BACKGROUND:Maxillofacial bone three-dimensional(3D)printing technology has been widely used in clinical diagnosis and treatment,but the data source before performing maxillofacial bone 3D printing mainly comes from the CT scanning data.The lens,thyroid and other parts of the human body are extremely sensitive to X-rays;therefore,it is particularly important to effectively reduce the dose of CT radiation when acquiring the data source.OBJECTIVE:To explore the feasibility of low-dose CT technology in optimizing radiation dose for maxillofacial bone 3D printing.METHODS:The medical records of 65 patients who underwent maxillofacial bone 3D printing in the Department of Stomatology at the General Hospital of Northern Theater Command from March 2021 to December 2023 were retrospectively collected and categorized into a conventional CT-dose 3D printing group(conventional CT-dose,120 kVp,automated tube current modulation,n=32)and a low-CT-dose 3D printing group(low-CT-dose group,80 kVp,automated tube current modulation,n=33).The effective dose of radiation was calculated and compared between the two groups.A Likert scale was used to evaluate the quality of 3D printing in the two groups,and the measurement bias and consistency between evaluators were measured using the Bland-Altman method.RESULTS AND CONCLUSION:(1)There was no significant difference in the general demographic characteristics(age,height,weight,body mass,sex,and body mass index)between the two groups(all P＞0.05).(2)The effective dose value of the low CT-dose 3D printing group was(0.3±0.1)mSv,which was about 62.5％lower than that in the conventional CT-dose 3D printing group[(0.8±0.1)mSv].(3)There was no significant difference in the subjective scoring of 3D printing quality between the two groups(all P＞0.05).The subjective consistency among evaluators was good,with Kappa values of 0.85,0.80,and 0.76.The scatter points in the Bland-Altman for both protocols were uniformly distributed within the standard deviation line,indicating good consistency between the two groups.To conclude,low-dose CT technology can be effectively applied in maxillofacial bone 3D printing,reducing radiation dose without affecting the quality of 3D printing.

BACKGROUND:Maxillofacial bone three-dimensional(3D)printing technology has been widely used in clinical diagnosis and treatment,but the data source before performing maxillofacial bone 3D printing mainly comes from the CT scanning data.The lens,thyroid and other parts of the human body are extremely sensitive to X-rays;therefore,it is particularly important to effectively reduce the dose of CT radiation when acquiring the data source.OBJECTIVE:To explore the feasibility of low-dose CT technology in optimizing radiation dose for maxillofacial bone 3D printing.METHODS:The medical records of 65 patients who underwent maxillofacial bone 3D printing in the Department of Stomatology at the General Hospital of Northern Theater Command from March 2021 to December 2023 were retrospectively collected and categorized into a conventional CT-dose 3D printing group(conventional CT-dose,120 kVp,automated tube current modulation,n=32)and a low-CT-dose 3D printing group(low-CT-dose group,80 kVp,automated tube current modulation,n=33).The effective dose of radiation was calculated and compared between the two groups.A Likert scale was used to evaluate the quality of 3D printing in the two groups,and the measurement bias and consistency between evaluators were measured using the Bland-Altman method.RESULTS AND CONCLUSION:(1)There was no significant difference in the general demographic characteristics(age,height,weight,body mass,sex,and body mass index)between the two groups(all P＞0.05).(2)The effective dose value of the low CT-dose 3D printing group was(0.3±0.1)mSv,which was about 62.5％lower than that in the conventional CT-dose 3D printing group[(0.8±0.1)mSv].(3)There was no significant difference in the subjective scoring of 3D printing quality between the two groups(all P＞0.05).The subjective consistency among evaluators was good,with Kappa values of 0.85,0.80,and 0.76.The scatter points in the Bland-Altman for both protocols were uniformly distributed within the standard deviation line,indicating good consistency between the two groups.To conclude,low-dose CT technology can be effectively applied in maxillofacial bone 3D printing,reducing radiation dose without affecting the quality of 3D printing.

Objective: To characterize the sequence polymorphism of HLA-A, -B, and -C loci in the northern Han Chinese population and to evaluate their selection signals and phylogenetic patterns based on long-read sequencing data. Methods: A total of 408 unrelated healthy blood donors were enrolled. Long-read sequencing of HLA-A, -B, and -C loci was performed using the PacBio Sequel II platform. The Ewens-Watterson neutrality test, sliding-window nucleotide diversity (π) and Tajima′s D analyses were conducted, together with genetic distance heatmaps, principal coordinates analysis (PCoA), and maximum likelihood phylogenetic analysis to assess polymorphism distribution, selection signals, and phylogenetic structure across the three loci. Results: The analyzed sequence lengths for the HLA-A, -B, and -C loci were 3 257 bp, 3 794 bp, and 3 831 bp, respectively; the numbers of locus-specific sequence types were 44, 82, and 56, with corresponding locus-specific sequence type diversities of 0.905 2, 0.964 9, and 0.939 8, respectively. The Ewens-Watterson test showed no significant deviation from neutrality (P>0.05). Sliding-window analysis revealed elevated π and Tajima′s D values in exons 2 and 3 as well as in certain intronic regions of HLA-A and HLA-B, whereas HLA-C exhibited relatively lower overall diversity. Genetic distance heatmaps, PCoA, and phylogenetic analysis consistently showed clear clustering in HLA-A and HLA-C, while HLA-B displayed the highest phylogenetic heterogeneity. Conclusion: HLA-A, -B, and -C gene sequences in the northern Chinese Han population exhibit high levels of polymorphism and marked regional heterogeneity. HLA-B shows greater diversity, stronger signals of selection, and more complex phylogenetic structure compared with HLA-A and HLA-C.

Objective:To analyze the risk factors associated with future exacerbations in patients with chronic obstructive pulmonary disease (COPD) who have no history of exacerbation in the past year.Methods:COPD patients with no exacerbation history in the past year, registered in the RealDTC study from January 2018 to December 2023, were enrolled. Demographic data, COPD Assessment Test (CAT) scores, modified Medical Research Council (mMRC) dyspnea questionnaire scores, forced expiratory volume in the first second predicted of percentage (FEV 1%pred), forced expiratory volume in one second (FEV 1) to forced vital capacity (FVC), Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification, GOLD groups, and inhaled medication regimens were collected. All patients were followed up for one year, and the number of exacerbations was recorded. Patients were divided into an exacerbation group and a non-exacerbation group based on the occurrence of exacerbations during the follow-up period. Logistic regression analysis was used to screen the influencing factors for exacerbations in COPD patients. Results:A total of 2 901 COPD patients were included, among which 633 patients (21.8%) experienced exacerbations during the follow-up period. Compared with the non-exacerbation group, patients in the exacerbation group were older, with higher CAT and mMRC scores, lower body mass index (BMI), FEV 1%pred, and FEV 1/FVC. The proportions of patients with high school education or above and those using long-acting β 2-agonist (LABA) + long-acting muscarinic antagonist (LAMA) medications were also lower (all P<0.05). Logistic regression analysis showed that age ( OR=1.010, 95% CI: 1.000-1.021), CAT score ≥20 ( OR=1.415, 95% CI: 1.074-1.865), education level of junior high school or below ( OR=1.243, 95% CI: 1.003-1.540), LABA + LAMA inhalation ( OR=0.605, 95% CI: 0.432-0.848), and BMI ( OR=0.969, 95% CI: 0.943-0.995) were independent risk factors for future exacerbations in COPD patients with no exacerbation history in the past year (all P<0.05). Conclusions:The risk of future exacerbations remains high in COPD patients with no exacerbation history in the past year. High CAT scores, low education levels, and low BMI are associated with future exacerbations. Clinicians should pay close attention to the management of such patients and implement appropriate interventions.

Objective To investigate the current status and analyze the factors affecting the osteoporosis knowledge among orthopedic nurses,and to provide references for improving osteoporosis knowledge among orthopedic nurses.Methods We investigated 5 681 orthopedic nurses from 621 hospitals in 31 provinces(autonomous regions/municipalities)using a convenient sampling method from September 2023 to November 2023.We collected information using a general information questionnaire and osteoporosis knowledge assessment tool.We used univariate and multivariate logistic regression to identify risk factors.Results A total of 5 204 orthopedic nurses were included.The total mean score of osteoporosis knowledge assessment tool of nurses was[13.00(12.00,14.00)],and 23.48％nurses had a low level of osteoporosis awareness.Logistic regression analysis showed that the age,title and position of the nurses,location of the hospital,the level of the hospital,whether to conduct the fracture liaison service/to set up the refracture prevention team,whether to use calcium tablets/vitamin D,whether to carry out anti-osteoporosis drug therapy,and whether to conduct topical lectures on osteoporosis or secondary fractures,were the factors that affected orthopedic nurses'knowledge of osteoporosis(P＜0.05).Conclusion The osteoporosis knowledge of orthopedic nurses needs to be improved.Nursing managers should carry out personalized interventions from both hospital and nurse levels to improve the osteoporosis knowledge of orthopedic nurses in our country.

Objective A cross-sectional survey on the postoperative home care status and barriers was conducted among elderly patients with osteoporotic fractures nationwide,in order to provide a basis for promoting the improvement of standardized home care for elderly patients with osteoporotic fractures.Methods From October to November 2023,a survey on the current situation and barriers of home environment protection was conducted among elderly patients with osteoporotic fractures in the orthopedic wards of 594 hospitals across 31 provinces(autonomous regions/municipalities directly under the central government)using a convenience sampling method.Results A total of 14,349 questionnaires were distributed,and 12,496 valid questionnaires were collected,resulting in an effective response rate of 87.09％.Among the patients,5,502 cases(44.03％)had implemented home-based prevention and treatment of osteoporosis before the fracture.2 095(16.77％)of the patients experienced a subsequent fracture,of which 65.11％of the patients who experienced a subsequent fracture received medication intervention after the initial fracture,while 19.86％of the patients who experienced a subsequent fracture did not comply with the treatment for osteoporosis after the initial fracture.Additionally,77.66％(n=1 627/2 095)of the patients received community medical services after the initial fracture.Barriers to care factors in the home environment after fracture from the patient's perspective presented the complexity of the social-ecological system model in 6 dimensions at 2 levels:micro(basic personal situation,physiological factors,psychological factors,and behavioural factors),and meso(social support factors,and healthcare worker factors).Conclusion In the vast majority of elderly patients in China,before osteoporotic fracture,home-based measures to prevent osteoporosis have not been adequately implemented;after the initial osteoporotic fracture,the pathway of re-fracture prevention and management in the patient's home environment is not yet complete and its popularity needs to be improved;the barriers to home care faced by elderly patients with osteoporotic fracture are complex.It is recommended to promote effective linkages among hospitals,community health centres and families to strengthen the closed-loop management of re-fracture prevention and management.

Objective To observe the value of 68Ga-DOTA-NOC PET/CT for diagnosing pheochromocytoma(PCC)and paraganglioma(PGL).Methods Thirty-eight patients with suspected or confirmed PCC/PGL who underwent 68 Ga-DOTA-NOC PET/CT were retrospectively enrolled,among them 20 cases underwent 131I-metaiodobenzylguanidine(MIBG)SPECT/CT during the same period.The value of 68Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL at individual and lesion levels were analyzed and compared to the results of 131I-MIBG SPECT/CT.Results Among 38 cases,there were 20 cases of PCC,14 cases of PGL,1 case of adrenocortical carcinoma and 3 cases of benign adrenal hyperplasia.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of 68 Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL in all 38 cases was 87.88％(29/33),60.00％(3/5),93.55％(29/31),42.86％(3/7)and 84.21％(32/38),respectively.Totally 188 lesions were detected in 34 cases,with detection rate of 89.95％(188/209).For 20 patients who underwent both 2 kinds examinations,the detection rate of bone,lymph node,liver,lung metastases and the overall lesions of 68Ga-DOTA-NOC PET/CT were all higher than those of 131I-MIBG SPECT/CT(all P＜0.05).No significant difference of diagnostic accuracy of PCC/PGL was found between 68 Ga-DOTA-NOC PET/CT and 131I-MIBG SPECT/CT(P＞0.05).Conclusion The value of 68 Ga-DOTA-NOC PET/CT for diagnosing PCC/PGL was comparable to that of 131I-MIBG SPECT/CT,but the former showed higher detection rate of metastases,hence being helpful to staging and risk stratification of PCC/PGL.

Objective:To analyze the risk factors associated with future exacerbations in patients with chronic obstructive pulmonary disease (COPD) who have no history of exacerbation in the past year.Methods:COPD patients with no exacerbation history in the past year, registered in the RealDTC study from January 2018 to December 2023, were enrolled. Demographic data, COPD Assessment Test (CAT) scores, modified Medical Research Council (mMRC) dyspnea questionnaire scores, forced expiratory volume in the first second predicted of percentage (FEV 1%pred), forced expiratory volume in one second (FEV 1) to forced vital capacity (FVC), Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification, GOLD groups, and inhaled medication regimens were collected. All patients were followed up for one year, and the number of exacerbations was recorded. Patients were divided into an exacerbation group and a non-exacerbation group based on the occurrence of exacerbations during the follow-up period. Logistic regression analysis was used to screen the influencing factors for exacerbations in COPD patients. Results:A total of 2 901 COPD patients were included, among which 633 patients (21.8%) experienced exacerbations during the follow-up period. Compared with the non-exacerbation group, patients in the exacerbation group were older, with higher CAT and mMRC scores, lower body mass index (BMI), FEV 1%pred, and FEV 1/FVC. The proportions of patients with high school education or above and those using long-acting β 2-agonist (LABA) + long-acting muscarinic antagonist (LAMA) medications were also lower (all P<0.05). Logistic regression analysis showed that age ( OR=1.010, 95% CI: 1.000-1.021), CAT score ≥20 ( OR=1.415, 95% CI: 1.074-1.865), education level of junior high school or below ( OR=1.243, 95% CI: 1.003-1.540), LABA + LAMA inhalation ( OR=0.605, 95% CI: 0.432-0.848), and BMI ( OR=0.969, 95% CI: 0.943-0.995) were independent risk factors for future exacerbations in COPD patients with no exacerbation history in the past year (all P<0.05). Conclusions:The risk of future exacerbations remains high in COPD patients with no exacerbation history in the past year. High CAT scores, low education levels, and low BMI are associated with future exacerbations. Clinicians should pay close attention to the management of such patients and implement appropriate interventions.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Objective:To investigate the effect of Yiqi Shengqing Formula on neuronal damage in ischemic stroke(IS)rats by regulating brain-derived neurotrophic factor(BDNF)-extracellular regulated protein kinase(ERK)-cyclic adenosine monophosphate-responsive element binding protein(CREB)signal pathway.Methods:IS rat model was prepared by modified thread suppository method,and randomly divided into model group,low dose Yiqi Shengqing Formula(3 g/kg)group,high dose Yiqi Shengqing Formula(6 g/kg)group,high dose Yiqi Shengqing Formula(6 g/kg)+empty load group,high dose Yiqi Shengqing Formula(6 g/kg)+BDNF knockdown group,with 10 rats in each group,another 10 healthy rats were set as sham operation group.After intervention with Yiqi Shengqing Formula and plasmid,neural function of rats in each group was scored with Longa scoring method;Morris water maze test was used to detect cognitive impairment of rats in each group;Nissl staining was used to detect the number of neurons in ischemic peripheral brain tissue and hippocampus of rats in each group;synaptic morphology of ischemic peripheral brain tissue was detected by silver staining;levels of TNF-α and IL-8 in brain tissue and serum of rats in each group were measured by ELISA;expressions of BDNF-ERK-CREB signal pathway related proteins in rat brain were detected by Western blot.Results:Compared with sham operation group,synaptic morphology of ischemic peripheral brain tissue in model group was severely damaged,retention time in target quad-rant,times of crossing platform,the number of neurons in ischemic peripheral brain tissue and hippocampus,expressions of BDNF protein and p-ERK/ERK,p-CREB/CREB in brain tissue were decreased significantly(P<0.05),while neurological function score and levels of inflammatory factors TNF-α and IL-8 in brain tissue and serum were increased significantly(P<0.05).Compared with model group,synaptic morphological damage of ischemic peripheral brain tissue in rats in low dose Yiqi Shengqing Formula group and high dose Yiqi Shengqing Formula group was alleviated,retention time in target quadrant,times of crossing platform,the number of neurons in ischemic peripheral brain tissue and hippocampus,expressions of BDNF protein and p-ERK/ERK,p-CREB/CREB in brain tissue were increased(P<0.05),while neurological function score and levels of inflammatory factors TNF-α and IL-8 in brain tissue and serum were decreased(P<0.05).Compared with low dose Yiqi Shengqing Formula group,damage of synaptic morphology in ischemic peripheral brain tissue of rats in high dose Yiqi Shengqing Formula group was further alleviated,retention time in target quadrant,times of crossing platform,the number of neurons in ischemic peripheral brain tissue and hippocampus,expressions of BDNF protein and p-ERK/ERK,p-CREB/CREB in brain tissue were further increased(P<0.05),while neurological function score and levels of inflammatory factors TNF-α and IL-8 in brain tissue and serum were further reduced(P<0.05).Compared with high dose Yiqi Shengqing Formula group,synaptic morphological damage of ischemic peripheral brain tissue in high dose Yiqi Shengqing Formula+BDNF knockdown group was aggravated,retention time in target quadrant,times of crossing the platform,number of neurons in ischemic peripheral brain tissue and hippocampus,expressions of BDNF protein and p-ERK/ERK,p-CREB/CREB in brain tissue were decreased(P<0.05),while neurological function score and levels of inflammatory factors TNF-α and IL-8 in brain tissue and serum were increased(P<0.05);there was no significant changes in each index of rats in high dose Yiqi Shengqing Formula+empty load group(P>0.05).Conclusion:Yiqi Shengqing Formula can inhibit the neuroinflammation of IS rats by activating BDNF-ERK-CREB signal,thereby reducing the damage of its neurons and improving its neural function.