Positive effects of concomitant heavy metals and their reduzates on hexavalent chromium removal in microbial fuel cells

Cr(vi) laden wastewaters generally comprise a range of multiple heavy metals such as Au(iii) and Cu(ii) with great toxicity. In the present study, cooperative cathode modification by biogenic Au nanoparticles (BioAu) reduced from aqueous Au(iii) and in situ Cu(ii) co-reduction were investigated for the first time to enhance Cr(vi) removal in microbial fuel cells (MFCs). With the co-existence of Cu(ii) in the catholyte, the MFC with carbon cloth modified with nanocomposites of multi-walled carbon nanotubes blended with BioAu (BioAu/MWCNT) obtained the highest Cr(vi) removal rate (4.07 ± 0.01 mg L⁻¹ h⁻¹) and power density (309.34 ± 17.65 mW m⁻²), which were 2.73 and 3.30 times as high as those for the control, respectively. The enhancements were caused by BioAu/MWCNT composites and deposited reduzates of Cu(ii) on the cathode surface, which increased the adsorption capacity, electronic conductivity and electrocatalytic activity of the cathode. This study provides an alternative approach for efficiently remediating co-contamination of multiple heavy metals and simultaneous bioenergy recovery.

The cooperative cathode modification by BioAu from Au(iii) and in situ Cu(ii) co-reduction enhanced Cr(vi) removal and bioelectricity generation in MFCs.     

First principles study of Schottky barriers at Ga2O3(100)/metal interfaces

A low Schottky barrier height (SBH) of metal–semiconductor contact is essential for achieving high performance electronic devices. Based on first principles calculations, we have comprehensively investigated the interfacial properties of β-Ga₂O₃ (100) with different metals including Mg, Ni, Cu, Pd and Pt. SBHs have been calculated via layered partial density of states (PDOS) and validated by visual wavefunctions. The results surprisingly show that Mg contact possesses the lowest SBH of 0.23 eV, while other SBHs range from 1.06 eV for Ni, 1.17 eV for Pd and 1.27 eV for Cu to 1.39 eV for Pt. This shows that SBHs of β-Ga₂O₃ are not fully dependent on metal work functions due to a Fermi level pinning effect. The tunneling barrier was also calculated via electrostatic potential with a 72.85% tunneling probability of the Mg/Ga₂O₃ interface. The present study will provide an insight into characteristics of Ga₂O₃/metal interfaces and give guidance for metal choice for Ga₂O₃ electronic devices.

A low Schottky barrier height (SBH) of metal–semiconductor contact is essential for achieving high performance electronic devices.     

Multi-GBq production of the radiotracer [18F]fallypride in a droplet microreactor

Microfluidics offers numerous advantages for the synthesis of short-lived radiolabeled imaging tracers: performing ¹⁸F-radiosyntheses in microliter-scale droplets has exhibited high efficiency, speed, and molar activity as well as low reagent consumption. However, most reports have been at the preclinical scale. In this study we integrate a [¹⁸F]fluoride concentrator and a microdroplet synthesizer to explore the possibility of synthesizing patient doses and multi-patient batches of clinically-acceptable tracers. In the integrated system, [¹⁸F]fluoride (up to 41 GBq [1.1 Ci]) in [¹⁸O]H₂O (1 mL) was first concentrated ∼80-fold and then efficiently transferred to the 8 μL reaction chip as a series of small (∼0.5 μL) droplets. Each droplet rapidly dried at the reaction site of the pre-heated chip, resulting in localized accumulation of large amounts of radioactivity in the form of dried [¹⁸F]TBAF complex. The PET tracer [¹⁸F]fallypride was synthesized from this concentrated activity in an overall synthesis time of ∼50 min (including radioisotope concentration and transfer, droplet radiosynthesis, purification, and formulation), in amounts up to 7.2 GBq [0.19 Ci], sufficient for multiple clinical PET scans. The resulting batches of [¹⁸F]fallypride passed all QC tests needed to ensure safety for clinical injection. This integrated technology enabled for the first time the impact of a wide range of activity levels on droplet radiosynthesis to be studied. Furthermore, this substantial increase in scale expands the applications of droplet radiosynthesis to the production of clinically-relevant amounts of radiopharmaceuticals, and potentially even centralized production of clinical tracers in radiopharmacies. The overall system could be applied to fundamental studies of droplet-based radiochemical reactions, or to the production of radiopharmaceuticals labeled with a variety of isotopes used for imaging and/or targeted radiotherapeutics.

Using a micro-cartridge based radionuclide concentrator enables the production of multiple (10 s) of clinical doses of the PET tracer [¹⁸F]fallypride with a droplet micro-reactor platform (8 μL).     

A thermal energy storage composite by incorporating microencapsulated phase change material into wood

Phase change energy storage wood (PCESW) was prepared by using microencapsulated phase change materials (MicroPCM) as thermal energy storage (TES) materials and wood as the matrix. The incorporation of MicroPCM and wood was realized using a vacuum impregnation method. The morphology and microstructure of MicroPCM, delignified wood (DLW) and PCESW were observed by scanning electron microscopy (SEM); the thermal properties including phase change temperature, enthalpy, thermal stability, thermal conductivity of MicroPCM and PCESW were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and laser flash analysis (LFA). The results showed that: (1) delignification improved the porosity of wood and enhanced the impregnation effect, MicroPCM got into the delignified wood successfully and mainly distributed in the vessels; (2) PCESW had excellent energy storage capacity and suitable phase transition temperature for regulating indoor temperature; (3) PCESW had prior thermal stability at room temperature and great durability after 100 heating–cooling cycles; (4) addition of graphene greatly improved the thermal conductivity of PCESW. The TES composite can be used as an indoor temperature regulating material for building energy conservation.

Phase change energy storage wood (PCESW) was prepared by using microencapsulated phase change materials (MicroPCM) as thermal energy storage (TES) materials and wood as the matrix.     

Template-free synthesis and lithium-ion storage performance of multiple ZnO nanoparticles encapsulated in hollow amorphous carbon shells

Due to the limited utilization of electrode materials, the rational design and facile synthesis of composite structures are still challenging issues for lithium-ion batteries (LIBs). Herein, a simple approach has been developed to prepare multiple core–shell structures of ZnO nanoparticles (NPs) encapsulated in hollow amorphous carbon (AC) shells. The as-synthesized ZnO@AC composites showed a uniform dispersion of ZnO NPs, compliant buffer AC shells, and nanoscale void spaces between the ZnO NP cores and AC shells. As a result of their structural merits, the ZnO@AC composites were evaluated as anode materials for LIBs and delivered enhanced coulombic efficiency, high reversible capacity, high rate capability, and improved cycling stability.

Core–shell structure of ZnO@amorphous carbon shell was synthesized using a simple and effective method, and exhibited excellent electrochemical performance as anode of lithium-ion batteries.     

Enhanced sintering resistance of bimetal/SBA-15 catalysts with promising activity under a low temperature for CO methanation

According to its thermodynamic equilibrium analysis and strong exothermic characteristics, the major challenge of syngas methanation is to develop a high-efficient low-temperature catalyst with superior sintering resistance. In this study, bimetal-based SBA-15 catalysts were prepared via a citric acid-assisted impregnation method and applied in CO methanation. The obtained catalysts were characterized via X-ray diffraction, N₂ adsorption–desorption, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, H₂ temperature-programmed reduction and other techniques. Combining the structural characterization of the fresh and used catalyst, the function of the organic additive and metal promoters was revealed. The catalysts exhibited superior low-temperature activity and excellent sintering resistance owing to the electron migration from the additive metal to Ni, strong interaction between the metal and support and the confinement effect of the support. The catalyst with Mo as a promotor exhibited the best dispersion and the largest surface concentration of nickel, which resulted in its highest catalytic activity among the catalysts. The design and preparation of a highly effective catalyst can provide novel insight into the preparation of other catalysts.

Well-dispersed bimetallic catalysts with confinement effects and strong interaction lead to superior low-temperature activity and excellent thermostability.     

Diagnosis of female urethral diverticulum using transvaginal contrast-enhanced sonourethrography

Introduction and hypothesis

This study investigated the value of transvaginal contrast-enhanced sonourethrography for the diagnosis of female urethral diverticulum (UD) by comparing results of contrast-enhanced ultrasound images and surgical findings.

Methods

A total of 14 female UD patients underwent preoperative transvaginal contrast-enhanced sonourethrography between July 2010 and June 2012. History and physical examination were initially assessed by the same urologist. Transvaginal contrast-enhanced ultrasound imaging was performed and interpreted by the same ultrasonographer. Definite diagnosis was made by tracking the flow of the microbubbles into the cyst. Additionally, sagittal, cross-sectional, and dynamic images were obtained, and color Doppler ultrasound was applied in all cases. Data on the size, location, configuration, and opening of the UD was documented, and then compared with the surgical findings.

Results

The most common symptoms presenting in the UD patients included urinary incontinence (71.5 %), recurrent urinary tract infection (57.1 %), frequency (50 %), urgency (35.7 %), dysuria (35.7 %), and dyspareunia (21.4 %). On physical examination, 8 out of 14 patients (57.1 %) had a palpable anterior vaginal wall mass, while 6 out of 14 patients (42.9 %) had no palpable mass. Transvaginal contrast-enhanced sonourethrography revealed 17 diverticula orifices in total and correlated well with surgical findings regarding the size, location, configuration, and the opening of the UD.

Conclusions

In patients with chronic irritative bladder symptoms, but with no response to conventional treatment a high index of suspicion for UD should be maintained. Our study demonstrates that transvaginal contrast-enhanced sonourethrography is a useful tool for defining the size, location, configuration, and opening of the UD before surgery.     

Correlation between glycosylated hemoglobin and carotid intima-media thickness in non-diabetic peritoneal dialysis patients

Objective To investigate the correlation between glycosylated hemoglobin (HbA1c) and carotid intima?media thickness (CIMT) in non?diabetic peritoneal dialysis patients. Methods Forty?two non?diabetic peritoneal dialysis adult patients were enrolled in this study [mean age was (48.2±12.3) years, 50% was male]. CIMT was determined by carotid ultrasound. Patients were divided into two groups according to CIMT: CIMT normal group (CIMT＜0.9 mm) and CIMT thickening group (CIMT≥0.9 mm). HbA1c, 2?hour postprandial blood glucose (2hPBG) and other factors of the patients were analyzed with Spearman rank correlation and multiple linear regression. Results CIMT was correlated with age, 2hPBG, LDL?C, TG, TC, HbA1c in non?diabetic peritoneal dialysis patients (r＝0.355, 0.373, 0.416, 0.345, 0.351, 0.456, all P＜0.05). Multiple linear regression showed that HbA1c was the most powerful influence factor of CIMT（β＝0.459）. Conclusion HbA1c level is positively correlated with CIMT and may be a predictor of carotid atherosclerosis in non?diabetic peritoneal dialysis patients.     

前臂纵向不稳定的生物力学研究

目的研究前臂纵向不稳定的生物力学机制,为临床诊断及治疗提供可靠的理论依据。方法12具新鲜冷冻尸体上肢标本制成生物力学模型,固定于MTS858型生物材料实验机上加载恒定100N的轴向负荷,测试不同解剖状态对桡骨纵向位移及前臂纵向稳定性的影响。结果单纯切断骨间膜对前臂的纵向稳定性影响甚微。切除桡骨头,前臂的纵向稳定性降低,桡骨向近端移位明显,再切断骨间膜,将使上述改变加重。结论桡骨是维持前臂纵向稳定的主要结构,前臂骨问膜是次要稳定结构。桡骨头切除后骨间膜损伤是前臂纵向不稳定产生并发症的主要原因。     

经会阴直肠乙状结肠部分切除术治疗直肠脱垂临床研究

目的评价成人完全型直肠脱垂采用经会阴直肠乙状结肠部分切除术治疗直肠脱垂临床效果。方法对我科2006～2011年23例确诊为成人完全型直肠脱垂的患者采用经会阴直肠乙状结肠部分切除术治疗,收集临床资料做回顾性分析。结果 23例患者治疗效果满意,术后平均住院时间5d。术后随访8～48个月(平均36个月),20例无复发,3例轻度复发。结论采用经会阴直肠乙状结肠部分切除术治疗直肠脱垂临床效果比较满意。