Interfractional variations of the bladder, rectum and vagina may affect the accuracy of postoperative intensity-modulated radiotherapy in patients with cervical cancer. This study aimed to assess the ...interfractional variations with daily kV cone-beam computed tomography (CBCT). All the patients were instructed to control the filling status of the bladder and rectum. CBCT images were obtained daily after set-up and the bladder, rectum and vagina were contoured on each CBCT scan. All the contours were transferred to the planning CT following image fusion. Interfractional variations in pelvic organs were assessed with CBCT based on two reference lines, which were identified as A (the midsaggital line across the superior border of pubic symphysis) and B (a parallel line 1.5 cm above line A). The mean volume (range) of the bladder and rectum was 156.5 (1.7-626.5) and 48.2 (11.3-139.7) ml, respectively. The uniform planning target volume (PTV) margin of 10 mm failed to encompass the vagina in 17.3 and 18.1% of the fractions on lines A and B, respectively. The motion of the vagina (standard deviation) was 0.3 (0.3) and 0.1 (0.5) cm on lines A and B, respectively. The anteroposterior dimension and position of the vagina were significantly affected by the filling status of the bladder (P<0.05), but not by that of the rectum. Although instructions were given, the interfractional variations of the vagina and other pelvic organs were significant, which may exceed the uniform PTV margin; therefore, more effective methods to decrease these variations should be investigated.
The Painlevé property and Bäcklund transformation for the KdV equation with a self-consistent source are presented. By testing the equation, it is shown that the equation has the Painlevé property. ...In order to further prove its integrality, we give its bilinear form and construct its bilinear Bäcklund transformation by the Hirota's bilinear operator. And then the soliton solution of the equation is obtained, based on the proposed bilinear form.
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•K-containing catalyst revealed excellent high-temperature NH3-SCR activity.•The hydrothermal stability and resistance to P poisoning increased by K doping.•The presence of K could ...inhibit the formation of Cu-PO3-/PO43- species.•The existence of K could promote the formation of nitrate species on the catalyst.
Cu-SSZ-13 (Cu-Z) has been commercialized as an efficient catalyst for NOx removal in mobile sources. However, in practical applications, the catalyst faces problems of poisoning (K and P) and hydrothermal aging. Therefore, in this work, we investigated the effects of K on P poisoning and hydrothermal aging in Al-rich Cu2/Z (2 wt% Cu). The presence of 1 wt% K could not only improve the high-temperature activity, which could reach above 99% at 225–600 °C on the K1/Cu2/Z, but also enhanced the hydrothermal stability and the resistance of P poisoning. Combing with a series of characterizations, K was mainly present in the Brӧnsted acid sites in the CHA cage, which led to the transformation of part of Z-Cu(OH)+ to Z2-Cu2+, reducing dealumination and the formation of CuOx and CuAl2O4 species during hydrothermal aging. Moreover, the presence of K could inhibit the formation of Cu-PO3-/PO43- species by P poisoning of Z-Cu(OH)+ species. In-situ DRIFTS results showed that the catalysts followed both E-R and L-H mechanism at 150 ℃. K doping could promote the formation of nitrate species and thus favoring the L-H mechanism, which probably enhanced the NH3-SCR activity.
To study the set-up errors, PTV margin and toxicity of cone beam CT (CBCT) guided hypofractionated radiotherapy with active breathing control (ABC) for patients with non-small cell lung cancer ...(NSCLC) or metastatic tumors in lung.
32 tumors in 20 patients were treated. Based on the location of tumor, dose per fraction given to tumor was divided into three groups: 12 Gy, 8 Gy and 6 Gy. ABC is applied for every patient. During each treatment, patients receive CBCT scan for online set-up correction. The pre- and post-correction setup errors between fractions, the interfractional and intrafractional, set-up errors, PTV margin as well as toxicity are analyzed.
The pre-correction systematic and random errors in the left-right (LR), superior-inferior (SI), anterior-posterior (AP) directions were 3.7 mm and 5.3 mm, 3.1 mm and 2.1 mm, 3.7 mm and 2.8 mm, respectively, while the post-correction residual errors were 0.6 mm and 0.8 mm, 0.8 mm and 0.8 mm, 1.2 mm and 1.3 mm, respectively. There was an obvious intrafractional shift of tumor position. The pre-correction PTV margin was 9.5 mm in LR, 14.1 mm in SI and 8.2 mm in AP direction. After CBCT guided online correction, the PTV margin was markedly reduced in all three directions. The post-correction margins ranged 1.5 to 2.1 mm. The treatment was well tolerated by patients, of whom there were 4 (20%) grade1-2 acute pneumonitis, 3 (15%) grade1 acute esophagitis, 2 (10%) grade1 late pneumonitis and 1 (5%) grade 1 late esophagitis.
The positioning errors for lung SBRT using ABC were significant. Online correction with CBCT image guidance should be applied to reduce setup errors and PTV margin, which may reduce radiotherapy toxicity of tissues when ABC was used.
Cone Beam Computed Tomography (CBCT) plays a crucial role in Image-Guided Radiation Therapy (IGRT), providing essential assurance of accuracy in radiation treatment by monitoring changes in ...anatomical structures during the treatment process. However, CBCT images often face interference from scatter noise and artifacts, posing a significant challenge when relying solely on CBCT for precise dose calculation and accurate tissue localization. There is an urgent need to enhance the quality of CBCT images, enabling a more practical application in IGRT. This study introduces EGDiff, a novel framework based on the diffusion model, designed to address the challenges posed by scatter noise and artifacts in CBCT images. In our approach, we employ a forward diffusion process by adding Gaussian noise to CT images, followed by a reverse denoising process using ResUNet with an attention mechanism to predict noise intensity, ultimately synthesizing CBCT-to-CT images. Additionally, we design an energy-guided function to retain domain-independent features and discard domain-specific features during the denoising process, enhancing the effectiveness of CBCT-CT generation. We conduct numerous experiments on the thorax dataset and pancreas dataset. The results demonstrate that EGDiff performs better on the thoracic tumor dataset with SSIM of 0.850, MAE of 26.87 HU, PSNR of 19.83 dB, and NCC of 0.874. EGDiff outperforms SoTA CBCT-to-CT synthesis methods on the pancreas dataset with SSIM of 0.754, MAE of 32.19 HU, PSNR of 19.35 dB, and NCC of 0.846. By improving the accuracy and reliability of CBCT images, EGDiff can enhance the precision of radiation therapy, minimize radiation exposure to healthy tissues, and ultimately contribute to more effective and personalized cancer treatment strategies.
•Improving the quality of CBCT to enhance IGRT.•Using diffusion model to enhance the distinguishability of CBCT images.•Design an energy-guided function to enhance the synthesis details.•Our method achieves higher synthesis quality compared to other methods.
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•Polymer nanofilm-coated FeaCobOx catalysts were prepared by a solid-phase method.•The polymer nanofilm substantially minimized water-poisoning effect.•T50 of CO oxidation over the ...catalyst was 47°C in the presence of ∼0.6vol.% H2O.•The catalyst was not deactivated after 750h operation at 3.1vol.% H2O and 90°C.
Water-induced deactivation of the oxides catalysts (especially for the Co3O4-based catalysts) is a challenging problem. For this reason, highly effective, long-term stable, moisture-resistant polymer nanofilm-coated FeaCobOx catalysts were synthesized by a solid-phase method mediated with oxalic acid (OA)/ethlyene glycol (EG) for low-temperature CO oxidation. The effects of the Fe, OA and EG amounts and calcination temperature on the physicochemical and catalytic properties of the FeaCobOx catalysts were investigated by various characterization techniques. The results demonstrate that the FeaCobOx catalysts are structurally mesoporous, and nanostructured FeaCobOx and polymer nanofilm coating play major roles on their high catalytic activity and stability. The nanofilm-coated Fe3Co16Ox nanoparticles prepared under an optimized synthetic condition and calcined at 250°C possesses higher surface area (134m2/g), Co3+/Co2+ ratio (1.89) and oxygen vacancy (20.5%), and thus exhibits the excellent catalytic performance for CO oxidation, such as, T50 of −114°C under normal moisture (3–10ppm) and T50 of 47°C under moisture-rich (∼0.6vol.%) conditions. Remarkably, compared with the published results, its much-improved long-term catalytic stability (>1month) can be observed even at a very high moisture level (3.1vol.%) and relatively low temperature (90°C). The deactivation of the catalyst at lower temperature resulted from accumulated water and carbonates on the catalyst surface can also be substantially minimized, through the water vapor-resistant with the help of gas-permeable polymer nanofilm coating.
Mitomycin (MMC)/5-fluoroural (5-FU) with concurrent radiation is the standard treatment of anal squamous cell carcinoma (ASCC). The aim of this study is to evaluate the efficacy and safety of ...cisplatin/capecitabine (XP) as an alternative with intensity-modulated radiation therapy (IMRT) in ASCC setting.
We retrospectively screened all patients with stage I-IV ASCC from January 2010 to June 2019. The records of patients who received definitive chemoradiation with cisplatin/capecitabine (XP) and IMRT were collected and analyzed.
The first patient was treated with XP in 2017, so totally 11 patients were included in our study from January 2017 to June 2019. All patients have experienced clinical complete response (cCR). After a median follow-up of 30 months (range, 18-39 months), no patient had local recurrence or distant metastasis. Two-year colostomy-free survival (CFS) and two-year disease-free survival (DFS) were both 100%. The median overall survival (OS) has not reached. Grade 3 acute toxicities included leukopenia (1, 9.1%), neutropenia (2, 18.2%) and thrombocytopenia (2, 18.2%). No grade 4 acute adverse events occurred.
In our study, cisplatin/capecitabine combined with IMRT was safe in ASCC patients, with favorable efficacy as an alternative, and is expected to be explored in study with larger sample.
•A novel online denitration cost optimization system for power unit is proposed.•BP-based variable selection is applied to improve the model generalization ability.•Data-based LSSVM method is ...employed to construct the denitration cost model.•A novel GA-FARM optimization strategy is proposed to realize online optimization.
Reducing the denitration cost of coal-fired boilers is important to enhance the competitiveness of power generation companies. This study proposes a real operation data-based denitration cost optimization system that guides operators in economically adjusting the operation parameters of boilers. A data-driven least square support vector machine (LSSVM) learning method is utilized to predict the denitration cost of a coal-fired boiler. Back propagation (BP) is used here to select the input variables to simplify the model. With the pre-built BP-LSSVM-based denitration cost model, the genetic algorithm (GA) is then applied to obtain offline optimizations at the typical operating load points, which results in an Offline Optimal Expert Database (OOED). Once a load command is received, fuzzy association rule mining (FARM) is employed to extract the relationship between the operating load point and the optimal adjustable variables (AVs) in the OOED, thereby achieving the online denitration cost optimization of the power plant. For comparison, a single LSSVM method is also employed to build a denitration cost prediction model, and the GA and FARM proposed in this study are compared too. The results show that, compared with the single LSSVM method, the BP-LSSVM method not only predicts more accurately but also lowers the model complexity. In addition, considering the denitration cost, optimization time, and update time, the proposed BP-LSSVM-GA-FARM-based denitration cost optimization system is always better than traditional optimization methods.
Radiotherapy has been crucial in prostate cancer treatment. However, manual segmentation is labor intensive and highly variable among radiation oncologists. In this study, a deep learning based ...automated contouring model is constructed for clinical target volumes (CTVs) of intact and postoperative prostate cancer.BACKGROUNDRadiotherapy has been crucial in prostate cancer treatment. However, manual segmentation is labor intensive and highly variable among radiation oncologists. In this study, a deep learning based automated contouring model is constructed for clinical target volumes (CTVs) of intact and postoperative prostate cancer.Computed tomography (CT) data sets of 197 prostate cancer patients were collected. Two auto-delineation models were built for radical radiotherapy and postoperative radiotherapy of prostate cancer respectively, and each model included CTVn for pelvic lymph nodes and CTVp for prostate tumors or prostate tumor beds.METHODSComputed tomography (CT) data sets of 197 prostate cancer patients were collected. Two auto-delineation models were built for radical radiotherapy and postoperative radiotherapy of prostate cancer respectively, and each model included CTVn for pelvic lymph nodes and CTVp for prostate tumors or prostate tumor beds.In the radical radiotherapy model, the volumetric dice (VD) coefficient of CTVn calculated by AI, was higher than that of the one delineated by the junior physicians (0.85 vs. 0.82, p = 0.018); In the postoperative radiotherapy model, the quantitative parameter of CTVn and CTVp, counted by AI, was better than that of the junior physicians. The median delineation time for AI was 0.23 min in the postoperative model and 0.26 min in the radical model, which were significantly shorter than those of the physicians (50.40 and 45.43 min, respectively, p < 0.001). The correction time of the senior physician for AI was much shorter compared with that for the junior physicians in both models (p < 0.001).RESULTSIn the radical radiotherapy model, the volumetric dice (VD) coefficient of CTVn calculated by AI, was higher than that of the one delineated by the junior physicians (0.85 vs. 0.82, p = 0.018); In the postoperative radiotherapy model, the quantitative parameter of CTVn and CTVp, counted by AI, was better than that of the junior physicians. The median delineation time for AI was 0.23 min in the postoperative model and 0.26 min in the radical model, which were significantly shorter than those of the physicians (50.40 and 45.43 min, respectively, p < 0.001). The correction time of the senior physician for AI was much shorter compared with that for the junior physicians in both models (p < 0.001).Using deep learning and attention mechanism, a highly consistent and time-saving contouring model was built for CTVs of pelvic lymph nodes and prostate tumors or prostate tumor beds for prostate cancer, which also might be a good approach to train junior radiation oncologists.CONCLUSIONUsing deep learning and attention mechanism, a highly consistent and time-saving contouring model was built for CTVs of pelvic lymph nodes and prostate tumors or prostate tumor beds for prostate cancer, which also might be a good approach to train junior radiation oncologists.
Objective To explore the characteristics of early motor performance in toddlers with cerebral palsy by analyzing the results of Test of Infant Motor Performance (TIMP) when they were at an age of 2 ...to 4 months. Methods A cross-sectional trial was conducted on 17 children who were followed up in the Preterm High-Risk Infant Follow-Up Clinic of the Second Affiliated Hospital of Army Medical University as high-risk premature infants and diagnosed with cerebral palsy after 1 year of age from December 2018 to December 2022. The results of their TIMP assessments at an age of 2~4 months. With the data of TIMP Chinese norm samples at the same age as controls, the Z-values were calculated and the total score of TIMP, scores of the 7 postural subgroups (including totally 42 items), and scores of these 42 items were calculated and compared between the 2 groups. Results The Z-value of the total TIMP score for the cerebral palsy infants aged 2~4 months was only -0.95±1.11, which was significantly lower than that the expec
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