Directional manipulation of electron transfer in copper/nitrogen doped carbon by Schottky barrier for efficient anodic hydrazine oxidation and cathodic oxygen reduction.

Development of bifunctional hydrazine oxidation and oxygen reduction electrocatalysts with high activity and stability is of great significance for the implementation of direct hydrazine fuel cells. Combining zero-dimensional metal nanoparticles with three-dimensional nitrogen-doped carbon nanosheets is an attractive strategy for balancing performance and cost. However, the precise construction of these composites remains a significant challenge, and thorough study of their interaction mechanisms is lacking. Herein, the CuNPs/CuSA-NPCF catalyst was constructed by anchoring copper nanoparticles on a three-dimensional nitrogen-doped porous carbon nanosheet framework through coordination of polyvinyl pyrrolidone and copper ions. The Schottky barrier of metal-semiconductor matched the Fermi level of the rectifying contact, thus enabling directional electron transfer. The resulting electron-deficient Cu nanoparticles surface exhibited Lewis acidity, which was beneficial to adsorption of hydrazine molecule. While the electron-enriched Cu-N4/carbon surface improved the adsorption of oxygen molecule, and accelerated electron supply from Cu-N4 active sites to various oxygen intermediates. The CuNPs/CuSA-NPCF Mott-Schottky catalyst exhibited excellent catalytic activity for hydrazine oxidation reaction and oxygen reduction reaction in an alkaline media. The directional manipulation of electron transfer in heterogeneous materials was an attractive universal synthesis method, providing new approach for the preparation of efficient and stable hydrazine fuel cell catalysts.

ESBR Nanocomposites Filled with Monodisperse Silica Modified with Si747: The Effects of Amount and pH on Performance.

To prepare silica/rubber composites for low roll resistance tires, a novel strategy was proposed in this study, in which autonomous monodisperse silica (AS) was prepared and modified using 3-mercaptopropyloxy-methoxyl-bis(nonane-pentaethoxy) siloxane (Si747), after which silica/emulsion styrene butadiene rubber (ESBR) master batches were produced using the latex compounding technique. Meanwhile, the commercial precipitated silica (PS) was introduced as a control. In this study, the effects of amount of Si747 and pH value on the properties of the silica/ESBR composites were systematically analyzed. Thermal gravimetric analysis (TGA) and Fourier transform infrared (FTIR) results indicated that Si747 reduced the silanol group by chemical grafting and physical shielding, and the optimum amounts of Si747 for AS and PS modification were confirmed to be 15% and 20%, respectively. Under a pH of 9, ESBR/modified AS (MAS) composites with 15% Si747 presented better silica dispersion and a weaker Payne effect, compared with ESBR/modified PS (MPS) composites with 20% Si747. Meanwhile, in terms of dynamic properties, the ESBR/MAS composites exhibited a better balance of lower rolling resistance and higher wet skid resistance than the ESBR/MPS composites.

Association of occupational exposure to polycyclic aromatic hydrocarbons in workers with hypertension from a northeastern Chinese petrochemical industrial area.

Elevated urinary polycyclic aromatic hydrocarbon metabolites have been linked to an increased risk of cardiovascular diseases (CVDs). However, for petrochemical workers with potentially high PAH exposure, it remains largely unknown whether the link will be amplified. Thus, this work aimed to investigate 14 urinary mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) in 746 petrochemical workers working in a Chinese petrochemical industrial area and their association with the risk of hypertension using the binary logistic regression. Metabolites of naphthalene, fluorene, phenanthrene, and pyrene were frequently detected in the 746 urine samples analyzed (>98%), with Σ10OH-PAH concentration in the range of 0.906-358 ng/mL. 2-hydroxynaphthalene accounted for the largest proportion of ten detected OH-PAHs (60.8% of Σ10OH-PAHs). There were significant correlations between these metabolites and other factors, including gender, age, and body mass index. Diastolic blood pressure, not systolic blood pressure, was significant positively associated with the urinary Σ10OH-PAH concentrations of the petrochemical workers. Elevated urinary 2/3-OH-Flu was significantly associated with an increased risk of hypertension (adjusted odds ratio: 1.96, 95% confidence interval: 1.20-3.18, p = 0.007), suggesting that PAH exposure in petrochemical workers was a driving factor of hypertension. In the stratified analysis, the association was more pronounced in those who were overweight with older age. Although the PAH exposure risk in petrochemical workers based on the estimated daily intakes was relatively low. Given the long-term impact, we call attention to CVDs of petrochemical workers.

Co-hydrothermal carbonization of oil shale and rice husk: Combustion, pyrolysis characteristics, and synergistic effect.

Countries all over the world are looking for fuel to replace fossil energy due to environmental concerns and a scarcity of fossil fuels. Oil shale (OS) and rice husk (RH) are both viable fuels, although they both have issues like high ash content and poor calorific value. OS and RH were used as feedstock for high-quality fuel in this study, which uses a hydrothermal technique to provide a novel way to utilize OS and rice. At different hydrothermal temperatures (150, 200 and 250 °C), including combustion and pyrolysis processes, the thermogravimetric analyzer (TGA) was used to analyse thermal transformation characteristics of co-hydrothermal carbonization (co-HTC) of OS and RH, as well as the synergistic effects. Results showed that the co-HTC pretreatment had a significant effect on the thermal transformation behaviour of OS and RH. On the one hand, the co-HTC has higher volatile content than its calculated value. On the other hand, a synergistic effect was found in combustion processes, and this effect was the most obvious when the hydrothermal temperature was around 200 °C, and the characteristic peak of functional groups vibration was strong. Therefore, the co-HTC was considered suitable for combustion. The combination of co-HTC modification with subsequent thermochemical processes has positive implications for the energy production and utilization of organic waste.

Respiratory exposure to graphene oxide induces pulmonary fibrosis and organ damages in rats involving caspase-1/p38MAPK/TGF-ß1 signaling pathways.

Numerous studies have shown that graphene oxide (GO) respiratory exposure led to severe lung injury, but whether pulmonary fibrosis caused by GO respiratory exposure is related to the activation of the caspase-1/p38MAPK/TGF-ß1 remains unclear. In this study, rats were administrated GO by intratracheal instillation and fed for three months, and the molecular mechanisms of GO on the pulmonary fibrosis and other organ damage caused by GO respiratory exposure were examined. The results showed that the expression of caspase-1/p38MAPK/TGF-ß1 pathway-related factors were significantly elevated with the increase of exposure concentrations of GO. Those data proved that the caspase-1/p38MAPK/TGF-ß1 signaling pathway was involved in the pulmonary fibrosis caused by GO respiratory exposure. The trends of related factors also proved that the caspase-1/p38MAPK/TGF-ß1 pathway was likely to play a dominant role in the sub-acute and sub-chronic stages. The other organ damage examination found that the liver and spleen were damaged initially by the GO respiratory exposure. Meanwhile for the testicle, although the acute injury was severe, signs of recovery were found during the three-month trial period.

Effect of CaO and hydrothermal carbonization conditions on the fuel characteristics of rice husk hydrochars.

The effects of hydrothermal temperature and catalyst concentration on the basic elements and combustion characteristics and kinetic parameters of hydrochars were investigated using ultimate analyzer and thermogravimetric method with rice husk as the research object and CaO as the additives. The results showed that: (1) the fixed carbon content of hydrochars gradually increased with the increase of hydrothermal temperature, whereas the volatile content gradually decreased. When CaO was added, the changes of fixed carbon and volatile fraction gradually decreased with the increase of hydrothermal temperature, and H/C atomic ratio increased to different degrees, which had a certain inhibitory effect on the degree of hydrothermal carbonization of rice husk. (2) The peak of the volatile fraction combustion section of hydrochars combustion derivative thermogravimetric curve was higher than that of the fixed carbon combustion section. CaO concentration has less effect on the volatile combustion section, and the combustion peak of the fixed carbon section is significantly reduced. (3) When the heating rate of the combustion test is accelerated, the ignition and burnout temperatures of the sample increase and the overall combustion curve shifts to the high temperature region. (4) The comprehensive combustion index SN decreases with the increase in hydrothermal temperature. When the hydrothermal temperature is certain, the CaO concentration causes the SN to increase and then decrease, which finally reduces the combustion performance of hydrochars. (5) The activation energy of the fixed carbon combustion section of hydrochars is lower than that of the volatile combustion section, and the activation energy of both volatile and fixed carbon combustion sections gradually decreases after adding CaO. The primary reaction kinetic model was used to describe the combustion kinetics of hydrochars, and the correlation coefficients (R2) were all above 0.92, and the results were reliable.

Determination of Polycyclic Aromatic Hydrocarbons and Their Methylated Derivatives in Sewage Sludge from Northeastern China: Occurrence, Profiles and Toxicity Evaluation.

This paper assesses the occurrence, distribution, source, and toxicity of polycyclic aromatic hydrocarbons (PAHs), and their methylated form (Me-PAHs) in sewage sludge from 10 WWTPs in Northeastern China was noted. The concentrations of ∑PAHs, ∑Me-PAHs ranged from 567 to 5040 and 48.1 to 479 ng.g-1dw, which is greater than the safety limit for sludge in agriculture in China. High and low molecular weight 4 and 2-ring PAHs and Me-PAHs in sludge were prevalent. The flux of sludge PAHs and Me-PAHs released from ten WWTPs, in Heilongjiang province, was calculated to be over 100 kg/year. Principal component analysis (PCA), diagnostic ratios and positive matrix factorization (PMF) determined a similar mixed pyrogenic and petrogenic source of sewage sludge. The average values of Benzo[a]pyrene was below the safe value of 600 ng.g-1 dependent on an incremental lifetime cancer risk ILCR of 10-6. Sludge is an important source for the transfer of pollutants into the environment, such as PAHs and Me-PAHs. Consequently, greater consideration should be given to its widespread occurrence.

Robust Electrospun Nanofibers from Chemosynthetic Poly(4-hydroxybutyrate) as Artificial Dural Substitute.

Bioresorbable poly(4-hydroxybutyrate) (P4HB) may fulfill the specific requirements that are necessary for a dural substitute, including its high elasticity, long-term strength retention properties, and the biocompatibility without significant accumulation of acidic degradation products. However, commercial P4HB can only be produced by the bacterial fermentation, which limits its applications in the cerebrospinal system due to higher endotoxin restriction. Meanwhile, P4HB can be prepared via the ring-opening polymerization of γ-butyrolactone. In this contribution, high molecular weight P4HB from chemosynthesis is electrospun into fibrous membrane, showing good mechanical properties that match the natural dura mater. Such P4HB membrane induces fast cellular migration, adhesion, and proliferation of fibroblasts in vitro. Subcutaneous implantation in rats demonstrates excellent biocompatibility of the P4HB membrane with proper biodegradation behaviors. After implantation in the rabbit dural defect model as an onlay graft, the P4HB membranes prevent cerebrospinal fluid leakage and regenerate dura tissue without detecting any local or systematic infections or foreign body responses. Thus, the electrospun P4HB membranes may be particularly useful as artificial dural substitutes to induce wound closure and tissue regeneration, which will be of great benefit to neurosurgery in the future.

Using Platelet-Rich Plasma Hydrogel to Deliver Mesenchymal Stem Cells into Three-Dimensional PLGA Scaffold for Cartilage Tissue Engineering.

The synthetic biodegradable polyester-based rigid porous scaffolds and cell-laden hydrogels have been separately employed as therapeutic modality for cartilage repair. However, the synthetic rigid scaffolds alone may be limited due to the inherent lack of bioactivity for cartilage regeneration, while the hydrogels have insufficient mechanical properties that are not ideal for load-bearing cartilage applications. In the present study, a hybrid construct was designed to merge the advantage of 3D-printed rigid poly(lactic-co-glycolic acid) (PLGA) scaffolds with cell-laden platelet-rich plasma (PRP) hydrogels that can release growth factors to regulate the tissue healing process. PRP hydrogels potentially achieved the effective delivery of mesenchymal stem cells (MSCs) into PLGA scaffolds. This hybrid construct could obtain adequate mechanical properties and independently provide MSCs with appropriate clues for proliferation and differentiation. Real-time gene expression analysis showed that PRP stimulated both chondrogenic and osteogenic differentiation of MSC seeding into PLGA scaffolds. Finally, the hybrid constructs were implanted into rabbits to simultaneously regenerate both articular cartilage and subchondral bone within osteochondral defects. Our findings suggest that this unique hybrid system could be practically applied for osteochondral regeneration due to its capacity for cell transportation, growth factors release, and excellent mechanical strength, which would greatly contribute to the progress of cartilage tissue engineering.

Facile Preparation of Stereoblock PLA From Ring-Opening Polymerization of rac-Lactide by a Synergetic Binary Catalytic System Containing Ureas and Alkoxides.

Ring-opening polymerization (ROP) of cyclic esters/lactones by efficient catalysts is a powerful method for synthesis of biodegradable and biocompatible polyesters with well-defined structures. To develop catalytic systems that are fast, selective and controlled is a persistent effort of chemists. In this contribution, we report a binary urea/alkoxide catalytic system that could catalyze ROP of rac-LA in a fast (over 90% conversion within 1-2 min), stereoselective (P i up to 0.93) and controlled manner, indicated by narrow MW distributions, linear relationship between the monomer conversions and M ns, end-group fidelity, and chain extension experiments. Remarkably, the catalytic system described here is simple, easily prepared, and structurally tunable and thus has versatile catalytic performances.

8-O-acetyl shanzhiside methylester attenuates cerebral ischaemia/reperfusion injury through an anti-inflammatory mechanism in diabetic rats.

Inflammatory activation plays a vital role in the pathophysiological mechanisms of stroke and diabetes mellitus (DM), exerts the deleterious effects on the progression of the brain and leads to vascular damage in diabetic stroke. The objectives of this study were to investigate the effects of 8-O-acetyl shanzhiside methylester (ND01) on tumour necrosis factor-α (TNF-α)-stimulated SH-SY5Y cell line in vitro and the experimental ischaemic diabetic stroke model in vivo. TNF-α-stimulated SH-SY5Y cells were pre-incubated with ND01, then analysed protein expression. For in vivo experiment, the diabetic rats were subjected to middle cerebral artery occlusion (MCAO) for 30 min. followed by reperfusion for 23 hr. Treatment of SH-SY5Y cells with ND01 blocked TNF-α-induced nuclear transcription factor κB (NF-κB) activation and decreased high-mobility group box-1 (HMGB-1) expression. ND01 40 mg/kg demonstrated significant neuroprotective effect even after delayed administration at 4 hr after I/R. ND01 40 mg/kg attenuated the histopathological damage, decreased brain swelling, inhibited NF-κB activation and reduced HMGB-1 expression in ischaemic brain tissue. These data show that ND01 protects diabetic brain against I/R injury with a favourable therapeutic time-window by alleviating diabetic cerebral I/R injury and attenuating blood-brain barrier (BBB) breakdown, and its protective effects may involve HMGB-1 and NF-κB signalling pathway.

[To establish the syndrome-typing model of psoriasis vulgaris blood-heat syndrome based on the set pair analysis method].

OBJECTIVE: To establish corresponding set pair analysis mathematic model using the clinical symptoms of blood-heat type psoriasis vulgaris (BHTPV), thus guiding the clinical accuracy of clinical syndrome typing. METHODS: Recruited were 202 BHTPV with complete data after they were treated by yang subduing blood cooling method. Their clinical symptoms and signs were systematically collected. Using set pair analysis method, the therapeutic results of cured and markedly effective were recruited as the same portion, of effective as the different portion, and of ineffective as the contrary portion. The U value of each syndrome factor was calculated according to the formula. The correlation factor of syndrome typing of BHTPV was screened. The syndrome typing model of BHTPV was established according to the correlation factor. RESULTS: The main factors of BHTPV included the scale integral > 2.04, the erythema integral > 2.34, age > 50 years old, the area integral > 2.07, dry mouth, slippery pulse, yellowish fur, soggy pulse, dry and hard stool. The secondary factors included less sweat, insomnia, frequent pulse, any infiltration, erythra of any area, red tongue, depression, the disease course ranging 1-360 months, age ranging 16-50 years old, string-tight pulse, thin fur, the area integral ranging 0-2.07, white fur, purplish tongue, the scale integral ranging 0+ -2.04, and feeble pulse. The third factors included the erythema integral ranging 0-2.34 and pale red tongue. The set pair analytical model of BHT-PV was as follows: U = sigma An/N + sigma B(m)i/M + sigma C(p)j/P. CONCLUSIONS: U blood-heat syndrome > or = 0.75 could be judged as blood-heat syndrome. Satisfactory efficacy could be achieved by blood cooling method. For patients with U blood-heat syndrome < 0.75, no satisfactory efficacy could be achieved by blood cooling method alone since they were accompanied with other syndrome types.