The chemical constituents in dried roots of Atractylodes macrocephala were investigated in this study. Through utilizing normal-phase silica gel and ODS column chromatography, TLC, and semi-preparative HPLC, 4 new sesquiterpenoids were purified from the ethyl acetate extract of A. macrocephala. By various spectroscopic techniques, such as 1D and 2D NMR, HR-ESI-MS, IR, UV, and CD, their structures were identified as atractylmacron A (1), 9β-hydroxyasterolide (2), atractylenolide H (3), atractylenolide J (4). Compound 1 possesses a rare 6/7 bicyclic skeleton.

Human exhaled breath has great application prospects,e.g.,monitoring pharmacokinetics,disease diagnosis,due to its advantages such as non-invasive and high-frequency sampling.Breath samples can be collected from the oral and nasal cavity.However,the oral and nasal environment affect the chemical composition of breath sample.Therefore,the investigation on the chemical composition of mouth-exhaled breath and nose-exhaled breath is crucial for selection of appropriate sampling strategy for individual studies.In this work,secondary electrospray ionization-high resolution mass spectrometry(SESI-HRMS)was applied to analysis of respiratory metabolomics in real time.A quantitative analysis approach was established for 9 kinds of volatile organic compounds(VOCs)e.g.2-butanone,2-pentanone,ethyl acetate,methyl methacrylate,toluene,styrene,mesitylene,isoprene and limonene.The limit of detection was 2.3?240.8 ng/m3.The intra-day(n=6)and inter-day(n=18)relative standard deviations were 0.6%?4.6%and 4.3%?12.2%,respectively.Nine healthy subjects were recruited to investigate the chemical composition of mouth-exhaled and nose-exhaled breath.The results showed the good performance in quantitative analysis of 9 VOCs in breath air.It was found that the number of unique component(m/z)detected in mouth-exhaled breath(167)was 2.2 times greater than that detected in nose-exhaled breath(76),which might result from the complex environment in oral cavity.The signal intensity of commun component(163)was significantly different between mouth-exhaled breath and nose-exhaled breath.Additionally,the elemental composition analysis showed that the proportion of polar compounds detected in nose-exhaled breath was higher than that in mouth-exhaled breath.This study demonstrated that there was significant differences in the chemical composition between mouth-exhaled and nose-exhaled breath,which provided a theoretical basis for selection of exhalation mode.

Tuberous sclerosis complex(TSC)is a rare genetic disease that can lead to benign dysplasia in multiple organs such as the skin, brain, eyes, oral cavity, heart, lungs, kidneys, liver, and bones. Its main symptoms include epilepsy, intellectual disabilities, skin depigmentation, and facial angiofibromas, whilst incidence is approximately 1 in 10 000 to 1 in 6000 newborns. This case presents a middle-aged woman who initially manifested with epilepsy and nodular depigmentation. Later, she developed a lower abdominal mass, elevated creatinine, and severe anemia. Based on clinical features and whole exome sequencing, the primary diagnosis was confirmed as TSC. Laboratory and imaging examinations revealed that the lower abdominal mass originated from the uterus. CT-guided biopsy pathology and surgical pathology suggested a combination of leiomyoma and abscess. With the involvement of multiple organs and various complications beyond the main diagnosis, the diagnostic and therapeutic process for this patient highlights the importance of rigorous clinical thinking and multidisciplinary collaboration in the diagnosis and treatment of rare and challenging diseases.

ObjectiveDnaG primase in Mycobacterium tuberculosis (MtuDnaG) plays a vital role in DNA replication, making it a target for novel antituberculosis drug discovery. However, the mechanism of MtuDnaG priming is not fully understood, which hinders the screening of MtuDnaG inhibitors. In this work, the specific recognition sites (SRS) in ssDNA for MtuDnaG binding was investigated and the interactions between MtuDnaG and ssDNA template was discussed. MethodsBy biochemical and biophysical methods, the binding of the didomain of MtuDnaG (MtuP49, containing the zinc-binding domain and RNA polymerase domain) to ssDNA template with various trinucleotide sites was evaluated, the affinity of MtuP49 to ssDNA template was measured. ResultsThe present study suggested the 5'-GCG/C-3' as the potential SRS in ssDNA for specific binding to MtuDnaG. Besides,5'-GCG/C-3' sites were further identified within the oriC region of M. tuberculosis genome. Importantly, the 3' sequence flanking the 5'-GCG/C-3' site markedly affected the binding affinity of ssDNA to MtuP49. Mutagenesis studies showed that substitution of residue Arg31 in the zinc-binding domain affected the binding activity of MtuP49 to template ssDNA. Combined with the predicted structure of MtuP49, an intramolecular rearrangement of zinc-binding domain relative to the RNA polymerase domain was implied to be essential in the binding of MtuP49 to template ssDNA. ConclusionThis study firstly identified the SRS in ssDNA for MtuDnaG binding, the key factors affecting MtuDnaG binding to ssDNA was revealed. The above results provide evidence to shed light on the mechanism of MtuDnaG priming, and pave the way for development of novel DnaG-targeted antituberculosis drugs.

Objective: The study aimed to investigate the role of N6-methyladenosine (m6A) modification in spinal cord injury (SCI) and its underlying mechanism, focusing on the interplay between m6A methyltransferase-like 3 (METTL3), miR-30c, and autophagy-related proteins. Methods: An SCI model was established in rats, and changes in autophagy-related proteins, m6A methylation levels, and miR-30c levels were analyzed. Hydrogen peroxide (H2O2)-stimulated spinal cord neuron cells (SCNCs) were used to assess the impact of METTL3 overexpression. The effects of STM2457, an antagonist of METTL3, were evaluated on cell viability, apoptosis, and autophagy markers in H2O2-stimulated SCNCs. Results: In the SCI model, decreased levels of autophagy markers and increased m6A methylation, miR-30c levels, and METTL3 were observed. Overexpression of METTL3 in SCNCs led to reduced cell viability, increased apoptosis, and suppressed autophagy. Conversely, co-overexpression of autophagy-related protein 5 (ATG5) or miR-30c inhibition reversed these effects. Knocking out METTL3 yielded opposite results. STM2457 treatment improved cell viability, reduced apoptosis, and upregulated autophagy markers in SCNCs, which also enhanced functional recovery in rats as measured by the Basso-Beattie-Bresnahan score and inclined plate test. Conclusion STM2457 alleviated SCI by suppressing METTL3-mediated m6A modification of miR-30c, which in turn induces ATG5-mediated autophagy. This study provides insights into the role of m6A modification in SCI and suggests a potential therapeutic approach through targeting METTL3.

Objective: The study aimed to investigate the role of N6-methyladenosine (m6A) modification in spinal cord injury (SCI) and its underlying mechanism, focusing on the interplay between m6A methyltransferase-like 3 (METTL3), miR-30c, and autophagy-related proteins. Methods: An SCI model was established in rats, and changes in autophagy-related proteins, m6A methylation levels, and miR-30c levels were analyzed. Hydrogen peroxide (H2O2)-stimulated spinal cord neuron cells (SCNCs) were used to assess the impact of METTL3 overexpression. The effects of STM2457, an antagonist of METTL3, were evaluated on cell viability, apoptosis, and autophagy markers in H2O2-stimulated SCNCs. Results: In the SCI model, decreased levels of autophagy markers and increased m6A methylation, miR-30c levels, and METTL3 were observed. Overexpression of METTL3 in SCNCs led to reduced cell viability, increased apoptosis, and suppressed autophagy. Conversely, co-overexpression of autophagy-related protein 5 (ATG5) or miR-30c inhibition reversed these effects. Knocking out METTL3 yielded opposite results. STM2457 treatment improved cell viability, reduced apoptosis, and upregulated autophagy markers in SCNCs, which also enhanced functional recovery in rats as measured by the Basso-Beattie-Bresnahan score and inclined plate test. Conclusion STM2457 alleviated SCI by suppressing METTL3-mediated m6A modification of miR-30c, which in turn induces ATG5-mediated autophagy. This study provides insights into the role of m6A modification in SCI and suggests a potential therapeutic approach through targeting METTL3.

Amino acid surfactants (AAS) have excellent properties such as low toxicity,antibacterial,mildness,and corrosion resistance. In recent years,they have been widely applied in the field of daily chemicals,food and pharmaceutical industry. It is pointed out that the structure at molecular level largely affects the physical and chemical properties of AAS materials. In this work,the structures of solid-state N-lauroyl-L-alanine (NLLA) including intermolecular interactions,molecular local dynamics and molecular assembly were investigated by a variety of solid-state nuclear magnetic resonance (SSNMR) techniques. Based on 2D 1H-1H double quantum-single quantum (2D 1H-1H DQ-SQ),1H-1H DQ sideband pattern and molecular simulation,it was found that there was a stable intermolecular hydrogen bond formed between the carboxyl units of two NLLA molecules. Combined with the study of 2D frequency switched Lee—Goldberg heteronuclear correlation (2D 13C-1H FSLG-HETCOR) and 13C T1,another type of hydrogen bond was probed,which existed between amide units of neighboring molecules. In addition,the conformation of alkyl chain ends was investigated. According to 1D 13C{1H}cross polarization/magic angle spinning (CP/MAS) and 2D 13C-1H FSLG-HETCOR spectra,it was revealed that the alkyl-chain ends had both gauche and trans conformations. Moreover,the trans conformation showed two distinct 13C chemical shifts,originated from two NLLA molecular assembly forms. Accordingly,two NLLA molecular assembly structures were suggested which were transoid form and cisoid form. This work provided a SSNMR investigation strategy for characterizing the molecular local structure and dynamics of AAS materials,which helped task of researching and developing materials with improved chemical and physical properties.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

Objective:To evaluate the safety and efficiency of robotic visualization system(RVS)-assisted microsurgical re-construction of the reproductive tract in male rats and the satisfaction of the surgeons.Methods:We randomly divided 8 adult male SD rats into an experimental and a control group,the former treated by RVS-assisted microsurgical vasoepididymostomy(VE)or vaso-vasostomy(VV),and the latter by VE or VV under the standard operating microscope(SOM).We compared the operation time,me-chanical patency and anastomosis leakage immediately after surgery,and the surgeons'satisfaction between the two groups.Results:No statistically significant difference was observed the operation time between the experimental and the control groups,and no anasto-mosis leakage occurred after VV in either group.The rate of mechanical patency immediately after surgery was 100％in both groups,and that of anastomosis leakage after VE was 16.7％in the experimental group and 14.3％in the control.Compared with the control group,the experimental group achieved dramatically higher scores on visual comfort(3.00±0.76 vs 4.00±0.53,P＜0.05),neck/back comfort(2.75±1.16 vs 4.38±1.06,P＜0.01)and man-machine interaction(3.88±1.55 va 4.88±0.35,P＜0.05).There were no statistically significant differences in the scores on image definition and operating room suitability between the two groups.Conclusion:RVS can be used in microsurgical reconstruction of the reproductive tract in male rats and,with its advantages over SOM in ergonomic design and image definition,has a potential application value in male reproductive system micosurgery.