Synergistic flame retardancy of ZnO with piperazine pyrophosphate/melamine polyphosphate in PP

Common ZnO particles was used to improve the flame retardancy of piperazine pyrophosphate/melamine polyphosphate (PPAP/MPP) in PP composites. 0.5 wt% ZnO exhibited an exceptional synergism by analyzing LOI determination, UL-94 test, and CCT. The LOI increased from 29.9% (no ZnO) to 32.3%. The corresponding flame-retardant rating was improved from UL-94 V-2 to V-0. Additionally, ZnO significantly inhibited the formation of the smoke and CO during the combustion process. The TGA, the component and the structure of the heated FRPP and CCT residues were studied by FTIR, EDS, SEM, Raman spectra and 31P Nuclear Magnetic Resonance, revealing that PPAP/MPP was dominant in the flame retardant process by condensed phase actions. Furthermore, ZnO obviously promoted the formation of the char layer and increased its graphitization degree. Thus, the thermal stability and the strength of the intumescent char layer were improved and then to reinforce the flame retardancy of flame retardant PP (FRPP)

XuefuZhuyu decoction protected cardiomyocytes against hypoxia/reoxygenation injury by inhibiting autophagy

Abstract Background XuefuZhuyu decoction (XFZY) is a well-known traditional Chinese herbal medicine for the treatment of various cardiovascular diseases, such as unstable angina pectoris and myocardial ischemia-reperfusion injury. However, the mechanism by which XFZY contributes to the amelioration of cardiac injury remains unclear. Methods H9C2 cells were cultured under the hypoxic condition for 10 h and reoxygenated for 2 h. In the presence of various concentrations of XFZY for 12 h, the cell viability was measured by MTT assay. The protective effect of XFZY in hypoxia/reoxygenation (H/R) cell model was confirmed by measuring the amount of LDH released into the extracellular fluid. Cell apoptosis was measured by western blotting. The autophagy level of H9C2 cells and the correlative pathway were determined by transmission electron microscopy, Cyto-ID® Autophagy Detection Kit, and western blotting. Results In this study, we investigated the effects of XFZY on H/R induced cardiac injury. The results showed that treatment with XFZY significantly inhibited autophagy induced by H/R, with decreased formation of autophagosomes as well as the expression of LC3-II/LC3-I ratio and Beclin 1 after H/R. Importantly, inhibition of autophagy by XFZY resulted in enhanced cell viability and decreased apoptosis. XFZY also inhibited the activation of AMPK and upregulated the phosphorylation of mammalian target of Rapamycin (mTOR). Conclusions The cardioprotective effects of XFZY during H/R were mediated by inhibiting autophagy via regulating AMPK-mTOR signaling pathways

Fluid Flow and Heat Transfer Behaviors under Non-Isothermal Conditions in a Four-Strand Tundish

In the continuous casting process, the fluid flow of molten steel in the tundish is in a non-isothermal state. Because of the geometric shape and process parameters of a multi-strand tundish, the fluid flow behavior of each strand is quite inhomogeneous, and the difference in temperature, composition and inclusion content between each strand is great, which directly affects the quality of the steel products. In this paper, the fluid flow, heat transfer phenomena and inclusion trajectories in a four-strand tundish with and without flow-control devices (FCDs) are investigated using a water model and numerical simulation in isothermal and non-isothermal conditions. The results show that natural convection has a significant influence on the flow pattern and temperature distributions of molten steel in the tundish. Without FCDs, the average residence times of the molten steel in the tundish obtained by the isothermal water model, non-isothermal water model and non-isothermal mathematical model were 251.2 s, 263.3 s and 266.0 s, respectively, and the dead zone volumes were 21.51%, 29.26% and 28.21%, respectively. With FCDs, the average residence times of the molten steel obtained by the isothermal water model, non-isothermal water model and non-isothermal mathematical model were 293.0 s, 304.0 s and 305.2 s, respectively, and the dead zone volumes were 43.98%, 50.23% and 52.78%, respectively. The flow characteristics of the molten steel in the tundish were different between the isothermal and non-isothermal conditions. Compared with isothermal conditions, the numerical simulation results were closer to the water model results in non-isothermal conditions. The trial results showed that the fluid flow in a tundish has a non-isothermal characteristic, and the results in non-isothermal conditions can better reflect the actual fluid flow and heat transfer behaviors of molten steel in a tundish

Synergistic Fire Retardancy of Bis(1-methoxy-2,2,6,6-tetramethylpiperidin-4-yl)sebacate and Tris(2,4,6-tribromophenoxy)-1,3,5-triazine/Sb2O3 in HIPS

Bis(1-methoxy-2,2,6,6-tetramethylpiperidin-4-yl)sebacate (NORSM) was found to perform an exceptional synergistic effect with tris(2,4,6-tribromophenoxy)-1,3,5-triazine (TTBPC)/Sb2O3 in HIPS. The LOI of fire retardant HIPS (FR-HIPS) with 16 wt% of TTBPC/Sb2O3 increased from 23.8% to 25.2%, the flame retardant rating of FR-HIPS was improved from UL 94 V-2 to UL 94 V-0, and various heat release parameters such as peak heat release rate, total heat release, and mean effective heat of combustion were greatly lowered by combining NORSM of 0.50 wt%. The Py-GC/MS results revealed that NORSM induced the role of synergistic effect; the main mechanisms were as follows: the active radicals such as methoxy radicals and aminyl radicals produced by the pyrolysis of NORSM promote the release of bromine radicals from TTBPC and the formation of HBr and CO2, which improves the flame retardancy of TTBPC/Sb2O3; the above active radicals, together with HBr, quench active free radicals, such as the hydroxyl radical (OH), and decompose the free radical source, which interrupts the chain reaction during combustion and results in a more efficient flame retardant effect in gaseous phase

Eu3+-Activated Sr3ZnTa2O9 single-component white light phosphors: emission intensity enhancement and color rendering improvement

Single-component white light phosphors with a broad and full color spectrum are urgently required to overcome residual problems with commercial phosphors. In this paper, we describe how Eu3+, as the dopant of Sr3ZnTa2O9 (SZT), plays an important role in structural modulation (including structural order-disorder and intrinsic oxygen defects), as demonstrated by electronic structural calculations and systematic experiments. Furthermore, D-5(0) F-7(2) emission of Eu3+ provides the red component of the emission spectrum and increases the color rendering index of SZT:Eu3+ phosphors. Consequently, the resulting phosphor SZT:10%Eu3+ shows significantly enhanced emission intensity, and its broadband emission covers the entire visible region from 400 nm to 720 nm. A fabricated LED device using a near-ultraviolet 370 nm chip coated with a single-component, the SZT:10%Eu3+ phosphor, shows warm white emission with a high color rendering index (R-a = 82)

Non-contrast enhanced MRI for efficiency evaluation of high-intensity focused ultrasound in adenomyosis ablation

AbstractObjective To investigate the value of T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) in evaluating the therapeutic effect of high-intensity focused ultrasound (HIFU) in adenomyosis ablation.Material and methods One hundred eighty-nine patients with adenomyosis were treated with HIFU. The ablation areas on T2WI and DWI sequences were classified into different types: type I, relatively ill-defined rim or unrecognizable; subtype IIa, well-defined rim with hyperintensity; subtype IIb, well-defined rim with hypointensity. The volume of ablation areas on T2WI (VT2WI) and DWI (VDWI) was measured and compared with the non-perfused volume (NPV), and linear regression was conducted to analyze their correlation with NPV.Results The VT2WI of type I and type II (subtype IIa and subtype IIb) were statistically different from the corresponding NPV (p = 0.004 and 0.024, respectively), while no significant difference was found between the VDWI of type I and type II with NPV (p = 0.478 and 0.561, respectively). In the linear regression analysis, both VT2WI and VDWI were positively correlated with NPV, with R2 reaching 0.96 and 0.97, respectively.Conclusions Both T2WI and DWI have the potential for efficient evaluation of HIFU treatment in adenomyosis, and DWI can be a replacement for CE-T1WI to some extent

The mechanisms underlying the enrichment and action of glypican-1-positive exosomes in colorectal cancer cells

Background: Glypican-1 (GPC1) is overexpressed in several tumors, and GPC1+ exosomes have shown the potential to predict early colorectal cancer (CRC). However, the mechanisms underlying the enrichment and action of GPC1+ exosomes in CRC remain unknown. Methods: The expression of slit guidance ligand 2 (SLIT2), hypoxia-inducible factor (HIF)-1α/2α, and GPC1 in clinical CRC tissues was detected using immunohistochemistry and western blot. Exosomes were isolated from the supernatants of CRC cell cultures. The effects of SLIT2, hypoxia, heparin, and phospholipase C (PLC) on exosomal GPC1 expression and GPC1+ exosome enrichment in CRC cells were analyzed with western blot and flow cytometry. CRC cell proliferation was assessed with MTT and colony formation assays. Co-immunoprecipitation was used to detect the binding of GPC1 and SLIT2 in SW480 cells. Nude mice were subcutaneously inoculated with SW480 cells with different treatments. The Wnt signaling was detected. Results: SLIT2 was poorly expressed and GPC1, HIF-1α, and HIF-2α were highly expressed in human CRC tissues. SLIT2 in CRC cells inhibited GPC1+ exosome enrichment and exosomal GPC1 expression. PLC and heparin increased GPC1+ exosome enrichment in CRC cells in a concentration-dependent manner. Hypoxia increased the enrichment of GPC1+ exosomes in CRC cells depending on HIF-2α expression. GPC1+ exosomes stimulated CRC cell proliferation and xenograft tumor growth through activation of Wnt signaling. Conclusions: GPC1+ exosome enrichment is related to PLC and heparin. Hypoxia increases the enrichment of GPC1+ exosomes in CRC cells by activating HIF-2α and downregulating SLIT2. GPC1+ exosomes further drive CRC progression by activating Wnt signaling

Broad-band emission of A3B′B′′2O9 complex perovskites (A = Ba, Sr; B′ = Zn; B′′ = Ta, Nb) realized by structural variations of the B site order–disorder

Broad emission with a full and continuous color spectrum realized by crystal engineering is extensively desired to simulate natural sunlight and improve the white color quality. Herein, new insight into the modulation of B site order-disorder and intrinsic oxygen defects for complex perovskite (A(3)BB(2)O(9)) Sr3-xScxZnNb2O9 (0 x 0.1) phosphors is demonstrated for broad-band emission via crystal engineering. We elucidate that the spectrum of Sr3ZnNb2O9 synthesized at an optimal temperature exhibits two emission bands under near-ultraviolet excitation ((ex) = 374 nm) which is readily available from near ultraviolet chips. The two broad emission bands can be ascribed to charge transfer from the empty 4d (t(2g))-orbitals of Nb5+ ions to the filled 2p-orbitals of O2- ions and the intrinsic oxygen defects. Further, as a proposed strategy to optimize the luminescence property of Sr3ZnNb2O9 (SZN), we realized A-site nonequivalent doping to induce B-site disordering and cancel the luminescence quenching which results from B site ordering. The A-site nonequivalent doping efficiently offsets intrinsic oxygen defects, as validated by systematic analyses of experiments and DFT calculations. Consequently, the novel phosphor Sr3-xScxZnNb2O9 (x = 0.1) shows a high color rendering index (R-a = 82.2) and negligible color shift. In addition, its emission intensity is enhanced by approximate to 70 times as compared to the pristine Sr3ZnNb2O9

pH-gated nanoparticles selectively regulate lysosomal function of tumour-associated macrophages for cancer immunotherapy

Abstract Tumour-associated macrophages (TAMs), as one of the most abundant tumour-infiltrating immune cells, play a pivotal role in tumour antigen clearance and immune suppression. M2-like TAMs present a heightened lysosomal acidity and protease activity, limiting an effective antigen cross-presentation. How to selectively reprogram M2-like TAMs to reinvigorate anti-tumour immune responses is challenging. Here, we report a pH-gated nanoadjuvant (PGN) that selectively targets the lysosomes of M2-like TAMs in tumours rather than the corresponding organelles from macrophages in healthy tissues. Enabled by the PGN nanotechnology, M2-like TAMs are specifically switched to a M1-like phenotype with attenuated lysosomal acidity and cathepsin activity for improved antigen cross-presentation, thus eliciting adaptive immune response and sustained tumour regression in tumour-bearing female mice. Our findings provide insights into how to specifically regulate lysosomal function of TAMs for efficient cancer immunotherapy

Clinical utilization of multiple antibodies of Mycobacterium tuberculosis for serodiagnosis evaluation of tuberculosis: a retrospective observational cohort study

AbstractObjectives We aimed to investigate clinical uncertainties by characterizing the accuracy and utility of commercially available antibodies of Mycobacterium tuberculosis in the diagnostic assessment of suspected tuberculosis in high-burden countries.Methods We conducted a retrospective, descriptive, cohort study among participants aged ≥ 18 years with suspected tuberculosis in Nanning, Guangxi, and China. Participants were tested for M. tuberculosis infection using commercially available antibodies against Mycobacterum tuberculosis. Specificity, sensitivity, negative and positive predictive values, and negative and positive likelihood ratios of the tests were determined. Sputum specimens and bronchoalveolar lavage fluid were sent for mycobacterial culture, Xpert MTB/RIF assay, and cell-free M. tuberculosis DNA or RNA assay. Blood samples were used for IGRAs, T-cell counts (CD3 + CD4+ and CD3 + CD8+), and antibodies to tuberculosis test.Results Of the 1857 participants enrolled in this study, 1772 were included in the analyses, among which, 1311 were diagnosed with active tuberculosis. The specificity of antibody against 16kD for active tuberculosis was 92.7% (95% confidence interval [CI]: 89.3–95.4) with a positive likelihood ratio for active tuberculosis cases of 3.1 (95% CI: 2.1–4.7), which was higher than that of antibody to Rv1636 (90.5% [95% CI: 86.6–93.5]), antibody to 38kD (89.5% [95% CI: 85.5–92.7]), antibody against CFP-10 (82.6% [95% CI: 77.9–86.7]), and antibody against LAM (79.3% [95% CI: 74.3–83.7]). Sensitivity ranged from 15.8% (95% CI: 13.9–17.9) for antibody against Rv1636 to 32.9% (95% CI: 30.4–35.6) for antibody to LAM.Conclusions Commercially available antibodies against to Mycobacterium tuberculosis do not have sufficient sensitivity for the diagnostic evaluation of active tuberculosis. However, antibody against Rv1636 and 16kD may have sufficiently high specificities, high positive likelihood ratios, and correspondingly high positive predictive values to facilitate the rule-in of active tuberculosis