Economical Production of Phenazine-1-carboxylic Acid from Glycerol by Pseudomonas chlororaphis Using Cost-Effective Minimal Medium.

Phenazine compounds are widely used in agricultural control and the medicine industry due to their high inhibitory activity against pathogens and antitumor activity. The green and sustainable method of synthesizing phenazine compounds through microbial fermentation often requires a complex culture medium containing tryptone and yeast extract, and its cost is relatively high, which greatly limits the large-scale industrial production of phenazine compounds by fermentation. The aim of this study was to develop a cost-effective minimal medium for the efficient synthesis of phenazine compounds by Pseudomonas chlororaphis. Through testing the minimum medium commonly used by Pseudomonas, an ME medium for P. chlororaphis with a high production of phenazine compounds was obtained. Then, the components of the ME medium and the other medium were compared and replaced to verify the beneficial promoting effect of Fe2+ and NH4+ on phenazine compounds. A cost-effective general defined medium (GDM) using glycerol as the sole carbon source was obtained by optimizing the composition of the ME medium. Using the GDM, the production of phenazine compounds by P. chlororaphis reached 1073.5 mg/L, which was 1.3 times that achieved using a complex medium, while the cost of the GDM was only 10% that of a complex medium (e.g., the KB medium). Finally, by engineering the glycerol metabolic pathway, the titer of phenazine-1-carboxylic acid reached the highest level achieved using a minimum medium so far. This work demonstrates how we systematically analyzed and optimized the composition of the medium and integrated a metabolic engineering method to obtain the most cost-effective fermentation strategy.

Comparison of Three-Dimensional Navigation-Guided Percutaneous Iliosacral Screw and Minimally Invasive Percutaneous Plate for the Treatment of Zone II Unstable Sacral Fractures.

OBJECTIVE: The percutaneous IS screws and the minimally invasive percutaneous plate are the most popular internal methods for Zone II unstable sacral fractures. However, the choice of fixation remains controversial for orthopaedic surgeons. The purpose of study was to evaluate and compare the clinical results of percutaneous iliosacral (IS) screw fixation under three-dimensional (3D) navigation and minimally invasive percutaneous plate fixation in the treatment of Zone II unstable sacral fractures. METHODS: A retrospective study was performed, including 64 patients with Zone II unstable sacral fractures who underwent percutaneous IS screw fixation under 3D navigation (navigation group) and minimally invasive percutaneous plate fixation (plate group) from January 2011 and March 2021 in our department. The age, gender, fracture type, mechanism of injury, injury severity score (ISS), time from admission to operation, operative time, intraoperative blood loss, hospital stay, incision length, follow-up time, time to clinical healing, and complications were recorded and analyzed. Matta standard was used to assess fracture reduction outcomes. The Majeed function system assessed functional outcomes at the last follow-up. RESULTS: The average follow-up time was (14.42 ± 1.57) months in the navigation group and (14.79 ± 1.37) months in the plate group. No statistical difference between the two groups in age, gender, fracture type, mechanism of injury, ISS, time from admission to operation, and time to clinical healing. However, significant differences were detected in operative time, intraoperative blood loss, hospital stay, and incision length (p < 0.001). According to Matta standard at 2 days postoperatively, the excellent and good rate was 91.42% in the navigation group, and it was 93.10% in the plate group. There was no significant difference between the two groups (p = 0.961). According to Majeed function system at the follow-up, the excellent and good rate was 97.14% in the navigation group, and 93.10% in the plate group. The difference between the two groups was not statistically significant (p = 0.748). There were no neurovascular injuries associated with this procedure. The incidence of complications was 44.82% (13/29) in the plate group, while 14.28% (5/35) in the navigation group (p = 0.007). CONCLUSION: This study found that compared with minimally invasive percutaneous plate fixation, percutaneous IS screw fixation under 3D navigation is a suitable option for the treatment of Zone II unstable sacral fractures. This approach is characterized by its shorter operation time, less surgical trauma, less bleeding, less hospital time, and fewer complications.

Gut-derived fungemia due to Kodamaea ohmeri combined with invasive pulmonary aspergillosis: a case report.

BACKGROUND: Kodamaea ohmeri is a rare pathogen with high mortality and is found among blood samples in a considerable proportion; however, gastrointestinal infection of K. ohmeri is extremely rare. Invasive pulmonary aspergillosis is also an uncommon fungal; these two fungal infections reported concomitantly are unprecedented. CASE PRESENTATION: We described a case of a 37-year-old male who got infected with K. ohmeri and invasive pulmonary aspergillosis. We used the mass spectrometry and histopathology to identify these two fungal infections separately. For the treatment of K. ohmeri, we chose caspofungin. As for invasive pulmonary aspergillosis, we used voriconazole, amphotericin B, and then surgery. The patient was treated successfully through the collaboration of multiple disciplines. CONCLUSIONS: We speculate that the destruction of the intestinal mucosa barrier can make the intestine one of the ways for certain fungi to infect the human body.

Anti-GQ1b Antibody Syndrome with Visual Impairment: A Retrospective Case Series.

BACKGROUND: Anti-GQ1b antibody syndrome referred to a clinical spectrum characterized by acute onset of ataxia, ophthalmoplegia and areflexia, while visual deterioration was rarely reported in terms of ocular disorders. This study aimed to describe the clinical characteristics of anti-GQ1b antibody syndrome with visual impairment. METHODS: The database at the First Affiliated Hospital of Sun Yat-sen University was searched from 2014 to 2020. Patients with anti-GQ1b IgG were identified and divided into two groups according to the existence of optic neuropathy. Clinical and laboratory data of these subjects between the two groups were collected and analyzed. All patients were followed up by telephone to assess the outcome. RESULTS: A total of 12 patients with seropositive anti-GQ1b antibody were included, 75% of which got antecedent infection. Of these cases, 3 showed visual deterioration accompanied by abnormal orbital magnetic resonance imaging or visual evoked potentials, and the other 9 didn't show any evidence of vision impairment. Patients in the optic neuropathy group presented prominent visual impairments as initial symptoms and were more likely to suffer from facial weakness. There were 4 patients in normal visual acuity group complaining of blurred vision due to intraocular muscle paralysis, which was distinguished by subsequent examination. The combination of glucocorticoids and intravenous immunoglobulin was applied to treat patients with optic neuropathy. CONCLUSIONS: This study provides strong evidence that anti-GQ1b antibody syndrome can exhibit visual impairment, which helps further expand the clinical spectrum of anti-GQ1b antibody syndrome. More attention should be paid to the physical and supplementary ophthalmological examination to explore the pathogenesis and treatment of anti-GQ1b antibody syndrome.

Revalorization of the Cooking Water (Aquafaba) from Soybean Varieties Generated as a By-Product of Food Manufacturing in Korea.

Concerns regarding sustainability have prompted the search of value in the by-products of food manufacturing. Such is the case of the cooking water (CW) of chickpeas, which has shown its potential as a vegan egg white replacement. This study aimed to characterize and compare the CW from three novel legumes (black soybeans, BSB; yellow soybeans, YSB; and small black beans, SBB) obtained from the processing of Korean soybean foods, and the widely used CW from chickpeas (CH), with regard to total polyphenol, total carbohydrate, and protein contents, and further compare their foaming and emulsifying abilities and stabilities. Compositional analysis revealed that all the studied legumes possessed higher values than CH for all parameters. Furthermore, the CW from these legumes exhibited enhanced functional properties, particularly foaming capacity and stability. Taken together, our results suggest that the CW from BSB, YSB, and SBB, sourced from the manufacturing of legume food products, has the potential of being revalorized as a plant-based functional ingredient for vegan product development.

Construction of g-C3N4-BiOBrxI1-x Nanocomposites with Tunable Energy Band Structure for Enhanced Visible Light Photocatalytic CO2 Reduction.

The g-C3N4-BiOBrxI1-x nanocomposites were successfully prepared using solvothermal methods. The obtained g-C3N4-BiOBrxI1-x composites had tunable band structures and displayed preferable photocatalytic performance for CO2 reduction irradiated by visible light. Moreover, comparing to pure g-C3N4 and corresponding BiOBrxI1-x, all the obtained g-C3N4-BiOBrxI1-x nanocomposites exhibited distinctly higher activity for CO2 reduction, with 5% g-C3N4-BiOBr0.25I0.75 nanocomposites displaying the best photocatalytic performance. Enhanced photocatalytic performance of g-C3N4-BiOBrxI1-x nanocomposites may arrive from their advantages of high efficiency of electron-hole separation, tunable band structures, and rapid charge transfer. Moreover, a possible visible light induced photocatalytic mechanism on g-C3N4-BiOBrxI1-x nanocomposites was further proposed.

Au/CeO2/g-C3N4 Nanocomposite Modified Electrode as Electrochemical Sensor for the Determination of Phenol.

A convenient and simple phenol electrochemical sensor was constructed based on the Au/CeO2/ g-C3N4 nanocomposites, which were obtained by loading the gold-cerium oxide (Au/CeO2) nanoparticle on graphite-like carbon nitride (g-C3N4) through precipitation-reduction methods. The microstructure and morphology of Au/CeO2/g-C3N4 nanocomposite were verified using different techniques such as XRD, TEM, and HRTEM. Voltammetry and amperometry methods were used to study the electrochemical performance of the constructed phenol electrochemical sensors. The results demonstrated evidently that the combination of Au/CeO2 and g-C3N4 may improve sensing performances of phenol determination. The detection linear range of the sensor was 10-90 µM under the optimum parameters. The Au/CeO2/g-C3N4 based electrochemical sensor also has low detection limits (2.33 µM) and high sensitivities (0.1080 mA/µM) for phenol detection. In addition, the sensor also had considerably favorable anti-interference performance. As a consequence, the sensor demonstrated that the electrochemical system provided a promising effective strategy for detection of phenol.

Engineering of glycerol utilization in Pseudomonas chlororaphis GP72 for enhancing phenazine-1-carboxylic acid production.

Glycerol is a by-product of biodiesel, and it has a great application prospect to be transformed to synthesize high value-added compounds. Pseudomonas chlororaphis GP72 isolated from the green pepper rhizosphere is a plant growth promoting rhizobacteria that can utilize amount of glycerol to synthesize phenazine-1-carboxylic acid (PCA). PCA has been commercially registered as "Shenqinmycin" in China due to its characteristics of preventing pepper blight and rice sheath blight. The aim of this study was to engineer glycerol utilization pathway in P. chlororaphis GP72. First, the two genes glpF and glpK from the glycerol metabolism pathway were overexpressed in GP72ANO separately. Then, the two genes were co-expressed in GP72ANO, improving PCA production from 729.4 mg/L to 993.4 mg/L at 36 h. Moreover, the shunt pathway was blocked to enhance glycerol utilization, resulting in 1493.3 mg/L PCA production. Additionally, we confirmed the inhibition of glpR on glycerol metabolism pathway in P. chlororaphis GP72. This study provides a good example for improving the utilization of glycerol to synthesize high value-added compounds in Pseudomonas.

One-Pot Facile Synthesis of AgIO3/Ag2O/Ag Nanocomposites with Enhanced Photocatalytic Activity.

AgIO3/Ag2O/Ag nanocomposites with enhanced photocatalytic activities were synthesized by a onestep coprecipitation method at room temperature. The optimum hybrid of AgIO3/Ag2O = 1.25:1 with Ag nanoparticles (Ag NPs) loading (denoted as AA125) exhibited superior photocatalytic activity, demonstrating 97.19% tetracycline (TC) degradation within 60 min under simulated solar irradiation. This was approximately 10.44 and 2.63 times higher than that of pure Ag2O and AgIO3, respectively. The advanced photocatalytic activity can be ascribed to the synergetic effects of the heterostructured AgIO3/Ag2O/Ag and the strong surface plasmon resonance (SPR) effect of Ag NPs generated on the surface, which improved the separation and transfer efficiency of photoinduced electron-hole pairs. The results from radical scavenger experiments indicated that the degradation of TC was driven mainly by the participation of superoxide radical (·O-2).

Electrochemical Sensor for Determination of Pb2+ Based on Gold Nanoparticles.

We report the formation of gold nanoparticles on indium tin oxide conducting glass (ITO) surface via electrodeposition method at room temperature. The prepared nano-Au electrodes has been fabricated for sensitive detection of Pb2+, and showed highly selective response toward Pb2+. The electrochemical detection of Pb2+ were determined by differential pulse stripping voltammetric (DPSV). The nano-Au electrochemical sensor could detect Pb2+ from 0.5 to 10 µM with detection limits of 0.06 µM (S/N= 3) and sensitivity of 0.27996 mA µM-1. The proposed sensor is simple, reliable, sensitive, selective, and low-cost, thus holds potential for practical application in Pb2+ detection.

A Novel CdWO4/BiOCl p-n Heterojunction Nanocomposites with Excellent Photocatalytic Activity Under Simulated Solar Light.

Constructing heterojunction is an effective way to enhance the catalytic activities of semiconductor photocatalyst owing to its special synergistic effect. In this study, a novel p-n heterostructured CdWO4/BiOCl nanocomposites were synthesized by a facile hydrothermal and subsequently chemistry bath method. The photocatalytic performance of CdWO4/BiOCl heterojunctions was investigated by degrading phenol and RhB under simulated solar light irradiation. Highly improved photocatalytic activities were achieved on all CdWO4/BiOCl heterojunctions compared with both pure CdWO4 and BiOCl. The CdWO4/BiOCl heterojunction with optimal mole ratio of 25% CdWO4 displayed the highest photoactivity with RhB and phenol being completely degraded in 15 min and 6 h, respectively. Mechanism analysis revealed that the interface of p-n heterojunction of CdWO4/BiOCl composites can produce spontaneously electric field which can effectively separate photogenerated electrons and holes. Moreover, the active species research demonstrated that holes and superoxide radicals proved to be the principal active species during the photocatalytic process. This work demonstrated that the CdWO4/BiOCl photocatalyst may be a promising material for purifying the organic contaminant in practical application.

Biomass Assisted Synthesis of 3D Hierarchical Structure BiOX(X Cl, Br)-(CMC) with Enhanced Photocatalytic Activity.

3D hierarchical structure BiOX(X ═ Cl, Br)-(CMC) assembled from 2D nanosheets with {010} facets exposed have been successfully synthesized by the assistance of biomass solvent CMC-Na. All the nitrogen adsorption isotherms and photoelectrochemical results reflected that BiOX(X Cl, Br)-(CMC) exhibit higher specific surface area, superior optical absorption efficiency and separation efficiency of photoinduced electron-hole than BiOX(X═Cl, Br) 2D nanosheets exposed with {001} facets. Besides, 96.5% and 60.3% of tetracycline hydrochloride (TC) were photodegradated in 60 minutes under the visible light irradiation catalyzed by BiOBr-(CMC) and BiOCl-(CMC), which is much better than BiOBr and BiOCl. The formation and enhanced photocatalytic activity of 3D hierarchical structure BiOX-(CMC) may be ascribe to the bi-functional groups of CMC, which can affect the crystallization process and morphology of BiOX. According to the merit of environmental friendly and improved photocatalytic activity of the 3D hierarchitecture, we believe that this work broadens the possibility of designing efficient BiOX photocatalyst with {010} facets exposed.

Synthesis and enhanced visible light photocatalytic CO2 reduction of BiPO4-BiOBr x I1-x p-n heterojunctions with adjustable energy band.

A series of novel BiPO4-BiOBr x I1-x p-n heterojunctions were successfully prepared by a facile solvothermal method. The morphology, structure and optical properties of photocatalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and ultraviolet visible diffuse reflectance spectroscopy. The visible light photocatalytic activities of BiPO4-BiOBr x I1-x heterojunctions were investigated by photocatalytically reducing CO2. After 4 hours of irradiation, the 5% BiPO4-BiOBr0.75I0.25 heterojunction showed the highest photocatalytic activity with the yields of CO and CH4 up to 24.9 and 9.4 µmol gcat -1 respectively. The improved photocatalytic activity may be due to the formation of BiPO4-BiOBr x I1-x p-n heterojunctions which can effectively restrict the recombination rate of the photoexcited charge carriers. Moreover, the energy band structure of BiPO4-BiOBr x I1-x heterojunctions could be easily adjusted by changing the mole ratio of I and Br. The possible mechanism of the enhancement of the photocatalytic performance was also proposed based on experimental and theoretical analysis. The present study may provide a rational strategy to design highly efficient heterojunctions with an adjustable energy band for environmental treatment and energy conversion.

Voltage adjustment improves rigidity and tremor in Parkinson's disease patients receiving deep brain stimulation.

Deep brain stimulation of the subthalamic nucleus is recognized as the most effective treatment for moderate and advanced Parkinson's disease. Programming of the stimulation parameters is important for maintaining the efficacy of deep brain stimulation. Voltage is considered to be the most effective programming parameter. The present study is a retrospective analysis of six patients with Parkinson's disease (four men and two women, aged 37-65 years), who underwent bilateral deep brain stimulation of the subthalamic nucleus at the First Affiliated Hospital of Sun Yat-sen University, China, and who subsequently adjusted only the stimulation voltage. We evaluated motor symptom severity using the Unified Parkinson's Disease Rating Scale Part III, symptom progression using the Hoehn and Yahr scale, and the levodopa equivalent daily dose, before surgery and 1 and 2 years after surgery. The 2-year follow-up results show that rigidity and tremor improved, and clinical symptoms were reduced, while pulse width was maintained at 60 µs and frequency at 130 Hz. Voltage adjustment alone is particularly suitable for patients who cannot tolerate multiparameter program adjustment. Levodopa equivalent daily dose was markedly reduced 1 and 2 years after surgery compared with baseline. Our results confirm that rigidity, tremor and bradykinesia can be best alleviated by voltage adjustment. The trial was registered at ClinicalTrials.gov (identifier: NCT01934881).

Electrocatalysis and Detection of Nitrite on a Pd/Fe2O3 Nanocomposite Modified Glassy Carbon Electrode.

An electrochemical palladium/ferric oxide (Pd/Fe2O3) nanocomposite modified glassy carbon electrode (GCE) was fabricated by hydrothermal method of Fe2O3 and electrochemical deposition of palladium nanoparticles, respectively. As-prepared Pd/Fe2O3 composite modified electrode exhibits enhanced electrocatalytic activity towards the catalytic oxidation of nitrite compared to Fe2O3, PdNPs modified electrodes and bare electrode. The parameters such as the influence of amount of Pd nanoparticles deposition onto the Pd/Fe2O3 modified electrode (ME) and effect of solution pH were investigated and discussed in detail. Under the optimal conditions, the Pd/Fe2O3 modified GCE can be used to detect nitrite concentration in a wide linear range of 10 and 1000 µM with the detection limit of 0.1 µM. The presence of Cu2+, Na+, Cl-, PO3-4 SO2-4, Mg2+ K+, NO-3, and NH+4 showed a trivial effect on the response of nitrite determination, revealing that developed modified electrode has an excellent anti-interference ability to common ions. It also shows good stability and reproducibility.

A Novel Heterojunction AgI/WO3 Nanocomposite with the Highly Enhanced Photocatalytic Activity.

Herein, a novel visible-light-driven heterojunction AgI/WO3 nanocomposite was successfully prepared using a facile two-step hydrothermal-precipitation process and applied for photodegradation of organic pollutants. The information of phase structures, morphology, optical properties of the asprepared samples was analysed in detail by XRD, TEM, EDS, STEM, DRS measurement and so on. Formation of the heterostructure and intimate interactions between AgI and WO3 can promote highly effective photogenerated electron-hole pairs separation, which enable the heterojuctions to perform excellent photocatalytic activity as greatly enhanced photocatalysts compared to that of pristine AgI and WO3 for decomposing Rhodamine B (RhB) dye under visible light irradiation. In addition, the AgI/WO3 (1:1) nanocomposites exhibit optimal photocatalytic activity. Moreover, the as-prepared samples exhibit good stability, which is favorable for its potential application. Additionally, we have an analysis on a possible photocatalytic mechanism based on trapping experiments together with other experimental results.

An Innovative Electrochemical Sensor Ground on NiO Nanoparticles and Multi-Walled Carbon Nanotubes for Quantitative Determination of Nitrite.

An electrochemical sensor ground on nickel oxide (NiO) nanoparticles and multi-walled carbon nanotubes (MWCNTs) was exploited for the detection of nitrite. Scanning electron microscopy (SEM) ensure the morphology of the nanocomposite consisted of NiO nanoparticle and MWCNTs. High Resolution Transmission electron microscopy (HR-TEM) reveals that the structure of NiO nanoparticles and MWCNTs. Scanning transmission electron microscopy (STEM) persuasively verified presence of the C, Ni and O element. The electrochemical character of the nanocomposite were researched by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the behavior of electrochemical oxidation to nitrite on NiO/MWCNTs/CP was explored by chronoamperometry. In tests, the NiO/MWCNTs/CP shown a sensitive current response toward nitrite, the oxidation peak current are linearly related to nitrite concentration in the range from 10-6 M to 10-4 M (R = 0.997) with a sensitivity of 3.53 µA µM-1 and a detection limit of 0.25 µM (S/N = 3). The validity of utilizing the proposed electrode to determine nitrite in tap water was also demonstrated.

Enhanced Visible-Light-Responsive Photocatalytic Properties of Bi2MoO6-BiOCl Nanoplate Composites.

Bi2MoO6-BiOCl nanoplate composites were successfully synthesized by a simple solvothermal process. The morphology, microstructure and optical properties of the as-prepared Bi2MoO6-BiOCl nanocomposites were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Vis diffuse reflection spectroscopy (DRS). A noteworthy enhancement in the visible-light-responsive photocatalytic degradation of RhB was observed over the Bi2MoO6-BiOCl nanocomposites compared to its individual components. The enhanced photocatalytic performance of Bi2MoO6-BiOCl nanocomposites could be attributed to the heterojunction interface in the composite, which can both efficiently separate photogenerated electron-hole pairs and also restrain the recombination of photoinduced charges.

Construction of Magnetic Fe3O4@C@Ag3PO4 Nanocomposites with Excellent Visible Photocatalytic Performance.

A new magnetic Fe3O4@C@Ag3PO4 nanocomposites photocatalyst with visible light response has been prepared by solvothermal, hydrothermal and precipitation process. The photocatalyst exhibited high photocatalytic activity and stability for the degradation of rhodamine B (RhB). Almost 100% of RhB was photodegraded with the assistance of magnetic Fe3O4@C@Ag3PO4 nanocomposites after 40 min, and the photocatalyst showed no obvious loss of photocatalytic activity after four times of cyclic utilization. Furthermore, the magnetic Fe3O4@C@Ag3PO4 nanocomposites can be separated by external magnetic field. Further study proved that the photogenerated holes were the main active species in the degradation process.

FBS or BSA Inhibits EGCG Induced Cell Death through Covalent Binding and the Reduction of Intracellular ROS Production.

Previously we have shown that (-)-epigallocatechin gallate (EGCG) can induce nonapoptotic cell death in human hepatoma HepG2 cells only under serum-free condition. However, the underlying mechanism for serum in determining the cell fate remains to be answered. The effects of fetal bovine serum (FBS) and its major component bovine serum albumin (BSA) on EGCG-induced cell death were investigated in this study. It was found that BSA, just like FBS, can protect cells from EGCG-induced cell death in a dose-dependent manner. Detailed analysis revealed that both FBS and BSA inhibited generation of ROS to protect against toxicity of EGCG. Furthermore, EGCG was shown to bind to certain cellular proteins including caspase-3, PARP, and α-tubulin, but not LC3 nor ß-actin, which formed EGCG-protein complexes that were inseparable by SDS-gel. On the other hand, addition of FBS or BSA to culture medium can block the binding of EGCG to these proteins. In silico docking analysis results suggested that BSA had a stronger affinity to EGCG than the other proteins. Taken together, these data indicated that the protective effect of FBS and BSA against EGCG-induced cell death could be due to (1) the decreased generation of ROS and (2) the competitive binding of BSA to EGCG.