Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

Objective To establish orthotopic and ectopic pancreatic cancer models in C57BL/6N mice with normal immune function using in vivo imaging technology for visual characterization.Methods Orthotopic and ectopic pancreatic cancer models were established in Kunming mice by injecting a small volume of cell suspension containing firefly luciferase-expressing Panc02-luciferase pancreatic cancer cells into the head of the pancreas or the right axillary region.In vivo imaging technology was used to optimize the modeling method and timing in Kunming mice.Subsequently,the same method was applied to C57BL/6N mice using wild-type Panc02 pancreatic cancer cells to establish orthotopic and ectopic pancreatic cancer models with intact immune function.Key parameters,including body weight,inoculation positive rate,tumor growth time,tumor volume,and pathological characteristics across different organs,were compared be-tween the orthotopic and ectopic models in C57BL/6N mice to evaluate the applicability of these models.Results Both the small animal in vivo imaging experiments in Kunming mice and the tumor growth observation in C57BL/6N mice demonstrated that the construction periods for orthotopic and ectopic pancreatic cancer models were 20 days,with survival rates exceeding 90%.The inoculation positive rates in C57BL/6N mice were 92.3%for the orthotopic model and 78.6%for the ectopic model.On day 20 post-inoculation,the tumor volumes were(117.04±109.56)mm3 for the orthotopic model and(155.68±168.73)mm3 for the ectopic model,indicating high model success rates and consistent tumor growth.HE staining revealed pathological mitotic figures and poorly differentiated tumor tissues in both models of C57BL/6N mice,with no evidence of metastasis to other organs.Conclusions Orthotopic and ectopic pancreatic cancer models in immu-nocompetent mice were successfully developed in this study,mimicking early-stage pancreatic cancer characteristics.These models pro-vide a reliable platform for screening early diagnostic biomarkers and evaluating therapeutic interventions for pancreatic cancer.

Objective To establish orthotopic and ectopic pancreatic cancer models in C57BL/6N mice with normal immune function using in vivo imaging technology for visual characterization.Methods Orthotopic and ectopic pancreatic cancer models were established in Kunming mice by injecting a small volume of cell suspension containing firefly luciferase-expressing Panc02-luciferase pancreatic cancer cells into the head of the pancreas or the right axillary region.In vivo imaging technology was used to optimize the modeling method and timing in Kunming mice.Subsequently,the same method was applied to C57BL/6N mice using wild-type Panc02 pancreatic cancer cells to establish orthotopic and ectopic pancreatic cancer models with intact immune function.Key parameters,including body weight,inoculation positive rate,tumor growth time,tumor volume,and pathological characteristics across different organs,were compared be-tween the orthotopic and ectopic models in C57BL/6N mice to evaluate the applicability of these models.Results Both the small animal in vivo imaging experiments in Kunming mice and the tumor growth observation in C57BL/6N mice demonstrated that the construction periods for orthotopic and ectopic pancreatic cancer models were 20 days,with survival rates exceeding 90%.The inoculation positive rates in C57BL/6N mice were 92.3%for the orthotopic model and 78.6%for the ectopic model.On day 20 post-inoculation,the tumor volumes were(117.04±109.56)mm3 for the orthotopic model and(155.68±168.73)mm3 for the ectopic model,indicating high model success rates and consistent tumor growth.HE staining revealed pathological mitotic figures and poorly differentiated tumor tissues in both models of C57BL/6N mice,with no evidence of metastasis to other organs.Conclusions Orthotopic and ectopic pancreatic cancer models in immu-nocompetent mice were successfully developed in this study,mimicking early-stage pancreatic cancer characteristics.These models pro-vide a reliable platform for screening early diagnostic biomarkers and evaluating therapeutic interventions for pancreatic cancer.

Objective:To investigate the optimal reconstruction grade of IDream reconstruction technique in reducing image noise,optimizing image quality,and displaying liver cysts through the subjective assessment on the display of computed tomography (CT) image with differently reconstructive grades in IDream reconstruction technique of iterative reconstruction algorithm,and the objective evaluation of image quality of upper abdomen. Methods:The imaging data of CT plain scan of 53 patients with hepatic cysts who underwent plain scans on upper abdomen at Peking Union Medical College Hospital from August to September 2021 were retrospectively collected. All images were reconstructed to standard window images by using 6 kinds of methods that included filtered back projection (FBP) and IDream grades 1 to 5,which resulted in 6 groups of images that included FBP group and IDream grades 1-5. The CT values and standard deviation (SD) values of the liver,abdominal aorta,erector spine muscle,fat and spleen in images of each group were measured and recorded,respectively. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the images were calculated. Two CT diagnostic physicians with more than 8 years of experience conducted subjective scoring for the display in the images of hepatic cysts of each group. The objective parameters and the subjective scores of hepatic cysts of reconstructive images with different grades were compared. A one-way analysis of variance was adopted to analyze the objective parameters,and Kruskal-Wallis H test was conducted on the subjective score of the display of hepatic cysts. Results:There were no statistically significant differences in the CT values among different reconstruction grades on the liver,abdominal aorta,fat,erector spine muscle and spleen (P>0.05). In the FBP group and IDream grades 1 to 5 groups,the SD values of images gradually decreased with the increasing of the reconstruction grades,which were respectively (18.11±5.03),(15.37±4.97),(13.26±4.83),(11.68±4.56),(10.99±4.36) and (10.60±4.21) Hu. The SNR and CNR of the liver gradually increased. The differences in SD values,SNR,and CNR among the six groups of images were all statistically significant (F=20.75,17.72,3.15,P<0.05),respectively. The subjective scores for the display of hepatic cysts from the FBP group to IDream grades 1 to 4 were respectively (3.12±0.35),(3.63±0.46),(4.02±0.42),(4.61±0.48) and (4.63±0.48),which were gradually increasing,while the score for the IDream grade 5 group slightly decreased to (4.53±0.47). The subjective scores for hepatic cysts in the images of IDream grades 3 and 4 groups were the highest. The comparison of the average subjective scores of the images of hepatic cysts among the six reconstruction grades showed statistically significant differences (H=192.17,P<0.05). Conclusion:In CT plain scan on the upper abdomen,with the increasing of IDream reconstruction grades,the image noises gradually decrease,and objective parameters of images gradually enhance,and the reconstructions of IDream grades 3 and 4 can obtain the optimal image quality of upper abdomen at the objective score of hepatic cysts.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

Objective:To investigate the optimal reconstruction grade of IDream reconstruction technique in reducing image noise,optimizing image quality,and displaying liver cysts through the subjective assessment on the display of computed tomography (CT) image with differently reconstructive grades in IDream reconstruction technique of iterative reconstruction algorithm,and the objective evaluation of image quality of upper abdomen. Methods:The imaging data of CT plain scan of 53 patients with hepatic cysts who underwent plain scans on upper abdomen at Peking Union Medical College Hospital from August to September 2021 were retrospectively collected. All images were reconstructed to standard window images by using 6 kinds of methods that included filtered back projection (FBP) and IDream grades 1 to 5,which resulted in 6 groups of images that included FBP group and IDream grades 1-5. The CT values and standard deviation (SD) values of the liver,abdominal aorta,erector spine muscle,fat and spleen in images of each group were measured and recorded,respectively. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the images were calculated. Two CT diagnostic physicians with more than 8 years of experience conducted subjective scoring for the display in the images of hepatic cysts of each group. The objective parameters and the subjective scores of hepatic cysts of reconstructive images with different grades were compared. A one-way analysis of variance was adopted to analyze the objective parameters,and Kruskal-Wallis H test was conducted on the subjective score of the display of hepatic cysts. Results:There were no statistically significant differences in the CT values among different reconstruction grades on the liver,abdominal aorta,fat,erector spine muscle and spleen (P>0.05). In the FBP group and IDream grades 1 to 5 groups,the SD values of images gradually decreased with the increasing of the reconstruction grades,which were respectively (18.11±5.03),(15.37±4.97),(13.26±4.83),(11.68±4.56),(10.99±4.36) and (10.60±4.21) Hu. The SNR and CNR of the liver gradually increased. The differences in SD values,SNR,and CNR among the six groups of images were all statistically significant (F=20.75,17.72,3.15,P<0.05),respectively. The subjective scores for the display of hepatic cysts from the FBP group to IDream grades 1 to 4 were respectively (3.12±0.35),(3.63±0.46),(4.02±0.42),(4.61±0.48) and (4.63±0.48),which were gradually increasing,while the score for the IDream grade 5 group slightly decreased to (4.53±0.47). The subjective scores for hepatic cysts in the images of IDream grades 3 and 4 groups were the highest. The comparison of the average subjective scores of the images of hepatic cysts among the six reconstruction grades showed statistically significant differences (H=192.17,P<0.05). Conclusion:In CT plain scan on the upper abdomen,with the increasing of IDream reconstruction grades,the image noises gradually decrease,and objective parameters of images gradually enhance,and the reconstructions of IDream grades 3 and 4 can obtain the optimal image quality of upper abdomen at the objective score of hepatic cysts.

Objective To prepare quercetin nanocrystals,improve their dissolution rate,and investigate the effects of different stabilizer types and ratios on the stability of nanocrystals.Methods Quercetin nanocrystals were prepared by solvent ultrasonication,and three different stabilizers(polyvinylpyrrolidone-K30,poloxamer F188 and sodium dodecyl sulfate)were compared.The particle size was used as a screening index to investigate the stability of placement,the microscopic morphology of nanocrystals was characterized by scanning electron microscopy,infrared spectroscopy and X-ray diffraction,and the mechanism of action between stabilizers and nanocrystals was discussed.Results Through experimental screening,the results showed that povidone K30 had the best stable performance,the nanocrystals were also in the form of rod crystals,and the dissolution rate of nanocrystals was significantly higher than that of active pharmaceutical ingredients.Conclusion The type and amount of stabilizer will affect the stability of nanocrystals.

Objective:To explore the application effect of hydration therapy in patients with intermittent claudication (IC) of peripheral arterial disease, and to provide reference for clinical application.Methods:A randomized controlled trial method was used to select 86 patients with IC of peripheral arterial disease who attended the Department of Vascular Surgery of Shanxi Bethune Hospital from June to September 2023 as the study subjects by convenience sampling method, and they were divided into the control group and the intervention group by using the method of randomized numerical table, each group had 43 cases. In the control group, routine care was provided, and in the intervention group, hydration therapy was implemented on the basis of the control group. Ankle-brachial index, transcutaneous partial pressure of oxygen, and claudication distance were assessed in both groups 1d before and 6 months after the intervention.Results:Forty-two patients in each group completed the study, 21 males and 21 females, aged (61.33 ± 8.93) years in the intervention group; 24 males and 18 females, aged (61.33 ± 9.01) years in the control group. Compared with the ankle-brachial index, transcutaneous oxygen partial pressure and limp distance of the 2 groups 1 d before intervention, the differences were not statistically significant (all P>0.05), and 6 months after the intervention, the transcutaneous oxygen partial pressure of the patients in the intervention group was (37.69 ± 8.86) mmHg (1 mmHg=0.133 kPa), and that of the control group was (29.69 ± 7.79) mmHg, and the differences between the 2 groups were statistically significant ( t=4.40, P<0.05). The differences in patients′ transcutaneous partial pressure of oxygen and limp distance before and after intervention in the intervention group were -7.00 (-13.00, -1.75) mmHg and -50.00 (-100.00, 0.00) m, respectively, and in the control group were 0.01 (-1.00, 1.00) mmHg and 0.01 (-1.25, 20.00) m, respectively, and the differences between the 2 groups were statistically were statistically significant ( Z=5.59, 4.33, both P<0.05). Conclusions:Hydration therapy improves transcutaneous oxygen partial pressure values and claudication distance in patients with peripheral arterial disease IC, and improves microcirculation of the affected limbs in patients.

Objective To investigate the characteristics and clinicopathology of v-raf murine sarcoma viral oncogene homolog Bl(BRAF)V600E mutations in papillary thyroid carcinoma(PTC)in Air Force flight personnel.Methods Data of cases and test results of BRAF V600E mutation were collected from Air Force aviators pathologically diagnosed with PTC.A univariate analysis of the relationship between BRAF V600E mutations and clinicopathologic features was performed.Results The overall rate of BRAF V600E mutations among 55 PTC flight crew members was 70.91％.The univariate analysis showed that the number of lymph node metastases in the BRAF V600E mutated group was larger than in the BRAF V600E unmutated group,and the proportion of BRAF V600E mutations in flight crews at intermediate risk of recurrence was higher than that in those at low risk of recurrence(P＜0.05).The presence or absence of BRAF V600E mutations did not affect the results of medical evaluation of PTC in flight personnel.Conclusion The rate of PTC BRAF V600E mutations in Air Force flight crews is similar to that of the general Chinese population.BRAF V600E mutations are associated with an increased number of lymph node metastases and risk of recurrence,and follow-up is recommended for flight personnel with PTC,especially those with BRAF V600E mutations.

Objective To analyze the clinicopathological features and prognosis of polyomavirus nephropathy (PyVN) after kidney transplantation. Methods Clinical data of 44 patients who were diagnosed with PyVN after kidney transplantation were retrospectively analyzed. The causes of puncture and the time of pathological diagnosis were analyzed. Histological grading was carried out according to Banff 2018 classification. Clinical data and pathological characteristics of patients at all grades were statistically compared. BK viral DNA loads in the blood and urine were measured and renal allograft function were assessed. Clinical prognosis of all patients was compared among different groups and the risk factors affecting clinical prognosis were also analyzed. Results The time interval between pathological diagnosis of PyVN and kidney transplantation was 16(8, 29) months, and the increase of serum creatinine level was the main cause for puncture. Among 44 patients, 19 cases were classified as grade ⅠPyVN, 21 cases of grade Ⅱ PyVN and 4 cases of grade Ⅲ PyVN, respectively. Under optical microscope, there was no significant difference in the positive rate of virus inclusion bodies among different groups (P=0.148). Inflammatory cell infiltration, interstitial fibrosis and polyomavirus load in grade Ⅱ PyVN patients were all more or higher than those in grade Ⅰ counterparts. Inflammatory cell infiltration and polyomavirus load in grade Ⅲ patients were more or higher than those in grade Ⅰ counterparts. Polyomavirus load in grade Ⅲ patients was more or higher than that in grade Ⅱ counterparts. The differences were statistically significant (all P < 0.05/3). Upon diagnosis, BK viral DNA load was detected in the blood and urine of 39 patients. Among them, 38 patients were positive for BK virus in the urine and 30 patients were positive for BK virus in the blood. The serum creatinine level upon diagnosis was higher compared with that at postoperative 1 month. The serum creatinine level at the final follow-up was significantly higher than that upon diagnosis. The differences were statistically significant (P < 0.001, P=0.049). There was no significant difference in the serum creatinine level among patients with different grades of PyVN at postoperative 1 month (P=0.554). The serum creatinine level of patients with grade Ⅱ PyVN upon diagnosis was significantly higher than that of those with grade Ⅰ PyVN (P=0.007). The 1-, 3- and 5-year cumulative survival rates of renal allografts were 95%, 69% and 62%, respectively. The survival rates of renal allografts significantly differed among patients with different grades of PyVN. The higher the grade, the lower the survival rate (P=0.014). Univariate and multivariate Cox's regression analyses prompted that intrarenal polyomavirus load and serum creatinine level upon diagnosis were the independent risk factors for renal allograft dysfunction (all P < 0.05). Conclusions PyVN mainly occurs within 2 years after kidney transplantation. Clinical manifestations mainly consist of increased serum creatinine level, BK viremia and BK viruria. Postoperative routine monitoring of BK virus contributes to early diagnosis and protection of renal allografts. Banff 2018 classification may effectively predict the prognosis of renal allografts.