RESUMEN
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.
Asunto(s)
Grafito , Contaminantes Químicos del Agua , Bentonita/química , Plomo , Adsorción , Grafito/química , Contaminantes Químicos del Agua/químicaRESUMEN
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.
RESUMEN
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.
RESUMEN
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.