Dengue virus serotypes and related factors in children with dengue hemorrhagic fever in Southern Vietnam.

INTRODUCTION: After the Coronavirus Disease 2019 pandemic, a high number of cases and severe dengue in children were reported in some provinces in the south of Vietnam. This study aimed to determine the distribution of dengue virus serotypes and their correlation with demographic factors, disease severity, clinical manifestations, and laboratory findings. METHODOLOGY: This study employed a cross-sectional design. Ninety-six dengue-infected children admitted to Can Tho Children's Hospital between October 2022 and March 2023 were included. Confirmation of dengue infection was achieved through the real-time polymerase chain reaction (RT-PCR). RESULTS: Among the identified serotypes, DENV-2 accounted for the highest proportion (71.87%), followed by DENV-1 (23.96%), and DENV-4 (4.17%). DENV-3 was not detected. No significant demographic, disease severity, or laboratory differences were observed among the identified dengue serotypes. However, DENV-2 was associated with a higher occurrence of mucous membrane hemorrhages and gastrointestinal bleeding compared to other serotypes. CONCLUSIONS: Although DENV-2 was the most prevalent serotype responsible for dengue in children in southern Vietnam, it did not lead to more severe cases compared to other serotypes. This finding is crucial for evaluating the illness's prognosis.

Diagnostic performance of 128-slice computed tomography angiography in patients with suspected coronary artery disease.

Objectives: To determine the diagnostic performance and influencing factors of 128-slice coronary computed tomography angiography (CCTA) compared with invasive coronary angiography (ICA) in patients with suspected coronary artery disease (CAD). Methods: A cross-sectional analysis study enrolled 139 patients suspected of having CAD, who underwent and received a 128-slice CCTA and ICA. Results: The patient-based model showed high sensitivity and a positive predictive value of 93.2% and 95.3%, respectively (for stenosis ≥50%). However, these values were lower when analyzed using vessel-based (85.6% and 81.1%) and segment-based (73.9% and 66.6%) models. Specificity and negative predictive value were highest in the segment-based model, decreasing in vessel- and patient-based models at 96.4% and 95.4%, 90.5% and 90.0%, and 36.4% and 42.1%, respectively (for stenosis ≥70%). All diagnostic values were reduced when the calcium score was ≥400 Agatston units. Conclusion: 128-slice CCTA is an optimal, minimally invasive, and high-performance method to diagnose the stenosis and morphology of coronary artery lesions. The diagnostic performance of 128-slice CCTA is very high. Heart rate and body mass index do not affect diagnostic accuracy, whereas a calcium score ≥400 Agatston units is a factor that causes a decrease in diagnostic performance.

Through-Space, Lone-Pair Promoted Aromatic Substitution: A Relay Mechanism Can Beat Out Direct Activation.

We report a detailed experimental and theoretical analysis of through-space arene activation with halogens, tetrazoles and achiral esters and amides. Contrary to previously assumed direct activation through σ-complex stabilization, our results suggest that these reactions proceed by a relay mechanism wherein the lone pair-containing activators form exothermic π-complexes with electrophilic nitronium ion before transferring it to the probe ring through low barrier transition states. Noncovalent interactions (NCI) plots and Quantum Theory of Atoms in Molecules (QTAIM) analyses depict favorable interactions between the Lewis base (LB) and the nitronium ion in the precomplexes and the transition states, suggesting directing group participation throughout the mechanism. The regioselectivity of substitution also comports with a relay mechanism. In all, these data pave the way for an alternate platform of electrophilic aromatic substitution (EAS) reactions.