Objective: To explore the feasibility of synthetic magnetic resonance imaging (syMRI) combined with clinicopathological characteristics for the pre-treatment prediction of chemoradiotherapy (CRT) response in advanced nasopharyngeal carcinoma (ANPC). Materials and Methods: Patients with ANPC treated with CRT between September 2020 and June 2022 were retrospectively enrolled and categorized into response group (RG, n = 95) and non RGs (NRG, n = 32) based on the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The quantitative parameters from pre-treatment syMRI (longitudinal [T1] and transverse [T2] relaxation times and proton density [PD]), diffusion-weighted imaging (apparent diffusion coefficient [ADC]), and clinicopathological characteristics were compared between RG and NRG. Logistic regression analysis was applied to identify parameters independently associated with CRT response and to construct a multivariable model. The areas under the receiveroperating characteristic curve (AUC) for various diagnostic approaches were compared using the DeLong test. Results: The T1, T2, and PD values in the NRG were significantly lower than those in the RG (all P < 0.05), whereas no significant difference was observed in the ADC values between these two groups. Clinicopathological characteristics (Epstein–Barr virus [EBV]-DNA level, lymph node extranodal extension, clinical stage, and Ki-67 expression) exhibited significant differences between the two groups. Logistic regression analysis showed that T1, PD, EBV-DNA level, clinical stage, and Ki-67 expression had significant independent relationships with CRT response (all P < 0.05). The multivariable model incorporating these five variables yielded AUC, sensitivity, and specificity values of 0.974, 93.8% (30/32), and 91.6% (87/95), respectively. Conclusion SyMRI may be used for the pretreatment prediction of CRT response in ANPC. The multivariable model incorporating syMRI quantitative parameters and clinicopathological characteristics, which were independently associated with CRT response, may be a new tool for the pretreatment prediction of CRT response.

Objective: To explore the feasibility of synthetic magnetic resonance imaging (syMRI) combined with clinicopathological characteristics for the pre-treatment prediction of chemoradiotherapy (CRT) response in advanced nasopharyngeal carcinoma (ANPC). Materials and Methods: Patients with ANPC treated with CRT between September 2020 and June 2022 were retrospectively enrolled and categorized into response group (RG, n = 95) and non RGs (NRG, n = 32) based on the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The quantitative parameters from pre-treatment syMRI (longitudinal [T1] and transverse [T2] relaxation times and proton density [PD]), diffusion-weighted imaging (apparent diffusion coefficient [ADC]), and clinicopathological characteristics were compared between RG and NRG. Logistic regression analysis was applied to identify parameters independently associated with CRT response and to construct a multivariable model. The areas under the receiveroperating characteristic curve (AUC) for various diagnostic approaches were compared using the DeLong test. Results: The T1, T2, and PD values in the NRG were significantly lower than those in the RG (all P < 0.05), whereas no significant difference was observed in the ADC values between these two groups. Clinicopathological characteristics (Epstein–Barr virus [EBV]-DNA level, lymph node extranodal extension, clinical stage, and Ki-67 expression) exhibited significant differences between the two groups. Logistic regression analysis showed that T1, PD, EBV-DNA level, clinical stage, and Ki-67 expression had significant independent relationships with CRT response (all P < 0.05). The multivariable model incorporating these five variables yielded AUC, sensitivity, and specificity values of 0.974, 93.8% (30/32), and 91.6% (87/95), respectively. Conclusion SyMRI may be used for the pretreatment prediction of CRT response in ANPC. The multivariable model incorporating syMRI quantitative parameters and clinicopathological characteristics, which were independently associated with CRT response, may be a new tool for the pretreatment prediction of CRT response.

Objective: To explore the feasibility of synthetic magnetic resonance imaging (syMRI) combined with clinicopathological characteristics for the pre-treatment prediction of chemoradiotherapy (CRT) response in advanced nasopharyngeal carcinoma (ANPC). Materials and Methods: Patients with ANPC treated with CRT between September 2020 and June 2022 were retrospectively enrolled and categorized into response group (RG, n = 95) and non RGs (NRG, n = 32) based on the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The quantitative parameters from pre-treatment syMRI (longitudinal [T1] and transverse [T2] relaxation times and proton density [PD]), diffusion-weighted imaging (apparent diffusion coefficient [ADC]), and clinicopathological characteristics were compared between RG and NRG. Logistic regression analysis was applied to identify parameters independently associated with CRT response and to construct a multivariable model. The areas under the receiveroperating characteristic curve (AUC) for various diagnostic approaches were compared using the DeLong test. Results: The T1, T2, and PD values in the NRG were significantly lower than those in the RG (all P < 0.05), whereas no significant difference was observed in the ADC values between these two groups. Clinicopathological characteristics (Epstein–Barr virus [EBV]-DNA level, lymph node extranodal extension, clinical stage, and Ki-67 expression) exhibited significant differences between the two groups. Logistic regression analysis showed that T1, PD, EBV-DNA level, clinical stage, and Ki-67 expression had significant independent relationships with CRT response (all P < 0.05). The multivariable model incorporating these five variables yielded AUC, sensitivity, and specificity values of 0.974, 93.8% (30/32), and 91.6% (87/95), respectively. Conclusion SyMRI may be used for the pretreatment prediction of CRT response in ANPC. The multivariable model incorporating syMRI quantitative parameters and clinicopathological characteristics, which were independently associated with CRT response, may be a new tool for the pretreatment prediction of CRT response.

Objective: To explore the feasibility of synthetic magnetic resonance imaging (syMRI) combined with clinicopathological characteristics for the pre-treatment prediction of chemoradiotherapy (CRT) response in advanced nasopharyngeal carcinoma (ANPC). Materials and Methods: Patients with ANPC treated with CRT between September 2020 and June 2022 were retrospectively enrolled and categorized into response group (RG, n = 95) and non RGs (NRG, n = 32) based on the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The quantitative parameters from pre-treatment syMRI (longitudinal [T1] and transverse [T2] relaxation times and proton density [PD]), diffusion-weighted imaging (apparent diffusion coefficient [ADC]), and clinicopathological characteristics were compared between RG and NRG. Logistic regression analysis was applied to identify parameters independently associated with CRT response and to construct a multivariable model. The areas under the receiveroperating characteristic curve (AUC) for various diagnostic approaches were compared using the DeLong test. Results: The T1, T2, and PD values in the NRG were significantly lower than those in the RG (all P < 0.05), whereas no significant difference was observed in the ADC values between these two groups. Clinicopathological characteristics (Epstein–Barr virus [EBV]-DNA level, lymph node extranodal extension, clinical stage, and Ki-67 expression) exhibited significant differences between the two groups. Logistic regression analysis showed that T1, PD, EBV-DNA level, clinical stage, and Ki-67 expression had significant independent relationships with CRT response (all P < 0.05). The multivariable model incorporating these five variables yielded AUC, sensitivity, and specificity values of 0.974, 93.8% (30/32), and 91.6% (87/95), respectively. Conclusion SyMRI may be used for the pretreatment prediction of CRT response in ANPC. The multivariable model incorporating syMRI quantitative parameters and clinicopathological characteristics, which were independently associated with CRT response, may be a new tool for the pretreatment prediction of CRT response.

Objective: To explore the feasibility of synthetic magnetic resonance imaging (syMRI) combined with clinicopathological characteristics for the pre-treatment prediction of chemoradiotherapy (CRT) response in advanced nasopharyngeal carcinoma (ANPC). Materials and Methods: Patients with ANPC treated with CRT between September 2020 and June 2022 were retrospectively enrolled and categorized into response group (RG, n = 95) and non RGs (NRG, n = 32) based on the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The quantitative parameters from pre-treatment syMRI (longitudinal [T1] and transverse [T2] relaxation times and proton density [PD]), diffusion-weighted imaging (apparent diffusion coefficient [ADC]), and clinicopathological characteristics were compared between RG and NRG. Logistic regression analysis was applied to identify parameters independently associated with CRT response and to construct a multivariable model. The areas under the receiveroperating characteristic curve (AUC) for various diagnostic approaches were compared using the DeLong test. Results: The T1, T2, and PD values in the NRG were significantly lower than those in the RG (all P < 0.05), whereas no significant difference was observed in the ADC values between these two groups. Clinicopathological characteristics (Epstein–Barr virus [EBV]-DNA level, lymph node extranodal extension, clinical stage, and Ki-67 expression) exhibited significant differences between the two groups. Logistic regression analysis showed that T1, PD, EBV-DNA level, clinical stage, and Ki-67 expression had significant independent relationships with CRT response (all P < 0.05). The multivariable model incorporating these five variables yielded AUC, sensitivity, and specificity values of 0.974, 93.8% (30/32), and 91.6% (87/95), respectively. Conclusion SyMRI may be used for the pretreatment prediction of CRT response in ANPC. The multivariable model incorporating syMRI quantitative parameters and clinicopathological characteristics, which were independently associated with CRT response, may be a new tool for the pretreatment prediction of CRT response.

Objective:To investigate the impact of age,various hormonal levels,and biochemical markers on penile cavernous body vascular function in patients with erectile dysfunction(ED).Me-thods:A retrospective analysis of clinical data from male patients with ED who underwent color duplex Doppler ultrasonography(CDDU)and intracavernosal injection test(ICI)at the Reproductive Medicine Center of Peking University Third Hospital from January 2020 to August 2023.Data were managed and processed using SPSS 29.0,and a multivariable Logistic regression analysis was conducted.Results:A total of 700 ED patients were included,with 380 showing negative ICI results and 320 positive.In the study,84 patients had a peak systolic velocity(PSV)＜25 cm/s,while 616 had PSV ≥ 25 cm/s;202 patients had end-diastolic velocity(EDV)＞5 cm/s,and 498 had EDV ≤5 cm/s.264 patients had ab-normal PSV and/or EDV results,and 436 had normal results for both.Patients with vascular ED had sig-nificantly lower estrogen levels(t=-3.546,P＜0.001),lower testosterone levels(t=-2.089,P=0.037),and a higher rate of hyperglycemia(x2=12.772,P=0.002)compared with those with non-vascular ED.The patients with arterial ED were older(t=3.953,P＜0.001),had a higher rate of hyperglycemia(x2=9.518,P=0.009),and a higher estrogen/testosterone ratio(t=2.330,P=0.020)compared with those with non-arterial ED.The patients with mixed arteriovenous ED had higher age(t=3.567,P＜0.001),lower testosterone levels(t=-2.288,P=0.022),a higher rate of hyperglycemia(x2=12.877,P=0.002),and a larger estrogen/testosterone ratio(t=2.096,P=0.037)compared with those with normal findings.Multifactorial Logistic regression analysis indicated that higher levels of estrogen were a protective factor for vascular ED(OR=1.009,95％CI:1.004-1.014),and glucose 7.0 mmol/L was a risk factor(OR=0.381,95％CI:0.219-0.661).Older age was a risk factor for arte-rial ED(OR=0.960,95％CI:0.938-0.982).Additionally,older age(OR=0.976,95％CI:0.958-0.993)and glucose levels of 5.6-6.9 mmol/L(OR=0.591,95％CI:0.399-0.876)were also risk fac-tors for mixed arterio-venous ED.Conclusion:Hyperglycemia and aging may impair penile cavernous body vascular function,while higher levels of estrogen may have a protective effect on it.

Objective:To study the application of antimony cerium catalytic spectrophotometry using a fully automatic biochemical analyzer (hereinafter referred to as this method) in the determination of water iodine.Methods:Based on the principle of antimony cerium reoxidation reduction reaction catalyzed by iodine, the iodine content in water was determined in the range of 0 - 100 μg/L iodine mass concentration. The detection limit, precision and accuracy (determination of standard substances GBW09113j and GBW09114j for iodine composition analysis in water and the experiment of standard recovery) of this method were verified. This method was compared with the arsenic and cerium catalytic spectrophotometry recommended by the National Reference Laboratory for Iodine Deficiency Disorders.Results:Within the range of 0 - 100 μg/L iodine mass concentration, the qualitative and quantitative detection limits of this method were 0.81 and 2.70 μg/L, respectively (sampling quantity was 35 μl). In the precision experiment, the relative standard deviation of water samples with different iodine mass concentrations ranged from 1.2% to 4.0%. The determination results of the standard substances GBW09113j and GBW09114j for iodine composition analysis in water were both within the given standard value range. The standard recovery rates of water samples with low, medium and high iodine mass concentrations ranged from 101.0% to 106.0%, and the total average standard recovery rate was 103.2%. The results of the method comparison experiment showed that there was no statistically significant difference in the results of water iodine determination between the two methods ( t = - 0.78, P = 0.779). Conclusion:This method has a low detection limit, high precision and good accuracy, making it suitable for the detection of large quantities of samples in the monitoring of iodine deficiency disorders.

Objective:To analyze the prognostic factors of primary and metastatic tumor resection for metastatic renal carcinoma.Methods:Clinical data of 12 cases of renal carcinoma with distant metastasis admitted to the Peking University Third Hospital from June 2011 to December 2019 were analyzed retrospectively, including 10 males and 2 females. Age was from 36 to 67 years old, with average of 53.7 years old. BMI was 20.9-30.8 kg/m 2, with average of 25.8 kg/m 2.There were 6 cases of right kidney tumor and 6 cases of left kidney tumor. The diameter of the primary tumor was 2.7-16.0 cm, with an average of 7.1 cm. There were 2 cases of lung metastasis, 1 case of liver metastasis and 9 cases of bone metastasis. All the 12 patients underwent primary and metastatic tumorectomy. Postoperative pathological results showed 10 cases of clear cell carcinoma, 1 case of papillary type 2 tumor and 1 case of collecting duct carcinoma. The pathological results of the metastases were the same as those of the original lesions. Results:All the 12 patients underwent primary and metastatic renal carcinoma resection, among which 3 received postoperative chemotherapy and 6 received radiotherapy .Two patients were treated with targeted drugs. The interval between primary resection and metastatic resection was 1-84 months, and the median time was 2.5 months. In this study, 12 patients were followed up for 2-96 months, with the median survival time of 34 months, and mortality rate of 25%.There was no significant correlation between age( P=0.265), gender( P=0.183), BMI( P=0.152), primary tumor size ( P=0.082), radiotherapy, chemotherapy or targeted therapy ( P=0.915) and overall survival, and the interval between primary resection and metastatic resection ( P=0.046) was significantly correlated with overall survival. Conclusion:The interval between primary and metastatic tumor resection was a risk factor for the prognosis of patients.

Objective:To establish an automatic colorimetric method for determination of iodine in drinking water by enzyme-labeled instrument (hereinafter referred to as this method).Methods:The water iodine was measured in the range of 0 - 10 μg/L and 0 - 100 μg/L, experiments were carried out on linear relationship, detection limit, precision and accuracy of this method. And the results were compared with the National Reference Laboratory for Iodine Deficiency Disorders recommended arsenic cerium catalytic spectrophotometry method.Results:In the range of 0 - 10 μg/L and 0 - 100 μg/L, all│ r│ > 0.999 0, the detection limits were 0.6 and 1.1 μg/L (samples were 200 and 100 μl), respectively; the relative standard deviation ( RSD) of water samples of low, medium and high iodine mass concentrations were < 3%, the recovery rates ranged from 92.5% to 108.3% and 93.2% to 108.9%, with a total average recovery of 100.0% and 100.3%, respectively. This method and arsenic cerium catalytic spectrophotometry method were used to detect 40 water samples in the range of 0 - 10 μg/L and 0 - 100 μg/L, there was no significant difference in water iodine content between the two methods ( t = 0.99, P > 0.05). Conclusion:This method has good linear curve relationship for determination of water iodine content, good precision and high accuracy, and it is suitable for wide application.

Objective To investigate the causes and preventive measures for deviation of guide needle in orthopedics robot surgery.Methods A robotic surgery was simulated on a wooden stick.The guide needle was inserted under the guidance of the robot.A lateral deviation force was applied respectively onto the tail and tip of the needle.The actual offset distance at the guide needle tip was measured and compared with the 1mm offset allowed by robot monitoring.Results The offset distance of the guide needle tip was 0,5+0.07 mm when the deviation force was applied onto the tail,significantly smaller than the 1 mm offset allowed by the robot monitoring(l=22.588,P<0.001).The offset distance of the guide needle tip was 4.92+0.16 mm when the deviation force was applied onto the tip,significantly larger than the 1 mm offset allowed by the robot monitoring(t=17.416,P<0.001).Conclusions The deviation of guide needle may be caused chiefly by the deviation force onto the tip.As the actual offset distance of the guide needle tip may be larger than that shown on the robot monitor in orthopedics robotic surgery,the intraoperative monitoring should serve only as a reference to the deviation of the guide needle.The operative details may be the key to prevention of such deviations.