Superior performance of oxygen vacancy-enriched Cu-Co3O4/urushiol-rGO/peroxymonosulfate for hypophosphite and phosphite removal by enhancing singlet oxygen.

The treatment of wastewater containing hypophosphite [P(I)] and phosphite [P(III)] is challenged by limitations of traditional Fenton oxidation such as low efficiency, secondary pollution and high costs. This study introduced a facile solvent-thermal method to synthesize Cu-Co3O4 nanoparticles uniformly loaded on graphene (Cu-Co3O4/U-rGO) through the reduction and coordination effects of urushiol (U). As prepared Cu-Co3O4/U-rGO exhibited excellent activity in activating peroxymonosulfate (PMS) for the oxidation of P(I)/P(III) to phosphate [P(V)] (0.229 min-1), along with high stability and reusability (91.5 % after 6 cycles), low metal leaching rate (Co: 0.2 mg/L, Cu: 0.05 mg/L), insensitivity to common anions in water and a wide pH range (3-11). The activation mechanism involved the synergistic effects from both urushiol and graphene, which promoted redox of Cu+/Cu2+ and Co2+/Co3+ and induced abundant oxygen vacancies for PMS activation to produce singlet oxygen. Furthermore, the Cu-Co3O4/U-rGO/PMS was also excellent in the oxidative removal of organic phosphorus. This study is expected to advance strategies for the treatment of P(I)/P(III)-rich wastewater and provide new insights for the development of low-cost, highly efficient heterogeneous catalysts with abundant oxygen vacancies.

A Mild Phenotype of Overlapping Syndrome With Myelin-Oligodendrocyte Glycoprotein and Glial Fibrillary Acidic Protein Immunoglobulin G: Mimicking Viral Meningitis in a Patient.

INTRODUCTION: Glial fibrillary acidic protein (GFAP) astrocytopathy, an autoimmune central nervous system disorder characterized by the development of immunoglobulin G reactive with GFAP, has received growing attention in recent years. It is documented that GFAP-immunoglobulin G and other autoantibodies can be both detected in some patients. However, the coexistence of anti-myelin-oligodendrocyte glycoprotein (MOG) and GFAP antibodies is rarely reported. CASE: A 45-year-old man presented with headache, fever, backache, dysuria, tremble of hands, numbness of lower limbs, without diplopia, decreased vision, or other manifestations of optic neuritis. He was initially diagnosed with viral meningitis. After antiviral therapy, his headache, fever, and dysuria were improved, but the tremble of his upper limbs and numbness of his lower limbs still existed. A lumbar puncture was further performed and found both anti-GFAP and anti-MOG antibodies in the cerebrospinal fluid. No evidence of other immune disorders or infectious diseases was revealed. Meanwhile, a magnetic resonance scan showed enhancement of spinal pia mater in cervical, thoracic, and lumbar segments. He was then treated with immunoglobulin (intravenous immunoglobulin) therapy (25 g for 5 d), and steroid pulse therapy (methylprednisolone, 1 g for 5 d), followed by a gradual tapering of oral prednisolone. CONCLUSION: We reported a case of overlapping anti-GFAP and anti-MOG antibody-associated syndrome. This case enriches our understanding of the clinical manifestations of overlapping syndrome and expands the spectrum of this disorder.

Linezolid-Induced Pure Red Cell Aplasia: A Case Report.

Linezolid (LZD) has been widely used for treating the infections of multidrug-resistant gram-positive organisms. As we know, anemias induced by Linezolid (LZD) are common. However, LZD-induced pure red cell aplasia (PRCA) is very rare. In this paper, we report on a 68-year-old woman with intravascular stent infection who developed PRCA after treatment with LZD. The patient presented to our hospital with a 6-month history of fever after stent implantation for aneurysms in both lower limbs. Bone culture grew methicillin-resistant Staphylococcus hemolyticus (MRSH). She received LZD after developing adverse reactions to initial antibiotics. Although her infective symptoms were improved by LZD, progressive thrombocytopenia was observed 23 days after LZD therapy. Her platelets declined to 66*109/L and hemoglobin level was 10.1 g/dL. Thrombocytopenia recovered 12 days after cessation of LZD. LZD was administered again due to recovered fever. 57 days after LZD administration, her hemoglobin level was 4.1 g/dL and reticulocytes were 0.2%. Bone marrow smear revealed active granulocyte proliferation and markedly decreased erythropoiesis with vacuolar degeneration. 12 days after cessation of LZD, her hemoglobin and reticulocyte levels rose to 9.6 g/dL and 5.1%, respectively. LZD was used for the third time as fever and inflammatory markers progressively increased, but Hb was reduced to 6.7g/dL 15 days after LZD therapy. 12 days after cessation of LZD, the hemoglobin level rose to 11.9 g/dL. In summary, we suggest complete blood count and reticulocyte count should be monitored to detect bone marrow suppression during long-term LZD therapy, especially in patients aged over 58 and/or with pre-existing anemia, chronic infections, and renal insufficiency.

A Retrospective Analysis of Metagenomic Next Generation Sequencing (mNGS) of Cerebrospinal Fluid from Patients with Suspected Encephalitis or Meningitis Infections.

We determined the clinical value of metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) for the diagnosis of patients with suspected encephalitis or meningitis infection. Clinical data were collected and retrospectively analyzed from patients with suspected cases of encephalitis or meningitis who presented at four hospitals in Ningbo from January 1st, 2019 to December 31st, 2020. Of a total of 66 suspected cases, 41 (62.12%) were diagnosed with central nervous system infections, which included 18 cases (27.27%) of viral infection, 13 cases (19.70%) of bacterial infection, 3 cases (4.55%) of Mycobacterium tuberculosis, 5 cases (7.58%) of fungal infection, and 2 cases (3.03%) of Rickettsia infection. From these cases, mNGS identified 25 (37.88%) true-positive cases, 8 (12.12%) false-positive cases, 20 (30.30%) true-negative cases, and 13 (19.70%) false-negative cases. The sensitivity of mNGS was 65.79% with a specificity of 71.43%. The positive rate was higher compared with traditional methods (37.88% vs. 24.39%). The results indicate that mNGS technology is a more sensitive method for detecting suspected infectious encephalitis or meningitis compared with traditional pathogen detection methods.

Clinical and Microbiological Characteristics of a Community-Acquired Carbapenem-Resistant Escherichia coli ST410 Isolate Harbouring blaNDM-5-Encoding IncX3-Type Plasmid From Blood.

Objectives: The aim of this research was to investigate the clinical and microbiological characteristics of a case of community-acquired carbapenem-resistant Escherichia coli isolated from a patient with a bloodstream infection in China. Methods: Escherichia coli Huamei202001 was recovered from the first blood culture from a patient hospitalised in China. An antimicrobial susceptibility test was performed, and the genome was sequenced on an Illumina HiSeq X 10 platform with a 150-bp paired-end approach. The generated sequence reads were assembled using Unicycler, and the whole genome sequence data were analysed using bioinformatics tools. Moreover, the patient and her main family members obtained a faecal sample screening test for CRE, the positive strain was further isolated and the identification and antimicrobial susceptibility testing was performed. Results: Escherichia coli Huamei202001 belonged to sequence type 410. In addition, a blaNDM-5-encoding IncX3-type plasmid was responsible for the spreading of carbapenem resistance. Only the patient was detected as having a positive faecal sample screening test for CRE. Strain Fec01 was identified as E. coli, and the antibiotic susceptibility profile was the same as that of E. coli Huamei202001. Conclusions: Escherichia coli Huamei202001 is defined as community-acquired carbapenem-resistant Enterobacteriaceae. The clone ST410 that harbours the blaNDM-5-encoding IncX3-type plasmid is causing new high-risk clones globally. Thus, infection control measures should be strengthened to curb the dissemination of IncX3.

Extracellular electron transfer of Enterobacter cloacae SgZ-5T via bi-mediators for the biorecovery of palladium as nanorods.

In nature, microbes use extracellular electron transfer (EET) to recover noble metals. Most attention has been paid to the biorecovery process occurring intracellularly and on the cell surface. In this work, we report that Pd nanorods could be biosynthesized by Enterobacter cloacae SgZ-5T in the extracellular space. This bacterium possesses both a direct EET pathway through membrane redox systems and an indirect EET pathway via the self-secreted electron carrier hydroquinone (HQ). When exposed to Pd(II), the bacteria adjusted their metabolic pathway and membrane-bound proteins to secrete riboflavin (RF). However, no HQ was detected in the supernatant in presence of Pd(II). No significant change was observed through metabolomic analysis regarding the abundance of HQ in presence of Pd(II) compared to Pd(II)-free supernatant. Similar results were also obtained through transcriptomic analysis of YqjG gene encoding glutathionyl-HQ reductase synthase. X-ray photoelectron spectroscopic evidence indicated that HQ may adsorb to the surface of Pd nanorods. Moreover, the gene encoding RF synthase (ribE) was up-regulated in the present of Pd(II), suggesting that this bioreduction process induced RF synthase, which had been shown in previous results. The UV-vis spectroscopy data demonstrated that the Pd(II) reduction rate was enhanced by 5%, 5.5% and 30% by the addition of 3.33 µM HQ, 3.33 µM RF and the both, respectively. All these results revealed that the bi-mediators secreted by bacteria were beneficial for biorecovery of Pd. This work is of significance for understanding metal biorecovery processes and natural biogeochemical processes.

The clinical characteristic and risk of capsule incomplete and retention in Crohn's disease.

OBJECTIVE: To evaluate capsule endoscopy in terms of incomplete examinations and capsule retentions, to describe the characteristic of these events and to find risk factors for these events. METHODS: This retrospective and consecutive case-control study includes data of 204 capsule enteroscopy examinations in patients with Crohn's Disease, performed at the first hospital affiliated to zhejiang university medical school from June 2003 to April 2014. RESULTS: The frequency of complete examinations was 56.9%. Male gender (OR=2.48, P=0.026), abdominal pain (OR=2.88, P=0.002), melena/bloody stools/OB+ (OR=3.34, P=0.009) were risk factors for an incomplete examination. Capsule retention occurred in 8.33% (n=17). The ratio of male and female was 12:5. While the average age of these patients was 42.2±16.2, and the average course of disease was 52.5±46.6 months. Of the seventeen cases of retained capsules, four patients chose to undergo surgery to remove the capsule for occurring symptoms of intestinal obstruction, spontaneous passage occurred in twelve patients after medical treatment, and one patient still have the capsule retained after 16 months of expectation. The longest capsule retained time in patients was four years. Risk factors for capsule retention was abdominal distention (OR=8.45, P=0.006). CONCLUSIONS: The majority of capsule endoscopy retention develops into spontaneous passage after medical treatment. Therefore capsule endoscopy is considered a safe procedure, although obstructive symptoms and serious complications due to capsule retention can be found in patients with known Crohn's disease.

Investigation of Cr(VI) reduction and Cr(III) immobilization mechanism by planktonic cells and biofilms of Bacillus subtilis ATCC-6633.

In this study, we investigated the Cr(VI) uptake mechanism of planktonic cells and biofilms of Bacillus subtilis (B. subtilis) ATCC-6633. Data showed that the effect of planktonic cells on the Cr(VI) uptake was quite different from that of biofilms. Planktonic cells had strong ability of Cr(VI) reduction, while biofilms possessed a great potential of Cr(III) immobilization. For planktonic cells, 100 mg/L Cr(VI) could be completely reduced. Both exopolymeric substances and cytoplasmic extracts contributed to high capacity of Cr(VI) reduction. After the reduction, noticeable Cr(III) precipitates were accumulated on bacterial surfaces, but 37.5% Cr(III) still remained in the supernatant. For biofilms, the biofilm debris became the main active ingredient of the Cr(VI) reduction. However, only 20 mg/L Cr(VI) could be reduced probably because of unavailability of reducing active sites during the biofilm formation. Further studies showed that biofilms had a better Cr(III) immobilization capacity than planktonic cells with 100% Cr(III) immobilized. Moreover, for the first time, we proposed a strategy combining the advantages of both planktonic cells and biofilms, and a successful Cr(VI) removal from typical Cr(VI)-containing plating wastewater was achieved through a 10-L pilot-scale experiment.

Investigation of antibacterial activity and related mechanism of a series of nano-Mg(OH)2.

Here we reported the antibacterial effect and related mechanism of three nano-Mg(OH)(2) slurries using Escherichia coli as model bacteria. X-ray diffraction (XRD), scanning electron microscopy (SEM) and laser particle size analysis revealed that the as-synthesized Mg(OH)(2)_(MgCl2), Mg(OH)(2)_(MgSO4) and Mg(OH)(2)_(MgO) are all composed by nanoflakes with different sizes, and their aggregates in water are 5.5, 4.5, and 1.2 µm, respectively. Bactericidal tests showed that the antibacterial efficiency is conversely correlated with the size of Mg(OH)(2) aggregates. Transmission electron microscopy (TEM) observation have not provided evidence of cellular internalization, however, the antibacterial effect is positive correlation to the loss of integrity of cell walls. SEM and zeta potential analysis revealed that the adhering ability of Mg(OH)(2) on the bacterial surface is Mg(OH)(2)_(MgCl2) > Mg(OH)(2)_(MgSO4) > Mg(OH)(2)_(MgO), indicating the toxicity of Mg(OH)(2) may be caused by the electrostatic interaction-induced external adsorption. Confocal laser scanning microscopy (CLSM) further revealed that the adhering of Mg(OH)(2) on the bacterial surface could increase the permeability of cell membranes. Taken together, the antibacterial mechanism of nano-Mg(OH)(2) could be as follows: nano-Mg(OH)(2) adsorbed on the bacterial surface by charge attraction first, and then destroyed the integrity of cell walls, which resulting in the final death of bacteria.

Cr(VI) uptake mechanism of Bacillus cereus.

In this study, we investigated the Cr(VI) uptake mechanism in an indigenous Cr(VI)-tolerant bacterial strain -Bacillus cereus through batch and microscopic experiments. We found that both the cells and the supernatant collected from B. cereus cultivation could reduce Cr(VI). The valence state analysis revealed the complete transformation from Cr(VI) into Cr(III) by living B. cereus. Further X-ray absorption fine structure and Fourier transform infrared analyses showed that the reduced Cr(III) was coordinated with carboxyl and amido functional groups from either the cells or supernatant. Scanning electron microscopy and atomic force microscopy observation showed that noticeable Cr(III) precipitates were accumulated on bacterial surfaces. However, Cr(III) could also be detected in bacterial inner portions by using transmission electron microscopy thin section analysis coupled with energy dispersive X-ray spectroscopy. Through quantitative analysis of chromium distribution, we determined the binding ratio of Cr(III) in supernatant, cell debris and cytoplasm as 22%, 54% and 24%, respectively. Finally, we further discussed the role of bacterium-origin soluble organic molecules to the remediation of Cr(VI) pollutants.

Photocatalytic bactericidal mechanism of nanoscale TiO2 films on Escherichia coli.

Two kinds of nanoscale TiO2 films were prepared by magnetron sputtering and screen printing methods, respectively. Results show that both phase composition and specific surface area of the film affect the photocatalytic bactericidal efficiency. Time-series in situ atomic force microscopy (AFM) observation were further used to characterize the cellular responses of Escherichia coli (E. coli) in photocatalytic process. Some nanosized patches were found on the bacterial surface in the forepart of photocatalytic reaction. It suggested that the photocatalytic attack induced the self-protection of bacteria at first. Subsequently, some cracks on the surface and the enlargement of cell body indicated that the cell wall was damaged and lost its structure supporting function, and it eventually led to the death of bacteria.

The analysis of the immobilization mechanism of Ni(II) on Bacillus cereus.

This work focused on the identification of biosorption mechanism of Ni(II) by living Bacillus cereus (B. cereus) based on batch experiments and a variety of microscopic equipments. The adsorption equilibrium reached rapidly in 2 h and the maximum nickel adsorption capability of B. cereus was 17.7 mg x g(-1) (dry weight). Atomic force microscopy (AFM) analysis showed that the bacterial surface roughness increased from 7.9 +/- 0.5 nm to 12.6 +/- 1.6 nm during this process. Scanning electron microscopy (SEM) observation confirmed that there was Ni(II) on the bacterial surface. However, transmission electron microscopy (TEM) thin section analysis coupled with energy dispersive X-ray spectroscopy (EDS) revealed that Ni(II) could also be found in the inner portions of the bacteria. Inductive coupled plasma emission spectrometer (ICP-OES) quantitative analysis elucidated that over 70% of the immobilized Ni(II) was binding on the surface of bacteria. X-ray diffraction (XRD) analysis showed that the Ni(II) collected by the bacteria was amorphous. Fourier transform infrared (FT-IR) analysis indicated that amides and carboxylation functional groups might be involved in the coordination of Ni(II).

Layer-by-layer self-assembly polytungstogermanate multilayer films and their photocatalytic properties under sunlight irradiation.

The dilacunary decatungstogermanate [γ-GeW(10)O(36)](8-) (GeW(10)) and the monolacunary undecatungstogermanate [ß(2)-GeW(11)O(39)](8-) (GeW(11)) were employed as polyanions to layer-by-layer self-assembly with cationic thionine (TH) dye. The (GeW(10)/TH)(n) and (GeW(11)/TH)(n) composite films were characterized by UV-vis spectra, atomic force microscopy images (AFMs) and cyclic voltammograms (CV). Their photocatalytic activities were evaluated by photocatalytic degradation of methyl orange aqueous solution under sunlight irradiation. The results indicated that the (GeW(10)/TH)(n) and (GeW(11)/TH)(n) films exhibited the sunlight photocatalytic activities for methyl orange (MO) solution. The dye molecule TH extended the light absorption spectrum of polyoxometalates toward the visible light region. The photocatalytic mechanism of composite films was also discussed.

Evaluation of phase, microstructure and composition of human dentine after Er,Cr:YSGG laser irradiation.

This study aims to evaluate the composition, micro-structure and inorganic phase alternations of human dentine irradiated by Er,Cr:YSGG laser with water cooling spray system. X-ray diffraction (XRD) analysis indicated that the main inorganic phase of dentine before and after laser irradiation were all Hydroxyapatite (HA) structure, approximately 30 nm in size. No significant changes occurred in the average particle size after irradiation in four energy densities (6.18 J/cm2, 8.04 J/cm2, 9.89 J/cm2, 11.1 J/cm2). Atomic force microscope (AFM) phase image and the energy-dispersive spectroscope (EDS) analysis, however, demonstrated that the thermal effects of Er,Cr:YSGG laser with water-cooling spray system on the dentin surface was intense enough to induce notable decrease of the organic matter. Both scanning electron microscopy (SEM) and AFM analysis showed that the irradiated dentine presented rough surface morphology. The surface is clean and dentinal tubules are completely open. The ablation rate of both peri- and intertubular dentine increased at higher energy densities but no significant changes of gross appearance took place. Chemical analysis reveals that laser photothermal effect would decrease significantly the organic content of superficial dentinal layer. We conclude that the Er,Cr:YSGG laser, as a new type clinic laser, would not significantly influence the inorganic phase structure of the surface dentine layer, however, thermal ablation was occurred in organic component. Moreover, the rough ablated surface as well as the opened dentinal tubules induced by irradiation, might be advantageous to the infiltration of the adhesive materials, thus the adhesion of dental restoration could be enhanced. Further studies should focus on the correlation between bond strength and Er,Cr:YSGG lased dentine.

The cytotoxicity of NiO nanoparticle with borate capping.

The impact of surface capping on cytotoxicity of NiO nanoparticle was investigated with Escherichia coil (E.coli) in this work. The NiO nanoparticle and NiO nanoparticle capped by borate (denoted as NiO-borate) were synthesized by hydrothermal method. The average size of both nanoparticles is about 4.0 nm. The plate experiments demonstrated that NiO-borate nanoparticles show lower cytotoxicity than NiO nanopaticles. Further spectrophotometric analysis revealed that the concentration of both extracellular and intercellular Ni2+ in NiO-borate system were lower than that of uncapped one. Intracellular ICP-AES analysis also showed the concentration of Ni element was higher than Ni2+, suggesting the NiO nanoparticles might penetrate into the cellular interior. Comprehensive AFM, SEM and TEM observation illustrated both NiO-borate and NiO nanoparticles lead to the collapse of cellular body, the convex on the cell wall and the damage of cell wall ultimately. In summary, the surface capping with borate on NiO nanopaticles will suppress the release of the Ni2+ ions and impede the contact between the NiO nanoparticle and cell wall, which ultimately decreased the cytotoxicity of NiO nanoparticles.

Bioremediation of Cr(VI) and immobilization as Cr(III) by Ochrobactrum anthropi.

Bioremediation of Cr(VI) through reduction relies on the notion that the produced Cr(III) may be precipitated or efficiently immobilized. However, recent reports suggest that soluble organo-Cr(III) complexes are present in various chromate-reducing bacterial systems. This work was designed to explore the factors that affect the immobilization of Cr(III) in the Ochrobactrum anthropi system. X-ray absorption fine structure analysis on the cell debris clearly verified that coordination of Cr(III) occurs on the surfaces via the chelating coordination with carboxyl- and amido-functional groups. However, competitive coordination experiments of Cr(III) revealed that the small molecules such as amino acids and their derivatives or multicarboxyl compounds hold stronger coordination ability with Cr(III) than with cell debris. We speculate that it is the preferential coordination of Cr(III) to the soluble organic molecules in the bacterial culture medium that inhibits effective immobilization of Cr(III) on the cells. On the basis of this understanding, a strategy with two-step control of the medium was proposed, and this achieved successful immobilization of Cr(VI) as Cr(III) by O. anthropi and Planococcus citreus in 5-50 L pilot-scale experiments.

Ultraviolet-light-induced bactericidal mechanism on ZnO single crystals.

By comparing the photocatalytic bactericidal effect on different crystal faces of bulk ZnO crystal, we found that an electron degradation mechanism dominates the photocatalytic processes of ZnO material.

Surface treatment to enhance photocatalytic activity of ZnS complex nanostructure via a post-synthesis route.

ZnS nanosheet composed solely by wurtzite (001) face was synthesized in concentrated NaOH solution. The sample was subjected to surface treatment and characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) atomic force microscope (AFM). We further used the nanosheet for investigating the photocatalytic activity under different surface adsorption states. The photocatalytic activity after surface treatment was evaluated by the decolorization of rhodamine B (RhB) under UV irradiation. We found that the photocatalytic activity was greatly enhanced after surface modification. The microscopic change in the surface state was described in detail and the related mechanism was discussed. For the potential application in environmental protection, we have also done the cycle performance experiment. We propose that the surface modification strategy is beneficial for reasonably designing and exploring novel photocatalyst.

Microscopic investigations of the Cr(VI) uptake mechanism of living Ochrobactrum anthropi.

A basic understanding related to the immobilization of chromium by bacteria is essential for chromate pollutant remediation in the environment. In this work, we studied the Cr(VI) uptake mechanism of living Ochrobactrum anthropi and the influence of a bacterial culture medium on the Cr-immobilization process. It was found that the Cr-immobilization ratio of bacteria in Tris-HCl buffer is higher than in LB medium. X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) analysis revealed that the chromium accumulated on bacteria were mostly in Cr(III) states. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) observations showed that noticeable Cr(III) precipitates were accumulated on bacterial surfaces. AFM roughness analysis revealed that the surface roughness of bacteria increased greatly when the bacteria-Cr(VI) interaction was in Tris-HCl buffer rather than in LB solution. Transmission electron microscopy (TEM) thin section analysis coupled with energy-dispersive X-ray spectroscopy showed that Cr(III) is also distributed in bacterial inner portions. A chromium-immobilization mechanism considering the participation of both bacterial inner portions and bacterial surfaces of living Ochrobactrum anthropi was proposed, whereas the bacterial surface was the dominant part of the immobilization of Cr(III). This work also proved that the control of Cr immobilization by living Ochrobactrum anthropi could be achieved via adjusting the bacterial culture medium.