To investigate the bioelectrochemical enhanced anaerobic ammonia oxidation (anammox) nitrogen removal process, a bioelectrochemical system with coupled anammox cathode was constructed using a dual-chamber microbial electrolysis cell (MEC). Specifically, a dark incubation batch experiment was conducted at 30 ℃ with different influent total nitrogen concentrations under an applied voltage of 0.2 V, and the enhanced denitrification mechanism was investigated by combining various characterization methods such as cyclic voltammetry, electrochemical impedance spectroscopy and high-throughput sequencing methods. The results showed that the total nitrogen removal rates of 96.9%±0.3%, 97.3%±0.4% and 99.0%±0.3% were obtained when the initial total nitrogen concentration was 200, 300 and 400 mg/L, respectively. In addition, the cathode electrode biofilm showed good electrochemical activity. High-throughput sequencing results showed that the applied voltage enriched other denitrifying functional groups, including Denitratisoma, Limnobacter, and ammonia oxidizing bacteria SM1A02 and Anaerolineaceae, Nitrosomonas europaea and Nitrospira, besides the anammox bacteria. These electrochemically active microorganisms comprised of ammonium oxidizing exoelectrogens (AOE) and denitrifying electrotrophs (DNE). Together with anammox bacteria Candidatus Brocadia, they constituted the microbial community structure of denitrification system. Enhanced direct interspecies electron transfer between AOE and DNE was the fundamental reason for the further improvement of the total nitrogen removal rate of the system.
Denitrification ; Wastewater ; Anaerobic Ammonia Oxidation ; Nitrogen ; Oxidation-Reduction ; Bioreactors/microbiology* ; Ammonium Compounds ; Bacteria/genetics* ; Microbiota ; Sewage

Antioxidant enzymes fused with cell-penetrating peptides could enter cells and protect cells from irradiation damage. However, the unselective transmembrane ability of cell-penetrating peptide may also bring antioxidant enzymes into tumor cells, thus protecting tumor cells and consequently reducing the efficacy of radiotherapy. There are active matrix metalloproteinase (MMP)-2 or MMP-9 in most tumor cellular microenvironments. Therefore, a fusion protein containing an MMP-2/9 cleavable substrate peptide X, a cell-penetrating peptide R9, a glutathione S-transferase (GST), and a human Cu, Zn superoxide dismutase (SOD1), was designed and named GST-SOD1-X-R9. In the tumor microenvironment, GST-SOD1-X-R9 would lose its cell-penetrating peptide and could not enter tumor cells due to the cleavage of substrate X by active MMP-2/9, thereby achieving selected entering normal cells. The complete nucleotide sequence of SOD1-X-R9 was synthesized and inserted into the prokaryotic expression vector pGEX-4T-1. The pGEX4T-1-SOD1-X-R9 recombinant plasmid was obtained, and soluble expression of the fusion protein was achieved. GST-SOD1-X-R9 was purified by ammonium sulfate precipitation and GST affinity chromatography. The molecular weight of the fusion protein was approximately 47 kDa, consistent with the theoretical value. The SOD and GST activities were 2 954 U/mg and 328 U/mg, respectively. Stability test suggested that almost no change in either SOD activity or GST activity of GST-SOD1-X-R9 was observed under physiological conditions. The fusion protein could be partially digested by collagenase Ⅳ in solution. Subsequently, the effect of MMP-2/9 activity on transmembrane ability of the fusion protein was tested using 2D and 3D cultured HepG2 cells. Little extracellular MMP-2 activity of HepG2 cells was observed under 2D culture condition. While under the 3D culture model, the size and the MMP-2 activity of the HepG2 tumor spheroid increased daily. GST-SOD1-R9 proteins showed the same transmembrane efficiency in 2D cultured HepG2 cells, but the transmembrane efficiency of GST-SOD1-X-R9 in 3D cultured HepG2 spheres was reduced remarkably. This study provided a basis for further investigating the selectively protective effect of GST-SOD1-X-R9 against oxidative damage in normal cells.
Ammonium Sulfate ; Antioxidants ; Cell-Penetrating Peptides/pharmacology* ; Endopeptidases ; Glutathione Transferase/metabolism* ; Humans ; Matrix Metalloproteinase 2/genetics* ; Matrix Metalloproteinase 9/genetics* ; Recombinant Fusion Proteins ; Recombinant Proteins ; Superoxide Dismutase/metabolism* ; Superoxide Dismutase-1

A comprehensive quality control method was established to provide references for quality control and evaluation of substance benchmarks of Danggui Sini Decoction(DSD). The HPLC separation was performed on a Kromasil 100 C-8 column(4.6 mm×250 mm, 5 μm) with acetonitrile(A)-0.05% phosphoric acid in water(B) as mobile phase in a gradient elution mode at the flow rate of 1 mL·min~(-1). The column temperature was 25 ℃ and the detection wavelength was set at 275 nm. Under these conditions, the content of seven components, including paeoniflorin, liquiritin, cinnamic acid, cinnamaldehyde, ammonium glycyrrhetate, ligustilide, and asarinin was simultaneously determined. Under the same chromatographic conditions, the HPLC fingerprint method for analysis of 15 batches of DSD was established. The content determination of aristolochic acid I, using the same test solution as the content determination item, was performed on an ACQUITY UPLC BEH C_(18) column(2.1 mm×50 mm, 1.7 μm) with methanol(A)-water(including 0.1% formic acid and 5 mmol·L~(-1) ammonium formate)(B) as the mobile phase in a gradient elution mode at the flow rate of 0.4 mL·min~(-1) and the column temperature of 40 ℃ by LC-MS/MS. The MS conditions included electrospray ionization(ESI) as an ion source, positive ion ionization, selective reaction monitoring(SRM), the parent ion of 359.3, and the daughter ion of 297.8. The results of the methodological investigation all met the requirements of content determination/fingerprint determination. As a result, the content ranges of paeoniflorin, liquiritin, cinnamic acid, cinnamaldehyde, ammonium glycyrrhetate, ligustilide, and asarinin were 5.419 8-11.267 3, 1.023-3.669 8, 0.145 6-0.444 1, 0.099 1-0.321 9, 3.159 1-7.731 9, 0.146 4-0.471 7, and 0.237 3-0.401 0 mg·g~(-1), respectively. Twenty-two common peaks were selected and 10 of them were identified by the comparison with the reference substances. The fingerprint similarity of 15 batches of DSD was in the range of 0.91-0.996 and the content of aristolochic acid I in DSD was 300.03-638.13 ng·g~(-1). The method established in this study is reliable and easy to operate and has great practical value, which can be used for overall quality control of substance benchmarks for DSD.
Ammonium Compounds ; Benchmarking ; Chromatography, High Pressure Liquid/methods* ; Chromatography, Liquid ; Drugs, Chinese Herbal/chemistry* ; Quality Control ; Tandem Mass Spectrometry/methods* ; Water

Objective: To develop effective alternatives to natural enzymes, it is crucial to develop nanozymes that are economical, resource efficient, and environmentally conscious. Carbon nanomaterials that have enzyme-like activities have been extensively developed as substitutes for traditional enzymes. Methods: Carbide-derived carbons (CDCs) were directly synthesized via a one-step electrochemical method from a MAX precursor using an ammonium bifluoride electrolyte at ambient conditions. The CDCs were characterized by systematic techniques. Results: CDCs showed bienzyme-like activities similar to that of peroxidase and superoxide dismutase. We systematically studied the dependence of CDC enzyme-like activity on different electrolytes and electrolysis times to confirm activity dependence on CDC content. Additionally, the synthesis mechanism and CDC applicability were elaborated and demonstrated, respectively. Conclusion The demonstrated synthesis strategy eliminates tedious intercalation and delamination centrifugation steps and avoids using high concentrations of HF, high temperatures, and halogen gases. This study paves the way for designing two-dimensional material-based nanocatalysts for nanoenzyme and other applications.
Ammonium Compounds/chemical synthesis* ; Carbon/chemistry* ; Electrochemical Techniques ; Enzymes ; Fluorides/chemical synthesis* ; Humans ; Nanostructures ; Oxidation-Reduction

Anaerobic ammonia oxidation (ANAMMOX) process is an efficient and low-cost biological nitrogen removal process. However, it still faces some challenges in mainstream applications due to the limitation of substrate types and nitrate accumulation. In recent years, the combined process of anammox has been widely studied to solve the above problems. In this paper, the combined processes of anammox developed in recent years are reviewed, and discussed from the process principle, advantages and disadvantages, influencing factors, process extensibility and the key bottlenecks existing in the promotion and application, as well as the relevant work of the subject group. Finally, we take an outlook on the development of the combined anaerobic ammonia oxidation process in municipal domestic wastewater treatment.
Ammonium Compounds ; Anaerobiosis ; Bioreactors ; Denitrification ; Nitrogen ; Oxidation-Reduction ; Sewage ; Waste Water

A total of 15 batches of the substance reference of Guizhi Jia Gegen Decoction(GZGGD) were prepared and the characteristic fingerprints of them were established. Furthermore, the similarity of the fingerprints and peak attributes were explored. The extraction rate, and the content and the transfer rate ranges of the index components, puerarin, paeoniflorin, liquiritin, and ammonium glycyrrhizate were determined for the analysis of the quality value transfer. The result demonstrated that the fingerprints of the 15 batches of the samples showed high similarity(>0.99). A total of 15 characteristic peaks were identified from the fingerprints, with 10 for Puerariae Lobatae Radix, 1 for Cinnamomi Ramulus, 2 for Paeoniae Radix Alba, and 2 for Glycyrrhizae Radix et Rhizoma. The content of puerarin was 11.05-18.35 mg·g~(-1) and the average transfer rate was 21.27%-39.49%. The corresponding figures were 7.95-10.90 mg·g~(-1) and 23.28%-43.23% for paeoniflorin, 3.25-4.95 mg·g~(-1) and 32.31%-61.27% for ammonium glycyrrhizate, and 3.65-5.80 mg·g~(-1) and 14.57%-27.05% for liquiritin. The extraction rate of the 15 batches of samples was in the range of 16.85%-21.78%. In this paper, the quality value transfer of the substance reference of GZGGD was analyzed based on characteristic fingerprint, content of index components, and the extraction rate. This study is expected to lay a basis for the quality control and further development of GZGGD.
Ammonium Compounds ; Benchmarking ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal ; Paeonia

Apixaban, an inhibitor of direct factor Xa, is used for the treatment of venous thromboembolic events or prevention of stroke. Unlike many other anticoagulant agents, it does not need periodic monitoring. However, monitoring is still required to determine the risk of bleeding due to overdose or surgery. Usually, apixaban concentrations are indirectly quantified using an anti-factor Xa assay. However, this method has a relatively narrow analytical concentration range, poor selectivity, and requires an external calibrator. Therefore, the goal of current study was to establish an analytical method for determining plasma levels of apixaban using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). To this end, apixaban was separated using 2.5 mM ammonium formate (pH 3.0) (A) and 100% methanol containing 0.1% formic acid (B) using the gradient method with a Thermo hypersil GOLD column. The mass detector condition was optimized using the electrospray ionization (ESI) positive mode for apixaban quantification. The developed method showed sufficient linearity (coefficient of determination [r² ≥ 0.997]) at calibration curve ranges. The percentage (%) changes in accuracy, precision, and all stability tests were within 15% of the nominal concentration. Apixaban concentration in plasma from healthy volunteers was quantified using the developed method. The mean maximum plasma concentration (C(max)) was 371.57 ng/mL, and the median time to achieve the C(max) (T(max)) was 4 h after administration of 10 mg apixaban alone. Although the results showed low extraction efficiency (~16%), the reproducibility (% change was within 15% of nominal concentration) was reliable. Therefore, the developed method could be used for clinical pharmacokinetic studies.
Ammonium Compounds ; Anticoagulants ; Calibration ; Chromatography, Liquid ; Factor Xa ; Healthy Volunteers ; Hemorrhage ; Humans ; Mass Spectrometry ; Methanol ; Methods ; Plasma ; Stroke ; Tandem Mass Spectrometry

The present study aimed at evaluating serum immunoglobulin G (IgG) avidity to Porphyromonas gingivalis in elderly patients with mild and severe chronic periodontitis. The avidity of antibodies against P. gingivalis present in the sera of 18 patients with mild chronic periodontitis and 18 patients with severe chronic periodontitis was evaluated using an ammonium thiocyanate-dissociated enzyme-linked immunosorbent assay (ELISA). The results showed that the mean absorbance value in serum IgG antibody titers was significantly higher in the severe chronic periodontitis group than in the mild chronic periodontitis group (198 ± 35 ELISA unit [EU] vs. 142 ± 32 EU, p < 0.01). However, there was no significant difference between the two groups in antibody avidity (65 ± 57 EU vs. 54 ± 27 EU). These findings suggest that humoral immune responses to P. gingivalis between mild and severe chronic periodontitis in elderly patients are characterized by the differences in the quantity rather than the quality of the antibodies.
Aged ; Ammonium Compounds ; Antibodies ; Antibody Affinity ; Chronic Periodontitis ; Enzyme-Linked Immunosorbent Assay ; Geriatrics ; Humans ; Immunity, Humoral ; Immunoglobulin G ; Immunoglobulins ; Porphyromonas gingivalis ; Porphyromonas

PURPOSE: Owing to the increased agricultural use of the herbicide glufosinate ammonium (GLA), the incidence of GLA poisoning has recently increased. Therefore, we investigated the possible predictive factors associated with severe complications following GLA poisoning. METHODS: A retrospective analysis of medical records was conducted based on 76 patients who had visited our regional emergency medical center with GLA poisoning from 2006 to 2017. Severe complications were defined as respiratory failure requiring intubation, systolic blood pressure less than 90 mmHg, Glasgow Coma Scale (GCS) less than 8, and presence of seizure. RESULTS: Age, ingested amount and ingested amount per weight were significantly greater in the severe group (p<0.001). PSS grade 2 or higher was more common in the severe group (p<0.001), and In addition, the APACHE II score was significantly higher in the severe group (p<0.001), as were the SOFA scores (p=0.002). Serum ammonia levels were significantly higher in the severe group (p=0.007), while MDRD-GFR was smaller in the severe group (p=0.002). The spot urine protein levels were significantly higher in the severe group (p=0.005), as was the urine protein to creatinine ratio (p=0.001). Upon multivariate analysis, the amount ingested per weight and PSS grade 2 or higher were identified as significant predictors. CONCLUSION: Our study showed that MDRD-GFR was significantly lower in the severe group after GLA poisoning. PSS grade 2 or higher and ingested amount per weight may be useful to evaluate the severity of complications after GLA poisoning.
Ammonia ; Ammonium Compounds ; APACHE ; Blood Pressure ; Creatinine ; Emergencies ; Glasgow Coma Scale ; Humans ; Incidence ; Intubation ; Medical Records ; Multivariate Analysis ; Poisoning ; Respiratory Insufficiency ; Retrospective Studies ; Seizures

No abstract available.
Ammonium Compounds ; Corpus Callosum