RESUMO
The reason why heating is required remains elusive for the traditional synthesis of colloidal semiconductor quantum dots (QDs) of II-VI metal chalcogenide (ME). Using CdTe as a model system, we show that the formation of Cd-Te covalent bonds with individual Cd- and Te-containing compounds can be decoupled from the nucleation and growth of CdTe QDs. Prepared at an elevated temperature, a prenucleation-stage sample contains clusters that are the precursor compound (PC) of magic-size clusters (MSCs); the Cd-Te bond formation occurs at temperatures higher than 120 °C in the reaction. Afterward, the PC-to-QD transformation appears via monomers at lower temperatures in dispersion. Our findings suggest that the number of Cd-Te bonds broken in the PC reactant is similar to that of Cd-Te bonds formed in the QD product. For the traditional synthesis of ME QDs, heating is responsible for the M-E bond formation rather than for nucleation.
RESUMO
Background: Chronic hepatitis B virus infection (CHB) is a common infectious disease that poses a global economic and health burden due to its high morbidity and mortality. Studies have demonstrated that host genetic factors play critical roles in the susceptibility and outcome of CHB. Aims: In this study, we aimed to assess the potential role of genetic variants of the nucleostemin (NS) gene with respect to CHB susceptibility. Materials and Methods: Four single nucleotide polymorphisms (SNPs) in the NS gene were genotyped in 446 patients with CHB and 399 healthy controls all of Chinese Han origin using the polymerase chain reaction-ligation detection reaction method. Results: The results showed that the three SNPs, rs3733039, rs1866268, and rs11177, were significantly associated with CHB. After a Bonferroni correction, the positive association of the rs3733039 SNP with CHB remained significant. Further analyses based on gender demonstrated that these SNPs are associated with CHB in both the female and male subgroups. After correction for multiple comparisons, all three SNPs in the female group were associated with CHB, whereas only the rs1866268 SNP in the male group was associated with CHB. Haplotype analysis showed that the C-C-G and T-T-T haplotypes in the block consisting of rs3733039-rs1866268-rs11177 were significantly associated with CHB. Conclusion: Our study demonstrated a genetic association between SNPs in the NS gene and the risk of CHB in the Chinese Han population for the first time. Thus, variations in the NS gene might serve as potential genetic biomarkers of CHB.