Objective:To propose a novel radiotherapy marking method-the"#"-character method,which aimed at improving the accuracy and repeatability of positioning during radiotherapy.Methods:A specially"cross-shaped"stamp was designed by this study,which consisted of a handheld square base with a"cross-shaped"protrusion.Using this stamp,the extreme positions of end-expiration and end-inspiration were marked respectively at the laser-guided regions on the directly above and bilateral sides of the patient's body,and each position was printed a"+"character.Finally,a"#-shaped"signal was formed,which represented the full range of respiratory motion of patients.The study included two parts:surface displacement caused by respiration was simulated through a three-dimensional(3D)motion platform,which was used to conduct a phantom experiment for anthropomorphic dummy,A randomized controlled study involving 40 patients,who were treated between January and June 2024 at the Department of Radiotherapy,Cancer Hospital,Chinese Academy of Medical Sciences,were conducted.The cohort included 20 patients with breast tumor(Positioning the outer contour by exposing the chest)and 20 patients with thoracic tumor(fixed position of using thermoplastic film).These patients were divided into two groups for comparison,which received respectively the"#-shaped"method and the conventional"+-shaped"method.The cone-beam computed tomography(CBCT)images before treatment were used to compare the influences of the two kinds of marking methods on the positioning errors of patients with breast tumor and patients with thoracic tumor.Then,the statistical analysis was used to assess precision and accuracy of positioning.Results:The result of phantom experiment indicated that the positioning error of the"#-shaped"method was significantly better than that of the"+-shaped"method under various parameters of respiratory movement.Under three kinds of different respiratory cycles(3,4,and 5 seconds)and amplitudes(8,12,and 15 mm),the positioning errors of the"#-shaped"method were respectively(0.15±0.04)cm,(0.19±0.05)cm and(0.35±0.14)cm,while the"+-shaped"method were respectively(0.42±0.16)cm,(0.64±0.28)cm and(0.88±0.37)cm,and the differences were statistically significant(t=8.347,3.416,2.901,P<0.05).The results of actual patients indicated the positioning error[(0.97±0.32)cm]of the"#-shaped"method was significantly lower than[(1.62±0.47)cm]of the"+-shaped"method for patients with breast tumor(Positioning the outer contour by exposing the chest),and the difference was significant(t=3.615,P<0.05).On the other hand,the positioning error[(0.69±0.24)cm]of the"#-shaped"method was significantly lower than[(0.97±0.39)cm]of the"+-shaped"method for patients with thoracic tumor(fixed position of using thermoplastic film),and the difference also was significant(t=1.934,P<0.05).Conclusion:Compared to the conventional"+-shaped"method,the"#-shaped"method appears higher accuracy and repeatability during the positioning process of radiotherapy,which especially is suitable to the treatment for breast tumor and thoracic tumor that need accurately control the influences of respiratory motion.

Objective:To propose a novel radiotherapy marking method-the"#"-character method,which aimed at improving the accuracy and repeatability of positioning during radiotherapy.Methods:A specially"cross-shaped"stamp was designed by this study,which consisted of a handheld square base with a"cross-shaped"protrusion.Using this stamp,the extreme positions of end-expiration and end-inspiration were marked respectively at the laser-guided regions on the directly above and bilateral sides of the patient's body,and each position was printed a"+"character.Finally,a"#-shaped"signal was formed,which represented the full range of respiratory motion of patients.The study included two parts:surface displacement caused by respiration was simulated through a three-dimensional(3D)motion platform,which was used to conduct a phantom experiment for anthropomorphic dummy,A randomized controlled study involving 40 patients,who were treated between January and June 2024 at the Department of Radiotherapy,Cancer Hospital,Chinese Academy of Medical Sciences,were conducted.The cohort included 20 patients with breast tumor(Positioning the outer contour by exposing the chest)and 20 patients with thoracic tumor(fixed position of using thermoplastic film).These patients were divided into two groups for comparison,which received respectively the"#-shaped"method and the conventional"+-shaped"method.The cone-beam computed tomography(CBCT)images before treatment were used to compare the influences of the two kinds of marking methods on the positioning errors of patients with breast tumor and patients with thoracic tumor.Then,the statistical analysis was used to assess precision and accuracy of positioning.Results:The result of phantom experiment indicated that the positioning error of the"#-shaped"method was significantly better than that of the"+-shaped"method under various parameters of respiratory movement.Under three kinds of different respiratory cycles(3,4,and 5 seconds)and amplitudes(8,12,and 15 mm),the positioning errors of the"#-shaped"method were respectively(0.15±0.04)cm,(0.19±0.05)cm and(0.35±0.14)cm,while the"+-shaped"method were respectively(0.42±0.16)cm,(0.64±0.28)cm and(0.88±0.37)cm,and the differences were statistically significant(t=8.347,3.416,2.901,P<0.05).The results of actual patients indicated the positioning error[(0.97±0.32)cm]of the"#-shaped"method was significantly lower than[(1.62±0.47)cm]of the"+-shaped"method for patients with breast tumor(Positioning the outer contour by exposing the chest),and the difference was significant(t=3.615,P<0.05).On the other hand,the positioning error[(0.69±0.24)cm]of the"#-shaped"method was significantly lower than[(0.97±0.39)cm]of the"+-shaped"method for patients with thoracic tumor(fixed position of using thermoplastic film),and the difference also was significant(t=1.934,P<0.05).Conclusion:Compared to the conventional"+-shaped"method,the"#-shaped"method appears higher accuracy and repeatability during the positioning process of radiotherapy,which especially is suitable to the treatment for breast tumor and thoracic tumor that need accurately control the influences of respiratory motion.

AIM:To investigate the effects of the compound ANBP on wound healing in diabetic rats and ex-plore its mechanism of action.METHODS:Ninety male SD rats were randomly divided into blank,model,compound ANBP,Beifuxin,and nicotinamide mononucleotide(NMN)groups,with 16 rats in each group.Wound healing in each group was observed and samples were taken on days 3,7 and 14 to analyze the wound healing rate.Local histopathological changes were observed using HE and Masson staining.The expressions of pyruvate dehydrogenase E1 subunit alpha 1(PDHA1),citrate synthase(CS),isocitrate dehydrogenase(IDH1)and oxoglutarate dehydrogenase(OGDH)were de-tected through immunofluorescence and Western blot.The number and morphology of mitochondria in the wound tissue were observed using transmission electron microscopy.RESULTS:Histomorphological changes revealed significant im-provement in diabetic wound healing in the blank and compound ANBP groups compared to that of the model group.The wound healing rates of the blank,compound ANBP,Beifuxin,and NMN groups were significantly increased on days 3,7,and 14(P<0.01).Compared to the model group,granulation tissue generation was higher in the other groups,cover-ing the wound defect and producing abundant collagen fibers.At 3,7,and 14 days after intervention,the blank,com-pound ANBP,Beifuxin,and NMN groups showed significantly enhanced fluorescence intensities of TCA cycling-related enzymes PDHA1,CS,IDH1,and OGDH indicating increased expression of these enzymes.The levels of the TCA cy-cling-related enzymes were significantly increased(P<0.01)in the compound ANBP,Beifuxin and NMN groups but were significantly decreased(P<0.01)in the model group.An increase in the number and density of mitochondria and a de-crease in the cavitation rate of mitochondria with improved morphology(P<0.05)was observed in the group treated with compound ANBP.CONCLUSION:Compound ANBP may increase the number of mitochondria,improve mitochondrial morphology and function,upregulate the expression levels of PDHA1,CS,IDH1,and OGDH proteins,and accelerate the regeneration of wound granulation tissue,thus promoting the healing of diabetic wounds in rats.

Microorganisms are the dominant players driving the degradation and transformation of chloramphenicol (CAP) in the environment. However, little bacterial strains are able to efficiently degrade and mineralize CAP, and the CAP degrading pathways mediated by oxidative reactions remain unclear. In this study, a highly efficient CAP-degrading microbial consortium, which mainly consists of Rhodococcus (relative abundance >70%), was obtained through an enrichment process using CAP-contaminated activated sludge as the inoculum. A bacterial strain CAP-2 capable of efficiently degrading CAP was isolated from the consortium and identified as Rhodococcus sp. by 16S rRNA gene analysis. Strain CAP-2 can efficiently degrade CAP under different nutrient conditions. Based on the biotransformation characteristics of the detected metabolite p-nitrobenzoic acid and the reported metabolites p-nitrobenzaldehyde and protocatechuate by strain CAP-2, a new oxidative pathway for the degradation of CAP was proposed. The side chain of CAP was oxidized and broken to generate p-nitrobenzaldehyde, which was further oxidized to p-nitrobenzoic acid. Strain CAP-2 can be used to further study the molecular mechanism of CAP catabolism, and has the potential to be used in in situ bioremediation of CAP-contaminated environment.
Biodegradation, Environmental ; Chloramphenicol ; RNA, Ribosomal, 16S/genetics* ; Rhodococcus/genetics* ; Sewage

Objective We developed a method to expand margin of beam aperture for VMAT treatment planning of breast cancer and evaluated its effectiveness in clinic. Methods An expanded VMAT (E-VMAT) plan for breast cancer using Pinnacle39. 10 planning system was made. A small tissue-equivalent bolus was added at the middle of the breast surface as part of the target and the VMAT plan was generated with beam aperture automatically expanded. Then the tissue-equivalent bolus was removed and the final dose distribution was calculated. Ten patients with breast cancer undergoing breast conserving surgery were tested. The dosimetrical metrics and delivery efficiency were compared between the E-VMAT plans and the routine VMAT plans. Results On the BEV view, it was observed that in E-VMAT plans the collimator and MLC leaf positions was extended outside the skin along the anterior-posterior direction of the thorax. There were no significant differences in conformity index and homogeneity index of target volume between the two types of plans and the planned delivery efficiency was consistent (P>0. 05). Conclusions The method established in this study can automatically generate expansion of VMAT beam apertures and prevent missing of target volume due to respiratory motion and/ or setup error of the patient. The method does not require programming skill and available for different treatment planning systems.

Objective: To investigate the difference of prognostic factors and recurrence rates between papillary thyroid microcarcinoma (PTMC) and lager papillary thyroid carcinoma (PTC) and analyze the clinical pathological characteristics of PTMC suitable for surgery. Methods: A retrospective analysis on the clinicopathological features, expression level of of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E gene mutation and pigment epithelium-derived factor (PEDF), and postoperative follow-up results of the 251 PTC patients who underwent surgical treatment from October 2011 to October 2013, including 169 cases with PTMC and 82 with lager PTC (Tumor diameter>1 cm). Results: The BRAF V600E mutation rates of PTMC and lager PTC patients are 65.1%(110/169)and 78.0% (64/82) respectively, and the difference is statistically significant (P<0.05). The prevalence of extrathyroidal invasion (7.1%) and lymph nodes metastasis (27.2%) of the patients with PTMC were significantly lower than those of the patients with larger PTC (15.9% and 46.3%, respectively)(P<0.01). The follow-up durations for PTMC and lager PTC were (45.6±3.6) months and (45.0±3.4) months, respectively (P>0.05). There was no statistic significance for the difference in age, gender, coexistent hashimoto′s thyroiditis, PEDF expression, and recurrence rate between the patients with PTMC and with larger PTC (P>0.05). The recurrence rate of the patients who have the high risk factors of PTMC was 1.6%(2/122)and that of larger PTC was 4.9% (4/82). Conclusions Extrathyroid invasion, lymph node metastases and BRAF V600E gene mutation are the high risk factors of recurrent PTMC. The same treatment strategy should be considered for PTMC with coexistent high risk factors as that for larger PTC. For PTMC with BRAF V600E gene mutation, earlier surgical treatment is suggested. PTMC patients with BRAF V600E gene mutation and high cell subtype are suggested to undergo total thyroidectomy for the first operation in order to reduce the potential risk of recurrence.