUSION</b>In Shanghai, traffic accident has great impact on social and economic issues thus should be controlled effectively. Focus should be layed on control of traffic accident in downtown area and to decrease the number of deaths related to traffic accident in the urban area.</p>
