Characteristics and Influence Factors of Pb(II) Adsorption by Graphene Oxide-Montmorillonite Composite.

This study presents the fabrication of a novel porous composite of graphene oxide-montmorillonite (GO-MMT) through the modification of montmorillonite using the freeze-drying method for the purpose of Pb removal. The characterization of the GO-MMT composite was conducted using scanning electron microscopy, Fourier transform infrared spectrometry, and X-ray diffraction. The results from batch adsorption experiments revealed that the GO-MMT composite exhibited a superior capacity for Pb removal compared to MMT. Furthermore, a single factor experiment confirmed that the dosage of the GO-MMT composite or GO, pH, temperature, and reaction time all significantly influenced the adsorption of Pb by the GO-MMT composite, MMT, or GO. This superiority can be attributed to the presence of oxygen-containing functional groups, the site-blocking effect, and the ion exchange mechanism exhibited by the GO-MMT composite.

Broad neutralization against SARS-CoV-2 variants induced by a modified B.1.351 protein-based COVID-19 vaccine candidate

Beginning in late 2020, the emergence and spread of multiple variant SARS-CoV-2 strains harboring mutations which may enable immune escape necessitates the rapid evaluation of second generation COVID-19 vaccines, with the goal of inducing optimized immune responses that are broadly protective. Here we demonstrate in a mouse immunogenicity study that two doses of a modified B.1.351 spike (S)-Trimer vaccine (B.1.351 S-Trimer) candidate can induce strong humoral immune responses that can broadly neutralize both the original SARS-CoV-2 strain (Wuhan-Hu-1) and Variants of Concern (VOCs), including the UK variant (B.1.1.7), South African variant (B.1.351) and Brazil variant (P.1). Furthermore, while immunization with two doses (prime-boost) of Prototype S-Trimer vaccine (based on the original SARS-CoV-2 strain) induced lower levels of cross-reactive neutralization against the B.1.351 variant, a third dose (booster) administered with either Prototype S-Trimer or B.1.351 S-Trimer was able to increase neutralizing antibody titers against B.1.351 to levels comparable to neutralizing antibody titers against the original strain elicited by two doses of Prototype S-Trimer.

S-Trimer, a COVID-19 subunit vaccine candidate, induces protective immunity in nonhuman primates

SARS-CoV-2 is the underlying cause for the COVID-19 pandemic. Like most enveloped RNA viruses, SARS-CoV-2 uses a homotrimeric surface antigen to gain entry into host cells. Here we describe S-Trimer, a native-like trimeric subunit vaccine candidate for COVID-19 based on Trimer-Tag technology. Immunization of S-Trimer with either AS03 (oil-in-water emulsion) or CpG 1018 (TLR9 agonist) plus alum adjuvants induced high-levels of neutralizing antibodies and Th1-biased cellular immune responses in animal models. Moreover, rhesus macaques immunized with adjuvanted S-Trimer were protected from SARS-CoV-2 challenge compared to vehicle controls, based on clinical observations and reduction of viral loads in lungs. Trimer-Tag may be an important new platform technology for scalable production and rapid development of safe and effective subunit vaccines against current and future emerging RNA viruses.

Analysis of serum vitamin D levels and clinical characteristics in elderly patients with active pulmonary tuberculosis / 中华老年医学杂志

Objective:To investigate serum levels of 25-hydroxyvitamin D [25-(OH)D3], the vitamin D receptor(VDR), LL-37, cytokines such as interleukin 6(IL-6)and tumor necrosis factor-α(TNF-α)in elderly and non-elderly patients with pulmonary tuberculosis, and to study the correlation between serum vitamin D levels and clinical characteristics.Methods:A total of 56 elderly patients and 56 non-elderly patients with active pulmonary tuberculosis admitted to Chengdu Public Health Clinical Center from January 2019 to March 2019 were enrolled.The levels of 25-(OH)D3, VDR, LL-37, IL-6 and TNF-α were detected by ELISA and compared between the two groups.Clinical data such as the number of T lymphocytes, lesions and cavities in bilateral lung fields and extra-pulmonary tuberculosis were collected.Results:There were significant differences in serum vitamin D levels [(28.94±12.88)nmol/L vs.(34.47±12.78)nmol/L, t=3.650, P=0.025], while levels of VDR, LL-37, IL-6 and TNF-α(all P>0.05)were similar between the elderly and non-elderly groups.Besides, patients in the elderly group were associated with significantly lower levels of CD4 + T lymphocytes [(295.71±153.83)×10 6/L vs.(421.25±206.00)×10 6/L]and CD8 + T lymphocyte count [159.5(101.0, 239.0)×10 6/L vs.261.5(187.0, 409.0)×10 6/L]than those in the nonelderly group(all P=0.000). Also, there were more severe pulmonary tuberculosis cases in the elderly group than the non-elderly group [(51/56, 91.1%) vs.(28/56, 50.0%), χ2=22.730, P=0.000]. The serum level of 25-(OH)D3 was positively correlated with CD4 + T cell count in elderly patients( r=0.190, P< 0.05). Conclusions:Elderly patients with pulmonary tuberculosis have a high proportion of severe tuberculosis and reduced serum levels of vitamin D, CD4 + T cell count and CD8 + T cell count, compared with non-elderly patients.Attention should be paid to vitamin D levels and their potential impact on disease progression in elderly patients with active tuberculosis.