Aim: To provide an up-to-date review of the literature on skin-sparing mastectomy (SSM) for breast cancer (BC). The article also reviews the oncological safety, effects of radiotherapy (RT) on immediate breast reconst...Aim: To provide an up-to-date review of the literature on skin-sparing mastectomy (SSM) for breast cancer (BC). The article also reviews the oncological safety, effects of radiotherapy (RT) on immediate breast reconstruction (IBR), the indications for preserving the nipple-areola complex (NAC) and the emerging role of allogenic grafts as adjuncts to implant in IBR. Methods: Review of the English literature from 1965 to 2013 was carried out using Medline and PubMed research engines. Results: SSM is oncologically safe in appropriately selected cases of invasive breast cancer (IBC) and ductal carcinoma in-situ (DCIS) including IBC 5 cm, multi-centric tumours, DCIS and for risk-reduction surgery. Inflammatory breast cancer and tumours with extensive skin involvement represent contra-indications to SSM due to an unacceptable risk of local recurrence. Prior breast irradiation or the need for post-mastectomy radiotherapy (PMRT) do not preclude SSM with IBR, however the aesthetic outcome may be compromised by radiation. Preservation of the nipple-areola complex (NAC) has aesthetic and psychological benefits and is safe for peripherally located node negative unifocal tumours. An intraoperative frozen section protocol for the retro-areolar tissue should be performed when NAC preservation is considered. The advent of acellular dermal matrix has enhanced the scope of implant-based immediate reconstruction following SSM. Cell-assisted fat transfer is emerging as a promising technique to optimise the aesthetics outcome. There is no sufficient evidence to support the role of endoscopic mastectomy in clinical practice. Conclusion: Numerous retrospective and prospective studies show that SSM is oncolgically safe in appropriately selected cases and is aesthetically superior to non-SSM mastectomy. New tech-niques such as the use of acellular dermal matrix (ADM) and cell-assisted fat transfer have increased the use of implants for volume replacement following SSM. In the absence of randomized clinical trials, an updated systematic meta-analysis of published studies is required in order to consolidate the evidence.展开更多
Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quanti...Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quantitative and systematic analysis of data is necessary.Particularly,the FLASH effect response model to the dose or dose rate is still unclear.This study investigated the relationships between the FLASH effect and experimental parameters,such as dose,dose rate,and other factors by analyzing published in vivo experimental data from animal models.The data were modeled based on logistic regression analysis using the sigmoid function.The model was evaluated using prediction accuracy,receiver operating characteristic(ROC)curve,and area under the ROC curve.Results showed that the FLASH effect was closely related to the dose,mean dose rate,tissue type,and corresponding biological endpoints.The dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s^(-1).The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s^(-1).For the skin toxicity effect,the dose corresponding to a 50% probability of triggering the FLASH effect was 24 Gy.This study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments.展开更多
Background: Advantages of various mastectomy techniques include skin reduction and favorable aesthetics in Wise-pattern closures, and less visible scars in nipple-sparing mastectomies (NSM). This study compares postop...Background: Advantages of various mastectomy techniques include skin reduction and favorable aesthetics in Wise-pattern closures, and less visible scars in nipple-sparing mastectomies (NSM). This study compares postoperative complication profiles between Wise-pattern and nipple-sparing mastectomies in the obese population. Methods: A retrospective chart review of obese patients (BMI ≥ 30) who underwent staged breast reconstruction following Wise-pattern and nipple-sparing mastectomies at our institution between February 2016 and January 2020 was conducted. Complications between cohorts were analyzed using the independent samples t-test (2-sided) and the χ2 test. Results: A total of 232 breasts (163 Wise-pattern, 69 NSM) were re-constructed in 123 obese female patients (85 Wise-pattern, 38 NSM). Complication rates in both the Wise-pattern and NSM patient cohorts were similar following stage 1 (Wise-pattern: 30.7%, NSM: 39.1%, p = 0.212) and stage 2 (Wise-pattern: 16.6%, NSM: 15.9%, p = 0.907) of reconstruction. No statistically significant differences in rates of infection, dehiscence, seroma, hematoma or malposition of tissue expander (TE)/implant following stage 1 or stage 2 were found between cohorts. Conclusions: There were no significant differences in postoperative complication rates between the Wise-pattern and NSM cohorts of obese patients. NSM can be a viable surgical option in carefully selected obese patients and offer the advantage of concealed scarring.展开更多
Objective: To study the feasibility of radionuclide colloid 32P used for the treatment of stage II lung cancer by video enhanced minimal access muscle sparing thoracotomy (VEMAST). Methods: Video assisted thoracosc...Objective: To study the feasibility of radionuclide colloid 32P used for the treatment of stage II lung cancer by video enhanced minimal access muscle sparing thoracotomy (VEMAST). Methods: Video assisted thoracoscopic surgery (VATS) was carried out under general anesthesia. A double lumen endobronchial tube was intubated into trachea. One lung ventilation of the healthy side was done during operation. An incision of 8–10 cm long was made along the 4th or 5th intercostals. The lobectomy could be performed under VATS. Radionuclide colloid 32P was injected locally into the area where surgical cleaning of lymph node around was considered to be unsatisfactory or desection of the tumor was not completed. Results: The operation with VEMAST was successful in 29 patients. A conventional lobectomy by thoracotomy had to be done due to unusual bleeding from the pulmonary artery involved during VEMAST in one case and the procedure was interrupted because the pulmonary artery cloud not be separated from the tumor in another patient. There was no dead case or the patient who had any severe complication or adverse response to the radiant. Conclusion: Radionuclide therapy was performed to the treatment of stage II lung cancer with VEMAST in case that surgical resection was considered not to be satisfactory. Minithoractomy assisted with VATS lobectomy and radionuclide colloid 32P therapy is a safe and e?ective technique for some selected stage II lung cancer.展开更多
Level of repair analysis（LORA） is an important method of maintenance decision for establishing systems of operation and maintenance in the equipment development period. Currently, the research on equipment of repair...Level of repair analysis（LORA） is an important method of maintenance decision for establishing systems of operation and maintenance in the equipment development period. Currently, the research on equipment of repair level focuses on economic analysis models which are used to optimize costs and rarely considers the maintenance time required by the implementation of the maintenance program. In fact, as to the system requiring high mission complete success, the maintenance time is an important factor which has a great influence on the availability of equipment systems. Considering the relationship between the maintenance time and the spares stocks level, it is obvious that there are contradictions between the maintenance time and the cost. In order to balance these two factors, it is necessary to build an optimization LORA model. To this end, the maintenance time representing performance characteristic is introduced, and on the basis of spares stocks which is traditionally regarded as a decision variable, a decision variable of repair level is added, and a multi-echelon multiindenture（MEMI） optimization LORA model is built which takes the best cost-effectiveness ratio as the criterion, the expected number of backorder（EBO） as the objective function and the cost as the constraint. Besides, the paper designs a convex programming algorithm of multi-variable for the optimization model, provides solutions to the non-convex objective function and methods for improving the efficiency of the algorithm. The method provided in this paper is proved to be credible and effective according to the numerical example and the simulation result.展开更多
A collaborative optimization model for maintenance and spare ordering of a single-unit degrading system is proposed in this paper based on the continuous detection. A gamma distribution is used to model the material d...A collaborative optimization model for maintenance and spare ordering of a single-unit degrading system is proposed in this paper based on the continuous detection. A gamma distribution is used to model the material degradation. The degrading decrement after the imperfect maintenance action is assumed as a random variable normal distribution. This model aims to ob- tain the optimal maintenance policy and spare ordering point with the expected cost rate within system lifecycle as the optimization objective. The rationality and feasibility of the model are proved through a numerical example.展开更多
Redundancy is a common structure for warship system,and it is an effective way to improve the reliability of the system.In this paper, warship system is taken as the object of study,based on the system reliability equ...Redundancy is a common structure for warship system,and it is an effective way to improve the reliability of the system.In this paper, warship system is taken as the object of study,based on the system reliability equivalence principle, a spares demand rate calculation method for redundant system is proposed through structure transformation. According to the system analysis method, the general modeling data structure of spares support echelon and system indenture is established, and the mission success probability is taken as the optimization target to build the dynamic optimization model of carrying spares during the process of multi-phase. By introducing the Lagrange multiplier, the spares weight, volume and cost are transformed to the single target of the spares total scale, and the initial Lagrange factors and its dynamic adjustment policy is proposed. In a given example, the main influence factors of the carrying spares project are analyzed, and the study results are in accordance with the reality, which can provide a new approach to mission-oriented carrying spares optimization for the redundant system.展开更多
In order to optimize the spares configuration project at different stages during the life cycle, the factor of time is considered to relax the assumption of the spares steady demand in multi-echelon technique for reco...In order to optimize the spares configuration project at different stages during the life cycle, the factor of time is considered to relax the assumption of the spares steady demand in multi-echelon technique for recoverable item control (METRIC) theory. According to the method of systems analysis, the dynamic palm theorem is introduced to establish the prediction model of the spares demand rate, and its main influence factors are analyzed, based on which, the spares support effectiveness evaluation index system is studied, and the system optimization-oriented spares dynamic configuration method for multi-echelon multi-indenture system is proposed. Through the analysis of the optimization algorithm, the layered marginal algorithm is designed to improve the model calculation efficiency. In a given example, the multi-stage spares configuration project during its life cycle is gotten, the research result conforms to the actual status, and it can provide a new way for the spares dynamic optimization.展开更多
With the wide application of condition based maintenance(CBM) in aircraft maintenance practice, the joint optimization of maintenance and inventory management, which can take full advantage of CBM and reduce the aircr...With the wide application of condition based maintenance(CBM) in aircraft maintenance practice, the joint optimization of maintenance and inventory management, which can take full advantage of CBM and reduce the aircraft operational cost, is receiving increasing attention. In order to optimize the inspection interval, maintenance decision and spare provisioning together for aircraft deteriorating parts, firstly, a joint inventory management strategy is presented, then, a joint optimization of maintenance inspection and spare provisioning for aircraft parts subject to the Wiener degradation process is proposed based on the strategy.Secondly, a combination of the genetic algorithm(GA) and the Monte Carol method is developed to minimize the total cost rate.Finally, a case study is conducted and the proposed joint optimization model is compared with the existing optimization model and the airline real case. The results demonstrate that the proposed model is more beneficial and effective. In addition, the sensitivity analysis of the proposed model shows that the lead time has higher influence on the optimal results than the urgent order cost and the corrective maintenance cost, which is consistent with the actual situation of aircraft maintenance practices and inventory management.展开更多
Peripheral nerve injury often causes neuropathic pain and is associated with changes in the expression of numerous proteins in the dorsal horn of the spinal cord. To date, proteomic analysis method has been used to si...Peripheral nerve injury often causes neuropathic pain and is associated with changes in the expression of numerous proteins in the dorsal horn of the spinal cord. To date, proteomic analysis method has been used to simultaneously analyze hundreds or thousands of proteins differentially expressed in the dorsal horn of the spinal cord in rats or dorsal root ganglion of rats with certain type of peripheral nerve injury. However, a proteomic study using a mouse model of neuropathic pain could be attempted because of abundant protein database and the availability of transgenic mice. In this study, whole proteins were extracted from the ipsilateral dorsal half of the 4th-6th lumbar spinal cord in a mouse model of spared nerve injury（SNI）-induced neuropathic pain. In-gel digests of the proteins size-separated on a polyacrylamide gel were subjected to reverse-phase liquid-chromatography coupled with electrospray ionization ion trap tandem mass spectrometry（MS/MS）. After identifying proteins, the data were analyzed with subtractive proteomics using ProtAn, an in-house analytic program. Consequently, 15 downregulated and 35 upregulated proteins were identified in SNI mice. The identified proteins may contribute to the maintenance of neuropathic pain,and may provide new or valuable information in the discovery of new therapeutic targets for neuropathic pain.展开更多
文摘Aim: To provide an up-to-date review of the literature on skin-sparing mastectomy (SSM) for breast cancer (BC). The article also reviews the oncological safety, effects of radiotherapy (RT) on immediate breast reconstruction (IBR), the indications for preserving the nipple-areola complex (NAC) and the emerging role of allogenic grafts as adjuncts to implant in IBR. Methods: Review of the English literature from 1965 to 2013 was carried out using Medline and PubMed research engines. Results: SSM is oncologically safe in appropriately selected cases of invasive breast cancer (IBC) and ductal carcinoma in-situ (DCIS) including IBC 5 cm, multi-centric tumours, DCIS and for risk-reduction surgery. Inflammatory breast cancer and tumours with extensive skin involvement represent contra-indications to SSM due to an unacceptable risk of local recurrence. Prior breast irradiation or the need for post-mastectomy radiotherapy (PMRT) do not preclude SSM with IBR, however the aesthetic outcome may be compromised by radiation. Preservation of the nipple-areola complex (NAC) has aesthetic and psychological benefits and is safe for peripherally located node negative unifocal tumours. An intraoperative frozen section protocol for the retro-areolar tissue should be performed when NAC preservation is considered. The advent of acellular dermal matrix has enhanced the scope of implant-based immediate reconstruction following SSM. Cell-assisted fat transfer is emerging as a promising technique to optimise the aesthetics outcome. There is no sufficient evidence to support the role of endoscopic mastectomy in clinical practice. Conclusion: Numerous retrospective and prospective studies show that SSM is oncolgically safe in appropriately selected cases and is aesthetically superior to non-SSM mastectomy. New tech-niques such as the use of acellular dermal matrix (ADM) and cell-assisted fat transfer have increased the use of implants for volume replacement following SSM. In the absence of randomized clinical trials, an updated systematic meta-analysis of published studies is required in order to consolidate the evidence.
基金supported by the National Key R&D Program of China(No.2022YFC2402300)National Natural Science Foundation of China(No.12075330)。
文摘Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quantitative and systematic analysis of data is necessary.Particularly,the FLASH effect response model to the dose or dose rate is still unclear.This study investigated the relationships between the FLASH effect and experimental parameters,such as dose,dose rate,and other factors by analyzing published in vivo experimental data from animal models.The data were modeled based on logistic regression analysis using the sigmoid function.The model was evaluated using prediction accuracy,receiver operating characteristic(ROC)curve,and area under the ROC curve.Results showed that the FLASH effect was closely related to the dose,mean dose rate,tissue type,and corresponding biological endpoints.The dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s^(-1).The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s^(-1).For the skin toxicity effect,the dose corresponding to a 50% probability of triggering the FLASH effect was 24 Gy.This study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments.
文摘Background: Advantages of various mastectomy techniques include skin reduction and favorable aesthetics in Wise-pattern closures, and less visible scars in nipple-sparing mastectomies (NSM). This study compares postoperative complication profiles between Wise-pattern and nipple-sparing mastectomies in the obese population. Methods: A retrospective chart review of obese patients (BMI ≥ 30) who underwent staged breast reconstruction following Wise-pattern and nipple-sparing mastectomies at our institution between February 2016 and January 2020 was conducted. Complications between cohorts were analyzed using the independent samples t-test (2-sided) and the χ2 test. Results: A total of 232 breasts (163 Wise-pattern, 69 NSM) were re-constructed in 123 obese female patients (85 Wise-pattern, 38 NSM). Complication rates in both the Wise-pattern and NSM patient cohorts were similar following stage 1 (Wise-pattern: 30.7%, NSM: 39.1%, p = 0.212) and stage 2 (Wise-pattern: 16.6%, NSM: 15.9%, p = 0.907) of reconstruction. No statistically significant differences in rates of infection, dehiscence, seroma, hematoma or malposition of tissue expander (TE)/implant following stage 1 or stage 2 were found between cohorts. Conclusions: There were no significant differences in postoperative complication rates between the Wise-pattern and NSM cohorts of obese patients. NSM can be a viable surgical option in carefully selected obese patients and offer the advantage of concealed scarring.
文摘Objective: To study the feasibility of radionuclide colloid 32P used for the treatment of stage II lung cancer by video enhanced minimal access muscle sparing thoracotomy (VEMAST). Methods: Video assisted thoracoscopic surgery (VATS) was carried out under general anesthesia. A double lumen endobronchial tube was intubated into trachea. One lung ventilation of the healthy side was done during operation. An incision of 8–10 cm long was made along the 4th or 5th intercostals. The lobectomy could be performed under VATS. Radionuclide colloid 32P was injected locally into the area where surgical cleaning of lymph node around was considered to be unsatisfactory or desection of the tumor was not completed. Results: The operation with VEMAST was successful in 29 patients. A conventional lobectomy by thoracotomy had to be done due to unusual bleeding from the pulmonary artery involved during VEMAST in one case and the procedure was interrupted because the pulmonary artery cloud not be separated from the tumor in another patient. There was no dead case or the patient who had any severe complication or adverse response to the radiant. Conclusion: Radionuclide therapy was performed to the treatment of stage II lung cancer with VEMAST in case that surgical resection was considered not to be satisfactory. Minithoractomy assisted with VATS lobectomy and radionuclide colloid 32P therapy is a safe and e?ective technique for some selected stage II lung cancer.
基金supported by the National Natural Science Foundation of China(6110413261304148)
文摘Level of repair analysis（LORA） is an important method of maintenance decision for establishing systems of operation and maintenance in the equipment development period. Currently, the research on equipment of repair level focuses on economic analysis models which are used to optimize costs and rarely considers the maintenance time required by the implementation of the maintenance program. In fact, as to the system requiring high mission complete success, the maintenance time is an important factor which has a great influence on the availability of equipment systems. Considering the relationship between the maintenance time and the spares stocks level, it is obvious that there are contradictions between the maintenance time and the cost. In order to balance these two factors, it is necessary to build an optimization LORA model. To this end, the maintenance time representing performance characteristic is introduced, and on the basis of spares stocks which is traditionally regarded as a decision variable, a decision variable of repair level is added, and a multi-echelon multiindenture（MEMI） optimization LORA model is built which takes the best cost-effectiveness ratio as the criterion, the expected number of backorder（EBO） as the objective function and the cost as the constraint. Besides, the paper designs a convex programming algorithm of multi-variable for the optimization model, provides solutions to the non-convex objective function and methods for improving the efficiency of the algorithm. The method provided in this paper is proved to be credible and effective according to the numerical example and the simulation result.
基金supported by the National Natural Science Foundation of China (60904002 70971132)
文摘A collaborative optimization model for maintenance and spare ordering of a single-unit degrading system is proposed in this paper based on the continuous detection. A gamma distribution is used to model the material degradation. The degrading decrement after the imperfect maintenance action is assumed as a random variable normal distribution. This model aims to ob- tain the optimal maintenance policy and spare ordering point with the expected cost rate within system lifecycle as the optimization objective. The rationality and feasibility of the model are proved through a numerical example.
基金supported by the National Defense Pre-research Project in the 13th Five-Year(41404050502)the National Defense Science and Technology Fund of the Central Military Commission(2101140)
文摘Redundancy is a common structure for warship system,and it is an effective way to improve the reliability of the system.In this paper, warship system is taken as the object of study,based on the system reliability equivalence principle, a spares demand rate calculation method for redundant system is proposed through structure transformation. According to the system analysis method, the general modeling data structure of spares support echelon and system indenture is established, and the mission success probability is taken as the optimization target to build the dynamic optimization model of carrying spares during the process of multi-phase. By introducing the Lagrange multiplier, the spares weight, volume and cost are transformed to the single target of the spares total scale, and the initial Lagrange factors and its dynamic adjustment policy is proposed. In a given example, the main influence factors of the carrying spares project are analyzed, and the study results are in accordance with the reality, which can provide a new approach to mission-oriented carrying spares optimization for the redundant system.
基金supported by the National Defense Pre-research Project in 13th Five-Year(41404050502)the National Defense Science and Technology Fund of the Central Military Commission(2101140)
文摘In order to optimize the spares configuration project at different stages during the life cycle, the factor of time is considered to relax the assumption of the spares steady demand in multi-echelon technique for recoverable item control (METRIC) theory. According to the method of systems analysis, the dynamic palm theorem is introduced to establish the prediction model of the spares demand rate, and its main influence factors are analyzed, based on which, the spares support effectiveness evaluation index system is studied, and the system optimization-oriented spares dynamic configuration method for multi-echelon multi-indenture system is proposed. Through the analysis of the optimization algorithm, the layered marginal algorithm is designed to improve the model calculation efficiency. In a given example, the multi-stage spares configuration project during its life cycle is gotten, the research result conforms to the actual status, and it can provide a new way for the spares dynamic optimization.
基金supported by the Fundamental Research Funds for the Central Universities(NS2015072)
文摘With the wide application of condition based maintenance(CBM) in aircraft maintenance practice, the joint optimization of maintenance and inventory management, which can take full advantage of CBM and reduce the aircraft operational cost, is receiving increasing attention. In order to optimize the inspection interval, maintenance decision and spare provisioning together for aircraft deteriorating parts, firstly, a joint inventory management strategy is presented, then, a joint optimization of maintenance inspection and spare provisioning for aircraft parts subject to the Wiener degradation process is proposed based on the strategy.Secondly, a combination of the genetic algorithm(GA) and the Monte Carol method is developed to minimize the total cost rate.Finally, a case study is conducted and the proposed joint optimization model is compared with the existing optimization model and the airline real case. The results demonstrate that the proposed model is more beneficial and effective. In addition, the sensitivity analysis of the proposed model shows that the lead time has higher influence on the optimal results than the urgent order cost and the corrective maintenance cost, which is consistent with the actual situation of aircraft maintenance practices and inventory management.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2015RIDIAIA01059432)
文摘Peripheral nerve injury often causes neuropathic pain and is associated with changes in the expression of numerous proteins in the dorsal horn of the spinal cord. To date, proteomic analysis method has been used to simultaneously analyze hundreds or thousands of proteins differentially expressed in the dorsal horn of the spinal cord in rats or dorsal root ganglion of rats with certain type of peripheral nerve injury. However, a proteomic study using a mouse model of neuropathic pain could be attempted because of abundant protein database and the availability of transgenic mice. In this study, whole proteins were extracted from the ipsilateral dorsal half of the 4th-6th lumbar spinal cord in a mouse model of spared nerve injury（SNI）-induced neuropathic pain. In-gel digests of the proteins size-separated on a polyacrylamide gel were subjected to reverse-phase liquid-chromatography coupled with electrospray ionization ion trap tandem mass spectrometry（MS/MS）. After identifying proteins, the data were analyzed with subtractive proteomics using ProtAn, an in-house analytic program. Consequently, 15 downregulated and 35 upregulated proteins were identified in SNI mice. The identified proteins may contribute to the maintenance of neuropathic pain,and may provide new or valuable information in the discovery of new therapeutic targets for neuropathic pain.
