Objective:To explore the influence of artificial intelligence(AI)-assisted compressive sensing(ACS)technique with different acceleration factors on the image quality and scan time of three dimensional time-of-flight magnetic resonance angiography(3D-TOF-MRA)for brain.Methods:Thirty participants who underwent brain magnetic resonance imaging(MRI)at Tongzhou Branch of Beijing Friendship Hospital were recruited.All subjects underwent imaging scans about four different parameters:a non-accelerated technique(control group),ACS technique integrated with acceleration factor of 4.03(ACS4 group),ACS technique integrated with acceleration factor of 5.02(ACS5 group),and ACS technique integrated with acceleration factor of 6.06(ACS6 group).The image clarity,ranking of imaging capabilities of distal branch blood vessels and the ratio of pseudo-stenosis were qualitatively analyzed.The signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),edge sharpness,and scan time were quantitatively analyzed.Results:There was not difference in vessel clarity among three ACS groups at the proximal and middle intracranial segments.For distal segments of blood vessel,the ACS4 group[3.0(3.0,3.0)]and ACS5 group[3.0(3.0,3.0)]were better than ACS6[2.5(2.0,3.0)](q=29.800,27.500,P<0.05).The imaging capabilities of distal-branch vessel of ACS4 group and ACS5 group were better than ACS6 group.There was no stenosis in the proximal and middle segments of the images of the three ACS group,and there were no stenosis in the images of distal vessels of ACS4 group and ACS5 group.A total of 5 cases were pseudo-stenosis in the distal vessels of ACS6 group.Compared with the control group,the incidence of pseudo-stenosis in the distal vessels of ACS6 group was 16.7%.The SNR and CNR values of quantitative analysis for proximal vessels in ACS6 group were higher than them in ACS4 group(q=27.800,26.200,P<0.05),and there was not significant difference in them among ACS4 group,ACS6 group and ACS5 group(P>0.05).The differences of SNR and CNR values in the middle and distal segments of blood vessels among different groups were not significant(P>0.05).There was not significant difference in the edge sharpness of blood vessels among ACS4 group,ACS5 group,and ACS6 group(P>0.05),while all of them were higher than those of control group,and the differences were significant(q=48.150,53.367,44.883,P<0.001).Compared with control group,the scan-time of ACS4 group was reduced by 55.19%,and that of ACS5 group was reduced by 64.07%,and that of ACS6 group was reduced by 70%.Conclusion:ACS technique can accelerate the imaging speed of brain 3D-TOF-MRA and ensure image quality.It is clinically recommended to set the ACS acceleration factor as 5.02 to undergo brain 3D-TOF-MRA scans.

Objective To improve the national standardized method for determining biphenyl in workplace air, which was based on activated carbon tube sampling, carbon disulfide desorption, and gas chromatography, by developing a method using GDX-502 tubes for sampling, toluene for desorption, and gas chromatography. Methods Workplace air samples were collected using GDX-502 sampling tubes and desorbed with toluene, followed by determination with gas chromatography. Results The improved method demonstrated good linearity for biphenyl concentrations ranging from 0.33 to 330.00 mg/L, with a correlation coefficient of 0.999 9. The detection limit and lower limit of quantification were 0.06 and 0.21 mg/L, and the minimum detection concentration and minimum quantification concentration were 0.04 and 0.14 mg/m³ (based on 1.5 L air sample volume), respectively. The average desorption efficiency ranged from 96.6% to 101.1%. The within-run and between-run relative standard deviations were 0.6%-1.4% and 1.4%-3.3%, respectively, with 100.0% sampling efficiency. Samples remained stable for at least 14 days at room temperature. Conclusion The improved method for biphenyl detection demonstrates rapid and accurate performance, with the advantages of low detection limits and high sampling and desorption efficiency.

[摘 要] 目的：探讨白蛋白结合型紫杉醇联合PD-1抑制剂用于治疗一线化疗失败的骨与软组织肉瘤的疗效及安全性。方法：回顾性分析北京积水潭医院骨肿瘤科2017年8月至2020年8月收治的一线化疗失败的晚期骨与软组织肉瘤患者。患者接受白蛋白结合型紫杉醇（125~140 mg/m2，第1天和第8天）与PD-1抑制剂（信迪利单抗或特瑞普利单抗，每21 d一次）联合治疗。每2个治疗周期评估1次疗效，按RECIST 1.1标准评估肿瘤疗效，按NCI-CTCAE5.0标准评估不良反应。结果：共20名患者纳入研究，完成1至8个治疗周期，中位治疗周期数为3个。所有患者均可评估疗效，完全缓解4例（20%），部分缓解0例，稳定9例（45%），疾病进展7例（35%）。客观缓解率（ORR）为20%，疾病控制率（DCR）为65%。中位无进展生存期（PFS）为3.0个月。治疗期间主要不良反应包括2级白细胞减少（40%）、1-2级神经毒性反应（20%），以及2级甲状腺功能减退（10%）。结论：白蛋白结合型紫杉醇联合PD-1抑制剂治疗为一线化疗失败的晚期骨与软组织肉瘤患者提供了一种潜在的治疗选择，其不良反应可控，值得开展更大样本的前瞻性研究进一步验证其疗效。

Objective To establish a liquid chromatography method for the simultaneous determination of 13 aromatic amine compounds (AAs) in workplace air. Methods A total of 13 AAs in both vapor and aerosol phases were collected in workplace air using a new GDH-6 sampling tube. Samples were desorbed and eluted with methanol, separated using a Symmetry Shield™ RP₁₈ reversed-phase liquid chromatography column, and detected with a diode array detector. Quantification was performed using an external standard method. Results The linear range of the 13 AAs measured by this method was 0.02-373.60 μg/L with the correlation coefficients greater than 0.999 0. The minimum detection concentration was 0.09-14.37 μg/m³, and the minimum quantitative concentration was 0.31-47.90 μg/m³ (both calculated based on sampling 15.0 L of air and 3.0 mL of elution volume). The average desorption and elution efficiency ranged from 97.46% to 101.23%. The within-run relative standard deviation (RSD) was 0.10%-5.99%, and the between-run RSD was 0.17%-2.71%. Samples could be stably stored in sealed conditions at 2-8 ℃ for more than seven days. Conclusion This method is suitable for the simultaneous determination of 13 AAs in workplace air, including both vapor and aerosol phases.

Objective To establish a method for simultaneous determination of four high-molecular-weight thiol derivatives (TDs) in workplace air by gas chromatography. Methods The four kinds of vapor-phase macromolecular TDs (1-pentanethiol, 1-hexanethiol, 1-benzyl mercaptan, and n-octanethiol) in the workplace air were collected using the GDH-1 air sampling tubes, desorbed with anhydrous ethanol, separated on a DB-FFAP capillary column, and determined by flame ionization detector. Results The quantitation range of the four TDs was 0.30-207.37 mg/L, with the correlation coefficients greater than 0.999 00. The minimum detection mass concentrations and minimum quantitation mass concentrations were 0.18-0.32 and 0.60-1.05 mg/m³, respectively (both calculated based on the 1.5 L sample and 3.0 mL desorption solvent). The mean desorption efficiencies ranged from 87.07% to 103.59%. The within-run and between-run relative standard deviations were 1.92%-8.22% and 1.89%-8.45%, respectively. The samples can be stored at room temperature or 4 ℃ for three days and up to 7 days at -18 ℃. Conclusion This method is suitable for the simultaneous determination of four vapor-phase TDs in workplace air.

Objective To develop a solvent desorption-gas chromatography method for quantifying malononitrile in workplace air. Methods Malononitrile in workplace air was collected using a silica gel tube and desorbed with methanol. Separation was performed using DB-FFAP capillary column, and detection was performed by hydrogen flame ionization detector. Results The linear ranges of malononitrile were 4.00-600.00 mg/L, with the correlation coefficient of 0.999 92. The detection limit was 0.54 mg/L. The minimum detection concentration was 0.36 mg/m³ (based on a collected air volume of 1.5 L). The average desorption efficiency was 95.0%-101.0%. The within-run and between-run relative standard deviations were 0.9%-5.3% and 1.0%-6.8%, respectively. The sampling efficiency was 100.0%. The samples were stable at 4 ℃ for at least 14 days. Conclusion The solvent desorption-gas chromatography method established in this study for the determination of malononitrile in workplace air is simple to use, with high accuracy and good precision, and is suitable for the determination of malononitrile in workplace air.

Objective:To investigate the clinical efficacy of liquid nitrogen cryopreservation and reimplantation versus allograft reconstruction in patients underwent resection of primary malignant bone tumors of the long bones of the extremities.Methods:A retrospective analysis was conducted on 144 patients who underwent resection of primary malignant bone tumors of the long bones of the extremities followed by either liquid nitrogen cryopreservation and reimplantation or massive allografts reconstruction at the Beijing Jishuitan Hospital affiliated with Capital Medical University from January 2012 to July 2023. The study included 82 males and 62 females, with an average age of 23.8±12.3 years (range, 6-64 years). Patients were divided into two groups based on the reconstruction method: the cryopreservation and reimplantation group (72 cases) and the allograft group (72 cases). The following outcomes were recorded during follow-up: local tumor recurrence, bone union, union time, graft survival, and reasons for graft removal. Graft-related complications were recorded using the modified Henderson classification system of the International Limb Salvage Association. Limb function was assessed at the last follow-up using the Musculoskeletal Tumor Society score (MSTS-93).Results:All patients completed surgery and were followed up for a mean of 60.2±32.1 months (range, 12-149 months). At the last follow-up, 24 patients were dead from the tumor, 16 patients survived with the tumor (2 cases of local recurrence and 14 cases of distant metastasis), and 104 patients survived without the tumor. The bone union rate and union time in cryopreservation and reimplantation group were 90% (65/72) and 9.6±4.8 months, respectively, which was significantly superior to those in allograft group [68% (49/72) and 15.9±6.7 months, P<0.05]. The 5-year overall graft survival rate was 86.8% [95% CI (80.1%, 95.7%)] in cryopreservation and reimplantation group, higher than 73.2% [95% CI(68.4%, 84.5%)] in allograft group significantly (χ 2=7.122, P=0.017). The rates of graft removal due to non-union and infection in the cryopreservation and reimplantation group were 0% (0/72) and 1.4% (1/72), respectively, which were significantly lower than those in the allograft group [5.6% (4/72) and 9.7% (7/72), P<0.05]. Overall, 48.6% (70/144) of patients experienced at least one graft-related complication, with a complication rate of 33.3% in cryopreservation and reimplantation group, lower than the 61.1% in allograft group significantly (χ 2=11.146, P<0.001). The complications with the highest incidence rate were nonunion (20.8%, 30/144), followed by structural failure (17.4%, 25/144), tumor progression (10.4%, 15/144), infection (10.4%, 15/144), and soft tissue failure (5.6%, 8/144). The incidence rates of the atrophic non-union and the structural failure of grafts were 9.7% (7/72) and 1.4% (1/72) respectively in the cryopreservation and reimplantation group, which were significantly lower compared to the allograft group [29.2% (21/72) and 13.9% (10/72), P<0.05]. At the last follow-up, the MSTS-93 score was 89.7%±8.3% in the cryopreservation and reimplantation group, and 87.6%±7.5% in the allograft group, with no statistically significant difference ( t=0.326, P=0.542). Conclusion:Compared with allograft reconstruction, autologous inactivated bone grafting demonstrated superior bone union efficiency and fewer complications, it may be considered for reconstruction in cases whose tumor bone is not severely osteolytic or pathologically fractured.

Objective:To explore the influence of artificial intelligence(AI)-assisted compressive sensing(ACS)technique with different acceleration factors on the image quality and scan time of three dimensional time-of-flight magnetic resonance angiography(3D-TOF-MRA)for brain.Methods:Thirty participants who underwent brain magnetic resonance imaging(MRI)at Tongzhou Branch of Beijing Friendship Hospital were recruited.All subjects underwent imaging scans about four different parameters:a non-accelerated technique(control group),ACS technique integrated with acceleration factor of 4.03(ACS4 group),ACS technique integrated with acceleration factor of 5.02(ACS5 group),and ACS technique integrated with acceleration factor of 6.06(ACS6 group).The image clarity,ranking of imaging capabilities of distal branch blood vessels and the ratio of pseudo-stenosis were qualitatively analyzed.The signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),edge sharpness,and scan time were quantitatively analyzed.Results:There was not difference in vessel clarity among three ACS groups at the proximal and middle intracranial segments.For distal segments of blood vessel,the ACS4 group[3.0(3.0,3.0)]and ACS5 group[3.0(3.0,3.0)]were better than ACS6[2.5(2.0,3.0)](q=29.800,27.500,P<0.05).The imaging capabilities of distal-branch vessel of ACS4 group and ACS5 group were better than ACS6 group.There was no stenosis in the proximal and middle segments of the images of the three ACS group,and there were no stenosis in the images of distal vessels of ACS4 group and ACS5 group.A total of 5 cases were pseudo-stenosis in the distal vessels of ACS6 group.Compared with the control group,the incidence of pseudo-stenosis in the distal vessels of ACS6 group was 16.7%.The SNR and CNR values of quantitative analysis for proximal vessels in ACS6 group were higher than them in ACS4 group(q=27.800,26.200,P<0.05),and there was not significant difference in them among ACS4 group,ACS6 group and ACS5 group(P>0.05).The differences of SNR and CNR values in the middle and distal segments of blood vessels among different groups were not significant(P>0.05).There was not significant difference in the edge sharpness of blood vessels among ACS4 group,ACS5 group,and ACS6 group(P>0.05),while all of them were higher than those of control group,and the differences were significant(q=48.150,53.367,44.883,P<0.001).Compared with control group,the scan-time of ACS4 group was reduced by 55.19%,and that of ACS5 group was reduced by 64.07%,and that of ACS6 group was reduced by 70%.Conclusion:ACS technique can accelerate the imaging speed of brain 3D-TOF-MRA and ensure image quality.It is clinically recommended to set the ACS acceleration factor as 5.02 to undergo brain 3D-TOF-MRA scans.

Objective:To investigate the clinical efficacy of liquid nitrogen cryopreservation and reimplantation versus allograft reconstruction in patients underwent resection of primary malignant bone tumors of the long bones of the extremities.Methods:A retrospective analysis was conducted on 144 patients who underwent resection of primary malignant bone tumors of the long bones of the extremities followed by either liquid nitrogen cryopreservation and reimplantation or massive allografts reconstruction at the Beijing Jishuitan Hospital affiliated with Capital Medical University from January 2012 to July 2023. The study included 82 males and 62 females, with an average age of 23.8±12.3 years (range, 6-64 years). Patients were divided into two groups based on the reconstruction method: the cryopreservation and reimplantation group (72 cases) and the allograft group (72 cases). The following outcomes were recorded during follow-up: local tumor recurrence, bone union, union time, graft survival, and reasons for graft removal. Graft-related complications were recorded using the modified Henderson classification system of the International Limb Salvage Association. Limb function was assessed at the last follow-up using the Musculoskeletal Tumor Society score (MSTS-93).Results:All patients completed surgery and were followed up for a mean of 60.2±32.1 months (range, 12-149 months). At the last follow-up, 24 patients were dead from the tumor, 16 patients survived with the tumor (2 cases of local recurrence and 14 cases of distant metastasis), and 104 patients survived without the tumor. The bone union rate and union time in cryopreservation and reimplantation group were 90% (65/72) and 9.6±4.8 months, respectively, which was significantly superior to those in allograft group [68% (49/72) and 15.9±6.7 months, P<0.05]. The 5-year overall graft survival rate was 86.8% [95% CI (80.1%, 95.7%)] in cryopreservation and reimplantation group, higher than 73.2% [95% CI(68.4%, 84.5%)] in allograft group significantly (χ 2=7.122, P=0.017). The rates of graft removal due to non-union and infection in the cryopreservation and reimplantation group were 0% (0/72) and 1.4% (1/72), respectively, which were significantly lower than those in the allograft group [5.6% (4/72) and 9.7% (7/72), P<0.05]. Overall, 48.6% (70/144) of patients experienced at least one graft-related complication, with a complication rate of 33.3% in cryopreservation and reimplantation group, lower than the 61.1% in allograft group significantly (χ 2=11.146, P<0.001). The complications with the highest incidence rate were nonunion (20.8%, 30/144), followed by structural failure (17.4%, 25/144), tumor progression (10.4%, 15/144), infection (10.4%, 15/144), and soft tissue failure (5.6%, 8/144). The incidence rates of the atrophic non-union and the structural failure of grafts were 9.7% (7/72) and 1.4% (1/72) respectively in the cryopreservation and reimplantation group, which were significantly lower compared to the allograft group [29.2% (21/72) and 13.9% (10/72), P<0.05]. At the last follow-up, the MSTS-93 score was 89.7%±8.3% in the cryopreservation and reimplantation group, and 87.6%±7.5% in the allograft group, with no statistically significant difference ( t=0.326, P=0.542). Conclusion:Compared with allograft reconstruction, autologous inactivated bone grafting demonstrated superior bone union efficiency and fewer complications, it may be considered for reconstruction in cases whose tumor bone is not severely osteolytic or pathologically fractured.

[Objective]To investigate pulmonary function levels and associated influencing factors among rural elderly in Guangzhou,to identify high-risk populations for poor pulmonary function,and to reveal the relationship between the influencing factors of pulmonary function.[Methods]We recruited 1 500 residents aged 60 to 94 years from rural area of Conghua District,Guangzhou City using convenience sampling in 2023.Data on demographics,body measurements,medical history and lifestyle were collected via face-to-face questionnaires and physical examination.Meanwhile,expiratory function parameters including forced expiratory volume in one second(FEV1),forced vital capacity(FVC),FEV1/FVC,and the prevalence of airflow obstruction(AFO)were assessed using a portable spirometer.Age and sex distribution of pulmonary function in older adults at 5-year intervals was reported,and risk factors of AFO using multifactorial logistic regression models were analyzed.Furthermore,path analysis was further employed to explore the role of lifestyle in the association between other influencing factors and lung function.[Results]Among the 1 500 participants,the median age was 71 years(67-75),and 44.2%were male.Subjects identified as AFOs were generally older,more likely male,less educated,and had lower rates of moderate to vigorous physical activity(＜1 time/week)and lower lean body mass.Mean FEV1/FVC ratio was(82.0±16.4)%.FEV1/FVC was(79.80±17.58)%in men and(83.66±15.22)%in women.Older age,lower education,male sex and leanness were negatively associated with all pulmonary function outcomes(all P values＜0.05).Path analysis identified that age,gender,marital status,occupation and income may influence pulmonary function indirectly through lifestyle.[Conclusion]Rural elderly in Guangzhou exhibited lower pulmonary function levels,and male sex,non-married status,advanced age,lower education,smoking habits,insufficient engagement in moderate to vigorous physical activity,and lean body type were all associated with worse pulmonary function.