Ignition and Combustion Characterization of Nano-Al-AP and Nano-Al-CuO-AP Micro-sized Composites Produced by Electrospray Technique

AbstractMetal powders such as aluminum nanoparticles (Al NPs) have been found huge potential as reactive additives to highly increase energy density in various energetic systems such as propellants, explosives and pyrotechnics. However, it is suffering issues of agglomeration and post-combustion aggregates, which largely reduce the energy utilization efficiency and the energy release rate. One option to eliminate this disadvantage is to coat the nanoparticles with gas generator which can produce gas to prevent the sintering. This work use electrospray technique to assemble Al NPs and Al-CuO NPs into microparticles, with coating of gas generator-ammonium perchlorate (AP) to produce gas to prevent possible sintering, thus obtaining a highly reactive Al-based composites. The Al/CuO NPs composites are ignited in a confined cell to measure its combustion pressure history. The peak pressure and the pressurization rate of Al/CuO/AP is more than 3X higher and faster, compared to the physically mixed Al/CuO nanothermite. This work provides an ideal approach to prepare Al NPs based energetic materials such as solid propellant or solid fuel air explosives

Leaching resistance of hazardous waste cement solidification after accelerated carbonation

When cement-based materials are carbonated, some of their physicochemical properties are changed, which includes reductions of porosity by 20% and pH from 12-13 to 8–9. These changes can enhance the retention ability of cementitious solids containing hazard waste. This research studied the effect of carbonation on the leaching resistance of hazardous waste cement solidification. The finite element software COMSOL Multiphysics was used to simulate the process of accelerated carbonation and the effect of carbonation on leaching. Laboratory tests were conducted to validate the numerical models. Parametric studies from the numerical simulations revealed that carbonation could significantly improve leaching retention capabilities of cementitious solids containing hazardous wastes

Recipient Outcomes after ABO-Incompatible Liver Transplantation: A Systematic Review and Meta-Analysis

BACKGROUND: ABO-incompatible live transplantation (ILT) is not occasionally performed due to a relative high risk of graft failure. Knowledge of both graft and patient survival rate after ILT is essential for donor selection and therapeutic strategy. We systematically reviewed studies containing outcomes after ILT compared to that after ABO-compatible liver transplantation (CLT). METHODOLOGY/PRINCIPAL FINDINGS: We carried out a comprehensive search strategy on MEDLINE (1966-July 2010), EMBASE (1980-July 2010), Biosis Preview (1969-July 2010), Science Citation Index (1981-July 2010), Cochrane Database of Systematic Reviews (Cochrane Library, issue 7, 2010) and the National Institute of Health (July 2010). Two reviewers independently assessed the quality of each study and abstracted outcome data. Fourteen eligible studies were included which came from various medical centers all over the world. Meta-analysis results showed that no significantly statistical difference was found in pediatric graft survival rate, pediatric and adult patient survival rate between ILT and CLT group. In adult subgroup, the graft survival rate after ILT was significantly lower than that after CLT. The value of totally pooled OR was 0.64 (0.55, 0.74), 0.92 (0.62, 1.38) for graft survival rate and patient survival rate respectively. The whole complication incidence (including acute rejection and biliary complication) after ILT was higher than that after CLT, as the value of totally pooled OR was 3.02 (1.33, 6.85). Similarly, in acute rejection subgroup, the value of OR was 2.02 (1.01, 4.02). However, it was 4.08 (0.90, 18.51) in biliary complication subgroup. CONCLUSIONS/SIGNIFICANCE: In our view, pediatric ILT has not been a contraindication anymore due to a similar graft and patient survival rate between ILT and CLT group. Though adult graft survival rate is not so satisfactory, ILT is undoubtedly life-saving under exigent condition. Most studies included in our analysis are observational researches. Larger scale of researches and Randomized-Control Studies are still needed

Baicalin Ameliorates Experimental Liver Cholestasis in Mice by Modulation of Oxidative Stress, Inflammation, and NRF2 Transcription Factor

Experimental cholestatic liver fibrosis was performed by bile duct ligation (BDL) in mice, and significant liver injury was observed in 15 days. Administration of baicalin in mice significantly ameliorates liver fibrosis. Experimental cholestatic liver fibrosis was associated with induced gene expression of fibrotic markers such as collagen I, fibronectin, alpha smooth muscle actin (SMA), and connective tissue growth factor (CTGF); increased inflammatory cytokines (TNFα, MIP1α, IL1β, and MIP2); increased oxidative stress and reactive oxygen species- (ROS-) inducing enzymes (NOX2 and iNOS); dysfunctional mitochondrial electron chain complexes; and apoptotic/necrotic cell death markers (DNA fragmentation, caspase 3 activity, and PARP activity). Baicalin administration on alternate day reduced fibrosis along with profibrotic gene expression, proinflammatory cytokines, oxidative stress, and cell death whereas improving the function of mitochondrial electron transport chain. We observed baicalin enhanced NRF2 activation by nuclear translocation and induced its target genes HO-1 and GCLM, thus enhancing antioxidant defense. Interplay of oxidative stress/inflammation and NRF2 were key players for baicalin-mediated protection. Stellate cell activation is crucial for initiation of fibrosis. Baicalin alleviated stellate cell activation and modulated TIMP1, SMA, collagen 1, and fibronectin in vitro. This study indicates that baicalin might be beneficial for reducing inflammation and fibrosis in liver injury models

A Comprehensive Survey on Distributed Training of Graph Neural Networks

Graph neural networks (GNNs) have been demonstrated to be a powerful algorithmic model in broad application fields for their effectiveness in learning over graphs. To scale GNN training up for large-scale and ever-growing graphs, the most promising solution is distributed training which distributes the workload of training across multiple computing nodes. At present, the volume of related research on distributed GNN training is exceptionally vast, accompanied by an extraordinarily rapid pace of publication. Moreover, the approaches reported in these studies exhibit significant divergence. This situation poses a considerable challenge for newcomers, hindering their ability to grasp a comprehensive understanding of the workflows, computational patterns, communication strategies, and optimization techniques employed in distributed GNN training. As a result, there is a pressing need for a survey to provide correct recognition, analysis, and comparisons in this field. In this paper, we provide a comprehensive survey of distributed GNN training by investigating various optimization techniques used in distributed GNN training. First, distributed GNN training is classified into several categories according to their workflows. In addition, their computational patterns and communication patterns, as well as the optimization techniques proposed by recent work are introduced. Second, the software frameworks and hardware platforms of distributed GNN training are also introduced for a deeper understanding. Third, distributed GNN training is compared with distributed training of deep neural networks, emphasizing the uniqueness of distributed GNN training. Finally, interesting issues and opportunities in this field are discussed.Comment: To Appear in Proceedings of the IEE

Laboratory study on low-temperature coal spontaneous combustion in the air of reduced oxygen and low methane concentration

Provedena su laboratorijska ispitivanju u svrhu proučavanja spontanog izgaranja ugljena na niskoj temperaturi (30 ÷ 200 °C) u zraku s reduciranim kisikom (10 ÷ 21 %) i niskim koncentracijama metana (0 ÷ 3 %). Analiziralo se stvaranje ugljičnog monoksida kod spontanog izgaranja ugljena. Rezultati ispitivanja pokazuju da i koncentracije kisika i metana djeluju na spontano izgaranje ugljena. Pri datoj koncentraciji kisika koncentracija metana u zraku je imala pozitivan učinak na spontano izgaranje ugljena, a učinak se povećao s koncentracijom metana. Taj je učinak oslabio i smanjio se porastom temperature. Početna je temperature ugljičnog dioksida, kod koje se ugljični monoksid počeo javljati, porasla smanjenjem koncentracije kisika u zraku, a porast je donekle smanjen povećanjem koncentracije metana u zraku. Međutim, kako se koncentracija kisika smanjivala do određene vrijednosti, koncentracija metana je pokazivala malo ili nikakvog utjecaja na spontano izgaranje ugljena. Uzete su u obzir karakteristike ugljena kod niske temperature sorpcije kisika i metana kako bi se objasnili rezultati. Dobiveni rezultati su od posebne koristi u predviđanju i praćenju spontanog izgaranja ugljena u plinovitim ugljenokopima.Laboratory tests were conducted to study coal spontaneous combustion at low-temperature (30 ÷ 200 °C) in the air of reduced oxygen (10 ÷ 21 %) and low methane concentrations (0 ÷ 3 %). The production of carbon monoxide in coal spontaneous combustion was analysed. The test results show that both oxygen and methane concentrations affect coal spontaneous combustion. At given oxygen concentration the methane concentration in air had a positive impact on coal spontaneous combustion and the impact increased with methane concentration. This impact was weakened and diminished with the rise of temperature. The initial carbon dioxide temperate at which carbon monoxide started to appear increased with the reduction of oxygen concentration in the air and the increase was somewhat negated by the presence of increased methane concentration in air. However, as the oxygen concentration reduced to a certain value, methane concentration showed little or no influence on coal spontaneous combustion. The low temperature sorption characteristics of oxygen and methane by coal were applied to explain the results. The findings in this study are particularly useful in the prediction and control of coal spontaneous combustion in gassy coal mines

Mesenchymal stem cells improve mouse non-heart-beating liver graft survival by inhibiting Kupffer cell apoptosis via TLR4-ERK1/2-Fas/FasL-caspase3 pathway regulation

Abstract Background Liver transplantation is the optimal treatment option for end-stage liver disease, but organ shortages dramatically restrict its application. Donation after cardiac death (DCD) is an alternative approach that may expand the donor pool, but it faces challenges such as graft dysfunction, early graft loss, and cholangiopathy. Moreover, DCD liver grafts are no longer eligible for transplantation after their warm ischaemic time exceeds 30 min. Mesenchymal stem cells (MSCs) have been proposed as a promising therapy for treatment of certain liver diseases, but the role of MSCs in DCD liver graft function remains elusive. Methods In this study, we established an arterialized mouse non-heart-beating (NHB) liver transplantation model, and compared survival rates, cytokine and chemokine expression, histology, and the results of in vitro co-culture experiments in animals with or without MSC infusion. Results MSCs markedly ameliorated NHB liver graft injury and improved survival post-transplantation. Additionally, MSCs suppressed Kupffer cell apoptosis, Th1/Th17 immune responses, chemokine expression, and inflammatory cell infiltration. In vitro, PGE2 secreted by MSCs inhibited Kupffer cell apoptosis via TLR4-ERK1/2-caspase3 pathway regulation. Conclusion Our study uncovers a protective role for MSCs and elucidates the underlying immunomodulatory mechanism in an NHB liver transplantation model. Our results suggest that MSCs are uniquely positioned for use in future clinical studies owing to their ability to protect DCD liver grafts, particularly in patients for whom DCD organs are not an option according to current criteria

TetrazolateazidocopperIJII) coordination polymers: tuned synthesis, structure, and magnetic properties

As the first example of using a parent tetrazole and an azide together in preparing magnetic complexes, two novel tetrazolate-azido-bridged Cu(ii) coordination polymers, [Cu(tz)(N3)]n (1) and [Cu(tz)(N3)(NH3)2]n (2) (tz = tetrazolate), have been synthesized through the reaction of Htz, CuCl2, and NaN3 under hydrothermal conditions and in ammonia solution at room temperature, respectively. Single crystal X-ray structure analysis reveals that the two complexes possess distinct three-dimensional (3D) framework structures and can be topologically described as a 3-connected srs (SrSi2)-type net and a 4-connected cds (CdSO4)-type net, respectively. Both tetrazolate and azide groups also have different linkage modes in the two complexes. 1 contains end-on (EO) type azide bridges and 3-connected tetrazolate, while 2 possess end-to-end (EE) azide linkers and 2-coordinated tetrazolate. Magnetic measurements indicate that antiferrimagnetic interactions dominate between Cu(ii) ions in the two complexes with the corresponding magnetic coupling constant being J = -41.0 cm-1 in 1 and J = -8.62 cm-1 in 2

Association of MDR1 Gene SNPs and Haplotypes with the Tacrolimus Dose Requirements in Han Chinese Liver Transplant Recipients

BACKGROUND: This work seeks to evaluate the association between the C/D ratios (plasma concentration of tacrolimus divided by daily dose of tacrolimus per body weight) of tacrolimus and the haplotypes of MDR1 gene combined by C1236T (rs1128503), G2677A/T (rs2032582) and C3435T (rs1045642), and to further determine the functional significance of haplotypes in the clinical pharmacokinetics of oral tacrolimus in Han Chinese liver transplant recipients. METHODOLOGY/PRINCIPAL FINDINGS: The tacrolimus blood concentrations were continuously recorded for one month after initial administration, and the peripheral blood DNA from a total of 62 liver transplant recipients was extracted. Genotyping of C1236T, G2677A/T and C3435T was performed, and SNP frequency, Hardy-Weinberg equilibrium, linkage disequilibrium, haplotypes analysis and multiple testing were achieved by software PLINK. C/D ratios of different SNP groups or haplotype groups were compared, with a p value<0.05 considered statistically significant. Linkage studies revealed that C1236T, G2677A/T and C3435T are genetically associated with each other. Patients carrying T-T haplotype combined by C1236T and G2677A/T, and an additional T/T homozygote at either position would require higher dose of tacrolimus. Tacrolimus C/D ratios of liver transplant recipients varied significantly among different haplotype groups of MDR1 gene. CONCLUSIONS: Our studies suggest that the genetic polymorphism could be used as a valuable molecular marker for the prediction of tacrolimus C/D ratios of liver transplant recipients