Estimating energy release performance of oxidizer-activated aluminum fuel particles under ultrafast stimulus

Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.

Nomograms for Predicting Cancer-Specific Survival of Patients with Gingiva Squamous Cell Carcinoma:A Population-Based Study

The use of the traditional American Joint Committee on Cancer(AJCC)staging system alone has limitations in predicting the survival of gingiva squamous cell carcinoma(GSCC)patients.We aimed to establish a comprehensive prognostic nomogram with a prognostic value similar to the AJCC system.Methods:Patients were identified from SEER database.Variables were selected by a backward stepwise selection method in a Cox regression model.A nomogram was used to predict cancer-specific survival rates for 3,5 and 10 years in patients with GSCC.Several basic features of model validation were used to evaluate the performance of the survival model:consistency index(C-index),receiver operating characteristic(ROC)curve,calibration chart,net weight classification improvement(NRI),comprehensive discriminant improvement(IDI)and decision curve analysis(DCA).Results:Multivariate analyses revealed that age,race,marital status,insurance,AJCC stage,pathology grade and surgery were risk factors for survival.In particular,the C-index,the area under the ROC curve(AUC)and the calibration plots showed good performance of the nomogram.Compared to the AJCC system,NRI and IDI showed that the nomogram has improved performance.Finally,the nomogram's 3-year and 5-year and 10-year DCA curves yield net benefits higher than traditional AJCC,whether training set or a validation set.Conclusion:We developed and validated the first GSCC prognosis nomogram,which has a better prognostic value than the separate AJCC staging system.Overall,the nomogram of this study is a valuable tool for clinical practice to consult patients and understand their risk for the next 3,5 and 10 years.

Dementia studies in Chinese populations

Variations in the prevalence of dementia in different ethnic groups have been reported worldwide, and a number of reviews have provided a picture of epidemiological studies in dementia research. However, little is known about epidemiological studies in Chinese populations. In this review, we searched PubMed and the Web of Science for original research articles published in English up to July 2013 on the prevalence, incidence, risk factors, and prognosis of dementia in Chinese populations worldwide. Except for the prevalence, we included only population-based follow-up studies. We identified 25 studies in elderly Chinese residents in China's Mainland, Hong Kong, Taiwan, and Singapore, and found a higher prevalence of dementia in China's Mainland than in the other locations, which may be due to that the studies from China's Mainland are more recent than those from other locations. A notable increase in incidence was observed when dementia cases were diagnosed using 10/66 diagnostic criteria compared to other criteria. Studies on risk factors for dementia were limited and mostly from China's Mainland. Age, gender, education, smoking, and alcohol consumption were related to the risk of dementia in Chinese populations. Only two prognostic studies were identified, and age, gender, and residential area were related to the prognosis of dementia. In conclusion, the prevalence, incidence, and risk factors for dementia found in Chinese populations were comparable to other ethnic groups, but no conclusive results on prognosis were found. The differences in prevalence and incidence were influenced by the diagnostic criteria and the time of study. Longitudinal population-based studies on the incidence, risk factors, and prognosis of dementia in Chinese populations are required.