Potent Antibody Response Elicited by a Third Booster Dose of Inactivated COVID-19 Vaccine in Healthy Subjects.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine has been used worldwide on a large scale because of its potent ability to contain the coronavirus disease 2019 (COVID-19) pandemic, and the antibody response induced by the vaccine needs to be elucidated. Thus, we conducted a prospective trial in healthy subjects to observe the antibody response after three doses of inactivated vaccines. Our results showed that neutralizing antibody (NAb) levels were significantly higher after the booster vaccination compared to the second, a 4.9-fold increase, with the peak occurring at 28 days. The NAb level could be maintained for a longer period after the third vaccination, with higher levels still observed after 3 months. We did not observe significantly higher levels of SARS-CoV-2 spike-specific immunoglobulin G (S-IgG) and immunoglobulin M (IgM) after the third vaccination compared with the second vaccination; this was especially true for SARS-CoV-2 spike-specific immunoglobulin M (S-IgM), which was barely expressed. Notably, those who did not undergo NAb seroconversion after two doses of the vaccine produced high and long-lasting NAb after the third vaccination, confirming that they were not completely unresponsive to the vaccine. The NAb titer in younger subjects (aged 20-40 years) rose 3.4-fold compared with older subjects (aged 40-60 years) after the second vaccination, but the difference was narrowed after the third vaccination (2.8-fold increase). In addition, the levels of antibodies in older men were 3.4-fold lower than those in the older women after the third vaccination. Overall, this study elucidates the dynamic change in antibodies after three doses of vaccination, which provides a reference for the improvement of vaccination strategies.

Self-assembled nanoparticle with E protein domain III of DTMUV based on ferritin as carrier can induce a more comprehensive immune response and against DTMUV challenge in duck.

Duck Tembusu virus (DTMUV) causes severe reduction in egg production and neurological symptoms in ducklings. Vaccination is the primary measure used to prevent DTMUV infections. In this study, self-assembled nanoparticles with the E protein domain III of DTMUV, using ferritin as a carrier (EDⅢ-RFNp), were prepared using a prokaryotic expression system. Ducks were intramuscularly vaccinated with EDⅢ-RFNp, EDⅢ protein, an inactivated vaccine HB strain (InV-HB), and PBS. At 0, 4, and 6 weeks post-primary vaccination, the EDIII protein-specific antibody titre, IL-4, and IFN-γ concentrations in serum were determined by ELISA, and neutralising antibodies titres in sera were determined by virus neutralising assay. Peripheral blood lymphocytes proliferation was determined by CCK-8 kit. Following challenge with the virulent DTMUV strain, the clinical signals and survival rate of the vaccinated ducks were recorded, and DTMUV RNA levels in the blood and tissues of the surviving ducks were determined by real-time quantitative RT-PCR. The near-spherical EDⅢ-RFNp nanoparticles with 13.29 ± 1.43 nm diameter were observed by transmission electron microscope. At 4 and 6 weeks post-primary vaccination, special and Virus neutralisation (VN) antibodies, lymphocyte proliferation (stimulator index, SI), and concentrations of IL-4 and IFN-γ in the EDⅢ-RFNp group were significantly higher than in the EDⅢ and PBS groups. In the DTMUV virulent strain challenge test, the EDⅢ-RFNp-vaccinated ducks showed milder clinical signs and higher survival rates than EDⅢ- and PBS-vaccinated ducks. The DTMUV RNA levels in the blood and tissues of EDⅢ-RFNp-vaccinated ducks were significantly lower than those in EDⅢ- and PBS-vaccinated ducks. Additionally, the EDⅢ protein-special and VN antibodies, SI value, and concentration of IL-4 and IFN-γ in the InV-HB group was significantly higher than that of the PBS group at 4 and 6 weeks post-primary vaccination. InV-HB provided more efficient protection than PBS based on a higher survival rate, milder signals, and lower levels of the DTMUV virus in the blood and tissues. These results indicated that EDⅢ-RFNp effectively protected ducks against DTMUV challenge and could be a vaccine candidate to prevent DTMUV infection.

The biomarkers related to immune infiltration to predict distant metastasis in breast cancer patients.

Background: The development of distant metastasis (DM) results in poor prognosis of breast cancer (BC) patients, however, it is difficult to predict the risk of distant metastasis. Methods: Differentially expressed genes (DEGs) were screened out using GSE184717 and GSE183947. GSE20685 were randomly assigned to the training and the internal validation cohort. A signature was developed according to the results of univariate and multivariate Cox regression analysis, which was validated by using internal and external (GSE6532) validation cohort. Gene set enrichment analysis (GSEA) was used for functional analysis. Finally, a nomogram was constructed and calibration curves and concordance index (C-index) were compiled to determine predictive and discriminatory capacity. The clinical benefit of this nomogram was revealed by decision curve analysis (DCA). Finally, we explored the relationships between candidate genes and immune cell infiltration, and the possible mechanism. Results: A signature containing CD74 and TSPAN7 was developed according to the results of univariate and multivariate Cox regression analysis, which was validated by using internal and external (GSE6532) validation cohort. Mechanistically, the signature reflect the overall level of immune infiltration in tissues, especially myeloid immune cells. The expression of CD74 and TSPAN7 is heterogeneous, and the overexpression is positively correlated with the infiltration of myeloid immune cells. CD74 is mainly derived from myeloid immune cells and do not affect the proportion of CD8+T cells. Low expression levels of TSPAN7 is mainly caused by methylation modification in BC cells. This signature could act as an independent predictive factor in patients with BC (p = 0.01, HR = 0.63), and it has been validated in internal (p = 0.023, HR = 0.58) and external (p = 0.0065, HR = 0.67) cohort. Finally, we constructed an individualized prediction nomogram based on our signature. The model showed good discrimination in training, internal and external cohort, with a C-index of 0.742, 0.801, 0.695 respectively, and good calibration. DCA demonstrated that the prediction nomogram was clinically useful. Conclusion: A new immune infiltration related signature developed for predicting metastatic risk will improve the treatment and management of BC patients.

Development of receptor binding domain-based double-antigen sandwich lateral flow immunoassay for the detection and evaluation of SARS-CoV-2 neutralizing antibody in clinical sera samples compared with the conventional virus neutralization test.

Vaccination is an effective strategy to fight COVID-19. However, the effectiveness of the vaccine varies among different populations in varying immune effects. Neutralizing antibody (NAb) level is an important indicator to evaluate the protective effect of immune response after vaccination. Lateral flow immunoassay (LFIA) is a rapid, safe and sensitivity detection method, which has great potential in the detection of SARS-CoV-2 NAb. In this study, a fluorescent beads-based lateral flow immunoassay (FBs-LFIA) and a latex beads-based LFIA (LBs-LFIA) using double antigen sandwich (DAS) strategy were established to detect NAbs in the serum of vaccinated people. The limit of detection (LoD) of the FBs-LFIA was 1.13 ng mL- 1 and the LBs-LFIA was 7.11 ng mL- 1. The two LFIAs were no cross-reactive with sera infected by other pathogenic bacteria. Furthermore, the two LFIAs showed a good performance in testing clinical samples. The sensitivity of FBs-LFIA and LBs-LFIA were 97.44% (95%CI: 93.15%-99.18%) and 98.29% (95%CI: 95.84%-99.37%), and the specificity were 98.28% (95%CI: 95.37%-99.45%) and 97.70% (95%CI: 94.82%-99.06%) compared with the conventional virus neutralization test (cVNT), respectively. Notably, the LBs-LFIA was also suitable for whole blood sample, requiring only 3 µL of whole blood, which provided the possibility to detect NAbs at home. To sum up, the two LFIAs based on double antigen sandwich established by us can rapidly, safely, sensitively and accurately detect SARS-CoV-2 NAb in human serum.

Epidemiological survey and screening strategy for dengue virus in blood donors from Yunnan Province.

BACKGROUND: Dengue virus (DENV) infection is increasingly common in southern China and can be transmitted through blood transfusion but is not currently part of donor screening throughout the region. We assessed DENV prevalence among donors at the Xishuangbanna Blood Center, Yunnan, to support development of DENV screening strategies. METHODS: Blood samples were collected randomly between June 2019 and August 2019. These were screened for anti-DENV IgG and IgM using enzyme-linked immunosorbent assay (ELISA). Then, all reactive samples and some randomly-chosen non-reactive samples were used to detect DENV RNAs using real-time polymerase-chain-reaction (RT-PCR) assays. After RT-PCR, samples were further tested for soluble nonstructural protein 1 (NS1) using the colloidal gold method. Donors demographics were also collected and assessed. RESULTS: Over the study period, 2254 donor samples were collected and tested for anti-DENV IgG and IgM by ELISA. This revealed 598 anti-DENV IgG and/or IgM reactive samples, a serological prevalence of 26.53%. Of these, 26 were RT-PCR positive and/or NS1 positive. Significant differences in DENV prevalence were noted by occupation (P = 0.001), education (P < 0.001), and ethnicity (P = 0.026). CONCLUSION: The prevalence of DENV in Xishuangbanna Blood Center was higher than most other blood centers that have implemented DENV donor screening. Our study provides first-hand data about the prevalence of DENV and allows the development of a screening strategy for clinical use.

Supramolecular self-assembly for designing non-centrosymmetric crystals based on Keggin polyoxometallates and crown ether.

We report the synthesis of five novel crystals [(4-BrAni+)(DB[18]crown-6)]2[SMo12O402-]·2CH3CN (1), [(4-BrAni+)(B[18]crown-6)]2[SMo12O402-]·CH3CN (2), [(4-BrAni+)(B[18]crown-6)]3[PMo12O402-]·2CH3CN (3), [(3-AP+)3(B[18]crown-6)2][PMo12O403-] (4) and [NBu4+][(3-AP2+)(DB[30]crown-10)][PMo12O403-]·CH3CN (5) (4-BrAni+ = 4-bromoanilinium; B[18]crown-6 = benzo[18]-crown-6; DB[18]crown-6 = dibenzo[18]-crown-6; DB[30]crown-10 = dibenzo[30]-crown-10; 3-AP+ = 3-aminopyridinium; 3-AP2+ = 3-ammoniumpyridinium; NBu4+ = tetrabutylammonium). In order to construct non-centrosymmetric crystals, the five crystals were designed using a method to gradually introduce asymmetry into the building units. Crystal 1 was constructed with a symmetric supramolecular cation (SPC) [(4-BrAni+)(DB[18]crown-6)], resulting in a P21/n space group. The asymmetric SPC [(4-BrAni+)(B[18]crown-6)] was introduced into [SMo12O402-] to obtain crystal 2, which belongs to the symmetric P1[combining macron] space group. Introducing trivalent [PMo12O403-], [(4-BrAni+)(B[18]crown-6)] produced crystal 3 with a non-centrosymmetric Pc space group. The asymmetric sandwich SPC [(3-AP+)3(B[18]crown-6)2] was designed with multiple hydrogen bonding sites on the 3-AP+ cation, and crystal 4 was obtained with trivalent [PMo12O403-]. Crystal 4 has the properties of the chiral P1 space group. The distorted SPC (3-AP2+)(DB[30]crown-10) was constructed using flexible DB[30]crown-10, resulting in crystal 5 which matched the chiral P21 space group with trivalent [PMo12O403-]. This work focuses on strategies for the rational design of novel non-centrosymmetric crystals without a chiral synthon.

Maintenance of cyclic GMP-AMP homeostasis by ENPP1 is involved in pseudorabies virus infection.

In a previous study, we demonstrated that porcine cyclic GMP-AMP (cGAMP) synthase (cGAS) catalyzes cGAMP production and is an important DNA sensor for the pseudorabies virus (PRV)-induced activation of interferon ß (IFN-ß). Ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) has recently been identified as the hydrolase of cGAMP in rodents, but its role in porcine cells is not clear. Our recent study demonstrated that porcine ENPP1 is responsible for the homeostasis of cGAMP and is critical for PRV infection. Porcine ENPP1 mRNA is predominantly expressed in muscle. PRV infection was enhanced by ENPP1 overexpression and attenuated by silencing of ENPP1. During PRV infection, the activation of IFN-ß and NF-κB was reduced in ENPP1 overexpressed cells and promoted in ENPP1 knockdown cells. Investigation of the molecular mechanisms of ENPP1 during PRV infection showed that ENPP1 hydrolyzed cGAMP in PRV-infected or cGAMP-transfected cells and inhibited IRF3 phosphorylation, reducing IFN-ß secretion. These results, combined with those for porcine cGAS, demonstrate that ENPP1 acts coordinately with cGAS to maintain the reservoir of cGAMP and participates in PRV infection.

Cholesterol 25-hydroxylase acts as a host restriction factor on pseudorabies virus replication.

Cholesterol 25-hydroxylase (CH25H) catalyses the production of 25-hydroxycholesterol (25HC) from cholesterol by adding a second hydroxyl group at position 25. The aim of this study was to examine the antiviral effect of CH25H on pseudorabies virus (PRV), a swine pathogen that can cause devastating disease and economic losses worldwide. The results showed that porcine ch25h was induced by either interferon or PRV infection. PRV infection of porcine alveolar macrophages (3D4/21 cells) was attenuated by CH25H overexpression and enhanced by silencing of CH25H. Furthermore, treatment of 3D4/21 cells with 25HC inhibited the growth of PRV in vitro, suggesting that CH25H may restrict PRV replication by 25HC production. We further identified that the anti-PRV role of CH25H and 25HC was subject to their inhibitory effect on PRV attachment and entry. Collectively, these findings demonstrate that CH25H is an intrinsic host restriction factor in PRV infection of porcine alveolar macrophages.

[Comparison of green coffee beans volatiles chemical composition of Hainan main area].

Chemical component of Hainan green coffee beans was analyzed with solid phase microextraction-gas chromatography-mass spectrometry, and the discrepancy between two green coffee beans was differentiated through the spectrum database retrieval and retention index of compound characterization. The experimental results show that: the chemical composition of Wanning coffee beans and Chengmai coffee beans is basically the same. The quantity of analyzed compound in Wanning area coffee is 91, and in Chengmai area coffee is 106, the quantity of the same compound is 66, and the percent of the same component is 75.52%. The same compounds accounted for 89.86% of the total content of Wanning area coffee, and accounted for 85.70% of the total content of Chengmai area coffee.

Meta-barium borate, II-BaB2O4, at 163 and 293 K.

The single-crystal X-ray diffraction structure analysis of an excellent non-linear optical material, viz. II-BaB2O4 or Ba3(B3O6)2, has been carried out at 163 and 293 K. The two sets of structural data are compared and indicate a significant shortening of the c axial length in the unit cell at 163 K, whereas the a and b axial lengths essentially do not change.

Electrochemical reduction and voltammetric determination of metronidazole at a nanomaterial thin film coated glassy carbon electrode.

Simple and sensitive electrochemical method for the determination of metronidazole, based on a nanostructured film coated glassy carbon electrode (GCE), is described. Multi-walled carbon nanotubes (MWNT) was dispersed into water in the presence of a hydrophobic surfactant to give very stable and homogeneous MWNT suspension, and a MWNT-film coated GCE was achieved via evaporating solvent. Metronidazole yields a well-defined reduction peak whose potential is -0.71V at the MWNT-film coated GCE in pH 9.0 Britton-Robinson buffer. Compared with bare GCE, the MWNT-film modified GCE significantly enhances the reduction peak current of metronidazole. All the experimental parameters were optimized for the determination of metronidazole. The detection limit is 6x10(-9)mol/l at 2min accumulation. This method has been successfully used to determine metronidazole in the drugs. Furthermore, results obtained by the proposed method have been compared with spectrophotometric method.

A multi-wall carbon nanotubes-dicetyl phosphate electrode for the determination of hypoxanthine in fish.

An enzymeless sensor based on a multi-walled carbon nanotubes-dicetyl phosphate (MWCNT-DCP) film modified vitreous carbon electrode was developed for the determination of hypoxanthine. The MWCNT-DCP film modified electrode showed a remarkable enhancement effect on the oxidation peak current of hypoxanthine. Under the optimized conditions, the oxidation peak current is proportional to the concentration of hypoxanthine over the range from 5.0 x 10(-7) to 2.0 x 10(-4) mol L(-1) with a detection limit (S/N = 3) of 2.0 x 10(-7) mol L(-1). The MWCNT-DCP film modified electrode has been successfully used to detect hypoxanthine in fish samples.

A novel left-handed double helicate constructed from L-tartrate bridged molybdenum(vi) and gadolinium(iii) atoms.

The one-dimensional double helicate, [NH4][Mo2O4Gd(H2O)6(L-C4H2O6)2] x 4H2O (1), which was synthesized by the reaction of GdCl3, L-tartaric acid and ammonium molybdate in acidified water solution, is built up by two heft-handed single-helical chains, linked up further by eight-coordinated GdIII pieces in an enantiopure left-handed double helical configuration, of which each helix is formed by L-tartrate bridged six-coordinated MoVI atoms.

Electrocatalytic reduction of chloramphenicol at multiwall carbon nanotube-modified electrodes.

A multiwall carbon nanotube-modified glassy carbon (GC) electrode was employed for the investigation of chloramphenicol (CAP) reduction. Carbon nanotube coating can greatly lower the overpotential of the electrochemical reduction of CAP and promote the electrode reaction. CAP undergoes an irreversible reduction process in phosphate buffer by the modified electrode. The reduction peak current (Ip) was significantly increased. Effects of some important factors, including pH, scan rate, and amount of modifier, on the determination of CAP were investigated. In the range of 3 x 10(-7) to 1.2 x 10(-5) M, the reduction peak current (Ip) has a good linear relationship with the concentration of CAP. When the signal-to-noise ratio is 3, the detection limit is 4.5 x 10(-8) M. The relative standard deviation of 10 measurements for 3 x 10(-6) M CAP is 5.3%, suggesting an excellent reproducibility of the modified electrode. Interfering experiments show that the modified electrode has excellent selectivity for the detection of CAP. The modified electrode was used to determine CAP in eyedrops, and the recoveries were approximately 100%.

Fluorometric determination of DNA using a new ruthenium complex Ru(bpy)2PIP(V) as a nucleic acid probe.

A new ligand, 2-phenyl(5-fluoro)imidazo[f]-1,10-phenanthroline (PIP(V)), and its coordination compounds, Ru(bpy)2PIP(V), were synthesized. The fluorescence spectrum of the interaction between Ru(bpy)2PIP(V) and DNA was studied, and a very strong fluorescence peak at a wavelength of 589 nm appeared. The optimum condition of analyzing DNA was decided. The method is simple, convenient and fast, and also has high sensitivity and good selectivity. It has been satisfactorily employed for determinations in synthesized samples.

A three-dimensional zeolite-like organic-inorganic hybrid material constructed from (CuMo2O8N)n double helical chains linked via [Cu(4,4'-bpy)]n fragments.

The three-dimensional microporous [Cu2Mo2O8(4,4'-bpy)]n.3nH2O 1 contains (CuMo2O8N) double helical chains, which are built up from (CuIIO4N) square pyramids linked by (MoVIO4) tetrahedra and further connected to each other by 4,4'-bpy coordinated (CuIIO5N); the study of the physical properties of 1 demonstrates it is a paramagnetic semiconductor and a zeolite material; the specific channeling cavities in 1 have potential adsorption activities, indicating that 1 might be an attractive functional microporous solid material.

A novel compound with an interpenetrating 2D network structure constructed by [Mo5P2O23] and Ni-4,4'-bipyridine components: its synthesis, characterization and magnetic behaviour.

A Novel compound (Hbpy)2[[(H2O)3Ni(bpy)0.5Ni(bpy)(H2O)4]2[Mo5P2O23] [Ni((bpy)0.5)2(H2O)2][Mo5P2O23]].8H2O 1 (bpy = 4,4'-bipyridine) with an interpenetrating 2D network structure was synthesized hydrothermally and characterized by elemental analyses, IR, X-ray single crystal structure analysis and temperature-dependent magnetic susceptibility.

Synthesis and Structural Characterization of an Unusual Oxygen-Linked Double Cubane-Like Cluster {[Mo(3)PbOS(3)](OAc)(2)(py)(3)(dtp)(2)O}(2).

The unusual oxygen-linked double cubane-like cluster compound {[Mo(3)PbOS(3)](OAc)(2)(py)(3)(dtp)(2)O}(2) (A) (dtp = S(2)P(OEt(2))(-), OAc = CH(3)COO(-), py = C(5)H(5)N) was obtained for the first time by the reaction of the mixed S/O-bridged cluster [Mo(3)(&mgr;(3)-O)(&mgr;-S)(3)(dtp)(4)H(2)O] (B) with Pb(OAc)(2).3H(2)O in the presence of excess CH(3)COOH and pyridine. It has been characterized by IR, Raman, UV-vis, and X-ray structure analysis. The molecule contains a crystallographic center of inversion and can be viewed as consisting of two [Mo(3)PbOS(3)](6+) cubane-like cores linked through a pair of oxygen bridges with Mo-(&mgr;-O) bond lengths of ca. 1.89 Å. The cell dimensions are a = 11.705(8) Å, b = 19.527(8) Å, c = 20.670(9) Å, beta = 98.14(4) degrees, V = 4677(8) Å(3), Z = 2 in the space group P2(1)/n. The final R = 0.056, R(w) = 0.068 for 5424 reflections with I >/= 3sigma(I). The average Mo-Mo bond distance is 2.613(1) Å and the nonbonding Mo-Pb distances lie in the range from 3.997(1) to 4.090(1) Å. The spectra of IR, Raman, and UV-vis spectra are also shown in this paper.