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










Publication year range
1.
J Med Virol ; 96(4): e29611, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38639305

ABSTRACT

While micronutrients are crucial for immune function, their impact on humoral responses to inactivated COVID-19 vaccination remains unclear. We investigated the associations between seven key micronutrients and antibody responses in 44 healthy adults with two doses of an inactivated COVID-19 vaccine. Blood samples were collected pre-vaccination and 28 days post-booster. We measured circulating minerals (iron, zinc, copper, and selenium) and vitamins (A, D, and E) concentrations alongside antibody responses and assessed their associations using linear regression analyses. Our analysis revealed inverse associations between blood iron and zinc concentrations and anti-SARS-CoV-2 IgM antibody binding affinity (AUC for iron: ß = -258.21, p < 0.0001; zinc: ß = -17.25, p = 0.0004). Notably, antibody quality presented complex relationships. Blood selenium was positively associated (ß = 18.61, p = 0.0030), while copper/selenium ratio was inversely associated (ß = -1.36, p = 0.0055) with the neutralizing ability against SARS-CoV-2 virus at a 1:10 plasma dilution. There was no significant association between circulating micronutrient concentrations and anti-SARS-CoV-2 IgG binding affinity. These findings suggest that circulating iron, zinc, and selenium concentrations and copper/selenium ratio, may serve as potential biomarkers for both quantity (binding affinity) and quality (neutralization) of humoral responses after inactivated COVID-19 vaccination. Furthermore, they hint at the potential of pre-vaccination dietary interventions, such as selenium supplementation, to improve vaccine efficacy. However, larger, diverse studies are needed to validate these findings. This research advances the understanding of the impact of micronutrients on vaccine response, offering the potential for personalized vaccination strategies.


Subject(s)
COVID-19 , Selenium , Trace Elements , Adult , Humans , Micronutrients , COVID-19 Vaccines , Copper , COVID-19/prevention & control , SARS-CoV-2 , Zinc , Iron , Vaccination , Antibodies, Viral , Antibodies, Neutralizing
2.
Signal Transduct Target Ther ; 9(1): 114, 2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38678055

ABSTRACT

Developing a mucosal vaccine against SARS-CoV-2 is critical for combatting the epidemic. Here, we investigated long-term immune responses and protection against SARS-CoV-2 for the intranasal vaccination of a triple receptor-binding domain (RBD) scaffold protein (3R-NC) adjuvanted with a flagellin protein (KFD) (3R-NC + KFDi.n). In mice, the vaccination elicited RBD-specific broad-neutralizing antibody responses in both serum and mucosal sites sustained at high level over a year. This long-lasting humoral immunity was correlated with the presence of long-lived RBD-specific IgG- and IgA-producing plasma cells, alongside the Th17 and Tfh17-biased T-cell responses driven by the KFD adjuvant. Based upon these preclinical findings, an open labeled clinical trial was conducted in individuals who had been primed with the inactivated SARS-CoV-2 (IAV) vaccine. With a favorable safety profile, the 3R-NC + KFDi.n boost elicited enduring broad-neutralizing IgG in plasma and IgA in salivary secretions. To meet the challenge of frequently emerged variants, we further designed an updated triple-RBD scaffold protein with mutated RBD combinations, which can induce adaptable antibody responses to neutralize the newly emerging variants, including JN.1. Our findings highlight the potential of the KFD-adjuvanted triple-RBD scaffold protein is a promising prototype for the development of a mucosal vaccine against SARS-CoV-2 infection.


Subject(s)
Administration, Intranasal , Antibodies, Neutralizing , Antibodies, Viral , COVID-19 Vaccines , COVID-19 , Flagellin , SARS-CoV-2 , SARS-CoV-2/immunology , Humans , Flagellin/immunology , Flagellin/genetics , Flagellin/administration & dosage , COVID-19/prevention & control , COVID-19/immunology , Animals , Mice , COVID-19 Vaccines/immunology , COVID-19 Vaccines/administration & dosage , Antibodies, Neutralizing/immunology , Female , Antibodies, Viral/immunology , Vaccination , Male , Adult , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/genetics , Immunoglobulin G/immunology , Immunoglobulin G/blood , Immunoglobulin A/immunology , Middle Aged
3.
Vaccine ; 41(52): 7641-7646, 2023 Dec 18.
Article in English | MEDLINE | ID: mdl-38016845

ABSTRACT

A third dose of inactivated virus vaccine (IVV) boosts neutralizing antibodies, reducing SARS-CoV-2 transmission rate and COVID-19 severity. However, the impact of RBD-elicited antibodies and their neutralizing activity by the boost of IVV is unknown. We investigated the impact of IVV's boost shot on RBD-elicited antibodies and their neutralizing activity in 18 subjects receiving the second and third IVV doses. Using an RBD antibodies depletion assay, we assessed the neutralizing activity of RBD-elicited antibodies. After the second dose, RBD-antigen elicitation accounted for ∼60% of neutralizing activity, which increased to 82% after the IVV boost against ancestral SARS-CoV-2. Depleting class 3 and class 4-specific antibodies with the Beta-RBD protein revealed that NAbs targeting RBD class 1 and class 2 subdomains increased from 57% to 75% post-boost. These findings highlight the significant enhancement of RBD-specific antibodies, especially against RBD class 1 and class 2, with IVV booster doses. Our study offers valuable insights for optimizing COVID-19 vaccine strategies.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Epitopes , Vaccines, Inactivated , COVID-19 Vaccines , COVID-19/prevention & control , Antibodies , Antibodies, Blocking , Antibodies, Neutralizing , Antibodies, Viral
4.
PLoS Pathog ; 19(5): e1011123, 2023 05.
Article in English | MEDLINE | ID: mdl-37196033

ABSTRACT

SARS-CoV Spike (S) protein shares considerable homology with SARS-CoV-2 S, especially in the conserved S2 subunit (S2). S protein mediates coronavirus receptor binding and membrane fusion, and the latter activity can greatly influence coronavirus infection. We observed that SARS-CoV S is less effective in inducing membrane fusion compared with SARS-CoV-2 S. We identify that S813T mutation is sufficient in S2 interfering with the cleavage of SARS-CoV-2 S by TMPRSS2, reducing spike fusogenicity and pseudoparticle entry. Conversely, the mutation of T813S in SARS-CoV S increased fusion ability and viral replication. Our data suggested that residue 813 in the S was critical for the proteolytic activation, and the change from threonine to serine at 813 position might be an evolutionary feature adopted by SARS-2-related viruses. This finding deepened the understanding of Spike fusogenicity and could provide a new perspective for exploring Sarbecovirus' evolution.


Subject(s)
COVID-19 , Severe acute respiratory syndrome-related coronavirus , Humans , Severe acute respiratory syndrome-related coronavirus/genetics , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Proteolysis , Virus Replication , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism
5.
Arch Anim Breed ; 66(1): 131-139, 2023.
Article in English | MEDLINE | ID: mdl-37124941

ABSTRACT

We explore the relationship between the melanophilin (MLPH) gene and quail plumage color and provide a reference for subsequent quail plumage color breeding. In this experiment, real-time quantitative PCR (RT-qPCR) technology was used to analyze the relative mRNA expression levels of Korean quail (maroon) and Beijing white quail embryos at different developmental stages. Two single-nucleotide polymorphisms (SNPs) in the MLPH gene were screened based on the RNA-sequencing (RNA-Seq) data of skin tissues of Korean quail and Beijing white quail during the embryonic stage. Kompetitive allele-specific PCR (KASP) technology was used for genotyping in the resource population, and correlation analysis was carried out with the plumage color traits of quail. Finally, bioinformatics was used to predict the effects of these two SNPs on the structure and function of the encoded protein. The results showed that the expression level of the MLPH gene during embryonic development of Beijing white quail was significantly higher than that of Korean quail ( P < 0.01 ). The frequency distribution of the three genotypes (CC, CA and AA) of the Beijing white quail at the c.1807C  >  A mutation site was significantly different from that of the Korean quail ( P < 0.01 ). The frequency distribution of the three genotypes (GG, GA and AA) of the Beijing white quail at the c.2129G  >  A mutation site was significantly different from that of the Korean quail ( P < 0.01 ). And there was a significant correlation between the c.1807C  >  A mutation site and the white plumage phenotype. Bioinformatics showed that SNP1 (c.1807C  >  A) was a neutral mutation and that SNP2 (c.2129G  >  A) was a deleterious mutation. The prediction of protein conservation showed that the mutation sites of coding proteins R603S and G710D caused by SNP1 (c.1807C  >  A) and SNP2 (c.2129G  >  A) were highly conserved.

6.
Mol Nutr Food Res ; 67(4): e2200481, 2023 02.
Article in English | MEDLINE | ID: mdl-36564930

ABSTRACT

SCOPE: Adequate intake of whole grain foods is beneficial to type 2 diabetes mellitus (T2DM). Whether the preventive effects are related with metabolism of branched-chain amino acids (BCAAs) is unclear. The study aims to evaluate the effects of germinated brown rice (GBR) intervention on BCAAs metabolism in T2DM patients. METHODS AND RESULTS: In this randomized controlled trial, subjects with T2DM are instructed to consume 100 g day-1 GBR (GBR group, n=42) or equal staple food (Control group, n=25) for 3 months. Food frequency questionnaires (FFQ) and serum samples are collected before and after the intervention. In the GBR group, fasting blood glucose (FBG), fasting insulin (FINS), and serum BCAAs are decreased, and islet function is improved (p<0.05). Logistic regression analysis showed that FBG (odds ratios [OR]: 1.55, 95% confidence interval [CI]: 1.01-1.84) and energy (OR: 1.21, 95% CI: 1.09-1.30) are positively associated with serum total BCAAs level, while FINS is negatively associated (OR: 0.20, 95% CI: 0.04-0.88). Simultaneously, the key enzymes of BCAAs decomposition, which promotes glycolysis by activating pyruvate dehydrogenase (PDH), are significantly increased. CONCLUSION: GBR improves the indicators of T2DM patients, and the underlying mechanisms include improving insulin resistance and accelerating catabolism of BCAAs.


Subject(s)
Diabetes Mellitus, Type 2 , Insulin Resistance , Oryza , Humans , Amino Acids, Branched-Chain , Diabetes Mellitus, Type 2/metabolism , Insulin
7.
J Agric Food Chem ; 70(48): 15126-15133, 2022 Dec 07.
Article in English | MEDLINE | ID: mdl-36420856

ABSTRACT

Although sulforaphane (SFN) is reported to ameliorate the excessive accumulation of lipid droplets (LDs) in hepatocytes, its underlying mechanism remains unclear. This paper aims to investigate how SFN induces hepatic LD degradation via activating macroautophagy. High-fat diet and free fatty acids (FFAs) were used to induce excessive LD formation in hepatocytes in vivo and in vitro, respectively. SFN-induced macroautophagy was shown by the increased LC3 protein expression both (1.32 ± 0.18) in vivo and (2.43 ± 0.22) in vitro. The mRNA levels of Lc3 (1.99 ± 0.16), Atg4 (2.12 ± 0.23), Ulk1 (1.19 ± 0.12), Atg7 (1.25 ± 0.11), and Atg5 (0.81 ± 0.1) genes were elevated by SFN. SFN individually enhanced the localization of LC3 (0.41 ± 0.15), LAMP1 (0.66 ± 0.14), ATG7 (0.26 ± 0.08), and ATG5 (0.38 ± 0.09) with LDs, indicating the occurrence of lipophagy. In the components of LDs isolated from SFN treatment, the expressions of LC3, ATG7, and ATG5 protein were largely increased both in vivo and in vitro. LDs were visualized in autophagosomes which confirmed that the lipophagy was triggered by SFN. Moreover, SFN treatment improved the profile of FFAs which was characterized by increasing the FFAs in liver (total FFA: 261.51 ± 39.58 µM/g) and serum (total FFA: 967.59 ± 239.18 nM/mL). After silencing the nrf2 gene, ATG7 and ATG5 protein expressions were decreased and attenuated this induction by SFN. Nrf2 gene silencing inversely increased TG contents. In summary, SFN enhanced the LD degradation via stimulating lipophagy in a Nrf2-dependent manner.


Subject(s)
Lipid Metabolism , Liver , Autophagy-Related Protein 5/genetics
8.
Cell Mol Immunol ; 19(11): 1279-1289, 2022 11.
Article in English | MEDLINE | ID: mdl-36220993

ABSTRACT

The rapid mutation and spread of SARS-CoV-2 variants urge the development of effective mucosal vaccines to provide broad-spectrum protection against the initial infection and thereby curb the transmission potential. Here, we designed a chimeric triple-RBD immunogen, 3Ro-NC, harboring one Delta RBD and two Omicron RBDs within a novel protein scaffold. 3Ro-NC elicits potent and broad RBD-specific neutralizing immunity against SARS-CoV-2 variants of concern. Notably, intranasal immunization with 3Ro-NC plus the mucosal adjuvant KFD (3Ro-NC + KFDi.n) elicits coordinated mucosal IgA and higher neutralizing antibody specificity (closer antigenic distance) against the Omicron variant. In Omicron-challenged human ACE2 transgenic mice, 3Ro-NC + KFDi.n immunization significantly reduces the tissue pathology in the lung and lowers the viral RNA copy numbers in both the lung (85.7-fold) and the nasal turbinate (13.6-fold). Nasal virologic control is highly correlated with RBD-specific secretory IgA antibodies. Our data show that 3Ro-NC plus KFD is a promising mucosal vaccine candidate for protection against SARS-CoV-2 Omicron infection, pathology and transmission potential.


Subject(s)
COVID-19 Vaccines , COVID-19 , Animals , Humans , Mice , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , COVID-19 Vaccines/immunology , Immunity, Mucosal , Administration, Intranasal
9.
Antiviral Res ; 205: 105383, 2022 09.
Article in English | MEDLINE | ID: mdl-35917969

ABSTRACT

The frequently emerging SARS-CoV-2 variants have weakened the effectiveness of existing COVID-19 vaccines and neutralizing antibody therapy. Nevertheless, the infections of SARS-CoV-2 variants still depend on angiotensin-converting enzyme 2 (ACE2) receptor-mediated cell entry, and thus the soluble human ACE2 (shACE2) is a potential decoy for broadly blocking SARS-CoV-2 variants. In this study, we firstly generated the recombinant AAVrh10-vectored shACE2 constructs, a kind of adeno-associated virus (AAV) serotype with pulmonary tissue tropism, and then validated its inhibition capacity against SARS-CoV-2 infection. To further optimize the minimized ACE2 functional domain candidates, a comprehensive analysis was performed to clarify the interactions between the ACE2 orthologs from various species and the receptor binding domain (RBD) of SARS-CoV-2 spike (S) protein. Based on the key interface amino acids, we designed a series of truncated ACE2 orthologs, and then assessed their potential affinity to bind to SARS-CoV-2 variants RBD in silico. Of note, we found that the 24-83aa fragment of dog ACE2 (dACE224-83) had a higher affinity to the RBD of SARS-CoV-2 variants than that of human ACE2. Importantly, AAVrh10-vectored shACE2 or dACE224-83 constructs exhibited a broadly blockage breadth against SARS-CoV-2 prototype and variants in vitro and ex vivo. Collectively, these data highlighted a promising therapeutic strategy against SARS-CoV-2 variants.


Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/therapy , COVID-19 Vaccines , Dogs , Humans , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , Protein Binding , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus , Virus Internalization
10.
Emerg Microbes Infect ; 11(1): 2007-2020, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35899581

ABSTRACT

Dynamic changes of the paired heavy and light chain B cell receptor (BCR) repertoire provide an essential insight into understanding the humoral immune response post-SARS-CoV-2 infection and vaccination. However, differences between the endogenous paired BCR repertoire kinetics in SARS-CoV-2 infection and previously recovered/naïve subjects treated with the inactivated vaccine remain largely unknown. We performed single-cell V(D)J sequencing of B cells from six healthy donors with three shots of inactivated SARS-CoV-2 vaccine (BBIBP-CorV), five people who received the BBIBP-CorV vaccine after having recovered from COVID-19, five unvaccinated COVID-19 recovered patients and then integrated with public data of B cells from four SARS-CoV-2-infected subjects. We discovered that BCR variable (V) genes were more prominently used in the SARS-CoV-2 exposed groups (both in the group with active infection and in the group that had recovered) than in the vaccinated groups. The VH gene that expanded the most after SARS-CoV-2 infection was IGHV3-33, while IGHV3-23 in the vaccinated groups. SARS-CoV-2-infected group enhanced more BCR clonal expansion and somatic hypermutation than the vaccinated healthy group. A small proportion of public clonotypes were shared between the SARS-CoV-2 infected, vaccinated healthy, and recovered groups. Moreover, several public antibodies had been identified against SARS-CoV-2 spike protein. We comprehensively characterize the paired heavy and light chain BCR repertoire from SARS-CoV-2 infection to vaccination, providing further guidance for the development of the next-generation precision vaccine.


Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Receptors, Antigen, B-Cell/genetics , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus , Vaccination
11.
J Sep Sci ; 45(3): 739-751, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34865311

ABSTRACT

Trace amounts of components in traditional Chinese medicine are considered pharmacological active substances used for treating many serious diseases. However, purifying all the trace substances and making clear their structures are not easy. In this context, high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry based molecular networking was applied to investigate the chemical constituents of the roots of Aconitum kusnezoffii Reichb., which led to the identification of 33 nodes in different groups (N1-N33). Based on the excremental fragmentation pathway of known diterpenoid alkaloids (1-9) and comparisons of characteristic ions and characteristic loss of analogs in literature, the structures of unknown ions were deduced. This work lays a foundation for the evaluation of the clinical basis and mechanism of traditional Chinese medicine from the aspects of chemistry. In this paper, the method speculation of unknown natural products by means of molecular network method is expected to be applied in the discovery and change law of relevant active components in clinical pharmacology and the change of complex systems caused by trace active compounds.


Subject(s)
Aconitum , Alkaloids , Diterpenes , Drugs, Chinese Herbal , Aconitum/chemistry , Alkaloids/analysis , Chromatography, High Pressure Liquid , Chromatography, Liquid , Diterpenes/analysis , Drugs, Chinese Herbal/chemistry , Tandem Mass Spectrometry
12.
Opt Express ; 29(16): 25663-25674, 2021 Aug 02.
Article in English | MEDLINE | ID: mdl-34614891

ABSTRACT

Rare-earth-doped on-chip microlasers are of great significance in both fundamental research and engineering. To the best of our knowledge, this is the first report of Yb3+-doped and Er3+/Yb3+-codoped on-chip microsphere lasers fabricated via sol-gel synthesis. Laser emissions were observed in a band around 1040 nm in both Yb3+-doped and Er3+/Yb3+-codoped resonators pumped at 980 nm and had measured ultralow thresholds of 5.2 µW and 0.6 µW, respectively. Both single-mode and multi-mode emissions were recorded around 1040 nm in these lasers. Single-mode and two-mode emissions were obtained at 1550 nm in the Er3+/Yb3+-codoped lasers when pumped at 980 nm and 1460 nm, respectively. Furthermore, quality factors induced by different loss mechanisms in the microsphere lasers are theoretically estimated. These resonators are expected to contribute to the high-density integration of on-chip silica-based microlasers.

13.
Zhongguo Zhong Yao Za Zhi ; 46(12): 3066-3075, 2021 Jun.
Article in Chinese | MEDLINE | ID: mdl-34467697

ABSTRACT

Lycii Cortex, the dry root bark of Lycium barbarum(Solanaceae), is rich in chemical compositions with unique structures, such as organic acids, lipids, alkaloids, cyclopeptides and other components, and plays an important role in traditional Chinese medicine. It has the effect of cooling blood and removing steam, clearing lung and reducing fire. It is mainly used in the treatment of hot flashes due to Yin deficiency, hectic fever with night sweat, cough, hemoptysis and internal heat and diabetes. Modern pharmacological studies have shown that the crude extract or monomer of Lycii Cortex has a variety of pharmacological activities, such as hypoglycemic, hypotensive, hypolipidemic, antibacterial, and antiviral effects. In this paper, the chemical constituents and pharmacological effects of Cortex Lycii were reviewed in order to further clarify its effective substances, promote the development of medical undertakings, and ensure the "Healthy China" plan.


Subject(s)
Lycium , China , Hypoglycemic Agents , Medicine, Chinese Traditional , Plant Bark
14.
Zhongguo Zhong Yao Za Zhi ; 46(5): 1155-1159, 2021 Mar.
Article in Chinese | MEDLINE | ID: mdl-33787110

ABSTRACT

Chemical constituents of water extracts of Asplenium ruprechtii were investigated. Five compounds were isolated by silica gel, Sephadex LH-20 gel column chromatographies and preparative HPLC, and their structures were identified by various spectral analyses as aspleniumside G(1), trans-p-coumaric acid(2), trans-p-coumaric acid 4-O-ß-D-glucoside(3), cis-p-coumaric acid 4-O-ß-D-glucoside(4), and(E)-ferulic acid-4-O-ß-D-glucoside(5). Among them, compound 1 is a new 9,19-cycloartane glycoside.


Subject(s)
Glycosides , Triterpenes , Chromatography, High Pressure Liquid , Glucosides
15.
Chem Biodivers ; 17(12): e2000500, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33078897

ABSTRACT

We characterized a new cycloartane glycoside, herein known as aspleniumside F (1), along with five known compounds as kaempferol-3-O-[(6-O-(E)-feruloyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-galacopyranoside (2), quercetin-3-O-[(6-O-(E)-feruloyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-glucopyranoside (3), kaempferol-3-O-[(6-O-(E)-caffeoyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-glucopyranoside (4), kaempferol-3-O-[(6-O-(E)-caffeoyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-glucopyranosyl-7-O-ß-D-glucopyranoside (5), and kaempferol-3-O-[(6-O-p-coumaroyl)-ß-D-glucopyranosyl]-(1→2)-ß-D-glucopyranosyl-7-O-ß-D-glucopyranoside (6), from Asplenium ruprechtii Sa. Kurata, a folk medicine widely used to treat Thromboangiitis obliterans in China, Japan, and Korea. Based on spectroscopic, mainly 1D-, 2D-NMR and (+)-HR-ESI-MS, analyses as well as through comparisons with previous reports, its chemical structure was determined as 3ß,24,30-tri-ß-D-glucopyranosyl-23,25-dihydroxycycloartane (= (23R,24R)-3ß,24-bis-(ß-D-glucopyranosyloxy)-23,25-dihydroxy-9ß-9,19-cyclolanostan-29-yl ß-D-glucopyranoside). According to the 1 H coupling constant of anomeric protons and co-TLC of the acid hydrolysate with D-glucose, all three glycoside groups in 1 were revealed as ß-D-glucopyranosyl. Furthermore, SOD-like antioxidant activity evaluation via IC50 of 12.43, 6.78, 9.12, 6.94 and 4.85 µM revealed that compounds 2-6 had bioactivity.


Subject(s)
Glycosides/chemistry , Tracheophyta/chemistry , Triterpenes/chemistry , Carbon-13 Magnetic Resonance Spectroscopy , Molecular Structure , Proton Magnetic Resonance Spectroscopy
16.
Environ Sci Pollut Res Int ; 27(13): 15337-15349, 2020 May.
Article in English | MEDLINE | ID: mdl-32077017

ABSTRACT

A novel catalyst of Fe-Mn/AC was prepared and used as a heterogeneous catalyst to activate O3/Na2S2O8 for landfill leachate biochemical effluent treatment. The experimental results indicated that the highest COD (84%) and color (98%) removal was obtained at Fe-Mn/AC dosage 1.2 g/L, O3 concentration 1.2 g/L, Na2S2O8 dosage 6 g/L, initial pH 10, and reaction time 100 min. Three-dimensional and excitation emission matrix (3D-EEM) fluorescence spectrometry, Fourier transform infrared spectroscopy (FTIR), and gas chromatography mass spectrometry (GC/MS) of wastewater samples before and after treatment demonstrated that the leachate biochemical effluent contained a large amount of humic and fulvic acid organic compounds. After treatment with this coupling system, both the pollution level of dissolved organic matter (DOM) and the fluorescence intensity declined. The micro morphology of Fe-Mn/AC was characterized using scanning X-ray diffraction patterns (XRD), electron microscope spectra (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. It can be concluded that the microscopic morphology of the catalyst is porous. The main active components are amorphous MnO2 and multivalent iron oxides. Furthermore, the Fe-Mn/AC catalyst showed great reusability; the removal efficiency of COD was only reduced from 84% to 79% at the fourth reaction. Moreover, the COD removal efficiency could recover to 81% after catalyst regeneration.


Subject(s)
Wastewater , Water Pollutants, Chemical/analysis , Manganese Compounds , Organic Chemicals , Oxidation-Reduction , Oxides
17.
Opt Express ; 27(5): 7344-7353, 2019 Mar 04.
Article in English | MEDLINE | ID: mdl-30876299

ABSTRACT

Multiple-path interference plays a fundamental role in classical and quantum physics. In this work, we propose two general schemes to realize multiple electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) in coupled microresonators and optomechanical systems. We give explicit physical descriptions and find out that these two schemes are essentially equivalent to each other. More importantly, we experimentally demonstrate both multiple EIT and EIA by coupling a microtoroid to a microsphere that supports multiple high Q optical modes with dense modes distributions. The theory fits well with the experimental results. We believe that our study and experimental results lay a foundation for realizing arbitrary multiple pathways interference in applications.

18.
Opt Express ; 27(1): 63-73, 2019 Jan 07.
Article in English | MEDLINE | ID: mdl-30645359

ABSTRACT

We have studied the effect of geometry deformation on the mechanical frequencies and quality factors for different modes in the Whispering Gallery Mode (WGM) microresonators, that is unavoidable in the practical fabrication. The subsidence of the sphere and a more general condition with fewer symmetries and complex deformation of eccentricity, subsidence, and offset are first modeled in this paper, which could tune the mechanical frequency in a much wider spectral range than the pillar-diameter-induced perturbation. we also show that the mechanical quality factors for the non-whispering-gallery mechanical mode could be increased in the order of 4 magnitudes at a specific subsidence, and form a mechanical bound state in the continuum (BIC) which is induced by the symmetry breaking and reveals new mechanisms to confine radiation. A much broader BIC window width with higher mechanical quality factor could be achieved, which is of great importance in both fundamental research and scientific applications.

19.
Sci Bull (Beijing) ; 63(5): 287-292, 2018 Mar 15.
Article in English | MEDLINE | ID: mdl-36658798

ABSTRACT

Opto-thermal relaxation is one of the most important properties of nonlinear optical materials. Rapid and high precision measurement of this parameter is vital in both fundamental research and applications. Current measurement uses either complicated structure with poor precision or high power heating source with low efficiency. Here, we propose a pump-probe method (PPM) to optically measure the thermal relaxation using whispering gallery mode (WGM) microcavities. When the pump laser shines on a microcavity, the materials absorb the input power resonantly and heat up. Then the heat dissipates from the cavities to the surroundings. The opto-thermal effect induces a refractive index change reflected in the signal light transmission spectra. By analyzing the curve character of the transmission spectra of the signal response in the spontaneous relaxation process, the thermal relaxation time can be rapidly measured with high precision. Additionally, we systematically verify the PPM using microtoroids under various pump powers and at various locking points of the signal laser mode. The small rate of refractive index changes (∼10-8) can be discerned with an input pump power as low as 11.816 µW. Hence, the PPM can be used to detect refractive index perturbation, like gas or liquid sensing, temperature fluctuations with ultra-high sensitivity and be applied to optical materials analysis efficiently.

20.
Aging Ment Health ; 20(6): 567-74, 2016.
Article in English | MEDLINE | ID: mdl-25853449

ABSTRACT

OBJECTIVES: To assess the reliability and validity of the Chinese version of Aging Perceptions Questionnaire (C-APQ). METHOD: Participants aged 65 years and over were recruited from February 2012 to November 2012. The Aging Perceptions Questionnaire was translated into Chinese version professionally. Content validity was examined by a panel of seven experts; item reliabilities were assessed by test-retest; internal consistency was assessed by Cronbach's α coefficient; half of the sample (N = 379) was selected to explore factorial structure of the C-APQ by exploratory factor analysis (EFA) and another half of the sample (N = 379) was selected to confirm the findings from the EFA by confirmatory factor analysis (CFA). Statistical package SPSS version 18.0 and Amos 17.0 were used for the analysis. RESULTS: The Cronbach's α coefficient of the C-APQ was 0.884. The test-retest reliability was satisfactory, with all intraclass correlation coefficients greater than 0.4. The overall content validity index was greater than 0.99. Seven factors (timeline acute/chronic, timeline cyclical, emotional representations, control positive, control negative, consequences positive and consequences negative) were identified in EFA and confirmed in CFA. CONCLUSION: The C-APQ could be a reliable and a valid measure of the self-perceptions of aging in the elderly in China, which may help to improve the life quality and extend longevity of the elderly.


Subject(s)
Aging/psychology , Psychometrics/instrumentation , Self Concept , Surveys and Questionnaires/standards , Aged , Aged, 80 and over , China , Female , Humans , Male , Reproducibility of Results
SELECTION OF CITATIONS
SEARCH DETAIL
...