Background Metals and metalloids in fine particulate matter (PM_2.5) may cause damage to the respiratory and circulatory systems of the human body, and long-term exposure is prone to causing chronic poisoning, cancer, and other adverse effects. Objective To assess the distribution characteristics of metals and metalloids in outdoor PM_2.5 in a southern city of China, conduct source apportionment, and evaluate the associated health risks, thereby providing theoretical support for further pollution control measures. Methods PM_2.5 samples were collected in districts A, B, and C of a southern China city, and the concentrations of 17 metals and metalloids were detected by inductively coupled plasma-mass spectrometry (ICP-MS). Pollution sources were assessed through enrichment factor and principal components analysis, and the main pollution sources were quantified using absolute principal component scores-multivariate linear regression (APCS-MLR). Health risks were evaluated based on the Technical guide for environmental health risk assessment of chemical exposure (WS/T777—2021). Results The ambient air PM_2.5 concentrations in the city were higher in winter and spring, and lower in summer and autumn. The annual average concentrations of ambient PM_2.5 in districts A, B, and C were 36.7, 31.9, and 24.4 μg·m⁻³, respectively. The ambient PM_2.5 levels in districts B and C were below the second-grade limit set by the Ambient air quality standards (GB 3095—2012). The enrichment factors of cadmium (Cd), aluminum (Al), and antimony (Sb) were greater than 10, those of copper (Cu), lead (Pb), arsenic (As), nickel (Ni), mercury (Hg), and molybdenum (Mo) fell between 1 and 10, and those of manganese (Mn), vanadium (V), chromium (Cr), cobalt (Co), barium (Ba), beryllium (Be), and uranium (U) were below or equal to 1. The comprehensive evaluation of source analysis showed that the main pollution sources in districts A and C and the whole city were coal-burning. In district B, the main pollution source was also coal combustion, followed by industrial process sources and dust sources. The carcinogenic risks of As and Cr were between 1×10⁻⁶ and 1×10⁻⁴. However, the hazard quotients for 15 metals and metalloids in terms of non-carcinogenic risk were below 1. Conclusion Cr and As in the atmospheric PM_2.5 of the city present a certain risk of cancer and should be paid attention to. In addition, preventive control measures should be taken against relevant pollution sources such as industrial emission, dust, and coal burning.

Objective To evaluate the efficacy of Puerariae lobatae radix （PLR） and Anemarrhenae Rhizoma （AR） in preventing and treating Alzheimer’s disease （AD） and explore its potential mechanism of action by LC-MS serum metabolomics strategy. Methods The AD rat model was established by administering aluminum chloride （AlCl₃） and D-galactose （D-gal） for 20 weeks. The traditional Chinese medicine intervention group was given the PLR, AR, and PLR-AR extracts for 8 weeks by gavage. The model effect and efficacy were evaluated by Morris water maze test and biochemical indicators including SOD, NO, and MDA; Metabolomics research based on the UHPLC-Q/TOF-MS method was conducted, and relevant metabolic pathways were analyzed through the MetaboAnalyst online website. Results The learning and memory abilities of AD model rats were significantly decreased compared with the control group, and the levels of oxidative stress and lipid peroxides were significantly increased （P<0.05）, while the SOD content was decreased considerably （P<0.01）. The learning and memory abilities of AD model rats were improved, oxidative stress and lipid peroxidation levels were reversed, and serum SOD content was increased significantly after the intervention of PLR-AR, with better effects than single drugs. Through metabolomics, 70 differential metabolites were identified between the AD model group and the control group, mainly involving 10 pathways, including phenylalanine, tyrosine, and tryptophan biosynthesis, phenylalanine metabolism, and unsaturated fatty acid biosynthesis, et.al. The intervention of PLR-AR could adjust 47 metabolites, with 20 metabolites showing significant differences （P<0.05）. The significantly adjusted metabolites involve 6 pathways, including phenylalanine, tyrosine, and tryptophan biosynthesis, et al. Conclusion The combination of PLR and AR could significantly improve the learning and memory abilities of AD rat models. The mechanism may be related to the improvement of oxidative stress and lipid peroxidation levels, the increase of serum SOD content, and the regulation of phenylalanine, tyrosine, and tryptophan biosynthesis pathways.

Objective To investigate the eye lens and hand dose levels of interventional radiology workers in Baoji City, China, and to provide data reference for radiation protection. Methods In two general hospitals, the eye lens and finger doses of 121 interventional radiology workers were monitored between 2021 and 2023. The average annual dose levels and dose distribution were analyzed based on years, job positions, surgical sites, and duties during surgery. Results The average annual dose to the eye lens was 3.36 mSv, with the highest dose of 16.36 mSv. The average annual dose to the fingers was 3.38 mSv, with the highest dose of 17.72 mSv. The average annual dose to the eye lens and fingers decreased from 2021 to 2023. The average annual dose to the eye lens of the interventional surgeons was higher than those of the technicians and nurses, while the average annual dose to the fingers of the interventional surgeons was higher than that of the technicians. The average annual doses to the eye lens and fingers of the first operator were similar to those of the second operator, but both were higher than other personnel involved in the interventional surgery, and the differences were statistically significant (all P < 0.05). There were linear regression relationships between the annual doses to the eye lens and fingers and the effective whole-body dose of the interventional radiology workers. A paired test was conducted on the annual dose to the eye lens and fingers of the interventional workers for different surgical sites. The cardiovascular and peripheral vascular interventional workers had higher average annual doses to the eye lens than to the fingers, the cerebrovascular interventional workers had a higher average annual dose to the fingers than to the eye lens, and the differences were statistically significant. Conclusion The annual doses to the eye lens and fingers of the interventional radiology workers in Baoji City were lower than the national limits. However, some workers showed eye lens annual doses close to the new international standard limit (20 mSv). Special attention should be given to interventional physicians, especially the first and second surgeons.

Quantum dots (QDs), nanoscale semiconductor crystals, have emerged as a revolutionary class of nanomaterials with unique optical and electrochemical properties, making them highly promising for applications in disease diagnosis and treatment. Their tunable emission spectra, long-term photostability, high quantum yield, and excellent charge carrier mobility enable precise control over light emission and efficient charge utilization, which are critical for biomedical applications. This article provides a comprehensive review of recent advancements in the use of quantum dots for disease diagnosis and therapy, highlighting their potential and the challenges involved in clinical translation. Quantum dots can be classified based on their elemental composition and structural configuration. For instance, IB-IIIA-VIA group quantum dots and core-shell structured quantum dots are among the most widely studied types. These classifications are essential for understanding their diverse functionalities and applications. In disease diagnosis, quantum dots have demonstrated remarkable potential due to their high brightness, photostability, and ability to provide precise biomarker detection. They are extensively used in bioimaging technologies, enabling high-resolution imaging of cells, tissues, and even individual biomolecules. As fluorescent markers, quantum dots facilitate cell tracking, biosensing, and the detection of diseases such as cancer, bacterial and viral infections, and immune-related disorders. Their ability to provide real-time, in vivo tracking of cellular processes has opened new avenues for early and accurate disease detection. In the realm of disease treatment, quantum dots serve as versatile nanocarriers for targeted drug delivery. Their nanoscale size and surface modifiability allow them to transport therapeutic agents to specific sites, improving drug bioavailability and reducing off-target effects. Additionally, quantum dots have shown promise as photosensitizers in photodynamic therapy (PDT). When exposed to specific wavelengths of light, quantum dots interact with oxygen molecules to generate reactive oxygen species (ROS), which can selectively destroy malignant cells, vascular lesions, and microbial infections. This targeted approach minimizes damage to healthy tissues, making PDT a promising strategy for treating complex diseases. Despite these advancements, the translation of quantum dots from research to clinical application faces significant challenges. Issues such as toxicity, stability, and scalability in industrial production remain major obstacles. The potential toxicity of quantum dots, particularly to vital organs, has raised concerns about their long-term safety. Researchers are actively exploring strategies to mitigate these risks, including surface modification, coating, and encapsulation techniques, which can enhance biocompatibility and reduce toxicity. Furthermore, improving the stability of quantum dots under physiological conditions is crucial for their effective use in biomedical applications. Advances in surface engineering and the development of novel encapsulation methods have shown promise in addressing these stability concerns. Industrial production of quantum dots also presents challenges, particularly in achieving consistent quality and scalability. Recent innovations in synthesis techniques and manufacturing processes are paving the way for large-scale production, which is essential for their widespread adoption in clinical settings. This article provides an in-depth analysis of the latest research progress in quantum dot applications, including drug delivery, bioimaging, biosensing, photodynamic therapy, and pathogen detection. It also discusses the multiple barriers hindering their clinical use and explores potential solutions to overcome these challenges. The review concludes with a forward-looking perspective on the future directions of quantum dot research, emphasizing the need for further studies on toxicity mitigation, stability enhancement, and scalable production. By addressing these critical issues, quantum dots can realize their full potential as transformative tools in disease diagnosis and treatment, ultimately improving patient outcomes and advancing biomedical science.

Objective To campare biomechanical effects of different postural compression techniques on three-dimensional model of lumbar disc herniation(LDH)by finite element analysis.Methods Lumbar CT image of a 48-year-old female patient with LDH(heighted 163 cm,weighted 53 kg)was collected.Mimics 20.0,Geomagic Studio,Solidwords and other software were used to establish three-dimensional finite element model of LDH on L4,5 segments.Compression techniques under horizon-tal position,30° forward bending and 10° backward extension were simulated respectively.After applying the pressure,the ef-fects of compression techniques under different positions on stress,strain and displacement of various tissues of intervertebral disc and nerve root were observed.Results L4,5 segment finite element model was successfully established,and the model was validated.When compression manipulation was performed on the horizontal position,30° flexion and 10° extension,the annular stress were 0.732,5.929,1.286 MPa,the nucleus pulposus stress were 0.190,1.527,0.295 MPa,and the annular strain were 0.097,0.922 and 0.424,the strain sizes of nucleus pulposus were 0.153,1.222 and 0.282,respectively.The overall displace-ment distance of intervertebral disc on Y direction were-3.707,-18.990,-4.171 mm,and displacement distance of nerve root on Y direction were+7.836,+5.341,+3.859 mm,respectively.The relative displacement distances of nerve root and interverte-bral disc on Y direction were 11.543,24.331 and 8.030 mm,respectively.Conclusion Compression manipulation could make herniated intervertebral disc produce contraction and retraction trend,by increasing the distance between herniated interverte-bral disc and nerve root,to reduce symptoms of nerve compression,to achieve purpose of treatment for patients with LDH,in which the compression manipulation is more effective when the forward flexion is 30°.

Objective:To explore the properties of gelatin-polyethylene glycol hydrogel loaded with silver nanoparticle (AgNP) Chlorella (hereinafter referred to as the composite hydrogel) and its effects on healing of infected full-thickness skin defect wounds in mice. Methods:The research was an experimental research. The simple gelatin-polyethylene glycol hydrogel (hereinafter referred to as the simple hydrogel) and the composite hydrogel were prepared, and the appearance and injectability of the two hydrogels were observed at 55 and 37 ℃, and under the irradiation of 808 nm near-infrared light, respectively. An electronic universal testing machine was employed to assess the tensile and compressive stress-strain properties of both types of hydrogels at room temperature. Additionally, the cyclic compressive stress-strain properties of the composite hydrogel were examined at 80% of the maximum compressive stress. Staphylococcus aureus or Escherichia coli solution was added to phosphate buffer solution (PBS), simple hydrogel, and composite hydrogel, respectively. The part of composite hydrogel containing Staphylococcus aureus or Escherichia coli solution was irradiated with near-infrared light for 5 minutes. After each sample was incubated for 6 h, the dilution plating method was used to detect and calculate the mortality rates of the two bacteria at 24 h of culture ( n=5). The discarded foreskin tissue was taken from a 6-year-old healthy boy admitted to the Department of Urology of the First Affiliated Hospital of Naval Medical University for circumcision. Primary human fibroblasts (HFbs) were isolated using the enzyme extraction method, routinely cultured to the 3 rd to 6 th passages for subsequent cellular experiments. Composite hydrogel extracts with final mass concentrations of 100.0, 50.0, 25.0, 12.5, and 0 mg/mL were respectively prepared and used to culture HFbs, and the cell proliferation after 24 h of culture was detected using a cell counting kit 8 ( n=3). A total of twenty 6-8 weeks old C57BL/6J female mice were utilized, and a full-thickness skin defect was surgically created on the back of each mouse. The wounds were infected with Staphylococcus aureus solution. The infected mice were divided into blank control group, simple hydrogel group, composite hydrogel group, and combined treatment group according to the random number table, and the wounds were treated with PBS, simple hydrogel, composite hydrogel, and composite hydrogel+light irradiation (under the irradiation of 808 nm near-infrared light for 5 min), respectively, with 5 mice in each group. On post injury day (PID) 0 (immediately after the first wound treatment), 3, 7, and 14, an overall assessment of wound exudation and healing were conducted, and the wound healing rates on PID 7 and 14 were calculated ( n=5). On PID 14, hematoxylin-eosin staining was performed to observe histopathological changes in the mouse wound. Results:Both simple hydrogel and composite hydrogel were in a solution state at 55 ℃ and transition to a gel state when cooling to 37 ℃. After the two hydrogels were irradiated by near-infrared light, only the composite hydrogel reheated up and returned to the solution state again with injectability. The maximum tensile stress of the composite hydrogel was up to 301.42 kPa, with a corresponding strain of 87.19%; the maximum compressive stress was up to 413.79 kPa, with a corresponding strain of 91.67%, which was similar to the tensile and compressive properties of the simple hydrogel. After 10 compression cycles, the maximum compressive stress of the composite hydrogel still reached 84.1% of the first compressive stress. After 24 h of culture, the mortality rate of Staphylococcus aureus treated with simple hydrogel was significantly higher than that treated with PBS ( P<0.05); the mortality rates of Escherichia coli and Staphylococcus aureus treated with composite hydrogel alone were significantly higher than those treated with simple hydrogel ( P<0.05); the mortality rates of Escherichia coli and Staphylococcus aureus treated with composite hydrogel+light irradiation were significantly higher than those treated with composite hydrogel alone ( P<0.05). After 24 h of culture, compared with that cultured in composite hydrogel immersion solution with final mass concentration of 0 mg/mL, the proliferation activity of HFbs cultured in composite hydrogel immersion solution with final mass concentrations of 25.0 and 50.0 mg/mL was significantly enhanced ( P<0.05), while the proliferation activity of HFbs cultured in composite hydrogel immersion solution with final mass concentration of 100 mg/mL was significantly decreased ( P<0.05). On PID 0 and 3, more purulent secretions were seen in the wounds of mice in blank control group and simple hydrogel group, while only a small amount of exudate was observed in the wounds of mice in composite hydrogel group, and no obvious infection was observed in the wounds of mice in combined treatment group. On PID 7 and 14, the wound healing rates of mice in simple hydrogel group were significantly higher than those in blank control group ( P<0.05); the wound healing rates of mice in composite hydrogel group were significantly higher than those in simple hydrogel group ( P<0.05); the wound healing rates in combined treatment group were significantly higher than those in composite hydrogel group ( P<0.05). On PID 14, the wounds of mice in blank control group exhibited a high infiltration of inflammatory cells with no new epithelial layer observed; the wounds of mice in simple hydrogel group displayed a short length of newly formed epithelium with a small amount of inflammatory cells; the wounds of mice in composite hydrogel group exhibited continuous formation of new epithelium and a large amount of immature granulation tissue; the wounds of mice in combined treatment group showed continuous epithelialization with less immature granulation tissue. Conclusions:The prepared composite hydrogel exhibits excellent thermosensitivity, photothermal properties, and injectability, as well as excellent mechanical properties, antibacterial properties, and biocompatibility, and can promote the healing of infected full-thickness skin defect wounds in mice.

Objective To investigate the effect of intravenous infusion of low-dose remifentanil on obese scarred uterine puerperae undergoing cesarean section under epidural anesthesia.Methods A total of 87 obese scarred uterine puerperae undergoing cesarean section under epidural anesthesia were selected as the study subjects,and they were randomly divided into the conventional group(n=43)and the remifentanil group(n=44).From the beginning of skin incision,puerperae of the conventional group and the remifentanil group were intravenously injected with normal saline and low-dose remifentanil respectively until the end of the operation.The vital signs,pain and comfort scores,intraoperative complications of puerperae,and status of newborns were compared between the two groups at different points during the operation.Results During fetal extraction and peritoneal exploration,the heart rate,mean arterial pressure and pain scores of puerperae in the remifentanil group were lower than those in the conventional group,and the differences were statistically significant(P<0.05);the intraoperative comfort score of puerperae in the remifentanil group was higher than that in the conventional group,and the difference was statistically significant(P<0.05).The incidence of nausea and vomiting of puerperae in the remifentanil group was lower than that in the conventional group,and the difference was statistically significant(P<0.05).There was no significant difference in the Apgar score at 1 minute and 5 minutes after delivery,requiring initial resuscitation or pH value of umbilical vein blood between newborns delivered by puerperae of the two groups(P>0.05).Conclusion Intravenous infusion of 0.05 μg·kg-1·min-1 low-dose remifentanil not only significantly reduces intraoperative pain and improves comfort of obese scarred uterine puerperae undergoing cesarean section under epidural anesthesia,but also helps to reduce the incidence of adverse reactions and ensure maternal and infant safety.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.