Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add more filters










Publication year range
1.
World J Clin Cases ; 12(20): 4419-4426, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39015931

ABSTRACT

BACKGROUND: On June 30, 2021, China received certification from the World Health Organization for malaria elimination. However, this certification does not signify the absence of malaria within China. Due to the increasing frequency of international exchanges and collaborations, the threat of imported malaria persists in China. Consequently, the prevention and control of imported malaria have become a primary focus for our country to maintain its malaria elimination status. CASE SUMMARY: Herein, we present a case report of a 53-year-old Chinese man who worked in Africa for nearly two years. He was diagnosed with malaria in the Democratic Republic of the Congo between November 19 and November 23, 2022. After receiving effective treatment with oral antimalarial drugs, his condition improved, allowing him to return to China. He was later admitted to our hospital on January 12, 2023, during the coronavirus disease 2019 pandemic in Huangshi, China. Through a thorough evaluation of the patient's symptoms, clinical signs, imaging and laboratory test results, and epidemiological data, he was rapidly diagnosed with severe cerebral malaria. The patient underwent successful treatment through a series of intensive care unit interventions. CONCLUSION: The successful treatment of this imported case of severe cerebral malaria provides a valuable reference for managing patients with similar malaria infections and has significant clinical implications.

2.
Bioresour Technol ; 346: 126658, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34974097

ABSTRACT

Enhanced biological phosphorus removal (EBPR) process is susceptible to the changed operation condition, which results in an unstable treatment performance. In this work, long-term effect of coagulants addition, aluminum salt for the reactor R1 and iron salt for the reactor R2, on EBPR systems was comprehensively evaluated. Results showed that during the initial 30 days' coagulant addition, effluent chemical oxygen demand and phosphorus can be reduced below 25 and 0.5 mg·L-1, respectively. Further supply of metal salts would stimulate microbial extracellular polymeric substance excretion and induce reactive oxygen species accumulation, which destroyed the cell membrane integrity and deteriorated the phosphorus removal performance. Moreover, coagulants would decrease the relative abundance of Candidatus Accumulibacter while increase the relative abundance of Candidatus Competibacter, leading phosphors accumulating organisms in a disadvantage position. The results of this work might be valuable for the operation of chemical assisted biological phosphorus removal bioreactor.


Subject(s)
Betaproteobacteria , Phosphorus , Bioreactors , Extracellular Polymeric Substance Matrix , Glycogen , Polyphosphates
3.
ACS Appl Mater Interfaces ; 13(11): 13534-13540, 2021 Mar 24.
Article in English | MEDLINE | ID: mdl-33705092

ABSTRACT

Single-atom catalysts (SACs) have attracted great attention due to their high atom-utilization and catalytic efficiency. However, a universal synthetic route is still lacking, which restricts the SAC-related investigation and application. Here, we report a simple and cost-effective method to fabricate transition metal SACs through ion exchange and annealing procedures. Benefiting from the "egg-box" structure property of alginate, the metal ion can be effectively anchored into the organic center. Using CuCl2 as a representative transition metal ion, the Cu SAC structure was synthesized and identified by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy. Through optimizing CuCl2 concentration, the obtained Cu SAC exhibited a good oxygen reduction reaction activity, whose onset potential, half wave potential, and limiting current density are all comparable to those of 20 wt % Pt/C. Cu-N4 was identified as the responsible catalytic site. More importantly, other transition metal SACs can be easily synthesized via altering metallic solution, which proves the universality of our proposed method. This work may be valuable for the cost-effective and universal SAC synthetic method development.

4.
Sci Total Environ ; 747: 141464, 2020 Dec 10.
Article in English | MEDLINE | ID: mdl-32795803

ABSTRACT

The preservation of anammox granules is of great significance for the rapid start-up of the anammox process and improvement of performance stability. Therefore, it is necessary to explore an economical and stable preservation strategy. Exogenous extracellular polymeric substances (EPS) were used as protective agents for the preservation of anammox granules in this study. In brief, EPS from anammox sludge (A-EPS) and denitrifying sludge (D-EPS) were added to preserve anammox sludge at 4 °C and room temperature (15-20 °C). The results showed that A-EPS addition at 4 °C was the optimal condition for the preservation of anammox granules. After 90 days of preservation, the specific anammox activity (SAA) of the anammox granules remained at 92.7 ± 2.2 mg N g-1 VSS day-1 (remaining ratio of 33.4%), while that of the sludge with D-EPS addition at the same temperature was only 77.1 ± 3.2 mg N g-1 VSS day-1 (remaining ratio of 27.8%). The nitrogen removal efficiency of the experimental group with D-EPS at room temperature was 85.9%, and that of the A-EPS group reached 90.6% under the same temperature conditions. The abundance of the functional genes hzsA, hdh and nirS of the sludge (4 °C; A-EPS addition) after recovery were 138.5%, 317.1%, and 375.9%, respectively, of those of sludge from the D-EPS-added group at the same temperature. RDA revealed the contribution of proteins to the preservation process. Overall, this study provides an economical and robust strategy for the preservation of anammox granules.

5.
Chemosphere ; 244: 125577, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32050350

ABSTRACT

Persulfate based advanced oxidation process is a promising technology for refractory contaminants removal. Cobalt is considered as the most efficient metal in catalyzing peroxymonosulfate decomposition. Although different cobalt based nanomaterials have been developed, easy aggregation and metal ion leaching during catalytic reaction would result in its deficiency. To address the above issue, in this work, carbon supported Co/CoO core-shell nanocomposite was in-situ fabricated by using polyphenol-metal coordinate as precursor. Results indicated that cobalt nanoparticle with size of 10 nm was successfully prepared and well dispersed within the carbon matrix. By using as-prepared material as catalyst, 50 mg/L orange II was completely removed under the condition of 0.2 g/L peroxymonosulfate, 0.05 g/L catalyst, pH = 4.0-10.0. Both sulfate and hydroxyl radicals were formed during peroxymonosulfate decomposition, while sulfate radical dominated the pollutant removal. Mechanism study revealed that the cobalt was the key site for catalyzing peroxymonosulfate decomposition. This work might provide valuable information in designing and fabricating metal anchored carbon composite catalyst for efficiently and cost-effectively activate peroxymonosulfate.


Subject(s)
Coloring Agents/chemistry , Nanocomposites/chemistry , Peroxides/chemistry , Azo Compounds , Benzenesulfonates , Carbon/chemistry , Catalysis , Cobalt/chemistry , Models, Chemical , Oxidation-Reduction , Sulfates
6.
Sci Total Environ ; 705: 135959, 2020 Feb 25.
Article in English | MEDLINE | ID: mdl-31841900

ABSTRACT

The sustainable management and recirculation of phosphorus resources are essential to our human lives. In this work, phosphorus removal and recovery from secondary effluent were achieved using municipal wastewater-derived materials as adsorbents. Through modification with 0.5 M NaOH for 30 min, iron containing sludge that originated from the coagulation pretreatment of municipal wastewater was successfully converted to phosphorus adsorbent. The maximal adsorption capacity of the prepared adsorbent was estimated to be 22 mg-P/g, and the adsorption performance remained stable in the pH range of 5-8. FeO(OH) was identified as the key adsorption site, and the ligand exchange mediated chemical adsorption was the main mechanism for phosphorus removal by the prepared material. Moreover, a laboratory-scale continuous-flow adsorption column experiment showed that the surplus phosphorus in secondary effluent could be readily reduced to <0.1 mg/L. By pyrolysis of P-laden alkali-treated iron sludge under oxygen limited conditions, the phosphorus was recovered and successfully applied to support wheat growth. This work provides valuable information for both the sustainable management of phosphorus streams in wastewater and cyclic utilization of waste sludge.

7.
Chemosphere ; 226: 934-944, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31509923

ABSTRACT

The anaerobic ammonium oxidation (anammox) process has the advantages of a high nitrogen removal rate, low operational cost, and small footprint and has been successfully implemented to treat high-content ammonium wastewater. However, very little is known about the toxicity of the heavy metal element Ni(II) to the anammox process. In this study, the short- and long-term effects of Ni(II) on the anammox process in an upflow anaerobic sludge blanket (UASB) reactor were revealed. The results of the short-term batch test showed that the half maximal inhibitory concentration (IC50) of Ni(II) on anammox biomass was 14.6 mg L-1. A continuous-flow experiment was performed for 150 days of operation, and the results illustrated that after domestication, the achieved nitrogen removal efficiency was up to 93±0.03% at 10 mg L-1 Ni(II). The settling velocity, specific anammox activity and EPS content decreased as the Ni(II) concentration increased. Nevertheless, the content of heme c increased as the Ni(II) increased. These results indicate that short-term exposure to Ni(II) has an adverse impact on anammox process, but the anammox system could tolerate 10 mg L-1 Ni(II) stress after acclimation during continuous-flow operation for 150 days. High-throughput sequencing results indicated that the presence of Ni(II) had an impact on the microbial community composition in the anammox reactor, especially Candidatus Kuenenia. At Ni(II) concentrations of 0-10 mg L-1, the relative abundance of Candidatus Kuenenia decreased from 36.23% to 28.46%.


Subject(s)
Ammonium Compounds/chemistry , Bacteria/metabolism , Bioreactors/microbiology , Nickel/chemistry , Nitrogen/chemistry , Sewage/chemistry , Wastewater/chemistry , Anaerobiosis , Bacteria/growth & development , Oxidation-Reduction
8.
AMB Express ; 9(1): 112, 2019 Jul 22.
Article in English | MEDLINE | ID: mdl-31332555

ABSTRACT

Cellulase has many potential applications in ethanol production, extraction of medicinal ingredients, food, brewing, oil exploration, environmental protection. However, the widespread use of cellulase is limited by its relatively high production costs and low biological activity. Therefore, we studied the enzymatic properties and reusability of cellulase immobilized on multiwalled carbon nanotubes and sodium alginate for the first time. The results showed that the optimum temperature and pH of immobilized cellulase was 40 °C and 3.0, respectively. After 1 month of storage at 4 °C, the enzyme activity of immobilized cellulase dropped to 71.2% of the baseline. Immobilized cellulase was proved to be reusable and maintained ~ 70% of its activity after 7 cycles of repeated use. Versus free cellulase, the immobilized cellulase showed good thermal stability, pH resistance, storage stability and reusability, which could be beneficial in large-scale industrial manufacturing processes.

9.
Bioresour Technol ; 290: 121766, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31302464

ABSTRACT

Cadmium (Cd) can cause the deterioration of biological systems through inhibiting the enzymes activity and disturbing the microbial metabolism. Although the influence of Cd on conventional wastewater treatment process has been studied, the response of anammox to Cd exposure still remains unclear. This study firstly investigated the adaption and restoration of anammox biomass to Cd(II) stress. Results showed that long-term exposure of anammox bacteria to 2 mg L-1 Cd(II) was beneficial for the reactor performance, while 5 mg L-1 Cd(II) would cause the decline of SAA, extracellular polymeric substance content and relative abundance of Candidatus kuenenia by 40%, 25% and 31%, respectively. Furthermore, these indexes could approximately recover to the initial status after withdrawing Cd(II) from the influent. Overall, the anammox biomass exhibited a certain adaption and restoration ability to the suppression of Cd(II). This study may provide key valuable information for the biological treatment of wastewater containing Cd(II).


Subject(s)
Cadmium , Microbiota , Anaerobiosis , Biomass , Bioreactors , Extracellular Polymeric Substance Matrix , Nitrogen , Oxidation-Reduction
10.
Sci Total Environ ; 682: 374-381, 2019 Sep 10.
Article in English | MEDLINE | ID: mdl-31125751

ABSTRACT

Anammox and autotrophic desulfurization-denitrification (AADD) process is feasible for the nitrogen and sulfide removal in the same reactor, and the influence of excess nitrate produced by anammox could also be alleviated simultaneously. This study firstly proposed a novel strategy with inoculating single anammox sludge to start up the AADD process. Results demonstrated that the 90% nitrogen removal efficiency (NRE), 2.55kgm-3 d-1 nitrogen removal rate (NRR), and 95% sulfide removal efficiency (SRE) were obtained at the influent total nitrogen of 280mgL-1 and sulfide of 221.5mgL-1, and the final effluent nitrate concentration was as low as 8mgL-1 under the appropriate operation conditions. Tryptophan-like and protein-like substances were characterized as the main components in bound EPS. Thiobacillus (35.68%) and Pseudoxanthomonas (11.61%) were identified as the predominant genera. This study will pave a potential avenue to promote the treatment of high concentration nitrogen and sulfide in wastewater in the future.


Subject(s)
Waste Disposal, Fluid/methods , Autotrophic Processes , Bioreactors , Denitrification , Nitrates , Nitrogen , Sewage , Thiobacillus , Wastewater
11.
Eur J Pharmacol ; 670(1): 7-12, 2011 Nov 16.
Article in English | MEDLINE | ID: mdl-21951964

ABSTRACT

Cardiomyocyte stretching has been reported to be a major trigger for brain natriuretic peptide (BNP) release; however, an increase in circulating BNP is observed in patients with acute myocardial ischemia in the absence of increased left ventricular wall stress or cardiomyocyte stretching. In the present study, to investigate the direct and independent effects of acute myocardial ischemia on BNP expression and its mechanism, we established an in vitro glucose-free ischemia and hypoxia injured model of cultured rat cardiomyotes and proved hypoxia upregulated expressions of interleukin-6(il-6) and BNP. Further treatment with il-6 elicited dose- and time-dependent increases in BNP mRNA and protein expression as well as an upregulation in transforming growth factor-ß1 (TGF-ß1)/Smad2 expression, which was partially suppressed by a neutralizing antibody. In conclusion, our study showed that acute myocardial ischemia can directly upregulate BNP expression at the translational and transcriptional levels through the action of il-6, and this process is associated with the upregulation of TGF-ß1/Smad2 signal path.


Subject(s)
Cytokines/metabolism , Gene Expression Regulation , Myocardial Ischemia/genetics , Natriuretic Peptide, Brain/biosynthesis , Natriuretic Peptide, Brain/genetics , Protein Biosynthesis , Transcription, Genetic , Animals , Antibodies, Neutralizing/pharmacology , Cell Survival/drug effects , Cytokines/genetics , Gene Expression Regulation/drug effects , Hypoxia/complications , Inflammation/metabolism , Inflammation Mediators/metabolism , Interleukin-6/metabolism , Myocardial Ischemia/etiology , Myocardial Ischemia/metabolism , Myocardial Ischemia/pathology , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Natriuretic Peptide, Brain/metabolism , Protein Biosynthesis/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Signal Transduction/drug effects , Smad2 Protein/genetics , Smad2 Protein/metabolism , Transcription, Genetic/drug effects , Transforming Growth Factor beta1/genetics , Transforming Growth Factor beta1/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...