DHX collector for recovery of cassiterite: Mechanistic insights and practical implications

Yang Cao,Lei Sun,Qingqing Wang,Xin Wang,Yi Qiao,Wei Sun 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.127 No.-

This study addresses the efficiency and sustainability of tin resource utilization by exploring a novel collector,C16H33NO2 (DHX), in cassiterite flotation. DHX demonstrated superior collection efficiency and abroader effective pH range in micro-flotation tests. A peak cassiterite recovery of 92.2% was achievedwith DHX at pH 7.5 ± 0.3, while BHA could achieve only 69.6%. Furthermore, DHX consistently maintaineda recovery above 70% in a wide pH range from 3 to 11. The capacity of DHX to separate cassiteritefrom calcite in mixtures underlines its remarkable selectivity. Zeta potential and contact angle measurementsshowed strong DHX adsorption on cassiterite surfaces, leading to marked enhancements inhydrophobicity and potentially augmenting flotation efficiency. FTIR and XPS analyses further confirmedthe formation of a stable ring structure between the hydroxy and oxime groups in DHX anions and Snions on the cassiterite surface. In practical applications, such as a copper-zinc-tin polymetallic mine inYunnan, China, DHX exhibited promising recovery results in gravity separation tailings. Bench-scaleflotation tests on tin-bearing tailings (0.21% Sn) resulted in a concentrate with a tin grade and recoveryrate of 2.15% and 61.27%, respectively. These results highlight DHX’s immense potential as a cassiteriteflotation collector, outperforming conventional alternatives in performance.

Proteome analysis reveals global response to deletion of mrflbA in Monascus ruber

Qingqing Yan,Zhouwei Zhang,Yishan Yang,Fusheng Chen,Yanchun Shao 한국미생물학회 2018 The journal of microbiology Vol.56 No.4

Monascus spp. are commonly used for a wide variety of applications in the food and pharmaceutical industries. In previous studies, the knock-out of mrflbA (a putative regulator of the G protein α subunit) in M. ruber led to autolysis of the mycelia, decreased pigmentation and lowered mycotoxin production. Therefore, we aimed to obtain a comprehensive overview of the underlying mechanism of mrflbA deletion at the proteome level. A two-dimensional gel electrophoresis analysis of mycelial proteins indicated that the abundance of 178 proteins was altered in the ΔmrflbA strain, 33 of which were identified with high confidence. The identified proteins are involved in a range of activities, including carbohydrate and amino acid metabolism, hyphal development and the oxidative stress response, protein modification, and the regulation of cell signaling. Consistent with these findings, the activity of antioxidative enzymes and chitinase was elevated in the supernatant of the ΔmrflbA strain. Furthermore, deletion of mrflbA resulted in the transcriptional reduction of secondary metabolites (pigment and mycotoxin). In short, the mutant phenotypes induced by the deletion of mrflbA were consistent with changes in the expression levels of associated proteins, providing direct evidence of the regulatory functions mediated by mrflbA in M. ruber.

Energy Behavior of Sandstone Containing Weak Filling Joints with Multiple Angles under Dynamic Splitting Loads

Qingqing Su,Guangming Chang,Fulian Yang,Fengyan Qin 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.1

The impact of weak filling joints with multiple angles on the energy dissipation mechanism is significant for surrounding rock engineering to prevent and mitigate disasters. In the present study, the sandstone samples containing weak filling joints were prefabricated, and dynamic splitting tests were conducted under three nominal loading rates with a modified Split Hopkinson Pressure Bar system. The effects of nominal loading rates and joint angles on time–based curves and energy–based curves were investigated systematically. The test results indicated that the nominal loading rate and joint angle had remarkable influences on energy dissipation characteristics. The sample containing a larger joint angle preferred brittle failure, whereas the sample with a smaller joint angle failed with a plastic feature. Moreover, the reflection energy decreased as the joint angle increased, which was opposite to the evolution tendencies of transmission energy and absorption energy. The transmission energy and absorption energy had different sensitivities to changes in joint angle and nominal loading rate. The exponential function could excellently describe the dependence of transmission energy, reflection energy, and absorption energy on joint angles. With the incremental joint angle, the energy reflection ratio had a contrary tendency to the energy transmission ratio.

Adaptive Virtual Impedance of Grid-Tied Inverters to Enhance the Stability in a Weak Grid

Yan Du,Qingqing Sun,Xiangzhen Yang,Linbo Cui,Jian Zhang,Fei Wang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.3

In a weak grid, especially with a grid-voltage proportional feedforward controller, the grid-tied inverter tends to interact with the grid impedance and thus suff ers from poor power quality and even instability. In order to improve the stability, serial-parallel virtual impedance based on the derivative controllers of grid current and voltage is proposed in this paper. With the aim of optimizing the performance of the inverter for a variety of grid impedance, these derivative coeffi cients are adaptively tuned by the constraint of a minimum leading phase which is determined by the phase margin and the current tracking response. With this proposed adaptive virtual impedance, the grid-tied inverter can operate stably under a wide variety of grid impedance and voltage harmonic rejection performance is also improved. Simulation and experimental results validate the eff ectiveness of the proposed method and design methodology.

Polyetheretherketone implants with hierarchical porous structure for boosted osseointegration

Zhiyong Chen,Yu Chen,Yang Wang,JiaJia Deng,Xin Wang,Qingqing Wang,Yuehua Liu,Jiandong Ding,Lin Yu 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Good osseointegration is the key to the long-term stability of bone implants. Thermoplastic polyetheretherketone (PEEK) has been widely used in orthopedics; however, its inherent biological inertia causes fibrous tissue to wrap its surface, which leads to poor osseointegration and thus greatly limits its clinical applications. Methods Herein, we developed a facile yet effective surface modification strategy. A commonly used sulfonation coupled with “cold pressing” treatment in the presence of porogenic agent formed a three-dimensional hierarchical porous structure on PEEK surface. Subsequently, the effects of porous surface on the in vitro adhesion, proliferation and differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs) were evaluated. Finally, the osteoinduction and osseointegration of surface-porous PEEK implant were examined in the rat distal femoral defect model. Results In vitro results showed that the surface modification did not significantly affect the mechanical performance and cytocompatibility of PEEK substance, and the porous structure on the modified PEEK substrate provided space for cellular ingrowth and enhanced osteogenic differentiation and mineralization of BMSCs. In vivo tests demonstrated that the surface-porous PEEK implant could effectively promote new bone formation and had higher bone-implant contact rate, thereby achieving good bone integration with the surrounding host bone. In addition, this modification technique was also successfully demonstrated on a medical PEEK interbody fusion cage. Conclusion The present study indicates that topological morphology plays a pivotal role in determining implant osseointegration and this facile and effective modification strategy developed by us is expected to achieve practical applications quickly.

Distributed Model Predictive Control of Iron Precipitation Process by Goethite Based on Dual Iterative Method

Ning Chen,Jiayang Dai,Xiaojun Zhou,Qingqing Yang,Weihua Gui 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.5

Iron precipitation is a key process in zinc hydrometallurgy. The process consists of a series of continuousreactors arranged in descending order, overflowing zinc leach solution from one reactor to the next. In this paper,according to the law of mass conservation and the reaction kinetics, a continuously stirred tank reactor model ofa single reactor is first established. Then, a distributed model of cascade reactors is built with coupled controlbased on the single reactor model, considering the unreacted oxygen in leaching solution. Secondly, four reactorsin the iron precipitation process are considered as four subsystems, the optimization control problem of the processis solved by a distributed model predictive control strategy. Moreover, the control information feedback betweensuccessive subsystems is used to solve the optimization problem of each subsystem, because of the existing controlcoupling in their optimization objective function of pre and post subsystems. Next, considering the intractability ofthe optimization problem for subsystems with various constraints, a distributed dual iterative algorithm is proposedto simplify the calculation. With the consideration of its cascade structure and control couplings, the proposedalgorithm iteratively solves the primal problem and the dual problem of each subsystem. The application case showsthat distributed model predictive control based on dual iteration algorithm can handle coupled control effectivelyand reduce the oxygen consumption.

Increased Piezo1 channel activity in interstitial Cajal-like cells induces bladder hyperactivity by functionally interacting with NCX1 in rats with cyclophosphamide-induced cystitis

Qian Liu,Bishao Sun,Jiang Zhao,Qingqing Wang,Fan An,Xiaoyan Hu,Zhenxing Yang,Jie Xu,Mingjia Tan,Longkun Li 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

The Piezo1 channel is a mechanotransduction mediator, and Piezo1 abnormalities have been linked to several clinical disorders. However, the role of the Piezo1 channel in cystitis-associated bladder dysfunction has not been documented. The current study aimed to discover the functional role of this channel in regulating bladder activity during cyclophosphamide (CYP)-induced cystitis. One hundred four female rats were randomly assigned to the control, CYP-4h, CYP-48h and CYP-8d groups. CYP successfully induced acute or chronic cystitis in these rats. CYP treatment for 48h or 8d significantly increased Piezo1 channel expression in bladder interstitial Cajal-like cells (ICC-LCs), and the increase in CYP-8d rats was more prominent. In addition, 2.5 μM Grammostola spatulata mechanotoxin 4 (GsMTx4) significantly attenuated bladder hyperactivity in CYP-8d rats by inhibiting the Piezo1 channel in bladder ICCLCs. Furthermore, by using GsMTx4 and siRNA targeting the Piezo1 channel, we demonstrated that hypotonic stressinduced Piezo1 channel activation significantly triggered Ca2+ and Na+ influx into bladder ICC-LCs during CYPinduced chronic cystitis. In addition, the Piezo1 channel functionally interacted with the relatively activated reverse mode of Na+/Ca2+ exchanger 1 (NCX1) in bladder ICC-LCs from CYP-8d rats. In conclusion, we suggest that the functional role of the Piezo1 channel in CYP-induced chronic cystitis is based on its synergistic effects with NCX1, which can significantly enhance [Ca2+]i and result in Ca2+ overload in bladder ICC-LCs, indicating that the Piezo1 channel and NCX1 are potential novel therapeutic targets for chronic cystitis-associated bladder hyperactivity.

Graphene Oxide/Polyester Fabric Composite by Electrostatic Self-Assembly as a New Recyclable Adsorbent for the Removal of Methylene Blue

Di Wang,Dawei Li,Pengfei Lv,Qingqing Wang,Yang Xu,Qufu Wei 한국섬유공학회 2018 Fibers and polymers Vol.19 No.8

A novel graphene oxide/polyester (GO/PET) composite fabric as a recyclable adsorbent was prepared via electrostatic self-assembly. The structure, morphology, and properties of the GO/PET composite fabrics were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transformed infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and contact angle (CA), respectively. The absorption property was evaluated by the absorption amount and removal efficiency of methylene blue (MB) solution on the GO/PET composite fabric. The results indicated that the absorption amount was found to be 21.80 mg/g and the removal efficiency reached 99.93 % under the experimental conditions of GO concentration of 2 mg/ml, initial concentration of 50 mg/l, and area of 64 cm2. The experimental parameters were investigated including the concentration of GO, the initial concentration of MB solutions, and adsorbent area. Simultaneously, according to a series of dynamic analysis, the absorption process revealed that the kinetics was well-described by pseudo-second-order model. This study showed that the GO/PET composite fabric could be a recyclable, efficient adsorbent material for the environmental cleanup.

ZIF-8 Modified Nanofiber Composite Window Screen for Efficient Indoor PM2.5 and Formaldehyde Removal

Fan Liu,Tong Lu,Wanjun Bu,Hewei Xiang,Junjie Yang,Junli Li,Xu Zhao,Weili Shao,Qingqing Ni,Jianxin He 한국섬유공학회 2022 Fibers and polymers Vol.23 No.8

Because people spend a lot of time indoors every day, the presence of particulate matter with a diameter less than2.5 μm (PM2.5) and volatile organic molecular substances in indoor air adversely affect public health. These toxic compoundscan be removed from the air using high-efficiency air-filter materials with adsorption capacity. Metal-organic frameworks(MOFs) are among the most suitable materials for air purification as they are synthetic porous materials with excellentadsorption ability. In this study, the zeolitic imidazolate framework-8 (ZIF-8) is uniformly grown on the surface ofpolyacrylonitrile (PAN) nanofibers using an in situ growth method to prepare ZIF-8@PAN nanofiber composite membranes. The nanofiber composite membrane effectively removes PM2.5 and formaldehyde from the air. After loading the optimalamount of ZIF-8, the filtration efficiency of the nanofiber membrane for salt aerosol with a diameter of 0.3 μm increases from90.3 % to 96.9 %, and the removal rate of formaldehyde becomes 98 % within 20 min in the enclosed space of the laboratory. Moreover, after five repeated tests, the formaldehyde adsorption rate remains above 80 %. In addition, ZIF-8@PANnanofiber membranes are used to fabricate anti-haze window screens, which have great potential to improve indoor airquality and mitigate related health risks.

Cyclophosphamide-induced HCN1 channel upregulation in interstitial Cajal-like cells leads to bladder hyperactivity in mice

Qian Liu,Zhou Long,Xingyou Dong,Teng Zhang,Jiang Zhao,Bishao Sun,Jingzhen Zhu,Jia Li,Qingqing Wang,Zhenxing Yang,Xiaoyan Hu,Longkun Li 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are confirmed to be expressed in bladder interstitial Cajal-like cells (ICC-LCs), but little is known about their possible role in cystitis-associated bladder dysfunction. The present study aimed to determine the functional role of HCN channels in regulating bladder function under inflammatory conditions. Sixty female wild-type C57BL/6J mice and sixty female HCN1-knockout mice were randomly assigned to experimental and control groups, respectively. Cyclophosphamide (CYP)-induced cystitis models were successfully established in these mice. CYP treatment significantly enhanced HCN channel protein expression and Ih density and significantly altered bladder HCN1 channel regulatory proteins. Carbachol (CCH) and forskolin (FSK) exerted significant effects on bladder ICC-LC [Ca2+]i in CYP-treated wild-type (WT) mice, and HCN1 channel ablation significantly decreased the effects of CCH and FSK on bladder ICC-LC [Ca2+]i in both naive and CYP-treated mice. CYP treatment significantly potentiated the spontaneous contractions and CCH (0.001–10 μM)-induced phasic contractions of detrusor strips, and HCN1 channel deletion significantly abated such effects. Finally, we demonstrated that the development of CYP-induced bladder overactivity was reversed in HCN1 / mice. Taken together, our results suggest that CYP-induced enhancements of HCN1 channel expression and function in bladder ICC-LCs are essential for cystitis-associated bladder hyperactivity development, indicating that the HCN1 channel may be a novel therapeutic target for managing bladder hyperactivity.