Realgar-Induced Neurotoxicity: Crosstalk Between the Autophagic Flux and the p62-NRF2 Feedback Loop Mediates p62 Accumulation to Promote Apoptosis.

Realgar is a traditional Chinese medicine that contains arsenic. It has been reported that the abuse of medicine-containing realgar has potential central nervous system (CNS) toxicity, but the toxicity mechanism has not been elucidated. In this study, we established an in vivo realgar exposure model and selected the end product of realgar metabolism, DMA, to treat SH-SY5Y cells in vitro. Many assays, including behavioral, analytical chemistry, and molecular biology, were used to elucidate the roles of the autophagic flux and the p62-NRF2 feedback loop in realgar-induced neurotoxicity. The results showed that arsenic could accumulate in the brain, causing cognitive impairment and anxiety-like behavior. Realgar impairs the ultrastructure of neurons, promotes apoptosis, perturbs autophagic flux homeostasis, amplifies the p62-NRF2 feedback loop, and leads to p62 accumulation. Further analysis showed that realgar promotes the formation of the Beclin1-Vps34 complex by activating JNK/c-Jun to induce autophagy and recruit p62. Meanwhile, realgar inhibits the activities of CTSB and CTSD and changes the acidity of lysosomes, leading to the inhibition of p62 degradation and p62 accumulation. Moreover, the amplified p62-NRF2 feedback loop is involved in the accumulation of p62. Its accumulation promotes neuronal apoptosis by upregulating the expression levels of Bax and cleaved caspase-9, resulting in neurotoxicity. Taken together, these data suggest that realgar can perturb the crosstalk between the autophagic flux and the p62-NRF2 feedback loop to mediate p62 accumulation, promote apoptosis, and induce neurotoxicity. Realgar promotes p62 accumulation to produce neurotoxicity by perturbing the autophagic flux and p62-NRF2 feedback loop crosstalk.

Clinical Predictors of Functional Cure in Children 1-6 Years-old with Chronic Hepatitis B.

Background and Aims: Hepatitis B surface antigen (HBsAg) clearance is significantly more common in children with chronic hepatitis B (CHB) than in adults; however, the possible influencing factors related to HBsAg loss have yet to be found. This study aimed to explore the efficacy of long-term interferon (IFN)α therapy in treating children with CHB and analyzed the factors influencing functional cure after treatment. Methods: A total of 236 children aged 1-6 years and diagnosed with CHB via liver biopsy were included in the study, all receiving IFNα treatment (IFNα-2b monotherapy, IFNα-2b followed by lamivudine [LAM] or IFNα-2b combined with LAM) and followed up for 144 weeks. A comprehensive analysis was conducted on clinical data, including biochemical items, serum markers of hepatitis B virus (HBV) and immunological indexes, and logistic regression analysis was used to screen the influencing factors related to HBsAg loss. Results: The cumulative loss rates of HBsAg were 79.5%, 62.1% and 42.1% at 144 weeks after the start of treatment in the 1-3 years-old group, 3-5 years-old group and 5-7 years-old group, respectively (p<0.05). IFNα-2b combined with LAM treatment displayed the highest HBsAg loss rates compared with monotherapy and sequential treatment (p=0.011). Younger baseline age and lower HBsAg levels were independent factors for the prediction of HBsAg loss (p<0.05). The baseline PreS1 and hepatitis B core antibody levels in the HBsAg loss group were lower than those in the HBsAg non-loss group. In addition, the PreS1 level was positively corelated with the level of HBsAg, HBV DNA and liver inflammation. Conclusions: Long-term treatment with IFNα was effective in achieving HBsAg loss in CHB children aged 1-6 years-old. Age less than 3 years-old and lower HBsAg levels are independent predictors of functional cure in children with CHB.

Plasmonic Bi promotes the construction of Z-scheme heterojunction for efficient oxygen molecule activation.

Reactive oxygen species (ROS) are essential to photocatalytic degradation of antibiotics in water. In this work, we prepared Ag3PO4/Bi@Bi4Ti3O12 by simple in-situ reduction method and precipitation method, which improves the ability to capture visible light and increases the activity of photoinduced molecular oxygen activation, resulting in reactive oxygen species (ROS) such as superoxide radicals (•O2-), hydroxyl radicals (•OH), and H2O2. The excellent TC degradation efficiency derive from the SPR effect of the metal Bi on the surface enhances the light absorption intensity, and development of a Z-scheme heterojunction between Ag3PO4 and Bi4Ti3O12 promotes the activation of molecular oxygen. A possible photodegradation mechanism of the as-prepared photocatalyst was proposed. This work provides an insight perspective to the synthesis photocatalysts with molecular oxygen activation for environmental remediation.

Disruption of peroxisome proliferator-activated receptor α in hepatocytes protects against acetaminophen-induced liver injury by activating the IL-6/STAT3 pathway.

Background & Aims: Peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor abundantly expressed in liver. PPARα activator has been previously reported to protect against acetaminophen-induced hepatotoxicity, but fenofibrate, a lipid-lowering drug that activates PPARα, has a common side-effect causing liver injury. Thus, the exact effect of liver PPARα on drug-induced liver injury remains obscure. Methods: Hepatocyte-specific Ppara knockout mice and littermate wild-type control mice were intraperitoneally injected with acetaminophen (400 mg/kg body weight). Blood and liver samples were collected at different time points. We measured phase I and II cytochrome P450 enzymes, glutathione, reactive oxygen species, cytokines including Il6, and pSTAT3 by reverse transcriptase quantitative PCR, colorimetric, immunohistochemistry analyses and Western blotting. Results: Hepatic expression of PPARα was significantly decreased in DILI patients. Disruption of the Ppara gene in hepatocytes significantly reduced acetaminophen-induced liver injury in mice. ROS production rather than the expression levels of phase I and II cytochrome P450 enzymes was reduced in hepatocyte-specific Ppara knockout mice compared to control mice after acetaminophen administration. Mechanistically, hepatocyte-specific Ppara knockout mice had upregulated activation of the hepatoprotective pathway IL-6/STAT3 compared to wild-type mice, as evidenced by hepatic Il6 mRNA levels, hepatic protein levels of STAT3 and phosphorylated STAT3 were much higher in hepatocyte-specific Ppara knockout mice than in wild-type mice post acetaminophen injection. Conclusions: Hepatocyte-specific disruption of the Ppara gene protects against acetaminophen-induced liver injury by reducing oxidative stress and upregulating the hepatoprotective IL-6/STAT3 signaling pathway.

[Anti-interference hemoglobin analysis system by high performance liquid chromatography].

High performance liquid chromatography (HPLC) is currently the mainstream technology for detecting hemoglobin. Glycated hemoglobin (HbA1c) is a gold indicator for diagnosing diabetes, however, the accuracy of HbA1c test is affected by thalassemia factor hemoglobin F (HbF)/hemoglobin A2 (HbA2) and variant hemoglobin during HPLC analysis. In this study, a new anti-interference hemoglobin analysis system of HPLC is proposed. In this system, the high-pressure three-gradient elution method was improved, and the particle size and sieve plate aperture in the high-pressure chromatography column and the structure of the double-plunger reciprocating series high-pressure pump were optimized. The system could diagnose both HbA1c and thalassemia factor HbF/HbA2 and variant hemoglobin, and the performance of the system was anti-interference and stable. It is expected to achieve industrialization. In this study, the HbA1c and thalassemia factor HbF/HbA2 detection performance was compared between this system and the world's first-line brand products such as Tosoh G8, Bio-Rad Ⅶ and D10 glycosylated hemoglobin analysis system. The results showed that the linear correlation between this system and the world-class system was good. The system is the first domestic hemoglobin analysis system by HPLC for screening of HbA1c and thalassemia factor HbF/HbA2 rapidly and accurately.

Shear wave elastography may be sensitive and more precise than transient elastography in predicting significant fibrosis.

BACKGROUND: Noninvasive measurements including transient elastography (TE) and two-dimensional shear wave elastography (SWE) have been used clinically instead of liver biopsy for regular assessment of liver fibrosis in chronic hepatitis B (CHB) patients. AIM: To investigate the diagnostic efficiency of SWE compared to TE by assessing independent influencing factors and performance for diagnosing significant fibrosis based on our cohort of treatment-naive CHB patients. METHODS: Fifty-four treatment-naive CHB patients who underwent liver biopsy to determine whether to initiate antiviral therapy were enrolled. SWE, TE, serum tests and liver biopsy were performed for all participants. The fibrosis-4 and aspartate aminotransferase to platelet ratio index scores were also calculated. Potential independent influencing factors on SWE and TE values were analyzed. Based on liver pathology results, the agreement and correlation were determined, and a comparison of the two methods was performed. RESULTS: There were 27 cases (50%) of mild fibrosis (F0-F2) and 27 (50%) cases of significant fibrosis (F3-F6); fibrosis was assessed with the Ishak scoring system. Multivariate linear regression analyses revealed that the fibrosis stage was the only factor that affected the SWE values (P < 0.001), whereas the total bilirubin level (P = 0.013) and fibrosis stage (P = 0.037) were independent factors that affected TE values. Orthogonal partial least squares discriminant analysis showed that the number of independent factors (VIP > 1) was higher for TE than SWE. Bland-Altman analysis showed satisfactory agreement between liver stiffness measurements (LSMs) of SWE and TE. Both SWE and TE could significantly discriminate significant fibrosis from mild fibrosis (P < 0.001). SWE exhibited a higher correlation with LSMs of liver fibrosis than TE (r = 0.65 and 0.50, P < 0.001). The diagnostic performance of SWE was better than that of TE for significant fibrosis (F > 2). The areas under the receiver operating characteristic curves of SWE and TE were 0.786 and 0.714, respectively. The optimal LSM cutoff values of SWE and TE were 9.05 kPa and 8.15 kPa, respectively. CONCLUSION: Compared to the TE value, the SWE value was less affected by other factors. SWE may be more sensitive and precise than TE in predicting significant fibrosis (> F2) in CHB patients.

Efficacy of ursodeoxycholic acid combined with prednisolone and immunosuppressant triple therapy in the treatment of refractory primary biliary cholangitis / Eficacia del ácido ursodesoxicólico combinado con prednisolona y triple terapia inmunosupresora en el tratamiento de la colangitis biliar primaria refractaria

Background and AIM: To explore the efficacy treatment regimen in refractory PBC. METHODS: Triple treatment including ursodeoxycholic acid, prednisolone and immunosuppressant was prescribed to 47 refractory patients. Biochemistries, immune parameters, non-invasive liver fibrosis assessments were measured during follow-up. RESULTS: Triple therapy resulted in significant decrease in ALP, GGT, ALT, AST, TBIL, ALB, IgG, IgM, APRI, FIB-4 and S-INDEX. The biochemical cumulative normalization rates of ALP and other biochemical parameters were higher in long-term follow-up. Poor outcome was observed in patients with lower ALB, higher TBIL, PT, sp100 positivity and advanced liver pathology at baseline. Osteoporosis and bone fracture were observed in 15% patients. CONCLUSIONS: Triple therapy is associated with marked decrease and normalization of ALP and other parameters. ALB, TBIL, PT, sp100 and pathology were related with poor outcome. Osteoporosis should be closely monitored

ANTECEDENTES Y OBJETIVO: Explorar el régimen de tratamiento de eficacia en PBC refractario. MÉTODOS: Se prescribió un tratamiento triple que incluyó ácido ursodesoxicólico, prednisolona e inmunosupresor a 47 pacientes refractarios. Las bioquímicas, los parámetros inmunes, las evaluaciones no invasivas de fibrosis hepática se midieron durante el seguimiento. RESULTADOS: La triple terapia resultó en una disminución significativa de ALP, GGT, ALT, AST, TBIL, ALB, IgG, IgM, APRI, FIB-4 y S-INDEX. Las tasas de normalización bioquímica acumulada de ALP y otros parámetros bioquímicos fueron mayores en el seguimiento a largo plazo. Se observó un resultado deficiente en pacientes con ALB más bajo, TBIL más alto, PT, positivo de SP100 y enfermedad hepática avanzada al inicio del estudio. La osteoporosis y la fractura ósea se observaron en el 15% de los pacientes. CONCLUSIONES: La triple terapia se asocia con una marcada disminución y normalización de ALP y otros parámetros. ALB, TBIL, PT, SP100 y la enfermedad se relacionaron con un mal resultado. La osteoporosis debe estar bajo estrecha supervisión

Efficacy of ursodeoxycholic acid combined with prednisolone and immunosuppressant triple therapy in the treatment of refractory primary biliary cholangitis.

BACKGROUND AND AIM: To explore the efficacy treatment regimen in refractory PBC. METHODS: Triple treatment including ursodeoxycholic acid, prednisolone and immunosuppressant was prescribed to 47 refractory patients. Biochemistries, immune parameters, non-invasive liver fibrosis assessments were measured during follow-up. RESULTS: Triple therapy resulted in significant decrease in ALP, GGT, ALT, AST, TBIL, ALB, IgG, IgM, APRI, FIB-4 and S-INDEX. The biochemical cumulative normalization rates of ALP and other biochemical parameters were higher in long-term follow-up. Poor outcome was observed in patients with lower ALB, higher TBIL, PT, sp100 positivity and advanced liver pathology at baseline. Osteoporosis and bone fracture were observed in 15% patients. CONCLUSIONS: Triple therapy is associated with marked decrease and normalization of ALP and other parameters. ALB, TBIL, PT, sp100 and pathology were related with poor outcome. Osteoporosis should be closely monitored.

Wireless Electrochemotherapy by Selenium-Doped Piezoelectric Biomaterials to Enhance Cancer Cell Apoptosis.

Cancer residues around the surgical site remain a significant cause of treatment failure with cancer recurrence. To prevent cancer recurrence and simultaneously repair surgery-caused defects, it is urgent to develop implantable biomaterials with anticancer ability and good biological activity. In this work, a functionalized implant is successfully fabricated by doping the effective anticancer element selenium (Se) into the potassium-sodium niobate piezoceramic, which realizes the wireless combination of electrotherapy and chemotherapy. Herein, we demonstrate that the Se-doped piezoelectric implant can cause mitochondrial damage by increasing intracellular reactive oxygen species levels and then trigger the caspase-3 pathway to significantly promote apoptosis of osteosarcoma cells in vitro. Meanwhile, its good biocompatibility has been verified. These results are of great importance for future deployment of wireless electro- and chemostimulation to modulate biological process around the defective tissue.

Efficient removal of methyl orange by a flower-like TiO2/MIL-101(Cr) composite nanomaterial.

Nano-scale MOF composite materials prepared by combining inorganic semiconductors with controllable pore structures and functional active sites for the effective removal of organic dyes will exhibit more excellent adsorption activity. In this paper, MIL-101(Cr) was used as a carrier and two-step hydrothermal methods were successfully used to prepare flower-like TiO2/MIL-101(Cr) composite nano-adsorbents with different sizes. The results of XRD, SEM, XPS and other characterization methods showed that when the molar ratio of Ti : Cr was 0.2 : 1, the composite nano-adsorbent exhibited better adsorption performance and removal efficiency for methyl orange (MO) in aqueous solution. By assembling TiO2 on MIL-101(Cr), Ti replaced part of Cr, and the positively-charged TiO2/MIL-101(Cr) nanocomposite and negatively-charged MO in aqueous solution formed a strong interaction force. In addition, the π-π packing interactions of the benzene ring of MIL-101(Cr) and the electrostatic force between TiO2 and MIL-101(Cr) also enhanced the performance and adsorption efficiency of the adsorbent to a certain extent. The BET results showed that the large specific surface area and average pore diameter of the TiO2/MIL-101(Cr) nanocomposites effectively improved the adsorption performance of the composites. The results showed that the MO removal efficiency of 20% TiO2/MIL-101(Cr) can reach 93.03% at 80 min. But when 20% TiO2/MIL-101(Cr) was used to adsorb 70 mg·L-1 MO, the experimental maximum adsorption capacity was 242.02 mg·g-1.

Treatment of primary biliary cholangitis with ursodeoxycholic acid, prednisolone and immunosuppressants in patients not responding to ursodeoxycholic acid alone and the prognostic indicators.

BACKGROUND AND AIM: We reviewed the medical records of primary biliary cholangitis patients who were diagnosed by liver biopsy and treated with the corresponding treatment. We evaluated the therapeutic effect and long-term prognostic indicators. METHODS: This observational cohort study enrolled 80 eligible patients diagnosed by liver biopsy between December 2013 and December 2018 in our department. UDCA monotherapy or UDCA added to prednisolone and immunosuppressant triple therapy was prescribed to patients. We analyzed and compared the demographic characteristics, biochemistry profiles, immune parameters, and noninvasive liver fibrosis assessments at baseline as well as the treatment efficacy, long-term outcomes and adverse effects at baseline and at each visit between the two groups. The indicators that could affect prognosis were assessed. RESULTS: Thirty-eight primary biliary cholangitis patients received UDCA monotherapy (group A), and another 42 patients received UDCA, prednisolone and immunosuppressant triple therapy (group B). After therapy, all patients showed significant improvements in liver biochemical parameters, immune indicators, and noninvasive fibrosis indicators (Fibrosis-4 (FIB-4), aspartate aminotransferase-to-platelet ratio index (APRI)), all P values<0.0001. The Mayo score also decreased significantly after treatment (P=0.022). Triple therapy was more effective, and there was a significant difference between the two groups. In addition, multivariate analysis showed that anti-gp210 antibody positivity; antimitochondrial antibody (AMA) negativity; high alkaline phosphatase (ALP), total bilirubin (TBIL) and globulin levels; and a severe degree of fibrosis at baseline were independent predictors of a poor prognosis. CONCLUSIONS: Triple therapy was a treatment option for UDCA-refractory PBC patients. Anti-gp210 antibody positivity; AMA negativity; high ALP, TBIL and globulin levels; and a severe degree of fibrosis at baseline were associated with a poor prognosis.

A systematic review of lopinavir therapy for SARS coronavirus and MERS coronavirus-A possible reference for coronavirus disease-19 treatment option.

In the past few decades, coronaviruses have risen as a global threat to public health. Currently, the outbreak of coronavirus disease-19 (COVID-19) from Wuhan caused a worldwide panic. There are no specific antiviral therapies for COVID-19. However, there are agents that were used during the severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) epidemics. We could learn from SARS and MERS. Lopinavir (LPV) is an effective agent that inhibits the protease activity of coronavirus. In this review, we discuss the literature on the efficacy of LPV in vitro and in vivo, especially in patients with SARS and MERS, so that we might clarify the potential for the use of LPV in patients with COVID-19.

Site-saturation mutagenesis at amino acid 329 of Klebsiella pneumoniae halophilic α-amylase affects enzymatic properties.

Halophilic α-amylases possess optimal activity in high salt concentrations. Therefore, they can be used in many extreme conditions in industrialised production. In the present work, a halophilic α-amylase (KP) from Klebsiella pneumoniae was characterised, and it exhibited a high specific activity of 3512 U/mg under optimal conditions of 2 M NaCl at 50°C and pH 6.5, but only 97 U/mg in the absence of salt. Furthermore, threonine at position 329 (Thr-329) was found to be related to the non-halophilic properties of KP according to PCR-based site-saturation mutagenesis. The activity of a mutant KP in which this threonine was replaced by aspartic acid was improved 14.6-fold compared with the native enzyme under salt-free conditions, and was increased by 14.8% in the absence of salt. Additionally, the optimal enzymatic properties of KP, including pH and temperature, were altered very little by the amino acid replacement. A further three halophilic α-amylases displayed similar mutational results. The findings provide a reference for bidirectional transformation of KP and similar halophilic enzymes.

Fabrication of Mixed-Charge Polypeptide Coating for Enhanced Hemocompatibility and Anti-Infective Effect.

Medical catheters are prone to fouling by protein adsorption and platelet adhesion/activation due to their hydrophobic surface, resulting in bacterial adhesion/biofilm formation, associated infection, and thrombosis. Hence, an ultralow-fouling and exceptional infection-resistant coating on devices is urgently needed. Herein, we synthesized mussel-inspired cationic polypeptide (cPep) and mixed-charge polypeptide (mPep) via an N-carboxyanhydride ring opening polymerization method. In the view of the chemical structure, in addition to the catechol group of levodopa, the cationic group of l-lysine (K), and the hydrophobic group of l-phenylalanine (F), the mPep, comparing with cPep, contains the anionic group of l-glutamic acid (E) since the negatively charge amino acid sequence is newly introduced, so as to guarantee its bactericidal ability, low toxicity, and surface self-deposition. Both cPep and mPep coatings are conveniently obtained by a dopamine-assisted codeposition technique. Compared with the cPep coating, the mPep coating has a similar antibacterial activity level (>99%) against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Meanwhile, it is demonstrated that the mPep coating has most effective antibiofilm activity (>3 days) and protein/platelet-resistant ability in vitro, as well as improving hemocompatibility. Furthermore, the mPep-coated silicone catheter induces no inflammatory response and significantly lowers the bacterial cell number with 6 log reduction in a mouse model of infection. Consequently, the rationally designed mPep with a simple coating technique has great potential in combating against medical catheter-related clinical infections.

FluoroTome 1: An Apparatus for Tomographic Imaging of Radio-Fluorogenic (RFG) Gels.

Radio-fluorogenic (RFG) gels become permanently fluorescent when exposed to high-energy radiation with the intensity of the emission proportional to the local dose of radiation absorbed. An apparatus is described, FluoroTome 1, that is capable of taking a series of tomographic images (thin slices) of the fluorescence of such an irradiated RFG gel on-site and within minutes of radiation exposure. These images can then be compiled to construct a 3D movie of the dose distribution within the gel. The historical development via a laboratory-bench prototype to a readily transportable, user-friendly apparatus is described. Instrumental details and performance tests are presented.

Ratiometric fluorescence sensor for organophosphorus pesticide detection based on opposite responses of two fluorescence reagents to MnO2 nanosheets.

The detection of organophosphorus pesticides (OPs) has received considerable attention for their great harm to human beings. Herein, a novel ratiometric fluorescence biosensor was constructed for the determination of OPs by using Scopoletin (SC) and Amplex Red (AR) as probe pairs that have opposite responses to MnO2 nanosheets (MnO2 NS). MnO2 NS possess peroxidase-like catalytic activity, which could quench the fluorescence of SC as well as enhance the fluorescence of the non-fluorescent substance AR by oxidation. In the absence of OPs, acetylcholinesterase (AChE) hydrolyzed acetylcholine chloride (ATCh) into choline (TCh) and acetate. TCh led the decomposition of MnO2 NS to manganese ions (Mn2+), increasing signal of SC and decreasing signal of AR. In the presence of OPs, the activity of AChE was inhibited and the decomposition of MnO2 NS was hindered, therefore the fluorescence intensity of SC was weak and the fluorescence intensity of AR had an obvious increase. Moreover, under the optimal conditions, the ratio of fluorescence intensity response recorded on the AR/SC increases with increasing the concentration of DDVP. The method has wider linear range of 5.0 pg/mL ∼500 ng/mL with a detection limit of 1.6 pg/mL, which is superior to previously reported methods. This strategy has also been applied to a visual observation based on the color change of the solution under UV light.

A photodynamic antibacterial spray-coating based on the host-guest immobilization of the photosensitizer methylene blue.

In the "post-antibiotic era", healthcare-associated infection has become a global problem that threatens public health and causes huge economic losses. The development of antibacterial coatings based on non-antibiotic strategies is particularly important as drug-resistant bacteria continue to evolve. Photodynamic coatings are a high potential method to treat bacteria, however, the aggregation of photosensitizers on the coating affects the photodynamic capacity seriously. Herein, a photodynamic coating is developed based on the host-guest interaction between ß-cyclodextrin and the photosensitizer methylene blue (MB). The host-guest interaction avoids aggregation of MB and results in a high singlet oxygen quantum yield. Consequently, efficient photoantibacterial activity towards methicillin-resistant Staphylococcus aureus is achieved by the photodynamic coating with very low MB density (0.53 ± 0.06 µg cm-2).

A spatially varying charge model for regulating site-selective protein adsorption and cell behaviors.

Implanted materials that enter the body first interact with proteins in body fluids, and cells then perceive and respond to the foreign implant through this layer of adsorbed proteins. Thus, spatially specific regulation of protein adsorption on an implant surface is pivotal for mediating subsequent cellular behaviors. Unlike the surface modulation strategy for traditional biomaterials, in this research, materials with a nonuniform spatial distribution of surface charges were designed to achieve site-selective protein adsorption and further influence cell behavior by charge regulation. Spatially varying microdomains with different levels of piezoelectricity were generated via a focus laser beam-induced phase transition. In addition, after polarization, the zones with different levels of piezoelectricity showed significant differences in surface charge density. The results of scanning Kelvin probe force microscopy (SKPM) showed that the surface charge on the material exhibits a nonuniform spatial distribution after laser irradiation and polarization. Site-specific charge-mediated selective protein adsorption was demonstrated through a protein adsorption experiment. Cell behavior analysis showed that the increase in charge density was conducive to promoting cell adhesion and the formation of filopodia while the nonuniform spatial distribution of charge promoted an oriented arrangement of cells; both features accelerated cell migration. This study provides a new method for spatially regulating protein adsorption through surface charges to further influence cell behaviors.

The antibacterial effect of potassium-sodium niobate ceramics based on controlling piezoelectric properties.

The implant infection is one of the most serious postsurgical complications of medical device implantation. Therefore, the development of biocompatible materials with improved antibacterial properties is of great importance. It might be a new insight to apply the intrinsic electrical properties of biomaterials to solve this problem. Here, potassium-sodium niobate piezoceramics (K0.5Na0.5NbO3, KNN) with different piezoelectric constants were prepared, and the microstructures and piezoelectric properties of these piezoceramics were evaluated. Moreover, the antibacterial effect and biocompatibility of these piezoceramics were assayed. Results showed that these piezoceramics were able to decrease the colonies of bacteria staphylococcus aureus (S. aureus), favor the rat bone marrow mesenchymal stem cells (rBMSCs) proliferation and promote the cell adhesion and spreading. The above effects were found closely related to the surface positive charges of the piezoceramics, and the sample bearing the most positive charges on its surface (sample 80KNN) had the best performance in both antibacterial effect and biocompatibility. Based on our work, it is feasible to develop biocompatible antibacterial materials by controlling piezoelectric properties.

A cascade of a denitrification bioreactor and an aerobic biofilm reactor for heavy oil refinery wastewater treatment.

The performance of an efficient denitrification bioreactor-aerobic biofilm reactor cascade for heavy oil refinery wastewater treatment was investigated. Optimum operation parameters for denitrification were found as follows: (1) hydraulic retention time of 8 h; (2) C/NO3 --N molar ratio of 3.75 with acetate as the carbon source; (3) 20% (v/v) carrier filling ratio in the denitrification bioreactor. Under such optimal conditions, a volumetric removal of 0.82 kg N m-3 d-1 was obtained. As an alternative low-cost carbon source to acetate, secondary DAF effluent (COD/NO3 --N mass ratio of 5.4) was also detected and a stable activity of denitrification was achieved with adding 25% volume fraction of secondary DAF effluent. Effluent COD of the subsequent aerobic biofilm reactor further decreased satisfying the requirements of the current discharge standards. High-throughput sequencing results exhibited that Rhodocyclaceae and Comamonadaceae were the dominant denitrifiers in the denitrification reactor and Pseudomonas was the dominant microbe in the aerobic biofilm reactor.