Static Experimental Study on Flame Retardant and Explosion Suppression Performances of Fire Resistant Diesel Fuel

AbstractTo assess the flame retardant and explosion suppression performances of fire resistant diesel fuel, static experiments with ordinary diesel fuel (Diesel fuel 1, D1 for short) and fire resistant diesel fuel (Diesel fuel 2, D2 for short) detonated by explosives were performed in this study. The explosion process and surface temperature of the fireballs were recorded using a high-speed camera and an infrared thermal imager. Meanwhile, the overpressures of the explosion shock waves of the two diesels were also recorded using pressure sensors embedded in the ground. The experimental results show that the diesel fuels are dispersed and ignited to produce explosion fireball when explosive is detonated in fuel tank. At the same time, part of diesel fuel produces pool fire on the ground. The pool fire of D1 lasts about 3000ms, while D2 lasting only about 700ms. The maximum temperature and the duration of high temperature of D1 explosion fireball are 1558.8°C and 1392ms respectively, which are 1.11 and 1.29 times those of D2. In the position of 2 m far from the vertical projection point of the explosion center, the overpressure of the explosion shock wave of D1 is 53.30kPa, while that of D2 is 31.60kPa. Moreover, the overpressures of D1 are also higher in the other location of the pressure area. Therefore, it is proved that the explosive power of D2 is significantly lower than that of D1, and the flame retardant and explosion suppression performances of D2 is better than those of D1

Simple quantitative measurement based on DWI to objectively judge DWI-FLAIR mismatch in a canine stroke model

PURPOSEDiffusion-weighted imaging (DWI) - fluid attenuated inversion recovery (FLAIR) mismatch was proven useful to time the onset of wake-up stroke; however, identifying the status of FLAIR imaging has been mostly subjective. We aimed to evaluate the value of relative DWI signal intensity (rDWI), and relative apparent diffusion coefficient (rADC) in identifying the FLAIR status in the acute period.METHODSAutologous clot was used to embolize left middle cerebral artery in 20 dogs. Magnetic resonance imaging was performed 3–6 hours and 24 hours after embolization. DWI-FLAIR mismatch was defined as hyperintense signal detected on DWI, but not on FLAIR. The mean values of rDWI or rADC of FLAIR- and FLAIR+ lesions were compared and the critical cutoff values of rDWI and rADC for identifying the FLAIR status were determined.RESULTSStroke models were successfully established in all animals. DWI+ lesions were found in all 20 dogs from three hours, while FLAIR+ lesions were found in three, 11, 16, 19, and 20 dogs at five time points after embolization, respectively. The mean rDWI values were significantly different between FLAIR- and FLAIR+ lesions (P < 0.001), but rADC values were not (P = 0.73). Using rDWI=1.90 as the threshold value, excellent diagnostic efficacy was achieved (AUC, 0.88; sensitivity, 0.77; specificity, 0.88). However, rADC appeared not useful (AUC, 0.48; sensitivity, 0.52; specificity, 0.58) in identifying the FLAIR status.CONCLUSIONIn our embolic canine stroke model, rDWI was useful to identify FLAIR imaging status in the acute period, while rADC was not

Fluorescence Modified Chitosan-Coated Magnetic Nanoparticles for High-Efficient Cellular Imaging

Labeling of cells with nanoparticles for living detection is of interest to various biomedical applications. In this study, novel fluorescent/magnetic nanoparticles were prepared and used in high-efficient cellular imaging. The nanoparticles coated with the modified chitosan possessed a magnetic oxide core and a covalently attached fluorescent dye. We evaluated the feasibility and efficiency in labeling cancer cells (SMMC-7721) with the nanoparticles. The nanoparticles exhibited a high affinity to cells, which was demonstrated by flow cytometry and magnetic resonance imaging. The results showed that cell-labeling efficiency of the nanoparticles was dependent on the incubation time and nanoparticles’ concentration. The minimum detected number of labeled cells was around 104by using a clinical 1.5-T MRI imager. Fluorescence and transmission electron microscopy instruments were used to monitor the localization patterns of the magnetic nanoparticles in cells. These new magneto-fluorescent nanoagents have demonstrated the potential for future medical use

Comparison of Alkali-Buffering Effects and Co-digestion on High-Solid Anaerobic Digestion of Horticultural Waste

High-solid anaerobic digestion (HSAD) of horticultural waste by adding alkali (ADAA) was optimized in a batch system, and its performance was compared to co-digestion in a semi-continuous system. In the batch system, the process of ADAA was optimized by testing the time point of adding alkali and the type of alkali, both of which had significant influence on HSAD performance. The cumulative biogas yield of poplar leaf was the highest, 156.7 mL/g of volatile solids (VS), when adding CaO on the third day. In comparison to NaOH and Na2CO3, the biogas yield of the ADAA process adjusted with CaO was the highest. When the organic loading rate was 4.0 and 8.0 g of VS L-1 day(-1), the co-digestion system would produce 10.30 and 15.28% more methane than ADAA (CaO as alkali), respectively, which was due to the higher nutrients, broader diversity, and better growth of the microorganism in co-digestion of poplar leaf and chicken manure. Microbial community analysis of the seed sludge, co-digestion, and ADAA showed Methanosarcina, Methanosaeta, Methanobacterium, Methermicoccus, and Anaerosphaera were found to be the dominant methane -producing bacteria. The study confirms the advantages of co-digestion over ADAA for methane production from horticultural wastes.</p

Determinants of Active Online Learning in the Smart Learning Environment: An Empirical Study with PLS-SEM

A smart learning environment, featuring personalization, real-time feedback, and intelligent interaction, provides the primary conditions for actively participating in online education. Identifying the factors that influence active online learning in a smart learning environment is critical for proposing targeted improvement strategies and enhancing their active online learning effectiveness. This study constructs the research framework of active online learning with theories of learning satisfaction, the Technology Acceptance Model (TAM), and a smart learning environment. We hypothesize that the following factors will influence active online learning: Typical characteristics of a smart learning environment, perceived usefulness and ease of use, social isolation, learning expectations, and complaints. A total of 528 valid questionnaires were collected through online platforms. The partial least squares structural equation modeling (PLS-SEM) analysis using SmartPLS 3 found that: (1) The personalization, intelligent interaction, and real-time feedback of the smart learning environment all have a positive impact on active online learning; (2) the perceived ease of use and perceived usefulness in the technology acceptance model (TAM) positively affect active online learning; (3) innovatively discovered some new variables that affect active online learning: Learning expectations positively impact active online learning, while learning complaints and social isolation negatively affect active online learning. Based on the results, this study proposes the online smart teaching model and discusses how to promote active online learning in a smart environment

Integration of high-solid digestion and gasification to dispose horticultural waste and chicken manure

To realize full energy recovery from grass and chicken manure (CM), the integration of high-solid anaerobic digestion (HSAD) and gasification was investigated experimentally. The anaerobic biodegradability of grass can be enhanced through codigestion with CM. When the volatile solid (VS) ratio of CM to grass was 20:80, C/N ratio calculated to be 21.70, the cumulative biogas yield was the highest, 237 ml.(g VS)(-1). The enhancement of biogas production was attributed to the buffering effects of ammonia and rich trace elements in CM. In semi-continuous systems, when the organic loading rate was 4.0 g VS.L-1.d(-1), the HSAD process was stable, with the average biogas yield 168 ml.(g VS)(-1). More than 80% fractions of the digestates were volatile matters, which meant that the digestates can be used as feedstock for gasification to produce syngas. The VS ratio of grass to CM had significant overall energy generation through HSAD and gasification. Compared with gasification of digestate, cogasification with woodchips increased syngas yield and low heat value (LHV). Increasing of mass ratio of digestates to woodchips led to the decrease of LHV. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved

A novel nomogram to predict lymph node metastasis in cT1 non-small-cell lung cancer based on PET/CT and peripheral blood cell parameters

Abstract Background Accurately evaluating the lymph node status preoperatively is critical in determining the appropriate treatment plan for non-small-cell lung cancer (NSCLC) patients. This study aimed to construct a novel nomogram to predict the probability of lymph node metastasis in clinical T1 stage patients based on non-invasive and easily accessible indicators. Methods From October 2019 to June 2022, the data of 84 consecutive cT1 NSCLC patients who had undergone PET/CT examination within 30 days before surgery were retrospectively collected. Univariate and multivariate logistic regression analyses were performed to identify the risk factors of lymph node metastasis. A nomogram based on these predictors was constructed. The area under the receiver operating characteristic (ROC) curve and the calibration curve was used for assessment. Besides, the model was confirmed by bootstrap resampling. Results Four predictors (tumor SUVmax value, lymph node SUVmax value, consolidation tumor ratio and platelet to lymphocyte ratio) were identified and entered into the nomogram. The model indicated certain discrimination, with an area under ROC curve of 0.921(95%CI 0.866–0.977). The calibration curve showed good concordance between the predicted and actual possibility of lymph node metastasis. Conclusions This nomogram was practical and effective in predicting lymph node metastasis for patients with cT1 NSCLC. It could provide treatment recommendations to clinicians

Long Noncoding RNA SNHG4 Attenuates the Injury of Myocardial Infarction via Regulating miR-148b-3p/DUSP1 Axis

Objective. Long noncoding RNAs (lncRNAs), including some members of small nucleolar RNA host gene (SNHG), are important regulators in myocardial injury, while the role of SNHG4 in myocardial infarction (MI) is rarely known. This study is aimed at exploring the regulatory role and mechanisms of SNHG4 on MI. Methods. Cellular and rat models of MI were established. The expression of relating genes was measured by qRT-PCR and/or western blot. In vitro, cell viability was detected by MTT assay, and cell apoptosis was assessed by caspase-3 level, Bax/Bcl-2 expression, and/or flow cytometry. The inflammation was evaluated by TNF-α, IL-1β, and IL-6 levels. The myocardial injury in MI rats was evaluated by echocardiography, TTC/HE/MASSON/TUNEL staining, and immunohistochemistry (Ki67). DLR assay was performed to confirm the target relationships. Results. SNHG4 was downregulated in hypoxia-induced H9c2 cells and MI rats, and its overexpression enhanced cell viability and inhibited cell apoptosis and inflammation both in vitro and in vivo. SNHG4 overexpression also decreased infarct and fibrosis areas, relieved pathological changes, and improved heart function in MI rats. In addition, miR-148b-3p was an action target of SNHG4, and its silencing exhibited consistent results with SNHG4 overexpression in vitro. DUSP1 was a target of miR-148b-3p, which inhibited the apoptosis of hypoxia-induced H9c2 cells. Both miR-148b-3p overexpression and DUSP1 silencing weakened the effects of SNHG4 overexpression on protecting H9c2 cells against hypoxia. Conclusions. Overexpression of SNHG4 relieved MI through regulating miR-148b-3p/DUSP1, providing potential therapeutic targets

The Effect of Explosion-suppression Materials on the Effective Volume and Cook-off Properties of Fuel Tank

In this paper, three kinds of explosion-suppression materials including aluminum alloy, polyurethane foam and spherical polymer are measured to get the data of displacement ratio and retention ratio, which can be used to calculate the reduction ratio of effective volume of the oil tank. The results show that the displacement ratio of the three kinds of materials are respectively 2.0%, 2.5% and 5.2%, the retention ratio are respectively 1.1%, 3.2% and 0.4% and the reduction ratio of effective volume are respectively 3.1%, 5.7% and 5.6%. Meanwhile, the cook-off properties of the oil tank filled with spherical high molecular explosion-suppression materials were tested, the methanol in the tank didn’t explode, and materials in the tank didn’t deform and be destroyed during the experiments. All of the results showed that the spherical high molecular explosion-suppression materials presented a good explosion-suppression performance

A comparison of the biological effects of 125I seeds continuous low-dose-rate radiation and 60Co high-dose-rate gamma radiation on non-small cell lung cancer cells.

To compare the biological effects of 125I seeds continuous low-dose-rate (CLDR) radiation and 60Co γ-ray high-dose-rate (HDR) radiation on non-small cell lung cancer (NSCLC) cells.A549, H1299 and BEAS-2B cells were exposed to 125I seeds CLDR radiation or 60Co γ-ray HDR radiation. The survival fraction was determined using a colony-forming assay. The cell cycle progression and apoptosis were detected by flow cytometry (FCM). The expression of the apoptosis-related proteins caspase-3, cleaved-caspase-3, PARP, cleaved-PARP, BAX and Bcl-2 were detected by western blot assay.After irradiation with 125I seeds CLDR radiation, there was a lower survival fraction, more pronounced cell cycle arrest (G1 arrest and G2/M arrest in A549 and H1299 cells, respectively) and a higher apoptotic ratio for A549 and H1299 cells than after 60Co γ-ray HDR radiation. Moreover, western blot assays revealed that 125I seeds CLDR radiation remarkably up-regulated the expression of Bax, cleaved-caspase-3 and cleaved-PARP proteins and down-regulated the expression of Bcl-2 proteins in A549 and H1299 cells compared with 60Co γ-ray HDR radiation. However, there was little change in the apoptotic ratio and expression of apoptosis-related proteins in normal BEAS-2B cells receiving the same treatment.125I seeds CLDR radiation led to remarkable growth inhibition of A549 and H1299 cells compared with 60Co HDR γ-ray radiation; A549 cells were the most sensitive to radiation, followed by H1299 cells. In contrast, normal BEAS-2B cells were relatively radio-resistant. The imbalance of the Bcl-2/Bax ratio and the activation of caspase-3 and PARP proteins might play a key role in the anti-proliferative effects induced by 125I seeds CLDR radiation, although other possibilities have not been excluded and will be investigated in future studies