Incidence of community-acquired pneumonia among children under 5 years in Suzhou, China: a hospital-based cohort study.

OBJECTIVES: To depict the seasonality and age variations of community-acquired pneumonia (CAP) incidence in the context of the COVID-19 impact. DESIGN: Retrospective cohort study. PARTICIPANTS: The observational cohort study was conducted at Soochow University Affiliated Children's Hospital from January 2017 to June 2021 and involved 132 797 children born in 2017 or 2018. They were followed and identified CAP episodes by screening on the Health Information Systems of outpatients and inpatients in the same hospital. OUTCOME: The CAP episodes were defined when the diagnoses coded as J09-J18 or J20-J22. The incidence of CAP was estimated stratified by age, sex, birth year, health status group, season and month, and the rate ratio was calculated and adjusted by a quasi-Poisson regression model. Stratified analysis of incidence of CAP by birth month was conducted to understand the age and seasonal variation. RESULTS: The overall incidence of CAP among children aged ≤5 years was 130.08 per 1000 person years. Children aged ≤24 months have a higher CAP incidence than those aged >24 months (176.84 vs 72.04 per 1000 person years, p<0.001). The CAP incidence increased from October, peaked at December and January and the highest CAP incidence was observed in winter (206.7 per 1000 person years, 95% CI 204.12 to 209.28). A substantial decline of CAP incidence was observed during the COVID-19 lockdown from February to August 2020, and began to rise again when the communities reopened. CONCLUSIONS: The burden of CAP among children is considerable. The incidence of CAP among children ≤5 years varied by age and season and decreased during COVID-19 lockdown.

Chiral N,N'-Dioxide Ligands Tune Diastereoselectivity in Mg(II)-Catalyzed Asymmetric Ring-Opening Desymmetrization of Azetidiniums.

A diastereodivergent asymmetric desymmetrization of azetidinium salts with benzothiazoleamides as carbon nucleophiles through a chiral N,N'-dioxide/Mg(II) complex-promoted ring-opening reaction is realized by tuning ligands. Both syn- and anti-chiral δ-amino acid derivatives bearing benzothiazole structure were obtained in moderate to good yields and dr and ee values. DFT calculations indicated that the diastereodivergency stems from the different size of the chiral pocket formed by variable substructures of the ligands, leading to the opposite attack direction of the nucleophiles.

Co-inducible Catabolism of 2-Naphthol Initiated by Hydroxylase CehC1C2 in Rhizobium sp. X9 Removed Its Ecotoxicity.

2-Naphthol, which originates from various industrial activities, is widely disseminated through the discharge of industrial wastewater and is, thus, harmful to the water ecosystem, agricultural production, and human health. In this study, the carbaryl degrading strain Rhizobium sp. X9 was proven to be able to degrade 2-naphthol and reduce its toxicity to rice (Oryza sativa) and Chlorella ellipsoidea. Two-component hydroxylase CehC1C2 is responsible for the initial step of degradation and generates 1,2-dihydroxynaphthalene, which is further degraded by the ceh cluster. The transcription of gene cluster cehC1C2 could be induced when both 2-naphthol and glucose were added. A bioinformatic analysis revealed that two transcriptional regulators, the inhibitor CehR2 and the activator CehR3, could be involved in this process. Our study elucidated the molecular mechanism of microbial degradation of 2-naphthol and provided an effective strategy for the in situ remediation of 2-naphthol contamination in the environment.

Asymmetric Catalytic Synthesis of Hexahydropyrrolo-isoquinolines via Three-Component 1,3-Dipolar-Cycloaddition.

An asymmetric three-component 1,3-dipolar cycloaddition of 3,4-dihydroisoquinolines, bromoacetates and α,ß-unsaturated pyrazole amide is realized by using a chiral N,N'-dioxide-Y(OTf)3 complex as the catalyst. The process includes a base-promoted formation of dihydroisoquinolium ylides in situ, and a chiral Lewis acid-catalyzed asymmetric [3+2] cycloaddition with α,ß-unsaturated pyrazole amides. A series of hexahydropyrrolo-isoquinolines are obtained in moderate to good yields with excellent diastereo- and enantioselectivities.

Tandem Insertion-[1,3]-Rearrangement: Highly Enantioselective Construction of α-Aminoketones.

An enantioselective synthesis of α-aminoketone derivatives were readily available through a tandem insertion-[1,3] O-to-C rearrangement reaction. The rhodium salt and chiral N,N'-dioxide-indium(III) complex make up relay catalysis, which enables the O-H insertion of benzylic alcohols to N-sulfonyl-1,2,3-triazoles, and asymmetric [1,3]-rearrangement of amino enol ether intermediates, subsequently. Preliminary mechanistic studies suggested that the [1,3] O-to-C rearrangement step proceeded through an ion pair pathway.

Copper/guanidine-catalyzed asymmetric alkynylation of isatin-derived ketimines.

Isatin-derived ketimines undergo enantioselective alkynylation reactions in the presence of copper iodide and easily accessible guanidine-amides. The corresponding 3-alkynyl-3-aminooxyindoles are obtained in up to 95% yield and 96% ee. The guanidine plays a role in the formation of copper acetylide and the enantiodetermining step and the basic additive is excluded.