46 research outputs found
Speed Characteristics and Safety Risk Level Evaluation for Nighttime Roadway Work Area
AbstractMore and more roadway projects are conducted during nighttime to satisfy heavy travelling demands in the daytime. However, the Nighttime Roadway Work (NRW) produces several safety problems. As a developing region of China, these problems expose later than some developed countries, and there is scarcely any valid crash samples for NRW safety analysis. Therefore, a surrogate safety assessment philosophy is adopted in the paper. Firstly, the field survey and statistical analysis approaches are adopted to acquire percentile speed characteristics of vehicles passing through work-zones during nighttime. Secondly, a kind of safety risk evaluation model is established to assess NRW safety levels. The results reveal that 1) speeding problems severely exist in the NRW zone and safety risk levels are comparatively high; 2) from speed characteristics of NRW in a city expressway by lanes, speeding ratio in the activity area is higher than 90% and in the lane in transition area the ratio is higher than 30%; 3) from speed characteristics of NRW in a city expressway by vehicle types, speeding ratios of all type vehicles in the activity and transition area are higher than 90% and 30% respectively; 4) the speeding ratio in freeway NRW area is close to 100%; 5) the safety risk analysis indicates that risk levels of lanes in transition area are comparatively high, and also the safety risk level of large vehicles is higher compared to other type vehicles. Finally, several useful tips for the prevention of speeding in the NRW area are suggested
The work of Chinese chronic conditions: adaptation and validation of the Distribution of Co-Care Activities Scale
PurposeThe Distribution of Co-Care Activities Scale was adapted into Chinese for the purposes of this study, and then the psychometric characteristics of the Chinese version of the DoCCA scale were confirmed in chronic conditions.MethodsA total of 434 patients with chronic diseases were recruited from three Chinese cities. A cross-cultural adaptation procedure was used to translate the Distribution of Co-Care Activities Scale into Chinese. Cronbach's alpha coefficient, split-half reliability, and test-retest reliability were used to verify the scale's reliability. Content validity indices, exploratory factor analysis, and confirmatory factor analysis were used to confirm the scale's validity.ResultsThe Chinese DoCCA scale includes five domains: demands, unnecessary tasks, role clarity, needs support, and goal orientation. The S-CVI was 0.964. Exploratory factor analysis yielded a five-factor structure that explained 74.952% of the total variance. According to the confirmatory factor analysis results, the fit indices were within the range of the reference values. Convergent and discriminant validity both met the criteria. Also, the scale's Cronbach's alpha coefficient is 0.936, and the five dimensions' values range from 0.818 to 0.909. The split-half reliability was 0.848, and the test-retest reliability was 0.832.ConclusionsThe Chinese version of the Distribution of Co-Care Activities Scale had high levels of validity and reliability for chronic conditions. The scale can assess how patients with chronic diseases feel about their service of care and provide data to optimize their personalized chronic disease self-management strategies
Pathologic complete response of hepatoid adenocarcinoma of the stomach after chemo-immunotherapy: A rare case report and literature review
BackgroundHepatoid adenocarcinoma of the stomach (HAS) is a highly malignant subtype of gastric carcinoma with specific clinicopathological features and extremely poor prognosis. We present an exceedingly rare case of complete response after chemo-immunotherapy.Case DescriptionA 48-year-old woman with highly elevated serum alpha-fetoprotein (AFP) level was found to have HAS verified by pathological examination based on gastroscopy. Computed tomography scan was done and TNM staging of the tumor was T4aN3aMx. Programmed cell death ligand-1 (PD-L1) immunohistochemistry was performed, revealing a negative PD-L1 expression. Chemo-immunotherapy including oxaliplatin plus S-1 and PD-1 inhibitor terelizumab was given to this patient for 2 months until the serum AFP level decreased from 748.5 to 12.9 ng/mL and the tumor shrank. D2 radical gastrectomy was then performed and histopathology of the resected specimen revealed that the cancerous cells had disappeared. Pathologic complete response (pCR) was achieved and no evidence of recurrence has been found after 1 year of follow-up.ConclusionsWe, for the first time, reported an HAS patient with negative PD-L1 expression who achieved pCR from the combined chemotherapy and immunotherapy. Although no consensus has been reached regarding the therapy, it might provide a potential effective management strategy for HAS patient
Overview of the instrumentation for the Dark Energy Spectroscopic Instrument
The Dark Energy Spectroscopic Instrument (DESI) embarked on an ambitious 5 yr survey in 2021 May to explore the nature of dark energy with spectroscopic measurements of 40 million galaxies and quasars. DESI will determine precise redshifts and employ the baryon acoustic oscillation method to measure distances from the nearby universe to beyond redshift z > 3.5, and employ redshift space distortions to measure the growth of structure and probe potential modifications to general relativity. We describe the significant instrumentation we developed to conduct the DESI survey. This includes: a wide-field, 3.°2 diameter prime-focus corrector; a focal plane system with 5020 fiber positioners on the 0.812 m diameter, aspheric focal surface; 10 continuous, high-efficiency fiber cable bundles that connect the focal plane to the spectrographs; and 10 identical spectrographs. Each spectrograph employs a pair of dichroics to split the light into three channels that together record the light from 360–980 nm with a spectral resolution that ranges from 2000–5000. We describe the science requirements, their connection to the technical requirements, the management of the project, and interfaces between subsystems. DESI was installed at the 4 m Mayall Telescope at Kitt Peak National Observatory and has achieved all of its performance goals. Some performance highlights include an rms positioner accuracy of better than 0.″1 and a median signal-to-noise ratio of 7 of the [O ii] doublet at 8 × 10−17 erg s−1 cm−2 in 1000 s for galaxies at z = 1.4–1.6. We conclude with additional highlights from the on-sky validation and commissioning, key successes, and lessons learned
The development of a conflict hazardous assessment model for evaluating urban intersection safety / Transporto priemonių susidūrimo pavojaus vertinimo modelio raida, analizuojant susikirtimo taškų saugą miesto sankryžose /
Road safety conditions in China have worsened following rapid urbanization and motorization. For a long time now, China has ranked first in the world in the number of road accidents and fatalities. Therefore, evaluating safety levels is essential to implementing effective countermeasures. For developing countries like China, however, assessing safety levels via crash data statistical analysis is difficult because of limitations on a short history of collecting crash data, small samples and an incomplete collection of information. To address these limitations, the method of surrogate safety analysis using the traffic conflict technique (TCT) has become a widely used evaluation procedure. On the basis of the mechanism analysis of TCT, the paper presents a conflict hazardous assessment model (CHAM) for the mixed traffic safety evaluation of urban intersections. In the proposed model, the principle of the conservation of momentum is used. CHAM is a model used for assessing safety levels from the aspects of severe conflict numbers and conflict hazardous levels (CHLs) when traffic conflicts among mixed-traffic modes occur. Factors such as the conflict type and conflict angle of different traffic modes, weight and velocity are considered and incorporated into the model through the integration of the accident collision theory and the head injury criterion (HIC) index for head hazard assessments. The calibration and validation of CHL models are also carried out using 341 intersection crash reports in Beijing from 2006 to 2008. The results show that the established CHL models have good validity.
Santrauka
Greita urbanizacija ir transporto priemonių skaičiaus didėjimas pablogino kelių saugos sąlygas Kinijoje, kuri jau ilgą laiką pirmauja pasaulyje pagal keliuose įvykstančių nelaimingų atsitikimų ir mirčių skaičių. Todėl saugaus eismo lygio vertinimas ypač svarbus diegiant veiksmingas atsakomąsias priemones. Tokiose besivystančiose šalyse kaip Kinija saugaus eismo lygio vertinimas, pasitelkiant statistinius duomenis apie įvykusius nelaimingus atsitikimus, yra sudėtingas dėl nepakankamai ar netiksliai surinktų duomenų. Remiantis eismo įvykio mechanizmo analize, straipsnyje pristatomas transporto priemonių susidūrimo pavojaus vertinimo modelis, analizuojant įvairių transporto priemonių saugą miesto sankryžose. Pateiktame modelyje naudojamas judesio kiekio tvermės dėsnis. Modelis naudojamas įvertinant saugaus eismo lygius, atsižvelgiant į ypatingus atvejus ir susidūrimo pavojaus lygį, kai eismo įvykiai nutinka tarp skirtingų kategorijų transporto priemonių. Susidūrimo tipas, skirtingų transporto priemonių susidūrimo kampas, svoris ir greitis yra veiksniai, į kuriuos turi būti atsižvelgiama ir kurie yra modelio sudėtinės dalys, sujungiant į visumą transporto priemonių susidūrimo teoriją bei galvos traumų kriterijaus (HIC – head injury criteria) rodiklį. Modelis tikrinamas remiantis informacija apie transporto priemonių susidūrimus Pekine (Kinija) 2006–2008 m. Gauti rezultatai parodė, kad sukurtas modelis yra veiksminga priemonė.
Резюме
Быстрая урбанизация и темп увеличения количества транспортных средств на дорогах Китая резко ухудшили безопасность дорожного движения. Китай на протяжении многих лет лидирует по числу несчастных случаев (в том числе и со смертельным исходом), происходящих на дорогах. Поэтому оценка уровня безопасности дорожного движения имеет огромное значение при внедрении соответствующих мер. В таких развивающихся странах, как Китай, оценка уровня безопасности дорожного движения с использованием статистических данных осложняется и неэффективна из-за нехватки собранных данных, а зачастую и их неточности. В статье представлена модель оценки угрозы столкновения транспортных средств на городских перекрестках, которая основана на анализе механизма дорожно-транспортного происшествия. В представленной модели используется закон сохранения количества движения. Модель применяется для оценки уровня безопасности дорожного движения с учетом особых случаев, уровня угрозы столкновения и разных категорий транспортных средств. Составными частями модели являют ся тип столкновения, угол столкновения, масса и скорость движения транспортных средств. В модель также включена теория столкновения транспортных средств и критерий тяжести повреждений головы (HIC – head injury criteria). Модель проверена на основе информации о столкновениях транспортных средств в г. Пекине (Китай) в 2006–2008 гг. Полученные результаты свидетельствовали о достоверности представленной модели.
Reikšminiai žodžiai: miesto sankryža, saugus eismas, transporto priemonė, susidūrimas, pavojus, vertinimo modelis, eismo įvykis
Ключевые слова: перекресток, безопасность дорожного движения, транспортное средство, столкновение, угроза, модель оценки, дорожно-транспортное происшестви
Acute rhabdomyolysis and chylous ascites in a patient with cirrhosis and malignant hepatic tumor
Inhibitory Effect of Various Breads on DMH-Induced Aberrant Crypt Foci and Colorectal Tumours in Rats
Bread is rich in dietary fibre and many phytochemical compounds, which may influence chemoprevention of colon cancer. In the present study, we evaluated the effect of three kinds of bread on DMH-induced colorectal tumours in F344 rats. F344 rats were divided into four groups (Steinmetz Three-Grain bread, Steinmetz Country bread, White bread, and MF). All groups were injected with 1,2-dimethylhydrazine (DMH, 20 mg/kg body weight) once a week for 8 consecutive weeks from 5 weeks of age. To investigate the antioxidant effect of bread, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging rate of bread and the serum levels of 8-hydroxy-deoxyguanosine (8-OHdG) in rats were examined. The number of colorectal aberrant crypt foci (ACF) and the incidence of colorectal tumours were studied after 34 weeks of DMH treatment. The Steinmetz Three-Grain and Steinmetz Country bread groups had higher scavenging rates of the DPPH free radical and lower serum levels of 8-OHdG and incidence of ACF, adenomas, and adenocarcinomas of colon than the White bread and MF group. Steinmetz Three-Grain bread and Steinmetz Country bread have various ingredient combinations that may inhibit colorectal cancer progression