Objective: To investigate the distribution of IgM anti-A/B titers among group O whole blood donors in Jiangsu, establish a low-titer threshold, and analyze the demographic characteristics of low-titer donors, so as to provide data for recruiting low-titer group O whole blood (LTOWB) donors. Methods: Plasma samples from 1 009 group O whole blood donors were tested for IgM anti-A and anti-B titers using the microplate technique. The distribution of antibody titers was analyzed to establish a low-titer threshold. The distribution trends of titers across different demographic groups were also analyzed. Results: The peak titer for anti-A, anti-B were 64 (31.5%), 4 (23.8%), respectively, The proportion of donors with both anti-A and anti-B titers below 64 was 97.3% (982/1 009). The mean anti-A titer was higher than anti-B titer. Anti-A titers were higher in female donors than in male donors (P<0.05). The anti-A titers differed significantly among different age groups (P<0.05). However, no significant difference in titers was observed based on the number of donations (P>0.05). Conclusion: A titer of 64 can be used as the reference threshold of LTOWB in Jiangsu. Male donors of appropriate age are more suitable than female donors for establishing an emergency panel of LTOWB mobile donors.

OBJECTIVE: Blood culture remains the gold standard for diagnosing bloodstream infections. Clinical laboratories must ensure the quality of blood culture processes from receipt to obtaining definitive results. We examined laboratory analytical indicators associated with positive blood culture results. METHODS: Blood cultures collected from Peking Union Medical College Hospital between January 1, 2020, and December 31, 2022, were retrospectively analyzed. The mode of transportation (piping logistics delivery vs. staff), source of blood cultures (outpatient/emergency department vs. inpatient department), rotation of personnel, and time of reception (8:00-19:59 vs. 20:00-07:59) were compared between blood culture-positive and -negative results. RESULTS: Between 2020 and 2022, the total positive rate of blood culture was 8.07%. The positive rate of blood cultures in the outpatient/emergency department was significantly higher than that in the inpatient department (12.46% vs. 5.83%; P < 0.0001). The time-to-detection of blood cultures was significantly affected by the delivery mode and personnel rotation. The blood culture positive rate of the total pre-analytical time within 1 h was significantly higher than that within 1-2 h or > 2 h ( P < 0.0170). CONCLUSION Laboratory analytical indicators such as patient source, transportation mode, and personnel rotation significantly impacted the positive detection rate or time of blood culture.
Blood Culture/statistics & numerical data* ; Humans ; Retrospective Studies ; Emergency Service, Hospital/statistics & numerical data*

OBJECTIVE: Pseudomonas aeruginosa( P. aeruginosa) is a prevalent pathogenic bacterium involved in meningitis; however, the virulence factors contributing to this disease remain poorly understood. METHODS: The virulence of the P. aeruginosa A584, isolated from meningitis samples, was evaluated by constructing in vitro blood-brain barrier and in vivo systemic infection models. qPCR, whole-genome sequencing, and drug efflux assays of A584 were performed to analyze the virulence factors. RESULTS: Genomic sequencing showed that A584 formed a phylogenetic cluster with the reference strains NY7610, DDRC3, Pa58, and Pa124. Its genome includes abundant virulence factors, such as hemolysin, the Type IV secretion system, and pyoverdine. A584 is a multidrug-resistant strain, and its wide-spectrum resistance is associated with enhanced drug efflux. Moreover, this strain caused significantly more severe damage to the blood-brain barrier than the standard strain, PAO1. qPCR assays further revealed the downregulation of the blood-brain barrier-associated proteins Claudin-5 and Occludin by A584. During systemic infection, A584 exhibited a higher capacity of brain colonization than PAO1 (37.1 × 10 ⁶ CFU/g brain versus 2.5 × 10 ⁶ CFU/g brain), leading to higher levels of the pro-inflammatory factors IL-1β and TNF-α. CONCLUSION This study sheds light on the virulence factors of P. aeruginosa involved in meningitis.
Pseudomonas aeruginosa/genetics* ; Virulence Factors/metabolism* ; Animals ; Virulence ; Mice ; Pseudomonas Infections/microbiology* ; Blood-Brain Barrier/microbiology* ; Humans ; Female

The single photon counting imaging detector based on microchannel plate(MCP)has the characteristics of high sensitivity and low dark count rate,and has been applied to the optical remote sensing detection of weak ultraviolet spectral signals in space.In this work,by using planar array single photon counting imaging detector as the detector,flat-field concave grating as the splitter,and electrodeless discharge lamp(EDL)as the excitation light source,a dispersion detection system suitable for hydride generation-atomic fluorescence spectrometry(HG-AFS)was developed.The wavelength calibration of the system was carried out,and the negative high pressure and EDL stability time of the planar array single photon counting imaging detector were analyzed and optimized.The characteristic emission spectral lines of As and Bi elements excited in the wavelength range of 180-320 nm were analyzed,and the scattering interference in the wavelength range of 257.3-306.7 nm was discussed.The results showed that the AFS dispersion detection system based on the planar array single photon counting imaging detector could detect and analyze the HG-AFS fluorescence signal initially,and the influence of scattering interference on the detection results was effectively avoided.The system had the advantages including simple structure,no refrigeration and temperature control,no moving parts and simultaneous measurement of multi-band.

Peroxynitrite anion(ONOO-),which is originated from the reaction of nitric oxide(NO)and superoxide anion(O2-),plays a pivotal role in immune defense and signal regulation.Excessive levels of ONOO-may induce the occurrence of various diseases such as Alzheimer's disease,inflammation,cardiovascular disease and cancer,etc.Existing detection methods for ONOO-have limitations such as complexity,time consumption,and low cell biocompatibility.In this study,a novel fluorescent probe QFPD was developed using quinoline and diphenylphosphinamide as fluorescent keleton and recognition group,respectively.The strong oxidizing property of ONOO-triggerd the cleavage of phosphoramide bond,leading to fluorescence quenching and a visible color change of the solution from yellow to purple,thereby enabling"ON-OFF"type recognition of ONOO-.QFPD exhibited excellent characteristics including good selectivity and high sensitivity in fluorescence detection(Limit of detection of 1.37 μmol/L),large Stokes shift(130 nm),rapid response(10 min),and strong anti-interference ability.Additionally,QFPD demonstrated good biocompatibility and could realize real-time dynamic monitoring of endogenous ONOO-.Furthermore,QFPD was successfully applied to environmental toxicology research by visualizing the oxidative stress effects induced by microplastics polymethyl methacrylate(PMMA)and Hg2+exposure,which might be a novel tool for the mechanism research on oxidative stress associated with microplastic pollution and heavy metal exposure.

The construction of first-class universities and disciplines is a major strategic initiative of the Communist Party of China Central Committee and the State Council,and an important task for building a world-class higher education powerhouse.Forensic medicine was officially listed as a first-level discipline under the medical category in 2022,presenting unprecedented historical opportunities for the development of forensic medicine.Facing this significant strategic opportunity,this paper sorts out the disciplinary system of forensic medicine,carries out forward-looking planning for the develop-ment of the discipline,and looks forward to the development vision of the discipline:(1)Establish an organically connected three-stage forensic medicine talent training system to cultivate applied and innovative talents that meet the needs of China's socialist modernization construction;(2)Establish a unified standardized forensic practice qualification examination system,organically connect talent training with professional qualification examination,and optimize the professional development path of forensic medicine;(3)Widely intersect,integrate and transform forensic medicine with other multiple disciplines,expand and enrich the second-and third-level disciplinary systems of forensic medicine,and build a world-class forensic medicine discipline with Chinese characteristics.

Objective To establish and validate a method for simultaneous determination of 9 sedative-hypnotics in human plasma,and to explore the preliminary clinical application.Methods Plasma samples were precipitated with acetonitrile and determined by high performance liquid chromatography tandem mass spectrometry.The column was Agilent Poroshell 120 EC-C18(2.1 mm × 50.0 mm,2.7μm)and eluted with acetonitrile water containing 0.1％formic acid in an equal degree program at a flow rate of 0.3 mL·min-1.The column temperature was 20 ℃ and injection volume was 5 μL.The deprotonated ions of analytes were ionized by positive ion,electron spray ionization and multiple reaction monitoring mode.The specificity,standard curve and lower limit of quantification,precision and recovery,matrix effect,stability and dilution effect of the method were investigated.Results Excellent linear relationship with correlation coefficient of r2 ≥ 0.997 7 was obtained.The linear of esazolam,alprazolam,oxazepam,clonazepam,lorazepam,triazolam,midazolam,diazepam and zolpidem were 18-1 800,4.5-450,25-2 500,3.5-350,25-2 500,1.5-150,5.5-550,35-3 500,4-400 ng·mL-1,respectively.The lower limit of quantification were 18,4.5,25,3.5,25,1.5,5.5,35,4 ng·mL-1.The method was accurate and precise with acceptable intra-day and inter-day precisions(relative standard deviations were less than 20％for a lower limit of quantification and less than 15％for other quality control samples)and an accuracy of 86.21％-112.38％.The extraction recovery rate were 93.07％-110.50％.The matrix factors normalized by internal standard were 86.61％-108.41％,relative standard deviations were less than 15％.Plasma samples remained stable under various storage conditions.The precision and accuracy of plasma samples were acceptable after dilution.Conclusion The method is simple,rapid,sensitive and specific,and it can be used for simultaneous detection of the 9 sedative-hypnotics in human plasma.

Humans ; Female ; Deep Learning ; Ovarian Neoplasms/genetics* ; Carcinoma, Ovarian Epithelial/genetics* ; Neural Networks, Computer ; RNA

Diabetic ulcer is recognized as a chronic nonhealing wound, often associated with bacterial infection and tissue necrosis, which seriously affect patients' health and quality of life. The traditional treatment methods exist some problems, such as bacterial resistance and secondary trauma, so it is urgent to find new methods to meet the requirements of diabetic ulcer treatment. In this study, we prepared a drug delivery system (DFO@CuS nanoparticles) based on hollow copper sulfide (CuS) nanoparticles loaded with deferoxamine (DFO), which realized the synergistic therapy of promoting angiogenesis and photothermal antibacterial. The morphological structure and particle size distribution of DFO@CuS nanoparticles were characterized by transmission electron microscopy and particle size analyzer, respectively. The antibacterial effect of DFO@CuS nanoparticles was evaluated by the plate coating method. The effects of DFO@CuS nanoparticles on the proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) were evaluated by CCK-8 (cell counting kit-8) assay, cell scratch assay, and tube formation assay. The results showed that DFO@CuS nanoparticles were hollow and spherical in shape with an average particle size of (200.9 ± 8.6) nm. DFO@CuS nanoparticles could effectively inhibit the growth of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PA) under near-infrared (NIR) light irradiation. DFO@CuS nanoparticles showed negligible cytotoxicity and effective acceleration of cell migration and tube formation in a certain concentration range. In conclusion, the prepared DFO@CuS nanoparticles exhibit good photothermal antibacterial properties and pro-angiogenic effects, providing a basis for their application in the treatment of diabetic ulcer.

OBJECTIVE: To establish an efficient protocol for directed differentiation of human induced pluripotent stem cells (hiPSCs) into functional midbrain dopaminergic progenitor cells (DAPs) in vitro. METHODS: hiPSCs were induced to differentiate into DAPs in two developmental stages. In the first stage (the first 13 days), hiPSCs were induced into intermediate cells morphologically similar to primitive neuroepithelial cells (NECs) in neural induction medium containing a combination of small molecule compounds. In the second stage, the intermediate cells were further induced in neural differentiation medium until day 28 to obtain DAPs. After CM-DiI staining, the induced DAPs were stereotactically transplanted into the right medial forebrain bundle (MFB) of rat models of Parkinson's disease (PD). Eight weeks after transplantation, the motor behaviors of PD rats was evaluated. Immunofluorescence assay of brain sections of the rats was performed at 2 weeks after transplantation to observe the survival, migration and differentiation of the transplanted cells in the host brain microenvironment. RESULTS: hiPSCs passaged stably on Matrigel showed a normal diploid karyotype, expressed the pluripotency markers OCT4, SOX2, and Nanog, and were positive for alkaline phosphatase. The primitive neuroepithelial cells obtained on day 13 formed dense cell colonies in the form of neural rosettes and expressed the neuroepithelial markers (SOX2, Nestin, and PAX6, 91.3%-92.8%). The DAPs on day 28 highly expressed the specific markers (TH, FOXA2, LMX1A and NURR1, 93.3-96.7%). In rat models of PD, the hiPSCs-DAPs survived and differentiated into TH⁺, FOXA2⁺ and Tuj1⁺ neurons at 2 weeks after transplantation. Eight weeks after transplantation, the motor function of PD rats was significantly improved as shown by water maze test (P < 0.0001) and apomorphine-induced rotation test (P < 0.0001) compared with rats receiving vehicle injection. CONCLUSION HiPSCs can be effectively induced to differentiate into DAPs capable of differentiating into functional neurons both in vivo and in vitro. In rat models of PD, the transplanted hiPSCs-DAPs can survive for more than 8 weeks in the MFB and differentiate into multiple functional neurocytes to ameliorate neurological deficits of the rats, suggesting the potential value of hiPSCs-DAPs transplantation for treatment of neurological diseases.
Humans ; Rats ; Animals ; Induced Pluripotent Stem Cells ; Cell Differentiation/physiology* ; Neurons ; Parkinson Disease ; Mesencephalon ; Cells, Cultured