[Characteristics, Sources, and Health Risk Changes of Heavy Metal Pollution Carried by PM in Beijing and Evaluation of Policy Effectiveness].

To evaluate the effectiveness of air pollution prevention and control measures in Beijing, this study measured the content of 13 metal elements, including seven heavy metal elements [As, Cd, Co, Cr（Ⅵ）, Ni, Pb, and V], through daily PM sampling （ = 934） in the urban area of Beijing for four years. We analyzed the interannual changes in the concentration levels of various metals and the differences between heating and non-heating seasons, used a positive definite matrix factorization （PMF） model for quantitative source analysis, and used health risk assessment methods to evaluate the health risks of six metals. The results showed that, except for a few metal elements such as Cr（Ⅵ） and Ni, which showed an increase in concentration in individual years, the overall concentration of each element showed a downward trend.

Comparison of different internal fixation implants in the treatment of talar neck fractures: A finite element analysis.

Objectives: This study aimed to analyze the biomechanics of cannulated screws (CS) with or without a lateral locking plate (LLP) in talar neck fractures through a finite element analysis.

Patients And Methods: The computed tomography image of the talus from a healthy volunteer (adult male) was used to reconstruct a three-dimensional talar model. The method for fixing talar neck fractures with CS and an LLP was planned using computer-aided design software.

[Source Apportionment and Pollution Assessment of Soil Heavy Metal Pollution Using PMF and RF Model: A Case Study of a Typical Industrial Park in Northwest China].

Based on the concentration data of seven heavy metal elements[As, Cd, Cu, Pb, Hg, Ni, and Cr(Ⅵ)] in the surface soil of a typical industrial park in northwest China, the characteristics of heavy metal pollution in the industrial park were analyzed, and the ecological risk and pollution were evaluated using the potential ecological risk index and the index of geo-accumulation. The positive matrix factorization (PMF) model and random forest (RF) model were used for quantitative source analysis, and the emission data of sampling enterprises and empirical data of the source emission component spectrum were combined to identify the characteristic elements and determine the emission source category. The results showed that the heavy metals at all sampling points in the park did not exceed the second-class screening value of construction land in the soil pollution risk control standard for construction land (GB 36600-2018).

Rare pattern of Maisonneuve fracture: A case report.

Background: Maisonneuve fracture is a special type of ankle fracture that consists of proximal fibular fracture, a lesion of the inferior tibiofibular syndesmotic complex (interosseous ligament, anterior inferior tibiofibular ligament and posterior inferior tibiofibular ligament), and injury of the medial structure of the ankle (deltoid ligament tear or medial malleolar fracture). The accepted mechanism of Maisonneuve fracture is pronation external rotation according to the Lauge-Hansen classification. In this paper, we report a rare pattern of Maisonneuve fracture, which has the characteristics of both pronation external rotation ankle fracture and supination adduction ankle fracture.

[Concentrations, Sources, and Health Risks of PM Carrier Metals in the Beijing Urban Area and Suburbs].

To explore the differences in pollution characteristics, sources, and health risks of PM carrier metals in urban and suburban areas in Beijing, daily PM samples were collected from Haidian and Daxing from June to November 2017 and the concentration of PM and 13 constituent metals were analyzed. The sources of these 13 metal elements were analyzed by positive matrix factorization (PMF), and the health hazards of a subset of 9 metals were evaluated using health risk assessment. The results showed that the concentrations of PM and 10 metal concentrations in the urban area including Cr, Co, Mn, and Ni were significantly different from those in suburban areas (<0.

Pathoanatomy and Injury Mechanism of Typical Maisonneuve Fracture.

Objective: Maisonneuve fracture is a special type of injury which are rare in clinic. The manifestation of such fractures is variable. The aim of this study is to describe the pathoanatomical features of typical Maisonneuve fracture on the basis of radiographs, computed tomography (CT) scans, magnetic resonance imaging (MRI), and intraoperative exploration findings, and to investigate the injury mechanism of this variety.

[Bacterial Community Composition of Activated Sludge from Coking Wastewater].

Coking wastewater is a kind of highly toxic and refractory organic wastewater, and aerobic activated sludge, which is dominated by bacteria, determines the efficiency of coking wastewater treatment. However, the bacterial community structure of activated sludge from coking wastewater has rarely been reported. 454 sequencing technology was applied to investigate the structure and biodiversity of the bacterial community.

[Biodiversity of Thiocyanate-degrading Bacteria in Activated Sludge from Coking Wastewater].

Thiocyanate (SCN) is one of the main sources of COD in coking wastewater, and SCN removal efficiency of the aerobic unit impacts the requirement of discharging standard. Microbial population in the activated sludge plays an important role in SCN removal of coking wastewater treatment. However, the community structure has rarely been reported.

Performance of a haloalkaliphilic bioreactor and bacterial community shifts under different COD/SO₄²⁻ ratios and hydraulic retention times.

Sulfur dioxide from flue gas was converted into sulfate after the absorption of alkaline solutions. Haloalkaliphilic microorganisms have been used in reducing sulfate to decrease expenses and avoid sulfide inhibition. The effects of different COD/SO4(2-) ratios and hydraulic retention times (HRTs) on the sulfate removal efficiency and bacterial community were investigated in model experiments.

Performance of a haloalkaliphilic bioreactor under different NO3(-)/SO4(2-) ratios.

Effects of NO3(-)/SO4(2-) ratio on denitrification and sulfate removal efficiency were investigated in model experiments applying haloalkaliphilic bioreactor. The reduction of both substrates performed well at different NO3(-)/SO4(2-) ratios ranging from 17.6 to l.

[Degradation of phenol with a Fe/cu-catalytic heterogeneous-Fenton process].

The catalysts of Fe/AC, Cu/AC and Fe-Cu/AC with active carbon as support were prepared by a wet impregnation method, and were characterized using X-ray diffraction (XRD), nitrogen adsorption and X-ray photoelectron spectroscopy (XPS) measurements; the catalytic heterogeneous-Fenton processes of phenol degradation with these catalysts were also investigated, and the degradation mechanism was discussed with analysis of intermediate products and electron spin resonance (ESR) measurement. The results showed that the active component states varied in different catalysts; CuO was the main state of Cu in Cu/AC and Fe exhibited various valence states in Fe/AC. The degradation rate of phenol with Fe/AC, Cu/AC and Fe-Cu/AC as catalyst in the initial 60 min reached 96.

[Treatment of anterior cruciate ligament injury with peroneus longus tendon].

Objective: To evaluate the effects of anterior cruciate ligament reconstruction with peroneus longus tendon and observe the clinical outcomes of ankle joint after the resection of peroneus longus tendon.

Methods: From January 2006 to December 2009, 35 patients with anterior cruciate ligament injuries were recruited to undergo surgical procedures. There were 30 males and 5 females with an average age of 31.

[Operative treatment of displaced intra-calcaneal fractures].

Objective: To explore the clinical efficacies of displaced intra-calcaneal fractures with operative treatment.

Methods: From January 2005 to December 2010, 103 calcaneal patients (92 males, 11 females) were recruited. The mean age was 45.

[Therapeutic efficacies of bone grafing for calcaneal intra-calcaneal fractures].

Objective: To evaluate the efficacies of treating intra-calcaneal fractures with bone grafting.

Methods: From January 2005 to October 2011, a total of 182 calcaneal patients underwent operations for closed fractures. There were 159 males and 23 females with an average age of 41.

[Selective recovery of copper, zinc and nickel from printed circuit boards by ammonia leaching under pressure].

The ammonia/ammonium leaching process using oxygen as oxidant in autoclave was studied to extract copper, zinc and nickel from printed circuit board. Parameters such as leaching time, concentration of leaching reagents, stirring speed, oxygen pressure and temperature were optimized. The best results were achieved when the leaching was carried out at 55 degrees C for 150 minutes, using 4 mol/L NH4OH and 1 mol/L (NH4)2CO3 as leaching solution, with 700 r/min stirring speed and 0.

[Isolation of phenol-degrading bacteria from coking wastewater and their degradation gene].

Phenol and phenolic compounds are main pollutants in wastewater of coking factories. To identify the bacteria responsible for phenol removal in the activated sludge of a coking factory, we isolated bacteria from the sludge directly or after enrichment. From two samples from the aerobic and anaerobic pools, 28 strains belonging to 28 species of 20 genera were obtained after identification with BOX-PCR and further 16S rDNA sequence analyses.

[Advanced treatment of coking wastewater with a novel heterogeneous electro-Fenton technology].

A novel electro-catalytic reactor, with oxygen-reduction cathode (PAQ/GF), dimensionally stable anode (IrO2-RuO2 -TiO2/ Ti) and heterogeneous catalysts, is developed for advanced treatment of coking wastewater after biological process, integrating cathodic and anodic simultaneous oxidation processes. A PAQ/GF electrode was synthesized by the electro-polymerization of 2-ethyl anthraquinone on graphite felt, which was characterized with cyclic voltametry measurements; the results indicated that the PAQ/GF electrode showed high reversibility for oxidation-reduction reaction of anthraquinone and catalytic activity for O2 reduction to H2O2; 13.5 mmol/L H2O2 was obtained after electrolysis for 6 h at -0.

[The production of hydroxyl radical in HRP-NADH-H2O/O2 systems and its application in chlorobenzene removal].

The mechanism of radical generation in HRP-NADH-O2/H2O2 systems and state-change of horseradish peroxidase (HRP) was investigated by using ESR and UV measurements, and the novel enzyme-coenzymatic systems were performed to degrade chlorobenzene as a non-phenolic persistent organic pollutants. The UV results showed that compound III was produced from HRP oxidized by hydrogen peroxide with the catalysis of NADH, which would generate hydroxyl radical. The ESR results demonstrated the production of *OH and O2-.

[Marine SRB community reducing sulfate wastewater in flue gas desulfurization].

An SRB community (SRB-2) was enriched from marine sediment for the treatment of sulfate-rich wastewater of high salinity, and the effect of salinity, temperature, pH value, carbon source, concentration of sulfate and the form of Fe on the activity of SRB-2 was studied. The results show that SRB-2 is a halophilous and moderately mesophilous SRB community. The optimal conditions for its growth are as follows: temperature of 30-40 degrees C and pH value of 7.

[Study on spectrum of solvent extraction of chromium( VI) by primary amine].

The Cr(VI) solvent extraction in near neutral aqueous solution by primary amine was experimentally studied by the inductively couple plasma-atomic emission spectrometry (ICP-AES), laser Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance spectroscopy (1H NMR). The ICP-AES analysis of the aqueous phase before and after solvent extraction showed that primary amine could extract Cr(VI) from nearly neutral solution. Laser Raman spectroscopy of loaded organic phase showed that a new peak appeared at 890 cm(-1) after Cr(VI) was extracted by primary amine.

Electrochemical reduction of nitrobenzene at carbon nanotube electrode.

The electrochemical behaviors of nitrobenzene at a pyrolytic graphite electrode modified with carbon nanotubes (CNTs) were studied using cyclic voltammetry and constant-potential electrolysis technique, and the CNT-modified electrode was characterized with Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) measurements. A CNT-modified packed-bed flow reactor was also constructed for electrocatalytic reduction of nitrobenzene. The results showed that CNTs exhibited high activity for nitrobenzene reduction to aniline and the electrochemical reduction of nitrobenzene at CNT-modified electrode followed the pathway of nitrobenzene-->phenylhydroxylamine-->aniline.

Reductive dehalogenation of haloacetic acids by hemoglobin-loaded carbon nanotube electrode.

Hemoglobin (Hb) was immobilized on carbon nanotube (CNT) electrode to catalyze the dehalogenation of haloacetic acids (HAAs). FTIR and UV measurements were performed to investigate the activity-keep of Hb after immobilization on CNT. The electrocatalytic behaviors of the Hb-loaded electrode for the dehalogenation of HAAs were studied by cyclic voltammmetry and constant-potential electrolysis technique.

[Reductive dechlorination of trichloroacetic acid by bioelectrochemically catalytic method].

Direct electrochemical behaviors of hemoglobin (Hb) immobilized on carbon nanotube (CNT) modified carbon paste electrode with adsorption were investigated. Cyclic voltammetry of Hb-CNT-modified electrode showed a pair of well-defined and nearly reversible peaks for HbhemeFe(III) /Fe(II) redox couple in pH = 7 PBS buffers. The electrocatalytic behaviors of Hb-CNT-modified electrode for the reductive dechlorination of trichloroacetic acid (TCA) were studied by cyclic voltammmetry and fixed-potential electrolysis technique, and the reductive mechanism of TCA was discussed by analysis of reduction products.

Electrochemical dechlorination of chloroacetic acids (CAAs) using hemoglobin-loaded carbon nanotube electrode.

Hemoglobin (Hb) was immobilized on carbon nanotube (CNT) electrode to catalyze the dechlorination of chloroacetic acids (CAAs), and the electrocatalytic behaviors of the Hb-loaded electrode for the dechlorination of trichloroacetic acid (TCAA) were studied by cyclic voltammetry and constant-potential electrolysis technique. An Hb-loaded packed-bed flow reactor was also constructed for bioelectrocatalytic dechloriantion of CAAs from drinking water. The results showed that the reduced heme of Hb immobilized on CNT electrode was easily regenerated, and Hb exhibited a stable and high activity for reductive dechlorination of CAAs with significant lowering of overpotential.