Gobeil's model is one of the most widely used models to identify lead (Pb) pollution sources in the environment. It is based on a set of equations involving Pb isotope fractions. Although a well-established numerical method, Gobeil's model is often unable to provide an accurate estimation of each pollution sources' contribution. This paper comprehensively examines the drawbacks of Gobeil's model based on a numerical analysis and proposes a revised numerical method that provides a more accurate estimation of Pb pollution sources. Briefly, the mathematical inaccuracy of Gobeil's model mainly lies in the misinterpretation of "lead fingerprint ratio balance." To address this problem, the new analytic model relies on the mass balance of total lead in the contaminated sites, and uses a set of linear equations to obtain the contribution of each pollution source based on the lead fingerprint. A subsequent case study from an industrial park in Guanzhong area of Shaanxi Province in China shows that we can calculate the lead contribution rates accurately with the new model.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6950129 | PMC |
http://dx.doi.org/10.3390/ijerph16245059 | DOI Listing |
Mol Cell
July 2024
Duke University, Duke Human Vaccine Institute, Durham, NC 27710, USA; Duke University, Department of Biochemistry, Durham, NC 27710, USA; Duke University, Department of Surgery, Durham, NC 27710, USA. Electronic address:
A recombinant lineage of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant, named XBB, appeared in late 2022 and evolved descendants that successively swept local and global populations. XBB lineage members were noted for their improved immune evasion and transmissibility. Here, we determine cryoelectron microscopy (cryo-EM) structures of XBB.
View Article and Find Full Text PDFmBio
December 2021
Department of Biochemistry, Duke Universitygrid.26009.3d, Durham, North Carolina, USA.
Calcineurin is a critical enzyme in fungal pathogenesis and antifungal drug tolerance and, therefore, an attractive antifungal target. Current clinically accessible calcineurin inhibitors, such as FK506, are immunosuppressive to humans, so exploiting calcineurin inhibition as an antifungal strategy necessitates fungal specificity in order to avoid inhibiting the human pathway. Harnessing fungal calcineurin-inhibitor crystal structures, we recently developed a less immunosuppressive FK506 analog, APX879, with broad-spectrum antifungal activity and demonstrable efficacy in a murine model of invasive fungal infection.
View Article and Find Full Text PDFScience
August 2021
Duke Human Vaccine Institute, Durham, NC 27710, USA.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with multiple spike mutations enable increased transmission and antibody resistance. We combined cryo-electron microscopy (cryo-EM), binding, and computational analyses to study variant spikes, including one that was involved in transmission between minks and humans, and others that originated and spread in human populations. All variants showed increased angiotensin-converting enzyme 2 (ACE2) receptor binding and increased propensity for receptor binding domain (RBD)-up states.
View Article and Find Full Text PDFCell
May 2021
Duke Human Vaccine Institute, Durham, NC 27710, USA; Department of Medicine, Duke University, Durham, NC 27710, USA; Department of Immunology, Duke University, Durham, NC 27710, USA. Electronic address:
Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (V) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization.
View Article and Find Full Text PDFNature
June 2021
Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA.
Betacoronaviruses caused the outbreaks of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome, as well as the current pandemic of SARS coronavirus 2 (SARS-CoV-2). Vaccines that elicit protective immunity against SARS-CoV-2 and betacoronaviruses that circulate in animals have the potential to prevent future pandemics. Here we show that the immunization of macaques with nanoparticles conjugated with the receptor-binding domain of SARS-CoV-2, and adjuvanted with 3M-052 and alum, elicits cross-neutralizing antibody responses against bat coronaviruses, SARS-CoV and SARS-CoV-2 (including the B.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!