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A Minimality of the Rational Canonical Form
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作者 Heguo Liu Honglian Zhang 《Advances in Linear Algebra & Matrix Theory》 2019年第4期83-88,共6页
The rational canonical form theorem is very essential basic result of matrix theory, which has been proved by different methods in the literature. In this note, we provide an effcient direct proof, from which the mini... The rational canonical form theorem is very essential basic result of matrix theory, which has been proved by different methods in the literature. In this note, we provide an effcient direct proof, from which the minimality for the decomposition of the rational canonical form can be found. 展开更多
关键词 MINIMAL POLYNOMIAL RATIONAL CANONICAL Form Cyclic SUBSPACE
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New direction for surgery:Super minimally invasive surgery 被引量:2
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作者 En-Qiang Linghu 《World Journal of Gastroenterology》 SCIE CAS 2024年第12期1676-1679,共4页
The top goal of modern medicine is treating disease without destroying organ structures and making patients as healthy as they were before their sickness.Minimally invasive surgery(MIS)has dominated the surgical realm... The top goal of modern medicine is treating disease without destroying organ structures and making patients as healthy as they were before their sickness.Minimally invasive surgery(MIS)has dominated the surgical realm because of its lesser invasiveness.However,changes in anatomical structures of the body and reconstruction of internal organs or different organs are common after traditional surgery or MIS,decreasing the quality of life of patients post-operation.Thus,I propose a new treatment mode,super MIS(SMIS),which is defined as“curing a disease or lesion which used to be treated by MIS while preserving the integrity of the organs”.In this study,I describe the origin,definition,operative channels,advantages,and future perspectives of SMIS. 展开更多
关键词 Super minimally invasive surgery Minimally invasive surgery Treatment mode Traditional Surgery New direction for surgery
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Feasibility and safety of minimally invasive multivisceral resection for T4b rectal cancer:A 9-year review 被引量:4
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作者 Kai Siang Chan Biquan Liu +2 位作者 Ming Ngan Aloysius Tan Kwang Yeong How Kar Yong Wong 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第3期777-789,共13页
BACKGROUND Colorectal cancer is the third most common cancer and the second highest cause of cancer-related mortality worldwide.About 5%-10%of patients are diagnosed with locally advanced rectal cancer(LARC)on present... BACKGROUND Colorectal cancer is the third most common cancer and the second highest cause of cancer-related mortality worldwide.About 5%-10%of patients are diagnosed with locally advanced rectal cancer(LARC)on presentation.For LARC invading into other structures(i.e.T4b),multivisceral resection(MVR)and/or pelvic ex-enteration(PE)remains the only potential curative surgical treatment.MVR and/or PE is a major and complex surgery with high post-operative morbidity.Minimally invasive surgery(MIS)has been shown to improve short-term post-operative outcomes in other gastrointestinal malignancies,but there is little evi-dence on its use in MVR,especially so for robotic MVR.This is a single-center retrospective cohort study from 1st January 2015 to 31st March 2023.Inclusion criteria were patients diagnosed with cT4b rectal cancer and underwent MVR,or stage 4 disease with resectable systemic metastases.Pa-tients who underwent curative MVR for locally recurrent rectal cancer,or me-tachronous rectal cancer were also included.Exclusion criteria were patients with systemic metastases with non-resectable disease.All patients planned for elective surgery were enrolled into the standard enhanced recovery after surgery pathway with standard peri-operative management for colorectal surgery.Complex sur-gery was defined based on technical difficulty of surgery(i.e.total PE,bladder-sparing prostatectomy,pelvic lymph node dissection or need for flap creation).Our primary outcomes were the margin status,and complication rates.Cate-gorical values were described as percentages and analysed by the chi-square test.Continuous variables were expressed as median(range)and analysed by Mann-Whitney U test.Cumulative overall survival(OS)and recurrence-free survival(RFS)were analysed using Kaplan-Meier estimates with life table analysis.Log-rank test was performed to determine statistical significance between cumulative estimates.Statistical significance was defined as P<0.05.Meier estimates with life table analysis.Log-rank test was performed to determine statistical significance between cumulative estimates.Statistical significance was defined as P<0.05.RESULTS A total of 46 patients were included in this study[open MVR(oMVR):12(26.1%),miMVR:36(73.9%)].Patients’American Society of Anesthesiologists score,body mass index and co-morbidities were comparable between oMVR and miMVR.There is an increasing trend towards robotic MVR from 2015 to 2023.MiMVR was associated with lower estimated blood loss(EBL)(median 450 vs 1200 mL,P=0.008),major morbidity(14.7%vs 50.0%,P=0.014),post-operative intra-abdominal collections(11.8%vs 50.0%,P=0.006),post-operative ileus(32.4%vs 66.7%,P=0.04)and surgical site infection(11.8%vs 50.0%,P=0.006)compared with oMVR.Length of stay was also shorter for miMVR compared with oMVR(median 10 vs 30 d,P=0.001).Oncological outcomes-R0 resection,recurrence,OS and RFS were comparable between miMVR and oMVR.There was no 30-d mortality.More patients underwent robotic compared with laparoscopic MVR for complex cases(robotic 57.1%vs laparoscopic 7.7%,P=0.004).The operating time was longer for robotic compared with laparoscopic MVR[robotic:602(400-900)min,laparoscopic:Median 455(275-675)min,P<0.001].Incidence of R0 resection was similar(laparoscopic:84.6%vs robotic:76.2%,P=0.555).Overall complication rates,major morbidity rates and 30-d readmission rates were similar between la-paroscopic and robotic MVR.Interestingly,3-year OS(robotic 83.1%vs 58.6%,P=0.008)and RFS(robotic 72.9%vs 34.3%,P=0.002)was superior for robotic compared with laparoscopic MVR.CONCLUSION MiMVR had lower post-operative complications compared to oMVR.Robotic MVR was also safe,with acceptable post-operative complication rates.Prospective studies should be conducted to compare short-term and long-term outcomes between robotic vs laparoscopic MVR. 展开更多
关键词 LAPAROSCOPY Minimally invasive surgical procedures Multivisceral resection Pelvic Exenteration Rectal neoplasms Robotic surgical procedures
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Toward less invasive coloproctology: The future is out there 被引量:1
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作者 Sameh Hany Emile Jonathan Ragheb 《World Journal of Gastroenterology》 SCIE CAS 2024年第3期199-203,共5页
Medical care has undergone remarkable improvements over the past few decades.One of the most important innovative breakthroughs in modern medicine is the advent of minimally and less invasive treatments.The trend towa... Medical care has undergone remarkable improvements over the past few decades.One of the most important innovative breakthroughs in modern medicine is the advent of minimally and less invasive treatments.The trend towards employing less invasive treatment has been vividly shown in the field of gastroenterology,particularly coloproctology.Parallel to foregut interventions,colorectal surgery has shifted towards a minimally invasive approach.Coloproctology,including both medical and surgical management of colorectal diseases,has undergone a remarkable paradigm shift.The treatment of both benign and malignant colorectal conditions has gradually transitioned towards more conservative and less inva-sive approaches.An interesting paradigm shift was the trend to avoid the need for radical resection of rectal cancer altogether in patients who showed complete response to neoadjuvant treatment.The trend of adopting less invasive appro-aches to treat various colorectal conditions does not seem to be stopping soon as further research on novel,more effective and safer methods is ongoing. 展开更多
关键词 TOWARD Less invasive Minimally invasive Coloproctology FUTURE Colorectal surgery
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Description of a novel robotic early post-prostatectomy anastomotic repair technique and institutional outcomes 被引量:1
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作者 David Strauss Eric Cho +2 位作者 Matthew Loecher Matthew Lee Daniel Eun 《Asian Journal of Urology》 CSCD 2024年第3期366-372,共7页
Objective:A vesicourethral anastomotic leak(VUAL)is a known complication following robotic-assisted radical prostatectomy.The natural history of a VUAL has been well described and is frequently managed with prolonged ... Objective:A vesicourethral anastomotic leak(VUAL)is a known complication following robotic-assisted radical prostatectomy.The natural history of a VUAL has been well described and is frequently managed with prolonged catheterization.With increasing emphasis on patient reported outcomes,catheter duration and VUAL are associated with significant short-term quality of life impairment.We aimed to present a case series of our robotic early post-prostatectomy anastomotic repair technique,defined as revision within 6 weeks from index surgery.Methods:A single institution prospective database identified eleven patients with a VUAL from July 2016 to October 2022 who underwent robotic early post-prostatectomy anastomotic repair by a single surgeon.Patients were diagnosed with a VUAL on pre-operative CT urogram or CT/fluoroscopic cystogram.The primary outcome was resolution of the anastomotic leak,defined as no contrast extravasation on post-operative cystography.Secondary outcomes included post-repair catheter duration and continence on the last follow-up defined as pad(s)per day.Results:The mean time to intervention after robotic-assisted radical prostatectomy was 21 days.Eight of the eleven(72.7%)patients had no evidence of extravasation on postrepair cystogram.The range from intervention to first cystogram was 7e20 days.The median catheter duration for those with successful intervention was 10 days.The median catheter duration for those with the leak on initial post-operative cystogram was 20 days.At a mean follow-up time of 25 months,eight(72.7%)patients reported using no pads per day,and three(27.3%)patients reported one pad per day.Conclusion:Management of a VUAL has traditionally relied on prolonged catheter drainage and the tincture of time.As the role of robotic reconstruction has been shown to be a viable modality for management of bladder neck contracture,it is important to reconsider prior dogmas of urologic care.Our case series suggests that an early repair is safe and has a high success rate.Early robotic intervention gives providers an additional tool in aiding patient recovery. 展开更多
关键词 Minimally invasive surgery Vesicourethral anastomotic leak Robotic-assisted laparoscopic reconstruction
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Efficacy and safety of minimally invasive laparoscopic surgery under general anesthesia for ovarian cancer 被引量:1
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作者 Xian Qin Chen Chen +4 位作者 Yang Liu Xian-Hong Hua Jia-Yi Li Meng-Jie Liang Fang Wu 《World Journal of Clinical Cases》 SCIE 2024年第9期1569-1577,共9页
BACKGROUND Ovarian cancer is one of the most common malignant tumors in female reproductive system in the world,and the choice of its treatment is very important for the survival rate and prognosis of patients.Traditi... BACKGROUND Ovarian cancer is one of the most common malignant tumors in female reproductive system in the world,and the choice of its treatment is very important for the survival rate and prognosis of patients.Traditional open surgery is the main treatment for ovarian cancer,but it has the disadvantages of big trauma and slow recovery.With the continuous development of minimally invasive technology,minimally invasive laparoscopic surgery under general anesthesia has been gradually applied to the treatment of ovarian cancer because of its advantages of less trauma and quick recovery.However,the efficacy and safety of minimally invasive laparoscopic surgery under general anesthesia in the treatment of ovarian cancer are still controversial.AIM To explore the efficacy and safety of general anesthesia minimally invasive surgery in the treatment of ovarian cancer.METHODS The clinical data of 90 patients with early ovarian cancer in our hospital were analyzed retrospectively.According to the different surgical treatment methods,patients were divided into study group and control group(45 cases in each group).The study group received minimally invasive laparoscopic surgery under general anesthesia for ovarian cancer,while the control group received traditional open surgery for ovarian cancer.The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire(EORTC QLQ-C30),clinical efficacy and safety of the two groups were compared.RESULTS The intraoperative blood loss,length of hospital stay,postoperative gas evacuation time,and postoperative EORTC QLQ-C30 score of the study group were significantly better than those of the control group(P<0.05).The incidence of postoperative complications in the study group was significantly lower than in the control group(P<0.05).The two groups had no significant differences in the preoperative adrenocorticotropic hormone(ACTH),androstenedione(AD),cortisol(Cor),cluster of differentiation 3 positive(CD3+),and cluster of differentiation 4 positive(CD4+)indexes(P>0.05).In contrast,postoperatively,the study group's ACTH,AD,and Cor indexes were lower,and the CD3+and CD4+indexes were higher than those in the control group(P<0.05).CONCLUSION Minimally invasive laparoscopic surgery under general anesthesia in patients with early ovarian cancer can significantly improve the efficacy and safety,improve the short-term prognosis and quality of life of patients,and is worth popularizing. 展开更多
关键词 Early-stage ovarian cancer EFFICACY Minimally invasive LAPAROSCOPY SAFETY SURGERY
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Incompleteness and minimality of complex exponential system 被引量:8
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作者 Guan-tie DENG 《Science China Mathematics》 SCIE 2007年第10期1467-1476,共10页
A necessary and sufficient condition is obtained for the incompleteness of a complex exponential system E(A, M) in Cα, where Cα is the weighted Banach space consisting of all complex continuous functions f on the re... A necessary and sufficient condition is obtained for the incompleteness of a complex exponential system E(A, M) in Cα, where Cα is the weighted Banach space consisting of all complex continuous functions f on the real axis R with f(t)exp(-α(t)) vanishing at infinity, in the uniform norm ‖f‖α = sup{|f(t)e-α(t)|: t ∈ R} with respect to the weight α(t). If the incompleteness holds, then the complex exponential system E(∧, M) is minimal and each function in the closure of the linear span of complex exponential system E(∧, M) can be extended to an entire function represented by a Taylor-Dirichlet series. 展开更多
关键词 incompleteness minimality EXPONENTIAL SYSTEM
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Topological complexity, minimality and systems of order two on torus 被引量:2
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作者 qiao yi xiao 《Science China Mathematics》 SCIE CSCD 2016年第3期503-514,共12页
The dynamical system on T^2 which is a group extension over an irrational rotation on T^1 is investigated. The criterion when the extension is minimal, a system of order 2 and when the maximal equicontinuous factor is... The dynamical system on T^2 which is a group extension over an irrational rotation on T^1 is investigated. The criterion when the extension is minimal, a system of order 2 and when the maximal equicontinuous factor is the irrational rotation is given. The topological complexity of the extension is computed, and a negative answer to the latter part of an open question raised by Host et al.(2014) is obtained. 展开更多
关键词 topological complexity minimality 2-step nilsystem
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MINIMIZERS OF L^(2)-SUBCRITICAL VARIATIONAL PROBLEMS WITH SPATIALLY DECAYING NONLINEARITIES IN BOUNDED DOMAINS
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作者 陈彬 高永帅 +1 位作者 郭玉劲 吴越 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期984-996,共13页
This paper is concerned with the minimizers of L^(2)-subcritical constraint variar tional problems with spatially decaying nonlinearities in a bounded domain Ω of R~N(N≥1).We prove that the problem admits minimizers... This paper is concerned with the minimizers of L^(2)-subcritical constraint variar tional problems with spatially decaying nonlinearities in a bounded domain Ω of R~N(N≥1).We prove that the problem admits minimizers for any M> 0.Moreover,the limiting behavior of minimizers as M→∞ is also analyzed rigorously. 展开更多
关键词 decaying nonlinearity L~2-subcritical MINIMIZERS bounded domains mass concentration
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Minimally invasive reconstruction of extensive mid-lower ureteral strictures using a bilateral Boari flap
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作者 Shuaishuai Chai Hao Zhang +5 位作者 Gong Cheng Jiawei Chen Xincheng Gao Yuancheng Zhou Xingyuan Xiao Bing Li 《Asian Journal of Urology》 CSCD 2024年第3期377-383,共7页
Objective:To describe and evaluate the technique using bilateral Boari flap ureteroneocystostomy(BBFUNC)for bilateral mid-lower ureteral strictures.Methods:We retrospectively reviewed five patients who underwent minim... Objective:To describe and evaluate the technique using bilateral Boari flap ureteroneocystostomy(BBFUNC)for bilateral mid-lower ureteral strictures.Methods:We retrospectively reviewed five patients who underwent minimally invasive BBFUNC in our institution(Union Hospital,Wuhan,China)between July 2019 and December 2021.The bilateral ureters were mobilized and transected above the stenotic segments.The bladder was isolated and incised longitudinally from the middle of the anterior wall.Then,an inverted U-shaped bladder flap was created on both sides,fixed onto the psoas tendon,and anastomosed to the ipsilateral distal normal ureter.Following double-J stenting,the Boari flaps were tubularized,and the bladder was closed with continuous sutures.The patients’perioperative data and follow-up outcomes were collected,and a descriptive statistical analysis was performed.Results:No case converted to open surgery,and no intraoperative complication occurred.The median surgical time was 230(range 203-294)min.The median length of the bladder flaps was 6.2(range 4.3-10.0)cm on the left and 5.5(range 4.7-10.5)cm on the right side.All patients had not developed recurrent ureteral stenosis during the median follow-up time of 17(range 16-45)months and had a normal maximum flow rate after surgery.The median post-void residual was 7(range 0-19)mL.The maximal bladder capacity was decreased in one(20%)patient.Conclusion:The present study demonstrates that minimally invasive BBFUNC is feasible and safe in treating is limited. 展开更多
关键词 Reconstructive surgery Boariflap Ureteral stricture Ureteron-eocystostomy Minimally invasive
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Potential value of detection of minimal residual disease in colorectal cancer following radical resection
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作者 Wenji Pu Fang Chen +5 位作者 Yuan Tang Yanling Qu Yunzhu Han Jiandong Zha Jing Jin Fengming Kong 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2024年第4期442-454,共13页
Although there has been significant advancement in the identification and management of colorectal cancer(CRC)in recent years,there is still room for improvement in the current standard treatment regimen.One area of c... Although there has been significant advancement in the identification and management of colorectal cancer(CRC)in recent years,there is still room for improvement in the current standard treatment regimen.One area of concern is the lack of reliable tumor markers to predict treatment efficacy and guide tailored care.Due to its dynamic,effective,and non-invasive benefits over tissue biopsy,the detection of minimal or molecular residual lesions(MRD)based on circulating tumor DNA(ctDNA)is beneficial to the clinical development of drugs for patients with CRC after radical treatment,as well as for continuous monitoring of tumor recurrence and malignancy molecular gene evolution.The detection of ctDNA can currently be used to guide individual postoperative auxiliary treatment decisions(upgrade or downgrade treatment)in CRC,stratify the risk of clinical recurrence more precisely,and predict the risk of recurrence in advance of imaging examination,according to a large number of observational or prospective clinical studies.With increasing clarity comes the possibility of selecting a regimen of treatment based on postoperative ctDNA,which also improves the accuracy of clinical recurrence risk assessment for CRC.Therefore,it is anticipated that the identification of ctDNA would alter the current framework for dealing with CRC and lead to individualized,stratified precision therapy;however,additional confirmation will require subsequent high-quality,prospective,large-scale randomized controlled studies.This article will provide an overview of the definition and clinical significance of MRD,the primary indications and technological challenges for MRD detection,along with the advancement in clinical research about ctDNA detection following radical resection of the CRC. 展开更多
关键词 Colorectal cancer minimal residual disease circulating tumor DNA PROGNOSIS RECURRENCE biomarkers
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Depth First:Optimal Path Discovery Between Designated Nodes in Random Ring-Based Graphs
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作者 Li Qi Xu Jiasheng +4 位作者 Zhang Haonan Kang Huquan Fu Luoyi Long Fei Wang Xinbing 《China Communications》 SCIE CSCD 2024年第9期225-241,共17页
This paper focuses on optimally determining the existence of connected paths between some given nodes in random ring-based graphs.Serving as a fundamental underlying structure in network modeling,ring topology appears... This paper focuses on optimally determining the existence of connected paths between some given nodes in random ring-based graphs.Serving as a fundamental underlying structure in network modeling,ring topology appears as commonplace in many realistic scenarios.Regarding this,we consider graphs composed of rings,with some possible connected paths between them.Without prior knowledge of the exact node permutations on rings,the existence of each edge can be unraveled through edge testing at a unit cost in one step.The problem examined is that of determining whether the given nodes are connected by a path or separated by a cut,with the minimum expected costs involved.Dividing the problem into different cases based on different topologies of the ring-based networks,we propose the corresponding policies that aim to quickly seek the paths between nodes.A common feature shared by all those policies is that we stick to going in the same direction during edge searching,with edge testing in each step only involving the test between the source and the node that has been tested most.The simple searching rule,interestingly,can be interpreted as a delightful property stemming from the neat structure of ring-based networks,which makes the searching process not rely on any sophisticated behaviors.We prove the optimality of the proposed policies by calculating the expected cost incurred and making a comparison with the other class of strategies.The effectiveness of the proposed policies is also verified through extensive simulations,from which we even disclose three extra intriguing findings:i)in a onering network,the cost will grow drastically with the number of designated nodes when the number is small and will grow slightly when that number is large;ii)in ring-based network,Depth First is optimal in detecting the connectivity between designated nodes;iii)the problem of multi-ring networks shares large similarity with that of two-ring networks,and a larger number of ties between rings will not influence the expected cost. 展开更多
关键词 connectivity analysis cost minimization path discover ring-based graph
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Multi-Objective Optimization of the Ultrasonic Scalpel Rod and Tip with Improved Performance:Vibration Frequency,Amplitude,and Service Life
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作者 Jiaqi Zhao Yuhao Zhai +6 位作者 Xuzhe Jia Naiwen Deng Kunxu Li Guangchao Han Rong Chen Dong Wang Wei Bai 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第4期107-119,共13页
Ultrasonic scalpel design for minimally invasive surgical procedures is mainly focused on optimizing cutting performance.However,an important issue is the low fatigue life of traditional ultrasonic scalpels,which affe... Ultrasonic scalpel design for minimally invasive surgical procedures is mainly focused on optimizing cutting performance.However,an important issue is the low fatigue life of traditional ultrasonic scalpels,which affects their long-term reliability and effectiveness and creates hidden dangers for surgery.In this study,a multi-objective optimal design for the cutting performance and fatigue life of ultrasonic scalpels was proposed using finite element analysis and fatigue simulation.The optimal design parameters of resonance frequency and amplitude were determined.By setting the transition fillet and keeping the gain structure away from the node position to enable the scalpel to have a high service life with excellent cutting performance.The frequency modulation method of setting the vibration node bosses at the node position and setting the vibration antinode grooves at the antinode position was compared.Then,the mechanism of the influence of various design elements,such as tip,shank,node position,and antinode position,on the resonance frequency,amplitude,and fatigue life of the ultrasonic scalpel was analyzed,and the optimal design principles of the ultrasonic scalpel were obtained.The proposed ultrasonic scalpel design was confirmed by simulations,impedance measurements,and liver tissue cutting experiments,demonstrating its feasibility and enhanced performance.This research introduces innovative design strategies to improve the fatigue life and performance of ultrasonic scalpels to address an important issue in minimally invasive surgery. 展开更多
关键词 Multi-objective optimal design Minimally invasive surgical procedures Service life Ultrasonic scalpel
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Diabetic retinopathy identification based on multi-sourcefree domain adaptation
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作者 Guang-Hua Zhang Guang-Ping Zhuo +3 位作者 Zhao-Xia Zhang Bin Sun Wei-Hua Yang Shao-Chong Zhang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第7期1193-1204,共12页
AIM:To address the challenges of data labeling difficulties,data privacy,and necessary large amount of labeled data for deep learning methods in diabetic retinopathy(DR)identification,the aim of this study is to devel... AIM:To address the challenges of data labeling difficulties,data privacy,and necessary large amount of labeled data for deep learning methods in diabetic retinopathy(DR)identification,the aim of this study is to develop a source-free domain adaptation(SFDA)method for efficient and effective DR identification from unlabeled data.METHODS:A multi-SFDA method was proposed for DR identification.This method integrates multiple source models,which are trained from the same source domain,to generate synthetic pseudo labels for the unlabeled target domain.Besides,a softmax-consistence minimization term is utilized to minimize the intra-class distances between the source and target domains and maximize the inter-class distances.Validation is performed using three color fundus photograph datasets(APTOS2019,DDR,and EyePACS).RESULTS:The proposed model was evaluated and provided promising results with respectively 0.8917 and 0.9795 F1-scores on referable and normal/abnormal DR identification tasks.It demonstrated effective DR identification through minimizing intra-class distances and maximizing inter-class distances between source and target domains.CONCLUSION:The multi-SFDA method provides an effective approach to overcome the challenges in DR identification.The method not only addresses difficulties in data labeling and privacy issues,but also reduces the need for large amounts of labeled data required by deep learning methods,making it a practical tool for early detection and preservation of vision in diabetic patients. 展开更多
关键词 diabetic retinopathy multisource-free domain adaptation pseudo-label generation softmaxconsistence minimization
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A novel triple periodic minimal surface-like plate lattice and its data-driven optimization method for superior mechanical properties
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作者 Yanda WANG Yanping LIAN +2 位作者 Zhidong WANG Chunpeng WANG Daining FANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第2期217-238,共22页
Lattice structures can be designed to achieve unique mechanical properties and have attracted increasing attention for applications in high-end industrial equipment,along with the advances in additive manufacturing(AM... Lattice structures can be designed to achieve unique mechanical properties and have attracted increasing attention for applications in high-end industrial equipment,along with the advances in additive manufacturing(AM)technologies.In this work,a novel design of plate lattice structures described by a parametric model is proposed to enrich the design space of plate lattice structures with high connectivity suitable for AM processes.The parametric model takes the basic unit of the triple periodic minimal surface(TPMS)lattice as a skeleton and adopts a set of generation parameters to determine the plate lattice structure with different topologies,which takes the advantages of both plate lattices for superior specific mechanical properties and TPMS lattices for high connectivity,and therefore is referred to as a TPMS-like plate lattice(TLPL).Furthermore,a data-driven shape optimization method is proposed to optimize the TLPL structure for maximum mechanical properties with or without the isotropic constraints.In this method,the genetic algorithm for the optimization is utilized for global search capability,and an artificial neural network(ANN)model for individual fitness estimation is integrated for high efficiency.A set of optimized TLPLs at different relative densities are experimentally validated by the selective laser melting(SLM)fabricated samples.It is confirmed that the optimized TLPLs could achieve elastic isotropy and have superior stiffness over other isotropic lattice structures. 展开更多
关键词 lattice structure triple periodic minimal surface(TPMS) plate lattice structural optimization machine learning
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Colorectal resections for malignancy: A pilot study comparing conventional vs freehand robot-assisted laparoscopic colectomy
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作者 Shamir O Cawich Joseph Martin Plummer +1 位作者 Sahle Griffith Vijay Naraynsingh 《World Journal of Clinical Cases》 SCIE 2024年第3期488-494,共7页
BACKGROUND Laparoscopic colectomy is widely accepted as a safe operation for colorectal cancer,but we have experienced resistance to the introduction of the FreeHandffrobotic camera holder to augment laparoscopic colo... BACKGROUND Laparoscopic colectomy is widely accepted as a safe operation for colorectal cancer,but we have experienced resistance to the introduction of the FreeHandffrobotic camera holder to augment laparoscopic colorectal surgery.AIM To compare the initial results between conventional and FreeHandffrobot-assisted laparoscopic colectomy in Trinidad and Tobago.METHODS This was a prospective study of outcomes from all laparoscopic colectomies per-formed for colorectal carcinoma from November 29,2021 to May 30,2022.The following data were recorded:Operating time,conversions,estimated blood loss,hospitalization,morbidity,surgical resection margins and number of nodes har-vested.All data were entered into an excel database and the data were analyzed using SPSS ver 20.0.RESULTS There were 23 patients undergoing colectomies for malignant disease:8(35%)FreeHandff-assisted and 15(65%)conventional laparoscopic colectomies.There were no conversions.Operating time was significantly lower in patients under-going robot-assisted laparoscopic colectomy(95.13±9.22 vs 105.67±11.48 min;P=0.045).Otherwise,there was no difference in estimated blood loss,nodal harvest,hospitalization,morbidity or mortality.CONCLUSION The FreeHandffrobot for colectomies is safe,provides some advantages over conventional laparoscopy and does not compromise oncologic standards in the resource-poor Caribbean setting. 展开更多
关键词 LAPAROSCOPIC COLECTOMY Robot Surgery Minimally invasive
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Channel Estimation for Reconfigurable Intelligent Surface Aided Multiuser Millimeter-Wave/THz Systems
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作者 Chu Hongyun Pan Xue Li Baijiang 《China Communications》 SCIE CSCD 2024年第3期91-103,共13页
It is assumed that reconfigurable intelligent surface(RIS)is a key technology to enable the potential of mmWave communications.The passivity of the RIS makes channel estimation difficult because the channel can only b... It is assumed that reconfigurable intelligent surface(RIS)is a key technology to enable the potential of mmWave communications.The passivity of the RIS makes channel estimation difficult because the channel can only be measured at the transceiver and not at the RIS.In this paper,we propose a novel separate channel estimator via exploiting the cascaded sparsity in the continuously valued angular domain of the cascaded channel for the RIS-enabled millimeter-wave/Tera-Hz systems,i.e.,the two-stage estimation method where the cascaded channel is separated into the base station(BS)-RIS and the RIS-user(UE)ones.Specifically,we first reveal the cascaded sparsity,i.e.,the sparsity exists in the hybrid angular domains of BS-RIS and the RIS-UEs separated channels,to construct the specific sparsity structure for RIS enabled multi-user systems.Then,we formulate the channel estimation problem using atomic norm minimization(ANM)to enhance the proposed sparsity structure in the continuous angular domains,where a low-complexity channel estimator via Alternating Direction Method of Multipliers(ADMM)is proposed.Simulation findings demonstrate that the proposed channel estimator outperforms the current state-of-the-arts in terms of performance. 展开更多
关键词 atomic norm minimization cascaded channel estimation convex optimization mmWave/THz reconfigurable intelligent surface(RIS) sparsity
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Endoscopic diagnosis and management of gallbladder carcinoma in minimally invasive era:New needs,new models
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作者 La-Cuo Deqing Jun-Wen Zhang Jian Yang 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第11期4333-4337,共5页
Gallbladder cancer(GBC)is a rare and lethal malignancy;however,it represents the most common type of biliary tract cancer.Patients with GBC are often diagnosed at an advanced stage,thus,unfortunately,losing the opport... Gallbladder cancer(GBC)is a rare and lethal malignancy;however,it represents the most common type of biliary tract cancer.Patients with GBC are often diagnosed at an advanced stage,thus,unfortunately,losing the opportunity for curative surgical intervention.This situation leads to lower quality of life and higher mortality rates.In recent years,the rapid development of endoscopic equipment and techniques has provided new avenues and possibilities for the early and minimally invasive diagnosis and treatment of GBC.This editorial comments on the article by Pavlidis et al.Building upon their work,we explore the new needs and corresponding models for managing GBC from the endoscopic diagnosis and treatment perspective. 展开更多
关键词 ENDOSCOPY Diagnosis and treatment Gallbladder carcinoma Minimal invasive New need New model
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Numerical Methods for a Class of Quadratic Matrix Equations
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作者 GUAN Jinrui WANG Zhixin SHAO Rongxia 《应用数学》 北大核心 2024年第4期962-970,共9页
Quadratic matrix equations arise in many elds of scienti c computing and engineering applications.In this paper,we consider a class of quadratic matrix equations.Under a certain condition,we rst prove the existence of... Quadratic matrix equations arise in many elds of scienti c computing and engineering applications.In this paper,we consider a class of quadratic matrix equations.Under a certain condition,we rst prove the existence of minimal nonnegative solution for this quadratic matrix equation,and then propose some numerical methods for solving it.Convergence analysis and numerical examples are given to verify the theories and the numerical methods of this paper. 展开更多
关键词 Quadratic matrix equation M-MATRIX Minimal nonnegative solution Newton method Bernoulli method
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Exploring the landscape of minimally invasive pancreatic surgery: Progress, challenges, and future directions
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作者 Greta Donisi Alessandro Zerbi 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第10期3094-3103,共10页
Minimally invasive surgery(MI)has become the standard of care for many surgical procedures aimed at reducing the burden on patients.However,its adoption in pancreatic surgery(PS)has been limited by the pancreas’s uni... Minimally invasive surgery(MI)has become the standard of care for many surgical procedures aimed at reducing the burden on patients.However,its adoption in pancreatic surgery(PS)has been limited by the pancreas’s unique location and the complexity of the dissection and reconstruction phases.These factors continue to contribute to PS having one of the highest morbidity and mortality rates in general surgery.Despite a rough start,MIPS has gained widespread acceptance in clinical practice recently.Robust evidence supports MI distal pancreatectomy safety,even in oncological cases,indicating its potential superiority over open surgery.However,definitive evidence of MI pancre-aticoduodenectomy(MIPD)feasibility and safety,particularly for malignant lesions,is still lacking.Nonetheless,reports from high-volume centers are emer-ging,suggesting outcomes comparable to those of the open approach.The robotic PS increasing adoption,facilitated by the wider availability of robotic platforms,may further facilitate the transition to MIPD by overcoming the technical con-straints associated with laparoscopy and accelerating the learning curve.Alth-ough the MIPS implementation process cannot be stopped in this evolving world,ensuring patient safety through strict outcome monitoring is critical.Investing in younger surgeons with structured and recognized training programs can promote safe expansion. 展开更多
关键词 Minimally invasive surgery Minimally invasive pancreatic surgery Pancreatic surgery Robotic LAPAROSCOPIC PANCREATICODUODENECTOMY Distal pancrea-tectomy
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