In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics.Similarities and variations of components present significant analytical challenges.A two-dimensional(2D)liquid chromatography-mass spectrometry(LC-MS)method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium(CMS).A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated.For efficient and high-accuracy screening of CMS,a targeted method based on a self-constructed high resolution(HR)mass spectrum database of CMS components was established.The database was built based on the commercial MassHunter Personal Compound Database and Library(PCDL)software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening.On this basis,the unknown peaks in the CMS chromatograms were deduced and assigned.The molecular formula,group composition,and origins of a total of 99 compounds,of which the combined area percentage accounted for more than 95％of CMS components,were deduced by this 2D-LC-MS method combined with the MassHunter PCDL.This profiling method was highly efficient and could distinguish hundreds of components within 3 h,providing reliable results for quality control of this kind of complex drugs.

In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics. Similarities and variations of components present significant analytical challenges. A two-dimensional (2D) liquid chromatography-mass spectrometr (LC-MS) method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium (CMS). A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated. For efficient and high-accuracy screening of CMS, a targeted method based on a self-constructed high resolution (HR) mass spectrum database of CMS components was established. The database was built based on the commercial MassHunter Personal Compound Database and Library (PCDL) software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening. On this basis, the unknown peaks in the CMS chromatograms were deduced and assigned. The molecular formula, group composition, and origins of a total of 99 compounds, of which the combined area percentage accounted for more than 95% of CMS components, were deduced by this 2D-LC-MS method combined with the MassHunter PCDL. This profiling method was highly efficient and could distinguish hundreds of components within 3 h, providing reliable results for quality control of this kind of complex drugs.

Objective To propose a low-dose CT image denoising method based on an improved Corediff model to recover the detailed features of the image and enhance the image quality.Methods An RS-Corediff model was established by modifying the key component U-Net network of the Corediff model.Firstly,the residual module was introduced in the network input stage for feature extraction;secondly,a new downsampling module was designed in the U-Net network encoder,which learned the semantic information of the feature map by convolution and maintained the learning state during the downsampling process so as to fully extract the image features;thirdly,the feature splicing processing was used to further enhance the learning effect during the upsampling process of the U-Net network decoder;finally,the convolutional kernel size was modified to adjust the sensory field during the convolutional process of the whole U-Net network structure so as to obtain rich features.The RS-Corediff model was compared with the residual encoder-decoder convolutional neural network(RED-CNN)model and the Corediff model on the public dataset AAPM 2016 in order to verify its effectiveness for low-dose CT image denoising.Results The RS-Corediff model gained advantages over the RED-CNN and Corediff models with a peak signal-to-noise ratio(PSNR)of 41.269 8,structural similarity(SSIM)of 0.953 4 and root mean square error(RMSE)of 17.568 7.Conclusion The proposed method effectively preserves the texture and details of low-dose CT images during the denoising process to improve the overall quality of the images.[Chinese Medical Equipment Journal,2025,46(5):9-13]

Objective To propose a low-dose CT image denoising method based on an improved Corediff model to recover the detailed features of the image and enhance the image quality.Methods An RS-Corediff model was established by modifying the key component U-Net network of the Corediff model.Firstly,the residual module was introduced in the network input stage for feature extraction;secondly,a new downsampling module was designed in the U-Net network encoder,which learned the semantic information of the feature map by convolution and maintained the learning state during the downsampling process so as to fully extract the image features;thirdly,the feature splicing processing was used to further enhance the learning effect during the upsampling process of the U-Net network decoder;finally,the convolutional kernel size was modified to adjust the sensory field during the convolutional process of the whole U-Net network structure so as to obtain rich features.The RS-Corediff model was compared with the residual encoder-decoder convolutional neural network(RED-CNN)model and the Corediff model on the public dataset AAPM 2016 in order to verify its effectiveness for low-dose CT image denoising.Results The RS-Corediff model gained advantages over the RED-CNN and Corediff models with a peak signal-to-noise ratio(PSNR)of 41.269 8,structural similarity(SSIM)of 0.953 4 and root mean square error(RMSE)of 17.568 7.Conclusion The proposed method effectively preserves the texture and details of low-dose CT images during the denoising process to improve the overall quality of the images.[Chinese Medical Equipment Journal,2025,46(5):9-13]

The epidemiological and spatiotemporal clustering characteristics of dengue fever in Fujian Province were ana-lyzed,to provide a scientific basis for dengue fever prevention and control.Descriptive epidemiology,spatial autocorrelation a-nalysis,and spatiotemporal scanning were used to analyze dengue fever cases in Fujian Province from 2011 to 2023.In this peri-od,a total of 3 586 cases of dengue fever were reported in Fujian Province,including 2 360 local cases,1 134 imported cases from abroad,and 92 imported cases from China.Cases were reported in ten prefectures and cities of the province,and 81 out of 88 counties reported cases.Imported cases were reported throughout the year in Fujian Province,but the occurrence of local ca-ses showed clear seasonality.Local cases and domestic imports were concentrated in August to October,whereas overseas im-ports occurred primarily from June to October.The imported cases were mainly from Southeast Asian countries,but a trend of spreading from Southeast Asian countries to South Asia,Africa,the Americas,and other regions,was observed.Spatio-tem-poral clustering of dengue fever was found in Fujian Province(Moran's I value 0.14-0.66,P＜0.05),and the high-high ag-gregation areas were distributed primarily in Fuzhou,Quanzhou,and Putian.Spatio-temporal scanning detected three aggrega-tion areas:one main and two secondary.The aggregation time was from the end of July to October,and the distribution was primarily in Fuzhou,Quanzhou,Putian,Zhangzhou,and Xiamen.The distribution of dengue fever in Fujian Province showed clear spatial and temporal clustering from the end of July to October,and the distribution was primarily in Fuzhou,Quanzhou,Putian,Zhangzhou,and Xiamen.For high concentration areas,national health campaigns,mosquito prevention and control,epidemic surveillance,medical personnel training,and other relevant measures could be carried out in advance before local cases appear every year.Reduce local transmission of dengue fever due to importation.

The epidemiological and spatiotemporal clustering characteristics of dengue fever in Fujian Province were ana-lyzed,to provide a scientific basis for dengue fever prevention and control.Descriptive epidemiology,spatial autocorrelation a-nalysis,and spatiotemporal scanning were used to analyze dengue fever cases in Fujian Province from 2011 to 2023.In this peri-od,a total of 3 586 cases of dengue fever were reported in Fujian Province,including 2 360 local cases,1 134 imported cases from abroad,and 92 imported cases from China.Cases were reported in ten prefectures and cities of the province,and 81 out of 88 counties reported cases.Imported cases were reported throughout the year in Fujian Province,but the occurrence of local ca-ses showed clear seasonality.Local cases and domestic imports were concentrated in August to October,whereas overseas im-ports occurred primarily from June to October.The imported cases were mainly from Southeast Asian countries,but a trend of spreading from Southeast Asian countries to South Asia,Africa,the Americas,and other regions,was observed.Spatio-tem-poral clustering of dengue fever was found in Fujian Province(Moran's I value 0.14-0.66,P＜0.05),and the high-high ag-gregation areas were distributed primarily in Fuzhou,Quanzhou,and Putian.Spatio-temporal scanning detected three aggrega-tion areas:one main and two secondary.The aggregation time was from the end of July to October,and the distribution was primarily in Fuzhou,Quanzhou,Putian,Zhangzhou,and Xiamen.The distribution of dengue fever in Fujian Province showed clear spatial and temporal clustering from the end of July to October,and the distribution was primarily in Fuzhou,Quanzhou,Putian,Zhangzhou,and Xiamen.For high concentration areas,national health campaigns,mosquito prevention and control,epidemic surveillance,medical personnel training,and other relevant measures could be carried out in advance before local cases appear every year.Reduce local transmission of dengue fever due to importation.

Objective:To investigate the clinical efficacy and safety of ixazomib-containing regimens in the treatment of patients with multiple myeloma(MM).Methods:A retrospective analysis was performed on the clinical efficacy and adverse reactions of 32 MM patients treated with a combined regimen containing ixazomib in the Hematology Department of the First People's Hospital of Lianyungang from January 2020 to February 2022.Among the 32 patients,15 patients were relapsed and refractory multiple myeloma(R/RMM)(R/RMM group),17 patients who responded to bortezomib induction therapy but converted to ixazomib-containing regimen due to adverse events(AE)or other reasons(conversion treatment group).The treatment included IPD regimen(ixazomib+pomalidomide+dexamethasone),IRD regimen(ixazomib+lenalidomide+dexamethasone),ICD regimen(ixazomib+cyclophosphamide+dexamethasone),ID regimen(ixazomib+dexamethasone).Results:Of 15 R/RMM patients,overall response rate(ORR)was 53.3％(8/15),among them,1 achieved complete response(CR),2 achieved very good partial response(VGPR)and 5 achieved partial response(PR).The ORR of the IPD,IRD,ICD and ID regimen group were 100％(3/3),42.9％(3/7),33.3％(1/3),50％(1/2),respectively,there was no statistically significant difference in ORR between four groups(x2=3.375,P=0.452).The ORR of patients was 50％after first-line therapy,42.9％after second line therapy,60％after third line therapy or more,with no statistically significant difference among them(x2=2.164,P=0.730).In conversion treatment group,ORR was 88.2％(15/17),among them,6 patients achieved CR,5 patients achieved VGPR and 4 patients achieved PR.There was no statistically significant difference in ORR between the IPD(100％,3/3),IRD(100％,6/6),ICD(100％,3/3)and ID(60％,3/5)regimen groups(x2=3.737,P=0.184).The median progression-free survival(PFS)time of R/RMM patients was 9 months(95％CI:6.6-11.4 months),the median overall survival(OS)time was 18 months(95％CI:11.8-24.4 months).The median PFS time of conversion treatment group was 15 months(95％CI:7.3-22.7 months),the median OS time not reached.A total of 10 patients suffered grade 3-4 adverse event(AE).The common hematological toxicities were leukocytopenia,anemia,thrombocytopenia.The common non-hematological toxicities were gastrointestinal symptoms(diarrhea,nausea and vomit),peripheral neuropathy,fatigue and infections.Grade 1-2 peripheral neurotoxicity occurred in 7 patients.Conclusion:The ixazomib-based chemotherapy regimens are safe and effective in R/RMM therapy,particularly for conversion patients who are effective for bortezomib therapy.The AE was manageable and safe.

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

OBJECTIVE: To investigate the mechanism of nucleolin (NCL) involved in lymphoma proliferation by regulating thymidine kinase 1 (TK1). METHODS: Twenty-three patients with diffuse large B-cell lymphoma (DLBCL) were selected and divided into initial treatment group (14 cases) and relapsed/refractory group (9 cases). Serum TK1 and C23 protein in peripheral blood mononuclear cells were detected. Cell models of CA46-NCL-KD (CA46-NCL-knockdown) and CA46-NCL-KNC (CA46-NCL-knockdown negative control) were established by lentivirus vector mediated transfection in Burkitt lymphoma cell line CA46. The half maximal inhibitory concentration (IC₅₀) of CA46-NCL-KD, CA46-NCL-KNC, and CA46 to adriamycin were detected by cell proliferation assay (MTS). The expression of NCL mRNA and protein in CA46-NCL-KD and CA46-NCL-KNC cells were dectected by Q-PCR and Western blot, respectively. The cell cycle of CA46-NCL-KD, CA46-NCL-KNC, and CA46 cells were detected by flow cytometry. The expression of TK1 protein in CA46-NCL-KD and CA46-NCL-KNC cells was detected by an enhanced chemiluminescence (ECL) dot blot assay. RESULTS: The level of serum TK1 in the initial treatment group was 0.43(0-30-1.01) pmol/L, which was lower than 10.56(2.19-14.99) pmol/L in the relapsed/refractory group (P<0-01), and the relative expression level of NCL protein in peripheral blood was also significantly lower. The IC₅₀ of CA46-C23-KD cells to adriamycin was (0.147±0.02) μg/ml, which was significantly lower than (0.301±0.04) μg/ml of CA46-C23-KNC cells and (0.338±0.05) μg/ml of CA46 cells (P<0.05). Compared with CA46-NCL-KNC cells, the expression of NCL mRNA and protein, TK1 protein decreased in CA46-NCL-KD cells, and the proportion of S phase and G₂/M phase also decreased, while G0/G1 phase increased in cell cycle. CONCLUSION The increased expression of NCL in DLBCL and CA46 cells indicates low sensitivity to drug. NCL may participate in regulation of lymphoma proliferation by affecting TK1 expression, thereby affecting the drug sensitivity.
Humans ; Leukocytes, Mononuclear/metabolism* ; Apoptosis ; Cell Line, Tumor ; Lymphoma ; Thymidine Kinase/pharmacology* ; Doxorubicin/pharmacology* ; Cell Division ; RNA, Messenger/genetics*

Objective:This study aimed to investigate the effect of lipohypertrophy induced by insulin injection on blood glucose fluctuation in patients with type 1 diabetes mellitus.Methods:A total of 80 patients with type 1 diabetes mellitus were recruited between June 2021 and December 2021 from the First Affiliated Hospital of Nanjing Medical University. And these patients all received insulin injection more than six months. Lipohypertrophy was assessed by ultrasound scanning, and blood glucose fluctuation was evaluated using the flash glucose monitoring system(FGM). Univariate analysis and multivariate linear regression were used to analyze the relationship of lipohypertrophy and and core indicators of blood glucose fluctuation.Results:Compared with patients without lipohypertrophy, patients with lipohypertrophy had higher mean amplitude of glycemic excursions(MAGE), coefficient of variation(CV), mean of daily differences(MODD), standard deviation(SD) of blood glucose, time above range(TAR), and high blood glucose index(HBGI; all P<0.05), while time in range(TIR) of glucose markedly become lower( P<0.01). Moreover, multivariate linear regression analysis showed that lipohypertrophy detected by ultrasound was an independent influencing factor of TIR( β=-9.423, P=0.032), MAGE( β=1.114, P=0.039), CV( β=4.304, P=0.041), MODD( β=0.717, P=0.046) after adjusting for age at diagnosis, duration of insulin injection, fasting C-peptide, and daily dose of insulin per unit weight. Conclusion:Lipohypertrophy increases glycemic variability and imposes negative impact on glycemic control rate in patients type 1 diabetes mellitus.