34 results on '"Ang Cai"'
Search Results
2. Electrochemically Enabled Intramolecular Amino- and Oxysulfonylation of Alkenes with Sodium Sulfinates to Access Sulfonylated Saturated Heterocycles
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Xue-Qing Mou, Liang-Chen Ren, Min Wang, Huan-Huan Zhang, Ang Cai, Kuan-Xin Wan, Shi-Min Zhang, Bao-Dong Cui, Yun Zhang, and Yong-Zheng Chen
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Organic Chemistry - Published
- 2023
3. Diagnostic value of combination of exfoliative cytology with CA125, CEA, NSE, CYFRA21-1 and CA15-3 for lung cancer
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Liang Zhang, Jun Lei, Jing Xia, and Ang Cai
- Abstract
Background: To explore the diagnostic value of combination of exfoliative cytology with detection of tumor markers carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA), neuron specific enolase (NSE), cytokeratin 19 fragment antigen 21-1 (CYFRA21-1) and CA15-3 for lung cancer. Methods: A total of 256 patients were enrolled, including 164 males and 92 females aged (64.51±22.68) years old. Among them, 189 patients (100 males and 89 females) were randomly selected as Tumor group, and the remaining 67 patients were used for validation. Another 514 healthy people receiving physical examination in our hospital during the same period were selected, from which 397 cases (266 males and 131 females) were randomly selected as No Tumor group, and the remaining 117 cases were used for validation. The biochemical criteria were detected in all subjects. The diagnostic value of each index for lung cancer was analyzed using receiver operating characteristic (ROC) curves. Results: The results of ROC curve analysis revealed that in Tumor group, the area under curve (AUC) of exfoliative cytology, CA125, CYFRA21-1, CA15-3, CEA and NSE was ≥0.7, while that of CA72-4, CA19-9, TSGF, AFP, CA242, SCCAg and CA50 was Conclusions: The lung cancer prediction model balances sensitivity and specificity without reducing the diagnostic efficiency.
- Published
- 2022
4. MiR-1275 Targeting SPARC Promotes Gambogic Acid-Induced Inhibition of Gastric Cancer
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Ang Cai, Pengfei Xia, Xiaokang Zhou, Yao He, and Jun Lv
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Genetics ,General Medicine ,Molecular Biology ,Biochemistry ,Ecology, Evolution, Behavior and Systematics - Published
- 2023
5. Complementary Copper-Catalyzed and Electrochemical Aminosulfonylation of O-Homoallyl Benzimidates and N-Alkenyl Amidines with Sodium Sulfinates
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Xue-Qing Mou, Liang-Chen Ren, Mei Zhang, Min Wang, Yu-Fan Jin, Qing-Xin Guan, Ang Cai, Shi-Min Zhang, Hai Ren, Yun Zhang, and Yong-Zheng Chen
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Organic Chemistry ,Physical and Theoretical Chemistry ,Biochemistry - Published
- 2022
6. Expression of tight junction transmembrane protein Claudin-1 in gastric carcinoma and effects on tumor cell proliferation, invasion and migration
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Jun Lv, Zhuocui She, and Ang Cai
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digestive system diseases - Abstract
Background: Claudin-1 is involved in various cancers, but its expression and role in gastric carcinoma remain unclear. Materials and Methods: Gastric carcinoma and adjacent normal tissues were harvested from 60 patients. Claudin-1 expression was detected by RT-qPCR. The expressions in human gastric carcinoma MKN45, SGC7901 and MKN28 cells and immortalized human gastric epithelium GES-1 cells were determined by RT-qPCR and Western blotting. Claudin-1 was overexpressed in SGC7901 cells by lentiviral transfection, and they were divided into Control (untransfected), normal control (NC) (transfected with lentiviral vector) and Claudin-1 (transfected with Claudin-1 overexpression lentivirus) groups. The proliferation, invasion and migration of gastric carcinoma cells were detected through cell counting kit-8, Transwell and wound healing assays, respectively. The effects of Claudin-1 on the expressions of epithelial-mesenchymal transition (EMT) marker proteins E-cadherin and N-cadherin were detected by Western blotting. Ten 4-week-old male BALB/c nude mice were subcutaneously injected with lentivirus-treated SGC7901 cells to establish the transplanted tumor model, and the effect of overexpression of Claudin-1 was explored. Results: The expression of Claudin-1 in gastric carcinoma tissues was significantly lower than that in adjacent tissues (P Conclusion: Claudin-1 has low expression in gastric carcinoma tissues. Overexpression of Claudin-1 inhibits the proliferation, invasion, migration, and EMT of gastric carcinoma cells, and subcutaneous tumorigenesis in nude mice.
- Published
- 2022
7. Comparison of Fe30co20cr20ni20mo3.5 High Entropy Alloy Cladding Prepared by Plasma Cladding and Laser Cladding
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Mengzhao Li, Yicheng Zhou, Ang Cai, and Guodong Zhang
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- 2023
8. Inhibitory Effects and Surface Plasmon Resonance-Based Binding Affinities of Dietary Hydrolyzable Tannins and Their Gut Microbial Metabolites on SARS-CoV-2 Main Protease
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Hang Ma, Bongsup P. Cho, Dongli Li, Feng Xu, Huifang Li, Navindra P. Seeram, Joel A. Dain, Chang Liu, and Ang Cai
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viruses ,medicine.medical_treatment ,Hydrolyzable Tannin ,Article ,chemistry.chemical_compound ,gut microbial metabolites ,binding affinity ,Tannic acid ,medicine ,Humans ,Protease Inhibitors ,Gallic acid ,main protease (Mpro) ,Punicalagin ,Protease ,SARS-CoV-2 ,COVID-19 ,General Chemistry ,Surface Plasmon Resonance ,severe acute respiratory syndrome corona virus (SARS-CoV-2) ,Hydrolyzable Tannins ,Gastrointestinal Microbiome ,Molecular Docking Simulation ,Biochemistry ,chemistry ,Pyrogallol ,Polyphenol ,coronavirus disease 2019 (COVID-19) ,General Agricultural and Biological Sciences ,surface plasmon resonance (SPR) ,Peptide Hydrolases ,Ellagic acid - Abstract
Severe acute respiratory syndrome coronavirus (SARS-CoV-2) main protease (Mpro) inhibitors are considered as potential treatments for coronavirus disease 2019, and dietary polyphenols show promise in SARS-CoV-2 Mpro inhibition based on in silico studies. In the present study, we utilize a combination of biochemical-, surface plasmon resonance-, and docking-based assays to evaluate the inhibition and binding affinities of a series of tannins and their gut microbial metabolites on SARS-CoV-2 Mpro. The tested compounds (2–50 μM) were hydrolyzable tannins, including ellagitannins (punicalagin and ellagic acid) and gallotannins (tannic acid, pentagalloyl glucose, ginnalin A, and gallic acid), and their gut microbial metabolites, urolithins and pyrogallol, respectively. They inhibited SARS-CoV-2 Mpro (by 6.6–100.0% at 50 μM) and bound directly to the Mpro protein (with dissociation constants from 1.1 × 10–6 to 5.3 × 10–5 M). This study sheds light on the inhibitory effects of tannins and their metabolites on SARS-CoV-2 Mpro.
- Published
- 2021
9. Identification of SARS-CoV-2 Main Protease Inhibitors from a Library of Minor Cannabinoids by Biochemical Inhibition Assay and Surface Plasmon Resonance Characterized Binding Affinity
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Chang Liu, Tess Puopolo, Huifang Li, Ang Cai, Navindra P. Seeram, and Hang Ma
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Biological Products ,Cannabinoids ,SARS-CoV-2 ,Organic Chemistry ,Pharmaceutical Science ,COVID-19 ,Molecular Dynamics Simulation ,Surface Plasmon Resonance ,Viral Nonstructural Proteins ,Antiviral Agents ,Benzoates ,Analytical Chemistry ,Molecular Docking Simulation ,Cysteine Endopeptidases ,Chemistry (miscellaneous) ,main protease (Mpro) ,minor cannabinoids ,decarboxylation ,structure and activity relationship ,surface plasmon resonance ,binding ,Drug Discovery ,Molecular Medicine ,Humans ,Protease Inhibitors ,Physical and Theoretical Chemistry ,Coronavirus 3C Proteases - Abstract
The replication of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is mediated by its main protease (Mpro), which is a plausible therapeutic target for coronavirus disease 2019 (COVID-19). Although numerous in silico studies reported the potential inhibitory effects of natural products including cannabis and cannabinoids on SARS-CoV-2 Mpro, their anti-Mpro activities are not well validated by biological experimental data. Herein, a library of minor cannabinoids belonging to several chemotypes including tetrahydrocannabinols, cannabidiols, cannabigerols, cannabichromenes, cannabinodiols, cannabicyclols, cannabinols, and cannabitriols was evaluated for their anti-Mpro activity using a biochemical assay. Additionally, the binding affinities and molecular interactions between the active cannabinoids and the Mpro protein were studied by a biophysical technique (surface plasmon resonance; SPR) and molecular docking, respectively. Cannabinoids tetrahydrocannabutol and cannabigerolic acid were the most active Mpro inhibitors (IC50 = 3.62 and 14.40 μM, respectively) and cannabigerolic acid had a binding affinity KD=2.16×10−4 M). A preliminary structure and activity relationship study revealed that the anti-Mpro effects of cannabinoids were influenced by the decarboxylation of cannabinoids and the length of cannabinoids’ alkyl side chain. Findings from the biochemical, biophysical, and computational assays support the growing evidence of cannabinoids’ inhibitory effects on SARS-CoV-2 Mpro.
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- 2022
10. Complementary Copper-Catalyzed and Electrochemical Aminosulfonylation of
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Xue-Qing, Mou, Liang-Chen, Ren, Mei, Zhang, Min, Wang, Yu-Fan, Jin, Qing-Xin, Guan, Ang, Cai, Shi-Min, Zhang, Hai, Ren, Yun, Zhang, and Yong-Zheng, Chen
- Abstract
A complementary copper-catalyzed and electrochemical aminosulfonylation of
- Published
- 2022
11. Effect of Evodia rutaecarpa (Juss) Benth extract on Alzheimer disease in mice
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Yan-Ping Zhou, Ang Cai, Zhi-Guo Zhang, Liu Xiao, and Quan-Wei Yang
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medicine.medical_specialty ,biology ,medicine.diagnostic_test ,Amyloid beta ,business.industry ,Pharmaceutical Science ,Morris water navigation task ,Tropomyosin receptor kinase B ,medicine.disease ,Endocrinology ,nervous system ,Western blot ,Internal medicine ,biology.protein ,medicine ,Immunohistochemistry ,Pharmacology (medical) ,NeuN ,Alzheimer's disease ,business ,Neurotrophin - Abstract
Purpose: To investigate the protective effect of Evodia rutaecarpa (Juss.) Benth. extract (ERBE) against Alzheimer's disease in 3xTg-AD mice. Methods: The cognitive function of 3xTg-AD mice was assessed using Morris water maze test. The levels of amyloid beta deposits and NeuN in the mouse hippocampus were evaluated by immunohistochemistry. Brain neurotrophic derived factor (BDNF) and tyrosine kinase B (TrkB) expressions were determined by western blot analysis. Results: ERBE treatment significantly ameliorated learning and memory deficits in AD mice, as shown by increased time spent in the target zone during probe tests. The escape latency in the animals treated with 400 mg/kg ERBE (20.5 ± 1.3 s) was significantly higher than untreated 3xTg-AD mice (12.4 ± 1.3 s, p < 0.01). In addition, ERBE significantly decreased Aβ deposits, increased NeuN-positive cells, and upregulated the expressions of BDNF (1.4 ± 0.2, p < 0.05) and TrkB (1.1 ± 0.2, p < 0.05) in 3xTg AD mice. Conclusion: The results suggest that ERBE administration may be a useful strategy for treating memory impairment induced by several neurodegenerative diseases. Keywords: Evodia rutaecarpa, Alzheimer, Memory impairment, NeuN-positive cells
- Published
- 2020
12. Synergistic Inhibiting Effect of Phytochemicals in Rheum palmatum on Tyrosinase Based on Metabolomics and Isobologram Analyses
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Yin Xiong, Hye Kyong Kim, Övgü Çelikler Özer, Bert van Duijn, Henrie A. A. J. Korthout, Lihong Zi, and Ang Cai
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Organic Chemistry ,Pharmaceutical Science ,Rheum palmatum ,metabolomics ,Analytical Chemistry ,tyrosinase inhibitory activity ,catechin ,synergistic effect ,Chemistry (miscellaneous) ,Drug Discovery ,orthogonal partial least square-modelling ,Molecular Medicine ,gallic acid ,Physical and Theoretical Chemistry ,isobologram analysis - Abstract
Tyrosinase (TYR) plays a key role in the enzymatic reaction that is responsible for a range of unwanted discoloration effects, such as food browning and skin hyperpigmentation. TYR inhibitors could, therefore, be candidates for skin care products that aim to repair pigmentation problems. In this study, we used a metabolomics approach combined with the isobologram analysis to identify anti-TYR compounds within natural resources, and evaluate their possible synergism with each other. Rheum palmatum was determined to be a model plant for observing the effect, of which seven extracts with diverse phytochemicals were prepared by way of pressurized solvent extraction. Each Rheum palmatum extract (RPE) was profiled using nuclear magnetic resonance spectroscopy and its activity of tyrosinase inhibition was evaluated. According to the orthogonal partial least square analysis used to correlate phytochemicals in RPE with the corresponding activity, the goodness of fit of the model (R2 = 0.838) and its predictive ability (Q2 = 0.711) were high. Gallic acid and catechin were identified as the active compounds most relevant to the anti-TYR effect of RPE. Subsequently, the activity of gallic acid and catechin were evaluated individually, and when combined in various ratios by using isobologram analysis. The results showed that gallic acid and catechin in the molar ratios of 9:5 and 9:1 exhibited a synergistic inhibition on TYR, with a combination index lower than 0.77, suggesting that certain combinations of these compounds may prove effective for use in cosmetic, pharmaceutical, and food industries.
- Published
- 2023
13. Characterization of molecular interactions between cannabidiol and human plasma proteins (serum albumin and γ-globulin) by surface plasmon resonance, microcalorimetry, and molecular docking
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Chang Liu, Ang Cai, Huifang Li, Ni Deng, Bongsup P. Cho, Navindra P. Seeram, and Hang Ma
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Clinical Biochemistry ,Pharmaceutical Science ,Serum Albumin, Human ,Calorimetry ,Surface Plasmon Resonance ,Analytical Chemistry ,Molecular Docking Simulation ,Drug Discovery ,Cannabidiol ,Humans ,gamma-Globulins ,Spectroscopy ,Serum Albumin ,Protein Binding - Abstract
A cannabidiol (CBD) oral solution (Epidiolex®) has been approved by the United States Food and Drug Administration to treat seizure conditions. However, the biomedical and pharmaceutical applications of CBD are hindered partially due to a limited understanding of CBD's pharmacokinetic behaviors, such as its interactions with plasma proteins. Herein, we investigated the molecular interactions between CBD and two plasma proteins, namely, human serum albumin (HSA) and γ-globulin, using biophysical techniques including surface plasmon resonance (SPR), isothermal titration calorimetry, and differential scanning calorimetry, as well as molecular docking. CBD bound to HSA and γ-globulin in an exothermic manner (enthalpy: -9.3 ×10
- Published
- 2021
14. Application of Structured-light 3D Reconstruction in Virtual Assembly
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Jiaming Feng, Zhan Song, Jing Liu, Wan Youteng, Xiangjia Chen, Qi Wei, Juan Zhao, and Ang Cai
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Reverse engineering ,business.industry ,Computer science ,3D reconstruction ,Solid modeling ,3D modeling ,computer.software_genre ,Field (computer science) ,Structured-light 3D scanner ,Computer graphics (images) ,business ,computer ,Surface reconstruction ,Structured light - Abstract
3D modeling is a time-consuming and laborious work in virtual assembly. How to reconstruct parts with various shapes quickly and accurately is an important topic in the field of reverse engineering. In this paper, a popgun and its special-shaped parts are reconstructed by using a self-developed surface structured light scanning system and a commercial line structured light scanning system, with an accuracy less than 0.1mm. And the virtual assembly of the popgun is completed according to the high-precision 3D solid models.
- Published
- 2021
15. Conformational Insights Into Aminobiphenyl-Modified DNA: Implications for Mutation and Repair
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Ang Cai
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Genetics ,Modified dna ,Chemistry ,Mutation (genetic algorithm) - Published
- 2020
16. DNA base sequence effects on bulky lesion-induced conformational heterogeneity during DNA replication
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Stacey D. Wetmore, Ang Cai, Bongsup P. Cho, Satyakam Patnaik, and Katie A. Wilson
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DNA Replication ,Models, Molecular ,0301 basic medicine ,Population ,Stacking ,Biology ,Lesion ,DNA Adducts ,03 medical and health sciences ,chemistry.chemical_compound ,Structural Biology ,Genetics ,medicine ,Aminobiphenyl Compounds ,education ,Nuclear Magnetic Resonance, Biomolecular ,Conformational isomerism ,Fluorenes ,education.field_of_study ,Base Sequence ,030102 biochemistry & molecular biology ,Hydrogen bond ,DNA replication ,Deoxyguanosine ,DNA ,Surface Plasmon Resonance ,030104 developmental biology ,chemistry ,Duplex (building) ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Carcinogens ,Biophysics ,Nucleic Acid Conformation ,Thermodynamics ,medicine.symptom - Abstract
4-Aminobiphenyl (ABP) and its structure analog 2-aminofluorene (AF) are well-known carcinogens. In the present work, an unusual sequence effect in the 5′-CTTCTG1G2TCCTCATTC-3′ DNA duplex is reported for ABP- and AF-modified G. Specifically, the ABP modification at G1 resulted in a mixture of 67% major groove B-type (B) and 33% stacked (S) conformers, while at the ABP modification at G2 exclusively resulted in the B-conformer. The AF modification at G1 and G2 lead to 25%:75% and 83%:17% B:S population ratios, respectively. These differences in preferred conformation are due to an interplay between stabilizing (hydrogen bonding and stacking that is enhanced by lesion planarity) and destabilizing (solvent exposure) forces at the lesion site. Furthermore, while the B-conformer is a thermodynamic stabilizer and the S-conformer is a destabilizer in duplex settings, the situation is reversed at the single strands/double strands (ss/ds) junction. Specifically, the twisted biphenyl is a better stacker at the ss/ds junction than the coplanar AF. Therefore, the ABP modification leads to a stronger strand binding affinity of the ss/ds junction than the AF modification. Overall, the current work provides conformational insights into the role of sequence and lesion effects in modulating DNA replication.
- Published
- 2018
17. Characterization of Byproducts from Chemical Syntheses of Oligonucleotides Containing 1‑Methyladenine and 3‑Methylcytosine
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Fangyi Chen, James C. Delaney, Ke Bian, Bongsup P. Cho, Alvin C. Bach, Deyu Li, Qi Tang, Fatemeh Akhlaghi, Sravani Adusumalli, and Ang Cai
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0301 basic medicine ,Gel electrophoresis ,Exonuclease ,Chromatography ,biology ,Oligonucleotide ,Chemistry ,General Chemical Engineering ,010401 analytical chemistry ,General Chemistry ,Mass spectrometry ,01 natural sciences ,High-performance liquid chromatography ,Combinatorial chemistry ,Article ,0104 chemical sciences ,lcsh:Chemistry ,03 medical and health sciences ,030104 developmental biology ,lcsh:QD1-999 ,Desorption ,biology.protein - Abstract
Oligonucleotides serve as important tools for biological, chemical, and medical research. The preparation of oligonucleotides through automated solid-phase synthesis is well-established. However, identification of byproducts generated from DNA synthesis, especially from oligonucleotides containing site-specific modifications, is sometimes challenging. Typical high-performance liquid chromatography (HPLC), mass spectrometry (MS), and gel electrophoresis methods alone are not sufficient for characterizing unexpected byproducts, especially for those having identical or very similar molecular weight (MW) to the products. We used a rigorous quality control procedure to characterize byproducts generated during oligonucleotide syntheses: (1) purify oligonucleotides by different HPLC systems; (2) determine exact MW by high-resolution MS; (3) locate modification position by MS/MS or exonuclease digestion with matrix-assisted laser desorption ionization-time of flight analysis; and (4) conduct, where applicable, enzymatic assays. We applied these steps to characterize byproducts in the syntheses of oligonucleotides containing biologically important methyl DNA adducts 1-methyladenine (m1A) and 3-methylcytosine (m3C). In m1A synthesis, we differentiated a regioisomeric byproduct 6-methyladenine, which possesses a MW identical to uncharged m1A. As for m3C, we identified a deamination byproduct 3-methyluracil, which is only 1 Da greater than uncharged m3C in the ∼4900 Da context. The detection of these byproducts would be very challenging if the abovementioned procedure was not adopted.
- Published
- 2017
18. Bose-Fermi Anderson model with SU(2) symmetry: Continuous-time quantum Monte Carlo study
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Ang Cai and Qimiao Si
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Condensed Matter::Quantum Gases ,Physics ,Strongly Correlated Electrons (cond-mat.str-el) ,Quantum Monte Carlo ,FOS: Physical sciences ,02 engineering and technology ,Type (model theory) ,021001 nanoscience & nanotechnology ,Coupling (probability) ,01 natural sciences ,Condensed Matter - Strongly Correlated Electrons ,Quantum mechanics ,0103 physical sciences ,Density of states ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,0210 nano-technology ,Kondo model ,Anderson impurity model ,Special unitary group ,Spin-½ - Abstract
In quantum critical heavy fermion systems, local moments are coupled to both collective spin fluctuations and conduction electrons. As such, the Bose-Fermi Kondo model, describing the coupling of a local moment to both a bosonic and a fermionic bath, has been of extensive interest. For the model in the presence of SU(2) spin rotational symmetry, questions have been raised about its phase diagram. Here we develop a version of continuous-time Quantum Monte Carlo (CT-QMC) method suitable for addressing this issue; this procedure can reach sufficiently low temperatures while preserving the SU(2) symmetry. Using this method for the Bose-Fermi Anderson model, we clarify the renormalization-group fixed points and the phase diagram for the case with a constant fermionic-bath density of states and a power-law bosonic-bath spectral function $\rho_{b}(\omega) \propto \omega^{s}$ ($0, Comment: 13 pages, 15 figures
- Published
- 2019
19. Probing the Effect of Bulky Lesion-Induced Replication Fork Conformational Heterogeneity Using 4-Aminobiphenyl-Modified DNA
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Ang Cai, Bongsup P. Cho, Ke Bian, Qi Tang, Deyu Li, Rachel Carley, and Fangyi Chen
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DNA Replication ,Molecular Conformation ,Oligonucleotides ,Pharmaceutical Science ,conformational heterogeneity ,Article ,Analytical Chemistry ,Nucleobase ,4-aminobiphenyl ,steady state enzyme kinetics ,lcsh:QD241-441 ,03 medical and health sciences ,chemistry.chemical_compound ,lcsh:Organic chemistry ,Drug Discovery ,Aminobiphenyl Compounds ,Physical and Theoretical Chemistry ,surface plasmon resonance (SPR) binding kinetics ,Conformational isomerism ,Carcinogen ,Polymerase ,030304 developmental biology ,Klenow fragment ,0303 health sciences ,biology ,Base Sequence ,030302 biochemistry & molecular biology ,Organic Chemistry ,DNA ,In vitro ,bulky DNA lesion ,3. Good health ,Kinetics ,chemistry ,Chemistry (miscellaneous) ,Nucleic acid ,Biophysics ,biology.protein ,Carcinogens ,Molecular Medicine ,Nucleic Acid Conformation - Abstract
Bulky organic carcinogens are activated in vivo and subsequently react with nucleobases of cellular DNA to produce adducts. Some of these DNA adducts exist in multiple conformations that are slowly interconverted to one another. Different conformations have been implicated in different mutagenic and repair outcomes. However, studies on the conformation-specific inhibition of replication, which is more relevant to cell survival, are scarce, presumably due to the structural dynamics of DNA lesions at the replication fork. It is difficult to capture the exact nature of replication inhibition by existing end-point assays, which usually detect either the ensemble of consequences of all the conformers or the culmination of all cellular behaviors, such as mutagenicity or survival rate. We previously reported very unusual sequence-dependent conformational heterogeneities involving FABP-modified DNA under different sequence contexts (TG1*G2T [67%B:33%S] and TG1G2*T [100%B], G*, N-(2&prime, deoxyguanosin-8-yl)-4&prime, fluoro-4-aminobiphenyl) (Cai et al. Nucleic Acids Research, 46, 6356&ndash, 6370 (2018)). In the present study, we attempted to correlate the in vitro inhibition of polymerase activity to different conformations from a single FABP-modified DNA lesion. We utilized a combination of surface plasmon resonance (SPR) and HPLC-based steady-state kinetics to reveal the differences in terms of binding affinity and inhibition with polymerase between these two conformers (67%B:33%S and 100%B).
- Published
- 2019
20. Keto Acids React with Human Serum Albumin to Form Products Similar to Advanced Glycation Endproducts (SAGEs)
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Weixi Liu, Hang Ma, Xiaodan Tang, Joel A. Dain, Navindra P. Seeram, and Ang Cai
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Biochemistry ,Chemistry ,Genetics ,medicine ,Human serum albumin ,Molecular Biology ,Advanced Glycation Endproducts ,Biotechnology ,medicine.drug - Published
- 2019
21. Dynamical scaling of charge and spin responses at a Kondo destruction quantum critical point
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Stefan Kirchner, Zuodong Yu, Haoyu Hu, Qimiao Si, and Ang Cai
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Physics ,Condensed matter physics ,Strongly Correlated Electrons (cond-mat.str-el) ,General Physics and Astronomy ,FOS: Physical sciences ,Charge (physics) ,01 natural sciences ,Condensed Matter - Strongly Correlated Electrons ,Quantum critical point ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,Kondo model ,Quantum ,Scaling ,Critical exponent ,Lattice model (physics) ,Spin-½ - Abstract
Quantum critical points often arise in metals perched at the border of an antiferromagnetic order. The recent observation of singular and dynamically scaling charge conductivity in an antiferromagnetic quantum critical heavy fermion metal implicates beyond-Landau quantum criticality. Here we study the charge and spin dynamics of a Kondo destruction quantum critical point (QCP), as realized in an SU(2)-symmetric Bose-Fermi Kondo model. We find that the critical exponents and scaling functions of the spin and single-particle responses of the QCP in the SU(2) case are essentially the same as those of the large-N limit, showing that $1/N$ corrections are subleading. Building on this insight, we demonstrate that the charge responses at the Kondo destruction QCP are singular and obey $\omega/T$ scaling. This property persists at the Kondo destruction QCP of the SU(2)-symmetric Kondo lattice model., Comment: 5 pages, 4 figures; updated version, to appear in Phys. Rev. Lett
- Published
- 2019
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22. Formation of Products similar to Advanced Glycation End products (SAGEs) and Binding Affinities between Keto Acids with Human Serum Albumin
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Ang Cai, Hang Ma, Weixi Liu, Joel A. Dain, and Xiaodan Tang
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Biochemistry ,Chemistry ,Glycation ,Genetics ,medicine ,Human serum albumin ,Molecular Biology ,Biotechnology ,medicine.drug ,Binding affinities - Published
- 2020
23. Pomegranate phenolics inhibit type I collagen cross‐linking induced by glycative stress
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Weixi Liu, Navindra P. Seeram, George W. Dombi, Ang Cai, Hang Ma, and Joel A. Dain
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Stress (mechanics) ,Chemistry ,Genetics ,Extracellular ,Biophysics ,musculoskeletal system ,Molecular Biology ,Biochemistry ,Type I collagen ,Biotechnology ,Collagen fibril - Abstract
Collagen is a class of long-lived structural proteins in the extracellular space in various fibrous tissues including skin, tendons, and ligaments. Collagen fibrils are subjected to metabolic stres...
- Published
- 2018
24. Aerobic sludge granulation in a Reverse Flow Baffled Reactor (RFBR) operated in continuous-flow mode for wastewater treatment
- Author
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Balasubramanian Sellamuthu, Jun Li, Ang Cai, Jonathan Perreault, and Libin Ding
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biology ,Chemistry ,Settling time ,Environmental engineering ,Filtration and Separation ,Sequencing batch reactor ,Pulp and paper industry ,biology.organism_classification ,Analytical Chemistry ,Granulation ,Extracellular polymeric substance ,Wastewater ,Aerobic granulation ,Sewage treatment ,Nitrospira - Abstract
A novel Reverse Flow Baffled Reactor (RFBR) was constructed to achieve aerobic granulation in continuous-flow process in order to treat the high quantity of influent wastewater. Municipal wastewater was fed to a 120 L reactor and successfully produced aerobic granules revealing a sludge volume index (SVI) of 33 mL/g. Aerobic granules possessed higher extracellular polymeric substances (EPS) content than seed sludge. The protein/polysaccharide (PN/PS) ratio in the EPS was determined to be about 10:1. Bacterial community analysis revealed that most of the species (Bacteroidetes, Nitrospira and Proteobacteria) found in the seed sludge were preserved in the reactor, except Pedobacter species that was washed out from the reactor. Moreover, different bacterial species were identified in RFBR and SBR (sequencing batch reactor) granules due to different process and operational parameters. Presence of Fe, Ca, Al, Si and P in wastewater were aggregated in granules (acted as a core) and enhanced the granulation. However, the RFBR was operated in periodic feast-famine condition, short settling time, high height/diameter (H/D) ratio, and without sludge return pump, which led to successful granulation in continuous-flow mode.
- Published
- 2015
25. Structure activity related, mechanistic, and modeling studies of gallotannins containing a glucitol-core and α-glucosidase
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Daniel B. Niesen, Wen Tan, Bongsup P. Cho, Ang Cai, Ling Wang, Jun Xu, Qiong Gu, Navindra P. Seeram, and Hang Ma
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chemistry.chemical_classification ,Circular dichroism ,Molecular model ,Chemistry ,Stereochemistry ,General Chemical Engineering ,Isothermal titration calorimetry ,General Chemistry ,Enzyme ,Non-competitive inhibition ,Biochemistry ,medicine ,Binding site ,Acarbose ,medicine.drug ,Fluorescent tag - Abstract
Gallotannins containing a glucitol core, which are only produced by members of the maple (Acer) genus, are more potent α-glucosidase inhibitors than the clinical drug, acarbose. While this activity is influenced by the number of substituents on the glucitol core (e.g. more galloyl groups leads to increased activity), the mechanisms of inhibitory action are not known. Herein, we investigated ligand-enzyme interactions and binding mechanisms of a series of 'glucitol-core containing gallotannins (GCGs)' against the α-glucosidase enzyme. The GCGs included ginnalins A, B and C (containing two, one, and one galloyl/s, respectively), maplexin F (containing 3 galloyls) and maplexin J (containing 4 galloyls). All of the GCGs were noncompetitive inhibitors of α-glucosidase and their interactions with the enzyme were further explored using biophysical and spectroscopic measurements. Thermodynamic parameters (by isothermal titration calorimetry) revealed a 1:1 binding ratio between GCGs and α-glucosidase. The binding regions between the GCGs and α-glucosidase, probed by a fluorescent tag, 1,1'-bis(4-anilino-5-napththalenesulfonic acid, revealed that the GCGs decreased the hydrophobic surface of the enzyme. In addition, circular dichroism analyses showed that the GCGs bind to α-glucosidase and lead to loss of the secondary α-helix structure of the protein. Also, molecular modeling was used to predict the binding site between the GCGs and the α-glucosidase enzyme. This is the first study to evaluate the mechanisms of inhibitory activities of gallotannins containing a glucitol core on α-glucosidase.
- Published
- 2015
26. Anti-glycation and anti-oxidative effects of a phenolic-enriched maple syrup extract and its protective effects on normal human colon cells
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Navindra P. Seeram, Bongsup P. Cho, Yongqiang Liu, Nicholas A. DaSilva, David C. Rowley, Zhengxi Wei, Joel A. Dain, Jiadong Sun, Hang Ma, Weixi Liu, Shelby L. Johnson, Louis J. Kirschenbaum, Zahir A. Shaikh, and Ang Cai
- Subjects
0301 basic medicine ,Glycation End Products, Advanced ,Glycosylation ,Colon ,Acer ,medicine.disease_cause ,Article ,Antioxidants ,Cell Line ,03 medical and health sciences ,food ,Phenols ,Glycation ,Extracellular ,medicine ,Humans ,Bovine serum albumin ,Cytotoxicity ,Cell Proliferation ,chemistry.chemical_classification ,Reactive oxygen species ,030109 nutrition & dietetics ,biology ,Maple syrup ,Chemistry ,Plant Extracts ,General Medicine ,food.food ,Oxidative Stress ,Biochemistry ,Cell culture ,biology.protein ,Reactive Oxygen Species ,Oxidative stress ,Food Science - Abstract
Oxidative stress and free radical generation accelerate the formation of advanced glycation endproducts (AGEs) which are linked to several chronic diseases. Published data suggest that phenolic-rich plant foods, show promise as natural anti-AGEs agents due to their anti-oxidation capacities. A phenolic-enriched maple syrup extract (MSX) has previously been reported to show anti-inflammatory and neuroprotective effects but its anti-AGE effects remain unknown. Therefore, herein, we investigated the anti-glycation and anti-oxidation effects of MSX using biochemical and biophysical methods. MSX (500 μg mL−1) reduced the formation of AGEs by 40% in the bovine serum albumin (BSA)–fructose assay and by 30% in the BSA–methylglyoxal (MGO) assay. MSX also inhibited the formation of crosslinks typically seen in the late stage of glycation. Circular dichroism and differential scanning calorimeter analyses demonstrated that MSX maintained the structure of BSA during glycation. In the anti-oxidant assays, MSX (61.7 μg mL−1) scavenged 50% of free radicals (DPPH assay) and reduced free radical generation by 20% during the glycation process (electron paramagnetic resonance time scan). In addition, the intracellular levels of hydrogen peroxide induced reactive oxygen species were reduced by 27–58% with MSX (50–200 μg mL−1) in normal/non-tumorigenic human colon CCD-18Co cells. Moreover, in AGEs and MGO challenged CCD-18Co cells, higher cellular viabilities and rapid extracellular signal-regulated kinase (ERK) phosphorylation were observed in MSX treated cells, indicating its protective effects against AGEs-induced cytotoxicity. Overall, this study supports the biological effects of MSX, and warrants further investigation of its potential as a dietary agent against diseases mediated by oxidative stress and inflammation.
- Published
- 2017
27. Jasmine (Jasminum officinale L. var. grandiflorum) Flower Extracts Inhibit the Formation of Methylglyoxal Induced Advanced Glycation Endproducts
- Author
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Dongli Li, Joel A. Dain, Hang Ma, Xiaodan Tang, Navindra P. Seeram, and Ang Cai
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chemistry.chemical_compound ,chemistry ,Traditional medicine ,biology ,Methylglyoxal ,Genetics ,Jasminum officinale ,biology.organism_classification ,Molecular Biology ,Biochemistry ,Advanced Glycation Endproducts ,Biotechnology - Published
- 2019
28. DNA-binding studies of the natural β-carboline eudistomin U
- Author
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Seann P. Mulcahy, Patrick M. Tate, Ang Cai, Bongsup P. Cho, and Jennifer M. Giulietti
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Circular dichroism ,Clinical Biochemistry ,Intercalation (chemistry) ,Pharmaceutical Science ,010402 general chemistry ,Ring (chemistry) ,01 natural sciences ,Biochemistry ,Article ,chemistry.chemical_compound ,Structure-Activity Relationship ,Ultraviolet visible spectroscopy ,Drug Discovery ,Pyridine ,Molecule ,Molecular Biology ,Indole test ,Calorimetry, Differential Scanning ,010405 organic chemistry ,Circular Dichroism ,Organic Chemistry ,DNA ,0104 chemical sciences ,Crystallography ,chemistry ,Molecular Medicine ,Spectrophotometry, Ultraviolet ,Carbolines - Abstract
Eudistomin U is a member of the β-carboline class of heterocyclic amine-containing molecules that are capable of binding to DNA. The structure of eudistomin U is unique since it contains an indole ring at the 1-position of the pyridine ring. While simple β-carbolines are reported to intercalate DNA, an examination of the mode of binding of eudistomin U has been lacking. We report preliminary spectroscopic (UV–Vis, thermal denaturation, CD) and calorimetric (DSC) data on the binding of eudistomin U to DNA, which suggest that eudistomin U binds weakly according to a mechanism that is more complicated than other members of its class.
- Published
- 2016
29. Structure Activity Related, Mechanistic, and Modeling Studies of Gallotannins containing a Glucitol-Core and
- Author
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Hang, Ma, Ling, Wang, Daniel B, Niesen, Ang, Cai, Bongsup P, Cho, Wen, Tan, Qiong, Gu, Jun, Xu, and Navindra P, Seeram
- Subjects
Article - Abstract
Gallotannins containing a glucitol core, which are only produced by members of the maple (Acer) genus, are more potent α-glucosidase inhibitors than the clinical drug, acarbose. While this activity is influenced by the number of substituents on the glucitol core (e.g. more galloyl groups leads to increased activity), the mechanisms of inhibitory action are not known. Herein, we investigated ligand-enzyme interactions and binding mechanisms of a series of ‘glucitol-core containing gallotannins (GCGs)’ against the α-glucosidase enzyme. The GCGs included ginnalins A, B and C (containing two, one, and one galloyl/s, respectively), maplexin F (containing 3 galloyls) and maplexin J (containing 4 galloyls). All of the GCGs were noncompetitive inhibitors of α-glucosidase and their interactions with the enzyme were further explored using biophysical and spectroscopic measurements. Thermodynamic parameters (by isothermal titration calorimetry) revealed a 1:1 binding ratio between GCGs and α-glucosidase. The binding regions between the GCGs and α-glucosidase, probed by a fluorescent tag, 1,1′-bis(4-anilino-5-napththalenesulfonic acid, revealed that the GCGs decreased the hydrophobic surface of the enzyme. In addition, circular dichroism analyses showed that the GCGs bind to α-glucosidase and lead to loss of the secondary α-helix structure of the protein. Also, molecular modeling was used to predict the binding site between the GCGs and the α-glucosidase enzyme. This is the first study to evaluate the mechanisms of inhibitory activities of gallotannins containing a glucitol core on α-glucosidase.
- Published
- 2016
30. Critical local moment fluctuations and enhanced pairing correlations in a cluster Anderson model
- Author
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Kevin Ingersent, Jedediah Pixley, Qimiao Si, and Ang Cai
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Physics ,Superconductivity ,Condensed matter physics ,Strongly Correlated Electrons (cond-mat.str-el) ,Quantum Monte Carlo ,FOS: Physical sciences ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Moment (mathematics) ,Condensed Matter - Strongly Correlated Electrons ,Quantum mechanics ,Pairing ,Condensed Matter::Superconductivity ,0103 physical sciences ,Density of states ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,0210 nano-technology ,Pseudogap ,Quantum ,Anderson impurity model - Abstract
The appearance of unconventional superconductivity near heavy-fermion quantum critical points (QCPs) motivates investigation of pairing correlations close to a ``beyond Landau'' Kondo-destruction QCP. We focus on a two-Anderson-impurity cluster in which Kondo destruction is induced by a pseudogap in the conduction-electron density of states. Analysis via continuous-time quantum Monte-Carlo and the numerical renormalization group reveals a previously unstudied QCP that both displays the critical-local moment fluctuations characteristic of Kondo destruction and leads to a strongly enhanced singlet-pairing susceptibility. Our results provide new insights into the mechanism for superconductivity in quantum critical metals., Comment: 9 pages, 11 figures, published version
- Published
- 2016
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31. Cluster extended dynamical mean-field approach and unconventional superconductivity
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Ang Cai, Jedediah Pixley, and Qimiao Si
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Quantum phase transition ,Superconductivity ,Physics ,Strongly Correlated Electrons (cond-mat.str-el) ,Dynamical systems theory ,FOS: Physical sciences ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Condensed Matter - Strongly Correlated Electrons ,Mean field theory ,0103 physical sciences ,Cluster (physics) ,Strongly correlated material ,Statistical physics ,010306 general physics ,0210 nano-technology ,Anderson impurity model ,Equations for a falling body - Abstract
The extended dynamical mean field theory has played an important role in the study of quantum phase transitions in heavy fermion systems. In order to incorporate the physics of unconventional superconductivity, we develop a cluster version of the extended dynamical mean field theory. In this approach, we show how magnetic order and superconductivity develop as a result of inter-site spin exchange interactions, and analyze in some detail the form of correlation functions. We also discuss the methods that can be used to solve the dynamical equations associated with this approach. Finally, we consider different settings in which our approach can be applied, including the periodic Anderson model for heavy fermion systems., 15 pages, 2 figures, Replaced with published version
- Published
- 2015
32. Structure Analysis of Aerobic Granule from a Sequencing Batch Reactor for Organic Matter and Ammonia Nitrogen Removal
- Author
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Ang Cai, Yongjiong Ni, Jun Li, Danjun Wang, and Chao Chen
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Health, Toxicology and Mutagenesis ,aerobic granules ,Heterotroph ,lcsh:Medicine ,Sequencing batch reactor ,Article ,law.invention ,Microbiology ,Bioreactors ,Settling ,law ,Ammonium Compounds ,Bioreactor ,Microtome ,Organic matter ,structure ,Autotroph ,Organic Chemicals ,Biological Oxygen Demand Analysis ,Waste Products ,chemistry.chemical_classification ,Microscopy, Confocal ,freezing microtome ,lcsh:R ,Granule (cell biology) ,Public Health, Environmental and Occupational Health ,Aerobiosis ,microelectrode ,chemistry ,Chemical engineering ,dissolved oxygen ,Microelectrodes ,CLSM - Abstract
Aerobic granules were cultivated in a sequencing batch reactor (SBR). COD and ammonia nitrogen removal rate were 94% and 99%, respectively. The diameter, settling velocity and SVI10 of granules ranged from 2 to 5 mm, 80 to 110 m/h and about 40 mL/g, respectively. Freezing microtome images, DO concentration profiles by microelectrode, distribution of bacteria and EPS by confocal laser scanning microscopy (CLSM) show that the aerobic granules have a three-layer structure. Each layer has different thickness, character, bacteria, and DO transfer rate. A hypothesis for granule structure is proposed: the first layer, the surface of the granule, is composed mostly of heterotrophic organisms for organic matter removal, with a thickness range from 150 to 350 μm; the second layer, mostly composed of autotrophic organisms for ammonia nitrogen removal, with a thickness range from 250 to 450 μm; the third layer, located in the core of the granule, has mostly an inorganic composition and contains pores and channels.
- Published
- 2014
- Full Text
- View/download PDF
33. Aerobic sludge granulation in a full-scale sequencing batch reactor
- Author
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Jun Li, Ang Cai, Harald Horn, Guo-Xian Huang, and Libin Ding
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Article Subject ,General Immunology and Microbiology ,Bacteria ,Sewage ,Chemistry ,lcsh:R ,lcsh:Medicine ,Sequencing batch reactor ,General Medicine ,Pulp and paper industry ,Waste Disposal, Fluid ,General Biochemistry, Genetics and Molecular Biology ,Aerobiosis ,Microbiology ,Water Purification ,Granulation ,Activated sludge ,Bioreactors ,Wastewater ,Bioreactor ,Aerobic granulation ,Sewage treatment ,Waste disposal ,Research Article - Abstract
Aerobic granulation of activated sludge was successfully achieved in a full-scale sequencing batch reactor (SBR) with 50,000 m3 d−1for treating a town’s wastewater. After operation for 337 days, in this full-scale SBR, aerobic granules with an average SVI30of 47.1 mL g−1, diameter of 0.5 mm, and settling velocity of 42 m h−1were obtained. Compared to an anaerobic/oxic plug flow (A/O) reactor and an oxidation ditch (OD) being operated in this wastewater treatment plant, the sludge from full-scale SBR has more compact structure and excellent settling ability. Denaturing gradient gel electrophoresis (DGGE) analysis indicated thatFlavobacteriumsp., uncultured beta proteobacterium, unculturedAquabacteriumsp., and unculturedLeptothrixsp. were just dominant in SBR, whereas uncultured bacteroidetes were only found in A/O and OD. Three kinds of sludge had a high content of protein in extracellular polymeric substances (EPS). X-ray fluorescence (XRF) analysis revealed that metal ions and some inorganics from raw wastewater precipitated in sludge acted as core to enhance granulation. Raw wastewater characteristics had a positive effect on the granule formation, but the SBR mode operating with periodic feast-famine, shorter settling time, and no return sludge pump played a crucial role in aerobic sludge granulation.
- Published
- 2014
34. [Comparative research on anticancer activity between fresh and processed Gekko subpalmatus]
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Xin-Nan, Hou, Di, Geng, Ang, Cai, and Chun-Mei, Wang
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Carcinoma, Hepatocellular ,Body Weight ,Antineoplastic Agents ,Lizards ,Thymus Gland ,Inhibitory Concentration 50 ,Mice ,Random Allocation ,Liver Neoplasms, Experimental ,Cell Line, Tumor ,Materia Medica ,Animals ,Technology, Pharmaceutical ,Female ,Powders ,Neoplasm Transplantation ,Spleen ,Cell Proliferation - Abstract
To investigate the anticancer activity of fresh and processed Gekko subpalmatus on mouse H22 hepatocellular in vitro and in vivo comparatively.In vitro, the effect of different concentration fresh and processed Gekko subpalmatus on proliferation of H22 cells were measured by Monotetrazolium (MTT) assay. Mouse transplanted hepatoma H22 model was established to evaluate the anti-tumor activity of fresh and processed Gekko subpalmatus. Rate of restraining tumor, index of thymus and spleen were calculated after 14 days' treatment.In vitro, fresh and processed Gekko subpalmatus inhibited proliferation of H22 cells and the IC50 values were 8.53 mg/ml and 6.42 mg/ml. In vivo, the restraining tumor rates of fresh and processed Gekko subpalmatus each at the highest doses were 53.0% and 47.4%. Compared with those in CTX group, the indexes of thymus and spleen were markedly increased after all processed group's treatment. The indexes of the thymus increased after low dose fresh group's treatment. The indexes of the spleen of the moderate and high dose groups were higher than CTX group.Fresh and processed Gekko subpalmatus show significant anti-tumor activity in hepatoma cells both in vitro and in vivo. The processed samples can improve the immunity of the mouse.
- Published
- 2008
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