Synergistic Effect of Activated Carbon, NiO and Al₂O₃ on Improving the Thermal Stability and Flame Retardancy of Polypropylene Composites

It is difficult to enhance the char yields of polypropylene (PP) due to the preferential complete combustion. Successful formation of abundant char layer structure of PP upon flammability was obtained due to the synergistic effect of NiO, Al2O3 and activated carbon (AC). From characterization of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), it was revealed that the microstructure of residual char contained large amount of carbon nanotubes. Compared to the modification of AC, NiO and Al2O3 alone, the combination of AC, NiO and Al2O3 dramatically promotes the charring ability of PP. In the case of AC and NiO, NiO plays a role of dehydrogenation, resulting in the degradation product, while AC mainly acts as carbonization promoter. The addition of Al2O3 results in higher dispersion and smaller particle size of NiO, leading to greater exposure of active sites of NiO and higher dehydrogenation and carbonization activity. Compared to the neat PP, the decomposition temperature of the PP modified by combined AC, NiO and Al2O3 was increased by 90 ℃. The yield of residual char of AC-5Ni-Al-PP reached as high as 44.6%. From the cone calorimeter test, the heat release rate per unit area (HRR) and total heat release per unit area (THR) of PP composite follows the order AC-5Ni-Al-PP < AC-10Ni-Al-PP < AC-Ni-PP < AC-15Ni-Al-PP < AC-1Ni-Al-PP. Compared to the neat PP, the peak of HRR declined by 73.8%, 72.7%, 71.3%, 67.6% and 62.5%, respectively

Controllable Synthesis of Polar Modified Hyper-Cross-Linked Resins and Their Adsorption of 2‑Naphthol and 4‑Hydroxybenzoic Acid from Aqueous Solution

We synthesized a series of polar hyper-cross-linked resins, and the porosity and polarity of these resins were effectively tuned by feeding different amounts of glycidyl methacrylate (GMA). As the feeding amount of GMA increased, the Brunauer–Emmett–Teller surface area, pore volume, micropore area, and micropore volume sharply decreased; the pore size distribution of the resins showed a large population of pores in the microporous region extending to a higher part of the mesoporous region, and the O content increased while the static contact angle lowered. The adsorption experiments indicated that these resins were efficient for adsorption of 2-naphthol and 4-hydroxybenzoic acid (4-HBA). The adsorption process was very fast, and the kinetic data for the adsorption of 2-naphthol could be well-fitted by a pseudo-second-order rate equation, while those for the adsorption of 4-HBA could be characterized by a pseudo-first-order rate equation

High prevalence, genetic diversity and intracellular growth ability of Legionella in hot spring environments.

BACKGROUND: Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. METHODS: Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE) and sequence-based typing (SBT) were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. RESULTS: Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (p<0.01). The Legionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (p<0.01). Legionella pneumophila was the most frequently isolated species (98.9%), and the isolated serogroups included serogroups 3 (25.3%), 6 (23.4%), 5 (19.2%), 1 (18.5%), 2 (10.2%), 8 (0.4%), 10 (0.8%), 9 (1.9%) and 12 (0.4%). Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. CONCLUSIONS: Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control and prevention strategies are urgently needed

Janus Silver/Silica Nanoplatforms for Light-Activated Liver Cancer Chemo/Photothermal Therapy

Stimuli-triggered nanoplatforms have become attractive candidates for combined strategies for advanced liver cancer treatment. In this study, we designed a light-responsive nanoplatform with folic acid-targeting properties to surmount the poor aqueous stability and photostability of indocyanine green (ICG). In this Janus nanostructure, ICG was released on-demand from mesoporous silica compartments in response to near-infrared (NIR) irradiation, exhibiting predominant properties to convert light to heat in the cytoplasm to kill liver cancer cells. Importantly, the silver ions released from the silver compartment that were triggered by light could induce efficient chemotherapy to supplement photothermal therapy. Under NIR irradiation, ICG-loaded Janus nanoplatforms exhibited synergistic therapeutic capabilities both in vitro and in vivo compared with free ICG and ICG-loaded mesoporous silica nanoparticles themselves. Hence, our Janus nanoplatform could integrate ICG-based photothermal therapy and silver ion-based chemotherapy in a cascade manner, which might provide an efficient and safe strategy for combined liver cancer therapy

Circulating Cell‐Free DNAs as a Biomarker and Therapeutic Target for Acetaminophen‐Induced Liver Injury

Abstract Acetaminophen (APAP) overdose is a leading cause of drug‐induced liver injury and acute liver failure, while the detection, prognosis prediction, and therapy for APAP‐induced liver injury (AILI) remain improved. Here, it is determined that the temporal pattern of circulating cell‐free DNA (cfDNA) is strongly associated with damage and inflammation parameters in AILI. CfDNA is comparable to alanine aminotransferase (ALT) in predicting mortality and outperformed ALT when combined with ALT in AILI. The depletion of cfDNA or neutrophils alleviates liver damage, while the addition of cfDNA or adoptive transfer of neutrophils exacerbates the damage. The combination of DNase I and N‐acetylcysteine attenuates AILI significantly. This study establishes that cfDNA is a mechanistic biomarker to predict mortality in AILI mice. The combination of scavenging cfDNA and reducing oxidative damage provides a promising treatment for AILI

Characterization of subtypes and transmitted drug resistance strains of HIV among Beijing residents between 2001-2016.

BackgroundBeijing is a national and international hub potentially containing a broad diversity of HIV variants. Previous studies on molecular epidemiology of HIV in Beijing pooled together samples from residents and non-residents. Pooling residents and non-residents has potentially introduced bias and undermined a good assessment and the intervention among the autochthonous population. Here, we aimed to define HIV subtype diversity and investigate the TDR in Beijing residents exclusively.MethodsWe analyzed the demographic, clinical, and virological data collected between 2001 and 2016 from residents in Beijing. A population-based sequencing of the HIV pol gene was carried out using plasma specimens. Phylogenetic analysis was performed in order to classify sequences into their corresponding subtypes using an automated subtyping tool, the Context-Based Modeling for Expeditious Typing (COMET). Furthermore, the drug resistance mutations were determined using the World Health Organization list for surveillance of TDR mutations.ResultsData on TDR were available for 92% of 2,315 individuals with HIV infection, of whom 7.1% were women. The bioinformatic analysis of HIV strains from this study revealed that a combined 17 subtypes were circulating in Beijing, China between 2001 and 2016. The most common ones were CRF01_AE, CRF07_BC, and subtype B in Beijing during this period. The overall prevalence of TDR was 4.5% (95% confidence intervals[CI]: 3.6%-5.4%), with a declining trend over the period of spanning 2001 through 2016. In-depth class-specific analysis revealed that the prevalence of TDR for the nucleoside reverse-transcriptase inhibitors (NRTIs) was 1.0% (95% CI: 0.6-1.5), 0.9% (95% CI:0.6-1.4) for non-NRTIs and 2.8% (95% CI:2.1-3.5) for protease inhibitors. The prevalence of TDR was lower in individuals infected with the CRF07_BC HIV strain than those infected with CRF01_AE.ConclusionsOur data showed that the HIV epidemic in Beijing displayed a high genetic heterogeneity and a low and declining prevalence of TDR. In sharp contrast to Europe and North America, the declining trend of TDR between 2001 through 2016 was noticed while there was a widespread distribution of antiretroviral treatment in Beijing, China