Objective To investigate the predictive value of dual-energy CT quantitative parameters for assessing the short-term treatment efficacy of second-generation epidermal growth factor receptor-tyrosine kinase inhibitors(EGFR-TKIs)in patients with advanced lung adenocarcinoma.Methods A total of 77 patients with advanced lung adenocarcinoma who received second-generation EGFR-TKIs treatment were retrospectively included.All patients underwent non-contrast and contrast-enhanced dual-energy CT scans.The patients were divided into effective group(45 cases)and ineffective group(32 cases).The clinical data and CT morpho-logical features of the patients were collected,and the iodine concentration(ICA,ICV),normalized iodine concentration(NICA,NICV),and spectral curve slope(kA,kV)in the arterial and venous phases were obtained.The predictive model was constructed using statistically significant intergroup differences,and the predictive performance of the model was evaluated via the area under the curve(AUC)of the receiver operating characteristic(ROC)curves,calibration curves,and decision curve analysis(DCA).Results Signifi-cant differences were observed in ICA 90 keV,ICA 150 keV,kA and NICA 90 keV,NICA 150 keV between the effective group and the ineffective group(P<0.05).Univariate and multivariate logistic regression analyses identified that ICA 90 keV and ICA 150 keV as independent predictors of the short-term treatment efficacy of second-generation EGFR-TKIs.The AUC of the logistic regression model was 0.96[(95%confidence interval(CI)0.87-0.97].Conclusion The quantitative parameters of dual-energy CT can predict the short-term therapeutic efficacy of EGFR-TKIs in advanced lung adenocarcinoma to a certain extent.

Objective To investigate the predictive value of dual-energy CT quantitative parameters for assessing the short-term treatment efficacy of second-generation epidermal growth factor receptor-tyrosine kinase inhibitors(EGFR-TKIs)in patients with advanced lung adenocarcinoma.Methods A total of 77 patients with advanced lung adenocarcinoma who received second-generation EGFR-TKIs treatment were retrospectively included.All patients underwent non-contrast and contrast-enhanced dual-energy CT scans.The patients were divided into effective group(45 cases)and ineffective group(32 cases).The clinical data and CT morpho-logical features of the patients were collected,and the iodine concentration(ICA,ICV),normalized iodine concentration(NICA,NICV),and spectral curve slope(kA,kV)in the arterial and venous phases were obtained.The predictive model was constructed using statistically significant intergroup differences,and the predictive performance of the model was evaluated via the area under the curve(AUC)of the receiver operating characteristic(ROC)curves,calibration curves,and decision curve analysis(DCA).Results Signifi-cant differences were observed in ICA 90 keV,ICA 150 keV,kA and NICA 90 keV,NICA 150 keV between the effective group and the ineffective group(P<0.05).Univariate and multivariate logistic regression analyses identified that ICA 90 keV and ICA 150 keV as independent predictors of the short-term treatment efficacy of second-generation EGFR-TKIs.The AUC of the logistic regression model was 0.96[(95%confidence interval(CI)0.87-0.97].Conclusion The quantitative parameters of dual-energy CT can predict the short-term therapeutic efficacy of EGFR-TKIs in advanced lung adenocarcinoma to a certain extent.

In order to achieve high-efficiency expression of the porcine circovirus type 3 Cap protein in recombinant Escherichia coli,dissolved oxygen(DO)control strategy,oxygen uptake rate(OUR)control strategy and combined control strategy of DO and OUR were selected to investi-gate their effect on the expression of target protein in a 10 L fermenter.The high-density fermenta-tion process of recombinant E.coli was determined by investigating the best control range of OUR.The recombinant protein was identified by SDS-PAGE and Western blot,and the immunoge-nicity of the protein was evaluated by the animal experiment.The results showed that when the DO control strategy and OUR control strategy were used,the expression of target protein was low.Acetic acid was the key factor affecting the expression of target protein.When acetic acid concen-tration reached 1.02 g/L,Cap protein yield was reduced by 55.8％.In order to reduce the produc-tion of acetic acid,DO was selected to control oxygen supply before feeding,and OUR was selected as the parameter to control oxygen supply after feeding.When OUR value was maintained at 140-160 mmol/(L·h),the Cap protein yield was up to 650 mg/L.Western blot analysis confirmed that PCV3 Cap possessed antigenicity and specificity.Animal experiment showed that the antibody pos-itive rate was 100％after the second immunization,indicating that the target protein had better immunogenicity.The high density fermentation controlled by the combined control strategy of DO and OUR could achieve efficiently soluble expression of PCV3 Cap in the fermenter,which laid the foundation for the vaccine development.

Objective To explore the correlation value of high-resolution MRI on the cause,location and degree of nerve root com-pression and clinical symptoms of lumbar intervertebral foramen stenosis.Methods Patients with sciatic neuralgia underwent con-ventional MRI examination of the lumbar spine before treatment.MRI thin layer(1 mm)intervertebral disc axial scan was performed on patients with suspected L4/L5 and L5/S1 intervertebral foramen stenosis,and the value of conventional MRI and high-resolution MRI on intervertebral foramen stenosis location,etiology and Elisabeth typing was compared and analyzed.Intervertebral foramen mor-phometric indicators,nerve root length and short diameter were measured on high-resolution MRI post-processed images and their correlation with visual analogue scale(VAS)scores of clinical symptoms was analyzed.Results Sixty-one patients were effectively diagnosed with intervertebral foramen stenosis and nerve root compression after surgery or conservative treatment.The diagnosis rate of conventional MRI for the cause of intervertebral foramen stenosis was 75.4％,and the diagnosis rate of high-resolution MRI post-processed was 91.8％.The Elisabeth typing of lumbar intervertebral foramen stenosis was positively correlated with clinical symp-toms,while the nerve root short diameter and peri-nerve fat space area were negatively correlated with VAS score.Conclusion High-resolution MRI is significantly better than conventional MRI for the diagnosis of nerve root compression in intervertebral fora-men stenosis.It visually shows the location,cause and degree of nerve root compression,which can better guide the clinical and accu-rate minimally invasive surgery.

In order to achieve high-efficiency expression of the porcine circovirus type 3 Cap protein in recombinant Escherichia coli,dissolved oxygen(DO)control strategy,oxygen uptake rate(OUR)control strategy and combined control strategy of DO and OUR were selected to investi-gate their effect on the expression of target protein in a 10 L fermenter.The high-density fermenta-tion process of recombinant E.coli was determined by investigating the best control range of OUR.The recombinant protein was identified by SDS-PAGE and Western blot,and the immunoge-nicity of the protein was evaluated by the animal experiment.The results showed that when the DO control strategy and OUR control strategy were used,the expression of target protein was low.Acetic acid was the key factor affecting the expression of target protein.When acetic acid concen-tration reached 1.02 g/L,Cap protein yield was reduced by 55.8％.In order to reduce the produc-tion of acetic acid,DO was selected to control oxygen supply before feeding,and OUR was selected as the parameter to control oxygen supply after feeding.When OUR value was maintained at 140-160 mmol/(L·h),the Cap protein yield was up to 650 mg/L.Western blot analysis confirmed that PCV3 Cap possessed antigenicity and specificity.Animal experiment showed that the antibody pos-itive rate was 100％after the second immunization,indicating that the target protein had better immunogenicity.The high density fermentation controlled by the combined control strategy of DO and OUR could achieve efficiently soluble expression of PCV3 Cap in the fermenter,which laid the foundation for the vaccine development.

Objective To analyze the dose distribution of induced radiation in fixed proton beam therapy room and the influence of shielding materials, and to provide a basis for radiation protection and shielding material selection in proton therapy. Methods FLUKA was used to simulate the dose distribution of induced radiation in fixed proton beam therapy room, the dose over time, and the influence of different concrete materials. Results The dose of induced radiation was mainly concentrated around the target, and the dose rapidly decreased to 1/5-1/10 of the value at the time of stopping irradiation after cooling for 3-5 min. The induced radiation in concrete formed a slightly higher dose area at the end of the main beam near the inner side of the shield. The content of Fe, O, and H in concrete had significant effects on induced radiation (P < 0.01), and the dose was negatively correlated with the content of Fe. Conclusion The patients after proton therapy as well as the induced radiation in air and shielding materials are the main sources of external radiation dose for workers, and waiting for a period of time is the most effective way to protect the staff. Without considering the difficulty in construction and based on the analysis of shielding materials in protection against external irradiation and their influence on induced radiation, heavy concrete with a relatively high level of Fe is the best choice of the shielding material for proton therapy room.

Objective To analyze the occupational hazards and protective measures for personnel in an iodine-125(¹²⁵I) seed source production company. Methods In 2022, a ¹²⁵I seed source production enterprise in Guangdong Province was selected as the research subject. The occupational hazards in the workplace of the research subject was identified using the system engineering analysis method. The FLUAK program based on Monte Carlo method was used to simulate the blocking protection of the production of the ¹²⁵I seed source, and to estimate the dose of internal and external irradiation of seed source that affected workers. Results The main occupational radiation hazards in the seed production were non-sealed radioactive materials, including external irradiation from X-ray and γ ray and internal irradiation from aerosols formed by iodine volatilization. Estimated maximum dose equivalent rate around the chest and eye lens for workers were 0.52 and 0.02 μSv/h, respectively. The expected annual effective dose for workers in each work site was 0.035 mSv, and the expected annual equivalent dose to the eye lens for all workers in various work sites was 0.001 mSv. The maximum annual equivalent dose of operator's hand was 80.620 mSv. The maximum dose of internal irradiation to the worker was 18.750 mSv, which was caused by the volatilization of nuclides. Conclusion With effective protection measures for internal and external irradiation in place, the annual exposure doses for seed production personnel and operator’s hand are below the national limits. Adequate measures should be taken on hand protection.

Objective To study the dose level of proton beams outside the main shield of the 230 MeV proton therapy room with six different types of concrete as the main wall, and to obtain the shielding performance of six different types of concrete. Methods The FLUKA program was used to build a calculation model, and different concrete compositions were introduced into the FLUKA program to simulate the change in ambient dose equivalent rate of the focus with concrete thickness under 230 MeV proton beam irradiation. The transmission curves of six different types of concrete were fitted to obtain shielding performance parameters. Results On the condition that the 230 MeV proton beam irradiated to the water target in 90° direction and the concrete thickness exceeded 40 cm, the proton beam was exponentially decayed for six different types of concrete, and the fitted decay curves had a R² of > 0.99. The linear attenuation coefficients for normal concrete, barite concrete, magnetite concrete, limonite concrete, phosphorite concrete, and ferrosilicate concrete were 0.0148 cm⁻¹, 0.0172 cm⁻¹, 0.0196 cm⁻¹, 0.0219 cm⁻¹, 0.0256 cm⁻¹, and 0.0290 cm⁻¹, respectively. Conclusion The composition and proportion of elements in concrete materials directly affect the shielding ability of concrete against proton beams to a large extent, and the shielding performance of six different types of concrete against proton beams varies greatly. Therefore, shielding materials for the proton therapy room should be selected by a comprehensive consideration of the material compositions and shielding performance of concrete, the difficulty of construction, and construction cost.

Objective To investigate the radiation dose at the entrance of the accelerator treatment room, and to guide the radiation protection detection at the entrance of the treatment room. Methods The FLUKA program was used to build the model of accelerator head and treatment room. Under the simulation conditions of 10 MV and 600 cGy/min for the accelerator, the radiation dose rate inside the entrance of the treatment room was measured at different gantry angles, irradiation conditions, and labyrinths. Results The entrance dose rate with a water tank was significantly higher than that without a water tank under different inner labyrinth wall thicknesses and gantry angles. The entrance dose rate reached the maximum at the inner labyrinth wall thickness of 1800 mm and the gantry angle of 90°. When the inner labyrinth wall thickness was 1000 mm and the gantry angles were 0° and 180°, the entrance dose rate was significantly higher than that at other conditions. The dose rate at the entrance of the treatment room reached (82.26 ± 48.95) μSv/h to (314.09 ± 96.34) μSv/h under the following conditions: the inner labyrinth wall thickness of 1800 mm, the gantry angle of 90°, with a water tank, and the width of the inner labyrinth entrance of 1400-2200 mm. Conclusion The dose at the entrance of the accelerator treatment room mainly comes from the scattering and leakage radiation of the useful wire harness on the patient’s body surface, and the entrance dose rate increases with the increase in the width of the inner labyrinth entrance. In the entrance protection test, the gantry angle should be determined considering the inner labyrinth wall thickness, and the test should be performed at four angles in the uncertain case to ensure the comprehensiveness and accuracy of test results.

Objective:To compare clinical features of patients with pyogenic liver abscesses with and without septated lobulations.Methods:Patients diagnosed to have pyogenic liver abscesses who were treated in our hospital from January 2011 to March 2021 were enrolled into this retrospective study. There were 203 males and 132 females, with age of (56±14) years old. The patients were divided into two groups by findings on computed tomography and ultrasound into the septated lobulation group ( n=68) and the non-septated lobulation group ( n=267). The clinical data of these patients were compared. Results:In the septated lobulation group, the neutrophil count was 9.17(5.97, 12.33)×10 9/L and the TBil was 17.65(11.92, 27.84) μmol/L. These were significantly higher than the corresponding figures of 7.81(5.42, 10.81)×10 9/L, 12.90(9.00, 19.68) μmol/L, respectively in the non-septated lobulation group ( P<0.05). The difference in the maximum diameters of the septated lobulation group was also significantly larger than the non-septated lobulation group ( P=0.032). Additionally, pus culture showed the proportion of Klebsiella pneumoniae positive patients in the septated lobulation group was significantly higher than that in the non-septated lobulation group [41.18% (28/68) vs. 25.84% (69/267), P=0.013]. The use of fluoroquinolones in patients in the septated lobulation group was higher than that in the non-septated lobulation group [20.59% (14/68) vs. 10.11% (27/267), χ 2=5.54, P=0.019]. Conclusion:Compared to patients without septated lobulations, those with septated lobulations had a larger diameter of abscesses, a higher positive rate of Klebsiella pneumoniae on pus culture and a higher proportion of patients receiving fluoroquinolones.