Objective:To evaluate the effect of different reconstruction points of intrauterine applicator on the source dwell positions and plan dosimetry in intracavitary brachytherapy for cervical cancer.Methods:Clinical data of 43 patients with cervical cancer who had completed radical radiotherapy in Liuzhou Workers' Hospital from May 2020 to October 2022 were retrospectively analyzed. Among 43 patients, aged 32-79 years, 40 cases were diagnosed with squamous carcinoma and 3 cases of adenocarcinoma. All patients received external irradiation for 50.4 Gy / 28 fractions and CT-guided intracavitary brachytherapy (45° intrauterine applicator) was 36 Gy / 6 fractions. Brachytherapy was performed by using Fletcher applicator, the curvature of intrauterine applicator were 15°, 30°and45°. Two sets of brachytherapy plans were simulated for each patient. One set of plans extracted the simulated CT positioning images and the original plan of the patient's brachytherapy. The reconstruction point of the curved part of the 45° intrauterine applicator was adjusted to slice-by-slice reconstruction. The plan was optimized to meet clinical requirements according to the prescription, which was called the slice-by-slice group. In the other set of plans, slice-by-slice group was used as a template. The reconstruction points of the curved section of the 45° intrauterine applicator were adjusted to 1, 3, 5, and 7, without modifying the applicator weights and other parameters, which was called the average group 1, 3, 5 and 7. The deviation analysis of 15°, 30° and 45° intrauterine applicator with different number of reconstruction points was carried out, the reconstruction deviation of 45°, 30° and 15° intrauterine applicator at different reconstruction points was compared. Paired-sample t-test or Wilcoxon signed rank test were used to compare the differences in high-risk clinical target volume (HR-CTV) D 50%, D 90%, D 100%, V 100%, V 150%, V 200% and conformity index (CI) as well as D 2 cm3, D 1 cm3 and D 0.1 cm3 in bladder, rectum, and small intestine between two groups of 45° intrauterine applicator. Results:The reconstruction deviation in the average group was mainly from the vertical direction of the 45° intrauterine applicator. The mean reconstruction deviations of 45° (1, 3, 5, 7 reconstruction points), 30° (1, 3, 5 reconstruction points) and 15° (1, 2 reconstruction points) were 1.30 mm, 0.32 mm, 0.14 mm and 0.08 mm; 0.57 mm, 0.14 mm and 0.06 mm; 0.14 mm and 0.06 mm, respectively. There was no significant difference in the parameters of high-risk clinical target volume (HR-CTV) in the slice-by-slice group compared with the average group 5 and 7 (all P>0.005), and no significant difference was found between the average group 5 and 7 (all P>0.005). There were no statistically significant differences in bladder and rectum doses between the slice-by-slice group and the average groups or within the average groups (all P>0.005). The parameters of small intestine in the slice-by-slice group were higher than those of the average group 1, the difference was statistically significant ( P=0.002,<0.001,<0.001). The dose of small intestine in the slice-by-slice group was not statistically significant compared with those in the average group 5 and 7 (both P>0.005). The dose of small intestine in the average group 5 was not statistically significant compared with that in the average group 7 ( P>0.005). The small intestine dose deviations of D 0.1 cm3, D 1 cm3 and D 2 cm3 in the average groups at 1 reconstruction point were 2.41%±1.70%, 1.95%±1.27% and 1.71%±1.10%, respectively. Conclusion:The number of reconstruction points is recommended to be no less than 1, 3 and 5 of the curved part of the 15°, 30°and 45° Fletcher intrauterine applicator, respectively, during intracavitary brachytherapy for cervical cancer.

On August 2-4,2023,the"Third Summit Forum on'Building a Community of Shared Future for Doctors and Patients'"was jointly organized by institutions such as the Chinese Medical Ethics,the Hospital Humanities Management and Talent Training Special Committee of the China Population and Culture Promotion Association,Center for Ethical Studies of Renmin University of China,the Newspaper for China's Physicians,the China Health Law Society,the China Anti-Cancer Association,and the China Association For Ethical Studies in Harbin.The conference arranged a sub-forum for the"Seminar on the Construction of Chinese Medical Humanities",with domestic medical humanities scholars attending the conference.After heated discussions at the seminar,the Scholars'Consensus on the Construction and Development of Chinese Medical Humanities was formed.It was proposed that in the new era,it is urgent to build the medical humanities discipline,as well as lead the academic integration and development of medical humanities under the core socialist values.At the same time,for the construction of the medical humanities discipline,it is necessary to optimize the organizational mechanism,prosper and develop the overall framework of the medical humanities discipline,accelerate the construction of a professional teaching team for the medical humanities discipline,promote the establishment of a new carrier medical humanities education and teaching in cultivating morality and nurturing talents,as well as focus on solving problems related to the cultivation of medical humanities graduate students.

Objective:To analyze the correlation between the monitor units and pass rate of plan dose verification in the volumetric intensity modulated arc therapy (VMAT) plan.Methods:VMAT plans for 20 patients with nasopharyngeal carcinoma (NPC) and 30 patients with cervical cancer who underwent radiotherapy at Liuzhou Workers' Hospital from January to October 2020 were retrospectively chosen. The Detector 1500 array and Octavius 4D phantom from German PTW company were used for dose measurement. The pass rates of dose verification of relevant plans were analyzed under the conditions of 3%/2 mm and 2%/2 mm. The correlation between the monitor units and pass rate of plan dose verification in VMAT plans was assessed by Pearson's bivariate correlation analysis.Results:Under the condition of 3%/2 mm, the correlation coefficients between the monitor units and gamma pass rate were -0.873 ( P<0.001), -0.800 ( P<0.001), -0.781 ( P<0.001), -0.493 ( P=0.006) for NPC_1Arc, NPC_2Arc, NPC_1Arc+NPC_2Arc and Cervix_2Arc, respectively. Under the condition of 2%/2 mm, the correlation coefficients between the monitor units and gamma pass rate were -0.842 ( P<0.001), -0.770 ( P<0.001), -0.748 ( P<0.001) and -0.531 ( P=0.003) for NPC_1Arc, NPC_2Arc, NPC_1Arc+NPC_2Arc and Cervix_2Arc, respectively. Conclusion:Significant negative correlation can be observed between the monitor units and plan dose verification pass rate in VMAT plan.

Objective:To compare the safety and efficacy of laparoscopic and open hepatectomy for hepatolithiasis.Methods:Between January 2014 and May 2020, the clinicopathological data of 254 patients with hepatolithiasis who underwent laparoscopic or open hepatectomy at the First Department of Hepatobiliary Surgery,Affiliated Hospital of North Sichuan Medical College were collected retrospectively. There were 74 males and 180 females with age of (56±8) years (range: 38 to 77 years). Of the 254 patients, 162 underwent laparoscopic surgery (laparoscopic group) and 92 underwent open surgery (open group). Propensity score matching(PSM) was performed to match baseline characteristics of the two groups,and then the perioperative results and follow-up efficacy were compared between the two groups. The t-test, Mann-Whitney U test, χ 2 test or Fisher′s exact probability method was used to compare the perioperative data and follow-up results of the two groups after matching, respectively. Results:Each group had 63 patients after PSM with well-balanced baseline characteristics. There was no statistic difference in the type of hepatectomy,combined common bile duct exploration rate,T tube drainage placement rate,operation time,intraoperative transfusion rate,intraoperative accidental injury rate,initial and final stone clearance rate,and stone recurrence rate between the two groups. However,compared with the open hepatectomy group, the laparoscopic group had significantly lower intraoperative blood loss ( M(IQR))(300(175)ml vs. 350(145)ml, Z=3.227, P=0.001),shorter postoperative hospital stay((10.6±4.1)days vs. (14.0±4.0)days, t=4.634, P<0.01),shorter time to postoperative oral intake ((1.8±1.1)days vs. (2.9±1.6)days, t=4.556, P<0.01), and lower postoperative complication rate (25.4%(16/63) vs. 49.2%(31/63), χ2=7.635, P=0.006). Conclusion:Laparoscopic hepatectomy is safe and effective for hepatolithiasis with the advantages of less intraoperative blood loss,lower postoperative complications and faster postoperative recovery.

Objective:To compare the safety and efficacy of laparoscopic and open hepatectomy for hepatolithiasis.Methods:Between January 2014 and May 2020, the clinicopathological data of 254 patients with hepatolithiasis who underwent laparoscopic or open hepatectomy at the First Department of Hepatobiliary Surgery,Affiliated Hospital of North Sichuan Medical College were collected retrospectively. There were 74 males and 180 females with age of (56±8) years (range: 38 to 77 years). Of the 254 patients, 162 underwent laparoscopic surgery (laparoscopic group) and 92 underwent open surgery (open group). Propensity score matching(PSM) was performed to match baseline characteristics of the two groups,and then the perioperative results and follow-up efficacy were compared between the two groups. The t-test, Mann-Whitney U test, χ 2 test or Fisher′s exact probability method was used to compare the perioperative data and follow-up results of the two groups after matching, respectively. Results:Each group had 63 patients after PSM with well-balanced baseline characteristics. There was no statistic difference in the type of hepatectomy,combined common bile duct exploration rate,T tube drainage placement rate,operation time,intraoperative transfusion rate,intraoperative accidental injury rate,initial and final stone clearance rate,and stone recurrence rate between the two groups. However,compared with the open hepatectomy group, the laparoscopic group had significantly lower intraoperative blood loss ( M(IQR))(300(175)ml vs. 350(145)ml, Z=3.227, P=0.001),shorter postoperative hospital stay((10.6±4.1)days vs. (14.0±4.0)days, t=4.634, P<0.01),shorter time to postoperative oral intake ((1.8±1.1)days vs. (2.9±1.6)days, t=4.556, P<0.01), and lower postoperative complication rate (25.4%(16/63) vs. 49.2%(31/63), χ2=7.635, P=0.006). Conclusion:Laparoscopic hepatectomy is safe and effective for hepatolithiasis with the advantages of less intraoperative blood loss,lower postoperative complications and faster postoperative recovery.

Objective:To study the differences in the dosimetry and delivery time between helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) in postoperative radiotherapy of synchronous bilateral breast cancer (SBBC) and to explore the feasibility of clinical application of the HT technology.Methods:A retrospective analysis was conducted for nine SBBC patients who underwent modified radical postoperative radiotherapy in the Fourth Affiliated Hospital of Guangxi Medical University from February 2017 to May 2022. For each patient, the Precision planning system was used to formulate the HT plan, and the RayStation planning system was employed to develop the VMAT plan. All plans obtained were divided into HT group and VMAT group according to plan type. The paired sample t-test was used to compare the dosimetric parameters of the target volume and organ at risk (OAR) and delivery time between the two radiotherapy technologies. Results:The plans of both groups could meet the clinical treatment requirements. The coverage ( D95% and V100%), conformity index (CI), average dose ( Dmean), and median dose ( D50%) of the target volumes in the HT group were better than those in the VMAT group, and the differences were statistically significant ( t=-3.21, -3.39, -5.03, 3.76, 4.97, P < 0.05). The differences in the maximum dose ( D2%), minimum dose ( D98%), high dose volumes ( V107% and V110%), and homogeneity index (HI) of the target volumes between the two groups were not statistically significant ( P > 0.05). Regarding the OAR, the V20 and Dmean of both lungs in the HT group were significantly lower than those in the VMAT group, but the irradiation volume V5 of both lungs in the HT group was significantly higher than that in the VMAT group ( t=-3.01, 3.83, -2.81, P < 0.05). Moreover, V20, V30, V40, and Dmean of heart and the V20 and Dmean of liver in the HT group were significantly lower than those in the VMAT group, with statistically significant differences ( t=3.76, -2.83, -2.74, 5.93, 4.57, 4.48, P < 0.05). There was no significant difference in the radiation doses to other OARs (spinal cord, thyroid gland, and humerus head, P > 0.05). The delivery time of the HT group was significantly higher than that of the VMAT group ( t = 11.32, P < 0.05). Conclusions:Compared with VMAT, HT has greater dosimetric advantages, and can provide higher target coverage, conformability and average dose, and significantly reduce the overall radiation doses to both lungs, heart, and liver in OARs. However, the irradiation volume V5 at low-dose areas of both lungs and the delivery time in the HT group are higher than those in the VMAT group, but still meet the clinical treatment requirements. Therefore, it is feasible to apply the HT technology to the modified radical postoperative radiotherapy of SBBC.

The development and implement of microbial chassis cells can provide excellent cell factories for diverse industrial applications, which help achieve the goal of environmental protection and sustainable bioeconomy. The synthetic biology strategy of Design-Build-Test-Learn (DBTL) plays a crucial role on rational and/or semi-rational construction or modification of chassis cells to achieve the goals of "Building to Understand" and "Building for Applications". In this review, we briefly comment on the technical development of the DBTL cycle and the research progress of a few model microorganisms. We mainly focuse on non-model bacterial cell factories with potential industrial applications, which possess unique physiological and biochemical characteristics, capabilities of utilizing one-carbon compounds or of producing platform compounds efficiently. We also propose strategies for the efficient and effective construction and application of synthetic microbial cell factories securely in the synthetic biology era, which are to discover and integrate the advantages of model and non-model industrial microorganisms, to develop and deploy intelligent automated equipment for cost-effective high-throughput screening and characterization of chassis cells as well as big-data platforms for storing, retrieving, analyzing, simulating, integrating, and visualizing omics datasets at both molecular and phenotypic levels, so that we can build both high-quality digital cell models and optimized chassis cells to guide the rational design and construction of microbial cell factories for diverse industrial applications.
Bacteria/genetics* ; Metabolic Engineering ; Synthetic Biology

Objective: To evaluate the dosimetric effects of set-up errors on nasal NK/T cell lymphoma by introducing set-up errors into the radiotherapy planning system for dose reconstruction. Methods: Ten patients with nasal NK/T cell lymphoma were recruited. A non-coplanar volumetric modulated arc therapy plan was designed for CT image and clinical target area of each patient. After the completion of the plan, the set-up errors were introduced into the radiotherapy plan by changing the ISO of the treatment, and dose calculation was performed to reconstruct the dose distribution. Results: With the increase of system set-up errors, the dose of target was decreased and the order affected by set-up errors in different directions was: left-right direction> head-foot direction> front-rear direction. When the translational set-up errors in each direction were -3 mm to 3 mm and the rotating set-up errors were -3° to 3°, the range of dose change in all targets was less than ±3%. When the set-up errors in all directions were ≤ 3 mm, the dose of organ at risk was less than or similar to the prescribed dose. When the set-up errors were> 3 mm, the doses of lens, spinal cord, parotid gland and optic nerve gradually exceeded the prescribed dose. Only when the rotating set-up errors were ≥ 3°, the dose of lens exceeded the prescribed dose. Special attention should be paid to the influence of the greater set-up errors in the left and right direction on lens, spinal cord and parotid gland, as well as on the spinal cord due to the larger set-up errors in the front and rear direction. After the actual set-up errors were introduced from our department, it exerted slight effect on the irradiation dose of GTV and CTV, which was less than ±2%. In a few cases, the dose of organ at risk potentially exceeded the prescribed dose limit, and special attention should be diverted to overdose of the lens and optic nerve. Conclusions The set-up errors will result in target dose deficiency and overdose of organ at risk in nasal NK/T cell lymphoma, especially upon the set-up errors in the left and right direction. The effect of 3 mm and 3° set-up errors on target and organ at risk is limited. Therefore, it is recommended to maintain the single direction set-up errors within 3 mm and 3°. The actual set-up errors introduced from our department exert little effect on the target dose, but a small number of organs are at risk of exceeding the prescribed dose limit. It is necessary to increase the evaluation of the extension region of organ at risk.

The dissolution of nickel from nitinol alloy under different extraction conditions was investigated when biological tests of nitinol medical devices were carried out. It discussed the equivalence of these extraction conditions and found the best extraction conditions. In the experiment, two brands of nitinol were chosen and extracted under different extraction conditions according to GB/T 16886-12. Plasma emission spectrometer was used to analyse the concentration of nickel in extract liquid. The results show that there is no equivalence among these extraction conditions for nitinol materials. And it is suggested that (37 +/- 1) degree C, (72 +/- 2) h could be used as normal extraction condition and (70 +/- 2) degrees C, (24 +/- 2) h as accelerated extraction condition.
Alloys ; chemistry ; Biocompatible Materials ; Materials Testing ; Nickel ; chemistry ; Temperature ; Titanium