Co-pyrolysis of dyeing sludge and pine sawdust in a fluidized bed: Characterization and analysis of pyrolytic products and investigation of synergetic effects.

Co-pyrolysis of dyeing sludge (DS) and pine sawdust (PS) was carried out in a fluidized bed pyrolyser. The results revealed that addition of PS increased the yields of condensate and gas, and dramatically improved pore structure of co-pyrolysis char, enhancing immobilization of the metals, nutrient and pollution elements. Catalysts (Na-ZSM-5 and HZSM-5) significantly reduced tar and coke, strengthened the integrity of pore structure. Yield of nitrogen-containing compounds declined sharply from 88.66% to 8.14% when 25% of PS was added. Addition of 50% PS promoted ring opening to generate chain compounds and abundant oxygenates (such as ketones, aldehydes and carboxylic acids) in pyrolysis oil (PO) at 650 °C. Correspondingly, yield of gaseous products was inhibited except CO2 and H2 when PS content was dominant. The catalysts greatly increased yield of gaseous products by enhancing primary and secondary cracking depending on different feedstocks and catalysts (e.g., DS over Na-ZSM-5 and PS over HZSM-5). The maximum energy efficiency (69.75%) was obtained at 650 °C when 75% PS was added.

Iron-biochar production from oily sludge pyrolysis and its application for organic dyes removal.

In this study, a single-step pyrolysis approach was developed to directly convert oily sludge (OS) with high iron content into a magnetic iron-char catalyst for organic dyes removal. Magnetic iron-char catalysts were employed to degrade crystal violet (CV), methylene blue (MB), and sunset yellow (SY). The OC800 iron-char catalyst prepared from OS was not only rich in iron (mainly stable Fe3O4), but also showed favorable pore structures. Effects of operation parameters like temperature, H2O2 dosage, and pH on dye removal based on Fenton degradation were examined. In OC800 Fenton system (0.5 mL H2O2, 500 mg/L dye concentration, and pH = 2 in 50 mL solution), the maximum dye removal capacities of SY, CV, and MB were 83.61, 639.19, and 414.25 mg/g, respectively. In dyes degradation experiments, the prepared catalyst could be reused (more than 3 successive cycles) due to higher stability and less leaching of iron. One-step pyrolysis of OS with high iron content thereby represents a promising approach to transform sludge waste to functional biochar that removes hazardous dyes.

Pyrolysis of vegetable oil soapstock in fluidized bed: Characteristics of thermal decomposition and analysis of pyrolysis products.

This study investigated the effect of temperature on pyrolysis of soapstock in a fluidized bed reactor, and the characterization of soapstock chars (SCs) and pyrolysis oils (POs) were analyzed. TGA, TG-FTIR, TG-MS, and Py-GCMS were employed to investigate characteristics of SS pyrolysis. Experimental results indicated that the yield of SC decreased with increasing temperature. Pyrolysis oil (PO) yield reached the maximum of 21.05 wt% at 600 °C and the yield of non-condensable gas varied with temperatures. The content of carbon, hydrogen and nitrogen distributed in the SC decreased with the increasing temperature, and sulfur tended to be retained in SC during pyrolysis with the distribution ratio of 0.55-0.62. Ketones, alcohols and hydrocarbons were the dominate substances in PO, and higher temperature promoted the production of short-chain alkanes and the conversion of alkenes to benzene derivatives. SS pyrolysis can be divided into three stages. Stage I was mainly the evaporation of free water and light organics in the raw material. Decomposition and conversion of organics mainly occurred at stage II. Stage III was the decomposition of CaCO3 and secondary cracking of residual organics. Ca2+ delayed the pyrolysis reaction of fatty acids and promoted decarboxylation which was the main deoxygenation pathway, and alkene production. This study provided a theoretical basis for the application of soapstock thermochemical treatment. It is of great significance for the quality improvement of PO and pollution control for pyrolysis processes.

Influence of corn straw on distribution and migration of nitrogen and heavy metals during microwave-assisted pyrolysis of municipal sewage sludge.

This study explored pyrolysis characteristics, nitrogen transformation and migration of heavy metals during microwave-assisted pyrolysis of municipal sewage sludge in a continuously operated auger pyrolyser at different temperatures and corn straw ratios. The results showed higher temperatures and more corn straw resulted in more gas yield (e.g., CO2, CO, CH4 and H2) and less char yield. 5 wt% corn straw addition at 750 °C achieved high-quality bio-oil with less O-containing compounds, which was more favorable for upgrading to transportation fuels. Sludge chars prepared at higher corn straw ratios had lower ratios of H/C and N/C, and higher carbon content. Nitrogen transformation pathways and mechanisms were investigated. The residual ratio of heavy metals (except Cd) in sludge char was 67.74-100%. However, the residual ratio of Cd decreased significantly to 6.46% at 750 °C. Concentrations of all heavy metals in sludge char conformed to national standard (CJ/T 362-2011, China), and the potential ecological risk was slight. Sludge chars prepared in the presence of corn straw had lower ecological risk and higher retention capacity of heavy metals (e.g., Pb, Cr, Mn, Cu, Zn, and Ni) compared with pyrolysis of sewage sludge.

Neutrophil Extracellular Traps may be a Potential Target for Treating Early Brain Injury in Subarachnoid Hemorrhage.

Neuroinflammation is closely associated with poor prognosis in patients with subarachnoid hemorrhage (SAH). The purpose of this study was to investigate the role of neutrophil extracellular traps (NETs), which are important regulators of sterile inflammation, in SAH. In this study, markers of NET formation, quantified by the level of citrullinated histone H3 (CitH3), were significantly increased after SAH and correlated with SAH severity. CitH3 peaked at 12 h in peripheral blood and at 24 h in the brain. Administration of the peptidyl arginine deiminase 4 (PAD4) selective antagonist GSK484 substantially attenuated SAH-induced brain edema and neuronal injury. Moreover, the benefit of NET inhibition was also confirmed by DNAse I treatment and neutrophil depletion. Mechanistically, NETs markedly exacerbated microglial inflammation in vitro. NET formation aggravated neuroinflammation by promoting microglial activation and increased the levels of TNF-α, IL-1ß, and IL-6, while inhibiting NETs demonstrated anti-inflammatory effects by decreasing the levels of these proinflammatory factors. Moreover, neurogenic pulmonary edema (NPE), a severe nonneurological complication after SAH, is associated with a high level of NET formation. However, GSK484 effectively inhibited the formation of NETs in the lungs of NPE mice, thereby preventing the diffusion of neutrophilic infiltration and attenuating the swelling of the alveolar interstitium. In conclusion, NETs promoted neuroinflammation after SAH, while pharmacological inhibition of PAD4-NETs could reduce the inflammatory damage caused by SAH. These results supported the idea that NETs might be potential therapeutic targets for SAH.

Celastrol protects against early brain injury after subarachnoid hemorrhage in rats through alleviating blood-brain barrier disruption and blocking necroptosis.

BACKGROUND: Subarachnoid hemorrhage (SAH) is a life-threatening disease worldwide, and effective pharmaceutical treatment is still lacking. Celastrol is a plant-derived triterpene which showed neuroprotective potential in several types of brain insults. This study aimed to investigate the effects of celastrol on early brain injury (EBI) after SAH. METHODS: A total of sixty-one male Sprague-Dawley rats were used in this study. Rat SAH endovascular perforation model was established to mimic the pathological changes of EBI after SAH. Multiple methods such as 3.0T MRI scanning, immunohistochemistry, western blotting and propidium iodide (PI) labeling were used to explore the therapeutic effects of celastrol on SAH. RESULTS: Celastrol treatment attenuated SAH-caused brain swelling, reduced T2 lesion volume and ventricular volume in MRI scanning, and improved overall neurological score. Albumin leakage and the degradation of tight junction proteins were also ameliorated after celastrol administration. Celastrol protected blood-brain bairrer integrity through inhibiting MMP-9 expression and anti-neuroinflammatory effects. Additionally, necroptosis-related proteins RIP3 and MLKL were down-regulated and PI-positive cells in the basal cortex were less in the celastrol-treated SAH group than that in untreated SAH group. CONCLUSIONS: Celastrol exhibits neuroprotective effects on EBI after SAH and deserves to be further investigated as an add-on pharmaceutical therapy.

Role of the mitochondrial calcium uniporter in Mg2+-free-induced epileptic hippocampal neuronal apoptosis.

PURPOSE: Mitochondrial Ca2+ overload is closely associated with seizure-induced neuronal damage. The mitochondrial calcium uniporter (MCU) plays a crucial role in regulating mitochondrial Ca2+ homeostasis. However, the role of the MCU in seizure-induced neuronal damage remains elusive. Materials and methods: In this study, the hippocampal neuronal culture (HNC) model of acquired epilepsy (AE) was used to investigate the role of the MCU in seizure-induced neuronal injury. Results: We found an increase in mitochondrial Ca2+ concentration in the HNC model of AE. The MCU inhibitor, Ru360, significantly reduced the rate of seizure-induced cell apoptosis and mitochondrial reactive oxygen species (ROS) production; whereas, the MCU agonist, spermine, exacerbated these processes. In addition, Ru360 significantly attenuated seizure-induced endoplasmic reticulum (ER) stress, which is characterized by the expression of glucose-regulated protein 78 (GRP78) and C/-EBP homologous protein (CHOP), while spermine had the opposite effect. We also found that pre-treatment with the mitochondria-targeted antioxidant, mitoquinone, decreased GRP78 and CHOP expression. Moreover, knockdown of CHOP using CHOP-specific small interfering RNA reduced neuronal seizure-induced apoptosis. Conclusions: Taken together, our data indicate that MCU inhibition has a neuroprotective effect against seizure-induced neuronal damage and that this mechanism may involve reduction of ROS-mediated ER stress.

Both left upper lobectomy and left pneumonectomy are risk factors for postoperative stroke.

Retrospective studies have found that left upper lobectomy (LUL) may be a new risk factor for stroke, and the potential mechanism is pulmonary vein thrombosis, which more likely develops in the left superior pulmonary vein (LSPV) stump. The LSPV remaining after left pneumonectomy is similar to that remaining after LUL. However, the association between left pneumonectomy, LUL, and postoperative stroke remains unclear. Thus, we sought to analyze whether both LUL and left pneumonectomy are risk factors for postoperative stroke. We prospectively included consecutive patients who underwent resection between November 2016 and March 2018 at our institution with 6 months of follow-up. Baseline demographic and clinical data were taken. A logistic regression model was used to determine independent predictors of postoperative stroke. In our study, 756 patients who underwent an isolated pulmonary lobectomy procedure were screened; of these, 637 patients who completed the 6-month follow-up were included in the analysis. Multivariable logistic regression analysis adjusted for common risk factors showed that the LUL and left pneumonectomy were independent predictors of stroke (odds ratio, 18.12; 95% confidence interval, 2.12-155.24; P = 0.008). Moreover, diabetes mellitus also was a predictor of postoperative stroke. In conclusion, both LUL and left pneumonectomy are significant risk factors for postoperative stroke.

In Vivo Biocompatibility and Improved Compression Strength of Reinforced Keratin/Hydroxyapatite Scaffold.

A rapid freezing/lyophilizing/reinforcing process is suggested to fabricate reinforced keratin/hydroxyapatite (HA) scaffold with improved mechanical property and biocompatibility for tissue engineering. The keratin, extracted from human hair, and HA mixture were rapidly frozen with liquid nitrogen and then lyophilized to prepare keratin/HA laminar scaffold. The scaffold was then immersed in PBS for reinforcement treatment, and followed by a second lyophilization to prepare the reinforced keratin/HA scaffold. The morphology, mechanical, chemical, crystal and thermal property of the keratin/HA scaffold were investigated by SEM, FTIR, XRD, DSC, respectively. The results showed that the keratin/HA scaffold had a high porosity of 76.17 ± 3%. The maximum compressive strength and compressive modulus of the reinforced scaffold is 0.778 and 3.3 MPa respectively. Subcutaneous implantation studies in mice showed that in vivo the scaffold was biocompatible since the foreign body reaction seen around the implanted scaffold samples was moderate and became minimal upon increasing implantation time. These results demonstrate that the keratin/HA reinforced scaffold prepared here is promising for biomedical utilization.