BACKGROUND:One of the advantages of clear aligner treatment is molar distalization.However,tooth tilting movement and loss of anterior anchorage may occur during treatment.There are few studies on whether these problems can be improved by selecting clear aligners with different thicknesses and edges to improve the clinical treatment effect.OBJECTIVE:To analyze the control ability of clear aligners with different thickness and edges on the central incisor,lateral incisor,and second molar when pushing the maxillary second molar distally by three-dimensional finite element analysis.METHODS:Three-dimensional finite element analysis models of bilateral maxillary second molar distalization with clear aligner,maxillary dentition,periodontal ligament,and alveolar bone with different thicknesses and margins were established by Mimics,Geomagic Wrap,3-matic and SolidWorks software,respectively.There were 16 combinations of four thicknesses(0.4,0.5,0.625,and 0.75 mm)and four margins(scallop,straight,straight extension 2 mm and straight extension 4 mm).The data were imported into Ansys Workbench software for design and solution.The mean value,peak value and distribution of the periodontal ligament equivalent stress of the second molar,the equivalent stress and the maximum initial displacement of the second molar,and the control ability of each appliance on the second molar,central incisor,and lateral incisor were analyzed.RESULTS AND CONCLUSION:(1)The mean equivalent stress of periodontal ligament of the second molar,the equivalent stress of the second molar and the maximum initial displacement of the second molar increased with the extension of the appliance edge and the increase of the thickness of the appliance in the 16 groups of models.(2)When the thickness of appliances was the same,the maximum equivalent stress of the second molar in the linear appliance group was the highest,and the maximum equivalent stress of the second molar in the linear extended appliance group was greater than that in the scallop appliance group.When the edge of the appliance was the same,the periodontal ligament equivalent stress peak of the second molar increased with the increase of the thickness of the appliance.The equivalent stress distribution in the periodontal ligament of the second molar in the linear extendable appliance group was more uniform than that in the scallop appliance group and the linear appliance group.(3)When the thickness of the appliance was the same,the scallop-shaped appliance had the worst control on the second molar.When the edge of the appliance was the same,with the increase of the thickness of the appliance,the control of the second molar by the linear extender appliance was gradually stronger than that by the linear appliance.The control of the central incisor was stronger and more stable with the linear extended 2 mm appliance,while the control of the lateral incisor was stronger and more stable with the linear appliance.(4)The results showed that when using clear aligners to push molars distally,extending the edge of the appliance could improve the control of the molars and reduce the tilting movement of the teeth.The design of a straight extension margin of 2 mm for the central incisor and a straight edge for the lateral incisor can enhance the control of the anchorage incisor and reduce the labial inclination of the anterior teeth.

BACKGROUND:One of the advantages of clear aligner treatment is molar distalization.However,tooth tilting movement and loss of anterior anchorage may occur during treatment.There are few studies on whether these problems can be improved by selecting clear aligners with different thicknesses and edges to improve the clinical treatment effect.OBJECTIVE:To analyze the control ability of clear aligners with different thickness and edges on the central incisor,lateral incisor,and second molar when pushing the maxillary second molar distally by three-dimensional finite element analysis.METHODS:Three-dimensional finite element analysis models of bilateral maxillary second molar distalization with clear aligner,maxillary dentition,periodontal ligament,and alveolar bone with different thicknesses and margins were established by Mimics,Geomagic Wrap,3-matic and SolidWorks software,respectively.There were 16 combinations of four thicknesses(0.4,0.5,0.625,and 0.75 mm)and four margins(scallop,straight,straight extension 2 mm and straight extension 4 mm).The data were imported into Ansys Workbench software for design and solution.The mean value,peak value and distribution of the periodontal ligament equivalent stress of the second molar,the equivalent stress and the maximum initial displacement of the second molar,and the control ability of each appliance on the second molar,central incisor,and lateral incisor were analyzed.RESULTS AND CONCLUSION:(1)The mean equivalent stress of periodontal ligament of the second molar,the equivalent stress of the second molar and the maximum initial displacement of the second molar increased with the extension of the appliance edge and the increase of the thickness of the appliance in the 16 groups of models.(2)When the thickness of appliances was the same,the maximum equivalent stress of the second molar in the linear appliance group was the highest,and the maximum equivalent stress of the second molar in the linear extended appliance group was greater than that in the scallop appliance group.When the edge of the appliance was the same,the periodontal ligament equivalent stress peak of the second molar increased with the increase of the thickness of the appliance.The equivalent stress distribution in the periodontal ligament of the second molar in the linear extendable appliance group was more uniform than that in the scallop appliance group and the linear appliance group.(3)When the thickness of the appliance was the same,the scallop-shaped appliance had the worst control on the second molar.When the edge of the appliance was the same,with the increase of the thickness of the appliance,the control of the second molar by the linear extender appliance was gradually stronger than that by the linear appliance.The control of the central incisor was stronger and more stable with the linear extended 2 mm appliance,while the control of the lateral incisor was stronger and more stable with the linear appliance.(4)The results showed that when using clear aligners to push molars distally,extending the edge of the appliance could improve the control of the molars and reduce the tilting movement of the teeth.The design of a straight extension margin of 2 mm for the central incisor and a straight edge for the lateral incisor can enhance the control of the anchorage incisor and reduce the labial inclination of the anterior teeth.

Objective To explore the feasibility and image quality of respiratory-gated total-body ¹⁸F-FDG PET/CT imaging with a 4-minute acquisition in patients with malignant tumors. Methods Sixty-two patients with pathologically confirmed malignant tumors (118 lesions measured) who underwent total-body ¹⁸F-FDG PET/CT examination were consecutively enrolled at the Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, from September 23, 2021 to November 23, 2021, and their clinical and imaging data were retrospectively collected. PET data was acquired over 12 minutes with simultaneous respiratory waveform recorded. The data were reconstructed into four image sets: gated-12 group and gated-4 group (using all counts and the first 4-minute counts, respectively) and ungated-12 group and ungated-6 group (using all counts and the first 6-minute counts, respectively) reconstructed with respiratory gating that retained counts corresponding to the half respiratory window near end-expiration. Image quality assessment and quantitative analysis of lesions were performed and compared among the four image sets, and subgroup analyses were performed according to lesion location, size, and metabolic activity. Results The effective counts of 4 sets of PET images were highest in ungated-12 group, followed by ungated-6 group and gated-12 group, and lowest in gated-4 group (P＜0.001). Regardless of the metabolic level and size of the lesions, compared with the ungated-12 group and the ungated-6 group, the lesions in the gated-12 group showed higher maximum, average, and peak standardized uptake values (SUV_max, SUV_mean, and SUV_peak), tumor liver uptake ratio, tumor blood pool uptake ratio, and smaller metabolic volume (P＜0.05); There was no statistically significant difference in the above indicators between the gate-12 group and the gate-4 group. The background noise of gate-4 group images is slightly higher than that of gate-12 group images (Liver SUV_SD: [0.17＋0.05] vs [0.14＋0.04]); Blood pool SUV_SD: (0.08 ± 0.03) vs (0.06 ± 0.03). There was a statistically significant difference in subjective scores of PET image quality among the four groups (P＜0.001). The subjective scores of image quality in the gated-12 group (4.79 ± 0.41) were not significantly different from those in the non gated-12 group (4.97 ± 0.17) and non gated-6 group (4.79 ± 0.45), but were higher than those in the gated-4 group ([4.17 ± 0.45], P＜0.001)， And the scores have good consistency (Kappa＞0.75). Conclusion In total-body PET/CT imaging for malignant tumors, 4-minute respiratory-gated acquisition can achieve comparable quantitative performance to longer respiratory gating imaging while significantly shortening acquisition time. This approach demonstrates promising potential for clinical application.

Objective:To analyze the association between healthcare workers mental health,institu-tional supplies and facilities,inter-organizational coordination during infectious disease outbreaks,and the healthcare institution resilience.Methods:An online questionnaire survey was conducted among the healthcare workforce from 146 institutions in Beijing from January 13,2023 to February 9,2023,and a total of 1 434 eligible respondents were included.The sample comprised 408 responses from tertiary hos-pitals,117 from secondary hospitals,and 909 from primary care institutions.The resilience indicator for healthcare institutions was defined as the degree to which medical services met patient demands,with in-fluencing factors including physical factors,such as material shortages and facility space adaptation or ex-pansion,organizational factors such as information sharing and patient referral,and psychological factors were evaluated using job satisfaction(extrinsic satisfaction,intrinsic satisfaction),burnout(emotional exhaustion,depersonalization,reduced personal accomplishment),and depression status.Ordered mul-ticlassification Logistic regression was used to examine the impact of various factors on the degree to which healthcare services met patient needs;additionally,demographic factors that might influence institutional resilience were controlled.Results:During the emergency response phase,93％of hospitals maintained the capacity to meet patient needs,though tertiary hospitals demonstrated significantly higher rates of service inadequacy(21.05％).Material shortages were reported across all institutions,with tertiary hos-pitals experiencing more frequent multi-item shortages.Inter-institutional collaboration patterns revealed substantial variation:87.50％of primary care facilities,42.86％of secondary hospitals,and 31.58％of tertiary hospitals.Healthcare workers across all levels reported mild depressive symptoms and moderate-to-severe burnout levels.Regression analysis showed high satisfaction(overall satisfaction β=0.04,ex-trinsic satisfaction β=0.06,and intrinsic satisfaction β=0.08),low degree of job burnout(emotional exhaustion β=-0.04,depersonalization β=-0.07 and reduced personal accomplishment β=0.01),low degree of depression(β=-0.06)were significantly associated with higher healthcare institution re-silience.In addition,material shortages were significantly associated with lower resilience,and renova-tion and expansion of treatment spaces,and information sharing,were all associated with higher resilience.Demographic factors(age,gender,marital status,educational background,etc.)had no sig-nificant impact on resilience.Conclusion:Mental health status significantly influences healthcare institu-tion resilience.As human resources constitute the core asset of healthcare institutions,strategic optimiza-tion of workforce allocation and psychological support interventions can effectively strengthen resilience.Moreover,healthcare institution resilience is positively impacted by orderly material supply chains,timely resource distribution,and adaptive reconfiguration of clinical spaces.Finally,facilitating information sharing also enhances institutional resilience.

Objective To elucidate the correlation between specific nucleocapsid(N)protein mutant of the SARS-CoV-2 B.1.1.7 variant and clinical stratification in COVID-19 patients,revealing their impact on N protein liquid-liquid phase separation(LLPS)and host innate immune response.Methods Based on whole-genome sequencing data of the SARS-CoV-2 B.1.1.7 lineage from the GISAID database,non-synonymous mutation sites significantly associated with mild/severe clinical phenotypes were screened.For high-frequency N protein mutant,IFN-β promoter transcriptional activity was quantitatively measured using a dual-luciferase reporter system.qPCR was used to detect the mRNA expression levels of interferon(IFN)-β,interleukin(IL)-6 and tumor necrosis factor(TNF)-α.LLPS characteristics were observed by confocal microscopy.The ubiquitination status of host MAVS was detected by Western blot assay.Results A total of 17 640 non-synonymous mutation sites were identified,among which 65 were associated with mild cases and 20 were related to severe cases,with a mutation frequency>1%.The N protein mutation sites associated with severe cases were D3L,M234I and R203K-G204R-T205I.N protein and the mutants NM234I,NR203K-G204R-T205I inhibited the promoter activity of IFN-β(P＜0.05).Compared to the wild type N protein,NR203K-G204R-T205I mutation significantly reduced the mRNA levels of IFN-β,IL-6 and TNF-α(P＜0.05),and altered the phase separation state by dispersing the formation of LLPS condensates.However,N mutant did not affect the ubiquitination modification of host MAVS.Conclusion N protein mutants of the SARS-CoV-2 B.1.1.7 variant can influence the clinical prognosis of COVID-19 patients by altering LLPS status and suppressing the innate immune responses.These finding provides a theoretical basis for the design of antiviral drugs targeting the N protein.

BACKGROUND:With the aging of the population,the incidence of osteoporosis is increasing year by year,and osteoporotic spinal fracture,as one of the common complications,brings great pain and inconvenience to patients.As an effective treatment,percutaneous vertebroplasty has been widely used in clinical practice.However,cement leakage as a potential risk of this procedure has been the focus of researchers.OBJECTIVE:To investigate the causes and management strategies of cement leakage after percutaneous vertebroplasty for osteoporotic vertebral compression fractures.METHODS:A total of 100 osteoporotic vertebral compression fractures patients who underwent percutaneous vertebroplasty in the Department of Orthopedics of Beijing Pinggu District Hospital from March 2017 to February 2021 were selected as the study subjects.According to the 12-month follow-up results,the patients were divided into bone cement leakage group(n=27)and non-bone cement leakage group(n=73).Cox proportional risk regression analysis was used to screen the influencing factors of bone cement leakage after surgery,so as to construct and evaluate the nomogram model for predicting the risk of bone cement leakage after surgery.Visual analog scale score and Oswesry dysfunction index of 27 patients were observed before surgery,3 days and 12 months after surgery following bone cement leakage treatment.RESULTS AND CONCLUSION:(1)Among the 27 patients with bone cement leakage,24 patients had internal leakage of intervertebral disc endplate,no obvious symptoms or discomfort,and no special treatment.Pulmonary embolism occurred in 1 case,and the patient was treated with the help of respiratory department.Two patients with symptoms underwent percutaneous intervertebral foramen endoscopic bone cement removal.(2)CT value,fracture severity,bone cement viscosity,cortical fracture,and injection amount of bone cement were the independent influencing factors for postoperative bone cement leakage(P<0.05).(3)The calibration degree and differentiation degree of the nomogram model were good,and it had good clinical practicability.(4)For 27 patients with external bone cement leakage after surgery,visual analog scale score at 3 days and 12 months after surgery was significantly lower than that before surgery,and the difference was statistically significant(P<0.05).Oswesry dysfunction index score at 12 months after surgery was significantly lower than that at 3 days after surgery,and the difference was statistically significant(P<0.05).(5)The results show that the amount of bone cement injection,bone cement viscosity,cortical fracture,CT value,and fracture severity are the risk factors of bone cement leakage after percutaneous vertebroplasty.

Objective:To evaluate the feasibility and outcomes of transnasal endoscopic clipping of the paraclival internal carotid artery (ICA) in skull base surgery.Methods:The paraclival ICA was anatomically dissected in cadaveric head specimens. The clinical data of 15 patients with skull base lesions involving the ICA who admitted to the Department of Otorhinolaryngology Head and Neck Surgery at Tianjin Huanhu Hospital from January 2021 to December 2023 were retrospectively analyzed. Among them, 4 patients underwent transnasal endoscopic clipping of the paraclival ICA and concurrent lesion resection. The surgical methods were summarized, and the key points and indications of this technique were analyzed.Results:Intraoperative clipping of the ICA was successful and hemostatic in all 4 patients. Postoperatively, 3 patients had no complications, while 1 patient developed delayed ischemic cerebral infarction. Two patients were cured, 1 patient was maintained on immunotherapy, and 1 patient died. During follow-up, the clip was in situ in 1 patient, had detached in another, and was obscured by temporal muscle coverage in the remaining 2 patients.Conclusions:Transnasal endoscopic clipping of the paraclival ICA represents a potential option for managing the ICA in skull base surgery. However, it carries significant risks and limitations, mandating careful patient selection based on specific circumstances.

BACKGROUND:With the aging of the population,the incidence of osteoporosis is increasing year by year,and osteoporotic spinal fracture,as one of the common complications,brings great pain and inconvenience to patients.As an effective treatment,percutaneous vertebroplasty has been widely used in clinical practice.However,cement leakage as a potential risk of this procedure has been the focus of researchers.OBJECTIVE:To investigate the causes and management strategies of cement leakage after percutaneous vertebroplasty for osteoporotic vertebral compression fractures.METHODS:A total of 100 osteoporotic vertebral compression fractures patients who underwent percutaneous vertebroplasty in the Department of Orthopedics of Beijing Pinggu District Hospital from March 2017 to February 2021 were selected as the study subjects.According to the 12-month follow-up results,the patients were divided into bone cement leakage group(n=27)and non-bone cement leakage group(n=73).Cox proportional risk regression analysis was used to screen the influencing factors of bone cement leakage after surgery,so as to construct and evaluate the nomogram model for predicting the risk of bone cement leakage after surgery.Visual analog scale score and Oswesry dysfunction index of 27 patients were observed before surgery,3 days and 12 months after surgery following bone cement leakage treatment.RESULTS AND CONCLUSION:(1)Among the 27 patients with bone cement leakage,24 patients had internal leakage of intervertebral disc endplate,no obvious symptoms or discomfort,and no special treatment.Pulmonary embolism occurred in 1 case,and the patient was treated with the help of respiratory department.Two patients with symptoms underwent percutaneous intervertebral foramen endoscopic bone cement removal.(2)CT value,fracture severity,bone cement viscosity,cortical fracture,and injection amount of bone cement were the independent influencing factors for postoperative bone cement leakage(P<0.05).(3)The calibration degree and differentiation degree of the nomogram model were good,and it had good clinical practicability.(4)For 27 patients with external bone cement leakage after surgery,visual analog scale score at 3 days and 12 months after surgery was significantly lower than that before surgery,and the difference was statistically significant(P<0.05).Oswesry dysfunction index score at 12 months after surgery was significantly lower than that at 3 days after surgery,and the difference was statistically significant(P<0.05).(5)The results show that the amount of bone cement injection,bone cement viscosity,cortical fracture,CT value,and fracture severity are the risk factors of bone cement leakage after percutaneous vertebroplasty.

Objective:To investigate the impacts of nuclear receptor-interacting protein 1(NRIP1)on sepsis-evoked intesti-nal epithelial injury via transcriptional regulation of high mobility group box 1(HMGB1).Methods:The expression levels of NRIP1 and HMGB1 were detected by RT-qPCR and Western blot.The pathological changes of intestinal tissue were detected by HE staining.CCK-8 assay determined the optimal treatment time of LPS.Caco-2 cells were transfected with NRIP1 small interfering RNA(siRNA-NRIP1-1/2),and cell viability and apoptosis were detected by CCK-8 assay and flow cytometry,respectively.RT-qPCR and Western blot examined the expressions of inflammation-associated factors.Transepithelial resistance(TEER)was used to detect intestinal epi-thelial permeability.Western blot was used to detect the expressions of apoptosis and tight-junction related proteins.The binding rela-tionship between NRIP1 and HMGB1 was verified by luciferase reporting assay and chromatin immunoprecipitation assay(ChIP).After knocking down NRIP1 and overexpressing HMGB1 in LPS-treated Caco-2 cells,the functional experiment was performed again.Results:NRIP1 expression was fortified in the intestinal tissues of sepsis rats and LPS-treated Caco-2 cells.Interference with NRIP1 attenuated LPS-elicited Caco-2 cell viability injury,apoptosis,inflammatory response and barrier damage.Additionally,NRIP1 might activate HMGB1 expression at transcriptional level and HMGB1 elevation might reverse the impacts of NRIP1 absence on Caco-2 cell viability,apoptosis,inflammatory response as well as barrier function.Conclusion:NRIP1 may promote sepsis-elicited intestinal epi-thelial injury,which may be related to transcriptional activation of HMGB1.

Objective To elucidate the correlation between specific nucleocapsid(N)protein mutant of the SARS-CoV-2 B.1.1.7 variant and clinical stratification in COVID-19 patients,revealing their impact on N protein liquid-liquid phase separation(LLPS)and host innate immune response.Methods Based on whole-genome sequencing data of the SARS-CoV-2 B.1.1.7 lineage from the GISAID database,non-synonymous mutation sites significantly associated with mild/severe clinical phenotypes were screened.For high-frequency N protein mutant,IFN-β promoter transcriptional activity was quantitatively measured using a dual-luciferase reporter system.qPCR was used to detect the mRNA expression levels of interferon(IFN)-β,interleukin(IL)-6 and tumor necrosis factor(TNF)-α.LLPS characteristics were observed by confocal microscopy.The ubiquitination status of host MAVS was detected by Western blot assay.Results A total of 17 640 non-synonymous mutation sites were identified,among which 65 were associated with mild cases and 20 were related to severe cases,with a mutation frequency>1%.The N protein mutation sites associated with severe cases were D3L,M234I and R203K-G204R-T205I.N protein and the mutants NM234I,NR203K-G204R-T205I inhibited the promoter activity of IFN-β(P＜0.05).Compared to the wild type N protein,NR203K-G204R-T205I mutation significantly reduced the mRNA levels of IFN-β,IL-6 and TNF-α(P＜0.05),and altered the phase separation state by dispersing the formation of LLPS condensates.However,N mutant did not affect the ubiquitination modification of host MAVS.Conclusion N protein mutants of the SARS-CoV-2 B.1.1.7 variant can influence the clinical prognosis of COVID-19 patients by altering LLPS status and suppressing the innate immune responses.These finding provides a theoretical basis for the design of antiviral drugs targeting the N protein.