ObjectivePhotoacoustic pump-probe imaging can effectively eliminate the interference of blood background signal in traditional photoacoustic imaging, and realize the imaging of weak phosphorescence molecules and their triplet lifetimes in deep tissues. However, background differential noise in photoacoustic pump-probe imaging often leads to large fitting results of phosphorescent molecule concentration and triplet lifetime. Therefore, this paper proposes a novel triplet lifetime fitting method for photoacoustic pump-probe imaging. By extracting the phase of the triplet differential signal and the background noise, the fitting bias caused by the background noise can be effectively corrected. MethodsThe advantages and feasibility of the proposed algorithm are verified by numerical simulation, phantom and in vivo experiments, respectively. ResultsIn the numerical simulation, under the condition of noise intensity being 10% of the signal amplitude, the new method can optimize the fitting deviation from 48.5% to about 5%, and has a higher exclusion coefficient (0.88>0.79), which greatly improves the fitting accuracy. The high specificity imaging ability of photoacoustic pump imaging for phosphorescent molecules has been demonstrated by phantom experiments. In vivo experiments have verified the feasibility of the new fitting method proposed in this paper for fitting phosphoometric lifetime to monitor oxygen partial pressure content during photodynamic therapy of tumors in nude mice. ConclusionThis work will play an important role in promoting the application of photoacoustic pump-probe imaging in biomedicine.

Objective To investigate the distribution and antimicrobial resistance of bacterial isolates from blood samples in the hospitals participating in China Antimicrobial Surveillance Network (CHINET) from 2015 to 2021.Methods Bacterial strains isolated from blood samples were collected from 52 medical centers participating in CHINET from 2015 to 2021 for analysis of bacetrial distribution and antimicrobial resistance.Results A total of 153591 isolates were collected,48.8％ of which were gram-positive bacteria and 51.2％ were gram-negative bacteria.The top five bacterial strains were coagulase negative Staphylococcus (28.2％),Escherichia coli (20.7％),Klebsiella (13.7％),Enterococcus (7.2％),and Staphylococcus aureus (6.6％).Compard to female patients,male patients showed lower proportion of E.coli and higher proportions of other bacterial species in all the bacterial isolaets from blood samples.The proportions of Streptococcus pneumoniae and Salmonella in all the bacterial isolaets from blood samples were higher in children compared to adults.Enterobacterales species showed various resistance rates to antimicrobial agents.Overall,≥58.0％,≥36.8％ and ≥56.8％ of E.coli strains were resistant to cefotaxime,gentamicin and levofloxacin respectively over the 7-year period.However,less than 2.5％ of the E.coli strains were resistant to carbapenems.K.pneumoniae showed higher resistance rates to imipenem and meropenem than other Enterobacterales species.During the 7-year period,the prevalence of imipenem-resistant and meropenem-resistant K.pneumoniae increased from 21.4％ and 19.9％ in 2015 to 25.7％ and 26.6％ in 2021,respectively.However,carbapenems still maintained good antibacterial activity against other Enterobacterales,associaetd with lower resistance rates.In the 7-year period,Acinetobacter baumannii showed a dwonward trend in the resistance rates to imipenem and meropenem,but remained 72.9％ and 73.2％ respectively in 2021.The prevalence of imipenem-resistant and meropenem-resistant P.aeruginosa decreased from 26.7％ and 22.9％ in 2015 to 18.5％ and 14.7％ in 2021,respectively.The prevalence of PRSP was 1.5％ in the isolaets from adults and and 0.8％ in the isolates from children.Less than 3.0％ of the Enterococcus faecium and Enterococcus faecalis strains were resistant to vancomycin,teicolanin,or linezolid.The prevalence of methicillin-resistant S.aureus (MRSA) and coagulase negative Staphylococcus (MRCNS) was 32.1％ and 81.0％,respectively.The prevalence of MRSA was relatively stable,28.5％ in 2015 and 28.0％ in 2021.Conclusions Coagulase negative Staphylococcus,E.coli and K.pneumoniae were the main bacterial species isolated from blood samples in the hospitals participaing in the CHINET from 2015 to 2021.Significant sex and age differences were found in the distribution of bcterial isolates from blood samples.The overall resistance rates of the top bacetrial strains from blood samples to antimicrobial agents showed a downward trend.Ongoing surveillance of antimicrobial resistance for the isolates from blood samples is still essential for prescribing rational antimicrobial therapies and curbing bacterial resistance.

Objective To investigate whether Liuwei Dihuang Pills enhances the antigen cross-presenting ability of dendritic cell(DC)by increasing gap junctional intercellular communication(GJIC),and to explore the mechanisms involved.Methods Western Blot and immunofluorescence were used to observe the effects of Liuwei Dihuang Pills-containing serum on the expression and membrane localisation of gap junction protein connexin43(Cx43)in mouse melanoma cells(B16);Calcein-AM/DiI fluorescence tracer assay was used to observe the effects of Liuwei Dihuang Pills-containing serum on the function of GJIC in B16 cells;flow cytometry was used to observe the role of GJIC in the enhancement of DC antigen presenting ability by Liuwei Dihuang Pills-containing serum;and propidium iodide(PI)/Hoechst staining assay was used to observe the immunocidal effect of CD8+ T-lymphocytes.Results Western Blot and immunofluorescence experiments showed that Liuwei Dihuang Pills-containing serum led to the up-regulation of Cx43 expression;fluorescence tracer experiments proved that the GJIC function of B16 cells was significantly enhanced by Liuwei Dihuang Pills-containing serum;flow cytometry analyses showed that the DC antigen-presenting ability was enhanced by Liuwei Dihuang Pills-containing serum;and the results of PI/Hoechst staining showed that the immuno-killing effect of CD8+T-cells was more significant after the intervention of Liuwei Dihuang Pills-containing serum in B16-OVA.Conclusion Liuwei Dihuang Pills improve the GJIC function by up-regulating the Cx43 expression of melanoma cells,and then enhance the cross-presenting ability of DCs thus activating stronger CD8+ T-cell immunocidal responses.

Objective The aim of this study was to assess the impact of bisphenol A (BPA) and its substitute, bisphenol F (BPF), on the colonic fecal community structure and function of mice.Methods We exposed 6-8-week-old male C57BL/6 mice to 5 mg/(kg·day) and 50 μg/(kg·day) of BPA or BPF for 14 days. Fecal samples from the colon were analyzed using 16S rRNA sequencing. Results Gut microbiome community richness and diversity, species composition, and function were significantly altered in mice exposed to BPA or BPF. This change was characterized by elevated levels of Ruminococcaceae UCG-010 and Oscillibacter and decreased levels of Prevotella 9 and Streptococcus. Additionally, pathways related to carbohydrate and amino acid metabolism showed substantial enrichment. Conclusion Mice exposed to different BP analogs exhibited distinct gut bacterial community richness, composition, and related metabolic pathways. Considering the essential role of gut bacteria in maintaining intestinal homeostasis, our study highlights the intestinal toxicity of BPs in vertebrates.

Objective To investigate the influences of Lycium barbarum polysaccharide on apoptosis of corneal epithelial cells induced by hypertonicity through regulating adenosine monophosphate activated protein kinase(AMPK)/uncoordinated 51-like kinase 1(ULK1)autophagy pathway.Methods The ophthalmoxerosis cell model was established by osmotic pressure of 500 mOsm·L-1 on corneal epithelial cells.They were divided into model group,positive control group(0.3％sodium hyaluronate eye drops),inhibitor group(1 mg·mL-1 Lycium barbarum polysaccharide+10 μmol·L-1compound C),experimental-L,-H groups(0.5,1.0 mg·mL 1 Lycium barbarum polysaccharide),and normal cultured CRL-11135 cells were taken as blank group(no treatment was performed).Cell apoptosis was detected by flow cytometry.Autophagy was detected by MDC staining.Western blot was used to detect the expressions of p-AMPK/AMPK and p-ULK1/ULK1.Results The apoptosis rates of experimental-L,experimental-H,positive control,inhibitor,model and blank groups were(26.47±2.13)％,(13.68±2.21)％,(12.54±2.16)％,(18.73±2.12)％,(37.56±3.25)％and(6.35±2.14)％;the relative contents of autophagosomes were(59.63±8.14)％,(89.89±9.04)％,(90.31±9.13)％,(62.75±7.26)％,(43.11±6.45)％and(100.00±0.00)％;p-AMPK/AMPK were 0.45±0.07,0.64±0.08,0.66±0.06,0.53±0.04,0.34±0.05 and 0.87±0.06;p-ULKl/ULKl were 0.54±0.06,0.75±0.05,0.77±0.03,0.65±0.04,0.46±0.04 and 0.92±0.08,respectively.The above indexes in experimental-L,-H groups and positive control group were significantly different from those in model group(all P＜0.05);the above indexes in inhibitor group were significantly different from those in experimental-H group(all P＜0.05).Conclusion Lycium barbarum polysaccharide can inhibit the apoptosis of corneal epithelial cells induced by hypertonicity by activating the AMPK/ULK1 autophagy pathway.

Objective To explore the effect of propranolol on femoral fracture healing in mice through regulation of microRNA-92a-3p(miR-92a-3p)and its mechanism.Methods C57BL/6J male mice were randomly divided into sham group(equal amount of 0.9％NaCl),model group(equal amount of 0.9％NaCl),experimental group(50 mg·kg-1 propranolol administration),inhibitor group(mice were injected with 100 mg·kg-1 miR-92a-3p inhibitor via tail vein on the basis of the experimental group).Femur was severed and molded in all mice except sham operation group.X-ray was used to observe bone healing.Quantitative real time polymerase chain reaction was used to detect the expression of miR-92a-3p in femur tissues.The expression level of bone formation and bone metabolism markers was detected by enzyme linked immunosorbent assay.Western blot was used to detect the expression of pathway-related proteins.Results The X-ray scores of femur in sham group,model group and experimental group were 11.20±2.60,4.70±1.50 and 9.60±2.40,respectively;the relative expression levels of miR-92a-3p in sham operation group,model group,experimental group and inhibitor group were 1.00±0.09,0.73±0.06,0.90±0.07 and 0.78±0.06;alkaline phosphatase levels were(35.21±2.63),(43.16±3.29),(67.58±5.37)and(49.62±4.05)U·L-1,respectively;crosslaps levels were(4.57±0.52),(8.41±0.91),(4.26±0.67)and(5.73±0.84)ng·mL-1,respectively;the relative expression levels of brain derived neurotrophic factor were 1.00±0.14,0.58±0.05,0.83±0.09 and 0.71±0.06,respectively;the relative expression levels of phospho-tyrosine kinase receptor B were 1.00±0.12,0.62±0.05,0.89±0.08 and 0.76±0.07,respectively;the relative expression levels of phospho-extracellular regulated protein kinases were 1.00±0.11,0.54±0.04,0.78±0.07 and 0.65±0.05,respectively.The above indexes in the model group were compared with those in the sham group,those in the experimental group were compared with those in the model group,and those in the inhibitor group were compared with those in the experimental group,and the differences were statistically significant(P＜0.05,P＜0.001).Conclusion Propranolol can promote femoral fracture healing in mice,which may be achieved by up-regulating miR-92a-3p activation of brain derived neurotrophic factor/tyrosine kinase receptor B/extracellular regulated protein kinases signaling pathway.

In this paper, the antitussive and expectorant activity of platycodin D (PD) were studied by constructing a mouse cough induced by concentrated ammonia water and a mouse trachea phenol red excretion model. The mechanism of antitussive and expectorant effect of PD was studied by metabolomics. The animal experiment was approved by the Animal Ethics Committee of Jiangxi University of Chinese Medicine (approval number: JZLLSC-20220739). Then mice were randomly divided into the normal, model, positive drug, PD low-dose, PD medium-dose and PD high-dose group. The antitussive and expectorant effects of PD were evaluated using a cough mouse model induced by concentrated ammonia water and a mouse tracheal phenol red excretion model, respectively. UHPLC-LTQ-Orbitrap-MS was used to identify the metabolites of mouse lung tissue, and multivariate statistical analysis method of orthogonal partial least squares discriminant analysis (OPLS-DA) was used for metabolites profile analysis. The differential metabolites were screened by variable projected importance value (VIP) and t-test results. Pathways for enrichment of differentiated metabolites were analyzed using the MetaboAnalyst platform. The comparative method was applied to analyze the differences in mechanisms of PD, Deapio-platycodin D (DPD) and total platycosides fraction. The results showed that PD at different concentrations could significantly prolong (P < 0.05) the incubation period of cough mice induced by ammonia water, reduce the coughs frequency, and significantly increase (P < 0.05) the amount of phenol red excretion in phenol red excretion model mice. PD could regulate 6 metabolic pathways of phenylalanine, tyrosine and tryptophan biosynthesis, linoleic acid metabolism, phenylalanine metabolism, glycerophospholipid metabolism, and tyrosine metabolism to exert antitussive effect. It could also regulate 8 metabolic pathways of linoleic acid metabolism, glyoxylic acid and dicarboxylic acid metabolism, glycerol phospholipid metabolism, citric acid cycle and arachidonic acid metabolism to exert an expectorant effect. However, only linoleic acid metabolism and glycerophospholipid metabolism could be regulated by the PD, total platycosides fraction and DPD, which may be ascribed to the structural difference of the platycosides and the interaction between platycosides and the intestinal microbiota. Functional analysis showed that these metabolic pathways are closely related to the regulatory mechanisms of anti-inflammatory response, immune function regulation, neurotransmitter release, cell signal transduction, energy metabolism and cell apoptosis. This study shows that PD possesses good antitussive and expectorant activities. In addition, the mechanism difference of PD, total platycosides fraction and DPD imply that the apiose in PD and the interaction between PD and intestinal microbiota could exert an important effect on the antitussive and expectorant mechanism of the platycosides.

An integrated evaluation model based on the combination of traditional trait identification and modern chemical analysis was used for the identification of key indexes of grade classification and the establishment of grade quality standard of Lycium barbarum fruits (LBF) from Ningxia genuine producing area. Under the guidance of herbal examination and market survey, particle size, skin color and imperfection were taken as the external trait indicators; focusing on the comprehensiveness and validity of the quality evaluation, 2-O-β-D-glucopyranosyl-L-ascorbic acid (AA-2βG), zeaxanthin dipalmitate (ZD) and volatile ether extractives were used as important parameters involving in quality evaluation in addition to the pharmacopoeia test items and determination indicators such as moisture, ash, water-soluble extractives, Lycium barbarum polysaccharide (LBP) and betaine. The quality differences between different traits and grades of LBF as well as the relevance between character and quality were further investigated by mathematical and statistical means such as t-test analysis, correlation analysis and principal component analysis (PCA). Furthermore, the activities of extractives from different grades of LBF were compared at cellular level. The results showed that LBF were mainly preferred for large and red ones; except for betaine, the other index components were relatively high (moisture and ash were low) in the first-grade and samples with bright-red skin color. Besides, there was a significant correlation between skin color and moisture, water-soluble extractives, LBP, AA-2βG and ZD contents. Considering the results of the study and the market situation, the present study took the grain size and skin color of LBF as the core of evaluation, and at the same time introduced the multi-indicator components including LBP, AA-2βG, ZD, water-soluble extractives and moisture to further guide the grading, and established the quality standard of LBF grades combining the trait indexes and the chemical composition. More importantly, in vitro cell models both preliminarily confirmed that the first-grade LBF played a more significant "nourishing liver and kidney" effect, which provided an experimental basis for the quality control of LBF and promoted the realization of high quality and good price.

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]