3,620 research outputs found
Flame-Retardant and Thermal Degradation Mechanism of Caged Phosphate Charring Agent with Melamine Pyrophosphate for Polypropylene
An efficient caged phosphate charring agent named PEPA was synthesized and combined with melamine pyrophosphate (MPP) to flame-retard polypropylene (PP). The effects of MPP/PEPA on the flame retardancy and thermal degradation of PP were investigated by limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimetric test (CCT), and thermogravimetric analysis (TGA). It was found that PEPA showed an outstanding synergistic effect with MPP in flame retardant PP. When the content of PEPA was 13.3 wt% and MPP was 6.7 wt%, the LOI value of the flame retardant PP was 33.0% and the UL-94 test was classed as a V-0 rating. Meanwhile, the peak heat release rate (PHRR), average heat release rate (AV-HRR), and average mass loss rate (AV-MLR) of the mixture were significantly reduced. The flame-retardant and thermal degradation mechanism of MPP/PEPA was investigated by TGA, Fourier transform infrared spectroscopy (FTIR), TG-FTIR, and scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDXS). It revealed that MPP/PEPA could generate the triazine oligomer and phosphorus-containing compound radicals which changed the thermal degradation behavior of PP. Meanwhile, a compact and thermostable intumescent char was formed and covered on the matrix surface to prevent PP from degrading and burning
Experimental Test of Tracking the King Problem
In quantum theory, the retrodiction problem is not as clear as its classical
counterpart because of the uncertainty principle of quantum mechanics. In
classical physics, the measurement outcomes of the present state can be used
directly for predicting the future events and inferring the past events which
is known as retrodiction. However, as a probabilistic theory,
quantum-mechanical retrodiction is a nontrivial problem that has been
investigated for a long time, of which the Mean King Problem is one of the most
extensively studied issues. Here, we present the first experimental test of a
variant of the Mean King Problem, which has a more stringent regulation and is
termed "Tracking the King". We demonstrate that Alice, by harnessing the shared
entanglement and controlled-not gate, can successfully retrodict the choice of
King's measurement without knowing any measurement outcome. Our results also
provide a counterintuitive quantum communication to deliver information hidden
in the choice of measurement.Comment: 16 pages, 5 figures, 2 table
7-Piperazinethylchrysin inhibits melanoma cell proliferation by targeting Mek 1/2 kinase activity
Purpose: To investigate the growth-inhibitory effect of 7-piperazinethylchrysin (PEC) on melanoma cell lines.Methods: Cell viability was analyzed by trypan blue exclusion assays and the cell cycle by flow cytometry using ModFit LT software. Specifically, cells were stained with propidium iodide (0.5 mg/mL) supplemented with RNase A (50 mg/mL), and analyzed using flow cytometry and ModFit LT software.Results: In A375 and B16F10 cell cultures, proliferation was reduced to 79 and 72 %, respectively, on treatment with 30 μM PEC. PEC increased the proportion of A375 cells in G1/G0 phase to 71.23 %, versus 42.76 % in untreated cells. In B16F10 and A375 cells, treatment with PEC caused the inhibition of Mek 1/2 kinase activity and suppressed Erk 1/2 phosphorylation. The level of cAMP-response element binding protein was increased by PEC. The expression of microphthalmia-linked transcription factor was also increased by PEC treatment. Marked enhancement was observed in the level of tyrosinase in melanoma cells on treatment with PEC. Analysis of PBG-D expression showed a marked increase in B16F10 and A375 cells on the addition of PEC to cell cultures at 72 h. The level of PBG D expression was increased by 9- and 8.5-fold in B16F10 and A375 cells, respectively, on incubation with 30 μM PEC. The addition of a Mek 1/2 inhibitor (U0126) to the cultures promoted PEC-mediated growth inhibition.Conclusion: PEC inhibited melanoma cell proliferation, apparently by blocking the cell cycle at G0/G1 and downregulating the Ras/Raf/Mek/Erk pathway.Keywords: Tyrosinase, Kinase, Microphthalmia, Phosphorylation, 7-Piperazinethylchrysi
A retrospective clinicopathological study on oral lichen planus and malignant transformation: analysis of 518 cases
Objective: To investigate the epidemiological and clinical characteristics of a relatively large cohort of patients
with oral lichen planus (OLP) from eastern China.
Study design: A total of 518 patients with histologically confirmed OLP in a long-term follow-up period (6 months-
21.5 years) were retrospectively reviewed in our clinic.
Results: Of the 518 patients, 353 females and 165 males were identified. The average age at diagnosis was 46.3
years (range 9-81 years) with the buccal mucosa being the most common site (87.8%). At initial presentation, white
lichen and red lichen was seen in 52.3% and 47.7% patients, respectively. Of these, 5 (0.96%) patients previously
diagnosed clinically and histopathologically as OLP developed oral cancer. All of them were the females with no
a history of smoking or alcohol use.
Conclusions: Clinical features of eastern Chinese OLP patients were elucidated. Notably, approximately 1% of
OLP developed into cancer, which provides further evidence of potentially malignant nature of OLP
Separate density and viscosity measurements of unknown liquid using quartz crystal microbalance
Aqueous liquids have a wide range of applications in many fields. Basic physical properties like the density and the viscosity have great impacts on the functionalities of a given ionic liquid. For the millions kinds of existing liquids, only a few have been systematically measured with the density and the viscosity using traditional methods. However, these methods are limited to measure the density and the viscosity of an ionic liquid simultaneously especially in processing micro sample volumes. To meet this challenge, we present a new theoretical model and a novel method to separate density and viscosity measurements with single quartz crystal microbalance (QCM) in this work. The agreement of experimental results and theocratical calculations shows that the QCM is capable to measure the density and the viscosity of ionic liquid
Pathogen spectrum and immunotherapy in patients with anti-IFN-γ autoantibodies: A multicenter retrospective study and systematic review
BackgroundAnti-interferon-γ autoantibody (AIGA) positivity is an emerging immunodeficiency syndrome closely associated with intracellular infection in individuals without human immunodeficiency virus (HIV). However, the information on epidemiology, pathogen spectrum, and immunotherapy among these patients lack a systematic description of large data.MethodsThis systematic literature review and multicenter retrospective study aimed to describe the pathogen spectrum and review treatment strategies among patients with AIGA positivity.ResultsWe included 810 HIV-negative patients with AIGA positivity infected with one or more intracellular pathogens. Excluding four teenagers, all the patients were adults. The most common pathogen was nontuberculous mycobacteria (NTM) (676/810, 83.5%). A total of 765 NTM isolates were identified in 676 patients with NTM, including 342 (44.7%) rapid-grower mycobacteria, 273 (35.7%) slow-grower mycobacteria, and 150 (19.6%) unidentified NTM subtype. Even with long-term and intensive antimicrobial treatments, 42.6% of patients with AIGA positivity had recurrence and/or persistent infection. Sixty-seven patients underwent immunoregulatory or immunosuppressive therapy, and most (60) achieved remission. The most common treatment strategy was rituximab (27/67, 40.3%) and cyclophosphamide (22/67, 32.8%), followed by cyclophosphamide combined with glucocorticoids (8/67, 11.9%).ConclusionsIntracellular pathogen was the most common infection in patients with AIGA positivity. The predominant infection phenotypes were NTM, varicella-zoster virus, Talaromyces marneffei, and Salmonella spp., with or without other opportunistic infections. AIGA immunotherapy, including rituximab or cyclophosphamide, has yielded good preliminary results in some cases
Application of indocyanine green-mediated fluorescence molecular imaging technology in liver tumors resection: a systematic review and meta-analysis
BackgroundThis meta-analysis was dedicated to evaluating the safety and effectiveness of indocyanine green (ICG) -mediated fluorescence molecular imaging (FMI) technology in liver tumors resection.MethodsA literature search of PubMed, Embase databases, Cochrane Library, and Web of Science was performed to identify all clinical controlled studies exploring the effects of fluorescence imaging on liver tumors resection. Quality assessment and data extraction of studies were conducted independently by 3 reviewers. Mean difference (MD) and odds ratio (OR) with 95% confidence interval (CI) were calculated using a fixed-effects or random-effects model. The meta-analysis was performed with RevMan 5.3 software.Results14 retrospective cohort studies (RCSs) involving a total of 1227 patients were finally included. The results showed that Fluorescence-assisted liver tumors resection could improve the R0 resection rate (OR = 2.63; 95% CI: 1.46~4.73, p = 0.001), reduce overall complications (OR = 0.66; 95% CI: 0.44~0.97, p = 0.04), biliary fistula (OR = 0.20; 95% CI: 0.05~0.77, p = 0.02), intraoperative blood loss (MD = −70.76, 95% CI: −106.11 to −35.41; p < 0.0001), and shortens hospital stay (MD = −1.41, 95% CI: −1.90 to −0.92; p < 0.00001). There were no significant differences in the incidences of operative time (MD = −8.68, 95% CI: −18.59 to −1.22; p = 0.09), complications of grade III or above (OR = 0.73; 95% CI: 0.43~1.25, p = 0.26), liver failure (OR = 0.86; 95% CI: 0.39~1.89, p = 0.71), and blood transfusion (OR = 0.66; 95% CI: 0.42~1.03, p = 0.07).ConclusionCurrent evidence suggests that ICG-mediated FMI technology could enhance the clinical effectiveness of patients with liver tumors resection and is clinically worthy of promotion.Systematic review registrationPROSPERO, identifier CRD42022368387
Water‐assisted programmable assembly of flexible and self‐standing Janus membranes
Janus membranes with asymmetric wettability have been considered cutting-edge for energy/environmental-sustainable applications like water/fog harvester, breathable skin, and smart sensor; however, technical challenges in fabrication and accurate regulation of asymmetric wettability limit their development. Herein, by using water-assisted hydrogen-bonded (H-bonded) assembly of small molecules at water/oil interface, a facile strategy is proposed for one-step fabrication of membranes with well-regulable asymmetric wettability. Asymmetric orderly patterns, beneficial for mass transport based on abundant high-permeability sites and large surface area, are constructed on opposite membrane surfaces. Upon tuning water-assisted H-bonding via H-sites/configuration design and temperature/pH modulation, double-hydrophobic, double-hydrophilic, and hydrophobic-hydrophilic membranes are facilely fabricated. The Janus membranes show smart vapor-responsive curling and unidirectional water transport with promising flux of 1158±25 L m−2 h−1 under natural gravity and 31500±670 L·(m−2 h−1 bar−1) at negative pressure. This bottom-up approach offers a feasible-to-scalable avenue to precise-manipulation of Janus membranes for advanced applications, providing an effective pathway for developing tailor-made self-assembled nanomaterials
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