Effect of Extra-Framework Fe Species in Pt/Fe/ZSM-23 Catalysts on Hydroisomerization Performance of <i>n</i>‑Hexadecane

Pt/xFe/ZSM-23 catalysts with various Fe contents were prepared to explore the influence of extra-framework Fe (EF-Fe) on the n-hexadecane (n-C16) hydroisomerization performance. UV–vis and 57Fe Mössbauer spectroscopic results suggest that the Fe species composition was significantly different under various Fe contents, with (HO–Fe­(III)–O–Fe­(III)–OH) and [Fe­(OH)2]+ as the main Fe species at low Fe content (<1.98 wt %), whereas the Fe2O3 clusters/particles as the dominant ones at high Fe content (>1.98 wt %). Moreover, the concentration of Brønsted acid sites and Pt dispersion could be controlled by tailoring the Fe content. Correspondingly, the hydroisomerization performance of n-C16 over Pt/xFe/ZSM-23 catalysts was dramatically changed with various Fe contents. The Pt/1.98Fe/ZSM-23 catalyst with 1.98 wt % EF-Fe content exhibited considerably excellent hydroisomerization performance, and both n-C16 conversion and selectivity to iso-hexadecane (i-C16) could reach over 80 wt % when the reaction temperature was 310 °C

Structure–Activity Relationship Study of Momordica Saponin II Derivatives as Vaccine Adjuvants

VSA-2 is a recently developed semisynthetic saponin immunostimulant. It is prepared by incorporating a terminal-functionalized side chain to the branched trisaccharide domain at the C3 position of Momordica saponin II (MS II) isolated from the seeds of perennial Momordica cochinchinensis Spreng. Direct comparison of VSA-2 and the clinically proven saponin adjuvant QS-21 shows that VSA-2 is comparable to QS-21 in enhancing humoral and cellular immune responses. Structure–activity relationship studies show that structural changes in the side chain have a significant impact on saponins’ adjuvant activity. However, with the VSA-2 molecular framework intact, the new VSA-2 analogues with various substitution(s) at the terminal benzyl group of the side chain retain the ability of potentiating antigen-specific humoral and cellular responses

Table_1_Application of metagenomic next-generation sequencing in the diagnosis of pulmonary invasive fungal disease.docx

BackgroundMetagenomic next-generation sequencing (mNGS) is increasingly being used to detect pathogens directly from clinical specimens. However, the optimal application of mNGS and subsequent result interpretation can be challenging. In addition, studies reporting the use of mNGS for the diagnosis of invasive fungal infections (IFIs) are rare.ObjectiveWe critically evaluated the performance of mNGS in the diagnosis of pulmonary IFIs, by conducting a multicenter retrospective analysis. The methodological strengths of mNGS were recognized, and diagnostic cutoffs were determined.MethodsA total of 310 patients with suspected pulmonary IFIs were included in this study. Conventional microbiological tests (CMTs) and mNGS were performed in parallel on the same set of samples. Receiver operating characteristic (ROC) curves were used to evaluate the performance of the logarithm of reads per kilobase per million mapped reads [lg(RPKM)], and read counts were used to predict true-positive pathogens.ResultThe majority of the selected patients (86.5%) were immunocompromised. Twenty species of fungi were detected by mNGS, which was more than was achieved with standard culture methods. Peripheral blood lymphocyte and monocyte counts, as well as serum albumin levels, were significantly negatively correlated with fungal infection. In contrast, C-reactive protein and procalcitonin levels showed a significant positive correlation with fungal infection. ROC curves showed that mNGS [and especially lg(RPKM)] was superior to CMTs in its diagnostic performance. The area under the ROC curve value obtained for lg(RPKM) in the bronchoalveolar lavage fluid of patients with suspected pulmonary IFIs, used to predict true-positive pathogens, was 0.967, and the cutoff value calculated from the Youden index was −5.44.ConclusionsIn this study, we have evaluated the performance of mNGS-specific indicators that can identify pathogens in patients with IFIs more accurately and rapidly than CMTs, which will have important clinical implications.</p

Structure–Activity Relationship Study of Momordica Saponin II Derivatives as Vaccine Adjuvants

VSA-2 is a recently developed semisynthetic saponin immunostimulant. It is prepared by incorporating a terminal-functionalized side chain to the branched trisaccharide domain at the C3 position of Momordica saponin II (MS II) isolated from the seeds of perennial Momordica cochinchinensis Spreng. Direct comparison of VSA-2 and the clinically proven saponin adjuvant QS-21 shows that VSA-2 is comparable to QS-21 in enhancing humoral and cellular immune responses. Structure–activity relationship studies show that structural changes in the side chain have a significant impact on saponins’ adjuvant activity. However, with the VSA-2 molecular framework intact, the new VSA-2 analogues with various substitution(s) at the terminal benzyl group of the side chain retain the ability of potentiating antigen-specific humoral and cellular responses