Objective To investigate antimicrobial resistance and ceftriaxone resistance mechanisms in clinically isolated nontyphoidal Salmonella(NTS),and provide evidence for the prevention and control of NTS infection and rational use of antimicrobial agents.Methods 108 NTS isolates were isolated from stool specimens of outpatients with acute diarrhea in the Second Hospital of Tianjin Medical University and Tianjin Medical University General Hospital from May to October of 2014,NTS were performed antimicrobial susceptibility testing;non-ceftriaxone-susceptible isolates were typed by serological,multilocus sequence (MLST),and pulsed-field gel electrophoresis (PFGE)methods,extended-spectrumβ-lactamase (ESBL)detection and AmpC genes were detection.Results Among 108 NTS isolates,mono-drug resistance rate to 11 antimicrobial agents was 49.07% (n= 53),multidrug resistance rate was17.59% . Susceptibility rates to nalidixic acid,levofloxacin,ciprofloxacin,ceftriaxone,and ertapenem were 61.11% ,66.67% ,68.52% ,97.22% ,and 100.00% respectively. Three non-ceftriaxone-susceptible NTS isolates were detected,2 were ST11 Salmonellaenterica serotype (Sa8709,Sa8771),1 was ST34 Salmonellatyphimurium serotype(Sa8763). Cluster analysis of PFGE revealed that Sa8709 was highly similar to Sa8771 strains(91 .70% ), but the similarity to Sa8763 was low(55.80% );Sa8709 strain carried CTX-M gene,Sa8771 strain carried CTX-M and TEM genes,Sa8763 strain carried OXA gene. Conclusion Clinically isolated NTS in this area are low resistant to fluoroquinolones,multidrug resistant strains carrying ESBLs have emerged.

Objective To investigate the antibiotic susceptibilities and the profiles of virulence genes of clinically isolated Salmonella enterica serovars Schwarzengrund ( S. Schwarzengrund) strains for bet-ter understanding the epidemiological trend of this type of non-typhoidal Salomonella and to provide guide-lines for the prevention and treatment of S. Schwarzengrund infection. Methods Stool samples and clinical data of patients with acute diarrhea who received treatment in the Second Hospital of Tianjin Medical Univer-sity during May, 2014 to October, 2014 were collected for this study. Enrichment culture and biochemical identification were used to isolate and identify the S. Schwarzengrund strains. The isolated strains were fur-ther analyzed with serotyping analysis, drug susceptibility test, pulsed field gel electrophoresis ( PFGE) and multiple locus sequence typing ( MLST ) . The representative genes carried by Salmonella pathogenicity islands (SPI) 1-5, SPI regulators and virulence plasmids were amplified by PCR. The coding genes of CdtB-islet, which were cdtB, pltA and pltB were amplified and sequenced. Results In total, 16 (14. 8%) out of 108 non-typhoidal Salmonella strains were identified as S. Schwarzengrund strains and all of them were sus-ceptible to 11 kinds of antibiotics such as fluoroquinolone, ampicillin, ceftriaxone and trimethoprim-sulfame-thoxazole. PFGE categorized the 16 S. Schwarzengrund strains into 3 clusters including A clone ( 14 strains), B clone (1 strain) and C clone (1 strain). The strains that isolated from 8 patients who ate the same food belonged to one cluster ( A clone ) , suggesting that it was an outbreak of infection. The 16 S. Schwarzengrund strains showed identical MLST type, which was ST241. The representative genes carried by SPI1-5 ( invA, sitC, hilA, sseL, sifA, mgtC, siiE and sopB) , the regulatory gene ( phoP) and the cytole-thal distending toxin islet (CdtB-islet) coding genes (cdtB, pltA and pltB) were positive, while the genes carried by virulence plasmids (pefA, prot6E and spvB) were negative. The similarities in CdtB-islet coding genes and amino acids sequences between Salmonella typhi and S. Schwarzengrund strains in this study were more than 97% and 98%, respectively. Conclusion In this study, polyclonal S. Schwarzengrund strains of ST241 type were isolated from the patients. They were susceptible to common antibiotics, but carried the virulence genes contained in SPI1-5 and CdtB-islet coding genes and might cause an outbreak of infection. Attention should be paid to the tendency and threat of clinical S. Schwarzengrund infection and continuous surveillance and investigation should be performed.

Objective To investigate the interference of thyroglobulin antibodies ( TgAb ) on the measurement of thyroglobulin ( Tg) by 2 chemiluminescence immunoassays ( CLIAs) .Methods Data of 199 315 individuals with determined TgAb and Tg , including physical checkup subjects , differentiated thyroid carcinoma ( DTC) patients and patients with other diseases , were retrospectively collected in Peking Union Medical College Hospital from November 2012 to April 2015.The correlation between serum Tg level and serum TgAb concentration was analyzed and the positive rate of TgAb in physical checkup subjects was calculated.Furthermore, 290 serum samples with different TgAb concentration were applied in the recovery test by adding in confirmed serum Tg .The correlation between the recovery of confirmed serum Tg and TgAb concentrations was evaluated using Pearson correlation analysis .Results The serum Tg was all decreased with the elevated TgAb concentration in each group of subjects .The positive rate of TgAb was 10.84%(8 416/77 634) in physical checkup subjects .It was higher in females than in males and was increased with age.Recovery test showed that the average recoveries of confirmed serum Tg in TgAb-negative serum were 107.28%(86.30%-117.60%) and 107.94% (85.60%-124.10%) respectively in Roche and Beckman systems.But in TgAb-positive serum samples , the average recoveries in Roche and Beckman systems were 88.59% (35.85% -141.53%) and 95.77% (36.48% -131.78%) respectively, and 12.63%(24/190) and 13.68%(26/190) samples displayed a recovery less than 80%.The recovery rate of confirmed serum Tg showed a significantly negative correlation with elevated TgAb concentration , with r=-0.239 (P=0.001) in Roche and r=-0.251 (P<0.001) in Beckman.Conclusions TgAb-positive serum, especially with high concentration of TgAb , significantly interfered the measurement of Tg .Thus, serum TgAb should be determined together with serum Tg to explore whether there was an interference .To avoid misdiagnosis and inappropriate therapy , clinician should be informed once serum TgAb displayed positive.

Rhinovirus(RV)is the most common respiratory virus that can cause infectious diseases of the upper and lower respiratory tract, such as the common cold and bronchiolitis.Among them, bronchiolitis is the main cause of wheezing attacks in infants under 2 years old, and the prevalence is increasing year by year.Early research believed that the main etiology was respiratory syncytial virus(RSV), but in recent years, more and more bronchiolitis has been found that caused by rhinovirus infection.This article takes rhinovirus-infected bronchiolitis as the entry point, and reviews its epidemiological characteristics, pathogenesis, clinical manifestations, auxiliary examination, treatment and prevention.

Objective:To realize the optimization and upgradation of the detection method of you only look once(YOLO)algorithm model based on the improved YOLO network on the ultrasound image for breast tumor.Methods:A total of 659 images of breast tumor of the Kaggle database were selected as the initially dataset,and the image annotation tool Labelimg was used to conduct pre-labeling for the detection targets in the images.According to a ratio as 7:3,629 images of the 659 images were divided into the train set and validation set,and the other 30 images were used as the test set.The convolutional block attention module(CBAM)and bidirectional feature pyramid network(BiFPN)were introduced into the original YOLO algorithm to underwent structural improvement,which was named as YOLOv5-BiFPN-CBAM.Both the train set and validation set were placed in original YOLO algorithm model and YOLOv5-BiFPN-CBAM model to conduct train,which included 200 rounds of iterative training.The obtained optimal weight files were used in the final test of test set.Results:After 200 rounds of iterative train for two kinds of models,the test results of validation set indicated that the mean values of average precision of two kinds of models were respectively 72.1%and 80.5%for all ultrasound images of breast tumor.The result,that the optimal weight file of improved model was tested by test set,indicated the test ability of improved model was significantly enhanced than that of original model for small target in image.Conclusion:Compared with the original YOLO algorithm model,the improved YOLO algorithm model has higher recognition capability for image,which also enhances precision and sensitivity in identifying small targets of ultrasound images of breast tumor.This model is helpful to improve the diagnostic efficiency in clinical practice for breast tumor.

Objective To investigate the effects of low-dose ionizing radiation on the thyroid status and hormone levels of radiation workers. Methods Radiation workers who underwent occupational health examinations at a hospital in Guangzhou from 2015 to 2022 were selected as the subjects of this study. The levels of FT3, FT4 and TSH were analyzed, and the thyroid abnormality status of radiation workers in different groups were compared. Results A total of 1152 participants were included in this study, consisting of 885 (76.82%) males and 267 (23.18%) females, with an average age of (35.26 ± 10.16) years. The prevalence of thyroid abnormalities was 9.38%, which was significantly higher in females (13.86%) than in males (8.02%) (P < 0.05). The TSH level of females [(2.15 ± 1.29) mIU/L] was higher than that of males [(1.85 ± 1.20) mIU/L], while the levels of FT3 [(5.10 ± 0.64) pmol/L] and FT4 [(15.84 ± 2.32) pmol/L] in females were lower than those in males [(5.23 ± 0.63) pmol/L and (16.61 ± 2.75) pmol/L, P < 0.05]. The FT3 of industrial workers [(5.25 ± 0.63) pmol/L] was higher than that of medical workers [(5.10 ± 0.63) pmol/L], while the TSH of industrial workers [(1.80 ± 1.12) mIU/L] was lower than that of medical workers [(2.15 ± 1.37) mIU/L]. FT4 levels decreased with increasing age and duration of occupational exposure. Multivariable logistic regression analysis revealed that sex was a significant independent predictor of thyroid abnormalities among radiation workers. Female workers were more likely to experience thyroid abnormalities (β = −0.62, P < 0.05). Conclusion Low-dose ionizing radiation may have a certain impact on the thyroid status of radiation workers, especially for female workers, which requires further attention and research.

This study employed the α-glucosidase inhibitory activity model as an anti-diabetic assay and implemented a bioactivity-guided isolation strategy to identify novel natural compounds with potential therapeutic properties. Hypericum sampsoniiwas investigated, leading to the isolation of two highly modified seco-polycyclic polyprenylated acylphloroglucinols (PPAPs) (1 and 2), eight phenolic derivatives (3-10), and four terpene derivatives (11-14). The structures of compounds 1 and 2, featuring an unprecedented octahydro-2H-chromen-2-one ring system, were fully characterized using extensive spectroscopic data and quantum chemistry calculations. Six compounds (1, 5-7, 9, and 14) exhibited potential inhibitory effects against α-glucosidase, with IC₅₀ values ranging from 0.050 ± 0.0016 to 366.70 ± 11.08 μg·mL^-1. Notably, compound 5 (0.050 ± 0.0016 μg·mL^-1) was identified as the most potential α-glucosidase inhibitor, with an inhibitory effect about 6900 times stronger than the positive control, acarbose (IC₅₀ = 346.63 ± 15.65 μg·mL^-1). A docking study was conducted to predict molecular interactions between two compounds (1 and 5) and α-glucosidase, and the hypothetical biosynthetic pathways of the two unprecedented seco-PPAPs were proposed.
Molecular Structure ; Hypericum/chemistry* ; alpha-Glucosidases ; Magnetic Resonance Spectroscopy ; Glycoside Hydrolase Inhibitors/pharmacology*