Characterization of behaviour and hazards of fire and deflagration for high-energy Li-ion cells by over-heating

Fire and deflagration are extreme manifestation of thermal runaway (TR) of Li-ion cells, and they are characterized for fully charged LiNiCoAlO2 (LNCA) 18650 cells in this investigation. The cells are over-heated using a cone calorimeter under different incident heat fluxes. When the cells are exposed to the incident heat flux larger than 35 kW m−2, both fire and deflagration present. The pressure valve opens when the temperature of the cell is higher than 132 °C. The fire occurs with the valve opening when the concentration of the venting vapour in the air is higher than the lower flammability limit. The deflagration happens after the cell temperature arrives about 200 °C, and is mainly arising from the cathode decomposition, the combustion of solvents and the anode relevant thermal reactions. The extreme temperatures of the cell and the flame during deflagration are over than 820 and 1035 °C, respectively. The production of COx, mass loss, heat release rate (HRR) are quantitative identified, and are found increase as the increasing incident heat flux. Based on revised oxygen consumption method, the HRR and liberated heat during the fire and deflagration for the cells are up to 11.8 ± 0.05 kW and 163.1 ± 1.5 kJ, respectively

Association between childhood sexual abuse and early sexual debut among Chinese adolescents: The role of sexual and reproductive health education

BackgroundDespite accumulating evidence of the long-term impacts of childhood sexual abuse (CSA), few studies have investigated the association between CSA and early sexual debut among adolescents. In this study, we examine the relationship between CSA and early initiation of sexual intercourse among Chinese youth, and the role of school-based sex education in this association, based on a nationally representative survey.MethodsData were collected from the Survey of Youth Access to Reproductive Health in China (YARHC) conducted in 2009. Multivariable logistic regression models were used to investigate the association between CSA experience and early sexual debut, and the interaction terms between sexual and reproductive health education and CSA were included to examine the role of education in the association between CSA and early sexual debut.ResultsAmong 4,907 sexually experienced youth, 1,062 (21.6%) made their early sexual debut. After adjusting for sociodemographic characteristics, it was found that CSA experience was significantly associated with early sexual debut, with an adjusted odds ratio of 3.13 (95% CI: 1.67–5.87). Receiving any type of sexuality education (reproductive health, sexually transmitted disease (STD) and HIV prevention, or contraception use) was not associated with a decreased risk of early sexual debut.ConclusionOur results indicate a greater risk of early sexual debut among Chinese adolescents with a history of CSA, and only 46.7% sexually experienced youth had received prior sex education, which suggested an inadequacy of school-based sexuality education. To reduce this risk, targeted intervention with timely and adequate sexuality education for both early starters of sexual intercourse and CSA victims is warranted in China

StyleFool: Fooling Video Classification Systems via Style Transfer

Video classification systems are vulnerable to adversarial attacks, which can create severe security problems in video verification. Current black-box attacks need a large number of queries to succeed, resulting in high computational overhead in the process of attack. On the other hand, attacks with restricted perturbations are ineffective against defenses such as denoising or adversarial training. In this paper, we focus on unrestricted perturbations and propose StyleFool, a black-box video adversarial attack via style transfer to fool the video classification system. StyleFool first utilizes color theme proximity to select the best style image, which helps avoid unnatural details in the stylized videos. Meanwhile, the target class confidence is additionally considered in targeted attacks to influence the output distribution of the classifier by moving the stylized video closer to or even across the decision boundary. A gradient-free method is then employed to further optimize the adversarial perturbations. We carry out extensive experiments to evaluate StyleFool on two standard datasets, UCF-101 and HMDB-51. The experimental results demonstrate that StyleFool outperforms the state-of-the-art adversarial attacks in terms of both the number of queries and the robustness against existing defenses. Moreover, 50% of the stylized videos in untargeted attacks do not need any query since they can already fool the video classification model. Furthermore, we evaluate the indistinguishability through a user study to show that the adversarial samples of StyleFool look imperceptible to human eyes, despite unrestricted perturbations.Comment: 18 pages, 9 figures. Accepted to S&P 202

Silver nanoparticles induced neurotoxicity through oxidative stress in rat cerebral astrocytes is distinct from the effects of silver ions

The rapid development of silver nanoparticles (AgNPs) based products has raised increasing concerns in view of their potential hazardous risks to the environment and human health. The roles of the released silver ions in AgNPs induced cytotoxicities are being hotly debated. Using rat cerebral astrocytes, the neurotoxicological effects of AgNPs and silver ions were investigated. Acute toxicity based on Alamar Blue assay showed that silver ions were considerably more toxic than AgNPs. Comparative studies indicated that AgNPs increased caspase activities and induced cell apoptosis under cytotoxic level of exposures, while silver ions compromised cell membrane integrity and dominantly caused cell necrosis. Cellular internalization of silver provided the basis for the cytotoxicities of these two silver species. In contrast to silver ions, intracellular reactive oxygen species (ROS) generation occurred in time- and concentration-dependent manners in astrocytes upon AgNPs stimulation, which caused subsequent c-Jun N-terminal kinases UNK) phosphorylation and promoted the programmed cell death. Non-cytotoxic level of AgNPs exposure increased multiple cytokines secretion from the astrocytes, indicating that AgNPs were potentially involved in neuroinflammation. This effect was independent of silver ions as well. The distinct toxicological effects caused by AgNPs and silver ions provided the solid proofs for the particle-specific effects which should be concerned regarding the accurate assessment of AgNPs exposure risks. (C) 2015 Elsevier Inc. All rights reserved

Genetic analysis of oligo-recurrence breast cancer: correlation with clinical outcomes

Abstract Background We aimed to identify the relationship between the genomic characteristics and clinical outcomes of oligo-metastatic breast cancer. Methods Oligo-metastatic breast cancer diagnosed by pathology from January 2001 and August 2019 were reviewed and we matched the poly-metastatic patients based on the clinicopathological features of patients included. Clinicopathological values and data of genomic alterations were collected. Oligo-recurrence (oligo-R) was defined as a situation where disease progression occurred in less than 5 anatomical sites and other anatomic areas still suppressed by the ongoing therapy. Results A total of 26 breast cancer patients were enrolled in our study, including 14 patients with strict oligo-metastatic disease (oligo-R > 6 months) and 12 with simultaneous poly-metastatic disease. PIK3CA, TP53 and ERBB2 were the most common shared alterations identified in patients included. Based on the median time of oligo-R, we divided the patients with oligo-metastasis into longer oligo-R group (oligo-R > 31.04 months) and shorter oligo-R group (oligo-R ≤ 31.04 months). The analysis of PIK3CA mutation sites showed that H1047R mutation was closely associated with oligo-metastasis, rather than poly-metastasis. H1047R mutation also predicted a better prognosis (oligo-R > 31.04 months) in oligo-metastatic breast cancer. In addition, HER2 positive was more likely to be related to a good outcome in patients with oligo-metastasis. Conclusions Through the genetic analysis of samples from oligo-metastasis, we found the prognostic values of PIK3CA H1047R and HER2 in oligo- and poly-metastasis. We improved the stratification of prognosis and provided new insights for biological behaviors of oligo-metastatic breast cancer

Study on safe disposal of cephalosporins based on kinetic pyrolysis mechanism

Based on the global goals for cleaner production and sustainable development, the pyrolysis behavior of cephalosporin residues was studied by TG-MS method. The influence of full temperature window on the safe disposal of residues was analyzed based on the “3-2-2” and “1+1” of thermal analysis kinetics, and the gas by-products of thermal degradation were monitored. Results showed that the pyrolysis of distillation residues were divided into low and high-temperature zones, including six stages. Maximum error rate (8.55%) by multiple scan rate was presented based on “3-2-2” pattern and maximum total fluctuation (33.7) by single scan rate was presented based on “1+1” pattern, which implied that the comprehensive multi-level comparison method was very reliable. The E value “E” of six stages showed an increasing trend ranging 166.8 to 872.8 kJ/mol. LgA(mean) was 27.28. Most mechanism function of stage 1, 2 were Z-L-T equation (3D), stage 3, 4, 6 were Avrami-Erofeev equation (AE3, AE4, AE2/3) and stage 5 was Reaction Order (O2). In addition, various small molecular micromolecule substances were detected such as C2H4O, C2H6, NH3, CH4, CO2 under full temperature windows and a possible pyrolysis path of residues was provided

Association Between Childhood and Adolescent Sexual Abuse Experiences and High-Risk Sexual Behaviors Among Chinese Youth

Introduction: Adolescents are at high risk for negative health outcomes associated with high-risk sexual behaviors (HRSBs), and researchers have attempted to identify factors that influence such behavior so that meaningful prevention and intervention programs may be developed. Aim: To investigate the associations between CSA experience and HRSBs in Chinese youth aged 15-24 years old. Methods: Data were from the Survey of Youth Access to Reproductive Health in China, a national sample survey conducted in 2009. The following behaviors were classified as HRSBs: condom non-use during the first sexual experience, having sex with multiple partners, taking part in casual sex, engaging in commercial sex, taking part in anal sex, and condom non-use during the most recent sexual encounter. Differences in HRSBs between the sexes were examined. The χ2 test and binary logistic regression were used to estimate the association between CSA experience and HRSBs. Main Outcome Measure: The sexual behaviors of condom non-use during the first sexual experience, sexual activity with multiple partners, taking part in casual sex, engaging in commercial sex (defined as paying or receiving money/gifts in exchange for sex), taking part in anal sex, and condom non-using during the most recent sexual intercourse were classified as HRSBs. Results: 4,974 Sexually active youth were included in this study, 150 respondents (3.0%) reported CSA experience, and 3,950 (79.4%) sexually active youth had engaged in at least 1 type of HRSBs. The odds of having sex with multiple partners (odds ratio [OR] 4.31, 95% CI 3.07–6.07), casual sex (OR 3.65, 95% CI 2.55–5.24), commercial sex (OR 7.43, 95% CI 5.13–10.77), anal copulation (OR 2.54, 95% CI 1.57–4.12), or any of these HRSBs (OR 5.02, 95% CI 2.33–10.80) were significantly higher among those who had experienced CSA. There was a gender-specific difference in the associations of CSA with different types of HRSBs. Conclusion: Sexual abuse experience in childhood is highly correlated with HRSBs among Chinese youth, and the pattern of this association differs between males and females. Public knowledge and social assistance systems needs to be improved for children and youth in China. Gender-specific counter-measures may be more efficient for interventions.Ding R, Wen X, He P, et al. Association Between Childhood and Adolescent Sexual Abuse Experiences and High-Risk Sexual Behaviors Among Chinese Youth. Sex Med 2018;6:273–281. Key Words: Childhood Sexual Abuse, High-Risk Sexual Behaviors, Youth, Chin